# US 10,481,477 B2 · Projector apparatus

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- Number: US 10,481,477 B2
- Document ID: US10481477B2
- Status: Granted
- Kind: B2
- Application number: 16/068,285
- Filed: 2016-01-08
- Published: 2019-01-10
- Granted: 2019-11-19
- Earliest claimed: 2016-01-08
- Assignees: Maxell, Ltd.
- Applicants: Maxell, Ltd.
- Inventors: Hideki Nohechi; Takeshi Katayama; Naoto Kubota
- Web page: https://patentgrep.com/patent/US10481477B2

## CPC

- G03B 21/208: {Homogenising, shaping of the illumination light}
- G02B 7/008: {with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation}
- G03B 21/008: {using micromirror devices}
- H04N 9/3114: {by using a sequential colour filter producing one colour at a time}
- H04N 9/3152: {for shaping the light beam (beam shaping per se G02B27/09)}
- 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)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

An illumination optical system of a projector apparatus includes a rod lens which equalizes illuminance of illumination light incident on a micromirror device from lamps, and a plurality of light-shielding plates that shields unnecessary light not incident on the rod lens among the illumination light. The plurality of light-shielding plates is disposed on the incidence side of the rod lens such that each light-shielding plate is provided at a predetermined gap in an optical axis direction of the rod lens. Openings of each light-shielding plate are formed such that a light-shielding plate disposed on an emission side has a smaller passage area of illumination light than on an incidence side.

## Claims

### Claim 1

A projector apparatus which includes a light source which generates illumination light, an illumination optical system which collects the illumination light from the light source, a micromirror device which optically modulates the illumination light by displacing a plurality of mirror elements to generate image light, and a projection lens which projects the image light,
wherein the illumination optical system has a rod lens which equalizes illuminance of the illumination light incident on the micromirror device, and a plurality of light-shielding plates which shields unnecessary light not incident on the rod lens among the illumination light, and
the plurality of light-shielding plates is disposed on the incidence side of the rod lens such that each light-shielding plate is provided at a predetermined gap, and
wherein the shielding of unnecessary light causes a suppression of a rise in temperature of the plurality of light-shielding plates.

### Claim 2 (depends on 1)

The projector apparatus according to claim 1, wherein the plurality of light-shielding plates has respective openings through which the illumination light passes to the rod lens, and
areas of the openings of each light-shielding plate are different from each other, and a passage area of the illumination light is formed such that the light-shielding plate disposed on an emission side is smaller than on an incidence side.

### Claim 3 (depends on 2)

The projector apparatus according to claim 2, wherein the light-shielding plate disposed at least closest to the incidence side among the plurality of light-shielding plates has an inclined surface around the opening.

### Claim 4 (depends on 1)

The projector apparatus according to claim 1, wherein a light-shielding plate disposed at least closest to the incidence side among the plurality of light-shielding plates has a low reflectance by processing the surface to a roughened surface state.

### Claim 5 (depends on 1)

The projector apparatus according to claim 1, wherein the plurality of light-shielding plates is processed to have a roughened surface state on the surface of the incidence side of each of the light-shielding plates, and has a low reflectance.

### Claim 6 (depends on 5)

The projector apparatus according to claim 5, wherein a single aluminum composition is used as a material of the plurality of light-shielding plates.