Patent ID: 8436885

Claim:
An apparatus for generating a spatially modulated light, comprising: a laser light source; a spatial light modulator having a plurality of light modulator elements which are arranged in an element arrangement direction; and an illumination optical system for generating a linear illumination light from a light emitted from said laser light source, said linear illumination light being directed onto said plurality of light modulator elements, a section of said linear illumination light having a linear shape which is long in said element arrangement direction, wherein each light modulator element of said plurality of light modulator elements has strip-like moving reflective surfaces and strip-like fixed reflective surfaces which are elongated in a direction perpendicular to said element arrangement direction and are alternately arranged in said element arrangement direction, said moving reflective surfaces are sagged in a state where both end portions of said moving reflective surfaces are supported, and said each light modulator element changes between a state of emitting a zeroth order light and a state of emitting first order diffracted lights, to generate a group of signal lights, each of which is a zeroth order light or first order diffracted lights, from said plurality of light modulator elements, as a spatially modulated light, and said illumination optical system comprises: a first optical system for forming an intermediate image of said laser light source at an intermediate image position between said laser light source and said spatial light modulator, said intermediate image being formed with respect to a vertical direction which is a direction perpendicular to a horizontal direction corresponding to said element arrangement direction and perpendicular to an optical axis, said intermediate image being long in said horizontal direction; a slit member positioned at said intermediate image position and having a slit extending in said horizontal direction, said slit member blocking an undesired light which appears on both sides or one side of said intermediate image in said vertical direction; and a second optical system for reforming said intermediate image onto said spatial light modulator with respect to at least said vertical direction with using a light passing through said slit, to generate said linear illumination light, and said apparatus further comprising a holding member for holding said laser light source, said first optical system, and said slit member, and being attachable to and detachable from said second optical system.