| 摘要 |
PURPOSE:To give a straight movement in a simple way to a focused lens and its frame and to eliminate an increment of an optical system due to an eccentric turn of the optical axis, by moving the focused lens with a turn of a single operation member to perform the setting of distance, varying the magnification ratio with a shift of the lens toward the optical axis and performing the zooming with a shift of a compensating lens respectively. CONSTITUTION:An operation member 10 is pushed toward the optical axis to perform the zooming, and a variable magnification lens L2 moves with the guide of a straight movement groove 1a. In this case, the rotary power is transmitted to a compensating lens frame 9 by means of a couling member 15 for frame of L2. At the same time, the parallel displacement toward the optical axis is controlled for the frame 9 by an interlock of a guide pin 9b and a curved groove 1b. The distance is set by turning the member 10 around the optical axis. An intermediate member 4 interlocks a screw 2b of a focused lens frame 2 by means of a screw 4a, and the rotation of the frame 2 is controlled to a fixed member 1 and with a relation between a guide pin 3 and a straight movement groove 1c. Thus the frame 2 moves straight and in parallel to the optical axis. |
