JP2016047615A - Controller, control method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer controller capable of efficiently performing the printing.SOLUTION: The controller obtains a position of a first defective nozzle at a first image forming section for forming images on a first surface of a printing medium, and obtains a position of a second defective nozzle at a second image forming section for forming images on a second surface on the back of the first surface of the printing medium. Subsequently, on the basis of the position of the first defective nozzle and the position of the second defective nozzle, there are determined printing positions and printing surfaces of multiple images to be printed according to multiple printing jobs. At the determination, when printing data disposed in a printing area of the first defective nozzle or the second defective nozzle, of the printing medium is simplex printing data, it is determined that printing data is to be disposed in an area corresponding to the printing area of the defective nozzle, on the back of the printing surface of the defective nozzle, of the printing medium.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a technique for controlling printing of an image to be printed based on a plurality of print jobs.

  2. Description of the Related Art Conventionally, there is a technique in which a plurality of print jobs are combined and arranged on a print medium and printed and output at a time. Such a combination of a plurality of print jobs is called ganging. When this ganging is performed on roll paper, a plurality of print jobs are combined by laying out a plurality of print jobs in the transport direction and the direction orthogonal thereto. A plurality of print jobs combined by ganging are printed on a roll paper, and a printed matter corresponding to each print job is obtained by performing processing such as cutting after printing. This ganging makes it possible to improve output efficiency and effectively use the print medium.

  By the way, a printing form is known in which a printing head for the front side and the back side is connected in series in one printing apparatus, and the printing speed is improved by performing printing on the front side and the back side simultaneously or in one pass. This printing form is called tandem printing. Printing machines that further improve productivity by simultaneously performing ganging and tandem printing have also been developed.

  In a line head type inkjet printer, a print head having the same length as or including the width of the print medium is used, and the print medium side is transported to the print head while the position of the print head is fixed. Printing is performed. Since printing can be performed at once on the entire width of the printing medium, printing can be performed at a higher speed than the serial head method.

  Here, if a discharge failure such as non-ejection of ink or abnormal landing position of ink droplets occurs in the nozzle of the print head, the position of the print head is fixed in the line head method. Will occur. Therefore, if a discharge failure occurs, temporarily stop the printing device, replace the print head, perform cleaning, or continue printing until a certain break, and reprint the defective portion. It corresponds by doing. However, in this case, all printed matter from when the discharge failure occurs until the printing apparatus is stopped becomes defective.

  Japanese Patent Application Laid-Open No. 2004-228688 discloses a technique for assigning a print job to a print medium so as to avoid a defective nozzle when a defective nozzle occurs.

JP 2010-5880 A

  However, Patent Document 1 does not assume a printing apparatus including a plurality of print heads as in tandem printing, and there is a possibility that a printing medium is largely wasted. Specifically, for example, when a defective nozzle is generated on the print head side that prints one side, the nozzle in the print medium is normal even if the nozzle on the print head side that prints the other side is normal. Print jobs cannot be assigned to print areas to be printed. This may cause waste of the print medium.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a printing technique capable of performing efficient printing.

In order to achieve the above object, a control device according to the present invention comprises the following arrangement. That is,
A control apparatus that controls printing of an image to be printed based on a plurality of print jobs, and that acquires a position of a first defective nozzle in a first image forming unit that forms an image on a first surface of a print medium. An acquisition unit; a second acquisition unit that acquires a position of a second defective nozzle in a second image forming unit that forms an image on a second surface opposite to the first surface of the print medium; Based on the position of the first defective nozzle acquired by the acquisition unit and the position of the second defective nozzle acquired by the second acquisition unit, the printing position and the printing surface of the plurality of images to be printed based on the plurality of print jobs And when the print data arranged in the print area of the first defective nozzle or the second defective nozzle of the print medium is single-sided print data, The defective media of the print medium The printing surface of the Le in the region a opposite surface corresponding to the print area of the defective nozzle, determines to place the print data.

  According to the present invention, efficient printing can be performed.

1 is a diagram illustrating an overall configuration of a printing system. It is a block diagram explaining the system configuration example of a control apparatus. 2 is a block diagram illustrating a control configuration of the printing apparatus. FIG. FIG. 6 is a diagram illustrating an example of a multi-sided print job. It is a flowchart which shows the rendering process of a job control part. 6 is a flowchart illustrating print control processing of a job control unit. It is a figure which shows the example of an unprintable area | region. It is a figure which shows an example of a setting screen. It is a figure which shows an example of an error screen. 6 is a flowchart illustrating printing processing of an image forming unit. It is a figure which shows the example of confirmation of a printing result. 6 is a flowchart illustrating print layout rearrangement processing of a job control unit. It is a figure which shows the example of a printing result in the conventional print layout rearrangement process. FIG. 10 is a diagram illustrating an example of a print result in a print layout rearrangement process. 6 is a flowchart illustrating print layout rearrangement processing of a job control unit. It is a figure which shows the example of a printing result in the conventional print layout rearrangement process. FIG. 10 is a diagram illustrating an example of a print result in a print layout rearrangement process.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Embodiment 1>
In the first embodiment, a case where a defective nozzle (defective recording element) is generated in the print head on the front surface side in tandem printing capable of printing the front surface and the back surface of the print medium will be described. In addition, the relative arrangement | positioning of each component of the apparatus used by this embodiment, an apparatus shape, etc. are an illustration to the last, and are not limited only to them.

  FIG. 1 is a diagram showing a schematic configuration of a printing system. The printing system of FIG. 1 shows a system including a printing apparatus having only a printing function, but is not limited thereto. For example, a system that further includes a reading device that reads an image on a document and that functions as a copier or a composite device that includes other functions may be used. In addition, a roll sheet is described as an example of a print medium (or print sheet) for performing printing processing. However, a long continuous sheet that can continuously print a plurality of pages on the same surface without being cut halfway. It is not limited to a roll-shaped print medium. The continuous sheet may be cut automatically by the printing apparatus, may be cut by a user's manual instruction, or may be cut in a subsequent process.

  The material of the print medium is not limited to paper, and various materials can be used as long as they can be printed. The printing apparatus may be a printing apparatus that can print not only on a continuous sheet but also on a cut sheet that has been cut into a predetermined size. Further, the present invention is not limited to color recording using a plurality of color recording agents, and monochrome recording using only black (including gray) recording agents may be performed.

  FIG. 1 particularly shows an outline of the overall configuration of a printing system that uses a roll sheet (a continuous continuous sheet longer than the length of a printing unit (for example, one page) in the transport direction) as a printing medium. The printing system includes the following components 101 to 133, which are arranged in a plurality of housings.

  In FIG. 1, reference numeral 119 denotes a first printing apparatus. Reference numeral 120 denotes a second printing apparatus. The first printing device 119 and the second printing device 120 are provided in series with respect to the roll sheet conveyance path. Reference numeral 101 denotes a paper feed unit for supplying roll sheets (hereinafter referred to as sheets). Reference numeral 116 denotes a winding unit for winding the printed sheet. Reference numeral 108 denotes a sheet reversing device for reversing the front and back of the sheet. Reference numeral 115 denotes an image reading apparatus that captures an image on a printed sheet and confirms the contents. Reference numeral 117 denotes a controller device that controls the first printing device 119 and the second printing device 120 and performs rendering processing on print data. The print data is image data to be printed, for example. Reference numeral 133 denotes a network serving as a communication path for print jobs to the controller device 117. Reference numeral 118 denotes a host device that transmits a print job to the controller device 117.

  The host device 118 is a host computer that transmits a print job to the controller device 117 via the network 133. Here, the host device 118 connected to the network 133 is shown as a configuration for transmitting a print job, but the present invention is not limited to this. For example, a print job may be transmitted from the host device 118 directly connected to the controller device 117. Alternatively, when the controller device 117 includes a storage device that stores a portable storage medium such as a USB memory, a configuration may be adopted in which a print job is transmitted from the portable storage medium stored in the storage device.

  The controller device 117 determines how to distribute a plurality of print jobs received from the host device 118 to the first printing device 119 and the second printing device 120, determines the arrangement of each print job on the print medium, and print job. Perform the rendering process. Here, the controller device 117 performs various processing such as reception of a print job from the host device 118, rendering processing, and the like, but the present invention is not limited to this. For example, reception of a print job may be performed by another computer, or rendering processing may be performed by another computer. Further, as in a server configuration, processing may be separated for each blade, such as reception of a print job and rendering processing. In any case, the configurations of the host device 118, the network 133, and the controller device 117 are not limited to the forms shown in this embodiment.

  The first printing device 119 receives a multi-sided print job for front side printing of the sheet from the controller device 117 through the data transmission / reception IF 127. The first printing apparatus 119 includes a reading unit 102 such as a sensor / scanner that reads marks printed on a sheet, a print head 105, an ink tank 106 that supplies ink to the print head 105, and ink of an image printed on the sheet. A drying unit 107 for drying is provided. Further, the first printing apparatus 119 includes an encoder 123 that controls the conveyance amount and conveyance state of the sheet.

  The operation unit 103 of the first printing apparatus 119 is a unit for the user to perform various operations and to notify the user of various information. In the operation unit 103, for example, it is possible to check the print status for each order such as whether the image to be printed is being printed or has been printed. Further, the operation unit 103 is used to check various states of the apparatus such as the remaining ink amount and remaining sheet amount, to input head position adjustment values and registration adjustment values, and to instruct apparatus maintenance such as head cleaning. User operation and confirmation are possible. The operation unit 103 includes a controller (including a CPU or MPU), an output device for user interface information (a generator for display information, acoustic information, etc.), and a control unit 121 having various I / O interfaces. The control unit 121 controls various controls of the entire first printing apparatus 119. The control unit 121 includes a CPU, a RAM, and a ROM. The RAM is a memory for the CPU to perform processing such as temporary storage of data and buffering as necessary. The CPU can implement various processes by executing various programs stored in the ROM on the RAM.

  The second printing apparatus 120 receives a multi-side print job for printing the back side of the sheet from the controller apparatus 117 through the data transmission / reception IF 128. The second printing device 120 dries the ink printed on the sheet, the reading unit 109 such as a sensor / scanner that reads a mark printed on the sheet, the print head 112, the ink tank 113 that supplies ink to the print head 112, and the like. A drying unit 114 is provided. The second printing apparatus 120 includes an encoder 124 that controls the conveyance amount and conveyance state of the sheet.

  The operation unit 110 of the second printing apparatus 120 is a unit for the user to perform various operations and notify the user of various information. The operation unit 110 has the same function as the operation unit 103 of the first printing apparatus 119. The control unit 122 built in the operation unit 110 controls various controls of the entire second printing apparatus 120. The control unit 122 includes a CPU, a RAM, and a ROM. The RAM is a memory for the CPU to perform processing such as temporary storage of data and buffering as necessary. The CPU can implement various processes by executing various programs stored in the ROM on the RAM.

  Note that the configuration of the first printing device 119 and the second printing device 120 is not limited to the configuration shown in FIG. 1, and various units and sensors can be added as necessary.

  The printing system of the present embodiment is a system capable of duplex printing of sheets. The first printing device 119 performs front side printing in double-sided printing, and the second printing device 120 performs backside printing in double-sided printing, thereby realizing a double-sided printing function.

  With respect to the paper feeding unit 101 connected to the upstream side of the first printing apparatus 119, the user can load a sheet on a control bar in the paper feeding unit 101 and then load the sheet on the main body. When the sheet feeding unit 101 receives an instruction to start feeding from the controller device 117 via the command transmission / reception IF 129, the sheet feeding unit 101 starts sheet conveyance. The paper feeding unit 101 includes a loop creation control unit 104 that absorbs an error in the conveyance speed, and can adjust the conveyance speed. Here, the loop creation control unit 104 is provided in the paper feeding unit 101, but the loop creation control unit may be provided in the first printing apparatus 119. The sheet pulled out from the paper supply unit 101 is conveyed in the direction a in the drawing and reaches the first printing device 119.

  In the present embodiment, the sheet feeding unit 101 is configured to feed a sheet (roll-shaped continuous sheet), but may be configured to feed a cut sheet or a continuous sheet that is not rolled.

  The first printing apparatus 119 performs image printing on the first surface (front surface in the present embodiment) of the sheet. In the print head 105, independent print heads for a plurality of colors (seven colors in the present embodiment) are held along the sheet conveyance direction. Here, seven print heads corresponding to seven colors of C (cyan), M (magenta), Y (yellow), LC (light cyan), LM (light magenta), G (gray), and K (black) are included. . Of course, other colors may be used, and it is not necessary to use all of them. The first printing apparatus 119 forms an image on the sheet by ejecting ink from the print head 105 in synchronization with the conveyance of the sheet. The print head 105 is disposed at a position where the ink discharge destination does not overlap the rotation roller 125 that conveys the sheet.

  The ink tank 106 stores ink of each color independently. Ink is supplied from the ink tank 106 to a sub tank provided corresponding to each color by a tube, and ink is supplied from the sub tank to each print head 105 through the tube. The print head 105 has line heads of each color (seven colors in the present embodiment) aligned along the conveyance direction a during printing. The line head of each color may be formed with a single nozzle tip without a seam, or the divided nozzle tips may be regularly arranged in a single row or a staggered arrangement. . In the present embodiment, a so-called full multihead in which nozzles (recording elements) are arranged in a range that covers the width of the printing area of the maximum size sheet that can be used by the first printing apparatus 119 is used.

  As an ink jet method for discharging ink from a nozzle, various methods such as a method using a heating element, a method using a piezo element, a method using an electrostatic element, and a method using a MEMS element can be adopted. Ink is ejected from the nozzles of each print head based on the print job, and the ejection timing is determined by the output signal of the encoder 123.

  After the image is formed on the sheet, the sheet is conveyed to the drying unit 107. The drying unit 107 heats the sheet passing through the drying unit 107 with warm air (heated gas (air)) in order to dry the sheet provided with ink in a short time. Various drying methods such as cold air, heating with a heater, natural drying only by waiting, irradiation of electromagnetic waves such as ultraviolet light, etc. can be adopted instead of hot air.

  After the sheet in the drying unit 107 passes, the sheet is conveyed to the sheet reversing device 108. In the sheet reversing device 108, the sheet is reversed upside down (front and back) in order to print an image on the back surface of the sheet printed by the first printing device 119. A loop creation control unit 111 that absorbs an error in the sheet conveyance speed is provided on the downstream side of the sheet reversing device 108. Here, the loop creation control unit 111 is provided on the downstream side of the sheet reversing device 108, but may be provided in the second printing device 120. After passing through the loop creation control unit 111, the inverted sheet reaches the second printing apparatus 120.

  The second printing apparatus 120 performs image printing on the back side of the sheet. First, the reading unit 109 reads a mark printed for position detection printed on the front surface and image identification for identifying what image is printed on the front surface, and an image on the back surface corresponding to the front surface. And the print start position of the back side image are determined. The second printing apparatus 120 controls image printing on the back surface and printing timing according to the reading result by the reading unit 109.

  The print head 112 includes a print head 112 similar to the print head 105 of the first printing apparatus 119. The second printing apparatus 120 forms an image on the sheet by ejecting ink from the print head 112 in synchronization with the conveyance of the sheet. The print head 112 is disposed at a position where the ink discharge destination does not overlap the rotation roller 126 for conveying the sheet.

  The ink tank 113 and the drying unit 114 function similarly to the ink tank 106 and the drying unit 107 of the first printing apparatus 119. However, after the drying of the sheet by the drying unit 114 is completed, the sheet is conveyed to the image reading device 115.

  The image reading device 115 reads images printed on both sides of the sheet at the same time and confirms the contents. For example, the image reading device 115 is arranged so that two scanner sensors are opposed to each other, and can simultaneously read both sides of the sheet. Then, the print image or special pattern on the sheet is optically read to check whether there is a problem with the print image, the state check including the ink discharge states of the first printing device 119 and the second printing device, and the defective nozzle Various processes such as detection of the location of the site.

  As a method for confirming the state, the ink ejection state may be confirmed by reading a pattern for confirming the state of the print head 105/112, or the success or failure of printing by comparing with the original image may be confirmed. It may be confirmed. The confirmation method can be appropriately selected from various methods. In addition, when it is determined as NG when checking the state of the image and the state of the apparatus, a post-processing device that performs post-processing such as punching a hole or marking the image is provided. It may be possible to confirm which image state is a problem. In the present embodiment, the image reading apparatus 115 has two scanner sensors mounted on the downstream side of the second printing apparatus 120 to simultaneously read both sides of the sheet. However, the present invention is not limited to this. For example, a first scanner unit is connected to the downstream side of the first printing device 119, a printed image on the surface of the sheet is confirmed, and a second scanner unit is connected to the downstream side of the second printing device 120, A configuration in which a printed image on the back side of the sheet is confirmed may be used. Further, although the scanner unit reads an image on a sheet, an image on the sheet may be read using an area sensor such as a camera.

  After the processing by the image reading device 115 is completed, the sheet is conveyed to the sheet winding unit 116. The sheet winding unit 116 starts a winding operation after receiving a winding instruction from the controller device 117 through the command transmission / reception IF 130, and winds a sheet on which images are printed on both sides of the sheet.

  FIG. 2 is a block diagram illustrating an example of a system configuration of the controller device 117. The controller device 117 includes a control unit 301, an operation panel 310, and an image processing unit 312. The control unit 301 and the image processing unit 312 are connected by a system bus 311.

  The control unit 301 includes a job management communication IF 302, a CPU 303, a ROM 304, a RAM 305, an HDD 306, a data communication IF 307, a control communication IF 308, and a UI-IF 309. These units are connected to each other via a system bus 311. The control unit 301 controls the first printing device 119 and the second printing device 120 according to the input of the print job by using these units.

  The job management communication IF 302 is an interface for transmitting / receiving management job data such as a control command and a status signal when performing printing. The CPU 303 performs arithmetic processing based on the print job received by the control unit 301 and controls the operation of each unit. The ROM 304 holds programs, data, and the like for the CPU 303 to execute arithmetic processing and the like. The RAM 305 is a work area when the CPU 303 performs arithmetic processing or the like, and functions as a data holding unit that temporarily holds data used for arithmetic processing or the like. The HDD 306 holds management job data, a look-up table used when performing arithmetic processing and image processing, print data from the image processing unit 312, and the like.

  The data communication IF 307 is an interface for performing transmission / reception of print data and the like held in the HDD 306 between the first printing apparatus 119 and the second printing apparatus 120. The control communication IF 308 is an interface for transmitting and receiving control commands, status signals, and the like between the first printing apparatus 119 and the second printing apparatus 120. The UI-IF 309 is an interface for transmitting / receiving operation commands and the like to / from the operation panel 310.

  The operation panel 310 displays, for example, an input unit for a user to perform print settings and setting changes of the first printing device 119 and the second printing device 120, statuses of the first printing device 119 and the second printing device 120, and the like. And a display unit for notifying the user.

  Similar to the control unit 301, the image processing unit 312 includes a CPU, a ROM, and a RAM (not shown), and performs image processing based on a print job received by the controller device 117. For example, the image processing unit 312 performs color conversion (for example, RGB-YCbCr conversion) of image data to generate print data. The image processing unit 312 can also perform image processing such as resolution conversion, image analysis, and image correction as necessary. The print data obtained by the image processing unit 312 is stored in the HDD 306.

  FIG. 3 is a block diagram illustrating a control configuration of the printing apparatus. The printing system 202 processes a print job (job data) from the external device 201 such as the host device 118 and prints on a sheet. Here, the print job (job data) is composed of a page description language such as PDL, for example.

  The printing system 202 includes a job control unit 203, a rendering unit 204, a first image reading unit 205, and a second image reading unit 206.

  The job control unit 203 and the rendering unit 204 in FIG. 3 are assumed to be included in the controller device 117 in this embodiment. Note that the job control unit 203 may be included in the first printing device 119 or the second printing device 120, and the rendering unit 204 is also included in the first printing device 119 or the second printing device 120. May be. In the present embodiment, the first printing unit 222 is included in the first printing device 119, and the second printing unit 226 is included in the second printing device 120. However, the first printing unit 222 and the second printing unit are included. 226 may be included in one printing apparatus.

  The job control unit 203, which is a control device, has a job reception unit 207 that receives a print job from the external device 201, a job analysis unit 208 that analyzes the print job received by the job reception unit 207, and an analysis by the job analysis unit 208. And an analysis result storage unit 209 that stores the results. In addition, the communication unit 210 includes a communication unit 210 that communicates with the rendering unit 204, and an image storage unit 211 (storage medium) that stores the rendered bitmap data received from the rendering unit 204 via the communication unit 210.

  The job control unit 203 also includes a print layout determination unit 214 that determines a print layout, a print permission determination unit 215 that determines whether printing is possible, and a job that creates a print job that is executed by each printing unit (recording unit). And a creation unit 212.

  The job control unit 203 displays an image based on the bitmap data stored in the image storage unit 211 when a predetermined amount or more of the bitmap data is stored in the image storage unit 211 or when an instruction to start printing is received. Start printing. At this time, the job control unit 203 transmits the multi-sided print job created by the job creation unit 212 to the first printing unit 222 or the second printing unit 226 via the job transmission unit 213.

  The rendering unit 204 includes a communication unit 219 for communicating with the job control unit 203 and an image development unit 220. The image development unit 220 performs rendering processing based on the commands and data created by the job control unit 203, and generates bitmap data for printing. Thereafter, the rendering unit 204 transmits the rendered bitmap data to the job control unit 203 via the communication unit 219.

  The first image reading unit 205 includes a defective nozzle position storage unit 221 that stores a defective nozzle position, and an output result inspection unit 223 that detects an output result. The second image reading unit 206 includes a defective nozzle position storage unit 224 that stores defective nozzle positions, and an output result inspection unit 225 that detects output results.

  In addition, the first printing unit 222 and the second printing unit 226 each print on a printing medium according to the multi-sided print job transmitted from the job transmission unit 213. In the present embodiment, the first printing unit 222 prints on the front surface of the printing medium, and the second printing unit 226 prints on the back surface of the printing medium. However, the present invention is not limited to this. For example, a mode in which the first printing unit 222 performs printing on the back surface of the printing medium and the second printing unit 226 performs printing on the front surface of the printing medium can be employed. That is, the first printing unit 222 may perform printing on the first surface, and the second printing unit may perform printing on the second surface opposite to the first surface.

  Here, the multi-sided print job will be described. A multi-sided print job instructs each printing unit which bitmap data is to be printed on a printing medium. In this printing, a plurality of print jobs including pages having a size smaller than the width of continuous paper are laid out and printed on continuous paper. Thus, the use of paper can be made efficient by printing a plurality of print jobs at the same time. Note that cutting or the like is performed in a later process after printing. Cutting or the like may be performed by the above-described printing apparatus, may be performed by another cutting apparatus, or may be performed manually.

  As a format of a multi-sided print job, there is a type in which a print location is designated for each print job or a print position is designated for each bitmap data. For example, as shown in FIG. 4A, the multi-sided print job includes a print job format that designates each bitmap data and coordinates for printing the bitmap data. In addition, as shown in FIG. 4B, there is a print job format including a single piece of bitmap data in which the arrangement and composition of each bitmap data are performed in advance. By using a print job of these formats, it is possible to designate each bitmap data and its print position for the image forming unit.

  Although not shown, this print job format also instructs whether to print these bitmap data on the front surface or the back surface of the print medium. In the case of double-sided printing, in any type of multi-sided printing job, the image on the first side (for example, the front side) and the image on the second side (for example, the back side) are respectively corresponding images (that is, The image arranged on the opposite side of the print medium) is stored in association. What type of multi-sided print job is used may be selected in accordance with a format that can be recognized by the image forming unit to be used.

  A print job received from the external apparatus 201 is first stored in the job receiving unit 207 in the job control unit 203. The job analysis unit 208 analyzes the print setting value of the print job. Here, the print setting value is a setting value for single-side / double-side setting, vertical width / horizontal width, monochrome printing / color printing, and the like at the time of printing. The analysis result storage unit 209 stores the print setting value (job setting value) analyzed by the job analysis unit 208 for each print job. The communication unit 210 transmits the analysis result of the job analysis unit 208 and the print job to the rendering unit 204.

  The rendering unit 204 receives the analysis result and the print job received from the job control unit 203 by the communication unit 219, and develops (renders) the print job into bitmap data based on the analysis result by the image development unit 220. The developed bitmap data is transmitted from the communication unit 219 to the communication unit 210 in the job control unit 203, and the bitmap data received by the communication unit 210 is stored in the image storage unit 211.

  The first defective nozzle position acquisition unit 216 and the second defective nozzle position acquisition unit 217 respectively indicate the position of the defective nozzle in the first printing unit 222 and the position of the defective nozzle in the second printing unit 226, respectively. And from 224. The print layout determination unit 214 determines the print position of each bitmap data on the print medium. Specifically, the position of the defective nozzle of the first printing unit 222 acquired by the first defective nozzle position acquisition unit 216 and the position of the defective nozzle of the second printing unit 226 acquired by the second defective nozzle position acquisition unit 217, Based on the print setting value corresponding to each bitmap data, the printing position of each bitmap data is determined. Note that the print setting value is stored in the analysis result storage unit 209.

  The printability determination unit 215 confirms whether the ratio of the unprintable area in the print layout determined by the print layout determination unit 214 is larger than the threshold value specified by the user interface unit 218. If it is larger than the threshold value, the printability determination unit 215 displays the fact on the user interface unit 218 and notifies the user to stop printing. Note that the threshold of the unprintable area will be described later. In the present embodiment, the user interface unit 218 corresponds to the UI-IF 309 in FIG.

  The job creation unit 212 creates a multi-sided print job as a print job based on the bitmap data stored in the image storage unit 211 and the print position information of the bitmap data determined by the print layout determination unit 214. The job transmission unit 213 is an image forming unit corresponding to a surface (front side or back side) on which the multi-sided printing job is created by the job creating unit 212, specifically, the first printing unit 222 or the second printing unit. The data is transmitted to the printing unit 226.

  First, the first printing unit 222 converts the received bitmap data of the multi-sided print job into a color space (for example, CMYK) handled by the printer engine unit, and further performs binarization processing as necessary. . The first printing unit 222 prints the color-converted data at a position on the print medium designated by the multi-side print job. The output result inspection unit 223 detects the position of the defective nozzle in the first printing unit 222 by confirming the output result by the first printing unit 222, that is, the printing result by the first printing unit 222, and stores the defective nozzle position. The detected position of the defective nozzle is recorded in the part 221.

  First, the second printing unit 226 converts the received bitmap data of the multi-sided print job into a color space (for example, CMYK) handled by the printer engine unit, and further performs binarization processing as necessary. . The second printing unit 226 prints the color-converted data at a position on the print medium designated by the multi-side print job. The output result inspection unit 225 detects the position of the defective nozzle in the second printing unit 226 by confirming the output result by the second printing unit 226, that is, the printing result by the second printing unit 226, and stores the defective nozzle position. The detected position of the defective nozzle is recorded in the unit 224.

  Each of the pair of scanner sensors of the image reading device 115 corresponds to the output result inspection unit 223 and the output result inspection unit 225, and the defective nozzle position storage unit 221 and the defective nozzle position storage unit 224 are included in the image reading device 115. For example, the first image forming unit includes the defective nozzle position storage unit 221 and the output result inspection unit 223, and the second image formation unit includes the defective nozzle position storage unit 224 and the output result inspection unit 225. You may make it prepare.

  Next, the rendering process of the job control unit 203 will be described with reference to the flowchart of FIG. The rendering process shown in FIG. 5 is realized by the job control unit 203 of the printing system 202 executing a program stored in the ROM.

  First, in step S <b> 401, the job control unit 203 receives a print job from the external apparatus 201. In step S <b> 402, the job control unit 203 analyzes the received print job. In step S <b> 403, the job control unit 203 renders the print job received by the rendering unit 204. In step S <b> 404, the job control unit 203 stores bitmap data, which is a rendering result from the rendering unit 204, in the image storage unit 211.

  The printing process of the job control unit 203 will be described with reference to the flowchart of FIG. Note that the print control processing shown in FIG. 5 is realized by the job control unit 203 of the printing system 202 executing a program stored in the ROM. Also, the printing process is executed at a timing when bitmap data is stored in the image storage unit 211 by a certain amount or when a printing instruction from the user is received.

  First, in step S <b> 501, the job control unit 203 acquires a job setting value corresponding to each bitmap data stored in the image storage unit 211 from the analysis result storage unit 209. In step S502, the job control unit 203 determines a print layout for each bitmap data.

  In step S503, it is determined whether there is a defective nozzle. If there is a defective nozzle (YES in S503), the process proceeds to S504. On the other hand, if there is no defective nozzle (NO in S503), the process proceeds to S507.

  In step S <b> 504, the job control unit 203 rearranges the print layout so as not to be affected by the defective nozzle when there is a defective nozzle. Details of this process will be described later.

  In step S <b> 505, the job control unit 203 calculates the ratio of the unprintable area to the entire roll paper in the print layout after the rearrangement. The non-printable area is specifically an area where bitmap data cannot be arranged on both the front and back surfaces. Here, the region where the bitmap data cannot be arranged is a region where the nozzle cannot be used due to a nozzle failure, that is, a region where printing cannot be performed, and details will be described later with reference to FIG. FIG. 7 shows a specific example of the unprintable area, and the shaded area is the unprintable area. By managing the ratio of the unprintable area as shown in FIG. 7, the printing apparatus can be controlled in accordance with the ratio of the unprintable area.

  Here, the ratio of the unprintable area is obtained based on the area where the print head in the sheet cannot be used on each of the front surface and the back surface. The present embodiment is a so-called line head type printer in which the nozzles of the print head are arranged in a direction (sheet width direction) perpendicular to the sheet conveyance direction. Therefore, 100 is multiplied by the value obtained by dividing the total width in which printing is not performed in the direction (second direction) orthogonal to the sheet conveyance direction (first direction) by the sheet width in the second direction. Is. In the case of the example of FIG. 7, since there are a plurality of non-printable areas in the sheet width direction on both the front and back surfaces, the sum of these values is obtained by dividing the sheet width and multiplying by 100. It becomes.

  As described above, the unprintable area refers to an area in which the print head cannot be used in the sheet width direction, and is obtained for each surface. That is, even if it is an area where printing cannot be performed on one side, but it is an area where printing can be performed on the other side, even if printing is not performed on that area, Do not count.

  In step S <b> 506, the job control unit 203 determines whether the calculated ratio of the unprintable area is smaller than the specified threshold value, that is, less than the threshold value. This threshold value can be designated from the user interface unit 218, for example. FIG. 8 shows an example of a setting screen 700 provided by the user interface unit 218. Through this setting screen 700, the user can specify the percentage of the unprintable area allowed through the ratio specifying control 710. In the setting screen 700 of FIG. 8, when the user inputs an arbitrary value for the ratio of the unprintable area allowed through the ratio designation control 710 and inputs an OK button 720, the value designated by the ratio designation control 710 is set. It can be entered as a threshold. Therefore, printing according to the user's request becomes possible. For example, if you want to reduce the waste of paper as much as possible even if you stop the printing device, you can enter a small value on the setting screen 700 in FIG. 8, or if you want to prioritize not stopping the printing device over the waste of paper Enter a larger value.

  If the ratio of the unprintable area is smaller than the threshold (YES in S506), the job control unit 203 performs printing on each of the first printing unit 222 and the second printing unit 226 in S507 according to the print layout rearranged in S504. Create a multi-sided print job. If it is determined in S503 that there is no defective nozzle (NO in S503), a multi-sided print job is created according to the print layout determined in S502.

  In step S <b> 508, the job control unit 203 transmits the multi-sided print jobs for the first image forming unit and the second image forming unit to the corresponding ones of the first printing unit 222 and the second printing unit 226, respectively. Instruct.

  On the other hand, if the ratio of the unprintable area is equal to or greater than the threshold (NO in S506), the job control unit 203 displays an error display indicating that printing is not possible in S509. FIG. 9 shows an example of an error screen 800 that notifies the user interface unit 218 that printing is not possible. The user can prevent the waste paper amount from exceeding the proportion of the unprintable area allowed by the user by stopping the printing upon receiving the notification on the error screen 800. In addition, the error screen 800 of FIG. 9 includes a status display unit 810 that displays the designated allowable rate and the current unprintable area rate, so that the user can check how many unprintable areas have occurred in the current print head. can do.

  As described above, in the present embodiment, the defective nozzle is specified based on the output result of the printed matter. Therefore, acquisition of the defective nozzle position, determination of the print layout, and the like are performed while executing printing. Here, S503 to S509 are performed during execution of printing of the preceding print job. Of the printed materials printed during the execution of S503 to S509, those printed in the discharge failure affected area are defective images (failure images). For this reason, the printed matter determined to be defective in printing is rearranged so as to be printed again.

  The printing process of the image forming unit (the first printing unit 222 and the second printing unit 226) will be described with reference to the flowchart of FIG. Note that the print processing shown in FIG. 10 is realized by the job control unit 203 of the printing system 202 executing a program stored in the ROM.

  First, in step S901, the image forming unit receives a multi-sided print job. In step S <b> 902, the image forming unit executes color conversion and binarization processing of bitmap data included in the multi-sided print job as necessary. In step S903, the image forming unit prints the bitmap data included in the multi-sided print job at a position specified by the multi-sided print job. In step S <b> 904, the image forming unit checks the printing result with the image reading device 115 and detects a defective nozzle. Here, FIG. 11 shows a state in which a printing result is read by the image reading device 115 and defective nozzles are detected. By comparing this read result with print image data (for example, rendered bitmap data), it is possible to detect in which part a defective nozzle has occurred. FIG. 11 shows an example in which defective nozzles are generated in a printing unit that prints an image on the surface of a sheet.

  In step S905, the image forming unit stores the detected position of the defective nozzle in the defective nozzle position storage unit. By storing the position of the defective nozzle, it is possible to determine the print layout in consideration of the position of the defective nozzle when the job control unit 203 determines the print layout.

  Details of the print layout rearrangement processing in step S503 will be described with reference to the flowchart in FIG. In the print layout rearrangement process, bitmap data is not arranged on the area affected by the defective nozzle on the front side, and the position on the back side (the side opposite to the printing side of the defective nozzle) of that area. Only bitmap data for single-sided printing setting is placed in. Thereby, the nozzle on the back surface side which is the opposite surface side of the defective nozzle can be effectively used, and the waste of the printing medium can be reduced.

  First, in S1101 and S1102, the job control unit 203 stores the positions of defective nozzles in the first printing unit 222 (front side) and the second printing unit 226 (back side), respectively, as defective nozzle position storage unit 221 and defective nozzle position storage. Acquired from the unit 224. In step S <b> 1103, the job control unit 203 selects all the areas on the specific area (non-discharge influence area) identified from the positions of the defective nozzles acquired in steps S <b> 1101 and S <b> 1102 based on the printing position of each bitmap data on the back surface determined in step S <b> 502. The processing of S1104 to S1106 is executed for the bitmap data. Here, the undischarge-affected area is an area corresponding to a defective nozzle of the line head as shown in FIG. In other words, the undischarge-affected area is a print area assigned to a defective nozzle of the line head. This undischarge-affected area is an area where printing cannot be performed accurately due to the occurrence of defective nozzles. When non-discharge occurs, the influence continues until the non-discharge of the defective nozzle is resolved, and image quality deterioration such as white stripes occurs in all images after the non-discharge occurs.

  In step S <b> 1104, the job control unit 203 determines whether the target bitmap data is bitmap data (double-sided print data) for duplex printing setting. If it is not duplex printing data (NO in S1104), the process returns to S1103 to process the next bitmap data of interest. On the other hand, if the print data is double-sided print data (YES in S1104), in step S1105, the job control unit 203 sets a single-sided print setting bitmap that has the same width size as the bitmap data of interest in an area other than the undischarge-affected area on the front side. It is determined whether there is data (single-sided printing data). If there is no single-sided print data of the same width (NO in S1105), the process returns to S1103 to process the next bitmap data of interest. On the other hand, if there is single-sided print data (YES in S1105), in S1106, the job control unit 203 exchanges the print position of the single-sided print data and the print position of the target bitmap data (double-sided print data).

  In step S1107, the job control unit 203 executes the processes in steps S1107 to S1110. Specifically, for all the bitmap data on the discharge failure affected area identified from the positions of the defective nozzles acquired in S1101 and S1102, based on the printing position of each bitmap data after the printing position exchange in S1106, S1107 The process of ~ S1110 is executed.

  First, in step S1108, the job control unit 203 determines whether the target bitmap data is single-sided print data. If it is not single-sided print data (NO in S1108), the process returns to S1107 to process the next bitmap data of interest. On the other hand, if it is single-sided print data (YES in step S1108), in step S1109, the job control unit 203 determines whether the position on the back side of the single-sided print data is a discharge failure affected area. If it is a discharge failure effect area (YES in S1109), the process returns to S1107 to process the next bitmap data of interest. On the other hand, if it is not the discharge failure influence area (NO in S1109), in S1110, the job control unit 203 moves the single-sided print data to the position on the back side.

  In step S1111, the job control unit 203 determines all bitmap data on the defective print area specified from the defective nozzle positions acquired in steps S1101 and S1102 based on the print position of each bitmap data after the print position is moved in step S1110. The process of S1112 is executed. That is, in step S1112, the job control unit 203 moves the bitmap data arranged in the discharge failure affected area to a vacant place (area) other than the specific area that is the discharge failure affected area on the front side. In other words, the bitmap data arranged in the printing area of the defective nozzle is arranged on the same surface as the printing surface of the defective nozzle and outside the printing area of the defective nozzle.

  Here, how a printing position of each bitmap data is changed by the processing of S1101 to S1112 when a defective nozzle occurs on the front side will be described using a specific example.

  First, an example of layout without considering the position of the defective nozzle will be described with reference to FIG. Here, for simplicity of explanation, the number of bitmap data is set to 12 (data 1 to 12). However, the number of bitmap data is not limited to this. For example, more bitmap data is printed on a roll paper during actual printing. The printing process is performed continuously.

  FIG. 13A shows an arrangement diagram of each bitmap data when the print layout is determined in S503 without considering the position of the defective nozzle. In FIG. 13A, the right side shows a state where bitmap data is arranged on the surface of the roll paper, and the left side shows a state where bitmap data is arranged on the back side of the roll paper. In the center of the figure, there is a paper reversing unit, which indicates that the paper is reversed. The printing device assigns bitmap data to each nozzle of the line head, conveys the roll paper in the conveyance direction, and when the roll paper moves below the line head, ejects ink from each nozzle of the line head to the roll paper. Print each side of.

  How to read each symbol in FIG. 13 is as shown in FIG. Specifically, in FIG. 13, each square represents a page, and in the case of duplex printing, the page number (N) on the front side and the page number (N ′) on the back side are displayed in correspondence with each other. In the case of printing, the front side page is indicated by a thick frame, and the corresponding area on the back side is indicated by x. A dotted line represents an area to be printed.

  FIG. 13B shows the result of printing the bitmap data arranged in FIG. In FIG. 13B, a rectangular hatched portion is bitmap data that causes printing failure, and it can be seen that printing failure occurs due to the influence of defective nozzles. When a defect occurs in a part of the plurality of nozzles included in the surface line head that prints the surface, an area that is printed using the nozzles becomes an undischarge-affected area. In FIG. 13B, the third, sixth, ninth and twelfth pages are defective. And the 9th page and the 12th page are double-sided printing, and even if no defect has occurred in any of the plurality of nozzles provided in the back surface line head for printing the back surface, the 9th page and the 12th page are It is determined that printing is defective.

  FIG. 14 shows how the layout changes and the printing result when the layout is rearranged based on the flowcharts of FIGS. 6 and 12. The way of viewing the figure is the same as in FIG.

  First, in S502 of FIG. 6, the printing position and printing surface on the roll paper are determined without considering the defective nozzle. The arrangement at this time has the same result as in FIG.

  In the processing of S1103, S1104, S1105, and S1106, the printing position of the double-sided printing data on the front-side undischarge-affected area is exchanged with the printing position of single-sided printing data other than the front-side undischarge-affected area. FIG. 14A shows the result when the processes of S1103, S1104, S1105, and S1106 are executed on the layout of FIG. Specifically, the exchange of the printing positions of the bitmap data of the data 4 and the data 9 and the exchange of the printing positions of the bitmap data of the data 8 and the data 12 are performed. That is, the single-sided print data is arranged in the discharge failure affected area, and the double-sided print data scheduled to be placed in the discharge failure affected area is arranged in an area other than the discharge failure affected area.

  Furthermore, in the processing of S1107, S1108, S1109, and S1110, the single-sided print data on the undischarge-affected area on the front side is moved to the back side of those printing positions. FIG. 15B shows the result when the processes of S1107, S1108, S1109, and S1110 are executed on the layout of FIG. Specifically, the bitmap data of data 3, data 6, data 4 and data 8 is moved from the front surface to the back surface. Thereby, the arrangement of the bitmap data in the discharge failure affected area is eliminated.

  Finally, in the processing of S1111 and S1112, the bitmap data remaining on the discharge failure affected area is moved to an area other than the discharge failure affected area. In this embodiment, since bitmap data does not already exist in the discharge failure affected area in FIG. 14B, the layout is not changed even if the processes of S1111 and S1112 are executed.

  FIG. 14C is a result of printing the result arranged in FIG. 14B. In the figure, there is no bitmap data that causes printing failure, and printing is performed due to the influence of defective nozzles on the front side. Defects can be prevented.

  As described above, according to the first embodiment, a defective print is not generated because a print layout is created by avoiding a defective nozzle, that is, in a region other than the specific region. In addition, the waste of print media is reduced by rearranging the single-sided print data placed in the undischarge-affected area (specific area) on the front side to print in the print area on the back side of the print area assigned to the defective nozzle. can do. Therefore, the user can perform continuous printing without having to stop the printing apparatus and perform maintenance even if a defective nozzle occurs until the ratio of the unprintable area becomes equal to or greater than the specified threshold value. Further, by creating a print layout so as to effectively use the back side of the position of the defective nozzle, it is possible to reduce the waste of the print medium. Thus, in the present embodiment, an effect can be obtained regardless of the position of the defective nozzle.

<Embodiment 2>
In the second embodiment, a case where a defective nozzle is generated in the line head on the back side will be described. In particular, in the second embodiment, the print layout determined in S502 is rearranged so as not to be affected by defective nozzles on the back side in S503 of FIG.

  Details of the print layout rearrangement process in step S503 will be described with reference to the flowchart of FIG. Note that the print control processing shown in FIG. 5 is realized by the job control unit 203 of the printing system 202 executing a program stored in the ROM. In the print layout rearrangement process, the bitmap data is not arranged on the area affected by the defective nozzle on the back side, and only the bitmap data set for single-sided printing is arranged at the position on the front side of the area. As a result, the nozzles on the surface side of the defective nozzles can be effectively used, and waste of printing paper can be reduced. In the flowchart of FIG. 16, the front surface to be processed in the flowchart of FIG. 12 is replaced with the back surface.

  First, in steps S1501 and S1502, the job control unit 203 acquires the positions of defective nozzles of the first printing unit 222 (back side) and the second printing unit 226 (front side). In step S <b> 1503, the job control unit 203 determines all bitmap data on the discharge failure affected area identified from the position of the defective nozzle acquired in steps S <b> 1501 and S <b> 1502 based on the printing position of each bitmap data on the surface determined in step S <b> 502. , S1504 to S1506 are executed.

  In step S <b> 1504, the job control unit 203 determines whether the target bitmap data is bitmap data for duplex printing setting. If it is not double-sided print data (NO in S1504), the process returns to S1503 to process the next bitmap data of interest. On the other hand, if the print data is double-sided print data (YES in step S1504), in step S1505, the job control unit 203 determines the single-sided print setting bitmap data having the same width as the bitmap data of interest other than the undischarge-affected area on the back side ( It is determined whether there is single-sided printing data. If there is no single-sided print data (NO in S1505), the process returns to S1503 to process the next bitmap data of interest. On the other hand, if single-sided print data is present (YES in step S1505), in step S1506, the job control unit 203 exchanges the print position of the single-sided print data and the print position of the bitmap data of interest (double-sided print data).

  In step S <b> 1507, the job control unit 203 determines all bitmaps on the undischarge-affected area identified from the positions of the defective nozzles acquired in steps S <b> 1501 and S <b> 1502 based on the printing positions of the bitmap data after the printing position exchange in step S <b> 1506. The processing of S1508 to S1510 is executed for the data.

  First, in step S1508, the job control unit 203 determines whether the target bitmap data is single-sided print data. If it is not single-sided print data (NO in S1508), the process returns to S1507 to process the next bitmap data of interest. On the other hand, if it is single-sided print data (YES in step S1508), in step S1509, the job control unit 203 determines whether the position on the back side of the single-sided print data is a discharge failure affected area. If it is a discharge failure affected area (YES in S1509), the process returns to S1507 to process the next bitmap data of interest. On the other hand, if it is not the discharge failure affected area (YES in step S1509), in step S1510, the job control unit 203 moves the single-sided print data to the front side.

  In step S <b> 1511, the job control unit 203 determines all bitmap data on the defective print area specified from the position of the defective nozzle acquired in steps S <b> 1501 and S <b> 1502 based on the print position of each bitmap data after the print position movement in step S <b> 1510. , The process of S1512 is executed. In other words, in step S1512, the job control unit 203 moves the bitmap data to a vacant place (area) other than the specific area that is the undischarge-affected area on the back side.

  Here, how a printing position of each bitmap data is changed by the processing of S1501 to S1512 when a defective nozzle occurs on the back side will be described using a specific example.

  First, an example of layout without considering the position of the defective nozzle will be described with reference to FIG. Here, for simplicity of explanation, the number of bitmap data is set to 13 (data 1 to data 13). However, the number of bitmap data is not limited to this. For example, more bitmap data is printed on the roll paper during actual printing. The printing process is continuously performed.

  FIG. 16A shows an arrangement diagram of each bitmap data when the print layout is determined in S503 without considering the position of the defective nozzle. In FIG. 16A, the right side shows a state where bitmap data is arranged on the surface of the roll paper, and the left side shows a state where bitmap data is arranged on the back side of the roll paper. In the center of the figure, there is a paper reversing unit, which indicates that the paper is reversed. When the roll paper is transported in the transport direction, each bitmap data is moved below the line head, and ink is ejected there to execute printing on each surface of the roll paper. Also, how to read each symbol in FIG. 16 is as shown in FIG. 16 and is the same as FIG.

  FIG. 16B shows the result of printing the bitmap data arranged in FIG. In FIG. 16B, a rectangular hatched portion is bitmap data that causes printing failure, and it can be seen that printing failure occurs due to the influence of the defective nozzle.

FIG. 18 shows how the layout changes and the printing result when the layout is rearranged based on the flowchart of FIG.
First, in FIG. 6, the printing position and printing surface on the roll paper are determined without considering the defective nozzle in S502. The arrangement at this time has the same result as in FIG.

  In the processing of S1503, S1504, S1505, and S1506, the printing position of the double-sided print data on the non-discharge influence area on the back side is exchanged with the print position of the single-side print data other than the non-discharge influence area on the back side. FIG. 17A shows the result when the processes of S1503, S1504, S1505, and S1506 are executed on the layout of FIG. Specifically, the exchange of the printing positions of the bitmap data of data 11 and data 1 ′ and the exchange of the printing positions of the bitmap data of data 12 and data 7 ′ are performed.

  Furthermore, in the processing of S1507, S1508, S1509, and S1510, the single-sided print data on the undischarge-affected area on the back side is moved to the front side of those printing positions. FIG. 17B shows the results when the processing of S1507, S1508, S1509, and S1510 is executed on the layout of FIG. Specifically, the bitmap data of data 11, data 12 and data 13 is moved from the back surface to the front surface.

  Finally, in the processing of S1511 and S1512, the bitmap data remaining on the undischarge affected area on the back side is moved to an area other than the undischarge affected area. FIG. 17C shows the result when the processes of S1511 and S1512 are executed for the print layout of FIG. Specifically, the data 13 ′ is moved to an area other than the discharge failure affected area. As a result, there is no print data arrangement in the discharge failure affected area.

  FIG. 17D is a result of printing the result arranged in FIG. 17C. In the figure, there is no bitmap data that causes printing failure, and printing is performed due to the influence of defective nozzles on the back side. Defects can be prevented.

  As described above, according to the second embodiment, since a print layout is created while avoiding defective nozzles, no print defects occur. Further, it is possible to reduce waste of printing paper by rearranging the single-sided print data arranged in the area corresponding to the defective nozzle on the back surface so as to print on the front side of the area corresponding to the defective nozzle on the back surface. Therefore, even if a defective nozzle occurs, the user does not need to stop the printing apparatus and perform maintenance, and can perform continuous printing. Further, by creating a print layout so as to effectively use the surface side of the position of the defective nozzle, waste of the print medium can be reduced.

(Other embodiments)
The present invention is not limited to the embodiment described above. For example, in S1105 and S1505, it is determined whether there is single-sided print data having the same width outside the discharge failure affected area, but the present invention is not limited to this. If there is a large margin between data, the image printed by the data does not need to have the same width, for example, whether it is less than or equal to the sum of the print width of the data to be exchanged and the print width of the margin You may make it do.

  Furthermore, even when defective nozzles are generated in both the front side and the back side print heads, it is possible to prevent the occurrence of defective printing by determining the print layout according to the flowcharts of FIG. 12 and FIG. By effectively using the side, it is possible to reduce waste of the print medium.

  Even when a plurality of defective nozzles are generated in each print head, the occurrence of defective printing can be prevented by determining the print layout for each defective nozzle according to the flowcharts of FIGS.

  Further, in the above-described embodiment, the case where a defective nozzle occurs in either the front surface line head or the back surface line head has been described, but the case where a defective nozzle occurs in both the front surface line head and the back surface line head is also supported. can do. Further, for example, S1503 to S1512 may be executed after executing S1101 to S1110, or S1103 to S1112 may be executed after executing S1501 to 1512.

Further, in the above-described embodiment, if the opposite surface area corresponding to the discharge failure affected area becomes blank by moving the recording position of the double-sided print data arranged in the discharge failure affected area, the image has already been processed. If single-sided printing data is available, they may be arranged. Thereby, waste of printing paper can be further reduced.
In the above-described embodiment, the print layout is rearranged after the print layout is determined. However, the present invention is not limited to this. For example, after determining that there is a defective nozzle without determining the print layout twice, the print layout may be determined based on the position of the defective nozzle.

  In addition, the function of the above embodiment is realizable also with the following structures. That is, it is also achieved by supplying a program code for performing the processing of the present embodiment to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus executing the program code. In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code also realizes the function of the present embodiment.

  Further, the program code for realizing the function of the present embodiment may be executed by one computer (CPU, MPU), or may be executed by a plurality of computers cooperating. Also good. Further, the program code may be executed by a computer, or hardware such as a circuit for realizing the function of the program code may be provided. Alternatively, a part of the program code may be realized by hardware and the remaining part may be executed by a computer.

  202: Printing device 203: Job control unit 204: Rendering unit 205: First image reading unit 206: Second image reading unit 207: Job receiving unit 208: Job analysis unit 209: Analysis result storage unit 210: Communication unit 211: Image storage unit 212: Job creation unit 213: Job transmission unit 214: Print layout determination unit 215: Printability determination unit 216: First defective nozzle position acquisition unit 217 Second defective nozzle position acquisition unit, 218: user interface unit, 219: communication unit, 220: image processing unit, 221: defective nozzle position storage unit, 222: first printing unit, 223: output result inspection unit, 224: defective Nozzle position storage unit, 225: output result inspection unit, 226: second printing unit

Claims (11)

First acquisition means for acquiring the position of the first defective nozzle in the first image forming unit that forms an image on the first surface of the print medium;
Second acquisition means for acquiring a position of a second defective nozzle in a second image forming unit that forms an image on a second surface opposite to the first surface of the print medium;
Print positions of a plurality of images to be printed based on a plurality of print jobs based on the position of the first defective nozzle acquired by the first acquisition unit and the position of the second defective nozzle acquired by the second acquisition unit Determining means for determining the print surface and
With
When the print data arranged in the print area of the first defective nozzle or the second defective nozzle of the print medium is single-sided print data, the determining means includes a print surface of the defective nozzle of the print medium, Is determined to arrange the print data in an area opposite to the print area of the defective nozzle. When the opposite surface side of the print data arranged in the printing area of one defective nozzle among the first defective nozzle and the second defective nozzle includes the printing area of the other defective nozzle, The control device according to claim 1, wherein it is determined that the print data is arranged outside a print area on a print surface side of the one defective nozzle. When the print data arranged in the print area of one of the first defective nozzles and the second defective nozzle is double-sided print data, the determining means is outside the print area of the defective nozzle. It is determined that the single-sided printing data to be arranged and the printing position are exchanged, and the exchanged single-sided printing data is arranged in an area opposite to the printing surface of the defective nozzle and corresponding to the printing area of the defective nozzle. The control device according to claim 1 or 2. The apparatus further comprises a transmission unit configured to transmit the plurality of images to be printed to the first image forming unit and the second image forming unit based on the printing surface and the printing position determined by the determining unit. Item 4. The control device according to any one of Items 1 to 3. A specifying means for specifying a ratio of an unprintable area in which the image to be printed is not printed on the print medium;
Determining means for determining whether the ratio specified by the specifying means is less than a threshold;
When it is determined by the determination by the determination unit that the ratio specified by the specifying unit is not less than a threshold value, a notification unit that notifies that fact;
The control device according to claim 1, further comprising: The control device according to claim 5, further comprising setting means for setting the threshold value. Each of the first acquisition unit and the second acquisition unit compares the position of the first defective nozzle by comparing the image to be printed with the image on the print medium on which the image to be printed is printed. The control device according to claim 1, wherein the position of the second defective nozzle is acquired. The nozzles of each of the first image forming unit and the second image forming unit are arranged in a range corresponding to a width in a direction orthogonal to the transport direction of the print medium. The control device according to any one of 1 to 7. The control apparatus according to claim 1, comprising at least one of the first image forming unit and the second image forming unit. A first acquisition step of acquiring a position of a first defective nozzle in a first image forming unit that forms an image on a first surface of a print medium;
A second acquisition step of acquiring a position of a second defective nozzle in a second image forming unit that forms an image on a second surface opposite to the first surface of the print medium;
Print positions of a plurality of images to be printed based on a plurality of print jobs based on the position of the first defective nozzle acquired in the first acquisition step and the position of the second defective nozzle acquired in the second acquisition step And a determination step for determining the printing surface,
With
In the determining step, when the print data arranged in the print area of the first defective nozzle or the second defective nozzle of the print medium is single-sided print data, the print surface of the defective nozzle of the print medium Is determined to place the print data in an area corresponding to the print area of the defective nozzle on the opposite surface.   The program for functioning a computer as each means of the control apparatus of any one of Claims 1 thru | or 9, or making a computer perform the control method of Claim 10.

Images