METHODS AND APPARATUS TO MANAGE DISPLAY LUMINANCE

• US 20200135074A1
• Filed: 12/27/2019
• Published: 04/30/2020
• Est. Priority Date: 12/27/2019
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wooster, Roland, Sameer Kalathil, Perazhi
• Granted Patent: US 11,217,132 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0613 The adjustment depending on the type of the information to be displayed
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/141 the light conveying information used for selecting or modulating the light emitting or modulating element
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

Methods, apparatus, systems and articles of manufacture are disclosed to manage display luminance, for the purpose of power efficiency, halo reduction, and flicker prevention. An example apparatus includes a backlight analyzer to determine a first baseline luminance level associated with a first segment of a backlight of a screen of a display device based on pixel data defining a frame of content to be displayed via the screen and to determine a second baseline luminance level associated with a second segment of the backlight different than the first segment based on the pixel data, a segment-pair ratio analyzer to determine a segment-pair luminance ratio between the first and second segments based on the first and second baseline luminance levels, and a luminance controller to adjust an amount of power provided to at least one of the first segment of the backlight or the second segment of the backlight when the segment-pair luminance ratio satisfies a threshold.

Claims

1. An apparatus comprising:

a backlight analyzer to;

determine a first baseline luminance level associated with a first segment of a backlight of a screen of a display device based on pixel data defining a frame of content to be displayed via the screen; and

determine a second baseline luminance level associated with a second segment of the backlight different than the first segment based on the pixel data; and

a segment-pair ratio analyzer to determine a segment-pair luminance ratio between the first and second segments based on the first and second baseline luminance levels; and

a luminance controller to adjust an amount of power provided to at least one of the first segment of the backlight or the second segment of the backlight when the segment-pair luminance ratio satisfies a threshold.

2. The apparatus of claim 1, wherein the first and second segments are adjacent to one another.

3. The apparatus of claim 1, wherein the backlight analyzer is to:

determine the first baseline luminance level based on a brightest pixel value in the pixel data corresponding to a first region of the frame associated with the first segment; and

determine the second baseline luminance level based on a brightest pixel value in the pixel data corresponding to a second region of the frame associated with the second segment.

4. The apparatus of claim 1, further including a backlight ratio analyzer to determine a value for a local dimming factor, the threshold defined based on the local dimming factor.

5. The apparatus of claim 4, wherein the value is within a range of potential local dimming factor values, different ones of the potential local dimming factor values to indicate respective ones of different limits on the segment-pair luminance ratio between the first and second segments.

6. The apparatus of claim 5, wherein the different limits include a range of percentage differentials ranging from a 0 percent difference to a 100 percent difference.

7. The apparatus of claim 5, wherein the different limits include a range of multiplier differentials ranging from no difference to differing by a factor of 100.

8. The apparatus of claim 5, wherein the different limits include an unrestricted differential, the unrestricted differential corresponding to no limit on the segment-pair luminance ratio between the first and second segments.

9. The apparatus of claim 5, wherein the local dimming factor is to be represented by a single byte of data, different ones of the potential local dimming factor values corresponding to different values assigned to the single byte of data.

10. The apparatus of claim 9, wherein the different values for the single byte of data include a first range of values corresponding to a percentage differential range, a second range of values corresponding to a multiplier differential range, and a separate value corresponding to an unrestricted differential.

11. The apparatus of claim 5, wherein the backlight ratio analyzer is to determine the local dimming factor based on at least one of a type of usage of the display device, an ambient lighting condition, or user input.

12. The apparatus of claim 1, wherein the backlight analyzer is to determine a global luminance ratio between a third baseline luminance level and a full power luminance level of the backlight, the third baseline luminance level corresponding to a brightest pixel value in the pixel data corresponding to an entirety of the frame, the luminance controller to adjust the power provided to both the first segment of the backlight and the second segment of the backlight based on the global luminance ratio.

13. The apparatus of claim 1, further including a power saving analyzer to determine a value for a global dimming factor, the luminance controller to adjust the power provided to both the first segment of the backlight and the second segment of the backlight based on the global dimming factor.

14. The apparatus of claim 13, wherein the value corresponds to one of a range of possible values for the global dimming factor, different ones of the possible values to indicate respective ones of different percentages of a power saving opportunity, the power saving opportunity corresponding to a global luminance ratio between a third baseline luminance level and a full power luminance level for the backlight, the third baseline luminance level corresponding to a brightest pixel value in the pixel data corresponding to an entirety of the frame.

15. The apparatus of claim 14, wherein the different percentages of the power saving opportunity range from a 0 percent power saving to a 100 percent power saving, the luminance controller to:

reduce the power provided to the first and second segments of the backlight so that an operating luminance level of the first and second segments corresponds to the third baseline luminance level when the value for the global dimming factor corresponds to the 100 percent power saving; and

provide full power to the first and second segments when the value for the global dimming factor corresponds to the 0 percent power saving.

16. The apparatus of claim 14, wherein the global dimming factor is to be represented by a single byte of data, different ones of the possible values corresponding to different values assigned to the single byte of data.

17. The apparatus of claim 13, wherein the power saving analyzer is to determine the value for the global dimming factor based on a type of usage of the apparatus.

18. The apparatus of claim 13, wherein the power saving analyzer is to determine the value for the global dimming factor based on an ambient lighting condition of an environment surrounding the apparatus.

19. The apparatus of claim 13, wherein the power saving analyzer is to determine the value for the global dimming factor based on a user input.

20. A method comprising:

determining, by executing an instruction with at least one processor, a first baseline luminance level associated with a first segment of a backlight of a screen of a display device based on pixel data of a frame of content to be displayed via the screen; and

determining, by executing an instruction with the at least one processor, a second baseline luminance level associated with a second segment of the backlight different than the first segment based on the pixel data; and

determining, by executing an instruction with the at least one processor, a segment-pair luminance ratio between the first and second segments based on the first and second luminance levels; and

adjusting an amount of power provided to at least one of the first segment of the backlight or the second segment of the backlight when the segment-pair luminance ratio satisfies a threshold.

31. The method of claim 20, further including:

determining a value for a global dimming factor; and

adjusting the power provided to both the first segment of the backlight and the second segment of the backlight based on the global dimming factor.

21-30. -30. (canceled)

32-37. -37. (canceled)

38. At least one non-transitory computer readable medium comprising instructions that, when executed, cause at least one processor to at least:

determine a first baseline luminance level associated with a first segment of a backlight of a screen of a display device based on pixel data of a frame of content to be displayed via the screen;

determine a second baseline luminance level associated with a second segment of the backlight different than the first segment based on the pixel data;

determine a segment-pair luminance ratio between the first and second baseline luminance levels; and

adjust an amount of power provided to at least one of the first segment of the backlight or the second segment of the backlight when the segment-pair luminance ratio satisfies a threshold.

49. The at least one non-transitory computer readable medium of claim 38, wherein the instructions, when executed, cause the at least one processor to determine a value for a global dimming factor, to adjust the power provided to both the first segment of the backlight and the second segment of the backlight based on the global dimming factor.

39-48. -48. (canceled)

50-55. -55. (canceled)