# US 8,770,698 B2 · Print control method and print apparatus

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- Number: US 8,770,698 B2
- Document ID: US8770698B2
- Status: Granted
- Kind: B2
- Application number: 12/957,291
- Filed: 2010-11-30
- Published: 2011-09-01
- Granted: 2014-07-08
- Earliest claimed: 2010-02-26
- Assignees: Canon Kabushiki Kaisha
- Applicants: Takayuki Ochiai
- Inventors: Takayuki Ochiai
- Web page: https://patentgrep.com/patent/US8770698B2

## CPC

- B41J 13/0045: {concerning sheet refeed sections of automatic paper handling systems, e.g. intermediate stackers (printing on both faces B41J3/60)}
- B41J 3/60: for printing on both faces of the printing material
- B41J 11/008: {Controlling printhead for accurately positioning print image on printing material, e.g. with the intention to control the width of margins}
- B41J 11/0095: {Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end}
- B41J 11/66: Applications of cutting devices
- B41J 11/663: {Controlling cutting, cutting resulting in special shapes of the cutting line, e.g. controlling cutting positions, e.g. for cutting in the immediate vicinity of a printed image}
- B41J 11/70: cutting perpendicular to the direction of paper feed
- B41J 15/00: Devices or arrangements {of selective printing mechanisms, e.g. ink-jet printers or thermal printers,} specially adapted for supporting or handling copy material in continuous form, e.g. webs
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A reference mark is recorded in an area between one image and the next image sequentially printed on a first surface of a continuous sheet. In a print on a second surface of the sheet, the recorded reference mark is read, and a print position of the image on a second surface of the sheet is set. A plurality of images are sequentially printed on the second surface on the basis of this setting.

## Claims

### Claim 1

A method of performing duplex printing, the method comprising:
printing, by an inkjet head, a plurality of images on a first surface of a sheet, wherein the sheet is continuous;
recording a reference mark in an area between one image and a next image sequentially printed on the first surface;
reversing, by a reverse unit, the sheet where the plurality of images are printed on the first surface and feeding the reversed sheet for printing by the inkjet head again;
performing, by a decurl unit, decurling of the sheet fed from the reverse unit;
reading the reference mark recorded on the first surface of the reversed sheet fed from the reverse unit through the decurl unit;
setting, based on the reading of the reference mark, a position to be printed of an image on a second surface which is a back of the first surface;
printing, by the inkjet head, a plurality of images on the second surface;
recording a cut mark in a margin area between one image and a next image sequentially printed on the second surface based on the reading of the reference mark;
detecting the cut mark on the second surface within a limited search range which is narrower than the margin area and is set inside the margin area;
setting a first cut position and a second cut position for cutting off the margin area in response to the detection of the cut mark within the limited search range, or setting the first cut position and the second cut position by estimating a position of the cut mark based on information on already detected cut mark in response to no detection of the cut mark within the limited search range;
cutting the sheet at the first cut position and the second cut position; and
discharging each of cut sheets on which the images are formed both on the first and second surfaces.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising:
estimating, in response to not detecting the cut mark in the search range of the second surface, a position of the cut mark based on information on already detected cut mark; and
cutting the sheet based on the estimated position of the cut mark.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising:
recording a last cut mark on the first surface after a last image of the plurality of images on the first surface and detecting the last cut mark;
setting, in response to detecting the last cut mark, a cut position of the sheet based on the detection of the last cut mark, and estimating, in response to not detecting the last cut mark, a position of the last cut mark to set the cut position based on the estimation; and
cutting the sheet where the printing is performed on the first surface at the set cut position.

### Claim 4 (depends on 1)

The method according to claim 1,
wherein reversing the sheet includes winding the sheet where the printing is performed on the first surface around a winding rotary member and inversely rotating the winding rotary member to feed the wound sheet to perform the printing on the second surface.

### Claim 5

An apparatus capable of performing duplex printing, the apparatus comprising:
a sheet feeding unit configured to feed a sheet, wherein the sheet is continuous;
a print unit having an inkjet head configured to perform printing on the sheet fed from the sheet feeding unit;
a reverse unit configured to reverse the printed sheet and feed the reversed sheet to the print unit again;
a decurl unit configured to perform decurling of the sheet fed from the reverse unit;
a reader arranged to read a reference mark recorded on the sheet;
a cutter unit configured to cut the sheet;
a detecting unit configured to detect a cut mark on the sheet; and
a control unit, wherein the control unit controls in a manner that:
the print unit prints a plurality of images on a first surface of the sheet,
the print unit records the reference mark in an area between one image and a next image sequentially printed on the first surface,
the reverse unit reverses the sheet where the plurality of images are printed on the first surface,
the decurl unit performs decurling of the sheet fed from the reverse unit,
the reader reads the reference mark recorded on the first surface of the reversed sheet fed from the reverse unit through the decurl unit, wherein a position to be printed of an image on a second surface, which is a back of the first surface of the sheet, is set based on the reading of the reference mark,
the print unit prints a plurality of images on the second surface of the sheet fed from the reverse unit,
the print unit records a cut mark in a margin area between one image and a next image sequentially printed on the second surface based on the reading of the reference mark,
the detecting unit detects the cut mark on the second surface within a limited search range, which is narrower than the margin area and is set inside the margin area, in order to set a first cut position and a second cut position for cutting off the margin area based on the detection of the cut mark,
the control unit sets a first cut position and a second cut position for cutting off the margin area in response to the detection of the cut mark within the limited search range, or the control unit sets the first cut position and the second cut position by estimating a position of the cut mark based on information on already detected cut mark in response to no detection of the cut mark within the limited search range, and
the cutter unit cuts the sheet at the first cut position and the second cut position, and each of cut sheets on which the images are formed both on the first and second surfaces is discharged.

### Claim 6 (depends on 5)

The apparatus according to claim 5,
wherein the reverse unit includes a winding rotary member which winds the sheet where the printing is performed on the first surface and inversely rotates to feed the wound sheet to the print unit again.

### Claim 7 (depends on 5)

The apparatus according to claim 5, further comprising a scanner unit provided between the print unit and the cutter unit and configured to read inspection patterns or images formed on the sheet for inspecting or recovering the print head.