Projection video display apparatus and brightness adjustment method therefor

• US 20060139245A1
• Filed: 12/22/2005
• Published: 06/29/2006
• Est. Priority Date: 12/27/2004
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sugiyama, Tooru
• Application Number:
  US11/316,464
• Publication Number:
  US 20060139245A1
• Time in Patent Office: Days
• US Class Current: 345/60
• CPC Class Codes: G03B 21/008 using micromirror devices
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• 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

This invention is applied to a projection video display apparatus which causes a DMA to modulate light from a light source having a plurality of two-dimensionally arrayed LEDs in accordance with a video signal and projects the modulated video light onto a screen via a projection optical lens. The two-dimensionally arrayed LEDs are sequentially turned off from outside to inside when a drive device for ON/OFF-driving the LEDs of the light source is designated to darken the light source. Alternatively, the two-dimensionally arrayed light-emitting elements are sequentially turned on from inside to outside when the drive device is designated to brighten the light source.

Claims

1. A projection video display apparatus comprising:

a light source device which has two-dimensionally arrayed light-emitting elements;

an optical space modulation element which receives light generated by the light source device, executes optical space modulation in accordance with a video signal, and outputs video light obtained by the optical space modulation;

a projection device which projects the video light from the optical space modulation element to a screen via a projection optical lens;

a light-emitting element driving device which ON/OFF-drives each of the light-emitting elements in the light source device;

a designation device which designates a brightness level of the light source device; and

an adjustment device which adjusts brightness of the light source device by controlling the ON/OFF driving operation of the light-emitting element driving device in accordance with the brightness level designated by the designation device,

wherein the adjustment device compares the brightness level designated by the designation device with a current brightness level, controls the light-emitting element driving device to sequentially turn off the two-dimensionally arrayed light-emitting elements from outside to inside when the screen is designated to be darkened, and controls the light-emitting element driving device to sequentially turn on the two-dimensionally arrayed light-emitting elements from inside to outside when the screen is designated to be brightened.

2. An apparatus according to claim 1, wherein the designation device designates the brightness level in accordance with a user'"'"'s operation input.

3. An apparatus according to claim 1, wherein the designation device includes an optical sensor which measures a peripheral illuminance on the screen, and designates the brightness level on the basis of a peripheral temperature obtained by the optical sensor.

4. A projection video display apparatus comprising:

a plurality of light source devices each of which has two-dimensionally arrayed light-emitting elements, and emits one of three primary colors of R, G, and B;

an optical space modulation element which sequentially receives light beams time-divisionally generated by said plurality of light source devices, executes optical space modulation in accordance with a video signal, and outputs video light obtained by the optical space modulation;

a projection device which projects the video light from the optical space modulation element to a screen via a projection optical lens;

a light-emitting element driving device which ON/OFF-drives the light-emitting elements in said plurality of light source devices;

a designation device which designates a brightness level of the light source device; and

an adjustment device which adjusts brightness of the light source device by controlling the ON/OFF driving operation of the light-emitting element driving device in accordance with the brightness level designated by the designation device,

wherein the adjustment device compares the brightness level designated by the designation device with a current brightness level, controls the light-emitting element driving device to sequentially turn off the two-dimensionally arrayed light-emitting elements from outside to inside when the screen is designated to be darkened, and controls the light-emitting element driving device to sequentially turn on the two-dimensionally arrayed light-emitting elements from inside to outside when the screen is designated to be brightened.

5. An apparatus according to claim 4, wherein the adjustment device synchronously adjusts the brightness levels of the light sources of R, G, and B on the basis of the designated color temperature.

6. A brightness adjustment method applied to a projection video display apparatus which modulates light generated by a light source which has two-dimensionally arrayed light-emitting elements by an optical space modulation element in accordance with a video signal, and projects video light obtained by the modulation onto a screen via a projection optical lens, comprising:

designating a brightness level of the light source; and

adjusting brightness of the light source by controlling the ON/OFF driving operation of the light-emitting element of the light source in accordance with the brightness level designated in the designating,

wherein in the adjusting, the brightness level designated in the designating is compared with a current brightness level, the light-emitting element driving device is controlled to sequentially turn off the two-dimensionally arrayed light-emitting elements from outside to inside when the screen is designated to be darkened, and the light-emitting element driving device is controlled to sequentially turn on the two-dimensionally arrayed light-emitting elements from inside to outside when the screen is designated to be brightened.

7. A method according to claim 6, wherein in the designating, the brightness level is designated in accordance with a user'"'"'s operation input.

8. A method according to claim 6, wherein in the designating, the brightness level is designated on the basis of a peripheral illuminance measurement result on the screen.

9. A brightness adjustment method applied to a projection video display apparatus which has two-dimensionally arrayed light-emitting elements, and modulates light beams time-divisionally generated by said plurality of light source devices emitting three primary colors of R, G, and B, and projects the video light to a screen via a projection optical lens, comprising:

designating a brightness level of the light source device; and

adjusting brightness of the light source device by controlling the ON/OFF driving operation of the light-emitting elements of said plurality of the light source devices in accordance with the brightness level designated in the designating,

wherein in the adjusting, the brightness level designated in the designating is compared with a current brightness level, the light-emitting element driving device is controlled to sequentially turn off the two-dimensionally arrayed light-emitting elements from outside to inside when the screen is designated to be darkened, and the light-emitting element driving device is controlled to sequentially turn on the two-dimensionally arrayed light-emitting elements from inside to outside when the screen is designated to be brightened.

10. A method according to claim 9, wherein in the adjusting, the brightness levels of the light sources of R, G, and B are synchronously adjusted on the basis of the designated color temperature.