Laser beam level instrument
US4221483A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 1978 |
| Grant date | Sep 9, 1980 |
| Priority date | — |
| Expiry date | Nov 20, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C15/004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A lightweight, portable laser beam level instrument has an optical path which includes a solid state light source; a pendulous, positive lens; a rotatable pentaprism or mirror equivalent; and a glass plate which is tilted to provide fine tuning. The level instrument also includes a damping mechanism, a waterproof enclosure and a clip-in battery pack. The solid state light source is a diode in a specific embodiment and produces an intense beam of rapidly diverging infrared laser light. The postiive lens is suspended below the diode at approximately the focal length of the lens from the diode to collimate the light. The pendulous suspension lens maintains the beam in a truly vertical position with respect to the earth to provide self-leveling in a limited range of movement of the instrument. The pentaprism or equivalent converts this vertical beam to a horizontal beam. The glass plate is positioned between the diode and the lens and can be tilted in two orthogonal degrees of adjustment to provide a fine tuning for optical centering of the diode and the lens. Oscillation of the pendulous lens is damped by magnetic or air damping.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.