Patent ID: 7210796

Claim:
An optical apparatus, comprising: optical components including a reflection mirror provided in an optical path of light beams emitted from a light source; a case for optical components that houses and holds the plural optical components in a predetermined position with respect to an illumination optical axis of the light beams; a protruded part mounted to a back surface of a reflection surface of a reflection mirror, having a convex curved surface protruded to an outside of the surface of the reflection mirror and being in contact with a side wall when the reflection mirror is set along the side wall; a pair of fixing parts respectively mounted to the back surface of the reflection surface of the reflection mirror so as to sandwich the protruded part therebetween and projecting to the outside of the reflection mirror; the case for optical components being formed from a component housing member in the shape of a container having an opening through which the plural optical components are housed inside and a lid member that closes the opening of the component housing member; the reflection mirror being set along a side wall of the component housing member; and the side wall being provided with a pair of fixing grooves extending along a direction of housing the reflection mirror in the component housing member, guiding movement of the pair of fixing parts in setting the reflection mirror in the component housing member, and enabling the pair of fixing parts to be provided with play.