DRIVING CIRCUIT OF SOLID-STATE IMAGE PICKUP ELEMENT

PURPOSE:To realize a solid-state image pickup element with uniform characteristics by providing a variable bias voltage supplying means which can apply variable bias voltage instead of the 0 volt determined by the earth potential for the voltage to be applied to be applied to the reading electrode by the voltage pulse. CONSTITUTION:Between the source terminal 9-3 of FET9 and the earth the variable current 13 is inserted. First of all, the line selecting electrode 3-1 and reading electrode 4-1 are made low potential to form a potential well and after the potential holes due to light incidence are accumulated, voltage impulse is applied to the gate terminal 9-2 of FET9 and the reading electrode 4-1 is set to a reference potential. At the time the potential of the reading electrode 4-1 becomes potential VBX by means of the variable power supply 13. Therefore, the bias voltage between the board 1 and the reading electrode 4-1 becomes -VBB+VBX and the optimum size of the potential well is determined.