| 摘要 |
PURPOSE:To simplify the constitution of a processing system of constant-voltage pulses, by staggering the generation points of the constant-voltage pulses and variable-voltage pulses in terms of time through the on-off operation of a switching element. CONSTITUTION:A load resistance 52 is connected in series with the switching element 29 such as a phototransistor, a variable resistance 36 whose resistance value is varied according to photographic information is connected to the connection point between the both, and feeding means 53 and 54 are provided for feeding a current to the serial connecting body of a load resistance 52 and the variable resistance 36 when the switching element 29 is off, sending out a pulse voltage with specific amplitude determined by the load resistance 36 when the switching element is on or a voltage determined by the load resistance 52 and variable resistance 36 when off. Consequently, the specific information voltage is generated when the phototransistor 29 is off and pulses with constant amplitude are generated when on; and a waveform shaping circuit 55 processes those constant-amplitude pulses. Therefore, the constitution of the processing system for the constant-voltage pulses is simplified. |
