| 发明名称 |
OPTICAL SYSTEM AND OPTICAL APPARATUS INCLUDING THE SAME |
| 摘要 |
An optical system includes an optical element made of resin and a reflection portion configured to reflect ultraviolet radiation. The reflection portion is provided on an optical surface located closer to an object side than the optical element, and conditional expressions 0.10≦Lu/L≦0.90 and |tan−1(H0/Lr)−tan−1{H0(Lr−Lu)/(Ru×Lr)}|≦25° are satisfied, in which H0 represents a maximum height, from an optical axis, of an optical surface closest to the object side, Lu represents a distance from the optical surface closest to the object side to the reflection portion, Lr represents a distance from the optical surface closest to the object side to the optical element, L represents a total length of the optical system, and Ru represents a radius of curvature of the optical surface on which the reflection portion is provided. |
| 申请公布号 |
US2017031071(A1) |
申请公布日期 |
2017.02.02 |
| 申请号 |
US201615209438 |
申请日期 |
2016.07.13 |
| 申请人 |
CANON KABUSHIKI KAISHA |
发明人 |
Ishibashi Tomohiko |
| 分类号 |
G02B5/28;G02B1/04;G02B27/00;G02B5/08 |
主分类号 |
G02B5/28 |
| 代理机构 |
|
代理人 |
|
| 主权项 |
1. An optical system, comprising:
an optical element made of resin; and a reflection portion configured to reflect ultraviolet radiation, wherein the reflection portion is provided on an optical surface located closer to an object side than the optical element, and wherein following conditional expressions are satisfied:
0.10≦Lu/L≦0.90, and|tan−1(H0/Lr)−tan−1{H0(Lr−Lu)/(Ru×Lr)}|≦25°, in which H0 represents a maximum height, from an optical axis, of an optical surface closest to the object side, Lu represents a distance from the optical surface closest to the object side to the reflection portion, Lr represents a distance from the optical surface closest to the object side to the optical element, L represents a total length of the optical system, and Ru represents a radius of curvature of the optical surface on which the reflection portion is provided. |
| 地址 |
Tokyo JP |
