# US 8,783,877 B2 · Projection type display apparatus for displaying an image

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- Number: US 8,783,877 B2
- Document ID: US8783877B2
- Status: Granted
- Kind: B2
- Application number: 13/459,715
- Filed: 2012-04-30
- Published: 2012-08-23
- Granted: 2014-07-22
- Earliest claimed: 2008-09-25
- Assignees: Hitachi Consumer Electronics Co., Ltd.
- Applicants: Nobuyuki Kimura
- Inventors: Nobuyuki Kimura
- Web page: https://patentgrep.com/patent/US8783877B2

## CPC

- G03B 21/142: {Adjusting of projection optics}
- G03B 21/14: Details
- H04N 9/3155: {for controlling the light source (light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406)}
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

The present invention provides a projection type display apparatus for displaying an image by which reduction of contrast is suppressed, including: a light source; a first lens array and a second lens array having a plurality of lens cell areas; a collecting lens; a display element; a projection lens; and a light shielding unit which light-shields the light fluxes from the first lens array to the second lens array, wherein the light shielding unit light-shields at least parts of all the lens cell areas except for the lens cell area in contact with an optical axis among a plurality of rectangular lens cell areas of the second lens array, and a light shielding area in the lens cell area in contact with the optical axis is smaller than that in any of the lens cell areas except for the lens cell area in contact with the optical axis.

## Claims

### Claim 1

A projection type display apparatus, comprising:
a light source;
two lens arrays through which light emitted from the light source passes;
a display element which receives light from the two lens arrays;
a projection lens which projects light emitted from the display element; and
a light shielding unit which light-shields light between the two lens arrays,
wherein, one of the two lens arrays has a plurality of lens cell areas arranged in a matrix manner including four lens cell areas in contact with an optical axis, a first group of L (L is an integer number of 3 or larger) lens cell areas in which the L lens cell areas include one adjacent lens cell area adjacent to each of the four lens cell areas in the first direction, and in which the other L−1 lens cell areas arranged in series straightly in the first direction next to the one adjacent lens cell area, and a second group of M (M is an integer number of 1 or larger) lens cell areas adjacent to each of the four lens cell area in second direction, which is the different direction from the first direction, the total of the lens cell areas include more lens cell areas than or equal to 8 lens cell areas in the first direction and include more lens cell areas than or equal to 4 lens cell areas in the second direction;
wherein, in one light shielding condition of the light shielding unit, the light shielding unit light-shields the plurality of lens cell areas so that 1) each cell area in the first group of lens cell areas is light-shielded partially but not fully light-shielded, 2) each cell area in the second group of lens cell areas is light-shielded partially but not fully light-shielded, 3) each cell area in the four lens cell areas in contact with the optical axis is light-shielded partially or light-unshielded, and 4) each cell area in the other lens cell areas is light-shielded fully or partially.

### Claim 2 (depends on 1)

A projection type display apparatus according to claim 1, wherein
in said light shielding condition, a light shielding area of one of the four lens cell areas is smaller than that of any lens cell area of the first group of L lens cell areas.

### Claim 3 (depends on 1)

A projection type display apparatus according to claim 1, wherein
in said light shielding condition, a light shielding area of one of the four lens cell areas is 50% or less of the lens area, and a light shielding area of each of the first group of L lens cell areas is 50% or more of the lens cell area.

### Claim 4 (depends on 1)

A projection type display apparatus according to claim 1, wherein
in said light shielding condition, a light shielding area of any lens cell areas except the four lens cell areas is larger than that of one of the four lens cell areas.

### Claim 5

A projection type display apparatus, comprising:
a light source;
two lens arrays which splits light from the light source passes;
a collecting lens which collects which collects lights from the two lens arrays;
a display element which receives lights from the collecting lens;
a projection lens which projects light emitted from the display element; and
a light shielding unit which light-shields light between the two lens arrays,
wherein, a second lens array of the two lens arrays has a plurality of lens cell areas arranged in a matrix manner including four lens cell areas in contact with an optical axis, a first group of L (L is an integer number of 3 or larger) lens cell areas in which the L lens cell areas include one adjacent lens cell area adjacent to each of the four lens cell areas in first direction, and in which the other L−1 lens cell areas arranged in series straightly in the first direction next to the one adjacent lens cell area, and a second group of M (M is 1) lens cell areas adjacent to each of the four lens cell area in second direction, which is the different direction from the first direction, the total of the lens cell areas include more lens cell areas than or equal to 8 lens cell areas in the first direction and include more lens cell areas than or equal to 4 lens cell areas in the second direction;
wherein, in one light shielding condition of the light shielding unit, the light shielding unit light-shields the plurality of lens cell areas so that 1) each cell area in the first group of lens cell areas is light-shielded partially but not fully light-shielded, 2) each cell area in the second group of lens cell areas is light-shielded partially but not fully light-shielded, 3) each cell area in the four lens cell areas in contact with the optical axis is light-shielded partially or light-unshielded, and 4) each cell area in the other lens cell areas is light-shielded fully or partially.

### Claim 6 (depends on 5)

A projection type display apparatus according to claim 5, wherein
in said light shielding condition, a light shielding area of one of the four lens cell areas is smaller than that of any lens cell area of the first group of L lens cell areas.

### Claim 7 (depends on 5)

A projection type display apparatus according to claim 5, wherein
in said light shielding condition, a light shielding area of one of the four lens cell areas is less than 50% of the lens area, and a light shielding area of each of the first group of L cell areas is more than 50% of the lens cell area.

### Claim 8 (depends on 5)

A projection type display apparatus according to claim 5, wherein
in said light shielding condition, a light shielding area of any lens cell areas except the four lens cell areas is larger than that of one of the four lens cell areas.