摘要 |
PURPOSE: To prevent the drop of output voltage that is caused by the parasitic capacitance of a reading horizontal line by using the output terminal of a signal reading circuit where the potential of signal source is transmitted by an insulat ed gate type transistor Tr circuit as the source of an insulated gate type Tr. CONSTITUTION: The emitter output potential VE of a signal source S is transferred to the gate of an output MOSFET Tr6 via an insulated gate type MOSFET Tr3. Thus the gate potential of the Tr6 is set at V6 G≃VE. The drain of the Tr6 is connected to a power supply Vcc via a reading MOSFET Tr5 together with the source of the Tr6 used as an output terminal that is led to a reading horizontal line. When the Tr5 is turned on, the Tr6 operates to vary the source potential V6 S according to the gate potential V6 G and to satisfy VE≃V6 G. Then the influence of the parasitic capacitance CH is eliminated and the output potential of the signal source S is outputted with almost no drop due to a fact that the source of the Tr6 is connected to a horizontal line.
|