| 摘要 |
PROBLEM TO BE SOLVED: To provide a light quantity controller of an electronic endoscope capable of obtaining the light quantity adjustment control of a fast reaction speed and simultaneously preventing the overheat of an electronic endoscope tip. SOLUTION: In the light quantity controller of the electronic endoscope of this invention, a detection circuit 31 detects luminance components from image pickup signals generated by a CCD 11 and supplies them to a stability judgement circuit 35, a diaphragm control circuit 38 and an element shutter control circuit 39. A shutter control target value setting circuit 37 sets an exposure target value for controlling the exposure of the CCD 11. The element shutter control circuit 38 can control the exposure of the CCD corresponding to the luminance components detected by the wave detection circuit 31 and the exposure target value set by the shutter control target value setting circuit 37. The stability judgement circuit 35 appropriately changes the exposure target value set by the shutter control target value setting circuit 37 corresponding to the stability of the luminance components judged from the size of the luminance components detected by the detection circuit 31 and the fluctuation rate with time of the luminance components, and makes it be inputted from the shutter control target value setting circuit 37 to the element shutter control circuit 39. COPYRIGHT: (C)2005,JPO&NCIPI
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