In order to adjust position of color combining optical system relative to a color
separating optical system accommodated in an optical component casing for producing
a projector, a white laser beam is irradiated on an optical axis of a light beam
passing through the optical component casing and is separated by the color separating
optical system, the separated respective color lights being incident on a light-incident
end surface of the color combining optical system to be combined, the combined
light beam being detected by a sensor, in which the position is adjusted while
detecting the combined light beam.
