JP2017007171A - Image formation apparatus and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply image data to image formation means in a necessary order for image formation while suppressing a memory capacity required on an image formation apparatus side even in a case where image formation is performed on both surfaces of a recording medium in an interleaf system.SOLUTION: When two-sided printing in an interleaf system is performed in response to a request from a printing job transmission device 100, a transfer request unit 244 sequentially determines whether image data of which page is required in accordance with progress of printing, and requests transmission of an image of the determined page to a printing job transmission device 100, an image data storage unit 245 stores the image data transmitted in response to the request in a page buffer 251 in association with the page number, and an image data supply unit 246 transmits the image data to an image formation unit 260 by reading the image data of the page to be printed on a sheet supplied to the image formation unit 260, out of the image data stored in the page buffer 251 in response to the request from the image formation unit 260.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus and an image forming system.

2. Description of the Related Art Conventionally, when an image of a multi-page document is formed on a recording medium such as paper in an image forming apparatus, a technique of rearranging the page order of image data in the order in which image formation is performed and supplying the image data to an image forming unit. Are known.
For example, when image formation is performed on both sides of a sheet by the interleaf method in which a plurality of sheets are placed on a sheet conveyance path, an image of a page on the first side of one sheet is formed and then another sheet is formed. While forming an image of another page, it is necessary to form an image of a page corresponding to the back side of the certain page on the second surface of the certain sheet at the timing when the certain sheet is fed again to the image forming unit. .

Patent Document 1 describes a technique in which an image forming apparatus rearranges image data in an order necessary for double-sided image formation by such an interleaf method.
In Patent Document 2, the controller of the image forming apparatus obtains in advance information on hardware for performing image formation, predicts the number of possible interleafs according to the information, and determines the interleaf to be implemented within that range. The document describes that the image data is developed in the order necessary for image formation in the interleaf.

However, in such a conventional technique, the image forming apparatus side is provided with a page order rearrangement function, and therefore there is an area for storing a large number of pages of image data (or print data before development) for rearrangement. It was necessary.
Further, the number of sheets that can be placed on the sheet conveyance path in the interleaf system varies depending on the hardware of the image forming apparatus, and also varies depending on the settings used for image formation, such as the size of the sheet to be used. Therefore, it has been difficult to rearrange in advance in an external device.

  The present invention has been made in view of such circumstances, and is necessary for image formation while suppressing the memory capacity required on the image forming apparatus side even when images are formed on both sides of a recording medium by the interleaf method. It is an object to enable image data to be supplied to the image forming means in a proper order.

  In order to achieve the above object, the image forming apparatus according to the present invention includes an image forming unit that forms an image on a recording medium based on image data received from an external transmission device, and the image forming unit includes a plurality of pages. When an image of each page of a document is formed on both sides of a recording medium by the interleaf method, it is sequentially determined which page of image data is necessary according to the progress of the image formation, and Transmission request means for requesting transmission of the image of the determined page, and a buffer for storing the image data transmitted from the transmission apparatus in response to the request of the transmission request means in a predetermined storage means in association with the page number In response to a request from the control unit and the image forming unit, the image data stored in the storage unit should be formed on a recording medium supplied to the image forming unit. Reads out the image data of the over-di, is provided with a control means for forming an image on a recording medium based on image data that was read to the image forming means.

  According to the above configuration, even when images are formed on both sides of the recording medium by the interleaf method, image data is supplied to the image forming unit in the order required for image formation while suppressing the memory capacity required on the image forming apparatus side. can do.

1 is a diagram illustrating a configuration of an image forming system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a hardware configuration of the image forming apparatus illustrated in FIG. 1. FIG. 2 is a diagram illustrating a configuration of functions related to execution of a print job included in the print job transmission apparatus and the image forming apparatus illustrated in FIG. 1. FIG. 5 is a diagram illustrating an example of a printing execution order of each page when performing interleaf duplex printing. FIG. 4 is a sequence diagram illustrating an example of an operation of each unit illustrated in FIG. 3 when the image forming apparatus illustrated in FIG. 1 executes a print job. 6 is a flowchart of processing corresponding to a function of a command processing unit executed by a CPU of the image forming apparatus. Similarly, it is a flowchart of processing corresponding to the function of the image data processing unit. FIG. 4 is a diagram illustrating an example of data stored in an image data processing unit during execution of a print job. FIG. 9 is a diagram illustrating an example of data at the time when execution of a print job has progressed more than in FIG. 8. FIG. 10 is a diagram illustrating an example of data at the time when execution of a print job has progressed further than in FIG. 9. FIG. 11 is a diagram illustrating an example of data at the time when execution of a print job has progressed further than in FIG. 10. FIG. 12 is a diagram illustrating an example of data at the time when execution of a print job has progressed further than in FIG. 11. FIGS. 13A and 13B are diagrams illustrating a timing at which the image data processing unit acquires image data of each page from the print job transmission apparatus and a timing at which the image data processing unit transfers to the image forming unit when executing the print job described with reference to FIGS. . FIG. 5 is a diagram illustrating an example of a print execution order of each page different from FIG. 4 when performing interleaf duplex printing. FIG. 15 is a diagram illustrating an example of data stored in an image data processing unit when performing double-sided printing illustrated in FIG. 14.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows the configuration of an image forming system according to an embodiment of the present invention.
An image forming system 1 illustrated in FIG. 1 is configured by connecting a print job transmitting apparatus 100 and an image forming apparatus 200 via a communication path 300.

  Among these, the print job transmitting apparatus 100 receives an instruction for causing the image forming apparatus 200 to execute printing from a user or another apparatus, generates print job data to be executed by the image forming apparatus 200 according to the instruction, and generates an image. This is a transmission apparatus having a function of transmitting to the forming apparatus 200. The print job transmission apparatus 100 can also be referred to as an upper apparatus in the sense that it is an upper apparatus instructing printing as viewed from the image forming apparatus 200.

  Note that. A print job generated and transmitted by the print job transmitting apparatus 100 includes bibliographic information (number of pages, file name, image size, etc.) of a document to be printed and settings used for printing (paper size, paper type, number of copies, single-sided / Double-sided, face-up / down, post-processing presence / absence, and the like) and image data of each page of the document to be printed.

  As will be described in detail later, when the print job transmitting apparatus 100 causes the image forming apparatus 200 to execute printing, the bibliographic information of the document to be printed in the print job and the settings used for printing are first formed together with the print request together with image formation. Transmit to device 200. Thereafter, the image data of each page is transmitted to the image forming apparatus 200 in response to a request from the image forming apparatus 200.

On the other hand, the image forming apparatus 200 is an embodiment of the image forming apparatus of the present invention, and has a function of forming an image on a recording medium based on a print job received from the print job transmitting apparatus 100. A specific procedure for image formation will be described later. The recording medium to be used here is a printing paper (which is simply referred to as “paper”), but is not limited to paper, and may be a resin sheet or a film. In addition, the image formation is performed by electrophotographic printing here, but other methods may be used. A method other than printing may be used.
The communication path 300 can be configured using communication means of any standard regardless of wired wireless, and may be network communication or peer-to-peer communication.

Next, FIG. 2 shows a hardware configuration of the image forming apparatus 200.
As shown in FIG. 2, the image forming apparatus 200 includes a CPU 201, a ROM 202, a RAM 203, an HDD (hard disk drive) 204, a communication I / F (interface) 205, an operation unit 206, a display unit 207, and an engine I / F 208. These are connected by a system bus 210. In addition, an engine unit 209 connected to the engine I / F 208 is provided.

The CPU 201 controls the entire image forming apparatus 200 by executing a program stored in the ROM 202 or the HDD 204 using the RAM 203 as a work area, thereby realizing various functions including those described later with reference to FIG. To do.
The ROM 202 and the HDD 204 are non-volatile storage media (storage means), and store various programs executed by the CPU 201 and various data described later.
A communication I / F 205 is an interface for communicating with other apparatuses such as the print job transmission apparatus 100. What is necessary is just to provide the thing according to the specification of the communication path to be used.

The operation unit 206 is an operation means for accepting an operation from a user, and can be configured by various keys, buttons, a touch panel, and the like.
The display unit 207 is a presentation unit for presenting the operation state, setting content, message, and the like of the image forming apparatus 200 to the user, and includes a liquid crystal display, a lamp, and the like.

Note that the operation unit 206 and the display unit 207 may be externally attached. In addition, when the image forming apparatus 200 does not need to receive an operation from the user directly (the operation may be accepted by an external apparatus connected via the communication I / F 205 or information may be presented), the operation is performed. The unit 206 and the display unit 207 need not be provided.
The engine I / F 208 is an interface for connecting the engine unit 209 to the system bus 210 and enabling control from the CPU 201. The engine unit 209 is a module for realizing a function including mechanical movement, such as an image forming unit that forms an image on a sheet based on image data.

  The print job transmitting apparatus 100 may have different specific performance, but has the same hardware configuration as that shown in FIG. 2 except for the engine I / F 208 and the engine unit 209.

  One characteristic point in this embodiment is that the image forming apparatus 200 acquires image data of each page to be printed from the print job transmitting apparatus 100 and supplies the acquired image data to the image forming unit. It is. Hereinafter, this point will be specifically described.

FIG. 3 is a diagram illustrating a configuration of functions related to execution of a print job provided in the print job transmission apparatus 100 and the image forming apparatus 200. Each function shown in FIG. 3 is realized by controlling required hardware by the CPU of each device executing a required program.
As illustrated in FIG. 3, the print job transmission apparatus 100 includes a job instruction reception unit 121, a print request transmission unit 122, and an image data transmission unit 123.

  Among these, the job instruction receiving unit 121 has a function of receiving a print instruction to be executed by the image forming apparatus 200 from a user or another apparatus. This instruction includes designation of a document to be printed and designation of settings used for printing. The image forming apparatus used for printing may be selected from a plurality of candidates.

  The print request transmission unit 122 generates a print job indicating the content of printing to be executed by the image forming apparatus 200 in accordance with the printing instruction received by the job instruction receiving unit 121, and performs command processing of the image forming apparatus 200 based on the print job. A function of transmitting a print request to the unit 230 is provided. As described above, this print job includes the bibliographic information of the document to be printed, the settings used for printing, and the image data of each page of the document to be printed. Bibliographic information and settings used for printing.

  The image data transmission unit 123 has a function of transmitting image data of an image to be printed by the image forming apparatus 200 to the image forming apparatus 200 in response to an image data transmission request from the image forming apparatus 200. The image data to be transmitted can be specified by a page number, and can be specified by using a job ID that is identification information of a print job, a file name of a document to be printed, and the like as necessary. Further, since the transmission request for image data is not always sent in the order of page numbers, when the print request transmission unit 122 transmits a print request to the image forming apparatus 200, image data drawing processing for all pages is performed. The image data transmission unit 123 may be ready for transmission.

  On the other hand, the image forming apparatus 200 is roughly provided with functions of a controller unit 220 and an image forming unit 260. Among these, the image forming unit 260 is a function realized mainly by the engine unit 209, and the controller unit 220 is a function realized by a part other than the engine unit 209.

The functions of the controller unit 220 are divided into a command processing unit 230, an image data processing unit 240, and a memory unit 250.
Among these, the command processing unit 230 has a function of causing the image forming unit 260 to perform image formation in accordance with a command such as a print request received from the print job transmitting apparatus 100. More specifically, the print request receiving unit 231, the print instruction unit 232, the page information generation unit 233, the transfer order notification unit 234, and the transfer status notification unit 235 are provided.

  The print request receiving unit 231 has a function of receiving a print request transmitted from the print job transmitting apparatus 100 and generating internal control data for causing the image forming unit 260 to execute printing according to the request. In this internal control data, for example, the paper tray to be used is selected according to the specification of the paper size and type, and the image of what page in what order on the paper according to the specification of face-up / down of paper discharge after printing This is data for specifying whether to print.

  The print instruction unit 232 has a function of instructing the image forming unit 260 to perform printing based on the internal control data generated by the print request receiving unit 231. This print instruction includes information necessary for the image forming unit 260 to determine the printing order of each page, such as the number of pages of a document to be printed, the presence / absence of double-sided printing, and the paper size. In the case of the interleaf method in which printing is performed by simultaneously loading a plurality of sheets on the sheet conveyance path, the number of sheets that can be loaded on the sheet conveyance path varies depending on the sheet size. Affect.

  For example, consider a case in which a 20-page document is printed by face-down paper discharge with an 8-sheet interleaf on which a maximum of 8 sheets are simultaneously placed on the sheet transport path. Of the two sides of the paper, the first side to be printed is referred to as the “first side”. Which side is the “first side” is not necessarily related to the direction in which the printed paper is discharged and the front and back sides of the printed document.

In the case of the 8-sheet interleaf described above, as shown in FIG. 4, an odd page is first printed on the first surface of 8 sheets of paper. After that, the first sheet passes through the double-sided conveyance path and is fed alternately with the new sheet. Therefore, the odd number page on the first side of the new sheet passes through the double-sided conveyance path. The even-numbered pages are printed alternately on the second side of the reversed paper. Then, after the printing of the first side is completed on all 10 sheets of paper to be used, an even page is printed on the second side of the 8 sheets of paper that are then fed through the duplex conveying path. Accordingly, printing of each page is executed in the order indicated by the numbers in the squares in the drawing.
However, for example, if the number of interleafs is 6, odd pages are first printed on the first side of 6 sheets of paper, and then odd pages are printed on the first side and even pages on the second side. Since printing is performed alternately, the printing order of each page is different from that shown in FIG.

Returning to the description of FIG. 3, the page information generation unit 233 has a function of generating a page number list indicating the printing order of each page for each printing surface of the paper based on the internal control data generated by the print request reception unit 231. Prepare. Further, it has a function of transferring the list to the image data processing unit 240 and registering it in the page information setting queue 241.
The contents of the page number list for each print surface are, for example, shown as data in the page information setting queue 241 in FIG. That is, the number of pages in the document to be printed on the first side of each sheet from the first sheet to the end used for printing, and the document on the second side of each sheet from the first sheet to the end. This indicates how many pages are printed.

  Further, the transfer order notification unit 234 prints a page number list indicating the print execution order of each page in the image forming unit 260 according to the notification transmitted from the image forming unit 260 in response to the print instruction transmitted by the print instruction unit 232. The function to generate. Further, it has a function of transferring the list to the image data processing unit 240 and registering it in the data transfer request queue 242. As shown in FIG. 4, the contents of the print order page number list are obtained by arranging the timing of printing an image of each page on paper in chronological order without distinguishing between the first side and the second side. The image data of each page is transferred from the image data processing unit 240 to the image forming unit 260 in this order.

This print order page number list need not be generated for all pages at once. Each time the print execution order is notified for a new page from the image forming unit 260, the notified list may be passed to the image data processing unit 240 and additionally registered in the data transfer request queue 242. The notification from the image forming unit 260 and the registration in the data transfer request queue 242 may not be synchronized.
In response to the transfer preparation completion notification from the image data processing unit 240, the transfer status notification unit 235 indicates that the image data processing unit 240 is ready to transfer one page of image data to the image forming unit 260. A function of notifying the forming unit 260 is provided.

  Next, the image data processing unit 240 acquires the image data used for printing from the print job transmission apparatus 100 and the image according to the page number list passed from the command processing unit 230 and the image data transfer instruction from the image forming unit 260. A function of performing transmission to the forming unit 260 is provided. More specifically, the functions include a page information setting queue 241, a data transfer request queue 242, a page buffer management table 243, a transfer request unit 244, an image data storage unit 245, and an image data supply unit 246.

The page information setting queue 241 registers a page number list that is passed from the page information generation unit 233 and indicates the printing order of each page for each printing surface of the paper, and transmits the information to the transfer request unit 244 as information indicating the acquisition order of the image data. Provide the functions to provide.
The data transfer request queue 242 registers a print order page number list indicating the print execution order of each page, which is passed from the transfer order notification unit 234, and provides it to the image data supply unit 246 as information indicating the transmission order of the image data. It has a function.

  The page buffer management table 243 has a function of registering information indicating which page of image data is stored in which area of the page buffer 251. In addition, information indicating whether each area of the page buffer 251 is an area for registering image data of an image to be printed on either the first side or the second side may be registered. Here, this information is also registered.

  When the page buffer 251 has an empty space, the transfer request unit 244 requests the print job transmission apparatus 100 to specify the page number in the order indicated by the page number list registered in the page information setting queue 241. And a function for requesting transmission of image data of the page. The transfer request unit 244 acquires the page number of the image data to be acquired next from the list of the first surface and the second surface corresponding to the empty area of the page buffer 251, and lists the page numbers. Delete from.

  The image data storage unit 245 has a function of storing the image data transmitted from the print job transmission apparatus 100 in response to the image data transmission request transmitted by the transfer request unit 244 in a free area of the page buffer 251. In addition, this storage is based on whether the transfer request unit 244 has acquired the page number from the list of the first surface or the second surface when generating the image data transmission request, and the storage area corresponding to the corresponding surface. To do.

  In response to the image data transfer instruction transmitted from the image forming unit 260, the image data supply unit 246 stores the images registered in the page buffer 251 in the order indicated by the page number list registered in the data transfer request queue 242. A function of reading data and transmitting it to the image forming unit 260 is provided. More specifically, when receiving the image data transfer instruction, the image data supply unit 246 obtains the page number of the image data to be transmitted next from the head of the data transfer request queue 242, and extracts the page number from the list. delete. Then, the image data corresponding to the acquired page number is read from the page buffer 251 and transmitted to the image forming unit 260.

  The image data supply unit 246 also has a function of releasing the area of the page buffer 251 that stores the image data that has been transmitted to the image forming unit 260 as a free area. This release can be performed by writing information to the page buffer management table 243 that the corresponding area is an empty area.

  The memory unit 250 has a function of storing various data, and particularly includes a page buffer 251 that is a storage unit that stores image data of an image to be printed received from the print job transmission apparatus 100 for each page. The page buffer 251 includes an area for storing image data for two pages for each of the image printed on the first side and the image printed on the second side.

  The image forming unit 260 has a function of executing printing in accordance with a print instruction transmitted from the command processing unit 230. More specifically, the printing order determination unit 261, the image data request unit 262, and the print execution unit 263 are provided.

The print order determination unit 261 has a function of determining the order in which the images of each page are printed on paper based on various information included in the received print instruction. As described above, this order depends on, for example, the number of interleaves. For example, the function for determining how many interleaves are performed based on the total number of printed pages, the paper size, and the like is also used. Prepared.
The printing order determination unit 261 also has a function of sending a printing order notification to the command processing unit 230 and notifying the determined printing order.

  When the print execution unit 263 can accept the image data of the next page to be printed, the image data request unit 262 transfers the image data requesting the image data processing unit 240 to transmit the image data of the next page. A function for transmitting an instruction is provided. Here, there is no need to specify a page number.

  The print execution unit 263 has a function of an image forming unit that forms an image on a sheet based on image data transmitted from the image data processing unit 240 in response to an image data transfer instruction transmitted by the image data request unit 262. Of course, it also has functions such as paper conveyance necessary for image formation and reversal paper feeding.

  In the image forming apparatus 200 described above, the page information generation unit 233 and the transfer request unit 244 correspond to a transmission request unit. The image data storage unit 245 corresponds to buffer control means. The image data supply unit 246 corresponds to the control unit.

Next, FIG. 5 illustrates the operation of each unit illustrated in FIG. 3 when the image forming apparatus 200 executes a print job that prints an image of each page of a document including a plurality of pages on both sides of a sheet using the interleaf method. An example is shown. Note that the correspondence between each functional unit and operation, which is finer than that shown in FIG. 5, will be described in the description of each step.
The operation related to the execution of the print job in the image forming apparatus 200 is triggered by the reception of the print request transmitted from the print job transmitting apparatus 100 (S11). This reception is performed by the print request reception unit 231 of the command processing unit 230.

  When the print request accepting unit 231 accepts the print request, the command processing unit 230 causes the page information generating unit 233 to print the page to be printed on the first and second sides of the paper in the accepted print job and the page indicating the printing order. A number list is generated and transmitted to the image data processing unit 240 (S12). The image data processing unit 240 registers this list in the page information setting queue 241 (S13).

On the other hand, the print instruction unit 232 of the command processing unit 230 generates a print instruction including the number of pages of a document to be printed and settings used for printing based on the received print job, and transmits the print instruction to the image forming unit 260. (S14).
In the image forming unit 260, upon receiving this print instruction, the print order determining unit 261 determines the order in which the images of each page are printed on the paper based on the content (S15), and notifies the command processing unit 230 as a print order notification. Transmit (S16).

  In the command processing unit 230, when the printing order notification is received, the transfer order notification unit 234 generates a printing order page number list according to the content of the notification, and transmits this to the image data processing unit 240 (S17). The image data processing unit 240 registers this list in the data transfer request queue 242 (S18).

  On the other hand, when the page number is registered in the page information setting queue 241 in step S13, the image data processing unit 240 determines, based on the information, about the page to be printed on the first side and the page to be printed on the second side. An image data transmission request designating each of the first two pages is transmitted to the print job transmitting apparatus 100 (S19). Note that the process of step S19 may be performed prior to steps S14 to S18. Further, the notification in step S19 may be transmitted separately for each page.

When the print job transmission apparatus 100 receives the image data transmission request in step S19, the image data transmission unit 123 transmits the image data of the designated page of the document to be printed to the request source image forming apparatus 200. (S20).
When receiving the image data, the image data storage unit 245 of the image data processing unit 240 stores the image data in the storage area of the page buffer 251 corresponding to the surface on which the image of the page is printed in association with the page number (S21). ). In the image data processing unit 240, when the image data storage unit 245 completes the storage in step S21, all of the image data necessary for printing is ready to be transferred to the image forming unit 260 at this point, and preparations for starting printing are complete. A transfer preparation completion notification indicating this is transmitted to the command processing unit 230 (S22).

  In the command processing unit 230, when the transfer status notification unit 235 receives this notification, it transmits a transfer preparation completion notification to the image forming unit 260 (S23). In the image forming unit 260, when the image data requesting unit 262 detects this notification, the image forming unit 260 instructs the image data processing unit 240 to transfer image data for one page (S24). Note that the image formation process in the printing process is performed after the transfer instruction and after the image data is transferred. The process before the image formation, such as the conveyance of the sheet to the vicinity of the transfer portion, is performed from step S14. If it is later, it may be started before Step S23 and Step S24.

  In the image data processing unit 240, when receiving the transfer instruction in step S24, the image data supply unit 246 acquires the first page number registered in the data transfer request queue 242 (registered in step S18). Then, the image data of the page is read from the page buffer 251 (S25). Then, the read image data is transmitted to the image forming unit 260 (S26). Step S25 and step S26 are performed in parallel.

In the image forming unit 260, the print execution unit 263 prints an image for one page on a sheet according to the received image data (S27).
In addition, when the image data processing unit 240 completes reading and transmission of image data for one page, an empty area is created in the page buffer 251, and the transfer request unit 244 that has detected the page then selects a page to be printed next. The designated image data transmission request is transmitted to the print job transmitting apparatus 100 (S28). At this time, the page number to be printed next is acquired from the page information setting queue 241 on the same side as the image data transmitted in step S26, that is, the side corresponding to the empty area of the page buffer 251, and the page number is acquired. Is specified.

When the print job transmission apparatus 100 receives the image data transmission request in step S28, the image data transmission unit 123 receives the image data of the specified page in the document to be printed, as in step S20. To the image forming apparatus 200 (S29).
When the image data processing unit 240 of the image forming apparatus 200 receives the image data, the image data processing unit 240 stores the image data in a free area of the page buffer 251 in association with the page number (S30). This free area should also be a storage area corresponding to the print surface on which the page to be saved is printed.

  In the image data processing unit 240, when the storage in step S30 is completed, the image data storage unit 245 notifies the command processing unit 230 that preparation for transferring image data for one page is newly completed (S31). In the command processing unit 230, the transfer status notification unit 235 receives this notification, and notifies the image forming unit 260 that preparation for transfer of image data for one page is newly completed (S32).

  Similarly, when the image data processing unit 240 detects that a free area has been created in the page buffer 251, the image data of the next page to be printed on the print surface corresponding to the free area of the page buffer 251 is transmitted as a print job. Obtained from the device 100. When there are no more pages to be printed on the corresponding printing surface, image data of another printing surface may be acquired, or the generated empty area may be left as it is.

  In addition to the flow of steps S28 to S32, in the image forming unit 260, when the printing in step S27 is completed, the image data requesting unit 262 transfers image data for the next page to the image data processing unit 240. An instruction is given (S33). In this example, the image data for each page is initially stored in the page buffer 251 for two pages, so the second image data transfer instruction may be given at an arbitrary timing convenient for printing.

  When the image data supply unit 246 of the image data processing unit 240 receives the transfer instruction in step S33, the page indicated by the first page number registered in the data transfer request queue 242 is the same as in steps S25 and S26. Are read from the page buffer 251 and transmitted to the image forming unit 260 (S34). In the image forming unit 260, the print execution unit 263 prints an image for one page on a sheet according to the received image data.

After that, when the printing of one page is completed, the image data requesting unit 262 instructs the image data processing unit 240 to transfer the next page of image data. However, the third and subsequent transmissions are performed after confirming that a transfer preparation completion notification corresponding to the transfer instruction has been received. If the notification in step S23 is counted as the first time, the next image data transfer instruction may be transmitted if the same number of transfer preparation completion notifications as the number of image data transfer instructions already transmitted are received. For example, when a third image data transfer instruction is sent, it is only necessary to receive a transfer preparation completion notification twice (in addition to step S23).
If this operation is repeated for the number of pages of the document to be printed, all pages of the document can be printed.

Next, processing executed by the CPU 201 in executing the operation shown in FIG. 5 will be described.
First, FIG. 6 shows a flowchart of processing corresponding to the function of the command processing unit 230.
When the CPU 201 receives a print request from the print job transmission apparatus 100, the CPU 201 starts the processing shown in the flowchart of FIG.

In this process, the CPU 201 first generates a page number list of pages to be printed on the first side and the second side of the paper based on the received print request (S101). The generated list is transmitted to the image data processing unit 240 and registered in the page information setting queue 241 (S102), and a print instruction is transmitted to the image forming unit 260 (S103).
Thereafter, the CPU 201 waits for reception of a printing order notification (S16 in FIG. 5) from the image forming unit 260 or transfer preparation completion notification (S22, S31, etc. in FIG. 5) from the image data processing unit 240.
When the printing order notification is received (Yes in S104), the CPU 201 transmits the page number list notified by the printing order notification to the image data processing unit 240 and registers it in the data transfer request queue 242 (S105).

  When the transfer preparation completion notification is received (Yes in S106), the CPU 201 transmits a transfer preparation completion notification with the same meaning to the image forming unit 260 (S107). When transmission of the transfer preparation completion notification is completed for all pages (Yes in S108), it is determined that the processing of the command processing unit 230 regarding the print job that has triggered the processing of FIG. 6 is completed, and the processing of FIG. finish. If No in step S108, the process returns to step S104 and the process is repeated.

  In the above processing, steps S101 and S102 are functions of the page information generation unit 233, step S103 is a function of the print instruction unit 232, step S105 is a function of the transfer order notification unit 234, and step S107 is a transfer status notification unit 235. Corresponds to the function.

Next, FIG. 7 shows a flowchart of processing corresponding to the function of the image data processing unit 240.
When the CPU 201 receives the page number list to be registered in the page information setting queue 241 transmitted from the command processing unit 230 in step S102 of FIG. 6, the CPU 201 starts the processing shown in the flowchart of FIG.

  In this process, the CPU 201 first registers the page number included in the received list in the page information setting queue 241 (S111, see FIG. 8). Thereafter, the CPU 201 transmits an image data transmission request designating the first two pages of the first and second sides of the registered page numbers to the print job transmission apparatus 100 (S112). Then, the image data of each page transmitted from the print job transmitting apparatus 100 in response to this request is stored in the page buffer 251 in association with the page number (S113). Thereafter, the CPU 201 transmits a transfer preparation completion notification indicating that image data necessary for starting printing is accumulated in the page buffer 251 to the command processing unit 230 (S114).

  Thereafter, the CPU 201 receives the print order page number list, the image data transfer instruction from the image forming unit 260, or the free space in the page buffer 251 transmitted from the command processing unit 230 in step S105 in FIG. Wait for any of the detections to occur.

When the print order page number list is received (Yes in S115), the CPU 201 registers the page numbers included in the received list in the data transfer request queue 242 (S116, see FIG. 10).
When the image data transfer instruction is received (Yes in S117), the CPU 201 reads out the image data of the page number registered at the head of the data transfer request queue 242 from the page buffer 251 and transmits it to the image forming unit 260 (S118). ). When transmission of image data for all pages is completed (Yes in S119), it is determined that the processing of the image data processing unit 240 regarding the print job that has triggered the processing of FIG. 7 is complete, and the processing of FIG. To do. If No in step S119, the process returns to step S115 and is repeated.

  If the CPU 201 detects that there is a free area in the page buffer 251 (Yes in S120), the CPU 201 retrieves the page number registered at the head of the print surface corresponding to the detected free area from the page information setting queue 241. An image data transmission request designating the page number is transmitted to the print job transmission apparatus 100 (S121). Then, the image data of the corresponding page transmitted from the print job transmitting apparatus 100 in response to this request is stored in the free area of the page buffer 251 in association with the page number (S122). Thereafter, a transfer preparation completion notification indicating that the image data of the corresponding page is stored in the page buffer 251 is transmitted to the command processing unit 230 (S123), and the process returns to step S115 to repeat the process.

  In the above processing, steps S112 and S121 correspond to the function of the transfer request unit 244, and steps S113, S114, S122, and S123 correspond to the function of the image data storage unit 245. Step S118 corresponds to the function of the image data supply unit 246.

  Next, specific examples of image data transfer from the print job transmitting apparatus 100 to the image forming section 260 of the image forming apparatus 200 when executing a print job by the functions of the respective sections described above will be described with reference to FIGS. I will explain. In this example, as shown in FIG. 4, a 20-page document is printed by face-down discharge with 8 sheets of interleaf.

  If the image forming apparatus 200 forms an image on the upper surface of the paper and discharges the paper without turning it upside down, in face-down paper discharge, first, an odd page is printed on the first surface of the paper, and then Even pages are printed on the reversed paper and discharged. In addition, printing may be performed on all the surfaces in ascending order of page numbers. Therefore, the page information generation unit 233 of the command processing unit 230 generates a page number list in which odd pages are arranged in ascending order for the first surface and even pages are arranged in ascending order for the second surface. Transmit (S12 in FIG. 5, S101, S102 in FIG. 6).

FIG. 8 shows a state in which this page number list is registered in the page information setting queue 241. In the state of FIG. 8, the data transfer request queue 242 and the page buffer 251 are empty. The page buffer management table 243 stores information indicating which surface each storage area corresponds to in the page buffer 251 having a storage area capable of storing image data for four pages. Each storage area of the page buffer 251 is used to store image data to be printed on the corresponding surface.
Next, the transfer request unit 244 of the image data processing unit 240 designates the first two pages (first to fourth pages) of the first side and the second side among the page numbers registered in the page information setting queue 241. A data transmission request is transmitted to the print job transmission apparatus 100 (S19 in FIG. 5 and S112 in FIG. 7). Then, the image data storage unit 245 stores the image data of each page transmitted from the print job transmission apparatus 100 in the page buffer 251 and registers it in the page buffer management table 243 (S21 in FIG. 5, FIG. 5). 7 S113). At this time, image data to be printed on the first surface is registered in a storage area corresponding to the first surface, and image data to be printed on the second surface is registered in a storage area corresponding to the second surface.

FIG. 9 shows a state in which image data for the first two pages of each printing surface is registered in the page buffer 251 in this way. In this example, since the image data processing unit 240 has not yet received the print order page number list to be registered in the data transfer request queue 242, the data transfer request queue 242 is empty.
Thereafter, when the image data processing unit 240 receives the print order page number list, the list is stored in the data transfer request queue 242. FIG. 10 shows this state.

  Thereafter, when the image data processing unit 240 receives an image data transfer instruction from the image forming unit 260, the image data supply unit 246 receives a page number registered at the head from the data transfer request queue 242 (“1 in the example of FIG. 10). Page ”), image data of the page number is read from the page buffer 251 and transmitted to the image forming unit 260. At this time, the read page number is deleted from the data transfer request queue 242.

  Further, when the transmission of the image data for the first page is completed, the image data supply unit 246 indicates in the page buffer management table 243 information that the storage area storing the image data for the first page has become a free area. Write. The transfer request unit that has detected this is the page number of the next page to be printed on the first page from the page information setting queue 241 because the storage area corresponding to the first page is an empty area. In the example of FIG. 10, the first “5 pages”) is acquired, and an image data transmission request designating the page number is transmitted to the print job transmitting apparatus 100 (S28 in FIG. 5, S121 in FIG. 7).

  Then, the image data storage unit 245 stores the image data transmitted from the print job transmission apparatus 100 in an empty area of the page buffer 251 and registers this in the page buffer management table 243. When the storage area corresponding to the first side is free, the newly acquired image data is also image data to be printed on the first side, and the same applies to the second side. Even if the process “store in” is performed, the correspondence between the storage area of the page buffer 251 and the printing surface on which the image data stored therein is printed is not destroyed.

  In the example described here, as shown in FIG. 4, printing on the first surface continues up to the eighth sheet (15 pages). Then, every time transmission of one page of image data from the page buffer 251 to the image forming unit 260 is completed, the image data processing unit 240 outputs image data of the next page to be printed on the first surface from the print job transmission apparatus 100. Is stored in the page buffer 251. Accordingly, image data for two pages may be stored first, and the latter is faster in the transfer from the page buffer 251 to the image forming unit 260 and the transfer from the print job transmitting apparatus 100 to the page buffer 251. However, as long as it can be performed at a similar speed, the situation that the image data necessary for the page buffer 251 is not generated does not occur, and printing can be continued.

FIG. 11 shows the state of each part at the time when printing has progressed to the eighth sheet (15 pages) in this way.
After the 15th page, the first sheet is returned to the image forming unit 260, and the image on the second page is printed on the second side. However, these two pages of images are also prepared in the page buffer 251 first. Therefore, even when the first page number read by the image data supply unit 246 from the data transfer request queue 242 in response to the reception of the image data transfer instruction is an even two pages, it is the same as when the odd page number is read. The image data of the page number can be read from the page buffer 251 and transmitted to the image forming unit 260.
The acquisition of image data to be stored in the free area generated in the page buffer 251 also takes the odd page of the odd page except that the next page number is taken out from the second-side queue corresponding to the free area in the page information setting queue 241. It can be done in exactly the same way.

FIG. 12 shows the state of each part at the time when printing on the first side has been completed to the end and printing has progressed to the point where printing on the second eight sheets is left behind.
At this time, all the image data on the first surface has been transferred to the image forming unit 260, and there is no image data to be acquired from the print job transmitting apparatus 100. In such a case, an empty area corresponding to the first surface of the page buffer 251 may be left as it is. Although it is conceivable to store the image data to be printed on the second side in the free area, changing the correspondence between the storage area of the page buffer 251 and the printing side in the middle makes the process complicated, and printing on the second side This is because the storage area for storing image data to be stored is sufficient for two pages.

  Thereafter, as in the above, the image data processing unit 240 causes the print job transmission apparatus 100 to generate a free space generated by the transmission each time transmission of one page of image data from the page buffer 251 to the image forming unit 260 is completed. The process of acquiring the image data of the next page to be printed on the surface corresponding to the area and storing it in the page buffer 251 is repeated. As a result, the images of all pages can be printed by the image forming unit 260 in the order in which the image forming unit 260 determines and stores them in the data transfer request queue 242 via the command processing unit 230.

FIG. 13 shows the timing at which the image data processing unit 240 acquires the image data of each page from the print job transmission apparatus 100 and the timing at which it is transmitted to the image forming unit 260 in the operation described above. The squares arranged in two stages indicate the period required for transmitting image data for one page, and the numbers in the squares indicate the page numbers of the image data.
The arrow from the lower stage to the upper stage indicates that the acquisition of the next page of image data from the print job transmission apparatus 100 is started when the transmission of one page of image data to the image forming unit 260 is triggered. After the transmission of pages 17 and 19 is completed, there is no image data to be acquired from the print job transmission apparatus 100, and therefore image data is not acquired.

Next, as another example, FIG. 14 shows an example in which a 20-page document is printed by face-up discharge with 8-sheet interleaf.
If the image forming apparatus 200 performs image formation on the upper surface of the paper and discharges the paper without turning it upside down, in face-up paper discharge, first, even pages are printed on the first surface of the paper, Thereafter, an odd page is printed on the inverted paper and discharged. In addition, printing may be performed on all the surfaces in ascending order of page numbers.

In the case of an 8-sheet interleaf, printing is first performed on the first side of eight sheets, and then printing is alternately performed on the second side of the sheet that has passed through the duplex conveying path and the first side of a new sheet. After the printing on the first side of all the sheets is completed, printing on the second side of the eight sheets of paper fed through the double-sided conveyance path is performed in the face down of FIG. Same as the case.
Therefore, the printing order of each page in the image forming unit 260 is as shown in FIG.

  In this case, the page information generation unit 233 of the command processing unit 230 generates a page number list in which even pages are arranged in ascending order on the first surface and odd pages are arranged in ascending order on the second surface. Further, the printing order determination unit 261 generates a printing order page number list indicating the order shown in FIG. If these lists are set in the page information setting queue 241 and the data transfer request queue 242, respectively, as shown in FIG. 15, the image forming apparatus 200 is the same as the operation described with reference to FIGS. The algorithm can perform printing in the order shown in FIG. Of course, it is sufficient for the page buffer 251 to have an area for four pages of image data.

  In the image forming system 1 or the image forming apparatus 200 described above, based on the page number list generated by the page information generating unit 233, the transfer request unit 244 determines which page of image data is required as printing progresses. The determination is made sequentially, and the print job transmitting apparatus 100 is requested to transmit the image data of the determined page. Further, the image data storage unit 245 stores the image data transmitted from the print job transmission apparatus 100 in response to the request in a predetermined page buffer 251 in association with the page number.

  As a result, even if the print execution unit 263 prints the image of each page in any page order, the image data of each page can be prepared in the page buffer 251 at the timing necessary for printing. Printing can be executed without delay. On the other hand, the page buffer 251 only stores image data of pages that are sequentially required as printing progresses, and the image data transmitted to the image forming unit 260 may be deleted. The required storage capacity can be reduced.

In the case of the interleaf method, if the paper is divided into the first and second sides, the number of pages to be printed on each paper and the order thereof can be used regardless of how many sheets are held on the paper conveyance path. There is no effect. Therefore, printing on the first side of the (n + 1) th sheet is always performed after printing on the first side of the nth sheet. The same applies to the second surface.
Therefore, for each print side of the paper, a list of pages to be printed on that side is created and saved as the page information setting queue 241, and which page of image data is required next is determined according to the list. Good.
In this case, for example, when printing is performed on the first side of the nth sheet, there is a possibility that printing is performed on the first side of the (n + 1) th sheet, and image data used for the printing is generated. Can be easily grasped to be stored in the page buffer 251.

  Further, the page buffer 251 is provided with a first area for storing image data to be printed on the first side of the paper and a second area for storing image data to be printed on the second side of the paper. After image data to be printed on the first and second sides of the first sheet is stored, image formation may be started. In this way, image formation can be started without any delay in a state where necessary image data is stored in the page buffer 251 regardless of the order in which the pages are printed.

After that, when image data used for printing on the first side of a certain sheet is read out, the image data used for printing on the first side of the next sheet is acquired from the print job transmitting apparatus 100 and the page buffer. 251 may be stored. When image data used for printing on the second side of a certain sheet is read, the image data used for printing on the second side of the next sheet is acquired from the print job transmitting apparatus 100 and stored in the page buffer 251. It is good to memorize.
In this way, for example, when printing on the first side of the nth sheet is performed and printing on the first side of the (n + 1) th sheet is likely to be performed, the n + 1th sheet is printed. Image data used for printing on the first surface can be stored in the page buffer 251.

If the transfer of the image data is extremely fast and the transfer of the required image data can be completed only in the time corresponding to the interval between the sheets in the printing process, the page buffer 251 stores each of the first side and the second side. Only one page of image data may be stored.
However, if the transfer of the image data is not so fast, the page buffer 251 may store the image data for two pages on each of the first side and the second side. In this case, image formation is preferably started after image data to be printed on the first and second sides of the first and second two sheets is stored in the page buffer 251. When printing on the first side of the nth sheet is performed and there is a possibility that printing on the first side of the (n + 1) th sheet occurs, the first side of the (n + 1) th sheet is already set. The image data used for printing is stored in the page buffer 251 and acquisition of the image data used for printing on the first surface of the next n + 2 sheet is preferably started.

This is the end of the description of the embodiment. In the present invention, the specific configuration of the apparatus, the specific processing procedure, the data format, the specific image forming order of each page, and the like have been described in the exemplary embodiment. It is not limited to things.
For example, the correspondence between the storage area of the image data in the page buffer 251 and the print surface may not be fixed. If it is known that printing on the first side continues and printing on the second side is not performed for a while, a large storage area corresponding to the first side is taken. However, even in this case, it is desirable to secure an area for storing image data used for printing the first surface of the paper for at least one page.

  Even if the image data used for printing on the second side is not stored in the page buffer 251 at a certain point in time, the printing on the second side is performed when the first side printing proceeds and a free area is created in the page buffer 251 thereafter. If the image data used for is stored, the progress of printing itself is possible. However, if the image data used for printing the first side cannot be stored in the page buffer 251 at the timing of printing the first side, the other part cannot be printed first, and the printing is not performed at all. It is because it becomes impossible to progress.

  In the embodiment described above, the print job transmission apparatus 100 and the image forming apparatus 200 are connected on a one-to-one basis, but this is not essential. The print job transmitting apparatus 100 can selectively transmit a print request to a plurality of image forming apparatuses 200, or the image forming apparatus 200 can receive a print request from the plurality of print job transmitting apparatuses 100. Conceivable. Both may be used.

Further, it is not impeded that the functions of the image forming apparatus 200 are provided in a distributed manner in a plurality of apparatuses, and these apparatuses cooperate to function as an image forming system having the same functions as the image forming apparatus 200.
In addition, it is needless to say that the configurations of the embodiments and modifications described above can be arbitrarily combined and implemented as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1: Image forming system 100: Print job transmission apparatus 121: Job instruction reception part 122: Print request transmission part 123: Image data transmission part 200: Image formation apparatus 201: CPU 202: ROM 203: RAM, 204: HDD, 205: Communication I / F, 206: Operation unit, 207: Display unit, 208: Engine I / F, 209: Engine unit, 210: System bus, 220: Controller unit, 230: Command processing unit 231: Print request reception unit, 232: Print instruction unit, 233: Page information generation unit, 234: Transfer order notification unit, 235: Transfer status notification unit, 240: Image data processing unit, 241: Page information setting queue, 242 : Data transfer request queue, 243: Page buffer management table, 244: Transfer request unit, 245: Image data storage unit, 24 : The image data supply unit, 250: memory unit, 251: page buffer, 260: image forming unit, 261: print order determination unit, 262: image data request unit, 263: printing unit, 300: channel

JP 2004-347627 A JP 2008-44221 A

Claims (8)

Image forming means for forming an image on a recording medium based on image data received from an external transmission device;
When the image forming unit forms an image of each page of a document consisting of a plurality of pages on both sides of a recording medium by an interleaf method, it sequentially determines which page of image data is required according to the progress of the image formation. Transmission request means for determining and requesting the transmission device to transmit an image of the determined page;
Buffer control means for storing image data transmitted from the transmission device in response to a request from the transmission request means in a predetermined storage means in association with the page number;
In response to a request from the image forming unit, image data of a page to be formed on a recording medium supplied to the image forming unit is read out from the image data stored in the storage unit, and the image forming unit stores the image data. An image forming apparatus comprising: control means for forming an image on a recording medium based on the read image data. The image forming apparatus according to claim 1,
When the transmission request unit forms an image on both sides of the recording medium by the interleaf method, a list of pages on which the image is formed is created for each side of the recording medium, and an image of which page is determined according to the list. An image forming apparatus for determining whether data is necessary. The image forming apparatus according to claim 1, wherein
The storage means stores a first area for storing image data of an image to be formed on the first surface of the recording medium, and a second area for storing image data of an image to be formed on the second surface of the recording medium. With
The transmission request means first requests the transmission apparatus to transmit an image to be formed on the first surface and the second surface of the first recording medium,
The control unit causes the image forming unit to start image formation after image data of images to be formed on the first and second surfaces of the first recording medium is stored in the storage unit. Image forming apparatus. The image forming apparatus according to claim 3, wherein
The storage means stores at least two pages of image data of an image to be formed on the first surface of the recording medium and at least two image data of an image to be formed on the second surface of the recording medium. A second area for storing pages,
The transmission request unit first requests the transmission device to transmit images to be formed on the first and second surfaces of the first and second recording media,
The control unit causes the image forming unit to start image formation after image data of images to be formed on the first and second surfaces of the first and second recording media is stored in the storage unit. An image forming apparatus. The image forming apparatus according to claim 3, wherein:
The transmission requesting unit is configured such that when the control unit reads out image data of an image to be formed on the first surface of a certain recording medium, the image to be formed on the first surface of the recording medium next to the certain recording medium. Is transmitted to the transmission device, and the control means reads the image data of the image to be formed on the second surface of a certain recording medium, the second of the recording medium next to the certain recording medium. An image forming apparatus that requests the transmitting apparatus to transmit an image to be formed on a surface. An image forming apparatus according to any one of claims 1 to 5,
The control means, when forming an image of each page of a document consisting of a plurality of pages on both sides of a recording medium by an interleaf method, is generated based on the number of pages of the document and a setting used for the image formation, In accordance with the information on the order in which the image forming unit forms the image of each page, the image data of the page to be formed on the recording medium is read from the storage unit, and the image forming unit stores the image data on the recording medium based on the read image data. An image forming apparatus for forming an image. An image forming apparatus according to any one of claims 3 to 5,
The first surface of the recording medium on which the image forming unit first forms an image is the first surface,
The transmission request means transmits an image to the transmission device so that the storage means can secure an area for storing image data of an image to be formed on the first surface of the recording medium for at least one page. An image forming apparatus characterized in that the above request is made. A transmission device for generating image data of an image to be formed on a recording medium for each page, and transmitting the generated image data to the requesting image forming device for each page in response to a request; An image forming system comprising a forming apparatus,
The image forming apparatus includes:
Image forming means for forming an image on a recording medium based on image data received from the transmission device;
When the image forming unit forms an image of each page of a document consisting of a plurality of pages on both sides of a recording medium by an interleaf method, it sequentially determines which page of image data is required according to the progress of the image formation. Transmission request means for determining and requesting the transmission device to transmit an image of the determined page;
Buffer control means for storing image data transmitted from the transmission device in response to a request from the transmission request means in a predetermined storage means in association with the page number;
In response to a request from the image forming unit, image data of a page to be formed on a recording medium supplied to the image forming unit is read out from the image data stored in the storage unit, and the image forming unit stores the image data. An image forming system comprising: control means for forming an image on a recording medium based on the read image data.

Images