LCD Display Unit for Use in a Reflection Display System in a Motor Vehicle, and Reflection Display System

Abstract

An LCD display unit for a reflection display system in a motor vehicle includes an LCD pixel matrix for selectively controlling picture elements for presenting a display image on a display area; a backlight arrangement, which is divided into selectively controllable dimming zones in order to illuminate regions containing multiple picture elements with background light; and a control unit, which is configured to control the LCD pixel matrix so that the display image is output, the display image being distorted using a warping function in order to compensate for a distortion of the display image as a result of reflection from a reflection region. The dimming zones have a shape and a size determined by the warping function.

Claims

1.-7. (canceled)

8. A liquid crystal display (LCD) display unit for a reflection display system in a motor vehicle, the LCD display unit comprising: an LCD pixel matrix for selectively controlling image points for presenting a display image on a display surface; a backlight arrangement, which is divided into selectively controllable dimming zones in order to light regions having a plurality of image points with backlight; and a control unit, which is configured to control the LCD pixel matrix such that the display image that is output is distorted via a warping function in order to compensate for a distortion of the display image due to reflection at a reflection region, wherein the dimming zones have a shape and a size that are determined by the warping function.

9. The LCD display unit according to claim 8, wherein the dimming zones are formed such that the dimming zones adjoin one another, with a result that the display surface of the LCD pixel matrix on which the display image is to be presented is fully lightable.

10. The LCD display unit according to claim 8, wherein a shape of each of the dimming zones is distorted via the warping function proceeding from a rectangular shape of a display region that is to be backlit so as to be rectangular.

11. The LCD display unit according to claim 8, wherein a shape of each of the dimming zones is distorted via the warping function proceeding from rectangular shapes of display regions that are to be backlit so as to be rectangular of different sizes.

12. The LCD display unit according to claim 8, wherein each of the dimming zones of the backlight arrangement has an area and distribution that depend on display images to be displayed.

13. The LCD display unit according to claim 12, wherein the display images to be displayed are aligned with at least one of a horizontal or a vertical axis of the display surface.

14. The LCD display unit according to claim 13, wherein the display images to be displayed are formed as symbols or rectangular display fields which are selectively displayable.

15. The LCD display unit according to claim 8, wherein a collimation optical arrangement is configured to direct light from the backlight arrangement in a preferred direction.

16. The LCD display unit according to claim 8, wherein the dimming zones are configured in a shape of ring segments.

17. A reflection display system for a motor vehicle, the reflection display system comprising: the LCD display unit according to claim 8, and a windshield with a reflection region which is curved in a surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIGS. 1a and 1b show a schematic cross-sectional illustration through a motor vehicle with a reflection display system or an internal-view illustration of the motor vehicle.

[0021] FIGS. 2a and 2b show an illustration of an output display image and of a perceived display image.

[0022] FIG. 3 shows a cross-sectional illustration of an LCD display device with a backlight arrangement.

[0023] FIG. 4 shows an exemplary illustration of a backlight arrangement with dimming zones which are embodied so as to be distorted according to a warping function to be applied.

[0024] FIG. 5 shows an exemplary illustration of a backlight arrangement with dimming zones of different sizes.

[0025] FIG. 6 shows a segmentation of the backlight arrangement adapted to a windshield of variable curvature, resulting in an asymmetric arrangement of the dimming zones.

DETAILED DESCRIPTION OF THE DRAWINGS

[0026] FIGS. 1a and 1b show a schematic cross-sectional illustration through a motor vehicle with a reflection display system 1 and an illustration from the viewing angle of the driver of the motor vehicle. The reflection display system 1 is arranged on a top side of an instrument panel 4 and has a display unit 2 which comprises a display surface 3 for presenting a display image. The display unit 2 is arranged on the top side of the instrument panel 4 below a windshield 5.

[0027] The display surface 3 is oriented relative to the windshield 5 such that a display image displayed on the display surface 3 of the display unit 2 is reflected at a lower region of the inside of the windshield 5, in a reflection region R, and can be perceived as a reflected image by a vehicle occupant in an eye region B. The orientation of the display unit 2 or of its display surface 3 is consequently preferably substantially parallel to the vehicle longitudinal axis and vehicle lateral axis or deviates therefrom by an angle of no more than 0-20.

[0028] The display unit 2 is controlled by a control unit 9 to output a display image such that a corresponding display image can be perceived by the vehicle occupant. The control unit 9 can be designed to control the display unit 2 such that a display image which is distorted with the aid of a warping function is displayed. Proceeding from a display image to be perceived, the warping function is used to apply an image distortion function, which is then inverted again by the reflection at the generally curved reflection region R, with the result that the vehicle occupants perceive the original display image to be perceived.

[0029] The display unit 2 is mounted in a recess 6 in the instrument panel, with the result that the vehicle occupant cannot look directly at the display surface 3 of the display unit 4 and dazzling of the vehicle occupants due to direct light from the display surface 3 into the eye region B is avoided.

[0030] The display unit 2 is preferably designed as a light-emitting display unit, in particular as an LCD display unit with a backlight of high brightness, in order to provide a highly luminous display image, with the result that the reflected image generated can be perceived via the corresponding region of the windshield 5 even at high ambient brightness.

[0031] Since the windshield 5 and the reflection region R generally have a curvature, it is necessary for using the inside of the windshield 5 as the reflection surface that the displayed display image of the display unit 2 be distorted so that it can be perceived without distortion by the vehicle occupant. FIG. 2a shows by way of example a display image as it is to be perceived by the vehicle occupant, and FIG. 2b shows a display image which is output via the display surface of the LCD display unit.

[0032] Proceeding from the generally rectangular display image to be perceived in the example of FIG. 2a, a warping function is applied which distorts the display image to be displayed according to the example in FIG. 2b. The warping function generally causes the distortion of a display image that is to be presented substantially as rectangular into a banana-shaped distortion in order to compensate for the curvature of the windshield 5 in the lateral direction and height direction.

[0033] FIG. 3 shows in cross section the schematic setup of an LCD display unit 2 with a two-dimensional backlight arrangement 21 and, arranged thereon, a two-dimensional LCD pixel matrix 22. The backlight arrangement 21 can be provided with a collimation optical layer 23 in order to direct the backlight emitted by the backlight arrangement into a preferential direction such that the display image is directed in particular into the eye region B of the vehicle occupant.

[0034] As shown in FIG. 4, the backlight arrangement 21 has dimming zones 24 which adjoin one another in the manner of segments such that the entire area of the backlight arrangement 21 is fully lightable. The dimming zones 24 are separately controllable so that it is possible to set their brightnesses. It is also possible for dimming zones 24 to be completely deactivated, so that no backlight is output. No bothersome gray region is produced in the region of deactivated dimming zones 24. The dimming zones 24 each have one or more LEDs, which are provided with a collimation optical layer 23 each in order to emit the backlight in a direction-dependent manner.

[0035] For use in a reflection display system 1 in a motor vehicle, the dimming zones 24 of the backlight arrangement 21 are designed in terms of shape and size such that they deviate from a typical, purely rectangular field arrangement in accordance with a warping function to be applied. The dimming zones 24 are consequently distributed below the display image A, which is likewise distorted according to the warping function.

[0036] That means that the otherwise rectangular individual dimming zones are distorted according to the warping function which is based on the curvature of the windshield 5 and the angle between the windshield 5 and the display surface of the LCD display unit 2.

[0037] As shown in FIG. 5, the dimming zones 24 can be designed in different sizes depending on the frequencies of the image points to be presented thereby in the individual regions of the dimming zones 24. It can be seen that display contents are presented more frequently in the central region of the display surface than at the peripheral regions. For this reason, the dimming zones 24 are greater at the peripheral regions than in the central region.

[0038] FIG. 6 shows a segmentation of the backlight arrangement 21 which has been adapted to a windshield 5 of variable curvature such that an asymmetric arrangement of the dimming zones 24 is produced.

[0039] The dimming zones 24 which have been adapted according to the warping function are advantageous in particular if the display images to be presented are optimized accordingly for the display with corresponding non-distorted dimming zones. If the displays are preferably generated such that the non-distorted display image can be lit with as few dimming zones 24 as possible, this is possible in the LCD display unit 2 according to embodiments of the present invention even with the distorted display image because the dimming zones 24 have an identical distortion.

LIST OF REFERENCE SIGNS

[0040] 1 Reflection display system [0041] 2 Display unit [0042] 3 Display surface [0043] 4 Instrument panel [0044] 5 Windshield [0045] 6 Recess [0046] 9 Control unit [0047] 21 Backlight arrangement [0048] 22 LCD pixel matrix [0049] 23 Collimation optical layer [0050] 24 Dimming zones [0051] R Reflection region [0052] B Eye region