Charge transfer device and driving method for the same

A charge transfer device comprising:

• a plurality of vertical transfer channels;
• a transfer gate electrode placed at ends of the plurality of vertical transfer channels for receiving signal charge from the plurality of vertical transfer channels and for outputting the signal charge;
• a plurality of horizontal transfer channels including two-phase charge-coupled devices having a first signal line and a second signal line and a plurality of layers of gate electrodes for transferring the signal charge from the transfer gate electrode in a horizontal direction;
• and
• a conductive portion for supplying a transfer control signal to the horizontal transfer channels;
• wherein each of the gate electrodes, which is connected to one of the first and second signal lines adjacent to a transfer channel under the transfer gate electrode, is made independent for each transfer channel by electrically connecting the gate electrodes to the conductive portion on the transfer gate electrode, and
• wherein the residual gate electrodes connected to the other signal line are common to the plurality of horizontal transfer channels.

A driving method for a charge transfer device comprising:

• a plurality of vertical transfer channels;
• a transfer gate electrode placed at ends of the plurality of vertical transfer channels for receiving signal charge from the plurality of vertical transfer channels and for outputting the signal charge;
• a plurality of horizontal transfer channels including two-phase charge-coupled devices having a first signal line and a second signal line and a plurality of layers of gate electrodes for transferring the signal charge from the transfer gate electrode in a horizontal direction;
• and
• a conductive portion for supplying a transfer control signal to the horizontal transfer channels,
• wherein each of the gate electrodes which are connected to one of the first and second signal lines adjacent to a transfer channel under the transfer gate electrode is formed as an independent electrode for each transfer channel by electrically connecting the gate electrode to the conductive portion on the transfer gate electrode, and
• wherein the residual gate electrodes connected to the other signal line form a common electrode to the plurality of horizontal transfer channels,
• the driving method for the charge transfer device for applying a voltage to one signal line serving as the common electrode among the plurality of transfer channels so that a channel potential is kept to be low while charge is transferred from one horizontal transfer channel to another horizontal transfer channel through the transfer gate during a quiescent period of the horizontal transfer,
• wherein a clock is applied only to the other signal line which serves as the independent electrode for each of the plurality of horizontal transfer channels and a signal line of the transfer gate, thereby transferring a charge from one horizontal transfer channel to another horizontal transfer channel.