US4493554A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining physical characteristics of objects and object surfaces
Assignee: LMI Technologies Inc
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Filing: 1981-08-24
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Granted: 1985-01-15
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Expires: 2001-08-24
Abstract
Abstract A method of determining physical characteristics of a surface. Light or other electromagnetic radiation is directed onto a first portion of a surface and the reflected radiation is received such as by a photodiode. The radiation is also directed onto at least two further portions of the surface and located on either side of and proximate to the first portion. The radiation reflected by the further portions is also received. The radiation reflected from the first portion is compared with the radiation reflected from the two further portions. The radiation and comparison steps are repeated and the comparisons are used to determine a physical characteristic of the surface, such as the presence of one or more flaws. In another embodiment, light or other electromagnetic radiation is used to determine object dimension, such as bore dimension.
Inventors
- 👤 Timothy R. Pryor
- 👤 Omer L. Hageniers
- 👤 Walter J. Pastorius
- 👤 Nicholas Liptay-Wagner
- 👤 Donald A. Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:22
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/954; G01B; G01B11/00; G01B11/24
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
124 words
A method for detecting defects in a bore surface comprising: illuminating a circumference of a bore surface with light, said illumination being effected by directing light onto a curved mirror to concentrate light into an intense ring of light on the circumference of said bore surface; imaging the intense ring of light reflected from the circumference of said bore onto a circular photodetector array comprising a plurality of discrete photodetector elements, said elements being capable of generating output signals responsive to the intensity of light incident thereon, said imaging being effected with optical means comprising said curved mirror which collects reflected light from multiple angles; scanning said circular array; and automatically analyzing the output of said array to detect defects in said bore surface.
Claim 2
Independent Claim
124 words
A method for detecting defects in a bore surface comprising: illuminating a circumference of a bore surface with light, said illumination being effected by directing light onto a curved mirror to concentrate light into an intense ring of light on the circumference of said bore surface; imaging the intense ring of light reflected from the circumference of said bore onto a circular photodetector array comprising a plurality of discrete photodetector elements, said elements being capable of generating output signals responsive to the intensity of light incident thereon, said imaging being effected with optical means comprising said curved mirror which collects reflected light from multiple angles; scanning said circular array; and automatically analyzing the output of said array to detect defects in said bore surface.
Claim 3
Dependent Claim
47 words
A method according to claim 1 wherein said analyzing step is effected by comparing the radiation reflected from a first selected surface portion of a ring-shaped illuminated portion of said bore with radiation reflected from at least two further portions of ring-shaped illuminated portions of said bore.
Claim 4
Dependent Claim
26 words
A method according to claim 1 wherein said curved mirror is parabolic and wherein said illuminating step comprises directing substantially parallel light onto said parabolic mirror.
Claim 5
Dependent Claim
28 words
A method according to claim 1 wherein multiple scans of said array are made and wherein said bore is axially traversed relative to said intense ring of light.
Claim 6
Dependent Claim
48 words
A method according to claim 1 wherein the video data from said photodetector array is fed to a storage video display together with position data along the bore length, so as to provide a display of the part surface as it is moved relative to said photodetector array.
Claim 7
Dependent Claim
24 words
A method according to claim 5 wherein said display is provided of the defects on the surface called out by an automatic processing unit.
Claim 8
Dependent Claim
25 words
A method according to claim 2 further comprising an additional comparison step to determine the number of scans in which a defect indication has appeared.
Claim 9
Dependent Claim
18 words
A method according to claim 2 wherein said comparison is made with respect to upper and/or lower thresholds.
Claim 10
Dependent Claim
32 words
A method according to claim 2 wherein a signal delay device is utilized to allow comparison of light magnitude from an instantaneous surface portion with other portions detected by said photodetector array.
Claim 11
Dependent Claim
19 words
A method according to claim 2 wherein said comparison is made only at certain preselected areas of said surface.
Claim 12
Dependent Claim
25 words
A method according to claim 2 including the further step of providing an average of sequential outputs from the same photodetector obtained on successive scans.
Claim 13
Dependent Claim
18 words
A method according to claim 7 wherein a count of said scans is compared against a preset limit.
Claim 14
Dependent Claim
21 words
A method according to claim 12 wherein the only scans counted are those which have defects greater than a preset number.
Claim 15
Dependent Claim
26 words
A method according to claim 9 wherein an average of said other portions is used in said comparison with said magnitude of the instantaneous surface portion.
Claim 16
Dependent Claim
22 words
A method according to claim 14 wherein said average is weighted to constitute upper and/or lower threshold levels for making said comparison.
Claim 17
Dependent Claim
30 words
A method according to claim 9 incorporating the further step of disabling flaw indication output until a sufficient number of detector outputs of said array have entered said delay device.
Claim 18
Dependent Claim
123 words
Apparatus for detecting defects in a bore surface comprising: means for illuminating a circumference of a bore surface with light, said illumination means comprising a curved mirror for concentrating light into an intense ring of light on the circumference of said bore surface; means for imaging the intense ring of light reflected from the circumference of said bore onto a circular photodetector array comprising a plurality of discrete photodetector elements, said elements being capable of generating output signals responsive to the intensity of light incident thereon, said imaging means comprising said curved mirror which collects reflected light from multiple angles means for scanning said circular array; and means for automatically analyzing the output of said array to detect defects in said bore surface.
Claim 19
Dependent Claim
123 words
Apparatus for detecting defects in a bore surface comprising: means for illuminating a circumference of a bore surface with light, said illumination means comprising a curved mirror for concentrating light into an intense ring of light on the circumference of said bore surface; means for imaging the intense ring of light reflected from the circumference of said bore onto a circular photodetector array comprising a plurality of discrete photodetector elements, said elements being capable of generating output signals responsive to the intensity of light incident thereon, said imaging means comprising said curved mirror which collects reflected light from multiple angles means for scanning said circular array; and means for automatically analyzing the output of said array to detect defects in said bore surface.
Claim 20
Dependent Claim
45 words
Apparatus according to claim 17 wherein said analyzing means comprises means for comparing the radiation reflected from a first selected surface portion of a ring-shaped portion of said bore with radiation reflected from at least two further portions of ring-shaped illuminated portions of said bore.
Claim 21
Dependent Claim
28 words
Apparatus according to claim 17 wherein said curved mirror is parabolic and wherein said illuminating means comprises means for directing substantially parallel light on to said parabolic mirror.
Claim 22
Dependent Claim
37 words
Apparatus according to claim 17 wherein said scanning means comprises means for making multiple scans of said array and wherein said apparatus further comprises means for axially traversing said intense ring of light relative to said bore.
Claim 23
Dependent Claim
23 words
Apparatus according to claim 17 further comprising guided wave fiber means for transmitting, receiving, or for transmitting and receiving light from said surface.
Claim 24
Dependent Claim
49 words
Apparatus according to claim 17 further comprising means for feeding the video data from said photodetector array to a storage video display together with position data along the bore length, so as to provide a display of the part surface as it is moved relative to said photodetector array.
Claim 25
Dependent Claim
21 words
Apparatus according to claim 17 further comprising means for accumulating detected defects to provide a count for comparison to preset limits.
Claim 26
Dependent Claim
24 words
Apparatus according to claim 18 further comprising an additional comparison means for determining the number of scans in which said defect indication has appeared.
Claim 27
Dependent Claim
30 words
Apparatus according to claim 18 further comprising a signal delay device for allowing comparison of light magitude from an instantaneous surface portion with other portions defected by said photodetector array.
Claim 28
Dependent Claim
23 words
Apparatus according to claim 18 further comprising means for providing an average of sequential outputs from the same photodetector obtained on successive scans.
Claim 29
Dependent Claim
28 words
Apparatus according to claim 25 further comprising means for disabling flaw indication output until a sufficient number of detector outputs of said array have entered said delay device.
Claim 30
Dependent Claim
20 words
Apparatus according to claim 25 further comprising means for disabling said delay device during the array retrace or blanking time.
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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) | 1988-01-15 | 1988-07-16 | 1989-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-15 | 1992-07-16 | 1993-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-15 | 1996-07-16 | 1997-01-15 | $7700.00 | Window Closed / Lapsed |