Patent ID: 8267529

Claim:
An optical device comprising: a housing; and a reflection member disposed at a predetermined position within the housing, the housing including: a receiving opening through which the reflection member is inserted to be accommodated in the housing, and an attachment unit to which the reflection member is attached, the reflection member including: a front portion having a reflection area for reflecting supplied light, a back portion positioned on a side opposite to the front portion, and a fixing unit attached to the back portion and positioned within a surface of the back portion, the fixing unit being configured to be fixed to the attachment unit, and the fixing unit having an opening, the opening being configured to detachably accept a position control jig that is inserted into the opening in an attachment direction that is parallel to a direction in which the reflection member is inserted into the receiving opening, wherein: the fixing unit includes: a substantially cylindrical pin extending in the attachment direction, and a contact portion contacting the attachment unit; and the attachment unit includes: a hole through which the pin is inserted, and a support portion which contacts the contact portion and supports the fixing unit, wherein: one of the contact portion and the support portion has a curved surface centered on a line extending in a direction of inserting the pin through the hole and expanding toward the other of the contact portion and the support portion; the other of the contact portion and the support portion has a flat surface substantially orthogonal to the attachment direction; and a predetermined clearance allowing rotation of the reflection member with a fulcrum of the rotation of the reflection member located at a contacting area between the curved surface and the flat surface is provided between an edge of the hole and the pin inserted through the hole.