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EP-4741907-A1 - DISPLAY DEVICE WITH STRAY LIGHT SUPPRESSION

EP4741907A1EP 4741907 A1EP4741907 A1EP 4741907A1EP-4741907-A1

Abstract

The present invention relates to a display device (1) with stray light suppression. The display device (1) comprises a display panel (2) and a transparent element (3) arranged on a top surface (20) of the display panel (2). The material of the transparent element (3) is selected such that no change in refractive index occurs at the transition from the display panel (2) to the transparent element (3). The transparent element (3) has a curved top surface (30) configured to deflect incident stray light (SL) towards a light trap (LF).

Inventors

  • KREIPE, HANS-PETER
  • Habermehl, Kai

Assignees

  • AUMOVIO Germany GmbH

Dates

Publication Date
20260513
Application Date
20251022

Claims (10)

  1. Display device (1) with: - a display panel (2); and - a transparent element (3) arranged on a top side (20) of the display panel (2); wherein the material of the transparent element (3) is selected such that no refractive index jump occurs at the transition from the display panel (2) to the transparent element (3), and wherein the transparent element (3) has a curved top surface (30) designed to deflect incident stray light (SL) towards a light trap (LF).
  2. Display device (1) according to claim 1, wherein the display panel (2) is flat.
  3. Display device (1) according to claim 2, wherein the display panel (2) is arranged obliquely relative to a viewing direction (R).
  4. Display device (1) according to claim 1, wherein the display panel (2) is curved.
  5. Display device (1) according to one of the preceding claims, comprising a transparent disc (4) for reflecting an image displayed by the display panel (2) towards a viewer (6).
  6. Display device (1) according to claim 5, wherein the transparent disc (4) has a blackened area (40).
  7. Display device (1) according to one of the preceding claims, with a backlight (5) which is designed such that the backlight (5) emitted light (L) illuminates the head position of one or more viewers (6).
  8. Display device (1) according to one of the preceding claims, wherein the light trap (LF) is designed as a light-absorbing wall (7).
  9. Display device (1) according to one of the preceding claims, wherein the display device (1) on its own or in combination with other display devices (1) forms a display band.
  10. Display device (1) according to claim 9, wherein light shaping in the display strip is implemented such that for at least a part of the display strip image content is permanently and/or switchably visible only for one of several viewing positions.

Description

The present invention relates to a display device with stray light suppression. The number and size of display devices in vehicles are constantly increasing. Display devices can be found, for example, as instrument clusters for the driver, central displays, and passenger displays. Head-up displays are increasingly common in vehicles. A head-up display, also known as a HUD, is a display system that allows the viewer to maintain their current viewing direction by projecting the information into their field of vision. While such systems were initially used primarily in aviation due to their complexity and cost, they are now being mass-produced in the automotive industry. Head-up displays generally consist of an image-generating unit (PGU), an optical unit, and a mirror unit. The image-generating unit creates the image, using at least one display element. Most modern head-up displays use LCD-based displays (LCD: Liquid Crystal Display) for image generation. The optical unit directs the image to the mirror unit. The mirror unit is a partially reflective, translucent disc. The viewer thus sees the content displayed by the image-generating unit as a virtual image while simultaneously seeing the real world behind the disc. In automotive applications, the windshield often serves as the mirror unit, and its curved shape must be taken into account during the display process. Through the interaction of... The optical unit and mirror unit produce a virtual image that is an enlarged representation of the image generated by the imaging unit. In an alternative design, displays are positioned relative to the windshield in such a way that they are visible over the windshield, and the virtual depth is directly proportional to the distance from the windshield. Such displays are called Scenic View displays. Currently, the image content of Scenic View displays is reflected off a black-tinted area of the windshield to prevent direct sunlight or light from other light sources from hitting the display. Without this black-tinted area, sunlight or ambient light could pass directly onto the display and be superimposed on the image content as back reflection or backscattering. This can distract or disturb the driver, which must be avoided. Against this background, he describes DE 10 2010 032 998 A1 A head-up display for a motor vehicle, comprising a projection device by which an image to be displayed is projected onto the windshield of the motor vehicle, which acts as a combining device. The projection device has a semi-transparent cover facing the windshield, which is designed to reflect ambient light incident on the cover from the outside onto an absorber surface. The absorber surface is formed, at least in part, by an inner coating of the windshield. WO 2019/238849 A1 This describes a device for generating a virtual image with interference suppression. The device comprises a light source, a display element for generating an image, and an anti-glare element. The anti-glare element has a curved surface. It is an object of the invention to provide an improved display device with interference suppression. This problem is solved by a display device having the features of claim 1. Preferred embodiments of the invention are the subject of the dependent claims. According to a first aspect of the invention, a display device comprises a display panel and a transparent element arranged on the upper surface of the display panel. The material of the transparent element is selected such that no change in refractive index occurs at the transition from the display panel to the transparent element. The transparent element has a curved upper surface designed to deflect incident stray light towards a light trap. In the solution according to the invention, the display panel is placed under a cover whose surface is curved in such a way as to deflect the incident light appropriately. The surface thus meets the requirements of geometric anti-reflection. In addition, the material of the cover is selected so that there is no change in the surface texture from the outer surface to the display panel. The cover is shaped so that the space between the display panel and the curved surface is completely filled with the cover material. In this way, disruptive back reflections are avoided. The display device can, for example, be installed in a shaft in such a way that any incident stray light is directed into a shaft wall that acts as a light trap. According to one aspect of the invention, the display panel is designed to be flat. This allows a commercially available display panel to be used for the implementation of the display device, which is advantageous in terms of manufacturing costs. According to one aspect of the invention, the display panel is arranged at an angle relative to a viewing direction. This allows the curvature of the transparent element to be conveyed across the surface of the display panel. In this way, less material is required for the manuf