Image display device and mobile object

• US 10,031,343 B2
• Filed: 02/04/2015
• Issued: 07/24/2018
• Est. Priority Date: 02/05/2014
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Saisho, Kenichiroh, Inamoto, Makoto
• Primary Examiner(s): Cheng, Joe H
• Application Number:
  US15/111,668
• Publication Number:
  US 20160334637A1
• Time in Patent Office: 1,266 Days
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 26/101 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 Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: G02B 27/0911 Anamorphotic systems
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/1033 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G03B 21/2073 Polarisers in the lamp house peculiar to electronic spatial light modulators H04N9/3197
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

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.

Claims

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.