| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic exposure controller capable of performing the photometry of a subject with high accuracy and a low voltage. SOLUTION: When a photometric switch 75 is turned on, a photoelectric current corresponding to the luminance of a subject is generated in a photodiode 16 and a potential difference is generated across a resistance 77a. When the luminance of the subject is smaller than a threshold, since the potential difference of the resistance 77a is low, an FET 80 becomes to be in an OFF state. When the luminance is equal to or larger than a threshold, since the potential difference of the resistance 77a is high, the FFT 80 is turned on. When the FET 80 is in the OFF state, first and second transistors 81, 82 are turned on and a solenoid 60 is energized. The solenoid 60 makes a camera to be in a large diaphragm state by retreating a disphragm plate 63 from a photographing optical path. When the FET 80 is in the ON state, since the second transistor 82 is turned off, the solenoid 60 is not energized and the diaphragm plate 63 is positioned in the photographic optical path to make the camera to be in a small diaphragm state. |
