| 摘要 |
PROBLEM TO BE SOLVED: To visually recognize the photographing range of a lens of an arbitrary focal distance by a zoom finder. SOLUTION: A plurality of moving lens groups to perform the power variation of the zoom finder are connected with a zoom motor which is providing a freely turnable cam shaft having a plurality of flange-like cams and a large gear. The origin of the power variation operation of the zoom finder is decided by a shield plate and a photointerrupter(PI) coaxially moving together with the cam shaft. A required focal distance value is inputted by an electronic dial 37 while depressing a preview button 33. A value thereof and an origin data or the focal distance information of the lens are calculated by a central processing unit(CPU), an equivalent pulse is outputted to the motor driver and the zoom motor is turned so that the moving lens groups are moved to a required position. When the preview button is released, the zoom motor is reversely rotated so that the motor is returned to an initial position. Thus, the required photographing range of the lens is visually recognized without exchanging the lens. |
