DE102011016424A1 - Indicating instrument e.g. coolant level indicator, for passenger car, has light conductor plate made of polymethyl methacrylate and comprising main surface that forms portion of display area of display element - Google Patents

Abstract

The instrument (4) has a light conductor plate (8) made of polymethyl methacrylate and comprising a main surface (9) and two side surfaces (10, 11). Light uncoupling elements i.e. light scattering nanoparticles (14), are arranged in a portion of the plate. Light sources (7, 15) i.e. LEDs, are arranged adjacent to the respective side surfaces and independently controlled by a control device. The main surface forms a portion of a display area (6) of a display element (3). The main surface forms a region of a scale (12) of the indicator. An independent claim is also included for a method for operating an indicating instrument.

Description

The application relates to a display instrument for displaying an operating state of a motor vehicle and a method for operating a display instrument.

From the DE 195 40 813 C1 is a display unit for a motor vehicle with an opaque dial, the scales, numbers and characters are durchleutbar known. On the side facing away from the observer of the dial, a light source for scanning the scales, numbers and characters is arranged. Between the dial and the light source, a light valve is arranged, the light transmittance is changeable adjustable.

The object of the application is to provide a display instrument for displaying an operating state of a motor vehicle and a method for operating a display instrument, which allow an improved visualization of the operating state.

This object is achieved with the subject matter of the independent claims. Advantageous developments emerge from the dependent claims.

A display instrument for displaying an operating state of a motor vehicle has, according to one aspect of the application, a display element with a display surface. In addition, the indicating instrument has at least one first light source. Furthermore, the display instrument has a light guide plate, wherein the light guide plate has a first main surface, a first side surface and a second side surface. In addition, the light guide plate has light coupling-out elements at least in a partial region of the volume of the light guide plate. The at least one first light source is disposed adjacent one of the first and second side surfaces. The main surface at least partially forms a portion of the display surface of the display element.

The display instrument according to the aforementioned embodiment enables an improved visualization of the operating state in that the main surface of the light guide plate at least partially forms a portion of the display surface of the display element. The operating state can thus be visualized by a continuous display without visible limitation of partitions. The visualization of the operating state thus appears more realistic. In addition, there is a cost advantage over known display displays.

The main surface preferably forms at least partially an area of a scale of the display element.

In one embodiment, the at least one first light source is arranged to be movable. This advantageously makes it possible to reduce the number of light sources. For example, in this embodiment, the indicating instrument has exactly one first light source.

In a further preferred embodiment, the light guide plate PMMA (polymethyl methacrylate) on. Furthermore, the light guide plate as elements auskoppelnde preferably on light scattering nanoparticles. The components mentioned advantageously make it possible to provide a uniformly illuminated display area.

Light-scattering nanoparticles here and in the following are understood to mean particles with a diameter of 0.01 to 0.5 micrometers, which scatter the incident light largely isotropically. In this case, colorless particles having a refractive index which differs from the other material of the light guide plate by 0.06 ≦ Δn ≦ 0.4 are preferably selected, which are distributed in the volume. The nanoparticles may additionally be surrounded by a coating layer, which improves the embedding.

By embedding the light-scattering nanoparticles results in a material that is largely transparent in the unlit state, while it shows an effective all-round light emission at a Lichteinkopplung on the first and / or second side surface.

Furthermore, the at least one first light source is formed in one embodiment as a light emitting diode. This allows a space-saving arrangement of the light source and a cost-effective lighting.

Furthermore, the display instrument may have a cover, wherein the cover partially covers the main surface of the light guide plate. Thus, in this embodiment, only the area of the main surface not covered by the cover is visible to a viewer, for example the driver of the motor vehicle. The cover thus forms a partial masking of the main surface.

The light guide plate may be cuboid. This geometry is particularly suitable for display surfaces.

In a further embodiment, the light guide plate at least in the region of Display surface of the display element on a three-dimensional bulge, for example, a lenticular bulge. Thus, in this embodiment, the main surface is lens-shaped at least in the area of the display surface of the display element. This leads advantageously to a plastic, three-dimensional view for a viewer.

The indicating instrument is preferably selected from the group consisting of a level indicator of an operating means of the motor vehicle and a state of charge display of at least one energy storage device of the motor vehicle. As a result, the occupants of the motor vehicle, in particular the driver of the motor vehicle, information about the respective operating state of the motor vehicle can be provided.

The operating means is for example selected from the group consisting of a coolant of an engine of the motor vehicle, a lubricant of the engine, a brake fluid, a windscreen washer and compressed air at least one tire of the motor vehicle.

In a further embodiment, the display instrument further has at least one second light source and at least one control device for the at least one first and one second light source. The at least one second light source is disposed adjacent one of the first and second side surfaces. The at least one first and one second light source are independently controllable by the at least one control device. This advantageously makes it possible to illuminate different segments of the light guide plate and thus the display surface of the display element, depending on the number of light sources switched on. Thus, it is possible to visually differentiate individual parts of the display area, for example, individual parts of the scale.

The at least one first light source is preferably designed to emit light in a first color and the at least one second light source to emit light in a second color different from the first color. This advantageously makes it possible to realize differently illuminated segments of the display area, for example scaling. Here and below "color" is understood to mean a specific section within the visible light spectrum. Furthermore, here and hereinafter, a color other than a color is understood to mean that the former color occupies a portion within the wavelength range of the visible light spectrum shifted from that portion within the wavelength range of the visible light spectrum occupied by the second-mentioned color.

The light coupling elements are homogeneously distributed in the light guide plate in one embodiment. This allows a particularly uniform illumination of the first main surface.

The indicating instrument is for example part of a combination instrument of the motor vehicle. In further embodiments, the indicating instrument is arranged separately from the instrument cluster. The indicating instrument can thus also be provided as a stand-alone element.

The application also relates to a method for operating a display instrument according to one of the said embodiments, wherein the method comprises the following steps. A determination is made of a value to be displayed by means of the display instrument. In addition, the at least one first and / or a second light source is controlled in such a way that a first area of the display area which can be illuminated by means of the light guide plate is illuminated, the illuminated first area containing the value to be displayed.

The method for operating a display instrument according to the application has the advantages already mentioned in connection with the display instrument according to the application, which are not listed again at this point in order to avoid repetition.

In one embodiment, the display instrument forms a level indicator of a resource of the motor vehicle. The operating means is for example selected from the group consisting of a coolant of an engine of the motor vehicle, a lubricant of the engine, a brake fluid, a windscreen washer and compressed air at least one tire of the motor vehicle. Determining the value to be displayed by means of the display instrument in this embodiment includes determining a level of the resource. The level can thus be continuously displayed without visible boundary of partitions by means of the display instrument.

In addition, it is preferably determined whether the determined fill level falls below a predetermined threshold value. If the determined level falls below the predetermined threshold value, a warning message continues to be issued. The issuing of the warning message preferably includes a driving of the at least one first and / or a second light source. As a result, an optical warning message can be output by means of the display element in an advantageous manner. The driving of at least a first and a second Light source is preferably such that the color of the illuminated first area is changed. Furthermore, an acoustic warning message can be issued additionally or alternatively.

In a further embodiment, it is determined whether the determined level exceeds a predetermined threshold. If the determined level exceeds the predetermined threshold value, a warning message continues to be issued.

In a further embodiment, the display instrument forms a state of charge indicator of at least one energy storage device of the motor vehicle. Determining the value to be displayed by means of the display instrument in this embodiment includes determining a state of charge of the at least one energy storage device.

In addition, it is preferably determined whether the determined state of charge falls below a predetermined threshold value. If the determined state of charge falls below the predetermined threshold value, a warning message is issued. As a result, the occupants of the motor vehicle, in particular the driver of the motor vehicle, can be made aware of a low state of charge of the energy storage device. This is especially important for electric vehicles. The issuing of the warning message includes, for example, a driving of the at least one first and / or a second light source. The driving of the at least one first and one second light source is preferably carried out such that the color of the illuminated first region is changed.

Furthermore, the driving of the at least one first and / or a second light source can take place such that the at least one first and / or a second light source lights up periodically. As a result, the occupants of the motor vehicle, in particular the driver of the motor vehicle, can be made more aware of the value to be displayed in each case.

The motor vehicle is in the aforementioned embodiments, for example, a passenger car or a truck.

Embodiments of the application will now be explained with reference to the accompanying figures.

1 shows a motor vehicle with a combination instrument;

2 shows a display instrument with a display element according to an embodiment of the application;

3 shows a control device for the indicating instrument according to 2 ;

4A shows a flowchart of a method for operating a display instrument according to a first embodiment of the application;

4B shows a flowchart of a method for operating a display instrument according to a second embodiment of the application;

4C shows a flowchart of a method for operating a display instrument according to a third embodiment of the application.

1 shows a motor vehicle 2 with a combination instrument 1 , The car 2 is a passenger car in the embodiment shown. The instrument cluster 1 has several, in 1 not shown on display instruments. Further details will be explained in connection with the following figures.

In addition shows 2 a gauge 4 with a display element 3 of in 1 shown combination instrument according to a first embodiment of the application.

The indicating instrument 4 has a light guide plate 8th on, with the light guide plate 8th a first main surface 9 , a first side surface 10 and a second side surface 11 having. Furthermore, the light guide plate 8th Light outcoupling elements at least in a partial region of the volume of the light guide plate 8th on. The light guide plate 8th has in the embodiment shown, light scattering nanoparticles 14 as light-coupling elements on. Illustrative are the light scattering nanoparticles 14 in 2 shown schematically and not to scale.

For example, the light-scattering nanoparticles 14 homogeneous in the light guide plate 8th distributed.

Furthermore, the indicating instrument 4 several first light sources 7 and two second light sources 15 and two third light sources 20 on. The light sources 7 . 15 and 20 are both adjacent to the first side surface in the illustrated embodiment 10 as well as to the second side surface 11 arranged. These are the light sources 7 . 15 and 20 covered by a cover, not shown, and thus for a viewer, such as the driver of the motor vehicle, not visible why they are in 2 schematically represented by broken lines.

The light sources 7 . 15 and 20 are each formed as light emitting diodes. Here are the first light sources 7 designed to emit light in a first color, for example to emit light in a green color. The second light sources 15 are designed to emit light in a second, different from the first color color, for example, to emit light in a red color. The third light sources 20 are designed to emit light in a third, different from the first and the second color color, such as orange.

The main surface 9 forms an area of a display area 6 of the display element 3 , where the main surface 9 in the embodiment shown at least partially a portion of a scale 12 of the display element 3 forms. For this purpose, the light guide plate 8th several, for example by means of engraving in the first main surface 9 introduced scale ranges 5 on. As a material, the light guide plate 8th transparent PMMA into which the light-scattering nanoparticles 14 are introduced. The cover, not shown covers the main surface in the embodiment shown 9 the light guide plate 8th in the area outside the scale 12 , This is only the area of the main surface not covered by the cover 9 ie the scale ranges 5 , visible to the viewer. The area of the main surface not visible to the viewer 8th is in 2 schematically bounded by broken lines.

In the embodiment shown, the light guide plate 8th doing a three-dimensional, lenticular bulge in the range of the scale 12 of the display element 3 on. This leads advantageously to a plastic, three-dimensional view for a viewer. The bulge may for example be embossed in the scale area and is in the in 2 shown top view not shown in detail.

The indicating instrument 4 forms in the embodiment shown, a level indicator of a resource of the motor vehicle or a state of charge indicator of at least one energy storage device of the motor vehicle. The operating means is selected from the group consisting of a coolant of an engine of the motor vehicle, a lubricant of the engine, a brake fluid, a windshield washer and compressed air at least one tire of the motor vehicle.

As will be further explained in connection with the following figures, by means of driving the first light sources 7 , the second light sources 15 and the third light sources 20 a first, by means of the light guide plate 8th illuminated area of the display area 6 illuminated, wherein the illuminated first region includes the value to be displayed of the level of the resource or the state of charge of the at least one energy storage device.

The embodiment shown thus enables the realization of a cost-optimized display system in the motor vehicle, in particular for fluid levels, such as cooling water, windscreen washer fluid and oil level. By means of the indicating instrument 4 In the embodiment shown, the different fluid levels are displayed in the instrument cluster and a warning function is activated when a critical level is reached, that is to say when the level drops below a predetermined threshold value. In further embodiments, the indicating instrument is arranged separately from the instrument cluster. The indicating instrument can thus also be provided as a stand-alone element. The display system is realized by the use of the transparent optical waveguide material, in which the coupling-out elements in the form of the nanoparticles 14 are executed. The respective filling level is determined by a laterally mounted, so-called bar graph of directionally injecting LEDs, which are the light sources 7 . 15 and 20 form, represented.

It is thus a cost-effective display instrument 4 provided, which makes it possible in particular to visualize the levels of fluids in the motor vehicle cost. The indicating instrument 4 can be integrated into existing, used space. As already explained, this is due to the transparent light guide plate 8th with integrated coupling and decoupling elements in the form of nanoparticles 14 reached. In the light guide plate 8th is coupled laterally light of the LEDs, wherein the LEDs are arranged in the form of a bar graph display. The arrangement of the light sources 7 . 15 and 20 offers the advantage that the liquid levels can be displayed continuously, without visible boundaries of partitions. The visualization of the levels is thus more realistic. By changing the coupled color by controlling the corresponding, different light sources 7 . 15 respectively. 20 the fluid level can be changed in color according to priority. The color change can also serve as a warning function of the display system.

3 shows a control device 16 for the in 2 shown display instrument. Components with the same functions as in 2 are denoted by the same reference numerals and will not be explained again below.

The control device 16 is via a control line 17 with the first light source 7 and via a control line 18 with the second light source 15 connected. For reasons of clarity are in 3 only one respective first light source 7 and a second light source 15 the multiple light sources 7 respectively. 15 shown. The first light source 7 and the second light source 15 are independent of each other by the control device 16 controllable.

Furthermore, the control device 16 via a signal line 19 with a sensor 13 connected, the sensor 24 for determining the level of the corresponding operating means or for determining the state of charge of the energy storage device of the motor vehicle is formed.

4A shows a flowchart of a method for operating a display instrument according to a first embodiment of the application. The indicating instrument is designed according to one of the aforementioned embodiments.

In one step 30 a determination is made of a value to be displayed by means of the display instrument. It continues in one step 40 a driving of the at least one first and / or a second light source such that a first, illuminated by the light guide plate area of the display surface is illuminated. The illuminated first area contains the value to be displayed.

4B shows a flowchart of a method for operating a display instrument according to a second embodiment of the application.

The display instrument is designed as a level indicator of a resource of the motor vehicle. In this case, determining the value to be displayed by means of the display instrument includes in the step 30 determining a level of the resource.

The resource is, for example, selected from the group consisting of a coolant of an engine of the motor vehicle, a lubricant of the engine, a brake fluid and a windshield washer.

Furthermore, in one step 35 determines whether the determined level falls below a predetermined threshold.

If the filling level does not fall below the predetermined threshold value, this takes place in one step 40 a driving the at least one first light source according to the step 40 the in 4A shown first embodiment.

On the other hand, if the determined filling level falls below the predetermined threshold value, this takes place in one step 50 a driving of the at least one second light source such that an optical warning message is output by means of the indicating instrument.

In a further embodiment, in the step 35 determines whether the detected level exceeds a predetermined threshold.

If the filling level does not exceed the predetermined threshold value, this takes place in one step 40 a driving the at least one first light source according to the step 40 the in 4A shown first embodiment.

On the other hand, if the determined filling level exceeds the predetermined threshold value, this takes place in one step 50 a driving of the at least one second light source such that an optical warning message is output by means of the indicating instrument.

It is still possible that in the step 35 determines whether the determined level is within a predetermined range. For example, it may be determined whether the tire air pressure is within a predetermined range.

4C shows a flowchart of a method for operating a display instrument according to a third embodiment of the application.

The display instrument forms a state of charge indicator of at least one energy storage device of the motor vehicle. Determining the value to be displayed by the indicating instrument in the step 30 includes determining a state of charge of the at least one energy storage device.

In one step 35 In the embodiment shown, it is determined whether the determined state of charge falls below a predetermined threshold value.

If the state of charge does not fall below the predetermined threshold value, this takes place in one step 40 a driving the at least one first light source according to the step 40 the in 4A shown first embodiment.

On the other hand, if the state of charge falls below the predetermined threshold value, this takes place in one step 50 a driving of the at least one second light source such that an optical warning message is output by means of the indicating instrument.

Although at least one exemplary embodiment has been shown in the foregoing description, various changes and modifications may be made. The above embodiments are merely examples and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing description provides the skilled person with a plan Implementation of at least one exemplary embodiment, wherein numerous changes in the function and arrangement of elements described in an exemplary embodiment can be made without departing from the scope of the appended claims and their legal equivalents.

LIST OF REFERENCE NUMBERS

1

instrument cluster

2

motor vehicle

3

display element

4

Gauge

5

scale range

6

display area

7

light source

8th

Light guide plate

9

main surface

10

side surface

11

side surface

12

scale

13

sensor

14

nanoparticles

15

light source

16

control device

17

control line

18

control line

19

signal line

20

light source

30

step

35

step

40

step

50

step

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19540813 C1 [0002]

Claims (15)

Display instrument for displaying an operating state of a motor vehicle ( 2 ) - an indicator ( 3 ) with a display area ( 6 ), - at least one first light source ( 7 ), - a light guide plate ( 8th ), wherein the light guide plate ( 8th ) a first main surface ( 9 ), a first side surface ( 10 ) and a second side surface ( 11 ) and light-coupling elements at least in a partial region of the volume of the light guide plate ( 8th ), wherein the at least one first light source ( 7 ) adjacent to one of the first and second side surfaces ( 10 . 11 ) and wherein the main surface ( 9 ) at least partially a portion of the display area ( 6 ) of the display element ( 3 ). Display instrument according to claim 1, wherein the main surface ( 9 ) at least partially a range of a scale ( 12 ) of the display element ( 3 ). Display instrument according to claim 1 or claim 2, wherein the at least one first light source is arranged to be movable. Display instrument according to one of the preceding claims, wherein the light guide plate ( 8th ) PMMA and light-coupling elements light-scattering nanoparticles ( 14 ) having. Display instrument according to one of the preceding claims, wherein the at least one first light source ( 7 ) is designed as a light emitting diode. Display instrument according to one of the preceding claims, wherein the light guide plate ( 8th ) at least in the area of the display area ( 6 ) of the display element ( 3 ) has a bulge. Display instrument according to one of the preceding claims, wherein the indicating instrument ( 4 ) is selected from the group consisting of a fill level indicator of a resource of the motor vehicle ( 2 ) and a state of charge indicator of at least one energy storage device of the motor vehicle ( 2 ). A display instrument according to claim 7, wherein the operating means is selected from the group consisting of a coolant of an engine of the motor vehicle, a lubricant of the engine, a brake fluid, a windscreen washer and compressed air at least one tire of the motor vehicle. Display instrument according to one of the preceding claims, further comprising at least one second light source ( 15 ) and at least one control device ( 16 ) for the at least one first and one second light source ( 7 . 15 ), wherein the at least one second light source ( 15 ) adjacent to one of the first and second side surfaces ( 10 . 11 ) and wherein the at least one first and one second light source ( 7 . 15 ) independently of each other by the at least one control device ( 16 ) are controllable. Display instrument according to claim 9, wherein the at least one first light source ( 7 ) for emitting light in a first color and the at least one second light source ( 15 ) is adapted to emit light in a second color different from the first color. Display instrument according to one of the preceding claims, wherein the indicating instrument ( 4 ) Is part of a combination instrument of the motor vehicle. Method for operating a display instrument ( 4 ) according to one of claims 1 to 11, wherein the method comprises the following steps: - determining by means of the indicating instrument ( 4 ) to be displayed, - controlling the at least one first and / or a second light source ( 7 . 15 ) such that a first, by means of the light guide plate ( 8th ) illuminated area of the display area ( 6 ), wherein the illuminated first area includes the value to be displayed. A method according to claim 12, wherein the indicating instrument ( 4 ) a level indicator of a resource of the motor vehicle ( 2 ) and wherein determining the by means of the indicating instrument ( 4 ) value to be displayed includes determining a level of the resource. A method according to claim 12, wherein the indicating instrument ( 4 ) a charge state display of at least one energy storage device of the motor vehicle ( 2 ) and wherein determining the by means of the indicating instrument ( 4 ) indicates a determination of a state of charge of the at least one energy storage device. Method according to one of claims 12 to 14, wherein the driving of the at least one first and / or a second light source ( 7 . 15 ) such that the at least one first and / or one second light source ( 7 . 15 ) lights up periodically.

Images