Patent US4494874A successfully refreshed from Google Patents.
US4494874A
Expired / Lapsed
US
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Detection of three-dimensional information using a projected point or line of light
Assignee: Solid Photography Inc
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Filing: 1981-07-07
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Granted: 1985-01-22
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Expires: 2001-07-07
Abstract
Abstract An object is scanned first with a flying light spot from a variable-intensity light-spot projector, and the reflected light is used as signals to point by point modify the output of the projector in accordance with the intensity of the respective reflective-light signal. Thereupon the object is scanned a second time and the projector instructed to apply less light than before to those points of the object from which a strong reflected-light signal was received during the first scan, and to apply more light to points from which a weak reflected-light signal was received during the first scan.
Inventors
- 👤 Paul DiMatteo
- 👤 Joseph Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:49
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
202 words
A method of detecting three-dimensional information, comprising the steps of: projecting a variable-intensity flying spot of light onto an object to be scanned; effecting a first scan by causing relative movement between object and light spot; receiving light-intensity signals in a single reflected light ray from the object point-by-scanned-point and modifying the intensity of the light spot in accordance with each received signal; effecting a second scan by causing relative movement between object and light spot; and reducing the light-spot intensity during the second scan at such points of the object where the signal was strong during the first scan, and increasing the light-spot intensity during the second scan at such points where the signal was weak during the first scan, said steps of effecting a first scan and a second scan comprising measurements of a multiplicity of points independent of light intensity at the object, so that accuracy of said measurements is not influenced by the light intensity at the object, the light-spot intensity during said second scan being dependent on said light-intensity signals of said first scan for preventing inaccuracy due to measurement delay and lag in modifying by a distance equal to scan velocity multiplied by measurement delay time.
Claim 2
Independent Claim
202 words
A method of detecting three-dimensional information, comprising the steps of: projecting a variable-intensity flying spot of light onto an object to be scanned; effecting a first scan by causing relative movement between object and light spot; receiving light-intensity signals in a single reflected light ray from the object point-by-scanned-point and modifying the intensity of the light spot in accordance with each received signal; effecting a second scan by causing relative movement between object and light spot; and reducing the light-spot intensity during the second scan at such points of the object where the signal was strong during the first scan, and increasing the light-spot intensity during the second scan at such points where the signal was weak during the first scan, said steps of effecting a first scan and a second scan comprising measurements of a multiplicity of points independent of light intensity at the object, so that accuracy of said measurements is not influenced by the light intensity at the object, the light-spot intensity during said second scan being dependent on said light-intensity signals of said first scan for preventing inaccuracy due to measurement delay and lag in modifying by a distance equal to scan velocity multiplied by measurement delay time.
Claim 3
Dependent Claim
192 words
In an arrangement for detecting three-dimensional information, a combination comprising: means for projecting a variable-intensity flying spot of light onto a object to be scanned; and means for receiving during a first scanning of the object, light-intensity signals in a single reflected light ray back from the object, point-by-scanned-point and for modifying the intensity of the projected light spot in accordance with each such signal received, for reducing, during the subsequent second scan, the light-spot intensity at such points of the object where the signal was strong during the first scan, and for increasing the light-spot intensity during the second scan at such points of the object where the signal was weak during the first scan, said first scan and second scan comprising measurements of a multiplicity of points independent of light intensity at the object so that accuracy of said measurements is not influenced by the light intensity at the object, the light-spot intensity during said second scan being dependent on said light-intensity signals of said first scan for preventing inaccuracy due to measurement delay and lag in modifying by a distance equal to scan velocity multiplied by measurement delay time.
Claim 4
Dependent Claim
192 words
In an arrangement for detecting three-dimensional information, a combination comprising: means for projecting a variable-intensity flying spot of light onto a object to be scanned; and means for receiving during a first scanning of the object, light-intensity signals in a single reflected light ray back from the object, point-by-scanned-point and for modifying the intensity of the projected light spot in accordance with each such signal received, for reducing, during the subsequent second scan, the light-spot intensity at such points of the object where the signal was strong during the first scan, and for increasing the light-spot intensity during the second scan at such points of the object where the signal was weak during the first scan, said first scan and second scan comprising measurements of a multiplicity of points independent of light intensity at the object so that accuracy of said measurements is not influenced by the light intensity at the object, the light-spot intensity during said second scan being dependent on said light-intensity signals of said first scan for preventing inaccuracy due to measurement delay and lag in modifying by a distance equal to scan velocity multiplied by measurement delay time.
Claim 5
Dependent Claim
19 words
A combination as defined in claim 2, wherein said projection means comprises a variable light-intensity flying light spot projector.
Claim 6
Dependent Claim
14 words
A combination as defined in claim 2, wherein said receiving means comprises a camera.
Claim 7
Dependent Claim
15 words
A combination as defined in claim 2, wherein said reducing means comprises a control logic.
Claim 8
Dependent Claim
29 words
A combination as defined in claim 3, wherein said receiving means comprises a camera; and said reducing means comprises a control logic connected between said camera and said projector.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |