| 摘要 |
PURPOSE:To increase the region having the even light intensity on a scanning surface, by approximately equalizing the form between each edge of a beam spot on a hologram and each edge of the hologram in the same direction. CONSTITUTION:A correcting means for laser spot form consisting of a mask 4 is provided into an optical path reaching a hologram 2 from a laser beam source. A pierced hole 5 of the mask 4 is formed according to the forms of edges 2a and 2b of the hologram 2. Accordingly an agreement is obtained between edges 6a and 6b of a beam spot corrected by edges 5a and 5b of the hole 5 and the edges 2a and 2b of the hologram 2. As a result, the beam spot never spillover from the hologram 2, so that the region of the even light intensity on the scanning surface is increased. |
