| 发明名称 | Objective optical system | ||
| 摘要 | Provided is an objective optical system comprising, in order from an object side: an aperture stop; a positive first group; a second group; a positive third group; and a fourth group, wherein the first group is formed of a single meniscus lens or plano-convex lens, whose convex surface faces an image side, the second group is formed of a single lens, the third group is formed of a cemented lens consisting of a positive lens and a negative lens, the fourth group is formed of a single lens, and Conditional Expressions (7) and (8) below are satisfied, where f is a focal length of an entire system, f4 is a focal length of the fourth group, and f2 is a focal length of the second group. −0.5<f/f4<−0.001 (7)0.1≦|f4/f2|≦5. (8) | ||
| 申请公布号 | US8767307(B2) | 申请公布日期 | 2014.07.01 |
| 申请号 | US201314109015 | 申请日期 | 2013.12.17 |
| 申请人 | Olympus Medical Systems Corp. | 发明人 | Nakamura Minoru;Ushio Yasuaki |
| 分类号 | G02B21/02;G02B9/34;G02B23/24;G02B13/00;A61B1/00 | 主分类号 | G02B21/02 |
| 代理机构 | Kenyon & Kenyon LLP | 代理人 | Kenyon & Kenyon LLP |
| 主权项 | 1. An objective optical system comprising, in order from an object side: an aperture stop; a positive first group; a second group; a positive third group; and a fourth group, wherein the first group is formed of a single meniscus lens or plano-convex lens, whose convex surface faces an image side, the second group is formed of a single lens, the third group is formed of a cemented lens consisting of a positive lens and a negative lens, the fourth group is formed of a single lens, and Conditional Expressions (7) and (8) below are satisfied: −0.5<f/f4<−0.001, and (7)0.1≦|f4/f2|≦5,where f is a focal length of an entire system,f4 is a focal length of the fourth group, andf2 is a focal length of the second group. | ||
| 地址 | Tokyo JP | ||