Rangefinder with reduced noise receiver
US7508497B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 23, 2004 |
| Grant date | Mar 24, 2009 |
| Priority date | — |
| Expiry date | Oct 21, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rangefinder and method are provided for measuring a distance between the rangefinder and a target by measuring the flight time of a beam reflected from the target. In an embodiment, a receiver having reduced noise detects weak reflections from the targets or targets with poor reflectivity. The receiver generates a voltage signal proportional to a reflected beam, clamps the voltage signal to remove a portion of the noise therefrom, and compares the voltage signal to a threshold. In some embodiments, the receiver also filters the voltage signal to remove a portion of the noise therefrom. In an embodiment, the sensitivity of the receiver is increased as a function of time to reduce the likelihood of detecting stray reflections from objects other than the intended target. In some embodiments, the rangefinder collects calibration data with each range measurement or group of range measurements. The calibration data comprise a plurality of simulated range measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.