Patent EP0517543A2 successfully refreshed from Google Patents.
EP0517543A2
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Ink jet recording method
Assignee: Canon Inc
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Filing: 1992-06-05
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Granted: —
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Expires: 2012-06-05
Abstract
Abstract After an ink-jet recording head (1) with a plurality of discharging portions (Nos. 1-128) arranged is main-scanned in a direction perpendicular to the direction of the discharging portion arrangement to record a first image area, sub-scanning of the head is performed. Before the head is main-scanned to record a second image area, the sub-scanning is performed so that a few discharging portions (Nos. 1-3) on an upper edge portion of the head (1) in second main-scanning overlap part of the first image area. Ink droplets land on pixels in the overlapping portion twice for each main-scanning, and image density of the pixels in the overlapping portion is controlled by the sum number of the landing ink droplets. This enables image density unevenness of image density, a "black stripe banding" or a "white stripe banding" in a boundary of an image area being recorded in each main-scanning to be markedly reduced.
Inventors
- 👤 Shinji c/o Canon Kabushiki Kaisha Takagi
- 👤 Hideki c/o Canon Kabushiki Kaisha Tanaka
- 👤 Tatsuo c/o Canon Kabushiki Kaisha Kimura
- 👤 Jun c/o Canon Kabushiki Kaisha Ashiwa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 11:53
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/12; H04N1/126; H04N1/128; B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/21; B41J2/2121; B41J2/2128; B41J2/2132; G; G06; G06K; G06K15/00; G06K15/02; G06K15/10; G06K15/102; G06K15/105; G06K15/107; H04N1/19; H04N1/191; H04N1/1911; G06K2215/00; G06K2215/101; G06K2215/111; H04N2201/00; H04N2201/04; H04N2201/0402; H04N2201/0414
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
246 words
An ink-jet recording method, in which a plurality of ink droplets for each pixel are overlapped and landed on a recording medium to form each pixel by a recording head with a plurality of ink discharging portions arranged thereon and a tone wedge of an image data is represented by controlling an area of each pixel on a basis of the number of the plurality of ink droplets characterized by comprising: recording one image area by main-scanning of said recording head and said recording medium relative thereto in a direction other than a direction of said ink discharging portion arrangement; sub-scanning said recording head and said recording medium relative thereto in a direction perpendicular to a direction of said main-scanning; and recording the following image area by main-scanning said recording head and said recording medium relative thereto, wherein said sub-scanning is performed in a manner that part of said one image area overlaps part of said following image area, and the number of ink droplets discharged from at least one ink discharging portion of said plurality of ink discharging portions, which relates to recording of pixels included in an overlapping portion of said one and following image areas, is restricted when said one and following image areas are recorded, so that a tone wedge of a recording image of said pixels included in said overlapping portion is represented by a total number of ink droplets being discharged when said one and following image areas are recorded.
Claim 2
Dependent Claim
104 words
An ink-jet recording method as claimed in claim 1, wherein the number of discharging portions for recording pixels included in said overlapping portion is two or more, said number of ink droplets being discharged from said two or more discharging portions for recording said overlapping portion, is gradually decreased toward a discharging portion disposed in an edge portion of said recording head when said one image area is recorded, and is gradually increased from a discharging portion disposed in an edge portion of said recording head when said following image area is recorded, so that said total number of discharged ink droplets is obtained.
Claim 3
Dependent Claim
89 words
An ink-jet recording method as claimed in claim 1, further characterized in that the step of adjusting an amount of said sub-scanning and/or a record starting position of said main-scanning, wherein each pixel included in said overlapping portion is formed by partially overlapping one image portion being formed by a group of ink droplets discharged when said one image area is recorded with a following image portion being formed by a group of ink droplets discharged when said following image area is recorded, by less than a pixel pitch.
Claim 4
Dependent Claim
47 words
An ink-jet recording method as claimed in claim 1, further characterized in that said total number of ink droplets is the number of ink droplets being determined to obtain a predetermined tone wedge of a recording image of pixels when said pixels are formed without overlapping thereof.
Claim 5
Dependent Claim
34 words
An ink-jet recording method as claimed in claim 1, further characterized in that said recording head comprises heating elements each of which produces thermal energy for discharging ink in response to an electric current.
Claim 6
Dependent Claim
276 words
An ink-jet recording method, in which a plurality of ink droplets for each pixel are overlapped and landed on a recording medium to form each pixel by a recording head with a plurality of ink discharging portions arranged thereon and a tone wedge of an image data is represented by controlling an area of each pixel on a basis of the number of the plurality of ink droplets characterized by comprising: recording a one image area by main-scanning of said recording head and said recording medium relative thereto in a direction other than a direction of said ink discharging portion arrangement; sub-scanning said recording head and said recording medium relative thereto in a direction different from a direction of said main-scanning, by a length less than a width of said one image area; and recording a following image area by main-scanning said recording head and said recording medium relative thereto, whereby said one and following image areas are partially overlapped with each other, wherein the number of discharging portions for recording pixels included in an overlapping portion of said one and following image areas is two or more, said number of ink droplets being discharged from said two or more discharging portions for recording said overlapping portion, is gradually decreased toward a discharging potion disposed in an edge portion of said recording head when said one image area is recorded, and is gradually increased from a discharging portion disposed in an edge portion of said recording head when said following image area is recorded, so that a total number of discharged ink droplets, being discharged when said one and following image areas are recorded is obtained.
Claim 7
Dependent Claim
33 words
An ink-jet recording method as claimed in claim 6, characterized in that said recording head comprises heating elements each of which produces thermal energy for discharging ink in response to an electric current.
Claim 8
Dependent Claim
243 words
An ink-jet recording method, in which a plurality of ink droplets for each pixel are overlapped and landed on a recording medium to form each pixel by a recording head with a plurality of ink discharging portions arranged thereon and a tone wedge of an image data is represented by controlling an area of each pixel on a basis of the number of the plurality of ink droplets characterized by comprising: recording a one image area by main-scanning of said recording head and said recording medium relative thereto in a direction other than a direction of said ink discharging portion arrangement; sub-scanning said recording head and said recording medium relative thereto in a direction different from a direction of said main-scanning, by a length less than a width of said one image area; recording a following image area by main-scanning said recording head and said recording medium relative thereto, whereby said one and following image areas are partially overlapped with each other; and adjusting an amount of said sub-scanning and/or a record starting position of said main-scanning, wherein each pixel included in an overlapping portion of said one and following image areas is formed by partially overlapping one image portion being formed by a group of ink droplets discharged when said one image area is recorded with a following image portion being formed by a group of ink droplets discharged when said following image area is recorded, by less than a pixel pitch.
Claim 9
Dependent Claim
33 words
An ink-jet recording method as claimed in claim 8, characterized in that said recording head comprises heating elements each of which produces thermal energy for discharging ink in response to an electric current.
Claim 10
Dependent Claim
238 words
An ink-jet recording method, in which at least one ink droplet for each pixel is landed on a recording medium to form each pixel by a recording head with a plurality of ink discharging portions arranged thereon and a tone wedge of an image data is represented by controlling an area of each pixel on a basis of an quantity of ink based on density data characterized by comprising: recording one image area by main-scanning of said recording head and said recording medium relative thereto in a direction other than a direction of said ink discharging portion arrangement; sub-scanning said recording head and said recording medium relative thereto in a direction perpendicular to a direction of said main-scanning; and recording the following image area by main-scanning said recording head and said recording medium relative thereto, wherein said sub-scanning is performed in a manner that part of said one image area overlaps part of said following image area and said density data corresponding to at least one discharging portion of said plurality of discharging portions, which relates to recording of pixels included in an overlapping portion of said one and following image areas, is restricted when said one and following image areas are recorded, so that tone wedge of a recording image of said pixels included in said overlapping portion is represented by a total of quantity of ink discharged when said one and following image areas are recorded.
Claim 11
Dependent Claim
101 words
An ink-jet recording method as claimed in claim 10, characterized in that the number of discharging portions for recording pixels included in said overlapping portion is two or more, said density data corresponding to said two or more discharging portions for recording said overlapping portion, is gradually decreased toward a discharging portion disposed in an edge portion of said recording head when said one image area is recorded, and is gradually increased from a discharging portion disposed in an edge portion of said recording head when said following image area is recorded, so that said total of ink quantity is obtained.
Claim 12
Dependent Claim
29 words
An ink-jet recording method as claimed in claim 11, characterized in that the number of ink droplets being landed on one pixel is controlled based on said density data.
Claim 13
Dependent Claim
46 words
An ink-jet recording method as claimed in claim 12, characterized in that said total number of ink droplets is the number of ink droplets being determined to obtain a predetermined tone wedge of a recording image of pixels when said pixels are formed without overlapping thereof.
Claim 14
Dependent Claim
33 words
An ink-jet recording method as claimed in claim 10, characterized in that said recording head comprises heating elements each of which produces thermal energy for discharging ink in response to an electric current.
Claim 15
Dependent Claim
89 words
An ink-jet recording method as claimed in claim 10, further characterized in that the step of adjusting an amount of said sub-scanning and/or a record starting position of said main-scanning, wherein each pixels included in said overlapping portion is formed by partially overlapping one image portion being formed by a group of ink droplets discharged when said one image area is recorded and a following image portion being formed by a group of ink droplets discharged when said following image area is recorded, by less than a pixel pitch.
Claim 16
Dependent Claim
42 words
An ink-jet recording method as claimed in claim 10, characterized in that said total of ink quantity is density data being determined to obtain a predetermined tone wedge of a recording image of pixels when said pixels are formed without overlapping thereof.
Claim 17
Dependent Claim
33 words
An ink-jet recording method as claimed in claim 10, characterized in that said recording head comprises heating elements each of which produces thermal energy for discharging ink in response to an electric current.
Claim 18
Dependent Claim
60 words
An ink jet recording apparatus or method in which an image is recorded as a plurality of parallel scans, characterised in that the edge portions of each scan are recorded to taper in intensity, and in that the edge portions of adjacent scans overlap, so as to reduce formation of dark or light bands due to variations in scan separation.
Claim 19
Independent Claim
39 words
A method or apparatus for printing in a series of scans across a recording medium in which some image elements are printed in each of two overlapping scans, a proportion of the required density being provided by each scan.
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