US4332475A
Expired / Lapsed
US
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Edge timing in an optical measuring apparatus
Assignee: Zygo Corp
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Filing: 1980-06-03
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Granted: 1982-06-01
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Expires: 2000-06-03
Abstract
Abstract An electro-optical sensor is described which provides a high resolution measurement of the location of the edge of an object. By passing the electrical pulse produced by an edge sensor into a multiply tapped delay line the location of the edge of an object can be measured with high resolution.
Inventors
- 👤 Frank C. Demarest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:42
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/028; G01B11/08; G01B11/10; G01B11/105
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
126 words
In a device for measuring the size of an object by scanning a beam of radiant energy past the object into a photosensor, and the time between the passage of the beam from one edge of the object to the next is measured by the number of pulses from a fixed period time base elapsing during said passage, the improvement which comprises providing: (1) an electrical edge pulse produced by an edge sensor; (2) a fixed frequency time base; (3) means for generating a multiplicity of pulses from the edge pulse, each successive pulse being delayed by an additional identical fraction of the period of the time base; and (4) means for indicating which delayed pulse occurs immediately before the next transition of the time base.
Claim 2
Dependent Claim
126 words
In a device for measuring the size of an object by scanning a beam of radiant energy past the object into a photosensor, and the time between the passage of the beam from one edge of the object to the next is measured by the number of pulses from a fixed period time base elapsing during said passage, the improvement which comprises providing: (1) an electrical edge pulse produced by an edge sensor; (2) a fixed frequency time base; (3) means for generating a multiplicity of pulses from the edge pulse, each successive pulse being delayed by an additional identical fraction of the period of the time base; and (4) means for indicating which delayed pulse occurs immediately before the next transition of the time base.
Claim 3
Dependent Claim
32 words
The device of claim 1, in which element 3 is provided by a multiply tapped delay line where the delay for each tap is an identical fraction of the time base period.
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) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |