Image display device and mobile object

Patent metadata

Field	Value
Publication number	US-10031343-B2
Application number	US-201515111668-A
Country	US
Kind code	B2
Filing date	Feb 4, 2015
Priority date	Feb 5, 2014
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

An image display device including a laser light source; an optical element; and a transmitting-reflecting member, the image display device which displays an image by forming the image by light which is emitted from the laser light source and making image light after forming the image to be incident on the transmitting-reflecting member, wherein the laser light source is arranged such that there are more S polarization components of the image light which is incident on the transmitting-reflecting member with respect to the transmitting-reflecting member than P polarization components, and a mobile object including the image display device.

First claim

The invention claimed is:

1. An image display device, comprising:
a laser light source;
an optical element; and
a transmitting-reflecting member,
the image display device which displays an image by forming the image by light which is emitted from the laser light source and making image light after forming the image to be incident on the transmitting-reflecting member,
wherein the laser light source is arranged such that there are more S polarization components of the image light which is incident on the transmitting-reflecting member with respect to the transmitting-reflecting member than P polarization components,
wherein an effective cross-section of the light which is emitted from the laser light source has a direction of a long diameter and a direction of a short diameter which is perpendicular to the direction of the long diameter, and
wherein the optical element is configured to reverse the direction of the long diameter and the direction of the short diameter of the effective cross-section of the light transmitted through the optical element.

2. The image display device according to claim 1 , wherein the optical element is arranged on an optical path between the laser light source and the transmitting-reflecting member, and is a lens array which includes a plurality of lenses on which the image is formed, and each of the plurality of lenses is arranged such that the direction of the long diameter and the direction of the short diameter of the effective cross-section of the light which is emitted from the laser light source are reversed before and after the light which is emitted from the laser light source is transmitted through each of the lenses.

3. The image display device according to claim 2 , wherein each of the plurality of lenses has different curvatures regarding first and second directions which are perpendicular to each other in a plane perpendicular to an optical axis.

4. The image display device according to claim 3 , wherein the direction of the short diameter of the effective cross-section of the light which is emitted from the laser light source coincides with a direction of one of the first and second directions of each of the lenses in which a curvature is larger.

5. The image display device according to claim 2 , wherein the image includes a long axis direction and a short axis direction and the long axis direction of the image is aligned with a long diameter direction of an effective cross-section of light which passed through the plurality of lenses.

6. The image display device according to claim 1 , wherein an effective cross-section of the image light which is incident on the transmitting-reflecting member is horizontally long.

7. The image display device according to claim 1 , wherein the effective cross-section is a portion in which a relative intensity is 20% to 80% in a cross-section of light in the optical path between the laser light source and the transmitting-reflecting member.

8. The image display device according to claim 1 , wherein the image is horizontally long.

9. The image display device according to claim 1 , wherein a ratio of the S polarization components to the light which is emitted from the laser light source is 100%.

10. The image display device according to claim 1 , wherein an incidence angle of the image light which is incident on the transmitting-reflecting member is approximately Brewster's angle.

11. The image display device according to claim 1 , wherein the laser light source is a semiconductor laser.

12. A mobile object which is driven by a driver, comprising:
the image display device according to claim 1 ,
wherein the driver visually recognizes a virtual image of the image via the transmitting-reflecting member.

13. The mobile object according to claim 12 , wherein the transmitting-reflecting member is a window member through which the driver visually recognizes outside of the mobile object.

Assignees

• Saisho Kenichiroh
• Inamoto Makoto
• Ricoh Co Ltd

Inventors

• Saisho Kenichiroh
• Inamoto Makoto

Classifications

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title

• G02B2027/0118

  comprising devices for improving the contrast of the display / brillance control visibility · CPC title

• G02B2027/0114

  comprising dichroic elements · CPC title

• G02B27/0101

  characterised by optical features (G02B27/0172 takes precedence) · CPC title

• G02B3/0006

  Arrays (G02B3/02, G02B5/188 take precedence) · CPC title