| 摘要 |
PURPOSE:To control the position of a lens with high following ability even in the case the moving direction of an object is switched halfway by predicting the position of an image surface in accordance with the moving state of the object. CONSTITUTION:An image signal is inputted in a microcomputer PRS from a line sensor-device for detecting focus SNS. The microcomputer PRS judges whether or not a difference VA-V2 between the average speed VA of the movement of the image surface and image surface moving speed V2 from detecting focus previous time till detecting the focus this time is larger than a specified value. In the case VA-V2 is positive, it shows a negative acceleration state. In the case it is larger than the specified value, reverse control calculation is performed by judging that the moving direction is reversed. Otherwise, whether the average speed VA is negative or positive is judged. In the case VA is positive, forward control calculation is performed by judging that a subject comes close. Otherwise, a backward control calculation is performed to control the subject which goes away. |
