Digital pixel image sensor
AssigneeFacebook Technologies, LLC
InventorXinqiao LIU
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Abstract
Disclosed herein are techniques for digital imaging. A digital pixel image sensor includes a digitizer in each pixel of a plurality of pixels, where the digitizer digitizes analog output signals from a photodiode of the pixel using a comparator, a global reference ramp signal, and a clock counter. In some embodiments, the comparator includes a pre-charging circuit, rather than a constant biasing circuit, to reduce the power consumption of each pixel. In some embodiments, each pixel includes a digital or analog correlated double sampling (CDS) circuit to reduce noise and provide a higher dynamic range.
Claims1
A digital pixel image sensor, comprising:
- a plurality of pixels, each pixel comprising:
- a photodiode;
- a charge storage device configured to convert charge generated by the photodiode to a voltage;
- and
- a comparator configured to compare the voltage against a ramp signal to output a decision;
- a counter;
- and
- a memory configured to store a count value from the counter for the each pixel based on the decision output from the each pixel.
Dependencies are inferred from the claim text.