Lens assembly and fabrication method thereof
US10996442B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 2018 |
| Grant date | May 4, 2021 |
| Priority date | — |
| Expiry date | Aug 26, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B9/62
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens assembly including a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, arranged from the magnification side to the reduction side, is provided. The fourth lens and the fifth lens are combined into a cemented lens having an aspherical surface. The lens assembly includes 5 to 6 lenses with a refractive power. The first lens is a glass lens, and the others are aspherical lenses. R1 is the radius of curvature of the lens surface of the first lens facing the magnification side, R2 is the radius of curvature of the lens surface of the first lens facing the reduction side, T is the thickness, on the optical axis of the lens assembly, of the first lens, wherein the refractive index of the first lens>1.55, the Abbe number of the first lens>55, and R1-R2-T<8.8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.