Optical sensor acquiring image frames corresponding to ambient light flickers
AssigneePixart Imaging Inc.
InventorZI-HAO TAN
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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 recognize a frequency of ambient light flicker and adjust an acquiring phase of the image frame.
Claims20
An optical sensor, comprising:
- a photodiode, configured to detect ambient light flicker to generate a light signal;
- a wave converter, configured to receive the light signal and to generate a square wave signal;
- a pixel array, configured to acquire image frames according to frame ticks;
- and
- a digital backend, configured to
- count the square wave signal using a sampling frequency,
- generate a trigger tick for adjusting the frame ticks,
- compare a counting value of a last square wave signal in a count period with at least one count threshold to identify whether a frequency of the ambient light flicker is a first frequency or a second frequency when the trigger tick is generated, and
- generate the frame ticks corresponding to the first frequency and the second frequency.
An optical sensor, comprising:
- a photodiode, configured to detect ambient light flicker to generate a light signal;
- a wave converter, configured to receive the light signal and to generate a square wave signal;
- a pixel array, configured to acquire image frames according to frame ticks;
- and
- a digital backend, configured to
- count the square wave signal using a sampling frequency,
- generate a trigger tick for adjusting the frame ticks, and
- compare a counting value of a last square wave signal in a count period with at least one count threshold to identify whether a frequency of the ambient light flicker is a first frequency or a second frequency when the trigger tick is generated,
- wherein the pixel array is configured to acquire the image frames corresponding to the first frequency and the second frequency.
Dependencies are inferred from the claim text.