| 摘要 |
PURPOSE:To contrive to reduce the consumed power and avoid the reflux of excess signal charges flowing into a floating diffused region by making the threshold voltage of the output gate equal to that of the reset gate, and setting the output gate at the ground potential. CONSTITUTION:The impurity regions 12 under the output gate 17 and the reset gate 18 are provided with impurity regions 22 of the conductivity type reverse to that of a semiconductor substrate 11, and the ground potential is impressed on the gate 17. In such a construction, potentials are induced under transfer electrodes 161-163 according to levels of clock signals phi1 and phi2, the signal charges are successively transferred toward the floating diffused region 13 and then accumulated therein. At this time, since the threshold voltages of said gates 17 and 18 are set equally, the potential wall under the gate 18 becomes always deeper than that under the gate 17 or equal to it. Accordingly, even when excess signal charges generate, they are exhausted to the drain region 14, causing no reflux in the direction of registor. Because of the ground of the gate 18, the consumed power can be reduced. |
