Image projection apparatus and associated cooling system and method

Patent metadata

Field	Value
Publication number	US-10284833-B2
Application number	US-201715408638-A
Country	US
Kind code	B2
Filing date	Jan 18, 2017
Priority date	Jan 25, 2016
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

An image projection apparatus is configured to project an image onto a projection receiving part. The image projection apparatus includes: a light source; an optical modulator configured to form the image using light from the light source; a control unit configured to control the light source and the optical modulator; and a temperature detector configured to detect an environmental temperature. The control unit is configured to control at least one of the light source and the optical modulator to adjust color tone of the image depending on the environmental temperature detected by the temperature detector.

First claim

What is claimed is:

1. An image projection apparatus configured to project an image onto a projection receiving part, the image projection apparatus comprising:
a light source;
an optical modulator configured to form the image using light from the light source;
a temperature detector configured to detect an environmental temperature; and
circuitry configured to
control the light source and the optical modulator, and
control the optical modulator to adjust color tone of the image depending on the environmental temperature detected by the temperature detector, wherein the optical modulator changes, based on the environmental temperature, a portion of a green period when green light is to be guided to a projection receiving part, to a black period when the green light is not to be guided to the projection receiving part,
the green period being longer than the black period and being divided into three sub-periods, and
the black period being a middle sub-period of the three sub-periods.

2. The image projection apparatus according to claim 1 , wherein conditions for performing the color tone adjustment of the image, control of electric power supplied to the light source, and control of rotational speed of a cooling fan vary between a case where the environmental temperature is increasing and a case where the environmental temperature is decreasing.

3. The image projection apparatus according to claim 1 , wherein conditions for performing the color tone adjustment of the image, control of electric power supplied to the light source, and control of rotational speed of a cooling fan vary between a case where the image projection apparatus is used in a high-altitude area and a case where the image projection apparatus is used in a low-altitude area.

4. The image projection apparatus according to claim 1 , wherein the circuitry is further configured to perform a sequential projection temperature adjustment, the sequential adjustment including
performing the color tone adjustment of the image,
control of electric power supplied to the light source, and
control of rotational speed of a cooling fan,
wherein a sequence order of the sequential adjustment is based on a first detected temperature threshold, a second detected temperature threshold, and a third detected temperature threshold.

Assignees

• Kado Takahiro
• Ricoh Co Ltd

Inventors

• Kado Takahiro

Classifications

• G03B21/14

  Details · CPC title

• H04N9/3155

  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) · CPC title

• G03B21/16

  Cooling; Preventing overheating · CPC title

• G03B21/206 Primary

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

• H04N9/3194 Primary

  including sensor feedback · CPC title