EP0461759A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Recording apparatus for performing recording using recording head
Assignee: Canon Inc
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Filing: 1991-05-10
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Granted: —
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Expires: 2011-05-10
Abstract
Abstract A correction data production apparatus includes a detecting unit (1014) for reading a test pattern formed by a recording head (1001) having a plurality of recording elements constituting an array, and for detecting a density distribution of a range of the array of the plurality of recording elements, a corresponding unit (1101A) for causing the density distribution detected by the detecting unit to correspond to the plurality of recording elements on the basis of a reference position where a density of an end portion of the density distribution reaches a predetermined threshold value, a production unit (1020) for producing correction data for an image formation density uniforming drive conditions in correspondence with the plurality of recording elements on the basis of the density distribution corresponded by the corresponding unit, and a changing unit (1101B) for changing the threshold value in accordance with characteristics of the test pattern.
Inventors
- 👤 Akio Canon Kabushiki Kaisha Suzuki
- 👤 Toshimitsu C/O Canon Kabushiki Kaisha Danzuka
- 👤 Haruhiko C/O Canon Kabushiki Kaisha Moriguchi
- 👤 Yoshihiro C/O Canon Kabushiki Kaisha Takada
- 👤 Yasushi C/O Canon Kabushiki Kaisha Miura
- 👤 Hisashi C/O Canon Kabushiki Kaisha Fukushima
- 👤 Masami C/O Canon Kabushiki Kaisha Izumizaki
- 👤 Nobuhiko C/O Canon Kabushiki Kaisha Takekoshi
- 👤 Nobuyuki C/O Canon Kabushiki Kaisha Watanabe
- 👤 Eiichi C/O Canon Kabushiki Kaisha Takagi
- 👤 Haruhiko C/O Canon Kabushiki Kaisha Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:03
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/35; B41J2/355; B41J2/3555; B41J11/00; B41J11/009; B41J11/0095; B41J2/005; B41J2/01; B41J2/135; B41J2/165; B41J2/16585; B41J2/16588; B41J2/21; B41J2/2132; B41J2/2135; B41J2/2139; B41J2/36; B41J29/00; B41J29/38; B41J29/393; H; H04; H04N; H04N1/00; H04N1/40; H04N1/401; H04N1/4015; H04N1/46; H04N1/56; H04N1/60; H04N1/603; H04N1/6033; B41J2/17; B41J2/1707; B41J2202/00; B41J2202/01; B41J2202/12
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
138 words
A correction data production apparatus comprising: detecting means for reading a test pattern formed by a recording head having a plurality of recording elements constituting an array, and for detecting a density distribution of a range of said array of said plurality of recording elements; corresponding means for causing the density distribution detected by said detecting means to correspond to said plurality of recording elements on the basis of a reference position where a density of an end portion of the density distribution reaches a predetermined threshold value; producing means for producing correction data for an image formation density uniforming drive conditions in correspondence with said plurality of recording elements on the basis of the density distribution corresponded by said corresponding means; and changing means for changing the threshold value in accordance with characteristics of the test pattern.
Claim 2
Dependent Claim
174 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; detecting means for reading a test pattern formed by said recording head and for detecting a density distribution of a range of said array of said plurality of elements; corresponding means for causing the density distribution detected by said detecting means to correspond to said plurality of recording elements on the basis of a reference position where a density of an end portion of the density distribution reaches a predetermined threshold value; producing means for producing correction data for image formation density uniforming drive conditions in correspondence with said plurality of recording elements on the basis of the density distribution corresponded by said corresponding means; changing means for changing the threshold value in accordance with the density of the test pattern; and correcting means for correcting the drive conditions of said plurality of recording elements on the basis of the produced correction data at the time of image formation.
Claim 3
Dependent Claim
100 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; reading means for reading a density of a test pattern formed by said recording head; uneven image density correcting means for correcting drive conditions of said plurality of recording elements on a read result so as to uniform an image formation density; and regulating means for causing said reading means to read a reference density sample prior to reading of the test pattern and regulating said reading means on the basis of a read result.
Claim 4
Dependent Claim
122 words
An image forming apparatus comprising: reading means for reading a density of a test pattern which corresponds to each of a plurality of recording elements of a recording head, the test pattern being recorded by said plurality of recording elements of said recording head; eliminating means for eliminating error information, received from an area outside a test pattern area, from density information obtained by said reading means when a density of a test pattern end portion corresponding to an end portion of an array of said plurality of recording elements is determined; and means for uniforming the image densities of said plurality of recording elements on the basis of density information from which the error information is eliminated by said eliminating means.
Claim 5
Dependent Claim
141 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; signal generating means for causing said recording head to record a predetermined test pattern; reading means for reading the test pattern formed by said recording head under the control of said signal generating means; read value correcting means for correcting a read value of a given portion associated with a read value of a portion adjacent to said given portion, said given portion corresponding to an end portion of said array of said plurality of recording elements; and drive correcting means for correcting drive conditions of said recording head on the basis of the end portion value corrected by said read value correcting means and the read value of a portion except for the end portion.
Claim 6
Dependent Claim
93 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; reading means for reading a test pattern formed by said recording head in a direction corresponding to a direction of said array; means for setting a size of a read range of the test pattern at a main scanning position such that a sub-scanning length is larger than a main scanning length; and correcting means for correcting recording head drive conditions on the basis of the read result.
Claim 7
Dependent Claim
97 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; density reading means for reading a density of a test patern formed by said recording head; uneven image density correcting means for correcting drive conditions of said plurality of recording elements to uniform an image formation density on the basis of the read result; and means for regulating floating of the recording medium having the test pattern thereon at a position near a read position of said uneven image density reading means.
Claim 8
Dependent Claim
94 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; scanning means for causing said recording head to scan the recording medium at the time of image formation; reading means, interlocked with said recording head or a carriage having said recording head thereon and mounted in a member driven by said scanning means, for reading a test pattern formed by said recording head; and correcting means for correcting recording head drive conditions on the basis of the read result.
Claim 9
Dependent Claim
85 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; reading means for reading a test pattern formed by said recording head; correcting means for correcting recording head drive conditions on the basis of the read result; protecting means, having a light-transmitting member arranged on at least a light path portion of said reading means, for protecting said reading means from contamination; and cleaning means for cleaning said light-transmitting member.
Claim 10
Dependent Claim
82 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements constituting an array, for performing image formation on a recording medium; reading means for reading a test pattern formed by said recording head; correcting means for correcting recording head drive conditions on the basis of the read result; protecting means for protecting said reading means from contamination; and means for retracting said protecting means to open an optical path of said reading means at the time of reading.
Claim 11
Dependent Claim
147 words
An image forming apparatus comprising: a recording head, having a plurality of recording elements consituting an array, for performing image formation on a recording medium; signal generating means for causing said recording head to record a predetermined test pattern; reading means, having a reading sensor, for sequentially reading the test pattern formed by said recording head under the control of said signal generating means upon movement of said reading sensor; control means for obtaining a difference between a read position and a position of the test pattern on the basis of a read result of said reading sensor of said reading means, and correcting the read position on the basis of the calculated difference; and means for correcting drive conditions of said plurality of recording elements of said recording head on the basis of a read result at a read position corrected by said read control means.
Claim 12
Independent Claim
27 words
An apparatus according to any of Claims 1 to 11, wherein said changing means changes the threshold value in accordance with a density of the test pattern.
Claim 13
Independent Claim
27 words
An apparatus according to any of Claims 1 to 11, wherein said changing means changes the threshold value in accordance with a colour of the test pattern.
Claim 14
Independent Claim
24 words
An apparatus according to any of Claims 1 to 11, wherein said recording head has recording agents having different colours to perform multi-colour recording.
Claim 15
Independent Claim
29 words
An apparatus according to any of Claims 1 to 11, wherein each of said plurality of recording elements of said recording head has an orifice for injecting an ink.
Claim 16
Dependent Claim
53 words
An apparatus according to Claim 15, wherein said each recording element comprises heat energy generating means, arranged in correspondence with each orifice, for causing a change in state of the ink by heat, injecting the ink from said orifice on the basis of the change in state, and forming a flying ink droplet.
Claim 17
Independent Claim
20 words
An apparatus according to any of Claims 1 to 11, wherein said recording head is of a serial scanning type.
Claim 18
Independent Claim
19 words
An apparatus according to any of Claims 1 to 11, wherein said recording head is of a full-line type.
Claim 19
Dependent Claim
38 words
An apparatus according to Claim 3, wherein said regulating means has first and second reference density samples having different densities and causes said reading means to read at least one of the first and second reference density samples.
Claim 20
Dependent Claim
23 words
An apparatus according to Claim 3, wherein said regulating means regulates at least one of offset and gain values of said reading means.
Claim 21
Dependent Claim
27 words
An apparatus according to Claim 19, wherein the first reference density sample is a halftone sample having an optical density higher than that of the test pattern.
Claim 22
Dependent Claim
27 words
An apparatus according to Claim 19, wherein the second reference density sample is a halftone sample having an optical density lower than that of the test pattern.
Claim 23
Dependent Claim
18 words
An apparatus according to Claim 4, wherein the error information is produced by reading a reference density sample.
Claim 24
Dependent Claim
46 words
An apparatus according to Claim 5, wherein said read value correcting means substitutes the read value of said given portion corresponding to said end portion of said array of said plurality of recording elements into the read value of said portion adjacent to said given portion.
Claim 25
Dependent Claim
48 words
An apparatus according to Claim 5, wherein said read value correcting means calculates to convert the read value of said given portion corresponding to said end portion of said array of said plurality of recording elements into the read value of said portion adjacent to said given portion.
Claim 26
Dependent Claim
30 words
An apparatus according to Claim 8, wherein said reading means is scanned on a member for regulating a recording surface of the recording medium at the time of image formation.
Claim 27
Dependent Claim
56 words
An apparatus according to Claim 9, wherein said recording head is scanned in a predetermined direction with respect to the recording medium at the time of image formation, said reading means is arranged in a member interlocked with scanning, and said cleaning means is engaged with said light-transmitting member during scanning, thereby cleaning said light-transmitting member.
References Cited (Backward Citations)
No citation records indexed.
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