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EP0516366A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Ink jet recording apparatus and method capable of increasing density

Assignee: Canon Inc
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Filing: 1992-05-26
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Granted: —
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Expires: 2012-05-26
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Abstract

Abstract A paper feed operation is performed by a width less than one pixel (1/2) in addition to an integer multiple number of pixels (n/2) with respect to a basic number of pixels inherent to an ink jet recording apparatus having a multi nozzle head having n nozzles. When a plurality of times of pixel recording operations are performed for a single pixel region, ink dots land at a distance less than one pixel (1/2) at the pixel density. Thus, a variation in ink surface density on a recording sheet in an overlapping print operation is reduced, thereby efficiently increasing the image density, and preventing blurring by promoting absorption and evaporation of an ink to and from a paper sheet.

Inventors

  • 👤 Miyuki C/O Canon Kabushiki Kaisha Matsubara
  • 👤 Hiromitsu Canon Kabushiki Kaisha Hirabayashi
  • 👤 Shigeyasu Canon Kabushiki Kaisha Nagoshi
  • 👤 Atsushi Canon Kabushiki Kaisha Arai
  • 👤 Kentaro Canon Kabushiki Kaisha Yano
  • 👤 Yuji Canon Kabushiki Kaisha Akiyama
  • 👤 Hitoshi Canon Kabushiki Kaisha Sugimoto
  • 👤 Kiichiro C/O Canon Kabushiki Kaisha Takahashi
  • 👤 Naoji C/O Canon Kabushiki Kaisha Otsuka

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 11:46
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/21; B41J2/2132; B41J2/2121; B41J2/2125; B41J2/135; B41J2/14; B41J2002/14475

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 107 words
An ink jet recording apparatus comprising a multi head for ejecting ink droplets from a plurality of multi nozzles, comprising: paper feed means for performing a paper feed operation by a width not less than one pixel in addition to an integer multiple number of pixels with respect to basic pixels inherent to said ink jet recording apparatus; and ejection means for performing a plurality of times of ink ejections, so as to have ink landing points within a distance less than one pixel at a density of the pixels, before and after the paper feed operation by said paper feed means for a single pixel region.
Claim 2
Dependent Claim 38 words
An apparatus according to claim 1, wherein the latter landing points are present at positions moved in both a paper feed direction and in a direction perpendicular to the paper feed direction from the former basic landing points.
Claim 3
Dependent Claim 60 words
An apparatus according to claim 1, wherein the latter landing points are present at positions where an overlapping area of ink dots which are spread to have, as centers, the former basic landing point, the basic landing point adjacent to the former basic landing pint, and the latter landing point shifted at a position less than one pixel is minimized.
Claim 4
Dependent Claim 34 words
An apparatus according to claim 1, the latter landing points are present at positions moved by a 1/2 pixel in both vertical and horizontal directions from an array of the former basic landing points.
Claim 5
Dependent Claim 29 words
An apparatus according to claim 1, wherein a plurality of said multi heads are arranged, and only some of said plurality of multi heads print the latter landing points.
Claim 6
Dependent Claim 32 words
An apparatus according to claim 5, wherein said plurality of multi heads eject inks in different colors, and only the multi head for ejecting a black ink prints the latter landing points.
Claim 7
Dependent Claim 34 words
An apparatus according to claim 1, wherein a print operation of the latter landing points and a print operation of the former basic landing points are performed by different nozzles of said multi head.
Claim 8
Dependent Claim 38 words
An apparatus according to claim 1, wherein said multi head causes a change in state including formation of a bubble in an ink by heat energy, and ejects the ink on the basis of the change in state.
Claim 9
Dependent Claim 100 words
An ink jet recording method for performing recording using a multi head for ejecting ink droplets from a plurality of multi nozzles, comprising: ejecting an ink at first landing points for basic pixels in a first scan operation; performing a paper feed operation by a width less than one pixel in addition to an integer multiple number of pixels with respect to the basic pixels; and ejecting the ink at second landing points at a distance less than one pixel at a density of the pixels, within a single pixel region of the basic pixels, in a second scan operation.
Claim 10
Dependent Claim 38 words
A method according to claim 9, wherein said multi head causes a change in state including formation of a bubble in an ink by heat energy, and ejects the ink on the basis of the change in state.
Claim 11
Dependent Claim 71 words
An ink jet recording apparatus comprising a recording head for ejecting an ink from a plurality of ejection orifices to a recording medium, wherein a plurality of times of ink ejections are performed for one-pixel regions of basic pixels inherent to said ink jet recording apparatus, and at least one of said plurality of times of ink ejections has a smaller ink ejection amount than the remaining times of ink ejections.
Claim 12
Dependent Claim 16 words
An apparatus according to claim 11, wherein two ink ejections are performed for the one-pixel regions.
Claim 13
Dependent Claim 41 words
An apparatus according to claim 12, wherein landing points formed by the two ink ejections are aligned at positions separated by a distance of a 1/2 pixel in a paper feed direction and a direction perpendicular to the paper feed direction.
Claim 14
Dependent Claim 50 words
An apparatus according to claim 13, wherein the ink ejections are performed such that a sum of ejection amounts of ink dots landing at the two ink landing points is minimized when an area of dots landing at the two ink landing points satisfy an area of each one-pixel region.
Claim 15
Dependent Claim 74 words
An apparatus according to claim 13, wherein the ink ejection for one of the two landing points and the paper feed operation by a sum of the integer multiple number of pixels and a 1/2 pixel, and the other ink ejection in a smaller amount than the one ink ejection and the paper feed operation by a width obtained by subtracting a 1/2 pixel from the integer multiple number of pixels are alternately performed.
Claim 16
Dependent Claim 38 words
An apparatus according to claim 11, wherein said recording head causes a change in state including formation of a bubble in an ink by heat energy, and ejects the ink on the basis of the change in state.
Claim 17
Dependent Claim 83 words
An ink jet recording apparatus comprising a recording head for ejecting an ink from a plurality of ejection orifices to a recording medium, wherein first and second ink ejections are performed for one-pixel regions of basic pixels inherent to said ink jet recording apparatus, dots landing in the first ink ejection partially overlap each other, and the second ink ejection is performed in an amount smaller than that in the first ink ejection so as to satisfy an area of the one-pixel region.
Claim 18
Dependent Claim 38 words
An apparatus according to claim 17, wherein said recording head causes a change in state including formation of a bubble in an ink by heat energy, and ejects the ink on the basis of the change in state.
Claim 19
Dependent Claim 117 words
An ink jet recording apparatus comprising: a recording head for ejecting an ink from a plurality of ejection orifices to a recording medium; main scanning means for performing a main scanning operation of said recording head with respect to said recording medium; sub scanning means for performing a sub scanning operation by a width less than one pixel in addition to an integer multiple number of pixels with respect to one pixel formed on said recording medium; and ejection means for causing said main scanning means to perform the main scanning operation before and after the sub scanning operation by said sub scanning means, and performing a plurality of times of ink ejections within a one-pixel region.
Claim 20
Dependent Claim 45 words
An apparatus according to claim 19, further comprising ejection amount control means for controlling an amount of ink ejected from said recording head, said ejection amount control means changing the amount of ink in the plurality of times of ink ejections by said ejection means.
Claim 21
Dependent Claim 38 words
An apparatus according to claim 19, wherein said recording head causes a change in state including formation of a bubble in an ink by heat energy, and ejects the ink on the basis of the change in state.

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