Head module

Abstract

Provided is a head module capable of suppressing complexity of wiring in a printer. A head module 20 is provided with: an ejection head 21 having a drive element 21b for ejecting ink; a connection terminal 22 which receives print data generated by a control substrate 10 and added with address data corresponding to the ejection head 21 and a voltage generated by a power supply substrate 11 from a hub substrate 12 via first wiring L1 and to which the first wiring L1 is connected; and a head substrate 23 which generates a head drive voltage for driving the drive element 21b on the basis of the print data and the voltage each received by the connection terminal 22.

Description

Head Module

[0001] The present invention relates to a head module for an inkjet printer.

[0002] Conventionally, inkjet printers including a plurality of head units have been disclosed in, for example, Patent Document 1. In the printer of Patent Document 1, a hub is connected to each head unit via a signal line to transmit print data, and a power source is connected to each head unit via a power supply line separate from the signal line to supply power.

[0003] Japanese Unexamined Patent Application Publication No. 2011-201204

[0004] However, in the case of the printer disclosed in Patent Document 1, since a signal line and a power supply line are connected to each head unit, wiring around the head unit becomes complicated.

[0005] Accordingly, an object of the present disclosure is to provide a head module capable of suppressing the complexity of wiring in a printer.

[0006] The head module according to the present disclosure includes: an ejection head having a drive element that ejects ink; a connection terminal that receives print data, which is generated by a control board and added with address data corresponding to the ejection head, and a voltage generated by a power supply board from a hub board via a first wiring, and to which the first wiring is connected; and a head board that generates a head drive voltage for driving the drive element based on the print data and the voltage received at the connection terminal.

[0007] According to this configuration, since data and voltage can be transmitted to the head module through a single wiring, the number of wirings can be reduced compared to a case where data and voltage are transmitted through separate wirings, the complexity of wiring near the head module is reduced, and wiring connection work becomes easier. Furthermore, since address data indicating a destination is received together with print data and voltage, each head board can identify print data addressed to itself even when a plurality of head boards are connected to a hub board.

[0008] According to the present disclosure, a head module capable of suppressing the complexity of wiring in a printer can be provided.

[0009] Figure 1 is a schematic plan view showing the configuration of a printing apparatus equipped with a head module according to an embodiment. Figure 2 is a block diagram showing the functional configuration of the printing apparatus. Figure 3 is a schematic diagram illustrating the mechanism for transmitting print data and voltage between a hub board and a head board. Figure 4 is a cross-sectional view of a LAN cable. Figure 5 is a schematic perspective view of a head module. Figure 6 is a block diagram showing another example of the configuration of a head module.

[0010] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the following, the same reference numerals will be used for the same or corresponding elements throughout all drawings, and redundant explanations will be omitted.

[0011] [1. Printing Apparatus] Figure 1 is a schematic plan view showing an example of the configuration of a printing apparatus 1 equipped with a head module 20 according to an embodiment of the present disclosure. The printing apparatus 1 shown in Figure 1 is a serial head type inkjet printer. Accordingly, the printing apparatus 1 prints an image on the recording medium A by alternately repeating the steps of forming an image by ejecting ink from the ejection head 21 of the head module 20 mounted on the carriage 3 while moving the carriage 3 back and forth, and transporting the recording medium A.

[0012] Hereinafter, the reciprocating movement direction of the carriage 3 will be referred to as the left-right direction, and the transport direction of the recording medium A that intersects the left-right direction will be referred to as the front-back direction. Furthermore, the direction that intersects both the left-right and front-back directions will be referred to as the up-down direction. However, the directions relating to the printing device 1 and the head module 20 are not limited to these.

[0013] Furthermore, while this embodiment exemplifies a serial head printer as the printing device 1, it is not limited to this. For example, a line head printer can also be exemplified as the printing device 1. In this case, the head modules according to this disclosure can be applied to multiple head modules mounted on the line head.

[0014] As shown in Figure 1, the printing apparatus 1 is equipped with a box-shaped housing 2. Inside this housing 2 are a carriage 3 equipped with a head module 20, a platen 4, a moving device 5, a transport device 6, an ink tank 7, a control board 10, and a power supply board 11, among other things.

[0015] The carriage 3 is, for example, a box-shaped container with an open top, and is equipped with multiple head modules 20. Each head module 20 is equipped with a discharge head 21. The discharge head 21 is a flow path unit made of a stack of plates and having multiple nozzle holes 21a (see Figure 5) on its lower surface, and a drive element 21b (see Figure 2), such as a piezoelectric actuator, which applies liquid discharge pressure in a pressure chamber formed at the top of the flow path unit.

[0016] The ejection head 21 includes multiple ejection heads that eject different liquids. For example, the ejection head 21 may include an ejection head for ejecting a base ink such as white ink, an ejection head for ejecting a pretreatment liquid such as a coagulation liquid that aggregates particles in the white ink, an ejection head for ejecting a basic color ink to be ejected on top of the base ink, an ejection head for ejecting a special color ink that expands the color gamut, and an ejection head for ejecting a posttreatment liquid such as a coating ink that protects the underlying colorant. On the other hand, the printing apparatus 1 may be configured to have only one ejection head 21, and therefore may be configured to have only one head module 20.

[0017] Each head module 20 is equipped with one of these multiple ejection heads 21. In other words, the printing apparatus 1 is equipped with multiple head modules 20 corresponding to multiple ejection heads 21. In the case of the printing apparatus 1 shown in Figure 1, these multiple head modules 20 are arranged in a staggered pattern, with two adjacent head modules 20 offset from each other to the left and right, and the whole arrangement running in the front-to-back direction. It is also possible to have a configuration in which one head module 20 is equipped with two or more ejection heads 21.

[0018] The printing apparatus 1 includes a platen 4 positioned opposite the ejection head 21. The platen 4 has a rectangular flat surface for supporting the recording medium A from below and is located at a predetermined distance below the ejection head 21.

[0019] The printing apparatus 1 is equipped with a moving device 5 that moves the carriage 3 back and forth in the left-right direction. The moving device 5 has a moving motor 31 (see Figure 2), two guide rails 32, and an endless belt 33. The two guide rails 32 extend left and right across the platen 4 and are positioned far apart front to back, sandwiching all the ejection heads 21 between them. The carriage 3 is supported by these two guide rails 32 so that it can move back and forth in the left-right direction.

[0020] The endless belt 33 is wound around two pulleys 34 located near both the left and right ends of one of the guide rails 32, and is connected to the carriage 3 at predetermined points. The rotating shaft of the moving motor 31 is connected to one of the pulleys 34 via a reduction gear. Therefore, when the moving motor 31 is driven to rotate, the endless belt 33 moves, and the carriage 3 moves left and right along the guide rail 32.

[0021] The printing apparatus 1 includes a transport device 6 that transports the platen 4 while supporting the recording medium A. The transport device 6 includes, for example, a transport motor 41 (see Figure 2), a base 42, and a linear actuator. The base 42 has a rectangular parallelepiped shape in plan view, with its front-to-back dimension being larger than its left-to-right dimension. Inside it is a linear actuator consisting of a ball screw and a nut that screws onto the ball screw, and a transport motor 41 that drives the linear actuator.

[0022] A slit 42a extending in the front-rear direction is formed on the upper surface of the base 42, and the nut of the linear actuator inside the base 42 and the platen 4 above the base 42 are connected by a support arm provided through this slit 42a. Therefore, when the transport motor 41 operates, the linear actuator is driven and the nut moves in the front-rear direction, and the recording medium A moves in the front-rear direction together with the platen 4. The transport device 6 may also be configured to include a platen that does not move in the front-rear direction and a transport roller that transports the recording medium A in the front-rear direction by rotating while in contact with the recording medium A.

[0023] The printing apparatus 1 is equipped with a plurality of tanks 7 for storing various liquids to be supplied to the ejection head 21. Each tank 7 is provided for a specific type of liquid. These tanks 7 are housed inside the housing 2, for example, by opening a retractable cover provided on the housing 2. One end of a flexible tube 7a is connected to each tank 7, and the other end is connected to a liquid supply port on the ejection head 21. Therefore, the liquid in each tank 7 is sent to the ejection head 21 through the tube 7a.

[0024] The control board 10 is a computer equipped with a memory unit and an arithmetic unit, and is configured to include circuits such as a processor like an MPU or an integrated circuit like an ASIC. Based on the input image data, the control board 10 generates data for forming (printing) an image on the recording medium A. This data includes printing data related to the discharge of liquid from the discharge head 21, control commands for operating the moving device 5, and control commands for operating the transport device 6. The printing data includes information such as address data that identifies the discharge head 21 used during printing, a drive element 21b that operates in this discharge head 21, and the size of the liquid droplets discharged by driving this drive element 21b.

[0025] The control board 10 transmits the print data from the generated data to the head module 20 via the hub board 12 (see Figure 2), which will be described later, and transmits each control command to the moving device 5 and the transport device 6. Image data is input to the control board 10 from an input device (scanner, etc.) provided in the printing device 1, or from an external computer or external storage device (USB memory, etc.) via a communication interface.

[0026] The power supply board 11 is equipped with a power supply circuit. In the case of the printing apparatus 1 according to this embodiment, the power supply board 11 receives a voltage from an external commercial power supply PS, converts the received voltage to a power supply voltage used by the printing apparatus 1 (for example, 48V), and then supplies it to each part including the control board 10, the moving device 5, and the transport device 6.

[0027] Figure 2 is a block diagram showing the functional configuration of the printing device 1. The configuration of the printing device 1 will be further explained with reference to Figure 2.

[0028] The moving device 5 includes a moving drive circuit 30 in addition to the moving motor 31 and other components described above. The moving drive circuit 30 is electrically connected to the moving motor 31 and controls the operation (rotation speed) of the moving motor 31. Therefore, the moving device 5 can move the carriage 3 in the left-right direction and stop it at any position. Such a moving device 5 operates according to control commands from the control board 10, and the drive voltage for the moving motor 31 is supplied from the power supply board 11. Note that the moving device 5 is not limited to the above configuration. For example, the moving drive circuit 30 may not be provided in the moving device 5 but may be provided in the control board 10.

[0029] The conveying device 6 includes a conveying drive circuit 40 in addition to the conveying motor 41 and other components described above. The conveying drive circuit 40 is electrically connected to the conveying motor 41 and controls the operation (rotational speed) of the conveying motor 41. Therefore, the conveying device 6 can convey the platen 4 intermittently or continuously in the forward and backward directions. Such a conveying device 6 also operates according to control commands from the control board 10, and the drive voltage for the conveying motor 41 is supplied from the power supply board 11. Note that the conveying device 6 is not limited to the above configuration. For example, the conveying drive circuit 40 may not be provided in the conveying device 6 but may be provided in the control board 10.

[0030] On the other hand, the carriage 3 is equipped with a hub board 12 in addition to the head module 20 described above. Furthermore, each head module 20 is equipped with a head board 23 in addition to the ejection head 21. Note that in Figure 2, the ejection head 21 and head board 23 are shown for only one of the multiple head modules 20, and their depiction for the other head modules 20 is omitted, but the other head modules 20 are also equipped with ejection heads 21 and head boards 23 in the same way.

[0031] The hub board 12 is a circuit that relays information between the control board 10 and the multiple head boards 23. In other words, the hub board 12 receives print data from the control board 10 and transmits the received print data to the head boards 23. The head boards 23 are equipped with head drive circuits and are connected to each drive element 21b of the ejection head 21. The head boards 23 control the operation of each drive element 21b based on the print data received via the hub board 12. Consequently, the ejection head 21 ejects liquid onto the recording medium A from the corresponding nozzle holes 21a in accordance with the operation of the drive elements 21b.

[0032] [2. Wiring connecting each part] As shown in Figure 2, the control board 10 and the hub board 12 are connected by a second wiring L2. Therefore, the hub board 12 receives print data from the control board 10 through the second wiring L2. The configuration of this second wiring L2 is not particularly limited, but in this embodiment it is made up of a LAN (Local Area Network) cable.

[0033] Furthermore, the power supply board 11 and the hub board 12 are connected by a third wiring L3. Therefore, the hub board 12 receives voltage from the power supply board 11 through the third wiring. The configuration of this third wiring L3 is not particularly limited, and a known power supply cable suitable for transmitting the voltage to be used can be used.

[0034] Furthermore, the moving device 5 is connected to the control board 10 by a fourth wiring L4 and to the power supply board 11 by a fifth wiring L5. Therefore, the moving device 5 is driven by the voltage received through the fifth wiring L5 based on the control command received through the fourth wiring L4. Similarly, the transport device 6 is connected to the control board 10 by a sixth wiring L6 and to the power supply board 11 by a seventh wiring L7. Therefore, the transport device 6 is driven by the voltage received through the seventh wiring L7 based on the control command received through the sixth wiring L6. Moreover, the control board 10 and the power supply board 11 are connected by an eighth wiring L8.

[0035] The configurations of the fourth and sixth wirings L4 and L6 for signal transmission connected to the control board 10 are not particularly limited, and a LAN cable may be used, similar to the second wiring L2, or other known communication lines capable of transmitting control commands may be used. Similarly, the configurations of the fifth and seventh wirings L5 and L7 for power supply connected to the power supply board 11 are not particularly limited, and a known power supply cable capable of transmitting voltage may be used.

[0036] Furthermore, the wiring connections to the mobile device 5 and the transport device 6 are not limited to the connection configurations described above. For example, as a first modification, one or both of the fifth wiring L5 connected to the mobile device 5 and the seventh wiring L7 connected to the transport device 6 may be connected to an external power supply PS (see Figure 1) outside the printing device 1, rather than to the power supply board 11. In this case, an AC motor can be used as the mobile motor 31 or the transport motor 41.

[0037] As a second modification, the fourth wiring L4 connected to the moving device 5 may be configured to be connected to the transport device 6 instead of the control board 10. In this case, the transport device 6 and the moving device 5 are connected in series to the control board 10, and a communication method such as EtherCAT (Ethernet for Control Automation Technology) can be used to transmit control commands. Similarly, the sixth wiring L6 connected to the transport device 6 may be configured to be connected to the moving device 5 instead of the control board 10. In this case as well, control commands can be transmitted in the order of control board 10, moving device 5, and transport device 6 using, for example, EtherCAT.

[0038] On the other hand, the hub board 12 and the head boards 23 of each head module 20 are connected by a first wiring L1. That is, one end of the first wiring L1 is connected to the hub board 12 and the other end is connected to a connection terminal 22, which is electrically connected to the head board 23. In addition, the head board 23 and each drive element 21a of the ejection head 21 are connected by wiring La.

[0039] The first wiring L1 is a cable capable of simultaneously transmitting print data and voltage. That is, print data and voltage are transmitted from the hub board 12 to one head board 23 via a single first wiring L1. In this embodiment, a LAN cable is used as such the first wiring L1. When a LAN cable is used for the first wiring L1, data and voltage can be transmitted using, for example, PoE (Power over Ethernet) technology.

[0040] Figure 3 is a schematic circuit diagram illustrating PoE technology using a LAN cable. The LAN cable has four pairs of twisted-pair wires, each consisting of eight wires twisted together in pairs. In Figure 3, the wires labeled 1 and 2, 3 and 6, 4 and 5, and 7 and 8 each constitute a twisted-pair wire. The hub board side end of each twisted-pair wire is connected to the communication lines of the hub board 12 via a pulse transformer PT1. The head board side end of each twisted-pair wire is also connected to the communication lines in the head board 23 via a pulse transformer PT2.

[0041] Therefore, the print data received by the hub board 12 from the control board 10 is input to the twisted pair wires via the pulse transformer PT1 within the hub board 12 and transmitted. The print data transmitted through each twisted pair wire is then received by the head board 23 via the pulse transformer PT2.

[0042] Furthermore, the hub board 12 generates a predetermined power supply voltage from the voltage received from the power supply board 11. As shown in Figure 3, the positive voltage of this power supply voltage is applied to the potential midpoints of the wires labeled 1 and 2 and 4 and 5, while the negative voltage is applied to the potential midpoints of the wires labeled 3 and 6 and 7 and 8.

[0043] Therefore, the power supply voltage generated by the hub board 12 from the voltage received from the power supply board 11 is transmitted to the head board side via the twisted pair wires indicated by reference numerals 1 and 2 or 3 and 6 for positive potential, and via the twisted pair wires indicated by reference numerals 4 and 5 or 7 and 8 for negative potential. Thus, for example, the power supply voltage can be received at the head board 23 by taking the difference between the positive potential transmitted through the twisted pair wires indicated by reference numerals 1 and 2 and the negative potential transmitted through the twisted pair wires indicated by reference numerals 7 and 8. Note that the hub board 12 may also be configured to send the received voltage to the head board 23 as is, without transforming the voltage received from the power supply board 11.

[0044] As shown in FIG. 3, the head substrate 23 is provided with a transformer VC. The potential midpoint of the conductive wires labeled 1 and 2 and the potential midpoint of the conductive wires labeled 4 and 5 are connected to the positive terminal of the transformer VC, and the potential midpoint of the conductive wires labeled 3 and 6 and the potential midpoint of the conductive wires labeled 7 and 8 are connected to the negative terminal of the transformer VC. This transformer VC converts (transforms) the power supply voltage received as described above into a voltage suitable for operation of each part of the head module 20, and transmits the voltage to each part.

[0045] As described above, the first wiring L1 configured by a LAN cable can transmit print data and voltage in parallel at the same time. Therefore, between the hub substrate 12 and each head substrate 23, there is no need to separately provide a print data transmission cable and a voltage transmission cable, and connection via a single first wiring L1 is sufficient. Then the head substrate 23 generates a head driving voltage for driving each driving element 21b based on the received print data and voltage. The generated head driving voltage is applied to the corresponding driving element 21b at appropriate timing, to drive the driving element 21b.

[0046] Note that for transmission of data and voltage by PoE, pair lines used for data transmission and pair lines used for voltage transmission such as "Alternative A" and "Alternative B" can be selected from several combinations for use. In the transmission of data and voltage through the first wiring L1 of the present embodiment, the combination of pair lines to be used is not particularly limited, and any combination may be used as long as data and voltage can be transmitted by a single first wiring L1. Further, the technology used for simultaneous transmission of data and voltage via a LAN cable is not limited to PoE, and other transmission technologies may be used.

[0047] [3. Other Configurations] As described above, the hub substrate 12 relays transmission of print data between the control substrate 10 and the plurality of head substrates 23. Accordingly, as such a hub substrate 12, a switching hub can be suitably used as an example. In this case, the control substrate 10 adds address data corresponding to the ejection head 21 to be driven to the print data, and transmits the print data to the hub substrate 12. The hub substrate 12 refers to the address data added to the print data received from the control substrate 10, and transmits the print data to the head module 20 corresponding to this address data.

[0048] In this way, the print data generated by the control substrate 10 is appropriately transmitted to the head substrate 23 of the head module 20 having the ejection head 21 that is to perform a liquid ejection operation based on the print data. Note that the hub substrate 12 is not limited to a switching hub, and may be configured of, for example, a repeater hub. In this case, since the print data is transmitted to all the head modules 20, each head module 20 may refer to the address data added to the print data and determine whether the print data is addressed to itself.

[0049] Further, the connection terminal 22 is a terminal that receives the print data added with address data and a voltage via the first wiring L1, and is connected to the first wiring L1. When a LAN cable is used as the first wiring L1, the connection terminal 22 can be configured of a known LAN jack to which a LAN cable can be connected.

[0050] Figure 4 is a cross-sectional view of a LAN cable used for the first wiring L1, etc. As shown in Figure 4, this LAN cable has eight conductors 51a to 51h running through the internal space of a tubular resin outer sheath 50. In order to show an example of the correspondence between the conductors 51a to 51h shown in Figure 4 and the conductors numbered 1 to 8 in Figure 3, Figure 4 includes the numbers assigned to the corresponding conductors in Figure 3 in parentheses next to the reference numerals 51a to 51h of each conductor. The outer surface of each conductor 51a to 51h is covered with an insulating film 52a to 52h, and two of each constitute a total of four pairs of twisted pair wires. A shield 53 is provided between these eight conductors 51a to 51h and the outer sheath 50. The shield 53 is made of a film, for example, having an aluminum film, and is wound around to enclose all of the conductors 51a to 51h.

[0051] This reduces the influence of external noise and enables stable transmission and reception of print data. In particular, when the printing device 1 is configured such that multiple head boards 23 are connected to the hub board 12, multiple first wirings L1 are located relatively close to each other. Even in such cases, by using the LAN cable described above as the first wiring L1, interference between cables can be suppressed and communication quality can be improved.

[0052] In Figure 4, reference numeral 54 denotes the drain wire. The drain wire 54 is provided between the outer sheath 50 and the shield 53, or inside the shield 53, in contact with the shield 53, and is made of a metal wire. The drain wire 54 is an arbitrary configuration in the LAN cable, but if it is provided, the head board 23 can be grounded, thus providing protection against leakage current to the head board 23.

[0053] Figure 5 is a schematic external perspective view showing an example of a specific configuration of the head module 20. As shown in Figure 5, the head module 20 includes a rectangular plate-shaped support plate 60. A discharge head 21 is provided at the lower part of the support plate 60, and a head substrate 23 is provided at the upper part of the support plate 60. A connection terminal 22 is also provided at the upper end of the support plate 60. This connection terminal 22 is configured to receive the first wiring L1 from the side (horizontally).

[0054] Furthermore, a vertical wall portion 61 is provided on the upper surface of the support plate 60, facing the front of the connection terminal 22. An opening 62 forming a through hole is formed in this vertical wall portion 61 at a position corresponding to the connection terminal 22, and a terminal cover 63 is provided in the opening 62. In the example shown in Figure 5, the opening 62 is circular, and the terminal cover 63 is provided so as to close this opening 62.

[0055] The terminal cover 63 is made of, for example, synthetic rubber and has an annular frame portion 63a and a plurality of fins 63b extending inward from the frame portion 63a. Each fin 63b is fan-shaped, with the arc portion of the fan shape connected to the frame portion 63a, and the vertices of each fin being arranged to be close to each other. In other words, the terminal cover 63 has an annular frame portion 63a and a membrane portion that occupies the inside of the frame portion 63a, and the plurality of fins 63b described above are formed by making a plurality of cuts along the radial direction in the membrane portion.

[0056] Such fins 63b are flexible, and when the fins 63b are bent, a gap is formed in the central part of the terminal cover 63. The first wiring L1 is routed through the gap in the terminal cover 63 as described above and connected to the connection terminal 22. In this state, the terminal cover 63 covers the connection portion between the first wiring L1 and the connection terminal 22. This prevents ink mist caused by ink ejected from the ejection head 21 from adhering to the connection portion between the first wiring L1 and the connection terminal 22. Furthermore, as described above, since the connection terminal 22 is configured such that the first wiring L1 is connected from the side, it is possible to prevent ink mist from adhering to the connection terminal 22 compared to a configuration in which it is connected from above, for example.

[0057] Furthermore, as shown in Figure 5, the head module 20 includes a substrate cover 64 that covers the upper surface 23a of the head substrate 23. The substrate cover 64 is box-shaped with an open bottom and is placed over the support plate 60 from above, covering each circuit element on the head substrate 23 so as to be enclosed inside. The substrate cover 64 has engaging parts, such as claw-shaped parts (not shown), which engage with the support plate 60. In addition, a closing member 65 is provided on the outer circumference of the upper surface 23a of the head substrate 23, at a position opposite the opening edge at the lower end of the substrate cover 64. This closing member 65 is a member that closes the gap between the upper surface 23a of the head substrate 23 and the substrate cover 64, and is made of, for example, sponge.

[0058] In this way, the substrate cover 64 prevents ink mist from adhering to the head substrate 23. Furthermore, the sealing member 65 prevents ink mist from entering through the gap between the head substrate 23 and the substrate cover 64, thereby further preventing ink mist from adhering to the head substrate 23.

[0059] [4. Effects] As described above, the head module 20 according to this disclosure is equipped with a connection terminal 22 to which a first wiring L1 on which print data and voltage are transmitted is connected. This makes it possible to transmit print data and voltage to the head module 20 with a single wire. Therefore, the number of wires can be reduced compared to when print data and voltage are transmitted by separate wires, the complexity of the wiring near the head module 20 is reduced, and the wiring connection work becomes easier. In addition, since address data indicating the destination is also received along with the print data, even when multiple head boards 23 are connected to the hub board 12, the print data can be transmitted to the appropriate head board 23.

[0060] In recent years, there has been a variety of printing demands, and as with the printing apparatus 1 of this disclosure, there is a possibility of installing many more ejection heads, such as ejection heads for pre-treatment liquids, ejection heads for post-treatment liquids, and ejection heads for various spot inks. When many ejection heads are installed, many head modules are also installed, and the complexity of the wiring, especially on the carriage, becomes more pronounced. In contrast, by adopting the head module 20 of this disclosure, the complexity of the wiring can be eliminated as described above. It should be noted that the advantages of the effects of this disclosure become more pronounced when the printing apparatus 1 is equipped with many head modules 20, but even with a configuration that has only one head module 20, the effect of reducing the complexity of the wiring is achieved.

[0061] Furthermore, the head module 20 according to this disclosure has a connection terminal 22 to which a LAN cable, which is the first wiring L1, is connected. By using a LAN cable in this way, high-speed and long-distance communication of print data becomes possible, so the ejection head 21 can be operated suitably even when the head module 20 has many drive elements 21b or when the cable length is long. It is more preferable that the LAN cable used has a cable length of 3m or more and a communication speed of 1Gbps or more. A LAN cable with such specifications is more suitable for the high-speed and long-distance communication described above.

[0062] Furthermore, in this disclosure, the hub board 12 is connected to the control board 10 by a second wiring L2, which is a LAN cable on which print data is transmitted, and to the power supply board 11 by a third wiring L3, which is a power supply cable on which voltage is transmitted. The connection terminal 22 is connected to a first wiring L1 on which print data and voltage are transmitted from the hub board 12. As a result, even when multiple head boards 23 are connected to the hub board 12, the control board 10 and the hub board 12 can be connected with just two cables. Therefore, the wiring configuration of the cables is simplified, and the occurrence of entanglement between the first wiring L1 and the two cables can be suppressed.

[0063] [5. Modifications] The configuration of each part of the printing apparatus 1, including the head module 20, is not limited to those described above. For example, as shown in Figure 6, the head module 20 may further include a cooling unit 66. As the cooling unit 66, for example, an electrically driven air-cooling fan or a Peltier element can be used. Such a cooling unit 66 is connected to the head board 23 by wiring Lb. The wiring Lb is a power supply line, and the voltage generated by the head board 23 from the voltage received at the connection terminal 22 is transmitted to the cooling unit 66 through this wiring Lb.

[0064] This allows for cooling of elements on the head board 23 and the ejection head 21, and also enables power supply to the cooling unit 66 based on the voltage received at the connection terminal 22. The head module 20 may also be equipped with non-electric heat dissipation fins or the like instead of an electrically driven cooling unit 66.

[0065] This disclosure can be applied to the head module of an inkjet printer.

[0066] 1 Printing device 10 Control board 11 Power supply board 12 Hub board 20 Head module 21 Discharge head 21b Drive element 23 Head board 63 Terminal cover 65 Blocking member 66 Cooling unit L1 First wiring

Claims

1. A head module comprising: an ejection head having a drive element for ejecting ink; a connection terminal to which print data generated by a control board and to which address data corresponding to the ejection head is attached, and a voltage generated by a power supply board are received from a hub board via a first wiring, and the first wiring is connected; and a head board that generates a head drive voltage for driving the drive element based on the print data and the voltage received at the connection terminal.

2. The head module according to claim 1, wherein the connection terminal is a terminal to which the first wiring, a LAN (Local Area Network) cable, is connected.

3. The head module according to claim 1, wherein the hub board is connected to the control board by a LAN cable through which the print data is transmitted, and is connected to the power supply board by a power supply cable through which the voltage is transmitted, and the first wiring through which the print data and the voltage are transmitted from the hub board is connected to the connection terminal.

4. The head module according to claim 1, wherein the ejection head has a plurality of nozzle holes that eject ink downward when driven by the drive element, and the first wiring is connected to the connection terminal from the side.

5. The head module according to claim 1, further comprising a terminal cover that covers the connection portion between the connection terminal and the first wiring.

6. The head module according to claim 1, further comprising a closing member that closes the gap between the upper surface of the head substrate and the substrate cover that covers the upper surface.

7. The head module according to claim 2, wherein the connection terminal is a terminal to which a cable having a shield between the conductor and the outer sheath to suppress the effects of noise is connected as the LAN cable.

8. The head module according to claim 1, comprising a cooling unit and a power supply line that supplies power to the cooling unit with a voltage generated from the voltage received at the connection terminal.

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