Patent ID: 7349018
Filing Date: 2008-03-25
Classification: H01L,H04N

Abstract:
1. A method for operating a CMOS image sensor including a plurality of pixels, each of said pixels including a photo-sensor element producing charge carriers in proportion to its illumination and storage means capable of being coupled to and uncoupled from said photo-sensor element at a determined instant in order to store, on a memory node of said pixel, a measuring signal representative of said charge carriers produced by said photo-sensor element during an exposure phase, each pixel including: the first and second terminals of the coupling means being respectively connected to the source terminal of the first MOS transistor and to the source terminal of the second MOS transistor; and wherein said first or second MOS transistor is operated at least partially in weak inversion so that, during the exposure phase of said photo-sensor element, the pixel has at least partially a logarithmic response for illumination levels higher than a determined illumination level which can be zero.