CN-122018160-A - Display device with stray light suppression

Abstract

The invention relates to a display device (1) with stray light suppression. The display device (1) has a display panel (2) and a transparent element (3) arranged on an upper side (20) of the display panel (2). The material of the transparent element (3) is selected such that there is no abrupt change in refractive index in the transition from the display panel (2) to the transparent element (3). The transparent element (3) has a curved upper side (30) which is designed to deflect incident Stray Light (SL) in the direction of the optical trap (LF).

Inventors

• H-P. Kreppe
• K. Habermal

Assignees

• 大陆汽车科技有限公司

Dates

Publication Date

20260512

Application Date

20251020

Priority Date

20241111

Claims (10)

1. 1. A display device (1), the display device having: -a display panel (2), and -A transparent element (3) arranged on an upper side (20) of the display panel (2); Wherein the material of the transparent element (3) is selected such that no refractive index jump is present in the transition from the display panel (2) to the transparent element (3), wherein the transparent element (3) has a curved upper side (30) which is designed for deflecting incident Stray Light (SL) in the direction of the light trap (LF).
2. 2. A display device (1) according to claim 1, characterized in that the display panel (2) is implemented planar.
3. 3. A display device (1) according to claim 2, characterized in that the display panel (2) is arranged obliquely with respect to the viewing direction (R).
4. 4. A display device (1) according to claim 1, characterized in that the display panel (2) is embodied as curved.
5. 5. A display device (1) according to any of the preceding claims, characterized in that the display device has a transparent glass (4) for reflecting an image displayed by the display panel (2) towards the viewer (6).
6. 6. The display device (1) according to claim 5, characterized in that the transparent glass (4) has a blackened area (40).
7. 7. The display device (1) according to any of the preceding claims, characterized in that it has a backlight (5) designed such that light (L) emitted from the backlight (5) illuminates the head position of one or more observers (6).
8. 8. A display device (1) according to any of the preceding claims, characterized in that the light trap (LF) is designed as a light-absorbing wall (7).
9. 9. The display device (1) according to any of the preceding claims, characterized in that the display device (1) forms a display band alone or in combination with other display devices (1).
10. 10. A display device (1) according to claim 9, characterized in that the light shaping in the display band is realized in such a way that for at least a part of the display band, the image content is permanently and/or switchably visible only to one of a plurality of viewing positions.

Description

Display device with stray light suppression Technical Field The present invention relates to a display device with stray light/disturbing light suppression. Background The number and area of display devices in vehicles is increasing. Display devices are available on the market, for example as a combination meter for the driver, as a central display and as a co-driver display. Head-up displays are also becoming more common in vehicles. A Head-Up Display (english: head-Up-Display, also called HUD) is understood as a Display system in which a viewer can keep his viewing direction, since the content to be displayed is superimposed into his field of view. Such systems were primarily used in the aeronautical field initially due to their complexity and cost, and these systems have now also been installed on a large scale in the vehicle field. Head-up displays are generally composed of an imaging unit or PGU (english: picture Generating Unit, chinese: image generation unit), an optical unit and a mirror unit. The imaging unit generates an image and uses at least one display element for this purpose. Most head-up displays today use LCD-based displays (LCD-full: liquid CRYSTAL DISPLAY, chinese: liquid crystal display) to generate images. The optical unit directs the image onto the mirror unit. The mirror unit is a partially reflective, light transmissive glass. Thus, the observer sees the content presented by the imaging unit as a virtual image and at the same time sees the real world behind the glass. In the field of vehicles, windshields are often used as mirror units, the curved shape of which must be taken into account when displaying. By the synergistic effect of the optical unit and the mirror unit, the virtual image is an enlarged representation of the image generated by the imaging unit. In an alternative embodiment, the display is arranged relative to the windscreen in such a way that a view of the display is provided through the windscreen and the virtual depth is given directly by the distance to the windscreen. Such displays are known as landscape view displays (Scenic-VIEW DISPLAY). Currently, the image content of a landscape view display is mirrored through the darkened area of the windshield to avoid direct incidence of sunlight or other light source light onto the display. If there is no such darkened area in the windshield, sunlight or extraneous light can reach the display directly and overlap the image content as back reflection or back scattering. This may lead to distraction or disturbance of the driver, which must be avoided. Against this background, DE 10 2010 032 998 A1 describes a head-up display for a motor vehicle, which has a projection device by means of which an image to be displayed is projected onto a front window pane of the motor vehicle, which serves as a combination device. The projection device has a translucent cover portion directed toward the front window, the translucent cover portion being configured to reflect external light impinging on the cover portion from the outside onto the absorption surface. The absorption surface is at least partially formed by the inner coating of the front pane. WO 2019/238849 A1 describes an instrument for generating virtual images with stray light suppression. The instrument has a light source, a display element for generating an image, and an antiglare element. The antiglare element has a curved surface. Disclosure of Invention It is an object of the invention to provide an improved display device with stray light suppression. This object is achieved by a display device having the features of claim 1. Preferred embodiments of the invention are the subject matter of the dependent claims. According to a first aspect of the present invention, a display device has a display panel and a transparent element arranged on an upper side of the display panel. The material of the transparent element is chosen such that there is no abrupt change in refractive index in the transition from the display panel to the transparent element. The transparent element has a curved upper side which is designed to deflect incident stray light in the direction of the optical trap. In the solution according to the invention, the display panel is placed under a cover, the surface of which is curved in such a way that the incident light is deflected appropriately. The surface here meets the requirements of geometric antireflection. Further, the material of the cover is selected such that there is no abrupt change in refractive index from the outer surface to the display panel. The cover is formed such that a space between the display panel and the curved surface is completely filled with a material of the cover. In this way, disturbing back reflections are avoided. The display device may for example be mounted in a tank such that incident stray light is diverted into the tank wall acting as an optical trap. According to an aspect of the present invention, the display panel