Albada finder
US4429978A · kind A · utility
10Cited by
3References
25Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1982 |
| Grant date | Feb 7, 1984 |
| Priority date | — |
| Expiry date | Apr 6, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B23/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A four-lens-element albada finder comprising a field mask lens having a field mask and an eyepiece of a positive lens to improve the sight of the visual field and field mask images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.