| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive camera where the driving noise of a motor is suppressed and the rotation is highly accurately controlled. SOLUTION: A driving device 43 is constituted of the motor 50, a reduction mechanism 51 and a revolution detecting mechanism 52. The reduction mechanism 51 is constituted of a worm gear 53 fixed to a rotary shaft 50a, and a worm wheel 54 engaged with the worm gear 53, and the revolution speed of the motor 50 is reduced and a driving gear 55 is rotated by the reduction mechanism 51. The rotation of the driving gear 55 is transmitted to a feed screw 36 via a gear 48. The revolution detecting mechanism 52 is constituted of a spur gear 56 integrally molded with the worm wheel 53, an idle gear 57 engaged with the spur gear, an impeller 58 rotated interlocking with the idle gear 57 and a photointerrupter 59 for photoelectrically detecting the rotation of the impeller 58. A moving cylinder 38 moves straight in accordance with the lead of the feed screw 36 to which the rotation of the driving gear 55 is transmitted. A lens barrel 7b connected to the moving cylinder 38 is guided by a guide shaft 44, then, moved in the optical axis direction. |
