Aging compensation for virtual reality headset display device

1. A display system comprising:

an electronic display;

a processor; and

a non-transitory computer readable storage medium having instructions encoded thereon that, when executed by the processor, cause the processor to:

determine an aging factor corresponding to initial display data used to drive a display portion of the electronic display during one or more monitored frames, the aging factor indicative of an amount of aging of pixels in the display portion of the electronic display during the one or more monitored frames due to being driven by the initial display data;

increase an aging counter for the display portion based on the determined aging factor, the aging counter indicating a cumulative aging of pixels in the display portion of the electronic display based upon the aging factor determinations;

determine a compensation value for the display portion based on the aging counter for the display portion;

modify input display data for the display portion during a subsequent frame according the determined compensation value; and

drive the display portion with the modified input display data during the subsequent frame.

2. The display system of claim 1 , wherein determining the aging factor comprises determining an average digital level used to drive one or more contiguous pixels in the display portion during the one or more monitored frames.

3. The display system of claim 1 , wherein determining the aging factor comprises determining an average driving voltage supplied to one or more contiguous pixels in the display portion during the one or more monitored frames.

4. The display system of claim 1 , wherein the one or more monitored frames include a plurality of monitored frames, and wherein determining the aging factor comprises determining an average duty cycle of one or more contiguous pixels in the display portion during the plurality of monitored frames.

5. The display system of claim 1 , wherein the display portion comprises one or more subpixels for a single color channel, the one or more subpixels included in one or more contiguous pixels of the electronic display.

6. The display system of claim 1 , wherein determining the aging factor comprises selecting the one or more monitored frames by periodically sampling a superset of frames including the one or more monitored frames.

7. The display system of claim 1 , wherein increasing the aging counter for the display portion comprises:

comparing the aging factor to a plurality of thresholds defining a plurality of non-overlapping intervals over a range of the aging factor;

determining that the aging factor is included in one of the intervals in response to the aging factor being greater than a lower threshold of said one of the intervals and less than an upper threshold of said one of the intervals;

in response to determining that the aging factor data is included in said one of the intervals, obtaining a count increase value corresponding to the interval; and

increasing the aging counter for the display portion by the count increase value.

8. The display system of claim 7 , wherein obtaining the count increase value comprises:

obtaining a plurality of aging parameters corresponding to said one of the intervals;

determining a difference between the aging factor and one of the lower threshold of said one of the intervals and the upper threshold of the said one of the intervals; and

determining the count increase value by combining the determined difference with the aging parameters corresponding to said one of the intervals.

9. The display system of claim 1 , wherein determining the compensation value comprises obtaining the compensation value from a lookup table based on the aging counter and the input display data.

10. The display system of claim 1 , wherein determining the compensation value comprises:

accessing a first aging counter for first subpixels corresponding to a first color channel;

accessing a second aging counter for second subpixels corresponding to a second color channel;

accessing a third aging counter for third subpixels corresponding to a third color channel;

determining the compensation value for the first subpixels based on the first aging counter, the second aging counter, and the third aging counter in order to maintain color balance between the first color channel, the second color channel, and the third color channel.

11. The display system of claim 1 ,

wherein determining the compensation value comprises determining the compensation value according to the input display data at a processing bit depth greater than a display bit depth used to drive the electronic display, and

wherein modifying the input display data during the subsequent frame comprises: determining the modified input display data at the higher bit depth; and converting the modified input display data to the display bit depth.

12. The display system of claim 1 ,

wherein the electronic display is driven by display data with digital levels less than a panel threshold,

wherein the input display data has digital levels less than an input threshold that is less than the panel threshold, and

wherein modifying the input display data during the subsequent frame comprises increasing a digital level of the input display data according to the determined compensation value such that the modified input display data includes a digital level greater than the input threshold and less than the panel threshold.

13. A method comprising:

determining an aging factor corresponding to initial display data used to drive a display portion of an electronic display during one or more monitored frames, the aging factor indicative of an amount of aging of pixels in the display portion of the electronic display during the one or more monitored frames due to being driven by the initial display data;

increasing an aging counter for the display portion based on the determined aging factor, the aging counter indicating a cumulative aging of pixels in the display portion of the electronic display based upon the aging factor determinations;

determining a compensation value for the display portion based on the aging counter for the display portion;

modifying input display data for the display portion during a subsequent frame according the determined compensation value; and

sending the modified input display data to the electronic display for driving the display portion during the subsequent frame.

14. The method of claim 13 , wherein determining the aging factor comprises determining an average digital level used to drive one or more contiguous pixels in the display portion during the one or more monitored frames.

15. The method of claim 13 , wherein determining the aging factor comprises selecting the one or more monitored frames by periodically sampling a superset of frames including the one or more monitored frames.

16. The method of claim 13 , wherein increasing the aging counter for the display portion comprises:

comparing the aging factor to a plurality of thresholds defining a plurality of non-overlapping intervals over a range of the aging factor;

determining that the aging factor is included in one of the intervals in response to the aging factor being greater than a lower threshold of said one of the intervals and less than an upper threshold of said one of the intervals;

in response to determining that the aging factor data is included in said one of the intervals, obtaining a count increase value corresponding to the interval; and

increasing the aging counter for the display portion by the count increase value.

17. The method of claim 13 , wherein determining the compensation value comprises obtaining the compensation value from a lookup table based on the aging counter and the input display data.

18. The method of claim 13 , wherein determining the compensation value comprises:

accessing a first aging counter for first subpixels corresponding to a first color channel;

accessing a second aging counter for second subpixels corresponding to a second color channel; and

determining the compensation value for the first subpixels based on the first aging counter and the second aging counter in order to maintain color balance between the first color channel and the second color channel.

19. The method of claim 13 ,

wherein the electronic display is driven by display data with digital levels less than a panel threshold,

wherein the input display data has digital levels less than an input threshold that is less than the panel threshold, and

wherein modifying the input display data during the subsequent frame comprises increasing a digital level of the input display data according to the determined compensation value such that the modified input display data includes a digital level greater than the input threshold and less than the panel threshold.

20. A non-transitory computer readable storage medium having instructions encoded thereon that, when executed by a processor, cause the processor to:

determine an aging factor corresponding to initial display data used to drive a display portion of the electronic display during one or more monitored frames, the aging factor indicative of an amount of aging of pixels in the display portion of the electronic display during the one or more monitored frames due to being driven by the initial display data;

increase an aging counter for the display portion based on the determined aging factor, the aging counter indicating a cumulative aging of pixels in the display portion of the electronic display based upon the aging factor determinations;

determine a compensation value for the display portion based on the aging counter for the display portion;

modify input display data for the display portion during a subsequent frame according the determined compensation value; and

send the modified input display data to the electronic display for driving the display portion during the subsequent frame.