Image display device and headup display equipped with image display device

Patent metadata

Field	Value
Publication number	US-10838202-B2
Application number	US-201815975871-A
Country	US
Kind code	B2
Filing date	May 10, 2018
Priority date	Nov 30, 2015
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

Image display device is used in a head-up display. Image display device includes an illumination unit, light guide plate, light beam controller, and display unit. The illumination unit includes a plurality of light sources. Light guide plate includes incident surface into which light from the illumination unit enters, incident surface including a plurality of convex surfaces each of which is opposed to each of the plurality of light sources, and output surface disposed in a direction intersecting incident surface and from which the light incident from incident surface is output. Light beam controller controls a traveling direction of the light output from output surface. Display unit transmits the light output from light beam controller to display an image.

First claim

The invention claimed is:

1. An image display device used in a head-up display, the image display device comprising:
an illumination unit including a plurality of light sources;
a light guide plate including an incident surface which light from the illumination unit enters, the incident surface including a plurality of convex surfaces which is opposed to the respective plurality of light sources, an output surface disposed in a direction intersecting the incident surface and from which the light incident from the incident surface is output, and a counter surface opposed to the output surface;
a light beam controller that is arranged to cover a part of the output surface and controls a traveling direction of the light output from the output surface; and
a display that transmits the light output from the light beam controller to display an image,
wherein a first lenticular lens array is provided on a part of the output surface on which the light beam controller is not arranged.

2. The image display device according to claim 1 , wherein
the plurality of light sources are arrayed in a first direction, and
the first lenticular lens array is arrayed in a second direction intersecting the first direction.

3. The image display device according to claim 2 , wherein a second lenticular lens array arrayed in the first direction intersecting the first lenticular lens array is arrayed on a part of the output surface on which the light beam controller is arranged.

4. The image display device according to claim 3 , wherein
the second lenticular lens array has a plurality of cylindrical shape parts, and
a generating axis of each of the plurality of cylindrical shape parts is parallel to the second direction.

5. The image display device according to claim 1 , wherein the plurality of convex surfaces are curved while projecting in a direction opposed to the respective plurality of light sources, and
an axis of a curvature center in each of the plurality of convex surfaces is perpendicular to the output surface.

6. The image display device according to claim 1 , wherein
at least a part of the counter surface is inclined with respect to the output surface.

7. The image display device according to claim 1 , wherein the light guide plate includes a reflection member disposed close to the counter surface.

8. The image display device according to claim 1 , wherein a gap between at least a part of the counter surface and the output surface decreases with increasing distance from the incident surface.

9. The image display device according to claim 1 , wherein a part of the counter surface, opposed to a part of the output surface on which the light beam controller is not arranged, is substantially parallel to the output surface, and a part of the counter surface, opposed to a part of the output surface on which the light beam controller is arranged, is inclined with respect to the output surface.

10. The image display device according to claim 1 , further comprising a concave lens between the light beam controller and the display.

11. The image display device according to claim 1 , wherein
the first lenticular lens array has a plurality of cylindrical shape parts, and
a generating axis of each of the plurality of cylindrical shape parts is parallel to the first direction.

12. The image display device according to claim 1 , wherein
a plurality of prism shape parts arrayed in the second direction are arrayed on a part of the counter surface opposed to a part of the output surface on which the light beam controller is not arranged.

13. The image display device according to claim 12 , wherein
a generating axis of each of the plurality of prism shape parts is parallel to the first direction.

14. The image display device according to claim 1 , wherein
a plurality of prism shape parts arrayed in the second direction are arrayed on a part of the counter surface opposed to a part of the output surface on which the light beam controller is arranged.

15. The image display device according to claim 14 , wherein
a generating axis of each of the plurality of prism shape parts is parallel to the first direction.

16. A head-up display comprising:
an image display device including
an illumination unit including a plurality of light sources,
a light guide plate including an incident surface which light from the illumination unit enters, the incident surface including a plurality of convex surfaces which is opposed to the respective plurality of light sources, an output surface disposed in a direction intersecting the incident surface and from which the light incident from the incident surface is output, and a counter surface opposed to the output surface,
a light beam controller that is arranged to cover a part of the output surface and controls a traveling direction of the light output from the output surface, and
a display that transmits the light output from the light beam controller to display an image,
a lenticular lens array being provided on a part of the output surface on which the light beam controller is not arranged; and

a reflection optical unit that reflects the light output from the image display device,
wherein the light output from the reflection optical unit is introduced to an eye-box of an observer through a transparent member, and the observer is caused to visually recognize a virtual image.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Asai Yosuke

Classifications

• G02B6/002 Primary

  by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces · CPC title

• G02B6/0038

  Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide · CPC title

• G02B6/0046

  Tapered light guide, e.g. wedge-shaped light guide · CPC title

• G02B6/0053

  Prismatic sheet or layer; Brightness enhancement element, sheet or layer · CPC title

• G02B6/0033

  Means for improving the coupling-out of light from the light guide · CPC title