Reference light beam projector
US4293218A · kind A · utility
17Cited by
6References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1978 |
| Grant date | Oct 6, 1981 |
| Priority date | — |
| Expiry date | Dec 28, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C15/004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A reference light beam projector of the type which produces a modulated plane of light for use as a reference in many different applications such as for aligning railroad tracks. This modulated reference plane is formed by projecting a collimated light beam along a predetermined path and providing means for variably refracting the beam so to effectively variably bend the beam back and forth along a plane. Specifically, the means for variably refracting the beam is a rotating optical element comprising a window through which the beam is transmitted and variably refracted as the optical element is rotated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.