| 摘要 |
PURPOSE:To prevent a lens from varying in shape with temperature by mounting a lens with an elastic member between so that a taper part provided to the outer circumferential part of the lens is in contact with a taper part in a lens barrel. CONSTITUTION:The taper part 31 is formed at the outer circumferential part 30a of the lens 30 and a film 70 with low friction is formed; and the taper part 24 is formed at the lens abutting part 21 of the lens frame 20 correspondingly. Both taper parts 31 and 24 are brought into contact with each other and the lens 30 is pressed fixedly by a press ring 40 while the elastic part 60 is interposed between a lens press part 32 and the screw part 41 of the press ring 40. Even when the lens 30 has radial variation in size with temperature, the lubricating operation between the taper parts 24 and 31 prevents the variation in lens shape. |
