Head system

Abstract

To quickly transmit printing data to a head module connected to a portion away from a controller.SOLUTION: A head system according to one embodiment described in the disclosure comprises a controller, a plurality of heads, and a plurality of head modules connected in series to each other through a communication cable, which transfer printing data transmitted by the controller, from an upstream side to a downstream side. Each of the head modules is connected to each of the heads and comprises a storing part and a switch for switching destination to which the communication cable at an upstream side is connected. When receiving the printing data that are processed by an own head module from the upstream side, the switch is switched so as to connect the communication cable at the upstream side to the storing part. When receiving the printing data that are processed by the head module arranged closer to a downstream side than the own head module from the upstream side, the switch is switched so as to connect the communication cable at the upstream side to the communication cable at the downstream side.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present technology relates to a head system.

Background Art

[0002] A liquid discharge control device has been proposed that includes a plurality of head control units for controlling the discharge of a discharge unit provided in a liquid discharge head, and the plurality of head control units are connected in a daisy chain (connected in series) (for example, Patent Document 1). Each head control unit controls so that droplets are discharged from the discharge unit according to image data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Among the head control units (head modules) connected in series, the head module (upstream head module) connected close to the controller that transmits image data (print data) stores, in addition to the print data processed by its own head module (the head module itself), the print data processed by the head module (downstream head module) connected to a location far from the controller, and then transfers the print data processed by the downstream head module. Therefore, it takes a long time from when the controller transmits the print data until the downstream head module receives it.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a head system capable of quickly transmitting print data to a head module connected to a location far from the controller.

Means for Solving the Problems

[0006] A head system according to an embodiment of the present disclosure includes a controller, a plurality of heads, and a plurality of head modules that are serially connected via a communication cable and transfer print data transmitted by the controller from upstream to downstream. Each of the head modules is connected to each of the heads and includes a storage unit and a switch that switches a connection destination of the upstream communication cable. When the switch receives print data to be processed by its own head module from upstream, it is switched to connect the upstream communication cable and the storage unit. When the switch receives print data to be processed by a head module downstream of its own head module from upstream, it is switched to connect the upstream communication cable and the downstream communication cable.

Advantages of the Invention

[0007] In the head system according to an embodiment of the present disclosure, it is possible to quickly transmit print data to a head module connected at a location far from the controller.

Brief Description of the Drawings

[0008]

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Modes for Carrying Out the Invention

[0009] (Embodiment 1)

[0010] The following description will be based on the drawings showing the printer according to Embodiment 1 of the present invention. FIG. 1 is a schematic plan view of the printer 1. In FIG. 1, the conveyance direction of the recording paper 100 corresponds to the front-rear direction of the printer 1. Also, the width direction of the recording paper 100 corresponds to the left-right direction of the printer 1. Further, the direction orthogonal to the front-rear direction and the left-right direction, that is, the direction perpendicular to the plane of FIG. 1 corresponds to the up-down direction of the printer 1. The printer 1 corresponds to a liquid ejection device.

[0011] As shown in FIG. 1, the printer 1 includes a platen 3 housed in a case 2, four inkjet heads 4, two conveyance rollers 5 and 6, and a control device 7, etc. The printer 1 corresponds to a liquid ejection device, and the conveyance rollers 5 and 6 correspond to a conveyance device.

[0012] The upper surface of the platen 3 is passed through by the recording paper 100. The four inkjet heads 4 are arranged side by side in the conveyance direction above the platen 3. Each inkjet head 4 is a so-called line type head. Ink is supplied to the inkjet head 4 from an ink tank (not shown). Different colors of ink are supplied to the four inkjet heads 4.

[0013] As shown in FIG. 1, the two conveyance rollers 5 and 6 are respectively arranged on the rear side and the front side with respect to the platen 3. The two conveyance rollers 5 and 6 are respectively driven by a motor (not shown) to convey the recording paper 100 on the platen 3 forward. The conveyance rollers 5 and 6 correspond to a conveyance device. The control device 7 is connected to an external device 9 such as a PC so as to be capable of data communication, and controls each part of the printer 1 based on the print data sent from the external device 9.

[0014] FIG. 2 is a block diagram of the control device 7 and the inkjet head 4. The control device 7 and the inkjet head 4 constitute a head system. The control device 7 includes a controller 7a. The controller 7a includes a control unit 7b, a storage unit 7c, and a communication interface (I / F) 7d. The control unit 7b includes an integrated circuit, for example, an FPGA. Note that the control unit 7b may include a processor, for example, a CPU, or an ASIC or the like. The storage unit 7c includes a main storage device and an auxiliary storage device. Examples of the main storage device include a RAM. Examples of the auxiliary storage device include a ROM and a rewritable storage medium, for example, an EEPROM, a Flash ROM, a hard disk, and the like. A control program is stored in the auxiliary storage device. The control unit 7b reads the control program from the auxiliary storage device and executes it in the main storage device. The control program may be installed in the auxiliary storage device from a recording medium 70 (see FIG. 1), for example, an optical disk or a portable flash memory. Note that the control program may be downloaded from a server connected to the printer 1 via a communication network to the auxiliary storage device. The communication I / F 7d is connected to a communication cable 51. The control device 7 controls the printer 1 based on the control program.

[0015] The inkjet head 4 includes a plurality of head modules 41. The plurality of head modules 41 are arranged, for example, in the left-right direction and are connected in series via a communication cable 51. The plurality of head modules 41 have, for example, a first head module 41(1), a second head module 41(2), a third head module 41(3),..., an nth head module 41(n) (n is a natural number). The first head module 41(1) is located at the leftmost position, and the nth head module 41(n) is located at the rightmost position. The first head module 41(1) is located closest to the control device 7 among all the head modules 41, and the nth head module 41(n) is located farthest from the control device 7 among all the head modules 41.

[0016] Note that the left side of FIG. 2 corresponds to the upstream, and the right side corresponds to the downstream. The leftmost head module 41 (the first head module 41(1)) shown in FIG. 2 is the most upstream head module 41, and the rightmost head module 41 (the nth head module 41(n)) is the most downstream head module 41.

[0017] A head 40 is connected to each head module 41. When the head module 41 receives print data (see FIG. 4) to be processed by its own head module 41 (the head module 41 itself), it drives the head 40 connected to its own head module 41.

[0018] FIG. 3 is a block diagram of the head module 41. The head module 41 includes a control unit 41a, a storage unit 41b, a communication I / F 41c, a communication I / F 41d, and a switch 41e. The control unit 41a includes a processor such as a CPU or an MPU. Note that the control unit 41a may include an integrated circuit such as an FPGA or an ASIC. The storage unit 41b includes a volatile memory such as an SDRAM, a rewritable non-volatile storage medium such as an EEPROM, a FlashROM, or a hard disk. The communication I / Fs 41c and 41d are connected to a communication cable 51.

[0019] The switch 41e is connected to the communication I / Fs 41c and 41d. The control unit 41a is connected to the switch 41e. The storage unit 41b is connected to the control unit 41a. The switch 41e can be switched to a state (the first state) of connecting the upstream communication cable 51 connected via the communication I / F 41c to the control unit 41a and the storage unit 41b, or a state (the second state) of connecting the upstream communication cable 51 connected via the communication I / F 41c to the downstream communication cable 51 connected via the communication I / F 41d.

[0020] FIG. 4 is an explanatory diagram showing print data. When the controller 7a receives print data from, for example, an external device 9, it transmits the print data based on the received print data to the downstream side. In FIG. 4, the right side indicates the head of the data, and the left side indicates the end of the data. The same applies to FIGS. 7, 11, and 13. When the controller 7a and the head module 41 transmit and receive data, they transmit and receive data from the head of the data. The print data is data processed by the received head module 41 to drive the head 40. The print data includes, for example, information regarding the type and amount of ink ejected by the head 40. When the controller 7a transmits the print data to the downstream side, it specifies which of the first head module 41(1) to the nth head module 41(n) the kth head module 41(k) for processing the transmitted print data is. The controller 7a adds a switching flag to the print data to switch the switches 41e of the head modules 41 (the first head module 41(1) to the k−1th head module 41(k−1)) located upstream of the specified kth head module 41(k) to the second state. That is, k−1 switching flags are added to the print data. Note that the switching flag may be a flag for switching the switch 41e of the specified kth head module 41(k) to the first state. In this case, one switching flag is added to one print data. A marker indicating the data boundary is provided at the boundary between each switching flag and the print data.

[0021] The data received by the head module 41 is held in, for example, a buffer area provided in the communication I / F 41c. Among the data held in the communication I / F 41c, the data from the head to the first marker is separated and transmitted to the switch 41e side. The switch 41e of the head module 41 is in the first state in the initial state. That is, when the head module 41 receives print data and a switching flag is added to the received print data, the control unit 41a of the head module 41 acquires the first switching flag. When no switching flag is added to the print data received by the head module 41, the control unit 41a acquires the print data.

[0022] When a switching flag is added to the head of the print data received by the head module 41, the control unit 41a of the head module 41 acquires the first switching flag. The control unit 41a that has acquired the switching flag switches the switch 41e to the second state. As a result, among the data received by the head module 41, the switching flags and print data held in the communication I / F 41c other than the first switching flag are transferred to the downstream side. That is, the switching flag is information indicating the head module 41 that processes the print data. When the control unit 41a acquires the switching flag, it determines that the print data received by the head module 41 is not the print data processed by its own head module 41. When the control unit 41a does not acquire the switching flag, it determines that the print data received by the head module 41 is the print data processed by its own head module 41. After a predetermined time has elapsed since the control unit 41a switches the switch 41e to the second state, the control unit 41a switches the switch 41e to the first state. As a result, after the transfer of the print data is completed, the switch 41e is switched to the first state.

[0023] When a switching flag is not added to the head of the printing data received by the head module 41, the control unit 41a of the head module 41 acquires the printing data. The control unit 41a stores the acquired printing data in the storage unit 41b, and based on the printing data stored in the storage unit 41b, executes a process of driving the head 40 connected to its own head module 41.

[0024] FIG. 5 is a flowchart showing the process by the control unit 7b of the controller 7a. When the control unit 7b of the controller 7a receives printing data from an external device 9, for example, it starts the following process. The control unit 7b specifies the printing data to be transmitted based on the printing data (S1). The control unit 7b specifies the head module 41 that processes the printing data to be transmitted (S2). The control unit 7b adds a switching flag for switching the switch 41e of the head module 41 upstream of the specified k-th head module 41(k) to the second state to the printing data (S3), and transmits the printing data downstream (S4). The control unit 7b determines whether all the printing data related to the printing data has been transmitted (S5). If not all the printing data has been transmitted (S5: NO), the control unit 7b returns the process to S1. If all the printing data has been transmitted (S5: YES), the control unit 7b ends the process.

[0025] FIG. 6 is a flowchart showing the process by the control unit 41a of the head module 41. The control unit 41a of the head module 41 that has received the printing data determines whether it has acquired the switching flag (S11). If the switching flag has been acquired (S11: YES), the control unit 41a switches the switch 41e to the second state (S12). The control unit 41a determines whether a predetermined time has elapsed after switching the switch 41e to the second state (S13). If the predetermined time has not elapsed (S13: NO), the control unit 41a returns the process to S13 and waits until the predetermined time elapses. If the predetermined time has elapsed (S13: YES), the control unit 41a switches the switch 41e to the first state (S14) and returns the process to S11.

[0026] When the switching flag has not been acquired (S11: NO), the control unit 41a of the head module 41 holds the switch 41e in the state switched to the first state (S15), acquires print data (S16), causes the control unit 41a to store the print data in the storage unit 41b (S17), drives the head 40 based on the print data (S18), and returns the process to S11.

[0027] In the head system according to the first embodiment, when the received print data is not the print data to be processed by the own head module 41, the switch 41e of the head module 41 that has received the print data is switched so as to transfer the received print data to the downstream side without storing it in the storage unit 41b based on the switching flag. Thereby, it is possible to quickly transmit the print data to the downstream head module 41.

[0028] (Embodiment 2) The control unit 41a of the head module 41 according to the second embodiment acquires the print data received by the head module 41, and based on the information indicating the position where the ink is to be attached on the recording paper 100 (print position information) given to the print data acquired by the control unit 41a and the position information of the own head module 41, determines whether the print data received by the head module 41 is the print data to be processed by the own head module 41. When the print data received by the head module 41 is the print data to be processed by the own head module 41, the control unit 41a stores the print data in the storage unit 41b and drives the head 40. When the print data received by the head module 41 is not the print data to be processed by the own head module 41, the control unit 41a switches the switch 41e to the second state and transfers the print data to the downstream side.

[0029] FIG. 7 is an explanatory diagram showing print data according to Embodiment 2. The controller 7a according to Embodiment 2 specifies a position on the recording paper 100 where ink is to be attached based on the print data to be transmitted downstream. The controller 7a adds information (print position information) indicating the position where ink is to be attached on the specified recording paper 100 to the head of the print data, and transmits the data with the print position information added to the print data downstream.

[0030] The head module 41 that has received the data with the print position information added to the print data duplicates, for example, the print position information added to the received print data in the communication I / F 41c that receives the data. The data received by the head module 41 is held in, for example, a buffer area provided in the communication I / F 41c, and the duplicated print position information is transmitted to the switch 41e side. Since the switch 41e of the head module 41 is in the first state in the initial state, the control unit 41a acquires the duplicated print position information. The control unit 41a determines whether the received print data is the print data to be processed by the own head module 41 based on the acquired print position information and the position information of the own head module 41 stored in advance in the storage unit 41b. The position information of the own head module 41 stored in advance in the storage unit 41b is information indicating a range where ink can be attached on the recording paper 100 by ink ejection by the head 40 connected to the own head module 41. When the received print data is the print data to be processed by the own head module 41, the control unit 41a holds the switch 41e in the state switched to the first state, and acquires the print data received by the head module 41. When the received print data is not the print data to be processed by the own head module 41, the control unit 41a switches the switch 41e to the second state. At this time, the print data received by the head module 41 is transferred downstream together with the added print position information.

[0031] FIG. 8 is a flowchart showing the processing by the control unit 7b of the controller 7a according to Embodiment 2. When the control unit 7b of the controller 7a receives print data from an external device 9, for example, the control unit 7b that starts the following processing identifies the print data to be transmitted based on the print data (S21). The control unit 7b identifies the print position information based on the print data to be transmitted (S22). The control unit 7b adds the identified print position information to the print data (S23) and transmits the print data to the downstream side (S24). The control unit 7b determines whether all the print data related to the print data has been transmitted (S25). If not all the print data has been transmitted (S25: NO), the control unit 7b returns the process to S21. When all the print data has been transmitted (S25: YES), the control unit 7b ends the process.

[0032] FIG. 9 is a flowchart showing the processing by the control unit 41a of the head module 41 according to Embodiment 2. The control unit 41a of the head module 41 that has received the print data acquires the print position information (S31). The control unit 41a reads out the position information of its own head module 41 from the storage unit 41b (S32) and determines whether the received print data is the print data to be processed by its own head module 41 based on the print position information and the position information of its own head module 41 (S33). If the received print data is not the print data to be processed by its own head module 41 (S33: NO), the control unit 41a switches the switch 41e to the second state (S34). When the switch 41e is switched to the second state, the print position information and the print data held in the communication I / F 41c are transmitted to the downstream communication cable 51 via the communication I / F 41d. The control unit 41a determines whether a predetermined time has elapsed since the switch 41e was switched to the second state (S35). If the predetermined time has not elapsed (S35: NO), the control unit 41a returns the process to 35 and waits until the predetermined time elapses. When the predetermined time has elapsed (S35: YES), the control unit 41a switches the switch 41e to the first state (S36) and returns the process to S31.

[0033] When the received print data is the print data to be processed by the own head module 41 (S33: YES), the control unit 41a of the head module 41 holds the switch 41e in the switched-to the first state (S37), and acquires the print data (S38). The control unit 41a stores the print data in the storage unit 41b (S39). The control unit 41a drives the head 40 based on the print data (S40), and returns the process to S31.

[0034] In the head system according to the second embodiment, the control unit 41a of the head module 41 determines whether or not the received print data is the print data to be processed by the own head module 41 based on the print position information and the position information of the head module 41. Thereby, the controller 7a does not need to specify the head module 41 that processes the print data to be transmitted, and can transmit the print data quickly.

[0035] (Embodiment 3) The controller 7a of the head system according to the third embodiment sequentially transmits a plurality of print data in order of the head modules 41 to be processed to the downstream side from the print data to be processed by the upstream head module 41. The data amount of each print data differs depending on the head module 41 to be processed. When the switch 41e of the head module 41 starts receiving the first print data among the consecutive print data, it is switched to the first state, and after completing the reception of a predetermined data amount, it is switched to the second state.

[0036] FIG. 10 is a block diagram of the head module 41 according to Embodiment 3. The switch 41e of the head module 41 according to Embodiment 3 includes a switch control circuit 41f. The switch control circuit 41f includes an integrated circuit such as an ASIC or an FPGA, for example. Note that the switch 41e may include a processor such as a CPU or an MPU. When the head module 41 starts receiving print data, the switch control circuit 41f switches the switch 41e to the first state. The switch control circuit 41f measures the amount of data received by the head module 41 and sent to the control unit 41a via the switch 41e in the first state. When the head module 41 completes receiving a predetermined amount of data and the control unit 41a acquires the predetermined amount of data, the switch control circuit 41f switches the switch 41e to the second state.

[0037] FIG. 11 is an explanatory diagram showing print data according to Embodiment 3. The controller 7a according to Embodiment 3 sequentially transmits a plurality of print data up to the print data (n-th print data) processed by the n-th head module 41 (n), namely, the print data (first print data) processed by the first head module 41(1) and the print data (second print data) processed by the second head module 41(2), to the downstream side continuously. The data amount of each print data is different, and each head module 41 stores the data amount of the print data processed by its own head module 41 as a predetermined data amount. Each head module 41 causes the control unit 41a to acquire a predetermined data amount from the head of the print data received by the switch 41e, and transfers the subsequent print data downstream, thereby storing only the print data processed by its own head module 41 in the storage unit 41b.

[0038] FIG. 12 is a flowchart showing an example of the processing of the switch control circuit 41f of the switch 41e according to Embodiment 3. The switch control circuit 41f determines whether or not the head module 41 has started receiving print data (S51). If the head module 41 has not started receiving print data (S51: NO), the switch control circuit 41f returns the process to S51 and waits until the head module 41 starts receiving print data. When the head module 41 has started receiving print data (S51: YES), the switch control circuit 41f switches the switch 41e to the first state (S52). If the switch 41e is already in the first state even in S52, the switch control circuit 41f maintains the switch 41e in the first state. The switch control circuit 41f determines whether or not the head module 41 has completed receiving a predetermined amount of data (S53). If the head module 41 has not completed receiving a predetermined amount of data (S53: NO), the switch control circuit 41f returns the process to S53 and waits until the head module 41 completes receiving a predetermined amount of data. When the head module 41 has completed receiving a predetermined amount of data (S53: YES), the switch control circuit 41f switches the switch 41e to the second state (S54). The switch control circuit 41f determines whether or not the head module 41 has completed transferring the print data processed by the head module 41 other than itself to the downstream side (S55). Note that in S55, the switch control circuit 41f determines whether or not the transfer has been completed based on the elapsed time since the switch 41e was switched to the second state or the amount of print data transmitted to the communication I / F 41d via the switch 41e. If the transfer has not been completed (S55: NO), the switch control circuit 41f returns the process to S55 and waits until the transfer is completed. When the transfer has been completed (S55: YES), the switch control circuit 41f returns the process to S51.

[0039] In the head system according to Embodiment 3, based on the amount of data received by each head module 41, the switch 41e is switched, so that the print data processed by the own head module 41 is stored in the storage unit 41b, and the other print data is transferred to the downstream side. Since the controller 7a can continuously transmit a plurality of print data to the downstream side, it is possible to quickly transmit the print data.

[0040] (Embodiment 4) The controller 7a of the head system according to Embodiment 4 adds an error detection code to the print data and transmits it. The switch 41e of the head module 41 according to Embodiment 4 includes a switch control circuit 41f in the same manner as the switch 41e according to Embodiment 3. The switch control circuit 41f determines whether or not data corruption has occurred in the received print data and whether or not errors are included based on the error detection code added to the print data.

[0041] FIG. 13 is an explanatory diagram showing print data according to Embodiment 4. The controller 7a according to Embodiment 4 continuously transmits a plurality of pieces of print data downstream in the same manner as in Embodiment 3, but adds an error detection code to the end of each piece of print data. The error detection code is, for example, a parity bit. The controller 7a acquires the distance between the k-th head module 41(k) that processes the print data and the controller 7a for each piece of print data. The distance between the k-th head module 41(k) and the controller 7a is determined by the value of k. Based on the distance between the k-th head module 41(k) that processes the print data and the controller 7a, the controller 7a determines the number of bits of the parity bit to be added to the print data. The farther the k-th head module 41(k) that processes the print data is from the controller 7a, the higher the probability of data corruption occurring before the print data reaches the k-th head module 41(k). Therefore, the farther the k-th head module 41(k) that processes the print data is from the controller 7a, the more the controller 7a increases the number of bits of the added parity bit to improve the accuracy of error detection. Specifically, for example, the controller 7a adds a parity bit having a number of bits equal to the value obtained by dividing the value of k of the k-th head module 41(k) that processes the print data by 2 and rounding up the decimal part to the print data. When the number of bits of the parity bit is p bits, the error detection code indicates the remainder when the number of bits having a value of "1" in the bit string indicating the print data transmitted from the controller 7a is divided by 2 p and indicates the remainder when divided by 2.

[0042] The switch control circuit 41f of the k-th head module 41(k) counts the number of bits with the value "1" included in the data sequence of the printing data received by the k-th head module 41(k). The switch control circuit 41f divides the counted number of bits by the number of bits of the error detection code added to the end of the printing data, and calculates the remainder. The switch control circuit 41f determines whether or not the calculated remainder matches the value indicated by the error detection code. When the calculated remainder matches the value indicated by the error detection code, the switch control circuit 41f controls the switch 41e in the same manner as in Embodiment 3. When the calculated remainder does not match the value indicated by the error detection code, the switch control circuit 41f transmits information requesting retransmission of the printing data to the controller 7a.

[0043] FIG. 14 is a flowchart showing the processing by the control unit 7b of the controller 7a according to Embodiment 4. When the control unit 7b of the controller 7a receives print data from, for example, an external device 9, the control unit 7b starts the following processing. The control unit 7b identifies a plurality of print data to be transmitted based on the print data (S61). The control unit 7b adds an error detection code to the end of each print data based on each print data to be transmitted (S62). The control unit 7b sequentially transmits the plurality of print data with the error detection code added to the end continuously downstream from the print data processed by the first head module 41(1) (S63), and ends the processing.

[0044] FIG. 15 is a flowchart showing an example of the processing of the switch control circuit 41f according to Embodiment 4. The switch control circuit 41f determines whether or not the head module 41 has started receiving print data (S71). If the head module 41 has not started receiving print data (S71: NO), the switch control circuit 41f returns the process to S71 and waits until the head module 41 starts receiving print data. When the head module 41 has started receiving print data (S71: YES), the switch control circuit 41f switches the switch 41e to the first state (S72). If the switch 41e is already in the first state even in S72, the switch control circuit 41f holds the switch 41e in the first state. The switch control circuit 41f determines whether or not the head module 41 has completed receiving a predetermined amount of data (S73). In the present embodiment, when the head module 41 has completed receiving a predetermined amount of data, the head module 41 has received the print data to be processed by the own head module 41 and the error detection code added to the print data. If the head module 41 has not completed receiving a predetermined amount of data (S73: NO), the switch control circuit 41f returns the process to S73 and waits until the head module 41 completes receiving a predetermined amount of data.

[0045] When the head module 41 has completed receiving a predetermined amount of data (S73: YES), the switch control circuit 41f determines whether the print data received by the head module 41 contains an error based on the error detection code added to the print data (S74). If the print data contains an error (S74: YES), the switch control circuit 41f transmits information requesting retransmission of the print data to the controller 7a (S75), and returns the process to S71. The controller 7a that has received the information requesting retransmission of the print data retransmits the print data to the downstream side. Note that the controller 7a may retransmit only the print data processed by the head module 41 that has transmitted the information requesting retransmission of the print data to the downstream side. If the print data does not contain an error (S74: NO), the switch control circuit 41f advances the process to S76. The processes according to S76 to S77 are the same as the processes according to S54 to S55 shown in FIG. 12.

[0046] In the head system according to Embodiment 4, it is possible to detect an error due to data corruption when the print data is transmitted from the controller 7a to the head module 41. Further, by increasing the number of bits of the error detection code added to the print data processed by the head module 41 connected to a location far from the controller 7a, it is possible to efficiently detect an error in the print data.

[0047] (Embodiment 5) The head system according to Embodiment 5 includes a non-switch head module that does not include the switch 41e. The non-switch head module is connected to at least some of the head modules 41 included in the head system via a second communication cable 52 different from the communication cable (first communication cable) 51.

[0048] FIG. 16 is a block diagram of the control device 7 and the inkjet head 4 according to Embodiment 5. The inkjet head 4 according to Embodiment 5 includes a non-switch head module 42. The non-switch head module 42 is connected to the head module 41 via a second communication cable 52 different from the first communication cable 51. In the present embodiment, two non-switch head modules 42 are arranged in the left-right direction and are serially connected to the downstream side of each head module 41 via the second communication cable 52. A (2k - 1)-th non-switch head module 42(2k - 1) is connected to the downstream side of the k-th head module 41(k), and a 2k-th non-switch head module 42(2k) is connected to the downstream side of the (2k - 1)-th non-switch head module 42(2k - 1). Further, a head 40 is connected to each non-switch head module 42.

[0049] Note that the non-switch head module 42 does not necessarily have to be connected to the downstream side of all the head modules 41, and may be connected to the downstream side of some of the head modules 41. Further, the number of non-switch head modules 42 connected to the downstream side of one head module 41 is not limited to two, and may be one, or three or more. The number of non-switch head modules 42 connected to the downstream side of each head module 41 may be different.

[0050] FIG. 17 is a block diagram of the head module 41 and the non-switch head module 42 according to Embodiment 5. The head module 41 according to Embodiment 5 includes a communication I / F 41g. The communication I / F 41g is connected to the control unit 41a of the head module 41 and the second communication cable 52.

[0051] The non-switch head module 42 includes a second control unit 42a, a second storage unit 42b, second communication I / Fs 42c and 42d. The second control unit 42a includes a processor such as a CPU or an MPU. Note that the second control unit 42a may include an integrated circuit such as an FPGA or an ASIC. The second storage unit 42b includes a volatile memory such as an SDRAM, a rewritable non-volatile storage medium such as an EEPROM, a FlashROM, or a hard disk. The second communication I / Fs 42c and 42d are connected to a second communication cable 52. The second control unit 42a is connected to the second communication I / Fs 42c and 42d. The second storage unit 42b is connected to the second control unit 42a.

[0052] The switch 41e of the k-th head module 41(k) according to Embodiment 5 is switched to the first state when the k-th head module 41(k) receives print data processed by the k-th head module 41(k), print data processed by the (2k - 1)-th non-switch head module 42(2k - 1), or print data processed by the 2k-th non-switch head module 42(2k). When the control unit 41a of the k-th head module 41(k) acquires print data, the acquired print data is stored in the storage unit 41b, and it is determined whether the acquired print data is print data processed by any of the k-th head module 41(k), the (2k - 1)-th non-switch head module 42(2k - 1), or the 2k-th non-switch head module 42(2k). When the acquired print data is print data processed by the k-th head module 41(k), the control unit 41a drives the head 40 connected to the k-th head module 41(k) based on the print data. When the acquired print data is print data processed by either the (2k - 1)-th non-switch head module 42(2k - 1) or the 2k-th non-switch head module 42(2k), the control unit 41a transmits the print data stored in the storage unit 41b to the downstream side via the communication I / F 41g and the second communication cable 52.

[0053] When the (2k - 1)th non-switch head module 42(2k - 1) receives printing data from the kth head module 41(k), the second control unit 42a of the (2k - 1)th non-switch head module 42 acquires the printing data. The second control unit 42a stores the acquired printing data in the second storage unit 42b, and determines whether the acquired printing data is the printing data to be processed by either the (2k - 1)th non-switch head module 42(2k - 1) or the 2kth non-switch head module 42(2k). When the acquired printing data is the printing data to be processed by the (2k - 1)th non-switch head module 42(2k - 1), the second control unit 42a drives the head 40 connected to the (2k - 1)th non-switch head module 42(2k - 1) based on the printing data stored in the second storage unit 42b. When the acquired printing data is the printing data to be processed by the 2kth non-switch head module 42(2k), the second control unit 42a transmits the printing data stored in the second storage unit 42b to the downstream side via the second communication I / F 42d and the second communication cable 52.

[0054] When the 2kth non-switch head module 42(2k) receives printing data from the (2k - 1)th non-switch head module 42, the second control unit 42a of the 2kth non-switch head module 42 acquires the printing data. The second control unit 42a stores the acquired printing data in the second storage unit 42b, and drives the head 40 connected to the 2kth non-switch head module 42(2k) based on the printing data stored in the second storage unit 42b.

[0055] As described above, the number of non-switch head modules 42 connected to the downstream side of one head module 41 is not limited to two. The non-switch head module 42 to which another non-switch head module 42 is connected on the downstream side performs the same processing as the (2k - 1)th non-switch head module 42(2k - 1) described above. The non-switch head module 42 to which no other non-switch head module 42 is connected on the downstream side performs the same processing as the 2kth non-switch head module 42(2k) described above.

[0056] In the head system according to Embodiment 5, the control unit 41a of the k-th head module 41(k) acquires the print data processed by the (2k - 1)-th non-switch head module 42(2k - 1) or the 2k-th non-switch head module 42(2k). The control unit 41a of the k-th head module 41(k) transmits the print data to the downstream side via a second communication cable 52 different from the communication cable 51 that connects the k-th head module 41(k) and the (k + 1)-th head module 41(k + 1). Thereby, after the k-th head module 41(k) transmits the print data to the (2k - 1)-th non-switch head module 42(2k - 1) or the 2k-th non-switch head module 42(2k), for example, each head module 41 can transfer the print data to the downstream side during the time until the (2k - 1)-th non-switch head module 42(2k - 1) or the 2k-th non-switch head module 42(2k) receives the print data. As a result, the print data is efficiently transmitted to the downstream head module 41 or the non-switch head module 42.

[0057] (Embodiment 6) The head system according to Embodiment 6 includes a non-memory unit head module that does not include the switch 41e and the memory unit 41b. The non-memory unit head module is connected to at least some of the head modules 41 included in the head system via a second communication cable 52 different from the communication cable (first communication cable) 51.

[0058] FIG. 18 is a block diagram of the control device 7 and the inkjet head 4 according to Embodiment 6. The inkjet head 4 according to Embodiment 6 includes a non-memory head module 43. The non-memory head module 43 is connected to the head module 41 via a second communication cable 52 different from the first communication cable 51. The non-memory head module 43 according to the present embodiment is connected one by one to the downstream side of each head module 41, but it is not necessary to be connected to the downstream side of all the head modules 41, and it may be connected to the downstream side of some of the head modules 41. In the present embodiment, a k-th non-memory head module 43(k) is connected to the downstream side of the k-th head module 41(k).

[0059] FIG. 19 is a block diagram of the head module 41 and the non-memory head module 43 according to Embodiment 6. The head module 41 according to Embodiment 6 includes a communication I / F 41g. The communication I / F 41g is connected to the control unit 41a of the head module 41 and the second communication cable 52.

[0060] The non-memory head module 43 includes a second communication I / F 43c and a recording circuit 43a. The recording circuit 43a includes an integrated circuit such as an ASIC or an FPGA. Note that the recording circuit 43a may include a processor such as a CPU or an MPU. A head 40 is connected to each non-memory head module 43.

[0061] When the switch 41e of the k-th head module 41(k) according to Embodiment 6 receives print data processed by the k-th head module 41(k) or print data processed by the k-th non-memory unit head module 43(k), it is switched to the first state. When the control unit 41a of the k-th head module 41(k) acquires print data, it stores the acquired print data in the storage unit 41b and determines whether the acquired print data is the print data to be processed by the k-th head module 41(k) or the k-th non-memory unit head module 43(k). When the acquired print data is the print data to be processed by the k-th head module 41(k), the control unit 41a drives the head 40 connected to the k-th head module 41(k) based on the print data. When the acquired print data is the print data to be processed by the k-th non-memory unit head module 43(k), the control unit 41a transmits the print data stored in the storage unit 41b to the downstream side via the communication I / F 41g and the second communication cable 52.

[0062] When the k-th non-memory unit head module 43(k) receives print data from the k-th head module 41(k), the recording circuit 43a of the k-th non-memory unit head module 43(k) acquires the print data. The recording circuit 43a drives the head 40 connected to the k-th head module 41(k) based on the acquired print data.

[0063] In the head system according to Embodiment 6, the control unit 41a of the k-th head module 41(k) acquires the printing data processed by the k-th non-memory head module 43(k). The control unit 41a of the k-th head module 41(k) transmits the printing data downstream via a second communication cable 52 different from the communication cable 51 that connects the k-th head module 41(k) and the (k + 1)-th head module 41(k + 1). Thereby, after the k-th head module 41(k) transmits the printing data to the k-th non-memory head module 43(k), for example, each head module 41 can transfer the printing data downstream during the time until the k-th non-memory head module 43(k) receives the printing data. Thereby, the printing data is efficiently transmitted to the downstream head module 41 or the k-th non-memory head module 43(k).

[0064] (Embodiment 7) The head system according to Embodiment 7 includes a sub-head module including a second storage unit and a second switch. The sub-head module is connected to at least some of the head modules 41 included in the head system via a second communication cable 52 different from the communication cable (first communication cable) 51.

[0065] FIG. 20 is a block diagram of the control device 7 and the inkjet head 4 according to Embodiment 7. The inkjet head 4 according to Embodiment 7 includes a sub-head module 44. The sub-head module 44 is connected to the head module 41 via a second communication cable 52 different from the first communication cable 51. In the present embodiment, two sub-head modules are arranged in the left-right direction and are serially connected to the downstream side of each head module 41 via the second communication cable 52. A (2k - 1)-th sub-head module 44(2k - 1) is connected to the downstream side of the k-th head module 41(k), and a 2k-th sub-head module 44(2k) is connected to the downstream side of the (2k - 1)-th sub-head module 44(2k - 1). Further, a head 40 is connected to each sub-head module 44.

[0066] Note that the sub-head module 44 does not necessarily need to be connected to the downstream side of all the head modules 41, and may be connected to the downstream side of some of the head modules 41. Also, the number of sub-head modules 44 connected to the downstream side of one head module 41 is not limited to two, and may be one, or three or more. The number of sub-head modules 44 connected to the downstream side of each head module 41 may be different. Also, a plurality of other sub-head modules 44 may be connected to the downstream side of the sub-head module 44.

[0067] FIG. 21 is a block diagram of the head module 41 and the sub-head module 44 according to Embodiment 7. The head module 41 according to Embodiment 7 includes a communication I / F 41g. The communication I / F 41g is connected to the control unit 41a of the head module 41 and the second communication cable 52.

[0068] The sub-head module 44 includes a second control unit 44a, a second storage unit 44b, second communication I / Fs 44c and 44d, and a second switch 44e. The second control unit 44a includes a processor such as a CPU or an MPU. Note that the second control unit 44a may include an integrated circuit such as an FPGA or an ASIC. The second storage unit 44b includes a volatile memory such as an SDRAM, a rewritable non-volatile storage medium such as an EEPROM, a FlashROM, or a hard disk, and the like. The second communication I / Fs 44c and 44d are connected to the second communication cable 52.

[0069] The second switch 44e is connected to the second communication I / Fs 44c and 44d. The second control unit 44a is connected to the second switch 44e. The second storage unit 44b is connected to the second control unit 44a. The second switch 44e switches to a state (first state) of connecting the upstream second communication cable 52 connected via the second communication I / F 44c, the second control unit 44a, and the second storage unit 44b, or a state (second state) of connecting the upstream second communication cable 52 connected via the second communication I / F 44c and the upstream second communication cable 52 connected via the second communication I / F 44c.

[0070] The switch 41e of the k-th head module 41(k) according to Embodiment 7 switches to the first state when the k-th head module 41(k) receives print data processed by the k-th head module 41(k), print data processed by the (2k - 1)-th sub-head module 44(2k - 1), or print data processed by the 2k-th sub-head module 44(2k). When the control unit 41a of the k-th head module 41(k) acquires print data, the acquired print data is stored in the storage unit 41b, and it is determined which of the k-th head module 41(k), the (2k - 1)-th sub-head module 44(2k - 1), or the 2k-th sub-head module 44(2k) processes the acquired print data. When the acquired print data is the print data processed by the k-th head module 41(k), the control unit 41a drives the head 40 connected to the k-th head module 41(k) based on the print data. When the acquired print data is the print data processed by either the (2k - 1)-th sub-head module 44(2k - 1) or the 2k-th sub-head module 44(2k), the control unit 41a transmits the print data stored in the storage unit 41b downstream via the communication I / F 41g and the second communication cable 52.

[0071] Similar to the switch 41e of the head module 41, when the second switch 44e of each sub-head module 44 receives the printing data processed by its own sub-head module 44, it is switched to the first state, and when it receives the printing data processed by the sub-head module 44 connected downstream of its own sub-head module 44, it is switched to the second state. The second control unit 44a of each sub-head module 44 switches the second switch 44e to the first state or the second state based on the switching flag or the printing position information added to the printing data received by its own sub-head module 44. Note that the second switch 44e includes a second switch control circuit, and the second switch control circuit may switch the second switch 44e to the first state or the second state based on the data amount of the received printing data.

[0072] In the head system according to Embodiment 7, the control unit 41a of the k-th head module 41(k) acquires the printing data processed by the (2k - 1)-th sub-head module 44(2k - 1) or the 2k-th sub-head module 44(2k). The control unit 41a of the k-th head module 41(k) transmits the printing data downstream via a second communication cable 52 different from the communication cable 51 connecting the k-th head module 41(k) and the (k + 1)-th head module 41(k + 1). Thereby, after the k-th head module 41(k) transmits the printing data to the (2k - 1)-th sub-head module 44(2k - 1) or the 2k-th sub-head module 44(2k), for example, each head module 41 can transfer the printing data downstream during the time until the (2k - 1)-th sub-head module 44(2k - 1) or the 2k-th sub-head module 44(2k) receives the printing data. Thereby, the printing data is efficiently transmitted to the downstream head module 41 or sub-head module 44.

[0073] (Embodiment 8) The head module 41 of the head system according to Embodiment 8 includes an SoC.

[0074] FIG. 22 is a block diagram of a head module 41 according to Embodiment 8. The head module 41 according to Embodiment 8 includes an SoC 410. The control unit 41a, communication I / F 41c, communication I / F 41d, and switch 41e of the head module 41 are mounted on the SoC 410. Note that the storage unit 41b according to the present embodiment functions as an external storage unit of the SoC 410, but the storage unit 41b may be mounted on the SoC 410.

[0075] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The technical features described in each embodiment can be combined with each other, and 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. Also, the independent claims and dependent claims described in the claims can be combined with each other in all possible combinations regardless of the citation form. Further, although the claims use a form (multi-claim form) of describing a claim that cites two or more other claims, the present invention is not limited to this. A form of describing a multi-claim (multi-multi-claim) that cites at least one multi-claim may be used.

Description of Reference Numerals

[0076] 1 Printer 2 Case 3 Platen 4 Inkjet Head 5 Conveyor Roller 6 Conveyor Roller 7 Control Device 7a Controller 7b Control Unit 7c Storage Unit 9 External Device 40 Head 41 Head Module 41a Control Unit 41b Storage Unit 41e Switch 41f Switch Control Circuit 42 Non-Switch Head Module 42a Second control unit 42b Second memory unit 42d Second communication I / F 43 Non-memory head module 43a Recording circuit 44 Sub-head module 44a Second control unit 44b Second memory unit 44e Second switch 51 Communication cable (first communication cable) 52 Second communication cable 70 Recording medium 100 Recording paper 410 SоC

Claims

1. A controller, a plurality of heads, a plurality of head modules that are serially connected via a communication cable and transfer print data transmitted by the controller from upstream to downstream and comprising: each of said head modules is connected to each of said heads, a storage unit, and a switch for switching the connection destination of the upstream communication cable and comprising: said switch is switched to connect the upstream communication cable and the storage unit when the print data processed by the self-head module is received from upstream, and is switched to connect the upstream communication cable and the downstream communication cable when the print data processed by the head module downstream of the self-head module is received from upstream a head system.

2. said switch is switched to connect the upstream communication cable and the storage unit when starting to receive print data, and is switched to connect the upstream communication cable and the downstream communication cable when completing the reception of a predetermined data volume after starting to receive print data The head system according to claim 1.

3. said head module comprises a control unit, said control unit determines whether the received print data is the print data to be processed by the self-head module based on the information indicating the head module given to the received print data, when the received print data is the print data to be processed by the self-head module, switches said switch to connect the upstream communication cable and the storage unit, when the received print data is not the print data to be processed by the self-head module, switches said switch to connect the upstream communication cable and the downstream communication cable The head system according to claim 1.

4. said head module comprises a control unit, said control unit determines whether the received print data is the print data to be processed by the self-head module based on the print position information given to the received print data and the position information of the self-head module, when the received print data is the print data to be processed by the self-head module, switches said switch to connect the upstream communication cable and the storage unit, when the received print data is not the print data to be processed by the self-head module, switches said switch to connect the upstream communication cable and the downstream communication cable The head system according to claim 1.

5. The controller attaches an error detection code to the print data and transmits it to the head module. The switch determines whether the received print data contains an error based on the error detection code. When it is determined that the received print data contains an error, information requesting retransmission of the print data is transmitted to the controller. The head system according to any one of claims 1 to 4.

6. The controller identifies the head module that processes the print data based on the print data to be transmitted. obtains the distance between the identified head module and the controller. determines the number of bits of the error detection code to be attached to the print data based on the obtained distance. The head system according to claim 5.

7. Comprises a non-switch head module without the switch. At least some of the head modules and the non-switch head module are connected via a second communication cable different from the communication cable. The head system according to any one of claims 1 to 4.

8. Comprises a non-memory head module without the memory unit. At least some of the head modules and the non-memory head module are connected via a second communication cable different from the communication cable. The head system according to any one of claims 1 to 4.

9. Comprises a sub-head module having a second memory unit and a second switch. At least some of the head modules and the sub-head module are connected via a second communication cable different from the communication cable. The head system according to any one of claims 1 to 4.

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