Printing device, printing method and computer program

Abstract

To provide a printing device and the others which can suppress memory capacities from increasing.SOLUTION: A printing device comprises a main control circuit, a sub control circuit group, connected in series to the main control circuit, through which print data from the main control circuit is transferred from an upstream side to a downstream side, and a head group that is driven by the sub control circuit group. The sub control circuit group includes sub control circuits including a first sub control circuit at a most-upstream side and n-sub control circuits at a most-downstream side (n is 2 or more integers). The print data include print data including first print data corresponding to the first sub control circuit and n-print data corresponding to the n-sub control circuits. The print data including the first print data and the n-print data are data corresponding to one line. The main control circuit executes a transmission process of transmitting the print data including the first print data and the n-print data to the first sub-control circuits.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present technology relates to a printing device that performs printing by ejecting liquid from a head, a printing method, and a computer program. [Background technology]

[0002] An image forming system has been proposed that includes a PC that generates image data, and a receiving board and multiple distribution boards that are serially connected to the PC. Multiple head controllers are connected to each distribution board. The receiving board can transmit image data (print data) along with identification information for the distribution board and the head controller to the most upstream distribution board, thereby transmitting the print data to the desired head controller (see Patent Document 1). [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] Since it is necessary to store not only the print data but also the identification information, the storage capacities of the receiving board and the distribution board must be large.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a printing device, a printing method, and a computer program that can suppress an increase in storage capacity. [Means for solving the problem]

[0006] A printing device according to one embodiment of the present disclosure comprises a main control circuit, a group of sub-control circuits connected in series to the main control circuit and transferring print data from the main control circuit from upstream to downstream, and a group of heads driven by the group of sub-control circuits, wherein the group of sub-control circuits includes a first sub-control circuit at the most upstream position to an nth sub-control circuit at the most downstream position (n is a natural number greater than or equal to 2), the print data includes first print data corresponding to the first sub-control circuit to nth print data corresponding to the nth sub-control circuit, each piece of print data from the first print data to the nth print data is one line's worth of data, and the main control circuit executes a transmission process to transmit the first print data to the nth print data to the first sub-control circuit.

[0007] A printing method according to one embodiment of the present disclosure is a printing method executed by a printing device including a main control circuit, a group of sub-control circuits connected in series to the main control circuit and transferring print data from the main control circuit from upstream to downstream, and a group of heads driven by the group of sub-control circuits, wherein the group of sub-control circuits includes a first sub-control circuit at the most upstream position to an nth sub-control circuit at the most downstream position (n is a natural number of 2 or more), the print data includes first print data corresponding to the first sub-control circuit to the nth print data corresponding to the nth sub-control circuit, each piece of print data from the first print data to the nth print data is data for one line, and the main control circuit transmits the first print data to the nth print data to the first sub-control circuit.

[0008] A computer program according to one embodiment of the present disclosure is a computer program executable by a printing device having a main control circuit, a group of sub-control circuits connected in series to the main control circuit and transferring print data from the main control circuit from upstream to downstream, and a group of heads driven by the group of sub-control circuits, wherein the group of sub-control circuits includes a first sub-control circuit at the most upstream position to an nth sub-control circuit at the most downstream position (n is a natural number of 2 or more), the print data includes first print data corresponding to the first sub-control circuit to the nth print data corresponding to the nth sub-control circuit, each piece of print data from the first print data to the nth print data is data for one line, and the main control circuit executes a process of transmitting the first print data to the nth print data to the first sub-control circuit. Effect of the Invention

[0009] In the printing device, printing method, and computer program according to an embodiment of the present disclosure, the main control circuit transmits only one line of data, which makes it possible to suppress an increase in the storage capacity of the main control circuit and each sub-control circuit. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic plan view of a printing device according to a first embodiment. [Diagram 2] FIG. 2 is a plan view perspective view of an inkjet head. [Diagram 3] FIG. 2 is a block diagram of a control device and an inkjet head. [Figure 4] 13 is an explanatory diagram illustrating the positional relationship between the nozzles of the kth head module and the nozzles of the (k-1)th head module, and the nozzle usage ratio. FIG. [Diagram 5] 11 is a flowchart illustrating a data transmission process by a main control circuit. [Figure 6] 11 is a flowchart illustrating a printing process performed by a sub-control circuit. [Figure 7] 10 is a flowchart illustrating a print process by a sub-control circuit according to a second embodiment. [Figure 8] 13 is a flowchart illustrating a printing process by a sub-control circuit according to a modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Embodiment 1) The present invention will be described below with reference to the drawings showing a printing device 1 according to a first embodiment. Fig. 1 is a simplified plan view of the printing device 1. In Fig. 1, the conveying direction of the recording paper 100 corresponds to the front-rear direction of the printing device 1. The width direction of the recording paper 100 corresponds to the left-right direction of the printing device 1. The recording paper 100 corresponds to a recording medium. The direction perpendicular to the front-rear direction and the left-right direction, i.e., the direction perpendicular to the paper surface of Fig. 1, corresponds to the up-down direction of the printing device 1.

[0012] As shown in FIG. 1, the printing device 1 includes a platen 3 housed in a case 2, four inkjet heads 4, two transport rollers 5 and 6, and a control device 7. A recording paper 100 passes over the upper surface of the platen 3. The four inkjet heads 4 are lined up in the transport direction above the platen 3. Each inkjet head 4 is a so-called line-type head. Ink is supplied to the inkjet heads 4 from an ink tank (not shown). Different color inks are supplied to the four inkjet heads 4.

[0013] As shown in Fig. 1, the two transport rollers 5, 6 are disposed on the rear and front sides, respectively, of the platen 3. The two transport rollers 5, 6 are each driven by a motor (not shown) and transport the recording paper 100 on the platen 3 forward. The two transport rollers 5, 6 correspond to a transport section. The control device 7 controls the printing device 1 based on a control program. The control device 7 is connected to an external device 9 such as a PC so as to be able to perform data communication, and drives each section of the printing device 1 to execute printing based on print data transmitted from the external device 9.

[0014] 2 is a planar perspective view of the inkjet head 4. The inkjet head 4 includes a plurality of heads 42. The heads 42 correspond to head units. The plurality of heads 42 are arranged in two rows in the front-rear direction. In the front row, four heads 42 are arranged along the left-right direction, and in the rear row, five heads are arranged along the left-right direction. A plurality of nozzles 42a are provided on the underside of the heads 42. Note that the number of heads 42 and the number of rows are not limited and can be changed.

[0015] 3 is a block diagram of the control device 7 and the inkjet head 4. The control device 7 includes a main control circuit 7a. The main control circuit 7a includes a control unit 7b, a main memory unit 7c, an auxiliary memory unit 7d, and a communication interface (I / F) 7e. The control unit 7b includes a logic circuit, for example, an FPGA. The control unit 7b may include a processor, for example, a CPU or an ASIC. The main memory unit 7c is, for example, a RAM.

[0016] An example of the main memory unit is a RAM. An example of the auxiliary memory unit is a ROM and a rewritable storage medium, such as an EEPROM, an EPROM, or a hard disk. A control program is stored in the auxiliary memory unit. The control unit 7b reads the control program from the auxiliary memory unit to the main memory unit and executes it. The control program may be installed in the auxiliary memory unit from a recording medium 70 (see FIG. 1), such as an optical disk or a portable flash memory. The control program may be downloaded to the auxiliary memory unit from a server connected to the printing device 1 via a communication network. The communication I / F 7d is connected to the communication cable 50. The control device 7 controls the printing device 1 based on the control program.

[0017] The inkjet head 4 includes a plurality of head modules 40. The plurality of head modules 40 are arranged in a line in the left-right direction, for example. The plurality of head modules 40 include, for example, a first head module 40(1), a second head module 40(2), ..., an nth head module 40(n) (n is a natural number). The first head module 40(1) is located on the leftmost side, and the nth head module 40(n) is located on the rightmost side. Of all the head modules 40, the first head module 40(1) is located closest to the control device 7, and the nth head module 40(n) is located farthest from the control device 7.

[0018] Each of the first head module 40(1) to the nth head module 40(n) includes a sub-control circuit 41, a head 42, an upstream I / F 43a, and a downstream I / F 43b. The multiple heads 42 correspond to a head group. The sub-control circuit 41 includes a control unit 41a, a main memory unit 41b, and an auxiliary memory unit 41c. The sub-control circuit 41 includes, for example, an ASIC or SoC. The multiple sub-control circuits 41 correspond to a sub-control circuit group.

[0019] The control unit 41a controls the operation of the sub-control circuit 41. The control unit 41a may include, for example, a CPU, or may include a logic circuit such as an FPGA. The main memory unit 41b is, for example, a RAM. The auxiliary memory unit 41c is, for example, a rewritable non-volatile memory such as an EPROM or EEPROM. Hereinafter, the sub-control circuits 41 of the first head module 40(1) to the nth head module 40(n) are also referred to as the sub-control circuit 41(1) to the sub-control circuit 41(n).

[0020] Each of the I / Fs 7e, 43a, 43b is an interface capable of bidirectional communication, and is connected in series by a connector and a communication cable 50. The I / F 7e transmits print data to the I / F 43a of the sub-control circuit 41(1). The I / F 43b of the sub-control circuit 41(1) transfers the print data to the I / F 43a of the sub-control circuit 41(2), and the I / F 43b of the sub-control circuit 41(2) transmits the print data to the I / F 43a of the sub-control circuit 41(3). In this manner, the print data is transferred in sequence up to the I / F 43a of the sub-control circuit 41(n). Each sub-control circuit 41 drives the head 42 based on the print data to eject ink.

[0021] FIG. 4 is an explanatory diagram for explaining the positional relationship between the nozzles 42a of the kth head module 40(k) and the nozzles 42a of the k-1th head module 40(k-1), and the usage ratio of the nozzles 42a. Numbers 1 to 12 in FIG. 4 indicate the first to 12th positions of the nozzles 42a in the left-right direction, with the first position indicating the rightmost position and the 12th position indicating the leftmost position. For example, the head 42 of the kth head module 40(k) includes nozzles 42a(1) to 42a(8). The nozzles 42a(1) to 42a(8) are located at the first to eighth positions, respectively. The head 42 of the k-1th head module 40(k-1) includes nozzles 42a(5) to 42a(12). The nozzles 42a(5) to 42a(12) are located at the fifth to twelfth positions, respectively.

[0022] Nozzles 42a(5) through 42a(8) of the kth head module 40(k) and nozzles 42a(5) through 42a(8) of the k-1th head module 40(k) are positioned so as to overlap in the front-to-rear direction, i.e., in the transport direction of the recording paper 100. In Fig. 4, L indicates the boundary line between nozzles 42a(1) through 42a(6) of the kth head module 40(k) and nozzles 42a(7) through 42a(12) of the k-1st head module 40(k).

[0023] When sending print data from the main control circuit 7a to the kth head module 40(k), the main control circuit 7a sends print data to be ejected from nozzles 42a(1) to 42a(6) of the kth head module 40(k). When sending print data from the main control circuit 7a to the k-1th head module 40(k-1), the main control circuit 7a sends print data to be ejected from nozzles 42a(7) to 42a(12) of the k-1st head module 40(k-1). In other words, the boundary line L distinguishes between the print data sent from the main control circuit 7a to the kth head module 40(k) and the k-1st head module 40(k-1).

[0024] The k-th head module 40(k) obtains print data to be ejected from its own nozzle 42a(7) and nozzle 42a(8) from the k-1st head module 40(k-1). The k-1st head module 40(k-1) obtains print data to be ejected from its own nozzle 42a(5) and nozzle 42a(6) from the k-th head module 40(k).

[0025] The graph on the right side of Fig. 4 shows an example of the usage ratio of nozzle 42a. The solid line graph shows the usage ratio of nozzle 42a(1) through nozzle 42a(8) of the kth head module 40(k). As shown in the solid line graph, the usage ratio of nozzle 42a(1) through nozzle 42a(4) of the kth head module 40(k) is 100%. The usage ratio of nozzle 42a(5) of the kth head module 40(k) is 80%, the usage ratio of nozzle 42a(6) is 60%, the usage ratio of nozzle 42a(7) is 40%, and the usage ratio of nozzle 42a(8) is 20%.

[0026] The dashed-dotted line graph shows the usage ratio of nozzle 42a(5) to nozzle 42a(12) of the k-1th head module 40(k-1). As shown in the dashed-dotted line graph, the usage ratio of nozzle 42a(5) of the k-1th head module 40(k-1) is 20%, the usage ratio of nozzle 42a(6) is 40%, the usage ratio of nozzle 42a(7) is 60%, and the usage ratio of nozzle 42a(8) is 80%. The usage ratio of nozzle 42a(9) to nozzle 42a(12) of the k-1th head module 40(k-1) is 100%.

[0027] That is, when the nozzles 42a overlap in the transport direction of the recording paper 100, the usage ratio of each of the nozzles 42a overlapping in the transport direction is corrected so that the total usage ratio of the multiple nozzles 42a overlapping in the transport direction becomes 100%.

[0028] 5 is a flowchart explaining the data transmission process by the main control circuit 7a. The main control circuit 7a executes each process according to the flowchart, for example, when in a standby state. The control unit 7b judges whether or not to start transmitting one line of print data (S1). For example, when the control unit 7b receives one line of print data from the external device 9, the control unit 7b starts transmitting the print data. When it is judged not to start transmitting the print data (S1: NO), for example, when the amount of received print data is less than one line, the control unit 7b returns the process to step S1.

[0029] When it is determined that transmission of one line of print data should be started (S1: YES), the control unit 7b assigns n to a variable M indicating the ordinal number of the head module 40, that is, an ordinal number indicating the n-th head module 40(n) located at the most downstream (S2). Here, n is assumed to be 2 or more. The variable M is pre-stored in the main storage unit 7c.

[0030] The control unit 7b creates the Mth print data (S3). The control unit 7b transmits the Mth print data to the first sub-control circuit (S4). The control unit 7b determines whether M is 1 or not (S5). If M is not 1 (S5: NO), the control unit 7b decrements M by one (S6) and returns the process to step S3. The Mth print data is transferred from the first sub-control circuit to the Mth sub-control circuit. The main control circuit 7a transmits the k+1th print data to the first sub-control circuit, and after transmitting the k+1st print data, transmits the kth print data to the first sub-control circuit. The k+1st print data is transferred from the first sub-control circuit to the k+1st sub-control circuit, and the kth print data is transferred from the first sub-control circuit to the kth sub-control circuit. If M is 1 (S5: YES), the control unit 7b ends the process.

[0031] The first print data to the nth print data are print data corresponding to the sub-control circuit 41(1) to the sub-control circuit 41(n). The total amount of the first print data to the nth print data constitutes one line's worth of data. That is, each of the print data from the first print data to the nth print data is one line's worth of data. For example, when a print instruction for one page is sent from the external device 9 to the control device 7, the control unit 7b repeatedly sends one line's worth of data, i.e., the first print data to the nth print data, to the sub-control circuit 41(1) to the sub-control circuit 41(n) until the print process for one page is completed.

[0032] FIG. 6 is a flowchart explaining the printing process by the sub-control circuit 41(k). The control unit 41a of the sub-control circuit 41(k) judges whether or not the printing data has been received (S11). If it is judged that the printing data has been received (S11: YES), that is, if it is judged that the printing data is stored in the main memory unit 41b, the control unit 41a judges whether or not a predetermined amount of printing data has been transmitted to the sub-control circuit 41(k+1), that is, downstream (S12). The predetermined amount of printing data is the total amount of printing data from the k+1th printing data corresponding to the sub-control circuit 41(k+1) to the nth printing data corresponding to the sub-control circuit 41(n). The auxiliary memory unit 41c of the sub-control circuit 41(k) stores the total amount of printing data from the k+1th printing data to the nth printing data in advance. The process of step S12 constitutes a first judgment process.

[0033] When it is determined that a predetermined amount of print data has been sent to the sub-control circuit 41(k+1) (S12: YES), the control unit 41a stores the print data stored in its own main memory unit 41b as the kth print data (S13). That is, when print data is received after the print data from the k+1th print data to the nth print data are sent to the sub-control circuit 41(k+1), the control unit 41a stores the received print data (kth print data) in its own main memory unit 41b. The process of step S13 constitutes a first storage process.

[0034] The control unit 41a determines whether or not all of the kth print data have been stored (S14). For example, the capacity of the main memory unit 41b of the sub-control circuit 41(k) corresponds to the amount of data of the kth print data. The control unit 41a of the sub-control circuit 41(k) determines that all of the kth print data have been stored when, for example, the remaining capacity of the main memory unit 41b falls below a threshold. The threshold is stored in advance in the auxiliary memory unit 41c. The kth print data may be stored in the auxiliary memory unit 41c. In this case, when the remaining capacity of the auxiliary memory unit 41c falls below the threshold, it is determined that all of the kth print data have been stored.

[0035] When it is determined that all of the kth print data have been stored (S14: YES), the control unit 41a notifies the sub-control circuit 41(k-1), i.e., upstream, that all of the kth print data have been stored (S15). The control unit 41a drives the head 42 based on the kth print data and executes printing (S16). That is, after executing the reception process of the sth print data, the sub-control circuit 41(s) (s is a natural number from 1 to n) executes a drive process to drive the head 42 of the sth head module 40(s) based on the sth print data.

[0036] After printing, the control unit 41a deletes the kth print data from the main storage unit 41b (S17) and determines whether the printing process is complete (S18). For example, when a print instruction for one page is sent from the external device 9 to the control device 7, the control unit 41a determines whether the printing process for one page is complete. If it is determined that the printing process is complete (S18: YES), the control unit 41a ends the process. If it is determined that the printing process is not complete (S18: NO), the control unit 41a returns the process to step S11.

[0037] In step S11, if it is determined that print data has not been received (S11: NO), the control unit 41a advances the process to step S14.

[0038] In step S12, when it is determined that the predetermined amount of print data has not been transmitted to the sub-control circuit 41(k+1) (S12: NO), the control unit 41a determines whether or not an inquiry has been received from the downstream sub-control circuit 41 as to whether print data to be transmitted to the downstream sub-control circuit 41 has been stored (S19). When it is determined that an inquiry has not been received from the downstream sub-control circuit 41 (S19: NO), the control unit 41a returns the process to step S11.

[0039] When it is determined that an inquiry has been received from the downstream sub-control circuit 41 (S19: YES), the control unit 41a determines whether the downstream print data is stored in the main memory unit 41b (S20). When it is determined that the downstream print data is not stored in the main memory unit 41b (S20: NO), the control unit 41a returns the process to step S11. When it is determined that the downstream print data is stored in the main memory unit 41b (S20: YES), the control unit 41a transmits the downstream print data to the downstream sub-control circuit 41 (S21). The control unit 41a deletes the downstream print data from the main memory unit 41b (S22) and returns the process to step S11.

[0040] That is, when the sub-control circuit 41(k) receives any one of the print data from the k+1th print data to the nth print data, it stores the received print data from any one of the print data from the k+1th print data to the nth print data in its own main memory unit 41b. When the sub-control circuit 41(k) transmits the print data stored in its own main memory unit 41b from the print data from the k+1th print data to the k+1st sub-control circuit, it deletes the print data stored in its own main memory unit 41b from the print data from the k+1th print data to the nth print data from its own main memory unit 41b.

[0041] In step S14, when it is determined that all of the k-th print data have not been stored (S14: NO), the control unit 41a determines whether or not a predetermined time has elapsed since the print data was received in step S11 (S23). When it is determined that the predetermined time has not elapsed (S23: NO), the control unit 41a returns the process to step S11. When it is determined that the predetermined time has elapsed (S23: YES), the control unit 41a inquires of the upstream sub-control circuit 41 whether or not the k-th print data has been stored (S24). That is, the sub-control circuit 41(s) determines whether or not the s-th print data has been stored in its own main memory unit 41b, and when it determines that the s-th print data has not been stored in its own main memory unit 41b, it notifies the upstream that the s-th print data is insufficient. After executing the process of step S24, the control unit 41a returns the process to step S11. Step S14 constitutes a second determination process. Step S24 constitutes a first notification process.

[0042] In the printing device according to the first embodiment, the main control circuit 7a transmits only one line's worth of data to the sub-control circuit 41. This makes it possible to suppress an increase in the storage capacity of the main memories 7c and 41b of the main control circuit 7a and each sub-control circuit 41.

[0043] When the sub-control circuit 41(k) receives print data after transmitting downstream print data, i.e., the k+1th print data to the nth print data, it stores the print data, i.e., the kth print data. Therefore, even if identification information is not added to the kth print data, the sub-control circuit 41(k) can receive the kth print data. Since there is no need to add identification information, the storage capacity of the main memory units 7c and 41b can be reduced compared to when identification information is added.

[0044] (Embodiment 2) The present invention will be described below with reference to the drawings showing a printer 1 according to a second embodiment. Among the components of the printer 1 according to the second embodiment, the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted. FIG. 7 is a flowchart for explaining the printing process by the sub-control circuit 41(k). The control unit 41a of the sub-control circuit 41(k) determines whether or not print data has been received (S31). If it is determined that print data has been received (S31: YES), the control unit 41a determines whether or not a notification that reception of the print data has been completed has been received from the downstream sub-control circuit 41, i.e., the sub-control circuit 41(k+1) to the sub-control circuit 41(n) (S32). Step S32 constitutes a third determination process.

[0045] When it is determined that the downstream sub-control circuit 41 has notified it that the reception of the print data has been completed (S32: YES), the control unit 41a stores the print data stored in its own main memory unit 41b as the k-th print data (S33). That is, the s-th sub-control circuit determines whether or not it has received a notification indicating that the reception of the print data has been completed from the downstream, and when it has determined that it has received a notification indicating that the reception of the print data has been completed from the downstream, it stores the print data in its own main memory unit 41b. Step S33 constitutes a second storage process.

[0046] The control unit 41a determines whether all of the kth print data have been stored (S34). For example, the capacity of the main memory unit 41b of the sub-control circuit 41(k) corresponds to the amount of data of the kth print data. The control unit 41a of the sub-control circuit 41(k) determines that all of the kth print data have been stored when, for example, the remaining capacity of the main memory unit 41b falls below a threshold. The threshold is stored in advance in the auxiliary memory unit 41c. The kth print data may be stored in the auxiliary memory unit 41c. In this case, when the remaining capacity of the auxiliary memory unit 41c falls below the threshold, it is determined that all of the kth print data have been stored. Step S34 constitutes a fourth determination process.

[0047] When it is determined that all of the k-th print data have been stored (S34: YES), the control unit 41a determines whether or not an inquiry has been received from the downstream sub-control circuit 41 as to whether print data to be transmitted to the downstream sub-control circuit 41 has been stored (S35). When it is determined that an inquiry has not been received from the downstream sub-control circuit 41 (S35: NO), the control unit 41a notifies the sub-control circuit 41(k-1), i.e., the upstream, that all of the k-th print data have been stored (S36). That is, the s-th sub-control circuit determines whether or not a notification indicating that reception of print data has been completed has been received from the downstream, and when it is determined that a notification indicating that reception of print data has been completed has been received from the downstream, it stores the print data in its own main memory unit 41b. Step S36 constitutes a second notification process.

[0048] The control unit 41a drives the head 42 based on the kth print data and executes printing (S37). After executing printing, the control unit 41a deletes the kth print data from the main memory unit 41b (S38) and determines whether the print process has been completed (S39). For example, when a print instruction for one page is sent from the external device 9 to the control device 7, the control unit 41a determines whether the print process for one page has been completed. If it is determined that the print process has been completed (S39: YES), the control unit 41a ends the process. If it is determined that the print process has not been completed (S39: NO), the control unit 41a returns the process to step S31.

[0049] In step S31, if it is determined that print data has not been received (S31: NO), the control unit 41a advances the process to step S34.

[0050] In step S32, if it is determined that the downstream sub-control circuit 41 has not notified it that the reception of the print data is complete (S32: NO), the control unit 41a transmits the print data, i.e., the downstream print data, to the downstream sub-control circuit 41 (S40). That is, the sth sub-control circuit determines whether or not it has received a notification indicating that the reception of the print data is complete from the downstream, and transmits the print data downstream if it has determined that it has not received a notification indicating that the reception of the print data is complete from the downstream. The control unit 41a deletes the downstream print data from the main memory unit 41b (S41) and returns the process to step S31.

[0051] In step S34, when it is determined that all of the kth print data have not been stored (S34: NO), the control unit 41a returns the process to step S31.

[0052] In step S35, when it is determined that an inquiry has been received from the downstream sub-control circuit 41 (S35: YES), the control unit 41a determines whether the downstream print data is stored in the main memory unit 41b (S42). When it is determined that the downstream print data is not stored in the main memory unit 41b (S42: NO), the control unit 41a returns the process to step S31. When it is determined that the downstream print data is stored in the main memory unit 41b (S42: YES), the control unit 41a transmits the downstream print data to the downstream sub-control circuit 41 (S43). The control unit 41a deletes the downstream print data from the main memory unit 41b (S44), and returns the process to step S31.

[0053] Note that the control unit 41a may erroneously determine in step S32 that the downstream sub-control circuit 41 has notified it that the reception of the print data is complete, even though the control unit 41a has not been notified by the downstream sub-control circuit 41 that the reception of the print data is complete, and may erroneously determine in step S34 that all of the k-th print data has been stored. By providing step S35, the downstream print data can be transmitted to the downstream sub-control circuit 41.

[0054] (Example of change) A modified example in which the configuration of the printer 1 according to the second embodiment is partially modified will be described below. Fig. 8 is a flowchart for explaining the printing process by the sub-control circuit 41(k) according to the modified example of the second embodiment. In Fig. 8, the processes of steps S31 to S44 are the same as those in Fig. 7, and therefore detailed explanations thereof will be omitted. Here, steps S51 to S53 will be described.

[0055] The control unit 41a of the sub-control circuit 41(k) determines whether or not print data has been received (S31). If it is determined that print data has been received (S31: YES), the control unit 41a determines whether or not a predetermined amount of print data, i.e., the kth print data, has been stored (S51). If it is determined that the predetermined amount of print data has not been stored (S51: NO), the control unit 41a proceeds to step S32.

[0056] If it is determined that the predetermined amount of print data has been stored (S51: YES), that is, if the k-th print data has been stored in the main memory unit 41b of the sub-control circuit 41(k) but upstream print data has been erroneously sent to the sub-control circuit 41(k), the control unit 41a notifies the sub-control circuit 41(k-1), that is, upstream, that all of the k-th print data has been stored (S52), and deletes the print data received in step S31 (S53).The control unit 41a proceeds to step S37.

[0057] It should be noted that a computer program can be deployed to be executed on a single computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0058] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. The matters described in each embodiment can be combined with each other. In addition, the independent claims and dependent claims described in the claims can be combined with each other in all combinations regardless of the citation format. Furthermore, the claims use a format (multiple claim format) in which a claim cites two or more other claims, but this is not limited to this. A format in which a multiple claim (multi-multi claim) citing at least one multiple claim may be used. [Explanation of symbols]

[0059] 1 Printing device 7 Control device 7b Control section 7c Main memory 7d Auxiliary storage 40 Head Module 41 Sub-control circuit 41a Control section 41b Main memory 41c Auxiliary storage section

Claims

1. A main control circuit; a sub-control circuit group connected in series to the main control circuit and transferring print data from the main control circuit from upstream to downstream; a group of heads driven by the sub-control circuit group; Equipped with The sub-control circuit group includes a first sub-control circuit at the most upstream side to an n-th sub-control circuit at the most downstream side (n is a natural number of 2 or more), the print data includes first print data corresponding to the first sub-control circuit through n-th print data corresponding to the n-th sub-control circuit, Each of the first print data to the nth print data is data for one line, The main control circuit executes a transmission process for transmitting the first print data to the nth print data to the first sub-control circuit. Printing device.

2. The sub-control circuit group includes a kth sub-control circuit and a k+1th sub-control circuit (k is a natural number from 1 to n-1), The main control circuit, in the transmission process, Sending the k+1 print data to the first sub-control circuit; After transmitting the (k+1)th print data, the kth print data is transmitted to the first sub-control circuit. The printing device of claim 1 .

3. The kth sub-control circuit includes a storage unit, The kth sub-control circuit is a first determination process for determining whether or not print data from the k+1th print data corresponding to the k+1th sub-control circuit to the nth print data corresponding to the nth sub-control circuit have been transmitted downstream when the print data is received from the upstream; a first storage process for storing the print data in the storage unit of the device itself when the device receives the print data after transmitting the print data from the k+1 print data to the n print data to the k+1 sub-control circuit; Run The print data stored in the storage unit of the kth sub-control circuit is the kth print data. The printing device according to claim 2 .

4. The kth sub-control circuit is When receiving any one of the print data from the k+1 print data to the n print data, storing the received print data from the print data from the k+1 print data to the n print data in the storage unit of the printer itself; When the print data stored in the storage unit of the device itself among the print data from the k+1 print data to the n print data is transmitted to the k+1 sub-control circuit, the print data stored in the storage unit of the device itself among the print data from the k+1 print data to the n print data is deleted from the storage unit of the device itself. The printing device according to claim 3 .

5. The sub-control circuit group includes an s-th sub-control circuit (s is a natural number from 1 to n), The s sub-control circuit is a second determination process for determining whether the sth print data has been stored in the storage unit of the device itself; a first notification process for notifying an upstream device of a lack of the sth print data when it is determined that the sth print data is not stored in the storage unit of the device itself; Run 5. The printing device according to claim 3.

6. The sub-control circuit group includes an s-th sub-control circuit (s is a natural number from 1 to n), the head group includes an s-th head driven by the s-th sub-control circuit, The s sub-control circuit is A receiving process for receiving the sth print data; After the receiving process is executed, a driving process is executed to drive the sth head based on the sth print data. Run 5. The printing device according to claim 1.

7. The sub-control circuit group includes an s-th sub-control circuit (s is a natural number from 1 to n), The s sub-control circuit is execute a third determination process to determine whether or not a notification indicating that reception of the print data has been completed has been received from the downstream; If it is determined that a notification indicating that reception of the print data has been completed has not been received from the downstream, the print data is transmitted to the downstream.

3. The printing device according to claim 1 or 2.

8. the print data includes s-th print data corresponding to the s-th sub-control circuit, The s sub-control circuit includes a storage unit, The s sub-control circuit is a fourth determination process for determining whether the sth print data has been stored in the storage unit of the device itself; a second notification process for notifying an upstream side that the sth print data has been stored when it is determined that the sth print data has been stored in the storage unit of the device itself; Run The printing device according to claim 7.

9. The s sub-control circuit includes a storage unit, The s sub-control circuit is a second storage process of storing the print data in the storage unit of the device itself when the print data is received after it is determined in the third determination process that a notification indicating that reception of the print data has been completed has been received from the downstream device; Run The printing device according to claim 7.

10. When the s sub-control circuit receives the print data after determining in the third determination process that a notification indicating that reception of the print data has been completed has been received from the downstream, the s sub-control circuit executes a second storage process of storing the print data in the storage unit of the s sub-control circuit. The printing device according to claim 8.

11. A printing method executed by a printing device including a main control circuit, a sub-control circuit group connected in series to the main control circuit and transferring print data from the main control circuit from upstream to downstream, and a head group driven by the sub-control circuit group, comprising: The sub-control circuit group includes a first sub-control circuit at the most upstream side to an n-th sub-control circuit at the most downstream side (n is a natural number of 2 or more), the print data includes first print data corresponding to the first sub-control circuit to nth print data corresponding to the nth sub-control circuit, Each of the first print data to the nth print data is data for one line, The main control circuit transmits the first print data to the nth print data to the first sub-control circuit. Printing method.

12. A computer program executable by a printing device including a main control circuit, a sub-control circuit group connected in series to the main control circuit and transferring print data from the main control circuit from upstream to downstream, and a head group driven by the sub-control circuit group, The sub-control circuit group includes a first sub-control circuit at the most upstream side to an n-th sub-control circuit at the most downstream side (n is a natural number of 2 or more), the print data includes first print data corresponding to the first sub-control circuit through n-th print data corresponding to the n-th sub-control circuit, Each of the first print data to the nth print data is data for one line, The main control circuit includes: The first print data to the nth print data are transmitted to the first sub-control circuit. A computer program that executes a process.

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