Patent US5319442A successfully refreshed from Google Patents.
US5319442A
Expired / Lapsed
US
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Optical inspection probe
Assignee: Renishaw Metrology Ltd
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Filing: 1992-08-11
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Granted: 1994-06-07
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Expires: 2012-08-11
Abstract
Abstract An optical inspection probe, used on a coordinate measuring machine, includes a sensing module having a CCD array and an imaging module releasably mountable thereon. The position of a feature on the surface is measured using the probe by calculating the instant of time at which an image of the feature will pass across a predesignated pixel Q c of the array. The calculation is performed on the basis of the relative velocity of the probe and the surface as determined from two consecutively scanned image frames of the CCD array. The probe may be used to determine, for example, the position of an edge of a surface by moving the probe laterally with respect to the surface or, may be used to measure the position of a predetermined height of a surface by projecting a light beam onto the surface at an angle to the optical axis and measuring the position of the resulting spot on the surface.
Inventors
- 👤 John I. Rosser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:58
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/024
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
173 words
An optical inspection probe for use on a movable arm of a coordinate positioning machine to determine a position of a feature of a surface, the probe comprising: a sensing device having a light sensitive array which includes a plurality of discrete light sensitive cells, each of which outputs a signal corresponding to the intensity of light incident thereon; an imaging device having one or more optical components for imaging said feature on said array; processing means for a) analysing said image by, inter alia, sequentially scanning each cell of said array to determine the value of each said signal, a single scan of said array constituting an image frame; and b) determining in advance, from two or more said image frames, an instant of time at which the image of said feature will reach a predetermined cell of said array, and for generating at said instant a trigger signal for instructing a control system of said machine to determine a position of the movable arm relative to said feature of said surface.
Claim 2
Dependent Claim
173 words
An optical inspection probe for use on a movable arm of a coordinate positioning machine to determine a position of a feature of a surface, the probe comprising: a sensing device having a light sensitive array which includes a plurality of discrete light sensitive cells, each of which outputs a signal corresponding to the intensity of light incident thereon; an imaging device having one or more optical components for imaging said feature on said array; processing means for a) analysing said image by, inter alia, sequentially scanning each cell of said array to determine the value of each said signal, a single scan of said array constituting an image frame; and b) determining in advance, from two or more said image frames, an instant of time at which the image of said feature will reach a predetermined cell of said array, and for generating at said instant a trigger signal for instructing a control system of said machine to determine a position of the movable arm relative to said feature of said surface.
Claim 3
Dependent Claim
58 words
An optical inspection probe according to claim 1 wherein the processing means includes means for determining, from at least to of said image frames, the speed and direction of relative travel of the probe and the surface, and calculating from speed and direction a time interval between the second of said image frames and said instant of time.
Claim 4
Dependent Claim
68 words
An optical inspection probe according to claim 2 wherein the processing means includes means for determining the processing time required to calculate said time interval, and for comparing said time interval with said processing time in order to determine whether a further calculation of said time interval may be made before said instant of time, and where sufficient time remains, performing a further calculation of said time interval.
Claim 5
Dependent Claim
29 words
An optical inspection probe according to claim 3, wherein said processing means includes means for generating a corrected value of said time interval by subtracting the processing time therefrom.
Claim 6
Dependent Claim
47 words
An optical inspection probe according to claim 1, wherein the probe has an optical axis extending orthogonal to said array and illuminating means for generating a light beam to illuminate an area of said surface, wherein said light beam extends at an angel to the optical axis.
Claim 7
Dependent Claim
45 words
An optical inspection probe according to claim 1, wherein said sensing device and said imaging device are provided in the form of a sensing module and an imaging module and means are provided for releasably and repeatably retaining said imaging module on said sensing module.
Claim 8
Independent Claim
169 words
A method of inspecting a surface to determine a position of a feature thereon, using a coordinate positioning machine having an optical inspection probe connected to a movable arm of the machine, the optical inspection probe including an array of light sensitive elements each of which outputs a signal corresponding to an intensity of light incident thereon, and one or more optical elements for imaging said feature on said array, the method comprising the steps of: analysing said image by, inter alia, sequentially scanning each light sensitive element of said array to determine a value of each said signal, a single scan of said array constituting an image frame; determining in advance, from two or more said image frames, an instant of time at which an image of said feature will reach a predetermined cell of said array, and generating at said instant a trigger signal for instructing a control system of said machine to determine a position of the movable arm relative to said feature of said surface.
Claim 9
Independent Claim
169 words
A method of inspecting a surface to determine a position of a feature thereon, using a coordinate positioning machine having an optical inspection probe connected to a movable arm of the machine, the optical inspection probe including an array of light sensitive elements each of which outputs a signal corresponding to an intensity of light incident thereon, and one or more optical elements for imaging said feature on said array, the method comprising the steps of: analysing said image by, inter alia, sequentially scanning each light sensitive element of said array to determine a value of each said signal, a single scan of said array constituting an image frame; determining in advance, from two or more said image frames, an instant of time at which an image of said feature will reach a predetermined cell of said array, and generating at said instant a trigger signal for instructing a control system of said machine to determine a position of the movable arm relative to said feature of said surface.
Claim 10
Dependent Claim
48 words
The method according to claim 7, further comprising the step of generating , from a light source in said probe, a bema of light which is incident upon siad surface, and extends in a direction non-parallel to a direction of relative movement of said surface and said arm.
Claim 11
Independent Claim
173 words
A method of operating an optical inspection probe for use on a movable arm of a coordinate positioning machine in determining a position of a feature of a surface, the probe comprising: a light sensitive array including a plurality of discrete light sensitive cells, each cell outputting a signal corresponding to an intensity of light incident thereon, and an imaging device having at least one optical component for imaging said feature on said array, the method comprising the steps of: analysing said image by sequentially scanning each cell of said array to determine a value of each said signal, a single scan of said array constituting an image frame; and determining in advance, from two or more of said image frames, an instant of time at which an image of said feature will reach a predetermined cell of said array, and generating at said instant a trigger signal for instructing a control system of said coordinate positioning machine to determine a position of the movable arm relative to said feature of said surface.
Claim 12
Independent Claim
173 words
A method of operating an optical inspection probe for use on a movable arm of a coordinate positioning machine in determining a position of a feature of a surface, the probe comprising: a light sensitive array including a plurality of discrete light sensitive cells, each cell outputting a signal corresponding to an intensity of light incident thereon, and an imaging device having at least one optical component for imaging said feature on said array, the method comprising the steps of: analysing said image by sequentially scanning each cell of said array to determine a value of each said signal, a single scan of said array constituting an image frame; and determining in advance, from two or more of said image frames, an instant of time at which an image of said feature will reach a predetermined cell of said array, and generating at said instant a trigger signal for instructing a control system of said coordinate positioning machine to determine a position of the movable arm relative to said feature of said surface.
Claim 13
Dependent Claim
55 words
The method according to claim 9, further comprising the steps of determining, from at least two of said image frames, a speed and direction of relative travel of the probe and the surface, and calculating from said speed and direction a time interval between the second of said image frames and said instant of time.
Claim 14
Dependent Claim
63 words
The method according to claim 10, further comprising the steps of determining the processing time required to calculate said time interval and comparing said time interval with said processing time in order to determine whether a further calculation of said time interval may be made before said instant of time, and where sufficient time remains, performing a further calculation of said time interval.
Claim 15
Dependent Claim
25 words
The method according to claim 11, further comprising the step of generating a corrected value of said time interval by subtracting the processing time therefrom.
References Cited (Backward Citations)
JPS60194302A
Cited
US4970653A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-06-06 | 1997-12-06 | 1998-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-06 | 2001-12-06 | 2002-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-06 | 2005-12-06 | 2006-06-07 | $7700.00 | Window Closed / Lapsed |