US3729619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for surface inspection of moving material with defect type recognition
Assignee: United States Steel Corp
•
Filing: 1971-03-04
•
Granted: 1973-04-24
•
Expires: 1991-03-04
Abstract
Abstract An inspection system for the surface of a strip of moving material where defects have a different appearance than the remainder of the strip. A plurality of photosensitive diodes positioned across the material detects defects periodically for a predetermined number of transverse scanning lines. Diode outputs are counted to give totals for area, length and maximum width of a defect in terms of scanning grids. A computer determines the defect shape, and therefore the type of defect, from the ratios between area, width, and length.
Inventors
- 👤 J Laycak
- 👤 G Readal
- 👤 S Prellwitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:18
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G06; G06T; G06T7/00; G06T7/0002; G06T7/0004; G06T7/0006; B; B21; B21B; B21B38/00; G06T2207/00; G06T2207/10; G06T2207/10016; G06T2207/30; G06T2207/30108; G06T2207/30124; G06T2207/30164
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
279 words
Apparatus for determining the shape of surface defects on moving material comprising a first plurality of spaced apart detectors located along a line at an angle to the direction of travel of the material with each detector providing a first output when a surface defect is detected, means for providing a pulse for each movement of the material a predetermined distance, a first counting means connected to said means for providing a pulse for counting a predetermined number of pulses, a second counting means responsive to the occurrence of each pulse and connected to said first plurality of detectors, said first counting means and said means for providing a pulse for counting the number of said first outputs upon the occurrence of each pulse for said predetermined number of pulses, a third counting means responsive to the occurrence of each pulse and connected to said first plurality of detectors, said first counting means and said means for providing a pulse for counting those pulses during which there is a first output for said predetermined number of pulses, a fourth counting means responsive to the occurrence of each pulse and connected to said first plurality of detectors, said first counting means and said means for providing a pulse for counting the maximum number of said first outputs upon the occurrence of a pulse for said predetermined number of pulses, and means responsive to the last of the predetermined number of pulses and connected to said first, second, third and fourth counting means for determining the ratio of the count in said second counting means to the product of the count in said third counting means and said fourth counting means.
Claim 2
Dependent Claim
279 words
Apparatus for determining the shape of surface defects on moving material comprising a first plurality of spaced apart detectors located along a line at an angle to the direction of travel of the material with each detector providing a first output when a surface defect is detected, means for providing a pulse for each movement of the material a predetermined distance, a first counting means connected to said means for providing a pulse for counting a predetermined number of pulses, a second counting means responsive to the occurrence of each pulse and connected to said first plurality of detectors, said first counting means and said means for providing a pulse for counting the number of said first outputs upon the occurrence of each pulse for said predetermined number of pulses, a third counting means responsive to the occurrence of each pulse and connected to said first plurality of detectors, said first counting means and said means for providing a pulse for counting those pulses during which there is a first output for said predetermined number of pulses, a fourth counting means responsive to the occurrence of each pulse and connected to said first plurality of detectors, said first counting means and said means for providing a pulse for counting the maximum number of said first outputs upon the occurrence of a pulse for said predetermined number of pulses, and means responsive to the last of the predetermined number of pulses and connected to said first, second, third and fourth counting means for determining the ratio of the count in said second counting means to the product of the count in said third counting means and said fourth counting means.
Claim 3
Dependent Claim
34 words
Apparatus according to claim 1 in which said means for determining ratio includes means for determining the ratio of the count in the third counting means to the count in the fourth counting means.
Claim 4
Dependent Claim
28 words
Apparatus according to claim 1 in which said material is a source of radiation and said first plurality of detectors is responsive to the radiation from said material.
Claim 5
Dependent Claim
40 words
Apparatus according to claim 1 which includes a source of electromagnetic radiation located to direct said electromagnetic radiation onto the surface of said material and said first plurality detectors is located to receive said electromagnetic radiation reflected from said material.
Claim 6
Dependent Claim
46 words
Apparatus according to claim 4 in which said first plurality of detectors includes a first group of detectors responsive to a first wave length band of said electromagnetic radiation and a second group of detectors responsive to a second wave length band of said electromagnetic radiation.
Claim 7
Dependent Claim
83 words
Apparatus according to claim 4 in which said source of electromagnetic radiation is light and each detector includes a fiber optic light pipe with one end near the surface of said material and a photosensitive diode at the other end of the light pipe and which includes circuit means connected to said diodes for providing said first outputs, each one associated with a diode when light reflected from said surface and passed through the associated light pipe is below the diode threshold intensity.
Claim 8
Dependent Claim
149 words
Apparatus according to claim 1 in which said second counting means includes a shift register connected to receive said first outputs from said first plurality of detectors, means connected to said means for providing a pulse and responsive to the occurrence of a pulse for transferring said first outputs into said shift register, a first delay means connected to said means for providing a pulse and responsive to the occurrence of a pulse for providing a first delay pulse, a clock pulse source, means connected to said first delay means, said shift register and said clock pulse source and responsive to the occurrence of a first delayed pulse for shifting said first outputs out of said shift register, a first counter and a first gating means connected to said clock pulse source and said shift register for connecting said first outputs from said shift register into said first counter.
Claim 9
Dependent Claim
215 words
Apparatus according to claim 7 in which the fourth counting means includes a second counter, a third counter, a comparator connected to the second and third counters and to said means for providing a pulse and responsive to the occurrence of a pulse for comparing the counts in the second and third counters, a second delay means connected to said means for providing a pulse and responsive to the occurrence of a pulse for providing a second delayed pulse occurring before the first delayed pulse and a second gating means connected to said comparator, said shift register, said second delay means and said second and third counters and responsive to the occurrence of said second delayed pulse for retaining in one counter the larger of the counts in the second and third counters while resetting the other counter to zero and enabling the other counter to receive said first outputs from the shift register upon the occurrence of the next first delayed pulse and, when the count in the second counter equals the count in the third counter, for retaining the count in one counter and resetting the other counter to zero and enabling the other counter to receive said first outputs from the shift register upon the occurrence of the next first delayed pulse.
Claim 10
Dependent Claim
190 words
Apparatus according to claim 1 in which said material is a sheet and which includes a second plurality of optical detectors with each detector providing a second output when a surface defect is detected on the other side of said sheet, a fifth counting means responsive to the occurrence of each pulse and connected to said second plurality of detectors, said means for providing a pulse and said first counting means for counting the number of said second outputs upon the occurrence of each pulse for said predetermined number of pulses, a sixth counting means responsive to the occurrence of each pulse and connected to said second plurality of detectors, said first counting means and said means for providing a pulse for counting those pulses during which there is a second output for said predetermined number of pulses and a seventh counting means responsive to the occurrence of each pulse and connected to said second plurality of detectors, said first counting means and said means for providing a pulse for counting the maximum number of said second outputs upon the occurrence of a pulse for said predetermined number of pulses.
Claim 11
Dependent Claim
76 words
Apparatus according to claim 9 which includes means responsive to the last of said predetermined number of pulses and connected to said first, fifth, sixth and seventh counting means for determining the ratio of the count in said fifth counting means to the product of the count in said sixth counting means and said seventh counting means and the ratio of the count in said sixth counting means to the count in said seventh counting means.
Claim 12
Dependent Claim
41 words
Apparatus according to claim 9 which includes a movable C frame for holding said first and second plurality of detectors and means responsive to production process conditions for moving said C frame to a position for inspecting and for beginning inspection.
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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |