| US 7,508,599 B2 | ||
| Optical system with wavelength selecting device | ||
| Kouichi Ohshita, Tokyo (Japan); and Mami Muratani, Tokyo (Japan) | ||
| Assigned to Nikon Corporation, Tokyo (Japan) | ||
| Filed on Aug. 13, 2007, as Appl. No. 11/838,088. | ||
| Application 11/838088 is a division of application No. 11/207728, filed on Aug. 22, 2005, granted, now 7,256,949. | ||
| Application 10/945113 is a division of application No. 10/316917, filed on Dec. 12, 2002, granted, now 6,870,687, filed on Mar. 22, 2005. | ||
| Application 11/207728 is a continuation of application No. 10/945113, filed on Sep. 21, 2004, abandoned. | ||
| Claims priority of application No. 2001-378795 (JP), filed on Dec. 12, 2001; application No. 2001-380637 (JP), filed on Dec. 13, 2001; and application No. 2002-179148 (JP), filed on Jun. 19, 2002. | ||
| Prior Publication US 2007/0291365 A1, Dec. 20, 2007 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G02B 9/00 (2006.01); G02B 5/28 (2006.01) | ||
| U.S. Cl. 359—754 [359/589] | 10 Claims |
| 1. An optical system comprising:
a plurality of lens elements having respective lens surfaces; and
an optical member including an interference film formed on one of the lens surfaces of the lens elements;
the optical system including a negative lens group and a positive lens group adjacent to the negative lens group;
the positive lens group including a positive lens element located most toward the object side of the positive lens group;
and
the optical member being formed on the image side surface of the positive lens element;
wherein the following conditional expressions are satisfied:
0<|Φ/R|<0.6
0°≤|B|<13°
where Φ denotes the effective diameter of the lens surface, R denotes the radius of curvature of the lens surface, and B denotes
an angle of the principal ray passing through the lens surface relative to the optical axis at the lens surface in the air
side.
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