Printing device

Abstract

To provide a printing device with which it is possible to suppress the shortage of image data for controlling a head by a sub-control unit.SOLUTION: The sub-control unit of the own module of the printing device executes a first transfer operation to transfer image data for a directly below module and image data for a lower module among the image data stored in a sub-storage unit of the own module, to the sub-control unit of the directly below module, transfers the image data for the directly below module and the image data for the lower module to the sub-control unit of the directly below module by a packet in volume of a second prescribed value or greater when the free capacity of the sub-storage unit of the directly below module is greater than or equal to a first prescribed value in the first transfer operation, and transfers the image data for the directly below module and the image data for the lower module to the sub-control unit of the directly below module by a packet in volume of less than the second prescribed value when the free capacity of the sub-storage unit of the directly below module is less than the first prescribed value.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a line head type printing device. [Background technology]

[0002] An image forming apparatus disclosed in Patent Document 1 is known as a conventional printing apparatus. This image forming apparatus includes a receiving board and multiple distribution boards connected to the receiving board. The receiving board transmits image data for each head to the distribution board, which stores the received image data in memory. If the next destination distribution board has sufficient free memory space and can accept the image data, the distribution board transfers the image data to the next destination distribution board. The distribution board is also connected to multiple heads, and distributes the image data from the memory to the heads. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-146253 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the image forming device of the above-mentioned Patent Document 1, if the next destination distribution board cannot receive the image data, the receiving board cannot transfer the image data to the next destination distribution board. Therefore, even if the distribution board beyond the next destination has sufficient free space in the memory, it cannot receive the image data, so there is a risk of a shortage of data distributed from the memory to the head.

[0005] The present disclosure has been made to solve such problems, and aims to provide a printing device that can transfer image data in multiple sub-controllers connected in series, while suppressing a shortage of image data for controlling the head by the sub-controller. [Means for solving the problem]

[0006] A printing device according to an aspect of the present disclosure includes a plurality of head modules connected in series, the plurality of head modules including a head module which is a self module, a direct-below module which is a head module located adjacent to the self module in the connection order of the head modules, and a lower module which is a head module located lower than the direct-below module, and a main control unit, the self module having a head that ejects ink onto a print medium, a sub-storage unit which stores image data, and a sub-controller which controls the head based on the image data, the direct-below module having a head that ejects ink onto a print medium, a sub-storage unit which stores image data, and a sub-controller which controls the head based on the image data, the lower module having a head that ejects ink onto a print medium, a sub-storage unit which stores image data, and a sub-controller which controls the head based on the image data, and the main control unit, the sub-controller of the self module, and the sub-controller of the direct-below module, The sub-controller of the lower module is connected in series, and the sub-controller of the own module executes a first receiving operation of receiving free space in the sub-storage unit of the direct-below module from the sub-controller of the direct-below module, a first determination operation of determining whether the free space in the sub-storage unit of the direct-below module is equal to or greater than a first predetermined value, a first transfer operation of transferring the image data for the direct-below module and the image data for the lower module, among the image data stored in the sub-storage unit of the own module, to the sub-controller of the direct-below module, and a print operation of causing the head of the own module to print using the image data. In the first transfer operation, if the free space in the sub-storage unit of the direct-below module is equal to or greater than the first predetermined value, the sub-controller of the own module transfers the image data for the direct-below module and the image data for the lower module to the sub-controller of the direct-below module in packets having a capacity equal to or greater than a second predetermined value, and if the free space in the sub-storage unit of the direct-below module is less than the first predetermined value,The image data for the immediately-below module and the image data for the lower module are transferred to the sub-control unit of the immediately-below module in packets having a capacity less than the second predetermined value.

[0007] A printing device according to an aspect of the present disclosure includes a plurality of head modules connected in series, the plurality of head modules including a head module which is a self module, a direct-below module which is a head module located adjacent to the self module in the connection order of the head modules, and a lower module which is a head module located lower than the direct-below module, and a main control unit, the self module having a head that ejects ink onto a print medium, a sub-storage unit which stores image data, and a sub-controller which controls the head based on the image data, the direct-below module having a head that ejects ink onto a print medium, a sub-storage unit which stores image data, and a sub-controller which controls the head based on the image data, the lower module having a head that ejects ink onto a print medium, a sub-storage unit which stores image data, and a sub-controller which controls the head based on the image data, the main control unit, the sub-controller of the self module, the sub-controller of the direct-below module, and the sub-controller of the lower module are connected in series, when any one of the head modules and the lower modules is designated as the Nth module, and the head module located immediately below the Nth module in the connection order of the head modules is designated as the N+1th module, the sub-controller of the own module executes a first acquisition operation of acquiring a stock amount of the image data for the N module among the image data stored in the sub-storage unit of the N module, and a stock amount of the image data for the N+1 module among the image data stored in the sub-storage unit of the N+1 module, a third determination operation of determining whether or not the stock amount in the sub-storage unit of the N module is less than the stock amount in the sub-storage unit of the N+1 module, a second transfer operation of transferring the image data for the N module or the image data for the N+1 module among the image data stored in the sub-storage unit of the own module to the sub-controller of the immediately-below module, and a print operation of causing the head of the own module to print using the image data,When the stock amount of the sub-storage unit of the N module is less than the stock amount of the sub-storage unit of the N+1 module, the image data for the N module is transferred to the sub-control unit of the immediately-below module, and when the stock amount of the sub-storage unit of the N module is equal to or greater than the stock amount of the sub-storage unit of the N+1 module, the image data for the N+1 module is transferred to the sub-control unit of the immediately-below module.

[0008] A printing device according to an aspect of the present disclosure includes a main control unit, a plurality of head modules connected in series, the plurality of head modules including a top module connected to the main control unit, any one of the Nth modules other than the top module, and an N+1th module located next to the lower level of the Nth module in the connection order of the head modules, and a main memory unit that stores image data, the top module having a head that ejects ink onto a print medium, a sub-memory unit that stores image data, and a sub-controller that controls the head based on the image data, the Nth module having a head that ejects ink onto a print medium, a sub-memory unit that stores image data, and a sub-controller that controls the head based on the image data, the N+1 module having a head that ejects ink onto a print medium, a sub-memory unit that stores image data, and a sub-controller that controls the head based on the image data, the main control unit is configured to control the amount of the image data stored in the sub-memory unit of the Nth module stored in the sub-memory unit of the Nth module, and executing a second acquisition operation of acquiring a stock amount of the image data for the N+1 module from the image data stored in the sub-storage unit of the N+1 module; a fourth determination operation of determining whether the stock amount in the sub-storage unit of the N module is less than the stock amount in the sub-storage unit of the N+1 module; a transmission operation of transmitting the image data for the N module or the image data for the N+1 module from the image data stored in the main storage unit to the sub-controller of the highest module; and a print operation of causing the head of the highest module, the head of the N module, and the head of the N+1 module to print using the image data, and in the transmission operation, if the stock amount in the sub-storage unit of the N module is less than the stock amount in the sub-storage unit of the N+1 module, transmitting the image data for the N module to the sub-controller of the highest module, and if the stock amount in the sub-storage unit of the N module is equal to or greater than the stock amount in the sub-storage unit of the N+1 module,The image data for the N+1 module is transmitted to the sub-controller of the highest module. Effect of the Invention

[0009] According to the present disclosure, when the free space of the direct sub-storage unit is large, the head data is transferred to the direct sub-control unit in a large packet. This allows the head data to be transferred quickly to the direct sub-control unit, thereby reducing the shortage of head data in the sub-storage unit at the lower level. Also, when the free space of the direct sub-storage unit is small, the head data is transferred to the direct sub-control unit in a small packet. This reduces the head data that cannot be stored in the direct sub-storage unit and is discarded, and the head data is efficiently transferred to the direct sub-control unit, thereby reducing the shortage of head data in the sub-storage unit at the lower level. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic top view of a printing apparatus according to the present disclosure; [Diagram 2] FIG. 2 is a block diagram showing the configuration of a printing device. [Diagram 3] FIG. 4 is a diagram showing a sub-storage unit in which head data is stored; [Figure 4] 10 is a flowchart illustrating an example of a printing process performed by a sub-control unit. [Diagram 5] 6 is a flowchart showing an example of a printing process performed by a main control unit. [Figure 6] 5 is a flowchart showing an example of a first process in FIG. 4. [Figure 7] 5 is a flowchart showing an example of a second process in FIG. 4. [Figure 8] 5 is a flowchart showing an example of a third process in FIG. 4. [Figure 9] 5 is a flowchart showing an example of a fourth process in FIG. 4. [Figure 10] 13 is a flowchart showing an example of a third process performed by a printing device according to a first modified example. [Figure 11] 13 is a flowchart showing an example of a fourth process performed by a printing device according to a first modified example. [Figure 12] Fig. 12A is a flowchart showing an example of print processing by a sub-controller of the printing device according to embodiment 2. Fig. 12B is a flowchart showing an example of print processing by a main controller of the printing device according to embodiment 2. [Figure 13] 12B is a flowchart showing an example of a third process in FIG. 12A. [Figure 14] 12C is a flowchart showing an example of a fifth process in FIG. 12B. [Figure 15] 12C is a flowchart showing an example of a fourth process in FIG. 12B. [Figure 16] 13 is a flowchart showing an example of a third process performed by a printing device according to a second modified example. [Figure 17] 13 is a flowchart showing an example of a fifth process performed by a printing device according to a second modified example. [Figure 18] 13 is a flowchart showing an example of a fourth process performed by a printing device according to a second modified example. [Figure 19] 13 is a flowchart showing an example of a third process performed by a printing device according to a third modified example. [Figure 20] 13 is a flowchart showing an example of a fifth process performed by a printing device according to a third modified example. [Figure 21] 13 is a flowchart showing an example of a fourth process performed by a printing device according to a third modified example. [Figure 22] Fig. 22A is a flowchart showing an example of print processing by a sub-controller of the printing device according to embodiment 3. Fig. 22B is a flowchart showing an example of print processing by a main controller of the printing device according to embodiment 3. [Diagram 23] 22C is a flowchart showing an example of a sixth process of FIG. 22B. [Figure 24] 13 is a flowchart showing an example of a sixth process performed by a printing device according to a fourth modified example. [Diagram 25] 13 is a flowchart showing an example of a sixth process performed by a printing device according to a fifth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following, the same or corresponding elements are denoted by the same reference numerals throughout the drawings, and duplicated descriptions thereof will be omitted.

[0012] <Embodiment 1> <Printing device> 1, the printing device 10 according to the first embodiment of the present disclosure is, for example, an inkjet printer that ejects ink from a head 20 onto a print medium A while transporting the print medium A. For example, the print medium A may be a sheet material such as paper or fabric. In the following, the transport direction in which the print medium A is transported by the printing device 10 is referred to as the front-rear direction, the cross direction that intersects (for example, perpendicular to) the transport direction is referred to as the left-right direction, and the direction that intersects (for example, perpendicular to) the transport direction and the cross direction is referred to as the up-down direction. However, the directions related to the printing device 10 are not limited to these.

[0013] The printing device 10 employs a line head system and is equipped with a head unit 22 having a plurality of heads 20. In the head unit 22, the plurality of heads 20 are arranged alternately in the left-right direction. The head 20 is provided with a plurality of nozzles 21 that eject ink onto the printing medium A.

[0014] Furthermore, the printing device 10 includes a transport device 11 that transports the print medium A. The transport device 11 includes, for example, a transport roller 11a and a transport motor 11b, and the transport roller 11a is rotated by the drive of the transport motor 11b to transport the print medium A in the front-rear direction.

[0015] 2, the printing device 10 includes a main control circuit 31 and sub-control circuits 41 for a plurality of head modules 40 electrically connected to the main control circuit 31. The main control circuit 31 is also electrically connected to the transport device 11 and controls the driving of the transport device 11. Details of the head modules 40 will be described later.

[0016] The main control circuit 31 includes a main control unit 32, as well as a main storage unit 33 and a communication interface 34 electrically connected to the main control unit 32. The communication interface 34 is communicably connected to an external device different from the printing device 10. Examples of the external device include an external server, a storage medium, a computer, and a mobile terminal connected via a communication network such as the Internet. The main storage unit 33 is made up of memories such as RAM, ROM, flash memory, and / or a hard disk, and stores computer programs for performing various data processing of the printing device 10, and data such as image data. The image data includes data (e.g., raster data) indicating an image to be printed on the printing medium A.

[0017] The main control unit 32 is composed of a processor such as a CPU, and executes a computer program stored in the main storage unit 33. As a result, the main control circuit 31 controls the driving of each part of the printing device 10 and executes various processes of the printing device 10, such as printing processing. The main control circuit 31 may be composed of a single device that performs centralized control, or may be composed of multiple devices that perform distributed control.

[0018] The sub-control circuit 41 includes a sub-controller 42 and a sub-storage unit 43 electrically connected to the sub-controller 42. The sub-storage unit 43 is made up of memories such as RAM and ROM, and stores computer programs for performing various data processing of the printing device 10, and data such as image data. The sub-controller 42 is made up of a processor such as a CPU, and executes the computer programs stored in the sub-storage unit 43. As a result, the sub-control circuit 41 controls the driving of each part of the head module 40 and executes various processes of the head module 40, such as printing processing. The printing processing will be described later.

[0019] <Head module> In the example of FIG. 2, the multiple head modules 40 include a first head module 40(1) to a K-th (K: a natural number equal to or greater than 2) head module 40(K). The head module 40 has a head 20 and a sub-control circuit 41 that controls the head 20. Therefore, the multiple head modules 40 include a first head 20(1) that is the head 20 of the first head module 40(1) to a K-th head 20(K) that is the head 20 of the K-th head module 40(K). In addition, the multiple head modules 40 include a first sub-control circuit 41(1) that is the sub-control circuit 41 of the first head module 40(1) to a K-th sub-control circuit 41(K) that is the sub-control circuit 41 of the K-th head module 40(K).

[0020] Moreover, the sub-control circuit 41 has a sub-controller 42 and a sub-storage unit 43. Therefore, the multiple head modules 40 are equipped with a first sub-controller 42(1) which is the sub-controller 42 of the first sub-control circuit 41(1) through a K-th sub-controller 42(K) which is the sub-controller 42 of the K-th sub-control circuit 41(K). Moreover, the multiple head modules 40 are equipped with a first sub-storage unit 43(1) which is the sub-storage unit 43 of the first sub-control circuit 41(1) through a K-th sub-storage unit 43(K) which is the sub-storage unit 43 of the K-th sub-control circuit 41(K).

[0021] The first head module 40(1) to the K-th head module 40(K) are connected in series in this order by the wiring 13. In the connection order of the head modules 40, the first head module 40(1) is the top module 40a1 closest to the main control circuit 31 and is connected to the main control circuit 31. The K-th head module 40(K) is the bottom module 40e1 furthest from the main control circuit 31. These head modules 40 have their own module 40c, a directly above module 40b, an upper module 40a, a directly below module 40d, and a lower module 40e. As a result, the main control unit 32 of the main control circuit 31, the sub-control unit 42 of the upper module 40a, the sub-control unit 42 of the directly above module 40b, the sub-control unit 42 of the own module 40c, the sub-control unit 42 of the directly below module 40d, and the sub-control unit 42 of the lower module 40e are connected in series. For example, in the example of Figure 2, when the own module 40c is the third head module 40(3), the upper module 40a is the first head module 40(1), the directly above module 40b is the second head module 40(2), the directly below module 40d is the fourth head module 40(4), and the lower module 40e is the fifth head module 40(5) to the Kth head module 40(K).

[0022] The direct-above module 40b is an adjacent head module 40 connected to the own module 40c in a higher order than the own module 40c. The upper module 40a is a head module 40 higher than the direct-above module 40b in the connection order. The direct-below module 40d is an adjacent head module 40 connected to the own module 40c in a lower order than the own module 40c in the connection order. The lower module 40e is a head module 40 lower than the direct-below module 40d in the connection order.

[0023] In the following, the head module 40, its components, and head data, which is image data for the head module 40, may be described with the position (for example, own, upper, directly above, directly below, lower) according to the connection order of the head module 40. For example, the sub-control circuit 41, sub-controller 42, sub-storage unit 43, and head 20 provided in the own module 40c may be referred to as the own sub-control circuit 41c, the own sub-controller 42c, the own sub-storage unit 43c, and the own head 20c, respectively. In addition, image data for the own module 40c may be referred to as the own head data. The reference characters of the components of the upper module 40a are marked with a, the reference characters of the components of the directly above module 40b are marked with b, the reference characters of the components of the directly below module 40d are marked with d, and the reference characters of the components of the lower module 40e are marked with e.

[0024] <Head data> Based on image data, the printing device 10 drives the heads 20 to eject ink from the nozzles 21 while transporting the print medium A using the transport device 11. This image data has position information for dots that form an image and size information for ink droplets that form the dots. Therefore, based on this position information, the main control unit 32 assigns image data to each of the multiple heads 20 and obtains head data, which is image data corresponding to the heads 20. In this way, the main control unit 32 divides the image data into multiple head data and transmits them to multiple sub-controllers 42.

[0025] This head data is transferred from the first sub-controller 42(1) connected to the main controller 32 to the lower in the order of connection of the head modules 40 in the multiple sub-controllers 42. At this time, as shown in FIG. 3, when the sub-controller 42 receives the head data from the direct-sub-controller 42b, it stores it in its own sub-storage unit 43c. This sub-storage unit 43 stores data for its own head, data for the direct-subhead, and data for the lower head. Then, the sub-controller 42 transmits the data for its own head out of the head data stored in its own sub-storage unit 43c to its own head 20c, and transmits (transfers) the data for the direct-subhead and the data for the lower head to the direct-subcontroller 42d. This transfer of the head data is performed based on the free space in the direct-sub-storage unit 43d.

[0026] That is, even if the sub-controller 42 transmits the head data to the direct-sub-controller 42d, if the free space of the direct-sub-storage unit 43d is small, the direct-sub-storage unit 43d cannot store the head data. Therefore, the sub-controller 42 transmits the head data to the direct-sub-controller 42d according to the free space of the direct-sub-storage unit 43d. Therefore, the sub-controller 42 executes in parallel a first process (step S10) of storing the head data, a second process (step S20) of transmitting the head data to the head 20, a third process (step S30) of transmitting the free space of the sub-storage unit 43, and a fourth process (step S40) of transferring the head data to the direct-sub-controller 42d according to the flowchart shown in the example of FIG. 4. Each process will be described later.

[0027] <Printing process> As described above, the printing device 10 drives the head 20 to eject ink from the nozzles 21 while transporting the print medium A using the transport device 11 based on image data. Here, the main control unit 32 controls the transport device 11 based on the image data, and transmits head data based on the image data to the sub-control unit 42. In addition, the sub-control unit 42 controls the head 20 based on the head data while receiving and transmitting (transferring) the head data.

[0028] <Printing process by the main control unit> Specifically, the main control unit 32 performs various processes according to the flowchart showing an example of a printing process in Fig. 5. First, the main control unit 32 determines whether or not to acquire image data from the main storage unit 33 or the communication interface 34 (step S60). If the main control unit 32 has not acquired image data (step S60: NO), the main control unit 32 ends the process.

[0029] On the other hand, if the main control unit 32 acquires image data (step S60: YES), it executes in parallel a control process for the transport device 11 based on the image data (step S61), a process for sending data for the head (step S62), and a discharge control process (step S63). In the process of step S61, the main control unit 32 acquires a control signal for the transport device 11 based on the image data, and transmits this control signal to the transport device 11. This control signal includes the start and stop of transport of the print medium A, as well as the transport speed. Based on this control signal, the transport device 11 transports the print medium A in the forward and backward directions.

[0030] Furthermore, in the processing of step S62, the main control unit 32 assigns image data to each head 20 of the multiple head modules 40, acquires head data which is image data for the head module 40, and transmits the head data to the highest level first sub-control unit 42(1) with the sub-control unit 42 of that head module 40 as the destination. As a result, the head data is transmitted (transferred) in the multiple sub-control units 42 to the destination sub-control unit 42.

[0031] Furthermore, in the process of step S63, the main control unit 32 controls the ejection of ink from the head 20. That is, while the print medium A is being transported by the transport device 11 based on the transport signal, ink is ejected from the head 20 based on the head data, thereby printing. In this printing, in order to eject ink at a desired position on the print medium A being transported, ink is ejected from the head 20 at an ejection timing based on the transport signal. Therefore, the main control unit 32 transmits an ink ejection timing signal based on the transport signal to the first sub-control unit 42(1), with each of the multiple sub-control units 42 as the destination. As a result, the ejection timing signal is transmitted (transferred) in the multiple sub-control units 42 to the destination sub-control unit 42.

[0032] <Printing process by the sub-controller> Each of the multiple sub-controllers 42 executes the first process to the fourth process in parallel according to a flowchart showing an example of the printing process in Fig. 4. Note that, below, a process in the case where the sub-controller 42c of the own module 40c is the third sub-controller 42(3) will be described, but the sub-controllers 42 of the other head modules 40 also execute the same process as the third sub-controller 42(3). When this third head module 40(3) is the own module 40c, according to the connection order of the head modules 40, the first head module 40(1) is the upper module 40a, the second head module 40(2) is the immediately above module 40b, the fourth head module 40(4) is the immediately below module 40d, and the fifth head module 40(5) to the Kth head module 40(K) are the lower modules 40e.

[0033] This third sub-control unit 42(3) executes the first process according to the flowchart showing an example of the first process in Fig. 6. In the first process, first, the third sub-control unit 42(3) determines whether or not head data has been received from the second sub-control unit 42(2) (step S11). Here, while the third sub-control unit 42(3) has not received head data (step S11: NO), it monitors the reception of the head data.

[0034] Then, when the third sub-controller 42(3) receives the head data (step S11: YES), it stores the head data in the third sub-storage unit 43(3) (step S12). This head data is transferred downward in the multiple sub-controllers 42. For this reason, the third sub-storage unit 43(3) stores the third head data, which is data for its own head, the fourth head data, which is data for the head directly below, and the fifth head data to the Kth head data, which are data for the lower heads. Of the head data stored in this third sub-storage unit 43(3), the third head data is used in the second process, and the fourth head data to the Kth head data are used in the third process.

[0035] That is, the third sub-controller 42(3) executes the second process according to the flowchart showing an example of the second process in Fig. 7. In the second process, first, the third sub-controller 42(3) determines whether or not an ejection timing signal has been received from the second sub-controller 42(2) (step S21). Here, while the third sub-controller 42(3) does not receive an ejection timing signal (step S21: NO), it monitors the reception of the signal.

[0036] Then, when the third sub-controller 42(3) receives the ejection timing signal (step S21: YES), it transmits the third head data, which is among the head data stored in the third sub-storage unit 43(3), to the third head 20(3). As a result, the third sub-controller 42(3) ejects ink from the third head 20(3) based on the third head data in synchronization with the ejection timing signal, and prints an image on the print medium A through this printing operation (step S22).

[0037] The third sub-controller 42(3) also executes the third process according to a flow chart showing an example of the third process in Fig. 8. In the third process, the third sub-controller 42(3) transmits the third free space, which is the free space in the third sub-storage unit 43(3), to the second sub-controller 42(2) addressed to the second sub-controller 42(2) (step S31). This third free space may be transmitted, for example, at a predetermined time interval, when an ejection timing signal is received, when the third free space reaches a predetermined capacity, and when requested by the direct-sub-controller 42b.

[0038] The third free space is the difference between the capacity that can be stored in the third sub-memory unit 43(3) and the amount of head data stored in the third sub-memory unit 43(3). If this third free space is small, and the head data is transferred in a large packet from the second sub-control unit 42(2) to the third sub-control unit 42(3), it cannot be stored in the third sub-memory unit 43(3) and is discarded. Therefore, the third sub-control unit 42(3) notifies (transmits) the second sub-control unit 42(2) of the third free space of the third sub-memory unit 43(3) so that the head data is transferred based on the third free space.

[0039] Similarly to the third sub-controller 42(3), the fourth sub-controller 42(4) also notifies (transmits) the third sub-controller 42(3) of a fourth free space, which is the free space in the fourth sub-storage unit 43(4). In response to this, the third sub-controller 42(3) executes a fourth process based on this fourth free space, according to a flowchart showing an example of the process in FIG. 9. In the fourth process, the third sub-controller 42(3) executes a first receiving operation to receive the fourth free space from the fourth sub-controller 42(4) (step S41). Then, the third sub-controller 42(3) determines whether the fourth free space is equal to or greater than a first predetermined value (first determining operation, step S42). If the fourth free space is greater than or equal to the first predetermined value in this first determination operation (step S42: YES), the third sub-control unit 42(3) transfers the data for the directly below head and the data for the lower head in a first packet to the fourth sub-control unit 42(4) (first transfer operation, step S43).

[0040] In this case, the data for the direct head and the data for the lower head are data for the fourth head to the Kth head. The first packet is a packet with a capacity equal to or larger than a second predetermined value. In the first transfer operation, the third sub-control unit 42(3) acquires the head data whose destinations are the direct sub-control unit 42d and the lower sub-control unit 42e from the head data stored in the third sub-storage unit 43(3). The third sub-control unit 42(3) divides each of the head data for the direct sub-control unit 42d and the lower sub-control unit 42e into first packets, and transfers the first packets to the fourth sub-control unit 42(4) with the sub-control unit 42 corresponding to the head data as the destination.

[0041] Also, if the fourth free space is less than the first predetermined value in the first determination operation (step S42: NO), the third sub-control unit 42(3) transfers the data for the fourth head to the data for the Kth head in a second packet (first transfer operation, step S44). The second packet is a packet with a capacity smaller than the first packet and less than the second predetermined value. In this first transfer operation, the third sub-control unit 42(3) acquires the head data whose destinations are the direct sub-control unit 42d and the lower sub-control unit 42e from the head data stored in the third sub-storage unit 43(3). Then, the third sub-control unit 42(3) divides each of the direct sub-control unit 42d and the lower sub-control unit 42e into second packets, and transfers the second packets to the fourth sub-control unit 42(4) with the sub-control unit 42 corresponding to the head data as the destination.

[0042] Such head data is transferred downstream in the order of connection among multiple sub-controllers 42, so image data tends to run short in the downstream sub-storage unit 43, which requires time for transfer. In contrast, when the fourth free space is large, the head data is transferred to the fourth sub-controller 42(4) in a large first packet. This allows the head data to be quickly transferred to the fourth sub-controller 42(4), reducing the shortage of head data in the downstream sub-storage unit 43.

[0043] Furthermore, when the fourth free space is small, if the head data is transferred to the fourth sub-controller 42(4) in the large first packet, the head data is discarded without being stored in the fourth sub-memory unit 43(4). In contrast, if the head data is transferred to the fourth sub-controller 42(4) in the small second packet, the transfer time is longer than when the data is transferred in the first packet. During this time, the head data in the fourth sub-memory unit 43(4) is sent to the fourth head 20(4) in the second process or transferred to the fifth sub-controller 42(5) in the fourth process, so that the fourth free space increases. Therefore, the amount of discarded head data is reduced, and the head data is efficiently transferred to the fourth sub-controller 42(4), so that the shortage of head data in the lower sub-memory unit 43 can be reduced.

[0044] Also, for example, there may be a case where the data for the fourth head stored in the fourth sub-storage unit 43(4) is small and the fourth free space is large. In such a case, if the data for the fourth head to be transmitted from the fourth sub-storage unit 43(4) to the fourth head 20(4) in the second process becomes insufficient and the timing at which the data for the fourth head is transmitted to the fourth head 20(4) does not match the ink ejection timing of the fourth head 20(4), printing will be interrupted. In response to this, the data for the head is transferred to the fourth sub-control unit 42(4) in the first packet, which has a large capacity, so that the data for the head is transferred quickly to the fourth sub-control unit 42(4). Therefore, it is possible to reduce the delay in transmitting the data for the fourth head to the fourth head 20(4) and suppress interruptions in printing.

[0045] <First Modification> In the printer 10 according to the first embodiment, the sub-controller 42 transfers the head data based on the free space in the direct sub-storage unit 43d, as shown in the example of Fig. 9. In contrast, in the printer 10 according to the first modified example, the sub-controller 42 transfers the head data based on the free space in the direct sub-storage unit 43d and the stock amount of direct head data, as shown in the example of Fig. 11.

[0046] Specifically, in the printing device 10 according to the first modified example, each of the sub-controllers 42 executes a first process in Fig. 6 and a second process in Fig. 7. Also, each of the sub-controllers 42 executes a third process according to the flowchart shown in place of Fig. 8, and a fourth process according to the flowchart shown in the example of Fig. 11 in place of Fig. 9.

[0047] In the third process of the example of FIG. 10, the third sub-controller 42(3) transmits the free space and the stock amount of the data for the third head in the third sub-storage unit 43(3) to the second sub-controller 42(2) (step S31a). This stock amount is the data amount of the data for the own head stored in the own sub-storage unit 43c. Since this data for the own head is used for ink ejection from the own head 20c in the second process, if the stock amount of the data for the own head is small, there is a risk that the transmission to the own head 20c will not be in time for the ejection timing, causing printing to stop. Therefore, the third sub-controller 42(3) notifies (transmits) the free space and stock amount of the third sub-storage unit 43(3) to the second sub-controller 42(2).

[0048] The fourth sub-control unit 42(4) also notifies (transmits) the third sub-control unit 42(3) of the fourth free space, which is the free space of the fourth sub-storage unit 43(4), and the fourth stock amount, which is the stock amount of data for the fourth head in the fourth sub-storage unit 43(4) (step S31a). In response to this, the third sub-control unit 42(3) executes the fourth process of the example of FIG. 11 based on the fourth free space and the fourth stock amount. According to the flowchart of FIG. 11, the processes of steps S41a, S43a, and S44a are executed instead of steps S41, S43, and S44 in the flowchart of FIG. 9, and the processes of steps S45 and S46 are executed between steps S41a and S42.

[0049] That is, first, the third sub-control unit 42(3) executes a first receiving operation to receive the fourth free space and the fourth stock amount from the fourth sub-control unit 42(4) (step S41a). The third sub-control unit 42(3) judges whether the fourth stock amount is equal to or greater than a third predetermined value (second judging operation, step S45). If the fourth stock amount is less than the third predetermined value in this second judging operation (step S45: NO), the third sub-control unit 42(3) acquires head data whose destination is the direct sub-control unit 42d from among the head data stored in the third sub-storage unit 43(3), and transfers the fourth head data, which is the direct head data, to the fourth sub-control unit 42(4) (first transferring operation, step S46).

[0050] In this way, when the amount of data for the fourth head in the fourth sub-storage unit 43(4) is small, there is a risk that the transmission of the data for the fourth head in the second process to the fourth head 20(4) will not arrive in time for the ejection timing, causing printing to be interrupted. Therefore, by transferring the data for the fourth head before the data for the fifth head and subsequent heads in the fourth process, it is possible to reduce the delay in sending the data for the fourth head to the fourth head 20(4) and prevent printing from being interrupted.

[0051] On the other hand, if the fourth stock amount is equal to or greater than the third predetermined value in the second determination operation (step S45: YES), the third sub-control unit 42(3) executes the first determination operation (step S42). If the fourth free space is equal to or greater than the first predetermined value in this first determination operation (step S42: YES), the third sub-control unit 42(3) transfers each of the fifth head data through the Kth head data, which are destined for the lower sub-control unit 42e, of the head data stored in the third sub-storage unit 43(3) to the fourth sub-control unit 42(4) in a first packet (first transfer operation, step S43a). Furthermore, if the fourth free space is less than the first predetermined value in the first determination operation (step S42: NO), the third sub-control unit 42(3) transfers each of the data for the fifth head to the data for the Kth head, which are destined for the lower sub-control unit 42e, from the head data stored in the third sub-memory unit 43(3) to the fourth sub-control unit 42(4) in second packets (first transfer operation, step S44a).

[0052] According to this, when the fourth stock amount is small, the shortage of data for the fourth head in the fourth sub-storage unit 43(4) can be reduced by transferring the data for the fourth head to the fourth sub-controller 42(4). Therefore, the delay in sending the data for the fourth head to the fourth head 20(4) in the second process can be reduced, and printing interruptions can be suppressed.

[0053] Furthermore, when the fourth stock amount is large, the head data is transferred to a sub-controller 42 lower than the fourth sub-controller 42(4). This makes it possible to reduce a shortage of head data in the lower sub-memory unit 43. Here, when the fourth free space is large, the head data is transferred in the first packet, so that the head data is transferred quickly, making it possible to reduce a shortage of head data in the lower sub-memory unit 43. Furthermore, when the fourth free space is large, the head data is transferred in the second packet, so that the amount of head data discarded is reduced, and the head data is transferred efficiently, making it possible to reduce a shortage of head data in the lower sub-memory unit 43.

[0054] <Embodiment 2> In the printing device 10 according to the above-mentioned first embodiment, each of the multiple sub-controllers 42 transfers head data based on the free space of the direct-sub-storage unit 43d, etc. In contrast, in the printing device 10 according to the second embodiment of the present disclosure, a sub-controller 42 among the multiple sub-controllers 42 transfers head data based on the amount of head data stored in the sub-storage unit 43 of the Nth module 40n and the sub-storage unit 43 of the N+1 module 40n1 among the direct-sub-storage unit 43d and the lower sub-storage unit 43e, etc.

[0055] The Nth module 40n is any one of the head modules 40 among the direct-below module 40d and the lower module 40e. The N+1th module 40n1 is a head module 40 located next to the Nth module 40n in the connection order of the head modules 40 among the direct-below module 40d and the lower module 40e, and is the direct-below module 40d of the Nth module 40n. For example, when the third head module 40(3) is the own module 40c, the Nth module 40n and the N+1st module 40n1 are two adjacent head modules 40 among the fourth head module 40(4) to the Kth head module 40(K). In FIG. 2, the Nth module 40n is represented as the fourth head module 40(4) and the N+1st module 40n1 is represented as the fifth head module 40(5), but the Nth module 40n and the N+1st module 40n1 are not limited thereto.

[0056] In addition, the sub-control circuit 41, the sub-controller 42, the sub-storage unit 43, and the head 20 in the Nth module 40n, and the image data for the Nth module 40n may be referred to as the Nth sub-control circuit 41n, the Nth sub-controller 42n, the Nth sub-storage unit 43n, and the Nth head 20n, and the data for the Nth head. The sub-control circuit 41, the sub-controller 42, the sub-storage unit 43, and the head 20 in the N+1th module 40n1, and the image data for the N+1th module 40n1 may be referred to as the N+1th sub-control circuit 41n1, the N+1th sub-controller 42n1, the N+1th sub-storage unit 43n1, and the N+1th head 20n1, and the data for the N+1th head.

[0057] In the printing device 10 according to the second embodiment, the Nth sub-control unit 42n and the N+1th sub-control unit 42n1 execute the first process (step S10), the second process (step S20), and the third process (step S30) in parallel according to the flowchart showing an example of the printing process in FIG. 12A. The third sub-control unit 42(3) executes the first process (step S10), the second process (step S20), the fifth process (step S70), and the fourth process (step S40) in parallel according to the flowchart showing an example of the printing process in FIG. 12B. Furthermore, the sub-control units 42 other than the Nth sub-control unit 42n, the N+1th sub-control unit 42n1, and the third sub-control unit 42(3) execute the first process (step S10) and the second process (step S20) in parallel. The first process and the second process are similar to the first process in FIG. 6 and the second process in FIG. 7, respectively. Through this second process, each of the sub-controllers 42 executes a printing operation using its own head 20c based on the data for its own head.

[0058] Here, each of the Nth sub-control unit 42n and the N+1th sub-control unit 42n1 executes the third process of FIG. 12A according to the flowchart shown in the example of FIG. 13. In this third process, the Nth sub-control unit 42n transmits the Nth stock amount, which is the stock amount of the data for the Nth head stored in the Nth sub-storage unit 43n, to the sub-control unit 42b directly above the Nth sub-control unit 42n, with the third sub-control unit 42(3) as the destination (step S32). Also, the N+1th sub-control unit 42n1 transmits the N+1st stock amount, which is the stock amount of the data for the N+1th head stored in the N+1th sub-storage unit 43n1, to the Nth sub-control unit 42n, which is the sub-control unit 42b directly above the N+1th sub-control unit 42n1, with the third sub-control unit 42(3) as the destination. As a result, the Nth stock amount and the N+1st stock amount are transmitted (transferred) to the third sub-control unit 42(3).

[0059] In response to this, the third sub-control unit 42(3) executes the fifth process of Fig. 12B according to the flowchart shown in the example of Fig. 14. In this fifth process, the third sub-control unit 42(3) executes a second receiving operation to receive one of the Nth stock amount and the N+1st stock amount from the fourth sub-control unit 42(4) (step S71). The third sub-control unit 42(3) stores the stock amount received in this second receiving operation in the third sub-storage unit 43(3) (storage operation, step S72).

[0060] The third sub-control unit 42(3) also executes a second receiving operation to receive the other of the Nth stock amount and the N+1st stock amount from the fourth sub-control unit 42(4) (step S73). The third sub-control unit 42(3) stores the stock amount received in this second receiving operation in the third sub-storage unit 43(3) (storage operation, step S74). In this manner, the third sub-control unit 42(3) stores the Nth stock amount and the N+1st stock amount in the third sub-storage unit 43(3).

[0061] Then, the third sub-control unit 42(3) executes the fourth process of FIG. 12B according to the flowchart shown in the example of FIG. 15. In this fourth process, the third sub-control unit 42(3) acquires the Nth stock amount and the N+1st stock amount from the third sub-storage unit 43(3) (first acquisition operation, step S48). Note that the method of acquiring the Nth stock amount and the N+1st stock amount in this first acquisition operation is not limited to this. For example, the third sub-control unit 42(3) may acquire the Nth stock amount and the N+1st stock amount by receiving the Nth stock amount and the N+1st stock amount from the fourth sub-control unit 42(4).

[0062] Then, the third sub-control unit 42(3) judges whether the Nth stock amount is less than the N+1th stock amount (third judgment operation, step S49). If the Nth stock amount is less than the N+1th stock amount in this third judgment operation (step S49: YES), the third sub-control unit 42(3) executes a second transfer operation (step S50). In this second transfer operation, the third sub-control unit 42(3) transfers the Nth head data, the destination of which is the Nth sub-control unit 42n, from among the head data stored in the third sub-storage unit 43(3) to the fourth sub-control unit 42(4).

[0063] On the other hand, if the Nth stock amount is equal to or greater than the N+1th stock amount in the third determination operation (step S49: NO), the third sub-controller 42(3) executes a second transfer operation (step S51). In this second transfer operation, the third sub-controller 42(3) transfers the N+1th head data, of the head data stored in the third sub-storage unit 43(3), whose destination is the N+1th sub-controller 42n1, to the fourth sub-controller 42(4).

[0064] Then, the third sub-control unit 42(3) increments N by 1 (step S52) and determines whether the incremented N is K or not (step S53). If N is not equal to K (step S53: NO), the third sub-control unit 42(3) returns to the process of step S48 and executes the subsequent processes. As a result, if N is equal to K (step S53: YES), the Nth sub-control unit 42n has reached the lowest Kth sub-control unit 42(K), and the third sub-control unit 42(3) ends the process.

[0065] In this way, the head data is transferred to a sub-controller 42 having a smaller stock amount in the sub-storage unit 43, which is lower than the own sub-controller 42c, and the stock amount in the sub-storage unit 43 is equalized. This prevents the free space in some of the sub-storage units 43 from becoming small, reduces the amount of head data that is not stored in the sub-storage unit 43 with a small free space and is discarded, and the head data can be efficiently transferred to the lower level, preventing a shortage of head data in the lower level. In addition, it prevents the stock amount in some of the sub-storage units 43 from becoming small, reduces a delay in sending head data from the sub-storage unit 43 with a small stock amount to the head 20, and prevents interruptions to printing.

[0066] In addition, the Nth stock amount and the N+1st stock amount are stored in the third sub-storage unit 43(3). This means that the third sub-control unit 42(3) does not need to receive these from the Nth sub-control unit 42n and the N+1st sub-control unit 42n1 each time the third determination operation is performed, and the third determination operation and the transfer operation of the head data based on the determination result can be performed quickly, thereby preventing a shortage of head data in the lower order.

[0067] <Second Modification> In the printing device 10 according to the second embodiment, the sub-controller 42 executes the third determination operation based on the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 15. In contrast, in the printing device 10 according to the second modified example, the sub-controller 42 executes the third determination operation based on the position information of the N+1th sub-controller 42n1 in addition to the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 18.

[0068] Specifically, in the printing device 10 according to the second modified example, the Nth sub-controller 42n executes the process of step S32 in FIG. 13 as the third process of FIG. 12A, and transmits the Nth stock amount to the directly above sub-controller 42b with the third sub-controller 42(3) as the destination. In response to this, the N+1th sub-controller 42n1 executes step S32a in FIG. 16 as the third process of FIG. 12A, and transmits the N+1st stock amount and the N+1st position information, which is the position information of the N+1st sub-controller 42n1, to the directly above sub-controller 42b with the third sub-controller 42(3) as the destination. This N+1st position information is the position from the main control circuit 31 according to the connection order in the multiple head modules 40 connected in series. In this way, the Nth stock amount, the N+1st stock amount, and the N+1st position information are transferred to the third sub-controller 42(3).

[0069] In response to this, the third sub-control unit 42(3) executes the fifth process of Fig. 12B in accordance with the flowchart of Fig. 17. In the process of Fig. 17, instead of receiving and storing the Nth stock amount and the N+1st stock amount in the process of Fig. 14, the Nth stock amount, the N+1st stock amount, and N+1st position information are received and stored.

[0070] 17, the third sub-control unit 42(3) executes a third receiving operation to receive one of the Nth stock amount and the N+1th stock amount and N+1th position information from the fourth sub-control unit 42(4) (step S71a). The third sub-control unit 42(3) stores the information received in the third receiving operation in the third sub-storage unit 43(3) (storage operation, step S72a).

[0071] The third sub-control unit 42(3) also executes a third receiving operation to receive the other of the Nth stock amount and the N+1th stock amount and the N+1th position information from the fourth sub-control unit 42(4) (step S73a). The third sub-control unit 42(3) stores the information received in this third receiving operation in the third sub-storage unit 43(3) (storage operation, step S74a). In this way, by the fifth process, the third sub-control unit 42(3) stores the Nth stock amount, the N+1th stock amount, and the N+1th position information in the third sub-storage unit 43(3).

[0072] Then, the third sub-control unit 42(3) executes the fourth process of Fig. 12B according to the flowchart shown in the example of Fig. 18. According to the flowchart of Fig. 18, the processes of steps S48a and S49a are executed instead of steps S48 and S49 in the flowchart of Fig. 15, and the process of step S54 is executed between steps S48a and S49a.

[0073] That is, in the fourth process, the third sub-control unit 42(3) acquires the Nth stock amount, the N+1th stock amount, and the N+1th position information from the third sub-storage unit 43(3) (first acquisition operation, step S48a). Note that the method of acquiring the Nth stock amount, the N+1th stock amount, and the N+1th position information is not limited to this. For example, the third sub-control unit 42(3) may acquire the Nth stock amount, the N+1th stock amount, and the N+1th position information by receiving them from the fourth sub-control unit 42(4).

[0074] Then, the third sub-controller 42(3) acquires a weight corresponding to the N+1th position information from the third sub-storage unit 43(3) (step S54). Here, the lower the sub-controllers 42 are, the longer the time it takes to transfer the head data from the main control unit 32, and the more likely it is that the head data will be insufficient. Therefore, the lower the position of the sub-controller 42 is from the main control unit 32 according to the connection order of the multiple sub-controllers 42, the greater the weight of the sub-controller 42. The correspondence between the position information of the sub-controller 42 and the weight is stored in advance in the third sub-storage unit 43(3). For example, the weight corresponding to the position information is greater for the fifth sub-controller 42(5), which is lower than the fourth sub-controller 42(4), than for the fourth sub-controller 42(4).

[0075] Then, the third sub-control unit 42(3) judges whether the Nth stock amount is less than the N+1th stock amount multiplied by the weight (third judgment operation, step S49a). The Nth stock amount multiplied by the weight is the product of the weight and the N+1th stock amount. If the Nth stock amount is less than the N+1th stock amount multiplied by the weight (step S49a: YES), the third sub-control unit 42(3) transfers the Nth head data, of the head data stored in the third sub-storage unit 43(3), whose destination is the Nth sub-control unit 42n, to the fourth sub-control unit 42(4) (second transfer operation, step S50).

[0076] On the other hand, if the Nth stock amount is equal to or greater than the N+1th stock amount multiplied by the weight in the third judgment operation (step S49a: NO), the third sub-control unit 42(3) transfers the N+1th head data, of the head data stored in the third sub-storage unit 43(3), whose destination is the N+1th sub-control unit 42n1, to the fourth sub-control unit 42(4) (second transfer operation, step S51).Then, the third sub-control unit 42(3) increments N by 1 (step S52), and if the incremented N is equal to K (step S53: YES), the third sub-control unit 42(3) ends the fourth process.

[0077] In this way, weighting is applied to the (N+1)th sub-controller 42n1, which requires more time for transfer than the Nth sub-controller 42n, making it easier for head data to be transferred to lower levels in the multiple sub-controllers 42. This makes it possible to prevent a shortage of head data in the lower level sub-storage units 43.

[0078] <Third Modification> In the printing device 10 according to the second embodiment, the sub-controller 42 executes the third determination operation based on the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 15. In contrast, in the printing device 10 according to the third modified example, as shown in the example of Fig. 21, in addition to the Nth stock amount and the N+1st stock amount, the third determination operation is executed based on the acquisition time of the Nth position information and the Nth stock amount, which are position information of the Nth sub-controller 42n, and the acquisition time of the N+1st position information and the N+1st stock amount.

[0079] Specifically, in the printing device 10 according to the third modified example, the Nth sub-control unit 42n executes the process of step S32b in FIG. 19 as the third process of FIG. 12A, and transmits the Nth stock amount, the Nth acquisition time which is the acquisition time of the Nth stock amount, and the Nth position information which is the position information of the Nth sub-control unit 42n to the directly above sub-control unit 42b with the third sub-control unit 42(3) as the destination. Also, the N+1th sub-control unit 42n1 executes the process of step S32b in FIG. 19 as the third process of FIG. 12A, and transmits the N+1st stock amount, the N+1st acquisition time which is the acquisition time of the N+1st stock amount, and the N+1st position information to the directly above sub-control unit 42b with the third sub-control unit 42(3) as the destination.

[0080] The Nth acquisition time is the time when the Nth sub-control unit 42n acquires the stock amount of the data for the Nth head stored in the Nth sub-storage unit 43n. The N+1th acquisition time is the time when the N+1th sub-control unit 42n1 acquires the stock amount of the data for the N+1th head stored in the N+1th sub-storage unit 43n1. In this way, the Nth stock amount, the Nth acquisition time, and the Nth position information are transferred to the third sub-control unit 42(3) as the Nth module information, and the N+1th stock amount, the N+1th acquisition time, and the N+1th position information are transferred to the third sub-control unit 42(3) as the N+1th module information.

[0081] In response to this, the third sub-control unit 42(3) executes the fifth process of Fig. 12B according to the flowchart of Fig. 20. In the process of Fig. 20, instead of receiving and storing the Nth stock amount and the N+1st stock amount in the process of Fig. 14, Nth module information and N+1st module information are received and stored. The Nth module information includes the Nth stock amount, the Nth acquisition time, and the Nth position information, and the N+1st module information includes the N+1st stock amount, the N+1st acquisition time, and the N+1st position information.

[0082] 20, the third sub-control unit 42(3) executes a fourth receiving operation to receive one of the Nth module information and the N+1 module information from the fourth sub-control unit 42(4) (step S71b). The third sub-control unit 42(3) stores the information received in the fourth receiving operation in the third sub-storage unit 43(3) (storage operation, step S72b).

[0083] The third sub-control unit 42(3) also executes a fourth receiving operation to receive the other of the Nth module information and the N+1 module information from the fourth sub-control unit 42(4) (step S73b). The third sub-control unit 42(3) stores the information received in this fourth receiving operation in the third sub-storage unit 43(3) (storage operation, step S74b). In this way, by the fifth process, the third sub-control unit 42(3) stores both the Nth module information and the N+1 module information in the third sub-storage unit 43(3).

[0084] Then, the third sub-control unit 42(3) executes the fourth process of Fig. 12B according to the flowchart shown in the example of Fig. 21. According to the flowchart of Fig. 21, the processes of steps S48b and S49b are executed instead of steps S48 and S49 in the flowchart of Fig. 15, and the processes of steps S55 and S56 are executed between steps S48b and S49b.

[0085] That is, in the fourth process, the third sub-control unit 42(3) acquires the Nth module information and the N+1 module information from the third sub-storage unit 43(3) (first acquisition operation, step S48b). Note that the method of acquiring the Nth module information and the N+1 module information is not limited to this. For example, the third sub-control unit 42(3) may acquire the Nth module information and the N+1 module information by receiving the information from the fourth sub-control unit 42(4).

[0086] Then, the third sub-control unit 42(3) acquires an Nth estimated amount, which is an estimate of the Nth stock amount at the current time, based on the Nth stock amount of the Nth module information, the Nth acquisition time, and the Nth position information (step S55). Here, the multiple sub-control units 42 are connected in series, and the head data is transferred from the main control unit 32 according to the connection order. Therefore, the transfer time of the head data differs depending on the position of the sub-control unit 42 in the multiple sub-control units 42. Therefore, the third sub-control unit 42(3) acquires the Nth estimated amount based on the transfer amount of the Nth head data transferred to the Nth sub-control unit 42n of the Nth position information between the Nth acquisition time and the current time, and the Nth stock amount of the Nth head data in the Nth sub-storage unit 43n at the Nth acquisition time. For example, if there is the Nth location information, the third sub-controller 42(3) can calculate how long it took to transfer data between the Nth acquisition time and the Nth location information from the approximate data transfer speed and the positional relationship between the third sub-controller 42(3) and the Nth sub-controller 42n. Then, the Nth estimated amount is calculated by adding the increase or decrease in the stock amount after the calculated time has elapsed from the Nth acquisition time to the Nth stock amount.

[0087] Furthermore, the third sub-control unit 42(3) acquires an N+1-th estimated amount, which is an estimate of the N+1-th stock amount at the current time, based on the N+1-th stock amount, the N+1-th acquisition time, and the N+1-th position information (step S56). This N+1-th estimated amount is acquired in the same manner as the N-th estimated amount. Note that the N-th estimated amount and the N+1-th estimated amount at the current time may be acquired in sequence. For this reason, the current time at which the N-th estimated amount and the N+1-th estimated amount are acquired may have a time span that includes the difference between their acquisition times (e.g., several seconds).

[0088] Then, the third sub-control unit 42(3) determines whether the Nth estimated quantity is less than the N+1th estimated quantity (third determination operation, step S49b). If the Nth estimated quantity is less than the N+1th estimated quantity in this third determination operation (step S49b: YES), the third sub-control unit 42(3) transfers the Nth head data, of the head data stored in the third sub-storage unit 43(3), whose destination is the Nth sub-control unit 42n, to the fourth sub-control unit 42(4) (second transfer operation, step S50).

[0089] On the other hand, if the Nth estimated quantity is equal to or larger than the N+1th estimated quantity in the third judgment operation (step S49b: NO), the third sub-controller 42(3) transfers the N+1th head data, of the head data stored in the third sub-storage unit 43(3), whose destination is the N+1th sub-controller 42n1, to the fourth sub-controller 42(4) (second transfer operation, step S51).Then, the third sub-controller 42(3) increments N by 1 (step S52), and if the incremented N becomes equal to K (step S53: YES), the third sub-controller 42(3) ends the fourth process.

[0090] In this way, even if there is a difference in the transfer time of head data among multiple serially connected sub-controllers 42, the transfer destination of the head data is determined based on the Nth estimated value and the N+1 estimated value at the current time, taking this difference into consideration. This makes it possible to more accurately prevent a shortage of head data in the lower sub-storage unit 43.

[0091] <Embodiment 3> In the printing device 10 according to the second embodiment, a sub-controller 42 among the multiple sub-controllers 42 transfers head data based on the amount of head data stored in the Nth sub-storage unit 43n and the N+1st sub-storage unit 43n1 among the direct-lower sub-storage unit 43d and the lower sub-storage unit 43e. In contrast, in the printing device 10 according to the third embodiment of the present disclosure, the main controller 32 transfers head data based on the amount of head data stored in the Nth sub-storage unit 43n and the N+1st sub-storage unit 43n1 among the multiple sub-storage units 43.

[0092] The N-th module 40n is any one of the multiple head modules 40. The N+1-th module 40n1 is a head module 40 that is located next to the N-th module 40n in the connection order of the head modules 40 among the multiple head modules 40, and is a direct-below module 40d of the N-th module 40n.

[0093] In the printing device 10 according to the third embodiment, the Nth sub-controller 42n and the N+1th sub-controller 42n1 execute the first process (step S10), the second process (step S20), and the third process (step S30) in parallel according to the flow chart showing an example of the printing process in FIG. 22A. The sub-controllers 42 other than the Nth sub-controller 42n and the N+1th sub-controller 42n1 execute the first process (step S10) and the second process (step S20) in parallel. The first process and the second process are respectively similar to the first process in FIG. 6 and the second process in FIG. 7. Through the second process, each of the multiple sub-controllers 42 executes a printing operation by its own head 20c based on the data for its own head.

[0094] In this second process, each sub-controller 42 ejects ink from its own head 20c based on its own head data stored in its own sub-storage unit 43c, while synchronizing with the ink ejection timing signal. This ink ejection timing and head data are transmitted from the main control unit 32 to each sub-controller 42. Therefore, the main control unit 32 transmits this ink ejection timing and head data to each sub-controller 42, thereby causing each head 20 (for example, the first head 20(1), the Nth head 20n, and the N+1th head 20n1 of the highest module 40a1) to perform a printing operation.

[0095] 22A is similar to the third process in FIG 13. However, in the third process in FIG 22A, the Nth sub-control unit 42n transmits the Nth stock amount to the immediately-upper sub-control unit 42b with the main control unit 32 as the destination, and the N+1th sub-control unit 42n1 transmits the N+1th stock amount to the immediately-upper sub-control unit 42b with the main control unit 32 as the destination. As a result, the Nth stock amount and the N+1st stock amount are transmitted (transferred) to the main control unit 32.

[0096] In response to this, the main control unit 32 executes various processes according to a flowchart showing an example of the printing process in FIG. 22B. In the flowchart in FIG. 22B, a fifth process in step S70 and a sixth process in step S80 are executed instead of the process in step S62 in the flowchart in FIG. 5. This fifth process is similar to the fifth process in FIG. 14. However, in the fifth process in FIG. 22B, the main control unit 32 receives the Nth stock amount and the N+1st stock amount from the top first sub-control unit 42(1) and stores the Nth stock amount and the N+1st stock amount in the main storage unit 33. In addition, the receiving operation in which the main control unit 32 receives the Nth stock amount and the N+1st stock amount is referred to as a fifth receiving operation instead of the second receiving operation.

[0097] In the fifth process, the main control unit 32 executes a fifth receiving operation to receive one of the Nth stock amount and the N+1st stock amount from the first sub-control unit 42(1) (step S71). The main control unit 32 stores the stock amount received in the fifth receiving operation in the main storage unit 33 (storage operation, step S72). The main control unit 32 also executes a fifth receiving operation to receive the other of the Nth stock amount and the N+1st stock amount from the first sub-control unit 42(1) (step S73). The main control unit 32 stores the stock amount received in the fifth receiving operation in the main storage unit 33 (storage operation, step S74). In this way, the main control unit 32 stores the Nth stock amount and the N+1st stock amount in the main storage unit 33.

[0098] Then, the main control unit 32 executes a sixth process according to a flowchart shown in the example of Fig. 23. In this sixth process, the main control unit 32 acquires the Nth stock amount and the N+1st stock amount from the main storage unit 33 (second acquisition operation, step S81). Note that the method of acquiring the Nth stock amount and the N+1st stock amount in this second acquisition operation is not limited to this. For example, the main control unit 32 may acquire the Nth stock amount and the N+1st stock amount by receiving the Nth stock amount and the N+1st stock amount from the first sub-control unit 42(1).

[0099] Then, the main control unit 32 determines whether the Nth stock amount is less than the N+1th stock amount (fourth determination operation, step S82). If the Nth stock amount is less than the N+1th stock amount in this fourth determination operation (step S82: YES), the main control unit 32 transmits the Nth head data, of the head data stored in the main memory unit 33, whose destination is the Nth sub-control unit 42n, to the first sub-control unit 42(1) (transmission operation, step S83).

[0100] On the other hand, if the Nth stock amount is equal to or greater than the N+1st stock amount in the fourth determination operation (step S82: NO), the main control unit 32 transmits the N+1th head data, among the head data stored in the main memory unit 33, whose destination is the N+1st sub-control unit 42n1 to the first sub-control unit 42(1) (transmission operation, step S84).

[0101] Then, the main control unit 32 increments N by 1 (step S85) and determines whether the incremented N is K or not (step S86). If N is not equal to K (step S86: NO), the main control unit 32 returns to the process of step S81 and executes the subsequent processes. If N is equal to K (step S86: YES), the Nth sub-control unit 42n has reached the lowest Kth sub-control unit 42(K), and the main control unit 32 ends the sixth process.

[0102] In this way, head data is sent to sub-controllers 42 with smaller stock amounts in the sub-storage units 43, so the stock amounts in the sub-storage units 43 are uniform. This prevents the free space in some of the sub-storage units 43 from becoming smaller, reduces the amount of head data that is not stored in sub-storage units 43 with smaller free space and is discarded, and allows the head data to be efficiently transferred to lower levels in multiple sub-controllers 42, so it is possible to prevent a shortage of head data in lower levels. In addition, it is possible to prevent the stock amount in some of the sub-storage units 43 from becoming smaller, reduces delays in sending head data from sub-storage units 43 with smaller stock amounts to the head 20, and prevents printing interruptions.

[0103] In addition, the Nth stock amount and the N+1st stock amount are stored in the main storage unit 33. This eliminates the need for the main control unit 32 to receive these from the Nth sub-control unit 42n and the N+1st sub-control unit 42n1 each time the fourth determination operation is performed, and allows the main control unit 32 to quickly perform the fourth determination operation and the operation of transmitting head data based on the determination result, thereby making it possible to suppress a shortage of head data in lower stages.

[0104] <Fourth Modification> In the printing device 10 according to the third embodiment, the main control unit 32 executes the fourth determination operation based on the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 23. In contrast, in the printing device 10 according to the fourth modified example, the main control unit 32 executes the fourth determination operation based on the position information of the N+1th sub-control unit 42n1 in addition to the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 24.

[0105] Specifically, in the printing device 10 according to the fourth modified example, the Nth sub-control unit 42n transmits the Nth stock amount to the immediately-upper sub-control unit 42b with the main control unit 32 as the destination, as in step S32 of Fig. 13, as the third process of Fig. 22A. In response to this, the N+1th sub-control unit 42n1 transmits the N+1st stock amount and N+1st position information to the immediately-upper sub-control unit 42b with the main control unit 32 as the destination, as in step S32a of Fig. 16, as the third process of Fig. 12A. As a result, the Nth stock amount, the N+1st stock amount, and the N+1st position information are transmitted (transferred) to the main control unit 32.

[0106] In response to this, the main control unit 32 performs the fifth process of FIG. 22B to receive and store the Nth stock amount, the N+1th stock amount, and the N+1th position information, similarly to the fifth process of FIG. 17. The receiving operation of the main control unit 32 receiving the Nth stock amount, the N+1th stock amount, and the N+1th position information is referred to as the sixth receiving operation instead of the third receiving operation. That is, the main control unit 32 performs the sixth receiving operation to receive one of the Nth stock amount, the N+1th stock amount, and the N+1th position information from the first sub-control unit 42(1) (step S71a). The main control unit 32 stores the information received in the sixth receiving operation in the main storage unit 33 (storage operation, step S72a). In addition, the main control unit 32 performs the sixth receiving operation to receive the other of the Nth stock amount, the N+1th stock amount, and the N+1th position information from the first sub-control unit 42(1) (step S73a). The main control unit 32 stores the information received in this sixth receiving operation in the main storage unit 33 (storing operation, step S74a). In this manner, the main control unit 32 stores the Nth stock amount, the N+1th stock amount, and the N+1th position information in the main storage unit 33 through the fifth process.

[0107] Then, the main control unit 32 executes the sixth process of Fig. 22B in accordance with the flowchart of Fig. 24. According to the flowchart of Fig. 24, the processes of steps S81a and S82a are executed instead of steps S81 and S82 in the flowchart of Fig. 23, and the process of step S87 is executed between steps S81a and S82a.

[0108] That is, in the sixth process, the main control unit 32 acquires the Nth stock amount, the N+1th stock amount, and the N+1th position information from the main storage unit 33 (second acquisition operation, step S81a). Note that the method of acquiring the Nth stock amount, the N+1th stock amount, and the N+1th position information is not limited to this. For example, the main control unit 32 may acquire the Nth stock amount, the N+1th stock amount, and the N+1th position information by receiving them from the first sub-control unit 42(1).

[0109] Then, the main control unit 32 acquires a weight corresponding to the N+1th position information from the main storage unit 33 (step S87). Then, the main control unit 32 judges whether the Nth stock amount is less than the N+1th stock amount multiplied by the weight (fourth judgment operation, step S82a). If the Nth stock amount is less than the N+1th stock amount multiplied by the weight (step S82a: YES), the main control unit 32 transmits the Nth head data, of the head data stored in the main storage unit 33, whose destination is the Nth sub-control unit 42n, to the first sub-control unit 42(1) (transmission operation, step S83).

[0110] On the other hand, if the Nth stock amount is equal to or greater than the N+1th stock amount multiplied by the weight in the fourth determination operation (step S82a: NO), the main control unit 32 transmits the N+1th head data, of the head data stored in the main storage unit 33, whose destination is the N+1th sub-control unit 42n1 to the first sub-control unit 42(1) (transmission operation, step S84).Then, the main control unit 32 increments N by 1 (step S85), and if the incremented N becomes equal to K (step S86: YES), the main control unit 32 ends the sixth process.

[0111] In this way, weighting is applied to the (N+1)th sub-controller 42n1 that requires more time for transmission than the Nth sub-controller 42n, making it easier for the head data to be transmitted to lower levels in the multiple sub-controllers 42. This makes it possible to prevent a shortage of head data in the lower level sub-storage units 43.

[0112] <Fifth Modification> In the printer 10 according to the third embodiment, the main control unit 32 executes the fourth determination operation based on the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 23. In contrast, in the printer 10 according to the fifth modified example, the fourth determination operation is executed based on the Nth position information and the N acquisition time, and the N+1th position information and the N+1st acquisition time, in addition to the Nth stock amount and the N+1st stock amount, as shown in the example of Fig. 25.

[0113] Specifically, in the printing device 10 according to the fifth modified example, the Nth sub-control unit 42n transmits the Nth module information (the Nth stock amount, the Nth acquisition time, and the Nth position information) to the immediately-upper sub-control unit 42b with the main control unit 32 as the destination, as in step S32b of FIG. 19, as the third process of FIG. 22A. Also, the N+1th sub-control unit 42n1 transmits the N+1th module information (the N+1st stock amount, the N+1st acquisition time, and the N+1st position information) to the immediately-upper sub-control unit 42b with the main control unit 32 as the destination, as in step S32b of FIG. 19, as the third process of FIG. 22A. As a result, the Nth module information and the N+1st module information are transmitted (transferred) to the main control unit 32.

[0114] In response to this, the main control unit 32 receives and stores the Nth module information and the N+1 module information in the fifth process of FIG. 22B, similarly to the fifth process of FIG. 20. The receiving operation in which the main control unit 32 receives the Nth module information and the N+1 module information is called the seventh receiving operation instead of the fourth receiving operation. That is, in the fifth process of FIG. 20, the main control unit 32 executes the seventh receiving operation in which one of the Nth module information and the N+1 module information is received from the first sub-control unit 42(1) (step S71b). The main control unit 32 stores the information received in this seventh receiving operation in the main storage unit 33 (storing operation, step S72b). In addition, the main control unit 32 executes the seventh receiving operation in which the other of the Nth module information and the N+1 module information is received from the first sub-control unit 42(1) (step S73b). The main control unit 32 stores the information received in this seventh receiving operation in the main storage unit 33 (storing operation, step S74b). In this manner, the main control unit 32 stores both the Nth module information and the N+1th module information in the main storage unit 33 through the fifth process.

[0115] Then, the main control unit 32 executes the sixth process of Fig. 22B in accordance with the flowchart shown in the example of Fig. 25. According to the flowchart of Fig. 25, the processes of steps S81b and S82b are executed instead of steps S81 and S82 in the flowchart of Fig. 23, and the processes of steps S88 and S89 are executed between steps S81b and S82b.

[0116] That is, in the sixth process, the main control unit 32 acquires the Nth module information and the N+1 module information from the main storage unit 33 (second acquisition operation, step S81b). Note that the method of acquiring the Nth module information and the N+1 module information is not limited to this. For example, the main control unit 32 may acquire the Nth module information and the N+1 module information by receiving the information from the first sub-control unit 42(1).

[0117] Then, the main control unit 32 acquires an N-th estimated amount, which is an estimated amount of the N-th stock amount at the current time, based on the N-th stock amount, the N-th acquisition time, and the N-th position information of the N-th module information (step S88). Also, the main control unit 32 acquires an N+1 estimated amount, which is an estimated amount of the N+1 stock amount at the current time, based on the N+1 stock amount, the N+1 acquisition time, and the N+1 position information (step S89). Then, the main control unit 32 determines whether the N-th estimated amount is less than the N+1 estimated amount (fourth determination operation, step S82b). If the N-th estimated amount is less than the N+1 estimated amount in this fourth determination operation (step S82b: YES), the main control unit 32 transmits the N-th head data, which is destined for the N-th sub-control unit 42n, out of the head data stored in the main storage unit 33, to the first sub-control unit 42(1) (transmission operation, step S83).

[0118] On the other hand, if the Nth estimated amount is equal to or greater than the N+1th estimated amount in the fourth determination operation (step S82b: NO), the main control unit 32 transmits the N+1th head data, of the head data stored in the main memory unit 33, whose destination is the N+1th sub-control unit 42n1 to the first sub-control unit 42(1) (transmission operation, step S84).Then, the main control unit 32 increments N by 1 (step S85), and if this incremented N becomes equal to K (step S86: YES), the main control unit 32 ends the sixth process.

[0119] In this way, even if there is a difference in the transfer time of head data among multiple serially connected sub-controllers 42, the transfer destination of the head data is determined based on the Nth estimated value and the N+1 estimated value at the current time, taking this difference into consideration. This makes it possible to more accurately prevent a shortage of head data in the lower sub-storage unit 43.

[0120] The above-mentioned embodiments and each modification may be combined with each other as long as they do not exclude each other. In addition, many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art from the above description. Therefore, the above description should be construed as merely an example, and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. The details of the structure and / or function may be substantially changed without departing from the spirit of the present disclosure. [Explanation of symbols]

[0121] 10:Printing device 20: Head 31: Main module 33: Main memory section 40: Head module 42: Sub-storage unit 43: Sub-control section

Claims

1. A plurality of head modules connected in series, the plurality of head modules including a head module, a direct-below module that is a head module located adjacent to the direct-below module in the connection order of the head modules, and a lower module that is a head module located lower than the direct-below module; A main control unit, The module includes a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The direct-below module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The lower module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, the main control unit, the sub-control unit of the module itself, the sub-control unit of the direct-below module, and the sub-control unit of the lower module are connected in series; The sub-control unit of the module a first receiving operation for receiving a free space of the sub-storage unit of the immediately-below module from the sub-controller of the immediately-below module; a first determination operation for determining whether or not the free space of the sub-storage unit of the direct-below module is equal to or greater than a first predetermined value; a first transfer operation of transferring the image data for the direct-below module and the image data for the lower module among the image data stored in the sub-storage unit of the module itself to the sub-control unit of the direct-below module; a printing operation in which the head of the module itself prints using the image data; In the first transfer operation, When the free space of the sub-storage unit of the direct-below module is equal to or greater than the first predetermined value, the image data for the direct-below module and the image data for the lower module are transferred to the sub-control unit of the direct-below module in a packet having a capacity equal to or greater than a second predetermined value; When the free space of the sub-storage unit of the direct-below module is less than the first predetermined value, the image data for the direct-below module and the image data for the lower module are transferred to the sub-control unit of the direct-below module in a packet having a capacity less than the second predetermined value. Printing device.

2. The sub-control unit of the module In the first receiving operation, a free space of the sub-storage unit of the direct-below module and a stock amount of the image data for the direct-below module among the image data stored in the sub-storage unit of the direct-below module are received from the sub-control unit of the direct-below module; execute a second determination operation for determining whether or not the stock amount of the sub-storage unit of the directly-below module is equal to or greater than a third predetermined value; In the first transfer operation, When the stock amount of the sub-storage unit of the immediately-below module is less than the third predetermined value, the image data for the immediately-below module is transferred to the sub-control unit of the immediately-below module. The printing device of claim 1 .

3. The sub-control unit of the module In the first transfer operation, when the stock amount of the sub-storage unit of the immediately-below module is equal to or greater than the third predetermined value and the free space of the sub-storage unit of the immediately-below module is equal to or greater than the first predetermined value, the image data for the lower module is transferred to the sub-control unit of the immediately-below module in a packet having a capacity equal to or greater than the second predetermined value; The printing device according to claim 2 .

4. The sub-control unit of the module In the first transfer operation, when the stock amount of the sub-storage unit of the immediately-below module is equal to or greater than the third predetermined value and the free space of the sub-storage unit of the immediately-below module is less than the first predetermined value, the image data for the lower module is transferred to the sub-control unit of the immediately-below module in a packet having a capacity less than the second predetermined value; 4. The printing device according to claim 2 or 3.

5. A plurality of head modules connected in series, the plurality of head modules including a head module, a direct-below module that is a head module located adjacent to the direct-below module in the connection order of the head modules, and a lower module that is a head module located lower than the direct-below module; A main control unit, The module includes a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The direct-below module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The lower module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, the main control unit, the sub-control unit of the module itself, the sub-control unit of the direct-below module, and the sub-control unit of the lower module are connected in series; Among the direct-below module and the lower module, any one head module is defined as an N-th module, and the head module located next to the lower-level N-th module in the connection order of the head modules is defined as an N+1-th module. The sub-control unit of the module a first acquisition operation for acquiring a stock amount of the image data for the N module among the image data stored in the sub-storage unit of the N module, and a stock amount of the image data for the N+1 module among the image data stored in the sub-storage unit of the N+1 module; a third determination operation for determining whether or not the stock amount of the sub-storage unit of the Nth module is less than the stock amount of the sub-storage unit of the N+1th module; a second transfer operation of transferring the image data for the Nth module or the image data for the N+1th module among the image data stored in the sub-storage unit of the module itself to the sub-control unit of the module immediately below; a printing operation in which the head of the module itself prints using the image data; In the second transfer operation, When the stock amount of the sub-storage unit of the Nth module is less than the stock amount of the sub-storage unit of the N+1th module, the image data for the Nth module is transferred to the sub-control unit of the immediately-below module; When the stock amount of the sub-storage unit of the Nth module is equal to or greater than the stock amount of the sub-storage unit of the N+1th module, the image data for the N+1th module is transferred to the sub-control unit of the immediately-below module. Printing device.

6. The sub-control unit of the module a second receiving operation of receiving the stock amount of the sub-storage unit of the Nth module and the stock amount of the sub-storage unit of the N+1th module from the sub-control unit of the immediately-lower module; a storage operation of storing the stock amount of the sub-storage unit of the Nth module and the stock amount of the sub-storage unit of the N+1th module received in the second receiving operation in the sub-storage unit of the own module; The printing device according to claim 5 .

7. The sub-control unit of the module In the first acquisition operation, a stock amount of the sub-storage unit of the Nth module, a stock amount of the sub-storage unit of the N+1th module, and position information of the sub-control unit of the N+1th module are acquired; In the third determination operation, it is determined whether or not the stock amount of the sub-memory unit of the Nth module is less than the stock amount of the sub-memory unit of the Nth module multiplied by a weight corresponding to the position information of the sub-control unit of the Nth module; In the second transfer operation, When the stock amount of the sub-memory unit of the Nth module is less than the stock amount of the sub-memory unit of the Nth module multiplied by a weight corresponding to the position information of the sub-control unit of the Nth module, the image data for the Nth module is transferred to the sub-control unit of the immediately lower module; When the stock amount of the sub-memory unit of the Nth module is equal to or greater than the stock amount of the sub-memory unit of the Nth module multiplied by a weight corresponding to the position information of the sub-control unit of the Nth module, the image data for the Nth module is transferred to the sub-control unit of the immediately-below module. The printing device according to claim 5 .

8. The sub-control unit of the module a third receiving operation of receiving information on the stock amount of the sub-storage unit of the Nth module, the stock amount of the sub-storage unit of the N+1th module, and the position information of the sub-control unit of the N+1th module from the sub-control unit of the immediately-lower module; a storage operation for storing the stock amount of the sub-storage unit of the Nth module, the stock amount of the sub-storage unit of the N+1th module, and the position information of the sub-control unit of the N+1th module received in the third receiving operation in the sub-storage unit of the own module; The printing device according to claim 7.

9. The sub-control unit of the module In the first acquisition operation, a stock amount of the sub-storage unit of the Nth module, position information of the sub-control unit of the Nth module, an acquisition time of the stock amount of the sub-storage unit, a stock amount of the sub-storage unit of the N+1th module, position information of the sub-control unit of the N+1th module, and an acquisition time of the stock amount of the sub-storage unit are acquired; In the third determination operation, a determination is made as to whether or not an estimated amount of the stock of the sub-memory of the Nth module at the current time based on the stock amount of the sub-memory, the position information of the sub-controller, and the acquisition time is less than an estimated amount of the stock of the sub-memory of the N+1th module at the current time based on the stock amount of the sub-controller, the position information of the sub-controller, and the acquisition time; In the second transfer operation, When the estimated amount of stock of the sub-storage unit of the Nth module is less than the estimated amount of stock of the sub-storage unit of the N+1th module, the image data for the Nth module is transferred to the sub-control unit of the immediately-below module; When the estimated amount of stock of the sub-storage unit of the Nth module is equal to or greater than the estimated amount of stock of the sub-storage unit of the N+1th module, the image data for the N+1th module is transferred to the sub-control unit of the immediately-below module. The printing device according to claim 5 .

10. The sub-control unit of the module a fourth receiving operation of receiving the stock amount of the sub-storage unit of the Nth module, the location information of the sub-control unit, and the acquisition time, and the stock amount of the sub-storage unit of the N+1th module, the location information of the sub-control unit, and the acquisition time from the sub-control unit of the immediately subordinate module; a storage operation for storing the stock amount of the sub-storage unit of the Nth module, the location information of the sub-control unit, and the acquisition time received in the fourth receiving operation, and the stock amount of the sub-storage unit of the N+1th module, the location information of the sub-control unit, and the acquisition time in the sub-storage unit of the own module; The printing device of claim 9.

11. A main control unit; A plurality of head modules connected in series, the plurality of head modules including a top module connected to the main control unit, any one of the Nth modules other than the top module, and an N+1th module located next to the lower level of the Nth module in the connection order of the head modules; A main storage unit that stores image data, The top module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The Nth module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The N+1 module has a head that ejects ink onto a print medium, a sub-storage unit that stores image data, and a sub-control unit that controls the head based on the image data, The main control unit is A second acquisition operation for acquiring a stock amount of the image data for the N module among the image data stored in the sub-storage unit of the N module, and a stock amount of the image data for the N+1 module among the image data stored in the sub-storage unit of the N+1 module; a fourth determination operation for determining whether or not the stock amount of the sub-storage unit of the Nth module is less than the stock amount of the sub-storage unit of the N+1th module; a transmission operation of transmitting the image data for the Nth module or the image data for the N+1th module out of the image data stored in the main storage unit to the sub-controller of the highest module; executing a printing operation to cause the head of the top module, the head of the Nth module, and the head of the N+1th module to print using the image data; In the transmitting operation, When the stock amount of the sub-storage unit of the Nth module is less than the stock amount of the sub-storage unit of the N+1th module, the image data for the Nth module is transmitted to the sub-control unit of the highest module; When the stock amount of the sub-storage unit of the Nth module is equal to or greater than the stock amount of the sub-storage unit of the N+1th module, the image data for the N+1th module is transmitted to the sub-control unit of the highest module. Printing device.

12. The main control unit is a fifth receiving operation of receiving a stock amount of the sub-storage unit of the Nth module and a stock amount of the sub-storage unit of the N+1th module from the sub-control unit of the highest module; and a storing operation of storing in the main memory the stock amount of the sub-storage unit of the Nth module and the stock amount of the sub-storage unit of the N+1th module received in the fifth receiving operation. The printing device of claim 11.

13. The main control unit is In the second acquisition operation, a stock amount of the sub-storage unit of the Nth module, a stock amount of the sub-storage unit of the N+1th module, and position information of the sub-control unit of the N+1th module are acquired; In the fourth determination operation, it is determined whether or not the stock amount of the sub-memory unit of the Nth module is less than the stock amount of the sub-memory unit of the Nth module multiplied by a weight corresponding to the position information of the sub-control unit of the Nth module; In the transmitting operation, If the stock amount of the sub-memory unit of the Nth module is less than the stock amount of the sub-memory unit of the Nth module multiplied by a weight corresponding to the position information of the sub-control unit of the Nth module, the image data for the Nth module is transmitted to the sub-control unit of the highest module; When the stock amount of the sub-memory unit of the Nth module is equal to or greater than the stock amount of the sub-memory unit of the Nth module multiplied by a weight corresponding to the position information of the sub-control unit of the Nth module, the image data for the Nth module is transmitted to the sub-control unit of the highest module. The printing device of claim 11.

14. The main control unit is a sixth receiving operation of receiving, from the sub-control unit of the highest module, information on the stock amount of the sub-storage unit of the Nth module, the stock amount of the sub-storage unit of the N+1th module, and the position information of the sub-control unit of the N+1th module; a storage operation for storing in the main storage unit the stock amount of the sub-storage unit of the Nth module, the stock amount of the sub-storage unit of the N+1th module, and the position information of the sub-control unit of the N+1th module, which are received in the sixth receiving operation; The printing device of claim 13.

15. The main control unit is In the second acquisition operation, a stock amount of the sub-storage unit of the Nth module, position information of the sub-control unit of the Nth module, an acquisition time of the stock amount of the sub-storage unit, a stock amount of the sub-storage unit of the N+1th module, position information of the sub-control unit of the N+1th module, and an acquisition time of the stock amount of the sub-storage unit are acquired; In the fourth determination operation, a determination is made as to whether or not an estimated amount of the stock of the sub-memory of the Nth module at the current time based on the stock amount of the sub-memory, the position information of the sub-controller, and the acquisition time is less than an estimated amount of the stock of the sub-memory of the N+1th module at the current time based on the stock amount of the sub-controller, the position information of the sub-controller, and the acquisition time; In the transmitting operation, If the estimated amount of stock in the sub-memory unit of the Nth module is less than the estimated amount of stock in the sub-memory unit of the N+1th module, the image data for the Nth module is transmitted to the sub-control unit of the highest module; When the estimated amount of stock in the sub-storage unit of the Nth module is equal to or greater than the estimated amount of stock in the sub-storage unit of the N+1th module, the image data for the N+1th module is transmitted to the sub-control unit of the highest module. The printing device of claim 11.

16. The main control unit is a seventh receiving operation of receiving, from the sub-control unit of the highest module, the stock amount of the sub-storage unit of the Nth module, the location information of the sub-control unit, and the acquisition time, and the stock amount of the sub-storage unit of the N+1th module, the location information of the sub-control unit, and the acquisition time; a storage operation for storing in the main storage unit the stock amount of the sub-storage unit of the Nth module, the position information of the sub-control unit, and the acquisition time, which are received in the seventh receiving operation, and the stock amount of the sub-storage unit of the N+1th module, the position information of the sub-control unit, and the acquisition time, which are received in the seventh receiving operation; The printing device of claim 15.

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