CCD IMAGE SENSOR WITH OVERFLOW BARRIER FOR DISCHARGING EXCESS ELECTRONS AT HIGH SPEED

A charge transfer device comprises an array of photodiodes, vertical registers having channels for receiving charge packets from the photodiodes and vertical electrodes for shifting the charge packets along the channels of the vertical registers. A horizontal register has channels for receiving the charge packets from the vertical registers and horizontal electrodes for successively shifting the charge packets across the channels of the horizontal register. An overflow barrier region extends across and is embedded below the channels of the horizontal register for establishing a barrier potential. An overflow drain region is connected to the channels of the horizontal register for discharging charge packets which exceed the barrier potential.