US4687325A — Three-dimensional range camera

Claim 1

Independent Claim 149 words

A non-contact sensor system to measure range to an object from a reference plane comprising: a pattern generator and projector to produce a 1×N array of time and space coded light rays whose intensities can each be varied with time, and to project P sequential presentations of different light ray patterns onto a three-dimensional object, where P=1+log b N, b is the number of brightness levels and N is the number of rays; a linear array sensor which views, at an angle to projected light rays, points of light where said rays are incident on the surface of said object, and generates one-dimensional scan signals which have ray peaks at locations corresponding to imaged light; and a range profile processor to analyze said scan signals to uniquely identify all rays, determine depth from the displacement of said ray peaks from calibration, reference plane peaks, and provide a range map.

Claim 2

Dependent Claim 149 words

A non-contact sensor system to measure range to an object from a reference plane comprising: a pattern generator and projector to produce a 1×N array of time and space coded light rays whose intensities can each be varied with time, and to project P sequential presentations of different light ray patterns onto a three-dimensional object, where P=1+log b N, b is the number of brightness levels and N is the number of rays; a linear array sensor which views, at an angle to projected light rays, points of light where said rays are incident on the surface of said object, and generates one-dimensional scan signals which have ray peaks at locations corresponding to imaged light; and a range profile processor to analyze said scan signals to uniquely identify all rays, determine depth from the displacement of said ray peaks from calibration, reference plane peaks, and provide a range map.

Claim 3

Dependent Claim 55 words

The system of claim 1 and means for orthogonally sweeping said 1×N array of coded light rays by steps over a rectangular plane, whereby at each step one line of light points on the surface of said object are imaged by said linear array sensor and depth is measured to provide an area range map.

Claim 4

Dependent Claim 14 words

The system of claim 2 wherein said orthogonal sweep means is a rotating mirror.

Claim 5

Dependent Claim 52 words

The system of claim 1 wherein said pattern generator includes a sheet light source, and a rotating code wheel which has at least one group pattern comprised of one pattern per presentation having discrete regions whose light transmission coefficients are selected to spatially modulate the light sheet into said coded light rays.

Claim 6

Dependent Claim 54 words

The system of claim 1 wherein said pattern generator and projector includes a sheet light source, a rotating code wheel which has one or more group patterns each comprised of one pattern per presentation having clear and opaque regions to spatially modulate the light sheet into said coded light rays, and a projection lens.

Claim 7

Dependent Claim 83 words

The system of claim 1 wherein said pattern generator and projector includes a sheet light source, a rotating code wheel which has at least one group pattern comprised of one pattern per presentation having discrete regions whose light transmission coefficients are selected to spatially modulate the light sheet into said coded light rays, a reduction lens to project said coded rays onto the entrance of a coherent optical fiber bundle, and a projection lens to reimage said coded rays on the object surface.

Claim 8

Dependent Claim 48 words

The system of claim 1 wherein said pattern generator and projector includes a narrow laser beam source, a modulator to programmably vary the intensity of said laser beam, and a beam deflector to scan the modulated beam along a straight line and project it onto the object surface.

Claim 9

Dependent Claim 167 words

A three-dimensional range camera comprising: a pattern generator and projector to produce a 1×N array of time and space coded light rays which can each be varied with time and to project P sequential presentations of different subsets of said light rays onto a three-dimensional object, where P=1+log 2 N and N is the number of light rays; means for orthogonally sweeping said array of coded light rays by steps over a rectangular plane; a linear array, line scan camera to image points of light on the surface of said object where said light rays are incident, and generate after each presentation a one-dimensional scan signal which has ray peaks at locations corresponding to imaged light points, said line scan camera generating a set of said scan signals per step; and a range processor to analyze said scan signals, set by set, to uniquely identify all rays, determine depth from the displacement of said ray peaks from calibration, reference plane peaks, and output area range map data.

Claim 10

Dependent Claim 167 words

A three-dimensional range camera comprising: a pattern generator and projector to produce a 1×N array of time and space coded light rays which can each be varied with time and to project P sequential presentations of different subsets of said light rays onto a three-dimensional object, where P=1+log 2 N and N is the number of light rays; means for orthogonally sweeping said array of coded light rays by steps over a rectangular plane; a linear array, line scan camera to image points of light on the surface of said object where said light rays are incident, and generate after each presentation a one-dimensional scan signal which has ray peaks at locations corresponding to imaged light points, said line scan camera generating a set of said scan signals per step; and a range processor to analyze said scan signals, set by set, to uniquely identify all rays, determine depth from the displacement of said ray peaks from calibration, reference plane peaks, and output area range map data.

Claim 11

Dependent Claim 62 words

The range camera of claim 8 wherein said pattern generator includes a collimated light sheet source and a rotating code wheel which has group patterns each comprised of one pattern per presentation of discrete regions whose light transmission coefficients are selected to spatially modulate the light sheet into said coded light rays, said patterns being illuminated one at a time in sequence.

Claim 12

Dependent Claim 22 words

The range camera of claim 9 wherein said projector is a projection lens and said orthogonal sweep means is a rotating mirror.

Claim 13

Dependent Claim 59 words

The range camera of claim 8 wherein said pattern generator includes a sheet light laser source and a rotating code wheel which has sector-shaped group patterns each comprised of one pattern per presentation of clear and opaque regions to spatially modulate the light sheet into said coded light rays, said patterns being illuminated one at a time in sequence.

Claim 14

Dependent Claim 43 words

The range camera of claim 11 wherein said projector is comprised of a reduction lens to project said coded light rays onto the entrance of a coherent optical fiber bundle and a projection lens to reimage said coded rays on the object surface.

Claim 15

Dependent Claim 160 words

A range camera for profiling applications comprising: a narrow laser beam source; a modulator to vary the intensity of said laser beam; a beam deflector to scan the modulated beam along a straight line and project it onto the surface of an object; said modulator and beam deflector producing a 1×N array of time and space coded light rays and P sequential presentations of different subsets of said light rays, where P=1+log b N, b is the number of brightness levels and N is the number of light rays; a linear array, line scan camera to image points of light on the surface of said object where said light rays are incident, and generate a one-dimensional scan signal which has ray peaks at locations corresponding to imaged light; and a range processor to analyze said scan signals to uniquely identify all rays, determine depth from the displacement of said ray peaks from calibration, reference plane peaks, and output profile data.

Claim 16

Dependent Claim 160 words

A range camera for profiling applications comprising: a narrow laser beam source; a modulator to vary the intensity of said laser beam; a beam deflector to scan the modulated beam along a straight line and project it onto the surface of an object; said modulator and beam deflector producing a 1×N array of time and space coded light rays and P sequential presentations of different subsets of said light rays, where P=1+log b N, b is the number of brightness levels and N is the number of light rays; a linear array, line scan camera to image points of light on the surface of said object where said light rays are incident, and generate a one-dimensional scan signal which has ray peaks at locations corresponding to imaged light; and a range processor to analyze said scan signals to uniquely identify all rays, determine depth from the displacement of said ray peaks from calibration, reference plane peaks, and output profile data.

Claim 17

Dependent Claim 18 words

The range camera of claim 13 wherein said modulator and beam deflector are controlled by said range processor.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-08-17	1991-02-16	1991-08-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-08-17	1995-02-16	1995-08-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-08-17	1999-02-16	1999-08-18	$7700.00	Window Closed / Lapsed

Three-dimensional range camera

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