| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic endoscope apparatus with an autofocus function executing a quick AF control following the movement of the beating in a magnified image and prevented from impeding a diameter miniaturization of an endoscope due to the AF control. SOLUTION: A microcomputer 42 is provided with a passive AF control part 42A and an active AF control part 42B, when being (a) magnification or less, it is changed over into the passive AF control and, when being more than (a) magnification, changed over into the active AF control. This apparatus, in the passive AF control, executes a focus evaluation calculation by a high frequency signal of the image signal and drives movable lenses 23 and 24 to perform a mountain climbing operation based on the focus evaluation value. On the other hand, in the active AF control, this apparatus receives a reflected light from an object to be observed based on the light projection by a light receiving part 28B, and after executing a distance surveying (it may be the distance surveying using ultrasonic wave), drivingly controls the variable lenses 23 and 24. This active AF control can execute the AF operation in a short period of time and favorably grasp the movement even in executing the high magnification. COPYRIGHT: (C)2005,JPO&NCIPI
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