Patent ID: 7612951
Filing Date: 2009-11-03
Classification: G02B

Abstract:
1. A projection lens unit comprising: a projection lens system which enlarges and projects image light from an image formation device onto a screen; and a lens barrel which holds lenses of the projection lens system, wherein the lens barrel comprises: a movable lens barrel which holds one or a plurality of lenses, among the lenses of the projection lens system, having positive power and positioned closest to a side of the image formation device; a holding tube which holds the movable lens barrel so as to be movable in an optical axis direction; a reference surface perpendicular to the optical axis; a thermal deformation member including a bimetal member which is deformed so as to increase a thickness thereof at the time of a temperature increase and which is disposed between the reference surface and the movable lens barrel; and an elastic member which presses the movable lens barrel and the bimetal member in the optical axis direction toward the image formation device against the reference surface.