Lens driving device of single-lens reflex camera, etc.

Abstract

Abstract PURPOSE:To make the lens barrel of an interchangeable lens compact, reduce the cost of the interchangeable lens, and improve its performance, by using a frame-like armature coil and assembling a position detecting element and magnetism-to-electricity converting element for detecting the speed of revolution in the cavity of the frame. CONSTITUTION:A frame-like armature coil 19 having a bow-like cross section is fixedly installed to the inner peripheral surface of a cylinder 18 and faced to a field magnet 17. In the cavity of the frame of armature 19, a magnetism-to- electricity converting element for detecting the rotating position of the armature coil 19 is installed for each of the armature coil. Furthermore, in the cavity of the frame of either one armature coil, a magnetism-to-electricity converting element 21 for detecting the speed of revolution is installed. When such constitution is applied, a lens barrel 14 of the movable side automatically moves along the optical axis while rotating in a prescribed direction until the focus of the lens is adjusted and, when the focusing is made, the barrel 14 automatically stops at the position. Therefore, the lens barrel can be made compact, the cost can be reduced, and the performance can be improved.

Inventors

• 👤 Katsuyoshi Arisawa
• 👤 有澤　勝義

Bibliographic Details