Locator camera arrangement having multiple light sources

Patent metadata

Field	Value
Publication number	US-9631922-B2
Application number	US-201514942683-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Apr 5, 1999
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method for measuring a distance includes modulating the light beam at a first frequency, receiving a second beam by the optical detector to produce a first electrical signal having the first frequency and a first phase; modulating the light beam at a second frequency different than the first frequency; receiving the second beam by the optical detector to produce a second electrical signal having the second frequency and a second. After these steps, the retroreflector is moved while modulating the light beam continuously at the second frequency; and a first distance to the retroreflector is determined based at least in part on a the first and second frequencies and phases.

First claim

What is claimed is:

1. A laser based coordinate measuring device, comprising:
a distance meter that measures distance based at least in part on the speed of light;
a structure that is rotatable by a first angle and a second angle about two substantially orthogonal axes, the structure launching a beam from the distance meter;
a first encoder for measuring the first angle;
a second encoder for measuring the second angle;
a retroreflector target disposed remote from the rotatable structure;
a locator camera, which comprises an optical system having a lens, a photosensitive array, and a plurality of light sources, disposed on the rotatable structure for determining an approximate location of the target, wherein:
the plurality of light sources emits a cone of light for illuminating the retroreflector target;
wherein a first ray of light emitted by one of the plurality of light sources travels to the retroreflector target in a straight line, a second ray of light reflected by the retroreflector target travels to the lens in a straight line and forms a pattern of light on the photosensitive array;
an electronics system that analyzes the pattern of light on the photosensitive array to determine the approximate angular direction to the retroreflector target; and
an actuator system to orient the rotatable structure in accordance with the location determined by the locator camera.

2. The device of claim 1 , wherein the distance meter is coupled to the structure by an optical fiber.

3. The device of claim 1 , wherein a plurality of identical light sources are disposed in a ring surrounding the lens.

4. The device of claim 2 , wherein a plurality of identical light sources are disposed in a ring surrounding the lens.

Assignees

• Faro Tech Inc
• Faro Tech Inc

Inventors

• Bridges Robert E
• Brown Lawrence B
• West James K
• Ackerson D Scott

Classifications

• G01S17/66

  Tracking systems using electromagnetic waves other than radio waves · CPC title

• G01C3/08

  Use of electric radiation detectors · CPC title

• G01B11/03

  by measuring coordinates of points · CPC title

• G01S5/163

  Determination of attitude (using inertial means G01C9/00; control of attitude G05D1/49) · CPC title

• G01B11/02

  for measuring length, width or thickness (G01B11/08 takes precedence) · CPC title