US6154230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fractional dot column correction for better pen-to-pen alignment during printing
Assignee: Hewlett Packard Development Co LP
•
Filing: 1998-11-05
•
Granted: 2000-11-28
•
Expires: 2018-11-05
Abstract
Abstract Sub-pixel alignment is performed for dots from multiple printheads. In order to align, output from a first printhead is aligned with output from a second printhead, dot data is generated for the first printhead and for the second printhead. The dot data is generated from data input. The dot data indicates location of dots on a print medium. Dot shift data is used in order to make sub-pixel shifts in locations of first dots placed on the print medium by the first printhead in order to align the first dots placed on the print medium by the first printhead with second dots placed on the print medium by the second printhead. The first dots and the second dots are then placed on the print medium.
Inventors
- 👤 Clayton Louis Holstun
- 👤 William Edward Bland
- 👤 Ian Nigel Kirkwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:41
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/10; G06K15/102; B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/045; B41J2/04501; B41J2/04505; B41J2/04543; B41J2/0458; B41J2/21; B41J2/2132; B41J2/2135; B41J2202/00; B41J2202/01; B41J2202/17; G06K2215/00; G06K2215/0002; G06K2215/004; G06K2215/006
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
172 words
A method for alignment of output from a first printhead with output from a second printhead, the method comprising the following steps: (a) generating for the first printhead and the second printhead, from data input, dot data which indicates location of dots on a print medium; (b) using dot shift data in order to make sub-pixel shifts in locations of first dots placed on the print medium by the first printhead in order to align the first dots placed on the print medium by the first printhead with second dots placed on the print medium by the second printhead; and, (c) placing the first dots and the second dots on the print medium; wherein step (c) is performed utilizing a train of firing pulses firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein in step (b) sub-pixel shifts in location of the first dots are performed by selecting different firing pulses to place the first dots on the print medium.
Claim 2
Independent Claim
172 words
A method for alignment of output from a first printhead with output from a second printhead, the method comprising the following steps: (a) generating for the first printhead and the second printhead, from data input, dot data which indicates location of dots on a print medium; (b) using dot shift data in order to make sub-pixel shifts in locations of first dots placed on the print medium by the first printhead in order to align the first dots placed on the print medium by the first printhead with second dots placed on the print medium by the second printhead; and, (c) placing the first dots and the second dots on the print medium; wherein step (c) is performed utilizing a train of firing pulses firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein in step (b) sub-pixel shifts in location of the first dots are performed by selecting different firing pulses to place the first dots on the print medium.
Claim 3
Dependent Claim
21 words
A method as in claim 1 wherein in step (c) the first dots are a different color than the second dots.
Claim 4
Dependent Claim
16 words
A method as in claim 1 wherein in step (c) the second dots are black dots.
Claim 5
Dependent Claim
55 words
A method as in claim 1 wherein the dot shift data in step (b) is generated using the following steps: (d) printing a test pattern; (e) receiving from a user coded information based on the test pattern printed in step (d); (f) generating, by the printer, the dot shift data based on the coded information.
Claim 6
Dependent Claim
55 words
A method as in claim 1 wherein the dot shift data in step (b) is generated using the following steps: (d) printing a test pattern; (e) obtaining, by the printer, alignment information based on the test pattern printed in step (d); (f) generating, by the printer, the dot shift data based on the alignment information.
Claim 7
Dependent Claim
54 words
A method as in claim 1 wherein step (c) includes the following substeps: (c.1) providing pulses to the first printhead which result in ink being emitted through nozzles located on the first printhead; and (c.2) providing pulses to the second printhead which result in ink being emitted through nozzles located on the second printhead.
Claim 8
Dependent Claim
36 words
A method as in claim 6 wherein in substep (c.1) when placing the first dots on the print medium, sub-pixel shifts in locations of the first dots is achieved by shifting data to different firing pulses.
Claim 9
Dependent Claim
201 words
A printer comprising: a first printhead which places first dots on a print medium; a second printhead which places second dots on the print medium; and printer electronics, coupled to the first printhead and to the second printhead, which, from print data input, generate dot data which indicates location of the first dots on the print medium and location of the second dots on the print medium, the printer electronics including: sub-pixel adjustment means for using dot shift data in order to make sub-pixel shifts in locations of the first dots on the print medium; wherein in response to the dot data the first print head places the first dots on the print medium and the second print head places the second dots on the print medium; wherein the first printhead utilizes a train of firing pulses to place the first dots on the print media, firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein the sub-pixel adjustment means performs sub-pixel shifts in location of the first dots by selecting different firing pulses to be used by the first printhead to place the first dots on the print medium.
Claim 10
Dependent Claim
201 words
A printer comprising: a first printhead which places first dots on a print medium; a second printhead which places second dots on the print medium; and printer electronics, coupled to the first printhead and to the second printhead, which, from print data input, generate dot data which indicates location of the first dots on the print medium and location of the second dots on the print medium, the printer electronics including: sub-pixel adjustment means for using dot shift data in order to make sub-pixel shifts in locations of the first dots on the print medium; wherein in response to the dot data the first print head places the first dots on the print medium and the second print head places the second dots on the print medium; wherein the first printhead utilizes a train of firing pulses to place the first dots on the print media, firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein the sub-pixel adjustment means performs sub-pixel shifts in location of the first dots by selecting different firing pulses to be used by the first printhead to place the first dots on the print medium.
Claim 11
Dependent Claim
22 words
A printer as in claim 8 wherein the printer electronics generates the dot shift data from coded information received from a user.
Claim 12
Dependent Claim
26 words
A printer as in claim 8 wherein the printer electronics generates the dot shift data from alignment information the printer obtains from a printed test pattern.
Claim 13
Dependent Claim
30 words
A printer as in claim 8 wherein the printer electronics provides pulses to the first printhead which result in ink being emitted through a nozzle located on the first printhead.
Claim 14
Dependent Claim
18 words
A printer as in claim 8 wherein the first dots are a different color than the second dots.
Claim 15
Dependent Claim
13 words
A printer as in claim 8 wherein the second dots are black dots.
Claim 16
Dependent Claim
91 words
A printer as in claim 8 additionally comprising: a third printhead, coupled to the printer electronics, which places third dots on the print medium; wherein the dot data generated by the printer electronics also indicates location of the thirds dots on the print medium; wherein the sub-pixel adjustment means additionally uses the dot shift data in order to make sub-pixel shifts in locations of the third dots on the print medium; and wherein in response to the dot data the third print head places the third dots on the print medium.
Claim 17
Independent Claim
237 words
A method for alignment of output from a first printhead and output from a second printhead with output from a third printhead, the method comprising the following steps: (a) generating for the first printhead, the second printhead and the third printhead, from data input, dot data which indicates location of dots on a print medium; (b) using dot shift data in order to make sub-pixel shifts in locations of first dots placed on the print medium by the first printhead and in locations of second dots placed on the print medium by the second printhead in order to align the first dots placed on the print medium by the first printhead and the first dots placed on the print medium by the first printhead with third dots placed on the print medium by the third printhead; and, (c) placing the first dots, the second dots and the third dots on the print medium; wherein step (c) is performed utilizing a train of firing pulses, firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein in step (b) sub-pixel shifts in location of the first dots are performed by selecting different firing pulses to place the first dots on the print medium and sub-pixel shifts in location of the second dots are performed by selecting different firing pulses to place the second dots on the print medium.
Claim 18
Independent Claim
237 words
A method for alignment of output from a first printhead and output from a second printhead with output from a third printhead, the method comprising the following steps: (a) generating for the first printhead, the second printhead and the third printhead, from data input, dot data which indicates location of dots on a print medium; (b) using dot shift data in order to make sub-pixel shifts in locations of first dots placed on the print medium by the first printhead and in locations of second dots placed on the print medium by the second printhead in order to align the first dots placed on the print medium by the first printhead and the first dots placed on the print medium by the first printhead with third dots placed on the print medium by the third printhead; and, (c) placing the first dots, the second dots and the third dots on the print medium; wherein step (c) is performed utilizing a train of firing pulses, firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein in step (b) sub-pixel shifts in location of the first dots are performed by selecting different firing pulses to place the first dots on the print medium and sub-pixel shifts in location of the second dots are performed by selecting different firing pulses to place the second dots on the print medium.
Claim 19
Independent Claim
179 words
A method for alignment of output from different passes of a printhead, the method comprising the following steps: (a) generating from data input, for a first pass and a second pass, dot data which indicates location of dots on a print medium; (b) using dot shift data in order to make sub-pixel shifts in locations of a subset of the dots to be placed on the print medium in order to align first dots placed on the print medium during the first pass with second dots placed on the print medium during the second pass; and, (c) performing the first pass and the second pass to place the first dots and the second dots on the print medium; wherein step (c) is performed utilizing a train of firing pulses, firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein in step (b) sub-pixel shifts in location of the first dots are performed by selecting different firing pulses to place the subset of the dots on the print medium.
Claim 20
Independent Claim
179 words
A method for alignment of output from different passes of a printhead, the method comprising the following steps: (a) generating from data input, for a first pass and a second pass, dot data which indicates location of dots on a print medium; (b) using dot shift data in order to make sub-pixel shifts in locations of a subset of the dots to be placed on the print medium in order to align first dots placed on the print medium during the first pass with second dots placed on the print medium during the second pass; and, (c) performing the first pass and the second pass to place the first dots and the second dots on the print medium; wherein step (c) is performed utilizing a train of firing pulses, firing pulses within the train of firing pulses repeating at a frequency that is higher than a pixel frequency; and wherein in step (b) sub-pixel shifts in location of the first dots are performed by selecting different firing pulses to place the subset of the dots on the print medium.
Claim 21
Dependent Claim
21 words
A method as in claim 16 wherein in step (c) the first dots are a different color than the second dots.
Claim 22
Dependent Claim
16 words
A method as in claim 16 wherein in step (c) the second dots are black dots.
References Cited (Backward Citations)
US4626867A
Cited
US5049898A
Cited
EP0539157A2
Cited
US5250956A
Cited
US5350929A
Cited
US5494361A
Cited
US5448269A
Cited
EP0622236A2
Cited
US5600350A
Cited
US5604597A
Cited
US5480240A
Cited
EP0775587A1
Cited
US5847722A
Cited
EP0858049A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-11-28 | 2004-05-29 | 2004-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-11-28 | 2008-05-29 | 2008-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-11-28 | 2012-05-29 | 2012-11-28 | $7700.00 | Window Closed / Lapsed |