Patent Publication Number: US-11654679-B2

Title: Liquid discharging apparatus and wiring member

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation application of U.S. patent application Ser. No. 17/030,937, filed on Sep. 24, 2020, which is a continuation application of U.S. patent application Ser. No. 16/573,382, filed on Sep. 17, 2019, which claims priority from Japanese Patent Application No. 2018-178870, filed on Sep. 25, 2018, the disclosures of each of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     Field of the Invention 
     The present disclosure relates to a liquid discharging apparatus and a wiring member. 
     Description of the Related Art 
     Conventionally, there is known a liquid discharging apparatus provided with a plurality of head chips arranged in a first direction; a control board controlling discharging (jetting) of an ink by the plurality of head chips; and a flexible wiring board (flexible print circuit) electrically connecting the plurality of head chips with the control board. In this liquid discharging apparatus, the flexible wiring board has a first part extending in a second direction orthogonal to the first direction and having a wide width in the first direction, and a second part extending in the second direction and having a narrow width in the first direction which is smaller than that of the first part. An end of the first part is branched into a plurality of second parts each of which is connected to one of the plurality of head chips. On the other hand, an end, of the second part, which is on the side opposite to the first part is connected to a connector of the control board. Namely, since the plurality of head chips are connected to the control board via the flexible wiring board which is provided commonly with respect to the plurality of head chips, it is possible to reduce the number of the connector in the control board (see Japanese Patent Application Laid-open No. 2007-196455). 
     SUMMARY 
     In a case that, in the liquid discharging apparatus described in Japanese Patent Application Laid-open No. 2007-196455, the flexible wiring board connects the plurality of head chips with the control board, the flexible wiring board is bent at the first part, of which width in the first direction is wide, in a direction away from the plurality of head chips. Specifically, the flexible wiring board is bent at the first part along a bending line extending in the first direction. Due to this configuration, in such a case that the bendability of the flexible wiring board is low and that for example, any external force is applied to the flexible wiring board when the flexible wiring board is (being) connected to the connector of the control board, there is such a fear that each of the second parts of the flexible circuit board and one of the plurality of head chips might peel off or detached from each other at a joining part therebetween. 
     In view of the above-described situation, the present disclosure has been made; an object of the present disclosure is to provide a liquid discharging apparatus in which the bendability of a flexible wiring board is satisfactory, and the flexible wiring board and each of the head modules are less likely to peel off or detached from each other at a joining part therebetween. 
     According to a first aspect of the present disclosure, there is provided a liquid discharging apparatus including: liquid discharging modules which are arranged in a first direction along a predetermined plane; and a wiring member commonly joined to the liquid discharging modules, wherein the wiring member includes: first parts joined to the liquid discharging modules, respectively, in a state that the first parts are arranged side by side in the first direction along the predetermined plane; and second parts including: third parts extending from the first parts, respectively, in a second direction orthogonal to the first direction and along the predetermined plane, fourth parts extending in a third direction away from the predetermined plane, and fifth parts connected to first ends of the third parts and second ends of the fourth parts, respectively, the first ends being located on a side opposite to the first parts in the second direction, the second ends being located on a side close to the predetermined plane in the third direction; and a sixth part commonly connected to third ends of the fourth parts, the third ends being located on a side far from the predetermined plane in the third direction; and width in the first direction of each of the second parts is smaller than width in the first direction of the sixth part. 
     According to a second aspect of the present disclosure, there is provided a wiring member including: a sixth part which extends in a predetermined direction; second parts each of which extends in the predetermined direction from an end, of the sixth part, on one side in the predetermined direction; and an eighth part which extends in an orthogonal direction orthogonal to the predetermined direction and which connects ends of the second parts on the one side in the predetermined direction, with each other, wherein in each of the second parts, width thereof in the orthogonal direction is smaller than length thereof in the predetermined direction, and the width thereof in the orthogonal direction is smaller than width in the orthogonal direction of the sixth part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic plan view of a printer (ink-jet printer) according to a first embodiment of the present disclosure. 
         FIG.  2    is a block diagram depicting the electrical configuration of the ink-jet printer. 
         FIG.  3    is a view depicting a bottom surface of a head unit attached to a line head. 
         FIG.  4    is a cross-sectional view of  FIG.  3   , taken along a line IV-IV in  FIG.  3   . 
         FIG.  5    is a view depicting the configuration of a liquid discharging head in a plan view, in a state that piezoelectric elements are exposed by depicting a wiring board and a driver IC in a broken manner. 
         FIG.  6    is a circuit block diagram depicting the configuration of a circuit from which a driving signal for driving the piezoelectric elements is outputted to the piezoelectric elements. 
         FIG.  7    is a wave-form chart of a voltage signal inputted to the wiring board. 
         FIG.  8    is a plan view depicting the planar shape of a flexible wiring board before being bent. 
         FIG.  9    is a plan view depicting the arrangement of wirings in the flexible wiring board. 
         FIG.  10    is a view depicting a state that second parts are bent in a case that the flexible wiring board is mounted on the ink-jet printer. 
     
    
    
     EMBODIMENT 
     Overall Configuration of Ink-Jet Printer  11   
     An explanation will be given about the overall configuration of an ink-jet printer  11  (hereinafter referred to as “printer  11 ”) according to an embodiment of the present disclosure, with reference to  FIG.  1   . The printer  11  is an example of a “liquid discharging apparatus” of the present disclosure. Note that the embodiment which will be explained below is merely an example of the present disclosure, and the embodiment of the present disclosure can be changed or modified as appropriate, in a range not changing the gist of the present disclosure.  FIG.  1    depicts a state that the printer  11  is placed on a horizontal plane. In the following description, a side in front of the sheet surface of  FIG.  1    is referred to as “upper side” of the printer  11 , and a side beyond (far side of) the sheet surface of  FIG.  1    is referred to as “lower side” of the printer  11 . Further, a front-rear direction and left-right direction depicted in  FIG.  1    are defined as a conveyance direction and an apparatus width direction, respectively. The horizontal plane is an example of a “predetermined plane”. The conveyance direction is an example of a “second direction” and a “predetermined direction” of the present disclosure. The apparatus width direction is an example of a “first direction” and an example of an “orthogonal direction” of the present disclosure. The following explanation will be given while appropriately using the directional terms which are the front-rear, left-right and up-down (directions). 
     As depicted in  FIG.  1   , the printer  11  is mainly provided with a line head  13 , a platen  14 , a conveying mechanism  15 , a controller  100 , etc. The line head  13  has a plurality of head units  20  which are arranged along the apparatus width direction. Note that the line head  13  of the present embodiment has six pieces of the head unit  20 . The plurality of head units  20  have a same configuration. As depicted in  FIG.  3   , each of the head units  20  has a plurality of head modules  23 . Each of the head modules  23  is an example of a “liquid discharging module”. A plurality of nozzles N are open in the lower surface of each of the head modules  23 . As depicted in  FIG.  3   , the plurality of nozzle N are aligned in a nozzle-alignment direction which crosses the conveyance direction and the apparatus width direction. The nozzle-alignment direction is an example of a “fourth direction” of the present disclosure. The specific of the head unit  20  will be described later on. 
     The platen  14  is a stand or base on which a recording medium  12  is placed, and is arranged to face the lower surfaces of the respective head modules  23 . The conveying mechanism  15  has two conveying rollers  15   a,    15   b  which are arranged so as to sandwich the platen  14  in the conveyance direction therebetween, and a conveying motor  15   c  (see  FIG.  2   ). Two conveying rollers  15   a,    15   b  are driven while being synchronized with each other by the conveying motor  15   c.  The conveying mechanism  15  conveys the recording medium  12 , placed on the platen  14 , in the conveyance direction by the two conveying rollers  15   a,    15   b.    
     The controller  100  includes a CPU (Central Processing Unit)  110 , a ROM (Read Only Memory)  120 , a RAM (Random Access Memory)  130 , an ASIC (Application Specific Integrated Circuit)  140 , etc., as depicted in  FIG.  2   . The ROM  120  stores programs executable by the CPU  110 , a variety of kinds of fixed data, etc. The RAM  130  temporality stores data necessary for executing the program(s) (such as print data, etc.). The ASIC  140  is connected to various devices (units, components) or driving parts, etc., of the printer  11  such as the line head  13 , the conveying motor  15   c,  etc. Further, the ASIC  140  is connected to an external apparatus  160  such as a PC (Personal Computer) via a communication interface  150 . 
     The controller  100  controls the head units  20  of the line head  13 , the conveying motor  15   c,  etc., based on a printing instruction or command received from the external apparatus  160  to thereby execute a printing processing of printing an image, etc., on a recording medium  12 . While executing the printing processing, the controller  100  supplies, to the head units  20 , an electric signal for causing the line head  13  to discharge or jet an ink therefrom. Note that the controller  100  and the head units  20  are electrically connected to each other by a flexible wiring board  70  (see  FIG.  3   ) via which the electric signal is transmitted. Note that the flexible wiring board  70  is an exemplary wiring member of the present teaching, and the wiring member of the present teaching may include a flexible base material and wirings formed in the base material such as a flexible printed circuit (FPC), a chip on film (COF), and the like. 
     In the above explanation, although the variety of kinds of processing executed by the controller  100  is explained as being executed by the CPU  110 , it is allowable that the CPU  110  execute these processings in cooperation with the ASIC  140 . Further, it is also allowable that the controller  100  is provided with a plurality of pieces of the CPU  110  and that these CPUs  110  perform the processings in a sharing manner. Furthermore, it is also allowable that the controller  100  is provided with a plurality of pieces of the ASICs  140  and that these ASICs  140  execute the processings in a shared manner. Alternatively, it is allowable that only one piece of the ASIC  140  singly performs the processings. 
     Head Unit  20   
     As depicted in  FIG.  3   , each of the head units  20  has an outer shape that is parallelogram constructed of a pair of opposite sides parallel to the apparatus width direction, and a pair of opposite sides parallel to the nozzle-alignment direction. Each of the head units  20  has six pieces of the head module  23  which are arranged side by side to one another along the apparatus width direction. Each of the six head modules  23  extends in the nozzle-alignment direction. Each of the six head modules  23  have a same configuration, and electric signals corresponding to the six head modules  23 , respectively, are transmitted to the six head modules  23 , respectively, via one piece of the flexible wiring board  70 . 
     Head Module  23   
     As depicted in  FIG.  3   , the plurality of nozzles N via which the ink is discharged is formed in the bottom surface of each of the head modules  23 . The plurality of nozzles N form two nozzle rows which are nozzle rows NR 1 , NR 2  which are arranged side by side to each other in an orthogonal direction orthogonal to the nozzle-alignment direction; each of the nozzle rows are formed along the nozzle-alignment direction. The two nozzle rows NR 1 , NR 2  are formed in such a state that the positions thereof in the nozzle-alignment direction are shifted from each other. Note that the two nozzle rows NR 1 , NR 2  are formed of a same number of the nozzles, and that the plurality of nozzles N are formed with equal intervals (spacing distances) therebetween in each of the nozzle rows. Further, the present embodiment is configured such that two kinds of inks are discharged from each of the two nozzle rows, namely such that four kinds of inks are discharged from the two nozzle rows. For example, the present embodiment is configured such that an yellow ink Y and a cyan ink C are discharged from the nozzle row NR 1 , and a magenta ink M and a black ink Bk are discharged from the nozzle row NR 2 . 
     As depicted in  FIG.  4   , the head module  23  has a channel unit  30  forming a flow channel (channel) for the ink; a liquid discharging head  40  causing the ink to be discharged from the nozzles N; and a module case  25 . The channel unit  30  and the liquid discharging head  40  are attached to the module case  25  in a state that the channel unit  30  and the liquid discharging head  40  are stacked in the up-down direction. 
     The channel unit  30  is provided with, starting from the lower side thereof: a nozzle plate  31  formed with the plurality of nozzles N; a channel substrate  32 ; a pressure chamber substrate  33 ; and a vibration plate  41 . The nozzle plate  31 , the channel substrate  32 , the pressure chamber substrate  33  and the vibration plate  41  are fixed to one another while being staked on top of one another. The channel unit  30  is formed with: descenders  35  communicating with the nozzles N, respectively; pressure chambers  36  communicating with the descenders  35 , respectively; liquid supplying channels  37  communicating with the pressure chambers  36 , respectively; and a common liquid chamber  38  communicating with the liquid supplying channels  37 . Among those as described above, each of the descenders  35 , each of the pressure chambers  36  and each of the liquid supplying channels  37  are formed to correspond to one of the nozzles N. In contrast, one piece of the head module  23  is formed with four pieces of the common liquid chamber  38  corresponding to the four kinds of inks, respectively, and each of the common liquid chambers  38  are communicated with nozzles N from which a same kind of the ink is discharged. 
     The module case  25  is a member which is substantially box-shaped. A liquid introducing path  39 , configured to introduce an ink from a non-illustrated ink supply source to the common liquid chamber  38  in the channel unit  30  is formed in the inside of the module case  25 . The liquid introducing path  39 , together with the common liquid chamber  38 , is a space in which an ink common to a plurality of pieces of the pressure chamber  36  formed to be aligned in the channel unit  30  is stored. In the present embodiment, four pieces of the liquid introducing path  39  are formed corresponding to the four kinds of the ink, respectively. 
     The liquid discharging head  40  is provided with, starting from the lower side thereof: the vibration plate  41  formed with piezoelectric elements PZ; a wiring circuit board (wiring substrate)  60 , and a driver IC  65  which outputs a predetermined output voltage. Namely, the wiring substrate  60  has a first surface  60   a  facing (opposite to) the driver IC  65  and a second surface  60   b  facing the vibration plate  41 . 
     The vibration plate  41  is a plate-shaped member which is capable of elastically vibrating. The lower surface of the vibration plate  41  constructs the pressure chambers  36  of the channel unit  30 , and the upper surface of the vibration plate  41  has the plurality of piezoelectric elements PZ which are formed therein and which correspond to the plurality of nozzles N, respectively. Each of the piezoelectric elements PZ has a piezoelectric body  42  which expands and contracts in a case that an electric field acts thereon, and first and second electrodes  43  and  44  which are arranged to sandwich, in the up-down direction, the piezoelectric body  42  therebetween. The first electrode  43  is an individual electrode which is formed on the upper surface of the piezoelectric body  42 , corresponding to each of the pressure chambers  36  (each of the nozzles N). The second electrode  44  is an electrode which is formed on the upper surface of the vibration plate  41  corresponding to the plurality of pressure chambers  36  (plurality of nozzles N), and which is common to the plurality of piezoelectric elements PZ. In a case that a voltage is applied to the first and second electrodes  43  and  44  and that the electric field acts on a certain part or portion, of the piezoelectric body  42 , sandwiched by the first and second electrodes  43  and  44 , the certain part, of the piezoelectric body  44 , is deformed so as to project toward a certain pressure chamber  36  included in the plurality of pressure chambers  36  and corresponding to the certain part. This causes the vibration plate  41  to be curbed or bent, thereby imparting pressure (pressurizing) the ink inside the certain pressure chamber  36 . In this situation, the ink is discharged from a certain nozzle N included in the plurality of nozzles N and corresponding to the certain pressure chamber  36 . Note that in this case, the vibration plate  41  formed with the piezoelectric elements PZ is referred to as a piezoelectric-element formation substrate  45 . 
     The first surface  60   a  of the wiring substrate  60  is formed with a plurality of first output terminals  91  and a plurality of second output terminals  92 . The plurality of first and second output terminals  91  and  92  are electrically connected to the driver IC  65 , and an output voltage outputted from the driver IC  65  is transmitted to the plurality of first and second output terminals  91  and  92 . Namely, an electric circuit configured to selectively supply the output voltage with respect to the plurality of piezoelectric elements PZ, etc., are provided or mounted on the driver IC  65 , and bumps  69   a  and bumps  69   b  are formed on an active surface, of the driver IC  65 , which is a circuit formation surface. Further, the driver IC  65  is electrically connected to the first output terminals  91  by the bumps  69   a,  and is electrically connected to the second output terminals  92  by the bumps  69   b.  Namely, the driver IC  65  is attached to the first surface  60   a  of the wiring substrate  60  by means of a so-called Flip Chip mounting or packaging. 
     Furthermore, the wiring substrate  60  is formed with a plurality of through wirings  63  each of which is electrically connected either one of the first output terminals  91  and the second putout terminals  92 . Moreover, the second surface  60   b  of the wiring substrate  60  is formed with connecting wirings  63   a  and connecting wirings  63   b  electrically connected to the plurality of through wirings  63 , respectively. Namely, the first output terminals  91  and the second output terminals  92  formed on a side of the first surface  60   a  of the wiring substrate  60  are electrically connected to the connecting wirings  63   a  the connecting wirings  63   b,  respectively, which are provided on a side of the second surface  60   b  of the wiring substrate  60 . 
     Further, the second surface  60   b  of the wiring substrate  60  is formed with first conductive terminals  61  and second conductive terminals  62  each of which is electrically connected to the piezoelectric-element formation substrate  45 . In the present embodiment, the first conductive terminals  61  are each a resin bump which is constructed of an inner resin  64   a  and a connecting wiring  63   a  formed so as to cover the inner resin  64   a  therewith. Further, the second conductive terminals  62  are each a resin bump which is constructed of an inner resin  64   b  and a connecting wiring  63   b  formed so as to cover the inner resin  64   b  therewith. Namely, the output voltage outputted from the driver IC  65  is transmitted to the first conductive terminals  61  provided on the side of the second surface  60   b  of the wiring substrate  60 , and is also transmitted to the second conductive terminals  62  provided on the side of the second surface  60   b  of the wiring substrate  60 . Further, the output voltage transmitted to the first conducting terminals  61  is supplied to the first electrodes  43  of the piezoelectric-element formation substrate  45 , and the output voltage transmitted to the second conducting terminals  62  is supplied to the second electrode  44  of the piezoelectric-element formation substrate  45 , thereby causing the ink to be discharged from each of the nozzles N. 
     Further, the first and second conductive terminals  61  and  62  forms, in the liquid discharging head  40 , a gap having a predetermined size (dimension) between the piezoelectric-element formation substrate  45  and the wiring substrate  60  facing the piezoelectric-element formation substrate  45 . Namely, the first and second conductive terminals  61  and  62 , each provided as the plurality of conductive terminals, form the gap between the piezoelectric-element formation substrate  45  and the wiring substrate  60  such that the vibration plate  41  which deforms in the up-down direction does not make contact with the wiring substrate  60 . 
     Note that after the plurality of first conductive terminals  61  are connected between the piezoelectric-element formation substrate  45  and the wiring substrate  60 , it is allowable to fill a sealing member  46  formed of a resin in a space between the piezoelectric-element formation substrate  45  and the wiring substrate  60  and between first conductive terminals  61  which are adjacent to each other. By doing so, a space surrounded by the piezoelectric-element formation substrate  45 , the wiring substrate  60 , the first conductive terminals  61  and the sealing member  46  forms a sealed space SC in which the piezoelectric elements PZ are sealed (see  FIG.  4   ). In this meaning, the wiring substrate  60  is also a sealing substrate sealing the piezoelectric elements PZ therein. 
     Next, an explanation will be given about the configuration of the liquid discharging head  40 , with reference to  FIG.  5   . Note that the piezoelectric body  42  is omitted in the illustration of  FIG.  5   . As depicted in  FIG.  5   , the plurality of first electrodes  43  form, in the piezoelectric-element formation substrate  45 , an electrode row aligned in the nozzle-alignment direction so as to correspond to the nozzles N in the nozzle row NR 1 , respectively, and an electrode row aligned in the nozzle-alignment direction so as to correspond to the nozzles N in the nozzle row NR 2 , respectively. 
     The first electrodes  43  are formed with projecting electrodes  43   a,  respectively, each of which projects toward the outer circumference of the piezoelectric-element formation substrate  45 . The plurality of first conductive terminals  61  which are arranged along the nozzle-alignment direction are connected with respect to the projecting electrode  43   a,  respectively, as depicted as black (solid) circles in  FIG.  5   . Further, the plurality of second conductive terminals  62  are arranged along the nozzle-alignment direction, and are connected with respect to the second electrode  44  of the piezoelectric elements PZ, as depicted as black (solid) circles in  FIG.  5   . 
     In the liquid discharging head  40  of the present embodiment, the electric signal transmitted from the controller  100  via the flexible wiring board  70  is inputted to the wiring substrate  60 . Further, the driver IC  65  outputs a predetermined output voltage (driving voltage), based on the electric signal inputted to the wiring substrate  60 . 
     Next, an explanation will be given about the electric signal transmitted from the controller  100  via the flexible wiring board  70  and the output voltage outputted from the driver IC  65 , with reference to  FIG.  6   . Note that in the present embodiment, in the six head modules  23  aligned in the head unit  20 , the generation of the electric signal transmitted via the flexible wiring board  70  and the generation of the output voltage outputted to the piezoelectric elements PZ are performed with a similar circuit configuration. Accordingly, the explanation will be given about one piece among the six head modules  23 , as follows. 
     As depicted in  FIG.  6   , the controller  100  is provided with a main controlling part  52 , two voltage-signal generating circuits  53 ,  54 , and a constant-voltage generating circuit  55 . Further, an electric circuit configured to output a driving voltage VT to the first electrode  43  of each of the piezoelectric elements PZ and to output a constant voltage VBS to the second electrode  44  is constructed in the driver IC  65  possessed by the liquid discharging head  40 . 
     The main controlling part  52  outputs a variety of kinds of control signals, etc., for controlling the voltage-signal generating circuits  53 ,  54  and the electric circuit of the driver IC  65  in a case that an image data as an object (target) of printing is supplied from the external apparatus  160  such as the PC, etc. Specifically, the main controlling part  52  repeatedly supplies digital data dA to the voltage-signal generating circuit  53  as one of the voltage-signal generating circuits  53 ,  54 ; and the main controlling part  52  repeatedly supplies digital data dB to the voltage-signal generating circuit  54  as the other of the voltage-signal generating circuits  53 ,  54 . Here, the data dA defines the signal wave form of a first voltage signal which is an electric signal transmitted to the liquid discharging head  40 , and the data dB defines the signal wave form of a second voltage signal which is an electric signal transmitted to the liquid discharging head  40 . 
     After the voltage-signal generating circuit  53  as one of the voltage-signal generating circuits  53 ,  54  converts the data dA repeatedly supplied thereto into an analogue voltage, the voltage-signal generating circuit  53  outputs the first voltage signal, which is an analogue signal amplified for example by the class D amplification, to the liquid discharging head  40  as a driving signal COM-A. Similarly, after the voltage-signal generating circuit  54  as the other of the voltage-signal generating circuits  53 ,  54  converts the data dB repeatedly supplied thereto into an analogue voltage, the voltage-signal generating circuit  54  supplies the second voltage signal, which is an analogue signal amplified for example by the class D amplification, to the liquid discharging head  40  as a driving signal COM-B. Note that the two voltage-signal generating circuits  53 ,  54  have a similar circuit configuration except for being mutually different in the data inputted thereto and in the signal waveform of the voltage signal outputted therefrom; a constant voltage VH is used as the power source for the voltage-signal generating circuits  53 ,  54 . 
     Further, the main controlling part  52  outputs a control signal Sc for controlling the driving of the conveying motor  15   c  and controlling the conveyance of the recording medium  12 ; and the main controlling part  52  supplies, synchronizing with the control signal Sc, a variety of kinds of a control signal Ctr to the liquid discharging head  40 , as electric signals. Note that the control signal Ctr supplied to the liquid discharging head  40  is a digital (binary) voltage signal. In the present embodiment, the control signal Ctr includes a print data defining an ink amount of the ink to be discharged from the nozzle N, a clock signal used for transmitting the print data, a timing signal defining the print cycle, etc. 
     Furthermore, in addition to the driving signals COM-A, COM-B and the controlling signal Ctr, the constant voltage VBS generated by the constant-voltage generating circuit  55  is supplied from the controller  100  via the flexible wiring board  70 . Moreover, a voltage VH which is a constant potential as a power source for allowing the electric circuit of the driver IC  65  to operate, a voltage VL which is a constant potential and lower than the voltage VH, and a ground voltage GND (0 (zero) V) which is a constant potential and serves as the reference for the respective voltages, are supplied from the controller  100  via the flexible wiring board  70 . In other words, the voltage VH, the voltage VL and the ground voltage GND (0 V) which are the constant potentials, respectively, are supplied via the flexible wiring board  70  each as a constant-potential signal. 
     As depicted in  FIG.  7   , the driving signal COM-A in the present embodiment has a signal wave form wherein a trapezoidal wave form Adp 1  which is arranged at a first half period in the print cycle, and a trapezoidal wave form Adp 2  which is arranged at a latter half period in the print cycle are made to be continuous. The trapezoidal wave form Adp 1  and the trapezoidal wave form Adp 2  have a substantially same wave form; in a case that either one of the trapezoidal wave form Adp 1  and the trapezoidal wave form Adp 2  is supplied to the first electrode  43  of a certain piezoelectric element PZ included in the plurality of the piezoelectric elements PZ, each of the trapezoidal wave form Adp 1  and the trapezoidal wave form Adp 2  indicates a change in the voltage by which an intermediate amount of the ink is discharged from a nozzle N included in the plurality of the nozzles N and corresponding to the certain piezoelectric element PZ. 
     Further, the driving signal COM-B in the present embodiment has a signal wave form wherein a trapezoidal wave form Bdp 1  which is arranged at a first half period in the print cycle, and a trapezoidal wave form Bdp 2  which is arranged at a latter half period in the print cycle are made to be continuous. The trapezoidal wave form Bdp 1  and the trapezoidal wave form Bdp 2  have mutually different wave forms. Among the trapezoidal wave form Bdp 1  and the trapezoidal wave form Bdp 2 , the trapezoidal wave form Bdp 1  is a wave form for finely vibrating the ink in the vicinity of the nozzle N to thereby prevent any increase in the viscosity of the ink. Namely, in a case that the trapezoidal wave form Bdp 1  is supplied to the first electrode  43  of a certain piezoelectric element PZ included in the plurality of the piezoelectric elements PZ, the trapezoidal wave form Bdp 1  indicates a change in the voltage by which the ink is not discharged from a nozzle N included in the plurality of the nozzles N and corresponding to the certain piezoelectric element PZ. Further, in a case that the trapezoidal wave form Bdp 2  is supplied to the first electrode  43  of a certain piezoelectric element PZ included in the plurality of the piezoelectric elements PZ, the trapezoidal wave form Bdp 2  indicates a change in the voltage by which a small amount of the ink is discharged from a nozzle N included in the plurality of the nozzles N and corresponding to the certain piezoelectric element PZ, the small amount of the ink being smaller than the intermediate amount of the ink which is discharged in the case of applying the trapezoidal wave form Adp 1  or the trapezoidal wave form Adp 2  to the first electrode  43 . 
     On the other hand, the other constant voltages which are the voltage VBS, the voltage VH, the voltage VL and the ground voltage GND are each such a constant voltage of which voltage value is not changed (varied) or of which change is slight or small, during the print cycle. Note that the constant voltage VBS may be generated, for example as indicated by broken lines in  FIG.  7   , such that the voltage value thereof is changed with one print cycle as an unit period. Further, the voltage VH or the voltage VL may be generated by the constant-voltage generating circuit  55 . 
     Returning to  FIG.  6   , the driver IC  65  provided on the liquid discharging head  40  has a selection controlling part  66  and selecting parts  67  which correspond to the plurality of piezoelectric elements PZ, respectively, in one-to-one manner, as an electric circuit configured to supply the voltage selectively to the plurality of piezoelectric elements PZ. Namely, the driver IC  65  outputs the driving signal COM-A and the driving signal COM-B, which are transmitted from the controller  100  via the flexible wiring board  70 , selectively to the first electrode  43  of a piezoelectric element PZ among the plurality of piezoelectric elements PZ. 
     Specifically, the selection controlling part  66  once stores the clock signal transmitted from the controller  100  via the flexible wiring board  70  and the print data transmitted from the controller  100  via the flexible wiring board  70  while being synchronized with the clock signal, by a number same as the number of the nozzles N (piezoelectric elements PZ) of the head unit  20 . Then, according to the stored print data, the selection controlling part  66  instructs each of the selecting parts  67  to perform the selection between the driving signal COM-A and the driving signal COM-B, at a start timing of the print cycle (first half period, latter half period) which is defined by the timing signal transmitted from the controller  100  via the flexible wiring board  70 . Each of the selecting parts  67  selects either one (or selects none) of the driving signals COM-A and COM-B, and outputs the selected one of the driving signals COM-A and COM-B (or outputs non-selection of either one of the driving signals COM-A and COM-B) to the first electrode  43  via the first conductive terminal  61 , as the driving voltage VT to be applied to the piezoelectric element PZ corresponding thereto. 
     Further, the driver IC  65  outputs a constant voltage to the second electrode  44  of each of the piezoelectric elements PZ. Namely, in the present embodiment, the constant voltage VBS transmitted from the controller  100  via the flexible wiring board  70  is inputted to the driver IC  65  via the wiring substrate  60 . Afterwards, the inputted constant voltage VBS is outputted with respect to the second electrode  44  common to the plurality of piezoelectric elements PZ of the liquid discharging head  40 , from the driver IC  65  again via the second conductive terminals  62  provided on the wiring substrate  60 . 
     In the above-described manner, the driving voltage VT is outputted from the driver IC  65  selectively to respective one of the plurality of piezoelectric elements PZ, thereby applying the driving voltage VT selectively to the first electrodes  43  of the respective piezoelectric elements PZ, and applying the constant voltage VBS to the second electrode  44  (which is common to the plurality of piezoelectric elements PZ). As a result, any expansion and contraction according to the potential difference (difference in the potentials) between the driving voltage VT and the constant voltage VBS is generated in certain piezoelectric elements PZ which are included in the plurality of piezoelectric elements PZ and to which the driving voltage VT is selectively applied, and the ink is discharged from certain nozzles N which are included in the plurality of nozzles N and which correspond to the certain piezoelectric elements PZ, accompanying with the above-described expansion and contraction. Then, dots of different sizes are formed on the paper P depending on the amounts of the discharged ink(s). Therefore, the constant voltage VBS may also be considered as one of the driving signals. 
     Flexible Wiring Board  70   
     Next, an explanation will be given about the flexible wiring board  70  of the present embodiment. Firstly, the planar shape of the flexible wiring board  70  will be explained, with reference to  FIG.  8   . In a state depicted in  FIG.  8    before the flexible wiring board  70  is bent, the flexible wiring board  70  has a sixth part  71 , six second parts  72  branched from the sixth part  71 , and an eighth part  73  connecting or linking the ends of the six second parts  72  with one another. In other words, five through holes  77  defined by the sixth part  71 , the six second parts  72  and the eighth part  73  are formed in the flexible wiring board  70 . 
     The sixth part  71  is constructed of a wide-width part  71   a,  a tapered part  71   b  and a narrow-width part  71   c.  Width W 1  in the apparatus width direction of the wide-width part  71   a  is greater than width W 2  in the apparatus width direction of the narrow-width part  71   c.  Further, the width in the apparatus width direction of the tapered part  71   b  is made to be progressively smaller (tapered) from the wide-width part  71   a  toward the narrow-width part  71   c.  An input terminal  74  connectable to a connector of the controller  100  is arranged at the narrow-width part  71   c.    
     The six second parts  72  correspond to the six head modules  23 , respectively, and extend in the conveyance direction. Width W 3  in the apparatus width direction of each of the second parts  72  is smaller than the width W 1  of the wide-width part, and is smaller than the width W 2  of the narrow-width part. Namely, the width W 3  in the apparatus width direction of each of the second parts  72  is smaller than the width in the apparatus width direction of the sixth part  71 . Each of the second parts  72  is constructed of a first part  72   a  on a side of the eighth part  73  relative to a bending line F indicated in broken lines in  FIG.  8   , and a second part  72   b  on a side of the sixth part  71  relative to the bending line F. Note that a virtual boundary of each of the first part  72   a  with respect to the eighth part  73  extends in an orthogonal direction orthogonal to the nozzle-alignment direction. Accordingly, each of the third parts  72   a  has a trapezoidal shape of which side on the right side in the apparatus width direction is a short side, and of which side on the left side in the apparatus width direction is a long side. In the following explanation, the length of the short side of the first part  72  having the trapezoidal shape is defined as a “length L 1  in the conveyance direction of the first part  72   a ”. Further, a sum of the length L 1  in the conveyance direction of the first part  72   a  and length L 2  in the conveyance direction of the second part  72   b  is defined as “length L in the conveyance direction of the branched part  72 ”. In each of the second parts  72  of the present embodiment, the width W 3  in the apparatus width direction is smaller than the length L in the conveyance direction. 
     The eighth part  73  is constructed of first parts  73   a  which are provided on six locations arranged side by side to one another in the apparatus width direction, and seventh parts  73   b  which are provided on five locations arranged side by side to one another in the apparatus width direction. Each of the first parts  73   a  is rectangular-shaped, and extends in the nozzle-alignment direction. One end in the nozzle-alignment direction of each of the first parts  73   a  is continued to the first part  72   a  of one of the second parts  72  corresponding thereto. On the other hand, the other end in the nozzle-alignment direction of each of the first parts  73   a  is provided with a joint area  75 . The joint area  75  is an area which is joined to the wiring substrate  60  of the head module  23 , and at which an output terminal (to be) jointed to a contact point of the wiring substrate  60  is arranged. Each of the seventh parts  73   b  is continued to two first parts  73   a  included in the six first parts  73   a  and arranged at two locations which are adjacent in the apparatus width direction. In other words, the two first parts  73   a  arranged at the two locations which are adjacent in the apparatus width direction are linked by each of the seventh parts  73   b.  The eighth part  73  extending in the apparatus width direction is formed of the first parts  73   a  provided on the six locations and the seventh parts  73   b  provided on the five locations. 
     Next, the arrangement of wirings in the flexible wiring board  70  will be explained with reference to  FIG.  9   . Firstly, a COM-A wiring  76   a  configured to transmit the driving signal COM-A therethrough is arranged from the input terminal  74  along the outer shape of the flexible wiring board  70 . The COM-A wiring  76   a  is an example of a “driving-signal wiring” of the present disclosure. Further, similarly to the COM-A wiring  76   a,  a COM-B wiring  76   b  configured to transmit the driving signal COM-B therethrough is arranged from the input terminal  74  along the outer shape of the flexible wiring board  70 . The COM-B wiring  76   b  is also an example of the “driving-signal wiring” of the present disclosure. The COM-B wiring  76   b  is arranged on the inside of the COM-A wiring  76   a.  Note that each of the COM-A wiring  76   a  and the COM-B wiring  76   b  is cut or broken at a central portion in the apparatus width direction of the eighth part  73 . With this, a signal from the left side or a signal from the right side is allowed to be inputted into one piece of the joining part  73   a,  and it is possible to prevent signals from both of the left and right sides from being inputted into one piece of the joining part  73   a.    
     A GND wiring  76   c  is arranged in an annular shape further on the inside of the COM-B wiring  76   b,  so as to conform to the outer shape of the flexible wiring circuit  70  and the outer shape of the five through holes  77 . Namely, the GND wiring  76   c  is provided commonly with respect to the six head modules  23 . Six V-high wirings  76   d,  which are drawn from the input terminal  74  respectively toward the first parts  73   a  arranged at the six locations, are arranged in the inside of an area surrounded by the GND wiring  76   c.  The constant-potential signal is transmitted to each of the V-high wirings  76   d.  Note that the GND wiring  76   c  is drawn from a central portion in the apparatus width direction of each of the first parts  73   a  up to the input terminal  74 , such that the GND wiring  76   c  is along the V-high wiring  76   d  drawn from each of the first parts  73   a.  Further, control wirings  76   e  which are drawn from the input terminal  74  toward the first parts  73   a,  respectively, and which are arranged at the six locations, etc., are arranged in the inside of the area surrounded by the GND wiring  76   c.  The control signal  76   e  is transmitted to each of the control wirings  76   e.    
     By arranging the respective wirings (the variety of kinds of wirings) as depicted in  FIG.  9   , the GND wiring  76   c  is arranged along the V-high wirings  76   a  on one side or on the both sides relative to each of the V-high wirings  76   d.  With this, it is possible to lower a noise due to the electric current flowing through the V-high wirings  76   d  and reaching the COM-A signal  76   a  and/or the COM-B signal  76   b,  etc. 
     Note that the flexible wiring board  70  of the present embodiment is mounted on the printer  11  in a state that the flexible wiring board  70  is bent upward at the second parts  72 , as depicted in  FIG.  10   . In this state, the first part  72   a  of each of the second parts  72  extends in the conveyance direction along a horizontal plane, and the second part  72   b  of each of the second parts  72  extends in an up direction (upward) such that the second part  72   b  is away from the head module  23 . The up-down direction is an example of a “third direction” of the present disclosure. Further, in  FIG.  8   , parts, of the respective second parts  72 , overlapping with the bending line F each correspond to a bending part  72   c  depicted in  FIG.  10   . In other words, each of the fifth parts  72   c  is connected or linked to the end in the conveyance direction, of one of third parts  72   a  corresponding thereto, on the side opposite to the joining part  73   a,  and is connected or linked to the end on the lower side (lower end) of one of the fourth parts  72   b  corresponding thereto. The end in the conveyance direction, of each of the third parts  72   a,  on the side opposite to the joining part  73   a  is an example of a “first end” of the present disclosure. The lower end of each of the fourth parts  72   b  is an example of a “second end” of the present disclosure. Further, the end on the upper side (upper end) of each of the fourth parts  72   b  is an example of a “third end” of the present disclosure. 
     According to the printer  11  of the present embodiment as explained above, one piece of the flexible wiring board  70  is connected to one piece of the head unit  20 . Further, one piece of the head unit  20  includes six pieces of the head module  23 . Namely, a common flexible wiring board  70  is connected to the six head modules  23 . Accordingly, it is possible to reduce the number of the flexible wiring board, as compared with a case of connecting the flexible wiring board for each of the head modules, thereby making is possible to reduce the number of the connectors of the controller, as a result. 
     Further, in the printer  11  of the present embodiment, the flexible wiring board  70  has the sixth part  71 , the plurality of second parts  72  and the eighth part  73 . The width in the apparatus width direction of each of the second parts  72  is smaller than the width in the apparatus width direction of the sixth part  71 . Further, the flexible wiring board  70  is mounted on the printer  11  in a state that the flexible wiring board  70  is bent in the up direction at each of the second parts  72 . Owing to this configuration, the flexible wiring board  70  has a satisfactory bendability; even in such a case that any external force acts on the flexible wiring board while the flexible wiring board is (being) mounted on the printer  11 , the flexible wiring board  70  and the plurality of head modules  23  are less likely to peel off or detached from each other at the joining part therebetween. 
     Further, in the printer  11  of the present embodiment, the flexible wiring board  70  is connected to the ends, of the respective head modules  23 , in the nozzle-alignment direction. Owing to this configuration, the width in the orthogonal direction orthogonal to the nozzle-alignment direction of each of the head modules  23  can be made small, as compared with a case of connecting the flexible wiring board between two nozzle rows in each of the head modules  23 . 
     Furthermore, in the printer  11  of the present embodiment, the five through holes  77  are formed in the flexible wiring board  70 . Owing to this configuration, it is possible to easily position the flexible wiring board  70  with respect to the six head modules  23  while the flexible wiring board  70  is being jointed to the six head modules  23 . 
     Moreover, in the printer  11  of the present embodiment, the eighth part  73  continued from the six second parts  72  is provided on the flexible wiring board  70 . Further, the COM-A wiring  76   a  and the COM-B wiring  76   b  are arranged on the eighth part  73  commonly with respect to the plurality of head modules  23 . Owing to this configuration, it is possible to reduce the number of the wirings, as compared with a case of providing these wirings with respect to each of the head modules  23 . 
     Note that in the present embodiment, it is allowable that the widths of the COM-A wiring  76   a  and the COM-B wiring  76   b  arranged in the flexible wiring board  70  are not uniform. Namely, the widths of these wirings  76   a  and  76   b  may be adjusted such that the impedances in routes arriving at the six head modules  23  (driver ICs  65 ) are substantially same. For example, each of the COM-A wiring  76   a  and the COM-B wiring  76   b  may have such a width which becomes greater from the outer side toward the central side in the apparatus width direction, at the eighth part  73  of the flexible wiring board  70 . In a case that these wirings  76   a  and  76   b  are arranged along the outer shape of the flexible wiring board  70  and are cut at the central portion in the apparatus width direction as in the present embodiment, a distance up to a head module  23 , among the six head modules  23 , which is joined to the flexible wiring board  70  on the central side in the apparatus width direction is longer than a distance up to another head module  23 , among the six head modules  23 , which is joined to the flexible wiring board  70  at the outer side in the apparatus width direction. Accordingly, by making the width of each of the wirings  76   a  and  76   b  to be greater from the outer side toward the central side in the apparatus width direction, it is possible to made the difference in impedance among the routes to be small. Further, in view of further making the difference in impedance among the routes to be smaller, it is allowable that the plurality of head modules  23  have the connecting terminals which are to be connected with respect to the flexible wiring board  70  and which are disposed at mutually different positions among the plurality of head modules  23 . For example, it is allowable that the connection terminal of a head module  23 , among the plurality of head modules  23 , which is located at the central side in the apparatus width direction, is arranged such that the distance from the connecting terminal up to the driver IC  65  is shorter than that in another head module  23 , among the plurality of head modules  23 , which is arranged at the outer side in the apparatus width direction. 
     The above-described embodiment applies the present disclosure to an ink-jet head which discharges or jets an ink onto a recording paper sheet so as to print an image, etc., on the recording paper sheet. However, the present disclosure is applicable also to a liquid discharging apparatus usable in a variety of kinds of usage or application other than printing of image, etc. For example, it is also possible to apply the present disclosure to a liquid discharging apparatus configured to form a conductive pattern on a surface of a substrate by discharging or jetting a conductive liquid onto the substrate.