| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic exposure controller capable of compensating the difference of mechanical hysteresis by the moving direction of the opening/ closing control of a lens iris and performing highly accurate exposure control. SOLUTION: Based on a lookup table 1 or by exposure target value signals Et0 and Et inputted from a host computer 2, the position information F'p of the lens iris 12a and brightness signals Ep from an optical detection device 8, by an iris driver 11 driven by iris control signals Fi outputted from a CPU 9, for the lens iris 12a, a margin amount M1 is set for movement from a closing side to an opening side and the margin amount M2 is set for the movement from the opening side to the closing side. Then in the iris driver 11 the lens iris 12a is opening/closing controlled so as to be positioned inside a margin area and to set a target exposure level in the state of compensating the influence of the difference value of the hysteresis by the moving direction at the time of the opening/closing control and a target exposure level is highly accurately set by short control time.
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