Patent ID: 6903827

Claim:
A position adjusting method of color combining optical system used for producing a projector including a light source, a color separating optical system that separates a light beam irradiated by the light source into a plurality of color lights, an optical component casing that accommodates optical components constituting the color separating optical system, a plurality of optical modulators that modulate the respective color lights separated by the color separating optical system in accordance with image information, and a color combining optical system that combines the light beam modulated by the respective optical modulators to form an optical image, the position adjusting method adjusting the position of the color combining optical system relative to the optical components casing, comprising the steps of: irradiating a white laser beam on an optical axis of a light beam passing through the optical component casing; separating the white laser beam by the color separating optical system into the respective color lights to be incident on a light-incident end surface of the color combining optical system and detecting the light beam combined by the color combining optical system by a sensor; and three-dimensionally adjusting the position of the color combining optical system relative to the optical component casing while detecting the combined light.