Patent ID: 7692885
Filing Date: 2010-04-06
Classification: G02B

Abstract:
1. A lens barrel for a projector including a front group lens projecting an image on a screen and a rear group lens formed of a plurality of lenses shifting through a cam barrel, respectively, the lens barrel comprising: a rear barrel which is formed of resin and contains the rear group lens; and a front barrel which is formed of resin and contains the front group lens, wherein the front group lens is disposed to be focusable, an inner diameter of a portion containing the front group lens of the front barrel, is 1.15 times or more as large as an inner diameter of a portion containing the rear group lens of the rear barrel, and wherein the front barrel and the rear barrel are coupled by a connection portion, and wherein three reference faces are disposed on three locations dividing a circumference centered on an optical axis into three equal portions, the three reference faces have the same positions in an optical axis direction, and the three reference faces are integrally formed on coupling face of the front barrel or coupling face of the rear barrel, and wherein three adjustment faces are disposed on three locations dividing a circumference centered on an optical axis into three equal portions, the three adjustment faces have the same positions in the optical axis direction, the three adjustment faces are integrally formed as one set on the other coupling face, and plural sets of the adjustment faces are provided with change of the positions in the optical axis direction.