Frame transfer CCD sensor
After capturing the image in the bright portion of the sensor, the image is quickly shifted into the dark portion of the sensor. These are physically the same structures as the light-active pixels, however, they are mechanically covered in order to avoid incident light. Then line after line is read out via the horizontal shift register, amplified and digitalised.
The advantage of this technology is a higher fill factor of nearly 100 %, which, however, requires twice the silicon surface and thus the sensor is more expensive. After shifting the image to the dark portion, a new image can already be captured. This sensor type is less suitable for very short exposure times, as a strong smear effect would appear while shifting from the bright to the dark portion. A solution to this problem can only be a mechanic shutter or flashed image taking. Today this sensor type is hardly used in machine vision.