Delta image sensor with digital pixel storage

Abstract

A delta image sensor comprising an arrangement of pixels and a plurality of acquisition circuits corresponding to at least one pixel. Each acquisition circuit includes at least one sensor circuit comprising a photosensor configured to generate a sensor signal, VSIG, depending on a light signal; at least one analogue to digital conversion, A/D, circuit configured to convert a current VSIG to a digital signal; at least one digital storage circuit configured to store a representation of at least one digital signal corresponding to a previous VSIG; at least one digital comparison circuit configured to compare the level of the stored representation with the current VSIG to detect a changed level; and at least one digital output circuit configured to generate an event output under the condition of the changed level. The sensor circuit is configured to change an analogue function of its read-out characteristics to generate a respective changed VSIG.