Image generating device, head-up display comprising such a device and method for manufacturing an image generating device

Patent metadata

Field	Value
Publication number	US-10656452-B2
Application number	US-201716091832-A
Country	US
Kind code	B2
Filing date	Apr 7, 2017
Priority date	Apr 8, 2016
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

An image generating device comprises a light source producing a light beam and a screen ( 5 ) traversed by the light beam and designed to modify the light beam so as to form an image. The screen ( 5 ) comprises a transparent element ( 150 ) traversed by the light beam and designed to evacuate the heat generated at the level of the screen ( 5 ). Said transparent element ( 150 ) is made of sintered transparent ceramic. Also described are a head-up display comprising such a device, and a method for manufacturing an image generating device.

First claim

The invention claimed is:

1. An image-generating device comprising:
a light source that produces a light beam; and
a screen that is passed through by the light beam, wherein the screen modifies the light beam so as to form an image, and the screen is mounted in a first cover accommodated in a second cover,
wherein a first window is formed in a transverse portion of the second cover to allow the produced light beam to enter the screen,
wherein the screen comprises a transparent element that is passed through by the light beam and that is arranged to remove the heat generated in the screen,
wherein said transparent element is made of sintered transparent ceramic; and
wherein a second window is formed in a transverse portion of the first cover to allow the modified light beam to exit the screen.

2. The image-generating device as claimed in claim 1 , wherein said ceramic has a thermal conductivity higher than 40 W/mK.

3. The image-generating device as claimed in claim 1 , wherein said ceramic is a magnesium oxide.

4. The image-generating device as claimed in claim 1 , wherein said transparent element bears elements for polarizing the light beam.

5. The image-generating device as claimed in claim 1 , wherein the second cover is a metal cover and wherein the transparent element makes thermal contact with the metal cover.

6. The image-generating device as claimed in claim 5 , wherein the metal cover accommodates a liquid-crystal matrix array.

7. The image-generating device as claimed in claim 5 , wherein the transparent element makes contact with at least one external face of the metal cover.

8. The image-generating device as claimed in claim 5 , wherein the transparent element is accommodated in the interior of the metal cover.

9. The image-generating device as claimed in claim 5 , wherein the transparent element makes contact with a transverse portion of the metal cover encircling a window formed in the metal cover.

10. A head-up display comprising:
an image-generating device as claimed in claim 1 ; and
an image-projecting device for transmitting in the direction of a semi-transparent plate the images generated by the image-generating device.

11. A process for manufacturing an image-generating device comprising a light source that produces a light beam and a screen that is passed through by the light beam and that is designed to modify the light beam so as to form an image, the process comprising:
sintering a powder so as to obtain an element made of transparent ceramic;
mounting said element on the screen so that this element is passed through by the light beam and removes the heat generated in the screen;
mounting the screen in a first cover accommodated in a second cover;
forming a first window in a transverse portion of the second cover to allow the produced light beam to enter the screen; and
forming a second window in a transverse portion of the first cover to allow the modified light beam to exit the screen.

12. The process as claimed in claim 11 , wherein the sintering is a hot-isostatic-pressing process or a spark-plasma-sintering process.

13. The process as claimed in claim 11 , wherein the element made of transparent ceramic has a transmittance higher than 85 percent.

14. The process as claimed in claim 13 , wherein the element made of transparent ceramic has a thickness between 0.5 mm to 1.5 mm.

15. The process as claimed in claim 11 , further comprising providing an antireflection treatment on the element made of transparent ceramic.

16. An image-generating device comprising:
a light source that produces a light beam; and
a screen that is passed through by the light beam, wherein the screen modifies the light beam so as to form an image, and the screen is mounted in a first cover accommodated in a second cover,
wherein a first window is formed in a transverse portion of the second cover to allow the produced light beam to enter the screen,
wherein the screen comprises a transparent element that is passed through by the light beam and that is arranged to remove the heat generated in the screen,
wherein the screen comprises a metal cover and the transparent element is accommodated in an interior of the metal cover, and
wherein a second window is formed in a transverse portion of the first cover to allow the modified light beam to exit the screen.

17. The image-generating device as claimed in claim 16 , wherein the screen comprises:
an entrance polarizer;
a first glass sheet;
a liquid-crystal matrix array;
a second glass sheet;
a matrix array of color elements; and
an exit polarizer.

18. The image-generating device as claimed in claim 17 , wherein the entrance polarizer and the exit polarizer respectively have a first axis and a second axis perpendicular to each other.

19. The image-generating device as claimed in claim 17 , wherein for each pixel of the screen, the matrix array of color elements comprises a plurality of color elements through each of which is configured to make an adjustable light intensity passed by activating a corresponding element of the liquid-crystal matrix array.

20. The image-generating device as claimed in claim 19 , wherein a color of the pixel is obtained by the light beam passing through the plurality of color elements.

Assignees

• Valeo Comfort & Driving Assistance

Inventors

• Bisson Jean-François
• Le-Guyader Delphine
• Leon Renan
• Vivet Laurent

Classifications

• G02F1/133308

  Support structures for LCD panels, e.g. frames or bezels · CPC title

• G02B27/01

  Head-up displays · CPC title

• C04B2237/40

  Metallic · CPC title

• G02F1/133385 Primary

  with cooling means, e.g. fans · CPC title

• C04B37/04

  with articles made from glass · CPC title