US3941484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-contact dimensional measurement technique
Assignee: Bai Corp
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Filing: 1974-10-31
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Granted: 1976-03-02
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Expires: 1994-10-31
Abstract
Abstract A high-speed technique for making accurate dimensional measurements of objects without physically touching the objects. The technique involves generating a low-divergence, collimated light beam which acts to silhouette the object to be measured to produce an image thereof that can be viewed and analyzed by a programmed electro-optical scanner in a manner yielding highly accurate dimensional information substantially independent of the location of the object relative to the viewer.
Inventors
- 👤 Marc G. Dreyfus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:05
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/24; G01B11/2433; G01B11/02; G01B11/022
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
42 words
An electro-optical technique for the non-contact gauging of an object, said technique comprising the steps of illuminating the object with a low-divergence light beam acting to silhouette the object to produce an image thereof whose outline is defined by a Fresnel diffraction.
Claim 2
Dependent Claim
42 words
An electro-optical technique for the non-contact gauging of an object, said technique comprising the steps of illuminating the object with a low-divergence light beam acting to silhouette the object to produce an image thereof whose outline is defined by a Fresnel diffraction.
Claim 3
Dependent Claim
13 words
A technique as set forth in claim 1, wherein said beam is collimated.
Claim 4
Dependent Claim
37 words
A technique as set forth in claim 1, wherein said signal is analyzed to determine the point in the zone whose brightness is about 25% of the brightness which would exist in the absence of the object.
Claim 5
Dependent Claim
138 words
An electro-optical system for the non-contact gauging of an object, said system comprising: A. means to illuminate the object with a low-divergence beam acting to silhouette the object to produce an image thereof whose outline is defined by a Fresnel diffraction zone; B. means to scan said image along a given path to produce a video signal representing the varying brightness of the zone intersected by said path; C. level detection means to analyze said video signal representing the varying brightness of the zone intersected by the scan path to fix the point in the zone whose brightness is about 25% of the brightness which would exist in the absence of the object to produce a data signal; and D. data processing means responsive to said data signal to derive information therefrom regarding a dimension of said object.
Claim 6
Dependent Claim
138 words
An electro-optical system for the non-contact gauging of an object, said system comprising: A. means to illuminate the object with a low-divergence beam acting to silhouette the object to produce an image thereof whose outline is defined by a Fresnel diffraction zone; B. means to scan said image along a given path to produce a video signal representing the varying brightness of the zone intersected by said path; C. level detection means to analyze said video signal representing the varying brightness of the zone intersected by the scan path to fix the point in the zone whose brightness is about 25% of the brightness which would exist in the absence of the object to produce a data signal; and D. data processing means responsive to said data signal to derive information therefrom regarding a dimension of said object.
Claim 7
Dependent Claim
13 words
A system as set forth in claim 4, wherein said beam is collimated.
Claim 8
Dependent Claim
40 words
A system as set forth in claim 5, wherein said means to illuminate said object with a collimated beam includes an incandescent light source whose rays are collected by an off-axis collimator mirror whose rays are directed toward the object.
Claim 9
Dependent Claim
51 words
A system as set forth in claim 5, wherein said means to illuminate said object with a collimated beam includes a laser source producing a narrow, collimated light beam directed toward the object and beam-expanding collimator lenses to broaden the beam to encompass the area of the object to be silhouetted.
Claim 10
Dependent Claim
24 words
A system as set forth in claim 4, wherein said scan means includes an apertured rotating disc operating in conjunction with a light-sensitive detector.
Claim 11
Dependent Claim
17 words
A system as set forth in claim 4, wherein said scan means includes an image dissecting scanner-tube.
Claim 12
Dependent Claim
23 words
A system as set forth in claim 4, wherein said means to determine the brightness of the zone includes an analog level-gating circuit.
Claim 13
Dependent Claim
37 words
A system as set forth in claim 4, wherein said means to determine the brightness of said zone includes a bank of comparators to which the video signal is applied, each comparator having a different reference level.
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) | 1979-03-02 | 1979-09-01 | 1980-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-02 | 1983-09-01 | 1984-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-02 | 1987-09-01 | 1988-03-02 | $7700.00 | Window Closed / Lapsed |