Frame Transfer CCD
frame transfer CCD imager has a parallel register divided into two distinct
areas. The upper area is the image array, where images are focused and integrated.
The other area, the storage array, is identical in size and is covered with
an opaque mask to provide temporary storage for collected charge. After the
image array is exposed to light, the entire image is rapidly shifted to the
storage array. While the masked storage array is read, the image array integrates
charge for the next image. A frame transfer CCD imager can operate continuously
without a shutter at a high rate. The front illuminated Frame Transfer CCDs
suffer the same fate as the Full Frame CCDs, that is a reduced QE in the visible
with a particularly low QE in the blue. The combination of back illuminated
(CCD EEV 57) , the shutterless operation, relatively high frame rates and
very high QE is very desirable to have in a camera system.