Patent US4650335A successfully refreshed from Google Patents.
US4650335A
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US
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Comparison type dimension measuring method and apparatus using a laser beam in a microscope system
Assignee: Pentax Corp
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Filing: 1983-11-30
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Granted: 1987-03-17
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Expires: 2003-11-30
Abstract
Abstract A comparison-type dimension measurement system in which a laser 1 provides linearly polarized light that is directed by a polarization beam splitter 5 into a microscope system in which a specimen 13 is mounted. The reflected polarized light is rotated 90° by a quarter wave plate 9 and passes through the beam splitter to a multi-element line sensor 19. The laser light is scanned by a rotatable mirror 3 over the specimen. Threshold intensities are determined on indicia of known separation on a reference specimen and used to calibrate the distance measured by the line sensor.
Inventors
- 👤 Tokuhisa Ito
- 👤 Goro Kitamura
- 👤 Hidenori Horiuchi
- 👤 Masaaki Aoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:25
CPC Classifications
G; G01; G01B; G01B9/00; G01B9/04; G01B11/00; G01B11/02; G01B11/024
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
A comparison type measuring system for measuring a dimension of a test specimen relative to a reference specimen, comprising: a light source for producing a linearly polarized light beam; a microscope including a mount (13) for either of said specimens; means for directing said polarized beam through said microscope onto said mounted specimen; means for scanning said polarized beam over said mounted specimen; means for detecting light reflected from said mounted specimen by said scanned beam, said detecting means including a line sensor of a plurality of photo-sensitive elements; means for calculating an angular intensity distribution of said light reflected from said mounted specimen from outputs of said detecting means, said angular distribution calculating means comprising means for calculating a center of gravity of said angular intensity distribution; means for comparing said angular intensity distribution calculated by said angular distribution calculating means with an angular intensity distribution of said mounted reference specimen for measuring said test specimen dimension.
Claim 2
Dependent Claim
158 words
A comparison type measuring system for measuring a dimension of a test specimen relative to a reference specimen, comprising: a light source for producing a linearly polarized light beam; a microscope including a mount (13) for either of said specimens; means for directing said polarized beam through said microscope onto said mounted specimen; means for scanning said polarized beam over said mounted specimen; means for detecting light reflected from said mounted specimen by said scanned beam, said detecting means including a line sensor of a plurality of photo-sensitive elements; means for calculating an angular intensity distribution of said light reflected from said mounted specimen from outputs of said detecting means, said angular distribution calculating means comprising means for calculating a center of gravity of said angular intensity distribution; means for comparing said angular intensity distribution calculated by said angular distribution calculating means with an angular intensity distribution of said mounted reference specimen for measuring said test specimen dimension.
Claim 3
Dependent Claim
17 words
A dimension measuring system, as recited in claim 1, wherein said scanning means comprises a rotatable mirror.
Claim 4
Dependent Claim
57 words
A dimension measuring system, as recited in claim 1, wherein said directing means comprises: a polarization beam splitter (5) onto one face of which said polarized beam is directed and aligned with another face of which is the photosensitive part of said detecting means; a quarter-wave plate (9) disposed between said beam splitter and said mounted specimen.
Claim 5
Dependent Claim
32 words
A dimension measuring system, as recited in claim 1, wherein said comparing means comprises threshold setting means for determining a threshold level of intensity corresponding to indicia on said mounted reference specimen.
Claim 6
Dependent Claim
26 words
A dimension measuring system, as recited in claim 4, wherein said comparing means compares an intensity detected from said mounted test specimen with said threshold 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) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |