Patent ID: 7626746
Filing Date: 2009-12-01
Classification: G02B

Abstract:
1. A shutter unit for selectively opening and closing the optical path of a laser beam, comprising: a rotating member which rotates around an axis line that is substantially orthogonal to the optical axis of said laser beam, and which is provided with an opening for passing said laser beam therethrough and a reflective surface for reflecting said laser beam; an optical absorption member for absorbing the laser beam reflected with said reflective surface; and a drive motor having a rotational shaft disposed on said axis line, wherein said rotating member has a base portion which rotates around said axis line, and an inclined plate extending from said base portion to said optical axis side and inclined toward said axis line side, and is mounted on said rotational shaft, said opening is formed between said base portion and said inclined plate, said reflective surface is formed on the outer surface of said inclined plate in relation to said axis line, and reflects said laser beam in a direction substantially parallel to said axis line, said optical absorption member is disposed on the optical axis of the laser beam reflected with said reflective surface, said drive motor is disposed outside a housing accommodating said rotating member and said optical absorption member, said optical absorption member is disposed on inside wall of said housing in the opposite side of said drive motor across said optical axis, said laser beam entering said housing enters said optical absorption member when said reflective surface closes the optical path of said laser beam by the drive of said drive motor, and passes said opening when said reflective surface opens the optical path of said laser beam by the drive of said drive motor.