| 摘要 |
PURPOSE:To prevent blooming in a photoelectric converter by excluding an excessive signal carrier by energizing the anode terminal of a photoconductive film diode before feeding a signal of the photoconductive film diode to a transfer unit. CONSTITUTION:The cathode voltage phiD0 of a photoconductive film diode is equal to phiR under a gate 13 during the period T0-T1 of dark state. Both a terminal 9 and the gate 13 are zero potential during the photointegration period T1-T2, a route to a buried channel CCD is closed, and an element 6 starts discharging by the emission of a light. The cathode voltage of the element 6 is raised to the phiD2 of the element 6 in response to the incident light quantity at the time T2. A positive pulse (b) is applied to the anode of the element 6 at the time T2 for a short time, and the pulse amplitude is set to phiD1 becoming the maximum charge Qn capable of transferring channel from the discharging charge DELTAQD. Thus, the positive pulse during the period T3-T2 allows part of the QD to be discharge through the element 6 of forward bias in case of phiD1 phiD, the element 6 is refreshed to a voltage (i), and since DELTAQD=Qn in case of reading time during the period T4-T3, it is refreshed to a voltage (ii). According to this structure, a blooming phenomenon can be effectively prevented. |
