内視鏡用対物レンズおよび内視鏡
- 专利权人:
- 富士フイルム株式会社
- 发明人:
- 宮野 俊
- 申请号：
- JP2007101589
- 公开号：
- JP4919419B2
- 申请日:
- 2007.04.09
- 申请国别(地区):
- JP
- 年份:
- 2012
- 代理人:
- 摘要：
PROBLEM TO BE SOLVED: To provide an objective lens for an endoscope, wherein a chromatic aberration of magnification is successfully corrected while securing a long back focus.
SOLUTION: The objective lens for an endoscope includes, in order from the object side: a first lens having negative refractive power and formed such that a concave face is oriented on the image side a first cemented lens L23 formed by cementing a second lens and a third lens, one of which has positive refractive power and the other, negative refractive power a diaphragm a fourth lens L4 having positive refractive power and formed such that a face that is flat or has a curvature radius with a greater absolute value is oriented on the object side and a second cemented lens L56 formed by cementing, in order from the object side, a fifth lens with negative refractive power and a sixth lens with positive refractive power, and having positive refractive power as a whole. The objective lens satisfies the following formulae (1) and (2) Bf/f>2.5, (wherein f is a focal distance, Bf is a back focus, &nu
5 is the Abbes number of the fifth lens, &nu6 is the Abbes number of the sixth lens, RA is the curvature radius of the cemented face of the second cemented lens, d6 is the thickness of the center of the sixth lens, and n6 is the refractive index of the sixth lens).COPYRIGHT: (C)2009,JPO&INPIT
- 来源网站：
- 中国工程科技知识中心
