Laser range finder with non-linearity compensation
US4613231A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 7, 1984 |
| Grant date | Sep 23, 1986 |
| Priority date | — |
| Expiry date | Mar 7, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42C13/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The receiver (3') of a laser range finder operating on the pulse propagation and including a transmitter unit (1) and a first receiver unit (2) is sampled by a spike pulse (5) derived from the transmitter pulse in such a way as to produce a low-frequency representation (10). The non-linearity of the phase modulation of this spike pulse, which is detrimental in very accurate measurements taken over long distances, is eliminated in that the oscillations of high-frequency oscillator (8) are supplied to a second receiver unit (2') in which they are scanned by the same spike pulse (5) and are then also suitably transformed into a low-frequency representation (10'). A counter (12) then counts the low-frequency zero-passages of the oscillator, beginning with the onset of the low-frequency cycle, thereby eliminating all errors (FIG. 1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.