| 摘要 |
PURPOSE:To let photographic lens stop stably in optimum position with small driving power by providing a cam which indicates distance measurement signals in the form of shape to a member cooperating to the operation of a range finder. CONSTITUTION:The rotation of a scan motor 10 causes a disc 9 to move a cam supporting lever 7 to move to the right or left and this in turn oscillates a mirror supporting lever 6, thereby letting a moving mirror 3 subsequently scan from the shortest distant side. At the same time, a shield plate 8 which has a cam shape part 800 fixed to the supporting lever 7 is also moved. On the other hand, a non-contact type photoelectric detector 13 consisting of an LED 31 and photo transistor 132 is provided in such a manner as to hold the foregoing sheild plate 8 to the supporting part 12 of the photographic lens 11 driven by a motor 15. The cam shape 800 is beforehand determined according to the angle of oscillation of the moving mirror 3 and the mating pin is discriminated with the detector 13, by which driving of the motor 15 is controlled and the photographic lens 11 is stopped in the optimum position. |
