WO2013104919A1

WO2013104919A1 - Haptic feedback and pressure sensing

Info

Publication number: WO2013104919A1
Application number: PCT/GB2013/050055
Authority: WO
Inventors: Tom MONKHOUSE
Original assignee: Hiwave Technologies (Uk) Limited
Priority date: 2012-01-13
Filing date: 2013-01-11
Publication date: 2013-07-18
Also published as: GB201200587D0

Abstract

A method of providing haptic feedback comprises defining a pressure value profile, the pressure value profile comprising at least one pressure value threshold, defining at least one haptic response corresponding to said at least one pressure value threshold, measuring a pressure applied by the touch to the touch input surface at different times, comparing the measured pressure at different times to the defined pressure value profile, and, if the measured pressure at different times matches the defined pressure value profile, generating the defined corresponding haptic response.

Description

Haptic Feedback and Pressure Sensing

TECHNICAL FIELD

This invention relates to improvements to haptic feedback, and in particular to improvements to haptic feedback within touch sensitive devices including touch sensitive screens or panels.

BACKGROUND ART

US 4,885,565, US 5,638,060, US 5,977,867, US2002/0075135 describe touch-operated apparatus having tactile feedback for a user when touched.

In US 4,885,565 an actuator is provided for imparting motion to the CRT when the actuator is energised to provide tactile feedback. In US 5,638,060, a voltage is applied to a piezoelectric element which forms a switch to vibrate the element to apply a reaction force to a user's finger.

In US 5,977,867, a tactile feedback unit generates a mechanical vibration sensed by the user when the touch screen is touched with a finger or a pointer. The amplitude, vibration frequency and pulse length of the mechanical vibration are controlled, with the pulse width being long enough to be felt but short enough to terminate before the next key touch.

US2002/0075135 describes the use of a transducer to provide a pulse in the form of transient spike to simulate a button click.

BACKGROUND OF THE INVENTION

Haptic feedback relates to touch sensitive feedback, for example haptic feedback may provide a user with additional information regarding a touch event or experience. Haptic feedback may be provided for Personal Computer and PAD devices touch pads.

Haptic feedback may be provided for mobile (or cellular) telephones, where the haptic vibration response may be applied in response to a user touching a screen. Haptics also has applications in virtual reality, robotics, industrial and instrumental control, teleoperators, simuklators and gaming, for example.

Haptic feedback may be provided to give a synthetic 'button click' response equivalent to what a user would anticipate when interacting with a real button. This may relate to providing a button click response on a touch sensitive device in response to a touch on the touch sensitive device. The touch sensitive device may include a touch screen.

To provide a user with information of value the haptic response may mimic what a user would anticipate from interaction with a real system such as a mechanical key on a keyboard. Taking a haptic button click as an example, relaying contextual haptic information may relate to a haptic button click response occurring where the user is expecting it to occur in response to a touch at a touch location and not at another location or locations. Relaying contextual haptic information may relate to the haptic button click response occurring with a magnitude and at a time delay after a touch at a touch location that is representative of a real system in terms of the magnitude of the button click feedback response and the delay between the touch and the haptic button click feedback response and the variability, or lack of variability, in that delay. The present invention was made in an attempt to provide improved haptic feedback. SUMMARY OF THE INVENTION

In a first aspect, the invention provides a method of providing haptic feedback comprising: defining a pressure value profile, the pressure value profile comprising at least one pressure value threshold;

defining at least one haptic response corresponding to said at least one pressure value threshold;

measuring a pressure applied by the touch to the touch input surface at different times;

comparing the measured pressure at different times to the defined pressure value profile; and if the measured pressure at different times matches the defined pressure value profile, generating the defined corresponding haptic response.

Preferably, the pressure profile comprises a pressure value profile of pressure changes over time and defines at least one change in pressure value over time; and the defined corresponding haptic response is generated if the measured pressure at different times matches the defined change in pressure value over time.

Preferably, the pressure value profile defines a first change in pressure value over time comprising an increase in pressure value over time which crosses the at least one pressure value threshold, and a corresponding first haptic response is defined; and

the pressure value profile defines a second change in pressure value over time comprising a decrease in pressure value over time which crosses the at least one pressure value threshold, and a corresponding second haptic response is defined.

Preferably, the pressure value profile defines a first change in pressure value over time comprising an increase in pressure value over time which crosses a first pressure value threshold, and a corresponding first haptic response is defined; and

the pressure value profile defines a second change in pressure value over time comprising a decrease in pressure value over time which crosses a second pressure value threshold, and a corresponding second haptic response is defined;

wherein the first pressure value threshold corresponds to a higher pressure value than the second pressure value threshold. Preferably, the first haptic response and the second haptic response are the same.

Preferably, the first haptic response and the second haptic response are different.

Preferably, after the first haptic response has been generated the first haptic response will not be generated again until after the second haptic response has been generated.

Preferably, the first haptic response simulates a button being depressed.

Preferably, the second haptic response simulates a button being released.

Preferably, if the measured pressure at different times matches the defined first change in pressure value over time, generating a defined electrical output signal in addition to generating the defined corresponding haptic response. Preferably, the defined electrical output signal indicates that a user input has been received.

Preferably, the pressure value profile comprises a plurality of different pressure value thresholds; and, for each of this plurality of different pressure value thresholds:

the pressure value profile defines a change in pressure value over time comprising an increase in pressure value over time which crosses said pressure value threshold, and a corresponding first haptic response is defined; and/or

the pressure value profile defines a change in pressure value over time comprising a decrease in pressure value over time which crosses said pressure value threshold, and a corresponding second haptic response is defined.

Preferably, said first haptic responses are the same. Preferably, said second haptic responses are the same.

Preferably, said first haptic responses are different.

Preferably, said second haptic responses are the different.

Preferably, the pressure value profile comprises at least one pressure value threshold and the corresponding haptic response.

In a second aspect, the invention provides a method of providing haptic feedback comprising: defining a pressure value profile, the pressure value profile comprising at least one pressure value threshold;

defining a corresponding haptic response;

measuring a pressure applied by a touch to the touch input surface at different times;

determining a location of the touch on the touch input surface at said different times;

comparing the measured pressure at different times to the defined pressure value profile; and if the measured pressure is less than or equal to the at least one pressure value threshold, generating a defined electrical output signal which indicates the location of the touch; or if the measured pressure is greater than the at least one pressure value threshold, generating the defined corresponding haptic response.

Preferably, the method further comprises: if the measured pressure is greater than the at least one pressure value threshold, also generating a defined electrical output signal which indicates that a user input has been received and the location of the user input.

Preferably, the pressure value profile comprises at least one further pressure value threshold, the at least one further pressure value threshold having a lower value than said at least one pressure value threshold; and

not generating the defined electrical output signal which indicates the location of the touch if the measured pressure is less than or equal to the at least one further pressure value threshold.

if the measured pressure is less than or equal to the at least one further pressure value threshold, generating a defined electrical output signal which indicates the location of the touch and that the measured pressure is less than or equal to the at least one further pressure value threshold.

Preferably, the pressure value profile comprises at least one pressure value threshold and the corresponding haptic response. In a third aspect, the invention provide a method of providing haptic feedback comprising: defining a location and pressure value profile, the location and pressure value profile comprising at least one pressure value threshold and a corresponding location;

defining a corresponding haptic response;

comparing the measured pressure at different locations and times to the defined location and pressure value profile; and if the measured pressure is greater than the at least one pressure value threshold corresponding to the determined location, generating the defined corresponding haptic response. Preferably, the location and pressure value profile comprises at least one pressure value threshold and a corresponding location, and a corresponding haptic response and electrical output signal are defined; and the method further comprising:

when the measured pressure is greater than the at least one pressure value threshold corresponding to the determined location, generating the defined corresponding electrical output signal in addition to generating the defined corresponding haptic response.

Preferably, the defined electrical output signal indicates that a user input has been received and the location of the user input. Preferably, the location and pressure value profile defines at least one location having no corresponding haptic response.

Preferably, the location and pressure value profile defines at least one location having no corresponding electrical output signal.

Preferably, the location and pressure value profile comprises at least one pressure value threshold and a plurality of corresponding locations; and

the method comprises:

defining a corresponding haptic response;

measuring a pressure applied by a plurality of simultaneous touches to the touch input surface at different times;

determining the locations of each of the plurality of touches on the touch input surface at said different times; and

if the measured pressure is greater than the at least one pressure value threshold corresponding to the plurality of determined locations, generating the defined corresponding haptic response. Preferably, the location and pressure value profile comprises at least one pressure value threshold, a corresponding location and the corresponding haptic response.

In a fourth aspect, the invention provides a method of providing haptic feedback comprising: defining a location and pressure value profile, the location and pressure value profile comprising at least one pressure value threshold and a corresponding location;

defining a corresponding haptic response;

comparing the measured pressure at different times to the defined location and pressure value profile; and

if the measured pressure is less than or equal to the at least one pressure value threshold corresponding to the determined location, generating a defined electrical output signal which indicates the location of the touch; or

if the measured pressure is greater than the at least one pressure value threshold corresponding to the determined location, generating the defined corresponding haptic response.

Preferably, the method further comprises: if the measured pressure is greater than the at least one pressure value threshold corresponding to the determined location, also generating a defined electrical output signal which indicates that a user input has been received and the location of the user input.

not generating the defined electrical output signal which indicates the location of the touch if the measured pressure is less than or equal to the at least one further pressure value threshold. Preferably, the the pressure value profile comprises at least one further pressure value threshold, the at least one further pressure value threshold having a lower value than said at least one pressure value threshold; and if the measured pressure is less than or equal to the at least one further pressure value threshold, generating a defined electrical output signal which indicates the location of the touch and that the measured pressure is less than or equal to the at least one further pressure value threshold.

Preferably, the location and pressure value profile defines at least one location having no corresponding haptic response.

Preferably, the location and pressure value profile defines at least one location having no corresponding electrical output signal which indicates that a user input has been received.

the method comprises:

defining a corresponding haptic response;

if the measured pressure is greater than the at least one pressure value threshold corresponding to the plurality of determined locations, generating the defined corresponding haptic response.

Preferably, the location and pressure value profile comprises at least one pressure value threshold, a corresponding location and the corresponding haptic response.

In a fifth aspect, the invention provides a method of providing haptic feedback comprising: defining a pressure value profile, the pressure value profile comprising at least one pressure value threshold;

defining a corresponding haptic response;

comparing the measured pressure at different times to the defined pressure value profile; and if the measured pressure is greater than the at least one pressure value threshold, generating the defined corresponding haptic response,

wherein the defined corresponding haptic response is generated until the measured pressure is no longer greater than the pressure value threshold.

Preferably, the method further comprises:

determining a location of the touch on the touch input surface; and

if the measured pressure is greater than the at least one pressure value threshold, generating a defined electrical output signal in addition to generating the defined corresponding haptic response.

Preferably, the defined electrical output signal indicates the location of the touch.

Preferably, the pressure value profile comprises at least one first further pressure value threshold, the at least one first further pressure value threshold having a lower value than said at least one pressure value threshold; and

not generating the defined electrical output signal which indicates the location of the touch if the measured pressure is less than or equal to the at least one first further pressure value threshold.

if the measured pressure is less than or equal to the at least one first further pressure value threshold, generating a defined electrical output signal which indicates the location of the touch and that the measured pressure is less than or equal to the at least one further pressure value threshold.

Preferably, the pressure value profile comprises at least one second further pressure value threshold having a higher value than said at least one pressure value threshold, and a corresponding further haptic response is defined; and

if the measured pressure at different times is greater than the second further pressure value threshold, generating the defined corresponding further haptic response. Preferably, the method further comprises:

if the measured pressure is greater than the at least one second further pressure value threshold, generating a defined further electrical output signal in addition to generating the defined corresponding further haptic response.

Preferably, the defined further electrical output signal indicates that a user input has been received and the location of the user input.

Preferably, the pressure value profile comprises at least one further pressure value threshold and a corresponding location; and

a corresponding further haptic response is defined; and

the characteristics of the defined corresponding further haptic response are different for different locations. Preferably, the pressure value profile comprises at least one pressure value threshold and a corresponding location, and a corresponding haptic response is defined; and

the characteristics of the defined corresponding haptic response are different for different locations. Preferably, the pressure value profile comprises at least one pressure value threshold and the corresponding haptic response.

Preferably, the touch location is determined using bending waves propagating through the touch input surface.

Preferably, the haptic response is generated using bending waves propagating through the touch input surface.

In a sixth aspect, the invention provides a touch input apparatus arranged to provide haptic feedback, the apparatus comprising:

a touch input surface;

at least one pressure transducer arranged to produce an electrical pressure signal corresponding to a touch pressure applied to the touch input surface; a pressure processor arranged to determine a touch pressure value by processing the electrical pressure signal;

a pressure profile processor arranged to receive the touch pressure value, compare the touch pressure value to a predetermined touch pressure profile and, based on the results of the comparison, to selectively generate a haptic instruction signal and an output signal;

a haptic processor arranged to receive the haptic instruction signal and to process the haptic instruction signal to produce a haptic drive signal; and

at least one haptic transducer arranged to produce a haptic response from the haptic drive signal;

wherein the pressure processor, haptic processor and pressure profile processor are dedicated processors.

Preferably, the apparatus further comprises:

at least one location transducer arranged to produce a location signal corresponding to a location of the touch pressure applied to the touch input surface; and

a location processor arranged to determine a location value by processing the location signal; wherein the pressure profile processor is arranged to receive the location value; and wherein the location processor is a dedicated processor. Preferably, the pressure profile processor is arranged to receive the location value, compare the location and touch pressure values to a predetermined location and touch pressure profile and, based on the results of the comparison, to selectively generate a haptic instruction signal and an output signal. Preferably, the output signal comprises the location of the touch.

Preferably, the location transducer is arranged to produce the location signal using bending waves propagating through the touch input surface. Preferably, the haptic transducer is arranged to produce the haptic response using bending waves propagating through the touch input surface. Preferably, the pressure processor, haptic processor and pressure profile processor are combined in a single dedicated processor.

Preferably, the location processor is also combined in a single dedicated processor.

In a seventh aspect, the invention provides computer program code configured to, when run on a processor, cause the processor to perform any of the methods of the first to fifth aspects.

In an eighth aspect, the invention provides a computer readable medium carrying computer readable code configured to, when run on a computer, cause the computer to perform any of the methods of the first to fifth aspects.

In a ninth aspect, the invention provides a computer program product comprising computer readable code according to the seventh or eighth aspects.

BRIEF DESCRIPTION OF DRAWINGS

The prior art is diagrammatically illustrated and the invention is diagrammatically illustrated, by way of example, in the accompanying drawings in which:

Figure 1 shows a schematic view of a touch sensitive input device according to a first embodiment of the invention;

Figure 2 shows a schematic view of a touch sensitive input device according to second and third embodiments of the invention;

Figure 3 shows a representation of a location and pressure value profile useable by the input device of figure 2;

Figure 4 shows a schematic view of a touch sensitive input device according to a fourth embodiment of the invention;

Figure 5 shows a plan view of the touch sensitive input device of figure 4;

Figure 6 shows a cut away plan view of the touch sensitive input device of figure 4; and Figure 7 shows a schematic diagram of the signal and data processing circuitry of the touch sensitive input device of figure 4.

DETAILED DESCRIPTION In the present application the term user is used to refer to the entity interacting with a touch input device. The user may not be a human being. The user may, for example, be a machine or an animal. A first embodiment of the invention will be discussed with reference to figure 1. Figure 1 shows a schematic diagram of touch input device 1 able to providing haptic feedback. The touch input device 1 comprises a touch input surface 2, a pressure sensor 3, and a haptic transducer 4. The touch input device 1 acts as a touch input user interface for external circuitry (not shown in figure 1).

The touch input surface 2 may, for example, be comprised in a touch screen or a touch pad.

When a user touches the touch input surface 2, as indicated by arrow 5, the pressure applied to the touch input surface 2 is converted into a pressure output electrical signal by the pressure sensor 3. The user touch may be a touch using an extremity of the user. If the user is a human being, this extremity is typically a finger, or may be a touch using a stylus or other implement held by the user. If the user is a machine, the extremity may be any appropriate effector. If the user is an animal, the extremity may be any appropriate body part, for example a tentacle of an octopus.

The pressure sensor 3 comprises a pressure sensitive resistor having a resistance which varies with applied pressure. The pressure sensor 3 supplies the pressure output electrical signal to a pressure value processor 6, which determines the value of the applied pressure from the pressure output electrical signal.

The pressure value processor 6 provides the determined value of the applied pressure to a pressure profile processor 7. The pressure profile processor 7 compares the changes in the value of the applied pressure over time to a pre-determined pressure value profile stored in a memory 8 and, based on the results of the comparison, may selectively instruct a haptic processor 9 to generate a haptic response to the user touch. Further, based on the results of the comparison, the haptic processor 9 may selectively provide an output signal along an output line 10, the output signal indicating to some external circuitry (not shown) that a touch above a predetermined pressure value has been detected. When the haptic processor 9 receives instructions to generate a haptic response to a user touch the haptic processor 9 sends an electrical haptic response signal to the haptic transducer 4. The haptic transducer 4 comprises a piezo-electric transducer and converts the electrical haptic response signals into mechanical bending waves in the touch input surface 2.

The bending waves are transmitted through the touch input surface 2, and the resulting movement of the touch input surface 2 at the point where the user is touching the touch input surface 2 is sensed by the user, providing haptic feedback to the user. When a user touch is applying pressure to the touch input surface 2 the pressure profile processor 7 determines the value of the applied pressure at intervals over time and further determines from changes in the value of the applied pressure over time whether the applied pressure is increasing or decreasing. The stored predetermined pressure value profile defines at least one pressure value at which a user touch is to be recognised as a touch input and a haptic response is desired to be generated.

In practice, when a user wishes to input to a touch input device, for example as if the touch input device was a push button, a user touch is generally applied with a pressure that increases to a maximum value and then decreases again to a low value, or to zero if the user stops touching the device.

In a first example the stored predetermined pressure value profile defines a single applied pressure threshold value at which a user touch is to be recognised as a touch input and a haptic response is to be generated. When the pressure profile processor 7 identifies that the applied pressure value is increasing over time, and the applied pressure value crosses, that is rises above, the stored threshold value, the pressure profile processor 7 sends an instruction to the haptic processor 9 for a first haptic response to be made, and sends an output signal along the output line 10 to indicate that a touch above a predetermined pressure value has been detected. Subsequently, when the pressure profile processor 7 identifies that the applied pressure value is decreasing over time, and the applied pressure value crosses, that is drops below, the stored threshold, the pressure profile processor 7 sends an instruction to the haptic processor 9 for a second haptic response to be made. Thus, the first haptic response is made when a rising pressure touch crossing the threshold value is detected and the second haptic response is made when a falling pressure touch crossing the threshold value is detected.

The first haptic response is generated when an output signal indicating that a touch above a predetermined pressure value has been detected is sent. Accordingly, the first haptic response provides a touching user with haptic feedback confirming to the user that their touch has been detected. This provides an intuitively understood input mechanism to the user.

This arrangement of making a first haptic response as the applied touch pressure is increasing, a rising pressure touch, and a second haptic response as the applied touch pressure is decreasing, a falling pressure touch, mimics the haptic response provided by many physical switches or push buttons where a "click" is felt when the button is depressed, and a "click" is also felt when the button is released as the user touch lifts off the button. Accordingly, this arrangement may provide the advantage of allowing the physical sensation of pressing a mechanical push button or switch to be more accurately imitated. This may provide a more intuitive experience to users. In some examples it may not be necessary to determine whether the applied pressure value is increasing or decreasing. It may be sufficient to identify each time the applied pressure value crosses the threshold without determining the direction of the crossing, and to assume that the first crossing identified corresponds to an increase in pressure, with subsequent crossing alternately assumed to correspond to decreasing and increasing pressure respectively. In such examples the pressure profile processor 7 may include a memory identifying the assumed status of at least the previous crossing.

In some examples the haptic response may be comprised in the predetermined pressure value profile. In some examples the haptic response may be separate from the predetermined pressure value profile.

In some examples, further output signals may be sent providing further information about the user touch. In some examples, a further output signal may be sent when the applied pressure drops below the threshold value. In some examples, the output signal, or signals, may include further information, for example, the maximum pressure of the touch, the length of time for which the touch applied a pressure higher than a specific threshold, or the length of time between the pressure threshold crossings. In a second example the stored predetermined pressure value profile may define a plurality of different applied pressure threshold values. In one example the stored predetermined pressure profile may define a first applied pressure threshold value at which a user touch is to be recognised as a touch input and a first haptic response is to be generated, and a second threshold value at which a second haptic response is to be generated, the first threshold value being higher than the second threshold value. When the pressure profile processor 7 identifies that the applied pressure value is increasing over time, and the applied pressure value crosses the first stored threshold value, the pressure profile processor 7 sends an instruction to the haptic processor 9 for a first haptic response to be made, and sends an output signal along the output line 10 to indicate that a touch above a predetermined pressure value has been detected. Subsequently, when the pressure profile processor 7 identifies that the applied pressure value is decreasing over time, and the applied pressure value crosses the second stored threshold value, the pressure profile processor 7 sends an instruction to the haptic processor 9 for a second haptic response to be made. This arrangement of having different applied force thresholds for the first applied force haptic response and the second release force haptic response may allow the haptic response provided by a physical switch or push button to be more accurately imitated. This may provide a more intuitive experience to users. Further, this provides hysteresis, and may prevent an applied force which is sustained at a value close to a threshold value being incorrectly responded to as if it was a number of separate user touch inputs if small fluctuations in the applied force cause the value of the applied force to move repeatedly across the threshold value.

In some examples, further output signals may be sent providing further information about the user touch. In some examples, a further output signal may be sent when the applied pressure drops below the second threshold value. In some examples, the output signal, or signals, may include further information, for example, the maximum pressure of the touch, the length of time for which the touch applied a pressure higher than a specific threshold, or the length of time between the pressure threshold crossings. In some examples a signal identifying the measured value of the applied pressure of the user touch may be generated independently of the output signals discussed above. In some examples such a pressure value signal may be used to input data, for example to indicate line thickness or shading level.

In a third example the stored predetermined pressure profile may define a first applied pressure threshold value at which a user touch is to be recognised as a touch input and a first haptic response is to be generated, and a second threshold value at which a second haptic response is to be generated, the first threshold value being higher than the second threshold value similarly to the second example. In this example the pressure profile processor 7 may operate in a similar manner to the second example discussed above. Further, the pressure profile processor 7 may be adapted so that after the pressure profile processor 7 has identified that the applied pressure value is increasing over time and has crossed the first stored threshold value, and sent an instruction to the haptic processor 9 for a first haptic response to be made, and sent an output signal along the output line 10 to indicate that a touch above a predetermined pressure value has been detected, the pressure profile processor 7 does not respond to any subsequent identifications that the applied pressure value is increasing over time and has crossed the first stored threshold value until after the pressure profile processor 7 has subsequently identified that the applied pressure value is decreasing over time and has crossed the second stored threshold value, and the pressure profile processor 7 has sent an instruction to the haptic processor 9 for a second haptic response to be made.

Thus, in the third example, once the first haptic response has been made and the output signal sent, the first haptic response is not made again and the output signal is not sent again until after the second haptic response has been made.

This arrangement may allow a user to receive haptic feedback confirming the application and release of a touch input to indicate to the user that the touch input may be applied again, if desired. This may provide reassurance to a user that an intended number of user input presses have been made and responded to by the touch input device 1.

This arrangement of making a first haptic response as the applied touch pressure is increased and a second haptic response as the applied touch pressure is decreased, and requiring that the second haptic response is made before the first haptic response can be repeated in response to an increase in the applied pressure mimics the haptic response provided by many physical switches or push buttons where a "click" is felt when the button is depressed, and a "click" is also felt when the button is released, before the button can again be depressed. This arrangement may allow the haptic response provided by a physical switch or push button to be more accurately imitated. This may provide a more intuitive experience to users.

In some examples the first and second haptic responses may be identical. In some examples the first and second haptic responses may be different. The use of different first and second haptic responses may allow the haptic response provided by a physical switch or push button to be more accurately imitated. In some examples the second haptic response may be perceivably weaker than the first haptic response, while remaining perceptible. In some examples the first and second haptic responses may provide different characteristics, for example the first haptic response may have characteristics causing it to be perceived as a "click" imitative of the closing of a physical switch or push button, while the second haptic response may have characteristics causing it to be perceived as a softer "rebound" imitative of the re-opening of a released physical switch or push button. This may provide a more intuitive experience to users. In some examples one of the first and second haptic responses may be omitted. In some examples the touch input device may detect the applied pressure value crossing each of the first and second threshold values, but generate a haptic response only in response to the crossing of the second threshold value. In some examples the touch input device may detect the applied pressure value crossing each of the first and second threshold values, but generate a haptic response only in response to the crossing of the first threshold value.

In some examples the, or each, haptic response may be delayed for a predetermined time after detecting the applied pressure value crossing a respective threshold value. This may provide a more intuitive experience to users.

In a fourth example, the stored predetermined pressure profile may define a plurality of different first applied pressure threshold values at which a user touch is to be recognised as a touch input and first haptic responses and output signals are to be generated. In some examples the first haptic responses may all be identical. In some examples the first haptic responses may be different. The use of different first haptic responses may allow the haptic response provided by a physical switch or push button to be more accurately imitated. This may provide a more intuitive experience to users. In particular, in examples where a plurality of different first applied pressure threshold values are used, this may allow an increasing pressure user touch to be recognised as a user input and responded to by generating an output signal and a first haptic feedback a plurality of times, once at each of a series of different increasing threshold pressure values. In some examples the plurality of output signals may be the same. In other examples the plurality of output signals may be different.

In the fourth example, the stored predetermined pressure profile may define a plurality of different second pressure threshold values at which second haptic responses are to be generated. In some examples the second haptic responses may be identical. In some examples the second haptic responses may be different. The use of different second haptic responses may allow the haptic response provided by a physical switch or push button to be more accurately imitated. This may provide a more intuitive experience to users.

In particular, in the fourth example, when a plurality of different first applied pressure threshold values are used, a corresponding plurality of different second applied pressure threshold values may also be used, this may allow a decreasing pressure user touch to be responded to by generating a second haptic feedback a plurality of times, once at each of a series of different decreasing threshold pressure values. In some examples the touch input device 1 may be combined or integrated with a visual display to provide a touch sensitive display.

It will be understood that the touch input surface 2 must have suitable mechanical properties to allow it to transmit the pressure applied by a touch to the pressure sensor 3 and to transmit the haptic feedback generated by the haptic transducer 4 to the user.

In the first embodiment a separate pressure processor 6, pressure profile processor 7 and haptic processor 9 are separate processors. This is not essential. In some examples the functions of the described separate processors 6, 7 and 8 may be carried out by a different number of processors.

For simplicity the illustrated embodiment has only a single pressure sensor 3 and a single haptic transducer 4. In practice, some examples may have a plurality of pressure sensors and/or a plurality of haptic transducers.

A second embodiment of the invention will be discussed with reference to figure 2. Figure 2 shows a schematic diagram of touch input device 11 able to providing haptic feedback. The touch input device 11 comprises a touch input surface 12, a pressure sensor 13, a haptic transducer 14 and a touch position sensor 21. The touch input device 11 acts as a touch input user interface for external circuitry (not shown in figure 2).

The touch input surface 12 may, for example, be comprised in a touch screen or a touch pad.

When a user touches the touch input surface 12, as indicated by arrow 15, the touch generates a displacement of in the touch input surface 12. This displacement generates bending waves which are transmitted through the touch input surface 12 to the touch position sensor 21. The touch position sensor 21 converts the bending waves into a touch location output electrical signal. The user touch may be a touch using an extremity of the user, typically a finger, or may be a touch using a stylus or other implement held by the user.

The touch position sensor 21 comprises a piezo-electric transducer. The touch position sensor 21 supplies the location output electrical signal to a location processor 22, which determines the location of the touch from the location output electrical signal. The location processor 22 provides the determined location of the touch to a location and pressure profile processor 17.

Further, when a user touches the touch input surface 12, the pressure applied to the touch input surface 12 is converted into a pressure output electrical signal by the pressure sensor 13.

Similarly to the first embodiment, the pressure sensor 13 comprises a pressure sensitive resistor having a resistance which varies with applied pressure. The pressure sensor 13 supplies the pressure output electrical signal to a pressure value processor 16, which determines the value of the applied pressure from the pressure output electrical signal. The pressure value processor 16 provides the determined value of the applied pressure to the location and pressure profile processor 17.

The location and pressure profile processor 17 compares the changes in the touch location and value of the applied pressure over time to a pre-determined location and pressure value profile stored in a memory 18 and, based on the results of the comparison, may selectively instruct a haptic processor 19 to generate a haptic response to the user touch. Further, based on the results of the comparison, the location and pressure profile processor 17 may selectively provide an output signal along an output line 20.

When the haptic processor 19 receives instructions to generate a haptic response to a user touch, the haptic processor 19 sends an electrical haptic response signal to the haptic transducer 14. The haptic transducer 14 comprises a piezo-electric transducer and converts the electrical haptic response signals into mechanical bending waves in the touch input surface 12.

The bending waves are transmitted through the touch input surface 12, and the resulting displacements of the touch input surface 12 at the point where the user is touching the touch input surface 12 is sensed by the user, providing haptic feedback to the user.

In some situations the touch position sensor 21 may be able to detect the location of a user touch while the pressure sensor 13 is unable to detect any applied pressure. Although the present description refers to a touch position sensor the position of an object in close proximity to, but not actually touching, the touch input surface 12 may also be detected. It is possible for an object, such as a user finger or stylus, moving close to the touch input surface 12 to generate bending waves in the touch input surface 12 without actually contacting the touch input surface 12, for example due to displacement of the touch input surface 12 by local changes in air pressure produced by the moving object. Further, it is possible for an object, such as a user finger or stylus, moving across the touch surface 12 and in contact with the touch surface 12 to produce bending waves in the touch surface 12 by displacing the touch surface 12 while applying a very low pressure force on the touch surface 12. In these situations, for example, the applied pressure may be too small to be detected by the pressure sensor 13 while the user touch location can be detected by the touch position sensor 21. In a fifth example, the stored pre-determined location and pressure value profile defines at least one pressure value at which a user touch is to be recognised as a touch input and a haptic response is desired to be generated. When a user touch is detected by the touch position sensor 21 and the pressure value of the user touch is below the threshold value, the location and pressure profile processor 17 sends an output signal along the output line 20 identifying the location of the touch. If the pressure sensor 13 is unable to identify the user touch this is regarded as a pressure value below the threshold value. This may be regarded as the pressure value of a user touch which is not detected by the pressure sensor 21 being treated as having a pressure value of zero.

When a user touch is detected by the touch position sensor 21, and the pressure value of the user touch crosses, that is rises above, the stored threshold value, the location and pressure profile processor 17 sends an instruction to the haptic processor 19 for a first haptic response to be made and provides an output signal along the output line 20 identifying that a touch above the predetermined pressure value has been detected, and the location of the touch.

This arrangement of generating an output signal tracking a location of a touch and indicating when the pressure of the touch exceeds a predetermined pressure value, and also providing haptic feedback when the pressure of the touch exceeds the predetermined pressure value may allow improved user functionality. For example, if the touch input device 11 provides the output signals along line 30 to a device having a visual display the output signal tracking the location of the touch can be used to control the movement of a cursor shown on the visual display to track the location of the user touch on the touch input surface 12. When the output signal along the output line 20 indicates that a touch above the predetermined pressure value has been detected this can be treated as a location contextual user input having a meaning dependent on any active display elements, such as icons, displayed at the cursor location in a similar manner to a mouse click or a keystroke. The haptic response provides confirmation to the user that the user input has been detected.

This arrangement allows a user touch controlled cursor to "hover", moving across a visual display without activating any active display elements until a user deliberately increases the pressure of their touch to make an input. This may improve user functionality. For example, the risk of unwanted commands being inadvertently issued when a cursor lingers over an active display element, which may be encountered in systems using dwell time to indicate input, may be avoided. This arrangement may also allow mobile devices, or other devices with touchscreens, to be used effectively in cursor-like modes when interacting with content, for example websites, that are not well optimised for interaction with mobile or touch screen devices.

In a sixth example, the stored pre-determined location and pressure value profile defines at least one first pressure value at which a user touch is to be recognised as a location input and at least one second pressure value, higher that the first, at which a user touch is to be recognised as a touch input and a haptic response is desired to be generated.

When a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is below the first threshold value the location and pressure profile processor 17 sends an output signal along the output line 20 identifying the location of the touch and that the pressure value is below the first pressure value. If the pressure sensor 13 is unable to identify the user touch this is regarded as a pressure value below the threshold value. This may be regarded as the pressure value of a user touch which is not detected by the pressure sensor 21 being treated as having a pressure value of zero. When a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is above the stored first threshold value, the location and pressure profile processor 17 provides an output signal along the output line 20 identifying that a touch above the first pressure value has been detected, and the location of the touch. Subsequently, if a user touch is detected by the touch position sensor 21, and the pressure value of the user touch crosses, that is rises above, the stored second threshold value, the location and pressure profile processor 17 sends an instruction to the haptic processor 19 for a first haptic response to be made and provides an output signal along the output line 20 identifying that a touch above the second pressure value has been detected, and the location of the touch.

Alternatively, if the user touch is ended without the pressure value of the user touch ever rising above the stored second threshold value the first haptic response is not made, and the output signal is not generated. This arrangement of generating an output signal tracking a location of a touch and indicating when the pressure of the touch exceeds a first predetermined pressure value and a second predetermined pressure value, and also providing haptic feedback when the pressure of the touch exceeds the second predetermined pressure value may allow improved user functionality. For example, if the touch input device 11 provides the output signals along line 30 to a device having a visual display the output signal tracking the location of the touch can be used to control the movement of a cursor shown on the visual display to track the location of the user touch on the touch input surface 12 only when the applied pressure of the user touch exceeds the first pressure value. When the output signal along the output line 20 indicates that a touch above the second pressure value has been detected this can be treated as a location contextual user input having a meaning dependent on any active display elements, such as icons, displayed at the cursor location in a similar manner to a mouse click or a keystroke. The haptic response provides confirmation to the user that the user input has been detected.

This arrangement allows a user touch controlled cursor to move only when the user applies at least a first level of pressure with their touch, and also allows the cursor to "hover", moving across a visual display without activating any active display elements until a user deliberately increases the pressure of their touch to a higher second level to make an input. This may improve user functionality.

In a seventh example, touch input device 11 operates similarly to the sixth example with the exception that when a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is below the first threshold value the location and pressure profile processor 17 does not send any an output signal along the output line 20. In some situations where no action is to be taken in response to identifying the location of the touch having a pressure value below the first pressure value there may be no purpose in generating an output signal in this situation.

In an eighth example, the stored pre-determined location and pressure value profile may define different actions to be taken in response to sensed user touch pressure values at different locations on the touch input surface 12. Figure 3 shows a diagram of an example of such a stored pre-determined location and pressure value profile. In figure 3, the touch input surface 12 is divided into a number of sensitive areas 23 and a non- sensitive region 24 making up the remainder of the touch input surface 12.

The stored pre-determined location and pressure value profile defines the locations on the touch input surface 12 of the sensitive and non-sensitive regions together with at least one pressure value at which a user touch is to be recognised as a touch input and a haptic response is desired to be generated when the user touch is in a sensitive region. When a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is below the threshold value the location and pressure profile processor 17 sends an output signal along the output line 20 identifying the location of the touch. If the pressure sensor 13 is unable to identify the user touch this is regarded as a pressure value below the threshold value.

When a user touch is detected by the touch position sensor 21, the pressure value of the user touch crosses, that is rises above, the stored threshold value, and the location of the touch corresponds to the non-sensitive region 24, the location and pressure profile processor 17 sends an output signal along the output line 20 identifying the location of the touch.

When a user touch is detected by the touch position sensor 21, the pressure value of the user touch crosses, that is rises above, the stored threshold value, and the location of the touch corresponds to a sensitive region 23, the location and pressure profile processor 17 sends an instruction to the haptic processor 19 for a first haptic response to be made and provides an output signal along the output line 20 identifying that a touch above the predetermined pressure value has been detected, and the location of the touch. This arrangement of generating an output signal tracking a location of a touch and indicating when the pressure of the touch exceeds a predetermined pressure value at a predefined sensitive location, and also providing haptic feedback when the pressure of the touch exceeds the predetermined pressure value at a predefined sensitive location may allow improved user functionality.

For example, if the touch input device 11 provides the output signals along line 30 to a device having a visual display the output signal tracking the location of the touch can be used to control the movement of a cursor shown on the visual display to track the location of the user touch on the touch input surface 12, and the locations of the sensitive regions 23 can correspond to the locations of active display elements, such as buttons or icons, shown on the visual display. When the output signal along the output line 20 indicates that a touch above the predetermined pressure value has been detected this can be treated as a location contextual user input having a meaning dependent on the active display element displayed at the cursor location in a similar manner to a mouse click or a keystroke. The haptic response provides confirmation to the user that the user input to the active display element has been detected.

This arrangement allows a user touch controlled cursor to "hover", moving across a visual display without activating any active display elements until a user deliberately increases the pressure of their touch to make an input. This may improve user functionality. For example, the risk of unwanted commands being inadvertently issued when a cursor lingers over an active display element, which may be encountered in systems using dwell time to indicate input, may be avoided, because the haptic response is generated only when a user deliberately increases the pressure of their touch above the stored threshold value to make an input at a sensitive location. Further, the haptic response provides confirmation to a user that the user input has been made.

In the eighth example the pre-determined location and pressure value profile may define different pressure threshold values at different locations. In particular, the pre-determined location and pressure value profile may define a plurality of different sensitive areas 23 and may define different pressure threshold values for different ones of the sensitive areas 23. This may provide improved user functionality. In a ninth example, the features of the eighth example may be combined with the features of the sixth or seventh examples. Accordingly, the feature of the eighth example that predetermined location and pressure value profile may define different actions to be taken in response to sensed user touch pressure values at different locations on the touch input surface may be combined with the features of the sixth and seventh examples that the pre-determined location and pressure value profile defines at least one first pressure value at which a user touch is to be recognised as a location input and at least one second pressure value, higher that the first, at which a user touch is to be recognised as a touch input and a haptic response is desired to be generated. In the ninth example, the first pressure value at which a user touch is to be recognised as a location input may be constant across the entire touch input surface, while the second pressure value, higher than the first, at which a user touch is to be recognised as a touch input and a haptic response generated may be responded to only at the defined sensitive areas of the touch input surface.

In the second embodiment the touch position sensor 21 may be able to distinguish the locations of a plurality of simultaneous user touches. These plural user touches may be used to provide multiple channels for user input, either alone, or in combination with the user input channel described above provided by a press on the screen at a single location.

The location and pressure processor 17 may have a number of gesture profiles stored in the memory. Each gesture profile may be defined by multiple features of location and/or pressure, and their changes over time, for each of one or more touches. In some examples these gesture profiles may be stored together with the location and pressure value profiles in a profile library.

For example, where the locations of two user touches can be identified movement of the two touch locations toward one another may be treated as a first user input gesture, and movement of the two touch locations away from one another may be treated as a second user input gesture. These exemplary user input gestures may, for example, be used in an intuitive manner to control zoom of a displayed image by the first, moving together, gesture instructing a decrease in zoom and the second, moving apart, gesture instructing a decrease in zoom.

Such multiple channel input using a plurality of simultaneous user touches may be combined with the examples of the second embodiment described above. In such combined examples the location processor 22 may determine the location of each of a plurality of user touches and provide the determined locations of each of the user touches to the location and pressure profile processor 17. The location and pressure profile processor 17 compares changes in the determined locations of each of the user touches over time with gesture profiles stored in the memory 18 and determines if the changes in the locations of the user touches represent a user gesture. When the location and pressure profile processor 17 determines that the changes in the locations of the user touches represent a user gesture, this may be responded to in a corresponding manner to the detection of a user touch in the previous examples of the second embodiment. For example, the pressure profile processor 17 may only provide an output signal along the output line identifying that the user gesture has been detected and its location, and may only instruct the haptic processor 19 to make a haptic response if the user touches making up the user gesture have a pressure value above a predetermined threshold. In examples where sensitive and non- sensitive regions of the input surface 12 are defined the pressure profile processor 17 may also take into account the position of the user gesture when deciding a response. The position of the gesture may be regarded as being the position of one or more of the user touches making up the user gesture or a position derived from the positions of the user touches, such as a centroid of the positions of the user touches. In these examples, the location and pressure profile processor 17 may also respond to a single touch in the manner of the second embodiment.

In one example the total pressure of all of the user gestures making up the user gesture may be taken into account by the pressure profile processor 17 when deciding a response. In other examples the average pressure of all of the user gestures making up the user gesture may be taken into account by the pressure profile processor 17 when deciding a response. In examples where the pressure sensor and the pressure processor are able to determine the pressure of each user touch separately, the pressure of each of the user gestures making up the user gesture may be taken into account by the pressure profile processor 17 when deciding a response. The first and second embodiments of the invention can be combined to provide further advantages. In particular, applying the applying the first embodiment may provide a more intuitive experience to users of the second embodiment.

One example of such a combination is that the techniques of the first embodiment could be combined with the eighth or ninth examples of the second embodiment to provide a user with haptic feedback more accurately imitating a physical switch or push button when a user touch input in a predefined sensitive location is detected. This may allow user feedback to be provided more accurately imitating the predefined sensitive locations being physical push buttons. This may provide a more intuitive experience to users. In one example the visual display may display a graphical user interface (GUI) of a computer.

In some examples the touch input device 11 may be combined or integrated with a visual display to provide a touch sensitive display. In such examples it may not be necessary to display a cursor because the touch location on the display is visible to the user, and so may take the place of the cursor, which is rendered superfluous. In such examples where a cursor is not displayed references to the cursor in the present description should be regarded as references to the touch location.

A third embodiment of the invention will be discussed with reference to figure 2. The touch input device 11 of the third embodiment of the invention is similar to the touch input device 11 of the second embodiment, except that the location and pressure profile processor 17 compares the changes in the touch location and value of the applied pressure over time to a pre-determined pressure value profile stored in a memory 18 and, based on the results of the comparison, may selectively instruct a haptic processor 19 to generate a haptic response to the user touch. Further, based on the results of the comparison, the location and pressure profile processor 17 may selectively provide an output signal along an output line 20. In a tenth example, the stored pre-determined pressure value profile defines at least one first pressure threshold value at which a user touch is to be recognised as a location input and a haptic response is desired to be generated.

When a user touch is detected by the touch position sensor 21 and the pressure value of the user touch is below the first threshold value, the location and pressure profile processor 17 sends an output signal along the output line 20 identifying the location of the touch and that the pressure value is below the first pressure value. If the pressure sensor 13 is unable to identify the user touch this is regarded as a pressure value below the threshold value. This may be regarded as the pressure value of a user touch which is not detected by the pressure sensor 21 being treated as having a pressure value of zero.

When a user touch is detected by the touch position sensor 21 and the pressure value of the user touch is above the stored first threshold value, the location and pressure profile processor 17 sends an instruction to the haptic processor 19 for a first haptic response to be made and provides an output signal along the output line 20 identifying that a touch above the first pressure value has been detected, and the location of the touch. In this example the first haptic response is a continuous haptic response which is made for as long as the detected pressure value of the user touch is above the stored first threshold value. The continuous haptic response signal may be referred to as a "purr".

This arrangement of generating a continuous haptic response signal when the pressure of the user touch exceeds the first predetermined pressure value may allow improved user functionality by providing feedback to a user to confirm that the user touch is being detected.

In an eleventh example, the stored pre-determined pressure value profile defines a plurality of different haptic responses and user touch pressure values which are to be responded to by the different haptic responses. When a user touch is detected by the touch position sensor 21 the pressure value of the user touch is compared to the stored pre-determined pressure value profile by the location and pressure profile processor 17. The location and pressure profile processor 17 determines the specified haptic response corresponding to the determined pressure value and sends an instruction to the haptic processor 19 for the specified haptic response to be made, and provides an output signal along the output line 20 identifying the location of the touch. In this example the specified haptic response is a continuous haptic response which is made for as long as the touch can be detected and has different specified characteristics corresponding to different detected pressure values of the user. The continuous haptic response signal may be referred to as a "purr".

This arrangement of generating a continuous haptic response signal having characteristics corresponding to the applied pressure when the user touch is sensed may allow improved user functionality by providing feedback to a user to confirm that the user touch is being detected and to indicate the amount of force being applied by the user. In one example this continuous haptic response signal may inform a user when the applied pressure is close to a threshold pressure value where the user touch will be regarded as a user input commanding some action to be taken. This may allow the inadvertent issuing of unintended user commands to be reduced. The second and third embodiments may be combined to provide further advantages. In particular, the tenth and eleventh examples of the third embodiment may be combined with the sixth, seventh and ninth examples of the second embodiment. In a twelfth example of such a combination, when a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is below a stored threshold value the location and pressure profile processor 17 provides an output signal along the output line 20 identifying that a touch has been detected, and the location of the touch, and sends an instruction to the haptic processor 19 for a first haptic response to be made, this first haptic response being the continuous "purr" haptic response signal.

If a user touch is detected by the touch position sensor 21, and the pressure value of the user touch crosses, that is rises above, the stored threshold value, the location and pressure profile processor 17 provides an output signal along the output line 20 identifying that a touch above the stored pressure value has been detected, and the location of the touch, and sends instructions to the haptic processor 19 for the first haptic response to continue to be made, this first haptic response being the continuous "purr" haptic response signal, and for a second haptic response to be made, this second haptic response being different from the first haptic response, for example a short haptic response signal, such as a "click".

Alternatively, if the user touch is ended without the pressure value of the user touch ever exceeding the stored second threshold value the second haptic response is not made, and the output signal is not generated. In this case, when the user touch can no longer be detected the first "purr" haptic response will stop being made.

This arrangement of generating an output signal tracking a location of a touch and providing a first continuous haptic response signal, and generating an output signal tracking a location of a touch and indicating when the pressure of the touch exceeds a predetermined pressure value, and also providing a second haptic feedback when the pressure of the touch exceeds the predetermined pressure value, may allow improved user functionality. For example, if the touch input device 11 provides the output signals along line 30 to a device having a visual display the output signal tracking the location of the touch can be used to control the movement of a cursor shown on the visual display to track the location of the user touch on the touch input surface 12, and the first continuous haptic signal provides feedback to a user to confirm that the user touch is being detected and tracked. When the output signal along the output line 20 indicates that a touch above the stored threshold pressure value has been detected this can be treated as a location contextual user input having a meaning dependent on any active display elements, such as icons, displayed at the cursor location in a similar manner to a mouse click or a keystroke. The second haptic response provides confirmation to the user that this user input has been detected.

This arrangement allows a user touch controlled cursor to "hover", moving across a visual display without activating any active display elements until a user deliberately increases the pressure of their touch to a higher level to make an input, while providing haptic feedback confirming the status of the user touch. This may improve user functionality.

In a thirteenth example of such a combination the stored first predetermined pressure threshold value of the second embodiment may also be used as the first predetermined pressure threshold value of the third embodiment. Accordingly, when a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is below the first threshold values the location and pressure profile processor 17 may optionally send an output signal along the output line 20 identifying the location of the touch and that the pressure value is below the first pressure value.

If a user touch is detected by the touch position sensor 21, and the pressure value of the user touch is above the stored first threshold value, the location and pressure profile processor 17 provides an output signal along the output line 20 identifying that a touch above the first pressure value has been detected, and the location of the touch, and sends an instruction to the haptic processor 19 for a first haptic response to be made, this first haptic response being the continuous "purr" haptic response signal.

Alternatively, if the user touch is ended without the pressure value of the user touch ever exceeding the stored first threshold value no haptic response is made.

If a user touch is detected by the touch position sensor 21, and the pressure value of the user touch crosses, that is rises above, the stored second threshold value, the location and pressure profile processor 17 provides an output signal along the output line 20 identifying that a touch above the second pressure value has been detected, and the location of the touch, and sends instructions to the haptic processor 19 for the first haptic response to continue to be made, this first haptic response being the continuous "purr" haptic response signal, and for a second haptic response to be made, this second haptic response being a short haptic response signal, for example a "click".

Alternatively, if the user touch is ended without the pressure value of the user touch ever exceeding the stored second threshold value the second haptic response is not made, and the output signal is not generated. In this case, when the pressure of the user touch falls below the stored first threshold value the first "purr" haptic response will stop being made.

This arrangement of generating an output signal tracking a location of a touch and indicating when the pressure of the touch exceeds a first predetermined pressure value and providing a first continuous haptic response signal when the pressure of the user touch exceeds the first predetermined pressure value, and generating an output signal tracking a location of a touch and indicating when the pressure of the touch exceeds a second predetermined pressure value, and also providing a second haptic feedback when the pressure of the touch exceeds the second predetermined pressure value, may allow improved user functionality. For example, if the touch input device 11 provides the output signals along line 30 to a device having a visual display the output signal tracking the location of the touch can be used to control the movement of a cursor shown on the visual display to track the location of the user touch on the touch input surface 12 only when the applied pressure of the user touch exceeds the first pressure value, and the first continuous haptic signal provides feedback to a user to confirm that the user touch is being detected and tracked. When the output signal along the output line 20 indicates that a touch above the second pressure value has been detected this can be treated as a location contextual user input having a meaning dependent on any active display elements, such as icons, displayed at the cursor location in a similar manner to a mouse click or a keystroke. The second haptic response provides confirmation to the user that this user input has been detected. This arrangement allows a user touch controlled cursor to move only when the user applies at least a first level of pressure with their touch, and also allows the cursor to "hover", moving across a visual display without activating any active display elements until a user deliberately increases the pressure of their touch to a higher second level to make an input, while providing haptic feedback confirming the status of the user touch. This may improve user functionality.

In a fourteenth example, the stored pre-determined location and pressure value profile defines at least one pressure threshold value at which a user touch is to be recognised as a location input and a haptic response is desired to be generated, and also defines different haptic responses to be made in response to user touches at different locations.

The different haptic responses at different locations may define a different continuous haptic "purr" signal to be produced in response to a detected touch according to the tenth and eleventh examples, or in response to a detected touch having a pressure above a predetermined threshold according to the twelfth example, depending upon the location of the detected touch. This may provide improved user functionality. For example, the continuous haptic "purr" signal may have a first characteristic when the touch location is a sensitive location or region and a second characteristic different from the first when the touch location is a non-sensitive location or region. This may allow a user to distinguish between sensitive and non-sensitive regions of the touch input surface by touch. This may be advantageous for users with impaired vision, and for users in situations where it is inconvenient or undesirable for the user to look at the touch input device or any visual display linked to the touch input device. Further, this may be advantageous even when a user can see the touch input device or a linked visual display unit in order to provide a separate communication channel to confirm the location of a user touch. It should be noted that the continuous haptic "purr" signal may have a plurality of variable characteristics. Accordingly, the continuous haptic "purr" signal may vary in plural characteristics so that it can have characteristics based upon both location and applied pressure simultaneously, and/or can have different characteristics in each of a plurality of different locations.

The different haptic responses at different locations may define a different continuous haptic "purr" signal to be produced in response to a detected touch in an information providing region of the touch input surface. This may provide improved user functionality. For example, if the touch input device 11 provides the output signals along line 30 to a device having a visual display the output signal tracking the location of the touch can be used to control the movement of a cursor shown on the visual display to track the location of the user touch on the touch input surface 12, and the locations of the information providing region can correspond to the locations of information display elements, such as meter bars, dials or icons, shown on the visual display. When the output signal along the output line 20 indicates that a touch has been detected this can be treated as a contextual request for information having a meaning corresponding to the information display element displayed at the cursor location. The characteristics of the continuous "purr" haptic response are varied in dependence on the value of the relevant information to communicate this value to the user. This may allow a user to obtain information by touch. This may be advantageous for users with impaired vision, and for users in situations where it is inconvenient or undesirable for the user to look at the touch input device or any visual display linked to the touch input device. Further, this may be advantageous even when a user can see the touch input device or a linked visual display unit in order to provide a separate communication channel to provide information.

For example, if the information display element is a battery power level indicator, such as a charge level bar, the characteristics of the continuous "purr" haptic response may be varied in dependence on the level of battery charge.

This example may require the stored pre-determined location and pressure value profile to be periodically updated with new haptic signal characteristics as the value of the information to be communicated changes.

Some of the examples refer to a continuous "purr" haptic signal or response. The meaning of continuous is that the haptic signal may be perceived and identified by a user as a continuing or ongoing signal, and not necessarily that the signal has a finite magnitude at all times. The continuous signal may for example be a modulated, periodic or intermittent signal including periods when the signal has zero magnitude provided that the signal may be perceived and identified by a user as being continuing or ongoing. The skilled person is well aware that a signal may be regarded as continuous although it includes periods having zero magnitude. For example, continuous speech may include pauses and spaces when no actual sound is produced. The embodiments discussed above refer to characteristics of a haptic signal or response. There are many such characteristics which may be varied, for example, parameters such as amplitude, frequency and duration. Further, for haptic signals having a finite duration the parameters, for example amplitude and frequency, may be modulated or varied over time, and the form of this modulation may also be regarded as a characteristic of the haptic signal which may be varied. Further, for haptic signals having a finite duration it is known that the parameters of the haptic signal may be varied in a manner which will be perceived by a touching user as having a texture, for example "rough" or "smooth".

All of these characteristics may be varied in the present invention.

In particular, in the eleventh example the continuous "purr" haptic signal may have different perceived textures depending upon the applied pressure of the user touch.

In particular, in the thirteenth and fourteenth examples the continuous "purr" haptic signal may have a different perceived texture when the touch is in a sensitive region of the touch input surface than when the touch is in a non-sensitive region of the touch input surface. Further, the continuous "purr" haptic signal may have a different perceived texture when the touch is in different sensitive regions of the touch input surface. This arrangement may provide the advantage of allowing the physical sensation of the sensitive regions being mechanical push buttons or switches to be more accurately imitated. This may provide a more intuitive experience to users. The use of bending waves to generate haptic signals is particularly effective in producing different haptic sensations on a control surface, such as the touch input surface.

In the embodiments described above haptic signals are referred to, and it is explained that haptic signals having different characteristics may be produced depending on a location of a user touch. In some examples a haptic signal may be spatially uniform, having substantially the same characteristics across the whole of the touch input surface at any time. In some examples a haptic signal may be spatially variable, simultaneously having different characteristics at different locations on the touch input surface. In examples where the haptic signal is spatially variable it may be preferred to have the amplitude of the haptic signal be a maximum at the user touch location, and lower elsewhere. This may allow the amount of acoustic energy released by the touch input surface to be reduced, and so reduce the problem of unwanted buzz associated with providing the haptic response. The use of bending waves to generate haptic signals is particularly effective in producing spatially variable haptic signals, or spatially varied haptic signals, contemporaneously. In particular on a control surface, such as a touch input surface.

In the first to third embodiments only a single pressure sensor is used. This is not essential. In some examples a plurality of pressure sensors may be used.

In the first to third embodiments only a single haptic transducer is used. This is not essential. In some examples a plurality of haptic transducers may be used. In the second and third embodiments only a single touch position sensor is used. This is not essential. In some examples a plurality of touch position sensors may be used.

Figures 4 and 5 show side and plan views respectively of a touch input device 30 according to a fourth embodiment of the present invention. The touch input device 30 is able to detect touch input from a user and to generate haptic feedback to a user, and acts as a user interface for a computer 31.

The touch input device 30 comprises a main body 32 and a touch sensitive input surface 33 attached to the main body 32. The touch sensitive input surface 33 has a front face which may be touched by a user. The touch sensitive input surface 33 is formed by a sheet of relatively rigid material able to transmit bending waves. In some examples the touch sensitive input surface 33 may be formed of glass, plastics, or a metal. The touch sensitive input device 30 further comprises a touch sensing means, a haptic feedback generating means, and a pressure sensing means.

Figure 6 shows a plan view of the touch input device of figures 4 and 5 with the touch sensitive input surface 33 cut away. As can be seen in figure 6, the touch sensing means comprises a plurality of piezo-electric transducers 34 attached to the rear face of the touch sensitive input surface 4. The piezo-electric transducers 34 are arranged to generate electrical output location signals in response to received bending waves in the touch sensitive input surface 33.

The touch sensitive input surface 33 is attached to the main body 32 by a plurality of pressure sensors. Each pressure sensor comprises a force sensitive resistor 35 located between the rear face of the touch sensitive input surface 33 and the main body 32. The force sensitive resistors 35 are arranged to vary in resistance in response to applied pressure on the front face of the touch sensitive input surface 33, and so to produce electrical output pressure signals in response to the applied pressure.

The haptic feedback generating means comprises a plurality of piezo-electric transducers 36 attached to the rear face of the touch sensitive input surface 33. The piezo-electric transducers 36 are arranged to generate bending waves in the touch sensitive input surface 33 in response to received electrical haptic response signals.

The force sensitive resistors 35 are located to minimise interference with the propagation of bending waves through the touch sensitive input surface 33 to and from the piezo-electric transducers 34 and 36. The piezo-electric transducers 34 are arranged to maximise useful haptic output. The piezo-electric transducer 36 are arranged to maximise touch sensitivity. Further, the piezo-electric transducers 34 and 36 are located to minimise mutual interference between the piezo-electric transducers 34 and the piezo-electric transducer 36. In practice it may be necessary to select positions of the force sensitive resistors 35 and the piezo-electric transducers 34 and 36 which achieve a compromise between these different objectives. Figure 7 shows a schematic view of the electrical circuits of the touch input device 30. The piezo-electric transducers 34 send their electrical output location signals to a location processor 37. The location processor 37 processes the received electrical output location signals and determines the location of the user touch. The location processor 37 then sends a location signal identifying the location of the user touch to a pressure and location profile processor 38.

The force sensitive resistors 35 send their electrical output pressure signals to a pressure processor 39. The pressure processor 39 processes the received electrical output pressure signals and determines the applied pressure of the use touch. The pressure processor 39 then sands a pressure signal identifying the applied pressure of the user touch to the pressure and location profile processor 38.

The pressure and location profile processor 38 compares the received location signals and pressure signals to a pre-determined location and pressure value profile stored in a memory 40. Further, the pressure and location profile processor 38 stores the received location signals and pressure signals in the memory 40 so that changes over time in the values of the received location signals and pressure signals can be taken into account. In some examples the memory 40 may be separate from the pressure and location profile processor 38. In some examples the memory 40 may be comprised in the pressure and location profile processor 38.

In dependence on the results of the comparison, the pressure and location profile processor 38 may send a haptic instruction signal to a haptic processor 41. The pressure and location profile processor 38 may send an output signal along an output line 42 identifying the location of the user touch. The sending of this location information may always take place, or may be selectively carried out in dependence on the results of the comparison. In dependence on the results of the comparison, the pressure and location profile processor 38 may send an output signal along an output line 42 identifying that the pressure of the user touch has exceeded a predetermined threshold.

Further, the pressure and location profile processor 38 may send an output signal along an output line 42 identifying the applied pressure of the user touch. The sending of this pressure information may always take place, or may be selectively carried out in dependence on the results of the comparison.

The haptic processor 41 receives the haptic instruction signal and processes this to produce electrical haptic response signals, which are sent to one or more of the piezo-electric transducers 36. The piezo-electric transducers 36 convert the received electrical haptic response signals into bending waves in the touch sensitive input surface 33 to generate a desired haptic response. The output signals along the output line 42 may be supplied to a general purpose processor (not shown). In examples where the touch input device is comprised in or connected to a computing device, such as a laptop, smartphone, tablet computer or pc, the general purpose processor may be a central processor of the computing device.

In the present invention all of the processing associated with the touch input device is carried out by dedicated processors, in the illustrated example the location processor 37, pressure processor 39, pressure and location profile processor 38 and haptic processor 41, and only the desired output signals are sent to the general purpose processor. This may improve user functionality. In particular, this may allow the response time, or latency, of the touch sensitive input device, that is, the delay between a user touching the device and receiving any appropriate haptic feedback to be made shorter. In particular, this may allow the response time, or latency, of the touch sensitive input device to be made more consistent. These advantages may be provided because there is no requirement for processing by the general purpose processor in order to provide the desired haptic feedback. Since the general purpose processor will generally have other tasks to perform, there may be a long and/or variable delay before such processing could be carried out by the general purpose processor.

In some examples the touch input device according to the described examples may be comprised in a touch screen or touch display. In some examples the touch input device may be a touch pad or track pad.

In the illustrated example of the fourth embodiment four pressure sensors are used. This is not essential. In some examples a different number of pressure sensors may be used.

In the illustrated example of the fourth embodiment two haptic transducers are used. This is not essential. In some examples a different number of haptic transducers may be used.

In the illustrated example of the fourth embodiment four touch position sensors are used. This is not essential. In some examples a different number of touch position sensors may be used.

In some examples the location of the user touch is not determined. In such examples the location related components and functions of the touch sensitive input device will not be required and may be omitted. In one example the touch sensitive input device may be useable as a stand alone keyboard suitable for connection to a computing device as a data input peripheral. In such examples the touch sensitive input device may draw power from the computing device and provide input data to the computing device through a power and data connection. In particular, the power and data connection may be a USB connection.

The embodiments described above provide haptic feedback to a user. In some examples other types of response may be provided together with the haptic feedback to provide additional communication channels. In some examples the haptic feedback may be accompanied by an audio response. Where an audio response is provided this may be produced by a separate audio output device, such as a loudspeaker. Alternatively, or additionally, the touch input surface may be arranged to produce audio output in addition to haptic feedback. In some examples the haptic feedback may be accompanied by a visual response. Where a visual response is provided this may be produced by a separate visual display. Alternatively, the touch input device may have an integral visual display, In some examples the touch input device may be a touch screen device.

In the illustrated embodiments a separate location processor 37, pressure processor 39, pressure and location profile processor 38 and haptic processor 41 are used. The functions of these processors may be combined and carried out by a smaller number of processors if desired. In one example all of these processors could be replaced by a single processor carrying out all of their functions. In the second to fourth embodiments a separate pressure sensor and touch position sensor are used. This is not essential. In some examples a combined pressure senor and touch position sensor, or sensors, may be used. In examples where a combined pressure senor and touch position sensor, or sensors, are used it may be convenient to combine the functions of the pressure processor and location processor into a single combined pressure and location processor.

In the illustrated embodiments the pressure sensor comprises a force sensitive resistor having a resistance which varies with the applied pressure. The skilled person will be well aware how to use a force sensitive resistor to generate a pressure output electrical signal and how to process the pressure output signal to determine a value of an applied pressure. The use of a force sensitive resistor to measure pressure is not essential. In some examples other methods of pressure measurement may be used. In the illustrated embodiments the haptic transducer comprises a piezo-electric transducer and generates bending waves in the touch input surface in order to generate the desired haptic response. The skilled person will be well aware how to operate a piezo-electric transducer to generate bending waves and provide a desired haptic response. The use of a piezo-electric transducer to measure generate bending waves is not essential. In some examples other methods of generating bending waves may be used. In particular, a magnet and coil transducer may be used.

The use of bending waves to generate a desired haptic response is not essential. In some examples other methods of generating a desired haptic response may be used. However, bending waves may provide advantages of being configurable in use to selectively drive selected spatial areas to provide different haptic responses to other spatial areas, for example, different spatial areas may simultaneously provide haptic responses with different magnitudes. In the illustrated embodiments the touch position sensor comprises a piezo-electric transducer and senses bending waves in the touch input surface in order to generate the output touch position signal. The skilled person will be well aware how to operate a piezo-electric transducer to sense bending waves and provide an output touch position signal. The use of a piezo-electric transducer to sense bending waves is not essential. In some examples other methods of sensing bending waves may be used. In some examples a magnet and coil transducer may be used.

The use of bending waves to sense position is not essential. In some examples other methods of sensing a touch position may be used. In some examples a touch position may be sensed using surface waves, capacitive position sensing, or resistive position sensing. In some examples where resistive position sensing is used, the resistive position sensor may be used as the pressure sensors. In examples where resistive position sensing is used a transparent pressure sensitive resistive sheet may be located under the touch input surface.

In examples where capacitive position sensing is used in particular, it is possible that the touch position sensor may be able to detect a location of a user touch while the pressure sensor is unable to detect any applied pressure. As is well known, capacitive position sensors may be able to detect a touch location by close proximity of an object to a surface without actual contact. The features disclosed in the different embodiments discussed above and the alternatives are not exclusive. This means that features in any or all of the embodiments and alternatives may be exchanged and/or combined if desired.

The apparatus described above may be implemented at least in part in software. Those skilled in the art will appreciate that the apparatus described above may be implemented using general purpose computer equipment or using bespoke equipment. The hardware elements, operating systems and programming languages of such computers are conventional in nature, and it is presumed that those skilled in the art are adequately familiar therewith. Some of the figures provide functional block diagram illustrations of general purpose processing computer hardware. It is believed that those skilled in the art are familiar with the structure, programming and general operation of such computer equipment and as a result the drawings should be self-explanatory. Aspects of the technology outlined above may be embodied in programming. Program aspects of the technology may be thought of as "products" or "articles of manufacture" typically in the form of executable code and/or associated data that is carried on or embodied in a type of machine readable medium and/or in a plurality of such media. "Storage" type media include any or all of the tangible memory of the computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives and the like, which may provide non-transitory storage at any time for the software programming. All or portions of the software may at times be communicated through the Internet or various other telecommunication networks. Such communications, for example, may enable loading of the software from one computer or processor into another, for example, from a management server or host computer of the organisation providing event identification services into the event identification computer platform. Thus, another type of media that may bear the software elements includes optical, electrical and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links or the like, also may be considered as media bearing the software. As used herein, unless restricted to non-transitory, tangible "storage" media, terms such as computer or machine "readable medium" refer to any medium that participates in providing instructions to a processor for execution.

Hence, a machine readable medium may take many forms, including but not limited to, a tangible storage medium, a carrier wave medium or physical transmission medium. Nonvolatile storage media include, for example, optical or magnetic disks, such as any of the storage devices in any computer(s) or the like, such as may be used to implement the event identification, etc. shown in the drawings. Volatile storage media include dynamic memory, such as main memory of such a computer platform. Tangible transmission media include coaxial cables; copper wire and fiber optics, including the wires that comprise a bus within a computer system. Carrier-wave transmission media can take the form of electric or electromagnetic signals, or acoustic or light waves such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer- readable media therefore include for example: a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM, any other optical medium, punch cards paper tape, any other physical storage medium with patterns of holes, a RAM, a PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave transporting data or instructions, cables or links transporting such a carrier wave, or any other medium from which a computer can read programming code and/or data. Many of these forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to a processor for execution.

While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings. Those skilled in the art will appreciate that while the foregoing has described what are considered to be the best mode and, where appropriate, other modes of performing the invention, the invention should not be limited to specific apparatus configurations or method steps disclosed in this description of the preferred embodiment. It is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings. Those skilled in the art will recognize that the invention has a broad range of applications, and that the embodiments may take a wide range of modifications without departing from the inventive concept as defined in the appended claims.

Although the present invention has been described in terms of specific exemplary embodiments, it will be appreciated that various modifications, alterations and/or combinations of features disclosed herein will be apparent to those skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.

Claims

A method of providing haptic feedback comprising:

defining a pressure value profile, the pressure value profile comprising at least one pressure value threshold;

comparing the measured pressure at different times to the defined pressure value profile; and

if the measured pressure at different times matches the defined pressure value profile, generating the defined corresponding haptic response.

The method of claim 1, wherein:

the pressure profile comprises a pressure value profile of pressure changes over time and defines at least one change in pressure value over time; and

the defined corresponding haptic response is generated if the measured pressure at different times matches the defined change in pressure value over time.

The method of claim 2, wherein the pressure value profile defines a first change in pressure value over time comprising an increase in pressure value over time which crosses the at least one pressure value threshold, and a corresponding first haptic response is defined; and

The method of claim 2, wherein the pressure value profile defines a first change in pressure value over time comprising an increase in pressure value over time which crosses a first pressure value threshold, and a corresponding first haptic response is defined; and the pressure value profile defines a second change in pressure value over time comprising a decrease in pressure value over time which crosses a second pressure value threshold, and a corresponding second haptic response is defined;

wherein the first pressure value threshold corresponds to a higher pressure value than the second pressure value threshold.

5. The method of claim 3 or claim 4, wherein the first haptic response and the second haptic response are the same. 6. The method of claim 3 or claim 4, wherein the first haptic response and the second haptic response are different.

7. The method of claim 6, wherein, after the first haptic response has been generated the first haptic response will not be generated again until after the second haptic response has been generated.

8. The method of claim 6 or claim 7, wherein the first haptic response simulates a button being depressed. 9. The method of any one of claims 7 to 8, wherein the second haptic response simulates a button being released.

10. The method of any one of claims 3 to 9, wherein if the measured pressure at different times matches the defined first change in pressure value over time, generating a defined electrical output signal in addition to generating the defined corresponding haptic response.

11. The method of claim 10, wherein the defined electrical output signal indicates that a user input has been received.

12. The method of any preceding claim, wherein the pressure value profile comprises a plurality of different pressure value thresholds; and, for each of this plurality of different pressure value thresholds: the pressure value profile defines a change in pressure value over time comprising an increase in pressure value over time which crosses said pressure value threshold, and a corresponding first haptic response is defined; and/or

13. The method of claim 12, wherein said first haptic responses are the same.

14. The method of claim 12 or claim 13, wherein said second haptic responses are the same.

15. The method of claim 12, wherein said first haptic responses are different.

16. The method of claim 12 or claim 15, wherein said second haptic responses are the different.

17. The method of any preceding claim, wherein the pressure value profile comprises at least one pressure value threshold and the corresponding haptic response.

18. A method of providing haptic feedback comprising:

defining a corresponding haptic response;

comparing the measured pressure at different times to the defined pressure value profile; and if the measured pressure is less than or equal to the at least one pressure value threshold, generating a defined electrical output signal which indicates the location of the touch; or

if the measured pressure is greater than the at least one pressure value threshold, generating the defined corresponding haptic response.

19. The method of claim 18, further comprising: if the measured pressure is greater than the at least one pressure value threshold, also generating a defined electrical output signal which indicates that a user input has been received and the location of the user input.

20. The method of claim 19, wherein the pressure value profile comprises at least one further pressure value threshold, the at least one further pressure value threshold having a lower value than said at least one pressure value threshold; and not generating the defined electrical output signal which indicates the location of the touch if the measured pressure is less than or equal to the at least one further pressure value threshold.

21. The method of claim 19, wherein the pressure value profile comprises at least one further pressure value threshold, the at least one further pressure value threshold having a lower value than said at least one pressure value threshold; and if the measured pressure is less than or equal to the at least one further pressure value threshold, generating a defined electrical output signal which indicates the location of the touch and that the measured pressure is less than or equal to the at least one further pressure value threshold.

22. The method of any one of claims 19 to 21, wherein the pressure value profile comprises at least one pressure value threshold and the corresponding haptic response.

23. A method of providing haptic feedback comprising:

defining a location and pressure value profile, the location and pressure value profile comprising at least one pressure value threshold and a corresponding location; defining a corresponding haptic response;

comparing the measured pressure at different locations and times to the defined location and pressure value profile; and

24. The method of claim 23, wherein the location and pressure value profile comprises at least one pressure value threshold and a corresponding location, and a corresponding haptic response and electrical output signal are defined; and the method further comprising:

25. The method of claim 24, wherein the defined electrical output signal indicates that a user input has been received and the location of the user input.

26. The method of any one of claims 23 to 25, wherein the location and pressure value profile defines at least one location having no corresponding haptic response.

27. The method of any one of claims 23 to 26, wherein the location and pressure value profile defines at least one location having no corresponding electrical output signal.

28. The method of any one of claims 23 to 27, wherein the location and pressure value profile comprises at least one pressure value threshold and a plurality of corresponding locations; and the method comprises:

defining a corresponding haptic response;

29. The method of any one of claims 23 to 28, wherein the location and pressure value profile comprises at least one pressure value threshold, a corresponding location and the corresponding haptic response.

30. A method of providing haptic feedback comprising:

defining a location and pressure value profile, the location and pressure value profile comprising at least one pressure value threshold and a corresponding location;

defining a corresponding haptic response;

31. The method of claim 30, further comprising: if the measured pressure is greater than the at least one pressure value threshold corresponding to the determined location, also generating a defined electrical output signal which indicates that a user input has been received and the location of the user input.

32. The method of claim 31, wherein the pressure value profile comprises at least one further pressure value threshold, the at least one further pressure value threshold having a lower value than said at least one pressure value threshold; and not generating the defined electrical output signal which indicates the location of the touch if the measured pressure is less than or equal to the at least one further pressure value threshold.

33. The method of claim 31, wherein the pressure value profile comprises at least one further pressure value threshold, the at least one further pressure value threshold having a lower value than said at least one pressure value threshold; and if the measured pressure is less than or equal to the at least one further pressure value threshold, generating a defined electrical output signal which indicates the location of the touch and that the measured pressure is less than or equal to the at least one further pressure value threshold.

34. The method of any one of claims 31 to 33, wherein the location and pressure value profile defines at least one location having no corresponding haptic response.

35. The method of any one of claims 31 to 34, wherein the location and pressure value profile defines at least one location having no corresponding electrical output signal which indicates that a user input has been received.

36. The method of any one of claims 31 to 35, wherein the location and pressure value profile comprises at least one pressure value threshold and a plurality of corresponding locations; and

the method comprises:

defining a corresponding haptic response; measuring a pressure applied by a plurality of simultaneous touches to the touch input surface at different times;

37. The method of any one of claims 30 to 36, wherein the location and pressure value profile comprises at least one pressure value threshold, a corresponding location and the corresponding haptic response.

38. A method of providing haptic feedback comprising:

defining a corresponding haptic response;

if the measured pressure is greater than the at least one pressure value threshold, generating the defined corresponding haptic response,

39. The method of claim 38, further comprising:

determining a location of the touch on the touch input surface; and

40. The method of claim 39, wherein the defined electrical output signal indicates the location of the touch.

41. The method of claim 40, wherein the pressure value profile comprises at least one first further pressure value threshold, the at least one first further pressure value threshold having a lower value than said at least one pressure value threshold; and not generating the defined electrical output signal which indicates the location of the touch if the measured pressure is less than or equal to the at least one first further pressure value threshold.

42. The method of claim 40, wherein the pressure value profile comprises at least one first further pressure value threshold, the at least one first further pressure value threshold having a lower value than said at least one pressure value threshold; and if the measured pressure is less than or equal to the at least one first further pressure value threshold, generating a defined electrical output signal which indicates the location of the touch and that the measured pressure is less than or equal to the at least one further pressure value threshold.

43. The method of any one of claims 38 to 42, wherein the pressure value profile comprises at least one second further pressure value threshold having a higher value than said at least one pressure value threshold, and a corresponding further haptic response is defined; and

if the measured pressure at different times is greater than the second further pressure value threshold, generating the defined corresponding further haptic response.

44. The method of claim 43, further comprising:

45. The method of claim 44, wherein the defined further electrical output signal indicates that a user input has been received and the location of the user input.

46. The method of any one of claims 41 to 45, wherein the pressure value profile comprises at least one further pressure value threshold and a corresponding location; and a corresponding further haptic response is defined; and

the characteristics of the defined corresponding further haptic response are different for different locations. 47. The method of any one of claims 38 to 46, wherein the pressure value profile comprises at least one pressure value threshold and a corresponding location, and a corresponding haptic response is defined; and

the characteristics of the defined corresponding haptic response are different for different locations.

48. The method of any one of claims 3 to 47, wherein the pressure value profile comprises at least one pressure value threshold and the corresponding haptic response. 49. The method of any one of claims 18 to 37 and 39 to 48, wherein the touch location is determined using bending waves propagating through the touch input surface.

50. The method of any preceding claim, wherein the haptic response is generated using bending waves propagating through the touch input surface.

51. A touch input apparatus arranged to provide haptic feedback, the apparatus comprising:

a touch input surface;

at least one pressure transducer arranged to produce an electrical pressure signal corresponding to a touch pressure applied to the touch input surface;

a pressure processor arranged to determine a touch pressure value by processing the electrical pressure signal;

a haptic processor arranged to receive the haptic instruction signal and to process the haptic instruction signal to produce a haptic drive signal; and at least one haptic transducer arranged to produce a haptic response from the haptic drive signal;

52. The apparatus of claim 51, the apparatus further comprising:

a location processor arranged to determine a location value by processing the location signal;

wherein the pressure profile processor is arranged to receive the location value; and wherein the location processor is a dedicated processor. 53. The apparatus of claim 52, wherein the pressure profile processor is arranged to receive the location value, compare the location and touch pressure values to a predetermined location and touch pressure profile and, based on the results of the comparison, to selectively generate a haptic instruction signal and an output signal.

54. The apparatus of claim 52 or claim 53, wherein the output signal comprises the location of the touch.

55. The apparatus of any one of claims 51 to 54, wherein the location transducer is arranged to produce the location signal using bending waves propagating through the touch input surface.

56. The apparatus of any one of claims 51 to 55, wherein the haptic transducer is arranged to produce the haptic response using bending waves propagating through the touch input surface.

57. The apparatus of any one of claims 51 to 56, wherein the pressure processor, haptic processor and pressure profile processor are combined in a single dedicated processor.

58. The apparatus of claim 57, wherein the location processor is also combined in a single dedicated processor.

59. Computer program code configured to, when run on a processor, cause the processor to perform any of the methods of claims 1 to 50.

60. A computer readable medium carrying computer readable code configured to, when run on a computer, cause the computer to perform any of the methods of claims 1 to 50.

61. A computer program product comprising computer readable code according to claim

59 or claim 60.