JP2016215524A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variations of ejection timing of liquid.SOLUTION: A liquid discharge device comprises: a first head unit driven by a first driving signal and a second head unit driven by a second driving signal; a first generating section being provided to a first substrate and generating the first driving signal; a second generating section being provided to the first substrate and generating the second driving signal; first wiring electrically connecting the first head unit and the first generating section; and second wiring electrically connecting the second head unit and the second generating section. The first wiring includes: first external wiring electrically connecting the first head unit and the first substrate; and first internal wiring electrically connecting the first external wiring and the first generating section. The second wiring includes: second external wiring electrically connecting the second head unit and the first substrate; and second internal wiring electrically connecting the second external wiring and the second generating section. The first external wiring Lx2[1] is longer than the second external wiring Lx2[2], and the first internal wiring Lx1[1] is shorter than the second internal wiring Lx1[2].SELECTED DRAWING: Figure 11

Description

  The present invention relates to a liquid ejection apparatus.

  In a liquid discharge apparatus such as an ink jet printer, a discharge unit provided in a head unit is driven by a drive signal, and liquid such as ink filled in a cavity (pressure chamber) of the discharge unit is discharged from a nozzle of the discharge unit. Thus, a printing process for forming an image on the recording medium is executed. In general, in a liquid ejection apparatus such as an ink jet printer, a drive signal generation unit that generates a drive signal and a head unit are connected by wiring such as a flat cable or a flexible printed circuit board (for example, Patent Documents). 1 or 2).

JP 2011-062851 A JP 2009-023168

  Incidentally, there are cases where a plurality of head units are provided in the liquid ejection device, as in the case where the liquid ejection device is a line printer. When the liquid ejecting apparatus includes a plurality of head units, the liquid ejecting apparatus is provided with a plurality of wirings corresponding to the plurality of head units in order to supply a drive signal to each of the plurality of head units. . However, when a drive signal is supplied to a plurality of head units using a plurality of wirings, the drive signal supply timing may vary among the plurality of head units. As a result, there is a problem that the liquid ejection timing varies among the plurality of head units, and the image quality of the image formed on the recording medium is degraded.

The present invention has been made in view of the above-described circumstances. In the case where a drive signal is supplied using a plurality of wires, it is possible to reduce variations in the liquid discharge timing and to form an image with good image quality. The solution issue is the provision of technology.

  In order to solve the above problems, a liquid ejection apparatus according to the present invention is capable of ejecting a liquid driven by a first drive signal and a first head unit that can be ejected by a first drive signal and a second drive signal. A second head unit; a first substrate; a first generation unit provided on the first substrate for generating the first drive signal; and a first generation unit provided on the first substrate for generating the second drive signal. 2 generator, a first wiring that electrically connects the first head unit and the first generator, and a second wiring that electrically connects the second head unit and the second generator. The first wiring includes: a first external wiring that electrically connects the first head unit and the first substrate; and the first external wiring and the first generation unit are electrically connected to the first substrate. A first internal wiring connected to the first internal wiring, The wiring includes a second external wiring that electrically connects the second head unit and the first substrate, and a second electrical connection that electrically connects the second external wiring and the second generation unit in the first substrate. The first external wiring is longer than the second external wiring, and the first internal wiring is shorter than the second internal wiring.

According to the present invention, the first external wiring is longer than the second external wiring, and the first internal wiring is shorter than the second internal wiring. Therefore, according to the present invention, when the first external wiring is longer than the second external wiring and the first internal wiring is longer than the second internal wiring, or the first external wiring is the second external wiring. The difference between the length of the first wiring and the length of the second wiring can be reduced as compared with the case where the length is shorter than the external wiring and the first internal wiring is shorter than the second internal wiring.
When the difference between the length of the first wiring and the length of the second wiring is small, the difference between the resistance of the first wiring and the resistance of the second wiring can be reduced. In this case, the delay time that occurs when the first drive signal is supplied via the first wiring and the delay time that occurs when the second drive signal is supplied via the second wiring are substantially the same. As a result, the timing at which the first drive signal is supplied to the first head unit is substantially the same as the timing at which the second drive signal is supplied to the second head unit. The liquid discharge timing of the liquid and the liquid discharge timing of the second head unit can be made substantially the same. In other words, according to the present invention, when driving signals are supplied to a plurality of head units via a plurality of wires, it is possible to reduce variations in the liquid ejection timing from the plurality of head units.
In this specification, “substantially the same” means the same when removing various errors such as manufacturing errors and errors due to noise, even when they do not match completely, even when they do not match completely. It is used as a concept including possible ranges, for example, the case where they are designed to be the same even when they do not completely match.

  In the liquid ejection device described above, the length of the first wiring and the length of the second wiring may be substantially the same.

  According to this aspect, since the length of the first wiring and the length of the second wiring are substantially the same, the length of the first wiring and the length of the second wiring cannot be regarded as substantially the same. Compared with the case where it does, the difference of the resistance which the 1st wiring has and the resistance which the 2nd wiring has can be made small. Therefore, in the present invention, the delay time that occurs when the first drive signal is supplied via the first wiring and the delay time that occurs when the second drive signal is supplied via the second wiring are: As a result, the liquid ejection timing from the first head unit and the liquid ejection timing from the second head unit can be made substantially the same.

  In the above-described liquid ejecting apparatus, the resistance of the first wiring and the resistance of the second wiring may be substantially the same.

  According to this aspect, since the resistance of the first wiring and the resistance of the second wiring are substantially the same, the delay time that occurs when the first drive signal is supplied via the first wiring, The delay time generated when the drive signal is supplied through the second wiring can be made substantially the same. For this reason, it is possible to make the liquid discharge timing from the first head unit substantially the same as the liquid discharge timing from the second head unit.

  The liquid ejection apparatus described above is provided on the second substrate, the second substrate, a first designation signal that designates a waveform of the first drive signal generated by the first generation unit, and the second A designation unit that outputs a second designation signal that designates a waveform of the second drive signal generated by the generation unit; a third wiring that electrically connects the designation unit and the first generation unit; and the designation unit And a fourth wiring that electrically connects the second generation unit, and the length of the third wiring and the length of the fourth wiring may be substantially the same.

  According to this aspect, since the length of the third wiring and the length of the fourth wiring are substantially the same, it occurs when the first designation signal is supplied from the designation unit to the first generation unit via the third wiring. The delay time and the delay time generated when the second designation signal is supplied from the designation unit to the second generation unit via the fourth wiring can be made substantially the same. Therefore, the first drive signal and the second drive signal can be generated at substantially the same time. As a result, the first drive signal is supplied to the first head unit, and the second head unit is supplied to the second head unit. It is also possible to set the second drive signal to be supplied at substantially the same time. As a result, the liquid discharge timing from the first head unit and the liquid discharge timing from the second head unit can be made substantially the same.

  In the liquid ejection apparatus described above, the first drive signal includes a first waveform signal and a second waveform signal, and the first generation unit generates the first waveform signal. And a second generation circuit that generates the second waveform signal, wherein the first internal wiring includes a first connection wiring that electrically connects the first generation circuit and the first external wiring; A second connection wiring that electrically connects the second generation circuit and the first external wiring, and the length of the first connection wiring is substantially the same as the length of the second connection wiring. May be a feature.

  According to this aspect, since the length of the first connection wiring and the length of the second connection wiring are substantially the same, it can be considered that the length of the first connection wiring and the length of the second connection wiring are substantially the same. The difference between the resistance of the first connection wiring and the resistance of the second connection wiring can be reduced compared to the case where the differences are not possible. Therefore, in the present invention, the delay time that occurs when the first waveform signal of the first drive signal is supplied via the first connection wiring, and the second waveform signal of the first drive signal is the second connection wiring. The delay time generated when the liquid is supplied via the first head unit can be made substantially the same. As a result, the liquid from the discharge unit that is driven by the first waveform signal and discharges the liquid in the first head unit. And the liquid discharge timing from the discharge unit that discharges the liquid driven by the second waveform signal in the first head unit can be made substantially the same.

1 is a block diagram illustrating a configuration of an inkjet printer 1 according to an embodiment. 1 is a schematic partial cross-sectional view of an inkjet printer 1. FIG. 3 is a schematic cross-sectional view of a recording head Hd [q]. It is explanatory drawing which shows the change of the cross-sectional shape of the discharge part D when the separate drive signal Vin is supplied. 4 is a plan view showing an example of arrangement of nozzles N in the head module 5. FIG. It is a block diagram which shows the structure of head driver DR [q]. It is explanatory drawing which shows the decoding content of decoder DC. It is a timing chart which shows operation | movement of head driver DR [q]. It is a timing chart which shows the waveform of the individual drive signal Vin. 2 is a diagram illustrating connection between substrates in the ink jet printer. FIG. 2 is a diagram for explaining wiring in the ink jet printer. FIG. It is a figure which shows the connection of the board | substrates in the inkjet printer 1 which concerns on the modification 1. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, in each figure, the size and scale of each part are appropriately changed from the actual ones. Further, since the embodiments described below are preferable specific examples of the present invention, various technically preferable limitations are attached thereto. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms.

<< A. Embodiment >>
In the present embodiment, the liquid ejecting apparatus will be described by exemplifying an ink jet printer that ejects ink (an example of “liquid”) to form an image on a recording paper P (an example of “medium”).

<< 1. Overview of inkjet printers >>
The configuration of the inkjet printer 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a functional block diagram showing the configuration of the ink jet printer 1. When the print data Img indicating an image to be formed in the ink jet printer 1 is supplied from a host computer (not shown) such as a personal computer or a digital camera, the ink jet printer 1 records the image indicated by the print data Img on the recording paper. The printing process formed on P is executed. In the present embodiment, the case where the inkjet printer 1 is a line printer will be described as an example.

  As shown in FIG. 1, the inkjet printer 1 includes a head module 5 including a head unit HU provided with a discharge unit D for discharging ink, and a drive signal generation for generating a drive signal Com for driving the head unit HU. A drive module 8 having a section GR, a transport mechanism 7 for changing the relative position of the recording paper P with respect to the head module 5, a control section 6 for controlling the operation of each section of the inkjet printer 1, and a control program for the inkjet printer 1. And a storage unit 60 for storing other information.

  The storage unit 60 is necessary for executing various processes such as an EEPROM (Electrically Erasable Programmable Read-Only Memory), which is a kind of nonvolatile semiconductor memory for storing print data Img supplied from the host computer, and print processing. A RAM (Random Access Memory) that temporarily stores data or temporarily develops a control program for controlling each part of the ink jet printer 1 so that various processes such as a printing process are executed, and a control program And a PROM which is a kind of nonvolatile semiconductor memory to be stored.

  The control unit 6 includes a central processing unit (CPU), a field-programmable gate array (FPGA), and the like, and the CPU and the like operate according to a control program stored in the storage unit 60. Control the operation of each part.

Then, the control unit 6 controls the head module 5, the transport mechanism 7, and the drive module 8 based on the print data Img supplied from the host computer, so that the recording paper P corresponds to the print data Img. Controls execution of print processing for forming an image.
Specifically, the control unit 6 first stores the print data Img supplied from the host computer in the storage unit 60. Next, the control unit 6 sends a designation signal dCom for designating the waveform of the drive signal Com generated by the drive module 8 based on various data stored in the storage unit 60 such as the print data Img, and the head module 5. A print signal SI that determines whether or not ink is ejected in each of the plurality of ejection sections D provided and the ejection amount is generated. The control unit 6 generates a signal for controlling the operation of the transport mechanism 7 based on various data stored in the storage unit 60 such as the print data Img.
Thereby, the control unit 6 controls the operation of the transport mechanism 7 so as to transport the recording paper P in a predetermined direction, and ejects an amount of ink corresponding to the print data Img from the plurality of ejection units D. The operation of the head module 5 is controlled. Thereby, the control unit 6 adjusts the dot size and the dot arrangement formed by the ink ejected on the recording paper P, and controls the execution of the printing process for forming the image corresponding to the print data Img on the recording paper P. .

As shown in FIG. 1, the head module 5 includes Q head units HU (HU [1] to HU [Q]) (Q is a natural number of 2 or more). The q-th head unit HU [q] includes a head driver DR [q] and a recording head Hd [q] (q is a natural number satisfying 1 ≦ q ≦ Q). The recording head Hd [q] includes M ejection portions D (in this embodiment, M is a natural number of 4 or more).
Hereinafter, in order to distinguish each of the M ejection units D provided in the recording head Hd [q], they may be referred to as “first stage, second stage,..., M stage” in order. In the following, m stages of the ejection sections D provided in the recording head Hd [q] may be expressed as ejection sections D [q] [m] (the variable m is 1 ≦ m). ≦ natural number satisfying M).

Hereinafter, the print signal SI supplied to the recording head Hd [q] among the print signals SI generated by the control unit 6 is referred to as a print signal SI [q]. The print signal SI [q] is a digital signal, and M print signals SI [q] corresponding to the M ejection portions D [q] [1] to D [q] [M] on a one-to-one basis. [1] to SI [q] [M] are included. That is, the print signal SI [q] [m] determines whether or not ink is ejected from the ejection section D [q] [m] and the ejection amount.
Hereinafter, among the drive signals Com generated by the drive module 8, the drive signal Com supplied to the recording head Hd [q] is referred to as a drive signal Com [q]. The drive signal Com is an analog signal having a waveform for driving each ejection unit D.
Hereinafter, the designation signal dCom that designates the waveform of the drive signal Com [q] among the designation signals dCom generated by the control unit 6 is referred to as a designation signal dCom [q].

  As shown in FIG. 1, the drive module 8 includes Q head units HU [1] to HU [Q] and Q drive signal generators GR [1] to GR [Q] corresponding one-to-one. Prepare. Among these, the drive signal generator GR [q] generates the drive signal Com [q] by converting the designation signal dCom [q] supplied from the controller 6 into an analog signal and then amplifying it.

  As described above, the head unit HU [q] includes the head driver DR [q] and the recording head Hd [q]. The head driver DR [q] is a variety of signals such as a drive signal Com [q] supplied from the drive signal generator GR [q] of the drive module 8 and a print signal SI [q] supplied from the controller 6. Based on the above, an individual drive signal Vin for driving each of the ejection units D [q] [1] to D [q] [M] included in the recording head Hd [q] is generated. Hereinafter, among the individual drive signals Vin generated by the head driver DR [q], the individual drive signal Vin for driving the ejection unit D [q] [m] is referred to as an individual drive signal Vin [q] [m]. .

FIG. 2 is a partial cross-sectional view illustrating the outline of the internal configuration of the inkjet printer 1.
As shown in this figure, the ink jet printer 1 includes four ink cartridges 31. In addition, although the case where the ink cartridge 31 is provided in the head module 5 is shown in this figure, this is an example, and the ink cartridge 31 may be provided in another place of the inkjet printer 1.
The four ink cartridges 31 are provided in a one-to-one correspondence with four colors (CMYK) of black, cyan, magenta, and yellow. Each ink cartridge 31 includes the ink cartridge 31. Is filled with ink of a corresponding color.

  As shown in FIG. 2, the transport mechanism 7 includes a transport motor 71 serving as a drive source for transporting the recording paper P, a motor driver (not shown) for driving the transport motor 71, and a head module 5. A platen 74 provided on the side (the -Z direction in FIG. 2), a conveyance roller 73 that is rotated by the operation of the conveyance motor 71, a guide roller 75 that is rotatably provided around the Y axis in FIG. And a storage portion 76 for storing in a rolled state. When the inkjet printer 1 executes a printing process, the transport mechanism 7 feeds the recording paper P from the storage unit 76 and follows a transport path defined by the guide roller 75, the platen 74, and the transport roller 73. In the figure, for example, the sheet is conveyed at a conveyance speed Mv in the + X direction (the direction from the upstream side to the downstream side).

  Each of the plurality of ejection portions D provided in the head module 5 receives ink supply from any one of the four ink cartridges 31. Each ejection part D can be filled with ink supplied from the ink cartridge 31 and eject the filled ink from a nozzle N provided in the ejection part D. Specifically, each ejection unit D records dots for constituting an image by ejecting ink onto the recording paper P at a timing when the transport mechanism 7 transports the recording paper P onto the platen 74. Form on paper P. Then, full-color printing is realized by ejecting four CMYK inks as a whole from the total (Q × M) ejection units D provided in the head units HU [1] to HU [Q]. .

<< 2. Configuration of recording head >>
The recording head Hd [q] and the ejection unit D provided in the recording head Hd [q] will be described with reference to FIGS.

  FIG. 3 is an example of a schematic partial cross-sectional view of the recording head Hd [q]. In this figure, for convenience of illustration, one ejection section D among M ejection sections D [q] [1] to D [q] [M] of the recording head Hd [q] A reservoir 350 communicating with the one ejection unit D via an ink supply port 360 and an ink intake port 370 for supplying ink from the ink cartridge 31 to the reservoir 350 are shown.

  As shown in FIG. 3, the ejection unit D includes a piezoelectric element 300, a cavity 320 (an example of a “pressure chamber”) that can be filled with ink, a nozzle N communicating with the cavity 320, a vibration plate 310, Is provided. The ejection unit D ejects the ink in the cavity 320 from the nozzles N when the piezoelectric element 300 is driven by the individual drive signal Vin. The cavity 320 of the discharge part D is a space defined by a cavity plate 340 formed into a predetermined shape having a recess, a nozzle plate 330 on which a nozzle N is formed, and a vibration plate 310. The cavity 320 communicates with the reservoir 350 via the ink supply port 360. The reservoir 350 communicates with one ink cartridge 31 via the ink intake port 370.

In the present embodiment, for example, a unimorph (monomorph) type as shown in FIG. The piezoelectric element 300 is not limited to a unimorph type but may be a bimorph type or a laminated type.
The piezoelectric element 300 includes a lower electrode 301, an upper electrode 302, and a piezoelectric body 303 provided between the lower electrode 301 and the upper electrode 302. When the potential of the lower electrode 301 is set to a predetermined reference potential VSS and the individual drive signal Vin is supplied to the upper electrode 302, when a voltage is applied between the lower electrode 301 and the upper electrode 302, The piezoelectric element 300 bends (displaces) in the vertical direction in the drawing in accordance with the applied voltage, and as a result, the piezoelectric element 300 vibrates.

  A diaphragm 310 is installed in the upper surface opening of the cavity plate 340, and the lower electrode 301 is joined to the diaphragm 310. For this reason, when the piezoelectric element 300 vibrates by the individual drive signal Vin, the vibration plate 310 also vibrates. Then, the volume of the cavity 320 (pressure in the cavity 320) is changed by the vibration of the vibration plate 310, and the ink filled in the cavity 320 is ejected from the nozzle N. Ink is supplied from the reservoir 350 when the ink in the cavity 320 decreases due to ink ejection. Ink is supplied from the ink cartridge 31 to the reservoir 350 via the ink intake port 370.

  FIG. 4 is an explanatory diagram for explaining an ink ejection operation from the ejection unit D. FIG. For example, the head driver DR generates distortion in the piezoelectric element 300 by changing the potential of the individual drive signal Vin supplied to the piezoelectric element 300 of the ejection unit D in the state shown in FIG. Then, the diaphragm 310 of the discharge part D is bent in the + Z direction. Thereby, as shown in FIG.4 (b), compared with Fig.4 (a), the volume of the cavity 320 of the said discharge part D expands. Next, for example, the head driver DR changes the potential of the individual drive signal Vin in the state shown in FIG. 4B to change the vibration plate 310 of the vibration plate 310 in the state shown in FIG. The position is displaced in the −Z direction beyond the position, and the volume of the cavity 320 is rapidly contracted as shown in FIG. At this time, due to the compression pressure generated in the cavity 320, a part of the ink filling the cavity 320 is ejected as an ink droplet from the nozzle N communicating with the cavity 320.

  FIG. 5 shows the total (Q) provided in the Q recording heads Hd [1] to Hd [Q] provided in the head module 5 when the inkjet printer 1 is viewed in plan from the + Z direction or the −Z direction. FIG. 4 is an explanatory diagram for explaining an example of an arrangement of × M) nozzles N. In the following drawings, for convenience of explanation, the case where Q = 4 may be exemplified. That is, the case where the inkjet printer 1 includes four head units HU [1] to HU [4] may be exemplified.

  As shown in FIG. 5, each recording head Hd [q] includes a nozzle row NL-BK composed of a plurality of nozzles N, a nozzle row NL-CY composed of a plurality of nozzles N, and a nozzle composed of a plurality of nozzles N. There are provided four nozzle rows NL including a row NL-MG and a nozzle row NL-YL including a plurality of nozzles N. The nozzles N belonging to the nozzle row NL-BK are nozzles N provided in the discharge unit D that discharges black ink, and the nozzles N belonging to the nozzle row NL-CY are discharge units that discharge cyan ink. The nozzle N provided in D and the nozzle N belonging to the nozzle row NL-MG is the nozzle N provided in the discharge unit D that discharges magenta ink, and the nozzle N belonging to the nozzle row NL-YL is This is a nozzle N provided in the discharge section D that discharges yellow ink. Each of the four nozzle rows NL is provided so as to extend in the + Y direction or the −Y direction (hereinafter, the + Y direction and the −Y direction are collectively referred to as “Y-axis direction”) when viewed in plan. It has been.

  A region of the head module 5 in which (Q × M) nozzles N corresponding to (Q × M) ejection portions D are provided extends in a range YNL in the Y-axis direction. The range YNL is when the recording paper P (specifically, the recording paper P having the maximum width that can be printed by the inkjet printer 1 in the Y-axis direction) is printed. It becomes more than the range YP in the Y-axis direction.

5, the arrangement of the Q recording heads Hd [1] to Hd [Q] and the arrangement of the nozzle rows NL in each recording head Hd [q], that is, (Q × M) The arrangement of the nozzles N is merely an example, and the recording heads Hd [1] to Hd [Q] and the nozzle arrays NL may be arranged in any way. For example, in FIG. 5, each nozzle row NL is provided so as to extend in the Y-axis direction, but each nozzle row NL may be provided so as to extend in any direction within the XY plane. . For example, each nozzle row NL extends in an oblique direction in the drawing, which is different from both the Y-axis direction and the + X direction and the −X direction (hereinafter, the + X direction and the −X direction are collectively referred to as “X-axis direction”). It may be provided as follows. Further, for example, in FIG. 5, a plurality of nozzles N constituting each nozzle row NL are provided so as to be aligned in the Y-axis direction, but in the figure, even-numbered nozzles N and odd-numbered nozzles from the −Y side. It may be arranged in a so-called staggered manner so that the positions of N in the X-axis direction are different from each other.
In the present embodiment, the M recording units Hd [1] to Hd [Q] are uniformly provided with M ejection portions D, but the present invention is not limited to such an embodiment. Among the Q recording heads Hd [1] to Hd [Q], the number of ejection units D provided in one recording head Hd and the number of ejection units D provided in another recording head Hd are as follows: It may be different.

<< 3. Configuration and operation of head driver >>
Next, the configuration and operation of the head driver DR will be described with reference to FIGS.

<< 3.1. Drive signal generator >>
FIG. 6 is a block diagram showing the configuration of the head driver DR [q]. As shown in FIG. 6, the head driver DR [q] includes a combination of a shift register SR, a latch circuit LT, a decoder DC, and a switching unit TX, and M ejection units D [q] [1] to D [q] [M] have M in one-to-one correspondence. Hereinafter, each element constituting the M sets may be referred to as a first stage, a second stage,... In addition, an m-stage element may be expressed by adding a subscript [m] representing the number of stages m to a code for representing the element.

  The head driver DR [q] is supplied with a clock signal CL, a print signal SI [q], a latch signal LAT, a change signal CH, and a drive signal Com [q] from the control unit 6.

In the present embodiment, the drive signal Com includes a drive signal Com-A and a drive signal Com-B. Hereinafter, the drive signals Com-A and Com-B supplied to the head driver DR [q] are referred to as a drive signal Com-A [q] and a drive signal Com-B [q], respectively. The drive signal Com [q] (Com-A [q] and Com-B [q]) is a signal including a plurality of waveforms for driving the ejection unit D.
As described above, the print signal SI [q] is a digital signal that determines the amount of ink to be ejected by the ejection units D [q] [1] to D [q] [M], and the print signal SI [q] [ 1] to SI [q] [M] are included. Among these, the print signal SI [q] [m] indicates the presence / absence of ink ejection from the ejection part D [q] [m] and the amount of ink to be ejected by the ejection part D [q] [m]. It is specified by 2 bits, bit b1 and lower bit b2. Specifically, the print signal SI [q] [m] is an ejection of an amount of ink corresponding to a large dot and an ejection of an amount of ink corresponding to a medium dot to the ejection unit D [q] [m]. One of ink ejection corresponding to a small dot or ink non-ejection is designated (see FIG. 7).
The head driver DR [q] supplies an individual drive signal Vin [q] [m] having a waveform specified by the print signal SI [q] [m] to the discharge section D [q] [m]. .

The m-stage shift register SR temporarily holds a print signal SI [q] [m], which is a 2-bit signal corresponding to each ejection unit D [q] [m], of the print signal SI [q]. The M shift registers SR in the first to M stages sequentially transfer the print signal SI [q] [m] to the subsequent stage according to the clock signal CL. When the print signal SI [q] has been transferred to the M-stage shift register SR, that is, the m-stage shift register SR [m] has the m-stage print signal SI [q]. When the print signal SI [q] [m] that determines the ink discharge amount of the discharge section D [q] [m] is transferred, each shift register SR [m] receives the transferred 2-bit print signal SI [ Hold q] [m] temporarily.

  Each of the M latch circuits LT receives the print signal SI [q] [m] for 2 bits corresponding to each stage held in each of the M shift registers SR at the timing when the latch signal LAT rises. Latch all at once.

By the way, the operation period, which is a period during which the inkjet printer 1 executes the printing process, is composed of a plurality of unit periods Tu.
The control unit 6 supplies the print signal SI [q] to the head driver DR [q] every unit period Tu, and the latch circuit LT outputs the print signal SI [q] [m] every unit period Tu. Is supplied with a latch signal LAT. Further, the controller 6 supplies the designation signal dCom [q] and the clock signal CL to the drive signal generator GR [q], so that the drive signal generator GR [q] has the drive signal Com [q]. ] Is supplied to the head driver DR [q] every unit period Tu to control the operation of the drive signal generator GR [q]. As a result, in each unit period Tu, the control unit 6 causes the ejection unit D [q] [m] to eject an amount of ink corresponding to a large dot, an amount of ink equivalent to a medium dot, and a small dot. The operation of the head driver DR [q] is controlled so as to execute either the ejection of a corresponding amount of ink or the non-ejection of ink.

  In the present embodiment, the control unit 6 divides the unit period Tu into a control period Ts1 and a control period Ts2 based on the change signal CH. In the present embodiment, it is assumed that the control periods Ts1 and Ts2 have the same time length. Hereinafter, the control periods Ts1 and Ts2 may be collectively referred to as a control period Ts.

  The decoder DC decodes the print signal SI [q] [m] latched by the latch circuit LT and outputs a selection signal SL [q] [m]. In this embodiment, the selection signal SL [q] [m] selects the selection signal SLa [q] [m] for selecting the driving signal Com-A [q] and the driving signal Com-B [q]. Selection signal SLb [q] [m].

  FIG. 7 is an explanatory diagram showing the decoding contents of the m-stage decoder DC. As shown in the figure, the m-stage decoder DC outputs a selection signal SL [q] [m] in each of the control periods Ts1 and Ts2 of each unit period Tu. For example, when the print signal SI [q] [m] supplied in the unit period Tu is (b1, b2) = (1, 0), the m-stage decoder DC receives the selection signal SLa in the control period Ts1. [q] [m] is set to the H level, the selection signal SLb [q] [m] is set to the L level, the selection signal SLb [q] [m] is set to the H level, and the selection signal SLa is set in the control period Ts2. [q] [m] are set to L level.

As shown in FIG. 6, the head driver DR [q] includes M switching units so as to correspond to the M ejection units D [q] [1] to D [q] [M] on a one-to-one basis. With TX. Each switching unit TX includes a transmission gate TGa and a transmission gate TGb. Among these, the transmission gate TGa [m] provided in the m-stage switching unit TX [m] is turned on when the selection signal SLa [q] [m] is at the H level and turned off when the selection signal SLa [q] [m] is at the L level. The transmission gate TGb [m] provided in the m-stage switching unit TX [m] is turned on when the selection signal SLb [q] [m] is at the H level and turned off when the selection signal SLb [q] [m] is at the L level.
For example, when the print signal SI [q] [m] indicates (1, 0) (see FIG. 15), the transmission gate TGa [m] is turned on and the transmission gate TGb [m] is turned off in the control period Ts1. In the control period Ts2, the transmission gate TGa [m] is turned off and the transmission gate TGb [m] is turned on.

As shown in FIG. 6, the drive signal Com-A [q] is supplied to one end of the transmission gate TGa [m], and the drive signal Com [q] is supplied to one end of the transmission gate TGb [m]. The other ends of the transmission gates TGa [m] and TGb [m] are electrically connected to the m-stage output terminal OTN.
In the present embodiment, as shown in FIG. 6, in each control period Ts, the switching unit TX [m] causes one of the transmission gates TGa [m] and TGb [m] to be turned on and the other to be turned off. Controlled. That is, in each control period Ts, the switching unit TX [m] sends either the drive signal Com-A [q] or Com-B [q] to the individual drive signal via the m-stage output terminals OTN. It supplies to discharge part D [q] [m] as Vin [q] [m].

<< 3.2. Drive signal >>
FIG. 8 shows various signals supplied to the head driver DR [q] by the control unit 6 and the drive module 8 in each unit period Tu and the operation of the head driver DR [q] in each unit period Tu. It is a timing chart for explaining. In FIG. 8, for the convenience of illustration, a case where M = 4 is illustrated.

As shown in FIG. 8, the unit period Tu is defined by the pulse Pls-L included in the latch signal LAT, and the control periods Ts1 and Ts2 are the pulses Pls-C included in the pulse Pls-L and the change signal CH. It is prescribed by.
Prior to the start of each unit period Tu, the controller 6 supplies the print signal SI [q] to the head driver DR [q] in synchronization with the clock signal CL. Then, the shift register SR of the head driver DR [q] sequentially transfers the supplied print signal SI [q] to the subsequent stage according to the clock signal CL.

As illustrated in FIG. 8, the drive signal Com-A [q] output by the drive signal generator GR [q] in each unit period Tu is generated in the discharge waveform PA1 provided in the control period Ts1 and in the control period Ts2. And an ejection waveform PA2 provided.
The discharge waveform PA1 corresponds to a medium dot from the discharge part D [q] [m] when the individual drive signal Vin [q] [m] having the discharge waveform PA1 is supplied to the discharge part D [q] [m]. The waveform is such that a moderate amount of ink is ejected.
The ejection waveform PA2 corresponds to a small dot from the ejection part D [q] [m] when the individual drive signal Vin [q] [m] having the ejection waveform PA2 is supplied to the ejection part D [q] [m]. The waveform is such that a small amount of ink is discharged.
For example, the potential difference between the lowest potential (in this example, the potential Va11) of the ejection waveform PA1 and the highest potential (in this example, the potential Va12) is the lowest potential (in this example, the potential Va21) of the ejection waveform PA2 and the highest potential (in this example, the potential Va21). In this example, the potential difference is larger than the potential Va22).

As illustrated in FIG. 8, the drive signal Com-B [q] output from the control unit 6 in each unit period Tu has a slight vibration waveform PB.
The fine vibration waveform PB is generated when the individual drive signal Vin [q] [m] having the fine vibration waveform PB is supplied to the discharge portion D [q] [m] from the discharge portion D [q] [m]. Is a waveform that does not discharge. That is, the fine vibration waveform PB is a waveform for preventing the ink from thickening by giving a fine vibration to the ink inside the ejection portion D. For example, the potential difference between the lowest potential (in this example, the potential Vb11) of the micro-vibration waveform PB and the highest potential (in this example, the reference potential V0) is smaller than the potential difference between the lowest potential and the highest potential of the ejection waveform PA2. It is determined as follows.

<< 3.3. Individual drive signal >>
Next, the individual drive signal Vin [q] [m] output from the head driver DR [q] in the unit period Tu will be described with reference to FIG.

When the print signal SI [q] [m] supplied to the head driver DR [q] in the unit period Tu indicates (1, 1), the switching unit TX [m] displays the drive signal Com-A in the control period Ts1. [q] is selected to output the individual drive signal Vin [q] [m] having the ejection waveform PA1, and the drive signal Com-A [q] is selected in the control period Ts2 to have the ejection waveform PA2. Vin [q] [m] is output. Therefore, in this case, as shown in FIG. 9, the individual drive signal Vin [q] [m] supplied to the discharge section D [q] [m] in the unit period Tu includes the discharge waveform PA1 and the discharge waveform PA2. . As a result, the discharge unit D [q] [m] discharges a medium amount of ink based on the discharge waveform PA1 and a small amount of ink based on the discharge waveform PA2 in the unit period Tu. Large dots are formed on the recording paper P by the ink ejected twice.
When the print signal SI [q] [m] supplied to the head driver DR [q] in the unit period Tu indicates (1, 0), the switching unit TX [m] outputs the drive signal Com-A in the control period Ts1. [q] is selected to output the individual drive signal Vin [q] [m] having the discharge waveform PA1, and the drive signal Com-B [q] is selected in the control period Ts2 to have the fine vibration waveform PB. The signal Vin [q] [m] is output. Therefore, in this case, as shown in FIG. 9, the individual drive signal Vin [q] [m] supplied to the discharge section D [q] [m] in the unit period Tu has the discharge waveform PA1 and the fine vibration waveform PB. Including. As a result, the ejection unit D [q] [m] ejects a medium amount of ink based on the ejection waveform PA1 during the unit period Tu, thereby forming medium dots on the recording paper P.
When the print signal SI [q] [m] supplied to the head driver DR [q] in the unit period Tu indicates (0, 1), the switching unit TX [m] outputs the drive signal Com-B in the control period Ts1. [q] is selected to output the individual drive signal Vin [q] [m] having the fine vibration waveform PB, and the drive signal Com-A [q] is selected in the control period Ts2 to perform the individual drive having the discharge waveform PA2. The signal Vin [q] [m] is output. Therefore, in this case, as shown in FIG. 9, the individual drive signal Vin [q] [m] supplied to the discharge section D [q] [m] in the unit period Tu has the discharge waveform PA2 and the fine vibration waveform PB. Including. As a result, the ejection unit D [q] [m] ejects a small amount of ink based on the ejection waveform PA2 in the unit period Tu to form small dots on the recording paper P.
When the print signal SI [q] [m] supplied to the head driver DR [q] in the unit period Tu indicates (0, 0), the switching unit TX [m] outputs the drive signal Com in the control periods Ts1 and Ts2. -B [q] is selected and an individual drive signal Vin [q] [m] having a slight vibration waveform PB is output. Therefore, in this case, as shown in FIG. 9, the individual drive signal Vin [q] [m] supplied to the discharge section D [q] [m] in the unit period Tu includes two micro-vibration waveforms PB. As a result, the ejection unit D [q] [m] does not eject ink in the unit period Tu, and no dots are formed on the recording paper P (non-recording).

<< 4. Connection between head module and drive module >>
Next, referring to FIGS. 10 and 11, each head unit HU [q] included in the head module 5, each drive signal generator GR [q] included in the drive module 8, and the control unit 6. The electrical connection will be described.
FIG. 10 is a diagram illustrating the connection between the head unit HU [q] and the drive module 8 and the connection between the drive module 8 and the control unit 6. FIG. 11 is a diagram illustrating wiring for electrically connecting the head unit HU [q] and the driving module 8 and wiring for electrically connecting the driving module 8 and the control unit 6. . In FIG. 10, a case where Q = 4 will be described as an example. In FIG. 11, among the head units HU [1] to HU [Q] and the drive signal generators GR [1] to GR [Q], the head units HU [1] and HU [2] and the drive signal The generation units GR [1] and GR [2] are representatively shown.

As shown in FIG. 10, Q drive signal generation units GR [1] to GR [Q] included in the drive module 8 are provided on the drive substrate 800. The control unit 6 is provided on the control board 600. Each of the Q head units HU [1] to HU [Q] included in the head module 5 and the drive substrate 800 are connected by one flexible printed circuit board FCx. The drive board 800 and the control board 600 are connected by Q flexible printed boards FCy (FCy [1] to FCy [Q]). That is, as apparent from FIG. 10, in this embodiment, it is assumed that the drive module 8 is provided outside the head module 5.
In this embodiment, the head unit HU [q] and the drive board 800, and the drive board 800 and the control board 600 are connected by a flexible printed circuit board. For example, they are connected by a flexible flat cable. It may be a thing connected by other cables.

As shown in FIG. 10, the drive board 800 is provided with Q connectors Cx [1] to Cx [Q] so as to correspond to the drive signal generators GR [1] to GR [Q] on a one-to-one basis. It is done. The drive substrate 800 is provided with Q wirings Lx1 [1] to Lx1 [Q]. Among these, the wiring Lx1 [q] electrically connects the drive signal generator GR [q] and the connector Cx [q].
The flexible printed circuit board FCx has Q terminal portions tn1 [1] to tn1 [Q] corresponding to the connectors Cx [1] to Cx [Q] on a one-to-one basis. The terminal part tn1 [q] is connected to the connector Cx [q]. The flexible printed circuit board FCx has Q terminal portions tn2 [1] to tn2 [Q] corresponding to the head units HU [1] to HU [Q] on a one-to-one basis. The terminal part tn2 [q] is connected to a connector Cw [q] provided in the head unit HU [q]. The flexible printed circuit board FCx is provided with Q wirings Lx2 [1] to Lx2 [Q]. Among these, the wiring Lx2 [q] electrically connects the connector Cx [q] and the connector Cw [q].
Hereinafter, the wiring Lx1 [q] and the wiring Lx2 [q] are referred to as a wiring Lx [q]. That is, the wiring Lx [q] electrically connects the head unit HU [q] and the drive signal generator GR [q].

As shown in FIGS. 10 and 11, in the present embodiment, the wiring Lx2 [1] is longer than the wiring Lx2 [2]. For this reason, as shown in FIG. 11, in the wiring Lx1 [2], the routing portion PLx is provided so that the wiring Lx1 [2] is longer than the wiring Lx1 [1]. As a result, it is possible to reduce the difference between the length of the wiring Lx [1] and the length of the wiring Lx [2] compared to the case where the wiring Lx1 [2] does not have the routing portion PLx.
Furthermore, in the present embodiment, the routing portion PLx is provided so that the wiring Lx [1] and the wiring Lx [2] have substantially the same length.
In this specification, “substantially the same” means the same when removing various errors such as manufacturing errors and errors due to noise, even when they do not match completely, even when they do not match completely. It is a concept that includes possible ranges. For example, even if they are not exactly the same, they are referred to as “substantially the same” if they are identical in design.

  In the present embodiment, the wirings Lx [q] are arranged as necessary so that the lengths of the other wirings Lx [q] are substantially the same as the lengths of the wirings Lx [1] and Lx [2]. A lead section PLx is provided at Lx2 [q]. For example, when the wiring Lx2 [3] is shorter than the wiring Lx2 [1], a routing portion PLx that routes the wiring in the wiring Lx1 [3] is provided.

When the wiring Lx [1] is longer than the wiring Lx [2], for example, the impedance of the wiring Lx [1] is larger than the impedance of the wiring Lx [2]. The supply timing of the drive signal Com [1] is later than the supply timing of the drive signal Com [2] to the head unit HU [2]. In this case, even if the ink ejected from the head unit HU [1] and the ink ejected from the head unit HU [2] are to land at the same position in the X-axis direction, the head unit HU [1] There is a possibility that the ejected ink will land with a deviation in the −X direction from the ink ejected from the head unit HU [2]. Then, due to such deviation of the landing position, the quality of the image formed in the printing process may be deteriorated.
On the other hand, in this embodiment, since the wirings Lx [1] to Lx [Q] have substantially the same length, the supply timing of the drive signal Com to the head units HU [1] to HU [Q] is substantially the same. It can be. For this reason, it is possible to suppress the occurrence of landing position deviations in the X-axis direction in the head units HU [1] to HU [Q], and it is possible to prevent deterioration in image quality due to deviations in the landing positions.

  As shown in FIGS. 10 and 11, the drive board 800 is provided with Q connectors Cy [1] to Cy [Q] and Q wires Ly1 [1] to Ly1 [Q]. Among these, the wiring Ly1 [q] electrically connects the drive signal generator GR [q] and the connector Cy [q]. The control board 600 is provided with Q connectors Cz [1] to Cz [Q] and Q wires Lz [1] to Lz [Q]. Among these, the wiring Lz [q] electrically connects the control unit 6 and the connector Cz [q].

The flexible printed circuit board FCy [q] connects the connector Cy [q] and the connector Cz [q]. The flexible printed circuit board FCy [q] is electrically connected to the wiring Ly1 [q] and the wiring Lz [q] by electrically connecting the connector Cy [q] and the connector Cz [q]. A wiring Ly2 [q] is provided.
Hereinafter, the wiring Ly1 [q], the wiring Ly2 [q], and the wiring Lz [q] are referred to as a wiring Ly [q]. That is, the wiring Ly [q] electrically connects the control unit 6 and the drive signal generation unit GR [q].

  In the present embodiment, the wirings Ly [1] to Ly [Q] are provided so as to have substantially the same length. For this reason, the supply timing of the designation signal dCom to the drive signal generators GR [1] to GR [Q] can be made substantially the same. As a result, the supply timing of the designation signal dCom from the drive signal generators GR [1] to GR [Q] is made substantially the same, and the X-axis direction landing maintenance deviation occurs in the head units HU [1] to HU [Q]. Can be suppressed.

  As shown in FIG. 11, the drive signal generator GR [q] includes a drive signal generation circuit GR-A [q] for generating a drive signal Com-A [q] of the drive signal Com [q]; A drive signal generation circuit GR-B [q] for generating the drive signal Com-B [q] of the drive signal Com [q]. Further, the wiring Lx1 [q] provided on the driving substrate 800 is connected to the wiring Lx-A [q] for electrically connecting the driving signal generation circuit GR-A [q] and the connector Cx [q] to the driving circuit 800. Wiring Lx-B [q] for electrically connecting the signal generation circuit GR-B [q] and the connector Cx [q] is provided. Further, the wiring Ly1 [q] provided on the drive substrate 800 is connected to the wiring Ly-A [q] for electrically connecting the drive signal generation circuit GR-A [q] and the connector Cy [q] to the drive circuit 800. Wiring Ly-B [q] for electrically connecting the signal generation circuit GR-B [q] and the connector Cy [q] is provided.

In the present embodiment, the wiring Lx-A [q] and the wiring Lx-B [q] are provided so as to have substantially the same length. In the present embodiment, the wiring Ly-A [q] and the wiring Ly-B [q] are provided so as to have substantially the same length.
Specifically, for example, as shown in FIG. 11, the linear distance (shortest distance) between the drive signal generation circuit GR-A [q] and the connector Cx [q] is the drive signal generation circuit GR-B [ When the distance is longer than the linear distance between q] and the connector Cx [q], the wiring Lx-A [q] can be obtained by providing the routing portion PLb around the wiring Lx-B [q]. And the wiring Lx-B [q] may have substantially the same length.
Similarly, for example, the linear distance between the drive signal generation circuit GR-B [q] and the connector Cy [q] is the straight line between the drive signal generation circuit GR-A [q] and the connector Cy [q]. When the distance is longer than the distance, the wiring Ly-A [q] and the wiring Ly-B [q] are substantially the same by providing a routing portion PLa that routes the wiring in the wiring Ly-A [q]. It can be a length.

  As described above, in this embodiment, the wiring Lx-A [q] and the wiring Lx-B [q] are provided to have substantially the same length, and the wiring Ly-A [q] and the wiring Ly-B [ q] are provided so as to have substantially the same length, so that the drive signal Com-A [q] is supplied to the head unit HU [q] and the drive signal Com-B [q] is supplied to the head unit HU [q]. Can be set at substantially the same timing.

<< 5. Conclusion of embodiment >>
As described above, in this embodiment, when the wiring Lx2 [q1] is longer than the wiring Lx2 [q2], the routing portion PLx is provided in the wiring Lx1 [q2], and the wiring Lx1 [q2] is changed. It is longer than the wiring Lx1 [q1] (q1 is a natural number that satisfies 1 ≦ q1 ≦ Q. Q2 is a natural number that satisfies 1 ≦ q2 ≦ Q and is different from q1). As a result, the wiring Lx [q1] and the wiring Lx [q2] can have substantially the same length. That is, the transmission time of the drive signal Com [q1] via the wiring Lx [q1] and the transmission time of the drive signal Com [q2] via the wiring Lx [q2] can be made substantially the same. As a result, it is possible to prevent a deviation between the landing position of the ink discharged from the head unit HU [q1] and the landing position of the ink discharged from the head unit HU [q2]. .
10 and 11 exemplify the case of “q1 = 1” and “q2 = 2”. FIG. 10 also illustrates the case of “q1 = 4” and “q2 = 3”.

  In the present embodiment, the wiring Ly [q1] and the wiring Ly [q2] have substantially the same length. Thereby, the transmission time of the designated signal dCom [q1] via the wiring Ly [q1] and the transmission time of the designated signal dCom [q2] via the wiring Ly [q2] can be made substantially the same. As a result, it is possible to prevent a deviation between the landing position of the ink discharged from the head unit HU [q1] and the landing position of the ink discharged from the head unit HU [q2]. .

  In the present embodiment, the wiring Lx-A [q] and the wiring Lx-B [q] have substantially the same length. Thereby, the supply of the drive signal Com-A [q] to the head unit HU [q] and the supply of the drive signal Com-B [q] to the head unit HU [q] can be made substantially the same timing. Accordingly, it is possible to prevent the deterioration of the image quality due to the shift of the waveform of the drive signal Com-A [q] and the waveform of the drive signal Com-B [q] on the time axis.

In the above-described embodiment, when the wiring Lx2 [q1] is longer than the wiring Lx2 [q2], the wiring Lx [q1] including the wiring Lx2 [q1] and the wiring Lx1 [q1] is the “first wiring”. The wiring Lx1 [q1] is an example of “first internal wiring”, the wiring Lx2 [q1] is an example of “first external wiring”, and the wiring Lx [q1] is electrically connected. The head unit HU [q1] is an example of a “first head unit”, and the drive signal generator GR [q1] to which the wiring Lx [q1] is electrically connected is an example of a “first generator”. The drive signal Com [q1] supplied from the drive signal generator GR [q1] to the head unit HU [q1] is an example of a “first drive signal”.
In addition, when the wiring Lx2 [q1] is longer than the wiring Lx2 [q2], the wiring Lx [q2] including the wiring Lx2 [q2] and the wiring Lx1 [q2] is an example of the “second wiring”, and the wiring Lx1 [q2] is an example of “second internal wiring”, wiring Lx2 [q2] is an example of “second external wiring”, and head unit HU [q2] to which wiring Lx [q2] is electrically connected Is an example of a “second head unit”, and the drive signal generator GR [q2] to which the wiring Lx [q2] is electrically connected is an example of a “second generator”, and the drive signal generator GR [ The drive signal Com [q2] supplied from q2] to the head unit HU [q2] is an example of a “second drive signal”.
In the above-described embodiment, when the wiring Lx2 [q1] is longer than the wiring Lx2 [q2], the designation signal dCom [q1] that designates the waveform of the drive signal Com [q1] is the “first designation signal”. The designation signal dCom [q2] that designates the waveform of the drive signal Com [q2] is an example of “second designation signal”, and the control for generating the designation signal dCom [q1] and the designation signal dCom [q2] is an example. The unit 6 is an example of a “designating unit”, and the wiring Ly [q1] that electrically connects the control unit 6 and the drive signal generation unit GR [q1] is an example of a “third wiring”. The wiring Ly [q2] that electrically connects the drive signal generator GR [q2] is an example of a “fourth wiring”.

In the above-described embodiment, the drive substrate 800 on which the drive signal generation unit GR [q] is provided is an example of a “first substrate”, and the control substrate 600 on which the control unit 6 is provided is an example of a “second substrate”. It is.
In the above-described embodiment, the drive signal Com-A [q] of the drive signal Com [q] is an example of the “first waveform signal”, and the drive signal Com-B [ q] is an example of the “second waveform signal”, the drive signal generation circuit GR-A [q] that generates the drive signal Com-A [q] is an example of the “first generation circuit”, and the drive signal Com The drive signal generation circuit GR-B [q] that generates -B [q] is an example of a “second generation circuit”. Of the lines Lx1 [q], the line Lx2 [q] and the drive signal generation circuit GR− The wiring Lx-A [q] that electrically connects A [q] is an example of the “first connection wiring”. Among the wirings Lx1 [q], the wiring Lx2 [q] and the drive signal generation circuit GR-B The wiring Lx-B [q] that electrically connects [q] is an example of the “second connection wiring”.

<< B. Modification >>
Each of the above forms can be variously modified. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined within a range that does not contradict each other. In addition, about the element which an effect | action and a function are equivalent to embodiment in the modification illustrated below, the code | symbol referred by the above description is diverted and each detailed description is abbreviate | omitted suitably.

<Modification 1>
In the above-described embodiment, the flexible printed circuit board FCx is connected to the drive board 800 by the Q terminal portions tn1 [1] to tn1 [Q], but the present invention is not limited to such a mode. The flexible printed circuit board FCx may have any shape as long as it connects the head units HU [1] to HU [Q] and the driving board 800.
For example, the flexible printed circuit board FCx may be connected to the drive board 800 by one terminal portion tn1 as shown in FIG. In this case, the drive substrate 800 may include one connector Cx instead of the Q connectors Cx [1] to Cx [Q].
Further, for example, the flexible printed circuit board FCx is connected to the drive substrate 800 by the terminal portion tn3 provided in the + Y direction or the −Y direction of the drive substrate 800, instead of the terminal portion tn1 provided in the + Z direction of the drive substrate 800. It may be done.

  In the above-described embodiment, the drive board 800 and the control board 600 are connected by Q flexible printed boards FCy [1] to FCy [Q], but the present invention is limited to such an embodiment. Instead, the drive board 800 and the control board 600 may be connected by one or more flexible printed boards FCy. In this case, the drive board 800 includes one connector Cy instead of the Q connectors Cy [1] to Cy [Q], and the control board 600 includes the Q connectors Cz [1] to Cz [ Instead of Q], a single connector Cz may be provided.

<Modification 2>
In the embodiment and the modification described above, the lengths of the wirings Lx [1] to Lx [Q] are substantially the same. However, the present invention is not limited to such an embodiment, and the wirings Lx [1] to Lx [1] to The impedances of Lx [Q] may be substantially the same. For example, when the wiring Lx2 [q1] is longer than the wiring Lx2 [q2], instead of providing the routing portion PLx in the wiring Lx1 [q2] and making the wiring Lx1 [q2] longer than the wiring Lx1 [q1] In addition, the wiring Lx1 [q2] and the wiring Lx1 [q2] are made substantially the same length without providing the routing portion PLx, and the wiring Lx2 [q1] is made thicker than the wiring Lx2 [q2]. The impedances of Lx [q1] and wiring Lx [q2] may be substantially the same.
Similarly, in the above-described embodiment, the lengths of the wirings Ly1 [1] to Ly1 [Q] are substantially the same, but the impedances of the wirings Ly1 [1] to Ly1 [Q] may be substantially the same.
In the above-described embodiment, the lengths of the wirings Lx-A [q] and Lx-B [q] are substantially the same, but the impedances of the wirings Lx-A [q] and Lx-B [q] are substantially reduced. It may be the same.

<Modification 3>
In the embodiment and the modification described above, the wiring Lx [q1] and the wiring Lx [q2] have substantially the same length (or substantially the same impedance), but the present invention is limited to such an aspect. Instead, when the wiring Lx2 [q1] is longer than the wiring Lx2 [q2], the wiring Lx1 [q2] is longer than the wiring Lx1 [q1], so that the wiring Lx [q1] and the wiring Lx [q2] The wirings Lx1 [1] to Lx1 [Q] may be provided so that the difference in length between the wirings Lx2 [q2] and the wiring Lx2 [q2] is smaller than the difference in length. In other words, the lengths of the wirings Lx [1] to Lx [Q] are smaller than the lengths of the wirings Lx2 [1] to Lx2 [Q]. [Q] should be provided.

<Modification 4>
The inkjet printer 1 according to the embodiment and the modification described above is a line printer in which the nozzle row NL is provided so that the range YNL includes the range YP, but the present invention is not limited to such an aspect. The inkjet printer 1 may be a serial printer in which the head module 5 reciprocates in the Y-axis direction to execute print processing.

<Modification 5>
The inkjet printer 1 according to the embodiment and the modification described above can eject four colors of CMYK ink, but the present invention is not limited to such an aspect, and the inkjet printer 1 has at least one color. It is sufficient that the above ink can be ejected, and the ink color may be a color other than CMYK.
Moreover, although the inkjet printer 1 which concerns on embodiment mentioned above and a modification is provided with the nozzle row NL of 4 rows, what is necessary is just provided with the nozzle row NL of at least 1 or more rows.

<Modification 6>
In the embodiment and the modification described above, the drive signal Com-A includes two systems of signals, the drive signals Com-A and Com-B, but the present invention is not limited to such a mode, and the drive The signal Com only needs to include one or more systems of signals. That is, the drive signal Com may be a single signal, for example, a signal including only the drive signal Com-A, or a signal including three or more signals, for example, the drive signals Com-A, Com-B, and Com-C. But you can.
In the embodiment and the modification described above, the unit period Tu includes two control periods Ts1 and Ts2. However, the present invention is not limited to such a mode, and the unit period Tu has a single control period. It may consist of a period Ts or may include three or more control periods Ts.
In the embodiment and the modification described above, the print signal SI [q] [m] is a 2-bit signal, but the number of bits of the print signal SI [q] [m] depends on the gradation to be displayed, What is necessary is just to determine suitably according to the number of the control periods Ts included in the unit period Tu, the number of signal systems included in the drive signal Com, and the like.

<Modification 7>
In the embodiment and the modification described above, the drive module 8 is provided outside the head module 5, but the present invention is not limited to such a mode, and the drive module 8 may be mounted on the head module 5. Good.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 5 ... Head module, 6 ... Control part, 7 ... Conveyance mechanism, 8 ... Drive module, 31 ... Ink cartridge, 60 ... Memory | storage part, 600 ... Control board, 800 ... Drive board, D ... Discharge part, DR: head driver, FCx: flexible printed circuit board, FCy: flexible printed circuit board, GR: drive signal generator, Lx [q]: wiring, Ly [q]: wiring, Lx1 [q]: wiring, Lx2 [q] ... Wiring, Lx-A [q] ... wiring, Lx-B [q] ... wiring, Cx [q] ... connector, Cy [q] ... connector, Hd ... recording head, HU ... head unit, N ... nozzle.

Claims (5)

A first head unit driven by a first drive signal and capable of discharging liquid;
A second head unit that is driven by the second drive signal and can discharge liquid;
A first substrate;
A first generation unit provided on the first substrate and configured to generate the first drive signal;
A second generation unit provided on the first substrate for generating the second drive signal;
A first wiring that electrically connects the first head unit and the first generator;
A second wiring that electrically connects the second head unit and the second generator;
With
The first wiring is
First external wiring for electrically connecting the first head unit and the first substrate;
In the first substrate,
A first internal wiring that electrically connects the first external wiring and the first generator;
Including
The second wiring is
A second external wiring for electrically connecting the second head unit and the first substrate;
In the first substrate,
A second internal wiring that electrically connects the second external wiring and the second generator;
Including
The first external wiring is longer than the second external wiring,
The first internal wiring is shorter than the second internal wiring;
A liquid discharge apparatus characterized by that. The length of the first wiring and the length of the second wiring are substantially the same.
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. The resistance of the first wiring and the resistance of the second wiring are substantially the same.
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. A second substrate;
Provided on the second substrate;
A first designation signal for designating a waveform of the first drive signal generated by the first generator; and
A second designation signal for designating a waveform of the second drive signal generated by the second generator;
A specification part that outputs
A third wiring for electrically connecting the designation unit and the first generation unit;
A fourth wiring that electrically connects the designation unit and the second generation unit;
With
The length of the third wiring and the length of the fourth wiring are substantially the same.
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. The first drive signal is:
Including a first waveform signal and a second waveform signal;
The first generator is
A first generation circuit for generating the first waveform signal;
A second generation circuit for generating the second waveform signal;
With
The first internal wiring is
A first connection wiring for electrically connecting the first generation circuit and the first external wiring;
A second connection wiring for electrically connecting the second generation circuit and the first external wiring;
Including
The length of the first connection wiring and the length of the second connection wiring are substantially the same.
The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus according to claim 1.

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