| 摘要 |
PURPOSE:To realize a low-cost exposure control system which handles variation in source voltage by comparing the output of a source voltage rectifying means with a reference voltage and controlling a shutter speed on the basis of the constant in a storage means corresponding to the difference voltage. CONSTITUTION:The voltage output of a commercial power source 1 is inputted to a comparing means 7 through a voltage stepping-down means 2, rectifying means 3, smoothing means 4, and voltage adjusting means 5 and compared 7 with the reference voltage from a reference voltage means 6 to input the difference voltage to a CPU8. The CPU8 reads the constant corresponding to the difference voltage out of the memory 9 and sends it to a shutter driving means 10 to control a shutter 11 on the basis of the constant. Thus, the low-cost exposure control system which handles variation in source voltage is realized. |
