US 12,470,849 B2
Event sensor pixel with sensitivity and dynamic range optimization
Thomas Finateu, Veneux les Sablons (FR); Daniel Matolin, Freital (DE); and Christoph Posch, Bad Fischau-Brunn (AT)
Assigned to Prophesee, Paris (FR)
Filed by PROPHESEE, Paris (FR)
Filed on Dec. 14, 2023, as Appl. No. 18/540,381.
Claims priority of provisional application 63/387,685, filed on Dec. 15, 2022.
Prior Publication US 2024/0205567 A1, Jun. 20, 2024
Int. Cl. H04N 25/772 (2023.01); H04N 25/47 (2023.01); H04N 25/57 (2023.01); H04N 25/778 (2023.01); H04N 25/79 (2023.01); H10F 39/00 (2025.01)
CPC H04N 25/772 (2023.01) [H04N 25/47 (2023.01); H04N 25/57 (2023.01); H04N 25/778 (2023.01); H04N 25/79 (2023.01); H10F 39/809 (2025.01)] 58 Claims
OG exemplary drawing
 
1. A pixel circuit for use with an event sensor, comprising:
a photosensitive element configured to generate a current signal in response to a brightness of light impinging on the photosensitive element;
a first N-type transistor;
a second N-type transistor;
a first P-type transistor including a gate connected to a first bias voltage;
a second P-type transistor including a gate connected to a second bias voltage, the second bias voltage being a DC bias voltage that is adjusted responsive to at least one of a chip temperature or fabrication process variation of the pixel circuit; and
a voltage output that varies in response to the brightness of light impinging on the photosensitive element;
wherein the adjustment of the second bias voltage increases a saturation-free operating range of the pixel circuit and thereby improves a dynamic range of the pixel circuit.