Patent ID: 6525769
Filing Date: 2003-02-25
Classification: H04N

Abstract:
An imaging device comprising:an imaging array comprising a plurality of photo sensitive pixels arranged in a plurality of rows and columns, the imaging array further comprising an active area which can be selectively exposed to incident light to capture an image, a first optically dark area located adjacent to the active area and comprising at least one row of photo sensitive pixels, and a second optically dark area located adjacent to the active area and comprising at least one column of photo sensitive pixels, the photo sensitive pixels of the first and second optically dark areas are shielded from incident light; and a compensation circuit coupled to the imaging array, the compensation circuit generates an initial dark current offset value from the first optically dark area, and adjusts the initial dark current offset value using the second optically dark area, the compensation circuit comprises: a buffer circuit coupled to receive an output signal from the imaging array, a reference circuit to selectively couple a reference voltage to an input node of the buffer circuit, and an integration circuit to generate the initial dark current offset value, and adjust the initial dark current offset value.