US5089712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet advancement control system detecting fiber pattern of sheet
Assignee: HP Inc
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Filing: 1989-06-08
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Granted: 1992-02-18
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Expires: 2009-06-08
Abstract
Abstract A sheet advancement control system for use in printers such as inkjet printers includes a light source for directing a beam of light onto a localized area of a sheet, a photosensitive detector for providing output signals that vary according to microscopic patterns that are illuminated within the sheet by the directed light, a correlator for determining cross-correlations between pairs of detected patterns as the sheet is advanced in a printer and for computing displacements between matching patterns to, thereby, detect the displacement of a sheet within the printer.
Inventors
- 👤 William D. Holland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:45
CPC Classifications
B; B41; B41J; B41J29/00; B41J29/42; G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/342; H; H04; H04N; H04N1/00; H04N1/04; H04N1/047; H04N1/0473; H04N1/12; H04N2201/00; H04N2201/04; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04712; H04N2201/04734; H04N2201/04737
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
120 words
A sheet advancement control system for use in printers such as inkjet printers, comprising: light source means for directing a beam of light onto a localized area of a sheet; magnifier means for magnifying the light is incident on the localized area of the sheet; photosensitive fiber pattern detecting means for detecting the magnified light and for providing output signals that vary according to fiber patterns within the localized area of the sheet; correlator means for determining cross-correlations between pairs of detected fiber patterns as the sheet is advanced in a printer; and displacement detecting means connected to the correlator means for detecting displacement between correlated patterns, thereby, to detect displacements of a sheet as it advances within the printer.
Claim 2
Dependent Claim
120 words
A sheet advancement control system for use in printers such as inkjet printers, comprising: light source means for directing a beam of light onto a localized area of a sheet; magnifier means for magnifying the light is incident on the localized area of the sheet; photosensitive fiber pattern detecting means for detecting the magnified light and for providing output signals that vary according to fiber patterns within the localized area of the sheet; correlator means for determining cross-correlations between pairs of detected fiber patterns as the sheet is advanced in a printer; and displacement detecting means connected to the correlator means for detecting displacement between correlated patterns, thereby, to detect displacements of a sheet as it advances within the printer.
Claim 3
Dependent Claim
24 words
A sheet advancement control system according to claim 1 wherein the photosensitive means includes at least one charge-coupled diode for receiving the magnified light.
Claim 4
Dependent Claim
20 words
A sheet advancement control system according to claim 1 wherein the photosensitive means provides output signals that are analog signals.
Claim 5
Dependent Claim
30 words
A sheet advancement control system according to claim 3 further including analog-to-digital convertor means connected to the output of the photosensitive means for converting the analog signals to digital signals.
Claim 6
Dependent Claim
28 words
A sheet advancement control system according to claim 4 further including digital filter means connected to the analog-to-digital convertor means for extracting pattern information from the digital signals.
Claim 7
Dependent Claim
45 words
A sheet advancement control system according to claim 5 wherein the digital filter means operates to extract variations in the digital signals that result from the presence of microscopic patterns in the localized areas of the sheet which are illuminated by the light source means.
Claim 8
Dependent Claim
25 words
A sheet advancement control system according to claim 5 further including memory means connected to the digital filter means for storing the extracted pattern information.
Claim 9
Dependent Claim
26 words
A sheet advancement control system according to claim 6 further including memory means connected to store the extracted variations in the digital signals as pattern information.
Claim 10
Dependent Claim
18 words
A sheet advancement control system according to claim 7 wherein the memory means is a random access memory.
Claim 11
Dependent Claim
18 words
A sheet advancement control system according to claim 8 wherein the memory means is a random access memory.
Claim 12
Dependent Claim
28 words
A sheet advancement control system according to claim 1 wherein the correlator means is operative to detect the location of the primary peak of the computed cross-correlation functions.
Claim 13
Dependent Claim
50 words
A sheet advancement control system according to claim 11 wherein the correlator means is further operative to detect the displacement of a sheet that has advanced in a printer by detecting the relative displacement of the peak of the cross-correlation function computed for two or more locations of the sheet.
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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) | 1995-02-17 | 1995-08-19 | 1996-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-17 | 1999-08-19 | 2000-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-17 | 2003-08-19 | 2004-02-18 | $7700.00 | Window Closed / Lapsed |