JP2020059191A - Image formation apparatus, image formation method, distributed image formation system and image formation program - Google Patents

Abstract

To execute printing processing while avoiding occurrence of memory shortage on an image formation apparatus.SOLUTION: An image formation apparatus comprises: a storage area management unit 111 which predicts a consumption memory amount being a memory amount used in execution of RIP processing on the basis of an image formation job in accordance with reception of the image formation job, and determines whether or not it is possible to allocate the consumption memory amount to the RIP processing in a prescribed storage area; a retrieval processing unit 115 which retrieves at least another one image formation apparatus that can execute the RIP processing with the consumption memory amount in accordance with determination that it is not possible to allocate; a RIP processing proxy request unit 114 which transmits the image formation job to the retrieved another image formation apparatus to request acting as proxy in executing the RIP processing, starts reboot of the image formation apparatus after request, notifies the retrieved another image formation apparatus of completion of the reboot after completion of the reboot, and receives dot data from the retrieved another image formation apparatus; and an image formation unit which reproduces an image by forming dots on an image formation medium.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus, an image forming method, a distributed image forming system, and an image forming program, and more particularly to distributed processing.

  2. Description of the Related Art In recent years, image forming apparatuses have come to use a large number of memories as the resolution and the number of functions have increased. On the other hand, since the image forming apparatus is shared by a plurality of users in the office and various jobs such as copying, printing, and image data transmission can be processed in parallel, a large amount of memory is temporarily consumed due to the parallel processing. Sometimes. Further, since the image forming apparatus is required to process a large number of jobs by a plurality of users, it is also exposed to the problem of memory leak. In order to solve such a problem, for example, in Japanese Patent Laid-Open No. 2004-242242, a personal computer that sends a print job to an image forming apparatus detects the capacity of a storage area that can be used as a spool area and displays a print permission message. By doing so, a technique for preventing inappropriate printing including missing characters and garbled characters is proposed.

JP, 2004-227390, A

  However, conventionally, sufficient studies have not necessarily been conducted on a method for avoiding the occurrence of a memory shortage in an image forming apparatus.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a technique for realizing print processing while avoiding a memory shortage in an image forming apparatus.

  The present invention provides an image forming apparatus that can be used for distributed image forming processing. The image forming apparatus includes a storage unit having a predetermined storage area, a RIP processing unit that executes RIP processing for generating dot data representing a dot formation state on an image forming medium, and an image forming job receiving unit. Accordingly, it is possible to predict the consumed memory amount, which is the memory amount used for executing the RIP process based on the image forming job, and allocate the consumed memory amount to the RIP process in the predetermined storage area. A storage area management unit that determines whether or not the allocation is possible; and a search processing unit that searches for at least one other image forming apparatus capable of executing the RIP process with the consumed memory amount according to the determination that the allocation is not possible, The image forming job is transmitted to the other searched image forming apparatus to request the RIP processing to be performed on behalf of the other image forming apparatus, and after the request, the image forming apparatus is restarted. A RIP processing proxy request unit that starts and notifies the other image forming apparatuses that have been searched for after the restart is completed and that receives the dot data from the other image forming apparatuses that have been searched. And an image forming unit that reproduces an image by forming dots on an image forming medium based on the received dot data.

  A distributed image forming system of the present invention includes a plurality of the image forming apparatuses and executes a distributed image forming process.

  The present invention provides an image forming method for executing a distributed image forming process using a storage unit having a predetermined storage area. The image forming method includes a RIP processing step of executing a RIP processing for generating dot data representing a dot formation state on an image forming medium, and an RIP processing step based on the image forming job in response to reception of the image forming job. A storage area management step of predicting a consumed memory amount which is a memory amount used for executing the RIP process and determining whether or not the consumed memory amount can be allocated to the RIP process in the predetermined storage region; A search processing step of searching for at least one other image forming apparatus capable of executing the RIP processing with the consumed memory amount according to the determination that the allocation is not possible; On the other hand, the image forming job is transmitted, the proxy of the RIP process is requested, the restart of the image forming apparatus is started after the request, and the restart is completed. Based on the received dot data, a RIP processing proxy request step of notifying the other image forming apparatus searched out that the restart is completed, and receiving the dot data from the other image forming apparatus searched out. And an image forming step of forming dots on the image forming medium to reproduce the image.

  The present invention provides an image forming program that includes a storage unit having a predetermined storage area and controls an image forming apparatus that can be used for distributed image forming processing. The image forming program is a RIP processing unit that executes a RIP process for generating dot data that represents a dot formation state on an image forming medium; A storage area management unit that predicts a consumed memory amount that is a memory amount used for execution of a RIP process and determines whether the consumed memory amount can be allocated to the RIP process in the predetermined storage region, A search processing unit that searches for at least one other image forming apparatus capable of executing the RIP processing with the consumed memory amount in accordance with the determination that allocation is not possible, and for the searched other image forming apparatus, The image forming job is transmitted to request the substitution of the RIP processing, the restart of the image forming apparatus is started after the request, and after the restart is completed, An RIP processing proxy request unit that notifies the other image forming apparatus that has been searched of the completion of the restart and receives the dot data from the other image forming apparatus that has been searched, and an image based on the received dot data. The image forming apparatus functions as an image forming unit that forms dots on a forming medium and reproduces an image.

  According to the present invention, there is provided a technique for realizing print processing while avoiding a memory shortage in an image forming apparatus.

1 is a schematic configuration diagram showing an overall configuration of a distributed printing system according to an embodiment of the present invention. FIG. 3 is an explanatory diagram showing a relationship between each function and each process of the image forming apparatus according to the embodiment. 3 is an explanatory diagram illustrating an example of a state of each area of a main memory of the image forming apparatus according to an embodiment. FIG. FIG. 9 is an explanatory diagram showing another example of a state of each area of the main memory of the image forming apparatus according to the embodiment. 6 is a flowchart illustrating the content of a print processing procedure according to an embodiment. It is a flow chart which shows the contents of offload processing concerning one embodiment. It is a flowchart which shows the content of the offloading destination process which concerns on one Embodiment.

  Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an overall configuration of a distributed printing system 10 according to an embodiment of the present invention. The distributed printing system 10 is also called a distributed image forming system and executes a distributed image forming process. In the present exemplary embodiment, the distributed printing system 10 includes three image forming apparatuses 100 (100a to 100c) and a local area network (also simply referred to as LAN) 30 that connects them. That is, the distributed printing system 10 is configured by connecting a plurality of image forming apparatuses 100 to each other via the LAN 30. In this example, the three image forming apparatuses 100a to 100c have the same configuration as the image forming apparatus 100. The personal computer 20 is also connected to the LAN 30.

  The image forming apparatus 100 includes a control unit 110, an image reading unit 120, a RIP processing unit 130, a storage unit 140, a communication interface unit 150 (also called a communication I / F), an image forming unit 160, and a FAX. And a communication unit 170. The RIP processing unit 130 includes a PDL analysis unit 131, a color conversion processing unit 132, and a halftone processing unit 133. The image reading unit 120 reads an image from a document and generates an image data ID that is digital data. The RIP processing unit 130 executes RIP processing on the image data to generate dot data that is bitmap data. The FAX communication unit 170 executes FAX transmission / reception. In FAX transmission, binarization processing is executed.

  The image forming apparatus 100 is connected to the personal computer 20 via the LAN 30. The image forming apparatus 100 is connected to the post-processing device 40. The post-processing device 40 can perform post-processing such as punching processing, stapling processing, and alignment processing for aligning a bundle of print sheets on the print sheet on which an image is formed.

  The image forming unit 160 forms an image on a print medium (not shown) based on the dot data and discharges it. In the present embodiment, the image forming unit 160 forms an image on a print medium (not shown) based on the image data ID or the print job received from the personal computer 20 and discharges the image. The dot data is bitmap data that represents a dot formation state on the image forming medium. The print medium is also called an image forming medium. The print job is also called an image forming job.

  The control unit 110 includes control means such as a CPU (Central Processing Unit). Further, the control unit 110 has a controller function related to interfaces such as various I / O, USB (Universal Serial Bus), bus, and other hardware. The control unit 110 controls the entire image forming apparatus 100. In this example, the control unit 110 operates using a Linux (registered trademark) kernel as an operating system.

  The control unit 110 includes a storage area management unit 111, a memory management unit (also referred to as a memory management unit, MMU) 112, a main memory 113 having a predetermined storage area, a RIP process proxy request unit 114, and a search processing unit. 115 and. have. The main memory 113 is composed of a RAM (Random Access Memory). The CPU executes each process in the main memory 113 by using the storage area secured by the storage area management unit 111. The MMU 112 has a function of converting a virtual address into a physical address.

  The storage unit 140 is a storage device including a hard disk drive which is a non-transitory non-volatile recording medium. The storage unit 140 has a program storage area 141, a swap area 142, a BOX area 143, and a consumed memory information storage area 144. The program storage area 141 stores a program for executing each process executed by the control unit 110. The swap area 142 is an area reserved in advance for swapping out the data in the main memory 113. The BOX area 143 is an area reserved in advance for the user of the image forming apparatus 100 to save image data and other data. The consumed memory information storage area 144 is an area for storing information indicating the amount of memory consumed by each function such as a print function and a copy function.

  FIG. 2 is an explanatory diagram showing a relationship between each function and each process of the image forming apparatus 100 according to the embodiment. The image forming apparatus 100 has a print function, a copy function, a FAX function, a transmission function, a BOX function, and a maintenance function as main functions, and implements a plurality of processes for realizing each function. The print function is realized by a PDL analysis process, a color conversion process, and a halftone process. The copying function is realized by an image reading process, a color conversion process, and a halftone process. An image reading process and a binarization process are used for the FAX function.

  In this example, the transmission function is a function of reading an image and transmitting it as a pdf file to the personal computer 20. An image reading process and a PDF conversion process are used for the transmission function. The BOX function is a function of compressing image data and the like, storing it in the BOX area 143, reading it from the BOX area 143, and expanding it. An image reading process and a compression / decompression process are used for the BOX function. In this example, the maintenance function is a function of recording, for example, the remaining state of consumables (toner or the like) and the number of printed sheets, and transmitting the records to the support center. A management process is used for the maintenance function.

  FIG. 3 is an explanatory diagram illustrating an example of a state of each area of the main memory 113 of the image forming apparatus 100 according to the embodiment. The main memory 113 is composed of a text area 113T, a static area 113S, a heap area 113H, a free area 113F, and a stack area 113V.

  The text area 113T is also called a program area, and is a fixed-size area in which a program translated into a machine language is stored. The image forming apparatus 100 reads the program translated into the machine language from the program storage area 141 and stores it in the text area 113T at the time of startup. Each process operates by executing this machine language instruction in the CPU.

  The static area 113S is a fixed-size area in which static variables such as global variables are stored. Static variables are variables that do not change during the operation of each process. The stack area 113V is a fixed-size area in which automatic variables (local variables), function arguments, temporary variables such as return values, and the like are stored. Registers of the CPU can be temporarily saved in the stack area 113V.

  In the C language, for example, the heap area 113H is a dynamic area in which each process can secure a physical memory with the malloc function and release the physical memory with the free function. Each process operates by allocating a physical memory for the storage area required for its operation with the malloc function and releasing the physical memory with the free function after the completion of the operation. On the other hand, the free area 113F is an area excluding the area secured in the heap area 113H. Therefore, the heap area 113H and the free area 113F are areas that change according to the operation of each process (see the arrow in FIG. 3).

  Note that most of the free area 113F is actually used by the Linux (registered trademark) kernel of the control unit 110 for a buffer or a file cache. However, the Linux (registered trademark) kernel automatically releases the storage area for the buffer and the file cache according to the decrease in the free area 113F, and increases the available storage area so that it can be used by each process. You can However, the storage area for the buffer and the file cache is secured within a range in which the processing capability of the control unit 110 does not excessively decrease.

  Further, the Linux (registered trademark) kernel can be used in each process by swapping out to the swap area 142 of the storage unit 140 to increase the available storage area when the storage area for the buffer or the file cache becomes small. Can be However, since the storage unit 140 is a storage device including a hard disk drive, swap-out may cause a decrease in the processing capability of the control unit 110.

  FIG. 3A shows each area of the main memory 113 before starting the RIP processing. The text area 113T, the static area 113S, and the stack area 113V are areas having a fixed size during the operation of each process. In this example, it is assumed that the programs of all processes are stored in the text area 113T and all the processes are activated. Each process secures a storage area necessary for starting processing in the heap area 113H. The RIP process is started in response to a print job received from the personal computer 20 or a copy operation.

  FIG. 3B shows each area of the main memory 113 during the RIP process. In the RIP process, the control unit 110 activates at least the color conversion process and the halftone process. The color conversion process and the halftone process operate by repeatedly reserving the storage area required for each process with the malloc function and releasing it with the free function. As described above, the heap area 113H is increased due to the RIP processing.

  FIG. 4 is an explanatory diagram showing another example of a state of each area of the main memory 113 of the image forming apparatus 100 according to the embodiment. FIG. 4A shows each area of the main memory 113 after the RIP processing. The main memory 113 after the RIP processing is different from the main memory 113 before the RIP processing (see FIG. 3A) in that the non-open area remains and the storage area of the main memory 113 is reduced. Generation of such a non-open area is generally called a memory leak. Memory leaks are mitigated by garbage collection, but limitations have been noted.

  FIG. 4B shows each area of the main memory 113 after the RIP processing is restarted. In the RIP process, the color conversion process and the halftone process operate by repeatedly securing a storage area required for each process with the malloc function and releasing it with the free function. However, the empty area 113F is reduced due to the non-open area due to the memory leak. Since the image forming apparatus 100 is required to process a large number of jobs by a plurality of users, the inventor of the present application paid attention to the fact that the memory leak is a problem that cannot be ignored.

  FIG. 5 is a flowchart showing the content of the print processing procedure according to the embodiment. In the print processing procedure, the image forming apparatus 100 uses the PDL analysis process, the color conversion process, and the halftone process to form an image on a print medium (not shown) based on the print job received from the personal computer 20. This is the process of discharging.

  In step S100, the control unit 110 executes a print job reception process. In the print job receiving process, in response to the print job received from the personal computer 20, the CPU activates the PDL analysis process, the color conversion process, and the halftone process as necessary. The PDL analysis process, color conversion process, and halftone process use virtual addresses to set storage areas in virtual memory space. The MMU 112 secures the physical memory in the main memory 113 by converting the virtual address into a physical address.

  In step S200, the storage area management unit 111 of the control unit 110 executes a consumed memory prediction process. In the consumed memory prediction process, the storage area management unit 111 searches and acquires the consumed memory amount in the consumed memory information storage area 144 based on the attribute information indicating the attribute of the job and the activation states of the plurality of processes. . The consumed memory information is a database in which the contents of the functions such as the print function and the copy function are associated with the attribute information about the functions such as color printing / monochrome printing and the resolution (print function in this example) and the consumed memory amount.

  The attribute information may further include each activation state of the plurality of processes, that is, whether each process has been activated when the print job is received. This is because the amount of memory to be newly allocated decreases if the memory has already been activated. The consumed memory information represents the peak value (maximum value) of the used memory size during execution of each function.

  Note that the storage area management unit 111 controls the plurality of processes in the image forming apparatus 100 to control the plurality of processes in the image forming apparatus 100 when the data in which the activation states of the plurality of processes match is not stored in the consumed memory information storage area 144. You may make it search for the amount of memory consumption according to each starting state stored in the information storage area 144. The amount of memory consumed may be estimated by other methods.

  In step S300, the storage area management unit 111 acquires the free memory size. Since the Linux (registered trademark) kernel is used as the operating system, the free memory size can be obtained using, for example, the / proc / meminfo command. In this example, the free memory size is the memory size available for each process.

  In the present embodiment, the storage area management unit 111 determines the amount of memory that can be released by leaving a memory amount set in advance as a memory amount that does not excessively reduce the processing capacity among the storage areas for buffers and file caches, and the unused amount. The free memory size is calculated as the sum of the free area and the amount of memory that can be opened by swapping out data unnecessary for the printing function. However, since swap-out may cause a decrease in the processing capacity of the control unit 110, the free memory size may be calculated without presuming the swap processing. The free memory size may be calculated by another method.

  In step S400, the storage area management unit 111 determines whether the free memory size is insufficient with respect to the consumed memory amount which is the memory amount represented by the consumed memory information. If the free memory size is not insufficient, the storage area management unit 111 advances the process to step S500, and if the free memory size is insufficient, advances the process to step S600.

  In step S500, the RIP processing unit 130 executes RIP processing. In the RIP process, the PDL analysis unit 131 executes the PDL analysis process, the color conversion processing unit 132 executes the color conversion process, and the halftone processing unit 133 executes the halftone process.

  The PDL analysis process analyzes the print job described in the page description language, extracts objects such as text (characters), images, and vector graphics included in the print job, and executes drawing processing and font processing. The color conversion process executes color conversion processing to convert the RGB image data representing the object into CMYK image data that can be reproduced by the color material used by the image forming unit 160. In the halftone process, processing such as systematic dithering and error diffusion is performed on the CMYK image data, and the image forming unit 160 reduces the number of gradations that can be reproduced by toner dots.

  Thus, the print execution process is a process that consumes a very large amount of memory depending on the content of the print job. For this reason, the problem of memory leak often manifests itself in the print execution process, which may cause an error or a processing delay.

  In step S600, the RIP processing proxy request unit 114 of the control unit 110 executes offload processing. The offload process is a process of requesting another image device to perform the proxy process of the RIP process.

  FIG. 6 is a flowchart showing the content of the offload processing according to the embodiment. In step S610, the search processing unit 115 of the image forming apparatus 100a executes offload destination search processing. In the offload destination search process, the search processing unit 115 of the control unit 110 selects the RIP process offload process (alternative process) from the two image forming apparatuses 100b and 100c connected to the image forming apparatus 100a via the LAN 30. Search for a device capable of processing.

  Specifically, the search processing unit 115 transmits an inquiry notification including the consumed memory information indicating the predicted consumed memory amount to at least two image forming apparatuses 100b and 100c as other image forming apparatuses. In response to the reception of the inquiry notification, the storage area management unit 111 of the two image forming apparatuses 100b and 100c, in the main memory 113 of the image forming apparatus 100b and 100c, performs the RIP process on the memory amount represented by the consumed memory information. It is determined whether or not allocation is possible. The search processing unit 115 of the image forming apparatuses 100b and 100c returns a notification that allocation is possible to the inquiry notification, based on the determination that allocation is possible.

  In step S620, when the control unit 110 of the image forming apparatus 100a can detect an available image forming apparatus, the process proceeds to step S630 (print job transmission), and the available image forming apparatus cannot be detected. If so, the image forming apparatus 100a executes the RIP process (step S640). In this example, it is assumed that the image forming apparatus 100b has been searched.

  In step S630, the RIP process proxy request unit 114 of the image forming apparatus 100a executes a print job transmission process. In the print job transmission process, the RIP processing proxy request unit 114 of the image forming apparatus 100a transmits the print job to the image forming apparatus 100b. The image forming apparatus 100b transmits a reception completion notification to the image forming apparatus 100a in response to completion of reception of the print job. The control unit 110 of the image forming apparatus 100a stores the setting of the offload flag, the offload destination of the print job, and the information specifying the print job in the storage unit 140 based on the reception completion notification. The setting of the offload flag is a process of setting a flag indicating whether or not the offload process is requested during the restart.

  In step S650, control unit 110 of image forming apparatus 100a executes a restart process in response to the completion of storage in storage unit 140. As a result, the image forming apparatus 100a can eliminate the memory leak, which is the cause of the shortage of free memory, by the restart process. On the other hand, the image forming apparatus 100b executes the offload destination processing (step S900) in parallel with the restart processing of the image forming apparatus 100a.

  FIG. 7 is a flowchart showing the content of the offload destination processing according to the embodiment. In step S910, the image forming apparatus 100b executes print job reception processing. In the print job receiving process, the image forming apparatus 100b receives the print job from the image forming apparatus 100a.

  In step S920, the RIP processing unit 130 of the image forming apparatus 100b starts the RIP processing. The control unit 110 starts compression of the RIP data using the compression / expansion process. When the compression of the RIP data is completed, the control unit 110 waits until the restart of the image forming apparatus 100a is completed (step S930).

  On the other hand, the control unit 110 of the image forming apparatus 100a confirms the setting of the offload flag of the storage unit 140 according to the completion of the restart of the image forming apparatus 100a. When the setting of the offload flag indicates that the offload processing is requested during the restart, the search processing unit 115 of the image forming apparatus 100 a reads the offload destination of the print job from the storage unit 140. Then, the restart completion notification is transmitted to the offload destination (see step S660 in FIG. 6).

  In step S940 (see FIG. 7), control unit 110 of image forming apparatus 100b receives the restart completion notification. In step S950, the RIP processing unit 130 of the image forming apparatus 100b transmits the RIP data to the image forming apparatus 100a.

  The RIP processing unit 130 of the image forming apparatus 100a sets the size of the buffer area based on the predicted memory consumption amount, and secures the buffer area of the set size. The RIP processing unit 130 receives the RIP data using the buffer area (step S670 in FIG. 6) and provides the image forming unit 160 with the RIP data that is dot data. Note that decompression of RIP data is performed using a compression / decompression process.

  In step S700 (see FIG. 5), the image forming unit 160 executes image output processing. In the image output process, the image forming unit 160 forms an image on a print medium (not shown) based on the dot data and discharges it. In the present embodiment, the image forming unit 160 forms an image on a print medium (not shown) based on the image data ID or the print job received from the personal computer 20 and discharges the image.

  As described above, the distributed printing system 10 according to the present exemplary embodiment estimates the memory amount used in the processing of the print job of the one image forming apparatus 100a and compares the estimated memory amount with the available memory amount. When the shortage is predicted, the RIP processing can be offloaded to another image forming apparatus 100 (the image forming apparatus 100b in the above example).

  Further, the distributed printing system 10 can restart the one image forming apparatus 100a in parallel with the offload processing of the RIP processing in the other image forming apparatus 100b to solve the problem of the memory leak. . Thereby, the distributed printing system 10 can execute the printing process while solving the problem of the memory leak without spending excessive time.

  In addition, the user is not required to restart manually to eliminate the memory leak, and the restart is performed in parallel with the RIP processing of a large job that requires a long time for the RIP processing, so efficient operation is possible. Can be realized. In particular, when the post-processing device 40 is connected to the image forming apparatus 200 and the image forming job requests the execution of the post-processing, the post-processing can be executed, so that the convenience can be remarkably improved. it can.

  The present invention can be implemented not only in the above embodiment but also in the following modified examples.

  Modification: In the above-described embodiment, the image forming apparatus employs the Linux (registered trademark) kernel as the operating system, but the operating system is not necessarily limited to the Linux (registered trademark) kernel, and other operating systems are employed. Good.

10 distributed printing system 100 image forming apparatus 110 control unit 111 storage area management unit 112 memory management unit (MMU)
113 main memory 115 search processing unit 120 image reading unit 130 RIP processing unit 131 PDL analysis unit 132 color conversion processing unit 133 halftone processing unit 140 storage unit 141 program storage area 142 swap area 143 BOX area 150 communication interface unit 160 image forming unit

Claims (7)

An image forming apparatus that can be used for distributed image forming processing,
A storage unit having a predetermined storage area,
A RIP processing unit that executes a RIP process for generating dot data representing a dot formation state on an image forming medium;
In response to the reception of the image forming job, a consumed memory amount that is a memory amount used for executing the RIP process is predicted based on the image forming job, and the consumed memory amount is the RIP process in the predetermined storage area. A storage area management unit that determines whether or not it can be allocated to
A search processing unit that searches for at least one other image forming apparatus capable of executing the RIP processing with the consumed memory amount according to the determination that the allocation is not possible;
The image forming job is transmitted to the other searched image forming apparatus to request the RIP processing on behalf of the other image forming apparatus, the restart of the image forming apparatus is started after the request, and after the restart is completed. A RIP processing proxy request unit that notifies the other image forming apparatus that has been searched of the completion of the restart, and receives the dot data from the other image forming apparatus that has been searched;
An image forming unit that reproduces an image by forming dots on an image forming medium based on the received dot data,
An image forming apparatus including. The image forming apparatus according to claim 1, wherein
The search processing unit transmits, to the at least one other image forming apparatus, an inquiry notification including consumption memory information indicating the consumption memory amount, in response to the determination that the allocation is not possible.
In response to receiving the inquiry notification, the storage area management unit determines whether the consumed memory information can be allocated to the RIP process in the predetermined storage area,
The image forming apparatus, wherein the search processing unit returns a notification that the allocation is possible to the inquiry notification, based on the determination that the allocation is possible. The image forming apparatus according to claim 1, wherein
The RIP processing unit sets a size of a buffer area based on the consumed memory amount, secures a buffer area of the set size, and uses the secured buffer area to retrieve another image. An image forming apparatus that provides the dot data received from a forming apparatus to the image forming unit. The image forming apparatus according to any one of claims 1 to 3, wherein:
The image forming apparatus, a post-processing device for performing post-processing is connected to the image forming medium on which an image is formed,
The image forming apparatus is an image forming apparatus that requests execution of the post-processing.   A distributed image forming system comprising a plurality of image forming apparatuses according to claim 1 and performing a distributed image forming process. An image forming method for performing a distributed image forming process using a storage unit having a predetermined storage area,
A RIP process step of executing a RIP process for generating dot data representing a dot formation state on an image forming medium;
In response to the reception of the image forming job, a consumed memory amount that is a memory amount used for executing the RIP process is predicted based on the image forming job, and the consumed memory amount is the RIP process in the predetermined storage area. A storage area management step of determining whether or not it can be allocated to
A search processing step of searching for at least one other image forming apparatus capable of executing the RIP processing with the consumed memory amount in accordance with the determination that the allocation is not possible;
The image forming job is transmitted to the other searched image forming apparatus to request the RIP processing on behalf of the other image forming apparatus, the restart of the image forming apparatus is started after the request, and after the restart is completed. A RIP processing proxy request step of notifying the other image forming apparatus searched out of the completion of the restart and receiving the dot data from the other image forming apparatus searched out;
An image forming step of forming dots on an image forming medium based on the received dot data to reproduce an image. An image forming program for controlling an image forming apparatus, which comprises a storage unit having a predetermined storage area and can be used for distributed image forming processing,
A RIP processing unit that executes a RIP process for generating dot data representing a dot formation state on an image forming medium,
In response to the reception of the image forming job, a consumed memory amount that is a memory amount used for executing the RIP process is predicted based on the image forming job, and the consumed memory amount is the RIP process in the predetermined storage area. Storage area management unit that determines whether or not it can be allocated to
A search processing unit that searches for at least one other image forming apparatus capable of executing the RIP processing with the consumed memory amount according to the determination that the allocation is not possible,
The image forming job is transmitted to the other searched image forming apparatus to request the RIP processing on behalf of the other image forming apparatus, the restart of the image forming apparatus is started after the request, and after the restart is completed. Based on the received dot data, a RIP processing proxy request unit that notifies the other image forming apparatuses that have been searched of the completion of the restart and receives the dot data from the other image forming apparatuses that have been searched. An image forming program that causes the image forming apparatus to function as an image forming unit that forms dots on an image forming medium to reproduce an image.

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