Image formation device

Abstract

To provide an image formation device including: a first processor that is connected to an operation part and controls a first image formation part forming a first image by using a first color material group; and a second processor that controls a second image formation part forming a second image overlapping with the first image by using a second color material group, in which, when the first image formation part forms the first image by using the first color material group, the first processor acquires first color material group information regarding the first color material group from the first image formation part, when the second image formation part forms the second image by using the second color material group, the second processor acquires second color material group information regarding the second color material group from the second image formation part, and when power off of own device is instructed from the operation part thereafter, the first processor acquires the second color material group information from the second processor, and then turns off the power of own device.SOLUTION: A first processor acquires first color material group information. When power off of own device is instructed or power of own device is turned off after a second processor acquires second color material group information, the first processor is enabled to acquire the second color material group information.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] Patent document 1 describes a printing system equipped with a printing press control unit that controls the system to do at least one of the following: if the completion notification from the printing press to the host computer is lost, the printing press will send a result notification again; if the receipt notification from the host computer to the printing press is lost, the printing press will send a result notification again; if the completion notification from the printing press to the host computer is lost, the host computer will send a receipt notification again. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-86467 Summary of the Invention [Problem to be solved by the invention]

[0004] Suppose a first processor acquires first colorant group information about a first colorant group used by a first image forming unit when forming an image. Also, suppose a second processor acquires second colorant group information about a second colorant group used by a second image forming unit when forming an image. Thereafter, suppose an instruction to power off the device is received or the device is shut down. In this case, suppose a configuration is adopted that simply powers off or shuts down the device. However, if such a configuration is adopted, the first processor will be unable to acquire the second colorant group information.

[0005] The object of the present invention is to enable the first processor to acquire the second color material group information when, after the first processor acquires the first color material group information and the second processor acquires the second color material group information, the device is instructed to be powered off or the device is powered off. [Means for solving the problem]

[0006] The invention described in claim 1 is an image forming device comprising: a first processor connected to an operation unit and controlling a first image forming unit that forms a first image using a first color material group; and a second processor that controls a second image forming unit that forms a second image that is superimposed on the first image using a second color material group, wherein the first processor acquires first color material group information regarding the first color material group from the first image forming unit when the first image forming unit forms the first image using the first color material group; and the second processor acquires second color material group information regarding the second color material group from the second image forming unit when the second image forming unit forms the second image using the second color material group; and when the first processor is subsequently instructed to power off the device from the operation unit, the first processor powers off the device after acquiring the second color material group information from the second processor. The invention described in claim 2 is the image forming apparatus described in claim 1, in which the first processor controls a conveying device to discharge the paper on which the first image and the second image are formed after the first processor acquires the first colorant group information from the first image forming unit and the second processor acquires the second colorant group information from the second image forming unit. The invention described in claim 3 is an image forming apparatus described in claim 2, in which, when the first processor is instructed by the operation unit to turn off the power of the apparatus after the conveying device has completed discharging the paper, the first processor turns off the power of the apparatus after obtaining the second colorant group information from the second processor. The invention described in claim 4 is an image forming device described in claim 2, in which, when the operation unit instructs the first processor to turn off the power of the device before the conveying device has completed discharging the paper, the first processor waits for the conveying device to complete discharging the paper before turning off the power of the device. The invention described in claim 5 is the image forming device described in claim 1, in which the first processor, after acquiring the second color material group information from the second processor, counts the number of sheets of paper on which images are formed using the multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information acquired from the first image forming unit and the second color material group information, and then turns off the power of the device. The invention described in claim 6 is the image forming apparatus described in claim 5, wherein the second color material group includes a plurality of special color materials, and the plurality of color materials consists of all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group. The invention described in claim 7 is an image forming device comprising a first processor that controls a first image forming unit that forms a first image using a first color material group, and a second processor that controls a second image forming unit that forms a second image that is superimposed on the first image using a second color material group, wherein the first processor, when the first image forming unit forms the first image using the first color material group, acquires first color material group information about the first color material group from the first image forming unit and stores the first color material group information in a first non-volatile memory; when the second image forming unit forms the second image using the second color material group, the second processor acquires second color material group information about the second color material group from the second image forming unit and stores the second color material group information in a second non-volatile memory; and when the device is subsequently powered off and restarted, the first processor acquires the second color material group information stored in the second non-volatile memory from the second processor. The invention described in claim 8 is the image forming apparatus described in claim 7, in which the first processor stores the first colorant group information in the first non-volatile memory, and the second processor stores the second colorant group information in the second non-volatile memory, and then controls a conveying device to discharge the paper on which the first image and the second image are formed. The invention described in claim 9 is an image forming device described in claim 8, in which the first processor acquires the second colorant group information stored in the second non-volatile memory from the second processor when the device is turned off and restarted after the conveying device has completed discharging the paper. The invention described in claim 10 is the image forming apparatus described in claim 7, in which the first processor, after acquiring the second color material group information stored in the second non-volatile memory from the second processor, counts the number of sheets of paper on which images are formed using the multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information acquired from the first image forming unit and the second color material group information. The invention described in claim 11 is the image forming apparatus described in claim 10, wherein the second color material group includes a plurality of special color materials, and the plurality of color materials consists of all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group. [Effects of the Invention]

[0007] According to the invention of claim 1, when an instruction is given to turn off the power of the device after the first processor acquires the first color material group information and the second processor acquires the second color material group information, the first processor can acquire the second color material group information. According to the invention of claim 2, when an instruction to turn off the power of the device itself is given after the conveying device has discharged the paper, the first processor is more likely to be able to acquire the second color material group information. According to the invention of claim 3, when an instruction to turn off the power of the device is given after the conveying device has completed discharging the paper, the first processor can make the second color material group information available. According to the invention of claim 4, even if an instruction to turn off the power of the device itself is given before the conveying device has completed discharging the paper, the paper can still be discharged. According to the invention of claim 5, after the first processor acquires the first color material group information and the second processor acquires the second color material group information, if an instruction is given to turn off the power of the device, the number of sheets of paper can be counted for each combination or number of multiple color materials. According to the invention of claim 6, the number of sheets of paper can be counted for each combination or number of multiple color materials consisting of all color materials included in the first color material group, or multiple color materials consisting of all color materials included in the first color material group and at least one color material included in the second color material group. According to the invention of claim 7, if the power to the device is turned off after the first processor acquires the first colorant group information and the second processor acquires the second colorant group information, the first processor can acquire the second colorant group information. According to the eighth aspect of the invention, when the power to the device is cut off after the conveying device has discharged the paper, the first processor is more likely to be able to acquire the second color material group information. According to the invention of claim 9, when the power to the device is cut off after the conveying device has completed discharging the paper, the first processor can make the second color material group information available. According to the invention of claim 10, if the device is powered off after the first processor acquires the first color material group information and the second processor acquires the second color material group information, the number of sheets of paper can be counted for each combination or number of multiple color materials. According to the invention of claim 11, the number of sheets of paper can be counted for each combination or number of multiple color materials consisting of all color materials included in the first color material group, or multiple color materials consisting of all color materials included in the first color material group and at least one color material included in the second color material group. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of the overall configuration of an image forming system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of an image forming apparatus according to the present embodiment. [Figure 3] FIG. 2 is a diagram illustrating an example of functions of a terminal device and an image forming device. [Figure 4] 2 is a block diagram showing an example of the hardware configuration of a first control unit and a second control unit of the image forming apparatus according to the present embodiment. FIG. [Figure 5] 10 is a sequence diagram showing an example of the operation of the first control unit and the second control unit when performing a sheet count process. FIG. [Figure 6] FIG. 10 is a sequence diagram showing an example of the operation of the first control unit and the second control unit when the countermeasure in the first embodiment is taken. [Figure 7] 10 is a flowchart showing an example of the operation of the first main control unit when taking measures in the first embodiment. [Figure 8] FIG. 10 is a sequence diagram showing an example of the operation of the first control unit and the second control unit when a measure according to the second embodiment is taken. [Figure 9] 9A to 9C are diagrams showing the contents of the first management table and the second management table at some steps in FIG. 8. [Figure 10] FIG. 10 is a sequence diagram showing a first example of the operation of the first control unit and the second control unit when the power is turned off and then restarted. [Figure 11] FIG. 10 is a sequence diagram showing a second example of the operation of the first control unit and the second control unit when the power is turned off and then restarted. [Figure 12] 10 is a flowchart showing an example of the operation of the first main control unit when taking measures according to the second embodiment. [Figure 13] 10 is a flowchart showing an example of the operation of the second main control unit when taking measures according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0010] [Outline of this embodiment] This embodiment provides an image forming device that includes a first processor that controls a first image forming unit that forms a first image using a first color material group, and a second processor that controls a second image forming unit that forms a second image that is superimposed on the first image using a second color material group.

[0011] In this image forming apparatus, the first processor is connected to the operation unit. When the first image forming unit forms a first image using the first color material group, the first processor acquires first color material group information about the first color material group from the first image forming unit. When the second image forming unit forms a second image using the second color material group, the second processor acquires second color material group information about the second color material group from the second image forming unit. Furthermore, when the first processor is subsequently instructed to power off the device from the operation unit, the first processor powers off the device after acquiring the second color material group information from the second processor.

[0012] In this image forming apparatus, when the first image forming unit forms a first image using the first color material group, the first processor acquires first color material group information about the first color material group from the first image forming unit and stores the first color material group information in the first nonvolatile memory. When the second image forming unit forms a second image using the second color material group, the second processor acquires second color material group information about the second color material group from the second image forming unit and stores the second color material group information in the second nonvolatile memory. Furthermore, if the image forming apparatus is subsequently powered off and restarted, the first processor acquires the second color material group information stored in the second nonvolatile memory from the second processor.

[0013] Here, the image forming apparatus may be any apparatus that forms images, but the following description will be given taking an image forming apparatus that forms images in eight colors as an example. The first image forming unit and the second image forming unit may be any type of image forming unit. However, in the following, the first image forming unit will be described as an example of a unit of an image forming device that forms images in four colors. The second image forming unit will be described as an example of a unit of an image forming device that forms images in another four colors.

[0014] [Overall configuration of image formation system] FIG. 1 is a diagram showing an example of the overall configuration of an image forming system 1 according to the present embodiment. FIG. 2 is a diagram showing an example of the hardware configuration of the image forming apparatus 2 according to the present embodiment. FIG. 3 is a diagram illustrating an example of the functions of the terminal device 9 and the image forming device 2. As shown in FIG. The image forming system 1 includes an image forming apparatus 2 and a terminal device 9 connected to the image forming apparatus 2 via a communication line 5. The communication line 5 is not particularly limited as long as it is a line used for data communication between apparatuses. The communication line 5 may be, for example, the Internet, a wide area network (WAN), or a local area network (LAN). The communication line 5 may be either wired or wireless, or a combination of these may be used. The wireless LAN may be, for example, WiFi (registered trademark).

[0015] The image forming apparatus 2 includes a first image forming unit 10, a second image forming unit 20, a first control unit 100, and a second control unit 200 housed within a housing 3. The first image forming unit 10 and the second image forming unit 20 are two image forming units that together form an image on one sheet of paper S. The first control unit 100 controls the first image forming unit 10, and the second control unit 200 controls the second image forming unit 20. In the image forming apparatus 2, the first control unit 100 also controls a paper transport device 40 that transports the paper S. Details of the image forming apparatus 2 will be described later.

[0016] The terminal device 9 instructs the image forming apparatus 2 to form an image in eight colors on the paper S. The terminal device 9 may be, for example, a notebook PC, a desktop PC, a tablet PC, a tablet terminal, etc. The terminal device 9 may also be a multi-function mobile phone (a so-called "smartphone"), a mobile phone (a so-called "feature phone"), etc. The terminal device 9 may also be a personal digital assistant (PDA), etc.

[0017] The image forming apparatus 2 includes a first image forming unit 10 that forms an image on a sheet S, and a second image forming unit 20 that forms an image on the sheet S. The image forming apparatus 2 also includes a sheet holding unit 30 that holds the sheet S. The image forming apparatus 2 also includes a sheet transport device 40 that transports the sheet S held in the sheet holding unit 30 to the first image forming unit 10, etc. The image forming apparatus 2 also includes a fixing device 50 that applies heat and pressure to fix a toner image formed on the sheet S. The image forming apparatus 2 also includes a sheet stacking unit 60 that stacks sheets S on which an image has been formed by fixing the toner image by the fixing device 50. The image forming apparatus 2 also includes a user interface 70 that displays information, etc. Hereinafter, the user interface 70 may be referred to as the "UI 70." The image forming apparatus 2 also includes a first control unit 100 that controls the first image forming unit 10, the sheet transport device 40, the fixing device 50, etc. The image forming apparatus 2 also includes a second control unit 200 that controls the second image forming unit 20.

[0018] The first image forming section 10 has four image forming units 11. The four image forming units 11 are arranged in parallel at regular intervals and form toner images of the colors of the toner stored therein. Each image forming unit 11 has a photosensitive drum 12, a charger 13, and an LED (Light Emitting Diode) print head 14. The photosensitive drum 12 holds a toner image. The charger 13 charges the surface of the photosensitive drum 12. The LED print head 14 exposes the photosensitive drum 12 charged by the charger 13 based on image data for each color. The LED print head 14 then forms an electrostatic latent image on the photosensitive drum 12. Each image forming unit 11 also includes a developing device 15 and a drum cleaner 16. The developing device 15 develops the electrostatic latent image formed on the photosensitive drum 12. The drum cleaner 16 cleans the photosensitive drum 12 after transfer. In this embodiment, the developing device 15 of each image forming unit 11 contains yellow (Y), magenta (M), cyan (C), and black (K) toner. The developing device 15 of each image forming unit 11 forms a toner image of the respective color. Hereinafter, the color configuration of the toner contained in the four image forming units 11 of the first image forming section 10 may be referred to as the "first color configuration." The first color configuration is, for example, a color configuration consisting of yellow (Y), magenta (M), cyan (C), and black (K). The yellow (Y), magenta (M), cyan (C), and black (K) toners are an example of a first color material group. The first image forming unit 10 is an example of a first image forming unit that forms a first image using a first color material group.

[0019] Furthermore, the first image forming section 10 is equipped with an intermediate transfer belt 17. The color toner images formed on the photosensitive drums 12 of the image forming units 11 are transferred onto the intermediate transfer belt 17 in a multi-layered manner. The first image forming section 10 is also equipped with a primary transfer roll 18 and a secondary transfer roll 19. The primary transfer roll 18 sequentially transfers the color toner images formed on the image forming units 11 onto the intermediate transfer belt 17 (primary transfer). The secondary transfer roll 19 collectively transfers the color toner images transferred onto the intermediate transfer belt 17 in a superimposed state onto the paper S (secondary transfer).

[0020] The second image forming unit 20, like the first image forming unit 10, includes four image forming units 21. The second image forming unit 20 includes an intermediate transfer belt 27, a primary transfer roll 28, and a secondary transfer roll 29. Like the image forming unit 11, each image forming unit 21 includes a photosensitive drum 22, a charger 23, and an LED print head 24. Each image forming unit 21 also includes a developer 25 and a drum cleaner 26. In this embodiment, the developer 25 of each image forming unit 21 contains white, gold, silver, and clear toner. The developer 25 of each image forming unit 21 forms a toner image of the corresponding color. Note that the toner colors contained in the developer 25 of each image forming unit 21 are not limited to the above colors. For example, the toner colors may be red, blue, and green. Hereinafter, the color configuration of the toners contained in the four image forming units 21 of the second image forming unit 20 may be referred to as the "second color configuration." The second color configuration is, for example, a color configuration consisting of white, gold, silver, and clear. The white, gold, silver, and clear toners are an example of a second color material group, and in particular, a second color material group including multiple special color materials. The second image forming unit 20 is an example of a first image forming unit that forms a first image using the second color material group.

[0021] The paper transport device 40 includes an upper roll 41, a lower roll 42, and a transport belt 43. The upper roll 41 and the lower roll 42 are arranged vertically apart. The transport belt 43 is stretched across the upper roll 41 and the lower roll 42. The paper transport device 40 also includes a supply roll 44 and a transport roll 45. The supply roll 44 supplies the paper S held in the paper holding section 30 toward the transport belt 43. The transport roll 45 is arranged between the supply roll 44 and the transport belt 43. The paper transport device 40 also includes a plurality of sensors 46. The sensors 46 detect the passage of the paper S being transported. The paper transport device 40 is an example of a transport device that transports paper.

[0022] The fixing device 50 includes a heating roll 51 and a belt module 52. The heating roll 51 heats the conveyed paper S. The belt module 52 is pressed against the heating roll 51 to form a pressure section between the heating roll 51 and the belt module 52. The fixing device 50 fixes the toner image to the paper S by applying pressure and heat to the paper S on which the toner image has been formed in the pressure section. The UI 70 is configured by a touch panel or the like that combines a display device and a position input device. The display device may be a liquid crystal display or an organic EL display. The position input device may be a touch pad or the like. The UI 70 receives information from the user and displays the information to the user. The UI 70 is an example of an operation unit.

[0023] The image forming apparatus 2 configured as above operates as follows. A four-color toner image is formed on the photosensitive drum 12 of the image forming unit 11 of the first image forming section 10. The four-color toner image is primarily transferred onto the intermediate transfer belt 17 by the primary transfer roll 18. As a result, a superimposed toner image in which the four color toners are superimposed is formed on the intermediate transfer belt 17. Then, this superimposed toner image on the intermediate transfer belt 17 is transported as the intermediate transfer belt 17 moves. Specifically, this superimposed toner image is transported to a secondary transfer section in which a secondary transfer roll 19 is arranged.

[0024] In this way, the superimposed toner image of the first image forming unit 10 is transported to the secondary transfer unit. Then, at the same timing, the paper S is supplied from the paper holding unit 30 to the secondary transfer unit. The superimposed toner images are then secondarily transferred all at once onto the transported paper S at the secondary transfer unit. Specifically, the superimposed toner images are secondarily transferred by a transfer electric field formed by the secondary transfer roll 19. Hereinafter, the superimposed toner image formed by the first image forming unit 10 may be referred to as the "first image I1."

[0025] Meanwhile, toner images of the other four colors are formed on the photosensitive drums 22 of the image forming units 21 of the second image forming section 20. The toner images of the other four colors are primarily transferred onto the intermediate transfer belt 27 by the primary transfer roll 28. As a result, a superimposed toner image in which the toners of the other four colors are superimposed is formed on the intermediate transfer belt 27. Then, this superimposed toner image on the intermediate transfer belt 27 is transported as the intermediate transfer belt 27 moves. Specifically, this superimposed toner image is transported to a secondary transfer section in which a secondary transfer roll 29 is arranged.

[0026] In this way, the superimposed toner image of the second image forming unit 20 is transported to the secondary transfer unit. Then, in time with this, the paper S is supplied to this secondary transfer unit. The superimposed toner images of the second image forming unit 20 are then secondarily transferred collectively onto the transported paper S at the secondary transfer unit. The superimposed toner image has been electrostatically transferred onto the paper S by the first image forming unit 10. Therefore, the superimposed toner image of the second image forming unit 20 is secondarily transferred onto this electrostatically transferred superimposed toner image on the paper S. Specifically, the superimposed toner image of the second image forming unit 20 is secondarily transferred by a transfer electric field formed by the secondary transfer roll 29. Hereinafter, the superimposed toner image formed by the second image forming unit 20 may be referred to as the "second image I2."

[0027] Thereafter, the paper S onto which the superimposed toner image has been electrostatically transferred is transported to the fixing device 50. Here, the superimposed toner image is formed by superimposing the superimposed toner image of the first image forming unit 10 and the superimposed toner image of the second image forming unit 20. The toner image on the paper S transported to the fixing device 50 is heated and pressurized by the fixing device 50, and is fixed onto the paper S. Then, the paper S with the fixed image thereon is transported to the paper stacking unit 60 of the image forming apparatus 2.

[0028] For example, suppose that an original M is created using a document creation application on the terminal device 9. Then, this application generates instructions for forming an image of the original M on a sheet of paper S. The printer driver acquires the image formation instructions output from the application. The printer driver then converts the image formation instructions into commands in a format that can be interpreted by the image forming device 2. More specifically, the printer driver acquires an instruction for forming an image of the document M output from, for example, an application. The printer driver then converts this image formation instruction into a first image formation instruction and a second image formation instruction. The first image formation instruction is a command for forming an image in the first image forming unit 10. The second image formation instruction is a command for forming an image in the second image forming unit 20. The printer driver performs this conversion taking into account the respective characteristics of the first image forming unit 10 and the second image forming unit 20. The printer driver then outputs the first image formation instruction and the second image formation instruction to the first control unit 100.

[0029] As a result, the first control unit 100 controls the first image forming unit 10 based on the first image formation instruction. Then, the first image forming unit 10 forms a first image I1 using toner of the first color configuration. In addition, the second image formation instruction is transferred from the first control unit 100 to the second control unit 200. The second control unit 200, having received this transfer, controls the second image forming unit 20 based on the second image formation instruction. Then, the second image forming unit 20 forms a second image I2 using toner of the second color configuration. Thereafter, the image forming device 2 forms the first image I1 and the second image I2 superimposed on one sheet of paper S.

[0030] FIG. 4 is a block diagram showing an example of the hardware configuration of the first control unit 100 and the second control unit 200 of the image forming apparatus 2 according to the present embodiment.

[0031] The first control unit 100 includes a first main control unit 110 that controls the operations of the first image forming unit 10, the paper transport device 40, the fixing device 50, etc. The first control unit 100 includes a first subordinate control unit 120 that controls the operations of these devices under the control of the first main control unit 110.

[0032] The first main control unit 110 includes a CPU (Central Processing Unit) 111. The CPU 111 is an example of a first processor that controls the first image forming unit. The first main control unit 110 includes a ROM (Read Only Memory) 112 and a RAM (Random Access Memory) 113. The first main control unit 110 includes a storage unit 114 that is a nonvolatile memory. The storage unit 114 is an example of a first nonvolatile memory. The first main control unit 110 includes a communication unit 115 that is used for communication with an external device. The communication unit 115 may be, for example, a communication interface (communication I / F). The ROM 112 stores a basic program (operating system) executed by the CPU 111, various settings, etc. The CPU 111 uses the RAM 113 as a work area and executes programs read from the ROM 112 or the storage unit 114. The CPU 111 executes the programs to realize the functions of the first main control unit 110 described below.

[0033] The first main control unit 110 transmits and receives information to and from the first subordinate control unit 120, the second control unit 200, and the UI 70 via the communication unit 115. Furthermore, the first main control unit 110 receives an image formation instruction from the outside, for example, from the terminal device 9, via the communication unit 115. The first main control unit 110 analyzes the received image formation instruction.

[0034] Furthermore, the first main control unit 110 performs predetermined image processing on the received image data. The first main control unit 110 converts the received image data into data of the colors reproduced by the first image forming unit 10 and outputs the data. Here, the data of the colors reproduced by the first image forming unit 10 is data of the colors of the toner of the first image forming unit 10. In this example, this is YMCK data, which is yellow (Y), magenta (M), cyan (C), and black (K). This YMCK data is composed of Y color data, M color data, C color data, and K color data separated for each color. The first main control unit 110 also notifies the first subordinate control unit 120 of the size and material of the sheet S related to the received image formation instruction. The first main control unit 110 also transfers the received image formation instruction to the second control unit 200.

[0035] Like first main control unit 110, first slave control unit 120 includes CPU 121, ROM 122, and RAM 123. First slave control unit 120 also includes storage unit 124 and communication unit 125. CPU 121 uses RAM 123 as a work area and executes programs read from ROM 122 or storage unit 124. The functions of first slave control unit 120, which will be described below, are realized by CPU 121 executing the programs. The first slave control unit 120 exchanges control information with the first main control unit 110. As a result, the first slave control unit 120 controls exposure, development, transfer, etc. in the first image forming unit 10. The first slave control unit 120 controls the feeding and transport of the paper S in accordance with the transfer timing by the paper transport device 40. The first slave control unit 120 controls the fixing of the toner image by the fixing device 50, etc.

[0036] The second control unit 200 includes a second main control unit 210 that controls the operation of the second image forming unit 20. The second control unit 200 includes a second subordinate control unit 220 that controls the operation of the second image forming unit 20 under the control of the second main control unit 210. The second main control unit 210 transmits and receives information to and from the first main control unit 110 via a connection line 150.

[0037] The second main control unit 210 includes a CPU 211. The CPU 211 is an example of a second processor that controls the second image forming unit. The second main control unit 210 includes a ROM 212 and a RAM 213. The second main control unit 210 includes a storage unit 214 that is a nonvolatile memory. The storage unit 214 is an example of a second nonvolatile memory. The second main control unit 210 includes a communication unit 215 that is used for communication with an external device. The ROM 212 stores a basic program (operating system) executed by the CPU 211, various settings, etc. The CPU 211 uses the RAM 213 as a work area and executes programs read from the ROM 212 or the storage unit 214. The CPU 211 executes the programs to realize the functions of the second main control unit 210 described below.

[0038] The second main control unit 210 transmits and receives information to and from the second subordinate control unit 220, the first control unit 100, and the UI 70 via the communication unit 215.

[0039] The second main control unit 210 also performs predetermined image processing on the received image data. The second main control unit 210 converts the received image data into data of the colors reproduced by the second image forming unit 20 and outputs the converted data. Here, the data of the colors reproduced by the second image forming unit 20 is data of the colors of the toner of the second image forming unit 20. In this example, this data is white data, gold data, silver data, and clear data, which are white, gold, silver, and clear. In addition, the second main control unit 210 notifies the second subordinate control unit 220 of the size and material of the sheet S related to the received image formation instruction.

[0040] Similar to second main control unit 210, second slave control unit 220 includes CPU 221, ROM 222, and RAM 223. Second slave control unit 220 also includes storage unit 224 and communication unit 225. CPU 221 uses RAM 223 as a work area and executes programs read from ROM 222 or storage unit 224. The functions of second slave control unit 220, which will be described below, are realized by CPU 221 executing the programs. The second slave control unit 220 exchanges control information with the second main control unit 210. In this way, the second slave control unit 220 controls exposure, development, transfer, and the like in the second image forming unit 20.

[0041] After being started, the first control unit 100 and the second control unit 200 transmit and receive information to each other. As a result, the paper transport device 40 operates under the control of the first control unit 100 and transports the paper S. Then, the first image forming unit 10 performs second transfer of a four-color superimposed toner image onto the paper S. At the same time, the second image forming unit 20 performs second transfer of the other four-color superimposed toner images onto the paper S.

[0042] Generally, in a color printer, the number of color prints and the number of black and white prints are counted separately. One counting method is to count up one printed page when the image forming unit completes printing one page. Here, completion of printing can be replaced by paper ejection. However, even if the print instruction output to the image forming unit is for color printing, only black toner may be consumed during actual printing. For example, this can occur when an instruction is given to print a document consisting only of text information in color. In this case, the main control unit determines whether the print is color or black and white by receiving a pixel count from the slave control unit after the image forming unit completes printing. Here, the pixel count is information indicating how many pixels have been printed in YMCK. The main control unit can use this color or black and white determination result to determine whether to count up one color or black and white print.

[0043] Consider a case where this is applied to an image forming apparatus 2 that forms images in eight colors. In this case, when printing is completed in the first image forming unit 10, the first slave control unit 120 notifies the first main control unit 110 of the pixel count. Furthermore, when printing is completed in the second image forming unit 20, the second slave control unit 220 notifies the second main control unit 210 of the pixel count. The first main control unit 110 then integrates this information. One method for integrating this information is for the second main control unit 210 to notify the first main control unit 110 of the pixel count. This allows the first main control unit 110 to know the pixel counts from both the first slave control unit 120 and the second slave control unit 220. Therefore, the first main control unit 110 can determine whether printing is to be performed in eight colors or four colors. The first main control unit 110 may also be configured to determine whether printing is to be performed in five, six, or seven colors.

[0044] Here, pixel counting will be explained in detail. The pixel count is information indicating how many dots have been printed for each color, which is notified from the image forming unit. The pixel count may be expressed as the number of dots, or as a ratio of the area to the paper. The area ratio to the paper can be calculated as follows. That is, let X be the number of dots when a color is printed on the entire surface of the paper, and Y be the number of dots of that color actually printed on the paper. Then, the area ratio is the value of Y ÷ X. For example, let's say the number of dots on the entire surface of the paper is 30,000 dots, and the number of dots actually printed on the paper is 5,000 dots. Then, the area ratio is 16% (= 0.16). However, in the following, pixel counts are expressed in terms of the number of dots, and therefore the unit of pixel count is dots, but the unit may be omitted.

[0045] 5 is a sequence diagram showing an example of the operation of the first control unit 100 and the second control unit 200 when performing a process to count the number of printed sheets. Hereinafter, this process to count the number of printed sheets will be referred to as the "sheet count process." Note that this example of operation begins when the first main control unit 110 receives a print instruction.

[0046] First, the first main control unit 110 transmits a print instruction setting for setting a print instruction to the first slave control unit 120 (step 301). Next, the first main control unit 110 transmits a print instruction notification request for requesting notification of the print instruction to the second main control unit 210 (step 302).

[0047] As a result, first, the second main control unit 210 sends a print instruction setting that sets a print instruction to the second slave control unit 220 (step 303). Next, the second main control unit 210 sends a print instruction notification that notifies the second slave control unit 220 of the print instruction (step 304). Next, the second main control unit 210 sends a print instruction notification completion that indicates completion of the notification of the print instruction to the first main control unit 110 (step 305).

[0048] As a result, the first main control unit 110 transmits a print instruction notice to the first slave control unit 120 (step 306).

[0049] Then, first slave control unit 120 controls paper transport device 40, first image forming unit 10, etc. Through this control, first, paper transport device 40 supplies paper from paper holding unit 30 (step 307). Next, first image forming unit 10 starts printing on the paper supplied by paper transport device 40 (step 308). Then, first slave control unit 120 sends a first pixel count to first main control unit 110 (step 309). Here, the first pixel count is the pixel count for the color used in first image forming unit 10.

[0050] Meanwhile, the second slave control unit 220 controls the second image forming unit 20, etc. Through this control, the second image forming unit 20 starts printing on the paper supplied by the paper transport device 40 (step 310). Then, the second slave control unit 220 transmits a second pixel count to the second main control unit 210 (step 311). Here, the second pixel count is the pixel count for the color used in the second image forming unit 20.

[0051] Thereafter, first slave control unit 120 transmits a discharge completion to first main control unit 110 (step 312). Here, discharge completion is information indicating that paper transport device 40 has completed discharging the paper. Then, the first main control unit 110 transmits a print completion message to the second main control unit 210 (step 313). Here, print completion is information indicating that the image forming device 2 has completed printing on the paper.

[0052] As a result, the second main control unit 210 transmits a print completion receipt and a second pixel count to the first main control unit 110 (step 314). Here, the print completion receipt is information indicating that printing completion has been received. The second pixel count is the pixel count received from the second slave control unit 220 in step 311.

[0053] As a result, first, the first main control unit 110 determines the print color (step 315). Next, the first main control unit 110 counts up the number of sheets for that print color (step 316). Then, the first main control unit 110 sends a second pixel count receipt to the second main control unit 210 (step 317). Here, the second pixel count receipt is information indicating that the second pixel count has been received.

[0054] [First embodiment] (assignment) Consider a case in which the first main control unit 110 performs the sheet count process in the image forming apparatus 2. This is a possible scenario, since it would be difficult for the first main control unit 110 and the second main control unit 210 to count the number of sheets separately. The color information used in the sheet count process is the color information of the printed result. Therefore, once printing is complete, the second slave control unit 220 needs to notify the second main control unit 210 of the color information. In addition, the second main control unit 210 needs to notify the first main control unit 110 of the color information.

[0055] Here, the connection line between the second main control unit 210 and the second slave control unit 220 is a dedicated line. Therefore, the second main control unit 210 and the second slave control unit 220 can communicate with each other immediately. On the other hand, the connection line 150 (see FIG. 4) between the first main control unit 110 and the second main control unit 210 is a shared line for transmitting and receiving various information. Therefore, there is no guarantee that the first main control unit 110 and the second main control unit 210 can communicate with each other immediately. For example, suppose that communication related to a high-load process is being carried out between the first main control unit 110 and the second main control unit 210. In this case, a waiting time occurs until the first main control unit 110 receives the color information. Here, an example of a high-load process is a process for displaying information on the UI 70.

[0056] Therefore, the first main control unit 110 must wait until the color information arrives even after printing is physically completed and the paper is ejected.The first main control unit 110 must then perform the sheet count process after the color information arrives. However, even though it is necessary to wait for printing to be completed and the paper to be ejected, the user may turn off the power without waiting. This is because the paper appears to have been ejected at step 312 in Figure 5, and the user would want to turn off the power. If this happens, the processing from step 313 onwards in Figure 5 will not be executed. In other words, the color information will not reach the first main control unit 110, and the number of sheets will not be counted correctly.

[0057] (countermeasure) In the first embodiment, even if the first main control unit 110 receives a power-off operation from the UI 70, it does not immediately turn off the power. That is, the first main control unit 110 first checks whether the sheet count process is complete. If the sheet count process is not complete, the first main control unit 110 waits until it is complete. Then, after confirming that the sheet count process is complete, the first main control unit 110 turns off the power.

[0058] (General operation) 6 is a sequence diagram showing an example of the operation of the first control unit 100 and the second control unit 200 when this measure is taken. This example of the operation starts when the first main control unit 110 receives a print instruction.

[0059] Steps 401 to 412 in FIG. 6 are the same as steps 301 to 312 in FIG. Here, it is assumed that a power-off operation is performed on the UI 70 after step 412 is executed, and then the first main control unit 110 accepts the power-off operation from the UI 70 (step 413). Then, the first main control unit 110 transmits a print completion message to the second main control unit 210 (step 414). Here, print completion is information indicating that the image forming device 2 has completed printing on the paper.

[0060] As a result, the second main control unit 210 transmits a print completion receipt and a second pixel count to the first main control unit 110 (step 415). Here, the print completion receipt is information indicating that printing completion has been received. The second pixel count is the pixel count received from the second slave control unit 220 in step 411.

[0061] As a result, the first main control unit 110 first determines the print color (step 416). Next, the first main control unit 110 counts up the number of sheets for that print color (step 417). Then, the first main control unit 110 sends a second pixel count receipt to the second main control unit 210 (step 418). Here, the second pixel count receipt is information indicating that the second pixel count has been received. Thereafter, the first main control unit 110 sends a power-off instruction to the second main control unit 210 (step 419). That is, the first main control unit 110 holds off the power-off instruction until it has completely received the second pixel count and the print completion receipt. Then, in step 419, the first main control unit 110 sends this held power-off instruction to the second main control unit 210.

[0062] (Detailed configuration) Referring again to FIG. 4, the detailed configuration of the image forming apparatus 2 for realizing the general operation shown in FIG. 6 will be described.

[0063] The first main control unit 110 performs the following processes under the control of the CPU 111. That is, the first main control unit 110 sends the print instruction setting to the first slave control unit 120. The first main control unit 110 sends a print instruction notification request to the second main control unit 210. The first main control unit 110 receives a print instruction notification completion from the first main control unit 110. The first main control unit 110 sends the print instruction notification to the first slave control unit 120.

[0064] The first main control unit 110 also receives a first pixel count from the first slave control unit 120. Here, the first pixel count is a pixel count related to the colors used in the first image forming unit 10. In this case, the first pixel count is an example of first colorant group information related to the first colorant group. The CPU 111 is an example of a first processor that acquires the first colorant group information from the first image forming unit when the first image forming unit forms a first image using the first colorant group.

[0065] Furthermore, the first main control unit 110 controls the paper transport device 40 to transport the paper. The first main control unit 110 also controls the first image forming unit 10 and the second image forming unit 20 to form images on the paper. At this time, as described above, the first main control unit 110 receives a first pixel count from the first slave control unit 120. Also, as will be described later, the second main control unit 210 receives a second pixel count from the second slave control unit 220. After receiving this pixel count, the first main control unit 110 controls the ejection of the paper on which the images have been formed by the first image forming unit 10 and the second image forming unit 20. At this time, the first main control unit 110 receives an ejection completion notification from the first slave control unit 120. In this case, CPU 111 is an example of a first processor that acquires first colorant group information from the first image forming unit, and then controls the conveying device to discharge the paper on which the first image and second image are formed after the second processor acquires second colorant group information from the second image forming unit.

[0066] Furthermore, the first main control unit 110 receives a power-off operation from the UI 70. The first main control unit 110 then sends a print completion notification to the second main control unit 210. The first main control unit 110 receives a print completion notification and a second pixel count from the second main control unit 210. The first main control unit 110 determines the print colors based on the first pixel count and the second pixel count. For the combination or number of print colors, the first main control unit 110 counts up the number of sheets of paper on which images are formed using the print colors. Here, the print colors may be the colors of all the toners in the first image forming unit 10. The print colors may also include at least one toner color in the second image forming unit 20. The first main control unit 110 then sends a second pixel count notification to the second main control unit 210. The first main control unit 110 then sends a power-off instruction to the second main control unit 210. In this case, CPU 111 is an example of a first processor that, when subsequently instructed to power off its own device from the operation unit, acquires second color material group information from the second processor and then powers off its own device. After acquiring the second color material group information from the second processor, CPU 111 counts the number of sheets of paper on which images are formed using multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information and the second color material group information acquired from the first image forming unit, and then powers off its own device. The multiple color materials may consist of all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group.

[0067] For example, suppose that the first main control unit 110 receives a power-off operation after receiving a discharge completion notification from the first subordinate control unit 120. In response, the first main control unit 110 continues the processing after transmitting the print completion notification described above. In this case, the CPU 111 is an example of a first processor that, when an instruction to power off the device is received from the operation unit after the conveyance device has completed discharging the paper, turns off the power of the device after acquiring second colorant group information from the second processor.

[0068] Also, suppose that first main control unit 110 receives a power-off operation before receiving a discharge completion notification from first slave control unit 120. Then, first main control unit 110 waits for paper transport device 40 to discharge the paper and receive a discharge completion notification from first slave control unit 120. Then, first main control unit 110 performs the processes subsequent to the transmission of the print completion notification described above. In this case, CPU 111 is an example of a first processor that, when an instruction to power off its own device is received from the operation unit before the transport device has completed discharging the paper, waits for the transport device to complete discharging the paper before powering off its own device.

[0069] The second main control unit 210 performs the following processes under the control of the CPU 211. That is, the second main control unit 210 receives a print instruction notification request from the first main control unit 110. The second main control unit 210 sends print instruction settings to the second slave control unit 220. The second main control unit 210 sends a print instruction notification to the second slave control unit 220. The second main control unit 210 sends a print instruction notification completion to the first main control unit 110.

[0070] The second main control unit 210 also receives a second pixel count from the second slave control unit 220. Here, the second pixel count is a pixel count related to the colors used in the second image forming unit 20. In this case, the second pixel count is an example of second colorant group information related to the second colorant group. The CPU 211 is an example of a second processor that acquires second colorant group information related to the second colorant group from the second image forming unit when the second image forming unit forms a second image using the second colorant group.

[0071] Furthermore, the second main control unit 210 receives a printing completion notification from the first main control unit 110. The second main control unit 210 transmits a printing completion notification and a second pixel count to the first main control unit 110. The second main control unit 210 receives a second pixel count notification from the first main control unit 110. Thereafter, the second main control unit 210 receives a power-off instruction from the first main control unit 110.

[0072] (Detailed operation) 7 is a flowchart showing an example of the operation of the first main control unit 110 when the countermeasures in the first embodiment are implemented. This example of operation starts when a power-off operation is performed on the UI 70. As shown in FIG. 6, when this example of operation starts, the first main control unit 110 is assumed to be holding a first pixel count. The second main control unit 210 is assumed to be holding a second pixel count.

[0073] As shown in the figure, the first main control unit 110 first determines whether the image forming apparatus 2 is currently printing (step 501). Assume that it is determined in step 501 that the image forming apparatus 2 is printing. Then, the first main control unit 110 determines whether or not a discharge completion message has been received from the first slave control unit 120 (step 502).

[0074] Assume that it is determined in step 502 that the discharge completion has not been received from the first slave control unit 120. Then, the first main control unit 110 waits for the discharge completion to be received from the first slave control unit 120 (step 503). Then, the first main control unit 110 returns the process to step 502. On the other hand, if it is determined in step 502 that discharge completion has been received from the first slave control unit 120, the first main control unit 110 then determines whether or not a second pixel count has been received from the second main control unit 210 (step 504).

[0075] Assume that it is determined in step 504 that the second pixel count has not been received from the second main control unit 210. Then, the first main control unit 110 waits to receive the second pixel count from the second main control unit 210 (step 505). Then, the first main control unit 110 returns the process to step 505. On the other hand, suppose that it is determined in step 504 that the second pixel count has been received from the second main control unit 210. Then, the first main control unit 110 determines the print color in the image forming apparatus 2 (step 506). Specifically, the first main control unit 110 may determine the print color based on the first pixel count and the second pixel count. Here, the first pixel count is the one held by the first main control unit 110 when this operation example starts. The second pixel count is the one received from the second main control unit 210 in step 504. Next, the first main control unit 110 counts up the number of sheets for the printing color (step 507). Here, the printing color is the printing color determined in step 506. Thereafter, the first main control unit 110 transmits a power-off instruction to the second main control unit 210 (step 508).

[0076] On the other hand, it is assumed that it is determined in step 501 that the image forming apparatus 2 is not currently printing. In this case, the first main control unit 110 immediately sends a power-off instruction to the second main control unit 210 (step 508).

[0077] (summary) In the image forming apparatus 2 that forms images in eight colors, it is assumed that the user will turn off the power before the sheet count process is performed due to communication delays. In contrast, the first embodiment increases the possibility that the power will be turned off after the sheet count process is performed.

[0078] [Second embodiment] (assignment) It is conceivable that the image forming apparatus 2 may be in an inoperable state due to a power outage or other reason, in which case the first main control unit 110 will be unable to perform the sheet count process.

[0079] For example, suppose that a power outage or other interruption occurs after step 312 in Fig. 5 and before step 313 or step 314. In this case, the first pixel count acquired by the first main control unit 110 from the first slave control unit 120 is lost. Also, the second pixel count acquired by the second main control unit 210 from the second slave control unit 220 is lost. This results in a state where the printed matter is available, but the number of sheets count process has not been performed.

[0080] (countermeasure) In the second embodiment, the first main control unit 110 stores the first pixel count received from the first slave control unit 120 in the storage unit 114. Specifically, the first main control unit 110 stores the first pixel count in association with the print instruction number. Furthermore, the second main control unit 210 stores the second pixel count received from the second slave control unit 220 in the storage unit 214. Specifically, the second main control unit 210 stores the second pixel count in association with the print instruction number.

[0081] Thereafter, when the image forming apparatus 2 is restarted after being powered off, the following process is performed. That is, when the second main control unit 210 is started up, it checks whether or not a second pixel count remains in the memory unit 214. The second pixel count is linked to a print instruction number. Here, it is assumed that a second pixel count remains in the memory unit 214. In this case, the second main control unit 210 transmits the second pixel count together with the print instruction number to the first main control unit 110. As a result, the first main control unit 110 returns a second pixel count receipt to the second main control unit 210. Upon receiving the second pixel count receipt, the second main control unit 210 deletes the second pixel count from the memory unit 214.

[0082] The first main control unit 110 then checks whether any discharge completions remain for that print instruction number. If so, the first main control unit 110 performs a sheet count process. Specifically, the first main control unit 110 adds up the first pixel count and the second pixel count. Here, the first pixel count is the pixel count stored in the memory unit 114. The second pixel count is the pixel count received from the second main control unit 210. The first main control unit 110 also determines the toner combination used in printing. The first main control unit 110 then counts up the number of sheets for that toner combination or number. The first main control unit 110 then deletes the discharge completions and pixel counts from the memory unit 114.

[0083] On the other hand, suppose the first main control unit 110 has not received a discharge completion notification for that print instruction number. In this case, the first main control unit 110 does not add up the first pixel count and the second pixel count. The first main control unit 110 also does not perform the number of sheets count process. After that, the first main control unit 110 deletes the pixel count from the memory unit 114.

[0084] (General operation) 8 is a sequence diagram showing an example of the operation of the first control unit 100 and the second control unit 200 when this measure is taken. This example of the operation starts when the first main control unit 110 receives a print instruction.

[0085] First, the first main control unit 110 transmits a print instruction setting for setting a print instruction to the first slave control unit 120 (step 601). Next, the first main control unit 110 transmits a print instruction notification request for requesting notification of the print instruction to the second main control unit 210 (step 602).

[0086] As a result, the second main control unit 210 registers the information in the second management table (step 603). Here, the second management table is a table stored in the storage unit 214. Then, first, the second main control unit 210 sends a print instruction setting that sets a print instruction to the second slave control unit 220 (step 604). Next, the second main control unit 210 sends a print instruction notification that notifies the second slave control unit 220 of the print instruction (step 605). Next, the second main control unit 210 sends a print instruction notification completion that indicates the completion of the print instruction notification to the first main control unit 110 (step 606).

[0087] As a result, the first main control unit 110 registers the information in the first management table (step 607). Here, the first management table is a table stored in the storage unit 114. Then, the first main control unit 110 transmits a print instruction notice notifying the first slave control unit 120 of the print instruction (step 608).

[0088] Then, the first slave control unit 120 controls the paper transport device 40, the first image forming unit 10, etc. Through this control, first, the paper transport device 40 supplies paper from the paper holding unit 30 (step 609). Next, the first image forming unit 10 starts printing on the paper supplied by the paper transport device 40 (step 610). Then, the first slave control unit 120 sends the first pixel count to the first main control unit 110 (step 611). Then, the first main control unit 110 stores the first pixel count in the first management table (step 612). Here, the first pixel count is the pixel count for the color used in the first image forming unit 10.

[0089] Meanwhile, the second slave control unit 220 controls the second image forming unit 20 and the like. Through this control, the second image forming unit 20 starts printing on the paper supplied by the paper transport device 40 (step 613). Then, the second slave control unit 220 sends the second pixel count to the second main control unit 210 (step 614). Then, the second main control unit 210 stores the second pixel count in the second management table (step 615). Here, the second pixel count is the pixel count for the color used in the second image forming unit 20.

[0090] Thereafter, the first slave control unit 120 transmits a notification of completion of discharge to the first main control unit 110 (step 616). Then, the first main control unit 110 stores the notification of completion of discharge in the first management table (step 617). Here, the "completion of discharge" is information indicating that the paper transport device 40 has completed discharging the paper. Then, the first main control unit 110 sends a print completion message to the second main control unit 210 (step 618). Here, print completion is information indicating that the image forming device 2 has completed printing on the paper.

[0091] As a result, the second main control unit 210 transmits a print completion receipt and a second pixel count to the first main control unit 110 (step 619). Here, the print completion receipt is information indicating that printing completion has been received. The second pixel count is the pixel count saved in the second management table in step 615.

[0092] As a result, the first main control unit 110 stores the second pixel count in the first management table (step 620). Then, the first main control unit 110 transmits a second pixel count receipt to the second main control unit 210 (step 621). Here, the second pixel count receipt is information indicating that the second pixel count has been received. As a result, the second main control unit 210 deletes the information from the second management table (step 622). Meanwhile, the first main control unit 110 determines the print color (step 623). Next, the first main control unit 110 counts up the number of sheets for that print color (step 624). Then, the first main control unit 110 deletes the information from the first management table (step 625).

[0093] The operation shown in FIG. 8 will now be described in detail. Figure 9 shows the contents of the first management table and the second management table at several steps in Figure 8. Here, the print instruction number of the print instruction for the first main control unit 110 is set to JL1, and this print instruction is referred to as print instruction JL1. Also, the print instruction number of the print instruction for the second main control unit 210 is set to JF1, and this print instruction is referred to as print instruction JF1.

[0094] In step 603, the second main control unit 210 registers information in the second management table. In this case, print instruction JF1 has arrived at the second main control unit 210. Therefore, the second main control unit 210 registers JF1 as the print instruction number in the second management table. The second main control unit 210 also initializes the second pixel count in the second management table. In step 607, the first main control unit 110 registers information in the first management table. In this case, print instruction JL1 has arrived at the first main control unit 110. Therefore, the first main control unit 110 registers JL1 as the print instruction number in the first management table. The first main control unit 110 also initializes the first pixel count and second pixel count in the first management table. Furthermore, the first main control unit 110 sets the ejection completion status in the first management table to "not received."

[0095] Next, it is assumed that the sequence has progressed to the start of printing in steps 610 and 613. Then, it is assumed that the first main control unit 110 receives a first pixel count from the first slave control unit 120 in step 611 . Then, in step 612, the first main control unit 110 registers the received first pixel count in the first management table. In this example, the first main control unit 110 registers Y=500, M=300, C=200, and K=100. Also, assume that the second main control unit 210 receives a second pixel count from the second slave control unit 220 in step 614 . Then, in step 615, the second main control unit 210 registers the received second pixel count in the second management table. In this example, the second main control unit 210 registers white=400, gold=200, silver=300, and clear=100.

[0096] Next, it is assumed that the sequence proceeds to step 616. Then, it is assumed that the first main control unit 110 receives a notification from the first subordinate control unit 120 that ejection is complete. Then, in step 617, the first main control unit 110 changes the discharge completion status in the first management table to reception status.

[0097] Next, it is assumed that the sequence proceeds to step 619. Then, it is assumed that the first main control unit 110 receives a second pixel count from the second main control unit 210. Then, in step 620, the first main control unit 110 registers the received second pixel count in the first management table.

[0098] It is assumed that the sequence then proceeds to step 621. Then, it is assumed that the second main control unit 210 receives a second pixel count receipt from the first slave control unit 120. Then, in step 622, the second main control unit 210 deletes the information from the second management table. Also, it is assumed that the sequence has proceeded to steps 623 and 624. Then, it is assumed that the second main control unit 210 has determined the print color and counted up the number of sheets. Then, in step 625, the first main control unit 110 deletes the information from the first management table.

[0099] 10 is a sequence diagram showing a first operation example of the first control unit 100 and the second control unit 200 when they are restarted after being powered off. In particular, this first operation example is an operation example when they are restarted after being powered off with paper ejected. In other words, it is assumed that the first main control unit 110 has received a discharge completion notification from the first slave control unit 120. It is also assumed that the first main control unit 110 has not received a second pixel count from the second main control unit 210.

[0100] When the first control unit 100 and the second control unit 200 are started, they first execute an initial start-up sequence that is unrelated to a print instruction (step 630).

[0101] In this case, it is assumed that a second pixel count remains in the memory unit 214. Then, the second main control unit 210 transmits a print completion receipt and the second pixel count to the first main control unit 110 (step 631). Here, the print completion receipt is information indicating that printing completion has been received. Also, the second pixel count is the pixel count saved in the second management table in step 615 of FIG. 8.

[0102] As a result, the first main control unit 110 transmits a second pixel count receipt to the second main control unit 210 (step 632). Here, the second pixel count receipt is information indicating that the second pixel count has been received. As a result, the second main control unit 210 deletes the information from the second management table (step 633). Meanwhile, the first main control unit 110 determines the print color (step 634). Next, the first main control unit 110 counts up the number of sheets for that print color (step 635). Since the first main control unit 110 has received a notification of completion of ejection from the first slave control unit 120, it counts up the number of sheets in this manner. Then, the first main control unit 110 deletes the information from the first management table (step 636).

[0103] 11 is a sequence diagram showing a second operation example of the first control unit 100 and the second control unit 200 when they are restarted after being powered off. In particular, this second operation example is an operation example when they are restarted after being powered off with no paper being ejected. In other words, it is assumed that the first main control unit 110 has not received an ejection completion notification from the first slave control unit 120. It is also assumed that the first main control unit 110 has not received a second pixel count from the second main control unit 210.

[0104] When the first control unit 100 and the second control unit 200 are started, they first execute an initial start-up sequence that is unrelated to a print instruction (step 640).

[0105] In this case, it is assumed that a second pixel count remains in the memory unit 214. Then, the second main control unit 210 transmits a print completion receipt and the second pixel count to the first main control unit 110 (step 641). Here, the print completion receipt is information indicating that printing completion has been received. Also, the second pixel count is the pixel count saved in the second management table in step 615 of FIG. 8.

[0106] As a result, the first main control unit 110 transmits a second pixel count receipt to the second main control unit 210 (step 642). Here, the second pixel count receipt is information indicating that the second pixel count has been received. As a result, the second main control unit 210 deletes the information from the second management table (step 643). On the other hand, first main control unit 110 does not perform the sheet count process because it has not received a discharge completion notification from first slave control unit 120. Then, first main control unit 110 deletes the information from the first management table (step 644).

[0107] (Detailed configuration) Referring again to FIG. 4, the detailed configuration of the image forming apparatus 2 for realizing the general operations shown in FIGS. 8 to 11 will be described.

[0108] The first main control unit 110 performs the following processes under the control of the CPU 111. That is, the first main control unit 110 sends the print instruction setting to the first slave control unit 120. The first main control unit 110 sends a print instruction notification request to the second main control unit 210. The first main control unit 110 receives a print instruction notification completion notification from the second main control unit 210 and registers the information in the first management table. The first main control unit 110 sends the print instruction notification to the first slave control unit 120.

[0109] The first main control unit 110 also receives a first pixel count from the first slave control unit 120. The first main control unit 110 then registers the first pixel count in the first management table. Here, the first pixel count is a pixel count related to the colors used in the first image forming unit 10. In this case, the first pixel count is an example of first colorant group information related to the first colorant group. The CPU 111 is an example of a first processor that acquires the first colorant group information from the first image forming unit and stores the first colorant group information in a first non-volatile memory when the first image forming unit forms a first image using the first colorant group.

[0110] Furthermore, the first main control unit 110 controls the paper transport device 40 to transport the paper. The first main control unit 110 also controls the first image forming unit 10 and the second image forming unit 20 to form images on the paper. At this time, as described above, the first main control unit 110 receives a first pixel count from the first slave control unit 120. Also, as will be described later, the second main control unit 210 receives a second pixel count from the second slave control unit 220. After receiving this pixel count, the first main control unit 110 controls the discharge of the paper on which the image has been formed by the first image forming unit 10 and the second image forming unit 20. At this time, the first main control unit 110 receives a discharge completion notification from the first slave control unit 120. Then, the first main control unit 110 registers the discharge completion in the first management table. In this case, CPU 111 is an example of a first processor that acquires first colorant group information from the first image forming unit, and then controls the conveying device to discharge the paper on which the first image and second image are formed after the second processor acquires second colorant group information from the second image forming unit.

[0111] Furthermore, when the first main control unit 110 is restarted after being powered off, it sends a print completion notification to the second main control unit 210. The first main control unit 110 receives a print completion notification and a second pixel count from the second main control unit 210. The first main control unit 110 then registers the second pixel count in the second management table. The first main control unit 110 sends a second pixel count notification to the second main control unit 210. The first main control unit 110 determines the print colors based on the first pixel count and the second pixel count. For this combination or number of print colors, the first main control unit 110 counts up the number of sheets of paper on which images are formed with this print color. Here, the print colors may be the colors of all toners in the first image forming unit 10. Furthermore, the print colors may also include at least one toner color in the second image forming unit 20. The first main control unit 110 then deletes the information from the first management table. In this case, CPU 111 is an example of a first processor that, when the device is subsequently powered off and restarted, acquires the second color material group information stored in the second nonvolatile memory from the second processor. After acquiring the second color material group information stored in the second nonvolatile memory from the second processor, CPU 111 is an example of a first processor that counts the number of sheets of paper on which images are formed using multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information and the second color material group information acquired from the first image forming unit. The multiple color materials may consist of all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group.

[0112] For example, suppose that the first main control unit 110 is powered off and restarted after receiving a discharge completion notification from the first subordinate control unit 120. Then, the first main control unit 110 continues the above-described processes after transmitting the print completion notification. In this case, the CPU 111 is an example of a first processor that acquires the second colorant group information stored in the second nonvolatile memory from the second processor when the device itself is powered off and restarted after the conveying device has completed discharging the paper.

[0113] The second main control unit 210 performs the following processes under the control of the CPU 211. That is, the second main control unit 210 receives a print instruction notification request from the first main control unit 110. The second main control unit 210 sends print instruction settings to the second slave control unit 220. The second main control unit 210 sends a print instruction notification to the second slave control unit 220. The second main control unit 210 sends a print instruction notification completion to the first main control unit 110.

[0114] The second main control unit 210 also receives a second pixel count from the second slave control unit 220. Here, the second pixel count is a pixel count related to the colors used in the second image forming unit 20. In this case, the second pixel count is an example of second colorant group information related to the second colorant group. The CPU 211 is an example of a second processor that acquires second colorant group information related to the second colorant group from the second image forming unit when the second image forming unit forms a second image using the second colorant group, and stores the second colorant group information in a second non-volatile memory.

[0115] Furthermore, the second main control unit 210 receives a printing completion notification from the first main control unit 110. The second main control unit 210 transmits a printing completion notification and a second pixel count to the first main control unit 110. The second main control unit 210 receives a second pixel count notification from the first main control unit 110. Thereafter, the second main control unit 210 deletes the information from the second management table.

[0116] (Detailed operation) FIG. 12 is a flowchart showing an example of the operation of first main control unit 110 when measures according to the second embodiment are taken.

[0117] As shown in the figure, the first main control unit 110 first determines whether or not a print instruction number remains in the first management table (step 701). In other words, the first main control unit 110 determines whether or not a print instruction number has been deleted from the first management table. Assume that it is determined in step 701 that there are no print instruction numbers remaining in the first management table, in which case the first main control unit 110 ends the process. On the other hand, if it is determined in step 701 that the print instruction number remains in the first management table, the first main control unit 110 then determines whether or not a print completion receipt and a second pixel count have been received from the second main control unit 210 (step 702).

[0118] Assume that it is determined in step 702 that a print completion acknowledgment and a second pixel count have not been received from the second main control unit 210. Then, the first main control unit 110 waits to receive a print completion acknowledgment and a second pixel count from the second main control unit 210 (step 703). Then, the first main control unit 110 returns the process to step 702. On the other hand, if it is determined in step 702 that a print completion receipt and a second pixel count have been received from the second main control unit 210, the first main control unit 110 then registers the second pixel count in the first management table (step 704).Then, the first main control unit 110 transmits a second pixel count receipt to the second main control unit 210 (step 705).

[0119] Next, the first main control unit 110 determines whether or not the completion of ejection is registered in the first management table (step 706). It is assumed that it is determined in step 706 that discharge completion is registered in the first management table. Then, first, the first main control unit 110 determines the print color (step 707). Here, the print color may be determined based on the second pixel count received in step 702. Next, the first main control unit 110 counts up the number of sheets (step 708). Here, the counting up of the number of sheets may be performed for the print color determined in step 707. Thereafter, the first main control unit 110 deletes the pixel count and the discharge completion from the first management table (step 709). Here, the pixel count to be deleted includes the first pixel count and the second pixel count.

[0120] On the other hand, suppose that it is determined in step 706 that discharge completion is not registered in the first management table. In this case, the first main control unit 110 proceeds to step 709 without executing steps 707 and 708. That is, the first main control unit 110 deletes the pixel count and discharge completion from the first management table (step 709). Here, the pixel count to be deleted includes the first pixel count and the second pixel count. Furthermore, deleting discharge completion means that discharge completion is no longer registered. In this case, since discharge completion was not originally registered, the process of deleting discharge completion is not actually performed.

[0121] FIG. 13 is a flowchart showing an example of the operation of second main control unit 210 when taking measures in the second embodiment.

[0122] As shown in the figure, the second main control unit 210 first determines whether or not the print instruction number remains in the second management table (step 751). In other words, the second main control unit 210 determines whether or not the print instruction number has been deleted from the second management table. Assume that it is determined in step 751 that there are no print instruction numbers remaining in the second management table, in which case the second main control unit 210 ends the process. On the other hand, suppose that it is determined in step 751 that the print instruction number remains in the second management table. Then, the second main control unit 210 sends a print completion receipt and a second pixel count to the first main control unit 110 (step 752). Then, the second main control unit 210 determines whether or not a second pixel count receipt has been received from the first main control unit 110 (step 753).

[0123] Assume that it is determined in step 753 that a second pixel count receipt has not been received from the first main control unit 110. Then, the second main control unit 210 waits to receive a second pixel count receipt from the first main control unit 110 (step 754). Then, the second main control unit 210 returns the process to step 753. On the other hand, if it is determined in step 753 that a second pixel count receipt has been received from the first main control unit 110, the second main control unit 210 deletes the pixel count from the second management table (step 755). Here, the pixel counts to be deleted include the second pixel count.

[0124] The operations shown in FIGS. 12 and 13 will now be described in detail. In step 751 of FIG. 13, the second main control unit 210 determines whether or not there are any print instruction numbers remaining in the second management table that have not been deleted. As a result, if it is determined that there are print instruction numbers remaining that have not been deleted, then in step 752, the second main control unit 210 sends the second pixel count to the first main control unit 110. Here, the second pixel count is linked to the print instruction number.

[0125] 12, the first main control unit 110 receives the second pixel count from the second main control unit 210. Then, in step 704, the first main control unit 110 stores the second pixel count in the first management table. Thereafter, in step 705, the second main control unit 210 sends a second pixel count receipt to the second main control unit 210.

[0126] 13, the second main control unit 210 receives the second pixel count receipt from the first main control unit 110. Then, in step 755, the second main control unit 210 deletes the second pixel count from the second management table.

[0127] Thereafter, in step 706 of FIG. 12, the first main control unit 110 determines whether discharge completion is registered in the first management table. Alternatively, the first main control unit 110 may determine whether a pixel count is registered in the first management table. Here, the pixel count includes a first pixel count and a second pixel count. Also, a pixel count being registered means that the pixel count is not in the initial state. Although not shown in FIG. 12, this determination may be made, for example, in step 706.

[0128] When making such a determination, let us assume that pixel count and discharge completion are registered in the first management table. Then, in step 707 of Fig. 12, the first main control unit 110 determines the print color. Then, in step 708, the first main control unit 110 counts up the number of sheets. Thereafter, in step 709, the first main control unit 110 deletes the information from the first management table.

[0129] (summary) In the image forming apparatus 2 that forms images in eight colors, it is expected that the sheet count process will not be able to be executed if a power outage occurs, etc. In contrast, the second embodiment increases the possibility that the sheet count process will be executed properly when the apparatus is restarted.

[0130] [Processor] In this embodiment, the term "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.). Furthermore, the operations of the processor in this embodiment may not only be performed by one processor, but may also be performed by multiple processors located at physically separate locations working together. Furthermore, the order of the operations of the processor is not limited to the order described in this embodiment, and may be changed.

[0131] [Note] (((1))) a first processor connected to the operation unit and controlling a first image forming unit that forms a first image using a first color material group; a second processor that controls a second image forming unit that forms a second image superimposed on the first image using a second colorant group; Equipped with the first processor acquires first color material group information related to the first color material group from the first image forming unit when the first image forming unit forms the first image using the first color material group; the second processor acquires second colorant group information related to the second colorant group from the second image forming unit when the second image forming unit forms the second image using the second colorant group; When the first processor is subsequently instructed by the operation unit to power off the device, the first processor powers off the device after acquiring the second color material group information from the second processor. Image forming device. (((2))) The image forming apparatus described in (((1))), wherein the first processor controls a conveying device to discharge the paper on which the first image and the second image are formed after the first processor acquires the first color material group information from the first image forming unit and the second processor acquires the second color material group information from the second image forming unit. (((3))) The image forming apparatus described in (((2))) wherein, when the operation unit instructs the first processor to turn off the power of the device after the conveying device has completed discharging the paper, the first processor turns off the power of the device after obtaining the second color material group information from the second processor. (((4))) The image forming apparatus described in (((2))) is characterized in that, when the operation unit instructs the first processor to turn off the power of the apparatus before the conveying device has completed discharging the paper, the first processor waits for the conveying device to complete discharging the paper before turning off the power of the apparatus. (((5))) The image forming device described in any of (((1))) to (((4))), wherein, after acquiring the second color material group information from the second processor, the first processor counts the number of sheets of paper on which images are formed using the multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information acquired from the first image forming unit and the second color material group information, and then turns off the power of the device. (((6))) the second color material group includes a plurality of special color materials, The image forming apparatus described in (((5))), wherein the plurality of color materials consist of all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group. (((7))) a first processor that controls a first image forming unit that forms a first image using a first color material group; a second processor that controls a second image forming unit that forms a second image superimposed on the first image using a second colorant group; Equipped with the first processor, when the first image forming unit forms the first image using the first color material group, acquires first color material group information related to the first color material group from the first image forming unit and stores the first color material group information in a first nonvolatile memory; the second processor, when the second image forming unit forms the second image using the second color material group, acquires second color material group information related to the second color material group from the second image forming unit and stores the second color material group information in a second nonvolatile memory; When the device is subsequently powered off and restarted, the first processor acquires the second color material group information stored in the second nonvolatile memory from the second processor. Image forming device. (((8))) The image forming apparatus described in (((7))), wherein the first processor stores the first colorant group information in the first non-volatile memory, and the second processor stores the second colorant group information in the second non-volatile memory, and then controls a conveying device to discharge the paper on which the first image and the second image are formed. (((9))) The image forming apparatus described in (((8))) wherein the first processor acquires the second colorant group information stored in the second non-volatile memory from the second processor when the device is turned off and restarted after the conveying device has completed discharging the paper. (((10))) The image forming device described in any of (((7))) to (((9))), wherein the first processor acquires the second color material group information stored in the second non-volatile memory from the second processor, and then counts the number of sheets of paper on which images are formed using the multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information acquired from the first image forming unit and the second color material group information. (((11))) the second color material group includes a plurality of special color materials, The image forming apparatus described in (((10))), wherein the plurality of color materials consist of all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group.

[0132] According to the invention (((1))), when an instruction is given to turn off the power of the device after the first processor has acquired the first color material group information and the second processor has acquired the second color material group information, the first processor can acquire the second color material group information. According to the invention (((2))), when an instruction to turn off the power of the transport device is given after the transport device has transported the paper, the first processor is more likely to be able to acquire the second colorant group information. According to the invention (((3))), when an instruction to turn off the power of the device is given after the conveying device has completed discharging the paper, the first processor can make the second colorant group information available. According to the invention (((4))), even if an instruction to turn off the power of the transport device is given before the transport device has completed discharging the paper, the paper can still be discharged. According to the invention (((5))), when the first processor acquires first color material group information and the second processor acquires second color material group information, and then the device is instructed to be powered off, the number of sheets of paper can be counted for each combination or number of multiple color materials. According to the invention (((6))), the number of sheets of paper can be counted for each combination or number of multiple color materials consisting of all color materials included in the first color material group, or multiple color materials consisting of all color materials included in the first color material group and at least one color material included in the second color material group. According to the invention (((7))), if the power to the device is cut off after the first processor acquires the first color material group information and the second processor acquires the second color material group information, the first processor can acquire the second color material group information. According to the invention (((8))), when the power to the conveying device is cut off after the conveying device has conveyed the paper, the first processor is more likely to be able to acquire the second color material group information. According to the invention (((9))), if the power to the device is cut off after the conveying device has completed discharging the paper, the first processor can make the second colorant group information available. According to the invention (((10))), if the device is powered off after the first processor acquires the first color material group information and the second processor acquires the second color material group information, the number of sheets of paper can be counted for each combination or number of multiple color materials. According to the invention (((11))), the number of sheets of paper can be counted for each combination or number of multiple color materials consisting of all color materials included in the first color material group, or multiple color materials consisting of all color materials included in the first color material group and at least one color material included in the second color material group. [Explanation of symbols]

[0133] 1...image forming system, 2...image forming apparatus, 9...terminal device, 10...first image forming section, 20...second image forming section, 100...first control section, 110...first main control section, 120...first subordinate control section, 200...second control section, 210...second main control section, 220...second subordinate control section

Claims

1. a first processor connected to the operation unit and configured to control a first image forming unit that forms a first image using a first color material group; a second processor that controls a second image forming unit that forms a second image superimposed on the first image using a second colorant group; Equipped with the first processor acquires first color material group information related to the first color material group from the first image forming unit when the first image forming unit forms the first image using the first color material group; the second processor acquires second colorant group information related to the second colorant group from the second image forming unit when the second image forming unit forms the second image using the second colorant group; When the first processor is subsequently instructed to power off the device from the operation unit, the first processor powers off the device after acquiring the second color material group information from the second processor. Image forming device.

2. 2. The image forming apparatus of claim 1, wherein the first processor controls a conveying device to discharge the paper on which the first image and the second image are formed after the first processor acquires the first color material group information from the first image forming unit and the second processor acquires the second color material group information from the second image forming unit.

3. 3. The image forming apparatus according to claim 2, wherein when the operation unit instructs the first processor to turn off the power of the apparatus after the conveying device has completed discharging the paper, the first processor turns off the power of the apparatus after acquiring the second color material group information from the second processor.

4. 3. The image forming apparatus of claim 2, wherein when the operation unit instructs the first processor to turn off the power of the device before the conveying device has completed discharging the paper, the first processor waits for the conveying device to complete discharging the paper before turning off the power of the device.

5. 2. The image forming device of claim 1, wherein the first processor, after acquiring the second color material group information from the second processor, counts the number of sheets of paper on which images are formed using the multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information acquired from the first image forming unit and the second color material group information, and then turns off the power of the device.

6. the second color material group includes a plurality of special color materials, 6. The image forming apparatus according to claim 5, wherein the plurality of color materials are all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group.

7. a first processor that controls a first image forming unit that forms a first image using a first color material group; a second processor that controls a second image forming unit that forms a second image superimposed on the first image using a second colorant group; Equipped with the first processor acquires first color material group information relating to the first color material group from the first image forming unit when the first image forming unit forms the first image using the first color material group, and stores the first color material group information in a first nonvolatile memory; the second processor, when the second image forming unit forms the second image using the second color material group, acquires second color material group information related to the second color material group from the second image forming unit and stores the second color material group information in a second nonvolatile memory; When the device is subsequently powered off and restarted, the first processor acquires the second color material group information stored in the second nonvolatile memory from the second processor. Image forming device.

8. 8. The image forming apparatus of claim 7, wherein the first processor stores the first colorant group information in the first non-volatile memory, and the second processor stores the second colorant group information in the second non-volatile memory, and then controls a conveying device to eject the paper on which the first image and the second image are formed.

9. The image forming device according to claim 8, wherein the first processor acquires the second color material group information stored in the second non-volatile memory from the second processor when the device is powered off and restarted after the conveying device has completed discharging the paper.

10. 8. The image forming device of claim 7, wherein the first processor acquires the second color material group information stored in the second non-volatile memory from the second processor, and then counts the number of sheets of paper on which images are formed using the multiple color materials for each combination or number of multiple color materials included in the first color material group and the second color material group based on the first color material group information acquired from the first image forming unit and the second color material group information.

11. the second color material group includes a plurality of special color materials, 11. The image forming apparatus according to claim 10, wherein the plurality of color materials are all color materials included in the first color material group, or all color materials included in the first color material group and at least one color material included in the second color material group.

Images