Patent US4433386A successfully refreshed from Google Patents.
US4433386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface relief measuring equipment
Assignee: Nortel Networks Ltd
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Filing: 1980-12-08
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Granted: 1984-02-21
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Expires: 2000-12-08
Abstract
Abstract Surface relief analyzing equipment comprises a turntable and an audio frequency pick-up including a stylus. A substrate bearing the surface relief is rotated on the turntable at a fixed frequency and and analogue electrical signal produced at a pick-up transducer is passed through an a-d converter. Digital data is processed to produce an input to a display for registering a pictorial representation of the surface relief.
Inventors
- 👤 Grantley O. Este
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:37
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06; G01B7/063; G01B7/066
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
138 words
Apparatus for measuring the thickness of a coating comprising: a turntable for supporting and rotating a flat substrate bearing a regularly sectored coating pattern, wherein in use, the centers of the coating pattern and the turntable are substantially coincident; tracking means for bearing on a top surface of the patterned substrate, the tracking means vertically moveable in a direction perpendicular to the substrate; means for moving the tracking means radially of the turntable; a transducer operably connected to the tracking means for generating an electrical signal in response to vertical movement thereof; a band pass filter for passing a component of the transducer electrical output at a frequency corresponding to the frequency of traversal of the pattern sectors by the tracking means; and means for measuring amplitude of the filtered signal to provide an indication of coating thickness.
Claim 2
Dependent Claim
138 words
Apparatus for measuring the thickness of a coating comprising: a turntable for supporting and rotating a flat substrate bearing a regularly sectored coating pattern, wherein in use, the centers of the coating pattern and the turntable are substantially coincident; tracking means for bearing on a top surface of the patterned substrate, the tracking means vertically moveable in a direction perpendicular to the substrate; means for moving the tracking means radially of the turntable; a transducer operably connected to the tracking means for generating an electrical signal in response to vertical movement thereof; a band pass filter for passing a component of the transducer electrical output at a frequency corresponding to the frequency of traversal of the pattern sectors by the tracking means; and means for measuring amplitude of the filtered signal to provide an indication of coating thickness.
Claim 3
Dependent Claim
27 words
Apparatus as claimed in claim 1 in which the transducer and the tracking means are mounted on an arm spaced from the upper surface of the turntable.
Claim 4
Dependent Claim
15 words
Apparatus as claimed in claim 2 in which the tracking means is a mechanical stylus.
Claim 5
Dependent Claim
17 words
Apparatus as claimed in claim 3 further comprising a motor for driving the stylus along the arm.
Claim 6
Dependent Claim
41 words
Apparatus as claimed in claim 1 in which the means for measuring amplitude includes an analog-to-digital converter for digitizing an output signal from the band pass filter an output from the analog-to-digital converter forming one input to a data processing means.
Claim 7
Dependent Claim
58 words
Apparatus as claimed in claim 5, further comprising a phase locked loop having an input from the band pass filter, the phase locked loop operable to generate a timing signal which timing signal is taken to the data processing means to compensate for any deviation of the digitized signal output of the analog-to-digital converter from a preset phase.
Claim 8
Dependent Claim
40 words
Apparatus as claimed in claim 5 further comprising position monitoring means for monitoring the position at which the tracking means bears on the top surface of the patterned substrate, the data processing means having a second input representing said position.
Claim 9
Independent Claim
175 words
A method of measuring the thickness of a coating deposited on a surface by a coating process, the method comprising using said process to deposit onto a test substrate a regularly sectored coating pattern; supporting the test substrate on a turntable with a center of the coating pattern substantially coincident with a center of the turntable; bringing a tracking means to bear on a top surface of the patterned substrate, the tracking means being vertically moveable perpendicular to the substrate; rotating the turntable; simultaneously moving the tracking means progressively radially of the turntable; obtaining from a transducer operably connected to the tracking means an electrical signal corresponding to relative vertical movement produced in the tracking means by passage of the rotating regularly sectored coating pattern thereby; filtering the electrical signal to pass a component of the transducer electrical output at a frequency corresponding to the frequency of traversal of the patterned sectors by the tracking means; and measuring the amplitude of an output signal from the filter to provide an indication of the coating thickness.
Claim 10
Independent Claim
175 words
A method of measuring the thickness of a coating deposited on a surface by a coating process, the method comprising using said process to deposit onto a test substrate a regularly sectored coating pattern; supporting the test substrate on a turntable with a center of the coating pattern substantially coincident with a center of the turntable; bringing a tracking means to bear on a top surface of the patterned substrate, the tracking means being vertically moveable perpendicular to the substrate; rotating the turntable; simultaneously moving the tracking means progressively radially of the turntable; obtaining from a transducer operably connected to the tracking means an electrical signal corresponding to relative vertical movement produced in the tracking means by passage of the rotating regularly sectored coating pattern thereby; filtering the electrical signal to pass a component of the transducer electrical output at a frequency corresponding to the frequency of traversal of the patterned sectors by the tracking means; and measuring the amplitude of an output signal from the filter to provide an indication of the coating thickness.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-20 | 1987-08-22 | 1988-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-20 | 1991-08-22 | 1992-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-20 | 1995-08-22 | 1996-02-21 | $7700.00 | Window Closed / Lapsed |