US 12,323,724 B2
Systems and methods for analog image sensing and processing
John Gosson, Ottawa (CA); and Roger Levinson, San Jose, CA (US)
Assigned to blumind Inc., Ottawa (CA)
Filed by blumind Inc., Ottawa (CA)
Filed on Feb. 17, 2023, as Appl. No. 18/170,945.
Claims priority of provisional application 63/311,281, filed on Feb. 17, 2022.
Prior Publication US 2023/0262361 A1, Aug. 17, 2023
Int. Cl. H04N 25/76 (2023.01); H04N 25/772 (2023.01)
CPC H04N 25/7795 (2023.01) [H04N 25/772 (2023.01)] 18 Claims
OG exemplary drawing
 
1. An analog image processing system, comprising:
a pixel array comprising a plurality of pixels for sensing light;
a buffer for sampling a pixel voltage output by each pixel in the pixel array;
a switch for passing the pixel voltage to a capacitor, wherein the pixel voltage is applied to the capacitor when the switch is on, and wherein a discharge current is applied to the capacitor when the switch is off;
a comparator configured to sense the pixel voltage on the capacitor as the capacitor is discharged and generate output time pulses proportional to the pixel voltage; and
an N-type metal oxide semiconductor (NMOS) current source for supplying the discharge current, the current source calibrated to a reference discharge current by a charge-trapped transistor programming a threshold voltage shift into the current source thereby creating a shift in the discharge current.