JP5907341B2 - Printing system - Google Patents

Description

  The present invention relates to a printing system that performs duplex printing.

  As an example of a serial tandem configuration system in which two printing apparatuses are arranged in a column and perform high-speed printing, all the image data used for printing is stored in both the methods as shown in FIG. 12 (method disclosed in Patent Document 1). A system has been devised in which each printing device prints based on the image data of the page to be printed among the transmitted image data. In FIG. 12, the first printing apparatus performs printing on the front surface of the printing paper, and the second printing apparatus performs printing on the back surface.

  On the other hand, it is desirable to store the image data so that the image data once printed can be used again and printed. At this time, if all the image data is stored in both printing apparatuses, each printing apparatus has unnecessary image data that is not in charge of the own apparatus, and there is a problem that wasteful resources are consumed.

JP 2009-66937 A

  As one of the solutions, a system in which each printing apparatus holds only the image data handled by the printing apparatus as shown in FIG. FIG. 13 shows a serial tandem configuration system that performs high-speed printing by arranging two printing apparatuses in series, where the first printing apparatus is on the front side of the printing paper and the second printing apparatus is on the back side. When printing is performed, each printing apparatus holds only the image data handled by the own apparatus.

  However, when this system is applied, first, printing that shares the front and back surfaces is performed by two printing apparatuses, and then the image data used in the printing is used again. This time, N pages (N = Nint1 or more) If Nin1 printing is performed to collect and print images on one page, the image data for each device is insufficient for the image data held by each device alone. , Nin1 printing could not be performed using image data previously held in each printing apparatus.

  For example, as shown in FIG. 13, the printing apparatus 1 responsible for printing the front side in the first printing holds image data of A, C, E, and G, and the printing apparatus 2 responsible for printing the back side is B. When the image data of D, F, and H are held, the image data of A to D is then used, and as shown in FIG. When the B image is printed on the back side of the paper by the printing apparatus 2 and the C and D images are printed in 2 in 1, the printing apparatus 1 has the A and B image data, the printing apparatus 2 has the C, Although it is necessary to hold the image data of D, since the printing apparatus 1 does not hold the image data of B and the printing apparatus 2 does not hold the image data of C, printing cannot be performed as it is.

  The present invention is to solve the above problem, and after having the first printing device and the second printing device connected in series share the front and back surfaces of the printing paper and perform duplex printing, An object of the present invention is to provide a printing system capable of performing double-sided printing at Nin1 by using again the image data used in the double-sided printing.

  The gist of the present invention for achieving the object lies in the inventions of the following items.

[1] In a printing system in which first and second printing devices capable of duplex printing are connected in series by inverting the front and back surfaces of a sheet in the printing device.
Image data to be printed on the back surface of the first printing device when shared double-sided printing is performed in which the first printing device prints the front surface on the both surfaces of the paper by printing the back surface on the second printing device. The image data printed on the front side is not stored, the image data printed on the front side is not stored in the second printing device, and the image data printed on the back side is stored in the second printing apparatus. In printing that uses image data used in printing again, when performing Nin1 printing in which N pages of images are collected and printed on one page, N pages of N pages printed on the front and back of one sheet of paper are printed. of the portion of the page which stores the image data in the own apparatus among the N pages in the first printing apparatus to print on both sides of the paper according to the layout of the Nin1, the second printing device Printing system comprising the further control means Ru is printed on both sides of the sheet parts of the page which stores the image data in the own device in accordance with the layout of the Nin1 of the N page.

  In the above invention, two printing apparatuses capable of performing double-sided printing by inverting the front and back surfaces of the printing paper in the apparatus are connected in series, and when performing double-sided printing, one performs surface printing, The other unit prints the back side of the paper. When this printing is performed, each printing apparatus stores image data handled by the printing apparatus in preparation for reprinting. That is, the image data printed on the front surface is stored in the printing apparatus that printed the front surface, and the image data printed on the back surface is stored in the printing apparatus that printed the back surface. Thereafter, Nin1 printing (N = 2 or more) is performed in which images of N pages (an integer equal to or greater than N = 2) are aggregated and printed on one page using image data shared and stored by the two printing apparatuses. In the case of performing an integer), the two printing apparatuses respectively select Nin1 as the part of the page storing image data in its own apparatus among the N pages printed with the Nin1 layout on the front and back of one sheet of paper. Print on both sides of the paper according to the layout. As a result, the layout such as Nin1 (N is an integer of 2 or more) is changed without performing data transfer between the printing apparatuses while minimizing the number of image data stored in each printing apparatus. It is possible to cope with double-sided printing in the case of being performed.

[2] When the control means performs Nin1 printing in which images of N pages are combined and printed in one page in printing that uses image data used in the shared duplex printing again, the first printing apparatus While the second printing device is printing the image data stored in its own device on both sides of the paper, the first printing device is configured to print out the image data scheduled to be printed on the front surface with the Nin1 layout. The image data that is not stored in the own device is acquired from the second printing device, and the second printing device stores the image data that is scheduled to be printed on the back surface in the Nin1 layout. Unacquired image data from the first printing device,
The printing system according to [1], wherein the printing is switched to the shared duplex printing during printing.

  In the above-described invention, Nin1 prints N pages of images on one page in a print where the first printing device uses the image data used again when the second printing device prints the front side and the second printing device prints the back side. When performing printing, the first printing device and the second printing device are performing double-sided printing of the image data stored in their own devices, and the first printing device includes the image data scheduled to be printed on the surface. The image data that is not stored in the self apparatus is acquired from the second printing apparatus, and the second printing apparatus is configured to first select image data that is not stored in the self apparatus from the image data that is to be printed on the back side. From the printer. In the middle of printing, the first printing apparatus and the second printing apparatus switch from the method of duplex printing the image data portions stored in the respective apparatuses to shared duplex printing. As a result, the printing performance can be improved as compared with the case where printing is performed to the end without switching to shared duplex printing.

[3] wherein, the first printing device, to the second printing device, when printing the image data stored in the own device, printing in ascending order from the image data of the first page line Align, acquisition of image data which the own apparatus has not been stored, the image data of the last page row Align in descending order, image data to be printed on the surface of the paper in the Nin1 layout be printed next is first If the second printing apparatus has image data that is ready for printing with the Nin1 layout on the back side, it is switched from printing the next sheet to the shared duplex printing. The printing system according to [2], which is characterized.

  In the above-described invention, Nin1 prints N pages of images on one page in a print where the first printing device uses the image data used again when the second printing device prints the front side and the second printing device prints the back side. When printing is performed, the first printing device and the second printing device store the image data stored in their own device in the print page order (the order within the same page may be arbitrary). Double-sided printing is started from the data in ascending order, and during the printing, the first printing device acquires from the second printing device image data that the device itself does not store among the image data to be printed on the front surface. Then, the second printing apparatus acquires, from the first printing apparatus, image data that the self apparatus does not store among the image data scheduled to be printed on the back side. Image data is acquired in descending order from the last image data in the previous print page order. When the acquisition of image data has progressed and the image data scheduled to be printed on the front side of the paper to be printed next is in the first printing apparatus and the image data scheduled to be printed on the back side is in the second printing apparatus From the next sheet, the front side is printed by the first printing apparatus, and the back side is printed by the second printing apparatus. Thereby, after switching to shared duplex printing, the remaining duplex printing can be performed without transferring image data.

[4] In a printing system in which the first and second printing apparatuses are connected in series,
Image data to be printed on the back surface of the first printing device when shared double-sided printing is performed in which the first printing device prints the front surface on the both surfaces of the paper by printing the back surface on the second printing device. The image data printed on the front side is not stored, the image data printed on the front side is not stored in the second printing device, and the image data printed on the back side is stored in the second printing apparatus. in printing using the image data used for printing again, when performing aggregation to Nin1 printing for printing images of N pages on one page, the first printing device, printed on the surface by the Nin1 layout among the image data of the plan to the image data by the local apparatus is not stored is obtained from the second printing device, wherein the second printing device, the image data of scheduled to be printed on the back side in the Nin1 layout Of data, the printing system characterized by comprising a control means for performing the sharing duplex printing by obtaining the image data by the local apparatus does not store the first printing device.

  In the above invention, two printing apparatuses are connected in series, and one of the two connected printing apparatuses performs printing on the front surface and the other performs printing on the back surface. When this printing is performed, the image data printed on the front side is shared and stored in the printing apparatus that printed the front side, and the image data printed on the back side is stored in the printing apparatus that printed the back side. Thereafter, when performing Nin1 printing (an integer equal to or greater than N = 2) in which images of N pages are aggregated and printed on one page using image data shared and stored by the two printing apparatuses, The first printing device acquires image data that is not stored in the image data to be printed on the front surface from the second printing device, and the second printing device is scheduled to print on the back surface. Among the image data, image data that is not stored in the self apparatus is acquired from the first printing apparatus, and then printing on the front surface is performed by the first printing apparatus and printing on the back surface is performed by the second printing apparatus. Thereby, it is possible to cope with double-sided printing when the layout is changed such as Nin1 (N is an integer of 2 or more).

  According to the printing system of the present invention, the first and second printing apparatuses connected in series perform printing on the front surface with the first printing apparatus and printing on the back surface with the second printing apparatus. The image data printed on the front side is stored in the first printing apparatus, and the image data printed on the back side is stored in the second printing apparatus. Thereafter, in printing using the stored image data, the N page image is displayed. Even when Nin1 printing is performed in which printing is performed on a single page, it can be handled.

It is explanatory drawing which shows the printing system which concerns on embodiment of this invention, and the flow of a process. 1 is a block diagram illustrating a schematic configuration of an image forming apparatus installed on an upstream side in an image forming apparatus according to an embodiment of the present invention. 1 is a block diagram illustrating a schematic configuration of an image forming apparatus installed on a downstream side in an image forming apparatus according to an embodiment of the present invention. It is explanatory drawing which shows the example of a mode that shared double-sided printing is performed. It is explanatory drawing which shows the example of a mode that partial double-sided printing is performed. It is explanatory drawing which shows the example of a mode that shared double-sided printing is performed after transfer of image data. It is explanatory drawing which shows the example of a mode that combined double-sided printing is performed. It is explanatory drawing which shows the transfer order of the image data in combined duplex printing. It is explanatory drawing which shows the example of the process in combined duplex printing. It is a flowchart which shows the flow of the process which can respond to combined duplex printing. It is explanatory drawing which shows the example of the combination double-sided printing of the combination which improves printing performance most. It is explanatory drawing which shows a mode that all the image data is memorize | stored in each of two printers connected in series, and high-speed double-sided printing is performed. FIG. 4 is an explanatory diagram illustrating a state in which only necessary image data is stored in each printing apparatus and high-speed duplex printing is performed in a printing system in which two printing apparatuses are connected in series. It is explanatory drawing which shows a mode that high-speed double-sided printing is performed by 2in1.

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

  FIG. 1 shows a printing system 5 according to a first embodiment of the present invention. The printing system 5 includes an image forming apparatus 10A, an image forming apparatus 10B, and a sheet reversing device 70 disposed therebetween. The printing system 5 is connected to a PC terminal 60 through a LAN (Local Area Network) 3. The image forming apparatus 10A, the image forming apparatus 10B, and the sheet reversing device 70 are connected in series, and the upstream side is the image forming apparatus 10A and the downstream side is the image forming apparatus 10B. Further, the image forming apparatus 10A and the image forming apparatus 10B are collectively referred to as the image forming apparatus 10.

  The image forming apparatus 10 is a copy job that optically reads a document and prints the duplicate image data on a recording paper, a scan job that saves the image data of the read document as a file, or transmits it to an external device, a PC This is a so-called multi-function machine having a function of executing a job such as a print job for printing image data related to data sent from the printer on a recording sheet.

  The paper reversing device 70 reverses the front and back surfaces of the paper sent from the image forming apparatus 10A and sends it to the image forming apparatus 10B.

  The PC terminal 60 plays a role of submitting a print job to the image forming apparatus 10.

  The printing system 5 can perform duplex printing based on a print job received from the PC terminal 60. There are roughly two types of double-sided printing methods performed by the printing system 5. One is double-sided printing (hereinafter referred to as shared double-sided printing) in which the image forming apparatus 10A shares the printing paper with the image forming apparatus 10A and the backside with the image forming apparatus 10B, and the other method is image forming. In double-sided printing (hereinafter referred to as partial double-sided printing) in which a part of the front side and a part of the back side are printed by the apparatus 10A, and then the image forming apparatus 10B prints the remaining part of the front side and the remaining part of the back side. is there.

  FIG. 2 shows a schematic configuration of the image forming apparatus 10A. The image forming apparatus 10A includes a CPU (Central Processing Unit) 11 that controls the operation of the image forming apparatus 10A, a ROM (Read Only Memory) 12 connected to the CPU 11, a RAM (Random Access Memory) 13, and a nonvolatile memory. The memory 14, the hard disk device 15, the display unit 16, the operation unit 17, the scanner unit 18, the network I / F unit 19, the image processing unit 20, and the printer unit 21 are configured. The printer unit 21 includes a paper reversing unit 22, a paper transport unit 23, and an image forming unit 24, which will be described later.

  The CPU 11 is based on an OS (Operating System) program, on which middleware and application programs are executed. Various programs are stored in the ROM 12, and each function of the image forming apparatus 10A such as job execution is realized by the CPU 11 executing processes according to these programs. The RAM 13 is used as a work memory for temporarily storing various data when the CPU 11 executes a program, an image memory for storing image data, and the like.

  The nonvolatile memory 14 is a rewritable memory (flash memory) that can retain memory even when the power is turned off. The nonvolatile memory 14 stores device-specific information and various setting information. The hard disk device 15 is a large-capacity nonvolatile storage device, and stores an OS program, various application programs, print data and image data, an information history related to a job, and the like. In the figure, the hard disk device 15 is also referred to as HDD1.

  The display unit 16 is composed of a liquid crystal display (LCD) and the like, and fulfills a function of displaying contents related to various operations and settings. The operation unit 17 has a function of accepting various operations such as job input from the user and setting change. The operation unit 17 includes a touch panel that is provided on the screen of the display unit 16 and detects a pressed coordinate position, and includes a numeric keypad, a character input key, a start key, and the like outside the screen.

  The scanner unit 18 performs a function of optically reading a document and acquiring image data. The scanner unit 18 sequentially moves, for example, a light source that irradiates light on a document, a line image sensor that receives the reflected light for one line in the width direction, and a line-by-line reading position in the length direction of the document. An optical path composed of a lens, a mirror, and the like for guiding the reflected light from the original to the line image sensor to form an image, a conversion unit for converting the analog image data signal output from the line image sensor into digital image data, etc. It is configured with.

  The network I / F unit 19 communicates with other external devices connected through a network such as a LAN. In the present invention, the CPU 11 creates an instruction for printing based on the print job received from the PC terminal 60, and transmits it to the image forming apparatus 10B.

  The image processing unit 20 performs processing such as enlargement / reduction and rotation of image data, rasterization processing for converting print data into image data, and compression / decompression processing for image data.

  The printer unit 21 has a function of forming an image corresponding to image data on a recording sheet. Here, it has a sheet reversing unit 22, a sheet conveying unit 23, an image forming unit 24 (photosensitive drum, charging device, laser unit, developing device, transfer separation device, cleaning device, fixing unit, etc.), etc. It is configured as a so-called laser printer that forms an image by an electrophotographic process. The paper is transported by the paper transport unit 23, and the image forming unit 24 forms an image on the paper transported by the paper transport unit 23.

  The paper reversing unit 22 reverses the front and back surfaces of the printing paper after printing is performed by the image forming unit 24.

  The paper transport unit 23 transports paper from the paper feed tray to paper discharge (including paper discharge to the subsequent apparatus). The paper transport unit 23 is adapted to the print job, such as a path for reversing the front and back by the paper reversing unit 22 and re-feeding the paper to the image forming unit again, and a path for feeding the paper to the subsequent apparatus without passing through the paper reversing unit 22 Thus, the paper transport route can be switched.

  FIG. 3 shows a schematic configuration of the image forming apparatus 10B. The image forming apparatus 10B includes a CPU 31 that controls the operation of the image forming apparatus 10B, a ROM 32, a RAM 33, a nonvolatile memory 34, a hard disk device 35, a display unit 36, and an operation unit 37 that are connected to the CPU 31. A paper discharge tray 38, a network I / F unit 39, an image processing unit 40, and a printer unit 41 are provided. The printer unit 41 includes a paper reversing unit 42, a paper transporting unit 43, and an image forming unit 44. The image forming apparatus 10B basically has the same structure as the image forming apparatus 10A (however, the scanner unit 18 is not provided and a paper discharge tray 38 is added), and instead of discharging printed paper to a subsequent apparatus. The paper is discharged to the paper discharge tray 38.

  The CPU 31 is based on an OS program, on which middleware and application programs are executed. Various programs are stored in the ROM 32, and each function of the image forming apparatus 10B such as job execution is realized by the CPU 31 executing processing according to these programs. The RAM 33 is used as a work memory for temporarily storing various data when the CPU 31 executes a program, an image memory for storing image data, and the like.

  The nonvolatile memory 34 is a rewritable memory (flash memory) that can retain memory even when the power is turned off. The nonvolatile memory 34 stores device-specific information and various setting information. The hard disk device 35 is a large-capacity nonvolatile storage device, and stores an OS program, various application programs, print data and image data, an information history related to a job, and the like. In the drawing, the hard disk device 35 is also referred to as HDD 2.

  The display unit 36 is configured by a liquid crystal display or the like, and fulfills a function of displaying contents related to various operations and settings. The operation unit 37 has a function of accepting various operations such as job input from a user and setting change. The operation unit 37 is provided with a numeric keypad, a character input key, a start key, and the like outside the screen in addition to a touch panel provided on the screen of the display unit 36 to detect a pressed coordinate position.

  The network I / F unit 39 communicates with other external devices connected through a network such as a LAN. In the present invention, an instruction relating to printing is received from the image forming apparatus 10A.

  The image data processing unit 40 performs processes such as enlargement / reduction and rotation of image data, rasterization processing for converting print data into image data, and image data compression / decompression processing.

  The printer unit 41 has a function of forming an image corresponding to image data on a recording sheet. Here, the image forming unit 44, the sheet reversing unit 42, the sheet conveying unit 43, the photosensitive drum, the charging device, the laser unit, the developing device, the transfer separating device, the cleaning device, the fixing unit, etc. And a so-called laser printer that forms an image by an electrophotographic process. The paper is transported by the paper transport unit 43, and the image forming unit 44 forms an image on the paper transported by the paper transport unit 43. When image formation output (printing) is performed, the image formation target (recording paper) is moved in the sub-scanning direction while repeating image formation for one line in the main scanning direction, so that it is two-dimensionally printed on the recording paper. Images are formed.

  The paper reversing unit 42 reverses the front and back surfaces of the printing paper after printing by the image forming unit 44.

  The paper transport unit 43 transports paper from the paper feed tray to paper discharge. The paper transport unit 43 reverses the front and back with the paper reversing unit 42 and sends the paper again to the image forming unit. The paper feeding unit 43 sends a paper to the paper discharge tray 38 without going through the paper reversing unit 42. Accordingly, the paper conveyance path can be switched.

  The paper discharge tray 38 is a tray from which printing paper is discharged.

  FIG. 4 shows a specific example of processing performed by the printing system 5 when performing shared duplex printing. First, the PC terminal 60 transmits a double-sided print job to the image forming apparatus 10A. The transmitted print job here includes eight image data from A to H, and images of these eight image data are placed on each surface (front surface, back surface) of one sheet of printing paper, that is, An instruction for printing one page at a time in order is included.

  The image forming apparatus 10A that has received this print job saves the image data to be printed by the self apparatus, that is, the image data to be printed on the front surface. The image data printed on the back side is transmitted to the image forming apparatus 10B together with an instruction to print the image data by shared duplex printing. Here, the image data of A on the first surface, B on the back surface, C on the second surface, D on the back surface, E on the third surface, F on the back surface, G on the front surface, and H on the back surface. Therefore, the image forming apparatus 10A stores the image data A, C, E, and G, and the image data B, D, F, and H are transmitted to the image forming apparatus 10B.

  Printing is started in the image forming apparatus 10A, and images of A, C, E, and G image data are printed in order on the surface of the printing paper. The printing paper on which the image is printed is conveyed to the paper reversing device 70 by the paper conveying unit 23 without passing through the paper reversing unit 22, and the front and back surfaces are reversed by the paper reversing device 70 and conveyed to the image forming apparatus 10 </ b> B. . The image forming apparatus 10B prints images of B, D, F, and H image data on the back surface of the printing paper conveyed from the upstream according to the print instruction received from the image forming apparatus 10A.

  Since the printing paper conveyed from the upstream to the image forming apparatus 10B has its front and back surfaces reversed by the paper reversing device 70, in the image forming apparatus 10B, it is opposite to the surface (front surface) printed by the image forming apparatus 10A. It is printed on the surface (back side). When printing in the image forming apparatus 10B is finished, the printed printing paper is discharged to the paper discharge tray 38, and the process is finished.

  When the shared double-sided printing is performed, the image forming apparatus 10A and the image forming apparatus 10B store the image data used for the printing so that they can be used again. 4 is executed, the image forming apparatus 10A stores image data A, C, E, and G, and the image forming apparatus 10B stores image data B, D, F, and H, respectively. .

  After the shared duplex printing in FIG. 4, the user uses the A to H image data used in the shared duplex printing again from the PC terminal, and this time, a print job instructing duplex printing in 2 in 1 is sent to the image forming apparatus 10 </ b> A. Suppose you send it. In 2-in-1 printing, A and B image data on the front side of the first sheet, C and D image data on the back side, E and F image data on the front side of the second sheet, and G and H images on the back side An image based on the data will be printed. However, even if this print job is performed by shared duplex printing, the image forming apparatus 10A that prints the front side does not have image data B and F, and the image forming apparatus 10B has C and G image data. Therefore, the shared duplex printing cannot be started as it is.

  Therefore, the printing system 5 performs partial duplex printing in such a case. Image data transfer between the image forming apparatus 10A and the image forming apparatus 10B is performed by printing the data held by the image forming apparatus 10A and the image forming apparatus 10B on the front and back surfaces of the image forming apparatus 10B. Even if it is not, it is possible to support double-sided printing with Nin1 (an integer equal to or greater than N = 2) with the image data currently held by each.

  FIG. 5 shows a specific example in which partial duplex printing is performed in 2 in 1 after shared duplex printing in FIG. FIG. 5 shows a state where images are printed when printing paper passes through the image forming apparatus 10 </ b> A and the image forming apparatus 10 </ b> B when images of image data A to D are printed by partial duplex printing. An image printed by the apparatus during passage is indicated by a broken line, and an image already printed by the upstream apparatus is indicated by a solid line.

  First, the image forming apparatus 10A receives from the PC terminal 60 a print job instructing to perform double-sided printing in 2 in 1 by using again the image data A to H used in past shared double-sided printing (see FIG. 4). The image forming apparatus 10A creates a print instruction for partial duplex printing based on the print job, and transmits the print instruction to the image forming apparatus 10B.

  Thereafter, the printing system 5 starts partial duplex printing. Focusing on the first sheet, the image forming apparatus 10A prints an image of the image data A stored in the apparatus itself on the surface of the printing paper. At the time of this printing, the image of the image data A is printed with a size of 2 in 1 (half page size) and an arrangement of 2 in 1 (see FIG. 5).

  The printing paper on which the image data of A is printed is turned upside down by the paper reversing unit 22 inside the image forming apparatus 10A, conveyed again to the image forming unit 24, and then the second printing is performed. Is called.

  In the second printing by the image forming apparatus 10A, an image of C image data is printed on the back surface of the printing paper. At this time, an image of C image data is printed with a size of 2 in 1 and an arrangement of 2 in 1 (see FIG. 5). The printing paper on which the image data of A on the front side and the image data of C on the back side is printed is conveyed to the paper reversing device 70 by the paper transport unit 23, and the reverse side and the front surface of the printing paper are reversed by the paper reversing device 70. Carried to device 10B.

  Here, the paper conveyed to the image forming apparatus 10B is printed from the front surface by the image forming apparatus 10B because the front and back directions are reversed again by the paper reversing apparatus 70. In accordance with the instruction received from the image forming apparatus 10A, the image forming apparatus 10B prints the image of B image data on the back side of the conveyed printing paper in the size of 2in1 and the arrangement of 2in1. As a result, images A and B are printed on the front side of the paper, and an image C is printed on the back side.

  The printing paper is further turned upside down by the paper reversing unit 42 inside the image forming apparatus 10B, and is conveyed again to the printer unit 41 of the image forming apparatus 10B, and the second printing is performed.

  In the second printing by the image forming apparatus 10B, an image of the D image data is printed on the back side of the printing paper. At this time, the image is printed with a size of 2in1 and an arrangement of 2in1. As a result, images A and B are printed on the front surface, images C and D are printed on the back surface, and printing in a 2 in 1 layout is completed. When printing in the image forming apparatus 10B is completed, the printed printing paper is discharged to the paper discharge tray 38.

  Similar to the processing so far, partial double-sided printing is performed for the remaining image data images, and then the processing ends.

  In partial duplex printing, images of image data stored in the image forming apparatus 10A and the image forming apparatus 10B are printed on the front and back surfaces of the image forming apparatus 10A and the image forming apparatus 10B, thereby forming an image. Nin1 (N is an integer equal to or greater than 2) without transferring data between the image forming apparatus A and the image forming apparatus 10B while minimizing the number of image data stored in the apparatus 10A and the image forming apparatus 10B. Can support double-sided printing.

<Second Embodiment>
Hereinafter, the second embodiment will be described. Since the configuration of the printing system 5 according to the second embodiment is the same as that of the first embodiment described so far, the description thereof is omitted. The difference in the second embodiment is the processing procedure when performing Nin1 (an integer equal to or greater than N = 2) by using again the image data used in the shared duplex printing after shared duplex printing as shown in FIG. is there.

  In the second embodiment, the image forming apparatus 10A receives, from the image forming apparatus 10B, image data that is not stored (is insufficient) from the image forming apparatus 10B among image data that is to be printed on the front surface with the Nin1 layout. The image forming apparatus 10 </ b> B causes the image forming apparatus 10 </ b> A to transfer, from the image forming apparatus 10 </ b> A, image data that is not stored in the image forming apparatus 10 </ b> B that is scheduled to be printed on the back side with the Nin1 layout. When the transfer of the image data is completed, shared duplex printing is performed.

  FIG. 6 shows a specific example in which, after the shared duplex printing of FIG. 4, the missing image data among the image data stored in each of the devices 10 </ b> A and 10 </ b> B is migrated and the shared duplex printing is performed in 2 in 1. Show. In FIG. 6, the printing paper passes through the image forming apparatus 10 </ b> A and the image forming apparatus 10 </ b> B in the image data transfer apparatus 10 </ b> A and the image forming apparatus 10 </ b> B and the state of the image data transfer and the shared duplex printing after the transfer. In this case, an image is printed. An image printed by the apparatus during passage is indicated by a broken line, and an image already printed by the upstream apparatus is indicated by a solid line.

  First, the image forming apparatus 10 </ b> A receives from the PC terminal 60 a print job for instructing double-sided printing of image data A to H at 2 in 1. This print job does not include image data, but includes an instruction to use the image data stored in the image forming apparatus 10A and the image forming apparatus 10B at the time of shared duplex printing performed in the past. First, the image forming apparatus 10A communicates with the image forming apparatus 10B and grasps image data stored in each apparatus.

  After that, the image forming apparatus 10A stores the image data of the image printed on the surface of the printing paper with a 2 in 1 layout together with the transmission request of the image data stored in the image forming apparatus 10B. Image data of an image to be printed on the back side of the printing paper with a 2-in-1 layout is transmitted to the image forming apparatus 10B. The image forming apparatus 10B transmits the target image data to the image forming apparatus 10A according to the transmission request.

  Here, the image forming apparatus 10A transmits C and G image data to the image forming apparatus 10B, and the image forming apparatus 10B transmits B and F image data to the image forming apparatus 10A. When the image data necessary for execution of shared double-sided printing is prepared in each of the image forming apparatus 10A and the image forming apparatus 10B, the image forming apparatus 10A performs the shared double-sided printing using the image data. An instruction related to the processing in charge is transmitted to the image forming apparatus 10B. Thereafter, the printing system 5 starts shared duplex printing.

  Focusing on the first sheet, the image forming apparatus 10A prints images of A and B image data on the surface of the printing paper (see FIG. 6). The printed sheet is conveyed by the sheet conveying unit 23 to the sheet reversing device 70 without passing through the sheet reversing unit 22, and the front and back surfaces are reversed by the sheet reversing device 70 and conveyed to the image forming apparatus 10B. After the image forming apparatus 10 </ b> B prints the image of the C and D image data on the back surface of the conveyed printing paper, the printing paper is discharged to the paper discharge tray 38. For the second sheet, the image of the image data E to H is printed in the same manner, and the process ends.

  In shared duplex printing performed after the transfer of image data, shared duplex printing is performed after image data necessary for shared duplex printing is transferred between the image forming apparatus 10A and the image forming apparatus 10B. As a result, even if the image forming apparatus 10A and the image forming apparatus 10B are configured so that duplex printing cannot be performed in the respective apparatuses, the number of image data to be stored in the image forming apparatus 10A and the image forming apparatus 10B is minimized. However, double-sided printing can be performed as a whole, corresponding to double-sided printing (layout change) with Nin1 (N is an integer equal to or greater than 2). In the second embodiment, each of the image forming apparatus 10A and the image forming apparatus 10B only needs to be able to perform single-sided printing, and may not include a mechanism necessary for double-sided printing such as the paper reversing unit 22.

<Third Embodiment>
Hereinafter, a third embodiment will be described. Since the configuration of the printing system 5 according to the third embodiment is the same as that of the first embodiment, the description thereof is omitted. The difference in the third embodiment is that Nin1 (N = N = N) using image data stored in the image forming apparatus 10A and the image forming apparatus 10B at the time of shared double-sided printing after shared double-sided printing as shown in FIG. This is a correspondence method in the case of performing an integer of 2 or more.

  In the third embodiment, partial duplex printing described in the first embodiment is combined with shared duplex printing performed after image data migration described in the second embodiment (hereinafter, this method). Is called combination duplex printing). First, partial double-sided printing is executed, image data is transferred during the execution, and double-sided printing is performed by switching to shared double-sided printing during printing. Shared double-sided printing has better printing performance than partial double-sided printing, and data is transferred during partial double-sided printing, so all pages can be printed with only partial double-sided printing or shared double-sided printing after image data transfer. Printing performance can be improved compared to printing.

  For example, in FIG. 7, after the shared duplex printing in FIG. 4 is finished, when the image data A to H is printed in 2in1, the images of the image data A to D are printed by partial duplex printing. In addition, the image data of the F and G images is transferred, and the images of E to H are subjected to combination duplex printing in which printing is performed by shared duplex printing performed after the image data transfer. The figure shows how the image data is transferred, how the image data A to D are printed on the first sheet by partial duplex printing (upper side in FIG. 7), and E to H on the second sheet. The image of the image data is printed by shared duplex printing after the image data is transferred (lower part of FIG. 7). An image printed when passing through the image forming apparatus 10A and the image forming apparatus 10B is indicated by a broken line, and an image already printed by the upstream apparatus at the time of passing is indicated by a solid line.

  In the combined duplex printing, first, after the shared duplex printing in FIG. 4, the image forming apparatus 10 </ b> A receives a print job for instructing the duplex printing of the image data used in the past shared duplex printing from the PC terminal 60 in a 2 in 1 manner. . This print job itself contains no image data. Thereafter, the image forming apparatus 10A communicates with the image forming apparatus 10B and grasps image data stored in each apparatus. Thereafter, transfer of image data necessary to perform shared duplex printing is started while partial duplex printing is started.

  FIG. 8 shows image data of an image printed by partial duplex printing and image data of an image printed by shared duplex printing when combined duplex printing is performed in the present embodiment. In the drawing, the portion surrounded by the upper broken line is image data of an image printed by partial duplex printing, and the portion surrounded by the lower broken line is image data of an image printed by shared duplex printing.

  In the present embodiment, as shown in FIG. 8, the image data stored in the image forming apparatus 10A and the image forming apparatus 10B is the first in the print page order (the order in the same page may be arbitrary). Double-sided printing is started in ascending order from the image data to be obtained, and during the printing, the image forming apparatus 10A acquires image data that is not stored in the image forming apparatus 10B from the image forming apparatus 10B among image data to be printed on the front surface. The image forming apparatus 10B acquires from the image forming apparatus 10A image data that is not stored in the image forming apparatus 10B. Image data is acquired in descending order from the last image data in the previous print page order. For example, in the example of FIG. 7, among the image data A to H, partial duplex printing is performed by using B image and C image data in ascending order from the first image data A, and the last image H image data. The data is transferred in descending order from G to F.

  Returning to FIG. The image forming apparatus 10 </ b> A communicates with the image forming apparatus 10 </ b> B during the partial duplex printing to grasp the image data stored in each apparatus, and monitors the progress of the image data transfer. When image data shifts and image data capable of shared duplex printing on the next printing sheet is prepared in each of the image forming apparatus 10A and the image forming apparatus 10B, shared duplex printing becomes possible. If it is determined that the printing has been performed, the printing after the next printing sheet is switched from partial duplex printing to shared duplex printing. When switching, the image forming apparatus 10A transmits a change instruction to switch from partial duplex printing to shared duplex printing to the image forming apparatus 10B.

  In FIG. 9, in the combined duplex printing of FIG. 7, the image of the image data A to D is printed by partial duplex printing on the first sheet (upper side in FIG. 9) and E to H on the second sheet. The image of the image data is printed by shared duplex printing after the image data is transferred (lower part of FIG. 9).

  As a processing flow in FIG. 9, first, the image forming apparatus 10A communicates with the image forming apparatus 10B to grasp the image data stored in each apparatus. In the image data stored in the image forming apparatus 10A and the image forming apparatus 10B, when the image data required for the shared duplex printing is insufficient in each apparatus, first, the image forming apparatus 10A and the image forming apparatus 10B are used. Prints both sides of image data stored in its own device in ascending order from the top image data (in this case, image data of image A) in print page order (the order within the same page may be arbitrary) During the printing, the image forming apparatus 10A acquires from the image forming apparatus 10B image data that is not stored in the image forming apparatus 10B, and the image forming apparatus 10B Of the image data to be printed on the back side, the image data that is not stored in the apparatus is acquired from the image forming apparatus 10A. Image data is acquired in descending order from the last image data in the previous print page order.

  By the partial duplex printing, the image data transfer from E to H scheduled to be printed on the next printing paper is completed before the printing of the image data of A to D on the first printing paper is completed. Shared duplex printing is possible for the second sheet. Then, on the second printing paper, the image of E to H image data is printed by switching from partial duplex printing to shared duplex printing.

  FIG. 10 shows the flow of processing that can support combined duplex printing. First, the image forming apparatus 10A waits to receive a print job at Nin1 (step S101; No), and if received (step S101; Yes), proceeds to step S102.

  The image forming apparatus 10 </ b> A communicates with the image forming apparatus 10 </ b> B, and the image forming apparatus 10 </ b> A stores the image data stored in each apparatus and the image data to be printed on the surface when performing shared duplex printing with the Nin1 layout. Of the image data that has not been printed and the image data to be printed on the back side, the image data that is not stored in the image forming apparatus 10B is grasped (step S102).

  When the print job received in step S101 is printed by combined duplex printing and when it is printed by shared duplex printing after the image data transfer, the time required for printing by shared duplex printing after the image data transfer is estimated. If it is earlier than the case of printing by combination duplex printing (step S103; Yes), the process proceeds to step S104.

Here, it is assumed that “the amount of image data that can be printed on only K sheets of Nin1 duplex printing can be transferred while printing one sheet by partial duplex printing”, and “total number / (1 + K) = J (J is partial duplex printing). "The number of sheets that need to be printed. The decimal point is rounded up)"
・ The time required for combined duplex printing is
“J × processing time for partial duplex printing + (total number of sheets−J) × single processing time for shared duplex printing + time required for switching the printing method”
-The time required to perform shared duplex printing after image data transfer is
Since “image data transfer time + shared double-sided printing time” is obtained, the two are compared and determined.

  In step S103, even when printing by shared duplex printing is possible without transferring image data, it is not necessary to perform combined duplex printing, and thus the process proceeds to step S104.

  In step S104, image data necessary for shared duplex printing is transferred between the image forming apparatus 10A and the image forming apparatus 10B. Thereafter, printing is performed by shared duplex printing (step S105).

  Thereafter, if the printing of the last page is not completed (step S106; No), the process returns to step S104 and the process is continued. When printing of the final page is completed (step S106; Yes), the process is terminated.

  If the print job received in step S101 is executed by shared duplex printing after image data transfer is slower than the case of combined duplex printing (step S103; No), the process proceeds to step S108.

  In step S108, printing is started by partial duplex printing. At this time, image data that needs to be transferred in parallel is started to be transferred in descending order (step S109).

  If the transfer of image data proceeds and printing on the next printing paper can be performed by shared duplex printing (step S110; Yes), printing is switched from the next printing paper to shared duplex printing (step S110). S111). If printing on the next printing paper cannot be performed by shared duplex printing (step S110; No), the process returns to step S108 and continues.

  Thereafter, if the printing of the last page is not completed (step S112; No), the process returns to step S111 and continues. When printing of the final page is completed (step S112; Yes), the process is terminated. Note that when the printing is the fastest with only partial duplex printing (for example, when the number of images to be transferred is large but the number of printed sheets is small), there is no need to switch to shared duplex printing.

  In combination duplex printing, partial duplex printing is first executed, image data is transferred during the execution, and duplex printing is performed by switching to shared duplex printing during printing. As a result, the printing performance can be improved as compared with the case where all pages are printed only by partial duplex printing or only by shared duplex printing performed after transfer of image data.

  As described above, in the present invention, the image forming apparatus 10A and the image forming apparatus 10B are connected in series, and the printing on the front side and the printing on the back side of the printing paper are shared by the image forming apparatus 10A and the image forming apparatus 10B to perform double-sided printing. Printing by shared duplex printing can be performed. When printing by shared duplex printing, only necessary image data is stored in the image forming apparatus 10A and the image forming apparatus 10B. Further, after the shared double-sided printing is completed, the layout is changed from the previous shared double-sided printing using the image data stored in each apparatus during the shared double-sided printing (Nin1 {N = 2 It is also possible to perform double-sided printing. This layout is changed to any one of partial duplex printing, shared duplex printing performed after the image data described in the second embodiment is transferred, and combination duplex printing described in the third embodiment. Done in the way.

  When the amount of printing is larger than the transfer amount of image data (for example, when multiple copies are printed with the same image), shared duplex printing performed after transfer of image data is more efficient than partial duplex printing. If the print amount is small relative to the transfer amount of image data (for example, if the value of N in Nin1 is large and the print amount is small), partial duplex printing is more suitable for image data. Printing can be performed more efficiently than shared double-sided printing performed after the transition.

  The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to that shown in the embodiment, and there are changes and additions within the scope of the present invention. Are also included in the present invention.

  In the embodiment of the present invention, in combined duplex printing, partial duplex printing is started in ascending order from the top image data in the print page order (the order within the same page may be arbitrary). The image data is transferred (acquired) in descending order from the last image data in the print page order, but the order in which the image data is performed from which image data is not limited to this. For example, it is determined that partial double-sided printing is performed for a predetermined number of sheets that has been determined in advance, such as up to one third of the total number of printed sheets, and then shared double-sided printing is performed. Of the pages to be printed on both sides, they may be performed in ascending order from the top page (the order within the same page may be arbitrary). In addition, after switching from partial duplex printing to shared duplex printing, if the migration of the image data necessary for printing the next page has not yet been completed, the migration of the necessary image data Wait until is completed.

  In addition, for example, image data migration and switching from partial duplex printing to shared duplex printing may be performed so that the printing performance is most improved. FIG. 11 shows an example of a state in which combined duplex printing is performed so that the printing performance is most improved. First, partial double-sided printing is started in ascending order from the top image data in the print page order (the order in the same page may be arbitrary), and image data transfer is started (T1). The image data is not shifted from the last page, but is shifted from the image data of the page to be printed on the paper for which shared duplex printing is started in the print page order (the order in the same page may be arbitrary) in ascending order. When printing progresses and partial duplex printing is completed up to the page immediately before this page (T2), switching from partial duplex printing to shared duplex printing is performed. Even after switching to shared duplex printing, the transfer of image data is continued. When the transfer of the last image data is completed (T3), shared duplex printing on the last sheet is started. The page from which the image data transfer is started is set so that the timing at which the image data transfer ends is immediately before the start of shared duplex printing on the last sheet.

The time required to perform one partial duplex printing is Tx, the time required to perform one shared duplex printing is Ty, and the transfer time of image data required to perform one Nin1 printing by shared duplex printing is Tz, If P is the number of pages to be printed on both sides,
“Tx × P + Ty (all scheduled print counts−1−P) + printing method switching time ≧ Tz × (all prints−P)”
When the value of P is obtained so that the following equation is established, and partial duplex printing is performed for the number of sheets obtained by rounding up the decimal point of this value, switching to shared duplex printing is most effective. In this case, the page on which shared double-sided printing is started (the page on which the transfer of image data is started) is the page printed on the “number of P values rounded up + 1” sheet.

  In the embodiment of the present invention, the control of the printing system 5 when performing duplex printing is performed by the image forming apparatus 10A installed on the upstream side, but may be performed by the image forming apparatus 10B.

  In the embodiment of the present invention, when shared double-sided printing is first performed, all the image data of A to H are once transmitted from the PC terminal 60 to the image forming apparatus 10A, and then the images of B, D, F, and H are transmitted. Although the data is transmitted to the image forming apparatus 10B (see FIG. 4), the PC terminal 60 transmits image data A, C, E, and G to the image forming apparatus 10A, and B and D to the image forming apparatus 10B. , F, H image data may be transmitted directly.

  In the embodiment of the present invention, the printing system 5 can perform shared duplex printing, partial duplex printing, shared duplex printing performed after image data transfer, and combined duplex printing, but only shared duplex printing and partial duplex printing are possible. It may be possible, or only shared duplex printing performed after shared duplex printing and image data transfer may be possible.

  In the embodiment, the sheet reversing device 70 is installed between the image forming apparatus 10A and the image forming apparatus 10B. However, the sheet reversing unit 22 is not provided between the image forming apparatuses 10A and 10B. Alternatively, the paper reversing unit 42 may reverse the front and back of the paper.

  First, printing performed by shared duplex printing may be Min1 printing instead of 1in1 printing. (M ≠ N, an integer of 1 or more). In the present embodiment, the layout is changed from 1in1 to Nin1, but the layout change example is not limited to Nin1, and for example, the image data printed on the previous third page and the print on the previous fourth page are used. The printing may be performed by changing the order of the image data.

  When image data stored in the image forming apparatus 10A and the image forming apparatus 10B is printed in a layout designated by a print job in each apparatus, as in partial duplex printing, not only duplex printing, Single-sided printing may be used.

3 ... LAN
5. Printing system 10 (A, B) Image forming apparatus (upstream side, downstream side)
11 ... CPU
12 ... ROM
13 ... RAM
DESCRIPTION OF SYMBOLS 14 ... Non-volatile memory 15 ... Hard disk device 16 ... Display part 17 ... Operation part 18 ... Scanner part 19 ... Network I / F part 20 ... Image processing part 21 ... Printer part 22 ... Paper inversion part 23 ... Paper conveyance part 24 ... Image formation Unit 31 ... CPU
32 ... ROM
33 ... RAM
34 ... Non-volatile memory 35 ... Hard disk device 36 ... Display unit 37 ... Operation unit 38 ... Discharge tray 39 ... Network I / F unit 40 ... Image processing unit 41 ... Printer unit 42 ... Paper reversing unit 43 ... Paper transport unit 44 ... Image Forming unit 60 ... PC terminal 70 ... paper reversing device

Claims (4)

In the printing system in which the first and second printing devices capable of duplex printing are connected in series by reversing the front and back surfaces of the paper in the printing device,
Image data to be printed on the back surface of the first printing device when shared double-sided printing is performed in which the first printing device prints the front surface on the both surfaces of the paper by printing the back surface on the second printing device. The image data printed on the front side is not stored, the image data printed on the front side is not stored in the second printing device, and the image data printed on the back side is stored in the second printing apparatus. In printing that uses image data used in printing again, when performing Nin1 printing in which N pages of images are collected and printed on one page, N pages of N pages printed on the front and back of one sheet of paper are printed. of the portion of the page which stores the image data in the own apparatus among the N pages in the first printing apparatus to print on both sides of the paper according to the layout of the Nin1, the second printing device Printing system comprising the further control means Ru is printed on both sides of the sheet parts of the page which stores the image data in the own device in accordance with the layout of the Nin1 of the N page. In the printing for reusing the image data used in the shared duplex printing , the control means is configured to perform the Nin1 printing in which the images of N pages are aggregated and printed on one page, and the first printing device, the first The second printing apparatus is printing the image data stored on its both sides on the both sides of the paper, and the first printing apparatus is configured to print out the image data that is to be printed on the front side with the Nin1 layout. Obtains image data that is not stored from the second printing apparatus, and the second printing apparatus is an image that is not stored in the apparatus among the image data that is to be printed on the back surface with the layout of Nin1. Obtaining data from the first printing device;
The printing system according to claim 1, wherein the printing is switched to the shared duplex printing during printing. The control means, the first printing device, said the second printing device, when printing the image data stored in the own device, the row Align the print image data of the first page in ascending order, acquisition of image data which the own apparatus does not store the row Align in descending order from the image data of the last page, the image data to be printed on the surface of the paper in the Nin1 layout next printed on the first printing device When the second printing apparatus has image data that is prepared and is scheduled to be printed on the back side with the Nin1 layout, the printing is switched from the printing of the next sheet to the shared duplex printing. The printing system according to claim 2. In a printing system in which first and second printing apparatuses are connected in series,
Image data to be printed on the back surface of the first printing device when shared double-sided printing is performed in which the first printing device prints the front surface on the both surfaces of the paper by printing the back surface on the second printing device. The image data printed on the front side is not stored, the image data printed on the front side is not stored in the second printing device, and the image data printed on the back side is stored in the second printing apparatus. in printing using the image data used for printing again, when performing aggregation to Nin1 printing for printing images of N pages on one page, the first printing device, printed on the surface by the Nin1 layout among the image data of the plan to the image data by the local apparatus is not stored is obtained from the second printing device, wherein the second printing device, the image data of scheduled to be printed on the back side in the Nin1 layout Of data, the printing system characterized by comprising a control means for performing the sharing duplex printing by obtaining the image data by the local apparatus does not store the first printing device.