JP6874310B2 - Liquid discharge device - Google Patents

Description

The present invention relates to a liquid discharge device.

A liquid ejection device such as an inkjet printer performs a printing process of forming an image on a recording medium by driving a ejection portion of the liquid ejection head to eject a liquid such as ink filled in the cavity of the ejection portion. Execute.
In recent years, in such a liquid discharge device, in order to speed up the printing process or the like, a so-called line printer has been adopted as a liquid discharge head in which a plurality of discharge portions extend over a range equal to or larger than the width of a recording medium. Has been developed. In general, a line printer has a larger number of discharge portions provided in the liquid discharge head than a liquid discharge device such as a serial printer that executes a printing process while reciprocating the liquid discharge head. Therefore, in general, a line printer requires a large amount of electric power to drive a liquid discharge head as compared with a serial printer. Therefore, in a line printer, a drive signal for driving the liquid discharge head is usually supplied to the liquid discharge head by a plurality of wirings (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-093973

By the way, when the liquid discharge device is maintained, for example, when the liquid discharge head is replaced, the wiring for supplying the drive signal to the liquid discharge head may be inserted and removed from the liquid discharge head. However, when the number of discharge portions provided in the liquid discharge head is large and the number of wires for supplying the drive signal to the liquid discharge head is large, the wiring is misplaced when the wiring is inserted and removed from the liquid discharge head. There is a high possibility that work mistakes such as the above will occur. Further, when the number of wirings for supplying the drive signal to the liquid discharge head is large, the time and effort required for inserting and removing the wirings increases. Therefore, when the number of wires for supplying the drive signal to the liquid discharge head is large, the maintainability such as the success rate and work efficiency of the work in the maintenance work of the liquid discharge device may decrease.

The present invention has been made in view of the above circumstances, and it is possible to keep the degree of deterioration in maintainability small even when the number of wirings for supplying a drive signal to the liquid discharge head is increased. Providing the technology to be solved is one of the problems to be solved.

In order to solve the above problems, the liquid discharge device according to the present invention includes a liquid discharge head that discharges liquid, a first wiring to which a first drive signal for driving the liquid discharge head is supplied, and the above. The first drive signal and the second drive signal are supplied to the liquid discharge head from the second wiring and the first wiring and the second wiring to which the second drive signal for driving the liquid discharge head is supplied. The relay board is connected to a first connector connected to the first wiring, a second connector connected to the second wiring, and a head-side connector included in the liquid discharge head. The relay connector includes, for the head side connector, the first drive signal supplied from the first wiring to the first connector, and the second wiring to the second connector. The second drive signal supplied to the user is output.

According to the present invention, in order to connect the first wiring and the second wiring to the liquid discharge head by one relay connector via the relay board, the first wiring and the second wiring are connected to two connectors. This makes it possible to improve the maintainability of the liquid discharge device as compared with the case where the liquid discharge head is separately connected.
Further, according to the present invention, for example, when the liquid discharge head is removed from the liquid discharge device and the liquid discharge head is attached to the liquid discharge device in order to replace or repair the liquid discharge head, the liquid is used. Instead of connecting and disconnecting the first wiring and the second wiring individually to and from the discharge head, the relay connector and the head-side connector of the relay board may be connected and disconnected. Therefore, according to the present invention, it is possible to suppress the number of times of insertion / removal of the first wiring and the second wiring as compared with the case where the relay board is not provided, and the first wiring and the second wiring due to the insertion / removal can be suppressed. It is possible to suppress deterioration and failure of the wiring.

In the liquid discharge device described above, the liquid discharge head may be a line head capable of printing at a dot density of 600 dpi or more on a recording medium having a width of 297 mm or more.

In a line printer that employs a line head as a liquid discharge head, the number of discharge portions provided in the liquid discharge head is larger than that in a serial printer. In particular, when the liquid discharge head is provided with a discharge portion in a wide range or when printing with a high dot density is required, the number of discharge portions provided in the liquid discharge head is increased. When the number of discharge portions provided in the liquid discharge head is large, a large amount of electric power is required to drive the liquid discharge head.
On the other hand, according to this aspect, in order to supply drive signals (first drive signal and second drive signal) to the liquid discharge head by the first wiring and the second wiring, the liquid discharge head is driven. It is possible to drive the liquid discharge head even when a large amount of electric power is required.

In the liquid discharge device described above, one of the relay connector and the head-side connector is a receptacle type connector, and the other of the relay connector and the head-side connector is a header type connector, and the relay connector. And one or both of the head-side connectors may be characterized by having a floating structure.

According to this aspect, since at least one of the relay connector and the head side connector has a floating structure, the relative positional relationship between the first wiring, the second wiring, and the liquid discharge head is caused by vibration or the like. Even if it fluctuates, it is possible to maintain the state in which the relay connector and the head side connector are connected.

The liquid discharge device described above may be characterized in that the relay connector and the head-side connector are connected by a two-point contact structure.

According to this aspect, it is possible to more reliably supply the drive signal from the relay connector to the head side connector.

In the liquid discharge device described above, the relay connector and the head-side connector may be characterized by having a current capacity of 0.7 amperes or more per pin.

According to this aspect, it is possible to drive the liquid discharge head even when a large amount of electric power is required to drive the liquid discharge head.

In the liquid discharge device described above, the relay connector and the head-side connector may be characterized in that the effective fitting length is 1.5 mm or more.

According to this aspect, it is possible to more reliably supply the drive signal from the relay connector to the head side connector.

In the liquid discharge device described above, the relay connector and the head-side connector may be characterized in that the thickness is 5 mm or less.

According to this aspect, since a low-profile connector is adopted as the relay connector and the head-side connector, it is possible to reduce the size of the liquid discharge device as compared with the case where the low-profile connector is not adopted. ..

It is a block diagram which shows an example of the structure of the inkjet printer 1 which concerns on this invention. It is a perspective view which shows an example of the schematic internal structure of the inkjet printer 1. It is explanatory drawing for demonstrating an example of the structure of the discharge part D. It is a top view which shows an example of the arrangement of the nozzle N in a liquid discharge head 3. It is a block diagram which shows an example of the structure of a head unit HU. It is a timing chart for demonstrating an example of a printing process. It is explanatory drawing for demonstrating an example of a print signal SI and connection state designation signals SLa and SLb. It is a block diagram which shows an example of the structure of the connection state designation circuit 32. It is explanatory drawing for demonstrating an example of the connection between boards.

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

<< A. Embodiment >>
In the present embodiment, the liquid ejection device will be described by exemplifying an inkjet printer that ejects ink (an example of "liquid") to form an image on recording paper P (an example of "recording 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. Here, FIG. 1 is a functional block diagram showing an example of the configuration of the inkjet printer 1 according to the present embodiment. Further, FIG. 2 is a perspective view showing an example of a schematic internal structure of the inkjet printer 1.

The inkjet printer 1 is supplied with print data Img indicating an image to be formed by the inkjet printer 1 from a host computer (not shown) such as a personal computer or a digital camera. The inkjet printer 1 executes a printing process for forming an image indicated by print data Img supplied from the host computer on the recording paper P. Although details will be described later, in this embodiment, it is assumed that the inkjet printer 1 is a line printer.

As illustrated in FIG. 1, the inkjet printer 1 includes a liquid ejection head 3 including a head unit HU provided with an ejection unit D for ejecting ink, and a control unit 6 for controlling the operation of each portion of the inkjet printer 1. , A drive signal generation module 2 including a drive signal generation circuit 20 for generating a drive signal Com for driving the liquid discharge head 3 (more accurately, the discharge portion D provided by the liquid discharge head 3), and a liquid discharge head. A transport mechanism 7 for changing the relative position of the recording paper P with respect to 3 and a storage unit 5 for storing the control program of the inkjet printer 1 and other information are provided.
In the present embodiment, as illustrated in FIG. 1, the liquid discharge head 3 includes four head unit HUs, and the drive signal generation module 2 has four head units HUs having a one-to-one correspondence with the four head units HUs. It is assumed that the drive signal generation circuit 20 of the above is provided.

In the present embodiment, each head unit HU has a discharge module 30 including M discharge units D and a drive signal for switching whether or not to supply the drive signal Com output by the drive signal generation module 2 to the discharge module 30. A supply circuit 31 is provided (in this embodiment, M is a natural number satisfying 1 ≦ M).
In the following, in order to distinguish each of the M discharge portions D provided in each discharge module 30, they may be referred to as 1st stage, 2nd stage, ..., M stage in order. Further, the discharge unit D in the m stage may be referred to as a discharge unit D [m] (the variable m is a natural number satisfying 1 ≦ m ≦ M). Further, when the component or signal of the inkjet printer 1 corresponds to the number of stages m of the ejection unit D [m], the code for representing the component or signal corresponds to the number of stages m. It may be expressed with a subscript [m] indicating that it is.

The storage unit 5 includes, for example, a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a PROM (Programmable ROM). It is configured to include a memory, and stores various information such as print data Img supplied from a host computer and a control program of the inkjet printer 1.

The control unit 6 includes a CPU (Central Processing Unit). However, the control unit 6 may include a programmable logic device such as an FPGA (field-programmable gate array) instead of the CPU.
The control unit 6 controls each unit of the inkjet printer 1 by executing a control program stored in the storage unit 5 by a CPU provided in the control unit 6. Specifically, the control unit 6 controls the print signal SI for controlling the drive signal supply circuit 31 provided in the liquid discharge head 3 and the drive signal generation circuit 20 provided in the drive signal generation module 2. A waveform designation signal dCom for the purpose and a signal for controlling the transport mechanism 7 are generated.
Here, the waveform designation signal dCom is a digital signal that defines the waveform of the drive signal Com. The drive signal Com is an analog signal for driving the discharge unit D. The drive signal generation circuit 20 includes a DA conversion circuit and generates a drive signal Com having a waveform defined by the waveform designation signal dCom. In this embodiment, it is assumed that the drive signal Com includes the drive signal Com-A and the drive signal Com-B.
The print signal SI is a digital signal for designating the type of operation of the ejection unit D. Specifically, the print signal SI specifies the type of operation of the discharge unit D by designating whether or not to supply the drive signal Com to the discharge unit D. Here, the specification of the type of operation of the ejection unit D is, for example, whether or not to drive the ejection unit D, or whether ink is ejected from the ejection unit D when the ejection unit D is driven. It is to specify whether or not, and to specify the amount of ink ejected from the ejection unit D when the ejection unit D is driven.

When the print process is executed, the control unit 6 first stores the print data Img supplied from the host computer in the storage unit 5. Next, the control unit 6 has various data such as a print signal SI, a waveform designation signal dCom, and a signal for controlling the transport mechanism 7 based on various data such as print data Img stored in the storage unit 5. Generate a control signal. Then, the control unit 6 controls the transfer mechanism 7 so as to change the relative position of the recording paper P with respect to the liquid discharge head 3 based on various control signals and various data stored in the storage unit 5. The liquid discharge head 3 is controlled so that the discharge unit D is driven. As a result, the control unit 6 adjusts the presence / absence of ink ejection from the ejection unit D, the ink ejection amount, the ink ejection timing, and the like, and forms an image corresponding to the print data Img on the recording paper P. Controls the execution of processing.

FIG. 2 is a partial cross-sectional view illustrating an outline of the internal configuration of the inkjet printer 1. As shown in FIG. 2, in the present embodiment, it is assumed that the inkjet printer 1 includes four ink cartridges 40. Although FIG. 2 illustrates the case where the ink cartridge 40 is provided in the liquid ejection head 3, the ink cartridge 40 may be provided in another place of the inkjet printer 1.
The four ink cartridges 40 are provided in a one-to-one correspondence with four colors (CMYK) of cyan, magenta, yellow, and black, and each ink cartridge 40 is provided with the ink cartridge 40. Is filled with ink of the color corresponding to.

As shown in FIG. 2, the transport mechanism 7 includes a transport motor 71 as a drive source for transporting the recording paper P, a motor driver (not shown) for driving the transport motor 71, and a liquid discharge head 3. A platen 74 provided on the lower side (in the −Z direction in FIG. 2), a transfer roller 73 rotated by the operation of a transfer motor 71, a guide roller 75 rotatably provided around the Y axis in FIG. 2, and recording paper. A storage unit 76 for storing the P in a rolled state is provided.
When the inkjet printer 1 executes the printing process, the transport mechanism 7 feeds out the recording paper P from the storage unit 76 and follows the transport path defined by the guide roller 75, the platen 74, and the transport roller 73. , In the figure, transport is performed in the + X direction (direction from the upstream side to the downstream side; hereinafter, may be referred to as "transport direction Mv"). In the following, as shown in FIG. 2, the + X direction (transportation direction Mv) and the opposite -X direction are collectively referred to as the X-axis direction, and the + Z direction (upward direction) and the opposite -Z direction (downward direction). ) Is generically referred to as the Z-axis direction, and the + Y direction intersecting the X-axis direction and the Z-axis direction and the opposite −Y direction are collectively referred to as the Y-axis direction.

Each of the 4M ejection portions D provided in the liquid ejection head 3 receives ink from any one of the four ink cartridges 40. Each ejection unit D can fill the inside with the ink supplied from the ink cartridge 40, and eject the filled ink from the nozzle N (see FIG. 3) included in the ejection unit D. Specifically, each ejection unit D records dots for forming an image by ejecting ink to the recording paper P at the timing when the transport mechanism 7 conveys the recording paper P onto the platen 74. It is formed on paper P. Then, full-color printing is realized by ejecting four colors of CMYK ink as a whole from a total of 4M ejection portions D provided in the four head unit HUs included in the liquid ejection head 3.

<< 2. Overview of discharge module and discharge section >>
The discharge module 30 and the discharge unit D provided in the discharge module 30 will be described with reference to FIGS. 3 and 4.

FIG. 3 is a schematic partial cross-sectional view of the discharge module 30 in which the discharge module 30 is cut so as to include the discharge portion D.
As shown in FIG. 3, the discharge unit D includes a piezoelectric element PZ, a cavity 320 filled with ink, a nozzle N communicating with the cavity 320, and a diaphragm 310.
The cavity 320 is a space partitioned by the cavity plate 340, the nozzle plate 330 on which the nozzle N is formed, and the diaphragm 310. The cavity 320 communicates with the reservoir 350 via the ink supply port 360. The reservoir 350 communicates with the ink cartridge 40 corresponding to the ejection portion D via the ink inlet 370.
The piezoelectric element PZ has an upper electrode Zu, a lower electrode Zd, and a piezoelectric body Zm provided between the upper electrode Zu and the lower electrode Zd. Then, the lower electrode Zd is electrically connected to the feeding line LHd (see FIG. 5) set to the potential VBS, and the drive signal Com is supplied to the upper electrode Zu, so that between the upper electrode Zu and the lower electrode Zd. When a voltage is applied to, the piezoelectric element PZ is displaced in the + Z direction or the −Z direction according to the applied voltage. In this embodiment, a unimorph (monomorph) type as shown in FIG. 3 is adopted as the piezoelectric element PZ. The piezoelectric element PZ is not limited to the unimorph type, and a bimorph type, a laminated type, or the like may be adopted.
A diaphragm 310 is installed in the opening on the upper surface of the cavity plate 340. A lower electrode Zd is joined to the diaphragm 310. Therefore, when the piezoelectric element PZ is driven by the drive signal Com and displaced, the diaphragm 310 also displaces. Then, the volume of the cavity 320 changes due to the displacement of the diaphragm 310, and the ink filled in the cavity 320 is ejected from the nozzle N. When the ink in the cavity 320 is reduced due to the ejection of the ink, the ink is supplied from the reservoir 350.

FIG. 4 shows four ejection modules 30 included in the liquid ejection head 3 and a total of 4M nozzles N provided in the four ejection modules 30 when the inkjet printer 1 is viewed in a plan view from the + Z direction. It is explanatory drawing for demonstrating an example of arrangement.
As shown in FIG. 4, each discharge module 30 provided in the liquid discharge head 3 is provided with a nozzle row Ln. Here, the nozzle row Ln is a plurality of nozzles N provided so as to extend in a row in a predetermined direction. In the present embodiment, as an example, in each discharge module 30, four rows of nozzle rows Ln including a nozzle row Ln-BK, a nozzle row Ln-CY, a nozzle row Ln-MG, and a nozzle row Ln-YL Is provided. The nozzle N belonging to the nozzle row Ln-BK is a nozzle N provided in the ejection unit D for ejecting black ink, and the nozzle N belonging to the nozzle row Ln-CY is an ejection unit for ejecting cyan ink. The nozzle N provided in D and belonging to the nozzle row Ln-MG is the nozzle N provided in the ejection unit D for ejecting magenta ink, and the nozzle N belonging to the nozzle row Ln-YL is It is a nozzle N provided in the ejection portion D for ejecting yellow ink. Further, in the present embodiment, as an example, it is assumed that each of the four rows of nozzle rows Ln is provided so as to extend in the Y-axis direction when viewed in a plan view in each discharge module 30.

As shown in FIG. 4, the liquid discharge head 3 according to the present embodiment is a so-called line head. That is, in the liquid ejection head 3, the inkjet printer 1 executes a printing process on the recording paper P (to be exact, the recording paper P whose width in the Y-axis direction has the maximum printable width of the inkjet printer 1). In this case, the extension range YNL of a total of 4M nozzles N included in the liquid discharge head 3 in the Y-axis direction includes the range YP of the recording paper P in the Y-axis direction.

In this embodiment, the range YP is a range having a width of 297 mm or more. That is, the line head (liquid ejection head 3) included in the inkjet printer 1 according to the present embodiment has a size capable of printing on A4 size landscape recording paper P. Further, in the present embodiment, the liquid discharge head 3 is arranged with nozzles N so that printing with a dot density of 600 dpi or more is possible.

The arrangement of the four discharge modules 30 in the liquid discharge head 3 and the arrangement of each nozzle row Ln in each discharge module 30 shown in FIG. 4 are only examples. In each liquid discharge head 3, the discharge module 30 and each nozzle row Ln may be arranged in any manner.
For example, in FIG. 4, the nozzle row Ln is provided so as to extend in the Y-axis direction, but the nozzle row Ln may be provided so as to extend in an arbitrary direction in the XY plane. The nozzle row Ln may be provided so as to extend in a direction different from the Y-axis direction and the X-axis direction, for example, in an oblique direction in the drawing.
Further, in FIG. 4, each discharge module 30 is provided with four rows of nozzle rows Ln, but each discharge module 30 may be provided with one or more rows of nozzle rows Ln.
Further, in FIG. 4, a plurality of nozzles N constituting each nozzle row Ln are provided so as to be arranged in a row in the Y-axis direction. They may be arranged in a so-called staggered pattern so that their positions in the X-axis direction are different from each other.

<< 3. Head unit configuration >>
Hereinafter, the configuration of each head unit HU will be described with reference to FIG.

FIG. 5 is a block diagram showing an example of the configuration of the head unit HU. As described above, the head unit HU includes a discharge module 30 and a drive signal supply circuit 31. Further, the head unit HU is connected to the internal wiring LHa to which the drive signal Com-A is supplied from the drive signal generation module 2, the internal wiring LHb to which the drive signal Com-B is supplied from the drive signal generation module 2, and the potential VBS. It is provided with a set feeding line LHd.

As shown in FIG. 5, the drive signal supply circuit 31 includes M switches SWa (Swa [1] to SWa [M]) and M switches SWb (SWb [1] to SWb [M]). A connection state designation circuit 32 for designating the connection state of each switch is provided. As each switch, for example, a transmission gate can be adopted.
The connection state designation circuit 32 is a connection state designation signal that specifies on / off of the switches SWa [1] to SWa [M] based on the print signal SI, the latch signal LAT, and the change signal CNG supplied from the control unit 6. Generates SLa [1] to SLa [M] and connection state specification signals SLb [1] to SLb [M] that specify on / off of switches SWb [1] to SWb [M].
The switch SWa [m] is composed of the internal wiring LHa and the upper electrode Zu [m] of the piezoelectric element PZ [m] provided in the discharge portion D [m] according to the connection state designation signal SLa [m]. Switch between conducting and non-conducting. In the present embodiment, as an example, it is assumed that the switch SWa [m] is turned on when the connection state designation signal SLa [m] is at a high level and turned off when the connection state designation signal SLa [m] is at a low level.
The switch SWb [m] is composed of the internal wiring LHb and the upper electrode Zu [m] of the piezoelectric element PZ [m] provided in the discharge portion D [m] according to the connection state designation signal SLb [m]. Switch between conducting and non-conducting. In the present embodiment, as an example, it is assumed that the switch SWb [m] is turned on when the connection state designation signal SLb [m] is at a high level and is turned off when the connection state designation signal SLb [m] is at a low level.
Of the drive signals Com-A and Com-B, the signal actually supplied to the piezoelectric element PZ [m] of the discharge unit D [m] via the switch SWa [m] or SWb [m] is transmitted. It may be referred to as a supply drive signal Vin [m].

<< 4. Operation of head unit >>
Hereinafter, the operation of each head unit HU will be described with reference to FIGS. 6 to 8.

In the present embodiment, the operating period of the inkjet printer 1 includes one or more unit periods Tu. Then, the inkjet printer 1 can execute the printing process in each unit period Tu. Strictly speaking, the inkjet printer 1 can execute a process of driving each ejection unit D to eject ink from each ejection unit D in each unit period Tu. Then, the inkjet printer 1 repeatedly executes the printing process over a plurality of continuous or intermittent unit periods Tu, and ejects ink from each ejection unit D one or a plurality of times, thereby indicating the print data Img. Form an image.

FIG. 6 is a timing chart for explaining the operation of the inkjet printer 1 in the unit period Tu.
As shown in FIG. 6, the control unit 6 outputs a latch signal LAT having a pulse PlsL and a change signal CNG having a pulse PlsC. As a result, the control unit 6 defines the unit period Tu as the period from the rise of the pulse PlsL to the rise of the next pulse PlsL. Further, the control unit 6 divides the unit period Tu into two control periods Ts1 and Ts2 by the pulse PlsC.
The print signal SI includes individually designated signals Sd [1] to Sd [M] that specify the driving mode of the discharge units D [1] to D [M] in each unit period Tu. Then, when the printing process is executed in the unit period Tu, the control unit 6 includes the individually designated signals Sd [1] to Sd [M] prior to the start of the unit period Tu, as shown in FIG. The print signal SI is supplied to the connection state designation circuit 32 in synchronization with the clock signal CLK. In this case, the connection state designation circuit 32 generates the connection state designation signals SLa [m] and SLb [m] based on the individual designation signal Sd [m] in the unit period Tu.

As shown in FIG. 6, the drive signal generation circuit 20 outputs a drive signal Com-A having a waveform PX provided in the control period Ts1 and a waveform PY provided in the control period Ts2. In the present embodiment, the waveform PX and the waveform PY are determined so that the potential difference between the maximum potential VHX and the minimum potential VLX of the waveform PX is larger than the potential difference between the maximum potential VHY and the minimum potential VLY of the waveform PY. Specifically, when the ejection unit D [m] is driven by the drive signal Com-A having the waveform PX, an amount (medium amount) of ink corresponding to a medium dot is ejected from the ejection unit D [m]. As described above, the waveform of the waveform PX is determined. Further, when the ejection unit D [m] is driven by the drive signal Com-A having the waveform PY, the amount of ink corresponding to the small dots (a small amount) is ejected from the ejection unit D [m]. , Waveform PY waveform is determined. The potentials at the start and end of the waveform PX and the waveform PY are set to the reference potential V0.
Further, the drive signal generation circuit 20 outputs a drive signal Com-B having two waveforms PB provided in each of the control periods Ts1 and Ts2. In the present embodiment, the waveform PB is defined so that the potential difference between the maximum potential VHB and the minimum potential VLB of the waveform PB is smaller than the potential difference between the maximum potential VHY and the minimum potential VLY of the waveform PY. Specifically, when the ejection unit D [m] is driven by the drive signal Com-B having the waveform PB, the ejection unit D [m] is driven to such an extent that ink is not ejected from the ejection unit D [m]. The waveform of the waveform PB is determined. In the waveform PB, the potentials at the start and end are set to the reference potential V0. Further, in the present embodiment, the maximum potential VHB is assumed to be the reference potential V0.

FIG. 7 is an explanatory diagram for explaining an example of the relationship between the individually designated signal Sd [m] and the connection state designation signals SLa [m] and SLb [m] in the unit period Tu.
As shown in FIG. 7, in the present embodiment, it is assumed that the individually designated signal Sd [m] is a 2-bit digital signal (see FIG. 7). Specifically, the individually designated signal Sd [m] ejects an amount of ink (a large amount) corresponding to a large dot (“large dot)” with respect to the ejection unit D [m] in each unit period Tu. A value (1,1) that specifies (sometimes referred to as "formation of"), and a value (1,0) that specifies a medium amount of ink ejection (sometimes referred to as "formation of medium dots"). , A value (0,1) that specifies the ejection of a small amount of ink (sometimes referred to as "formation of small dots"), and a value (0,0) that specifies the non-ejection of ink. It is set to any one of the values.

When the individual designation signal Sd [m] is set to a value (1,1) that specifies the formation of large dots, the connection state designation circuit 32 sets the connection state designation signal SLa [m] to the control period Ts1 and It is set to a high level in Ts2, and the connection state designation signal SLb [m] is set to a low level in the control periods Ts1 and Ts2. In this case, the ejection unit D [m] is driven by the drive signal Com-A of the waveform PX during the control period Ts1 to eject a medium amount of ink, and the drive signal Com- of the waveform PY during the control period Ts2. Driven by A, it ejects a small amount of ink. As a result, the ejection unit D [m] ejects a large amount of ink in total in the unit period Tu, and large dots are formed on the recording paper P.
When the individual designation signal Sd [m] is set to a value (1,0) that specifies the formation of the middle dot, the connection state designation circuit 32 sets the connection state designation signal SLa [m] in the control period Ts1. It is set to a high level and a low level in the control period Ts2, and the connection state designation signal SLb [m] is set to a low level in the control period Ts1 and a high level in the control period Ts2, respectively. In this case, the ejection unit D [m] ejects a medium amount of ink in the unit period Tu, and medium dots are formed on the recording paper P.
When the individual designation signal Sd [m] is set to a value (0, 1) that specifies the formation of small dots, the connection state designation circuit 32 sets the connection state designation signal SLa [m] in the control period Ts1. The low level is set to the high level in the control period Ts2, and the connection state designation signal SLb [m] is set to the high level in the control period Ts1 and the low level in the control period Ts2, respectively. In this case, the ejection unit D [m] ejects a small amount of ink in the unit period Tu, and small dots are formed on the recording paper P.
When the individually specified signal Sd [m] is set to a value (0, 0) that specifies non-ejection of ink, the connection state specification circuit 32 controls the connection state specification signal SLa [m] during the control periods Ts1 and Ts2. Is set to a low level, and the connection state designation signal SLb [m] is set to a high level during the control periods Ts1 and Ts2. In this case, the ejection unit D [m] does not eject ink and does not form dots on the recording paper P in the unit period Tu.

FIG. 8 is a diagram showing an example of the configuration of the connection state designation circuit 32 according to the present embodiment. As shown in FIG. 8, the connection state designation circuit 32 generates connection state designation signals SLa [1] to SLa [M] and connection state designation signals SLb [1] to SLb [M].
Specifically, the connection state designation circuit 32 has a transfer circuit SR [1] to SR [M] and a latch circuit LT [M] so as to have a one-to-one correspondence with the discharge units D [1] to D [M]. It has 1] to LT [M] and decoders DC [1] to DC [M]. Of these, the individually designated signal Sd [m] is supplied to the transfer circuit SR [m]. In this figure, the individually designated signals Sd [1] to Sd [M] are supplied serially. For example, the individually designated signals Sd [m] corresponding to the m stage are transferred from the transfer circuit SR [1] to the transfer circuit SR. The case where the clock signal is sequentially transferred to [m] in synchronization with the clock signal CLK is illustrated. Further, the latch circuit LT [m] latches the individually designated signal Sd [m] supplied to the transfer circuit SR [m] at the timing when the pulse PlsL of the latch signal LAT rises to a high level. Further, the decoder DC [m] generates connection state designation signals SLa [m] and SLb [m] according to FIG. 7 based on the individual designation signal Sd [m], the latch signal LAT, and the change signal CNG. ..

<< 5. Connection between drive signal generation module and liquid discharge head >>
Hereinafter, with reference to FIG. 9, a configuration for electrically connecting the drive signal generation module 2 and the liquid discharge head 3 and the like will be described.
FIG. 9 shows a configuration for electrically connecting the drive signal generation module 2 and the liquid discharge head 3, a configuration for electrically connecting the control unit 6 and the drive signal generation module 2, and the control unit 6 and the liquid. It is explanatory drawing for demonstrating the structure for electrically connecting the discharge head 3.
In addition, in this specification, "electrical connection" is a concept including not only the case of being physically directly connected but also the case of being indirectly connected via a conductive substance or the like.

As shown in FIG. 9, the inkjet printer 1 includes a control board 600 provided with a control unit 6, a drive board 200 provided with four drive signal generation circuits 20 included in the drive signal generation module 2, and a liquid. A head substrate 300 provided with four discharge modules 30 included in the discharge head 3 is provided. Further, the inkjet printer 1 includes an FFC (Flexible Flat Cable) 80 for electrically connecting the control board 600 and the drive board 200, and an FFC 81 for electrically connecting the drive board 200 and the head board 300. The FFC 82, the drive-side relay board 201, the head-side relay board 301, and the FFC 83 and the FFC 84 for electrically connecting the control board 600 and the head board 300 are provided.

As shown in FIG. 9, in the present embodiment, as an example, it is assumed that the inkjet printer 1 includes four FFC 80s. The control board 600 is provided with four connectors Ca for connecting to the four FFC 80s, and the drive board 200 is provided with four connectors Cb for connecting to the four FFC 80s. Be done. One end of each FFC 80 is connected to the connector Ca, and the other end is connected to the connector Cb. As a result, the control unit 6 can supply the waveform designation signal dCom to the drive signal generation circuit 20 via the connector Ca, the FFC 80, and the connector Cb.

Further, in the present embodiment, as an example, when the inkjet printer 1 includes four FFC81s, four FFC82s, four drive-side relay boards 201, and four head-side relay boards 301. Is assumed.
Then, the drive board 200 is provided with four connectors Cc for connecting to the four drive-side relay boards 201. Further, each drive side relay board 201 has one connector Cd for connecting to the drive board 200, one connector Ce1 for connecting to the FFC 81, and one connector Ce2 for connecting to the FFC 82. And are provided. Then, the connector Cd of each drive-side relay board 201 is connected to the connector Cc of the drive board 200.
On the other hand, the head board 300 is provided with four connector Chs for connecting to the four head-side relay boards 301. Further, each head-side relay board 301 has one connector Cg for connecting to the head board 300, one connector Cf1 for connecting to FFC81, and one connector Cf2 for connecting to FFC82. And are provided. Then, the connector Cg of each head-side relay board 301 is connected to the connector Ch of the head board 300.
Then, one end of each FFC81 is connected to the connector Ce1 and the other end is connected to the connector Cf1. Further, one end of each FFC 82 is connected to the connector Ce2, and the other end is connected to the connector Cf2.

As a result, the drive signal generation circuit 20 passes through the connector Cc, the connector Cd, the drive side relay board 201, the connector Ce1, FFC81, the connector Cf1, the head side relay board 301, the connector Cg, and the connector Ch (hereinafter, The path is referred to as a "first path"), the drive signal Com is supplied to the drive signal supply circuit 31, and the connector Cc, connector Cd, drive side relay board 201, connector Ce2, FFC82, connector Cf2, and head. The drive signal Com can be supplied to the drive signal supply circuit 31 via the side relay board 301, the connector Cg, and the connector Ch (hereinafter, the path is referred to as a “second path”).

In the following, among the drive signal Coms supplied from the drive signal generation circuit 20 to the drive signal supply circuit 31, the drive signal Com supplied to the drive signal supply circuit 31 via the first path including the FFC 81 is referred to as ". The drive signal Com supplied to the drive signal supply circuit 31 via the second path including the FFC 82 is referred to as a “first drive signal”, and is referred to as a “second drive signal”. That is, in the present embodiment, the drive signal generation circuit 20 supplies the first drive signal to the drive signal supply circuit 31 by the first path, and supplies the second drive signal to the drive signal supply circuit 31 by the second path. Supply.
In the present embodiment, the first drive signal includes the drive signal Com-A and the drive signal Com-B, and the second drive signal includes the drive signal Com-A and the drive signal Com-B. That is, in the present embodiment, it is assumed that the first drive signal and the second drive signal are the same signal.
However, the present invention is not limited to such an aspect, and the first drive signal and the second drive signal may be different signals. For example, the drive signal generation circuit 20 may supply the drive signal Com-A as the first drive signal and the drive signal Com-B as the second drive signal to the drive signal supply circuit 31.

Further, in the present embodiment, one of the connector Cc and the connector Cd is a receptacle type connector, and the other of the connector Cc and the connector Cd is a header type connector. At least one of the connector Cc and the connector Cd is a connector having a floating structure. Therefore, even when the relative positional relationship between the FFC 81 and the drive board 200 or between the FFC 82 and the drive board 200 changes due to vibration or the like, the drive side relay board 201 is the drive board 200. It is possible to prevent the drive board 201 and the drive board 200 from being disconnected from each other and maintain the connected state of the drive side relay board 201 and the drive board 200.
Further, the connector Cc and the connector Cd are connected by a two-point contact structure, and the effective fitting length is 1.5 mm or more. Therefore, it is possible to more reliably maintain the electrical connection between the connector Cc and the connector Cd.
Further, the connector Cc and the connector Cd are provided with a plurality of pins, and the current capacity per pin is 0.5 ampere or more. Therefore, a large current signal can be transmitted via the connector Cb and the connector Cd.
Further, the connector Cc and the connector Cd are connectors that can be washed with an organic solvent-based detergent. Therefore, when foreign matter such as ink adheres to the connector Cc or the connector Cd, the foreign matter can be easily removed.

Further, in the present embodiment, one of the connector Cg and the connector Ch is a receptacle type connector, and the other of the connector Cg and the connector Ch is a header type connector. At least one of the connector Cg and the connector Ch is a connector having a floating structure. Therefore, even when the relative positional relationship between the FFC 81 and the head substrate 300 or between the FFC 82 and the head substrate 300 changes due to vibration or the like, the head side relay substrate 301 is the head substrate 300. It is possible to prevent the head board 301 from coming off and maintain the state in which the head board 301 and the head board 300 are connected.
Further, the connector Cg and the connector Ch are connected by a two-point contact structure, and the effective fitting length is 1.5 mm or more. Therefore, it is possible to more reliably maintain the electrical connection between the connector Cg and the connector Ch.
Further, the connector Cg and the connector Ch include a plurality of pins, and the current capacity per pin is 0.7 amperes or more. Therefore, a large current signal can be transmitted via the connector Cg and the connector Ch.
Further, the connector Cg and the connector Ch are connectors that can be washed with an organic solvent-based detergent. Therefore, when foreign matter such as ink adheres to the connector Cg or the connector Ch, the foreign matter can be easily removed.
The connector Cg and the connector Ch are low-profile connectors having a thickness of 5 mm or less. Therefore, even if the inkjet printer 1 is, for example, a small printer and there is no space inside the inkjet printer 1, the FFC 81 and FFC 82 are electrically connected to the head substrate 300 via the head-side relay substrate 301. Wiring can be provided to connect to.

Further, in the present embodiment, the control board 600 is provided with a connector Ci1 for connecting to the FFC83 and a connector Ci2 for connecting to the FFC84, and the head board 300 is provided with a connector for connecting to the FFC83. Cj1 and a connector Cj2 for connecting to the FFC84 are provided.
Then, the control unit 6 supplies the print signal SI, the clock signal CLK, the latch signal LAT, and the change signal CNG to the drive signal supply circuit 31 via the connectors Ci1, FFC83, and the connector Cj1. be able to.
Further, in the present embodiment, the head substrate 300 detects the residual vibration generated in the discharge unit D after the discharge unit D is driven by the drive signal Com (supply drive signal Vin), and shows the result of the detection. A residual vibration detection circuit (not shown) that outputs a vibration signal and a temperature detection circuit (not shown) that measures the temperature of the liquid discharge head 3 and outputs a temperature measurement signal indicating the measurement result are provided. Then, the residual vibration detection circuit and the temperature detection circuit can supply the residual vibration signal and the temperature measurement signal to the control unit 6 via the connectors Cj2, FFC84, and the connector Ci2. In the present embodiment, the control unit 6 can determine whether or not the ejection unit D can normally eject the ink based on the residual vibration signal, and based on the temperature measurement signal. , It can be determined whether or not the liquid discharge head 3 maintains a temperature equal to or lower than a predetermined temperature.

<< 6. Conclusion of the embodiment >>
As described above, the liquid discharge head 3 according to the present embodiment has a large number of discharge portions D having a high density so that printing with a dot density of 600 dpi or more is possible over a range YNL of 297 mm or more. It is an arranged line head. That is, in the inkjet printer 1 according to the present embodiment, the number of ejection portions D provided in the liquid ejection head 3 is larger than that in the serial printer or the like in which the liquid ejection head reciprocates in the Y-axis direction to execute the printing process. There are many. Therefore, the inkjet printer 1 according to the present embodiment requires a large amount of electric power to drive the liquid discharge head 3 as compared with a serial printer or the like.
On the other hand, the inkjet printer 1 according to the present embodiment supplies the drive signal Com for driving the liquid discharge head 3 from the drive signal generation circuit 20 to the drive signal supply circuit 31, and includes the FFC 81. It is executed by the route and the second route including the FFC82. Therefore, even when the liquid discharge head 3 has a large number of discharge portions D and a large amount of electric power is required to drive the liquid discharge head 3, the drive signal Com required for driving the liquid discharge head 3 is discharged. It can be supplied to the head 3.

Further, in the present embodiment, the FFC 81 and the FFC 82 are electrically connected to the head substrate 300 via the head side relay substrate 301. That is, according to the present embodiment, when the FFC 81 and the FFC 82 are attached / detached from the head substrate 300, the head side relay substrate 301 may be attached / detached from the head substrate 300. Therefore, in the present embodiment, the FFC 81 and the FFC 82 can be easily attached to and detached from the head substrate 300 as compared with the case where the FFC 81 and the FFC 82 are directly connected to the head substrate 300 without the head side relay substrate 301. It becomes. Therefore, according to the present embodiment, it is possible to improve maintainability when the liquid discharge head 3 is repaired or the like.
Further, according to the present embodiment, since the attachment / detachment of the FFC81 and FFC82 from the head substrate 300 is replaced by the attachment / detachment of the head side relay substrate 301 from the head substrate 300, each of the FFC81 and FFC82 is directly attached to the head substrate 300. Compared with the case of being connected, it is possible to suppress the number of times the FFC 81 and the FFC 82 are actually attached and detached from the substrate. Therefore, deterioration and failure of FFC81 and FFC82 can be suppressed.

Further, in the present embodiment, the FFC 81 and the FFC 82 are electrically connected to the drive board 200 via the drive side relay board 201. That is, according to the present embodiment, when the FFC 81 and the FFC 82 are attached / detached from the drive board 200, the drive side relay board 201 may be attached / detached from the drive board 200. Therefore, in the present embodiment, the FFC 81 and the FFC 82 can be easily attached to and detached from the drive board 200 as compared with the case where the FFC 81 and the FFC 82 are directly connected to the drive board 200 without the drive side relay board 201. It becomes. Therefore, according to the present embodiment, it is possible to improve maintainability when the drive signal generation module 2 is repaired or the like.
Further, according to the present embodiment, since the attachment / detachment of the FFC81 and FFC82 from the drive board 200 is replaced by the attachment / detachment of the drive side relay board 201 from the drive board 200, each of the FFC81 and FFC82 is directly attached to the drive board 200. Compared with the case of being connected, it is possible to suppress the number of times the FFC 81 and the FFC 82 are actually attached to and detached from the substrate. Therefore, deterioration and failure of FFC81 and FFC82 can be suppressed.

In the present embodiment, the head-side relay board 301 connected to the head board 300 is an example of the "relay board", and the FFC 81 to which the first drive signal is supplied is an example of the "first wiring". The FFC 82 to which the two drive signals are supplied is an example of the “second wiring”, and the connector Cf1 provided on the head side relay board 301 and connected to the FFC 81 is an example of the “first connector” and is attached to the head side relay board 301. The connector Cf2 provided and connected to the FFC 82 is an example of a “second connector”, and the connector Cg provided on the head side relay board 301 and connected to the head board 300 is an example of a “relay connector” and is provided on the head board 300. The connector Ch connected to the connector Cg is an example of a “head side connector”.

<< B. Modification example >>
Each of the above forms can be transformed in various ways. A specific mode of modification is illustrated below. Two or more embodiments arbitrarily selected from the following examples can be appropriately merged within a mutually consistent range. For the elements whose actions and functions are the same as those of the embodiment in the modified examples illustrated below, the reference numerals referred to in the above description will be diverted and detailed description of each will be omitted as appropriate.

<< Modification 1 >>
In the above-described embodiment, the drive-side relay board 201 and the head-side relay board 301 are electrically connected by two FFCs (FFC81 and FFC82), but the present invention is not limited to such an embodiment. Instead, the drive-side relay board 201 and the head-side relay board 301 may be connected by three or more FFCs. In this case, the drive signal Com required for driving the liquid discharge head 3 can be supplied to the liquid discharge head 3 which requires a large amount of electric power to drive.

<< Modification 2 >>
In the above-described embodiments and modifications, the components for electrically connecting the drive board 200 and the head board 300 include the drive side relay board 201 and the head side relay board 301. The components for electrically connecting the drive board 200 and the head board 300 include at least one of the drive side relay board 201 and the head side relay board 301. Just do it.
For example, the inkjet printer 1 may be configured without the drive-side relay board 201, and the drive board 200 and the head board 300 may be electrically connected by the FFC 81 and FFC 82 and the head-side relay board 301. In this case, the FFC 81 and FFC 82 may be directly connected to the connector provided on the drive board 200.
Further, for example, the inkjet printer 1 may be configured without the head-side relay board 301, and the drive board 200 and the head board 300 may be electrically connected by the FFC 81 and FFC 82 and the drive-side relay board 201. In this case, the FFC 81 and FFC 82 may be directly connected to the connector provided on the head substrate 300.

<< Modification 3 >>
In the above-described embodiment and modification, the liquid discharge head 3 includes four head units HU, but the present invention is not limited to such an embodiment, and the liquid discharge head 3 is one or more head units. It suffices to have a HU.

Further, in the above-described embodiments and modifications, the drive signal generation module 2 is provided with the drive signal generation circuit 20 so as to have a one-to-one correspondence with the head unit HU, but the present invention is limited to such an embodiment. The drive signal generation module 2 may be provided with two or more drive signal generation circuits 20 for one head unit HU, or may be provided for two or more head unit HUs. One drive signal generation circuit 20 may be provided. For example, the drive signal generation module 2 has a drive signal generation circuit 20 for supplying a drive signal Com-A and a drive for supplying a drive signal Com-B corresponding to one head unit HU. Two drive signal generation circuits 20 of the signal generation circuit 20 may be provided. Further, for example, the drive signal generation module 2 is provided with one drive signal generation circuit 20 for supplying the drive signal Com-A and the drive signal Com-B corresponding to the two head units HU. You may.

Further, in the above-described embodiments and modifications, the inkjet printer 1 includes a set of one or both of the drive-side relay board 201 and the head-side relay board 301, FFC81, and FFC82 (hereinafter, the set is referred to as a "relay member". ”) Is provided so as to have a one-to-one correspondence with the head unit HU, but the present invention is not limited to such an embodiment, and the inkjet printer 1 has one head unit HU. On the other hand, two or more relay members may be provided, or one relay member may be provided for two or more head unit HUs.

<< Modification 4 >>
In the above-described embodiment and modification, the control unit 6 is provided on the control board 600, and the drive signal generation circuit 20 of the drive signal generation module 2 is provided on the drive board 200, but the present invention is limited to such an embodiment. The control unit 6 and the drive signal generation circuit 20 may be provided on the same substrate.

1 ... Inkjet printer, 2 ... Drive signal generation module, 3 ... Liquid discharge head, 5 ... Storage unit, 6 ... Control unit, 7 ... Conveyance mechanism, 20 ... Drive signal generation circuit, 30 ... Discharge module, 31 ... Drive signal supply Circuit, 80 ... FFC, 81 ... FFC, 82 ... FFC, 200 ... Drive board, 201 ... Drive side relay board, 300 ... Head board, 301 ... Head side relay board, 600 ... Control board, Cc ... Connector, Cd ... Connector , Ce1 ... Connector, Ce2 ... Connector, Cf1 ... Connector, Cf2 ... Connector, Cg ... Connector, Ch ... Connector.

Claims (7)

A liquid discharge head that discharges liquid and
A supply wiring to which a drive signal including a first drive signal and a second drive signal for driving the liquid discharge head is supplied, and
From the supply wiring to the liquid discharge head
A relay board that relays the drive signal and
With
The relay board
A plurality of supply connectors to be connected to the supply wiring,
A relay connector that connects to the head-side connector of the liquid discharge head,
With
The number of the relay connectors provided on the relay board is smaller than the number of supply connectors provided on the relay board.
The relay connector
For the head side connector
Outputs the drive signal supplied to the plurality of supply connectors.
A liquid discharge device characterized by the fact that. The liquid discharge head
For recording media with a width of 297 mm or more
A line head capable of printing at a dot density of 600 dpi or more.
The liquid discharge device according to claim 1, wherein the liquid discharge device is characterized in that. One of the relay connector and the head side connector
It is a receptacle type connector and
The other of the relay connector and the head side connector is
It is a header type connector and
One or both of the relay connector and the head side connector
Has a floating structure,
The liquid discharge device according to claim 1 or 2, wherein the liquid discharge device is characterized in that. The relay connector and the head side connector are
Connect with a two-point contact structure,
The liquid discharge device according to any one of claims 1 to 3, wherein the liquid discharge device is characterized in that. The relay connector and the head side connector are
Has a current capacity of 0.7 amperes or more per pin,
The liquid discharge device according to any one of claims 1 to 4, wherein the liquid discharge device is characterized in that. The relay connector and the head side connector are
Effective mating length is 1.5 mm or more,
The liquid discharge device according to any one of claims 1 to 5, wherein the liquid discharge device is characterized in that. The relay connector and the head side connector are
The thickness is 5 mm or less,
The liquid discharge device according to any one of claims 1 to 6, wherein the liquid discharge device is characterized in that.

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