WO2003071565A1

WO2003071565A1 - Illuminated control

Info

Publication number: WO2003071565A1
Application number: PCT/SE2003/000042
Authority: WO
Inventors: Bo Mineur
Original assignee: Bo Mineur
Priority date: 2002-02-19
Filing date: 2003-01-15
Publication date: 2003-08-28
Also published as: SE0200524L; AU2003202188A1; SE522248C2; SE0200524D0

Abstract

An illuminated control (1) comprising an opaque front member (30) with transparent symbols (35; 35-1, 35-2), a settable control member (50) and at least one light source (60; 60-1, 60-2) is disclosed. The light source (60; 60-1, 60-2) is able to illuminate the symbols (35; 35-1, 35-2) and an optional indicator (52; 52-1, 52-2) in the control member (50) both with a color, preferably greenish, which is adapted for lighted environments, such as in daylight, and a color, preferably bluish or reddish, which is adapted for dark environments, such as during night. In addition, the night-adapted color should not substantially impair the scotopic vision of an operator reading the control (1). By switching between illumination color, a clear and reliable reading of the control (1) and a setting of the control member (50) in all environmental conditions are obtainable.

Description

ILLUMINATED CONTROL

TECHNICAL FIELD

The present invention generally relates to control and switch devices, and in particular to illuminated control and switch devices adapted for both daylight and dark environments.

BACKGROUND

Control and switch devices, such as circuit breakers, are found in many different locations and environments, e.g. in instrument panels in cars, ships, airplanes and trains, for controlling different machines in industry etc. Such controls comprise a control or switch member that is settable between different settings corresponding to different operation states of the equipment the control and switch device controls. For an example, a certain machine in a production line may be turned on or off by pushing a button of a control. In this case, the control can only have two different settings, one corresponding to on and the other corresponding to off. However, in some situations a more complex regulation is necessary, e.g. for a driving motor in a ship or boat. In such a case, the control may be set to several different settings corresponding to e.g. the output power of the motor. Thus, in a first setting the motor is shut off, whereas four other settings may e.g. be associated with 25 %, 50 %, 75 % and 100 %, respectively, of the maximum output power of the motor.

Regardless of the actual design of the control or switch device, it is sometimes necessary to be able to, continuously or intermittently, read the setting of the control. For instance, decisions concerning the operation of a machine in a production line might depend on the settings of one or several controls of a machine positioned upstream. In addition, a pilot in airplane or an engineer in a train must be able to read the settings of the control and switch devices to be able to perform a reliable operation of the airplane or train. The same applies to a first and/ or second mate on a ship. During daylight, reading of the control or switch devices is fairly straightforward. Though, problems may arise if rays from the sun dazzle the person reading the controls or if sun rays falls directly onto or nearby the control. The reading of the controls may then become almost impossible without first shading them. However, the largest problems arise in dark conditions, such as during the night. Several of the control or switch devices in ships and trains may only be read by first lighting a flashlight or a spotlight arranged in the vicinity of the control. Such an arrangement is of course not optimal since the operator then first has to look for the circuit breaker of the spotlight, which may be as hard to find as it is to read the control, or fetch the flashlight. Several solutions have therefore been suggested to integrate a light source in the control or switch device, illuminating it in dark environments.

US 6, 198,061 Bl discloses a switch device, in which a transparent key- top of seesaw-type is arranged over a screen of a display unit so that information displayed on the screen of the display unit is seen through the key- top. Due to the seesaw-design of the key-top a multiple display is enabled and visibility is improved.

A circuit breaker illuminated by a light source is disclosed in DE 28 56 557 Al. The circuit breaker comprises a switch arranged in a frame provided with symbols. A light source is arranged in the circuit breaker for providing light that is guided through the symbols, which are illuminated.

In US 5,878,870 a switch is disclosed. The switch comprises a knob with displaying sections, through which light from a light source may be transmitted, whereby an illumination of the switch is obtained. The switch further comprises a displaying member arranged in the knob such that the light from the light source is reflected by the surfaces of the displaying member. With such an arrangement an illumination for the entire displaying section with no irregularity is enabled. In addition, the design of the displaying member ensures a sufficient luminance. The solutions disclosed in the patents and patent application above refer to controls that are illuminated by a light source for facilitating finding the controls in dark environment. However, reading of the setting of the controls is not solved by the inventions above.

In DE 29 30 769 Al, a control for regulating e.g. heat and ventilation in a car is disclosed. The control is of an opaque plastic material with transparent symbols provided along its circumference. A nearby- arranged lamp provides light through these symbols. With this arrangement reading of the control by an operator is simplified.

DE 30 13 721 C2 discloses a push button arrangement where the setting of a transparent push button is indicated by a color change of a light transmitted through the button. In state of rest, i.e. when the button is not pressed, the light from a lamp passes a filter before it reaches the button. In this state, the light through the button is colored due to the properties of the filter. However, when the button is pushed the filter is pivoted around an axis away from the light path. Thus, since the light in this state does not pass the filter it is uncolored when it reaches the transparent button.

In the patent application and patent above, reading of the setting of a control is facilitated by providing a light source that either changes color depending on the setting of the control or indicates the setting through transparent symbols. However, the solutions above are all impaired by one big drawback, the light from the control degrades the scotopic or twilight vision of an operator reading the control. Using a spotlight or a flashlight also has this grave disadvantage. For a driver, such as a pilot, engineer or first and/ or second mate driving a vehicle, e.g. a car, airplane, train or ship, it is crucial to have good scotopic vision to safely navigate and drive the vehicle and at the same time be able to spot possible obstacles and suddenly appearing objects in the route of travel. Once the scotopic vision has been degraded, by e.g. lighting a flashlight or looking at a control illuminated according to DE 29 30 769 Al or DE 30 13 721 C2, it often takes 20 to 30 minutes until a satisfactory scotopic vision is recovered. During these 20 to 30 minutes, the vision of the driver may temporarily be so degraded that he/she does not spot obstacles or suddenly appearing objects, possibly leading to accidents. In addition, the driver may experience much stress during this time with degraded vision and may therefore perform operations and decisions that are not particularly well considered or even incorrect. Such operations and decisions may also lead to grave situations and accidents. In addition, the light from the above discussed controls is not adapted for daylight when rays from the sun fall onto the controls.

SUMMARY The present invention overcomes these and other drawbacks of the prior art arrangements.

It is a general object of the present invention to provide an illuminated control, which may easily be read by an operator.

It is another object of the invention to provide a control with an illumination that is adapted for dark environments, such as during nighttime, and should not impair the scotopic vision when read by an operator.

Yet another object of the invention is to provide a control with an illumination that is adapted for lighted environments, such as during daytime.

A further object of the invention is to provide a general illumination solution that may be applied to different designs of a control.

Yet a further object of the invention is to provide an illumination of a control without substantially increasing the overall size of the control. The above objects are met by the invention as defined by the accompanying claims. In general, a control comprising an opaque front member with transparent symbols and a settable control member is provided with a light source for illuminating the control and the symbols. During daylight and in other lighted environments the light source preferably provides a greenish colored light that is well adapted for such environmental conditions. In dark environments, such as during night, the light source transmits bluish or reddish light, which illuminates the control substantially without impairing the scotopic vision of an operator reading the control.

The front member may comprise a transparent sheet, onto which an opaque layer or foil is arranged. The transparent symbols are then obtained through engravings in the layer or foil. Light from the light source, which may be in form of a nearby arranged diode or a light guide forwarding light from a remote light generator, is then scattered in the front member and is diffracted in the engraved symbols. The control member of the control may be provided with an indicator, e.g. a light guide that forwards light from the front member into the control member. Thus, this indicator makes it possible to easily read the setting of the control member and thereby the operation state of the equipment being controlled by the control.

The coloring of the light according to the present invention may be obtained by introducing filters and/ or films in the light path. For an example, during daytime a yellowish filter or film may be arranged in the opening of the remote light generator. The yellowish light then passes an arranged bluish film resulting in a greenish colored light that is well adapted for lighted environments. During night the yellowish filter or film is simply removed to provide the desired bluish illumination of the control.

In another embodiment, colored diodes are arranged in a back member that is attached to the front member. These diodes are then able to illuminate the symbols and control member of the control with the colors and light according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which:

Fig. 1 is an illustration of an embodiment of a control embodying the present invention;

Fig. 2 is an illustration of another embodiment of a control embodying the present invention;

Fig. 3 is an illustration of yet another embodiment of a control embodying the present invention;

Fig. 4 is an exploded perspective view showing an embodiment of a control according the present invention with a light source employing light guides;

Fig. 5 is a sectional view taken along the line A-A in Fig. 4;

Fig. 6 is a sectional view taken along the line B-B in Fig. 4 illustrated with a remote light generator;

Fig. 7 is a sectional view taken along the line B-B in Fig. 4 illustrated with diodes;

Fig. 8 is an exploded perspective view showing another embodiment of a control according the present invention with a light source employing light guides;

Fig. 9 is a sectional view taken along the line A-A in Fig. 8;

Fig. 10 is an exploded perspective view showing yet another embodiment of a control according the present invention with a light source employing light guides;

Fig. 11 is a sectional view taken along the line A-A in Fig. 10; and

Fig. 12 is an exploded perspective view showing an embodiment of a control according the present invention with a light source employing light emitting diodes. DETAILED DESCRIPTION

Throughout the drawings, the same reference characters will be used for corresponding or similar elements.

The present invention is applicable to illuminated control and switch devices. Such control and switches are provided with transparent symbols, which may be illuminated by light from a light source. The symbols may include illustrative pictures, figures, letters and words describing or disclosing e.g. the function of the control and/ or the setting of a settable control member.

The basic idea of the present invention is to be able to provide both light of a color adapted for daylight and lighted environments and light of a color adapted for dark environments, such as during the night. In addition, the dark-adapted color should not impair the scotopic vision of an operator reading the control or switch device.

Several of the prior art illuminated controls are very hard to read in light environments, such as when rays from the sun are falling directly onto or near the control. These prior art controls are most often illuminated by light from a bulb or similar light source providing white light. However, symbols of the controls illuminated by white light are very hard to read with such light environmental conditions. Instead, experiments have shown that a greenish light is well adapted for providing a clear reading of symbols in a lighted environment. Therefore, a control or switch device according to the present invention may preferably be illuminated by greenish light in daylight and during similar environmental conditions.

Likewise, a clear reading during dark environments, such as during the night, is desired. In addition, the light illuminating the control during such conditions should not impair a reader's scotopic vision. Light of a reddish or bluish color has proven to have the desired properties. Therefore, a control or switch device according to the present invention should preferably be illuminable by reddish or bluish light during the night and in other dark environments.

A control or switch device embodying the present invention may be used in numerous applications where a clear reading of the control and its setting is desirable both in lighted and dark environments and where the light from the control should not impair a reader's scotopic vision. Such controls may be found in instrumental panels in different vehicles, such as cars, airplanes, trains and ships. A reader may then be able to read the control without endangering operation of the vehicle due to lost or reduced scotopic vision. In addition, a control according to the present invention may be well adapted for several applications in industrial environments, such as for controlling and regulating different machines and other electric equipment. The control may also be in the form of a circuit breaker, switching on and off lamps, motors, machines etc.

The actual design and shape of the control may vary and is closely associated with its actual operation. Figs. 1 to 3 schematically illustrate three possible designs of a control 1 embodying the present invention. Starting with Fig. 1, a control 1 with a turnable handle 50 is illustrated. The control 1 may be provided with transparent symbols 35-1, 35-2, which may be illuminated by light according to the present invention, i.e. preferably a greenish light during day and a reddish or bluish light during night. A first symbol 35-1 may be provided for illustrating the function of the control 1, e.g. by giving the name of the equipment the control 1 controls. In addition, a number of symbols 35- 2 may be arranged for indicating the different settings, to which the handle 50 of the control 1 may be turned. For the control 1 in Fig. 1, in a first setting OFF the controlled equipment is off, whereas a number of other settings PI, P2, P3 are used for different operation conditions, e.g. different operation powers of the equipment. The handle 50 may also preferably be provided with an indicator 52, e.g. in form of a light guide through which light (greenish, reddish or bluish) from the control 1 is transmitted. This illuminated indicator 52 makes it possible to easily and clearly read the setting of the turnable handle 50 and therefore the actual operation condition or program of the equipment, controlled by the control 1.

Another possible design of the control 1 is shown in Fig. 2. This control 1 has a settable seesaw-type switch 50 instead of the handle in Fig. 1. The seesaw- switch 50 may e.g. be altered between two settings corresponding to ON and OFF in Fig. 2 by pushing either side of the switch 50. As in Fig 1, transparent symbols 35-1, 35-2 may be provided for showing the function of the control 1 and/or its different operation states. Likewise, indicators 52-1, 52-2 may be arranged for indicating the setting of the switch 50 and its associated operation state. For an example, an upper indicator 52-1 may be illuminated when the controlled equipment is turned on and a lower indicator 52-2 is illuminated if the equipment is turned off. In Fig. 2, the switch 50 is in a setting corresponding to OFF, whereby the lower indicator 52-2 is illuminated, illustrated by being filled.

Yet another possible design of a control 1 according to the present invention is illustrated in Fig. 3. In this case the control 1 is provided with a push button 50. The push button 50 may be in an outer setting corresponding to OFF in Fig. 3, and in a depressed setting corresponding to ON. As above, transparent symbols 35-1, 35-2 may be arranged for indicating the function and/ or operation state of the control 1. An indicator 52 may preferably be arranged within the push button 50. Such an indicator 52 may be illuminated when e.g. the button 50 is depressed but not when it is in the outer setting.

As a person skilled in the art will realize, the actual design of the control may differ from the designs illustrated in Figs. 1 to 3 and the present invention is therefore not limited to the embodiments of Figs. 1 to 3. For an example, other control members than a handle, seesaw-type switch or button may be used. In addition, as was mentioned in the foregoing, other transparent symbols than letters and schematic pictures as in Figs. 1 to 3 may be used. Also the actual design of the indicator of the handle, switch or button may also differ from the illustrated ones and are therefore within the scope of the present invention. An exploded perspective view of an embodiment of a control 1 according to the present invention, in which light is provided from two light guides is illustrated in Fig. 4. The control 1 comprises an opaque front member 30 provided with transparent symbols 35-1, 35-2, which may be illuminated by a light source 60. In this embodiment the front member 30 comprises two transparent sheets 32-1, 32-2 onto which two layers or foils 34-1, 34-2 of an opaque material are arranged. The transparent sheets 32-1, 32-2 are made of a material with properties adapted for allowing light from the light source 60 to pass through the sheets 32-1, 32-2. Suitable materials include glass and different transparent plastic materials, e.g. acrylic plastics. The layers 34-1, 34-2 could be a metal foil, such as aluminium, which is arranged onto one of the sides of the sheets 32-1, 32-2. In addition, the opaque layers 34-1, 34-2 could be obtained by spraying a suitable substance, e.g. a colored aerosol, directly onto one of the sides of the sheets 32-1, 32-2. The transparent symbols 35-1, 35-2 are then obtained by performing engravings in the opaque layers or foils 34-1, 34-2. As was mentioned in connection to Figs. 1 to 3, a first symbol 35-1 may be engraved in an upper layer or foil 34-1 for providing a visualization of e.g. the function of the control 1 through an upper sheet 32- 1. Likewise, operation states of the control 1 may be indicated by symbols 35- 2 engraved in a lower layer or foil 34-2, in turn arranged onto a lower transparent sheet 32-2.

The front member 30 may then be arranged in a housing 40, which also houses a back member 10, in which the light source 60 is provided. An optional frame 20 may be provided in the housing 40 between the front member 30 and the back member 10. This frame 20 separates the back member 10 with the light source 60 from the front member 30 with a distance that is adapted for bringing the light source 60 in a correct position between the two transparent sheets 32-1, 32-2 of the front member 30. An attachment means 12 is provided on the back member 10 for allowing a handle 50 to be attached to the control 1. In the embodiment of Fig. 4, the light source 60 comprises two light guides 62-1, 62-2 guiding light from a remote light generator (not illustrated) to a head 64 of the light source 60. The light guides 62-1, 62-2 may be optical fibers or simple tubes or pipes of transparent material, e.g. plastics. When the back member 10 with the light source 60 is arranged in the housing 40 together with the optional frame 20 and the front member 30, the head 64 becomes positioned between the two transparent sheets 32-1, 32-2 of the front member 30 behind a covering portion 42 of the housing 40. The side of the head 64 facing the covering portion 42 is angled to form a general V- shape. The two angled sides of the V reflect light from the light guides 62-1, 62-2 out into the transparent sheets 32-1, 32-2 of the front member 30. When the light passes through the sheets 32-1, 32-2 it is diffracted in the engraved symbols 35-1, 35-2 in the opaque layers 34-1, 34-2 and the symbols 35-1, 35- 2 appear illuminated.

The turnable handle 50 may optionally be provided with an indicator 52 indicating the setting of the handle 50. In Fig. 4, the indicator 52 is in the form of a light guide forwarding the light passing from the head 64 of the light source 60 through the lower transparent sheet 32-2, thereby illuminating the indicator 52.

The light path through the control 1 is illustrated in Fig. 5, which is a sectional view taken along the line A-A in Fig. 4. In Fig. 5, the general V-shape of the head 64 of the light source 60 with two angled sides 66-1, 66-2 is more clearly shown. The light path from the light generator (not illustrated) to the light source 60 and through the front member 30 is illustrated with arrows. The light is transmitted in the light guide 62-1 to the head 64 where it is reflected on the angled sides 66-1, 66-2. The light is then brought into the upper transparent sheet 32- 1 by being reflected on one of the angled sides 66- 1 of the head 64 and is likewise forwarded into the lower sheet 32-2 after being reflected on the other angled side 66-2. With this arrangement the entire front member 30 including both the transparent sheets 32-1, 32-2 are effectively illuminated. The indicator 52 of the handle 50 is also clearly illustrated in Fig. 5. The indicator 52 is in the form of a light guide that forwards the light in the lower transparent sheet 32-2 into the indicator 52. Preferably, an end 54 of the indicator 52 facing the front member 30 is angled to allow light in the transparent sheet 32-2 to be reflected into the light guide, whereby the indicator 52 is illuminated.

Fig. 6 is a sectional view taken along the line B-B in Fig. 4 illustrated with a remote light generator 75. The light generator 75 may be a simple bulb or some other means able to generate light. The light from the generator 75 is forwarded through e.g. an optical fiber 70 or similar means. If two light guides 62-1, 62-2 are employed, as illustrated in Fig. 6, the optical fiber 70 is divided into two branches 72-1, 72-2 each transmitting the light to one of the light guides 62-1, 62-2. The light from the light generator 75 may be of white color. In order to color the light according to the present invention, filters or films 80-1, 80-2, 82 may be arranged in the light path, preferably in the vicinity of the head 64 of the light source 60 or nearby the light generator 75.

According to the invention, the control 1 is illuminated with a first color, preferably greenish, in lighted environments and with a second color, preferably bluish or reddish, in dark environments, whereby the light of the second color should not impair the scotopic vision of an operator reading the control 1.

A preferred way to obtain the colors of the present invention with an embodiment as in Figs. 4 to 6 is to arrange a filter or colored film 82 in or in the opening of the light generator 75. Such a filter or film 82 then colors the light from the light generator 75 yellowish. By arranging bluish films 80- 1 , 80- 2 in the light path, a resulting incoming greenish light to the head 64 of the light source 60 may be obtained. Thus, during daylight the bluish films 80-1, 80-2 together with the yellowish film or filter 82 in the light generator 75 accomplish the preferred greenish illumination of the control 1. However, in dark environments the yellowish filter or film 82 is removed or the light is diverted past the filter or film 82 so that the light coming into the head 64 only passes the bluish films 80-1, 80-2 and therefore is colored bluish.

Instead, if two light guides 62- 1 , 62-2 are employed, such as in Fig. 6, light of different colors may be transmitted in the different guides 62-1, 62-2. For an example, a first light guide 62- 1 may be provided with a yellowish film or filter 80-1 in order to transmit light of a yellowish color and a bluish film or filter 80-2 may likewise be arranged in a second light guide 62-2, which then transmits a bluish colored light. During daytime or in other lighted environments both the light guides 62-1, 62-2 are allowed to transmit light into the control 1. In such a case, the yellowish light of the first light guide 62- 1 and the bluish light from the second light guide 62-2 are mixed in the light source 60 and in the transparent sheets of the front member resulting in a greenish colored light. As a result, both the symbols and the indicator of the control member are illuminated with a greenish light that is well adapted for daylight. In dark environments, e.g. during the night, the yellowish light from the first light guide 62-1 is blocked somewhere in the first light guide 62-1 or in its associated light path branch 72-1. Thus, only the bluish light from the second light guide 62-2 is allowed to reach the light source 60 and illuminate the control 1.

If reddish light is employed instead of bluish light, e.g. the first light guide 62- 1 may provide greenish light during daytime using a greenish filter or film 80- 1, whereas the second light guide 62-2 is blocked. During night the first light guide 62-1 is blocked and reddish light is transmitted through the now unblocked second light guide 62-2, incorporating a reddish filter or film 80-2 into the control 1.

The actual position of the filters and/or films 80-1, 80-2, 82 may differ from the positions of Fig. 6. As was described above, in some embodiments all filters or films 80-1, 80-2, 82 are used, whereas in other embodiments the filter or film 82 may be omitted. Actually, any position in the light path between the light source 60 and the generator 75 is possible. For an example, all filter and/ or films 80-1, 80-2, 82 may be arranged in the vicinity of the light generator 75 or nearby the light source 60. However, if both a yellowish filter of film 82 and bluish films 80-1, 80-2 are used, a preferred positioning is as according to above and as in Fig. 6. If the yellowish filter or film 82 of the light generator 75 is omitted, the remaining filters or films 80-1, 80-2 are preferably positioned close to the light source 60 in order to provide an efficient illumination of the control 1.

The number of light guides 62-1, 62-2 laying on light into the control 1 may differ from what is illustrated in Figs. 4 to 6. For an example, it may be enough to use a single light guide, which provides greenish light during daytime and bluish or reddish light during night. The different colors may then originate from different filters or colored films that are introduced in the path from the light generator to the control. By simply changing filter or film, the color of the light may be changed. Likewise, a third light guide may be arranged for providing reddish light if the first two light guides provide bluish and yellowish or bluish and greenish light. The operator may then in dark environments choose between bluish and reddish illumination to suit the actual environmental conditions.

Once the now colored light comes into the head 64 it encounters optional prism-like members 68-1, 68-2 arranged in the head 64 for spreading the light from the light guides 62-1, 62-2 all along a longitudinal direction in the head 64. Theses optional prism members 68-1, 68-2 contributes to a homogenous spread of the light in the front member 30 and an effective illumination of the control 1.

Fig. 7 is a sectional view taken along the line B-B in Fig. 4 illustrated with a light generator in form of a diode 75-1, 75-2 arranged for each light guide 62- 1, 62-2. The color of the light from the diodes 75-1, 75-2 is according to the present invention, i.e. preferably greenish light in lighted environments and bluish or reddish light in dark environments. In such a case, a first diode 75-1 may transmit greenish light and is only active in lighted environments and a second only night active diode 75-2 provides bluish or reddish light in dark environments. Instead, the first diode 75-1 may provide yellowish light whereas the second diode 75-2 then may provide bluish light. In daytime both diodes 75-1, 75-2 are active and transmitting light that are mixed in the head 64 of the light source resulting in a greenish illumination of the control 1. During the night only the second diode 75-2 is active and illuminates the control 1 with a bluish light.

It may also instead be possible to use multi-color diodes, i.e. diodes that are able to transmit light of different colors. In such a case, the diodes preferably transmit greenish light daytime and reddish or bluish light nighttime.

Fig. 8 is an exploded perspective view showing another embodiment of a control 1 according the present invention. In this embodiment a front member 30 comprises only one transparent sheet 32 onto which an opaque layer or foil 34 with transparent symbols 35 is arranged. Two light sources 60-1, 60-2 are provided. A first light source 60-1 is arranged in an upper end of a back member 10, whereas a second light source 60-2 is arranged in a lower opposite end. If the back member 10 with the light sources 60-1, 60-2 and the front member 30 is introduced in a housing 40 together with an optional frame 20, the first light source 60-1 is covered by a first covering portion 42-1 of the housing 40 and a second covering portion 42-2 covers the second light source 60-2. As for the embodiment of Figs. 4 to 7, light is introduced into the control 1 through light guides 62-1, 62-2 of the first 60-1 and second 60-2 light source, respectively. The light is then forwarded into the front member 30, where it is diffracted in the engraved symbols 35 in the opaque layer or foil 34. As a result, the symbols 35 become illuminated and may be read by an operator. The design of heads 64-1, 64-2 of the light sources 60-1, 60-2 differs from the embodiment of Figs. 4 to 7. The heads 64-1, 64-2 lack the general V- shape and instead have an angled side, in which the incoming light may be reflected and spread into the transparent sheet 32 of the front member 30. The head 64-1 of the first light source 60-1 allows light to be reflected in a direction towards the opposite second light source 60-2 and vice versa.

In the illustrated embodiment, each light source 60-1, 60-2 is provided with a light guide 62-1, 62-2 transmitting light from a remote light generator (not illustrated) to the control 1. However, each light source 60-1, 60-2 may instead be connected to several light guides, e.g. two each giving a total of four light guides in the light sources 60-1, 60-2. It may also be possible to omit one of the light sources 60-1, 60-2, e.g. only having the first light source 60-1. The light from the single light source 60-1 may be enough to illuminate the entire transparent sheet 32. This may be used in particular when all symbols 35 are engraved on one side, facing the light source 60-1, of the handle 50.

A sectional view taken along the line A-A in Fig. 8 is illustrated in Fig. 9. The incoming light from the first light guide 62-1 of the first light source 60-1 is brought into the head 64-1 where it is reflected on an angled side 66-1 and forwarded into the transparent sheet 32. A corresponding angled side 66-2 is provided in the head 64-2 of the second light source 60-2 for forwarding light from the second light guide 62-2- into the transparent sheet 32.

Yet another embodiment of a control 1 according to the present invention is illustrated in an exploded perspective view in Fig. 10. This embodiment employs two light sources 60-1, 60-2, each having the same design as the light source in Figs. 4 to 7 except that only one light guide 62-1, 62-2 is connected to each light source 60-1, 60-2. With such an arrangement, a front member 30 becomes divided into three transparent sheets 32-1, 32-2, 32-3 with associated opaque layers or foils 34-1, 34-2, 34-3. The two light sources 60-1, 60-2 contributes to an efficient and homogenous illumination of the entire front member 30. As was discussed above, though only one light guide 62-1, 62-2 is connected to each light source 60-1, 60-2 in Fig. 10, more light guides may be employed for each light source 60-1, 60-2. Fig. 11 is a sectional view taken along the line A-A in Fig. 10 showing the light path coming into the control 1. Each head 64-1, 64-2 now has two angled sides 66-1 A, 66- IB and 66-2A, 66-2B, respectively, forming a general V- shape.

Although, the embodiments of Figs. 4 to 11 have been illustrated with a handle, other form of control members may be employed, such as illustrated in Figs. 2 and 3. The overall design of the control does not substantially change from the designs of the embodiments of Figs. 4 to 11 except for the control member. The indicators of the controls in Figs. 2 and 3 may be built upon similar basic design as the indicator of Figs. 4 to 11. Starting with a control 1 with a seesaw-type switch 50 according to Fig. 2, an indicator 52-1, 52-2 in form of a light guide may be arranged in each side of the switch 50. When one of the sides of the switch 50 is depressed, the angled end of the light guide of the associated indicator 52-2 comes into level with the transparent sheet. In such a case, light from the transparent sheet may be reflected on the angled end into the light guide and illuminates the indicator 52-2. The indicator 52-1 of the other outer side of the switch 50 is in this state leveled above and away from the transparent sheet so that no light therefrom may be reflected into the indicator 52-1. With such an arrangement, only the indicator 52-2 associated with the side of the switch 50 being depressed is illuminated and indicates the setting of the switch 50.

For a control member 50 in form of a push-button according to Fig. 3, a similar light guide designed indicator 52 as above may be used. When the button 50 is depressed, the angled end of the indicator 52 is moved into level with the transparent sheet of the front member. In this setting, light is passing from the front member through the angled end and into the light guide, illuminating the indicator. On the other hand, if the button 50 is in an outer setting, the angled end of the indicator 52 is leveled above and away from the transparent sheet so that no light may be reflected into the light guide. Thus, an efficient and simple design of the indicator 52 may be employed for several different designs of the control member 50 of the control 1. Instead of using a remote light generator and a light guide as in Figs. 4 to 11, light emitting diodes may be employed. Fig. 12 illustrates in an exploded perspective view an embodiment of a control 1 according the present invention with such light emitting diodes 60 as light source. The control 1 may have a similar overall design as the embodiments above, i.e. include an opaque front member 30 with transparent symbols 35 and a back member 10, in which the diodes 60 are arranged. The back member 10 and front member 30 may be connected in a housing 40, with an optional frame 20 separating them. The diodes 60 are preferably arranged in positions so that they become covered by the transparent symbols 35 in the front member 30 when introduced in the housing 40.

Instead of arranging the diodes 60 directly in the back member 10, the diodes may be arranged in a circuit board or similar means (not illustrated) that in turn is attachable to the back member 10.

In order to provide light of colors according to the present invention some of the diodes 60 may be used in lighted environments and other may be used in dark environments. It may instead be possible to use light emitting diodes 60 that are able to provide light of different colors, such that e.g. the diodes 60 transmit light of a greenish color during daytime and bluish or reddish color during night. In such a case, fewer diodes 60 need to be used than if the diodes are only of one color each. The actual design of the diodes 60 may differ from one application to another. In a first embodiment, small spot-like diodes 60 may be used so that several such diodes 60 are arranged in groups to cover the surfaces below the transparent symbols 35. Another embodiment may instead employ larger diodes, e.g. having a longitudinal design, which each is large enough to be arranged one and one and still provide sufficient illumination of the symbols 35.

A similar front member 30 as in Figs. 4 to 11 may be used, i.e. comprising a transparent sheet onto which an opaque layer of foil with engraved symbols is arranged. However, Fig. 12 illustrates another possible embodiment of the front member 30 that may be used not only for the control 1 of Fig. 12 but also for the embodiments of Figs. 4 to 11. The front member 30 is made of an opaque material, e.g. a plastic or metal material. The symbols 35 are then e.g. pressed or cut in the front member 30. The pressed or cut holes in the front member 30 corresponding to the symbols 35 may either be left empty, allowing direct passage to the diodes 60 or may be filled with a transparent material, e.g. glass or a transparent plastic material. Preferably, at least one of the diodes 60 should be positioned in the back member 10 to provide light to an indicator 52 in a handle 50. The light from the diode 60 then illuminates the indicator 52 giving an easy read of the setting of the handle 50.

The equipment according to the present invention illuminating the control does not substantially or only slightly increase the overall size of the control. This is very important in applications where the control is arranged e.g. with other controls, regulators and display windows in an instrumental panel in a car, train, ship or airplane. In such a case, the accessible space is strongly limited so any extra control size due to the illumination must be small. This object is met with a control according to the present invention. In addition, if several controls in an instrumental panel are to be illuminated according to the invention, a single light generator may be used to provide light to all or some of the controls. By using different filters or films in the controls, the illumination thereof may be performed with different colors, depending on the desires of an operator. For an example, all controls associated with a first motor may be illuminated bluish nighttime, whereas the controls of a second motor are illuminated reddish, thereby facilitating a distinction of the different controls.

Though a control according to the present invention have been disclosed with diodes or a remote light generator and a light guide as possible light sources, any light source may be used that can provide light with colors according to the present invention. Likewise the actual design of the parts of the control may differ from what is described above as long as their respective function remains substantially the same.

Although several specific embodiments of the invention have been illustrated and described herein, it should be obvious that, where applicable, the various features of the embodiments might be combined freely without departing from the scope of the invention.

The embodiments described above are merely given as illustrative examples of the present invention, and it should be understood that it is not limited thereto. Further modifications, changes and improvements that retain the basic underlying principles disclosed and claimed herein are within the scope of the invention.

Claims

1. A control (1) comprising: an opaque front member (30) provided with transparent symbols (35; 35-

1. 35-2); at least one light source (60; 60-1, 60-2) arranged in connection to said front member (30), being able to provide light of at least a first color and a second color through said front member (30), whereby a reading of said transparent symbols (35; 35-1, 35-2) is obtainable; and a control member (50) arranged in said control (1) for selecting between at least two settings, characterized in that said first color is adapted for daylight and lighted environmental conditions and said second color is adapted for dark environments and does not substantially impair the scotopic vision of an operator reading said control (1).

2. The control according to claim 1, characterized in that said first color is greenish.

3. The control according to claim 1 or 2, characterized in that said second color is bluish.

4. The control according to claim 1 or 2, characterized in that said second color is reddish.

5. The control according to any of the claims 1 to 4, characterized in that said at least one light source (60; 60-1, 60-2) is a light emitting diode (60).

6. The control according to claim 5, characterized in that said light emitting diode (60) is arranged in a back member (10), onto which said front member (30) is attached.

7. The control according to any of the claims 1 to 4, characterized in that said at least one light source (60; 60-1, 60-2) is a first light guide (60; 60-1, 60-2) providing light from a light generator (75; 75-1, 75-2) to said control (1).

8. The control according to claim 7, characterized by a forwarding member (64; 64-1, 64-2) arranged at an end of said first light guide (60; 60- 1 , 60-2) in vicinity of said front member (30) for forwarding light from said at least one light source (60; 60- 1, 60-2) to said transparent symbols (35; 35-1, 35-2).

9. The control according to claim 7 or 8, characterized by at least one filter or film (80- 1, 80-2, 82) arranged in the path of light from said light generator (75) to said at least one light source (60; 60-1, 60-2) for providing said first and said second color.

10. The control according to any of the preceding claims, characterized in that said front member (30) comprises a transparent sheet (32; 32-1, 32-2, 32-3), onto which a layer (34; 34-1, 34-2, 34-3) of opaque material is arranged, whereby said transparent symbols (35; 35-1, 35-2) are obtainable through engraving in said opaque layer (34; 34-1, 34-2, 34-3).

11. The control according to any of the preceding claims, characterized in that said control member (50) is selected from the list of: a push button; a seesaw-type switch; or a turning handle.

12. The control according to any of the preceding claims, characterized in that said control member (50) comprises an indicator (52; 52-1, 52-2) for indicating the setting of said control member (50) .

13. The control according to claim 12, characterized in that said indicator (52; 52-1, 52-2) is a second light guide for providing light from said at least one light source (60; 60-1, 60-2) to said control member (50), whereby the setting of said control member (50) is indicated by the light from said second light guide.

14. The control according to claim 13, characterized in that a first end (54) of said indicator (52; 52-1, 52-2) is angled for reflecting light from said at least one light source (60; 60-1, 60-2) into said indicator (52; 52-1, 52-2).

15. The control according to any of the preceding claims, characterized in that said control (1) is a circuit breaker.