Lens position control device

摘要

A lens position control device for an optical instrument, the instrument including a variator and a compensator, the latter of which also serves as a focusing lens, comprises a detecting circuit for detecting the positions of the variator and the focusing lens, a memory for storing information representing the location and size of an impossible-to-focus zone for the focusing lens as the function of the zooming position of the variator, and a control circuit responsive to detection of the fact that the focusing lens falls in the impossible-to-focus zone on the basis of the information stored in the memory for causing the focusing lens to retire from the impossible-to-focus zone or for prohibiting the focusing lens from further moving in a direction toward the impossible-to-focus zone.