| 摘要 |
PURPOSE:To restrict overflow of an electric charge while being transferred, by reducting an input charge from a source below the maximum accumulated charge under a transfer electrode lower than No.2 step. CONSTITUTION:An ion is injected into a charge accumulation region under No.1 step electrode 141, this surface potential is made to get closer to a surface potential of a barrier region 151 rather than to a surface potentials of charge accumulation regions lower than No.2 step 142, and an input charge to be set to No.1 step 141 is set to a less value than the maximum accumulation charge lower than No.2 setp 142. When a source 12 is OV and a potential of the electrode 141 is as low as 5V, a difference between a surface potential of No.1 step barrier region 151 and a potential of the source region 12 is , and when OV of the source 12 is varied to minus side or the low level of No.1 step 141 is varied to plus side, this mechanism effectively controls such an erroneous operation that a charge is input from the source 12 jumping over No.1 step barrier 151, and since overflow of a charge being transferred is prevented, as signal charge which is less than the maximum accumulation charge under the electrode is put in so as to prevent the erroneous operation. |
