Delta image sensor with externally writeable 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 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 to compare the level of the stored representation with the current VSIG to detect whether a changed level is present; and at least one digital output circuit configured to generate an event output under the condition of the changed level. A digital representation may be externally written to the digital storage circuit of the at least one pixel.