Projector and exposure adjustment method

• US 20060176377A1
• Filed: 02/02/2006
• Published: 08/10/2006
• Est. Priority Date: 02/04/2005
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Miyasaka, Noriaki
• Granted Patent: US 7,648,246 B2
• Time in Patent Office: Days
• US Class Current: 348/222.100
• CPC Class Codes: H04N 9/3179 Video signal processing therefor
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A projector of the invention includes: an imaging structure that photographs an image projected on a projection object to take a photographed image; an imaging control module that performs exposure adjustment in the imaging structure to attain a preset target exposure; a control module that sets the target exposure in the imaging control module; an angle information acquisition module that obtains angle information representing an inclination of the projector to the projection object; and a storage unit that stores a map representing a variation in target exposure against the angle information. The control module controls the angle information acquisition module to obtain the angle information, refers to the map stored in the storage unit to specify a target exposure corresponding to the obtained angle information, and sets the specified target exposure in the imaging control module. Even in the state of elevation projection, this arrangement of the invention enables distinct identification of a maximum brightness position in the photographed image.

Claims

1. A projector that projects an image on a projection object, the projector comprising:

an imaging structure that photographs the image projected on the projection object to take a photographed image;

an imaging control module that performs exposure adjustment in the imaging structure to attain a preset target exposure;

a control module that sets the target exposure in the imaging control module;

an angle information acquisition module that obtains angle information representing an inclination of the projector to the projection object; and

a storage unit that stores a map representing a variation in target exposure against the angle information,

wherein the control module controls the angle information acquisition module to obtain the angle information, refers to the map stored in the storage unit to specify the target exposure corresponding to the obtained angle information, and sets the specified target exposure in the imaging control module.

2. The projector in accordance with claim 1, wherein the map stored in the storage unit sets a greater target exposure corresponding to a piece of the angle information representing a greater inclination.

3. The projector in accordance with claim 2, the projector further comprising:

an analyzer module that analyzes the photographed image taken by the imaging structure and obtains positional information representing a peak position or a maximum brightness position in the photographed image; and

an image processing module that adjusts the projected image, based on the positional information obtained by the analyzer module.

4. The projector in accordance with claim 3, wherein the image processing module adjusts the projected image to correct a distortion of the projected image caused by the inclination of the projector to the projection object.

5. An exposure adjustment method adopted in a projector, which is equipped with an imaging structure of photographing an image projected on a projection object, to perform exposure adjustment in the imaging structure,

the exposure adjustment method comprising the steps of:

(a) obtaining angle information representing an inclination of the projector to the projection object;

(b) specifying a target exposure corresponding to the obtained angle information based on a map which represents a variation in the target exposure against the angle information; and

(c) performing exposure adjustment in the imaging structure to attain the specified target exposure.