Printing apparatus, printing method and computer program

Abstract

To provide a printing apparatus, a printing method and a computer program which can enhance efficiency of data transfer.SOLUTION: A printing apparatus includes: a main control circuit; a subsidiary control circuit group provided with a plurality of subsidiary control circuits which are connected in series and transmit printed data transmitted data by the main control circuit from upstream to downstream; and a plurality of heads. The subsidiary control circuits perform transfer demand decision processing which decides whether transmitting data-transfer demand to itself up to upstream or not based on the amount of data sent from itself to said head and the amount of data received from upstream, and transmission processing which transmits data transfer demand of itself to the upstream based on decision of the transfer demand decision processing.SELECTED DRAWING: Figure 5

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 executes a receiving process for a busy signal indicating whether image data (print data) can be received between the receiving board and the destination distribution board. When the receiving board receives a busy signal indicating that it is capable of receiving, it transmits print data to the distribution board, which then transmits 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] However, the receiving board cannot transmit print data to the desired head controller until it receives a busy signal indicating that it is ready to receive.

[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 improve the efficiency of data transfer. [Means for solving the problem]

[0006] A printing device according to one embodiment of the present disclosure comprises a main control circuit, a sub-control circuit group having a plurality of sub-control circuits connected in series and transmitting print data transmitted by the main control circuit from upstream to downstream, and a plurality of heads, wherein the sub-control circuit executes a transfer request determination process that determines whether or not to transmit a data transfer request to itself upstream based on the amount of data it transmits to the head and the amount of data it receives from upstream, and a transmission process that transmits its own data transfer request upstream based on the determination of the transfer request determination process.

[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 sub-control circuit group including a plurality of sub-control circuits connected in series and transmitting print data transmitted by the main control circuit from upstream to downstream, and a plurality of heads, wherein the sub-control circuit executes a transfer request determination process to determine whether or not to transmit its own data transfer request upstream based on the amount of data it transmits to the head and the amount of data it receives from upstream, and executes a transmission process to transmit its own data transfer request upstream based on the determination of the transfer request determination process.

[0008] A computer program according to one embodiment of the present disclosure is a computer program executable on a printing device having a main control circuit, a sub-control circuit group including a plurality of sub-control circuits connected in series and transmitting printing data transmitted by the main control circuit from upstream to downstream, and a plurality of heads, the computer program executing a transfer request determination process in which the sub-control circuit determines whether or not to transmit its own data transfer request upstream based on the amount of data it transmits to the head and the amount of data it receives from upstream, and executes a transmission process in which the sub-control circuit transmits its own data transfer request upstream based on the determination of the transfer request determination process. Effect of the Invention

[0009] In a printing device, printing method, and computer program according to one embodiment of the present disclosure, if it is determined that there is free capacity in the memory unit based on the amount of data to be sent from the sub-control circuit to the head (i.e., the amount of data to be deleted from the memory unit of the sub-control circuit) and the amount of data received from upstream (i.e., the amount of data stored in the memory unit of the sub-control circuit), a data transfer request is sent upstream. [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] FIG. 2 is a block diagram of the kth head module (k is a natural number equal to or smaller than n). [Diagram 5] 13 is a flowchart illustrating a data transfer process by SoC(k). [Figure 6] 13 is a flowchart illustrating a data transfer process by a SoC(k) according to the second embodiment. [Figure 7] 13 is a flowchart illustrating a data transfer process by a SoC(k) according to the third embodiment. [Figure 8] 13 is a flowchart illustrating a data transfer process by a SoC(k) according to the fourth embodiment. [Figure 9] 13 is a flowchart illustrating a data transfer process by a SoC(k) according to the fifth 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 according to a first embodiment. FIG. 1 is a simplified plan view of the printing device 1. In FIG. 1, the conveying direction of printing paper 100 corresponds to the front-rear direction of the printing device 1. The printing paper 100 is an example of a printing medium, and film or cloth may also be used as the printing medium. The width direction of the printing paper 100 corresponds to the left-right direction of the printing device 1. The direction perpendicular to the front-rear and left-right directions, 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 print sheet 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] 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 print paper 100 on the platen 3 forward. The control device 7 is connected to an external device 9 such as a PC so as to be able to communicate data with the external device 9, and controls each section of the printing device 1 based on print data sent 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. A plurality of nozzles 42a are provided on the bottom surface of the heads 42. The plurality of heads 42 include a first head row 421 having four heads 42 aligned in the left-right direction, and a second head row 422 having five heads 42 aligned in the left-right direction. The first head row 421 is disposed on the front side, and the second head row 422 is disposed on the rear side. The heads 42 are disposed in a staggered manner such that the four heads 42 of the first head row 421 are positioned between the five heads 42 of the second head row 422. The inkjet head 4 includes a driving mechanism (not shown) and can be moved to a flushing receiver (not shown) by the driving mechanism.

[0015] FIG. 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 storage unit 7c, and a communication interface (I / F) 7d. The control unit 7b includes a logic circuit, such as an FPGA. The control unit 7b may include a processor, such as a CPU or an ASIC. The storage unit 7c includes a main storage device and an auxiliary storage device. An example of the main storage device is a RAM. An example of the auxiliary storage device is a ROM and a rewritable storage medium, such as an EEPROM, a FlashROM, a hard disk, etc. A control program is stored in the auxiliary storage device. The control unit 7b reads the control program from the auxiliary storage device to the main storage device and executes it. The control program may be installed in the auxiliary storage device 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 storage device from a server connected to the printing device 1 via a communication network. The communication I / F 7d is connected to a forward communication path 51 and a backward communication path 52. The control device 7 controls the printing device 1 based on the control program.

[0016] The inkjet head 4 includes a plurality of head modules 40. The plurality of head modules 40 are arranged, for example, in the left-right direction, and are connected in series via a forward communication path 51 and also connected in series via a reverse communication path 52. The plurality of head modules 40 include, for example, a first head module 40(1), a second head module 40(2), a third head module 40(3), . . . , an n-th head module 40(n) (n is a natural number). The first head module 40(1) is located on the leftmost side, and the n-th head module 40(n) is located on the rightmost side. The first head module 40(1) is located closest to the control device 7 among all the head modules 40, and the n-th head module 40(n) is located farthest from the control device 7 among all the head modules 40.

[0017] FIG. 4 is a block diagram of the k-th head module 40(k) (k is a natural number equal to or smaller than n). The k-th head module 40(k) includes an SoC 41 and a head 42. Hereinafter, the SoC 41 of the k-th head module 40(k) will also be referred to as SoC(k), and the head 42 will also be referred to as head(k). SoC(k) corresponds to a sub-control circuit. The SoC(k) includes a control unit 41a, a memory unit 41b, a communication I / F 41c, a communication I / F 41d, a correction circuit 41e, a compression circuit 41f, a decompression circuit 41g, a data request circuit 41h, and an arbitration circuit 41j. The control unit 41a includes, for example, a logic circuit or a processor. The memory unit 41b includes a volatile memory such as an SDRAM, an EEPROM, a FlashROM, and a rewritable storage medium such as a hard disk. The memory unit 41b stores information such as an address indicating the non-ejecting nozzle 42a. The communication I / Fs 41 c and 41 d are connected to a forward communication path 51 and a backward communication path 52 .

[0018] The correction circuit 41e receives print data from the upstream in units of one line. When the correction circuit 41e receives print data from the upstream, it deletes the print data corresponding to the address indicating the non-ejecting nozzle 42a, i.e., corrects the print data, and transmits the print data to the compression circuit 41f. The compression circuit 41f compresses the print data received from the correction circuit 41e and transmits it to the storage unit 41b. The storage unit 41b stores the compressed print data. Note that the compression ratio in the compression circuit 41f of each head module 40 is not constant, and therefore the amount of print data stored in the storage unit 41b of each head module 40 is not constant, and the free space of the storage unit 41b of each head module 40 is also not constant. The amount of data that the SoC(k) receives from the upstream is the amount of print data corrected by the correction circuit 41e and the amount of print data compressed by the compression circuit 41f.

[0019] The storage unit 41b transmits the compressed print data to the decompression circuit 41g. The decompression circuit 41g decompresses the print data received from the storage unit 41b and transmits it to the head (k). The head (k) is driven based on the print data received from the decompression circuit 41g, and ejects ink from the nozzles 42a.

[0020] The storage unit 41b transmits information indicating the free space A to the data request circuit 41h. Based on the information including the free space A, the data request circuit 41h transmits a request for the next print data, i.e., the print data of the next line, to the arbitration circuit 41j. The arbitration circuit 41j receives a print data transfer request from the data request circuit 41h, i.e., a print data transfer request for SoC(k). The print data transfer request for SoC(k) constitutes its own print data transfer request. The arbitration circuit 41j receives print data transfer requests from downstream, i.e., print data transfer requests from SoC(k+1) to SoC(n). The arbitration circuit 41j arbitrates between its own print data transfer request and the print data transfer request from downstream, and transmits one of the transfer requests upstream.

[0021] 5 is a flowchart explaining the data transfer process by SoC(k). The data transfer process is executed during printing. The arbitration circuit 41j of SoC(k) judges whether the forward communication path 51 is free or not (S1). If the forward communication path 51 is free, when the arbitration circuit 41j requests the transfer of print data, the main control circuit 7a can transmit the requested print data using the forward communication path 51. If the arbitration circuit 41j judges that the forward communication path 51 is not free (S1: NO), the arbitration circuit 41j returns the process to step S1.

[0022] When it is determined that the forward communication path 51 is free (S1: YES), the arbitration circuit 41j acquires the free space A of the storage unit 41b of SoC(k) (S2). The arbitration circuit 41j calculates the amount of data to be transmitted to the head(k) during a predetermined period D, i.e., the amount of transmitted data B (S3). The arbitration circuit 41j calculates the amount of data to be received from SoC(k-1), i.e., from the upstream, during the period D, i.e., the amount of received data C (S4).

[0023] The arbitration circuit 41j determines whether the sum of the free space A and the amount of transmission data B is equal to or greater than the amount of received data C (S5). The process of step S5 by the arbitration circuit 41j constitutes a transfer request determination process. If it is determined that the sum of the free space A and the amount of transmission data B is equal to or greater than the amount of received data C (S5: YES), the arbitration circuit 41j transmits a request to SoC(k-1), i.e., upstream, to transfer print data to the correction circuit 41e of SoC(k) (S9), and determines whether printing is complete (S8). The process of step S9 by the arbitration circuit 41j constitutes a transmission process.

[0024] Hereinafter, the request to transfer print data is also simply referred to as a data transfer request. The data transfer request to the correction circuit 41e of SoC(k) constitutes a data transfer request to itself. If the arbitration circuit 41j determines that printing is not complete (S8: NO), it returns the process to step S1. If the arbitration circuit 41j determines that printing is complete (S8: YES), it ends the process.

[0025] If it is determined that the sum of the free space A and the amount of transmission data B is not equal to or greater than the amount of received data C (S5: NO), that is, if it is determined that the sum of the free space A and the amount of transmission data B is less than the amount of received data C, the arbitration circuit 41j determines whether or not a print data transfer request has been received from SoC(k+1), that is, from downstream (S6). If it is determined that a print data transfer request has not been received from downstream (S6: NO), the arbitration circuit 41j proceeds to step S8.

[0026] If it is determined that a print data transfer request has been received from downstream (S6: YES), the arbitration circuit 41j transmits the data transfer request from downstream to SoC(k-1), that is, upstream (S7), and proceeds to step S8.

[0027] (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. 6 is a flowchart explaining the data transfer process by SoC(k). The data transfer process is executed during printing.

[0028] The arbitration circuit 41j of SoC(k) determines whether the forward communication path 51 is available (S11). If the forward communication path 51 is available, when the arbitration circuit 41j requests the transfer of print data, the main control circuit 7a can transmit the requested print data using the forward communication path 51. If the arbitration circuit 41j determines that the forward communication path 51 is not available (S11: NO), the arbitration circuit 41j returns the process to step S11.

[0029] When it is determined that the forward communication path 51 is free (S11: YES), the arbitration circuit 41j acquires the free space A of the storage unit 41b of SoC(k) (S12). The arbitration circuit 41j calculates the amount of data to be transmitted to the head(k) during a predetermined period D, i.e., the amount of transmitted data B (S13). The arbitration circuit 41j calculates the amount of data to be received from SoC(k-1), i.e., from the upstream, during the period D, i.e., the amount of received data C (S14).

[0030] The arbitration circuit 41j determines whether or not a data transfer request has been received from SoC(k+1), i.e., from downstream (S15). If it is determined that a data transfer request has been received from downstream (S15: YES), the arbitration circuit 41j transmits the data transfer request from downstream to SoC(k-1), i.e., upstream (S16), and determines whether or not printing has been completed (S17). If it is determined that printing has not been completed (S17: NO), the arbitration circuit 41j returns the process to step S11. If it is determined that printing has been completed (S17: YES), the arbitration circuit 41j ends the process.

[0031] In step S15, when it is determined that a data transfer request has not been received from the downstream (S15: NO), the arbitration circuit 41j determines whether the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S18). When it is determined that the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S18: YES), the arbitration circuit 41j transmits a data transfer request to the correction circuit 41e of SoC(k) to SoC(k-1), i.e., upstream (S19), and proceeds to step S17. The data transfer request to the correction circuit 41e of SoC(k) constitutes a data transfer request to itself. When it is determined that the sum of the free space A and the transmission data amount B is not equal to or greater than the reception data amount C (S18: NO), i.e., when it is determined that the sum of the free space A and the transmission data amount B is less than the reception data amount C, the arbitration circuit 41j proceeds to step S17.

[0032] In the printing device according to the second embodiment, when an arbitration circuit 41j of SoC(k) receives a data transfer request from downstream, the arbitration circuit 41j transmits the data transfer request from downstream upstream, regardless of whether the sum of free space A and transmission data amount B is equal to or greater than the received data amount C. In other words, the arbitration circuit 41j prioritizes data transfer requests from downstream over data transfer requests to itself and transmits them upstream.

[0033] (Embodiment 3) The present invention will be described below with reference to the drawings showing a printer 1 according to embodiment 3. Among the components of the printer 1 according to embodiment 3, the same components as those in embodiments 1 and 2 are given the same reference numerals, and detailed description thereof will be omitted. In embodiment 3, when the downstream SoC 41 transmits a data transfer request to the upstream SoC 41, the downstream SoC 41 adds the free space of its own storage unit 41b to the data transfer request and transmits it.

[0034] FIG. 7 is a flowchart explaining the data transfer process by SoC(k). The data transfer process is executed during printing. The arbitration circuit 41j of SoC(k) judges whether the forward communication path 51 is free or not (S21). If the forward communication path 51 is free, when the arbitration circuit 41j requests the transfer of print data, the main control circuit 7a can transmit the requested print data using the forward communication path 51. If the arbitration circuit 41j judges that the forward communication path 51 is not free (S21: NO), the arbitration circuit 41j returns the process to step S21.

[0035] When it is determined that the forward communication path 51 is free (S21: YES), the arbitration circuit 41j acquires the free space A of the storage unit 41b of SoC(k) (S22). The arbitration circuit 41j calculates the amount of data to be transmitted to the head(k) during a predetermined period D, i.e., the amount of transmitted data B (S23). The arbitration circuit 41j calculates the amount of data to be received from SoC(k-1), i.e., from the upstream, during the period D, i.e., the amount of received data C (S24).

[0036] The arbitration circuit 41j judges whether the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S25). If it is judged that the sum of the free space A and the transmission data amount B is not equal to or greater than the reception data amount C (S25: NO), that is, if it is judged that the sum of the free space A and the transmission data amount B is less than the reception data amount C, the arbitration circuit 41j judges whether it has received a data transfer request from SoC(k+1), i.e., from downstream (S26). If it is judged that it has received a data transfer request from downstream (S26: YES), the arbitration circuit 41j transmits the data transfer request from downstream to SoC(k-1), i.e., upstream (S27), and judges whether printing has been completed (S28). If it is judged that printing has not been completed (S28: NO), the arbitration circuit 41j returns the process to step S21. If it is judged that printing has been completed (S28: YES), the arbitration circuit 41j ends the process.

[0037] In step S26, if it is determined that a data transfer request has not been received from downstream (S26: NO), the arbitration circuit 41j advances the process to step S28.

[0038] In step S25, when it is determined that the sum of the free space A and the transmission data amount B is equal to or larger than the reception data amount C (S25: YES), the arbitration circuit 41j determines whether or not a data transfer request has been received from SoC(k+1), i.e., from downstream (S29).When it is determined that a data transfer request has been received from downstream (S29: YES), the arbitration circuit 41j determines whether or not the free space A is equal to or larger than the free space added to the data transfer request from downstream, i.e., the free space of the storage unit 41b of the downstream SoC 41 (S30).

[0039] If it is determined that the available space A is equal to or greater than the available space in the memory unit 41b of the downstream SoC 41 (S30: YES), the arbitration circuit 41j transmits a data transfer request to the correction circuit 41e of SoC(k-1), i.e., upstream, (S31), and proceeds to step S28.

[0040] In step S29, if it is determined that a data transfer request has not been received from downstream (S29: NO), the arbitration circuit 41j advances the process to step S31. In step S30, when it is determined that the free space A is not equal to or larger than the free space of the storage unit 41b of the downstream SoC 41 (S30: NO), that is, when it is determined that the free space A is less than the free space of the storage unit 41b of the downstream SoC 41, the arbitration circuit 41j proceeds to step S27. That is, the arbitration circuit 41j transmits the data transfer request from the downstream to SoC(k-1), that is, upstream (S27).

[0041] (Embodiment 4) The present invention will be described below with reference to the drawings showing a printer 1 according to a fourth embodiment. Among the components of the printer 1 according to the fourth embodiment, the same components as those of the first to third embodiments are given the same reference numerals, and detailed description thereof will be omitted. In the fourth embodiment, when the downstream SoC 41 transmits a data transfer request to the upstream SoC 41, the downstream SoC 41 adds the free space of its own storage unit 41b and its own identifier to the data transfer request and transmits it.

[0042] Fig. 8 is a flowchart illustrating a data transfer process by SoC(k). The processes of steps S41 to S49 and S51 in Fig. 8 are the same as steps S21 to S29 and S31 in Fig. 7, so detailed descriptions thereof will be omitted. Here, step S50 will be mainly described. The arbitration circuit 41j determines whether the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S45). If it is determined that the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S45: YES), the arbitration circuit 41j proceeds to step S49.

[0043] In step S49, if it is determined that a data transfer request has been received from downstream (S49: YES), the arbitration circuit 41j determines whether the available space A is equal to or greater than the available space added to the data transfer request from downstream, i.e., the available space in the memory unit 41b of the downstream SoC 41 multiplied by a weighting coefficient (S50).

[0044] The weighting coefficient is determined, for example, as follows. The arbitration circuit 41j of SoC(k) refers to the identifier added to the data transfer request from downstream and calculates a weighting coefficient according to the distance between the downstream SoC that transmitted the data transfer request and SoC(k), i.e., the distance between the downstream SoC that transmitted the data transfer request and itself. As the distance between the downstream SoC and itself becomes longer, the time it takes for the data transfer request to arrive at SoC(k) becomes longer after it is transmitted from the downstream SoC, the amount of data transmitted from the downstream SoC to the head 42 increases, and the free space of the storage unit 41b of the downstream SoC becomes larger. That is, the free space of the downstream SoC received by the arbitration circuit 41j of SoC(k) is smaller than the actual free space at the time of reception.

[0045] Therefore, when the arbitration circuit 41j of SoC(k) receives a data transfer request from SoC(k+1), it calculates a weighting coefficient of standard coefficient*G1, when it receives a data transfer request from SoC(k+2), it calculates a weighting coefficient of standard coefficient*G2, and when it receives a data transfer request from SoC(k+3), it calculates a weighting coefficient of standard coefficient*G3. The standard coefficients G1, G2, and G3 are positive values, and G1 <G2<G3である。

[0046] If it is determined that the available capacity A is equal to or greater than the available capacity of the memory unit 41b of the downstream SoC 41 multiplied by the weighting coefficient (S50: YES), the arbitration circuit 41j transmits a data transfer request to the correction circuit 41e of SoC(k), i.e., to itself, i.e., to SoC(k-1), i.e., upstream (S51).

[0047] When it is determined that the free space A is not equal to or greater than the free space in the storage unit 41b of the downstream SoC 41 multiplied by the weighting factor (S50: NO), the arbitration circuit 41j transmits the data transfer request from the downstream to SoC(k-1), i.e., upstream (S47). In step S50, as the distance from SoC(k) increases, it becomes more likely that the free space A is not equal to or greater than the free space in the storage unit 41b of the downstream SoC 41 multiplied by the weighting factor. In other words, the transmission of a data transfer request from the downstream is given priority over the transmission of a data transfer request from SoC(k), i.e., its own data transfer request. It is to be noted that, in step S49, if it is determined that a data transfer request has not been received from the downstream (S49: NO), the arbitration circuit 41j proceeds to step S51.

[0048] (Embodiment 5) The present invention will be described below with reference to the drawings showing a printer 1 according to a fifth embodiment. Among the components of the printer 1 according to the fourth embodiment, the same components as those of the first to fourth embodiments are given the same reference numerals, and detailed description thereof will be omitted. In the fifth embodiment, when the downstream SoC 41 transmits a data transfer request to the upstream SoC 41, the downstream SoC 41 adds the free space of its own storage unit 41b, the time when it measured the free space, and its own identifier to the data transfer request and transmits it.

[0049] Fig. 9 is a flowchart illustrating a data transfer process by SoC(k). The processes of steps S61 to S69 and S71 in Fig. 8 are the same as steps S21 to S29 and S31 in Fig. 7, and therefore detailed descriptions thereof will be omitted. Here, step S70 will be described. The arbitration circuit 41j determines whether the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S65). If it is determined that the sum of the free space A and the transmission data amount B is equal to or greater than the reception data amount C (S65: YES), the arbitration circuit 41j proceeds to step S69.

[0050] In step S69, if it is determined that a data transfer request has been received from downstream (S69: YES), the arbitration circuit 41j determines whether the available space A is equal to or greater than the estimated available space of the memory unit 41b in the downstream SoC that sent the data transfer request (S70).

[0051] The estimated free space is determined, for example, as follows. The arbitration circuit 41j of SoC(k) acquires the time added to the data transfer request from downstream, i.e., the first time. The arbitration circuit 41j of SoC(k) acquires the time at which the data transfer request from downstream is received, i.e., the second time. The arbitration circuit 41j of SoC(k) calculates the time between the first time and the second time, and multiplies the time between the first time and the second time by the speed at which the downstream SoC transmits print data to the head 42. The multiplication result is the free space added to the storage unit 41b of the downstream SoC from the time the downstream SoC transmits the data transfer request until the data transfer request arrives at SoC(k). That is, the sum of the free space added to the data transfer request from downstream and the multiplication result is the estimated free space in the storage unit 41b of the downstream SoC.

[0052] If it is determined that the available space A is equal to or greater than the estimated available space in the memory unit 41b of the downstream SoC (S70: YES), the arbitration circuit 41j transmits a data transfer request to the correction circuit 41e of SoC(k-1), i.e., upstream, to itself (S71). If it is determined in step S69 that a data transfer request has not been received from the downstream (S69: NO), the arbitration circuit 41j proceeds to step S71.

[0053] When it is determined that the free space A is not equal to or greater than the estimated free space in the storage unit 41b of the downstream SoC (S70: NO), the arbitration circuit 41j transmits the data transfer request from the downstream to SoC(k-1), i.e., upstream (S67). In step S70, as the distance from SoC(k) increases, it becomes easier to determine that the free space A is not equal to or greater than the estimated free space in the storage unit 41b of the downstream SoC. That is, the transmission of a data transfer request from the downstream is prioritized over the transmission of a data transfer request from SoC(k), i.e., its own. Also, compared to the case where a weighting factor is used, the free space in the storage unit 41b of the downstream SoC can be estimated more accurately.

[0054] 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.

[0055] 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]

[0056] 1 Printing device 4 Inkjet head 7 Control device 7a Main control circuit 7b Control section 40 Head Module 41 SoC 41a Control section 41b Storage section 41c, 41d Communication I / F 41e Correction circuit 41f Compression circuit 41g Defrosting circuit 41h Data request circuit 41j arbitration circuit 42 Head

Claims

1. A main control circuit; a sub-control circuit group including a plurality of sub-control circuits connected in series and transmitting the print data transmitted by the main control circuit from upstream to downstream; With multiple heads Equipped with a transfer request determination process in which the sub-control circuit determines whether or not to transmit a data transfer request to itself upstream based on an amount of data to be transmitted from itself to the head and an amount of data received from the upstream; a transmission process for transmitting a data transfer request to an upstream device based on the determination of the transfer request determination process; Run Printing device.

2. The sub-control circuit includes: When a data transfer request is received from the downstream, the data transfer request is transmitted to the upstream; If the data transfer request is not received from the downstream, the transfer request determination process is executed. The printing device of claim 1 .

3. The sub-control circuit has a storage unit, The sub-control circuit includes: executes a first free space determination process for determining whether or not the free space of its own storage unit is equal to or greater than the free space of the storage unit of the sub-control circuit connected downstream when it determines that its own data transfer request is to be transmitted and receives a data transfer request from the sub-control circuit connected downstream; When it is determined in the first free space determination process that the free space in its own storage unit is equal to or larger than the free space in the storage unit of the sub-control circuit connected downstream, it transmits its own data transfer request upstream. When it is determined in the first free space determination process that the free space in its own storage unit is not equal to or greater than the free space in the storage unit of the sub-control circuit connected downstream, a data transfer request from the sub-control circuit connected downstream is transmitted upstream. The printing device of claim 1 .

4. The sub-control circuit has a storage unit, The sub-control circuit includes: executes a second free space determination process for determining whether or not the free space in its own memory unit is equal to or greater than the value obtained by multiplying the free space in the memory unit of the sub-control circuit connected downstream by a weighting coefficient according to the distance between itself and the sub-control circuit connected downstream when it determines that its own data transfer request will be transmitted and receives a data transfer request from the sub-control circuit connected downstream; When it is determined in the second free space determination process that the free space in the storage unit of the device itself is equal to or greater than the value, the device transmits a data transfer request to the upstream side of the storage unit itself; If it is determined that the free space in its own storage unit is not equal to or greater than the aforementioned value, it transmits a data transfer request from the downstream secondary control circuit upstream. The printing device of claim 1 .

5. The sub-control circuit has a storage unit, The sub-control circuit includes: executes a third free space determination process for determining whether or not the free space in its own memory unit is equal to or greater than an estimated free space in the memory unit of the sub-control circuit connected downstream according to the distance between itself and the sub-control circuit connected downstream and the time when the free space in its own memory unit was measured, when it determines that its own data transfer request will be transmitted and receives a data transfer request from the sub-control circuit connected downstream; When it is determined in the third free space determination process that the free space in the storage unit of the device itself is equal to or larger than the estimated free space, the device transmits a data transfer request to the upstream side of the storage unit of the device itself; When it is determined that the free space in its own storage unit is not equal to or larger than the estimated free space, a data transfer request is transmitted upstream from the sub-control circuit connected downstream. The printing device of claim 1 .

6. The sub-control circuit includes an arbitration circuit that arbitrates between its own data transfer request and the data transfer request from downstream. The printing device of claim 1 .

7. The head includes a plurality of nozzles. The sub-control circuit includes: a correction circuit that corrects the print data based on non-ejection information that indicates the non-ejecting nozzles; The amount of data received from the upstream is the amount of print data corrected by the correction circuit.

7. The printing device according to claim 1.

8. The sub-control circuit includes: A compression circuit for compressing data is provided, The amount of data received from the upstream is the amount of print data compressed by the compression circuit.

7. The printing device according to claim 1.

9. a transmission path for connecting the main control circuit and the sub-control circuit group in series and transmitting data from upstream to downstream; the sub-control circuit executes a transmission possibility determination process for determining whether transmission through the transmission path is possible; If it is determined in the transmission possibility determination process that transmission via the transmission path is possible, it is determined whether or not to transmit a data transfer request of the device upstream.

7. The printing device according to claim 1.

10. The sub-control circuit includes: In the transfer request determination process, after determining that the data transfer request of the device is not to be transmitted upstream, it is determined whether or not a data transfer request has been received from downstream. The printing device of claim 1 .

11. The sub-control circuit includes a memory unit, The sub-control circuit, in the transfer request determination process, Obtaining the free space of the storage unit of the device itself; Calculating an amount of data to be transmitted from the device to the head in a predetermined period of time; Calculating the amount of data received from the upstream during the predetermined period; determining whether or not the sum of the free space and the amount of data to be transmitted from the head to the head is greater than the amount of data received from the upstream by the head; If it determines that the sum is greater than the amount of data it receives from the upstream, it sends a data transfer request to the upstream. The printing device of claim 1 .

12. A printing method executed by a printing device including a main control circuit, a sub-control circuit group including a plurality of sub-control circuits connected in series and transmitting print data transmitted by the main control circuit from upstream to downstream, and a plurality of heads, comprising: the sub-control circuit executes a transfer request determination process for determining whether or not to transmit a data transfer request to the upstream based on an amount of data to be transmitted from the sub-control circuit to the head and an amount of data received from the upstream; A transmission process is executed to transmit a data transfer request to an upstream side based on the determination of the transfer request determination process. Printing method.

13. A computer program executable by a printing device including a main control circuit, a sub-control circuit group including a plurality of sub-control circuits connected in series and transmitting print data transmitted by the main control circuit from upstream to downstream, and a plurality of heads, executes a transfer request determination process in the sub-control circuit to determine whether or not to transmit a data transfer request to the upstream based on an amount of data to be transmitted from the sub-control circuit to the head and an amount of data received from the upstream; A transmission process is executed to transmit a data transfer request to an upstream side based on the determination of the transfer request determination process. A computer program that executes a process.

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