| 摘要 |
PROBLEM TO BE SOLVED: To provide a light quantity controller of an electronic endoscope capable of eliminating halation by performing electronic shutter control faster when the halation occurs and controlling a light quantity so as to prevent hunting near a halation threshold after the halation is eliminated. SOLUTION: In the light quantity controller of the electronic endoscope, when the halation occurs, a halation discrimination circuit 47 supplies the halation control signals 106 of "High" to a loop filter 46 and controls switching so as to conduct H output terminals of first and second circuits 46A and 46B. Thus, since element shutter control signals 104 can be outputted to a CCD driver 16 as they are without passing them through the loop filter 46, the element shutter control is performed fast and the halation is eliminated quickly. Thereafter, by switching the first and second switch circuits 46A and 46B, the loop filter 46 is operated and the hunting near a target value is prevented. COPYRIGHT: (C)2005,JPO&NCIPI
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