| 摘要 |
<p>Optical scanning apparatus including a rotating pyramidal mirror scanning wheel with reflector segments for deflecting a laser beam into and away from a doublet mirror roof reflector associated with said scanning wheel. The scanning wheel introduces components of vertical and horizontal angular deviation into the beam, the vertical deviation component being cancelled by inversion through the roof reflector while the horizontal angular component is doubled upon the second reflection from the scanning wheel so that the output beam is vertically wobble-free and stable while the beam is scanned through the sum of the horizontal angular components introduced by the wheel. The scanner is employed to create a flying spot scan from a laser beam in photosensitive plate exposure apparatus, one form of which employs superimposed laser read and expose (write) beams of different frequencies which are simultaneously scanned without chromatic aberration, and subsequently separated to read copy and to expose a photosensitive plate surface as in the production of printing plates.</p> |
