Drive device, liquid spray head

Abstract

A driving device and a liquid ejecting head accurately connect conductors of a plurality of components from terminal portions respectively arranged on respective substrates and conductors of a plurality of channels from a driving IC. The driving device according to the embodiment includes a first substrate, a second substrate, and a relay substrate. The first substrate arranges a plurality of components, and a plurality of first conductors for respectively supplying driving signals to the plurality of components are arranged at the terminal portions. The second substrate mounts a driving IC for driving the plurality of components, and a plurality of second conductors of a plurality of channels from the driving IC are arranged at the terminal portions. The relay substrate forms a plurality of third conductors from the terminal portion connected to the first substrate to the terminal portion connected to the second substrate, and at the terminal portion connected to the second substrate, third conductors having a width larger than the pitch of the second conductors are arranged at a density lower than the density of the second conductors, and the first conductors for supplying driving signals to the components are respectively connected to the second conductors of two or more channels from the driving IC.

Description

Technical Field

[0001] Embodiments of the present invention relate to a drive device and a liquid ejector head. Background Art

[0002] A liquid ejector head for ejecting a liquid is known. The liquid ejector head is mounted on, for example, an inkjet printer, a 3D printer, a dispensing device, or the like. The inkjet printer ejects ink droplets from an inkjet head to form an image or the like on the surface of a recording medium. The 3D printer ejects droplets of a forming material from a forming material ejector head and cures the droplets to form a three-dimensional formed object. The dispensing device ejects droplets of a sample and supplies a predetermined amount to a plurality of containers or the like.

[0003] The liquid ejector head has a plurality of channels for ejecting a liquid respectively. Each channel includes a nozzle for ejecting the liquid and an actuator for driving when ejecting the liquid from the nozzle. The actuators of the plurality of channels are formed on a common actuator substrate. A drive IC (Integrated Circuit) for driving these actuators uses a drive IC mounted on a flexible printed wiring board such as a COF (Chip on Film). When driving the actuator, the drive IC supplies a drive signal to each actuator through individual wirings for each channel. The individual wirings are formed on respective terminal portions of the actuator substrate and the flexible printed wiring board such that the wiring widths and pitches are the same, and are connected, for example, by thermocompression bonding.

[0004] Since a flexible printed wiring board having a drive IC such as a COF requires development costs, if a common flexible printed wiring board can be used for liquid ejector heads having different numbers of channels, the development costs can be suppressed. However, with the continuous development of multi-channelization of the drivers of flexible printed wiring boards having a drive IC such as a COF, the wiring widths and pitches have been miniaturized. Therefore, in the mounting process of the actuator substrate and the flexible printed wiring board, high-precision alignment of the connected wirings with each other is required. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a drive device and a liquid ejector head that can accurately connect conductors of a plurality of elements from terminal portions respectively arranged on respective substrates and conductors of a plurality of channels from a drive IC.

[0006] The driving device according to an embodiment of the present invention includes: a first substrate on which a plurality of elements are arranged, and a plurality of first conductors that supply driving signals to the plurality of elements respectively are arranged at a terminal portion; a second substrate on which a driving IC for driving the plurality of elements is mounted, and a plurality of second conductors of a plurality of channels from the driving IC are arranged at a terminal portion; and a relay substrate on which a plurality of third conductors are formed from a terminal portion connected to the first substrate to a terminal portion connected to the second substrate, and at the terminal portion connected to the second substrate, the third conductors having a width larger than a pitch of the second conductors are arranged at a lower density than the second conductors, and the first conductors that supply driving signals to the elements are respectively connected to the second conductors of two or more of the channels from the driving IC.

[0007] The liquid ejector according to an embodiment of the present invention includes: an actuator substrate on which actuators of a plurality of channels for ejecting liquid are arranged, and a plurality of first conductors that supply driving signals to the plurality of actuators respectively are arranged at a terminal portion; a flexible substrate on which a driving IC for driving the actuators is mounted, and a plurality of second conductors of a plurality of channels from the driving IC are arranged at a terminal portion; and a relay flexible substrate on which a plurality of third conductors are formed from a terminal portion connected to the actuator substrate to a terminal portion connected to the flexible substrate, and at the terminal portion connected to the flexible substrate, the third conductors having a width larger than a pitch of the second conductors are arranged at a lower density than the second conductors, and the first conductors that supply driving signals to the actuators are respectively connected to the second conductors of two or more of the channels from the driving IC. Description of the Drawings

[0008] Figure 1 It is an overall structural diagram of an inkjet printer including an inkjet head according to a first embodiment.

[0009] Figure 2 It is a perspective view of the above-described inkjet head.

[0010] Figure 3 It is a cross-sectional view of an actuator of the above-described inkjet head.

[0011] Figure 4 It is an unfolded view before connecting an actuator substrate, a relay flexible printed wiring board, a flexible printed wiring board, and a printed substrate to each other.

[0012] Figure 5 It is a top view of a state in which an actuator substrate, a relay flexible printed wiring board, a flexible printed wiring board, and a printed substrate are connected to each other.

[0013] Figure 6 It is a side view of a state in which an actuator substrate, a relay flexible printed wiring board, a flexible printed wiring board, and a printed substrate are connected to each other.

[0014] Figure 7 It is an enlarged view of the wiring connection portion between the relay flexible printed wiring board and the flexible printed wiring board.

[0015] Figure 8 It is an enlarged view of the wiring connection portion between the relay flexible printed wiring board and the flexible printed wiring board.

[0016] Figure 9 It is a perspective view of a display device according to the second embodiment.

[0017] Explanation of reference numerals

[0018] 10... Inkjet printer; 100 - 103... Inkjet heads; 2... Nozzle head; 22... Actuator substrate; 25... Nozzles; 3... Relay flexible printed wiring board; 30... Terminal portion; 32... Independent relay wiring; 4... Flexible printed wiring board; 41... Driver IC (driver chip); 43... Output wiring (separate wiring); 5... Printed circuit board; 6... Actuator; D... Driver (drive circuit). Detailed description of the specific embodiment

[0019] Hereinafter, the drive device and the liquid nozzle head according to the embodiment will be described in detail with reference to the drawings. It should be noted that in each figure, the same reference numerals are assigned to the same structures.

[0020] (First embodiment)

[0021] The drive device according to the first embodiment will be described in detail taking a liquid nozzle head as an example. The liquid nozzle head is, for example, an inkjet head mounted on an inkjet printer 10 that forms an image on a recording medium. Figure 1 The schematic structure of the inkjet printer 10 is shown. Inside the housing 11 of the inkjet printer 10, a cassette 12 for accommodating a sheet S as an example of a recording medium, an upstream conveyance path 13 of the sheet S, a conveyor belt 14 for conveying the sheet S taken out from the cassette 12, a plurality of inkjet heads 100 - 103 for ejecting ink droplets toward the sheet S on the conveyor belt 14, a downstream conveyance path 15 of the sheet S, a discharge tray 16, and a control board 17 are arranged. An operation unit 18 serving as a user interface is arranged on the upper side of the housing 11.

[0022] Image data to be printed on the sheet S is generated, for example, by a computer 200 as an external connection device. The image data generated by the computer 200 is transmitted to the control board 17 of the inkjet printer 10 through a cable 201, connectors 202, 203.

[0023] The pickup roller 204 supplies the sheet S one by one from the cassette 12 to the upstream conveyance path 13. The upstream conveyance path 13 is constituted by the conveyance roller pairs 131, 132 and the sheet guide plates 133, 134. The sheet S is conveyed via the upstream conveyance path 13 to the upper surface of the conveyor belt 14. The arrow 104 in the figure indicates the conveyance path of the sheet S from the cassette 12 to the conveyor belt 14.

[0024] The conveyor belt 14 is a net-shaped endless belt formed with a plurality of through holes on the surface. The three rollers, i.e., the drive roller 141, the driven rollers 142, 143, rotatably support the conveyor belt 14. The motor 205 rotates the conveyor belt 14 by rotating the drive roller 141. The 105 in the figure indicates the rotation direction of the conveyor belt 14. The negative pressure container 206 is disposed on the back side of the conveyor belt 14. The negative pressure container 206 is connected to the fan 207 for decompression. The fan 207 makes the inside of the negative pressure container 206 negative pressure by the formed air flow, and adsorbs and holds the sheet S on the upper surface of the conveyor belt 14. The 106 in the figure indicates the flow of the air flow.

[0025] The inkjet heads 100 to 103 as an example of the liquid nozzle are arranged to face the sheet S adsorbed and held on the conveyor belt 14 via a minute gap of, for example, 1 mm. The inkjet heads 100 to 103 eject ink droplets toward the sheet S respectively. The inkjet heads 100 to 103 print an image when the sheet S passes below. The inkjet heads 100 to 103 have the same structure except for the color of the ejected ink. The color of the ink is, for example, cyan, magenta, yellow, black.

[0026] The inkjet heads 100 to 103 are respectively connected to the ink tanks 315 to 318 and the ink supply pressure adjustment devices 321 to 324 via the ink flow paths 311 to 314. The ink tanks 315 to 318 are arranged above the inkjet heads 100 to 103 respectively. The ink supply pressure adjustment devices 321 to 324 adjust the pressure inside the inkjet heads 100 to 103 to a negative pressure, for example, -1.2 kPa relative to the atmospheric pressure so that ink does not leak from the nozzles 25 of the inkjet heads 100 to 103 during standby (refer to Figure 2 ). During image formation, the ink in the ink tanks 315 to 318 is supplied to the inkjet heads 100 to 103 through the ink supply pressure adjustment devices 321 to 324.

[0027] After image formation, the sheet S is conveyed from the conveyor belt 14 to the downstream conveyance path 15. The downstream conveyance path 15 is constituted by the conveyance roller pairs 151, 152, 153, 154 and the sheet guide plates 155, 156 that define the conveyance path of the sheet S. The sheet S is conveyed from the discharge port 157 to the discharge tray 16 via the downstream conveyance path 15. The arrow 107 in the figure indicates the conveyance path of the sheet S.

[0028] Next, the structures of the inkjet heads 100 to 103 will be described. Hereinafter, reference will be made to Figures 2 to 6 the inkjet head 100 for description, but the inkjet heads 101 to 103 also have the same structure as the inkjet head 100.

[0029] As shown in Figure 2 the figure, the inkjet head 100 includes a nozzle head 2 as an example of a liquid ejection unit. The nozzle head 2 includes a nozzle plate 21, an actuator substrate 22, a sealing member 23 that seals the openings of the pressure chambers 61 and the air chambers 62 formed in the actuator substrate 22, and an ink supply port 24 formed in the sealing member 23. The ink supply port 24 is connected to Figure 1 the ink supply pressure adjustment device 321 via an ink flow path 311.

[0030] The actuator substrate 22 as the first substrate is connected to a flexible printed wiring board 4 as the second substrate via a relay flexible printed wiring board 3 as a relay substrate. The flexible printed wiring board 4 is also connected to a printed substrate 5 as the third substrate. The relay flexible printed wiring board 3 is an example of a relay flexible substrate. The flexible printed wiring board 4 is an example of a flexible substrate.

[0031] The flexible printed wiring board 4 is mounted with an IC (Integrated Circuit) 41 for driving as a driver chip (hereinafter referred to as a driving IC). The driving IC 41 temporarily stores the print data transmitted from the control substrate 17 of the inkjet printer 10 via the printed substrate 5 and outputs a driving signal for ejecting ink at a predetermined timing.

[0032] The nozzle plate 21 as an example of a nozzle unit is a rectangular plate formed of, for example, a resin such as polyimide or a metal such as stainless steel. Nozzles 25 for ejecting ink are arranged along the length direction (X direction) of the nozzle plate 21. The nozzle density is set, for example, in the range of 150 to 1200 dpi. The nozzles 25 are not limited to one row and may be arranged in two or more rows. It should be noted that Figure 2 for the convenience of drawing, the number of nozzles 25 is shown less.

[0033] The actuator substrate 22 is, for example, a rectangular substrate formed of an insulating ceramic. On the actuator substrate 22, a plurality of pressure chambers 61 and air chambers 62 are alternately arranged along a first direction, for example, the X direction. The pressure chambers 61 communicate with the nozzles 25. The pressure chambers 61 communicate with the ink supply port 24 via, for example, a common ink chamber (not shown) formed in the actuator substrate 22 or the sealing member 23. On the other hand, the air chambers 62 adjacent to the pressure chambers 61 are, for example, enclosed spaces that do not communicate with the nozzles 25 and the common ink chamber (not shown).

[0034] As shown in Figure 3As shown, the pressure chamber 61 and the air chamber 62 are formed by cutting, in the second direction such as the Z direction, for example, a rectangular groove in the actuator substrate 22 through two piezoelectric members 26 and 27 laminated in directions opposite to each other in the polarization direction (as an example, the opposing direction). That is, the pressure chamber 61 and the air chamber 62 are separated by the piezoelectric members 26 and 27 laminated in the third direction such as the Y direction as side walls.

[0035] The electrodes 63 are integrally formed on the bottom surface and both side surfaces of the pressure chamber 61. The electrode 63 of the pressure chamber 61 is connected to a separate wiring 64 serving as a wiring electrode. The electrodes 65 are integrally formed on the bottom surface and both side surfaces of the air chamber 62. The electrode 65 of the air chamber 62 is connected to a common wiring 66 serving as a wiring electrode. That is, the connection point of the electrode 63 of the pressure chamber 61 and the separate wiring 64 is one terminal of the actuator 6. The connection point of the electrode 65 of the air chamber 62 and the common wiring 66 is the other terminal of the actuator 6. The electrodes 63 and 65 are formed of, for example, a nickel thin film. The actuator 6 disposed on the actuator substrate 22 is an example of an element disposed on the first substrate.

[0036] The separate wiring 64 is connected to the driver D (i.e., the drive circuit) of the drive IC 41. At this time, by adopting a wiring connection structure described in detail later, the separate wirings 64 from each actuator 6 are respectively connected to the two drivers D of the drive IC 41. That is, the actuator 6 of #1ch is connected to the drivers D of the two channels #1ch and #2ch of the drive IC 41. The same applies to the actuators 6 of other channels. The drive IC 41 supplies a drive voltage V1 as a drive signal to the actuator 6 of the channel for ejecting ink. At this time, the drive IC 41 is set so that the outputs of the two drivers D connected to one actuator 6 are the same output. On the other hand, the common wiring 66 is connected to, for example, ground (GND). According to this structure, the actuator 6 to which the drive voltage V1 is supplied is applied with an electric field in a direction intersecting (preferably orthogonal to) the polarization axis of the piezoelectric members 26 and 27, and the piezoelectric members 26 and 27 forming the side wall in the X direction of the pressure chamber 61 are deformed symmetrically in the X direction in a shear mode.

[0037] That is, the ink pressure chamber 61 is formed by being sandwiched by a pair of columnar actuators 6 using the piezoelectric members 26 and 27. A potential difference is applied to the two walls of the columnar actuator 6, that is, the inner wall and the outer wall of the pressure chamber 61, and the actuator 6 is deformed by charging the actuator 6. As a result, the volume of the pressure chamber 61 changes, and the ink pressure in the pressure chamber 61 changes. By adjusting the magnitude and timing of this change, ink is ejected from the nozzle 25.

[0038] Figures 4 to 6 The wiring structures of the actuator substrate 22, the relay flexible printed wiring board 3, the flexible printed wiring board 4, and the printed substrate 5 are respectively shown. Figure 4It is a developed view before connecting the respective substrates to each other. Figure 5 It is a top view of the state where the respective substrates are connected. Figure 6 It is a side view of the state where the respective substrates are connected. The actuator substrate 22 and the relay flexible printed wiring board 3 connect their terminal portions 20 and 30 to each other. The relay flexible printed wiring board 3 and the flexible printed wiring board 4 connect their terminal portions 31 and 40 to each other. The flexible printed wiring board 4 and the printed substrate 5 connect their terminal portions 42 and 50 to each other.

[0039] In the actuator substrate 22, individual wirings 64 led out from one terminal of each actuator 6 are respectively formed to the terminal portion 20. It should be noted that, Figure 4 and Figure 5 For the convenience of drawing, the illustration of the actuator 6 is simplified. The individual wirings 64 of the terminal portion 20 are, for example, formed as wirings having the same wiring width and arranged in parallel at equal intervals. The individual wiring 64 is formed in a thin film shape, for example, by nickel, aluminum, gold, or an alloy thereof. In order to ensure insulation, an insulating layer or an insulating member is provided, for example, in a region other than the terminal portion 20. The wiring width and the wiring interval of the individual wiring 64 in the terminal portion 20 are selected, for example, from within the range of 10 μm to 100 μm. As an example, the wiring density of the individual wiring 64 in the terminal portion 20 is set to a resolution of 150 dpi. The thickness of the individual wiring 64 is, for example, 0.4 μm. The individual wiring 64 formed in the terminal portion 20 of the actuator substrate 22 is an example of a first conductor from an element formed on the first substrate.

[0040] The common wiring 66 is formed on the surface of the actuator substrate 22 along the arrangement direction of the actuators 6 and is connected to the other terminal of each actuator 6. The common wiring 66 is also formed to the terminal portion 20. At this time, the common wiring 66 is preferably formed to the terminal portion 20 from both ends of the portion formed along the arrangement direction of the actuators 6 so that voltage drop caused by current concentration can be suppressed even when charging and discharging currents are supplied to the plurality of actuators 6. In the terminal portion 20, the common wiring 66 is also arranged on both sides sandwiching the group of individual wirings 64. The common wiring 66 is formed in a thin film shape, for example, by nickel, aluminum, gold, or an alloy thereof. In order to ensure insulation, an insulating layer or an insulating member is provided, for example, in a region other than the terminal portion 20. The wiring width of the common wiring 66 in the terminal portion 20 is, for example, 1.5 mm. The thickness of the common wiring 66 is, for example, 0.4 μm.

[0041] The relay flexible printed wiring board 3 is, for example, a flexible printed wiring board using a synthetic resin film such as polyimide. The relay flexible printed wiring board 3 forms independent relay wirings 32 and common relay wirings 33 respectively from one terminal portion 30 to another terminal portion 31. The number of the independent relay wirings 32 and the common relay wirings 33 is at least the same as the number of the individual wirings 64 and the common wirings 66 of the terminal portion 20 of the actuator substrate 22. Each of the wirings 32 and 33 is preferably formed on the same surface (single-sided) of the substrate. The number, wiring width, and wiring density of the independent relay wirings 32 in the terminal portion 30 are preferably set to be the same as the number, wiring width, and wiring density of the individual wirings 64 of the terminal portion 20 of the actuator substrate 22. On the other hand, the number and wiring width of the independent relay wirings 32 in the terminal portion 31 remain unchanged, but the wiring density is increased by an amount that narrows the width of the substrate to match the width of the flexible printed wiring board 4 as the connection target. The wiring density is, for example, a resolution of 300 dpi. The independent relay wiring 32 is an individual wiring formed on the relay flexible printed wiring board 3. Therefore, the independent relay wiring 32 formed in the terminal portion 31 of the relay flexible printed wiring board 3 is an example of the third conductor formed on the relay substrate.

[0042] The flexible printed wiring board 4 is, for example, a flexible printed wiring board using a synthetic resin film such as polyimide. That is, it is the same type of substrate as the relay flexible printed wiring board 3. The drive IC 41 is, for example, a driver chip formed on a silicon semiconductor substrate. A preferred example of the flexible printed wiring board 4 is COF (Chip on Film). Output wirings 43, input wirings 44, a power supply wiring 45 for voltage V1, a ground wiring 46, and a common wiring 47 are formed on the flexible printed wiring board 4. The reference numeral 48 is a portion for alignment. These wirings 43 to 47 and the drive IC 41 are preferably formed on the same surface (single-sided) of the substrate. In the case of COF, it is formed on one side, but in the case of being formed on both sides, vias and the like are additionally formed. The output wiring 43 led out from the drive IC 41 is formed to the terminal portion 40. The output wiring 43 is an individual wiring formed on the flexible printed wiring board 4. Therefore, the output wiring 43 formed in the terminal portion 40 of the flexible printed wiring board 4 is an example of the second conductor of each channel from the drive IC 41 mounted on the second substrate.

[0043] Here, with reference to Figure 7 The connection between the independent relay wiring 32 of the relay flexible printed wiring board 3 and the output wiring 43 will be described in more detail. Figure 7 (a) of is a top view of the connection portion between the independent relay wiring 32 and the output wiring 43. Figure 7 (b) of is a cross-sectional view of the connection portion between the independent relay wiring 32 and the output wiring 43. Figure 7Example (c) shows an example of the wiring width and wiring pitch of the independent relay wiring 32 and the output wiring 43. As described above, the multi-channeling of the drivers of the flexible printed wiring board 4 equipped with a driving IC 41 such as a COF is in progress. However, by making the wiring pitch finer without increasing the size of the substrate, the output wiring 43 in the terminal portion 40 is arranged in a high density. The number of channels of the driving IC 41 is, for example, 1500. The wiring density of the output wiring 43 in the terminal portion 40 is, for example, a resolution of 600 dpi. The wiring width of the output wiring 43 is, for example, 18 μm. The wiring pitch is, for example, 20 μm.

[0044] On the other hand, the number of channels for ejecting the ink of the nozzle head 2 also depends on the nozzle density, but is, for example, 700 to 1500. In this way, the relay flexible printed wiring board 3 is prepared so that the common flexible printed wiring board 4 can be used even when the number of channels for ejecting the ink (that is, the number of actuators 6) is smaller than the number of channels of the driving IC 41.

[0045] More specifically, the independent relay wiring 32 of the relay flexible printed wiring board 3 makes the wiring density of the terminal portion 31 low density according to the number of channels for ejecting the ink and the number of channels of the driving IC 41, and increases the wiring width. In Figure 7 Examples (a) to (c), as a preferable example, the wiring density of the independent relay wiring 32 in the terminal portion 31 of the relay flexible printed wiring board 3 is set to a low density that is half of the wiring density of the output wiring 43 in the terminal portion 40 of the flexible printed wiring board 4, and the wiring width is made the same as the width (spacing distance) L1 from one outer end of two adjacent output wirings 43 to the other outer end. That is, the wiring density is set to a resolution of 300 dpi and the wiring width is 56 μm. Further, the wiring width of the independent relay wiring 32 is set to 20 μm, which is the same as the wiring width of the output wiring 43.

[0046] By setting in this way, when the terminal portions 31 and 40 are overlapped with each other, the independent relay wiring 32 is connected to two adjacent output wirings 43, respectively. In addition, as a preferable form, all the output wirings 43 are connected to any one of the independent relay wirings 32. As a result, all the channels of the driving IC 41 can be used even if the number of channels for ejecting the ink and the number of channels of the driving IC 41 are different. Moreover, as Figure 3 shown, if the outputs of the two drivers D are used to drive one actuator 6 in the same manner, the driving ability of the actuator 6 using the piezoelectric members 26 and 27 is high. In addition, since the wiring width is increased, the impedance is correspondingly reduced.

[0047] Assume that as Figure 8As shown in (a), even when the wiring density of the terminal portion 31 of the relay flexible printed wiring board 3 is set to 300 dpi and the wiring width is the same as that of the output wiring 43 at 18 μm, the utilization rate of the channels of the drive IC 41 is also one-half. In addition, there may be insufficient driving ability for charging and discharging the actuator 6. In addition, assume that as shown in Figure 8 (b), when the wiring density of the terminal portion 31 is set to 600 dpi, two independent relay wirings 32 are connected into one, and the wiring density on the terminal portion 30 side is set to 300 dpi, the utilization rate of the channels of the drive IC 41 is increased, but high alignment accuracy of the wiring is required in the mounting process of connecting the substrates to each other. In addition, the wiring width of the independent relay wiring 32 is narrow, and accordingly the impedance becomes high, and there may be a limit in the driving ability for charging and discharging the actuator 6.

[0048] It should be noted that in Figure 7 , as a preferred example, a structure in which one independent relay wiring 32 is connected to two output wirings 43 is shown, but the wiring width of the independent relay wiring 32 can be changed to be connected to three or more output wirings 43. In addition, the wiring width of the independent relay wiring 32 is preferably the same as the width from one outer end to the other outer end of two adjacent output wirings 43, but it is sufficient as long as the width is at least larger than the pitch L2 of two adjacent output wirings 43 (refer to Figure 7 (a)). The wiring density and wiring width of the independent relay wiring 32 of the relay flexible printed wiring board 3 can be appropriately adjusted according to the number of channels for ejecting ink and the number of channels of the drive IC 41. Thus, a common flexible printed wiring board 4 can be used for various actuator substrates 22. The flexible printed wiring board 4 can also be connected in parallel with two or more on both sides or one side of one actuator substrate 22 according to the number of channels for ejecting ink.

[0049] Return Figures 4 to 6 is described. The input wiring 44 led out from the drive IC 41 is formed to the terminal portion 42 on the side connected to the printed substrate 5. Since the drive IC 41 can be controlled by serial communication, the number of the input wirings 44 can be smaller than the number of the output wirings 43. In addition, the common wiring 47 is formed from the terminal portion 40 to the terminal portion 42.

[0050] The power supply wiring 45 and the ground wiring 46 are respectively connected to the driving IC 41. The power supply wiring 45 and the ground wiring 46 are respectively formed to the terminal portion 42 connected to the printed substrate 5. The output wiring 43, the input wiring 44, the power supply wiring 45, the ground wiring 46, and the common wiring 47 are formed, for example, of copper into a thin film shape. The thickness is, for example, 8 μm. The wiring width and the wiring interval of the output wiring 43 of the terminal portion 40 are, for example, 10 μm to 30 μm. The wiring width and the wiring interval of the input wiring 44 of the terminal portion 42 are, for example, 0.15 mm. The wiring width of the power supply wiring 45 and the ground wiring 46 is, for example, 0.4 mm. The wiring width of the common wiring 47 is, for example, 0.85 mm.

[0051] The printed substrate 5 is a rigid via substrate formed by laminating multiple layers of an epoxy resin layer containing glass fibers and a copper wiring layer. Output wiring 51, power supply wiring 52, and ground wiring 53 are respectively formed on the terminal portion 50. The output wiring 51 is connected to the input wiring 44 of the flexible printed wiring board 4. The power supply wiring 52 is connected to the power supply wiring 45 of the flexible printed wiring board 4. The ground wiring 53 is connected to the ground wiring 46 and the common wiring 47 of the flexible printed wiring board 4. A signal for selectively driving each actuator 6 from the control substrate 17 of the inkjet printer 10 is supplied to the output wiring 51. A driving voltage V1 is supplied to the power supply wiring 52. The ground wiring 53 is connected to the ground (GND) through the control substrate 17 of the inkjet printer 10, for example.

[0052] As Figure 6 shown, as a preferred example, the terminal portion 20 of the actuator substrate 22 and the terminal portion 30 of the relay flexible printed wiring board 3 are connected via an anisotropic conductive film (ACF, Anisotropic Conductive Film) 7. More specifically, the terminal portion 20 of the actuator substrate 22 and the terminal portion 30 of the relay flexible printed wiring board 3 are arranged to face each other, with the ACF 7 interposed therebetween, and are thermocompression bonded, for example, using a thermocompression bonding tool, thereby connecting the wirings of the terminal portions 20 and 30 together. Thereby, the individual wiring 64 and the independent relay wiring 32, and the common wiring 66 and the common relay wiring 33 can be electrically connected respectively.

[0053] The terminal portion 31 of the relay flexible printed wiring board 3 and the terminal portion 40 of the flexible printed wiring board 4 are also connected via the ACF 7 in the same manner. The terminal portion 442 of the flexible printed wiring board 4 and the terminal portion 50 of the printed substrate 5 are also connected via the ACF 7 in the same manner.

[0054] The inkjet head 100 is not limited to the actuator 6 of the shear mode type in which the pressure chambers 61 and the air chambers 62 are arranged alternately. It may also be an actuator 6 of the shear mode · shared wall type in which the pressure chambers 61 are arranged continuously. In addition, it may also be an actuator of the drop-on-demand · piezoelectric type or the like.

[0055] In addition, in the above-described embodiments, the inkjet head 100 of the inkjet printer 10 has been described as an example of the liquid ejecting head. However, the liquid ejecting head may also be a forming material ejecting head of a 3D printer or a sample ejecting head of a dispensing device.

[0056] (Second Embodiment)

[0057] Next, a driving device according to the second embodiment will be described by taking a display device 8 such as a liquid crystal display or an organic electroluminescence display as an example. However, the same reference numerals are given to the same structures as those in the first embodiment, and the detailed description thereof is omitted.

[0058] The display device 8 includes a display substrate 80 such as a liquid crystal substrate. Although not shown, a plurality of elements such as liquid crystal elements are arranged in the X direction and the Y direction on the display substrate 80. The display substrate 80 is connected to the flexible printed wiring board 4 via the relay flexible printed wiring board 3. The flexible printed wiring board 4 is also connected to the printed substrate 5. Each element of the display substrate 80 is driven by a driving IC 41 mounted on the flexible printed wiring board 4.

[0059] According to any of the above-described embodiments, by interposing the relay flexible printed wiring board 3 between the substrates 22 and 80 on which elements such as the actuator 6 are arranged and the flexible printed wiring board 4 on which the driving IC 41 is mounted, and adjusting the wiring density and wiring width of the independent relay wiring 32 of the relay flexible printed wiring board 3, it is possible to connect the individual wirings 64 from a plurality of elements and the output wirings 43 of a plurality of channels from the driving IC 41 with high precision via the independent relay wiring 32.

[0060] Although several embodiments have been described, these embodiments are presented only as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are similarly included in the invention described in the claims and its equivalents.

Claims

1. A driving device, characterized in that, Comprising: A first substrate on which a plurality of elements are arranged, and a plurality of first conductors for supplying drive signals to the plurality of elements are arranged at a terminal portion; A second substrate on which a drive IC for driving the plurality of elements is mounted, and a second conductor of a plurality of channels from the drive IC is arranged at a terminal portion; And A relay substrate forms a plurality of third conductors from a terminal portion connected to the first substrate to a terminal portion connected to the second substrate, and at the terminal portion connected to the second substrate, the third conductors having a width larger than a pitch of the second conductors are arranged at a lower density than the second conductors, and the first conductors for supplying drive signals to the elements are respectively connected to the second conductors of two or more of the channels from the drive IC.

2. The driving device according to claim 1, wherein The drive IC is set such that outputs of two or more of the channels connected to one of the elements are the same output.

3. The driving device according to claim 1 or 2, wherein A width of the third conductor is the same as a width from an outer end of one of two or more adjacent second conductors to an outer end of the other.

4. The driving device according to claim 3, wherein The third conductor further makes a distance between adjacent third conductors the same as a distance between adjacent second conductors.

5. The driving device according to claim 1 or 2, wherein The first substrate further has a common wiring, and both ends of a portion formed along an arrangement direction of the plurality of elements of the common wiring are formed to a terminal portion of the first substrate.

6. The driving device according to claim 3, wherein The first substrate further has a common wiring, and both ends of a portion formed along an arrangement direction of the plurality of elements of the common wiring are formed to a terminal portion of the first substrate.

7. The driving device according to claim 4, wherein The first substrate further has a common wiring, and both ends of a portion formed along an arrangement direction of the plurality of elements of the common wiring are formed to a terminal portion of the first substrate.

8. The driving device according to claim 5, wherein The common wiring is connected to ground.

9. The driving device according to claim 6, wherein The common wiring is connected to ground.

10. A liquid spray head, characterized in that, Comprising: An actuator substrate on which actuators of a plurality of channels for ejecting liquid are arranged, and a plurality of first conductors for supplying drive signals to the plurality of actuators are arranged at a terminal portion; A flexible substrate on which a drive IC for driving the actuators is mounted, and a second conductor of a plurality of channels from the drive IC is arranged at a terminal portion; And The relay flexible substrate forms a plurality of third conductors from the terminal portion connected to the actuator substrate to the terminal portion connected to the flexible substrate, and at the terminal portion connected to the flexible substrate, the third conductors having a width larger than the pitch of the second conductor are arranged at a density lower than that of the second conductor, and the first conductors for supplying a drive signal to the actuator are respectively connected to the second conductors of two or more channels from the drive IC.

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