US 10,891,890 B1
Asymmetric pixel operation for compensating lens optics limitations
Min Hyuk Choi, San Jose, CA (US); Cheonhong Kim, Mountain View, CA (US); and Wook Jin Han, Singapore (SG)
Assigned to FACEBOOK TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed by FACEBOOK TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed on Aug. 13, 2019, as Appl. No. 16/539,941.
Int. Cl. G09G 3/20 (2006.01)
CPC G09G 3/2003 (2013.01) [G09G 3/2007 (2013.01); G09G 2320/066 (2013.01); G09G 2320/0626 (2013.01); G09G 2320/0673 (2013.01); G09G 2320/0693 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of calibrating display screens of artificial-reality devices, comprising:
at an artificial-reality device with a display comprising a plurality of pixels:
determining gray-level values for the plurality of pixels using a uniform test image, wherein each pixel has an initial luminance level proportional to its gray-level value;
grouping the plurality of pixels into a plurality of distinct non-overlapping segments according to the initial luminance levels of each of the plurality of pixels and an initial gamma band;
for each segment of the plurality of segments:
computing an overall luminance level and a luminance target for the segment according to the determined gray-level values for the pixels in the segment;
in accordance with a determination that the overall luminance level is below the luminance target for the segment, calculating calibration data for the segment to adjust the overall luminance level of the segment by: (i) increasing the gray-level of each pixel in the segment by a first predefined amount or (ii) selecting an alternative gamma band for the segment corresponding to a difference between the luminance target and the overall luminance level; and
storing the calibration data for the segment on the artificial-reality device; and
configuring the artificial-reality device to use the stored calibration data for the segments in subsequent display of images on the display, wherein a first pixel of the plurality of pixels has an adjusted luminance level that is either greater than its initial luminance level or less than its initial luminance level.