| 摘要 |
PURPOSE:To improve the utilization factor of printing rays emitted from a point light source by rotating a disk-shaped shielding plate radially formed with multiple slits extended in the radial direction and scanning with light rays passing these slits. CONSTITUTION:A shielding plate 10 is rotated by a rotation driving device 14 at a predetermined speed. Slits 11 are formed on this shielding plate 10, and the slits 11 are extended in the radial direction at a predetermined distance radially at multiple places. The rotary shaft of the shielding plate 10 is inclined at a predetermined angle against the tube axis 2a of a face plate 2, band-shaped printing rays emitted from a point light source 20 and having passed the slits 11 scan in sequence continuously in the arrow direction as the shielding plate 10 is rotated using the exposure membrane of the plate 2 as a band-shaped illumination section 7 with a fixed width W. Accordingly, the quantity of light rays shielded by the shielding plate is reduced and the utilization factor can be improved, and the necessary quantity can be exposed in a short time.
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