Cmos imager frame capture

Abstract

Abstract A CMOS imager capable of operating in a frame capture mode. The imager has an array of active pixel sensors (APS) which sense and store incident light levels at discrete points in the array and a shutter for determining the period of time that light is incident on the array. The shutter, such as a controlled liquid crystal, may be positioned on the array surface or some distance from it, allowing incident light to pass through the shutter and impinge on the array, or the shutter may be positioned at an oblique angle to the array to reflect incident light onto the array. When the APS's in the array are 4T or 5T APS's with a sensor node and a storage node, the two nodes may be connected through two or more series connected transistors or a long transistor to prevent sub-threshold currents. Also, the storage node may be connected to the gate of a feedback transistor to raise the voltage on the storage node as the voltage on the storage node degrades.

Inventors

• 👤 John Scott-Thomas
• 👤 Paul Hua
• 👤 Alain Rivard

Bibliographic Details