US4670659A
Expired / Lapsed
US
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Calibration method for an optical measuring system employing reference grids in a series of reference planes
Assignee: European Electronic Systems Ltd
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Filing: 1984-05-17
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Granted: 1987-06-02
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Expires: 2004-05-17
Abstract
Abstract The invention proposes an electro-optical measurement system to be used to measure the width and possibly also the thickness of a strip 14 being rolled. The strip is imaged onto an electro-optical transducer each of which views the whole width of the strip. To compensate for inaccuracies resulting from the imaging system, a calibration of the imaging system is effected by means of a grid of known dimensions. The calibration results are recorded during a setting up process and used by a digital or analogue computer to correct any measurements taken by the imaging system during operation. There is also disclosed an improved technique for edge detection and for processing video data in real time.
Inventors
- 👤 Peter W. Loose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:53
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/04; G01B11/046; G01B11/024; G01B11/06; G01B11/0691
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
92 words
A method of calibrating a width measurement device employing radiation sensor means, comprising placing a reference grid in a series of reference planes at different distances from said sensor means and scanning said reference grid by said sensor means in each of said reference planes to determine the values of output signals from said measurement device for known co-ordinates on said grid and thereby constructing a matrix of points in space extending in the direction of said sensor means for which the values of output signals from said measurement device are known.
Claim 2
Independent Claim
92 words
A method of calibrating a width measurement device employing radiation sensor means, comprising placing a reference grid in a series of reference planes at different distances from said sensor means and scanning said reference grid by said sensor means in each of said reference planes to determine the values of output signals from said measurement device for known co-ordinates on said grid and thereby constructing a matrix of points in space extending in the direction of said sensor means for which the values of output signals from said measurement device are known.
Claim 3
Dependent Claim
32 words
A method according to claim 1, wherein said output values are stored in a memory to provide a look-up table enabling the position of the edges of an object to be determined.
Claim 4
Dependent Claim
24 words
A method as in claim 2, wherein the positions corresponding to intermediate values between those stored in the memory are determined by linear interpolation.
Claim 5
Dependent Claim
42 words
A method as in claim 1, wherein computed positions corresponding to said values of output signals are compared with the known positions of the co-ordinates of said reference grid to determine a correction factor to be applied to said width measurement device.
References Cited (Backward Citations)
US3762818A
Cited
US3902811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |