JP2017061105A - Image forming device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which forms an image on a belt-like medium and prevents the medium from being output without an image formed thereon.SOLUTION: Conveying means 201 conveys a belt-like medium (for example, continuous paper). First image forming means 202a and second image forming means 202b are arranged on a conveyance passage of the medium in series, and form an image on the medium conveyed on the conveyance passage. Receiving means 203 receives an instruction for forming an image on the medium. Allocating means 204 allocates image forming processing corresponding to the instruction received by the receiving means 203 to the first image forming means 202a and the second image forming means 202b. The allocating means 204 allocates a processing amount which does not exceed a processing amount allocated to the first image forming means 202, to the second image forming means 202b arranged downstream of the first image forming means 202a.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus and a program.

  Various printing apparatuses that print on continuous paper have been proposed. For example, Patent Document 1 can be configured such that the first engine first prints on continuous paper, and the second engine continuously prints on the same surface of the continuous paper discharged from the first engine. The print control device that controls each engine has the same number of pages on the same side of the continuous paper by using the first engine for printing odd pages and the second engine for printing even pages. A printing apparatus having means for printing over a page is described.

Japanese Patent Laid-Open No. 2004-219862

  SUMMARY An advantage of some aspects of the invention is that an image forming apparatus that forms an image on a belt-like medium prevents an image from being output without being formed on the medium.

  According to a first aspect of the present invention, there is provided an image forming apparatus including a conveying unit configured to convey a belt-shaped medium and a plurality of media that are provided in series with the medium conveying path and that form an image on the medium conveyed to the conveying path. An image forming unit, a receiving unit that receives an instruction to form an image on the medium, and a unit that allocates an image forming process of the received instruction to the plurality of image forming units, and allocates to the first image forming unit And an allocating unit that allocates a processing amount not exceeding the processing amount to a second image forming unit provided downstream of the first image forming unit in the conveyance path.

  An image forming apparatus according to a second aspect of the present invention is the configuration according to the first aspect, further comprising a monitoring unit that monitors a processing status of the first image forming unit, and the allocation unit includes the first allocation unit. When the processing status of the image forming unit satisfies a predetermined condition, the processing allocated to the first image forming unit is allocated to the second image forming unit.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the allocating unit has a predetermined period during which the second image forming unit is not performing image forming processing. The allocation is performed so as to be less than a threshold value.

  An image forming apparatus according to a fourth aspect of the present invention is the configuration according to any one of the first to third aspects, wherein the first image forming unit and the second image forming unit have a plurality of colors. When a process assigned to the first image forming unit is executed by performing image formation using a color material, the total amount of the color material to be fixed on the medium by the first image forming unit is determined in advance. And calculating means for calculating each unit area, wherein the allocating means performs processing for at least one of the allocated processes when the total amount exceeds a predetermined threshold value. The image forming means is assigned to the image forming means.

  An image forming apparatus according to a fifth aspect of the present invention is the image processing apparatus according to any one of the first to fourth aspects, wherein the allocating unit supplies an image size of image data supplied to the second image forming unit. Is smaller than the image size of the image data supplied to the first image forming means.

  An image forming apparatus according to a sixth aspect of the present invention is the configuration according to any one of the first to fifth aspects, wherein the plurality of image forming means includes a plurality of second image forming means, The allocating unit performs processing allocation so that the processing amount allocated to the second image forming unit provided on the downstream side of the plurality of second image forming units is larger. .

  According to a seventh aspect of the present invention, there is provided a program for forming a plurality of images, which is provided in series with a transport unit that transports a belt-shaped medium and a transport path of the medium, and forms an image on the medium transported to the transport path. A step of accepting an image forming instruction to the medium and a step of allocating an image forming process of the accepted instruction to the plurality of image forming means to a first image forming means. And a step of allocating a processing amount not exceeding the processing amount to be allocated to a second image forming unit provided on the downstream side of the transport path from the first image forming unit.

According to the first and seventh aspects of the present invention, in an image forming apparatus that forms an image on a belt-shaped medium, it is possible to suppress an image from being output without being formed on the medium.
According to the second aspect of the present invention, when the processing status of the first image forming unit satisfies a predetermined condition, the image is output without being formed on the medium as compared with the case where the reassignment is not performed. This can be suppressed.
According to the third aspect of the present invention, it is possible to suppress the occurrence of color material clogging in the second image forming means.
According to the invention which concerns on Claim 4, deterioration of the quality of the image formed can be suppressed.
According to the invention which concerns on Claim 5, deterioration of the quality of the image formed can be suppressed.
According to the sixth aspect of the present invention, it is possible to prevent the image from being output without being formed on the medium, as compared with the case where the allocation is not performed so that the processing amount assigned to the downstream image forming unit is larger. be able to.

Block diagram showing the configuration of the system 1 Schematic diagram showing the configuration of the image forming unit 23 The figure which shows the function structure of the image forming apparatus 20. The figure which shows the hardware constitutions of the image forming apparatus 20 Processing block diagram of the image forming apparatus 20 The flowchart which shows the flow of a process of the process management part 212. The flowchart which shows the flow of a process of the image generation part 213. The flowchart which shows the flow of a process of the output control part 215. The flowchart which shows the flow of a process of the output process parts 231a and 232a. The flowchart which shows the flow of a process of the image generation part 213. The flowchart which shows the flow of a process of the output control part 215. Print processing time chart Block diagram showing an example of a configuration using an external image processing apparatus

[1] Configuration FIG. 1 is a block diagram showing a configuration of a system 1 according to the present embodiment. The system 1 includes a host 10 and an image forming apparatus 20. The host 10 is a device that outputs a print processing instruction to the image forming apparatus 20. The image forming apparatus 20 has a print function and forms an image on a medium according to an electrophotographic method. The image forming apparatus 20 may have a copy function and a facsimile function in addition to the print function.

  The image forming apparatus 20 includes a first controller 21, a second controller 22, and an image forming unit 23. The first controller 21 includes a reception unit 211, a process management unit 212, an image generation unit 213, a raster storage unit 214, an output control unit 215, and an output buffer 216. The receiving unit 211 receives various instructions such as a print processing instruction from the host 10. The process management unit 212 manages processes instructed by the host 10. The image generation unit 213 performs RIP (Raster Image Processor) processing on drawing data described in PDL (Page Description Language) to generate raster data indicating a raster image for each color material. The raster storage unit 214 stores raster data generated by the image generation unit 213. The output control unit 215 moves the raster data stored in the raster storage unit 214 to the output buffer 216.

  The second controller 22 includes an image generation unit 223, a raster storage unit 224, an output control unit 225, and an output buffer 226. The image generation unit 223 performs RIP processing on the drawing data described in PDL to generate raster data for each color material. The raster storage unit 224 stores raster data generated by the image generation unit 223. The output control unit 225 moves the raster data stored in the raster storage unit 224 to the output buffer 226.

  The image forming unit 23 includes a first engine unit 231 and a second engine unit 232. The first engine unit 231 and the second engine unit 232 are provided in series on the continuous paper conveyance path, and form an image on the continuous paper (medium) conveyed to the conveyance path in accordance with the supplied raster data. The output processing unit 231a supplies the raster data buffered in the output buffer 216 to the first engine unit 231. The output processing unit 232 a supplies the raster data buffered in the output buffer 226 to the second engine unit 232.

  FIG. 2 is a schematic diagram illustrating an example of the configuration of the image forming unit 23. The image forming unit 23 includes a first engine unit 231, a second engine unit 232, a pre-processing device 233, a post-processing device 234, a buffer device 235, a buffer device 236, and a buffer device 237. The preprocessing device 233 supplies continuous paper as a medium to the first engine unit 231 and the second engine unit 232. The continuous paper is conveyed in the direction of arrow P. In this example, the continuous paper is a belt-like medium having a sheet shape and a long shape in a transport direction (hereinafter referred to as “transport direction”) P. The continuous paper is transported in a continuous manner from a place where it is supplied (pre-processing device 233) to a place where an image is formed and stored (post-processing device 234).

  Each of the first engine unit 231 and the second engine unit 232 applies four types of toners (color materials) whose colors are yellow (Y), magenta (M), cyan (C), and black (K), respectively, to a sheet or the like. A color image is formed by fixing on a medium. In each of the first engine unit 231 and the second engine unit 232, a photosensitive drum, a charging device, a developing unit, and a primary transfer roll are provided on the intermediate transfer belt for each of Y, M, C, and K colors. It is provided along. The photosensitive drum holds an electrostatic latent image and a toner image formed on the surface. The surface of the photosensitive drum is charged to a predetermined potential by a charging device. The exposure unit irradiates (exposes) the surface of the charged photosensitive layer with light (exposure light) whose intensity and irradiation position are controlled according to the image data, and forms an electrostatic latent image representing the image indicated by the image data To do. The developing unit supplies a developer containing charged toner to the photosensitive drum to develop the electrostatic latent image into a toner image. The primary transfer roll is provided so as to sandwich the intermediate transfer belt at a position facing the photosensitive drum. Due to the voltage applied to the primary transfer roll and the photosensitive drum, a potential difference is generated between the photosensitive drum and the intermediate transfer belt, and the charged toner moves to the intermediate transfer belt. The toner image primarily transferred to the intermediate transfer belt is secondarily transferred to the medium, whereby a toner image is formed on the medium. The toner image formed on the medium is heated and fixed on the medium by the fixing unit.

  Note that the image forming unit 23 of the image forming apparatus 20 may form an image by an ink jet method that employs an ink (developer) as a developer instead of the configuration that employs the electrophotographic method. In this case, the portion where the ink is applied is dried by heating.

  In this example, the first engine unit 231 is provided on the upstream side of the second engine unit 232 in the continuous paper conveyance path. The output controller 215 of the first controller 21 controls the supply of raster data to the first engine unit 231. The output control unit 225 of the second controller 22 controls the supply of raster data to the second engine unit 232. By conveying the continuous paper to the conveyance path, an image is formed on the continuous paper by the first engine unit 231 and / or the second engine unit 232 provided in series on the conveyance path.

  In this example, the print processing instructed by the host is executed in a shared manner by the first engine unit 231 and the second engine unit 232. That is, the process management unit 212 assigns which engine performs the image forming process in units of pages, and the first engine unit 231 and the second engine unit 232 execute the assigned image forming process.

  The post-processing device 234 performs post-processing such as winding the medium on which the image is formed. The buffer device 235 is disposed between the preprocessing device 233 and the first engine unit 231, temporarily stores continuous paper discharged from the preprocessing device 233, and the preprocessing device 233 and the first engine unit 231 are continuous paper. It is a device that absorbs the deviation in the speed at which the material is conveyed. The buffer device 236 is disposed between the first engine unit 231 and the second engine unit 232, temporarily stores continuous paper discharged from the first engine unit 231, and stores the first engine unit 231 and the second engine unit 231. Reference numeral 232 denotes a device that absorbs a shift in speed at which continuous paper is conveyed. The buffer device 237 is disposed between the second engine unit 232 and the post-processing device 234, temporarily stores continuous paper discharged from the second engine unit 232, and the second engine unit 232 and the post-processing device 234 are continuous. It is a device that absorbs deviations in the speed of conveying paper.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the image forming apparatus 20. The image forming apparatus 20 includes a conveying unit 201, a first image forming unit 202a, a second image forming unit 202b, a receiving unit 203, an allocating unit 204, a monitoring unit 205, and a calculating unit 206. . The transport unit 201 transports a belt-shaped medium. The first image forming unit 202a and the second image forming unit 202b are provided in series in the medium conveyance path, and form an image on the medium conveyed in the conveyance path. In this example, the first image forming unit 202a is provided on the upstream side of the second image forming unit 202b in the medium conveyance path. The accepting unit 203 accepts an instruction to form an image on the medium. The allocation unit 204 allocates the image forming process of the instruction received by the receiving unit 203 to the first image forming unit 202a and the second image forming unit 202b. The allocating unit 204 applies a processing amount not exceeding the processing amount allocated to the first image forming unit 202a to the second image forming unit 202b provided on the downstream side of the conveyance path from the first image forming unit 202a. Allocate.

  The monitoring unit 205 monitors the processing status of the first image forming unit 202a. The calculation unit 206 calculates, for each predetermined unit area, the amount of color material that the first image forming unit 202a fixes on the medium when the process assigned to the first image forming unit 202a is executed. .

  FIG. 4 is a diagram illustrating a hardware configuration of the image forming apparatus 20. The image forming apparatus 20 includes a CPU (Central Processing Unit) 251, a memory 252, a storage device 253, a communication IF 254, a UI device 255, and a print IF 256. The CPU 251 is a control device (processor) that controls each unit of the image forming apparatus 20. The memory 252 is a volatile storage device that functions as a work area when the CPU 251 executes a program. The storage device 253 is a non-volatile storage device that stores programs and data. The communication IF 254 is an interface for performing communication via a communication line such as the Internet, a mobile communication network, and a telephone line. The UI device 255 includes, for example, a touch screen and keys. The print IF 256 is an interface for communicating with the image forming unit 23.

  In this example, when the CPU 251 executes the program stored in the storage device 253, the functions shown in FIG. 3 are implemented. The CPU 251 executing the program is an example of the accepting unit 203, the allocating unit 204, the monitoring unit 205, and the calculating unit 206. The first engine unit 231 is an example of the first image forming unit 202a, and the second engine unit 232 is an example of the second image forming unit 202b. The preprocessing device 233 is an example of the transport unit 201.

  FIG. 5 is an example of a processing block diagram of the image forming apparatus 20. In the figure, the image generation unit 213 includes a RIP processing unit 31, a raster management unit 32, and a raster generation speed management unit 33. The RIP processing unit 31 performs RIP processing on the drawing data to generate raster data. The converted raster data is stored in the raster storage unit 214. The raster generation speed management unit 33 monitors the generation speed of raster data. In this example, the raster generation speed management unit 33 measures the time until the image generation unit 213 generates raster data for one page and the writing to the raster storage unit 214 is completed. The raster management unit 32 determines whether the image generation unit 213 has generated raster data at a speed commensurate with the processing speed of the first engine unit 231. If the raster data cannot be generated, the raster management unit 32 allocates image formation processing for the page. Process to fix.

  The output control unit 215 includes an output management unit 51 and an output speed management unit 52. The output speed management unit 52 monitors the output speed of raster data. In this example, the output speed management unit 52 measures the time from the start of the process of reading out raster data for one page from the raster storage unit 214 until the writing to the output buffer 216 is completed. The output management unit 51 determines whether the output control unit 215 has been able to transfer data at a speed commensurate with the processing speed of the first engine unit 231. If the data transfer has not been performed, the output management unit 215 allocates image formation processing for the page. Process to redo.

  The image generation unit 223 corresponds to the RIP processing unit 31, the raster management unit 32, and the raster generation speed management unit 33 described above, and has a common function, such as an RIP processing unit 34, a raster management unit 35, and a raster generation speed management. Part 36 is provided. The output control unit 225 includes an output management unit 53 and an output speed management unit 54 that correspond to the output management unit 51 and the output speed management unit 52, respectively, and have common functions.

[2] Operation [2-1] Operation example 1
FIG. 6 is a flowchart showing a process flow of the process management unit 212. In step S101, the process management unit 212 determines whether an instruction for print processing has been received. If it is determined that it has been received, the process management unit 212 proceeds to the process of step S102. On the other hand, if it is determined that it has not been received, the process management unit 212 returns to the process of step S101 and waits until an instruction is received.

  In step S102, the process management unit 212 performs process allocation in accordance with preset distribution conditions. In this example, the process management unit 212 performs process allocation in units of pages in accordance with predetermined distribution conditions, and generates an image generation unit 213 corresponding to the first engine unit 231 and an image generation corresponding to the second engine unit 232. Request the RIP processing of the allocated image forming processing to the unit 223.

  In this example, the processing management unit 212 allocates a processing amount not exceeding the processing amount allocated to the first engine unit 231 to the second engine unit 232 on the downstream side. For example, when the processing amount is the number of pages, the processing management unit 212 may perform the allocation so that the number of processing pages allocated to the second engine unit 232 is smaller than the number of processing pages allocated to the first engine unit 231. Good. More specifically, for example, the process management unit 212 may distribute the ratio of the number of pages allocated to the first engine unit 231 and the number of pages allocated to the second engine unit 232 to be 3: 2. . When the process management unit 212 finishes the process of step S102, the process management unit 212 returns to the process of step S101 and waits until the next instruction is received.

  FIG. 7 is a flowchart showing a flow of processing performed by the image generation unit 213. In step S <b> 201, the image generation unit 213 determines whether a process in units of pages (hereinafter referred to as “page processing”) is requested from the process management unit 212. If it is determined that the request has been made (step S201; YES), the image generation unit 213 proceeds to the process of step S202. On the other hand, when it is determined that there is no request (step S201; NO), the image generation unit 213 returns to the process of step S201 and waits until a page process is requested.

  In step S202, the image generation unit 213 determines whether the raster storage unit 214 has a predetermined free space. If it is determined that there is free space (step S202; YES), the image generation unit 213 proceeds to the process of step S203. On the other hand, when it is determined that there is no free space in the raster storage unit 214 (step S202; NO), the image generation unit 213 returns to the process of step S202, and a predetermined free space is generated in the raster storage unit 214. Wait until.

  In step S203, the image generation unit 213 performs RIP processing on the supplied drawing data to generate raster data. The generated raster data is stored in the raster storage unit 214. When the process of step S203 is completed, the image generation unit 213 returns to the process of step S201 and waits until the next request is made.

  The image generation unit 223 also performs the same process as the image generation unit 213 illustrated in FIG. That is, the image generation unit 223 determines whether there is a predetermined free space in the raster storage unit 224 when there is a request for page processing. If there is free space, the image generation unit 223 performs RIP processing on the drawing data. To generate raster data. The generated raster data is stored in the raster storage unit 224.

  FIG. 8 is a flowchart showing the flow of processing performed by the output control unit 215. In step S <b> 301, the output control unit 215 determines whether data is stored in the raster storage unit 214. If it is determined that data is stored in the raster storage unit 214 (step S301; YES), the output control unit 215 proceeds to the process of step S302. On the other hand, if it is determined that no data is stored in the raster storage unit 214 (step S301; NO), the output control unit 215 returns to the process of step S301 and waits until data is stored in the raster storage unit 214. To do.

  In step S302, the output control unit 215 determines whether the output buffer 216 has a predetermined free space. If it is determined that there is free space, the output control unit 215 proceeds to the process of step S303. On the other hand, if it is determined that there is no free space, the output control unit 215 returns to the process of step S302 and waits until free space is generated in the output buffer 216.

  In step S <b> 303, the output control unit 215 reads raster data from the raster storage unit 214 and moves the raster data to the output buffer 216. In step S304, the output control unit 215 determines whether all raster data stored in the raster storage unit 214 has been moved. If it is determined that the data has been moved (step S304; YES), the output control unit 215 returns to the process of step S301 and waits until data is stored in the raster storage unit 214. On the other hand, when it is determined that there is raster data that has not been moved (step S304; NO), the output control unit 215 returns to the process of step S302 and performs a process for moving the raster data to the output buffer 216. .

  The output control unit 225 also performs the same processing as the output control unit 215 shown in FIG. That is, the output control unit 225 determines whether there is a predetermined free capacity in the output buffer 226 when raster data is stored in the raster storage unit 224. If it is determined that there is free space, the output control unit 225 moves the raster data from the raster storage unit 224 to the output buffer 226.

  FIG. 9 is a flowchart showing a flow of processing performed by the output processing unit 231a. In step S401, the output processing unit 231a determines whether data transfer is requested from the first engine unit 231. If it is determined that there is a transfer request (step S401; YES), the output processing unit 231a proceeds to the process of step S402. On the other hand, when it is determined that there is no transfer request (step S401; NO), the output processing unit 231a returns to the process of step S401 and waits until a transfer request is made from the first engine unit 231.

  In step S <b> 402, the output processing unit 231 a reads raster data from the output buffer 216 and transfers the raster data to the first engine unit 231. The first engine unit 231 forms an image on the conveyed continuous paper according to the supplied raster data. The continuous paper on which the image is formed is conveyed to the second engine unit 232 along the conveyance path.

  The output processing unit 232a also performs the same process as the output processing unit 232a shown in FIG. That is, when there is a data transfer request from the second engine unit 232, the output processing unit 232 a reads raster data from the output buffer 226 and transfers it to the second engine unit 232. In the second engine unit 232, an image is formed on the conveyed continuous paper according to the supplied raster data. In this way, an image is formed on continuous paper by the first engine unit 231 and the second engine unit 232.

  By the way, in the conventional apparatus, when an image is formed on continuous paper such as fanfold paper or roll paper, if the processing of the controller is not in time for the processing of the printer engine, the continuous paper is not transferred until the conveyance of the continuous paper is stopped. The image is output in a blank state (that is, an image is not formed). In order not to generate extra blank paper, it is necessary to stop the continuous paper transport device immediately when the processing of the controller lags behind the processing of the printer engine, but immediately stops the transport device that is operating This is difficult due to mechanical inertia and the like. The extra blank paper becomes useless, and it is necessary to perform an operation for removing the blank paper or to execute the printing process again in some cases. In contrast, in this embodiment, the processing of the controller may not be in time for the processing of the engine by distributing the processing so that the processing amount assigned to the upstream engine is larger than that of the downstream engine. It is suppressed.

[2-2] Operation example 2
FIG. 10 is a flowchart showing the flow of processing performed by the image generation unit 213 in this operation example. Of the processes shown in FIG. 10, the processes shown in steps S201 to S203 are the same as those shown in FIG. Note that, in this embodiment as well, the image generation unit 223 executes the process of FIG. 7 as in the first embodiment described above.

  In FIG. 10, when the image generating unit 213 finishes the process of step S203, the process proceeds to the process of step S204. In step S204, the image generation unit 213 determines whether raster data has been generated at a speed commensurate with the engine performance, that is, whether the RIP process is in time for the engine performance. In this example, “RIP processing is in time for engine performance” means that the image generation unit 213 generates raster data for one page and saves it within a period during which the first engine unit 231 forms an image for one page. This means that writing to the unit 214 has been completed. In this example, whether the RIP processing interval is longer is determined by comparing the interval for each page of the RIP processing with the interval for each page of the image forming processing by the first engine unit 231. Determined by whether or not. Note that the determination method is not limited to this. As another example of the determination, the image generation unit 213 may determine whether or not the number of pages of raster data stored in the raster storage unit 214 is equal to or less than a predetermined threshold.

  If it is determined in step S204 that raster generation has been performed at a speed commensurate with engine performance (step S204; YES), the image generation unit 213 returns to the process of step S201 and waits until the next processing request is accepted. On the other hand, when it is determined that the raster data cannot be generated at a speed that matches the engine performance (step S204; NO), the image generation unit 213 performs the image forming process for the page with the downstream engine in step S205. A request is made to reallocate to a certain second engine unit 232.

  In this example, the image generation unit 213 requests the output control unit 215 to reallocate the processing allocated to the upstream first engine unit 231 to the downstream second engine unit 232. The output control unit 215 transmits a processing request to the output control unit 225. When there is a predetermined free space in the output buffer 226 so that the second engine unit 232 performs image formation processing of the requested page, the output control unit 225 sends raster data from the raster storage unit 214 to the output buffer 226. Forward. The output processing unit 232 a stands by until a transfer request from the second engine unit 232 is received. When the transfer request is made, the raster data is read from the output buffer 226 and supplied to the second engine unit 232. In the second engine unit 232, an image is formed on the conveyed continuous paper according to the supplied raster data.

  If it is determined that the raster cannot be generated at a speed that matches the engine performance, the output control unit 225 does not transfer the raster data from the raster storage unit 214 to the output buffer 226, but the processing management unit 212 does not transfer the raster data. The RIP processing unit 34 of 223 may be directly instructed to execute from the generation of the raster data. The processing management unit 212 cannot perform raster generation at a speed that matches the engine performance of the first engine unit 231, but generates a raster at a speed that matches the engine performance of the second engine unit 232. If it is determined that the data can be processed, the raster data may be transferred from the raster storage unit 214 to the output buffer 226. In addition, when the process management unit 212 determines that the raster generation is faster by the RIP processing unit 34 of the image generation unit 223 than when the raster data is transferred from the raster storage unit 214 to the output buffer 226, the processing is completed. The RIP processing unit 34 may be instructed to generate the raster data described above.

  When the process of step S205 is completed, the image generation unit 213 returns to the process of step S201 and waits until a request for the next process is received.

  FIG. 11 is a flowchart showing the flow of processing performed by the output control unit 215 in this operation example. Among the processes shown in FIG. 11, the processes shown in steps S301 to S304 are the same as those shown in FIG. Note that the output control unit 225 also executes the process of FIG. 8 in this embodiment as in the first embodiment described above.

  In FIG. 11, when the output control unit 215 finishes the process of step S303, the process proceeds to the process of step S305. In step S <b> 305, the output control unit 215 determines whether data movement has been performed at a speed commensurate with engine performance. In this example, “data transfer is in time for engine performance” means that the output control unit 215 reads out raster data for one page from the raster storage unit 214 and outputs it while the engine forms an image for one page. This means that data could be written to the buffer 216. In this example, whether or not it is in time is determined by the output control unit 215 for each page in which the raster data is read from the raster storage unit 214 and transferred to the output buffer 216, and the image forming process by the first engine unit 231. This is compared with the interval for each page, depending on whether or not the data transfer interval is longer. Note that the determination method is not limited to this. As another example of the determination, for example, the output control unit 215 may determine whether or not the number of pages of raster data stored in the output buffer 216 is equal to or less than a predetermined threshold.

  In step S305, when it is determined that the data can be transferred at a speed commensurate with the engine performance (step S305; YES), the output control unit 215 proceeds to the process of step S304. On the other hand, when the data cannot be moved (step S305; NO), the output control unit 215 proceeds to the process of step S306. In step S306, the output control unit 215 requests that the image forming process for the page be reassigned to the second engine unit 232 on the downstream side.

  In this example, the output control unit 215 transmits a processing request to the output control unit 225. The output control unit 225 instructs the output processing unit 232a to perform image formation processing so that the second engine unit 232 performs image formation processing of the requested page. The output processing unit 232 a stands by until a transfer request from the second engine unit 232 is received. When a transfer request is made, the raster data is read from the output buffer 216 and supplied to the second engine unit 232. In the second engine unit 232, an image is formed on the conveyed continuous paper according to the supplied raster data.

  FIG. 12 is a diagram illustrating an example of a time chart of the image forming process according to the present embodiment. FIG. 12 illustrates a chart in the case where a delay with respect to the first engine unit 231 of the first controller 21 is detected for the processing of the page p31. When the delay is detected, the image generation unit 213 performs processing to redistribute the processing of the page p31 allocated to the upstream first engine unit 231 to the downstream second engine unit 232. The second engine unit 232 on the downstream side executes the image forming process for the page p31 in accordance with an instruction from the output control unit 225.

  In FIG. 11, when the process of step S306 is completed, the output control unit 215 proceeds to the process of step S304.

  By the way, the time required for the printing process varies depending on the contents of the drawing data to be processed, and the actual situation is that it will not be understood how long it will take unless it is actually processed. Depending on the content of the instructed image forming process, it may take an unexpected time to process the page. In addition, the time required for the printing process varies depending not only on the speed of the RIP process but also on the access speed of hardware such as a hard disk for processing. For example, the processing of a specific page may take time due to a malfunction of the hard disk drive.

  Here, in order to suppress the processing delay of the controller with respect to the engine, it is conceivable to secure the processing speed of the controller by additionally using an external image processing apparatus. For example, as shown in FIG. 13, it is conceivable to use an external RIP processing unit 239. However, even if an external image processing apparatus is used after it has been detected that the processing is not in time, there is a large overhead such as the start of processing and collection of the created image, and it may be difficult to actually make it in time.

  In this operation example, the processing time is measured for each page, and it is determined whether the processing of the first controller 21 is in time for the image forming processing timing in the first engine unit 231, and if not, the second engine unit 232 is informed. Processing is allocated. Thereby, it is suppressed that the process of a controller is not in time for the process of an engine.

[3] Modifications The above-described embodiments are merely examples of the present invention, and may be modified as follows. Moreover, you may implement combining embodiment mentioned above and each modification shown below as needed.

(1) In the above-described embodiment, the output controller 215 may calculate the total amount of color materials fixed by the first engine unit 231 on the continuous paper for each predetermined unit area. In this case, the output control unit 215 allocates image forming processing for at least one of the plurality of colors to the second engine unit 232 when the calculated total amount of the color material exceeds a predetermined threshold. In this case, the image forming process for one page is performed by the first engine unit 231 and the second engine unit 232 in a shared manner. For example, the first engine unit 231 performs image formation processing for three colors of yellow, magenta, and cyan, while the second engine unit 232 performs image formation processing for black.

  When the total amount of the color material that is superimposed at one place on the continuous paper exceeds a predetermined amount, the quality of the formed image may be deteriorated. On the other hand, in this modification, the output control unit 215 divides the first engine unit 231 and the second engine unit 232 into one page when the total amount of color material for each unit area exceeds a predetermined threshold. By performing image formation, deterioration of the quality of the formed image is suppressed.

(2) In the above-described embodiment, the processing management unit 212 converts the drawing data supplied to the image generation unit 223 so that the image represented by the drawing data is reduced to a predetermined ratio. Good. That is, the process management unit 212 generates the image so that the size of the image represented by the raster data supplied to the second engine unit 232 is smaller than the image represented by the raster data supplied to the first engine unit 231. The drawing data supplied to the unit 223 may be converted.

  As described above, the toner image of the continuous paper when the image is formed by the electrophotographic method is heated by the fixing unit. Even when the image is formed by the ink jet method, the continuous paper is dried by applying the applied ink. To be heated. And when forming an image by an inkjet system, the continuous paper which passed the 1st engine part 231 shrinks a little by this heating. For example, when the image processing of one page is shared by the first engine unit 231 and the second engine unit 232 for each color, the image formed by the first engine unit 231 is slightly shrunk by heating, so that the second The image formed by the engine unit 232 may be slightly shifted. In this modification, the first controller 21 reduces the image data supplied to the second engine unit 232 in advance, so that even if the image formation of one page is shared by a plurality of engines, the image data Degradation of quality is suppressed.

(3) In the above-described embodiment, the process management unit 212 performs the distribution of the upstream and downstream processes in units of pages. The distribution processing unit is not limited to a page unit. For example, the pages may be allocated in units of bands. As another example, distribution may be performed between a form (fixed data) in a page and variable data.

(4) In the above-described embodiment, the distribution ratio may be dynamically changed. For example, the processing management unit 212 may reduce the processing amount allocated to the second engine unit 232 when the number of pages of drawing data is less than a predetermined threshold.

  Further, the process management unit 212 may allocate the process instructed by the host 10 only to the first engine unit 231 without allocating the process to the second engine unit 232. In this case, the process management unit 212 instructs the image generation unit 213 to perform all the RIP processes of the print process requested from the host 10. The image generation unit 213 and the output control unit 215 perform the same processing as in the second operation example. In other words, the image generation unit 213 assigns the image forming process for the page to the second engine unit 232 when the RIP process cannot keep up with the engine performance. Further, the output control unit 215 assigns the image forming process for the page to the second engine unit 232 when the data transfer process cannot keep up with the engine performance. That is, when the controller process is not in time for the engine process, the process is assigned to the second engine unit 232.

  In the above-described aspect, the process management unit 212 may perform the process allocation so that the period during which the second engine unit 232 is not performing the image forming process is less than a predetermined threshold. In order to increase the margin for recovering the processing by the downstream engine, it is preferable to perform the processing by the upstream engine unless it is unavoidable. However, if there is too little processing on the downstream side, malfunction may occur due to the downstream engine not being used. For example, when an ink jet system is employed for a downstream engine, if the engine is not used for a certain period, the ink nozzles may be clogged due to drying. In this modified example, processing is allocated so that the period during which the second engine unit 232 is not operating does not exceed a predetermined threshold. Thereby, malfunctions such as clogging due to drying of the ink head in the second engine unit 232 on the downstream side are suppressed.

(5) In the above-described embodiment, the example in which the first engine unit 231 and the second engine unit 232 are provided in series in the continuous paper conveyance path has been described. The number of image forming engines provided in the conveyance path is not limited to two. Three or more image forming engines may be provided in series on the continuous paper conveyance path. In this case, when the image forming engine provided on the most upstream side is the first engine and the other image forming engines are the second engine, the process management unit 212 performs the distribution of the process when distributing the processes. The allocation may be performed such that the processing amount allocated to the second engine provided on the downstream side is larger than that of the other second engines. That is, the allocation may be performed such that the greater the distance from the first engine, the larger the processing amount to be allocated. In this case, the longer the distance from the first engine, the longer it takes for the continuous paper to be conveyed and the arrival at the second engine, so that it is possible to prevent the controller process from being in time for the engine process.

(6) The image forming apparatus 20 may be a printer that forms an image by a method other than the electrophotographic method and the inkjet method. The image forming apparatus 20 may form a black and white image or may form a color image.

(7) In the above-described embodiment, the program executed by the CPU 251 of the image forming apparatus 20 may be downloaded via a communication line such as the Internet. The program is provided in a state of being recorded on a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, or a semiconductor memory. May be.

DESCRIPTION OF SYMBOLS 1 ... System, 10 ... Host, 20 ... Image forming apparatus, 21 ... 1st controller, 22 ... 2nd controller, 23 ... Image forming part, 201 ... Conveyance means, 202a ... 1st image forming means, 202b ... 2nd Image forming means, 203 ... accepting means, 204 ... allocating means, 205 ... monitoring means, 206 ... calculating means, 211 ... receiving section, 212 ... processing management section, 213 ... image generating section, 214 ... raster storage section, 215 ... Output control unit, 216 ... Output buffer, 223 ... Image generation unit, 224 ... Raster storage unit, 225 ... Output control unit, 226 ... Output buffer, 251 ... CPU, 252 ... Memory, 253 ... Storage device, 254 ... Communication IF, 255 ... UI device, 256 ... Print IF

Claims (7)

Transport means for transporting a belt-shaped medium;
A plurality of image forming means provided in series with the medium conveyance path, and forming an image on the medium conveyed to the conveyance path;
Receiving means for receiving an instruction to form an image on the medium;
A means for allocating the image forming process of the accepted instruction to the plurality of image forming means, wherein a processing amount not exceeding a processing amount assigned to the first image forming means is greater than that of the first image forming means; And an allocating unit that allocates to a second image forming unit provided on the downstream side of the conveyance path. Monitoring means for monitoring the processing status of the first image forming means;
The allocating unit allocates the process assigned to the first image forming unit to the second image forming unit when the processing status of the first image forming unit satisfies a predetermined condition. The image forming apparatus according to 1. The image forming apparatus according to claim 1, wherein the allocating unit performs the allocation so that a period during which the second image forming unit is not performing an image forming process is less than a predetermined threshold. The first image forming unit and the second image forming unit perform image formation using color materials of a plurality of colors,
Calculating means for calculating, for each predetermined unit area, a total amount of color material to be fixed to the medium by the first image forming means when processing assigned to the first image forming means is executed; Have
The allocation unit allocates a process for at least one of the allocated processes to the second image forming unit when the total amount exceeds a predetermined threshold value. The image forming apparatus according to claim 1. 5. The allocation means makes the size of the image data supplied to the second image forming means smaller than the size of the image data supplied to the first image forming means. 6. The image forming apparatus according to claim 1. The plurality of image forming units include a plurality of the second image forming units,
2. The allocation unit performs processing allocation so that a processing amount allocated to a second image forming unit provided on the downstream side of the plurality of second image forming units is larger. The image forming apparatus according to claim 5. A computer having a transport unit that transports a belt-shaped medium, and a plurality of image forming units that are provided in series in the transport path of the medium and form an image on the medium transported to the transport path.
Receiving an instruction to form an image on the medium;
The step of allocating the image forming process of the accepted instruction to the plurality of image forming units, wherein the processing amount not exceeding the processing amount allocated to the first image forming unit is greater than that of the first image forming unit. Allocating to a second image forming means provided on the downstream side of the conveying path;
A program for running

Images