Patent ID: 7280143
Filing Date: 2007-10-09
Classification: H04N

Abstract:
1. An image sensor comprising: an array of pixel sensors; and a control circuit outside the array, wherein the control circuit comprises a first transistor having a gate under control of a reference signal and a current mirror circuit coupled to drive a control line of the array with a mirrored current that mirrors a current through the first transistor, wherein a plurality of the pixel sensors in the array are coupled to the control line, and wherein each of the pixel sensors that are coupled to the control line comprises: a photodiode; a second transistor having a gate coupled to a node of the photodiode; a third transistor having a terminal coupled to the node of the photodiode and a gate coupled to a terminal of the second transistor; a fourth transistor, the fourth transistors in the pixel sensors receiving respective selection signals that select which of the pixel sensors conducts the mirrored current; and a fifth transistor that is between the control line and the gate of the third transistor, wherein the second, third, fourth, and fifth transistors are the only transistors in the pixel sensor; and each of the second, third, fourth, and fifth transistors is an NMOS transistor.