| 摘要 |
A projection optical system that, by using projection light emanating from a light valve illuminated by illumination light, projects an enlarged image of an image displayed on the light valve onto a screen has, from the conjugate enlargement side: a front lens unit having a negative optical power as a whole, including at least one aspherical surface, having a first lens element having a negative optical power disposed at the conjugate-enlargement-side end thereof, and having a second lens element having a negative optical power disposed on the conjugate reduction side of the first lens element; optical path turning means, including a reflecting surface, for turning the light path of the light emanating from the front lens unit; a rear lens unit having a positive optical power as a whole, including at least one aspherical surface, and including a third lens element made of an anomalous dispersion material and having a positive optical power; and projection light preparing means disposed between the rear lens unit and the light valve and having at least one of the function of separating the illumination light and the projection light and the function of integrating together light of different colors. Here, the center of the light valve is not located on the optical axis of the rear lens unit. Moreover, relevant parameters fulfill prescribed conditions.
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