| 摘要 |
PURPOSE:To drive a correcting lens correctly at all times even when zooming is performed by replacing a defocusing quantity used for the arithmetic of a correcting method with a lens movement quantity which does not vary even by the zooming. CONSTITUTION:Even when the zooming is performed, a lens driving quantity DL3* for aligning a lens image plane position to a object image plane position f4* predicted at time t4 according to respective data before the zooming is found from the f4* and a lens image plane position l3* expected before the zooming. Then this is converted into a lens driving quantity DL3 after the zooming and DL3 driving is performed at am actual lens image plane position l3 at the time t3 to align a predicted image plane position f4 after the zooming with the image plane position l4 of the lens. Consequently, the defocusing quantity is corrected in the form of a lens movement quantity which does not depend upon focal length, so automatic focusing which follows up the motion of an object at all times is performed. |
