Display device, brightness adjustment device, backlight device, and method of adjusting brightness to prevent a flash from occuring

• US 8,836,635 B2
• Filed: 12/09/2009
• Issued: 09/16/2014
• Est. Priority Date: 12/11/2008
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Mori, Hideto, Inoue, Yasuo
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): SCHNIREL, ANDREW B
• Application Number:
  US13/127,748
• Publication Number:
  US 20110205442A1
• Time in Patent Office: 1,742 Days
• Field of Search: 345/77, 345/102
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• 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 2360/145 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 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

A display device is provided, including circuitry configured to calculate a table representing a relationship between an average brightness and a gain of a video signal; revise the table in order to reduce a change amount of a gain of each frame in the table; calculate an average brightness of a video signal input for each frame; calculate a gain of a video signal from the table based on the calculated average brightness; adjust a video signal using the calculated gain; and a display panel that includes a plurality of pixels that emit light in response to a video signal and displays a video based on the adjusted video signal. A brightness adjustment device, a backlight device, and a method of adjusting brightness, each including the circuitry, are also provided.

Claims

1. A brightness adjustment device, comprising:

circuitry configured to;

calculate a table representing a relationship between an average brightness and a gain of an input video signal, where the gain changes as a function of the average brightness;

calculate a slope of the function and compare the slope to a predetermined value;

revise the table, when the slope is greater than the predetermined value, in order to reduce a change amount of a gain of each frame in the table, such that the reduced change amount of the gain with respect to the change amount of the average brightness is equal to or less than the predetermined value;

calculate an average brightness of each frame of the input video signal;

calculate a gain of a video signal from the revised table based on the calculated average brightness; and

adjust the video signal using the calculated gain.

2. The brightness adjustment device according to claim 1, wherein the circuitry is further configured to individually control a peak brightness and power consumption by:

controlling the peak brightness while the power consumption is kept constant, and

controlling the power consumption while the peak brightness is kept constant.

3. The brightness adjustment device according to claim 1, wherein the circuitry is further configured to rewrite the table representing the relationship on a case-by-case basis.

4. The brightness adjustment device according to claim 1, wherein the circuitry is further configured to calculate the relationship based on one or more coefficients including external light, temperature, chromaticity, genre, and user.

5. A backlight device, comprising:

circuitry configured to;

calculate a table representing a relationship between an average brightness and a gain of a video signal input to a surface light source, where the gain changes as a function of the average brightness;

calculate a slope of the function and compare the slope to a predetermined value;

revise the table, when the slope is greater than the predetermined value, in order to reduce a change amount of a gain of each frame in the table, such that the reduced change amount of the gain with respect to the change amount of the average brightness is equal to or less than the predetermined value;

calculate an average brightness of each frame of the input video signal;

calculate a gain of a video signal from the revised table based on the calculated average brightness; and

adjust the video signal using the calculated gain.

6. The backlight device according to claim 5, wherein the circuitry is further configured to individually control a peak brightness and power consumption by:

controlling the peak brightness while the power consumption is kept constant, and

controlling the power consumption while the peak brightness is kept constant.

7. The backlight device according to claim 5, wherein the circuitry is further configured to rewrite the table representing the relationship on a case-by-case basis.

8. The backlight device according to claim 5, wherein the circuitry is further configured to calculate the relationship based on one or more coefficients including external light, temperature, chromaticity, genre, and user.

9. A method of adjusting a brightness, comprising:

calculating, using circuitry, a table representing a relationship between an average brightness and a gain of an input video signal, where the gain changes as a function of the average brightness;

calculating, using the circuitry, a slope of the function;

comparing, using the circuitry, the slope to a predetermined value;

revising the table, using the circuitry, when the slope is greater than the predetermined value, in order to reduce a change amount of a gain of each frame in the table, such that the reduced change amount of the gain with respect to the change amount of the average brightness is equal to or less than the predetermined value;

calculating, using the circuitry, an average brightness of each frame of the input video signal;

calculating, using the circuitry, a gain of a video signal from the revised table based on the calculated average brightness; and

adjusting, using the circuitry, the video signal using the calculated gain.

10. The method according to claim 9, further comprising individually controlling a peak brightness and power consumption by:

controlling the peak brightness while the power consumption is kept constant, and

controlling the power consumption while the peak brightness is kept constant.

11. The method according to claim 9, further comprising rewriting, using the circuitry, the table representing the relationship on a case-by-case basis.

12. The method according to claim 9, further comprising calculating the relationship based on one or more coefficients including external light, temperature, chromaticity, genre, and user.