US3609380A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiation sensitive defect scanner for transparent materials
Assignee: PPG Industries Inc
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Filing: 1968-11-29
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Granted: 1971-09-28
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Expires: 1988-11-29
Abstract
Abstract A method and apparatus for detecting defects in glass by scanning glass sheets with a beam of highly collimated light to detect defects in the glass interpositioned between a stationary collimated light source and a stationary detection device, as the defects interrupt the light beam. A collimated light source, a scanning prismatic mirror, and a light responsive detection source comprises the system. A multisided prismatic mirror is interpositioned between the light source and the detection device to provide an effective light path which is longer than the distance between the source and the detector, and scans the glass.
Inventors
- 👤 Hugh E Shaw Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:34
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G01N21/892; G01N21/896
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
135 words
A process for detecting defects in glass sheet material, which comprises directing a collimated light beam from a light source toward one side of glass sheet material, scanning a portion of said glass sheet material with said beam, said beam after passing through said material varying in intensity in response to the presence of defects in said material, and impinging said light beam onto a light intensity responsive device located on the other side of said sheet, characterized by the fact that the scanning is carried out by reflecting said beam by prismatic mirror onto a concave surface of a concave mirror and reflecting said beam from said concave mirror so as to traverse a portion of said glass sheet, said light intensity responsive device being located at the converging point of said concave mirror.
Claim 2
Dependent Claim
135 words
A process for detecting defects in glass sheet material, which comprises directing a collimated light beam from a light source toward one side of glass sheet material, scanning a portion of said glass sheet material with said beam, said beam after passing through said material varying in intensity in response to the presence of defects in said material, and impinging said light beam onto a light intensity responsive device located on the other side of said sheet, characterized by the fact that the scanning is carried out by reflecting said beam by prismatic mirror onto a concave surface of a concave mirror and reflecting said beam from said concave mirror so as to traverse a portion of said glass sheet, said light intensity responsive device being located at the converging point of said concave mirror.
Claim 3
Dependent Claim
33 words
A process according to claim 1, characterized by the fact that the scanning of the glass sheet is transverse to the movement of the glass sheet as it is conveyed along a path.
Claim 4
Dependent Claim
22 words
A process according to claim 1, characterized by the fact that the prismatic mirror is continuously rotated at a substantially constant speed.
Claim 5
Dependent Claim
38 words
A process according to claim 1, characterized by the fact that the reflecting surfaces of the prismatic mirror are substantially flat and are covered with silicon monoxide and that the concave mirror is also covered with silicon monoxide.
Claim 6
Dependent Claim
30 words
A process according to claim 1, characterized by the fact that the prismatic mirror, the concave mirror and the light source are on one side of the glass sheet material.
Claim 7
Dependent Claim
35 words
Apparatus according to claim 3, characterized by the fact that the means for producing the collimated light beam, the prismatic mirror and the concave mirror are positioned on the same side of the glass sheet.
Claim 8
Dependent Claim
129 words
Apparatus for detecting defects in an advancing sheet which comprises means for producing a collimated light beam on one side of the glass sheet and a light intensity detection device positioned on the opposite side of said glass sheet to collect said light beam after said beam passes through said glass sheet, characterized by a concave mirror mounted adjacent said glass sheet so as to reflect a beam of light through said glass sheet and a revolving prismatic mirror mounted in relation to said light source so as to reflect the light beam from said light source to said concave mirror and to cause the beam to scan an area of said advancing glass, said light intensity detection device being positioned at the converging point of said concave mirror.
Claim 9
Dependent Claim
129 words
Apparatus for detecting defects in an advancing sheet which comprises means for producing a collimated light beam on one side of the glass sheet and a light intensity detection device positioned on the opposite side of said glass sheet to collect said light beam after said beam passes through said glass sheet, characterized by a concave mirror mounted adjacent said glass sheet so as to reflect a beam of light through said glass sheet and a revolving prismatic mirror mounted in relation to said light source so as to reflect the light beam from said light source to said concave mirror and to cause the beam to scan an area of said advancing glass, said light intensity detection device being positioned at the converging point of said concave mirror.
Claim 10
Dependent Claim
21 words
Apparatus according to claim 7, characterized by the fact that the means for producing a collimated light beam comprises a laser.
Claim 11
Dependent Claim
30 words
Apparatus to claim 7, characterized by the fact that the faces of the prismatic mirror and the surface of the concave mirror are optically flat and coated with silicon monoxide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |