| 发明名称 |
OBLIQUE-VIEWING OBJECTIVE OPTICAL SYSTEM AND ENDOSCOPE FOR OBLIQUE VIEWING USING THE SAME |
| 摘要 |
An oblique-viewing objective optical system includes in order from an object side, a front-side lens group which includes a negative lens, an optical path converting element, an aperture stop, and a rear-side lens group having a positive refractive power, wherein the rear-side lens group includes a positive lens and a cemented lens having a positive refractive power, and the cemented lens includes in order from the object side a positive lens and a negative lens, and the following conditional expressions (1), (2), (3), (4), and (5) are satisfied:;−2.0<fF/f<−1.3 (1),;1.7<fR/f<2.7 (2),;0.63<|fF/fR|<0.88 (3),;2.4<D1/f<4.4 (4), and;1.1<D2/f<1.7 (5). |
| 申请公布号 |
US2017049305(A1) |
申请公布日期 |
2017.02.23 |
| 申请号 |
US201615342352 |
申请日期 |
2016.11.03 |
| 申请人 |
OLYMPUS CORPORATION |
发明人 |
TAKASUGI Yoshiharu |
| 分类号 |
A61B1/00;G02B23/02;G02B23/24 |
主分类号 |
A61B1/00 |
| 代理机构 |
|
代理人 |
|
| 主权项 |
1. An oblique-viewing objective optical system, comprising in order from an object side:
a front-side lens group which includes a negative lens; an optical path converting element; an aperture stop; and a rear-side lens group having a positive refractive power, wherein the rear-side lens group includes a positive lens and a cemented lens having a positive refractive power, and the cemented lens includes in order from the object side, a positive lens and a negative lens, and the following conditional expressions (1), (2), (3), (4), and (5) are satisfied:
−2.0<fF/f<−1.3 (1),1.7<fR/f<2.7 (2),0.63<|fF/fR|<0.88 (3),2.4<D1/f<4.4 (4), and1.1<D2/f<1.7 (5), where, fF denotes a focal length of the front-side lens group, fR denotes a focal length of the rear-side lens group, f denotes a focal length of the overall oblique-viewing objective optical system, D1 denotes an air-conversion length from an image-side surface of the negative lens in the front-side lens group up to the aperture stop, and D2 denotes an air-conversion length from an image-side surface of the rearmost lens in the rear-side lens group up to the image plane. |
| 地址 |
Tokyo JP |
