Anti-saturation readout method of frame transfer ccd without anti-overflow function

Abstract

The invention relates to an anti-saturation readout method of a frame transfer CCD without an anti-overflow function, comprising the following steps: controlling the clock in the storage area to shift down one line, and simultaneously controlling the clock in the imaging area to quickly shift up several lines, and transferring the charges exposed in the imaging area to The uppermost row is transferred; control the horizontal readout register and readout circuit to read out one row, and at the same time, the clock in the imaging area maintains the default level to avoid strong interference to the analog signal output by the CCD; repeat the first two steps until the entire frame is read image. While continuously transferring downward and horizontally reading out the image, intermittently transfer the charge exposed in the imaging area to the uppermost row, and use the anti-halation structure above the row to absorb the overflowed charge after saturation, which realizes The timely transfer and cleaning of the exposure charge in the imaging area avoids the phenomenon of saturation of a large number of pixels, overflow and diffusion of charges, and pollution of the readout image.

Description

technical field [0001] The invention belongs to the technical field of photoelectric detection, and in particular relates to an anti-saturation readout method of a frame transfer CCD without an anti-overflow function. Background technique [0002] Using methods such as "frame transfer-charge dumping / readout reset" multiple times in a row can achieve a shorter exposure time than the frame readout time on the frame transfer CCD, or even zero exposure time, so that more intense optical signals can be detected . The short exposure time is followed by a fast frame transfer and a long frame readout process. During frame readout, the imaging area clock is placed at a default level, that is, in the state of exposing and collecting charges. But for the application of strong light and short exposure time, the charge collected at this stage will be excessive and useless. Under strong light, the imaging area will soon be saturated with pixels. If the CCD does not have an anti-overfl...

AI Technical Summary

Problems solved by technology

[0003] The technical problem solved by the present invention is to overcome the deficiencies of the existing methods. Through the special design of the driving sequence, the timely cleaning of useless exposure charges in the imaging area during the frame readout period is realized on the frame transfer CCD, and the charge overflow and pollution after the pixel is saturated are avoided. Occurrence of readout image phenomenon provides an anti-saturation readout method for frame transfer CCD without anti-overflow function

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