Optical sensor synchronizing to ambient light flicker and operating method thereof
AssigneePixart Imaging Inc.
InventorsZi-Hao Tan, Joon-Chok Lee
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Abstract
There is provided an optical sensor including a photodiode, a wave converter, a pixel array and a processor. The photodiode detects ambient light flicker to generate sine waves. The wave converter converts the sine waves to square waves. The processor uses a sampling frequency to count the square waves, and identifies whether the ambient light flicker is well detected according to a counting value of each square wave and a counting value variation of multiple square waves within a count period to accordingly determine whether to adjust an acquiring phase of the image frame.
Claims20
An operating method of an optical sensor, comprising:
- counting a square wave signal, which is generated from an ambient light flicker, using a clock signal;
- synchronizing image frames to a flicker frequency of the ambient light flicker to eliminate an incorrect motion identification when the ambient light flicker is well detected;
- and
- not synchronizing the image frames to the flicker frequency when the ambient light flicker is not well detected,
- wherein whether the ambient light flicker is well detected or not is identified according to a counting value of every square wave signal within a count period as well as consistency of multiple counting values of all square wave signals within the count period.
An optical sensor, comprising:
- a pixel array, configured to acquire image frames;
- and
- a processor, configured to
- count square wave signals, each being generated from an ambient light flicker, using a clock signal within a count period, and
- generate a trigger tick for adjusting a timing of capturing image frames within a next count period according to a counting value of every square wave signal within the count period as well as consistency of multiple counting values of all square wave signals within the count period.
An optical sensor, comprising:
- a pixel array, configured to acquire image frames using a frame period;
- and
- a processor, configured to
- count a counting value of every square wave signal, each having a square wave period generated from an ambient light flicker, within a count period using a sampling frequency,
- adjust a phase of a secondly acquired image frame of a next count period behind the count period when the frame period is equal to the square wave period as well as a trigger tick is generated, and
- adjust a phase of a firstly acquired image frame of the next count period behind the count period when the frame period is multiple times of the square wave period as well as the trigger tick is generated.
Dependencies are inferred from the claim text.