DE102011016421A1 - Instrument panel for motor vehicle, has transparent instrument panel cover having transparent light guide plate with volume of light-scattering nanoparticles distributed at region of warning area - Google Patents

Abstract

The instrument panel (2) has a housing (6) that surrounds display section (5) and a warning area. A transparent instrument panel cover (7) is arranged on housing at a distance from display area. The cover has transparent light guide plate (8) having a volume of light-scattering nanoparticles (11) distributed at the region of the warning area.

Description

An instrument for a motor vehicle is described. The instrument has a display area, a warning area and a housing. The housing surrounds the display area and the warning area, with a transparent instrument cover being held by the housing at a distance from the display area.

From the publication DE 101 02 774 A1 For this purpose, a display device is known, in particular for a motor vehicle. This display device has a partially translucent display surface and a lighting device for the backlighting of the display surface. The backlight comprises a light guide, which extends on the back of the display surface, wherein light can be coupled laterally into the light guide. The light guide directs total reflection light to the display surface, wherein on the side facing away from the display surface smooth surface side of the light guide at individual locations a reflective coating is applied.

In order to illuminate a display symbol with the aid of a light guide body, a reflective coating in the form of the display symbol is applied to a smooth surface of the light guide body at points with display symbol, so that the transmitted through the light guide body by total reflection light radiation to the reflective structuring coating, which the shape of the display symbol causes the display symbol to light up in a seductive manner.

An object is to provide an instrument for a motor vehicle in which a light guide plate is not only used for backlighting and display of display symbols, but is useful for warning a driver of critical traffic situations, driving parameters or resource states.

This object is achieved with the subject matter of independent claim 1. Advantageous developments emerge from the dependent claims.

An embodiment of the invention provides an instrument for a motor vehicle. The instrument has a display area, a warning area and a housing surrounding the display area and the warning area. A transparent instrument cover is held by the housing at a distance from the display area. The instrument cover has a transparent light guide plate, in which a warning area is arranged. The light guide plate has light-scattering nanoparticles in its volume in the warning area.

With such an instrument and the instrument cover features, there is the advantage that under normal driving conditions, normal operating conditions, and in unproblematic traffic situations, the view of the instrument's display area through the instrument panel cover made of a transparent lightguide panel, despite the volume of instrument coverage in the warning area arranged light-scattering nanoparticles is unhindered possible, since these light-scattering nanoparticles remain invisible during normal viewing.

Only when light falls from edge sides of the light guide to the nanoparticles distributed in the volume of the warning area do they light up in a scattering light and cause the warning area to illuminate correspondingly bright in critical traffic situations or critical operating conditions or critical driving parameters. In this case, a light source can be switched so that it flashes the warning area to alert the driver to the critical conditions. In addition, the warning area or the illumination of the warning area may be coupled with audible warning signals to increase the driver's attention. Finally, it is possible to light the warning area in the dark weaker than in bright daylight, so as not to dazzle the driver.

In a further embodiment of the invention, the instrument cover forms a cover of an instrument cluster of programmable display areas, wherein an edge area or the entire instrument cover can be designed as a warning area.

Since a plurality of individual instruments can also be provided on a motor vehicle or on a dashboard, it is also possible to define different warning areas. Thus, in a further embodiment of the invention, an edge region as a warning range of a tachometer light up when the rotational speed of the engine comes into a critical operating state. With a speedometer, the rim portion of the speedometer may illuminate when, for example, a critical driving condition occurs during cornering, slippery or the like. The margins of other instruments, such as the coolant temperature gauge or fuel gauge, can have warning zones that either warn the edge of the instrument or the entire instrument of warning if a critical cooling water temperature is exceeded or a critical tank is not reached.

It is also possible to illuminate portions of the instrument cover to provide an enlarged warning area for critical To provide displays in an instrument cluster, for example, in addition to a speedometer and the fuel gauge and the water level indicator, but can be provided in very small display fields. By means of corresponding large-area warning areas in the volume of the light guide plate of the instrument cover with light-scattering nanoparticles, the driver can be made aware of critical states which such a instrument cluster conventionally displays in small format.

In a further embodiment, it is provided that the warning area, which has light-scattering nanoparticles in its volume, has outer contours and the light guide plate has cut-out contours. In order to provide a closed instrument cover, the outer contours of the warning area are materially connected to the recess contours of the light guide plate. With this fitting of outer contours of the warning area in the recess contours of the light guide plate, it is possible to use arbitrarily large areas of the instrument cover up to the entire instrument cover as a warning area.

To make such warning areas visible, the light guide plate has an edge which is coupled to a lighting device. Only when the illumination device is switched on and light is fed into the edge of the light guide plate can prepared warning areas also light up in color due to the now effective light-scattering nanoparticles and, depending on the color of the light source of the illumination device.

For this purpose, the illumination device has at least one light source, it being possible for light from the light source to be coupled into the edge of the instrument cover and for the nanoparticles to light up in the warning region in a light-scattering manner. A suitable light guide plate, in which such warning areas can be embedded, consists of a PMMA (polymethyl methacrylate) plastic, which is provided for the warning area with suitable light-scattering nanoparticles.

Since the attachment of light sources directly in the region of the edge of the light guide plate is often difficult for reasons of space, it is envisaged to arrange at least one light guide between the light source and the edge. The light source can have a light-emitting diode, which couples light at one end of a light guide, wherein the free end of the light guide can be materially connected to the edge of the light guide plate. In the cohesive connection, it is advantageous to provide a transparent and the refractive index of the light guide and light guide plate adapted adhesive to keep reflection losses between the light guide plate and the light guide end as low as possible.

In order to achieve the lowest possible coupling of the light into the instrument cover, the edge of the instrument cover can be at least partially bent towards one end of the light guide and coupled to the light conductor end. The bent edge region of the light guide plate may additionally have a reflective coating in order to minimize light or scattering losses here as well.

In another embodiment of the invention, it is provided that the edge of the instrument cover has an angled chamfer, to which a reflective coating is applied. At this beveled edge, the light guide can be introduced with its end orthogonal with respect to the light guide plate of the instrument cover, so that light exiting from the light guide end, enters the beveled edge of the light guide plate and is reflected there in the direction of the volume of the light guide plate.

Another way to light-illuminate the nanoparticles in the warning area of the light guide plate is to provide a light ring of a material of the light guide plate, which surrounds the edge of the instrument cover and has a higher concentration of light-scattering nanoparticles, as the warning area.

In order to enhance the effect of such a luminous ring, the luminous ring may have on its surfaces a reflective coating, wherein only the inner annular surface, with which the luminous ring contacts the edge of the light guide plate, remains free of a mirroring. In addition, the inner edge may be materially connected to the edge of the light guide plate, so that in turn the reflection scattered light in the light ring at the arranged there in high concentration light-scattering nanoparticles with high intensity is passed through the light guide plate to the warning area. On such a light ring of the light guide can be coupled tangentially and thus advantageously save space with its optical fiber end.

A dashboard may be equipped with a plurality of such individual instruments and have corresponding instrument covers with warning areas. In addition, a motor vehicle can in turn have such a dashboard and thus use the advantages of such instruments while increasing the safety of the motor vehicle in traffic.

Embodiments of the invention will now be described with reference to the accompanying figures.

1 schematically shows a perspective view of a motor vehicle;

2 shows a schematic perspective view of an instrument according to a first embodiment;

3 shows a schematic perspective view of an instrument of a second embodiment;

4 shows a schematic perspective view of an instrument of a third embodiment;

5 shows with the 5A and 5B Schematic diagrams of a light coupling to a warning area;

6 shows with the 6A and 6B Schematic diagrams of a modification of a light coupling to a warning area;

7 shows with the 7A and 7B Schematic diagrams of a further modification of a light coupling to a warning area;

8th shows with the 8A and 8B Schematic diagrams of a further modification of a light coupling to a warning area.

1 schematically shows a perspective view of a motor vehicle 4 , The motor vehicle 4 has an interior area 28 on. The interior 28 points in its front area 29 a dashboard 30 on. On the dashboard 30 are in the immediate field of vision 31 the motor vehicle driver instruments arranged such that reflections of windshield 38 , Side windows 39 and rear window 41 on instrument cover glasses of the instruments of the dashboard 30 not the field of vision 31 impair the driver, but rather by appropriate inclination of the instrument cover glasses to the bottom portion of the motor vehicle 4 are distracted.

Also, an additional anti-glare screen 42 of the dashboard 30 Glare from external light sources through the windshield 38 mitigate because the instrument cover glasses in the shade of the anti-glare screen 42 are arranged. Another way to clearly recognize warning symbols on the instruments is to integrate them into the instrument covers and make them appear brighter than reflections through the windscreen 38 , the side windows 39 and the rear window 41 may occur. A corresponding warning area of the instrument cover of the instruments may illuminate weaker in the dark than in the brightness, in order to avoid dazzling the driver.

2 shows a perspective view of an instrument 1 that has a display area 5 with a scale 45 for the speed display of the engine, wherein the display area 5 from a housing 6 which is spaced from the display area 5 an instrument cover 7 holding, in this first embodiment of a light guide plate 8th which consists in their volume 10 nanoparticles 11 distributed. These nanoparticles 11 are light-scattering and distributed throughout the light guide plate, leaving the entire instrument cover 7 not only protects the display area from contamination and damage, but also serves as a warning area, which can light up, for example, at a critical engine speed.

This will be in an edge 20 the instrument cover 7 and thus into the light guide plate 8th Light coupled, which lights up the nanoparticles light scattering, so that not only the instrument pointer 40 indicates the high speed, in this case between 7000 and 8000 revolutions per minute, but in addition the driver by a wide illumination of the instrument cover 7 a tachometer 34 is warned against the critical operating condition of the motor vehicle. In addition, the lighting of the edge 20 of the tachometer 34 be coupled with an audible warning to ensure that the driver leaves the critical speed range as quickly as possible, for example by engaging a higher gear.

While in 2 the entire instrument cover 7 as a warning area 9 is used, shows 3 in the following embodiment an instrument 2 in the display area 5 not only has a speed scale, but is also designed as an instrument cluster and provides further warnings small format. On the left side of the instrument pointer 40 is for example in a first display field 13 a critical cooling water temperature, a not completely closed vehicle door and a catalyst effect pointed out. On the right side of the instrument pointer 40 are in a second display field 14 For example, evidence of a tightened handbrake, on a non-functioning of the electrical control program or on a non-functioning of the anti-lock braking system.

Since such notes are displayed in a cluster instrument compared to the display of the speed measurement scale only small size, it is at This second embodiment of the invention provides two large warning areas 15 and 16 in the light guide plate 8th the instrument cover 7 to arrange. This can in case of problems of the components of the first display panel 13 a first warning area 15 when there are problems with components of the second display panel 14 may be a second warning area 16 , regardless of the first warning area 15 , light up. For every warning area 15 respectively. 16 are opposing light sources 21 provided the light 33 on the respective warning area 15 respectively. 16 from the edge 20 the instrument cover 7 out into the light guide plate 8th can couple.

Only for reasons of illustration here are the positions of the light sources 21 to be seen as points. Such light sources 21 However, they are arranged so that they are not visible and are often realized by optical fiber ends. Such optical fiber ends, as shown in the later figures, couple light 33 over the edge 20 in the light guide plate 8th and leave the nanoparticles 11 light scattering in the warning areas 15 respectively. 16 come on. The light sources can do this 21 be realized by color light sources such as colored light-emitting diodes, so that the warning areas can also different colors, depending on the degree of urgency from yellow to orange to red light up.

Green and blue flashing, light-emitting diodes are possible, but these are usually not common warning colors. In the case of non-critical driving parameters and uncritical operating states as well as uncritical traffic situations, such colors as green and blue would be the view of the display area 5 possibly impair, especially with switched off lighting sources undisturbed viewing through the light guide plate 8th is possible because the nanoparticles are then no longer visible.

To warning areas 15 and 16 with light-scattering nanoparticles 11 in a light guide plate 8th PMMA (polymethyl methacrylate) plastic can be embedded in the light guide plate 8th cut contours 18 be incorporated into which the warning areas 15 and 16 with their outer contours 17 cohesively be introduced such that a closed and level instrument cover 7 is formed. Also a filling of the recess contours 18 with the material of the warning areas 15 and 16 is conceivable.

4 shows a dashboard 30 with several instruments, taking for each instrument 3 a border area 12 with in the volume of the light guide plate 8th arranged light-scattering nanoparticles 11 is provided. Thus, in a tachometer 34 the border area lights up brightly if a critical speed range is reached. The same goes for a speedometer 35 who has a scale 45 for vehicle speeds in the display area 5 and in which a warning area 9 The ring is ring-shaped in an edge area 12 surrounds, can light up if critical speeds of the motor vehicle are reached.

This warning area can also light up if, for example, there is a risk of collision or if other driving parameters enter critical areas. For the two smaller coolant temperature gauge instruments 36 and fuel gauge 37 can warning areas 9 in the border areas 12 be provided to, for example, a critical coolant temperature of the coolant temperature gauge 36 or a critical fuel quantity of the fuel gauge 37 with the help of light-scattering nanoparticles 11 to light up.

For this it is necessary that light in the edge 20 the instrument cover 7 of the respective instrument 3 is coupled. To light in the narrow edge 20 the light guide plate 8th fiber optics can be used, the light from a light source to the edge 20 the instruments 3 to lead. A critical area is the transition from an optical fiber end to the edge 20 the instrument cover 7 ,

Such a coupling region should not have an air gap, especially since a double transition from one refractive index to another refractive index has to be run through and thus considerable reflection losses can occur. In order to minimize these reflection losses, it is intended to use a transparent adhesive whose refractive index matches the refractive indices of the light guide plate 8th , For example, made of polymethyl methacrylate and the light guide is adjusted. Modifications of coupling structures 44 will now be based on the following 5 to 8th explained in more detail.

5 shows with the 5A and 5B a section of a border area 12 with a coupling structure 44 in a plan view and a cross section.

As 5A in plan view, forming a plurality of optical fibers 22 a lighting device 19 for the edge 20 the light guide plate 8th made of plastic, which in its volume in the edge area 12 light-scattering nanoparticles 11 has, wherein this edge region 12 as a warning area 9 is designed to warn against critical traffic situations or critical driving parameters or critical operating conditions. If such critical areas are reached, it is possible to use optical fibers 22 , the material fit over a transparent adhesive layer 43 with the edge 20 the light guide plate 8th or the instrument cover 7 are connected, the light, for example, from a colored light emitting diode 46 is formed, coupled and the warning area 9 light up.

For such a warning area 9 with light-scattering nanoparticles arranged in the volume 11 at the edge 12 a light guide plate 8th It is possible to have a ring in the width of the border area 12 with light-scattering nanoparticles 11 cut out of a corresponding material and this annular disc with its inner edge on an outer edge of a disc of a light guide plate 8th stick so that the light guide plate disk from a peripheral area 12 as a warning area 9 with distributed in volume arranged light-scattering nanoparticles 11 is surrounded.

5B shows a cross section, from which it can be seen that in this coupling structure 44 the radius r of an instrument or an instrument housing is to be increased significantly at least in some areas, since the light guides 22 only in an arc with a minimum radius r with their optical fiber ends 23 to the edge 20 the light guide plate 8th can be introduced radially. Such a radial coupling structure 44 thus has the disadvantage that the housing circumference of the instrument at the coupling points, taking into account this minimum radius r, which must not be less than a light guide to increase. The radius r can be achieved by the embodiments of coupling structures shown below 44 be reduced.

6 shows with the 6A a view of the instrument cover 7 and with the 6B a cross section through this edge region of the coupling structure 44 , As 6B shows is a border area 32 the light guide plate 8th towards a fiber optic end 23 a light guide 22 bent. The angle α of the turn can be designed differently. Thus, the radial extent of the instrument housing can be reduced.

Another modification of the critical coupling structure 44 shows 7 , in which 7A a bottom view with three coupling points of the optical fiber ends 23 and 7B shows the corresponding cross-section. The edge 20 the light guide plate 8th is chamfered and a chamfer 24 is with a reflective coating 25 provided so that now the light guide end 23 no longer radial, but orthogonal with respect to the light guide plate 8th can be arranged to the nanoparticles 11 at the edge 12 light up in the direction of the arrow A in order to warn the vehicle driver of critical situations.

While in 7 the light guide end 23 orthogonal in the edge 20 is coupled in the following 8th a coupling structure 44 shown at the end of the optical fiber 23 tangential light in the border area 12 the light guide plate 8th couples. This is done around the edge 20 a light ring 26 as it is the horizontal section through the coupling structure 44 in 8A shows, laid. This light ring 26 can be made of the same light-conducting plastic material as the light guide plate 8th consist. The light ring 26 however, has a higher concentration of light-scattering nanoparticles than the warning range 9 at the edge 12 the light guide plate 8th ,

A tangential to the light ring 26 introduced optical fiber end 23 leave this light ring 26 brightly lit, in addition to a reflective coating 25 covered, the light ring 26 surrounds on three sides, like the 8B shows, leaving only an inner edge 27 of the light ring 26 remains mirror-free, in cohesive contact with the edge 20 the light guide plate 8th stands. The bending radius of the light guide 22 can be optimally adapted to a radius of curvature of the instrument housing, so that only the thickness of the light ring 26 will slightly increase the diameter of the case of the instrument.

LIST OF REFERENCE NUMBERS

1

instrument

2

instrument

3

instrument

4

motor vehicle

5

display area

6

casing

7

instrument cover

8th

Light guide plate

9

warning area

10

volume

11

nanoparticles

12

border area

13

display

14

display

15

warning area

16

warning area

17

outer contour

18

recessed contour

19

lighting device

20

edge

21

light source

22

optical fiber

23

Optical fiber end

24

chamfer

25

reflective coating

26

light ring

27

inner edge

28

interior

29

front area

30

dashboard

31

viewing area

32

border area

33

light

34

Speed Meter

35

speedometer

36

Cooling temperature display

37

Fuel Gauge

38

Windshield

39

side windows

40

instrument pointer

41

rear window

42

Anti-glare screen

43

adhesive layer

44

coupling structure

45

scale

46

led

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 10102774 A1 [0002]

Claims (15)

Instrument for a motor vehicle ( 4 ) comprising: - a display area ( 5 ), - a warning area ( 9 ), - a housing ( 6 ), which covers the display area ( 5 ) and warning area ( 9 ), - a transparent instrument cover ( 7 ) coming from the housing ( 6 ) at a distance to the display area ( 5 ) is held; the instrument cover ( 7 ) a transparent light guide plate ( 8th ), in which light-scattering nanoparticles ( 11 ) in volume ( 10 ) distributed at least in the warning area ( 9 ) are arranged. An instrument according to claim 1, wherein the instrument cover ( 7 ) a cover of an instrument cluster of programmable display areas ( 5 ). Instrument according to claim 1, wherein an edge region ( 12 ) of the instrument cover ( 7 ) or the entire instrument cover ( 7 ) as a warning area ( 9 ) is trained. Instrument according to claim 1, wherein in the field of view of display fields ( 13 . 14 ) of the display area ( 5 ) an enlarged limited warning area ( 15 . 16 ) in volume ( 10 ) of the light guide plate ( 8th ) of the instrument cover ( 7 ) light-scattering nanoparticles ( 11 ) having. Instrument according to one of the preceding claims, wherein the light guide plate ( 8th ) a border ( 20 ) provided with a lighting device ( 19 ) is coupled. Instrument according to one of the preceding claims, wherein the light guide plate ( 8th ) a PMMA (polymethylmethacrylic) plastic with the light-scattering nanoparticles ( 11 ) having. Instrument according to claim 5 or claim 6, wherein the illumination device ( 19 ) at least one light source ( 21 ), with whose light the edge ( 20 ) of the light guide plate ( 8th ) is illuminated. Instrument according to claim 7, wherein at least one light guide ( 22 ) between the light source ( 21 ) and the edge ( 20 ) is arranged. Instrument according to claim 8, wherein the edge of the instrument cover ( 7 ) at least partially to a light guide end ( 23 ) of the light guide ( 22 ) and with the light guide end ( 23 ) is coupled. Instrument according to one of claims 5 to 9, wherein the edge ( 20 ) of the instrument cover ( 7 ) an angled chamfer ( 24 ) having a reflective coating ( 25 ) and wherein light orthogonally with respect to the light guide plate ( 8th ) on the edge ( 20 ) of the instrument cover ( 7 ) is aligned. Instrument according to one of claims 5 to 10, wherein a light ring ( 26 ) made of the material of the light guide plate ( 8th ) the edge ( 20 ) of the instrument cover ( 7 ) and a higher concentration of light-scattering nanoparticles ( 11 ) than the warning area ( 9 ). Instrument according to claim 11, wherein the light ring ( 26 ) with its inner edge ( 27 ) cohesively with the edge ( 20 ) of the light guide plate ( 8th ) and the remaining surface of the illuminated ring ( 26 ) a reflective coating ( 25 ) having. Instrument according to claim 11 or claim 12, wherein the optical fiber end ( 23 ) is oriented such that light from the light source ( 21 ) tangentially into the light ring ( 26 ) can be coupled. Instrument panel with at least one instrument according to one of claims 1 to 13. Motor vehicle with a dashboard, comprising an instrument according to one of claims 1 to 13.

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