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US3909138A
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Method and apparatus for detecting skips in gravure printing
Assignee: GRAVURE ASSOCIATION OF AMERICA Inc
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Filing: 1974-06-03
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Granted: 1975-09-30
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Expires: 1994-06-03
Abstract
Abstract A method and apparatus for detecting skips in gravure prints including means for scanning an area of paper having gravure print thereon and generating output signals proportional to the amount of reflectivity of the area of the paper being scanned, stabilizing means for stabilizing the output signals to reduce the effects of signal drift, means for comparing the output signals from the stabilizing means with a reference signal level, filter means for passing a predetermined signal frequency band, pulse forming means electrically coupled to the filter means capable of generating a pulse in response to each filtered signal received, threshold means for activating the pulse forming means only when the filtered signals to the pulse forming means reach a predetermined signal level, and counter means for counting pulses generated by the pulse forming means.
Inventors
- 👤 Harvey F George
- 👤 Robert H Oppenheimer
- 👤 Charles G Marrara
- 👤 David W Cairns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:53
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
101 words
A method of detecting skips in gravure prints, comprising the steps of: a. scanning a paper sample which has been subjected to gravure printing; b. generating an output signal proportional to the amount of light reflected from a predetermined area of the paper sample which is being scanned; c. stabilizing the output signal; d. comparing the stabilized signal with a reference signal to produce a difference signal; e. filtering the difference signal; f. forming the difference signal into a pulse when the amplitude of the difference signal exceeds a predetermined amplitude level; and g. registering each pulse formed in a counter.
Claim 2
Independent Claim
101 words
A method of detecting skips in gravure prints, comprising the steps of: a. scanning a paper sample which has been subjected to gravure printing; b. generating an output signal proportional to the amount of light reflected from a predetermined area of the paper sample which is being scanned; c. stabilizing the output signal; d. comparing the stabilized signal with a reference signal to produce a difference signal; e. filtering the difference signal; f. forming the difference signal into a pulse when the amplitude of the difference signal exceeds a predetermined amplitude level; and g. registering each pulse formed in a counter.
Claim 3
Dependent Claim
55 words
The method recited in claim 1 including the steps of: h. inhibiting registration of the pulse in the counter until the counter is enabled by a control siGnal; i. applying a control signal to the counter only when the output signal generated in step (a) is produced within a predetermined area of the paper sample.
Claim 4
Dependent Claim
21 words
The method recited in claim 1 wherein: the step of stabilizing the output signal includes converting it into a log function.
Claim 5
Dependent Claim
25 words
The method recited in claim 1 wherein: the predetermined area from which the output signal is generated in step (b) includes a plurality of dots.
Claim 6
Independent Claim
146 words
An apparatus for detecting skips in gravure prints, comprising: means for scanning a predetermined area of a paper sample which has been subjected to gravure printing and generating an output signal representative of skips in gravure print smoothness; means for providing a signal proportional to the ratio in the signal level of skips and non-skips to substantially eliminate errors due to signal drift; means for comparing the ratio signal with a reference signal level to provide a difference signal; filter means electrically coupled to said comparing means for filtering the difference signal; means for forming a pulse electrically coupled to said filter means; threshold means for activating said pulse forming means only when the filtered signal to said pulse forming means reaches a predetermined signal level; and counter means electrically coupled to said pulse forming means for counting the pulses produced by said pulse forming means.
Claim 7
Independent Claim
146 words
An apparatus for detecting skips in gravure prints, comprising: means for scanning a predetermined area of a paper sample which has been subjected to gravure printing and generating an output signal representative of skips in gravure print smoothness; means for providing a signal proportional to the ratio in the signal level of skips and non-skips to substantially eliminate errors due to signal drift; means for comparing the ratio signal with a reference signal level to provide a difference signal; filter means electrically coupled to said comparing means for filtering the difference signal; means for forming a pulse electrically coupled to said filter means; threshold means for activating said pulse forming means only when the filtered signal to said pulse forming means reaches a predetermined signal level; and counter means electrically coupled to said pulse forming means for counting the pulses produced by said pulse forming means.
Claim 8
Dependent Claim
47 words
The apparatus as claimed in claim 5 including: means for defining an area of the paper sample to be scanned by said scanning means; means for activating said counter only when said scanning means is within the area of the paper sample established by said defining means.
Claim 9
Dependent Claim
21 words
The apparatus as claimed in claim 6 wherein: said activating means includes a pair of photocells coupled to an AND gate.
Claim 10
Dependent Claim
31 words
The apparatus as claimed in claim 7 wherein: said counter means includes a gate whose inputs include the output of said AND gate and the output of said pulse forming circuit.
Claim 11
Dependent Claim
14 words
The apparatus as claimed in claim 5 wherein: said scanning means includes a photomultiplier.
Claim 12
Dependent Claim
15 words
The apparatus as claimed in claim 5 wherein: said filter means is a bandpass filter.
Claim 13
Dependent Claim
20 words
The apparatus as claimed in claim 5 wherein: said scanning means scans a predetermined area including a plurality of dots.
Claim 14
Independent Claim
152 words
An apparatus for detecting skips in gravure prints, comprising: photosensitive means for scanning a paper sample which has been subjected to gravure printing and providing an output signal proportional to the amount of light reflected by the scanned portion of the paper sample; log means for converting the output signal into a ratio between the signal level for skips and non-skips; means for comparing the ratio signal with a reference signal level to provide a difference signal; bandpass filter means for removing unwanted signal components from the difference signal; pulse forming means electrically coupled to said bandpass filter means; threshold means for activating said pulse forming means only when the filtered signal reaches a predetermined level; a counter electrically coupled to said pulse forming means through a gate; and means electrically coupled to said gate for activating said counter only when said photosensitive means is scanning a predetermined area of the paper.
Claim 15
Independent Claim
152 words
An apparatus for detecting skips in gravure prints, comprising: photosensitive means for scanning a paper sample which has been subjected to gravure printing and providing an output signal proportional to the amount of light reflected by the scanned portion of the paper sample; log means for converting the output signal into a ratio between the signal level for skips and non-skips; means for comparing the ratio signal with a reference signal level to provide a difference signal; bandpass filter means for removing unwanted signal components from the difference signal; pulse forming means electrically coupled to said bandpass filter means; threshold means for activating said pulse forming means only when the filtered signal reaches a predetermined level; a counter electrically coupled to said pulse forming means through a gate; and means electrically coupled to said gate for activating said counter only when said photosensitive means is scanning a predetermined area of the paper.
Claim 16
Dependent Claim
36 words
The apparatus as claimed in claim 12, wherein: said photosensitive means includes an aperture having a diameter in the range of about 0.012 to 0.016 inches for scanning a plurality of dots on the paper sample.
References Cited (Backward Citations)
US3347131A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |