| 摘要 |
<p>A gamma switching circuit of a programmed shutter having a voltage conversion circuit which subjects to logarithmic compression an optical current which varies with gamma =1 with respect to brightness variation. A constant circuit has only an inflow current available and no outflow current is available at the output terminal thereof. A time setting circuit includes a switching circuit and a shutter controlling magnet driving circuit. The output terminal of the voltage conversion circuit is connected through a series circuit of two resistors to the output terminal of said constant voltage circuit, and the connection point between said two resistors is connected to the input terminal of said time setting circuit. The constant voltage circuit applies a voltage to one input terminal of a differential amplifier circuit, and the collector of a transistor whose base is connected to the output terminal of the differential amplifier circuit is connected to the other input terminal of the differential amplifier. The other input terminal of the differential amplifier is employed as an output terminal.</p> |
