CN100410749C - Light sensed touch controlled type liquid crystal display - Google Patents

Abstract

A liquid crystal display of light sensing and touch control type is prepared as setting the second base plate in parallel to and in facing to the first base plate, setting multiple pixel units between two said base plates, setting light reflection element on the first base plate and light sensor on the second one, using light sensor to output a sensing parameter according to light reflected from back light module by light reflection element, using variation of sensing parameter value to judge pixel unit position corresponding to place exerted by external force when external force is exerted on the first base plate.

Description

The touch-control liquid crystal display of light sensing

Technical field

The present invention relates to a kind of LCD, particularly a kind of touch-control liquid crystal display.

Background technology

Function advanced person's display gradually becomes the valuable feature of consumption electronic product now, and wherein LCD has become the display that various electronic equipments such as mobile phone, personal digital assistant (PDA), digital still camera, computer screen or the widespread use of mobile computer screen institute have the high-resolution color screen gradually.

Because LCD is carried for convenience and used now, the touch-control liquid crystal display panel that the user can directly touch also becomes the direction of the market development.Resistance-type traditionally or capacitance touching control display panels, it is that extra resistance capacitance assembly is set on panel, and judges the location coordinate that presses by the variation that detects the touch point magnitude of voltage.Yet, because assemblies such as resistance capacitance are to be set directly on the panel, thus can cause the light penetration rate of display panels to descend, and increase the integral thickness of panel.Another kind of optical touch control panel then is that a large amount of light sources and corresponding optics sensing component are set around display panels, and the light that utilizes the optics sensing component whether to detect corresponding light source is judged the location coordinate of touch point.Though such design is unlikely to reduce the light penetration rate of panel, can increase considerably the volume of product, therefore be not suitable for the demand of general Portable LCD yet.

Therefore if sensing component can be integrated among the liquid crystal panel, not only LCD overall weight and volume can be reduced, the lcd products of thin design will be helped stressing now.

Summary of the invention

The object of the present invention is to provide a kind of touch-control liquid crystal display, OPTICAL SENSORS directly is disposed within the display panels, make external force press when display panels, the light intensity that detects by OPTICAL SENSORS detects the position that external force presses.

One embodiment of the invention provide a kind of LCD, comprise one first substrate, one second substrate and a plurality of pixel cell.This second substrate is parallel and be intended for this first substrate.A plurality of pixel cells are formed between this first substrate and this second substrate, and each this pixel cell has a smooth reflecting element and an OPTICAL SENSORS.This light reflecting element is arranged on this first substrate.This OPTICAL SENSORS is formed on this second substrate, and this OPTICAL SENSORS is used for exporting a sensor parameter according to the light of this light reflecting element reflection from this backlight module.When applying an external force, can change this sensor parameter value of this OPTICAL SENSORS output, in order to judge with respect to this pixel cell position that applies the external force place in first substrate.

Description of drawings

Fig. 1 is the synoptic diagram of LCD of the present invention.

Fig. 2 is the display panels of Fig. 1 and the circuit diagram of judging unit.

Fig. 3 is the display panels of Fig. 1 and the local structure figure of light source.

Fig. 4 is that the display panels of Fig. 3 is exerted pressure in an external force and produced the synoptic diagram of deformation.

The reference numeral explanation

100 LCD, 102 gate drivers

104 source electrode drivers, 106 judging units

110 display panels, 112 sweep traces

114 data lines, 116 transmission lines

120 liquid crystal molecules, 130 light sources

154 smooth reflecting element 156 black-matrix layer

200 pixel cells, 202 switching transistors

204 memory capacitance, 206 liquid crystal capacitances

210 testing circuits, 150,152 electrically-conductive backing plates

212 change-over circuits, 250 decision unit

216 switch elements, 218 OPTICAL SENSORS

211 transistors, 214 operational amplifiers

221,222 input ends, 223 output terminals

Embodiment

See also Fig. 1, Fig. 1 is the synoptic diagram of LCD 100 of the present invention.LCD 100 comprises a light source 130, a gate drivers 102, one source pole driver 104, a judging unit 106 and a display panels 110.Said modules all is to be coated in the housing (figure does not show).Gate drivers 102 is used for producing the one scan signal, and is sent to display panels 110 by sweep trace 112.Source electrode driver 104 is to be used for producing a voltage data signal, and is sent to display panels 110 by data line 114.106 of judging units are coupled to display panels 110 by transmission line 116, and are used for detecting the touched position of display panels 110.This light source 130 can be cold cathode ray tube, and it is needed backlight to be used for producing display panels 110.

See also Fig. 2, Fig. 2 is the display panels 110 of Fig. 1 and the circuit diagram of judging unit 106.Display panels 110 comprises a plurality of pixel cells 200, and each pixel cell 200 comprises a switching transistor 202, a memory capacitance 204 and a liquid crystal capacitance 206.Liquid crystal capacitance 206 is made up of two electrodes, and an electrode is connected to voltage end Vcom altogether, and another electrode then is connected between switching transistor 202, two electrodes and is distributed with liquid crystal molecule.When the grid of switching transistor 202 receives sweep trace 112 when transmitting the sweep signal that gate drivers 102 produces, can give liquid crystal capacitance 206 by the voltage data signal that source electrode driver 104 produces via data line 114 conductings.The common-battery that the liquid crystal molecule of liquid crystal capacitance 206 then produces according to common-battery pressure side Vcom is pressed and the voltage difference of voltage data signal produces different orientations, with the light intensity of control by liquid crystal molecule.Memory capacitance 204 then is used for storing this voltage data signal, makes liquid crystal capacitance 206 still can keep this voltage data signal voltage difference between the voltage together when switching transistor 202 cuts out, and the light intensity by liquid crystal molecule is maintained fixed.In addition, display panels 110 is provided with a plurality of transistors 211 and a plurality of OPTICAL SENSORS 218.OPTICAL SENSORS 218 is used for producing different sensor parameters according to the light intensity size.For instance, OPTICAL SENSORS 218 can be a light sensing transistor, and it is coupled to a bias terminal Vbias, is used for producing different current sensors according to the light intensity size.211 in transistor is used for when opening, the current sensor that conducting OPTICAL SENSORS 218 produces.In addition, pixel cell 200 comprises a memory capacitance 219 in addition, is used for storing the current sensor that OPTICAL SENSORS 218 produces.

See also Fig. 3 and Fig. 4, Fig. 3 is the display panels 110 of Fig. 1 and the local structure figure of light source 120, and Fig. 4 is that the display panels 110 of Fig. 3 is exerted pressure in an external force and produced the synoptic diagram of deformation.Display panels 110 comprises one first substrate 150, one second substrate 152 and a black-matrix layer 156.First substrate 150 and second substrate 152 are transparent conductive substrates.Pixel cell 200 is formed between first substrate 150 and second substrate 152.Each pixel cell 200 comprises an OPTICAL SENSORS 218 and a smooth reflecting element 154.OPTICAL SENSORS 218 is formed on second substrate 152.154 of light reflecting elements are to protrude in first substrate 150, and corresponding to the position of OPTICAL SENSORS 218.Light reflecting element 154 is to be used for the light that reflection source 130 penetrates, so its material can be the metal with preferable reflection coefficient.In addition, black-matrix layer 156 can be lighttight resin, and it is formed at first substrate 150 and is not formed on the position corresponding to OPTICAL SENSORS 218, is used for covering the light that light source 130 sends.First and second substrate the 150, the 152nd, transparent conductive substrate has liquid crystal molecule 120 between the two substrates 150,152.As shown in Figure 3, when not having external force to put on first substrate 150, OPTICAL SENSORS 218 can receive the light that light source 130 sends.As shown in Figure 4, when an external force A put on a touch point of first substrate 150, first substrate 150 and second substrate 152 distance between this touch point can shorten.Light source 130 penetrated light and can be reflected by light reflecting element 154 this moment, when the light intensity that causes OPTICAL SENSORS 218 to receive does not force in this touch point be a little less than.Because OPTICAL SENSORS 218 produces current sensor according to the light intensity that receives, and the light intensity that receives is strong more, then current sensor is big more, therefore, OPTICAL SENSORS 218 is not forcing in the current sensor (as shown in Figure 3) that touch point produces, greater than forcing in the current sensor (as shown in Figure 4) that touch point produces.

See also Fig. 2.OPTICAL SENSORS 218 produces different current sensors according to different light intensities, and exports current sensor to change-over circuit 212.Change-over circuit 212 comprises an operational amplifier 214, a back coupling capacitor C f and a switch element 216.Operational amplifier 214 comprises a first input end 221, one second input end 222 and an output terminal 223.First input end is coupled to a reference voltage end Vref, and this reference voltage end Vref is used to provide a direct current reference voltage.Whole change-over circuit 212 can be considered an integrating circuit.When sweep trace 112 transmitted the one scan signal, switch element 216 can be closed (turn-off).Otherwise when sweep trace 112 did not transmit sweep signal, switch element 21 6 can be opened (turn-on), made short circuit between second input end 222 and the output terminal 223, and the voltage of output terminal 223 equals this DC reference voltage at this moment.When switch element 216 was closed (turn-off), the output voltage V out of the output terminal 22 3 of operational amplifier 214 met equation 1:

$\mathrm{Vout}=-\mathrm{Vc}=-\frac{I\×t}{\mathrm{Cf}}$ Equation 1

Wherein, I represents the current sensor that OPTICAL SENSORS 218 produces, t express time.

Next, operational amplifier 214 can be converted to a sensing voltage with the current sensor that OPTICAL SENSORS 218 transmits.Because less corresponding to the current sensor that the OPTICAL SENSORS 218 of the touch point that has external force to apply is exported, so the sensing voltage of change-over circuit output is also less.Final decision unit 250 can receive the sensing voltage that each operational amplifier 214 is exported, and judges the corresponding coordinate of touch point on display panels 110 according to the size of sensing voltage.

Owing to press different force size at first substrate 150, can make the distance of winning between substrate 150 and second substrate 152 also inequality, the related light intensity size that influences OPTICAL SENSORS 218 sensings with and the current sensor exported.So the size of the sensing voltage that operational amplifier 214 is exported is also different.Therefore, in design, except the coordinate that determines touched point, decision unit 250 also can be according to the output voltage size of each operational amplifier 214, and decision puts on the external force size of this touch point.

LCD of the present invention is that a plurality of OPTICAL SENSORS are integrated among the display panels, and the difference of the light intensity that OPTICAL SENSORS receives when pressing is judged the coordinate of touch point at display panels.Because OPTICAL SENSORS is incorporated in the display panels, not only can reduce LCD overall weight and volume, also helps stressing now the lcd products of thin design.

Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the present invention; when can doing various changes and modification, so protection scope of the present invention is as the criterion when looking the present patent application claim person of defining.

Claims (10)

1. LCD comprises:

One first substrate;

One second substrate, parallel and be intended for this first substrate;

One backlight module is used to provide the required light source of this display;

A plurality of pixel cells be formed between this first substrate and this second substrate, and each this pixel cell comprise:

One smooth reflecting element is arranged on this first substrate; And

One OPTICAL SENSORS is formed on this second substrate, and this OPTICAL SENSORS is used for exporting a sensor parameter according to the light of this light reflecting element reflection from this backlight module;

Wherein, when applying an external force, can change this sensor parameter value of this OPTICAL SENSORS output, apply this pixel cell position at external force place in order to judgement in first substrate.

2. LCD as claimed in claim 1 more comprises a judging unit, in order to receive this sensor parameter from this OPTICAL SENSORS output.

3. LCD as claimed in claim 2, wherein, this judging unit comprises:

A plurality of integrating circuit are used for exporting a sensing voltage according to this sensor parameter; And

One decision unit is used for judging the position that this sensing voltage is originated according to the sensing voltage of these a plurality of integrating circuit outputs.

4. LCD as claimed in claim 1, wherein, this OPTICAL SENSORS is a light sensing transistor, is used for producing this sensor parameter according to the light intensity to should light sensing transistorized this light reflecting element reflection.

5. LCD as claimed in claim 2 more comprises a plurality of transistors, and each transistor is formed on this second substrate and is coupled to this OPTICAL SENSORS, is used for transmitting this sensor parameter to this judging unit.

6. LCD as claimed in claim 1, it comprises a black-matrix layer in addition, is formed at this first substrate and is not formed on the position corresponding to this OPTICAL SENSORS, is used for covering the light that the light source of this backlight module sends.

7. LCD as claimed in claim 6, wherein, this light reflecting element protrudes on this first substrate position with respect to this OPTICAL SENSORS, is used for reflecting the light that this light source sends.

8. LCD as claimed in claim 6, wherein, this OPTICAL SENSORS is the light sensing transistor, is used for producing this sensor parameter according to the light intensity to should light sensing transistorized this light reflecting element reflection.

9. LCD as claimed in claim 8 wherein, more comprises a judging unit and comprises:

A plurality of integrating circuit are used for exporting a sensing voltage according to this sensor parameter; And

One decision unit is used for judging the position that this sensing voltage is originated according to the sensing voltage of these a plurality of integrating circuit outputs.

10. LCD as claimed in claim 8, wherein, this first, second substrate is a transparency carrier.

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