Objective lens system
US3989317A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1975 |
| Grant date | Nov 2, 1976 |
| Priority date | — |
| Expiry date | Feb 12, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B9/12
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Achromat objective lens systems and more particularly an objective lens system having a magnification .beta. on the order of 10 to 30X and designed to operate particularly for the monochromatic light whose wave length is on the order of 6328 A. The lens system consists of three lens components and four lenses. The first and second lens components are positive singlet lenses. The third lens component is a positive doublet lens composed of a negative meniscus lens and a biconvex lens. The lens system is constructed so as to satisfy the following three conditions: ______________________________________ 0.9f<d.sub.2 +d.sub.3 +d.sub.4 <1.3f (1) 0.8f<R.sub.6 <1.2f (2) 1.46<n.sub.1d <1.65 1.46<n.sub.2d <1.65 1.46<n.sub.4d <1.65 50<.nu..sub.1d <68 (3) 50<.nu..sub.2d <68 50<.nu..sub.4d <68 .nu..sub.3d <35 ______________________________________ Wherein f designates the overall focal length of the system given for a wave length light of 6328 A, R.sub.6 designates the radius of curvature of the cemented surface of the third lens component, d.sub.2 and d.sub.4 designate the separation between the first and second lens components and the separation between the second and third lens components, r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.