| 摘要 |
PURPOSE:To improve the accuracy of focus adjustment by inverting a correction direction of a focal face by a variable power lens at the start of variable power operation to a prescribed correction direction. CONSTITUTION:Drivers 117, 119 sets a phase of an exciting phase of a 4-phase motor to a forward phase rotation and reverse phase rotation depending on a phase rotation signal and output a signal while changing an applied voltage of a motor exciting phase depending on the received rotation frequency signal to turn on/off an output to motors 118, 120 while controlling the rotating direction and the rotating frequency of the motors 118, 120. When an inching zooming is repeated, that is, zooming is repeated momentarily such as telescopic drive/ stop, since a direction of focal point correction is set to an infinity at first, a defect of a conventional camera becoming unsharp gradually in the infinite direction is eliminated. Furthermore, the deterioration in the focus detection accuracy by zooming is prevented and the focus is adjusted with high precision at all times. |
