阅读说明：本技术 液体喷出装置 (Liquid ejecting apparatus ) 是由 竹内祐子 泷上雄太 西村秀彰 大谷胜彦 于 2020-11-26 设计创作，主要内容包括：提供一种液体喷出装置,能够减少由于布线阻抗等的影响而使控制信号的传输精度降低、形成于介质的图像的质量降低的可能性。在具有对介质喷出液体的喷出头的液体喷出装置中,具备：第一部件及第二部件,为了对介质喷出液体而驱动；第一控制电路及第二控制电路,控制喷出头的驱动；第一控制电路基板,设置有第一控制电路；以及第二控制电路基板,其设置有第二控制电路,第一部件与第一控制电路电连接,第二部件与第二控制电路电连接,第一控制电路基板与第一部件的最短距离比第一控制电路基板与第二部件的最短距离短,第二控制电路基板与第二部件的最短距离比第二控制电路基板与第一部件的最短距离短。(Provided is a liquid discharge device capable of reducing the possibility of deterioration in transmission accuracy of a control signal and deterioration in quality of an image formed on a medium due to the influence of wiring resistance and the like. A liquid ejecting apparatus having an ejection head that ejects liquid onto a medium, includes: a first member and a second member that are driven to eject a liquid onto a medium; a first control circuit and a second control circuit for controlling the driving of the ejection head; a first control circuit substrate provided with a first control circuit; and a second control circuit board provided with a second control circuit, the first component being electrically connected to the first control circuit, the second component being electrically connected to the second control circuit, the shortest distance between the first control circuit board and the first component being shorter than the shortest distance between the first control circuit board and the second component, the shortest distance between the second control circuit board and the second component being shorter than the shortest distance between the second control circuit board and the first component.)

1. A liquid ejection device is characterized in that,

the liquid ejecting apparatus includes an ejection head that ejects liquid onto a medium by driving the ejection head,

the liquid ejecting apparatus includes:

a first member and a second member that are driven to eject a liquid onto the medium;

a first control circuit and a second control circuit for controlling the driving of the ejection head;

a first control circuit substrate on which the first control circuit is provided; and

a second control circuit board on which the second control circuit is provided,

the first component is electrically connected to the first control circuit,

the second component is electrically connected to the second control circuit,

the shortest distance between the first control circuit board and the first component is shorter than the shortest distance between the first control circuit board and the second component,

the shortest distance between the second control circuit board and the second member is shorter than the shortest distance between the second control circuit board and the first member.

2. The liquid ejection device according to claim 1,

the liquid ejecting apparatus includes:

a case that houses the first member, the second member, the first control circuit board, and the second control circuit board; and

a transport section that transports the medium from which the liquid is ejected from the ejection head,

the housing includes a first face and a second face,

the first surface and the second surface are provided so as to overlap at least partially in a width direction of the medium that intersects a conveyance direction in which the medium is conveyed by the conveyance unit,

the shortest distance between the first control circuit board and the first surface is shorter than the shortest distance between the first control circuit board and the second surface,

the shortest distance between the second control circuit board and the second surface is shorter than the shortest distance between the second control circuit board and the first surface.

3. The liquid ejection device according to claim 2,

the shortest distance between the first control circuit board and the first surface is shorter than the shortest distance between the conveying unit and the first surface,

the shortest distance between the second control circuit board and the second surface is shorter than the shortest distance between the conveying section and the second surface.

4. The liquid ejection device according to any one of claims 1 to 3,

the liquid ejecting apparatus includes:

a drive signal output circuit that outputs a drive signal for driving the ejection head; and

a drive circuit board provided with the drive signal output circuit,

the second member includes the driving circuit substrate.

5. The liquid ejection device according to any one of claims 1 to 3,

the second component comprises an electric motor that converts electrical energy into mechanical energy.

6. The liquid ejection device according to any one of claims 1 to 3,

the driving of the ejection head is controlled based on an image signal input from an input terminal,

the first component includes the input terminal.

7. The liquid ejection device according to any one of claims 1 to 3, comprising:

a first mode in which liquid can be ejected from the ejection head; and

a second mode in which liquid is not ejected from the ejection head, the power consumption being smaller than that in the first mode,

in the second mode, the second control circuit stops operating.

Technical Field

The present invention relates to a liquid discharge apparatus.

Background

In an ink jet printer as an example of a liquid ejecting apparatus, the following techniques are known: a control signal generated by a control circuit or the like provided in an ink jet printer main body is transmitted to a print head (ejection head) having nozzles for ejecting ink, and the timing of ejection of ink is controlled based on the control signal to print an image, a document, or the like on a medium.

For example, patent document 1 discloses a liquid discharge apparatus including: a control signal generating unit as a control circuit generates a control signal corresponding to image data supplied from an external host, and controls, based on the control signal, the conveyance of a medium such as paper and the driving of each unit included in a liquid ejecting apparatus such as a head that ejects ink, thereby forming an image including characters, graphics, and the like corresponding to the supplied image data on the medium.

Patent document 1: japanese patent laid-open publication No. 2018-158487

Disclosure of Invention

However, in the liquid discharge apparatus described in patent document 1, since each part of the liquid discharge apparatus driven by the control signal output from the control circuit is disposed in a dispersed manner inside the liquid discharge apparatus, the wiring for transmitting the control signal becomes long, and as a result, the transmission accuracy of the control signal is lowered due to the influence of the wiring impedance or the like, and there is a possibility that the quality of an image formed on a medium is lowered.

In one aspect of the liquid ejecting apparatus of the present invention,

a liquid ejecting apparatus having an ejection head that ejects liquid onto a medium by driving, the liquid ejecting apparatus comprising:

a first member and a second member that are driven to eject a liquid onto the medium;

a first control circuit and a second control circuit that control driving of the ejection head;

a first control circuit board on which the first control circuit is provided; and

a second control circuit board on which the second control circuit is provided,

the first component is electrically connected to the first control circuit,

the second component is electrically connected to the second control circuit,

the shortest distance between the first control circuit board and the first component is shorter than the shortest distance between the first control circuit board and the second component,

the shortest distance between the second control circuit board and the second member is shorter than the shortest distance between the second control circuit board and the first member.

In one aspect of the liquid ejecting apparatus, the liquid ejecting apparatus includes:

a case that houses the first member, the second member, the first control circuit board, and the second control circuit board; and

a transport unit that transports the medium from which the liquid is ejected from the ejection head,

the housing includes a first face and a second face,

the first surface and the second surface are provided so as to overlap at least partially in a width direction of the medium that intersects a conveyance direction in which the medium is conveyed by the conveyance unit,

the shortest distance between the first control circuit board and the first surface is shorter than the shortest distance between the first control circuit board and the second surface,

the shortest distance between the second control circuit board and the second surface is shorter than the shortest distance between the second control circuit board and the first surface.

In one mode of the liquid ejecting apparatus,

the shortest distance between the first control circuit board and the first surface is shorter than the shortest distance between the conveying unit and the first surface,

the shortest distance between the second control circuit board and the second surface is shorter than the shortest distance between the conveying section and the second surface.

In one aspect of the liquid ejecting apparatus, the liquid ejecting apparatus may include:

a drive signal output circuit that outputs a drive signal for driving the ejection head; and

a drive circuit substrate provided with the drive signal output circuit,

the second member includes the driving circuit substrate.

In one mode of the liquid ejecting apparatus,

the second component comprises an electric motor that converts electrical energy into mechanical energy.

In one mode of the liquid ejecting apparatus,

the driving of the ejection head is controlled based on an image signal input from an input terminal,

the first component includes the input terminal.

In one aspect of the liquid ejecting apparatus, the liquid ejecting apparatus may include:

a first mode capable of ejecting liquid from the ejection head; and

a second mode in which liquid is not ejected from the ejection head, the second mode consuming less power than the first mode,

in the second mode, the second control circuit stops operating.

Drawings

Fig. 1 is an overall perspective view showing an external configuration of a liquid ejecting apparatus.

Fig. 2 is a cross-sectional view schematically showing a part of the internal configuration of the liquid ejection device.

Fig. 3 is an overall view schematically showing a part of the internal configuration of the liquid ejection device.

Fig. 4 is a diagram showing an electrical configuration of the liquid ejection device.

Fig. 5 is a diagram showing an example of waveforms of the drive signals COMA and COMB.

Fig. 6 is a diagram showing an example of the waveform of the drive signal VOUT.

Fig. 7 is a diagram showing a configuration of the drive signal selection circuit.

Fig. 8 is a diagram showing decoded contents of a decoder.

Fig. 9 is a diagram showing a configuration of the selection circuit.

Fig. 10 is a diagram for explaining an operation of the drive signal selection circuit.

Fig. 11 is a diagram showing the configuration of the ejection section.

Fig. 12 is a diagram for explaining the arrangement of the circuit boards when the liquid ejecting apparatus is viewed from the + Z side.

Fig. 13 is a diagram for explaining the arrangement of the circuit boards when the liquid ejecting apparatus is viewed from the + Y side.

Description of the reference numerals

1 … liquid ejection device, 2 … body, 3 … leg, 10 … housing, 11 … front wall, 12 … rear wall, 13 … first side wall, 14 … second side wall, 15 … upper wall, 20 … pedestal, 21 … storage section, 22 … medium, 23 … core member, 24 … scroll, 25 … opening, 31 … first holding section, 32 … second holding section, 33 … drive section, 35 … recording section, 36 … support table, 37 … guide shaft, 38 … carriage, 39 … head, 40 … carriage motor, 41 side frame … medium transport region, 45 … transport section, 46 … transport path forming section, 47 … intermediate roller, 48 … transport roller, 49 … transport path, 50 … paper exit member, 51 … cutting section, 53 side frame … paper exit, 57 … loading section, … maintenance unit, 3659 operation section, … operation section, power supply element side base plate, … electric power supply section, … base plate, … side, … electric power supply section, …, 101 … power supply voltage output circuit, 110 … first control circuit substrate, 111 … control circuit, 120 … second control circuit substrate, 121 … control circuit, 122 … differential signal conversion circuit, 123 … serial signal conversion circuit, 130 … drive circuit substrate, 131 … parallel signal recovery circuit, 132-1 to 132-n … drive circuit, 140 … ejection control circuit substrate, 141 … differential signal recovery circuit, 142 … temperature abnormality detection circuit, 150 to 159 … cable, 161, 162 … terminal, 200 … drive signal selection circuit, 220 … selection control circuit, 222 … shift register, 224 … latch circuit, 226 … decoder, 230 … selection circuit, 232a, 232b … inverter, 234a, 234b … transmission gate, 432 … shift register, 600 … ejection portion, 601 … piezoelectric body, 611, 612 … electrode, 621 …, 631 … cavity, 632 … nozzle plate, 641 … reservoir, 651 … nozzle, 661 … ink supply port.

Detailed Description

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are used for ease of illustration. The embodiments described below are not unreasonably restrictive to the contents of the present invention described in the claims. All the configurations described below are not necessarily essential to the present invention.

Here, in the present embodiment, an ink jet printer capable of printing on a large-sized medium having a short side width of a3(297mm) or more is described as an example of a liquid ejecting apparatus, and a so-called large format printer is used. Further, roll paper wound around a core member to form a roll will be described as an example of a medium for ejecting ink from the liquid ejecting apparatus according to the present embodiment. The type of medium from which the liquid ejecting apparatus ejects the ink is not limited to this, and may be, for example, paper cut into a predetermined size, fabric, or the like.

1. Structure of liquid ejecting apparatus

The external appearance structure of the liquid ejecting apparatus 1 according to the present embodiment will be described with reference to fig. 1 to 3. Fig. 1 is an overall perspective view showing an external configuration of the liquid ejecting apparatus 1. Fig. 2 is a cross-sectional view schematically showing a part of the internal configuration of the liquid ejection device 1. Fig. 3 is an overall view schematically showing a part of the internal configuration of the liquid ejection device 1.

As shown in fig. 1, the liquid discharge apparatus 1 includes a main body 2 and a plurality of leg portions 3. The main body 2 has a substantially rectangular parallelepiped shaped housing 10. The housing 10 has a front wall 11, a rear wall 12, a first side wall 13, a second side wall 14, and an upper wall 15. The housing 10 is coupled to a base frame 20 supported by the leg 3.

Here, in the liquid ejecting apparatus 1, a direction in which the base frame 20 faces the upper wall 15 is referred to as a height direction of the liquid ejecting apparatus 1, a direction in which the first side wall 13 faces the second side wall 14 in a direction along a plane orthogonal to the height direction is referred to as a width direction, and a direction in which the front wall 11 faces the rear wall 12 in a direction orthogonal to the width direction in a plane orthogonal to the height direction is referred to as a front-rear direction. In the liquid discharge apparatus 1, when the width direction and the front-rear direction are arranged on a horizontal plane, the height direction is parallel to the gravity direction. In the following description, the width direction is shown as a direction X, the front-rear direction is shown as a direction Y, and the height direction is shown as a direction Z. The side of the arrow in the direction X shown in the figure may be referred to as the + X side, the side of the arrow start point as the-X side, the side of the arrow start point in the direction Y as the + Y side, the side of the arrow start point as the-Y side, the side of the arrow start point in the direction Z as the + Z side, and the side of the arrow start point as the-Z side.

As shown in fig. 1 and 2, the main body 2 has a housing portion 21. The main body 2 of the housing portion 21 houses a cylindrical roll 24 in which an image-forming medium 22 is wound around a core member 23. Specifically, the housing section 21 is configured to be able to house the pair of reels 24 in a state of being aligned in the direction Z of the liquid discharge apparatus 1. Such a housing portion 21 has an opening 25 on the base frame 20 side of the front wall 11 of the housing 10, and is formed from the front wall 11 toward the rear wall 12.

As shown in fig. 1 to 3, a first holding portion 31 that is rotatably mounted on the main body 2 and holds one end of the roll body 24 and a second holding portion 32 that holds the other end of the roll body 24 are attached to each of the pair of roll bodies 24 stored in the storage portion 21 in a state of being detachable from the main body 2 through the opening 25. In a state where the first holding portion 31 and the second holding portion 32 are attached to the main body 2, the first holding portion 31 and the second holding portion 32 are arranged in the direction X inside the housing portion 21. In a state where the first holding portion 31 is attached to one end of the roll body 24 and the second holding portion 32 is attached to the other end of the roll body 24, the roll body 24 is placed on the housing portion 21, and the placement posture of the pair of roll bodies 24 is stabilized in a state where the first holding portion 31 and the second holding portion 32 are aligned in the direction X.

The first holding portion 31 is mounted on the first side frame 61 shown in fig. 3 so as to be rotatable about a rotation axis in a direction X which is a width direction. The second holding portion 32 is mounted on the second side frame 62 shown in fig. 3 so as to be rotatable about a direction along the direction X as the width direction. That is, the first holding portion 31 and the second holding portion 32 hold the roll body 24 in a rotatable state around the central axis of the core member 23.

The roll 24 held by the first holding portion 31 and the second holding portion 32 is rotationally driven by a driving portion 33 shown in fig. 3. The driving portion 33 is located closer to the first side wall 13 than the first holding portion 31. The driving unit 33 includes a driving motor, not shown. Then, the drive motor is driven in the normal direction, and the drive portion 33 rotates the first holding portion 31 and the second holding portion 32, so that the medium 22 wound around the roll body 24 is fed to the rear wall 12 side inside the casing 10.

As shown in fig. 1 to 3, a recording unit 35 is provided inside the casing 10. The recording unit 35 includes a support table 36, a guide shaft 37, a carriage 38, and a head 39.

The support base 36 is located closer to the upper wall 15 than the housing portion 21. The support base 36 is a plate-shaped member extending in the direction X inside the housing 10. The medium 22 unwound from the roll 24 is conveyed to the support table 36 inside the housing 10, and then the medium 22 is conveyed on the support table 36 from the rear wall 12 side toward the front wall 11 side.

The guide shaft 37 is positioned closer to the upper wall 15 than the support base 36. The guide shaft 37 is a rod-shaped member extending in a direction along the direction X. The guide shaft 37 supports the carriage 38. In other words, the carriage 38 is supported to be movable along the guide shaft 37. The carriage 38 is driven by a carriage motor 40 including a drive motor not shown. Thereby, the carriage 38 reciprocates in a direction along the guide shaft 37. Further, a head 39 is mounted on the support table 36 side of the carriage 38. The head 39 ejects ink to the medium 22 supported by the support table 36 at a predetermined timing. Thereby, an image is formed in the medium 22.

As shown in fig. 2, the main body 2 includes a conveying unit 45. The conveying portion 45 conveys the medium 22 unwound from the roll body 24 in cooperation with the first holding portion 31, the second holding portion 32, and the driving portion 33 inside the housing 10. This conveying unit 45 includes a conveying path forming unit 46, an intermediate roller 47, and a conveying roller 48.

The conveyance path forming portions 46 are provided corresponding to the pair of reels 24, respectively. The conveyance path forming portion 46 is located closer to the rear wall 12 than each of the pair of reels 24 stored in the storage portion 21, and forms a conveyance path 49 for guiding the medium 22 fed out from the reel 24 by the rotational driving of the first and second holding portions 31 and 32 to the rear wall 12 of the housing 10.

The intermediate roller 47 and the conveying roller 48 convey the medium 22 passing through the conveying path 49. The intermediate roller 47 and the conveying roller 48 each include a driving roller and a driven roller as a pair of rollers rotatably supported about a rotation axis in the direction X. The intermediate roller 47 and the transport roller 48 are supported by a drive roller and a driven roller, respectively, so as to sandwich the medium 22 from both front and back sides.

Such a conveying section 45 includes a driving motor not shown. The drive motor is driven in the normal direction, and the intermediate roller 47 and the conveyance roller 48 are driven to rotate. Thereby, the medium 22 is conveyed to the support table 36 via the conveying path 49 and the medium 22 is conveyed on the support table 36 from the rear wall 12 side to the front wall 11 side. In fig. 2, the medium 22 is shown being fed from both of the pair of reels 24, but the medium 22 may be fed from only one of the pair of reels 24 when an image is formed.

As shown in fig. 2, a paper exit member 50 and a cutting portion 51 are provided inside the casing 10. The paper exit member 50 is positioned on the front wall 11 side of the support table 36, supports the medium 22 that has passed through the support table 36, and conveys the medium 22 to a paper exit 53 formed in the front wall 11. The cutting unit 51 cuts the medium 22 to a predetermined size. Then, the medium 22 cut by the cutting unit 51 is discharged from the paper discharge port 53.

As shown in fig. 3, the main body 2 has a loading portion 57 on which a cartridge containing ink supplied from the head 39 is loaded. The mounting portion 57 is located closer to the second side wall 14 than the first holding portion 31 and the second holding portion 32, and closer to the upper wall 15 than the first holding portion 31 and the second holding portion 32. The cylinder is connected to the head 39 via a pipe or the like not shown. When the pressure inside the head 39 decreases as ink is ejected, the cartridge supplies the ink to the head 39 via the tube.

The main body 2 also has a maintenance unit 58 for performing maintenance of the head 39. The maintenance unit 58 is located closer to the second side wall 14 than the first holding portion 31 and the second holding portion 32 and closer to the base frame 20 than the head 39 is to the upper wall 15.

As shown in fig. 1 and 3, the main body 2 includes an operation unit 59. The operation portion 59 is provided on the upper wall 15 of the housing 10. The operation unit 59 may be formed of a touch panel, for example, and is used when a user inputs various information.

As described above, in the liquid ejecting apparatus 1 according to the present embodiment, the driving motor included in the driving unit 33 is driven, the first holding unit 31 and the second holding unit 32 are driven, and the driving motor included in the conveying unit 45 is driven, and the intermediate roller 47 and the conveying roller 48 are driven. Thereby, the medium 22 included in the cylindrical roll 24 is conveyed to the support table 36 via the conveyance path forming portion 46.

Here, at least one of the driving unit 33 and the conveying unit 45 that conveys the medium 22 ejected from the ink ejected from the head 39 is an example of the conveying unit. Further, a direction along the direction Y of the direction in which the medium 22 is conveyed by at least one of the driving portion 33 and the conveying portion 45 is an example of a conveying direction, and a direction along the direction X intersecting the direction Y is an example of a width direction of the medium 22. The casing 10 included in the liquid ejecting apparatus 1 is an example of a casing. Of the front wall 11, the rear wall 12, the first side wall 13, the second side wall 14, and the upper wall 15 included in the housing 10, the first side wall 13 and the second side wall 14 are provided so as to overlap at least partially in the direction along the direction X. The second side wall 14 is an example of a first surface of the housing 10, and the first side wall 13 is an example of a second surface of the housing 10.

2. Electrical structure of liquid ejecting apparatus

Next, an electrical configuration of the liquid ejecting apparatus 1 will be described with reference to fig. 4. Fig. 4 is a diagram showing an electrical configuration of the liquid ejection device 1. As shown in fig. 4, the liquid ejecting apparatus 1 includes a power supply circuit board 100, a first control circuit board 110, a second control circuit board 120, a drive circuit board 130, an ejection control circuit board 140, and a plurality of heads 39.

The power supply circuit board 100 is mounted with a power supply voltage output circuit 101. The power supply voltage output circuit 101 receives a voltage VAC from a commercial ac power supply provided outside the liquid discharge apparatus 1. Then, the power supply voltage output circuit 101 converts the input voltage VAC into a plurality of dc voltages including a voltage VHV that is a dc voltage of 42V and a voltage VDD that is a dc voltage of 3.3V. That is, the power supply voltage output circuit 101 is configured to include, for example, a feedback circuit in an AC/DC converter that converts an alternating-current voltage into a direct-current voltage. Further, the power supply voltage output circuit 101 may generate the voltage VHV and then generate the voltage VDD by dropping the voltage VHV. The power supply voltage output circuit 101 may generate a plurality of dc voltages by stepping up or stepping down the voltages VHV and VDD. The voltages VHV and VDD output from the power supply circuit board 100 are input to the first control circuit board 110 via the cable 151.

The first control circuit board 110 is mounted with a control circuit 111. The control circuit 111 operates with a dc voltage based on the voltages VHV and VDD as a power supply. The image signal IMG is input to the control circuit 111 from a host provided outside the liquid discharge apparatus 1. Then, the control circuit 111 executes image processing based on the image signal IMG, and outputs information on the image processing to the second control circuit board 120 as an image processing signal IP via the cable 152. Here, the image processing executed by the control circuit 111 includes, for example, a color conversion process of converting the input image signal IMG into color information RGB of red, green, and blue and then converting the color information RGB into color information ICMY corresponding to the color of ink contained in the cartridge, a halftone process signal of performing a halftone process on the color information ICMY, and the like.

The control circuit 111 is electrically connected to the operation unit 59. An operation information signal CS containing information input by the user through operation of the operation unit 59 is input to the control circuit 111 via the cable 153. Then, the control circuit 111 generates a signal for performing control corresponding to the operation information signal CS, and outputs it to the second control circuit substrate 120 together with the image processing signal IP or as a signal different from the image processing signal IP.

Here, the control circuit 111 may convert the image processing signal IP into a pair of differential signals and output the differential signals to the second control circuit board 120, or may convert the differential signals into optical signals and output the optical signals to the second control circuit board 120. The image processing performed by the control circuit 111 is not limited to the above-described color conversion processing or halftone processing, and the control circuit 111 may output a signal subjected to various kinds of image processing as the image processing signal IP.

The second control circuit board 120 is mounted with a control circuit 121, a differential signal conversion circuit 122, and a serial signal conversion circuit 123. The control circuit 121, the differential signal conversion circuit 122, and the serial signal conversion circuit 123 operate using a dc voltage based on the voltages VHV and VDD as a power supply voltage.

The control circuit 121 outputs control signals for controlling the respective parts of the liquid ejection device 1 based on the image processing signal IP input from the first control circuit board 110. Specifically, the control circuit 121 generates the original clock signal oSCK and the original print data signals oSI1 to oSIn as control signals for controlling the ejection of ink from the head 39 based on the image processing signal IP, and outputs the control signals to the differential signal conversion circuit 122.

The differential signal conversion circuit 122 converts the input original clock signal oSCK into a pair of differential signals dSCK +, dSCK —, and outputs the signals to the drive circuit board 130 via the cable 154. The differential signal conversion circuit 122 converts each of the input original print data signals oSI1 to oSIn into a pair of differential signals dSI1+ -dSIn +, dSI 1-dSIn-, and outputs the signals to the driver circuit board 130 via the cable 154. Here, the Differential signals dSCK +, dSCK-, and dSI1+ -dSIn +, dSI1- "dSIn-converted by the Differential signal conversion circuit 122 may be Differential signals of LVDS (Low Voltage Differential Signaling) transfer system, or Differential signals of various high-speed transfer systems such as LVPECL (Low Voltage Positive Emitter Coupled Logic) or CML (Current Mode Logic) other than LVDS.

The control circuit 121 generates the latch signal LAT and the switching signal CH as control signals for controlling the timing of ejecting ink from the head 39 based on the image processing signal IP input from the first control circuit board 110, and outputs the control signals to the drive circuit board 130 via the cable 154.

The control circuit 121 generates the base drive signals DA1 to DAn and DB1 to DBn serving as the basis of the drive signals COMA and COMB for driving the head 39 based on the image processing signal IP input from the first control circuit board 110, and outputs the generated signals to the serial signal conversion circuit 123.

The serial signal conversion circuit 123 converts the base drive signals DA1 to DAn and DB1 to DBn, which are input as parallel signals, into serial signals, converts the converted serial signals into a pair of differential signals sDAB +, sDAB —, and outputs the signals to the drive circuit board 130 via the cable 154. The serial signal conversion circuit 123 generates a pair of differential signals sDCK +, sDCK —, including a clock defining a recovery timing when recovering the pair of differential signals sDAB +, sDAB —, which includes the base drive signals DA1 to DAn, DB1 to DBn in series, to parallel signals, and outputs the differential signals sdbk +, sDAB —, to the drive circuit board 130 via the cable 154.

Further, the control circuit 121 generates a carriage control signal CMC for controlling driving of the carriage motor 40 that controls movement of the carriage 38, and outputs the carriage control signal CMC to the carriage motor 40 via the cable 155. Thereby, a drive motor, not shown, included in the carriage motor 40 is driven. The control circuit 121 generates a drive control signal DC1 for controlling the drive motor included in the drive unit 33 for controlling the conveyance of the medium 22, outputs the drive control signal DC1 to the drive unit 33 via the cable 156, generates a drive control signal DC2 for controlling the drive motor included in the conveyance unit 45 for controlling the conveyance of the medium 22, and outputs the drive control signal DC2 to the conveyance unit 45 via the cable 157. That is, the control circuit 121 generates a control signal for controlling the movement of the carriage 38 and the conveyance of the medium 22, and outputs the control signal to the corresponding configuration.

The drive circuit board 130 is mounted with a parallel signal recovery circuit 131 and n drive circuits 132-1 to 132-n. The pair of differential signals sDAB +, sDAB-, and the pair of differential signals sDAB +, sDAB-, output from the serial signal conversion circuit 123 of the second control circuit board 120 are input to the parallel signal recovery circuit 131. The parallel signal recovery circuit 131 recovers the pair of differential signals sDAB +, sDAB-at a timing defined by the pair of input differential signals sDCK +, sDCK-, and generates the base drive signals DA1 to DAn and DB1 to DBn in parallel. Then, the parallel signal recovery circuit 131 outputs the generated base drive signals DA1 to DAn and DB1 to DBn to each of the drive circuits 132-1 to 132-n.

The base drive signals DA1, DB1 are input to the drive circuit 132-1. The drive circuit 132-1 converts the input base drive signal DA1 into an analog signal, amplifies the converted analog signal by D stages to generate a drive signal COMA1, and outputs the drive signal COMA1 to the discharge control circuit board 140 via the cable 158. The drive circuit 132-1 converts the input base drive signal DB1 into an analog signal, amplifies the converted analog signal by D stages to generate a drive signal COMB1, and outputs the drive signal COMB1 to the discharge control circuit board 140 via the cable 158. The drive circuit 132-1 generates a reference voltage signal VBS1 serving as a reference for ejecting ink from the head 39, which will be described later, and outputs the reference voltage signal VBS1 to the ejection control circuit board 140 via the cable 158.

Similarly, the base drive signals DAN, DBn are input to the drive circuit 132-n. The driving circuit 132-n converts the input base driving signal DAn into an analog signal, amplifies the converted analog signal by D stages, generates a driving signal coma, and outputs the driving signal coma to the ejection control circuit board 140. The driving circuit 132-n converts the input base driving signal DBn into an analog signal, amplifies the converted analog signal by D stage, generates a driving signal COMBn, and outputs the driving signal COMBn to the ejection control circuit board 140. The driving circuit 132-n generates a reference voltage signal VBSn serving as a reference for the ink discharge from the head 39, which will be described later, and outputs the generated signal to the discharge control circuit board 140.

The drive circuit board 130 transmits the differential signals dSCK +, dSCK-, the differential signals dSI1+ - (dSIn +, dSI1- (dSIn), the latch signal LAT, the conversion signal CH, and the voltages VHV and VDD, which are input from the second control circuit board 120. Then, the differential signals dSCK +, dSCK-, dSI1+ dSIn +, dSI 1-dSIn, latch signal LAT, conversion signal CH, and voltages VHV and VDD transmitted from the drive circuit board 130 are output to the ejection control circuit board 140. That is, the drive circuit board 130 also functions as a relay board that relays a signal output from the second control circuit board 120.

Here, the differential signals dSCK +, dSCK-, dSI1+ dSIn +, dSI 1-dSIn, the latch signal LAT, the conversion signal CH, and the voltages VHV and VDD among the differential signals dSCK +, dSCK-, dSI1+, dSIn, and VHV, VDD inputted to the driving circuit board 130 may be inputted to each of the driving circuits 132-1 to 132-n. The drive circuits 132-1 to 132-n may drive the voltage VDD as a power supply voltage, and may generate the drive signals COMA1 to COMA and COMB1 to COMB bn by amplifying the base drive signals DA1 to DAn and DB1 to DBn to a voltage based on the voltage VHV at a timing defined by the latch signal LAT and the conversion signal CH. In this case, the driving circuits 132-1 to 132-n may generate the reference voltage signal VBSn by boosting the voltage VDD, respectively.

The ejection control circuit board 140 is provided with a differential signal recovery circuit 141, drive signal selection circuits 200-1 to 200-n, and a temperature abnormality detection circuit 142.

The pair of differential signals dSI1+ -dSIn +, dSI 1-dSIn and the pair of differential signals dSCK +, dSCK-are input to the differential signal recovery circuit 141. The differential signal recovery circuit 141 recovers the differential signals dSI1+ -dSIn +, dSI 1-dSIn into single-ended signals, generates the print data signals SI 1-SIn, and outputs them to the drive signal selection circuits 200-1 to 200-n, respectively. The differential signal recovery circuit 141 recovers the differential signals dSCK + dSCK-to single-ended signals to generate clock signals SCK, and outputs the clock signals SCK to the drive signal selection circuits 200-1 to 200-n, respectively.

The print data signal SI1, the clock signal SCK, the latch signal LAT, the conversion signal CH, and the drive signals COMA1, COMB1 are input to the drive signal selection circuit 200-1. The drive signal selection circuit 200-1 selects or deselects the drive signals COMA1 and COMB1 at a timing defined by the latch signal LAT and the conversion signal CH based on the print data signal SI1 to generate a drive signal VOUT1, and outputs the drive signal VOUT to the head 39-1. Similarly, the print data signal SIn, the clock signal SCK, the latch signal LAT, the conversion signal CH, and the drive signals coma and COMBn are input to the drive signal selection circuit 200-n. Then, the drive signal selection circuit 200-n selects or deselects the drive signals COMAn and COMBn at the timing defined by the latch signal LAT and the conversion signal CH based on the print data signal SIn, generates the drive signal VOUTn, and outputs the drive signal VOUTn to the head 39-n. Further, details regarding the configuration and operation of the drive signal selection circuits 200-1 to 200-n will be described below.

The temperature abnormality detection circuit 142 detects the temperatures of the discharge control circuit board 140 and the drive signal selection circuits 200-1 to 200-n mounted on the discharge control circuit board 140. Then, a temperature abnormality detection signal XHOT showing the presence or absence of a temperature abnormality of the discharge control circuit board 140 and the drive signal selection circuits 200-1 to 200-n is generated and output to the control circuit 121 mounted on the second control circuit board 120 via the drive circuit board 130. The temperature abnormality detection circuit 142 generates a temperature information signal TH indicating the detected temperature, and outputs the temperature information signal TH to the control circuit 121.

The head 39-1 is inputted with the driving signal VOUT1 outputted from the driving signal selecting circuit 200-1 and the reference voltage signal VBS 1. The head 39-1 is driven by the potential difference between the drive signal VOUT1 and the reference voltage signal VBS1, and ejects an amount of ink corresponding to the driving from the nozzles. Similarly, the head 39-n is inputted with the drive signal VOUTn and the reference voltage signal VBSn output from the drive signal selection circuit 200-n. The head 39-n is driven by the potential difference between the drive signal VOUTn and the reference voltage signal VBSn, and ejects ink corresponding to the driving from the nozzles. Further, details regarding the constitution and action of the head 39 will be described later.

Here, the head 39 that ejects ink as an example of liquid by driving based on the driving signal COM is an example of an ejection head. The liquid discharge apparatus 1 further includes control circuits 111 and 121 for controlling the driving of the head 39. The control circuit 111 is an example of a first control circuit, and the control circuit 121 is an example of a second control circuit. The first control circuit board 110 on which the control circuit 111 is provided is an example of a first control circuit board, and the second control circuit board 120 on which the control circuit 121 is provided is an example of a second control circuit board. The drive signals COMA and COMB are examples of drive signals, and at least one of the drive circuits 132-1 to 132-n that outputs the drive signals COMA and COMB is an example of a drive signal output circuit. The driver circuit board 130 on which the driver circuits 132-1 to 132-n are provided is an example of a driver circuit board.

The cables 151 to 158 electrically connecting the power supply circuit board 100, the first control circuit board 110, the second control circuit board 120, the drive circuit board 130, the discharge control circuit board 140, the heads 39, the carriage motor 40, the drive unit 33, the transport unit 45, and the operation unit 59 may include a plurality of cables, respectively. In addition, the cables 151 to 158 to be connected may be Flexible Flat Cables (FFC), coaxial cables, optical communication cables, or the like, depending on the type of signal to be transmitted.

3. Structure and operation of drive signal selection circuit

Next, the configuration and operation of the drive signal selection circuits 200-1 to 200-n will be described. The drive signal selection circuits 200-1 to 200-n have the same configuration. Therefore, the drive signal selection circuits 200-1 to 200-n will be simply referred to as the drive signal selection circuits 200 without being distinguished from each other. The print data signals SI, which are the print data signals SI1 to SIn, the drive signals COMA, which are the drive signals COMA1 to COMAn, and the drive signals COMB, which are the drive signals COMB1 to COMBn, are input to the drive signal selection circuit 200 for explanation. The drive signal selection circuit 200 outputs the drive signal VOUT to the head 39 by selecting or deselecting the drive signals COMA and COMB, and inputs the reference voltage signal VBS, which is the reference voltage signals VBS1 to VBSn, to the head 39 to which the drive signal VOUT is supplied.

First, an example of the waveforms of the driving signals COMA and COMB input to the driving signal selection circuit 200 and an example of the waveform of the driving signal VOUT output from the driving signal selection circuit 200 will be described.

Fig. 5 is a diagram showing an example of waveforms of the drive signals COMA and COMB. As shown in fig. 5, the drive signal COMA is a waveform in which a trapezoidal waveform Adp1 arranged in a period T1 from the rise of the latch signal LAT to the rise of the switching signal CH and a trapezoidal waveform Adp2 arranged in a period T2 from the rise of the switching signal CH to the rise of the latch signal LAT are continued. When the trapezoidal waveform Adp1 is supplied to the head 39, a small amount of ink is ejected from the corresponding nozzle, and when the trapezoidal waveform Adp2 is supplied to the head 39, a medium amount of ink larger than the small amount is ejected from the corresponding nozzle.

As shown in fig. 5, the drive signal COMB is a waveform in which the trapezoidal waveform Bdp1 disposed in the period T1 and the trapezoidal waveform Bdp2 disposed in the period T2 are continuous. When the trapezoidal waveform Bdp1 is supplied to the head 39, ink is not ejected from the corresponding nozzle. The trapezoidal waveform Bdp1 is a waveform for preventing an increase in ink viscosity by micro-vibrating ink in the vicinity of the orifice portion of the nozzle. When the trapezoidal waveform Bdp2 is supplied to the head 39, a small amount of ink is ejected from the corresponding nozzle, as in the case of supplying the trapezoidal waveform Adp 1.

Here, the voltages at the start timing and the end timing of each of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 are all the voltage Vc and are common. That is, trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 are waveforms starting at voltage Vc and ending at voltage Vc, respectively. In addition, the period Ta including the period T1 and the period T2 corresponds to a printing period in which dots are formed in the medium 22.

In fig. 5, the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 are illustrated as the same waveform, but the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 may be different waveforms. Note that, although the description is made on the case where the trapezoidal waveform Adp1 is supplied to the head 39 and the case where the trapezoidal waveform Bdp1 is supplied to the head 39, a small amount of ink is ejected from the corresponding nozzle. That is, the waveforms of the drive signals COMA and COMB are not limited to those shown in fig. 3, and signals having various combinations of waveforms may be used depending on the moving speed of the carriage 38 mounted on the head 39, the properties of the ink to be ejected, the material of the medium 22, and the like. Further, the waveforms of the driving signals COMA 1-COMan and COMB 1-COMBn corresponding to the heads 39-1-39-n may be different from each other.

Fig. 6 is a diagram showing an example of the waveform of the drive signal VOUT in each case where the size of dots formed on the medium 22 is "large dot", "middle dot", "small dot", and "non-recording".

As shown in fig. 6, the drive signal VOUT when the medium 22 has a "large spot" is a waveform in which the trapezoidal waveform Adp1 arranged in the period T1 and the trapezoidal waveform Adp2 arranged in the period T2 are continued in the period Ta. In the case where this drive signal VOUT is supplied to the head 39, a small amount of ink and a medium amount of ink are ejected from the corresponding nozzles in the period Ta. Thus, the respective inks are flicked and integrated in the medium 22, thereby forming a large dot.

The drive signal VOUT when the medium 22 forms the "midpoint" has a waveform in which the trapezoidal waveform Adp1 arranged in the period T1 and the trapezoidal waveform Bdp2 arranged in the period T2 are continuous in the period Ta. In the case where this drive signal VOUT is supplied to the head 39, a small amount of ink is ejected twice from the corresponding nozzle in the period Ta. Thus, the individual inks bounce and merge together in the media 22, forming a midpoint.

The drive signal VOUT when the "small dot" is formed in the medium 22 has a waveform in which the trapezoidal waveform Adp1 arranged in the period T1 and the waveform arranged in the period T2 and fixed at the voltage Vc are continuous in the period Ta. When the driving signal VOUT is supplied to the head 39, a small amount of ink is ejected from the corresponding nozzle in the period Ta. Thus, the ink bounces off in the medium 22 to form small dots.

The drive signal VOUT corresponding to "non-recording" in which dots are not formed on the medium 22 has a waveform in which the trapezoidal waveform Bdp1 disposed in the period T1 and the waveform disposed in the period T2 and fixed by the voltage Vc are continuous in the period Ta. When the driving signal VOUT is supplied to the head 39, the ink near the opening portion of the corresponding nozzle vibrates only slightly in the period Ta, and therefore the ink is not ejected. Thus, in the medium 22, the ink does not bounce off without forming dots.

Here, the waveform in which the voltage Vc is fixed is a waveform including a voltage at which the previous voltage Vc is held when any of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 is not selected as the drive signal VOUT. Thus, in the case where any one of the trapezoidal waveforms Adp1, Adp2, Bdp1, Bdp2 is not selected as the drive signal VOUT, it can be said that the voltage Vc is supplied to the head 39 as the drive signal VOUT.

The drive signal selection circuit 200 selects or deselects the waveforms of the drive signals COMA and COMB to generate a drive signal VOUT, and outputs the drive signal VOUT to the head 39. Fig. 7 is a diagram showing the configuration of the drive signal selection circuit 200. As shown in fig. 7, the drive signal selection circuit 200 includes a selection control circuit 220 and a plurality of selection circuits 230. In addition, the head 39 that supplies the drive signal VOUT output from the drive signal selection circuit 200 includes m ejection portions 600.

The print data signal SI, the latch signal LAT, the conversion signal CH, and the clock signal SCK are input to the selection control circuit 220. The selection control circuit 220 is provided with a group of shift registers (S/R)222, latch circuits 224, and decoders 226 corresponding to each of the m ejection sections 600 included in the head 39. That is, the drive signal selection circuit 200 includes a group of the shift register 222, the latch circuit 224, and the decoder 226, the number of which is the same as the number of m ejection portions 600 included in the head 39.

The print data signal SI is a signal of 2m bits in total, which includes 2-bit print data [ SIH, SIL ] for selecting any one of "large dot", "middle dot", "small dot", and "non-recording" for each of the m ejection sections 600, out of signals synchronized with the clock signal SCK. The input print data signal SI is held in the shift register 432 for each 2-bit amount of print data [ SIH, SIL ] included in the print data signal SI in correspondence with the m ejection units 600. Specifically, the m-stage shift registers 222 of the selection control circuit 220 corresponding to the m discharge units 600 are connected in cascade with each other, and the print data signal SI input in series is sequentially transferred to the subsequent stage in accordance with the clock signal SCK. In fig. 5, in order to distinguish the shift register 222, 1 stage, 2 stages, …, and m stages are shown in order from the upstream side to which the print data signal SI is input.

The m latch circuits 224 respectively latch the print data [ SIH, SIL ] of 2 bits held by the m shift registers 222 respectively by the rise of the latch signal LAT.

Fig. 8 is a diagram showing the decoded content of the decoder 226. The decoder 226 outputs selection signals S1, S2 according to the latched 2-bit print data [ SIH, SIL ]. For example, when the print data [ SIH, SIL ] of 2 bits is [1, 0], the decoder 226 outputs the logic level of the selection signal S1 as the H level and the L level in the periods T1 and T2, and outputs the logic level of the selection signal S2 as the L level and the H level in the periods T1 and T2 to the selection circuit 230.

The selection circuits 230 are provided corresponding to the respective ejection units 600. That is, the number of the selection circuits 230 included in the drive signal selection circuit 200 is equal to the total number m of the corresponding ejection portions 600. Fig. 9 is a diagram showing the configuration of the selection circuit 230 corresponding to one of the ejection units 600. As shown in fig. 9, the selection circuit 230 has inverters 232a, 232b and transfer gates 234a, 234b as a NOT circuit.

The selection signal S1 is input to the positive control terminal to which no circled mark is applied at the transfer gate 234a, is logically inverted by the inverter 232a, and is input to the negative control terminal to which a circled mark is applied at the transfer gate 234 a. In addition, the driving signal COMA is supplied to an input terminal of the transfer gate 234 a. The selection signal S2 is input to the positive control terminal not provided with a circle mark in the transfer gate 234b, is logically inverted by the inverter 232b, and is input to the negative control terminal provided with a circle mark in the transfer gate 234 b. In addition, the driving signal COMB is supplied to the input terminal of the transfer gate 234 b. Output terminals of the transfer gates 234a and 234b are commonly connected to output the drive signal VOUT.

Specifically, the transfer gate 234a is turned on between the input terminal and the output terminal when the selection signal S1 is at the H level, and is turned off when the selection signal S1 is at the L level. The transfer gate 234b is configured to be conductive between the input terminal and the output terminal when the selection signal S2 is at the H level, and to be nonconductive between the input terminal and the output terminal when the selection signal S2 is at the L level. As described above, the selection circuit 230 selects the waveforms of the drive signals COMA and COMB based on the selection signals S1 and S2, and outputs the drive signal VOUT.

Here, the operation of the drive signal selection circuit 200 will be described with reference to fig. 10. Fig. 10 is a diagram for explaining an operation of the drive signal selection circuit 200. The print data signal SI is input in serial in synchronization with the clock signal SCK, and is sequentially transferred to the shift register 222 corresponding to the ejection section 600. When the input of the clock signal SCK is stopped, the 2-bit print data [ SIH, SIL ] corresponding to each of the discharge units 600 is held in each of the shift registers 222. The print data [ SIH, SIL ] included in the print data signal SI is input in the order corresponding to the m-stage, …, 2-stage, and 1-stage ejection units 600 of the shift register 222.

When the latch signal LAT rises, the latch circuits 224 latch the 2-bit print data [ SIH, SIL ] held by the shift registers 222 together. In fig. 10, LT1, LT2, …, LTm show 2-bit print data [ SIH, SIL ] latched by the latch circuits 224 corresponding to the shift registers 222 of 1, 2, …, m stages.

The decoder 226 outputs the logic levels of the selection signals S1 and S2 in the periods T1 and T2, respectively, in accordance with the dot size defined by the latched 2-bit print data [ SIH, SIL ], as shown in fig. 8.

Specifically, when the print data [ SIH, SIL ] is [1, 1], the decoder 226 sets the selection signal S1 to the H, H level in the periods T1 and T2, and sets the selection signal S2 to the L level and the L level in the periods T1 and T2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 in the period T1 and selects the trapezoidal waveform Adp2 in the period T2. As a result, the drive signal VOUT corresponding to the "large dot" shown in fig. 6 is generated.

When the print data [ SIH, SIL ] is [1, 0], the decoder 226 sets the selection signal S1 to H level and L level in the periods T1 and T2, and sets the selection signal S2 to L level and H level in the periods T1 and T2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 in the period T1 and selects the trapezoidal waveform Bdp2 in the period T2. As a result, the drive signal VOUT corresponding to the "midpoint" shown in fig. 6 is generated.

When the print data [ SIH, SIL ] is [0, 1], the decoder 226 sets the selection signal S1 to H level and L level in the periods T1 and T2, and sets the selection signal S2 to L level and L level in the periods T1 and T2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 in the period T1, and does not select any of the trapezoidal waveforms Adp2 and Bdp2 in the period T2. As a result, the drive signal VOUT corresponding to the "small dot" shown in fig. 6 is generated.

When the print data [ SIH, SIL ] is [0, 0], the decoder 226 sets the selection signal S1 to the L level and the L level in the periods T1 and T2, and sets the selection signal S2 to the H level and the L level in the periods T1 and T2. In this case, the selection circuit 230 selects the trapezoidal waveform Bdp1 in the period T1, and does not select any of the trapezoidal waveforms Adp2 and Bdp2 in the period T2. As a result, the drive signal VOUT corresponding to "non-recording" shown in fig. 6 is generated.

As described above, the drive signal selection circuit 200 selects the waveforms of the drive signals COMA and COMB based on the print data signal SI, the latch signal LAT, the conversion signal CH, and the clock signal SCK, and outputs them as the drive signal VOUT. That is, the drive signals VOUT generated by selecting the waveforms of the drive signals COMA and COMB are also outputted from the drive circuits 132-1 to 132-n in a broad sense. That is, in the present embodiment, the drive signal VOUT is also an example of a drive signal for driving the head 39 separately.

4. Construction of the discharge head

Next, the configuration of one discharge unit 600 among the m discharge units 600 included in the head 39 will be described. Fig. 11 is a diagram illustrating the configuration of the discharge unit 600. As shown in fig. 11, the ejection section 600 includes a piezoelectric element 60, a vibration plate 621, a cavity 631, and a nozzle 651. The vibration plate 621 is displaced in accordance with the driving of the piezoelectric element 60 provided on the upper surface in fig. 9. The vibration plate 621 functions as a diaphragm that enlarges/reduces the internal volume of the cavity 631. The interior of the cavity 631 is filled with ink. The cavity 631 functions as a pressure chamber whose internal volume changes due to the displacement of the vibration plate 621 caused by the driving of the piezoelectric element 60. The nozzle 651 is an aperture portion formed in the nozzle plate 632 and communicating with the cavity 631. The internal volume of the chamber 631 is changed, and the ink stored in the chamber 631 is ejected from the nozzle 651. In addition, ink supplied from the ink supply port 661 is supplied to the cavity 631 via the reservoir 641.

The piezoelectric element 60 has a structure in which the piezoelectric body 601 is sandwiched between a pair of electrodes 611 and 612. In the piezoelectric body 601 having this structure, the center portions of the electrodes 611 and 612 and the vibrating plate 621 are bent in the vertical direction in fig. 11 with respect to both end portions in accordance with the potential difference between the electrodes 611 and 612. Specifically, the driving signal VOUT is supplied to the electrode 611 as one end of the piezoelectric element 60, and the reference voltage signal VBS is supplied to the electrode 612 as the other end. When the voltage of the drive signal VOUT is low, the piezoelectric element 60 is driven such that the central portion thereof is deflected upward, and when the voltage of the drive signal VOUT is high, the piezoelectric element 60 is driven such that the central portion thereof is deflected downward. The piezoelectric element 60 is deflected upward, and the vibration plate 621 is displaced upward, thereby expanding the internal volume of the cavity 631. Thus, ink is introduced from the reservoir 641. Further, the piezoelectric element 60 is deflected downward, and the vibration plate 621 is displaced downward, thereby reducing the internal volume of the cavity 631. Accordingly, ink of an amount corresponding to the degree of reduction of the internal volume of the chamber 631 is ejected from the nozzle 651.

As described above, the discharge unit 600 includes the piezoelectric element 60, and discharges ink to the medium 22 by driving the piezoelectric element 60. The piezoelectric element 60 is not limited to the illustrated configuration, and may be of a type that can eject ink in accordance with displacement of the piezoelectric element 60. The piezoelectric element 60 is not limited to bending vibration, and may be configured to vibrate in the longitudinal direction.

5. Arrangement of circuit boards in liquid ejecting apparatus

As described above, the liquid discharge apparatus 1 of the present embodiment includes: a power supply circuit board 100, a first control circuit board 110, a second control circuit board 120, a drive circuit board 130, an ejection control circuit board 140, and a plurality of heads 39. The power circuit board 100 and the first control circuit board 110 are electrically connected by a cable 151, the first control circuit board 110 and the second control circuit board 120 are electrically connected by a cable 152, the second control circuit board 120 and the drive circuit board 130 are electrically connected by a cable 154, and the drive circuit board 130 and the discharge control circuit board 140 are electrically connected by a cable 158. Then, the driving signal VOUT output from the ejection control circuit board 140 is output to the corresponding head 39, and ink is ejected from the head 39 and landed on the medium 22, thereby forming a desired image on the medium 22.

Next, a specific example of the arrangement of the power supply circuit board 100, the first control circuit board 110, the second control circuit board 120, the drive circuit board 130, and the discharge control circuit board 140 in the casing 10 of the liquid discharge apparatus 1 will be described with reference to fig. 12 and 13. Fig. 12 is a diagram for explaining the arrangement of the circuit boards when the liquid ejection device 1 is viewed from the + Z side. Fig. 13 is a diagram for explaining the arrangement of the circuit boards when the liquid ejection device 1 is viewed from the + Y side.

Here, the medium 22 is transported in a region surrounded by the first side frame 61 and the second side frame 62 in fig. 12, and in a region surrounded by the first side frame 61, the second side frame 62, and the top frame 63 connected to both the first side frame 61 and the second side frame 62 and positioned on the + Z side of the first side frame 61 and the second side frame 62 in fig. 13. That is, the conveyance path forming portion 46, the intermediate roller 47, and the conveyance roller 48 included in the conveyance portion 45 that conveys the medium 22 are provided in a region surrounded by the first side frame 61, the second side frame 62, and the top frame 63. The region surrounded by the first side frame 61, the second side frame 62, and the top frame 63 may be referred to as a medium conveyance region 41.

As shown in fig. 12 and 13, the power supply circuit board 100 is located on the-X side of the medium conveying region 41 and is mounted on the rear wall 12. The power circuit board 100 is electrically connected to the terminal 161 via the cable 150, and is electrically connected to the first control circuit board 110 via the cable 151.

The terminal 161 is located on the-X side of the power circuit substrate 100 and is mounted to the second side wall 14. The terminal 161 is electrically connected to the power circuit board 100 via the cable 150. Further, a voltage VAC is input to the terminal 161 from a commercial ac power supply outside the liquid discharge apparatus 1. As such a terminal 161, for example, a socket or the like connectable to a cable transmitting voltage VAC may be used. In the liquid ejecting apparatus 1, a cable for transmitting the voltage VAC may be a socket plug integrated with the terminal 161.

The first control circuit substrate 110 is located at a position on the + Z side of the power supply circuit substrate 100, among the-X sides of the medium conveying area 41, and is mounted on the rear wall 12. The first control circuit board 110 is electrically connected to the power circuit board 100 via a cable 151, to the second control circuit board 120 via a cable 152, to the operation portion 59 via a cable 153, and to the terminal 162 via a cable 159.

The operation unit 59 is mounted on the + Z side of the first control circuit board 110 in the-X side of the medium conveyance region 41, and is mounted on the upper wall 15. The operation unit 59 is electrically connected to the first control circuit board 110 via a cable 153.

The terminal 162 is located at the + Z side of the terminal 161 in the-X side of the first control circuit substrate 110, and is mounted to the second side wall 14. The terminal 162 is electrically connected to the first control circuit board 110 via a cable 159. The image signal IMG is input to the terminal 162 from a host provided outside the liquid discharge apparatus 1. As such a terminal 161, for example, a USB terminal or the like connected to a host in a communicable manner through a USB cable can be used. The terminal 161 may be a cable that can communicate with the host computer and is connected to the host computer so as to be able to communicate with the host computer, and may be a printer port, for example. The liquid discharge apparatus 1 and the host computer may be connected so as to be able to communicate by wireless communication, and in this case, a receiving antenna that receives a signal by the wireless communication corresponds to the terminal 162.

The second control circuit board 120 is located on the + X side of the medium conveyance region 41 and is mounted on the rear wall 12. The second control circuit board 120 is electrically connected to the first control circuit board 110 via a cable 152, the drive circuit board 130 via a cable 154, the carriage motor 40 via a cable 155, and the drive unit 33 via a cable 157.

The drive unit 33 is located on the-Z side of the second control circuit board 120 in the + X side of the medium conveyance region 41, and is mounted on the first side frame 61. The driving unit 33 is electrically connected to the second control circuit board 120 via a cable 157.

The carriage motor 40 is located on the + Z side of the second control circuit substrate 120 in the + X side of the medium conveyance area 41, and is attached to the guide shaft 37. The carriage motor 40 is electrically connected to the second control circuit substrate 120 via a cable 155.

The drive circuit board 130 is located on the + Z side of the medium conveyance region 41 and is mounted on the rear wall 12. In other words, the drive circuit board 130 and the medium conveyance region 41 are disposed so as to partially overlap when viewed in the direction Z. The drive circuit board 130 is electrically connected to the second control circuit board 120 via a cable 154, and is electrically connected to the discharge control circuit board 140 mounted on the carriage 38 via a cable 158.

As described above, in the present embodiment, the first control circuit board 110 and the second control circuit board 120 are electrically connected by the cable 152. Also, the first control circuit substrate 110 is located at a position on the second side wall 14 side of the housing 10 in the-X side of the medium conveying region 41. In the liquid ejecting apparatus 1, in order to eject ink onto the medium 22, the operation portion 59 for the user to input information and the terminal 162 for inputting the image signal IMG, which is image data formed on the medium 22, in the liquid ejecting apparatus 1 are located on the-X side of the medium conveying region 41.

The operation section 59 inputs the operation information signal CS to the control circuit 111 mounted on the first control circuit substrate 110 via the cable 153, and the terminal 162 inputs the image signal IMG to the control circuit 111 mounted on the first control circuit substrate 110 via the cable 159. That is, in the liquid ejecting apparatus 1, the operation portion 59 driven to eject ink onto the medium 22 is electrically connected to the control circuit 111 mounted on the first control circuit board 110, and the terminal 162 driven to eject ink onto the medium 22 is electrically connected to the control circuit 111 mounted on the first control circuit board 110. The operation unit 59, the terminal 162, and the first control circuit board 110 are located on the-X side of the medium conveyance area 41.

The second control circuit substrate 120 is located at a position on the first side wall 13 side of the housing 10 in the + X side of the medium conveyance region 41. In the liquid discharge apparatus 1, the carriage motor 40 for controlling the movement of the carriage 38 on which the plurality of heads 39 are mounted and the drive unit 33 for rotating the first holding unit 31 and the second holding unit 32 for controlling the conveyance of the medium 22 are located on the + X side of the medium conveyance area 41. The carriage control signal CMC is input to the carriage motor 40 via the cable 155, and the drive control signal DC1 is input to the drive unit 33 via the cable 156. That is, the carriage motor 40 driven to eject ink onto the medium 22 is electrically connected to the control circuit 121 mounted on the second control circuit board 120, and the driving unit 33 driven to eject ink onto the medium 22 is electrically connected to the control circuit 121 mounted on the second control circuit board 120. The carriage motor 40, the drive unit 33, and the second control circuit board 120 are located on the + X side of the medium conveyance area 41.

As described above, the liquid discharge apparatus 1 includes the casing 10 housing the first control circuit board 110 and the second control circuit board 120, the operation unit 59, the terminal 162, the carriage motor 40, and the drive unit 33. In the case 10, the first control circuit board 110 and the second control circuit board 120 are provided such that the shortest distance between the first control circuit board 110 and the second side wall 14 is shorter than the shortest distance between the first control circuit board 110 and the first side wall 13, and the shortest distance between the second control circuit board 120 and the first side wall 13 is shorter than the shortest distance between the second control circuit board 120 and the second side wall 14.

In the liquid ejecting apparatus 1, the operation portion 59 and the terminal 162 electrically connected to the first control circuit board 110 are provided in the vicinity of the first control circuit board 110 with respect to the second control circuit board 120, and the carriage motor 40 and the driving portion 33 electrically connected to the second control circuit board 120 are provided in the vicinity of the second control circuit board 120 with respect to the first control circuit board 110. In other words, the operation unit 59, the terminal 162, the carriage motor 40, and the drive unit 33 are provided such that the shortest distance between the first control circuit board 110 and the operation unit 59 and the terminal 162 is shorter than the shortest distance between the first control circuit board 110 and the carriage motor 40 and the drive unit 33, and the shortest distance between the second control circuit board 120 and the carriage motor 40 and the drive unit 33 is shorter than the shortest distance between the second control circuit board 120 and the operation unit 59 and the terminal 162.

This can shorten the wiring length of the cables 153 and 159 that electrically connect the first control circuit board 110 to the operation unit 59 and the terminal 162 that are driven to eject ink onto the medium 22, and can shorten the wiring length of the cables 155 and 156 that electrically connect the second control circuit board 120 to the carriage motor 40 and the drive unit 33 that are driven to eject ink onto the medium 22. Thus, the possibility of noise overlapping with the signals transmitted through each of the cables 153, 159, 155, 156 is reduced.

In the liquid ejecting apparatus 1 of the present embodiment, the drive circuit board 130 provided with the drive circuits 132-1 to 132-n for outputting the drive signals COMA1 to COMAn and COMB1 to COMBn for driving the plurality of heads 39 and the reference voltage signals VBS1 to VBSn is provided in the vicinity of the second control circuit board 120 on the + Z side of the medium transporting region 41 with respect to the first control circuit board 110. The drive circuit board 130 is electrically connected to the second control circuit board 120 via a cable 154. In this case, the drive circuit board 130 is provided so that the shortest distance between the first control circuit board 110 and the operation portion 59 and the terminal 162 is shorter than the shortest distance between the first control circuit board 110 and the drive circuit board 130, and the shortest distance between the second control circuit board 120 and the drive circuit board 130 is shorter than the shortest distance between the second control circuit board 120 and the operation portion 59 and the terminal 162.

This can shorten the wiring length of the cable 154 electrically connecting the second control circuit board 120 and each of the drive circuits 132-1 to 132-n mounted on the drive circuit board 130 driven to eject ink onto the medium 22. Thus, the possibility of noise overlapping the signal transmitted through the cable 154 is reduced.

Here, among the operation portion 59, the terminal 162, the carriage motor 40, the drive portion 33, and the drive circuit board 130 which are driven to eject ink onto the medium 22, at least one of the operation portion 59 and the terminal 162 is an example of a first member, and at least one of the carriage motor 40, the drive portion 33, and the drive circuit board 130 is an example of a second member. That is, the first section includes a terminal 162 as an input terminal to which an image signal IMG for driving the head 39 is input, and the second section includes: the carriage motor 40 includes at least one of a drive circuit board 130 provided with at least one of drive circuits 132-1 to 132-n for outputting drive signals COMA and COMB for driving the head 39 and a carriage motor 40 provided with a drive motor as a motor for converting electric energy into mechanical energy.

Here, the driving for ejecting ink to the medium 22 is not limited to the operation of direct driving for ejecting ink from the head 39 to the medium 22, and includes the operations accompanying the liquid ejecting apparatus 1 such as input driving for inputting a signal for ejecting ink from the head 39 to the medium 22, conveyance driving for conveying the medium 22 from which ink is ejected from the head 39, and head movement driving for moving the head 39 from which ink is ejected. In other words, the driving for ejecting ink onto the medium 22 includes an operation of indirectly driving for ejecting ink onto the medium 22 from the head 39.

In the liquid discharge apparatus 1 of the present embodiment, the first control circuit board 110 processes various control signals input to the liquid discharge apparatus 1 to discharge ink onto the medium 22, and drives the liquid discharge apparatus 1. On the other hand, the second control circuit board 120 outputs: the liquid ejection device 1 ejects ink onto the medium 22 by a signal for moving a carriage 38 provided with a head 39, a signal for conveying the medium 22, and signals for generating drive signals COMA and COMB for ejecting ink from the head 39. That is, the first control circuit board 110 performs signal conversion processing for converting a control signal input from the outside into a signal for ejecting ink onto the medium 22, and the second control circuit board 120 performs processing for operating various components for ejecting ink onto the medium 22 based on the signal input from the first control circuit board 110.

In such a first control circuit substrate 110 and a second control circuit substrate 120 that perform different processes, the voltage levels or frequencies of the processed signals are different. Therefore, it is preferable that the first control circuit substrate 110 and the second control circuit substrate 120 exist separately so that the signal generated by the first control circuit substrate 110 and the signal generated by the second control circuit substrate 120 do not interfere with each other.

Therefore, in the present embodiment, the medium conveyance area 41 including the conveyance portion 45 for conveying the medium 22 is provided between the first control circuit substrate 110 and the second control circuit substrate 120 so that the first control circuit substrate 110 and the second control circuit substrate 120 are separated. Specifically, the first control circuit substrate 110 is located on the-X side of the medium conveyance region 41 for conveying the medium 22, and the second control circuit substrate 120 is located on the + X side of the medium conveyance region 41 for conveying the medium 22. In other words, the first control circuit substrate 110 and the second control circuit substrate 120 are configured to: the shortest distance between the first control circuit board 110 and the second side wall 14 is shorter than the shortest distance between the medium conveyance area 41 including the conveyance section 45 and the second side wall 14, and the shortest distance between the second control circuit board 120 and the first side wall 13 is shorter than the shortest distance between the medium conveyance area 41 including the conveyance section 45 and the first side wall 13.

As a result, the first control circuit board 110 and the second control circuit board 120, which perform two different processes, can be disposed separately within the housing 10 of the liquid discharge apparatus 1, and as a result, the possibility that the signal generated by the first control circuit board 110 and the signal generated by the second control circuit board 120 interfere with each other is reduced.

Here, the liquid ejecting apparatus 1 ejects ink from the head 39 onto the medium 22 to form a desired image on the medium 22 in a print state, and includes: a standby state in which the image signal IMG is not input to the liquid ejecting apparatus 1 and the power consumption is smaller than a printing state in which ink is not ejected from the head 39 to the medium 22; and a sleep state in which the image signal IMG is not input to the liquid ejecting apparatus 1 and the power consumption is smaller than that in a waiting state in which ink is not ejected from the head 39 to the medium 22. In other words, the liquid ejection device 1 includes: a print state in which ink can be ejected from the head 39, and a standby state and a sleep state in which power consumption is small compared to the print state and ink is not ejected from the head 39.

In the liquid ejecting apparatus 1 of the present embodiment, as described above, the first control circuit board 110 performs processing for converting a control signal input from the outside into a signal for ejecting ink onto the medium 22, and the second control circuit board 120 performs processing for operating various components included in the liquid ejecting apparatus 1 in order to eject ink onto the medium 22 based on the signal output from the first control circuit board 110. That is, the control circuit 121 provided on the second control circuit substrate 120 does not generate a signal in the standby state and the sleep state. Therefore, the second control circuit board 120 can stop operating in at least one of the standby state and the sleep state. Thus, in the liquid ejecting apparatus 1 of the present embodiment including the first control circuit board 110 and the second control circuit board 120, since the first control circuit board 110 and the second control circuit board 120 perform different processes in the liquid ejecting apparatus 1, power consumption in a standby state and a sleep state in which ink is not ejected from the head 39 can be further reduced.

Here, the print state is an example of the first mode, and at least one of the standby state and the sleep state is an example of the second mode.

6. Effect of action

As described above, the liquid discharge apparatus 1 of the present embodiment includes: a first control circuit substrate 110 on which a control circuit 111 is provided; and a second control circuit substrate 120 provided with a control circuit 121. The operation unit 59 and the terminal 162 electrically connected to the control circuit 111 are provided in the vicinity of the first control circuit board 110 with respect to the second control circuit board 120, and the carriage motor 40 and the drive unit 33 electrically connected to the control circuit 121 are provided in the vicinity of the second control circuit board 120 with respect to the first control circuit board 110. That is, the shortest distance between the first control circuit board 110 and the operation unit 59 and the terminal 162 is shorter than the shortest distance between the first control circuit board 110 and the carriage motor 40 and the drive unit 33, and the shortest distance between the second control circuit board 120 and the carriage motor 40 and the drive unit 33 is shorter than the shortest distance between the second control circuit board 120 and the operation unit 59 and the terminal 162.

This can shorten the length of the wiring for transmitting signals to each of the operation unit 59, the terminal 162, the carriage motor 40, and the drive unit 33, which are dispersedly disposed inside the liquid discharge apparatus 1. Therefore, the influence of the wiring impedance between each of the operation unit 59, the terminal 162, the carriage motor 40, and the drive unit 33 and the first control circuit board 110 and the second control circuit board 120 is reduced, and the transmission accuracy of the signal is improved. Therefore, the accuracy of the ink ejected from the head 39 is improved, and as a result, the possibility of the quality of the image formed on the medium 22 being degraded is reduced.

The embodiments have been described above, but the present invention is not limited to these embodiments, and can be implemented in various ways without departing from the scope of the invention. For example, the above embodiments can be combined as appropriate.

The present invention includes substantially the same configurations (for example, configurations having the same functions, methods, and results, or configurations having the same objects and effects) as those described in the embodiments. The present invention includes a configuration in which non-essential portions of the configurations described in the embodiments are replaced. The present invention includes a configuration that can achieve the same operational effects as the configurations described in the embodiments or achieve the same object. The present invention includes a configuration obtained by adding a known technique to the configuration described in the embodiment.