Patent ID: 7528876

Claim:
A method for driving an image sensing device having an image cell with a photo-sensitive element, a detection node and an output pin, wherein a reference signal and, via an output line, a value present at the output pin, are applied to a comparator, the method comprising the steps of: transferring charges accumulated during a first period of time from the photo-sensitive element to the detection node, thereby obtaining a first voltage; generating a first value corresponding to the first voltage; comparing the first value with the reference signal and determining a signal representing the result of the comparing; transferring charges accumulated during a second period of time from the photo-sensitive element to the detection node, thereby obtaining a second voltage; generating a second value corresponding to the second voltage; and selectively applying one of the first value or the second value to a single buffer, depending on a value of the signal resulting from the comparing; wherein the first and the second periods of time are subsequent to each other and are nested within a frame or field period, wherein the first period of time is shorter than the second period of time, and wherein the second period of time ends on or after reselling the detection node after reading out the first value.