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Title: Light beam range finder

Abstract

A ``laser tape measure`` for measuring distance is disclosed which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to onemore » aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%. 7 figs.« less

Inventors:
Publication Date:
Research Org.:
University of California
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
672606
Patent Number(s):
US 5,767,953/A/
Application Number:
PAN: 8-486,081
Assignee:
Univ. of California, Oakland, CA (United States)
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 16 Jun 1998
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; OPTICAL RADAR; DESIGN; SEMICONDUCTOR LASERS; VISIBLE RADIATION; TIMING CIRCUITS; REFLECTION

Citation Formats

McEwan, T E. Light beam range finder. United States: N. p., 1998. Web.
McEwan, T E. Light beam range finder. United States.
McEwan, T E. Tue . "Light beam range finder". United States.
@article{osti_672606,
title = {Light beam range finder},
author = {McEwan, T E},
abstractNote = {A ``laser tape measure`` for measuring distance is disclosed which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%. 7 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {6}
}