| 摘要 |
PROBLEM TO BE SOLVED: To simplify constitution of an astigmatism correction means to make it an easy assembly and compact structure in an optical writing head comprising a plurality of light sources and dichroic mirrors. SOLUTION: Light from the light source 11 is transmitted through the dichroic mirrors DM1 and DM2, a "Selfoc" lens SLA, and a concave cylindrical lens 34 so as to form an image on photographic printing paper PP. Similarly, light from the light source 12 is transmitted through an astigmatism uniformizing member 31, reflected by the dichroic mirror DM1 and transmitted through the dichroic mirror DM2, and light from the light source 13 is transmitted through an astigmatism uniformizing member 32 and reflected by the dichroic mirror DM2 so as to form an image on the photographic printing paper PP. The thickness of the astigmatism uniformizing member 32 is twice as large as that of the astigmatism uniformizing member 31. The astigmatism of the light from each light source is uniformized and corrected by a common cylindrical lens 34. COPYRIGHT: (C)2009,JPO&INPIT
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