Christopher C Chagaris

US Patent:

8085388, Dec 27, 2011

Filed:

Dec 11, 2007

Appl. No.:

12/001606

Inventors:

Steven P. Kaufman - Hooksett NH, US
Arkady Savikovsky - Burlington MA, US
Christopher C. Chagaris - Manchester NH, US
Joel Stave - New Boston NH, US

Assignee:

Laser Projection Technologies, Inc. - Londonderry NH

International Classification:

G01C 3/08

US Classification:

356 501, 356 401, 356 51, 356 515

Abstract:

A 3D pulsed laser projection system scans an object to produce a dense 3D point cloud and projects a laser light beam onto an object as a glowing template. A high-sensitivity optical feedback system receives and detects a feedback beam of the output beam light diffusely reflected from the object. The feedback light and projected beam share the same beam path between steering mirrors and the object. A light suppression component controls stray scattered light, including ambient light, from being detected. A time-of-flight measurement subsystem provides a distance-to-object measurement for projected pulses. An acousto-optical modulator, variable gain detected signal amplification and variable photo-detector power together produce a dynamic range for detected reflected feedback signals of at least 100,000, and up to 500,000. Optical fiber cables spatially filter scattered light and isolate the photo-detectors thermally. The laser is preferably pulsed at least 50 kHz, with sampling of the projected and feedback reflected optical pulse signals at a sampling rate of up to 10 gigasamples per second.

US Patent:

8582087, Nov 12, 2013

Filed:

Dec 23, 2011

Appl. No.:

13/336568

Inventors:

Steven P. Kaufman - Hooksett NH, US
Arkady Savikovsky - Burlington MA, US
Christopher C. Chagaris - Manchester NH, US
Joel Stave - New Boston NH, US

Assignee:

Laser Projection Technologies, Inc. - Londonderry NH

International Classification:

G01C 3/08

US Classification:

356 501, 356 301, 356 401, 356 41, 356 51

Abstract:

A laser projection system is disclosed. The system includes a laser projector that projects a light beam to the surface of an object and scans that projected light beam over at least a portion of the surface, wherein a portion of the projected beam is diffusely reflected from the surface back to the system. The system further includes an optical signal detector that receives the feedback light beam and converts it to an image signal, a light suppression means for suppressing unwanted light from entering the optical signal detector, and a computer for producing a measurement of the distance from the projector to the object surface, and controlling the system to buck the laser projector into a coordinate system of the object using three or more features on the object, wherein at least one of the three or more features serves as a targetless fiducial point.

US Patent:

20060170870, Aug 3, 2006

Filed:

Feb 1, 2006

Appl. No.:

11/345784

Inventors:

Steven Kaufman - Hooksett NH, US
Arkady Savikovsky - Burlington MA, US
Christopher Chagaris - Manchester NH, US
Joel Stave - New Boston NH, US

Assignee:

Laser Projection Technologies, Inc. - Londonderry NH

International Classification:

G03B 21/26

US Classification:

353028000

Abstract:

A laser projection system scans an output laser light beam onto an object to detect features. A high-sensitivity optical feedback system receives and detects a feedback beam of the output beam light diffusely reflected from the object. The feedback light and projected output beam share the same beam path between beam-steering mirrors of the projector and the object. The laser projection system has light suppression components to control stray scattered light, including ambient light, from being detected. A computer of the laser projection system calculates fiducial points on the object from detected features to align the projection system with the object without using targets. This feature detection is used in a process to guide assembly and fabrication on or to the object, and to verify the accurate placement of parts and fabrication steps in place after they are assembled or processed. In one form, the detected feature is a light spot on the object produced by a second light source.