US Patent 9521337 Reset-marking pixel sensor

A self-resetting pixel having a memory element to record occurrence of an asynchronous pixel reset and circuitry to enable the memory element to be digitally sampled and cleared is disclosed, together with embodiments of digital image sensors formed by arrays or other collections of such pixels. By marking occurrence of asynchronous reset events within an in-pixel memory element that may be digitally oversampled during an exposure interval (i.e., repeatedly read-out in the form of, for example, a single-bit), it becomes possible to check for and detect asynchronous pixel reset events frequently and efficiently.