Patent Publication Number: US-11660860-B2

Title: Liquid jet head and liquid jet recording device

Description:
RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2020-162449, filed on Sep. 28, 2020, the entire content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a liquid jet head and a liquid jet recording device. 
     2. Description of the Related Art 
     Liquid jet recording devices equipped with liquid jet heads are used in a variety of fields, and a variety of types of liquid jet heads have been developed (see, e.g., JP-A-2011-46160 (Document 1)). 
     In such a liquid jet head, in general, it is required to reduce the manufacturing cost and the power consumption. 
     It is desirable to provide a liquid jet head and a liquid jet recording device in which both of the manufacturing cost and the power consumption can be reduced. 
     SUMMARY OF THE INVENTION 
     The liquid jet head according to an embodiment of the present disclosure includes a jet section configured to jet liquid, and at least one drive board configured to output a drive signal used to jet the liquid to the jet section. The drive board includes a first input terminal and a second input terminal to which transmission data transmitted from an outside of the liquid jet head is input, a plurality of drive devices which are in a series arrangement with each other between the first input terminal and the second input terminal, and which is configured to generate the drive signal based on the transmission data input via either one of the first input terminal and the second input terminal, a plurality of transmission lines which are disposed via the plurality of drive devices which are in the series arrangement with each other between the first input terminal and the second input terminal, and which are configured to transmit the transmission data, and a plurality of termination resistors disposed on the plurality of transmission lines. The drive devices each have a first input/output section and a second input/output section which are configured to input or output the transmission data. The plurality of drive devices include a first drive device located at one end of the series arrangement, and a second drive device located at another end of the series arrangement. The plurality of transmission lines include a first transmission line configured to couple the first input terminal and the first input/output section in the first drive device to each other, a second transmission line configured to couple the second input terminal and the second input/output section in the second drive device to each other, and at least one third transmission line configured to couple the second input/output section in the first drive device and the first input/output section in the second drive device to each other. The plurality of termination resistors include a first termination resistor disposed in a vicinity of the first input/output section in the first drive device on the first transmission line, a second termination resistor disposed in a vicinity of the second input/output section in the second drive device on the second transmission line, and a third termination resistor disposed in a vicinity of one end or another end on each of the at least one third transmission line. 
     The liquid jet recording device according to an embodiment of the present disclosure includes the liquid jet head according to the embodiment of the present disclosure. 
     According to the liquid jet head and the liquid jet recording device related to an embodiment of the present disclosure, it becomes possible to reduce both of the manufacturing cost and the power consumption. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram showing a schematic configuration example of a liquid jet device according to an embodiment of the present disclosure. 
         FIG.  2    is a perspective view schematically showing a schematic configuration example of a liquid jet head shown in  FIG.  1   . 
         FIG.  3    is a cross-sectional view schematically showing a configuration example of the liquid jet head shown in  FIG.  2   . 
         FIG.  4 A  is a plan view schematically showing a detailed configuration example of flexible boards shown in  FIG.  2    and  FIG.  3   . 
         FIG.  4 B  is a plan view schematically showing a detailed configuration example of other flexible boards shown in  FIG.  2    and  FIG.  3   . 
         FIG.  5    is a schematic diagram showing an arrangement configuration example of members in the flexible board shown in  FIG.  4 A . 
         FIG.  6    is a schematic diagram showing an arrangement configuration example of members in the other flexible board shown in  FIG.  4 B . 
         FIG.  7 A  is a circuit diagram showing an arrangement configuration example of a typical termination resistor in a transmission line. 
         FIG.  7 B  is a circuit diagram showing another arrangement configuration example of a typical termination resistor in a transmission line. 
         FIG.  7 C  is a circuit diagram showing another arrangement configuration example of typical termination resistors in a transmission line. 
         FIG.  8 A  is a circuit diagram showing another arrangement configuration example of typical termination resistors in a transmission line. 
         FIG.  8 B  is a circuit diagram showing another arrangement configuration example of typical termination resistors in a transmission line. 
         FIG.  9    is a schematic diagram showing an arrangement configuration example of members in a flexible board in a liquid jet head according to Modified Example 1. 
         FIG.  10    is a schematic diagram showing an arrangement configuration example of members in a flexible board in a liquid jet head according to Modified Example 2. 
         FIG.  11    is a schematic diagram showing an arrangement configuration example of members in a flexible board in a liquid jet head according to Modified Example 3. 
         FIG.  12 A  is a schematic diagram showing an arrangement configuration example of a termination resistor in a drive device according to Modified Example 4. 
         FIG.  12 B  is a schematic diagram showing another arrangement configuration example of a termination resistor in a drive device according to Modified Example 4. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present disclosure will hereinafter be described in detail with reference to the drawings. It should be noted that the description will be presented in the following order. 
     1. Embodiment (Arrangement Configuration Example of Drive Device, Transmission Line, and Termination Resistor) 
     2. Modified Example 1 through Modified Example 4 (Other Arrangement Configuration Examples of Termination Resistor) 
     3. Other Modified Examples 
     1. Embodiment 
     [Schematic Configuration of Printer  5 ] 
       FIG.  1    is a block diagram showing a schematic configuration example of a printer  5  as a liquid jet recording device according to an embodiment of the present disclosure.  FIG.  2    is a perspective diagram schematically showing a schematic configuration example of an inkjet head  1  as a liquid jet head shown in  FIG.  1   .  FIG.  3    is a cross-sectional view (a Y-Z cross-sectional view) schematically showing a configuration example of the inkjet head  1  shown in  FIG.  2   . 
     It should be noted that the scale size of each of the members is accordingly altered so that the member is shown large enough to recognize in the drawings used in the description of the specification. 
     The printer  5  is an inkjet printer for performing recording (printing) of images, characters, and the like on a recording target medium (e.g., recording paper P shown in  FIG.  1   ) using ink  9  described later. As shown in  FIG.  1   , the printer  5  is provided with the inkjet head  1 , a print control section  2 , and an ink tank  3 . 
     It should be noted that the inkjet head  1  corresponds to a specific example of a “liquid jet head” in the present disclosure, and the printer  5  corresponds to a specific example of a “liquid jet recording device” in the present disclosure. Further, the ink  9  corresponds to a specific example of a “liquid” in the present disclosure. 
     (A. Print Control Section  2 ) 
     The print control section  2  is for supplying the inkjet head  1  with a variety of types of information (data). Specifically, as shown in  FIG.  1   , the print control section  2  is arranged to supply each of constituents (drive devices  41  described later and so on) in the inkjet head  1  with a print control signal Sc. 
     It should be noted that the print control signal Sc is arranged to include, for example, image data, an ejection timing signal, and a power supply voltage for operating the inkjet head  1 . 
     (B. Ink Tank  3 ) 
     The ink tank  3  is a tank for containing the ink  9  inside. As shown in  FIG.  1   , the ink  9  in the ink tank  3  is arranged to be supplied to the inside (a jet section  11  described later) of the inkjet head  1  via an ink supply tube  30 . It should be noted that such an ink supply tube  30  is formed of, for example, a flexible hose having flexibility. 
     (C. Inkjet Head  1 ) 
     As represented by dotted arrows in  FIG.  1   , the inkjet head  1  is a head for jetting (ejecting) the ink  9  having a droplet shape from a plurality of nozzle holes Hn described later to the recording paper P to thereby perform recording of images, characters, and so on. As shown in, for example,  FIG.  2    and  FIG.  3   , the inkjet head  1  is provided with a single jet section  11 , a single I/F (interface) board  12 , four flexible boards  13   a ,  13   b ,  13   c , and  13   d , and two cooling units  141 ,  142 . 
     (C-1. I/F Board  12 ) 
     As shown in  FIG.  2    and  FIG.  3   , the I/F board  12  is provided with two connectors  10 , four connectors  120   a ,  120   b ,  120   c , and  120   d , and a circuit arrangement area  121 . 
     As shown in  FIG.  2   , the connectors  10  are each a part (a connector part) for inputting the print control signal Sc described above and supplied from the print control section  2  toward the inkjet head  1  (the flexible boards  13   a ,  13   b ,  13   c , and  13   d  described later). 
     The connectors  120   a ,  120   b ,  120   c , and  120   d  are parts (connector parts) for electrically coupling the I/F board  12  and the flexible boards  13   a ,  13   b ,  13   c , and  13   d , respectively. 
     The circuit arrangement area  121  is an area where a variety of circuits are arranged on the I/F board  12 . It should be noted that it is also possible to arrange that such a circuit arrangement area is disposed in other areas on the I/F board  12 . 
     (C-2. Jet Section  11 ) 
     As shown in  FIG.  1   , the jet section  11  is a part which has the plurality of nozzle holes Hn, and jets the ink  9  from these nozzle holes Hn. Such jet of the ink  9  is arranged to be performed (see  FIG.  1   ) in accordance with a drive signal Sd (a drive voltage Vd) supplied from each of the drive devices  41  described later on each of the flexible boards  13   a ,  13   b ,  13   c , and  13   d.    
     As shown in  FIG.  1   , such a jet section  11  is configured including an actuator plate  111  and a nozzle plate  112 . 
     (Nozzle Plate  112 ) 
     The nozzle plate  112  is a plate formed of a film material such as polyimide, or a metal material, and has the plurality of nozzle holes Hn described above as shown in  FIG.  1   . These nozzle holes Hn are formed side by side at predetermined intervals, and each have, for example, a circular shape. 
     Specifically, in the example of the jet section  11  shown in  FIG.  2   , the plurality of nozzle holes Hn in the nozzle plate  112  are constituted by a plurality of nozzle arrays (four nozzle arrays) in which the nozzle holes are arranged along the column direction (the x-axis direction). Further, these four nozzle arrays are arranged side by side along a direction (the Y-axis direction) perpendicular to the column direction. 
     (Actuator Plate  111 ) 
     The actuator plate  111  is a plate formed of a piezoelectric material such as PZT (lead zirconate titanate). The actuator plate  111  is provided with a plurality of channels (pressure chambers). These channels are each a part for applying a pressure to the ink  9 , and are arranged side by side so as to be parallel to each other at predetermined intervals. Each of the channels is partitioned with drive walls (not shown) formed of a piezoelectric body, and forms a groove section having a recessed shape in a cross-sectional view. 
     In such channels, there exist ejection channels for ejecting the ink  9 , and dummy channels (non-ejection channels) which do not eject the ink  9 . In other words, it is arranged that the ejection channels are filled with the ink  9  on the one hand, but the dummy channels are not filled with the ink  9  on the other hand. It should be noted that it is arranged that filling of the ink  9  to each of the ejection channels is performed via, for example, a flow channel (a common flow channel) commonly communicated with such ejection channels. Further, it is arranged that each of the ejection channels is individually communicated with the nozzle hole Hn in the nozzle plate  112  on the one hand, but each of the dummy channels is not communicated with the nozzle hole Hn on the other hand. These ejection channels and the dummy channels are alternately arranged side by side along the column direction (the X-axis direction) described above. 
     Further, on the inner side surfaces opposed to each other in the drive wall described above, there are respectively disposed drive electrodes. As the drive electrodes, there exist common electrodes disposed on the inner side surfaces facing the ejection channels, and active electrodes (individual electrodes) disposed on the inside surfaces facing the dummy channels. These drive electrodes and the drive devices  41  described later are electrically coupled to each other via each of the flexible boards  13   a ,  13   b ,  13   c , and  13   d . Thus, it is arranged that the drive voltages Vd (the drive signals Sd) described above are applied to the drive electrodes from the drive devices  41  via the flexible boards  13   a ,  13   b ,  13   c , and  13   d.    
     (C-3. Flexible Boards  13   a ,  13   b ,  13   c , and  13   d ) 
     The flexible boards  13   a ,  13   b ,  13   c , and  13   d  are each a board for electrically coupling the I/F board  12  and the jet section  11  as shown in  FIG.  2    and  FIG.  3   . It is arranged that these flexible boards  13   a ,  13   b ,  13   c , and  13   d  individually control the jet operations of the ink  9  in the four nozzle columns in the nozzle plate  112  described above, respectively. Further, as indicated by, for example, the reference symbols P 1   a , P 1   b , P 1   c , and P 1   d  in  FIG.  3   , it is arranged that the flexible boards  13   a ,  13   b ,  13   c , and  13   d  are folded around places (around clamping electrodes  433 ) where the flexible boards  13   a ,  13   b ,  13   c , and  13   d  have contact with the jet section  11 , respectively. It should be noted that it is arranged that electrical coupling between the clamping electrodes  433  and the jet section  11  is achieved by, for example, thermocompression bonding using an ACF (Anisotropic Conductive Film). 
     On each of such flexible boards  13   a ,  13   b ,  13   c , and  13   d , there are individually mounted the drive devices  41  (see  FIG.  3   ). These drive devices  41  are each a device for outputting the drive signal Sd (the drive voltage Vd) for jetting the ink  9  from the nozzle holes Hn in the corresponding nozzle array in the jet section  11 . Therefore, it is arranged that such a drive signal Sd is output from each of the flexible boards  13   a ,  13   b ,  13   c , and  13   d  to the jet section  11 . It should be noted that such drive device devices  41  are each formed of, for example, an ASIC (Application Specific Integrated Circuit). 
     Further, these drive devices  41  are each arranged to be cooled by the cooling units  141 ,  142  described above. Specifically, as shown in  FIG.  3   , the cooling unit  141  is fixedly disposed between the drive devices  41  on the flexible boards  13   a ,  13   b , and by the cooling unit  141  being pressed against these drive devices  41 , the drive devices  41  are cooled. Similarly, the cooling unit  142  is fixedly disposed between the drive devices  41  on the flexible boards  13   c ,  13   d , and by the cooling unit  142  being pressed against these drive devices  41 , the drive devices  41  are cooled. It should be noted that such cooling units  141 ,  142  can each be configured using a variety of types of cooling mechanisms. 
     [Detailed Configuration of Flexible Boards  13   a ,  13   b ,  13   c , and  13   d ] 
     Subsequently, a detailed configuration example of the flexible boards  13   a ,  13   b ,  13   c , and  13   d  described above will be described with reference to  FIG.  4 A ,  FIG.  4 B ,  FIG.  5   , and  FIG.  6    in addition to  FIG.  1    through  FIG.  3   . 
       FIG.  4 A  and  FIG.  4 B  are plan views (Z-X plan views) schematically showing a detailed configuration example of the flexible boards  13   a  through  13   d  shown in  FIG.  2    and  FIG.  3   . Specifically,  FIG.  4 A  shows a planar configuration example (a Z-X planar configuration example) of the flexible boards  13   a ,  13   c , and  FIG.  4 B  shows a planar configuration example (a Z-X planar configuration example) of the flexible boards  13   b ,  13   d . Further,  FIG.  5    schematically shows an arrangement configuration example of the members in the flexible boards  13   a ,  13   c  shown in  FIG.  4 A , and  FIG.  6    schematically shows an arrangement configuration example of the members in the flexible boards  13   b ,  13   d  shown in  FIG.  4 B . 
     First, as shown in each of  FIG.  4 A  and  FIG.  4 B , the following members are provided to each of these flexible boards  13   a  through  13   d . That is, there are provided a coupling electrode  130 , a first input terminal Tint, a second input terminal Tin 2 , a first transmission line Lt 1 , a second transmission line Lt 2 , third transmission lines Lt 31  through Lt 34 , a plurality of (five in this example) drive devices  41 , and the clamping electrodes  433  described above. 
     The coupling electrode  130  is disposed in an end part area at the I/F board  12  side in each of the flexible boards  13   a  through  13   d , and is an electrode for electrically coupling each of the flexible boards  13   a  through  13   d  and the I/F board  12  to each other. 
     It is arranged that transmission data Dt (the print control signal Sc described above) transmitted from the outside (the print control section  2  described above) of the inkjet head  1  is input to each of the first input terminal Tin 1  and the second input terminal Tin 2  (see  FIG.  1   ,  FIG.  2   ,  FIG.  4 A , and  FIG.  4 B ). Further, it is arranged that such transmission data Dt is transmitted to the inside of each of the flexible boards  13   a  through  13   d  via one of the first input terminal Tin 1  and the second input terminal Tin 2 . Specifically, as shown in, for example,  FIG.  4 A , it is arranged that in each of the flexible boards  13   a ,  13   c , the transmission data Dt is transmitted to the inside of each of the flexible boards  13   a ,  13   c  via the first input terminal Tin 1 . Meanwhile, as shown in, for example,  FIG.  4 B , it is arranged that in each of the flexible boards  13   b ,  13   d , the transmission data Dt is transmitted to the inside of each of the flexible boards  13   b ,  13   d  via the second input terminal Tin 2 . 
     The five drive devices  41  described above are mounted on each of the flexible boards  13   a  through  13   d  (at an obverse surface  51  side out of an obverse surface  51  and a reverse surface S 2 ) in the example shown in  FIG.  4 A  and  FIG.  4 B . As such five drive devices  41 , in the example shown in  FIG.  4 A  and  FIG.  4 B , there are disposed a single first drive device  411 , a single second drive device  415 , and three third drive devices  412  through  414 . Further, these five drive devices  41  are disposed in series (cascaded) to each other between the first input terminal Tin 1  and the second input terminal Tin 2 . Specifically, as shown in  FIG.  4 A  and  FIG.  4 B , the first drive device  411 , the third drive devices  412  through  414 , and the second drive device  415  are disposed in series from the first input terminal Tin 1  toward the second input terminal Tin 2  in this order in all of the flexible boards  13   a  through  13   d . In other words, the first drive device  411  is located at one end of the serial arrangement of such drive devices  41 , and at the same time, the second drive device  415  is located at the other end of this serial arrangement. Further, the plurality of (three in this example) third drive devices  412  through  414  are located between the first drive device  411  and the second drive device  415 . Each of these five drive devices  41  is arranged to generate the drive signal Sd described above based on the transmission data Dt input via one of the first input terminal Tin 1  and the second input terminal Tin 2  as described above. It should be noted that each of the drive signals Sd generated in such a manner is arranged to be supplied toward the jet section  11  via the clamping electrodes  433  described above on each of the flexible boards  13   a  through  13   d.    
     Further, a plurality of transmission lines for transmitting the transmission data Dt via the five drive devices  41  arranged in series to each other are disposed between the first input terminal Tin 1  and the second input terminal Tin 2 . Specifically, as shown in  FIG.  4 A  and  FIG.  4 B , the first transmission line La is disposed between the first input terminal Tin 1  and the first drive device  411 , and the second transmission line Lt 2  is disposed between the second input terminal Tin 2  and the second drive device  415 . Further, the third transmission line Lt 31  is disposed between the first drive device  411  and the third drive device  412 , and the third transmission line Lt 32  is disposed between the third drive device  412  and the third drive device  413 . The third transmission line Lt 33  is disposed between the third drive device  413  and the third drive device  414 , and the third transmission line Lt 34  is disposed between the third drive device  414  and the second drive device  415 . 
     Here, as described above, the input terminal (the first input terminal Tin 1  or the second input terminal Tin 2 ) to which the transmission data Dt is input is different (see  FIG.  4 A  and  FIG.  4 B ) between the flexible boards  13   a ,  13   c  and the flexible boards  13   b ,  13   d . Further, in accordance therewith, the transmission direction inside the board of the transmission data Dt input is different between the flexible boards  13   a ,  13   c  and the flexible boards  13   b ,  13   d . In other words, it is arranged that the transmission data Dt having been input from the first input terminal Tin 1  is transmitted to the first drive device  411 , the third drive devices  412 ,  413 , and  414 , and the second drive device  415  in this order (see  FIG.  4 A ) in each of the flexible boards  13   a ,  13   c . In contrast, it is arranged that the transmission data Dt having been input from the second input terminal Tin 2  is transmitted to the second drive device  415 , the third drive devices  414 ,  413 , and  412 , and the first drive device  411  in this order (see  FIG.  4 B ) in each of the flexible boards  13   b ,  13   d.    
     In such a manner, the input terminal to which the transmission data Dt is input and the transmission direction of transmission data Dt are different between the flexible boards  13   a ,  13   c  and the flexible boards  13   b ,  13   d . It should be noted that the flexible boards  13   a ,  13   c  and the flexible boards  13   b ,  13   d  are made the same in the structure of the substrate itself as each other, and the configurations of the flexible boards  13   a  through  13   d  are commonalized (shared) (see  FIG.  4 A  and  FIG.  4 B ). In other words, although the details will be described later, there is no need to prepare a plurality of types of flexible boards (drive boards) in accordance with the transmission direction of the transmission data Dt and so on, and it becomes to dispose only a single type of flexible board (drive board) in the inkjet head  1 . 
     Arrangement Configuration Example of Termination Resistor 
     Here, as shown in  FIG.  5    and  FIG.  6   , the five drive devices  41  (the first drive device  411 , the third drive devices  412  through  414 , and the second drive device  415 ) described above each have a pair of input/output sections (input/output terminals) for performing input/output (input or output) of the transmission data Dt. Specifically, the first drive device  411 , the third drive devices  412  through  414 , and the second drive device  415  each have a first input/output section Tio 1  and a second input/output section Tio 2 . 
     Therefore, as shown in  FIG.  5    and  FIG.  6   , the first transmission line Lt 1  described above is arranged to couple the first input terminal Tin 1  and the first input/output section Tio 1  in the first drive device  411  to each other. Further, the second transmission line Lt 2  is arranged to couple the second input terminal Tin 2  and the second input/output section Tio 2  in the second drive device  415  to each other. Further, the four third transmission lines Lt 31  through Lt 34  couple the second input/output section Tio 2  in the first drive device  411  and the first input/output section Tio 1  in the second drive device  415  to each other via the three third drive devices  412  through  414 . Specifically, the third transmission line Lt 31  couples the second input/output section Tio 2  in the first drive device  411  and the first input/output section Tio 1  in the third drive device  412  to each other. Further, the third transmission line Lt 32  couples the second input/output section Tio 2  in the third drive device  412  and the first input/output section Tio 1  in the third drive device  413  to each other. The third transmission line Lt 33  couples the second input/output section Tio 2  in the third drive device  413  and the first input/output section Tio 1  in the third drive device  414  to each other. The third transmission line Lt 34  couples the second input/output section Tio 2  in the third drive device  414  and the first input/output section Tio 1  in the second drive device  415  to each other. 
     Further, as shown in  FIG.  5    and  FIG.  6   , such a plurality of termination resistors as described below are disposed on these transmission lines (the first transmission line Lt 1 , the second transmission line Lt 2 , and the third transmission lines Lt 31  through Lt 34 ). Specifically, on the first transmission line Lt 1 , there is disposed a first termination resistor Rt 1  in the vicinity of the first input/output section Tio 1  in the first drive device  411 . Further, on the second transmission line Lt 2 , there is disposed a second termination resistor Rt 2  in the vicinity of the second input/output section Tio 2  in the second drive device  415 . 
     Further, on the respective four third transmission lines Lt 31  through Lt 34 , third termination resistors Rt 31  through Rt 34  are respectively disposed in the vicinity of one of an end and the other end. Specifically, as shown in  FIG.  5    and  FIG.  6   , the third termination resistor Rt 31  is disposed in the vicinity of one end (in the vicinity of an end part at the first drive device  411  side) on the third transmission line Lt 31 , namely in the vicinity of the second input/output section Tio 2  in the first drive device  411 . Further, the third termination resistor Rt 32  is disposed in the vicinity of the other end (in the vicinity of an end part at the second drive device  415  side) on the third transmission line Lt 32 , namely in the vicinity of the first input/output section Tio 1  in the third drive device  413 . The third termination resistor Rt 33  is disposed in the vicinity of one end (in the vicinity of an end part at the first drive device  411  side) on the third transmission line Lt 33 , namely in the vicinity of the second input/output section Tio 2  in the third drive device  413 . The third termination resistor Rt 34  is disposed in the vicinity of the other end (in the vicinity of an end part at the second drive device  415  side) on the third transmission line Lt 34 , namely in the vicinity of the first input/output section Tio 1  in the second drive device  415 . In such a manner, in the example shown in  FIG.  5    and  FIG.  6   , it is arranged that the third termination resistors Rt 31  through Rt 34  on the respective four third transmission lines Lt 31  through Lt 34  are alternately disposed in the vicinity of the end part at the first drive device  411  side and in the vicinity of the end part at the second drive device  415  side. 
     It should be noted that although the details will be described later, in general, it cannot be said that it is a preferable arrangement to dispose a termination resistor at the transmission end (output end) on the transmission line. It should be noted that when the length (line length) of the transmission line for the cascade connection between the plurality of drive devices is relatively short, it can be said that it hardly matters if the position of the termination resistor is slightly shifted from the reception end (input end) as the preferable arrangement. Further, in the example shown in  FIG.  5    and  FIG.  6   , it is arranged that each of the number (two) of the termination resistors disposed at the reception end side and the number (two) of the termination resistors disposed at the transmission end side is the same between when the transmission data Dt is input from the first input terminal Tin 1  side ( FIG.  5   ) and when the transmission data Dt is input from the second input terminal Tin 2  side ( FIG.  6   ). Thus, it is arranged to prevent a difference in transmission quality of the transmission data Dt from occurring depending on the input direction (the transmission direction) of the transmission data Dt. 
     Further, line lengths (L 31  through L 34 ) of such third transmission lines Lt 31  through Lt 34  are each set to a value smaller than ¼ of the signal wavelength λt obtained from the transmission frequency ft of the transmission data Dt (L 31  through L 34 &lt;λt×¼). Further, it is more preferable for each of the line lengths of the third transmission lines Lt 31  through Lt 34  to be set to a value smaller than ⅛ of the signal wavelength λt (L 31  through L 34 &lt;λt×⅛). This is because the value of ¼ corresponds to a phase of 90°, and is a limit value for such a short transmission line to be able to keep the transmission quality with which no transmission error occurs in a circuit at the reception side. Further, the value ⅛ corresponds to a phase of 45°, and can be said preferable since it is possible to suppress the deterioration of the transmission quality due to the phase shift to a lower level compared to the case of the value of ¼ as the limit value. 
     Here, the flexible boards  13   a  through  13   d  described above each correspond to a specific example of the “drive board” in the present disclosure. Further, the first input terminal Tin 1  and the second input terminal Tin 2  each correspond to a specific example of a “first input terminal” and a “second input terminal” in the present disclosure. Further, the first input/output section Tio 1  and the second input/output section Tio 2  each correspond to a specific example of a “first input/output section” and a “second input/output section” in the present disclosure. Further, the first drive device  411  corresponds to a specific example of a “first drive device” in the present disclosure, the second drive device  415  corresponds to a specific example of a “second drive device” in the present disclosure, and the third drive devices  412  through  414  each correspond to a specific example of a “third drive device” in the present disclosure. Further, the first transmission line Lt 1  corresponds to a specific example of a “first transmission line” in the present disclosure, the second transmission line Lt 2  corresponds to a specific example of a “second transmission line” in the present disclosure, and the third transmission lines Lt 31  through Lt 34  each correspond to a specific example of a “third transmission line” in the present disclosure. Further, the first termination resistor Rt 1  corresponds to a specific example of a “first termination resistor” in the present disclosure, the second termination resistor Rt 2  corresponds to a specific example of a “second termination resistor” in the present disclosure, and the third termination resistors Rt 31  through Rt 34  each correspond to a specific example of a “third termination resistor” in the present disclosure. 
     [Operations and Functions/Advantages] 
     (A. Basic Operation of Printer  5 ) 
     In the printer  5 , a recording operation (a printing operation) of images, characters, and so on to the recording target medium (the recording paper P and so on) is performed using a jet operation of the ink  9  by such an inkjet head  1  as described below. Specifically, in the inkjet head  1  according to the present embodiment, the jet operation of the ink  9  using a shear mode is performed in the following manner. 
     First, the drive devices  41  on each of the flexible boards  13   a ,  13   b ,  13   c , and  13   d  each apply the drive voltage Vd (the drive signal Sd) to the drive electrodes (the common electrode and the active electrode) described above in the actuator plate  111  in the jet section  11 . Specifically, each of the drive devices  41  applies the drive voltage Vd to the drive electrodes disposed on the pair of drive walls partitioning the ejection channel described above. Thus, the pair of drive walls each deform so as to protrude toward the dummy channel adjacent to the ejection channel. 
     On this occasion, it results in that the drive wall makes a flexion deformation to have a V shape centering on the intermediate position in the depth direction in the drive wall. Further, due to such a flexion deformation of the drive wall, the ejection channel deforms as if the ejection channel bulges. As described above, due to the flexion deformation caused by a piezoelectric thickness-shear effect in the pair of drive walls, the volume of the ejection channel increases. Further, by the volume of the ejection channel increasing, the ink  9  is induced into the ejection channel as a result. 
     Subsequently, the ink  9  having been induced into the ejection channel in such a manner turns to a pressure wave to propagate to the inside of the ejection channel. Then, the drive voltage Vd to be applied to the drive electrodes becomes 0 (zero) V at the timing at which the pressure wave has reached the nozzle hole Hn of the nozzle plate  112  (or timing in the vicinity of that timing). Thus, the drive walls are restored from the state of the flexion deformation described above, and as a result, the volume of the ejection channel having once increased is restored again. 
     In such a manner, the pressure in the ejection channel increases in the process that the volume of the ejection channel is restored, and thus, the ink  9  in the ejection channel is pressurized. As a result, the ink  9  having a droplet shape is ejected (see  FIG.  1   ) toward the outside (toward the recording paper P) through the nozzle hole Hn. The jet operation (the ejection operation) of the ink  9  in the inkjet head  1  is performed in such a manner, and as a result, the recording operation of images, characters, and so on to the recording paper P is performed. 
     (B. Functions/Advantages in Inkjet Head  1 ) 
     Subsequently, functions and advantages in the inkjet head  1  according to the present embodiment will be described in detail while compared to a configuration example ( FIG.  7 A  through  FIG.  7 C ,  FIG.  8 A , and  FIG.  8 B ) of a typical termination resistor in the related art. 
     B-1. Regarding Configuration Example of Typical Termination Resistor 
       FIG.  7 A  through  FIG.  7 C ,  FIG.  8 A , and  FIG.  8 B  are each a circuit diagram showing an arrangement configuration example of a typical termination resistor in the transmission line. 
     First, in recent years, the fast differential transmission such as LVDS (Low Voltage Differential Signaling) has become to be used many times inside the inkjet printer. Therefore, it matters how efficiently the fast differential lines are laid around in the inkjet head which is small in size. As a problem which occurs on that occasion, there can be cited a method of arranging the termination resistor on such a fast differential lines. 
     In recent years, there exists a device which can cope with the bidirectional transmission, namely in which the same port can be used as the reception end (the input end) and also as the transmission end (the output end). Such a device capable of performing the bidirectional transmission is suitable to increase the density of the component and the interconnections on the board, and is therefore very important in such a circuit required to be reduced in size as one located inside the inkjet head. In the typical inkjet head in the related art, such drive devices capable of performing the bidirectional transmission are used, and the cascade connection (series connection) of these drive devices is simplified to achieve an increase in circuit density. 
     However, in the inkjet head in recent years, in order to achieve an increase in production efficiency when performing printing, speeding up when transmitting the print data is required, and accordingly, such fast differential transmission as described above has become necessary. As such fast differential transmission, there has been known a variety of transmission method such as CML (Current Mode Logic) in addition to LVDS described above, and basically, it is arranged that the terminal resistor having the same value as the characteristic impedance of the fast differential lines is disposed at the reception end (the input end). 
     Specifically, it is arranged that when differential lines  300  as the fast differential lines are coupled between a transmission end  101  in a device  100  and a reception end  202  in a device  200  as shown in, for example,  FIG.  7 A , a termination resistor Rt is disposed at the input side of the reception end  202 . Further, in the example shown in  FIG.  7 B , the termination resistor Rt is disposed at an input part of such a reception end  202  in the inside of the device  200 . 
     Here, in such a transmission scheme (a method of performing the LVDS transmission from a single transmission end to a plurality of reception ends) of a so-called “multi-drop” type as described in, for example, Document 1, it is arranged that the termination resistor is disposed only to one of the reception ends. This is because when disposing the termination resistors to all of the reception ends, the termination resistance value becomes low, and thus, a heavy load is applied to a device at the reception side. It should be noted that when the termination resistor is disposed only to one of the reception ends in such a manner, in the reception end at a position relatively far from the termination resistor, there occurs reflection of the high-frequency signal, and thus, the quality of the digital signal waveform deteriorates, and therefore, the transmission error due to, for example, an error in the H (High)/L (Low) determination becomes apt to occur. Further, in order to solve this problem, a degree of freedom of an arrangement of the termination resistor and the devices is significantly decreased as a result. 
     Therefore, in the devices (the drive devices) in the inkjet head, the cascade connection described above for outputting the input data transmitted using the LVDS to the drive device in the posterior stage is performed in some cases when performing the data transmission to a plurality of drive devices. By performing such cascade connection, such a problem of the termination resistor as in the “multi-drop” type described above seems to be solved. 
     However, when adopting the cascade connection, there is a problem. Specifically, for example, in the inkjet head, in general, a plurality of nozzle arrays are operated by the drive devices in many cases, and therefore, a plurality of boards (drive boards) for driving the plurality of nozzle arrays also become necessary in many cases. Further, in such a case, the plurality of drive substrates are disposed in a flipped manner with respect to a metal member (a cooling unit or the like) in, for example, the inkjet head in many cases. Incidentally, as described above using  FIG.  3   , in the inkjet head  1  according to the present embodiment, the flexible boards  13   a ,  13   c  and the flexible boards  13   b ,  13   d  as the plurality of drive boards are disposed in a flipped manner with respect to the cooling units  141 ,  142 . 
     Further, in such a case, the reception end (the input end) in the plurality of cascaded drive devices is exchanged depending on the arrangement direction in some cases as shown in, for example,  FIG.  4 A  and  FIG.  4 B  described above. Then, in order to cope with this, there occurs a necessity of preparing a plurality of types of drive boards if this goes on. Specifically, it is assumed that the termination resistors are supposedly disposed at the first input terminal Tin 1  side (the reception end side (the input end side) in this case) in the respective drive devices  41  in the flexible boards  13   a ,  13   c  as the drive boards shown in  FIG.  4 A . Further, when applying such an arrangement configuration of the termination resistors also to the flexible boards  13   b ,  13   d  as the drive boards shown in  FIG.  4 B , the termination resistors are disposed at the transmission end side (the output end side) of the respective drive devices  41  as a result. Therefore, in such an arrangement configuration example of the termination resistors, it becomes unachievable to perform the effective data transmission, and therefore, in this case, there occurs a necessity of preparing two types of drive boards as a result. 
     When the plurality of types of drive boards become necessary in such a manner, when manufacturing the inkjet head, an increase in the management cost is incurred. 
     Therefore, in order to avoid such an increase in the management cost, it is desirable to reduce the types of the drive boards, but in that case, there arises a necessity of disposing the input/output terminals (input/output sections) capable of performing the bidirectional transmission in each of the drive devices. The drive board compatible with the bidirectional transmission can be achieved with relative ease in, for example, slow single-ended communication, but in the fast differential transmission such as the LVDS described above, the problem of the termination resistor is inevitably brought out. 
     For example, when the two drive devices cascaded to each other become compatible with the bidirectional transmission, the termination resistors become necessary at the both ends of the transmission line coupled to these two drive devices. Specifically, in the example shown in  FIG.  7 C , the termination resistors Rt 100 , Rt 200  are disposed at the both ends of the differential lines  300  coupled between the two devices  100 ,  200  compatible with the bidirectional transmission. Specifically, the termination resistor Rt 100  is disposed in the vicinity of the transmission end  101  and a reception end  102  in the device  100 , and at the same time, the termination resistor Rt 200  is disposed in the vicinity of a transmission end  201  and the reception end  202  in the device  200 . 
     In the case of the plurality of drive devices cascaded to each other in such a manner, when the termination resistors are disposed at the both ends of the transmission line, the voltage amplitude level satisfied at the reception end halves, and therefore, in order to compensate the voltage amplitude level, it is necessary to increase, for example, the current used in the transmission from the transmission end. In other words, in this case, the current consumption when performing the data transmission increases as a result. 
     Incidentally, it is possible to adopt a method of switching between an ON state (a valid state) and an OFF state (an invalid state) of the termination resistor by selective mounting of a control terminal or a component in order to avoid such an increase in current consumption. Specifically, in an example shown in  FIG.  8 A  and  FIG.  8 B , switches SW 1 , SW 2  for individually switching between the ON state and the OFF state of the termination resistors Rt 100 , Rt 200  are additionally disposed in the configuration example shown in  FIG.  7 C  described above. 
     Here, in the case of  FIG.  8 A , a control terminal Tc 1  is set to an “L” state to thereby set the switch SW 1  to the OFF state, and at the same time, a control terminal Tc 2  is set to an “H” state to thereby set the switch SW 2  to the ON state. In other words, in the case of  FIG.  8 A , since the termination resistor Rt 100  out of the two termination resistors Rt 100 , Rt 200  located at the both ends of the differential lines  300  is set to the invalid state, only the termination resistor Rt 200  is set to the valid state. In contrast, in the case of  FIG.  8 B , the control terminal Tc 1  is set to the “H” state to thereby set the switch SW 1  to the ON state, and at the same time, the control terminal Tc 2  is set to the “L” state to thereby set the switch SW 2  to the OFF state. In other words, in the case of  FIG.  8 B , since the termination resistor Rt 200  out of the two termination resistors Rt 100 , Rt 200  located at the both ends of the differential lines  300  is set to the invalid state, only the termination resistor Rt 100  is set to the valid state. 
     However, in such a method, the additional control terminals and components (the switches and so on) cause a significant stress on the drive board for the inkjet head which is already high in mounting density and wiring density. Further, the selective mounting of a component is a method which should be avoided as strictly as possible from a viewpoint of the management of the manufacture of the drive board. In other words, in considering the arrangement configuration of the termination resistors, such a method of switching between the valid state and the invalid state of the termination resistor can be said to be undesirable. 
     In such a manner, in the configuration example of the typical termination resistors in the related art, the management cost of the drive board increases, or the current consumption when performing the data transmission increases. As a result, in the configuration example of the typical termination resistors, it can be said that there is a possibility that the manufacturing cost of the inkjet head and the power consumption increase. 
     (B-2. Functions/Advantages) 
     In contrast, in the inkjet head  1  according to the present embodiment, since the following configuration is adopted, it is possible to obtain, for example, the following functions and advantages. 
     That is, first, in the inkjet head  1 , it is arranged that the transmission data Dt is exclusively input via one of the first input terminal Tin 1  and the second input terminal Tin 2  in each of the flexible boards  13   a ,  13   b ,  13   c , and  13   d . Further, it is arranged that the transmission data Dt is input/output in a bidirectional manner between the plurality of drive devices  41  disposed in series (cascaded) to each other between the first input terminal Tin 1  and the second input terminal Tin 2 . Specifically, it is arranged that the transmission data Dt is input/output in the bidirectional manner via the plurality of transmission lines (the first transmission line Lt 1 , the second transmission line Lt 2 , and the third transmission lines Lt 31  through Lt 34 ), the first input/output sections Tio 1  and the second input/output sections Tio 2 . 
     Thus, it becomes possible to commonalize (share) the configuration of the flexible boards  13   a ,  13   c  in which the transmission data Dt is input from the first input terminal Tin 1  and the configuration of the flexible boards  13   b ,  13   d  in which the transmission data Dt is input from the second input terminal Tin 2  when using the plurality of flexible boards  13   a ,  13   b ,  13   c , and  13   d  in the inkjet head  1 . As a result, in the inkjet head  1 , the management cost of the flexible boards  13   a ,  13   b ,  13   c , and  13   d  as the drive boards can be suppressed. 
     Here, when the transmission data Dt is input from the first input terminal Tin 1  (see  FIG.  5   ), the first termination resistor Rt 1  disposed in the vicinity of the reception end (the first input/output section Tio 1  in the first drive device  411 ) on the first transmission line Lt 1  functions as the termination resistor when inputting the transmission data Dt from the outside of the inkjet head  1 . In contrast, when the transmission data Dt is input from the second input terminal Tin 2  (see  FIG.  6   ), the second termination resistor Rt 2  disposed in the vicinity of the reception end (the second input/output section Tio 2  in the second drive device  415 ) on the second transmission line Lt 2  functions as the termination resistor when inputting the transmission data Dt from the outside of the inkjet head  1 . 
     Further, in either of the cases described above (see  FIG.  5   ,  FIG.  6   ), the third termination resistors Rt 31  through Rt 34  disposed on each of the third transmission lines Lt 31  through Lt 34  function as the termination resistors when transmitting the transmission data Dt (when performing the data transmission) between the drive devices  41  disposed in series to each other. Further, such third termination resistors Rt 31  through Rt 34  are disposed in one of the vicinity of one end and the vicinity of the other end on the third transmission lines Lt 31  through Lt 34 , respectively. Thus, it is possible to suppress the current consumption when performing the data transmission between the drive devices  41  compared to when, for example, disposed in the vicinity of the both ends on the third transmission lines described above (e.g., the case of  FIG.  7 C  described above). 
     According to the above, in the present embodiment, it is possible to suppress the current consumption when performing the data transmission while suppressing the management cost of the flexible boards  13   a ,  13   b ,  13   c , and  13   d  as the drive boards. As a result, in the present embodiment, it becomes possible to reduce both of the manufacturing cost of the inkjet head  1  and the power consumption. 
     Further, in the present embodiment, when the three or more drive devices  41  are disposed in series to each other, the third termination resistors Rt 31  through Rt 34  on each of the third transmission lines Lt 31  through Lt 34  are alternately disposed. Specifically, in the vicinity of the end part at the first drive device  411  side and in the vicinity of the end part at the second drive device  415  side, these third termination resistors Rt 31  through Rt 34  are alternately disposed. Thus, the difference in arrangement position between the third termination resistors Rt 31  through Rt 34  is reduced (a variation in arrangement position is reduced) between when the transmission data Dt is input from the first input terminal Tin 1  (see  FIG.  5   ) and when the transmission data Dt is input from the second input terminal Tin 2  (see  FIG.  6   ). Therefore, the quality when performing the data transmission between the drive devices  41  is substantially homogenized in these cases (see  FIG.  5    and  FIG.  6   ), and as a result, it becomes possible to realize the stable data transmission. 
     Further, in the present embodiment, since the line lengths L 31  through L 34  of the third transmission lines Lt 31  through Lt 34  are set to the values (L 31  through L 34 &lt;λt×¼) smaller than ¼ of the signal wavelength λt described above, the following is achieved. That is, when the transmission data Dt is transmitted on the third transmission lines Lt 31  through Lt 34 , even when the third termination resistors Rt 31  through Rt 34  are located at the transmission end (the output end) instead of the reception end (the input end) in accordance with the transmission direction of the transmission data Dt, the degradation (the deterioration of the transmission signal) of the quality when performing the data transmission hardly occurs. As a result, it becomes possible to realize the stable data transmission. 
     2. Modified Examples 
     Then, some modified examples (Modified Example 1 through Modified Example 4) of the embodiment described above will be described. It should be noted that hereinafter, the same constituents as those in the embodiment are denoted by the same reference symbols, and the description thereof will arbitrarily be omitted. 
     Modified Example 1 Through Modified Example 3 
     (Configuration) 
       FIG.  9    is a diagram schematically showing an arrangement configuration example of members in a flexible board  13 A in a liquid jet head (an inkjet head  1 A) according to Modified Example 1. Further,  FIG.  10    is a diagram schematically showing an arrangement configuration example of members in a flexible board  13 B in a liquid jet head (an inkjet head  1 B) according to Modified Example 2.  FIG.  11    is a diagram schematically showing an arrangement configuration example of members in a flexible board  13 C in a liquid jet head (an inkjet head  1 C) according to Modified Example 3. 
     It should be noted that these inkjet heads  1 A through  1 C each correspond to a specific example of the “liquid jet head” in the present disclosure. Further, a printer equipped with any one of these inkjet heads  1 A through  1 C corresponds to a specific example of the “liquid jet recording device” in the present disclosure. 
     First, in the inkjet head  1 A according to Modified Example 1 shown in  FIG.  9   , the following members are disposed in the flexible board  13 A having the first input terminal Tin 1  and the second input terminal Tin 2 . That is, in the flexible board  13 A, there are disposed the first drive device  411 , the second drive device  415 , the first transmission line Lt 1 , the second transmission line Lt 2 , the third transmission line Lt 31 , the first termination resistor Rt 1 , the second termination resistor Rt 2 , and the third termination resistor Rt 31 . The flexible board  13 A is obtained by modifying the flexible boards  13   a  through  13   d  in the embodiment shown in  FIG.  5    and  FIG.  6    in such a manner as described below, and the rest of the configuration is basically the same. That is, the flexible board  13 A is obtained by omitting (being not provided with) the three third drive devices  412  through  414 , and at the same time, omitting the three third transmission lines Lt 32  through Lt 34 , and the three third termination resistors Rt 32  through Rt 34 . Further, the third termination resistor Rt 31  is disposed in the vicinity of one end (in the vicinity of the end part at the first drive device  411  side) on the third transmission line Lt 31 , namely in the vicinity of the second input/output section Tio 2  in the first drive device  411 . 
     Further, in the inkjet head  1 B according to Modified Example 2 shown in  FIG.  10   , the following members are disposed in the flexible board  13 B having the first input terminal Tin 1  and the second input terminal Tin 2 . That is, in the flexible board  13 B, there are disposed the first drive device  411 , the second drive device  415 , the third drive device  412 , the first transmission line Lt 1 , the second transmission line Lt 2 , the third transmission lines Lt 31 , Lt 32 , the first termination resistor Rt 1 , the second termination resistor Rt 2 , and the third termination resistors Rt 31 , Rt 32 . The flexible board  13 B is obtained by modifying the flexible board  13 A in Modified Example 1 shown in  FIG.  9    in such a manner as described below, and the rest of the configuration is basically the same. That is, the flexible board  13 B is obtained by further providing the third drive device  412 , and at the same time, further providing the third transmission line Lt 32 , and the third termination resistor Rt 32 . Further, the third termination resistor Rt 32  is disposed in the vicinity of the other end (in the vicinity of the end part at the second drive device  415  side) on the third transmission line Lt 32 , namely in the vicinity of the first input/output section Tio 1  in the second drive device  415 . 
     Further, in the inkjet head  1 C according to Modified Example 3 shown in  FIG.  11   , the following members are disposed in the flexible board  13 C having the first input terminal Tin 1  and the second input terminal Tin 2 . That is, in the flexible board  13 C, there are disposed the first drive device  411 , the second drive device  415 , the third drive devices  412 ,  413 , the first transmission line Lt 1 , the second transmission line Lt 2 , the third transmission lines Lt 31 , Lt 32 , Lt 33 , the first termination resistor Rt 1 , the second termination resistor Rt 2 , and the third termination resistors Rt 31 , Rt 32 , R 33 . The flexible board  13 C is obtained by modifying the flexible board  13 B in Modified Example 2 shown in  FIG.  10    in such a manner as described below, and the rest of the configuration is basically the same. That is, the flexible board  13 C is obtained by further providing the third drive device  413 , and at the same time, further providing the third transmission line Lt 33 , and the third termination resistor Rt 33 . Further, the third termination resistor Rt 33  is disposed in the vicinity of the other end (in the vicinity of the end part at the second drive device  415  side) on the third transmission line Lt 33 , namely in the vicinity of the first input/output section Tio 1  in the second drive device  415 . Therefore, in the Modified Example 3, unlike the embodiment, Modified Example 1, and Modified Example 2 described above, the three third termination resistors Rt 31  through Rt 34  are not alternately disposed in the vicinity of the end part at the first drive device  411  side and in the vicinity of the end part at the second drive device  415  side, as a result. 
     (Functions/Advantages) 
     In Modified Example 1 through Modified Example 3 having such configurations, it is also possible to obtain basically the same advantages due to substantially the same function as that of the embodiment. Specifically, it is possible to suppress the current consumption when performing the data transmission while suppressing the management cost of the flexible boards  13 A,  13 B,  13 C as the drive boards. As a result, it becomes possible to reduce both of the manufacturing cost of the inkjet heads  1 A through  1 C and the power consumption. 
     Modified Example 4 
       FIG.  12 A  and  FIG.  12 B  are diagrams schematically showing the arrangement configuration example of the termination resistor Rt in drive devices  41 D 1 ,  41 D 2  in Modified Example 4. Specifically,  FIG.  12 A  shows the arrangement configuration example of the termination resistor Rt in the drive device  41 D 1 , and  FIG.  12 B  shows the arrangement configuration example of the termination resistor Rt in the drive device  41 D 2 . 
     It should be noted that the inkjet heads respectively provided with these drive devices  41 D 1 ,  41 D 2  each correspond to a specific example of the “liquid jet head” in the present disclosure. Further, printers respectively equipped with those inkjet heads each correspond to a specific example of the “liquid jet recording device” in the present disclosure. 
     First, in the drive device  41 D 1  shown in  FIG.  12 A , the termination resistor Rt is disposed inside (in the inside at the first input/output section Tio 1  side) the drive device  41 D 1 . The termination resistor Rt corresponds to at least one of the termination resistors (the first termination resistor Rt 1 , the second termination resistor Rt 2 , and the third termination resistors Rt 31  through Rt 34 ) described hereinabove. 
     In contrast, in the drive device  41 D 2  shown in  FIG.  12 B , the termination resistor Rt is disposed inside (in the inside at the second input/output section Tio 2  side) the drive device  41 D 2 . The termination resistor Rt also corresponds to at least one of the termination resistors described hereinabove. 
     Since at least one of the first termination resistor Rt 1 , the second termination resistor Rt 2 , and the third termination resistors Rt 31  through Rt 34  is disposed (incorporated) inside the drive devices  41 D 1 ,  41 D 2  in Modified Example 4 in such a manner, the following is achieved. That is, on the flexible boards  13   a ,  13   b ,  13   c , and  13   d  as the drive boards, reduction of the mounting components and circuit scale can be achieved. As a result, in Modified Example 4, it becomes possible to further reduce the manufacturing cost of the inkjet head, and to achieve reduction in size of the inkjet head. 
     3. Other Modified Examples 
     The present disclosure is described hereinabove citing the embodiment and some modified examples, but the present disclosure is not limited to the embodiment and so on, and a variety of modifications can be adopted. 
     For example, in the embodiment and so on described above, the description is presented specifically citing the configuration examples (the shapes, the arrangements, the number and so on) of each of the members in the printer  5  and the inkjet heads  1 ,  1 A through  1 C, but what described in the above embodiment and so on is not a limitation, and it is possible to adopt other shapes, arrangements, numbers and so on. 
     Specifically, for example, in the embodiment and so on described above, the description is presented specifically citing the configuration examples of the flexible board (the drive board), the drive device, the transmission line, the termination resistor, and so on, but these configuration examples are not limited to those described in the above embodiment and so on. For example, in the embodiment and so on described above, the description is presented citing when the “drive board” in the present disclosure is the flexible board as an example, but the “drive board” in the present disclosure can also be, for example, a nonflexible board. 
     Further, the numerical examples of the variety of parameters described in the above embodiment and so on are not limited to the numerical examples described in the embodiment and so on, and can also be other numerical values. Specifically, in the above embodiment and so on, for example, the description is presented citing when the line lengths L 31  through L 34  of the third transmission lines Lt 31  through Lt 34  are set to the values (L 31  through L 34 &lt;λt×¼) smaller than ¼ of the signal wavelength λt described above as an example, but this example is not a limitation. Specifically, in some cases, for example, it is possible for at least one of the line lengths L 31  through L 34  to be a value no smaller than ¼ of the signal wavelength λt (L 31  through L 34 ≥λt×¼). 
     Further, as the structure of the inkjet head, it is possible to apply those of a variety of types. Specifically, for example, it is possible to adopt a so-called side-shoot type inkjet head which emits the ink  9  from a central portion in the extending direction of each of the ejection channels in the actuator plate  111 . Alternatively, it is possible to adopt, for example, a so-called edge-shoot type inkjet head for ejecting the ink  9  along the extending direction of each of the ejection channels. Further, the type of the printer is not limited to the type described in the embodiment and so on described above, and it is possible to apply a variety of types such as an MEMS (Micro Electro-Mechanical Systems) type. 
     Further, for example, it is possible to apply the present disclosure to either of an inkjet head of a circulation type which uses the ink  9  while circulating the ink  9  between the ink tank and the inkjet head, and an inkjet head of a non-circulation type which uses the ink  9  without circulating the ink  9 . 
     Further, the series of processes described in the above embodiment and so on can be arranged to be performed by hardware (a circuit), or can also be arranged to be performed by software (a program). When arranging that the series of processes is performed by the software, the software is constituted by a program group for making the computer perform the functions. The programs can be incorporated in advance in the computer described above and are then used, or can also be installed in the computer described above from a network or a recording medium and are then used. 
     Further, in the above embodiment and so on, the description is presented citing the printer  5  (the inkjet printer) as a specific example of the “liquid jet recording device” in the present disclosure, but this example is not a limitation, and it is also possible to apply the present disclosure to other devices than the inkjet printer. In other words, it is also possible to arrange that the “liquid jet head” (the inkjet head) of the present disclosure is applied to other devices than the inkjet printer. Specifically, it is also possible to arrange that the “liquid jet head” of the present disclosure is applied to a device such as a facsimile or an on-demand printer. 
     In addition, it is also possible to apply the variety of examples described hereinabove in arbitrary combination. 
     It should be noted that the advantages described in the specification are illustrative only but are not a limitation, and other advantages can also be provided. 
     Further, the present disclosure can also take the following configurations. 
     &lt;1&gt; A liquid jet head configured to jet liquid comprising: a jet section configured to jet the liquid; and at least one drive board configured to output a drive signal used to jet the liquid to the jet section, wherein the drive board includes: a first input terminal and a second input terminal to which transmission data transmitted from an outside of the liquid jet head is input, a plurality of drive devices which are in a series arrangement with each other between the first input terminal and the second input terminal, and which is configured to generate the drive signal based on the transmission data input via either one of the first input terminal and the second input terminal, a plurality of transmission lines which are disposed via the plurality of drive devices which are in the series arrangement with each other between the first input terminal and the second input terminal, and which are configured to transmit the transmission data, and a plurality of termination resistors disposed on the plurality of transmission lines, the drive devices each have a first input/output section and a second input/output section which are configured to input or output the transmission data, the plurality of drive devices include: a first drive device located at one end of the series arrangement, and a second drive device located at another end of the series arrangement, the plurality of transmission lines include: a first transmission line configured to couple the first input terminal and the first input/output section in the first drive device to each other, a second transmission line configured to couple the second input terminal and the second input/output section in the second drive device to each other, and at least one third transmission line configured to couple the second input/output section in the first drive device and the first input/output section in the second drive device to each other, and the plurality of termination resistors include: a first termination resistor disposed in a vicinity of the first input/output section in the first drive device on the first transmission line, a second termination resistor disposed in a vicinity of the second input/output section in the second drive device on the second transmission line, and a third termination resistor disposed in a vicinity of one end or another end on each of the at least one third transmission line. 
     &lt;2&gt; The liquid jet head according to &lt;1&gt;, wherein the plurality of drive devices further include at least one third drive device located between the first drive device and the second drive device in the serial arrangement, the plurality of third transmission lines couple the second input/output section in the first drive device and the first input/output section in the second drive device to each other via the at least one third drive device, and the third termination resistors on each of the third transmission lines are alternately disposed in a vicinity of an end part at the first drive device side and in a vicinity of an end part at the second drive device side. 
     &lt;3&gt; The liquid jet head according to &lt;1&gt; or &lt;2&gt;, wherein a line length in the at least one third transmission line is set to a value smaller than ¼ of a signal wavelength obtained from a transmission frequency of the transmission data. 
     &lt;4&gt; The liquid jet head according to any one of &lt;1&gt; to &lt;3&gt;, wherein at least one of the first termination resistor, the second termination resistor, and the third termination resistor is disposed inside the drive device. 
     &lt;5&gt; A liquid jet recording device comprising the liquid jet head according to any one of &lt;1&gt; to &lt;4&gt;.