US 11,885,673 B2
Pixel circuit including an open-loop amplifier with well controlled gain for event-based vision sensor and method of controlling thereof
Daniel Matolin, Freital (DE); Denis Bourke, Dalkey (IR); and Christian Bouvier, Saulx les Chartreux (FR)
Assigned to Prophesee, Paris (FR)
Filed by PROPHESEE, Paris (FR)
Filed on Apr. 1, 2021, as Appl. No. 17/220,761.
Claims priority of provisional application 63/004,110, filed on Apr. 2, 2020.
Prior Publication US 2021/0310861 A1, Oct. 7, 2021
Int. Cl. G01J 1/42 (2006.01); G01J 1/46 (2006.01); H04N 25/77 (2023.01); H04N 25/778 (2023.01); H04N 25/766 (2023.01)
CPC G01J 1/4228 (2013.01) [G01J 1/46 (2013.01); H04N 25/766 (2023.01); H04N 25/77 (2023.01); H04N 25/778 (2023.01)] 44 Claims
OG exemplary drawing
 
1. An event-based vision sensor that includes a plurality of pixels, each pixel comprising:
a photosensitive element configured to generate a current signal in response to brightness of light impinging on the photosensitive element;
a converter configured to receive the current signal from the photosensitive element and generate a voltage signal based on the received current signal;
a capacitor electrically coupled to the converter in series and configured to receive the voltage signal from the converter;
an open-loop amplifier electrically coupled, at an input, to the capacitor in series and configured to generate, at an output, an amplified signal based on an output signal from the capacitor, wherein there is no feedback between the output and the input of the open-loop amplifier, and further wherein the open-loop amplifier comprises a plurality of stacked transistors providing a well-controlled and high-accuracy open-loop gain of the open-loop amplifier, wherein a gate of at least one of the plurality of stacked transistors is configured to receive a bias voltage that sets an operation point of the open-loop amplifier; and
a reset device electrically coupled between the input and the output of the open-loop amplifier and configured to reset the open-loop amplifier in response to a trigger signal being generated.