Multi lens for efficient collection of light at varying distances
US5347137A · kind A · utility
2Cited by
3References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1992 |
| Grant date | Sep 13, 1994 |
| Priority date | — |
| Expiry date | Jul 8, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B3/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Optical distance measuring apparatus has a focusing lens (16) directing light reflected from a target toward a detector (18), The lens has discrete or continuous zones each associated with a target distance. The area of the lens zones increases with an increase in associated target distance so as to compensate for a reduction in intensity according to the inverse square law.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.