Display brightness adjustment

• US 9,412,296 B2
• Filed: 05/30/2013
• Issued: 08/09/2016
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mirski-Fitton, Alexander D. S., Moffatt, Edwin P. J., Pilot, Richard W.
• Primary Examiner(s): Awad, Amr
• Assistant Examiner(s): CHOW, WING H
• Application Number:
  US13/905,765
• Publication Number:
  US 20130321369A1
• Time in Patent Office: 1,167 Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3225 using an active matrix

Abstract

A display comprising an array of pixels having individually adjustable brightness levels; an array of light sensors fixed relative to the pixel array; and a brightness controller for estimating a glare footprint on the pixel array from light level data provided by the sensor array and for adjusting the relative brightness levels of pixels that fall in the estimated glare footprint.

Claims

1. A display comprising:

an array of pixels having individually adjustable brightness levels;

an array of light sensors fixed relative to the pixel array, wherein the array of light sensors extends around the display; and

a brightness controller configured to estimate a glare footprint on the pixel array from light level data provided by the sensor array by connecting a light-to-dark change point for one of the array of light sensors located at one side of the display with a complementary dark-to-light change point for another of the array of light sensors located at another side of the display and to adjust the relative brightness levels of pixels that fall in the estimated glare footprint, wherein the array of light sensors in its entirety extends around the display in its entirety.

2. The display according to claim 1 wherein the array of light sensors extends around the display in at least two circuit sensor arrays, where a second circuit sensor array of the at least two circuit sensor arrays is concentric and staggered with respect to a first circuit sensor array of the at least two circuit sensor arrays, and wherein the light-to-dark change point is part of the first circuit sensor array and the brightness controller is configured to determine which direction the glare footprint is crossing the at least two circuit sensor arrays using the second circuit sensor array.

3. The display according to claim 1 wherein the array of light sensors is at least one of:

a single circuit of light sensors one sensor thick;

two circuits of light sensors two sensors thick;

three circuits of light sensors three sensors thick; and

more than three circuits of light sensors.

4. The display according to claim 1 wherein the brightness controller is configured to linearly traverse the array of light sensors to identify locations where light level changes by a threshold amount and fits a footprint shape with three or more edges bounded by edges of the pixel array and at least one line connecting the light-to-dark change point and the complementary dark-to-light change point, wherein the threshold of light level change depends on a difference between maximum and minimum light levels detected by the sensors and is user configurable.

5. The display according to claim 1 wherein the increase in brightness level of a pixel is based on an estimated amount of light falling at the pixel location.

6. The display according to claim 1 wherein the increase in brightness levels of a pixel is user adjustable.

7. The display according to claim 1 wherein the amount of light falling is estimated as uniform over a single footprint and is different for two or more footprints over the array and is higher for overlapping footprint areas.

8. The display according to claim 1, wherein the glare footprint comprises a plurality of distinct estimated glare footprints, where a given one of the plurality of distinct estimated glare footprints is presented on the display and is user selectable using the display.

9. A display comprising:

an array of pixels having individually adjustable brightness levels;

an array of light sensors fixed relative to the pixel array; and

a display controller comprising a processing unit, a memory, an input/output (I/O) interface configured to communicate with an external device that enables a user to interact with the display controller, and a brightness controller configured to estimate a glare footprint on the pixel array from light level data provided by the sensor array by connecting a light-to-dark change point for one of the array of light sensors located at one side of the display with a complementary dark-to-light change point for another of the array of light sensors located at another side of the display and to adjust the relative brightness levels of pixels that fall in the estimated glare footprint, wherein the display having pixels with individually adjustable brightness levels is an active matrix organic light emitting diode (AMOLED) display whereby pixels in the “

light”

areas are configured to have their brightness and contrast raised and pixels in the “

dark”

areas are configured to have their brightness lowered, wherein the array of light sensors in its entirety extends around the display in its entirety.

10. The display according to claim 9, wherein the brightness controller comprises sensor limit registers that are configured to record maximum and minimum sensor values for each sensor of the array of light sensors and used to determine when a sensor value change indicates a glare adjustment is needed for a given pixel of the array of pixels.

11. The method according to claim 9, further comprising:

calculating a threshold change based on a difference between maximum and minimum light levels detected by the array of sensors and a user adjustable threshold value.

12. A method for controlling brightness of a display, said display comprising an array of pixels having individually adjustable brightness levels and an array of light sensors fixed relative to the pixel array and extending around the display in its entirety, said method comprising:

estimating a glare footprint on the pixel array from light level data provided by the sensor array by connecting a light-to-dark change point for one of the array of light sensors located at one side of the display with a complementary dark-to-light change point for another of the array of light sensors located at another side of the display; and

adjusting the relative brightness levels of pixels that fall in the estimated glare footprint.

13. The method according to claim 12 wherein the array of light sensors extends around the display in at least two circuit sensor arrays, where a second circuit sensor array of the at least two circuit sensor arrays is concentric and staggered with respect to a first circuit sensor array of the at least two circuit sensor arrays, and wherein the light-to-dark change point is part of the first circuit sensor array and the brightness controller is configured to determine which direction the glare footprint is crossing the at least two circuit sensor arrays using the second circuit sensor array.

14. The method according to claim 12 wherein the array of light sensors is at least one of:

a single circuit of light sensors one sensor thick;

two circuits of light sensors two sensors thick;

three circuits of light sensors three sensors thick; and

more than three circuits of light sensors.

15. The method according to claim 12 further comprising linearly traversing the array of light sensors to identify locations where light level changes by a threshold amount and fits a footprint shape with three or more edges bounded by edges of the pixel array and at least one line connecting the light-to-dark change point and the complementary dark-to light change point, wherein the threshold of light level change depends on a difference between maximum and minimum light levels detected by the sensors and is user configurable.

16. The method according to claim 12 wherein the increase in brightness level of a pixel is based on an estimated amount of light falling at the pixel location.

17. The method according to claim 12 wherein the increase in brightness levels of a pixel is user adjustable.

18. An article of manufacture comprising a computer program stored on a non-transitory computer readable medium and loadable into the internal memory of a data processing system, comprising software code portions, when said computer program is run on the data processing system, for performing the method of claim 12.

19. The method according to claim 12, wherein the glare footprint comprises a plurality of distinct estimated glare footprints, where a given one of the plurality of distinct estimated glare footprints is presented on the display and is user selectable using the display.

20. The method according to claim 12, further comprising:

recording maximum and minimum sensor values for each sensor of the array of light sensors; and

using the recorded maximum and minimum sensor values to determine when a sensor value change indicates a glare adjustment is needed for a given pixel of the array of pixels.

21. A computer program product for controlling brightness of a display, said computer program product comprising a non-transitory computer readable recording medium having computer readable code stored thereon for performing the method of claim 12.