# US 8,540,374 B2 · Cooling arrangement for projector with optical modulation devices

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- Number: US 8,540,374 B2
- Document ID: US8540374B2
- Status: Granted
- Kind: B2
- Application number: 13/072,045
- Filed: 2011-03-25
- Published: 2011-09-29
- Granted: 2013-09-24
- Earliest claimed: 2010-03-29
- Assignees: Seiko Epson Corporation
- Applicants: Akira Egawa; Yasushi Tateno; Fumihide Sasaki
- Inventors: Akira Egawa; Yasushi Tateno; Fumihide Sasaki
- Web page: https://patentgrep.com/patent/US8540374B2

## CPC

- G03B 21/16: Cooling; Preventing overheating
- 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)

## Abstract

A projector includes: an optical modulation device configured to modulate an incident luminous flux; a projection optical device configured to project the luminous flux modulated by the optical modulation device; and a cooling device configured to cool the optical modulation device, wherein the cooling device includes a cooling fan, and a duct having a discharge portion that causes the air discharged from the cooling fan to circulate in a direction approximately parallel to the optical axis, and discharges it to a lateral side of the optical modulation device, and the duct is disposed in a state that, when the projection optical device and discharge portion are cut by a plane perpendicular to the optical axis, the height position of a first center between the upper end and lower end of the cross-section of the discharge portion and that of the optical axis differ from one another.

## Claims

### Claim 1

A projector comprising:
a plurality of optical modulation devices configured to modulate incident luminous flux;
a projection optical device configured to project the luminous flux modulated by the plurality of optical modulation devices;
a cooling fan configured to discharge air; and
a duct having a discharge portion in which the discharged from the cooling fan flows along a direction approximately parallel to an optical axis of the projection optical device toward the plurality of optical modulation devices, wherein
the air from the discharge portion cools the optical modulation devices from a lateral side thereof in disposed order, and
the duct is disposed in a position that, in a cross-sectional view of the projection optical device and discharge portion taken along a plane perpendicular to the optical axis, the height position of a first center between the upper end and lower end of the discharge portion differs from the height position of the optical axis.

### Claim 2 (depends on 1)

The projector according to claim 1, wherein
the duct includes a side wall portion following the external shape of the projection optical device.

### Claim 3 (depends on 2)

The projector according to claim 2, wherein
the cooling fan includes a discharge aperture from which air is discharged, and
the cooling fan is disposed in a position that, in a cross-sectional view of the discharge aperture taken along a plane perpendicular to the optical axis, the height position of a second center between the upper end and lower end of the discharge aperture approximately coincides with the height position of the first center.

### Claim 4 (depends on 1)

The projector according to claim 1, wherein
the cooling fan includes a discharge aperture from which air is discharged, and
the cooling fan is disposed in a position that, in a cross-sectional view of the discharge aperture taken along a plane perpendicular to the optical axis, the height position of a second center between the upper end and lower end of the discharge aperture approximately coincides with the height position of the first center.

### Claim 5 (depends on 1)

The projector according to claim 1, wherein
the discharge portion is disposed in a position overlapping part of one of the plurality of optical modulation devices in a direction along the optical axis.