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US6375307B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Printing apparatus and method

Assignee: Hewlett Packard Development Co LP
•
Filing: 2000-02-16
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Granted: 2002-04-23
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Expires: 2020-02-16
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Abstract

Abstract An inkjet printer prints swaths which overlap by, typically, one eighth of their width at each edge, each edge region having a reduced print density so that the combined density of the overlapping regions matches or exceeds that of non-overlapping regions. In a first embodiment, each edge region is printed with 50% printing density. In a second embodiment, the printing mask is modified so that each edge region comprises two sub-regions with differing print densities, e.g. a first outer sub-region with a printing density of 15% and a second sub-region with a printing density of 85%. In a third embodiment only one edge region has a reduced print density and comprises 3 sub-regions with different print densities, e.g. a first sub-region with a printing density of 6.75%, a second one with a printing density of 12.5% and a third one with a printing density of 25%.

Inventors

  • 👤 Lluis Vinals
  • 👤 Salvador Sanchez
  • 👤 Lawrence H White

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 12:11
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/485; B41J2/505; B41J2/5056; G; G06; G06K; G06K15/00; G06K15/02; G06K15/10; G06K15/102; G06K15/105

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 60 words
An inkjet printing apparatus having a printhead comprising a plurality of nozzles arranged along a printhead axis, the printing apparatus being arranged to print swaths which overlap the neighbouring swaths by a fraction of the swath width, wherein only one edge region of each swath which overlaps the neighbouring swaths has a reduced print density relative to the remaining regions.
Claim 2
Dependent Claim 60 words
An inkjet printing apparatus having a printhead comprising a plurality of nozzles arranged along a printhead axis, the printing apparatus being arranged to print swaths which overlap the neighbouring swaths by a fraction of the swath width, wherein only one edge region of each swath which overlaps the neighbouring swaths has a reduced print density relative to the remaining regions.
Claim 3
Dependent Claim 29 words
A printing apparatus according to claim 1 , wherein the overlapping fraction at each edge lies in the range between one sixteenth and one quarter of the swath width.
Claim 4
Dependent Claim 33 words
A printing apparatus according to claim 1 , wherein the reduced print density at the edge region is applied to overprint an area already printed at 100% print density by the remaining regions.
Claim 5
Dependent Claim 26 words
A printing apparatus according to claim 1 , wherein the edge region or regions are each divided into at least two sub-regions of differing print densities.
Claim 6
Dependent Claim 23 words
A printing apparatus according to claim 4 , wherein the printing density in the edge sub-region is in the range 5 to 15%.
Claim 7
Dependent Claim 29 words
A printing apparatus according to claim 5 wherein the printing density in the two consecutively adjacent sub-regions is in the range of 10 to 20% and 20 to 30%.
Claim 8
Dependent Claim 45 words
A printing apparatus according to claim 1 wherein the edge region is divided into at least two sub-regions of differing print densities, one of the sub-regions printing at a lower print density receiving ink from an higher number of nozzles than another of the sub-regions.
Claim 9
Dependent Claim 16 words
A printing apparatus according to claim 1 , wherein the printing apparatus prints in black ink.
Claim 10
Dependent Claim 55 words
A printing apparatus according to claim 1 , having an at least one failing nozzle in an edge region thereof, wherein the printing density of a corresponding nozzle in the other edge region, which prints along the same path in the adjacent scan, is arranged to print for compensating the at least one failing nozzle.
Claim 11
Dependent Claim 35 words
A printing apparatus according to claim 1 , wherein the sum of the printing density in two adjacent edge regions, which are printed along the same path in two adjacent scans, is more than 100%.
Claim 12
Dependent Claim 95 words
An inkjet printing apparatus having a printhead comprising a plurality of nozzles arranged along a printhead axis, the printing apparatus being arranged to print swaths which overlap the neighbouring swaths by a fraction of the swath width, only one edge region of each swath which overlaps the neighbouring swaths having a reduced print density relative to a swath central region, wherein said overlapping fraction at each edge is in the range between one sixteenth and one quarter of the swath width, and the combined density of the overlapping regions exceeds that of the central region.
Claim 13
Dependent Claim 95 words
An inkjet printing apparatus having a printhead comprising a plurality of nozzles arranged along a printhead axis, the printing apparatus being arranged to print swaths which overlap the neighbouring swaths by a fraction of the swath width, only one edge region of each swath which overlaps the neighbouring swaths having a reduced print density relative to a swath central region, wherein said overlapping fraction at each edge is in the range between one sixteenth and one quarter of the swath width, and the combined density of the overlapping regions exceeds that of the central region.
Claim 14
Dependent Claim 20 words
A printing apparatus according to claim 11 , wherein the overlapping fraction is substantially one eighth of the swath width.
Claim 15
Dependent Claim 26 words
A printing apparatus according to claim 11 , wherein the edge region or regions are each divided into at least two sub-regions of differing print densities.
Claim 16
Dependent Claim 23 words
A printing apparatus according to claim 13 , wherein the printing density in the edge sub-region is in the range 5 to 15%.
Claim 17
Dependent Claim 22 words
A printing apparatus according to claim 14 wherein the printing density in the adjacent sub-region is in the range 95 to 85%.
Claim 18
Dependent Claim 20 words
A printing apparatus according to claim 13 wherein each of the sub-regions occupy substantially one sixteenth of the swath width.
Claim 19
Dependent Claim 16 words
A printing apparatus according to claim 11 , wherein the printing apparatus prints in black ink.
Claim 20
Dependent Claim 55 words
A printing apparatus according to claim 11 , having an at least one failing nozzle in an edge region thereof, wherein the printing density of a corresponding nozzle in the other edge region, which prints along the same path in the adjacent scan, is arranged to print for compensating the at least one failing nozzle.
Claim 21
Independent Claim 94 words
A method of operating an inkjet printing apparatus having a printhead comprising a plurality of nozzles arranged subsequently along a printhead axis comprising the steps of printing swaths which overlap the neighboring swaths by a fraction of the swath width, so that the combined density of the overlapping regions exceeds that of non-overlapping regions, wherein said step of printing swaths includes the step of printing only one edge region of each swath which overlaps the neighboring swaths at a reduced print density relative to the printing density of remaining regions of said each swath.
Claim 22
Independent Claim 94 words
A method of operating an inkjet printing apparatus having a printhead comprising a plurality of nozzles arranged subsequently along a printhead axis comprising the steps of printing swaths which overlap the neighboring swaths by a fraction of the swath width, so that the combined density of the overlapping regions exceeds that of non-overlapping regions, wherein said step of printing swaths includes the step of printing only one edge region of each swath which overlaps the neighboring swaths at a reduced print density relative to the printing density of remaining regions of said each swath.

References Cited (Backward Citations)

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EP0517543A2 Cited
EP0532302A2 Cited
EP0645246A1 Cited
EP0730973A2 Cited
EP0761453A1 Cited
US5929876A Cited
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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) 2005-04-22 2005-10-22 2006-04-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2009-04-22 2009-10-22 2010-04-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2013-04-22 2013-10-22 2014-04-23 $7700.00 Window Closed / Lapsed

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