Patent ID: 7222976

Claim:
An optical device, having a plurality of optical parts comprising: a light source that emits light beams; a reflective mirror disposed on an optical path of the light beams emitted from the light source; an optical parts-use casing where an illumination optical axis of the light beams is set inside and which houses and retains the plural optical parts at a predetermined position with respect to the illumination optical axis; a swollen portion that is attached to an underside of a reflective surface of the reflective mirror, swells in an outward direction of the reflective mirror and is configured as part of a spherical surface; and a mirror orientation adjustment lever that is attached to the underside of the reflective surface of the reflective mirror, extends along the underside of the reflective mirror and planarly protrudes from an end edge of the reflective mirror, the reflective mirror being disposed along a side wall of the optical parts-use casing, and the side wall including, at a position where the reflective mirror is disposed, a concavely curved surface corresponding to the spherical surface of the swollen portion, and when the reflective mirror is disposed at the disposition position, the concavely curved surface supports the swollen portion.