Projection display device, method of controlling projection display device, and program for controlling projection display device

Patent metadata

Field	Value
Publication number	US-10747094-B2
Application number	US-201916517675-A
Country	US
Kind code	B2
Filing date	Jul 22, 2019
Priority date	Feb 23, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A HUD 100 includes a R light source 12 r , a G light source 12 g , and a B light source 12 b ; collimating lenses 13 r, 13 g , and 13 b that are arranged forwardly of the light sources; fly-eye lenses 16 and 17 that are arranged side by side on an optical path of light that exits from the collimating lenses; a light modulation element 20 that, based on image information, performs spatial modulation on light that has passed through the fly-eye lenses; a projection optical system 50 that projects image light onto a projection surface 7 , the image light acquired by the spatial modulation by the light modulation element; photodetection elements PD 1 and PD 2 that are fixed to a portion of the fly-eye lens 16 ; and an image light control unit 40 B that controls a brightness distribution of the image light based on a brightness of light detected by each of the photodetection elements.

First claim

What is claimed is:

1. A projection display device comprising:
a semiconductor light source;
a first lens that is arranged forwardly of the semiconductor light source and that collimates a light distribution of the semiconductor light source;
a second lens and a third lens that are two lenses arranged side by side on an optical path of light that exits from the first lens, and that each include a lens array arranged two-dimensionally in a lens surface perpendicular to a direction in which the two lenses are arranged side by side;
a light modulation element that, based on image information, performs spatial modulation on light that has passed through the second lens and the third lens;
a projection optical system that projects image light onto a projection surface, the image light acquired by the spatial modulation by the light modulation element;
a plurality of photodetection elements that, at different positions in a direction parallel to the lens surface, detect light incident upon the second lens or the third lens; and
an image light control unit that controls a brightness distribution of the image light based on a brightness of the light detected by each of the plurality of photodetection elements; and
a light source control unit that controls an output of the semiconductor light source based on information about the light detected by one of the plurality of photodetection elements that is arranged at a position closest to a center of the second lens or a center of the third lens.

2. The projection display device according to claim 1 ,
wherein distances of the plurality of photodetection elements from a center of the second lens and a center of the third lens differ from each other.

3. The projection display device according to claim 1 ,
wherein the image light control unit controls the brightness distribution of the image light in a case where the projection display device is started.

4. The projection display device according to claim 2 ,
wherein the image light control unit controls the brightness distribution of the image light in a case where the projection display device is started.

5. The projection display device according to claim 1 ,
wherein the image light control unit controls the brightness distribution of the image light in a case where an elapsed time from when the projection display device started exceeds a threshold value.

6. The projection display device according to claim 1 , further comprising:
a temperature sensor,
wherein the image light control unit controls the brightness distribution of the image light in a case where a temperature that is detected by the temperature sensor exceeds a threshold value.

7. The projection display device according to claim 1 ,
wherein the plurality of photodetection elements are fixed to a portion of the lens array that constitutes the second lens or a portion of the lens array that constitutes the third lens.

8. The projection display device according to claim 1 ,
wherein the light modulation element performs the spatial modulation by a plurality of movable mirrors arranged two-dimensionally, and
wherein the image light control unit controls the brightness distribution of the image light by controlling a driving signal of the movable mirrors.

9. The projection display device according to claim 1 ,
wherein the light modulation element is a reflective-type liquid crystal display element, and
wherein the image light control unit controls the brightness distribution of the image light by controlling a transmission amount of light of a pixel of the liquid crystal display element.

10. The projection display device according to claim 1 , further comprising:
an optical member that is arranged between one of the second lens and the third lens that is closer to the light modulation element and the light modulation element, and that has a plurality of light transmission regions arranged two-dimensionally at a surface parallel to the lens surface, a transmissivity of each of the plurality of light transmission regions being electrically controlled,
wherein the image light control unit controls the brightness distribution of the image light by controlling the transmissivities of the light transmission regions.

11. A method of controlling a projection display device comprising a semiconductor light source; a first lens that is arranged forwardly of the semiconductor light source and that collimates a light distribution of the semiconductor light source; a second lens and a third lens that are two lenses arranged side by side on an optical path of light that exits from the first lens, and that each include a lens array arranged two-dimensionally in a lens surface perpendicular to a direction in which the two lenses are arranged side by side; a light modulation element that, based on image information, performs spatial modulation on light that has passed through the second lens and the third lens; a projection optical system that projects image light onto a projection surface, the image light acquired by the spatial modulation by the light modulation element; and a plurality of photodetection elements that, at different positions in a direction parallel to the lens surface, detect light incident upon the second lens or the third lens, the method comprising:
an image light control step of controlling a brightness distribution of the image light based on a brightness of the light detected by each of the plurality of photodetection elements; and
a light source control step of controlling an output of the semiconductor light source based on information about the light detected by one of the plurality of photodetection elements that is arranged at a position closest to a center of the second lens or a center of the third lens.

12. The method of controlling a projection display device according to claim 11 ,
wherein distances of the plurality of photodetection elements from a center of the second lens and a center of the third lens differ from each other.

13. The method of controlling a projection display device according to claim 11 ,
wherein, in the image light control step, the brightness distribution of the image light is controlled in a case where the projection display device is started.

14. The method of controlling a projection display device according to claim 11 ,
wherein, in the image light control step, the brightness distribution of the image light is controlled in a case where an elapsed time from when the projection display device started exceeds a threshold value.

15. The method of controlling a projection display device according to claim 11 ,
wherein, in the image light control step, the brightness distribution of the image light is controlled in a case where a temperature that is detected by a temperature sensor that is mounted in the projection display device exceeds a threshold value.

16. The method of controlling a projection display device according to claim 11 ,
wherein the plurality of photodetection elements are fixed to a portion of the lens array that constitutes the second lens or a portion of the lens array that constitutes the third lens.

17. The method of controlling a projection display device according to claim 11 ,
wherein the light modulation element performs the spatial modulation by a plurality of movable mirrors arranged two-dimensionally, and
wherein, in the image light control step, the brightness distribution of the image light is controlled by controlling a driving signal of the movable mirrors.

18. The method of controlling a proje

Assignees

• Fujifilm Corp
• Fujifilm Coporation

Inventors

• Asuma Nobuko

Classifications

• G03B21/208 Primary

  Homogenising, shaping of the illumination light · CPC title

• G03B21/16

  Cooling; Preventing overheating · CPC title

• G03B21/2053 Primary

  Intensity control of illuminating light (controlled by video signal processing H04N5/74 or H04N9/31) · CPC title

• G03B21/206

  Control of light source other than position or intensity · CPC title

• H04N9/3182

  Colour adjustment, e.g. white balance, shading or gamut (white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607) · CPC title