Large area, fast frame rate charge coupled device

• Main Authors: Wen, David, Onishi, Steve
• Format: Patent
• Language: English
• Published: 16.11.2004

Charge coupled devices (CCDs) are light sensitive elements that are formed on a semiconductor wafer. CCDs contain a plurality of photodetecting picture elements (pixels). The pixels can detect light and output an electrical signal in response to the light. The magnitude of the output electrical signal is indicative of the intensity of the light that reaches the pixel. Large area, fast frame rate, charge coupled devices (CCDs) are provided. Interline transfer CCDs can have interleaved pinned photodiodes and vertical shift registers. The interline transfer CCDs are ideal for producing high frame rate video images from a continuous light source. The photodiodes transfer charge indicative of the previous video frame to an adjacent vertical shift register with little or no lag, while light from the current video frame is integrating in the photodiodes. The charge signals only have to travel a short distance from a photodiode to an adjacent vertical shift register. The charge signals indicative of each video frame are then shifted out of the vertical shift registers. Each vertical shift register has a doping gradient that increases the charge transfer rate. All of these factors provide a fast and efficient video frame rate, even in a large area CCD.