Frame Transfer CCD

 

The 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.