US3694658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Veneer inspection system
Assignee: Coe Manufacturing Co
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Filing: 1970-10-22
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Granted: 1972-09-26
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Expires: 1990-10-22
Abstract
Abstract On-line apparatus for inspecting a moving strip of veneer for the presence of cracks, knotholes, voids and similar type wood defects utilizing light transmission through the material to detect discontinuities therein. Light radiation transmitted through such a wood defect is detected by a scanner head formed of a plurality of flexible, light-conducting optical fibers whose terminal ends are positioned adjacent the surface of the veneer strip on the side opposite the light source and at spaced locations along the transverse width of the strip. The detected light radiation is conveyed by the flexible fibers to a corresponding array of photoelectric transducers which are strobe interrogated in serial sequence so as to generate as an output a composite waveform indicative of the light transmissibility pattern of the cross-section of veneer strip passing over the scanner head at the instant of the strobe. This strobe interrogation process is repeated at regular close intervals, so as to generate successive waveforms representative of the character of the wood strip passing over the scanner head. The presence of through-wood defects produces corresponding variations in the successive waveform outputs of the photosensor array which, after digitizing, are fed into arithmetic and logic circuitry. Counter and comparator elements operate on this digital information to measure the cross-grain and with-grain dimensions of individual defects and generate an actuating signal when a defect exceeds predetermined dimensional limits. The logic circuitry distinguishes cracks and splits on the one hand, which have large with-grain and quite narrow cross-grain dimension, from knotholes and other voids in the wood having substantially larger cross-grain dimension than cracks or splits.
Inventors
- 👤 Gerald L Watson
- 👤 Don Latshaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:28
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G01N21/892; G01N21/898; G01N21/8986
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
172 words
In a scanner, for use in inspecting a moving strip of planar material and responsive to incident light energy transmitted through openings or other defects appearing in said material, comprising an array of flexible, longitudinally-extending lightconducting optical fibers whose first terminal ends are respectively situated at spaced positions proximate to said strip and extending transversely of the direction of strip movement, and whose second terminal ends are optically coupled in one-toone relationship to a corresponding array of photoelectric transducer elements for converting said incident light energy into an electrical output, the improvement wherein the respective second terminal ends of the array of optical fibers are each secured inside corresponding bore openings formed in a block member which is adapted to mate with a keyway channel provided in a holder member, said holder member containing the array of corresponding photoelectric transducer elements, the assembly of said block and holder members serving to hold and maintain said first terminal ends of said optical fiber array in positional alignment with their respective photoelectric transducer elements.
Claim 2
Dependent Claim
172 words
In a scanner, for use in inspecting a moving strip of planar material and responsive to incident light energy transmitted through openings or other defects appearing in said material, comprising an array of flexible, longitudinally-extending lightconducting optical fibers whose first terminal ends are respectively situated at spaced positions proximate to said strip and extending transversely of the direction of strip movement, and whose second terminal ends are optically coupled in one-toone relationship to a corresponding array of photoelectric transducer elements for converting said incident light energy into an electrical output, the improvement wherein the respective second terminal ends of the array of optical fibers are each secured inside corresponding bore openings formed in a block member which is adapted to mate with a keyway channel provided in a holder member, said holder member containing the array of corresponding photoelectric transducer elements, the assembly of said block and holder members serving to hold and maintain said first terminal ends of said optical fiber array in positional alignment with their respective photoelectric transducer elements.
Claim 3
Dependent Claim
92 words
A scanner according to claim 1 further comprising adjustable shutter means formed of longitudinally-movable thin, short strips of opaque material situated on one of said members between said respective second terminal ends of said optical fibers and their associated photoelectric transducer elements contained on said holder member, whereby the adjustment of the position of a respective strip blocks off a selectable portion of the light energy transmitted by the optical fiber associated therewith in order thereby to provide means for normalizing the responses of said photoelectric transducer elements to a uniform level.
Claim 4
Dependent Claim
322 words
Flaw detection apparatus for inspecting a moving strip of planar material comprising: a. an illumination source on one side of said strip projecting light thereon, b. a scanner situated on the other side of said strip and producing an electrical output in response to light transmitted through any openings appearing in the material passing between said illumination source and said scanner, c. pulse converter means for converting said electrical output of said scanner into a series of pulse train waveforms respectively representative of the instantaneous light transmission pattern across the width of the material taken at spaced locations along the length of said strip, d. accumulator means for accumulating the results of a predetermined number of successive pulse trains corresponding to successive scans of said material as it passes between said illumination source and said scanner, e. first counter means for totaling the resultant pulses collected in said accumulator means, f. means for comparing the pulse total in said first counter with a first predetermined value so as to provide an output signal from said apparatus when said value is exceeded, said output signal denoting the presence of an opening in said strip whose major dimension exceeds a tolerance limit, g. second counter means for totaling the number of pulses in each of said pulse trains produced by said pulse converter means, h. means for comparing the total obtained by said second counter means with a second predetermined value so as to derive a second signal when said second value is exceeded, and i. third counter means for counting the number of times said second signal is produced and generating a third signal when the count in said third counter exceeds a third predetermined value, said third signal serving as an additional output signal from said apparatus denoting the presence of an opening in said material whose size exceeds a set of predetermined tolerance limits on both its transverse and longitudinal dimensions.
Claim 5
Dependent Claim
322 words
Flaw detection apparatus for inspecting a moving strip of planar material comprising: a. an illumination source on one side of said strip projecting light thereon, b. a scanner situated on the other side of said strip and producing an electrical output in response to light transmitted through any openings appearing in the material passing between said illumination source and said scanner, c. pulse converter means for converting said electrical output of said scanner into a series of pulse train waveforms respectively representative of the instantaneous light transmission pattern across the width of the material taken at spaced locations along the length of said strip, d. accumulator means for accumulating the results of a predetermined number of successive pulse trains corresponding to successive scans of said material as it passes between said illumination source and said scanner, e. first counter means for totaling the resultant pulses collected in said accumulator means, f. means for comparing the pulse total in said first counter with a first predetermined value so as to provide an output signal from said apparatus when said value is exceeded, said output signal denoting the presence of an opening in said strip whose major dimension exceeds a tolerance limit, g. second counter means for totaling the number of pulses in each of said pulse trains produced by said pulse converter means, h. means for comparing the total obtained by said second counter means with a second predetermined value so as to derive a second signal when said second value is exceeded, and i. third counter means for counting the number of times said second signal is produced and generating a third signal when the count in said third counter exceeds a third predetermined value, said third signal serving as an additional output signal from said apparatus denoting the presence of an opening in said material whose size exceeds a set of predetermined tolerance limits on both its transverse and longitudinal dimensions.
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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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |