| 摘要 |
<p>PURPOSE:To correct the positive and negative errors of a voltage which corresponds to preset shutter speed second time, by adding prescribed second to manually set second time, and thus calculating digital shutter second time. CONSTITUTION:When a brush 10b is put off an auto position and a voltage which corresponds to desired second time is selected through a resistance 10, the selected voltage is applied to the A/D converter consisting of an operational amplifier 22 and a capacitor 24 through an analog switch 16 closed during manual operation. At this time, digital shutter second time which corresponds to the set voltage passed through the AND gate 37 of the capacitor 24 is counted by T type FFs 40-42 for intermediate stage second time and T type FFs 46-48 for respective stages. In this case, the FF42 which corresponds to a 1/2 stage, etc., is set by a D type FF35, etc., to a point one clock before the start of counting and the counting is started at the 1/2 stage; and outputs of the FFs 40-41 for intermediate stages succeeding the FF42 are not inputted to a circuit 51 and discarded. Therefore, even the negative correction of the precision of the voltage which corresponds to preset second time is performed.</p> |
