# US 11,910,101 B2 · Optical sensor cancelling image flicker > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,910,101 B2 - Document ID: US11910101B2 - Status: Granted - Kind: B2 - Application number: 18/117,404 - Filed: 2023-03-04 - Published: 2023-06-29 - Granted: 2024-02-20 - Earliest claimed: 2021-09-10 - Applicants: Pixart Imaging Inc. - Inventors: En-Feng Hsu - Web page: https://patentgrep.com/patent/US11910101B2 ## CPC - H04N 23/745: Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination - H04N 23/73: by influencing the exposure time - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract There is provided an optical sensor that acquires a first image frame corresponding to a first flicker period and acquires a second image frame corresponding to a second flicker period. The optical sensor respectively adds pixel data of every two pixels in neighboring rows of the first image frame and the second image frame to generate a low-resolution image frame for the motion detection. ## Claims ### Claim 1 An optical sensor, configured to acquire image frames corresponding to a flicker period of ambient light, the optical sensor comprising: a pixel array, comprising multiple pixel rows configured to acquire pixel data; a readout circuit, configured to respectively read the pixel data of the multiple pixel rows; and a processor, configured to respectively add the pixel data of an N′th pixel row and an N+1′th pixel row among the multiple pixel rows to generate a first output image, wherein N is a positive number from 1, wherein a third exposure start time of a third pixel row of the multiple pixel rows is later than a first exposure start time of a first pixel row of the multiple pixel rows and is prior to a second exposure start time of a second pixel row of the multiple pixel rows. ### Claim 2 (depends on 1) The optical sensor as claimed in claim 1, wherein a longitudinal resolution of the first output image is a half of a number of the multiple pixel rows. ### Claim 3 (depends on 1) The optical sensor as claimed in claim 1, wherein the processor is configured to generate the first output image in a power saving mode, and the processor is further, in a normal mode, configured to sequentially add the pixel data of an M′th pixel row and an M+1′th pixel row among the multiple pixel rows to generate a second output image, wherein M is a positive integer from 1. ### Claim 4 (depends on 3) The optical sensor as claimed in claim 3, wherein a longitudinal resolution of the second output image is smaller than a number of the multiple pixel rows and is larger than a longitudinal resolution of the first output image. ### Claim 5 (depends on 1) The optical sensor as claimed in claim 1, wherein an exposure interval of the multiple pixel rows is ½ or ¼ of the flicker period. ### Claim 6 (depends on 1) The optical sensor as claimed in claim 1, wherein a time difference between exposure start times of the N+1′th pixel row and the N′th pixel row among the multiple pixel rows is between ½ to ¾ of the flicker period. ### Claim 7 (depends on 1) The optical sensor as claimed in claim 1, wherein an exposure interval of the multiple pixel rows is smaller than or equal to a half of the flicker period. ### Claim 8 (depends on 1) The optical sensor as claimed in claim 1, wherein the pixel array is configured to acquire the pixel data using a rolling shutter. ### Claim 9 (depends on 1) The optical sensor as claimed in claim 1, wherein a time difference between exposure start times of the pixel rows among the multiple pixel rows is separated by one readout interval. ### Claim 10 An optical sensor, configured to acquire image frames corresponding to a flicker period of ambient light, the optical sensor comprising: a pixel array, comprising multiple pixel rows configured to acquire pixel data; a readout circuit, configured to respectively read the pixel data of the multiple pixel rows; and a processor, configured to respectively add the pixel data of an N′th pixel row and an N+1′th pixel row among the multiple pixel rows to generate a first output image, wherein N is a positive number from 1, wherein a time difference between exposure start times of the N+1′th pixel row and the N′th pixel row among the multiple pixel rows is between ½ to ¾ of the flicker period. ### Claim 11 (depends on 10) The optical sensor as claimed in claim 10, wherein the processor is configured to generate the first output image in a power saving mode, and the processor is further, in a normal mode, configured to sequentially add the pixel data of an M′th pixel row and an M+1′th pixel row among the multiple pixel rows to generate a second output image, wherein M is a positive integer from 1. ### Claim 12 (depends on 11) The optical sensor as claimed in claim 11, wherein a longitudinal resolution of the second output image is smaller than a number of the multiple pixel rows and is larger than a longitudinal resolution of the first output image. ### Claim 13 (depends on 10) The optical sensor as claimed in claim 10, wherein an exposure interval of the multiple pixel rows is ½ or ¼ of the flicker period. ### Claim 14 (depends on 10) The optical sensor as claimed in claim 10, wherein an exposure interval of the multiple pixel rows is smaller than or equal to a half of the flicker period. ### Claim 15 An optical sensor, configured to acquire image frames corresponding to a flicker period of ambient light, the optical sensor comprising: a pixel array, comprising multiple pixel rows configured to acquire pixel data; a readout circuit, configured to respectively read the pixel data of the multiple pixel rows; and a processor, configured to respectively add the pixel data of an N′th pixel row and an N+1′th pixel row among the multiple pixel rows to generate a first output image, wherein N is a positive number from 1, wherein a time difference between exposure start times of the pixel rows among the multiple pixel rows is separated by one readout interval. ### Claim 16 (depends on 15) The optical sensor as claimed in claim 15, wherein the processor is configured to generate the first output image in a power saving mode, and the processor is further, in a normal mode, configured to sequentially add the pixel data of an M′th pixel row and an M+1′th pixel row among the multiple pixel rows to generate a second output image, wherein M is a positive integer from 1. ### Claim 17 (depends on 16) The optical sensor as claimed in claim 16, wherein a longitudinal resolution of the second output image is smaller than a number of the multiple pixel rows and is larger than a longitudinal resolution of the first output image. ### Claim 18 (depends on 15) The optical sensor as claimed in claim 15, wherein an exposure interval of the multiple pixel rows is ½ or ¼ of the flicker period. ### Claim 19 (depends on 15) The optical sensor as claimed in claim 15, wherein an exposure interval of the multiple pixel rows is smaller than or equal to a half of the flicker period. ### Claim 20 (depends on 15) The optical sensor as claimed in claim 15, wherein a time difference between exposure start times of the N+1′th pixel row and the N′th pixel row among the multiple pixel rows is between ½ to ¾ of the flicker period.