CCd imagers

摘要

In a CCD imager 1, charge is accumulated in pixels of an image area 2 representative of the intensity of incident radiation and is subsequently transferred to a store section 3 and then on a row by row basis to an output register 4 by applying suitable drive pulses to electrodes 7 and 8. Signal charge in the output register 4 is transferred to a multiplication register 5 by drive pulses applied to electrodes 9 and 10 to give charge transfer in the direction shown by the arrows. One or more drive pulses applied to the electrodes of the multiplication register 5 are of sufficiently large amplitude to produce high field regions in the register element to cause signal multiplication by impact ionisation. This gives a low noise amplification of the signal charge, the multiplied signal charge being detected at charge detection circuit 6.