DISPLAY APPARATUS AND DRIVING METHOD THEREOF

• US 20100007656A1
• Filed: 06/29/2009
• Published: 01/14/2010
• Est. Priority Date: 07/10/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hirai, Tadahiko, Okamoto, Kaoru, Sumioka, Jun
• Granted Patent: US 8,395,613 B2
• Time in Patent Office: Days
• US Class Current: 345/214
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2320/046 Dealing with screen burn-in prevention or compensation of the effects thereof
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

Display image quality degradation caused by a burn-in phenomenon is prevented in a self-emission type display apparatus. A degradation characteristic acquisition circuit acquires degradation characteristics of a pixel region, and a boundary portion detection circuit detects a boundary of the degradation characteristics. A correction amount operation circuit arithmetically operates a correction amount based on the boundary, and a video signal correction circuit corrects a video signal. The correction amount is determined based on the boundary of the degradation characteristics such that emission luminance is gently varies in a periphery of a boundary of a pixel due to the burn-in phenomenon, and whereby the burn-in phenomenon becomes inconspicuous.

Claims

1. A display apparatus which comprises a plurality of pixels disposed in a matrix pattern, each of the pixels emitting light;

an acquisition unit for acquiring degradation characteristics of an emission luminance of the pixel from a video signal or a signal output from the pixel;

a detection unit for detecting a boundary of pixels showing different degradation characteristics of the plurality of pixels based on the degradation characteristics acquired by the acquisition unit;

a calculation unit for calculating a correction amount of the video signal to the pixels in a periphery of the boundary such that the emission luminance is gently varied in the periphery of the boundary when the plurality of pixels in the periphery of the boundary detected by the detection unit are caused to emit light with a same video signal; and

a correction unit for correcting the video signal based on the correction amount calculated by the calculation unit,

wherein a video image is displayed by the plurality of pixels based on the corrected video signal.

2. The display apparatus according to claim 1, wherein the detection unit is a circuit that arithmetically operates, for each of the pixels, a first derivative in the degradation characteristics from an adjacent one of the pixels.

3. The display apparatus according to claim 1, wherein the detection unit is a circuit that arithmetically operates a second derivative of the degradation characteristics between pixels adjacent to each other.

4. The display apparatus according to claim 1, wherein the plurality of pixels include a pixel for emitting red light, a pixel for emitting green light, and a pixel for emitting blue light, and the acquisition unit, the correction unit, the detection unit, and the calculation unit are provided with respect to at least one of the red, green, and blue emission colors.

5. The display apparatus according to claim 1, wherein the acquisition unit, the correction unit, the detection unit, and the calculation unit are provided with respect to a part of a pixel region comprising the plurality of pixels.

6. A display apparatus driving method of driving a display apparatus that comprises a plurality of pixels and displays a video image using the plurality of pixels, each of the plurality of pixels emitting light, the plurality of pixels being disposed in a matrix pattern, the method comprising:

the acquisition step of acquiring degradation characteristics of an emission luminance of the pixel from a video signal or a signal output from the pixel;

the detection step of detecting a boundary of pixels showing different degradation characteristics of the plurality of pixels based on the acquired degradation characteristics;

the calculation step of calculating a correction amount of the video signal to the pixels in a periphery of the boundary such that the emission luminance is gently varied in the periphery of the boundary when the plurality of pixels in the periphery of the detected boundary are caused to emit light with a same video signal;

the correction step of correcting the video signal based on the calculated correction amount; and

the display step of displaying the video image in the plurality of pixels based on the corrected video signal.

7. The display apparatus driving method according to claim 6, wherein some pixels of the plurality of pixels constitute a fixed pattern display region in which a constant image is displayed, and the detection step and the calculation step are performed to the pixels provided in the fixed pattern display region.