| 摘要 |
PURPOSE:To obtain a multiple focus lens which facilitates variation in focal length, restoration, and movement of a variation part by making a detachable lens made of soft synthetic resin adsorbed to a part of the lens. CONSTITUTION:The lens 2 made of soft synthetic resin differs in focal length from the lens 1 of a main body. In order that this lens 2 is made contact to the lens 1 of the main body tightly, the radius of curvature of the side where the lens of soft synthetic resin tightly contacts with the main body lens should be a little bit smaller than that of the main body lens, but almost neither distortion of an image nor variation in degree due to the suction is recognized within a >=1mm. maximum interval DELTAH of the gap formed between the lens 2 and main body lens 1. Thus, this multiple focus lens facilitates the attachment and detachment of the lens for varying the focal length locally, and the attachment position is selected optionally. |
