| 摘要 |
PURPOSE:To eliminate a capacitor of large capacitance and to facilitate an IC formation by supplying video bias to a solid-state image pickup element by d.c. feedback of a pre-amplifier and replacing source bias of initial step FET generated at this time with a given voltage source of a transistor. CONSTITUTION:A pre-amplifier made up of amplifier A1- amplifier D4 is connected to a solid-state image pickup element 5, and FETs 6 are arranged at initial step of each amplifier 1-4. A given voltage source composed of PNP transistors TR21, 22 is connected to the source of FETs 6. Source voltage of FETs 6 is supplied from the emitter of TR21 of the given voltage source and drain voltage is supplied from TR22 through TRs 7 connected to FETs 6. Video bias that becomes gate voltage of FETs 6 is determined through the feedback loop in which drain current determined by a resistance 10 flows. Connection is made from the emitters of TR21, 22 to amplifiers 1-4 in common and a capacitor of large capacitance is eliminated. |
