| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical system capable of easily obtaining high optical performance by preventing unnecessary stress from being added to a cemented lens when the lens is held in a lens holding frame, and reducing the occurrence of double refraction of a material due to the stress. <P>SOLUTION: In an optical system including a cemented lens, an image side lens of the cemented lens has an outer diameter larger than that of an object side lens, and a periphery of the image side lens has a positioning part for determining a position of the cemented lens in an optical axis direction. A distance L on the optical axis from an image surface to a lens surface closest to the object side in the cemented lens and a focal distance f of the optical system are appropriately set, respectively. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
