Global and cluster contrast detection in vision neuromorphic sensors

An event-based vision sensor comprising:

• an array of pixel circuits, each configured to produce a respective photocurrent, wherein the array of pixel circuits is divided into one or more clusters of multiple pixel circuits, each pixel circuit comprising a photodiode connected to generate the photocurrent of the pixel circuit between a ground and a node common to all pixel circuits of the cluster;
• and
• a cluster control circuit configured, for each cluster, to generate (i) a summation of the photocurrents produced by the pixel circuits of the cluster and (ii) cluster events based on changes in the summation of the photocurrents, the cluster control circuit comprising a cluster current sensor connected between the common node and a voltage source for measuring the summation of the photocurrents;
• wherein each pixel circuit of a cluster further comprises:
• a transimpedance amplifier connected between the photodiode and the common node to sense the photocurrent, the transimpedance amplifier including a bias current source;
• and
• a bypass switch connected between the photodiode and the common node.