| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a projecting lens system able to form a sharp image on a dome-shaped screen. <P>SOLUTION: A projecting lens system 10 for projecting projection light to a dome-shaped screen 9 from inside, the projection light being emitted from a target projection surface 2. In this lens system, a first lens group G1 includes a first lens L1 of meniscus type a concave face S1 of which is oriented toward the screen 9 and at least the periphery of which has negative refractive power, a second lens group G2 includes a second lens L2 of meniscus type a convex face S4 of which is oriented toward the target projection surface 2, and a third lens group G3 includes a third lens L3 whose convex face S6 of which is oriented toward the screen 9. Both faces of the first lens L1 are aspheric and includes negative refractive power that increases toward the periphery thereof from an optical axis 100. A distance d3 between an aperture stop St and a convex face S2 of the first lens L1 is shorter than a distance d4 between the aperture stop St and a concave face S3 of the second lens L2. <P>COPYRIGHT: (C)2013,JPO&INPIT |
