Lens unit and image observing device
US12429668B2 · kind B2 · utility
0Cited by
13References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2019 |
| Grant date | Sep 30, 2025 |
| Priority date | — |
| Expiry date | Nov 18, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0172
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens unit includes a first lens and a second lens. The first lens is a Fresnel lens that has a first lens surface having a Fresnel structure on the second lens side, and has a positive refractive power. The second lens is a Fresnel lens that has a second lens surface having a Fresnel structure on the first lens side, and has a positive refractive power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.