| 摘要 |
PURPOSE:To reduce the cost and prevent the voltage drop at the beginning of exposure control circuit by using a single quartz vibrator which works at all times for a digital clock and the exposure control circuit in common. CONSTITUTION:Clock pulse from quartz vibrator 11 is sent to clock circuit 12 to divide its frequency into the pulse signal of predetermined period and count it. Data, such as, counted year, month, day, and time, etc. are inputted into multiplexer 14, and desired data are selected by the signal of display mode control circuit 13 to display it on display unit 16 with the driver 15. Besides, switch 24 is closed by the semi-push of shutter button to measure the brightness of object to be photographed. This brightness, film sensitivity, and diaphragm information are digital- counted by the clock pulse from the vibrator 11 to calculate the shutter speed. The shutter speed is shown in the display unit 16 by operating the control circuit 13. Further, shutter control circuit 23 is controlled by the shutter speed signal from the photometry operation circuit 21 by depressing the release button. Then it controls the energization time of magnet so as to control the shutter speed. At the same time the data letter of the display unit 16 is photographed in the film. |
