| 摘要 |
In a video endoscope apparatus in which an objective and a solid state imaging sensor are provided in the distal end portion of the inserting portion thereof, which is to be inserted into a cavity of a body, and the image of the wall of the cavity picked-up by the solid state image sensor is displayed on a monitor, the solid state image sensor is vibrated at a predetermined frequency of 10 Hz in the direction of the optical axis of the objective by means of the piezoelectric element, the peak value of the image signal supplied from the solid state image sensor is detected on each horizontal scanning line, the peak value detected thereby is passed through a band pass filter having a central frequency of 10 Hz, the signal passed through the band pass filter is synchronously detected by using a sampling signal which has a frequency of 10 Hz and is synchronized with said vibration, a focusing error correcting signal is generated by comparing a synchronously detected signal and a reference signal, and the solid state image sensor is moved in and in-focused position by supplying the focusing error correcting signal to the piezoelectric element.
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