Printing apparatus and processing method therefor

Patent metadata

Field	Value
Publication number	US-9340009-B2
Application number	US-201514679252-A
Country	US
Kind code	B2
Filing date	Apr 6, 2015
Priority date	Aug 5, 2010
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A printing apparatus includes a full-line printhead in which a plurality of chips, on each of which a plurality of nozzle arrays are juxtaposed, are arranged in the nozzle arrayed direction, and which prints by the entire width of a printing medium using a plurality of nozzles arranged on the plurality of chips. The printing apparatus discharges ink from a predetermined number of successive nozzles on each nozzle array of each chip toward a printing medium during conveyance, thereby forming a plurality of first patterns corresponding to at least one nozzle array of each chip on the printing medium in the nozzle arrayed direction, reads the plurality of first patterns from the printing medium during conveyance using a sensor, calculates the shift amount of an ink attached position based on the plurality of read first patterns and corrects the attached position of ink based on the shift amount.

First claim

What is claimed is:

1. A printing apparatus that includes a plurality of nozzle arrays each of which has a plurality of nozzles each discharging ink and being arrayed in a predetermined direction, and that prints on a printing medium by discharging ink from the respective nozzles of the plurality of nozzle arrays while moving the plurality of nozzle arrays and the printing medium relatively in an intersecting direction which intersects the predetermined direction, the apparatus comprising:
a control unit configured to control forming, on the printing medium by the plurality of nozzle arrays, of a plurality of patterns corresponding to the plurality of nozzle arrays respectively while moving the plurality of nozzle arrays and the printing medium relatively in the intersecting direction, such that the plurality of patterns formed on the printing medium are arrayed in the predetermined direction; and
a determination unit configured to determine a shift amount of a relative printing position between the plurality of nozzle arrays in the intersecting direction, based on a reading result obtained by causing a reading unit to read the plurality of patterns while conveying the printing medium in the intersecting direction, the reading unit including a sensor which has a plurality of reading elements arranged in the predetermined direction such that a reading region that is read by the plurality of reading elements includes a forming region of the plurality of patterns in the predetermined direction,
wherein the control unit controls forming of the plurality of patterns such that a first pattern and a second pattern among the plurality of patterns is formed by a first nozzle array among the plurality of nozzle arrays, and
the determination unit determines the shift amount using a distance, in an image obtained from the reading result, between a pattern formed by a nozzle array which is different from the first nozzle array and a straight line which passes through the first pattern and the second pattern.

2. The apparatus according to claim 1 , wherein color of ink discharged from nozzles is the same for the plurality of nozzle arrays.

3. The apparatus according to claim 1 , wherein colors of ink discharged from nozzles are different from each other for the plurality of nozzle arrays.

4. The apparatus according to claim 3 , further comprising a plurality of printheads in which colors of ink discharged from nozzles are different from each other,
wherein the plurality of nozzle arrays are provided to the plurality of printheads, respectively.

5. The apparatus according to claim 1 , wherein
each of the plurality of patterns includes a plurality of dots which are randomly arranged, and
the determination unit determines the shift amount using pattern matching between the plurality of patterns.

6. The apparatus according to claim 5 , the plurality of patterns are formed with a same pattern.

7. The apparatus according to claim 1 , wherein the determination unit adjusts, based on the shift amount, a timing for causing the nozzles of each of the plurality of nozzle arrays to discharge ink, such that the shift amount falls within an allowable range.

8. The apparatus according to claim 1 , further comprising the reading unit.

9. A printing apparatus that includes a printhead which has a first nozzle array and a second nozzle array each of which has a plurality of nozzles each discharging the same color ink and being arrayed in a predetermined direction, the first nozzle array and the second nozzle array being arranged in an intersecting direction which intersects the predetermined direction so as to be shifted from each other in the predetermined direction to form an overlapping portion in which parts of each other are overlapped in the predetermined direction, and that prints on a printing medium by discharging ink from the respective nozzles of the first nozzle array and the second nozzle arrays while moving the printhead and the printing medium relatively in the intersecting direction, the apparatus comprising:
a control unit configured to control forming of a plurality of patterns on the printing medium by the first nozzle array and the second nozzle array while moving the printhead and the printing medium relatively in the intersecting direction, such that the plurality of patterns are arrayed in the predetermined direction, the plurality of patterns including patterns formed on the printing medium by the first nozzle array and patterns formed on the printing medium by the second nozzle array; and
a determination unit configured to determine a shift amount of a relative printing position between the first nozzle array and the second nozzle array in the intersecting direction, based on a reading result obtained by causing a reading unit to read the plurality of patterns while conveying the printing medium in the intersecting direction, the reading unit including a sensor which has a plurality of reading elements arranged in the predetermined direction such that a reading region that is read by the plurality of reading elements includes a forming region of the plurality of patterns in the predetermined direction,
wherein the control unit controls forming of the plurality of patterns such that a first pattern and a second pattern among the plurality of patterns is formed by the first nozzle array, and
the determination unit determines the shift amount using a distance, in an image obtained from the reading result, between a pattern formed by the second nozzle array and a straight line which passes through the first pattern and the second pattern.

10. The apparatus according to claim 9 , wherein
each of the plurality of patterns includes a plurality of dots which are randomly arranged, and
the determination unit determines the shift amount using pattern matching between the plurality of patterns.

11. The apparatus according to claim 10 , the plurality of patterns are formed with a same pattern.

12. The apparatus according to claim 9 , wherein the determination unit adjusts, based on the shift amount, a timing for causing the nozzles of each of the first nozzle array and the second nozzle array to discharge ink, such that the shift amount falls within an allowable range.

13. The apparatus according to claim 9 , further comprising the reading unit.

14. A printing method for printing on a printing medium by discharging ink from each nozzle in a plurality of nozzle arrays each of which has a plurality of nozzles each discharging ink and being arranged in a predetermined direction, while moving the plurality of nozzle arrays and the printing medium relatively in an intersecting direction which intersects the predetermined direction, the method comprising:
controlling forming of a plurality of patterns corresponding to the plurality of nozzle arrays respectively on the printing medium by the plurality of nozzle arrays while moving the plurality of nozzle arrays and the printing medium relatively in the intersecting direction, such that the plurality of patterns formed on the printing medium are arrayed in the predetermined direction; and
determining a shift amount of a relative printing position between the plurality of nozzle arrays in the intersecting direction, based on a reading result obtained by causing a reading unit to read the plurality of patterns while conveying the printing medium in the intersecting direction, the reading unit including a sensor which has a plurality of reading elements arranged in the predetermined direction such that a reading region that is read by the plurality of reading elements includes a forming region of the plurality of p

Assignees

• Canon Kk

Inventors

• Murayama Yoshiaki
• Azuma Satoshi
• Kosaka Kei
• Torigoe Makoto
• Nagoshi Shigeyasu

Classifications

• B41J2/2135 Primary

  Alignment of dots · CPC title

• B41J2/04586

  controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type · CPC title

• B41J29/393

  Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} · CPC title

• B41J2/04508 Primary

  aiming at correcting other parameters · CPC title

• B41J2/2146

  for line print heads · CPC title