JP2016210014A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer which can efficiently perform printing of a test pattern image for detecting a nozzle in which ink discharge failure occurs.SOLUTION: An image S from a printing job is printed on an image printing area As in a page unit of a roll sheet 9, and a test pattern image T is printed only with ink discharged from a nozzle discharging ink when the image S from the printing job is printed on a margin area Am between two continuous image printing areas As, As in the sub-scanning direction X. With this, ink consumption is suppressed in comparison to printing of a general test pattern image t by discharging ink from a nozzle discharging no ink when the image S from the printing job is printed. Also, the necessity of performing processing and work of checking ink discharge failure from the test pattern image T is eliminated for the nozzle which is not needed to check the ink discharge failure when printing the image S from the printing job.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a printing apparatus having a line-type inkjet head in which a plurality of line heads in which a plurality of nozzles for ejecting ink are arranged in the main scanning direction are arranged for each color at intervals in the sub-scanning direction orthogonal to the main scanning direction.

  In the field of inkjet printing apparatuses, printing apparatuses having line-type inkjet heads that enable high-speed printing by performing printing in the main scanning direction in a so-called one-pass are becoming widespread.

  In this type of printing apparatus, a line head in which a plurality of nozzles for ejecting ink are arranged in the main scanning direction is used. In particular, in a printing apparatus capable of printing two or more colors, color-specific line heads are arranged at intervals in the sub-scanning direction orthogonal to the main scanning direction.

  Then, when the printing paper passes under the line head of each color while transporting the printing paper in the sub-scanning direction, an ink droplet is ejected from each nozzle of the line head, thereby forming an image on the printing paper. ing.

  In this type of printing apparatus, the quality of a printed image is deteriorated when ink ejection failure from a nozzle occurs. Therefore, it is performed to print a test pattern image and detect a nozzle causing an ink ejection failure (for example, Patent Document 1).

JP 2001-277777 A

  The present invention has been made by paying attention to the printing apparatus having the above-described line-type inkjet head, and an object of the present invention is to efficiently print a test pattern image for detecting a nozzle causing an ink ejection failure. It is an object of the present invention to provide a printing apparatus that can be performed automatically.

  In a printing apparatus having a line-type inkjet head, a large amount of printing may be performed by taking advantage of high printing processing capability. One example is address printing on a portion exposed from an envelope window portion of an envelope paper or contents paper in combination with a seal enclosing device. In such address printing, ink is ejected from a part of the nozzles of the line head, and an image is printed only on a part of the sheet.

  In such a case, the nozzles that eject ink corresponding to the address printed image are limited to a part of the whole. Therefore, it is sufficient to check ink ejection defects by printing a test pattern image for a part of the nozzles.

  If a test pattern image is printed by ejecting ink from all nozzles, ink will be ejected from nozzles that do not need to check for ink ejection failure, resulting in excessive ink consumption. Then, a process or operation for confirming an ink ejection defect is performed for a nozzle that does not need to be confirmed from the printed test pattern image, and the process and the operation become more complicated than necessary.

Therefore, in order to achieve the above object, a printing apparatus according to the first aspect of the present invention includes:
A printing apparatus that prints an image on printing paper that is transported in a sub-scanning direction orthogonal to the main scanning direction by ejecting ink from a plurality of nozzles arranged in the main scanning direction of the line head based on an input print job In
Nozzle specifying means for specifying a nozzle for ejecting ink when printing the image among the nozzles of the line head based on the print job;
Test pattern image generation means for generating image data of a test pattern image to be printed on printing paper by discharging ink from the nozzle specified by the nozzle specifying means;
A test pattern printing unit that prints the test pattern image on a printing paper using the image data generated by the test pattern image generation unit when printing the image of the print job on the printing paper;
It is characterized by providing.

  The printing apparatus according to the second aspect of the present invention is the printing apparatus according to the first aspect of the present invention, wherein the test pattern image is read from the printing paper and the ink is ejected from the nozzle specified by the nozzle specifying means. The apparatus further comprises discharge failure detection means for detecting a failure.

  Further, the printing apparatus according to the third aspect of the present invention is the printing apparatus according to the first or second aspect of the present invention, wherein the test pattern printing unit is on a roll-shaped printing paper on which an image of the print job is printed. The test pattern image is printed in a margin between pages.

  A printing apparatus according to a fourth aspect of the present invention is the printing apparatus according to the first or second aspect of the present invention, wherein the test pattern printing means includes a margin portion in a sheet of paper on which an image of the print job is printed. The test pattern image is printed on the printer.

  According to the present invention, it is possible to efficiently print a test pattern image for detecting a nozzle causing an ink ejection failure.

  That is, according to the printing apparatus of the first aspect of the present invention, when a print job is input, the nozzle that ejects ink is specified when printing an image on printing paper by the print job, and the specified nozzle The test pattern image generated by the test pattern image generating means is printed on the printing paper by the ink discharged from the printer.

  Therefore, only the nozzles that eject ink when printing a print job image are ejected when printing a test pattern image, and the nozzles that do not eject ink when printing a print job image are tested. Ink is not ejected even when a pattern image is printed.

  Therefore, when printing a test pattern image from a nozzle that does not require confirmation of ink ejection failure when printing an image of a print job, ink is not ejected and ink is not consumed excessively. In addition, there is no need to perform a process or operation for confirming ink ejection defects for nozzles that do not need to be confirmed from the printed test pattern image.

  Therefore, it is possible to efficiently print the test pattern image for detecting the nozzle causing the ink ejection failure.

  Further, according to the printing apparatus according to the second aspect of the present invention, in the printing apparatus according to the first aspect of the present invention, from the result of reading the test pattern image generated by the test pattern image generation unit from the printing paper, a print job is obtained. Ink ejection failure at nozzles that eject ink when printing this image can be detected efficiently.

  Further, according to the printing apparatus according to the third aspect of the present invention, in the printing apparatus according to the first or second aspect of the present invention, when the printing paper is a roll-like continuous paper, the image of the printing job is between pages. The image is printed on the printing paper with a margin between them. Therefore, by printing the test pattern image in the margin between the pages of the printing paper, the printing paper is further consumed by printing the test pattern image in addition to the printing paper consumed for printing the image of the print job. Can be prevented.

  In the case of a configuration further including ejection failure detection means as in the printing apparatus according to the second aspect of the present invention, the printed paper after printing while printing the print job image and the test pattern image on the printing paper. The test pattern image printed in the margin between the pages in FIG. 5 can be read in parallel with the detection of the nozzle with defective ink discharge based on the result.

  Further, according to the printing apparatus according to the fourth aspect of the present invention, in the printing apparatus according to the first or second aspect of the present invention, when the printing paper is a sheet of paper, the portion where the image of the print job is printed By printing the test pattern image in the margin portion, it is possible to prevent the printing paper from being further consumed by printing the test pattern image in addition to the printing paper consumed to print the print job image. The blank portion on which the test pattern image is printed can be subjected to post-processing such as makeup cutting later.

It is explanatory drawing which shows schematic structure of the line type inkjet recording device which concerns on one Embodiment of this invention. It is explanatory drawing which shows the head holder of FIG. 1 from the downward direction. It is a block diagram which shows the structure of the control system of the line-type inkjet recording device of FIG. 4 is a flowchart illustrating an example of a test pattern image generation and printing process performed by a CPU of the control unit in FIG. 3 according to a program stored in a ROM. 1A is an explanatory diagram showing a test pattern image printed on a roll paper by the printer unit of FIG. 1 together with a print job image, and FIG. 1B is a general test pattern image printed on the roll paper together with the print job image. It is explanatory drawing shown. It is explanatory drawing which shows schematic structure of the line type inkjet recording device which concerns on other one Embodiment of this invention. It is a block diagram which shows the structure of the control system of the line type inkjet recording device of FIG. FIG. 7 is an explanatory diagram illustrating an image of a print job that the printer unit of FIG. 6 prints on a sheet of paper. (A) is explanatory drawing which shows the test pattern image which the printer part of FIG. 6 prints on a sheet paper, (b) is explanatory drawing which shows the general test pattern image printed on a sheet paper.

  Hereinafter, embodiments of a printing apparatus according to the present invention will be described with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention is to arrange the components and the like as follows. Not specific. The technical idea of the present invention can be variously modified within the scope of the claims.

  In the following description, in the drawing, the sheet conveyance direction is the X-axis direction or the sub-scanning direction, and the direction orthogonal to the conveyance direction is the Y-axis direction, the main scanning direction, or the width direction of the recording medium. Further, a direction orthogonal to the X-axis and Y-axis directions is taken as a Z-axis direction or a vertical direction.

  FIG. 1 is an explanatory diagram showing a schematic configuration of a line type ink jet recording apparatus according to an embodiment of the present invention. A line-type ink jet recording apparatus 1 shown in FIG. 1 (corresponding to a printing apparatus in the claims, hereinafter abbreviated as an ink jet recording apparatus 1) includes a sending unit 2, a head lower conveyance unit 3, a printer unit 4, and a winding unit. 6 and a control unit 10.

  In the present embodiment, the feeding unit 2 is a roll paper 9 (corresponding to the roll-shaped printing paper in the claims) wound around the paper tube 9a and pivotally supported by the roll paper storage unit 7, and a tension roller 2a for adjusting tension. Then, the sheet is fed to the head lower conveyance unit 3 by the sheet feeding roller 2b. The head lower transport unit 3 transports the roll paper 9 sent out from the sending unit 2 to the downstream side of the printer unit 4 by the driving roller 3a.

  The printer unit 4 includes four head units 21, 22, 23, and 24 of C color (cyan), K color (black), M color (magenta), and Y color (yellow) held in the head holder 25, Sensor 26.

  Each head unit 21, 22, 23, 24 is arranged to face the head lower conveyance unit 3, and has a width equal to or larger than the recording area width of the roll paper 9 in the main scanning direction X orthogonal to the conveyance direction of the paper 9. It is a line head having.

  FIG. 2 is an explanatory view of the head holder 25 as viewed from the head lower conveyance unit 3 side. As shown in FIG. 2, each head unit 21 to 24 has a plurality of head blocks 21 a to 24 a arranged in the main scanning direction Y. In each head unit 21 to 24, the plurality of head blocks 21 a to 24 a The positions in the sub-scanning direction X are alternately shifted.

  A plurality of nozzles 21b to 24b are provided at intervals in the main scanning direction Y on the surface of each head block 21a to 24a that faces the lower head transport unit 3. The nozzles 21b to 24b eject ink in a pattern corresponding to the image to a position corresponding to each pixel of the roll paper 9 conveyed to the roll paper 9 so that images are continuously printed on the roll paper 9 in units of pages. Is done.

  The line sensor 26 reads an image printed on the roll paper 9 with each color ink of CKMY discharged from the nozzles 21 b to 24 b of the head units 21, 22, 23, and 24, and rolls before the winding unit 6. It is arranged on the transport path of the paper 9.

  The winding unit 6 shown in FIG. 1 winds the roll paper 9 on which an image has been printed by the printer unit 4 and passed through the line sensor 26 onto the winding roll 6b without slackness via the tension adjustment dancer roller 6a.

  FIG. 3 is a block diagram showing the configuration of the control system of the inkjet recording apparatus 1. As shown in FIG. 3, the control unit 10 is provided with a CPU 90, a RAM 92 that functions as a working area for the CPU 90, and an external storage device 93 that is used for storing various firmware and data.

  The control unit 10 is connected to a client terminal 30 constituted by a PC (personal computer) or the like via the external interface unit 11. The control unit 10 receives the print job from the client terminal 30 and prints out the image of the received print job on the roll paper 9 so that the sending unit 2, the under-head transport unit 3, the printer unit 4, and the winding unit 6 are printed. Etc. are controlled.

  An operation panel 19 is connected to the CPU 90 of the control unit 10. The operation panel 19 has a display and operation buttons (none of which are shown), and can display various states of the ink jet recording apparatus 1 and perform various inputs on the operation panel 19.

  Next, generation of a test pattern image corresponding to an image to be printed on the roll paper 9 by a print job from the client terminal 30 and roll paper performed by the CPU 90 of the control unit 10 executing a program stored in the ROM 91. A procedure of processing related to printing on the printer 9 will be described with reference to the flowchart of FIG.

  As shown in FIG. 4, the CPU 90 first checks whether a print job has been input from the client terminal 30 (step S1). If it has not been input (NO in step S1), it waits until it is input, and if it has been input (YES in step S1), the CPU 90 converts the image data of the input print job into drop data ( Step S3).

  That is, the image data of the print job is data indicating the RGB pixel values generated by using the application software of the client terminal 30, and this is a format corresponding to printing by the head units 21 to 24 of the printer unit 4. To drop data, which is image data. The drop data is data indicating the number of ink drops (ink amount) ejected from the nozzles 21 b to 24 b of the head blocks 21 a to 24 a to the locations corresponding to the pixels of the roll paper 9.

  Next, the CPU 90 specifies the nozzles 21b to 24b that eject ink when performing image printing by the print job based on the converted drop data (step S5), and ink is supplied from only the specified nozzles 21b to 24b. Image data of a test pattern image to be ejected and printed is generated (step S7).

  Subsequently, the CPU 90 executes printing of the print job image and the test pattern image on the roll paper 9 (step S9), and further identifies the test pattern image read from the roll paper 9 by the line sensor 26 in step S5. Ink ejection failure at the nozzles 21b to 24b thus detected is detected (step S11).

  FIG. 5A is an explanatory diagram showing a test pattern image T that the printer unit 4 prints on the roll paper 9 together with the image S of the print job. FIG. 5B is a general view printed on the roll paper 9 together with the image S of the print job. It is explanatory drawing which shows the test pattern image t.

  As shown in FIG. 5A, in printing in step S9, the image S by the print job is printed in the page-by-page image printing area As of the roll paper 9, and two image printing areas As continuous in the sub-scanning direction X are printed. , As, the test pattern image T generated in step S7 is printed in the blank area Am.

  Here, the test pattern image T exists only at the position where the image S by the print job in the main scanning direction Y exists, and is printed only by the ink ejected from the nozzles 21b to 24b corresponding to the position. .

  In general, as shown in FIG. 5B, a test pattern image t exists over the entire width of the image printing area As in the main scanning direction Y, and therefore, when the image S is printed by a print job. Ink is also ejected from the nozzles 21b to 24b that do not eject ink.

  For this reason, in the general test pattern image t shown in FIG. 5B, ink is ejected from the nozzles 21b to 24b that do not need to check the ejection failure of the ink when the image S of the print job is printed, Ink is consumed excessively.

  On the other hand, in the test pattern image T printed on the roll paper 9 by the inkjet recording apparatus 1 of the present embodiment shown in FIG. 5A, the nozzle 21b that ejects ink when the image S is printed by the print job. Ink is ejected only from ˜24b. For this reason, when the test pattern image T is printed from the nozzles 21b to 24b that do not need to check the ink discharge failure, the ink is not discharged and the ink is not excessively consumed.

  Next, as shown in FIG. 4, the CPU 90 confirms from the detection result in step S11 whether or not there is any ink ejection failure in the nozzles 21b to 24b specified in step S5 (step S13).

  If there is no ejection failure (NO in step S13), the process proceeds to step S17 to be described later. If there is a ejection failure (YES), the CPU 90 stores the page number where the ejection failure is detected in the RAM 92. After the error process to be performed (step S15), the process proceeds to step S17.

  In addition, the page number of the ejection failure stored in the RAM 92 is, for example, cut in a post-processing step in which the printed roll paper 9 taken up by the take-up roll 6b is cut for each page by an offline roll cutter (not shown). It can be used to extract a page corresponding to a subsequent ejection failure.

  In step S17, the CPU 90 confirms whether printing of the image S and the test pattern image T by the print job has been completed. If not completed (NO in step S17), the process returns to step S9. If completed (YES in step S17), the series of processes is terminated.

  As is apparent from the above description, in this embodiment, step S5 in the flowchart of FIG. 4 is processing corresponding to the nozzle specifying means in the claims, and step S7 in FIG. 4 is in the claims. This process corresponds to the test pattern image generating means. Further, in this embodiment, step S9 in FIG. 4 is a process corresponding to the test pattern printing unit in the claims, and step S11 in FIG. 4 is a process corresponding to the ejection failure detection unit in the claims. It has become.

  According to the inkjet recording apparatus 1 of the present embodiment configured as described above, the test pattern image T is printed only by the ink ejected from the nozzles 21b to 24b that eject ink when the image S is printed by the print job. Is done.

  For this reason, the nozzles 21b to 24b that do not eject ink when the image S is printed by a print job are also printed from the printed test pattern image t, such as a general test pattern image t that is printed by ejecting ink. For the nozzles 21b to 24b that do not need to be confirmed, it is possible to eliminate the need to perform processing and work for confirming ink ejection defects.

  Therefore, it is possible to prevent an increase in the burden of ink discharge failure detection, and when the image S is printed by the print job from the test pattern image T of FIG. 5A read from the roll paper 9 by the line sensor 26. For the nozzles 21b to 24b that do not need to be confirmed, it is possible to eliminate the need for the CPU 90 of the control unit 10 to perform processing for confirming ink ejection defects.

  Since the test pattern image T is printed only with the ink ejected from the nozzles 21b to 24b that eject ink when the image S is printed by the print job, the amount of ink used can be suppressed to the minimum necessary. Thus, it is possible to efficiently print the test pattern image T for detecting the nozzles 21b to 24b causing the ejection failure.

  Further, according to the inkjet recording apparatus 1 of the present embodiment, the test pattern image T is printed while the image S is printed by the print job (while the print job is executed), and the ink is applied when the image S is printed. It is possible to simultaneously detect ink discharge failures of the nozzles 21b to 24b that discharge.

  That is, since the test pattern image T is printed corresponding to the image S of each page of the roll paper 9, the image S is printed from the test pattern image T using the nozzles 21b to 24b causing the ink ejection failure. The specified page can be identified without interrupting the print job, and can be taken out after cutting.

  In the above embodiment, the inkjet recording apparatus 1 that prints an image on the roll paper 9 has been described as an example. However, the present invention can also be applied to an inkjet recording apparatus that prints an image on a sheet of paper.

  FIG. 6 is an explanatory diagram showing a schematic configuration of a line type ink jet recording apparatus according to another embodiment of the present invention. A line type ink jet recording apparatus 31 shown in FIG. 6 (corresponding to a printing apparatus in claims, hereinafter abbreviated as “ink jet recording apparatus 31”) includes a sending unit 2 and a head under transport unit of the ink jet recording apparatus 1 shown in FIG. 1 and the inkjet recording apparatus 1 shown in FIG. 1 in that the take-up unit 6 and the roll paper storage unit 7 are changed to a paper feed unit 32, a transport unit 33, a paper discharge unit 34, and a paper feed tray 35, respectively. Is different.

  Further, the line type ink jet recording apparatus 31 of the present embodiment is shown in the block diagram of FIG. 7 in place of the sending unit 2, the underhead transport unit 3 and the winding unit 6 shown in FIG. As described above, the configuration differs from the inkjet recording apparatus 1 shown in FIG. 1 in that the paper feeding unit 32, the transport unit 33, and the paper discharge unit 34 are connected.

  Then, the paper feed unit 32 of the ink jet recording apparatus 31 of the present embodiment picks up the sheet paper 36 (corresponding to the printing paper in the claims) stacked on the paper feed tray 35 one by one by the pickup roller 8, The feeding unit 3 is configured to feed. In the present embodiment, a case will be described in which the sheet 36 is “Nobi” size paper that cuts the margin area around the image print area after printing.

  In addition, the transport unit 33 of the ink jet recording apparatus 31 of the present embodiment transports the sheet paper 36 fed by the paper feed unit 32 to the transport belt 16 by the registration roller 12, and further transports the sheet paper by the transport belt 16. 36 is conveyed to the paper discharge unit 34 side. The conveyor belt 16 is an endless belt that is stretched around the driven roller 13, the tension roller 14, and the driving roller 15, and a platen 17 is disposed inside (downward) the conveyor belt 16.

  The transport belt 16 and the platen 17 are provided with a number of holes (not shown). In the transport section 33, the suction fan 18 sucks air through the holes, so that the sheet 36 is transferred to the transport belt 16. Adsorbed and transported.

  In the printer unit 4, an image is printed page by page in the image printing area As (see FIG. 8) of the sheet 36 by the ink of each color ejected from the nozzles 21 b to 24 b of the head units 21 to 24. The image printed on the sheet 36 is read by the line sensor 26.

  The paper discharge unit 34 sandwiches the sheet paper 36 on which the image is formed by the printer unit 4 with the discharge roller pair 27 and discharges the sheet 36 to the discharge tray 28. The discharge tray 28 can store a plurality of discharged sheets 36.

  Next, the CPU 90 of the control unit 10 generates a test pattern image corresponding to an image to be printed on the sheet 36 by a print job from the client terminal 30 by executing a program stored in the ROM 91 and the sheet. A procedure of processing related to printing on the leaf paper 36 will be described.

  In the line type inkjet recording apparatus 31 of the present embodiment, the procedure performed by the CPU 90 of the control unit 10 is basically the same as the procedure performed by the CPU 90 of the control unit 10 of the inkjet recording apparatus 1.

  The CPU 90 converts the image data of the print job (YES in step S1) input from the client terminal 30 into drop data (step S3), and based on this, the print job is described in detail with reference to the flowchart of FIG. The nozzles 21b to 24b that eject ink when printing an image are identified (step S5), and image data of a test pattern image to be printed is generated by ejecting ink only from the identified nozzles 21b to 24b (step S5). Step S7).

  Subsequently, the CPU 90 prints the print job image and the test pattern image on the sheet 36 (step S9), and further, from the content of the test pattern image read from the sheet 36 by the line sensor 26, the step S5. Ink ejection failure at the nozzles 21b to 24b specified in step S11 is detected (step S11).

  Here, when the image of the print job that the printer unit 4 prints on the image print area As of the sheet 36 is the image S as shown in the explanatory diagram of FIG. 8, the sheet 36 is displayed on the sheet 36 in step S9a. As shown in FIG. 9A, the image S is printed in the image printing area As, and the test pattern image T similar to that shown in FIG. 5A is printed in the surrounding margin area Am.

  In this case as well, in the general test pattern image t shown in FIG. 9B, ink is ejected from the nozzles 21b to 24b that do not need to confirm ink ejection defects when printing the image S of the print job. Although the ink is excessively consumed, the excessive consumption of ink is prevented in the test pattern image T shown in FIG.

  4 will be described in detail again. Next, the CPU 90 confirms from the detection result in step S11 whether or not there is an ink ejection failure in the nozzles 21b to 24b specified in step S5 (see FIG. 4). Step S13).

  If there is no ejection failure (NO in step S13), the process proceeds to step S17 to be described later. If there is a ejection failure (YES), the CPU 90 stores the page number where the ejection failure is detected in the RAM 92. After performing the error processing to be stored in (Step S15), the processing proceeds to Step S17.

  The page number of the ejection failure stored in the RAM 92 is, for example, in a post-processing step in which a blank portion Am of the printed sheet 36 discharged to the paper discharge unit 34 is cut by a post-processing device (not shown). It can be used to extract a page corresponding to a discharge failure after cutting.

  In step S17, the CPU 90 confirms whether printing of the image S and the test pattern image T by the print job has been completed. If not completed (NO in step S17), the process returns to step S9. If completed (YES in step S17), the series of processes is terminated.

  Also in this embodiment, step S5 in the flowchart of FIG. 4 is processing corresponding to the nozzle specifying means in the claims, and step S7 in FIG. 4 is processing corresponding to the test pattern image generating means in the claims. It has become. Also in this embodiment, step S9 in FIG. 4 is a process corresponding to the test pattern printing unit in the claims, and step S11 in FIG. 4 is a process corresponding to the ejection failure detection unit in the claims. It has become.

  Also in the ink jet recording apparatus 31 of the present embodiment configured as described above, the test pattern image T is printed only by the ink ejected from the nozzles 21b to 24b that eject ink when the image S is printed by the print job. . For this reason, the same effect as the ink jet recording apparatus 1 of the embodiment described above can be obtained.

  In each of the above-described embodiments, as an error process (step S17 in FIG. 4) performed when there is an ink ejection failure (YES in step S13 in the flowchart of FIG. 4), the page number where the ejection failure is detected is displayed. The data is stored in the RAM 92. However, marking that indicates an error in a margin portion of a corresponding page of defective ejection by a separately provided marking unit may be performed as error processing.

  Further, in each of the embodiments described above, the line sensor 26 is provided in front of the winding unit 6 and the paper discharge unit 34 of the printer unit 4, and the test pattern image T printed by the printer unit 4 is read and the nozzles 21 b to 21 b. 24b ink ejection failure was detected.

  However, for example, an off-line roll cutter that cuts the printed roll paper 9 for each page or a post-processing device that cuts the margin portion Am of the printed sheet 36 is provided with a line sensor. You may make it perform the process which detects the ink discharge defect of the nozzles 21b-24b from the reading result of the test pattern T. FIG. In such a case, based on the detection result, processing for discarding the corresponding page portion with ejection failure or discarding the entire printed matter including the corresponding page with ejection failure may be performed.

  In the above-described embodiment shown in FIG. 5A or 9A, the test pattern image is printed on the downstream side of the print image. However, the test pattern image is printed on the upstream side of the print image. May be.

DESCRIPTION OF SYMBOLS 1,31 Line type inkjet recording apparatus 2 Sending part 2a, 6a Dancer roller 2b Paper feed roller 3 Under head conveyance part 3a Drive roller 4 Printer part 6 Winding part 6b Winding roll 7 Roll paper accommodating part 8 Pickup roller 9 Roll paper ( Printing paper)
9a Paper tube 10 Control unit 11 External interface unit 12 Registration roller 13 Driven roller 14 Tension roller 15 Drive roller 16 Conveying belt 17 Platen 18 Suction fan 19 Operation panel 21 K color head unit 21a-24a Head block 21b-24b Nozzle 22 C color Head unit 23 M color head unit 24 Y color head unit 25 Head holder 26 Line sensor 27 Discharge roller pair 28 Discharge tray 32 Paper feed unit 33 Transport unit 34 Paper discharge unit 35 Paper feed tray 36 Sheet paper (printing paper)
90 CPU
91 ROM
92 RAM
93 External storage device Am Margin area As Image printing area S Image by print job T, t Test pattern image X Sub-scanning direction Y Main-scanning direction

Claims (4)

A printing apparatus that prints an image on printing paper that is transported in a sub-scanning direction orthogonal to the main scanning direction by ejecting ink from a plurality of nozzles arranged in the main scanning direction of the line head based on an input print job In
Nozzle specifying means for specifying a nozzle for ejecting ink when printing the image among the nozzles of the line head based on the print job;
Test pattern image generation means for generating image data of a test pattern image to be printed on printing paper by discharging ink from the nozzle specified by the nozzle specifying means;
A test pattern printing unit that prints the test pattern image on a printing paper using the image data generated by the test pattern image generation unit when printing the image of the print job on the printing paper;
A printing apparatus comprising:   The printing apparatus according to claim 1, further comprising a discharge failure detection unit that reads the test pattern image from a print sheet and detects a discharge failure of ink at the nozzle specified by the nozzle specifying unit.   The printing apparatus according to claim 1, wherein the test pattern printing unit prints the test pattern image on a margin portion between pages on a roll-shaped printing paper on which an image of the print job is printed.   The printing apparatus according to claim 1, wherein the test pattern printing unit prints the test pattern image on a blank portion of a sheet of paper on which the image of the print job is printed.

Images