US4772127A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface inspection apparatus
Assignee: GCA Corp
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Filing: 1984-12-18
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Granted: 1988-09-20
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Expires: 2004-12-18
Abstract
Abstract In the surface inspection apparatus disclosed herein, an elongate array of electro-optical shutters is interposed between a laser beam which scans across the surface to be inspected and a photodetector system which collects light scattered from the surface along the scan line. The shutters are operated in a shifting pattern in synchronism with the scanning means thereby to block unwanted regular signal components.
Inventors
- 👤 Eric T. Chase
- 👤 Sergey V. Broude
- 👤 George S. Quackenbos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:02
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95623; G01N21/17; G01N21/47; G01N2021/4704; G01N2021/4711; G01N21/94; G01N2201/00; G01N2201/06; G01N2201/067; G01N2201/08; G01N2201/0833
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
109 words
Surface inspection apparatus comprising: means for generating a light beam; means for scanning said beam in a line across a surface to be inspected; photodetector means; optical means for collecting light scattered from said surface along said line and coupling the collected light to said photodetector; an elongate array of electro-optical shutters adjacent said line and optically interposed between said scanning means and said coupling means; means for operating said shutters in a shifting pattern in synchronism with said scanning to block light scattered directly toward said coupling means and thereby improve the detectability of light scattered transversely to said coupling means by an irregularity associated with said surface.
Claim 2
Dependent Claim
109 words
Surface inspection apparatus comprising: means for generating a light beam; means for scanning said beam in a line across a surface to be inspected; photodetector means; optical means for collecting light scattered from said surface along said line and coupling the collected light to said photodetector; an elongate array of electro-optical shutters adjacent said line and optically interposed between said scanning means and said coupling means; means for operating said shutters in a shifting pattern in synchronism with said scanning to block light scattered directly toward said coupling means and thereby improve the detectability of light scattered transversely to said coupling means by an irregularity associated with said surface.
Claim 3
Dependent Claim
13 words
Apparatus as set forth in claim 1 wherein said line is essentially straight.
Claim 4
Dependent Claim
37 words
Apparatus as set forth in claim 2 wherein said apparatus includes a cylindrical lens system for collecting scattered light and wherein said shutters are arranged in an essentially straight line between said lens and said photodetector means.
Claim 5
Dependent Claim
35 words
Apparatus as set forth in claim 3 further comprising a fiber optic assembly for collecting light from a linear field formed by said lens system and concentrating said light in a spot adjacent said photodetector.
Claim 6
Dependent Claim
40 words
Apparatus as set forth in claim 1 wherein said shutters are controlled in response to data stored in a shift register and said data is shifted along said shift register to effect the shifting pattern of energization of said shutters.
Claim 7
Dependent Claim
40 words
Apparatus as set forth in claim 1 wherein said data comprises a single bit which is shifted along said shift register to operate that shutter which is aligned with the area of the surface then being illuminated by said beam.
Claim 8
Dependent Claim
34 words
Apparatus as set forth in claim 6 wherein said scanning means comprises a mirror driven by a triangular waveform and clocking of said shift register is controlled by digitizing the amplitude of said waveform.
Claim 9
Dependent Claim
100 words
A surface inspection apparatus comprising: means for generating a light beam; means for scanning said beam across a surface to be inspected; photodetector means; optical means for collecting light scattered from said surface and coupling the collected light to said photodetector; an array of electro-optical shutters optically interposed between said scanning means and said coupling means; and means for operating said shutters in a pattern shifting in synchronism with said scanning to block light scattered directly toward said coupling means and thereby improve the detectability of light scattered transversely to said coupling means by an irregularity associated with said surface.
Claim 10
Dependent Claim
100 words
A surface inspection apparatus comprising: means for generating a light beam; means for scanning said beam across a surface to be inspected; photodetector means; optical means for collecting light scattered from said surface and coupling the collected light to said photodetector; an array of electro-optical shutters optically interposed between said scanning means and said coupling means; and means for operating said shutters in a pattern shifting in synchronism with said scanning to block light scattered directly toward said coupling means and thereby improve the detectability of light scattered transversely to said coupling means by an irregularity associated with said surface.
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) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |