Illuminator, projection display device and method for driving the same

• US 20050017990A1
• Filed: 05/24/2004
• Published: 01/27/2005
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yoshida, Shohei
• Granted Patent: US 7,683,857 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: 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

Abstract

The invention provides a projection display device capable of appropriate light control depending on the kind of the image, the ambient brightness and so on, a method for driving the same, and an illuminator used in the same. The light flux of illumination can be adjusted on the basis of image information. The allowable light control range (dimming control) can be optimally set depending on the information (usage information) on the kind of viewed content, the brightness of viewing environment, the gain of a screen and the like.

Claims

1. An illuminator used to illuminate a light modulation device of a projection display device, comprising:

a light source; and

a light control device that adjusts a light flux of the light source on the basis of image information and usage information.

2. The illuminator according to claim 1, the light control device including a light flux setting device that sets the light flux of the light source on the basis of image information and a dimming-range setting device that sets a dimming range in which dimming is allowed on the basis of the usage information,

the light control device adjusting the light flux of the light source on the basis of the set light flux and inhibits dimming exceeding the dimming range.

3. The illuminator according to claim 2, when the amount of dimming of the set light flux exceeds the dimming range, the light flux of the light source is adjusted depending on a dimming amount within the dimming range.

4. The illuminator according to claim 1, the usage information being manually set.

5. The illuminator according to claim 2, further comprising a brightness measuring device that measures a brightness of a usage environment;

the dimming-range setting device setting the dimming range on the basis of the brightness of the usage environment.

6. The illuminator according to claim 2, further comprising a gain measuring device that measures a gain of a screen, the dimming-range setting device setting the dimming range on the basis of the gain.

7. A projection display device, comprising:

the illuminator according to claim 1;

a light modulation device that modulates light emitted from the illuminator to form an image; and

a projection device that projects the image.

8. A projection display device according to claim 7, further comprising an image-signal expanding device that expands an image signal on the basis of a dimming amount of the light source.

9. The projection display device according to claim 8, when the dimming amount in the light flux set by a light flux setting device is within the dimming range, the image-signal expanding device expands the image signal by an expansion coefficient that is a reciprocal of the light flux, whereas when the dimming amount in the set light flux is out of the dimming range, the image-signal expanding device expands the image signal by an expansion amount larger than the reciprocal.

10. A method for driving the projection display device according to claim 9, comprising:

setting the dimming range in which dimming is allowed on the basis of the usage information;

adjusting the light flux of the light source within the range on the basis of image signals in unit time (during a period); and

expanding the image signals on the basis of the dimming amount of the light source and transmitting the expanded image signals to the light modulation device to form an image.