Patent ID: 7830545
Filing Date: 2010-11-09
Classification: B41J,G02B,G03G,H04N

Abstract:
1. An optical unit adapted to perform exposure, the optical unit comprising: a base body having optical parts and having an opening; and a cover adapted to cover the opening portion of the base body, the cover being fixed to the base body at three points in a first plane, the cover being further fixed to the base body at a second plane positioned on the base body and being adjacent to the first plane and at a third plane positioned on the base body and being not parallel to the second plane, wherein the cover is fixed to the base body at two points in the second plane and at one point in the third plane, and wherein the cover is fixed via fasteners through fastener holes, wherein at least one of the fastener holes has two partial cylindrical surfaces formed on both sides of the at least one fastener hole, and wherein each of the partial cylindrical surfaces has a center axis parallel to the first plane and the second plane.