Laser diode distance measurement
US5267016A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1991 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Nov 27, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/481
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser diode distance measurement device includes a laser diode 10 which emits light 20 to a lens 22 which provides focussed light 24 incident on a target 26. The light 24 is reflected from the target 26 back to the laser diode 10 which causes the laser diode 10 to emit a light 28 which exhibits intensity pulses (due to coherent interference) related to the distance L to the target 26. A photodetector 30 provides a feedback signal indicative of the intensity of the light 28 to a distance measurement circuit 18. The laser diode 10 is driven by an up-ramp signal that reduces electronic processing and at a frequency that reduces speckle noise. The distance measurement circuit 18 blanks-out a portion of the feedback signal during discontinuities of the laser diode drive signal to minimize associated noise from distorting the distance measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.