Liquid discharge device and head unit

Abstract

To provide a liquid discharge device that can accurately detect a temperature of a print head.SOLUTION: The liquid discharge device is provided with: a print head which has a vibration plate that is deformed by driving a piezoelectric element, a pressure chamber, positioned at one side of the vibration plate, which stores liquid and whose volumes are varied when the vibration plate is deformed, a nozzle that discharges liquid in accordance with variation of the volumes of the pressure chamber and a temperature detecting part, positioned at the other side of the vibration plate, which outputs a head temperature signal corresponding to a temperature of the pressure chamber; a temperature information output circuit that outputs a temperature information signal corresponding to the head temperature signal obtained in a predetermined cycle; a temperature information output circuit that retains a plurality of temperature information obtained by obtaining the head temperature signal for each sampling cycle; and a processor that determines the number of samples of temperature information that is used for generating a temperature information signal on the basis of a temperature information group for adjustment including the plurality of temperature information, where the number of samples determined by the processor is memorized in the temperature information output circuit.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device and a head unit. [Background technology]

[0002] The liquid ejection device includes a printer having a piezoelectric element, a pressure chamber, and a nozzle communicating with the pressure chamber. The print head is driven by a piezoelectric element. By changing the volume of the pressure chamber, the liquid supplied to the pressure chamber is ejected from the nozzle. In a liquid ejection device equipped with such a print head, ink stored in the print head By controlling the drive of the piezoelectric element based on the temperature of the ink, ejection control suitable for the temperature of the ink is performed. Techniques for achieving this are known.

[0003] For example, Patent Document 1 discloses a method for detecting the temperature of a print head by a temperature detection unit provided inside the print head. The temperature of the print head is detected, and the piezoelectric element is driven based on the detected temperature of the print head. A technique for controlling the above is disclosed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2024-051474 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 does not allow accurate detection of the temperature of the print head. There was room for improvement in terms of [Means for solving the problem]

[0006] One aspect of the liquid ejection device according to the present invention is a drive circuit that outputs a drive signal; a print head that receives the drive signal and ejects liquid; A head temperature signal corresponding to the temperature of the print head is acquired at a predetermined sampling period. a temperature information output circuit that outputs a temperature information signal corresponding to the acquired head temperature signal; a processor that controls the printhead and the drive circuitry; Equipped with The print head includes: The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric body, The piezoelectric element is positioned between the first electrode and the second electrode in the stacking direction. a piezoelectric element that receives the drive signal and is driven; The piezoelectric element is positioned on one side of the stacking direction and deformed by driving the piezoelectric element. a diaphragm that The liquid is stored in the cavity, and the cavity is located on one side of the vibration plate in the stacking direction. a pressure chamber substrate provided with a pressure chamber whose volume changes with deformation of the moving plate; a nozzle that ejects liquid in response to a change in the volume of the pressure chamber; a pressure chamber temperature sensor that is located on the other side of the vibration plate in the stacking direction and that responds to the temperature of the pressure chamber; a temperature detection unit that outputs a head temperature signal; and The temperature information output circuit outputs the head temperature signal in multiple steps obtained at each sampling period. Holds temperature information for a number of The processor outputs the plurality of pieces of temperature information held by the temperature information output circuit to a temperature adjustment unit. and adjusting the temperature information signal based on the acquired temperature information group for adjustment. determining the number of samples of the temperature information to be used for generation; The number of samples determined by the processor is stored in the temperature information output circuit. .

[0007] One aspect of the head unit according to the present invention is a print head that receives a drive signal and ejects liquid; A head temperature signal corresponding to the temperature of the print head is acquired at a predetermined sampling period. a temperature information output circuit that outputs a temperature information signal corresponding to the acquired head temperature signal; Equipped with The print head includes: The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric body, The piezoelectric element is positioned between the first electrode and the second electrode in the stacking direction. a piezoelectric element that receives the drive signal and is driven; The piezoelectric element is positioned on one side of the stacking direction and deformed by driving the piezoelectric element. a diaphragm that The liquid is stored in the cavity, and the cavity is located on one side of the vibration plate in the stacking direction. a pressure chamber substrate provided with a pressure chamber whose volume changes with deformation of the moving plate; a nozzle that ejects liquid in response to a change in the volume of the pressure chamber; a pressure chamber temperature sensor that is located on the other side of the vibration plate in the stacking direction and that responds to the temperature of the pressure chamber; a temperature detection unit that outputs a head temperature signal; and The temperature information output circuit outputs the head temperature signal in multiple steps obtained at each sampling period. The number of samples determined based on the number of temperature information is stored. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a liquid ejection device. [Figure 2] FIG. 2 is an exploded perspective view showing the structure of a print head. [Figure 3] FIG. 2 is a plan view of the print head 22 as viewed along the Z axis. [Figure 4] FIG. 4 is a cross-sectional view of the print head taken along the line Aa in FIG. 3. [Figure 5] FIG. 5 is a detailed view of the main part of FIG. 4 showing the details of the main part. [Figure 6] FIG. 4 is a cross-sectional view of the print head taken along the line Bb in FIG. 3. [Figure 7] FIG. 2 is a diagram illustrating a functional configuration of the liquid ejection device. [Figure 8] 10 is a diagram showing an example of a signal waveform of a drive signal COM. FIG. [Figure 9] FIG. 2 is a diagram illustrating a configuration of a drive signal selection circuit. [Figure 10] FIG. 10 is a diagram showing an example of the decoded content in the decoder. [Figure 11] FIG. 2 is a diagram illustrating a configuration of a selection circuit. [Figure 12] 10A and 10B are diagrams for explaining the operation of a drive signal selection circuit. [Figure 13] FIG. 2 is a diagram illustrating an example of the configuration of a temperature detection circuit. [Figure 14] FIG. 2 is a diagram illustrating an example of the configuration of a temperature information output circuit. [Figure 15] FIG. 2 is a diagram illustrating an example of the configuration of a shift register. [Figure 16] FIG. 10 is a diagram showing an example of timing for acquiring the temperature of the print head. [Figure 17] 10A and 10B are diagrams illustrating an example of a method for determining the optimal number of samples of the holding temperature information dtr, and a method for acquiring the temperature of the print head 22 based on the optimal number of samples. [Figure 18] FIG. 10 illustrates an example of a sample number determination process. [Figure 19] FIG. 10 is a diagram illustrating an example of a temperature information acquisition process. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. The embodiments described below are for convenience only. The contents of the disclosure are not unduly limited. Furthermore, all of the configurations described below are included in the present invention. It is not necessarily a required component.

[0010] 1. Schematic configuration of the liquid ejection device FIG. 1 is a diagram showing a schematic configuration of a liquid ejection device 1. The liquid ejection device 1 of this embodiment includes: A carriage 21 mounted with a print head 22 that ejects ink as an example of liquid is moved. The ink ejection mechanism moves back and forth along the scanning axis and ejects ink onto the medium P being transported along the transport direction. In this way, a desired image is formed on the medium P by a so-called serial printing inkjet printer. The medium P in the liquid ejection device 1 may be a printing paper, a resin film, a fabric, etc. Any printing object can be used. The liquid ejection device 1 is a serial printing type. This is not limited to inkjet printers, but also applies to line printing inkjet printers. The liquid ejection device 1 is not limited to an inkjet printer. It is not a color material ejection device used in the manufacture of color filters for liquid crystal displays, etc., but an organic Electrode material used for forming electrodes in EL displays, FEDs (surface-emitting displays), etc. Discharge device, bioorganic substance discharge device used in biochip manufacturing, three-dimensional modeling device, and textile printing equipment It may be a position or the like.

[0011] In the following description, the three mutually orthogonal spatial axes, the X-axis, the Y-axis, and the Z-axis, are referred to as In the following description, the X-axis, the Y-axis, and the Z-axis are used. When specifying the direction of the arrow, the tip of the arrow indicating the direction along the X axis is the +X side, The starting point side is called the -X side, and the tip side of the arrow indicating the direction along the Y axis in the figure is the +Y side. is called the -Y side, the tip side of the arrow indicating the direction along the Z axis is the +Z side, and the starting point side is the -Z It is called the side.

[0012] As shown in FIG. 1, the liquid ejection device 1 includes a control unit 10, a head unit 20, a moving unit The printer includes a knit 30, a transport unit 40, and an ink container 90.

[0013] The ink container 90 stores a plurality of types of ink to be ejected onto the medium P. The ink container 90 in which such ink is stored may be an ink cartridge, a flexible filter, or the like. It uses a bag-shaped ink pack made of rubber and an ink tank that can be refilled with ink. It is possible.

[0014] The control unit 10 includes a CPU (Central Processing Unit) and an FPGA (Field Programmable Gate Array). The head unit includes a processing circuit such as a memory gate array (MGA) and a storage circuit such as a semiconductor memory. The controller 20 controls each element of the liquid ejection device 1 .

[0015] The head unit 20 includes a carriage 21 and a plurality of print heads 22. The edge 21 is fixed to an endless belt 32 included in a moving unit 30, which will be described later. The print heads 22 are mounted on a carriage 21. Each of the rods 22 receives a control signal Ctrl-H output from the control unit 10 and a drive signal Ctrl-H. A signal COM is input to each of the print heads 22. Ink stored in the container 90 is supplied via a tube or the like (not shown). The head 22 controls the ink container 20 based on the input control signal Ctrl-H and the drive signal COM. At this time, the print head 22 ejects ink. The direction along the Z axis from the -Z side to the +Z side along the Z axis is defined as the discharge direction. It may be referred to as.

[0016] The moving unit 30 includes a carriage motor 31 and an endless belt 32. The motor 31 operates based on the control signal Ctrl-C input from the control unit 10. The endless belt 32 extends along the X axis and moves in accordance with the operation of the carriage motor 31. This causes the carriage 21 fixed to the endless belt 32 to move along the X axis. That is, the moving unit 30 moves the plurality of print heads mounted on the carriage 21. The drive 22 is reciprocated along the X axis. When the direction along the X axis along which the multiple print heads 22 mounted on the printer move is referred to as the scanning direction, There is.

[0017] The transport unit 40 includes a transport motor 41 and a transport roller 42. 1 operates based on a control signal Ctrl-T input from the control unit 10. The rollers 42 rotate in accordance with the operation of the transport motor 41 while holding the medium P therebetween. As a result, the medium P sandwiched between the transport rollers 42 moves from the −Y side to the +Y side along the Y axis. That is, the transport unit 40 transports the medium P along the Y axis from the -Y side to the +Y side. In the following description, the medium P is conveyed from the -Y side to the +Y side. The direction toward the Y side may be referred to as the transport direction.

[0018] In the liquid ejection device 1 configured as above, the moving unit 30 controls the movement of the carriage 21. The transport unit 40 controls the reciprocating movement of the medium P along the transport direction. The carriage 21 is controlled to move back and forth along the scanning direction and the medium P In conjunction with the conveyance of the sheet in the conveying direction, the print head 22 mounted on the carriage 21 moves in the direction of the ink jet head. As a result, the ink ejected by the print head 22 is applied to any surface of the medium P. The ink droplets can be made to land on the medium P, forming a desired image on the medium P.

[0019] 2. Schematic structure of the print head Next, an example of the structure of the print head 22 of the head unit 20 will be described. FIG. 2 is an exploded perspective view showing the structure of the print head 22, and FIG. 22 along the Z axis, and FIG. 4 is a plan view of the Aa cross section shown in FIG. FIG. 5 is a detailed view of the main part of FIG. 4; 6 is a cross-sectional view of the print head 22 taken along the line Bb in FIG. 3, the peripheral configuration of the pressure chamber substrate 310 is mainly illustrated, and the protective substrate 330, the case member 340, etc. 4, the configuration of the piezoelectric element 60 is shown in a simplified manner.

[0020] As shown in FIG. 2, the print head 22 includes a pressure chamber substrate 310, a communication plate 315, a nozzle The plate 320, the compliance substrate 345, the protection substrate 330, the case member 340, and The piezoelectric element 60 includes a wiring substrate 420, a vibration plate 350, and a piezoelectric element 60, which will be described later.

[0021] The pressure chamber substrate 310 may be, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates. As shown in FIG. 3, the pressure chamber substrate 310 has a plurality of pressure chambers arranged along the Y axis. Two rows of pressure chambers, each with a row of chambers 312, are formed along the X axis. The pressure chambers 312 are arranged such that the positions of the pressure chambers 312 forming each pressure chamber row along the X axis are the same. The pressure chambers are arranged in a straight line along the Y axis. 6, the pressure chamber substrate 312 is partitioned by a partition wall 311. The arrangement of the pressure chambers 312 in the nozzle 10 is not limited to the above arrangement, and may be, for example, The pressure chambers 312 are arranged in rows such that the positions of the pressure chambers 312 along the X axis are different. In the following description, the pressure may be arranged on a straight line along the Y axis. Of the two pressure chamber rows formed on the pressure chamber substrate 310, the pressure chamber row located on the +X side is referred to as the first pressure chamber row. The pressure chamber row located on the -X side of the first pressure chamber row may be referred to as the "first pressure chamber row," and the pressure chamber row located on the -X side of the first pressure chamber row may be referred to as the "second pressure chamber row." be.

[0022] In addition, the pressure chamber 312 has a length along the X axis in a plan view seen from the +Z side, and a length along the Y axis. It is formed in a rectangular shape, which is longer than the length along the +Z direction. The shape of the pressure chamber 312 in plan view is not limited to a rectangle, but may be a parallelogram. The shape may be a polygon, a circle, an oval, or the like. Here, the oval shape means a rectangular shape. This refers to a shape that is based on a rectangular shape with semicircular ends in the longitudinal direction, and is also called a rounded rectangular shape or an oval shape. , egg-shaped, etc.

[0023] As shown in FIG. 2, a communication plate 315 and a nozzle plate 316 are provided on the +Z side of the pressure chamber substrate 310. 320 and a compliance substrate 345 are laminated together.

[0024] As shown in FIGS. 2, 4, and 5, the communication plate 315 is provided with a nozzle communication passage 316, a first nozzle communication passage 316, a second nozzle communication passage 316, a third nozzle communication passage 316, a fourth nozzle communication passage 316, a fifth ... A second manifold portion 317, a second manifold portion 318, and a supply communication passage 319 are formed. The first manifold portion 317 penetrates the communication plate 315 in the direction along the Z axis. The second manifold portion 318 communicates with the first manifold portion 317, and the communication plate 315 is The first manifold does not penetrate in the direction along the axis, but opens onto the +Z side surface. The second manifold portion 317 and the second manifold portion 318 are connected to a common liquid chamber through which the plurality of pressure chambers 312 communicate. The supply communication passage 319 constitutes a part of the manifold 400. 2, and one of the pressure chambers 312 in the direction along the X axis is provided independently. The end of the manifold 400 communicates with the second manifold portion 318. The ink stored in the nozzles 316 is supplied to each pressure chamber 312. The chamber 312 and the nozzle 321 are in communication with each other.

[0025] Such a communication plate 315 may be a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates. A composite substrate, a metal substrate, or the like can be used. As the metal substrate, for example, a stainless steel substrate can be used. The communicating plate 315 has a coefficient of thermal expansion that is approximately the same as that of the pressure chamber substrate 310. It is preferable to use the same material. Even if the temperature changes, the pressure chamber substrate 310 and the communication plate 3 This reduces the risk of warping of 15.

[0026] The nozzle plate 320 is located on the opposite side of the communicating plate 315 from the pressure chamber substrate 310, i.e., The nozzle plate 320 is located on the +Z side of the through plate 315. The nozzle plate 320 has a nozzle communication passage 31 A plurality of nozzles 321 are formed in communication with the pressure chambers 312 via the nozzles 6. Specifically, The nozzle plate 320 has a nozzle array in which a plurality of nozzles 321 are arranged in parallel along the Y axis. Two rows of nozzles are formed along the X axis. These two rows of nozzles correspond to a first pressure chamber row and a second pressure chamber row. The nozzles 321 correspond to the nozzles forming each nozzle row. The positions of the modules 321 and 322 are aligned along the Y axis so that they are in the same position along the X axis. The arrangement of the nozzles 321 in the nozzle plate 320 is not limited to the above arrangement. For example, the plurality of nozzles 321 may be arranged such that the nozzles 321 form each nozzle row. They may be arranged on a line along the Y axis so that their positions along the X axis are different. That is, the print head 22 of this embodiment has a plurality of nozzles 321. are positioned side by side along the Y axis in the nozzle plate 320.

[0027] The material of such a nozzle plate 320 is not particularly limited, and may be, for example, a silicon substrate, a glass substrate, or the like. A glass substrate, an SOI substrate, various ceramic substrates, and a metal substrate may be used. An organic material such as a resin may also be used. Examples of metal substrates that can be used include stainless steel substrates. It is preferable that the material of the port 320 has a thermal expansion coefficient substantially equal to that of the communicating plate 315. Therefore, when the temperature of the nozzle plate 320 and the communication plate 315 changes, the difference in the thermal expansion coefficient This can reduce the risk of warping of the nozzle plate 320 and the communication plate 315 due to the above.

[0028] The compliance substrate 345, together with the nozzle plate 320, It is located on the opposite side to the chamber substrate 310, that is, on the +Z side of the communication plate 315. The surface substrate 345 is located around the nozzle plate 320 and is formed on the communication plate 315. The openings on the +Z side of the first manifold portion 317 and the second manifold portion 318 are sealed. The compliance substrate 345 is made up of a sealing film 346 made of a flexible thin film and a metal or other and a fixed substrate 347 made of a hard material. In the area facing 400, an opening 348 is formed that is completely removed in the thickness direction. That is, one surface of the manifold 400 is sealed only by the flexible sealing film 346. The Compliance Department 349 has been established.

[0029] On the other hand, the opposite side of the pressure chamber substrate 310 from the nozzle plate 320, etc., i.e., the pressure chamber substrate A vibration plate 350 and a piezoelectric element 60 are laminated on the −Z side of 310. The vibration plate 350 is located on the +Z side of the piezoelectric element 60 in the direction along the Z axis, and Plate 310 is located on the +Z side of diaphragm 350 in the direction along the Z axis.

[0030] Furthermore, on the −Z side of the pressure chamber substrate 310, a retaining plate having approximately the same size as the pressure chamber substrate 310 is provided. The protective substrate 330 is positioned and bonded with an adhesive or the like. A holding portion 331 is formed as a space for protecting the element 60. The holding portion 331 is The protective substrate 60 is provided independently for each row of the piezoelectric elements 60 arranged in parallel along the protective substrate 60. The protection substrate 330 has two holding portions 331 arranged along the X axis. 30 is located between two holding portions 331 aligned along the X axis and penetrates in the direction along the Z axis. A through hole 332 is formed.

[0031] Moreover, on the protection substrate 330, a manifold 400 communicating with the plurality of pressure chambers 312 is provided. A case member 340 is fixed to define the force chamber substrate 310. has substantially the same shape as the above-mentioned communication plate 315 in plan view from the -Z side, and 30 and is also joined to the above-mentioned communication plate 315.

[0032] The case member 340 is formed with a housing portion 341. The housing portion 341 is formed with a pressure chamber substrate. The space has a depth that can accommodate the protective substrate 310 and the protective substrate 330. The protective substrate 330 has an opening on the 330 side that is wider than the surface of the protective substrate 330 that is bonded to the pressure chamber substrate 310. The opening surface of the accommodation portion 341 on the nozzle plate 320 side is connected to the pressure chamber base. When the plate 310 and the protection substrate 330 are housed, the plate 315 seals the space. are.

[0033] The case member 340 also has two outer sides of the storage section 341 in the direction along the X axis. A third manifold portion 342 is formed in the case member 340. The third manifold portion 342 provided in the communication plate 315 and the first manifold portion provided in the communication plate 315 are connected to each other. The manifold 400 is formed by the first manifold portion 317 and the second manifold portion 318. Such manifolds 400 are provided successively along the Y axis, and each The supply communication passage 319 that connects the pressure chamber 312 and the manifold 400 is oriented in the direction along the Y axis. are arranged side by side.

[0034] The case member 340 is connected to the manifolds 400. A supply port 344 for supplying ink is formed in the case member 340. A connection port 343 is provided in communication with the through hole 332 of the protection substrate 330 and through which the wiring substrate 420 is inserted. It is formed.

[0035] The print head 22 is connected to the ink container 9 via an ink tube or the like (not shown). 0 is taken in from the supply port 344. The path from the manifold 400 to the nozzle 321 is filled with the ink. , the integrated circuit 421 outputs a drive signal CO to each of the piezoelectric elements 60 corresponding to the pressure chambers 312. A signal based on M is supplied. This causes the piezoelectric element 60 to bend and deform. The vibration plate 350 is deformed by the shape of the vibration plate 350. The internal pressure of the nozzle 321 changes, and ink is ejected from each nozzle 321 in response to the change in the internal pressure. can be.

[0036] Next, the pressure chamber substrate 310, which includes the above-mentioned vibration plate 350 and piezoelectric element 60, The details of the configuration formed on the -Z side will be described. The print head 22 is formed on a pressure chamber substrate 31. In addition to the vibration plate 350 and the piezoelectric element 60, individual Separate lead electrode 391, common lead electrode 392, measurement lead electrode 393, and resistance wiring 4 It has 01.

[0037] As shown in FIGS. 4 to 6, the vibration plate 350 is made of a silicon oxide film provided on the pressure chamber substrate 310 side. The elastic film 351 is made of zirconia, and the zirconium oxide film is provided on the elastic film 351. and an insulating film 352. The pressure chambers 31 formed in the pressure chamber substrate 310 are The liquid flow path including 2 is formed by anisotropically etching the pressure chamber substrate 310 from the +Z side surface. The vibration plate 350 seals the opening on the +Z side surface of the pressure chamber substrate 310. That is, the pressure chambers 312 formed in the pressure chamber substrate 310 are positioned so as to stop the The surface on the -Z side of the liquid flow path is made up of a vibration plate 350 including an elastic film 351. The configuration of the moving plate 350 is not particularly limited, and for example, it may be made up of an elastic film 351 and an insulating film 35 2, or any other film other than the elastic film 351 and the insulating film 352. The diaphragm 350 may be configured to include other films such as Examples of the material include films of silicon and silicon nitride.

[0038] The piezoelectric element 60 is made up of piezoelectric elements stacked in order from the +Z side, which is the vibration plate 350 side, to the −Z side. The piezoelectric element 60 has a pole 360, a piezoelectric body 370, and an electrode 380. 60, an electrode 380, and a piezoelectric body 370, and In the direction along the Z axis where the piezoelectric body 370 is stacked, the piezoelectric body 370 is Such a piezoelectric element 60 generates a pressure change in the pressure chamber 312. It functions as a piezoelectric actuator.

[0039] Specifically, both the electrode 360 ​​and the electrode 380 are electrically connected to the wiring substrate 420. An integrated circuit mounted on the wiring board 420 is connected to one of the electrodes 360 and 380. A signal based on the drive signal COM output from the output 421 is supplied to the other of the electrodes 360 and 380. A signal of a reference potential is supplied to the wiring board 420. is a voltage between a signal based on the drive signal COM supplied from the integrated circuit 421 and a signal at the reference potential. The potential difference generated between the electrode 360 ​​and the electrode 380 causes the piezoelectric element 37 Then, in response to the deformation of the piezoelectric body 370, the vibration plate 350 deforms or vibrates. The volume of the pressure chamber 312 changes due to the deformation or vibration of the diaphragm 350. The change in internal pressure caused by the volume change is applied to the ink contained in the pressure chamber 312. As a result, the ink is ejected from the nozzle 321 via the nozzle communication passage 316. In the following description, the driving signal output from the integrated circuit 421 mounted on the wiring board 420 is A signal based on the signal COM is supplied to the electrode 360, and the reference potential of the signal COM propagates through the wiring board 420. The description will be given assuming that a signal is provided to electrode 380 .

[0040] In the following description, in the piezoelectric element 60, a voltage is applied between the electrode 360 ​​and the electrode 380. When a potential difference occurs, the portion of the piezoelectric body 370 where piezoelectric distortion occurs is called an active portion 410. The portion of the body 370 where no piezoelectric strain occurs may be referred to as the inactive portion 415. In the piezoelectric element 60, the portion where the piezoelectric body 370 is sandwiched between the electrode 360 ​​and the electrode 380 is the active portion 41. 0, and the portion where the piezoelectric body 370 is not sandwiched between the electrodes 360 and 380 is the inactive portion. In the following description, when the piezoelectric element 60 is driven, the The part that displaces in the direction of the Z axis is called the flexible part, and the part that does not displace in the direction of the Z axis is called the non-flexible part. That is, in the piezoelectric element 60, the pressure chamber 312 is The opposing portions correspond to the flexible portions, and the portions outside the pressure chamber 312 correspond to the non-flexible portions. Active section 410 may also be referred to as the active section, and inactive section 415 may also be referred to as the inactive section.

[0041] Generally, one of the electrodes 360 and 380 located in the active portion 410 is activated. The active portion 410 is configured as an independent individual electrode, and the other is configured as a common electrode common to the active portion 410. In the following description, the signal based on the drive signal COM output from the integrated circuit 421 is The electrode 360 ​​to which the signal is supplied is an individual electrode, and the signal of the reference potential propagating through the wiring board 420 The following description will be given assuming that the electrode 380 to which the signal is supplied is a common electrode.

[0042] Specifically, the electrode 360 ​​is located on the +Z side of the piezoelectric body 370, and The electrodes 360 are separated into individual electrodes for each active portion 410. The electrodes 360 are individually provided corresponding to the plurality of pressure chambers 312. In the direction of the electrode 3, the width of the electrode 3 is narrower than the width of the pressure chamber 312. The end of 60 is located inside the region facing the pressure chamber 312 in the direction along the Y axis. The end 360a on the +X side and the end 360b on the −X side of the electrode 360 ​​are respectively This is located outside the pressure chamber 312. For example, as shown in FIG. The end 360a is located on the +X side of the end 312a of the pressure chamber 312 on the +X side. The portion 360b is located closer to the -X side than the end 312b of the pressure chamber 312 on the -X side.

[0043] The material of such an electrode 360 ​​is not particularly limited, and may be, for example, platinum (Pt), iridium ( Metals such as Ir, gold (Au), and titanium (Ti), and indium oxide (ITO) Conductive materials such as conductive metal oxides such as zinc may also be used, and platinum (Pt), iridium (Ir) and the like may also be used. The material used is a laminate of multiple materials such as titanium (Ti), iridium (Ir), gold (Au), and titanium (Ti). In the following description, the electrode 360 ​​in this embodiment is made of platinum (Pt).

[0044] As shown in FIG. 3, the piezoelectric body 370 has a predetermined length along the X axis. , are provided continuously in the direction along the Y axis. The chambers 312 are provided continuously with a predetermined thickness along the direction in which they are arranged side by side. The thickness of the conductive body 370 is not particularly limited, and may be, for example, 1000 to 4000 nanometers. It is formed to a thickness of about 1 / 4 inch.

[0045] 5, the length of the piezoelectric body 370 in the direction along the X axis is The length of the pressure chamber 312 is longer than the length along the X axis, which is the longitudinal direction. On both sides of the inclined direction, the piezoelectric body 370 extends to the outside of the pressure chamber 312. As shown, the piezoelectric body 370 extends to the outside of the pressure chamber 312 in the direction along the X axis. This improves the strength of the diaphragm 350. Therefore, the risk of cracks occurring in the vibration plate 350 and the piezoelectric element 60 is reduced.

[0046] 5, in the first pressure chamber row, the end 3 on the +X side of the piezoelectric body 370 70a is located on the +X side, which is outside the end 360a of the electrode 360. The end 360a of the electrode 360 ​​is covered with the piezoelectric body 370. The end 370b on the −X side is located on the +X side, which is more inward than the end 360b of the electrode 360. That is, the end 360 b of the electrode 360 ​​is not covered with the piezoelectric body 370 .

[0047] 3 and 6, the piezoelectric body 370 has other regions corresponding to the partition walls 311. The groove portion 371 is formed in the area thinner than the other area. , is formed by completely removing the piezoelectric body 370 in the direction along the Z axis. The piezoelectric body 370 has a portion thinner than the other region, and the piezoelectric body 370 is formed on the bottom surface of the groove 371. Not only when the piezoelectric element 370 is formed thinner than other parts, but also when the piezoelectric element 370 is formed along the Z axis The length of the groove 371 in the Y-axis direction, That is, the width of the groove 371 is equal to or wider than the width of the partition wall 311. In this embodiment, the width of the groove 371 is wider than the width of the partition wall 311. The portion 371 is formed to have a rectangular shape when viewed from the -Z side. However, the shape of the groove 371 in plan view from the -Z side is not limited to a rectangular shape, and may be a polygon with pentagons or more. It may be rectangular, circular, elliptical, or the like.

[0048] By providing grooves 371 in the piezoelectric body 370, the pressure chamber 312 of the vibration plate 350 is The rigidity of the part facing the end in the direction along the diaphragm 350, that is, the arm part of the diaphragm 350, is reduced. , the piezoelectric element 60 can be displaced more effectively.

[0049] Such a piezoelectric body 370 is formed on the electrode 360 ​​and exhibits an electromechanical conversion function. Perovskite-structured crystalline film made of ferroelectric ceramic material, so-called perovskite type Examples of the material of the piezoelectric body 370 include zirconate titanate. Ferroelectric piezoelectric materials such as lead (PZT) and niobium oxide, nickel oxide or magnesium oxide are used. The metal oxides such as lead titanate (PbTiO 3), lead zirconate titanate (Pb(Zr,Ti)O3), lead zirconate (PbZr O3), lead lanthanum titanate ((Pb,La),TiO3), lead lanthanum zirconate titanate Titanium ((Pb,La)(Zr,Ti)O3) or magnesium zirconium niobate Lead titanate (Pb(Zr,Ti)(Mg,Nb)O3) can be used. The piezoelectric body 370 of this embodiment will be described as being made of lead zirconate titanate (PZT).

[0050] The material of the piezoelectric body 370 is not limited to lead-based piezoelectric materials containing lead, but may be any other material containing no lead. It is also possible to use lead-free piezoelectric materials. Examples of such lead-free piezoelectric materials include For example, bismuth ferrate (BiFeO3, abbreviated as "BFO"), barium titanate (BaT iO3), abbreviated as "BT"), potassium sodium niobate ((K,Na)(NbO3), abbreviated as "BT" "KNN"), potassium sodium lithium niobate ((K,Na,Li)(NbO3) ), potassium sodium lithium tantalate niobate ((K,Na,Li)(Nb,Ta )O3), bismuth potassium titanate ((Bi1 / 2K1 / 2)TiO3, abbreviated as "BKT" ), bismuth sodium titanate ((Bi1 / 2Na1 / 2)TiO3, abbreviated as "BNT") , bismuth manganate (BiMnO3, abbreviated as "BM"), bismuth, potassium, titanium and Complex oxides containing iron and having a perovskite structure (x[(BixK1-x)TiO3]- (1-x) [BiFeO3], abbreviated as "BKT-BF"), bismuth, iron, barium and titanium The complex oxide ((1-x)[BiFeO3]-x[B aTiO3, abbreviated as "BFO-BT") and metals such as manganese, cobalt, and chromium (1-x)[Bi(Fe1-yMy)O3]-x[BaTiO3](M Examples of the element include Mn, Co, and Cr).

[0051] As shown in FIGS. 3, 5, and 6, the electrode 380 is connected to the piezoelectric body 370 via the electrode 360. The common electrode 410 is located on the opposite side to the piezoelectric body 370 and on the −Z side of the piezoelectric body 370. That is, the electrode 380 is provided in common to the plurality of pressure chambers 312. The electrode 380 has a predetermined length along the X axis and a predetermined length along the Y axis. The electrode 380 is provided continuously over the inner surface of the groove 371, i.e., the piezoelectric The insulating film 352 is also provided on the side surface of the groove 371 of the body 370 and on the bottom surface of the groove 371. In addition, the electrode 380 is attached to only a part of the inner surface of the groove 371. It is not necessary to provide the groove 371 over the entire inner surface thereof.

[0052] 5, in the first pressure chamber row, the end 3 on the +X side of the electrode 380 80a is positioned outside the end 360a of the electrode 360 ​​covered with the piezoelectric body 370. That is, the end 380a of the electrode 380 is disposed on the +X side of the pressure chamber 312. The +X side is outside the portion 312a, and outside the end 360a of the electrode 360. In this embodiment, the end 380a of the electrode 380 is located on the +X side along the X axis. In the direction of the active portion, the active portion substantially coincides with the end 370a of the piezoelectric body 370. The edge of the +X side of 410, that is, the boundary between the active portion 410 and the inactive portion 415, is the electrode 360. The end 360a is defined by the end 360a.

[0053] On the other hand, the end 380b on the −X side of the electrode 380 is located outside the end 312b of the pressure chamber 312. The piezoelectric element 370 is located on the -X side, i.e., on the +X side, which is inside the end 370b of the piezoelectric element 370. As described above, the end 370b of the piezoelectric body 370 is more positive than the end 360b of the electrode 360. Therefore, the end 380b of the electrode 380 is located on the inner side of the electrode 360. The electrode 38 is located on the piezoelectric body 370, which is closer to the +X side than the end 360b of the electrode 38. On the −X side of the end 380b of the piezoelectric element 370, there is a portion where the surface of the piezoelectric element 370 is exposed. In this way, the end 380b of the electrode 380 is connected to the end 370b of the piezoelectric body 370 and the end 360 of the electrode 360. Therefore, the end of the active portion 410 on the -X side, That is, the boundary between the active portion 410 and the inactive portion 415 is defined by the end 380b of the electrode 380. It is determined.

[0054] The material of the electrode 380 is not particularly limited, and may be, for example, the same as the electrode 360. , platinum (Pt), iridium (Ir), gold (Au), titanium (Ti) and other metals, IT Even if conductive materials such as conductive metal oxides such as indium tin oxide, abbreviated as O, are used, Often, multiple materials such as platinum (Pt), iridium (Ir), gold (Au), and titanium (Ti) are used. The electrode 380 of this embodiment may be made of iridium. The explanation will be given assuming that (Ir).

[0055] In addition, the outside of the end 380b of the electrode 380, i.e., the further end 380b of the electrode 380 On the −X side, there is a wiring portion that is in the same layer as the electrode 380 but is electrically discontinuous with the electrode 380. The wiring portion 385 is provided so as not to come into contact with the end portion 380b of the electrode 380. The piezoelectric element 370 is provided on the −X side of the piezoelectric element 370 with a gap therebetween. The wiring portion 385 is formed over the electrode 360. The wiring portion 385 is independent for each active portion 410. That is, the wiring portions 385 are arranged at predetermined intervals in the direction along the Y axis. The wiring portion 385 may be formed in a layer different from the electrode 380. However, it is preferable to form the wiring portion 385 in the same layer as the electrode 380. The manufacturing process can be simplified and costs can be reduced.

[0056] Further, individual lead electrodes 391 are connected to the electrodes 360 constituting the piezoelectric element 60. 380 are electrically connected to a common lead electrode 392 which is a common electrode for driving. The ends of the individual lead electrodes 391 and the common lead electrode 392 connected to the piezoelectric element 60 are The opposite end is electrically connected to a wiring board 420. A control unit 10, a temperature information output circuit 26, and a plurality of circuits (not shown) for connecting to the control unit 10, the temperature information output circuit 26, and a plurality of circuits (not shown) Such a wiring board 420 is, for example, an FPC (Flexible Printed Circuit) It consists of a printed circuit.

[0057] In this embodiment, the individual lead electrodes 391 and the common lead electrode 392 are connected to the protection substrate 330. The wiring board is provided with a through hole 332 formed in the wiring board. 420. The wiring board 420 is also electrically connected to the piezoelectric element 60. An integrated circuit 421 is mounted on the device to output a signal for this purpose.

[0058] In this embodiment, the individual lead electrode 391 and the common lead electrode 392 are formed in the same layer. are electrically discontinuous. The manufacturing process is simplified compared to when the common lead electrode 392 is formed separately. Of course, the individual lead electrodes 391 and the common lead electrode 39 2 may be formed from different layers.

[0059] The material of the individual lead electrode 391 and the common lead electrode 392 has electrical conductivity. There is no particular limitation as long as the material is used, and examples thereof include gold (Au), copper (Cu), titanium (Ti), and titanium. W, Nickel (Ni), Chromium (Cr), Platinum (Pt), Aluminum (A In this embodiment, the individual lead electrodes 391 and the common lead The electrode 392 will be described as being made of gold (Au). The lead electrode 392 improves the adhesion between the electrode 360, the electrode 380 and the diaphragm 350. The adhesive layer may have an adhesive layer for preventing adhesion.

[0060] The individual lead electrodes 391 are provided for each active portion 410, i.e., for each electrode 360. For example, as shown in FIG. 5, in the first pressure chamber row, the individual lead electrode 391 is 385, the piezoelectric body 370 is connected to the vicinity of the end 360b of the electrode 360 ​​provided on the outside of the piezoelectric body 370. and is drawn out in the direction along -X onto the pressure chamber substrate 310, actually onto the vibration plate 350. are.

[0061] On the other hand, as shown in FIG. 3, in the first pressure chamber row, the common lead electrode 392 is At both ends of the piezoelectric body 370 in the direction of vibration, the piezoelectric body 370 vibrates from the electrode 380 that constitutes the common electrode. The common lead electrode 392 is extended to the −X side onto the plate 350. 3 and 5, for example, in the first pressure chamber row, The extension portion 392a extends in the direction along the Y axis in a region corresponding to the end portion 312a of the pressure chamber 312. The extension portion 392b is provided in a region corresponding to the end portion 312b of the pressure chamber 312, and extends along Y The extension portions 392a and 392b are provided to extend in the direction along the axis. The active portion 410 is provided continuously in the direction along the Y axis.

[0062] Further, the extension portion 392a and the extension portion 392b are spaced apart from each other in the direction along the X axis. 2 to the outside of the pressure chamber 312. The active portion 410 is located outside the pressure chamber 312 at both ends of the pressure chamber 312 in the direction along the X axis. The extension portion 392a and the extension portion 392b apply pressure to the active portion 410. It extends to the outside of the chamber 312 .

[0063] As shown in FIG. 5, a resistive wiring 401 is provided on the −Z side surface of the diaphragm 350. The resistance wire 401 utilizes the property that the electrical resistance value changes depending on the temperature, and The material of the resistive wiring 401 is a material whose electrical resistance value is temperature dependent. The material is, for example, gold (Au), platinum (Pt), iridium (Ir), aluminum Aluminum (Al), Copper (Cu), Titanium (Ti), Tungsten (W), Nickel (Ni), Chromium (Cr) or the like can be used.

[0064] Of these, platinum (Pt) has a large change in resistance due to temperature, and is highly stable and accurate. Furthermore, platinum (Pt) has a high linearity in the change in resistance value with respect to temperature change. Therefore, platinum (Pt) is preferably used as the material for the resistive wiring 401. The wiring 401 is preferably made of platinum (Pt). In this case, the resistive wiring 401 is in the same layer as the electrode 360 ​​and is electrically discontinuous with the electrode 360. In other words, the resistive wiring 401 is formed on the −Z side surface of the diaphragm 350. The wiring pattern is laminated on the −Z side surface of the diaphragm 350 in the direction along the Z axis. The wiring pattern contains platinum (Pt).

[0065] As shown in FIG. 3, one end of the resistance wiring 401 is connected to the measurement lead electrode 393a. The other end of the resistance wiring 401 is connected to the measurement lead electrode 393b. The electrodes 393a and 393b are electrically connected to the wiring board 420. The temperature of the pressure chamber 312 detected by the anti-wire 401 varies depending on the temperature of the pressure chamber 312. A signal having a voltage value corresponding to the electrical resistance value is output from the print head 22.

[0066] In this embodiment, the resistive wiring 401 is covered with the piezoelectric body 370 and is In the direction of the arrow, the resistive wiring 401 is located between the vibration plate 350 and the piezoelectric element 370. a meandering pattern on the first pressure chamber row side located on the +X side in the direction along the X axis, and a meandering pattern on the first pressure chamber row side located on the +X side in the direction along the X axis; and a second pressure chamber row side meander pattern located on the -X side in the direction perpendicular to the first pressure chamber. The row-side meandering pattern is, when viewed from the -Z side, a pattern that communicates with each pressure chamber 312 that constitutes the first pressure chamber row. The second pressure passage 314 is positioned so as to overlap with the supply communication passage 319, and meanders in the direction along the Y axis. The chamber row side meandering pattern is connected to each pressure chamber 312 constituting the second pressure chamber row when viewed from the -Z side. The supply passage 319 is positioned so as to overlap with the supply passage 319, and snakes along the Y axis. That is, the resistance wiring 401 is connected to a first pressure chamber corresponding to a first pressure chamber row formed by a plurality of pressure chambers 312. The chamber row side meandering pattern and the second pressure chamber corresponding to the second pressure chamber row formed by the plurality of pressure chambers 312 and a chamber row side serpentine pattern.

[0067] 4 and 5, the Z-axis of the pressure chamber 312 and the resistance wiring 401 are The distance along the axis is shorter than the dimension of the pressure chamber 312 along the Z axis. In addition, for example, in the first pressure chamber row, the end 312a of the pressure chamber 312 on the +X side and the resistance wiring 4 The longest distance between the pressure chamber 312 and the pressure chamber 312 in the direction along the X axis is Therefore, the electrical resistance value of the resistance wiring 401 changes depending on the temperature change of the pressure chamber 312. It is easy to adapt and change.

[0068] Measurement lead electrodes 39 including measurement lead electrodes 393a and 393b In this embodiment, the lead electrode 3 is made of the same layer as the individual lead electrode 391 and the common lead electrode 392. However, it is formed so as to be electrically discontinuous. 3 is formed separately from the individual lead electrode 391 and the common lead electrode 392, The manufacturing process can be simplified and the cost can be reduced. 3 is formed in a layer different from the individual lead electrodes 391 and the common lead electrode 392. Good too.

[0069] The material of such measuring lead electrode 393 is not particularly limited as long as it is a conductive material. For example, gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel Ni (Ni), chromium (Cr), platinum (Pt), aluminum (Al), etc. can be used. In the following description, the measurement lead electrode 393 of this embodiment is made of gold (Au). That is, the material of the measuring lead electrode 393 in this embodiment is the same as that of the individual lead electrode 3 91 and the common lead electrode 392. The measurement lead electrode 393 is a resistance wire. An adhesive layer that improves adhesion to the wire 401 and the diaphragm 350 may be provided.

[0070] As described above, in this embodiment, the measurement lead electrode 393 is formed on the protection substrate 330. The wiring board 420 is electrically connected to the wiring board 420 through the through hole 332. As a result, the resistance wiring 401 that changes depending on the temperature of the pressure chamber 312 The electrical resistance value is output from the print head 22 via the wiring board 420.

[0071] That is, the print head 22 of the head unit 20 of this embodiment has an electrode 36 0, electrode 380, and piezoelectric body 370, In the direction along the Z axis where the layers are stacked, the piezoelectric body 370 is located between the electrode 360 ​​and the electrode 380. a piezoelectric element 60 that is driven by receiving a drive signal COM, and a The vibration plate is located on the +Z side, which is one side of the direction along the axis, and is deformed by driving the piezoelectric element 60. 350, and is located on the +Z side, which is one side of the diaphragm 350 in the direction along the Z axis, and A pressure chamber 312 is provided in which air is stored and the volume of which changes with the deformation of the vibration plate 350. a pressure chamber substrate 310 in which ink is ejected in accordance with the change in the volume of the pressure chamber 312; 21, and a pressure chamber 350 located on the other side, i.e., the -Z side, of the vibration plate 350 in the direction along the Z axis. and a resistance wiring 401 for acquiring a temperature corresponding to the temperature of the sensor 312.

[0072] 3. Configuration of the liquid ejection device Next, the functional configuration of the liquid ejection device 1 will be described. As shown in FIG. 7, the liquid ejection device 1 includes a control unit 10, a head unit 11, a 20, a carriage motor 31, a transport motor 41, an encoder sensor 92, and and an alarm circuit 94.

[0073] The control unit 10 includes a drive circuit 50, a reference voltage output circuit 52, and a control circuit 100. The control circuit 100 is composed of a processing circuit such as a CPU or FPGA and a semiconductor memory. The control circuit 100 includes a memory circuit. The control circuit 100 is connected to the outside of the liquid ejection device 1 so as to be able to communicate with the outside. An image information signal including image data and the like is input from an external device such as a host computer. The control circuit 100 controls the liquid ejection device 1 based on the input image information signal. The control circuit 100 generates various signals and outputs them to the corresponding components. It controls the print head 22 and the drive circuit 50.

[0074] As a specific example, the control circuit 100 receives an encoder sensor signal in addition to the image information signal described above. The head unit 20 receives the scanning position of the carriage 21 from the sensor 92. The control circuit 100 receives the position detection signal PS. Based on this, the scanning position of the carriage 21 and the print head mounted on the carriage 21 are The control circuit 100 then determines the scanning position of the head unit 20 including the input 22. The image information signal to be input and various signals corresponding to the grasped scanning position of the head unit 20 are transmitted. Generate and output to the corresponding configuration.

[0075] In detail, the control circuit 100 controls the head unit 20 in accordance with the scanning position of the head unit 20. Generates a control signal Ctrl-C to control the movement of the carrier 20 along the scan axis. This outputs the signal to the carriage motor 31, which then operates the carriage motor 31. The movement of the head unit 20 mounted on the scanner 21 along the scanning axis and the scanning position are controlled. The control circuit 100 also generates a control signal Ctrl-T for controlling the transport of the medium P. Then, the signal is output to the transport motor 41. This causes the transport motor 41 to operate, and the transport of the medium P The control signal Ctrl-C is sent to a driver (not shown) to control the movement along the feed direction. After being converted into a signal through a circuit, the signal may be input to the carriage motor 31. Ctrl-T is converted into a signal through a driver circuit (not shown) and then driven by the transport motor 41 may be entered into

[0076] The control circuit 100 also controls the image information signal input from the external device and the head unit 2. 0 scanning position, and a control signal Ctrl- for controlling the head unit 20 based on H, the print data signals SI1 to SIn, the change signal CH, the latch signal LAT, and A clock signal SCK is generated and output to the head unit 20.

[0077] Furthermore, the control circuit 100 includes a temperature measuring device for acquiring information on the temperature of the head unit 20. The control circuit 100 generates a data acquisition request signal TD and outputs it to the head unit 20. The temperature information signal TD includes information about the temperature of the head unit 20 in response to the temperature acquisition request signal TD. The control circuit 100 receives the temperature information signal TI. The temperature of the drive unit 20 is detected, and the control signal Ctrl- H, Ctrl-C, and Ctrl-T are corrected and output to the corresponding configuration. The temperature of the ink jet head 22 is measured by the liquid ejection device 1 and the head 22 in response to the temperature information signal TI. As a result, the operation of the liquid ejection device 1 and the head unit 20 Therefore, the ejection accuracy of the ink ejected from the nozzle is improved.

[0078] The control circuit 100 also generates a control signal Ctrl-H as a basic drive signal, which is a digital signal. The drive circuit 50 generates a drive signal dA and outputs it to the drive circuit 50. The drive circuit 50 outputs the drive signal COM to the A drive signal COM having a signal waveform defined by the drive signal dA is generated, and the drive signal COM is output to the head unit 2. Output to 0.

[0079] Specifically, the basic drive signal dA output from the control circuit 100 is input to the drive circuit 50. The driving circuit 50 converts the inputted basic driving signal dA into a digital / analog signal, and then converts it into an analog signal. The converted analog signal is amplified by class D to generate the drive signal COM, which is then sent to the head unit 2. 0. That is, the control circuit 100 outputs the control signal corrected based on the temperature information signal TI. The driving circuit 50 outputs the basic driving signal dA as the signal Ctrl-H, and the temperature information signal TI The drive signal COM having a corrected signal waveform according to the base drive signal dA corrected based on the Here, the basic drive signal dA output by the control circuit 100 is a signal wave of the drive signal COM. The basic drive signal dA is a digital signal that defines the shape of the drive signal CO. It is sufficient to specify the signal waveform of M, and it may be an analog signal. The circuit 50 amplifies the signal waveform defined by the basic drive signal dA in a class A, class B, or class AB manner. The drive signal COM may be generated by amplifying the signal.

[0080] As described above, the drive circuit 50 generates and outputs the drive signal COM based on the basic drive signal dA. At this time, the basic drive signal dA input to the drive circuit 50 is The basic drive signal dA to be output is also determined based on the temperature information signal TI. Therefore, the driving circuit 50 corrects the temperature of the head unit 20. The drive signal COM corrected based on the above is output.

[0081] The reference voltage output circuit 52 generates a reference voltage signal VBS and outputs it to the head unit 20. This reference voltage signal VBS is a signal having a constant voltage value that serves as a reference for driving the piezoelectric element 60. The voltage of the reference voltage signal VBS is supplied to the common electrode 380. The value may be, for example, a constant signal at ground potential, or at a potential such as 5.5V or 6V. It may also be a constant signal.

[0082] The control circuit 100 also includes a drive circuit 50, a reference voltage output circuit 52, and a head unit A control signal Ctrl-M is generated to notify the user of the operating status of the control signal Ctrl-M. The notification circuit 94 notifies the user of information corresponding to the control signal Ctrl-M. This notifies the user of the operating status of the liquid ejection device 1. The information may be displayed by text or images, or by sound. It may also be a speaker that announces the information.

[0083] The head unit 20 includes a plurality of print heads 22, namely, print heads 22-1 to 22-n, a temperature information output circuit 26, and a temperature detection circuit 28. Each of the nodes 22-1 to 22-n includes a drive signal selection circuit 200, a temperature detection circuit 250, and and a plurality of piezoelectric elements 60.

[0084] The print head 22-1 receives a print data signal SI1 output from the control circuit 100, A shift signal CH, a latch signal LAT, a clock signal SCK, a drive signal COM, and a reference voltage A signal VBS is input. A clock signal SCK and a line are input to the print head 22-1. The latch signal LAT, the change signal CH, the print data signal SI1, and the drive signal COM are The signal is input to the signal selection circuit 200.

[0085] The drive signal selection circuit 200 receives the input clock signal SCK, latch signal LAT, The signal wave included in the drive signal COM is generated based on the change signal CH and the print data signal SI1. By selecting or not selecting the shape, the drive signals corresponding to the plurality of piezoelectric elements 60 are generated. Then, the drive signal selection circuit 200 generates the drive signal VOUT. , one end of each of the corresponding piezoelectric elements 60, and each of the electrodes 360 which are individual electrodes. At this time, the other end of the plurality of piezoelectric elements 60 is connected to the electrode 38 which is a common electrode. A reference voltage signal VBS is input to all of the piezoelectric elements 60. Each of these is a drive signal VOUT input to the electrode 360 ​​and a base signal VB input to the electrode 380. As a result, the piezoelectric element 60 is displaced by an amount corresponding to the displacement of the piezoelectric element 60. The ink is ejected from the corresponding nozzles 321 of the print head 22-1.

[0086] That is, the print head 22-1 receives the drive signal COM and ejects ink. At least a part of the drive signal selection circuit 200 is programmed as the integrated circuit 421 described above. It may be mounted on the wiring board 420 of the print head 22-1.

[0087] The temperature detection circuit 250 of the print head 22-1 detects the temperature of the print head 22- The temperature detection circuit 250 detects the temperature of the print head 22-1. The head temperature signal TC1 corresponding to the temperature is output to the temperature information output circuit 26. The detection circuit 250 is partly provided in the print head 22-1 and partly provided in the print head 22-2. It may be provided outside the print head 22-1. The part of the temperature detection circuit 250 thus formed corresponds to the resistive wiring 401 described above. The temperature detection circuit 250 outputs a head temperature signal T corresponding to the temperature of the print head 22-1. The voltage value of C1 changes according to the resistance value of the resistive wiring 401, which changes with temperature. Then, the voltage value of the head temperature signal TC1 output by the temperature detection circuit 250 is The temperature of the print head 22-1 is determined depending on the temperature of the pressure chamber 312 of the print head 22-1. It changes.

[0088] The print heads 22-2 to 22-n have different input and output signals. It has the same configuration as the print head 22-1 and performs the same operations. The print head 22-i (i is any one of 2 to n) receives a clock signal SCK, a latch signal signal LAT, change signal CH, print data signal SIi, drive signal COM, and reference voltage signal Then, the drive signal selection circuit 20 of the print head 22-i receives the signal VBS. 0 is the input clock signal SCK, latch signal LAT, change signal CH, and print The signal waveform of the drive signal COM is selected or not selected based on the data signal SIi. Then, a drive signal VOUT corresponding to each of the plurality of piezoelectric elements 60 is generated, and the corresponding piezoelectric The print head 22-i has a plurality of piezoelectric elements. A reference voltage signal VBS is commonly input to the electrode 380 of the element 60. The print head 22-i has a plurality of piezoelectric elements 60 that are driven, and in response to the driving of the piezoelectric elements 60, The amount of ink is ejected from the nozzle 321 of the print head 22-i. The print heads 22-2 to 22-n also receive the drive signal COM and eject ink. do.

[0089] The temperature detection circuit 250 of the print head 22-i detects the temperature of the print head 22-i. The head temperature signal TCi having a voltage value corresponding to the temperature of i is output to the temperature information output circuit 26. At least a part of the drive signal selection circuit 200 of the print head 22-i is The integrated circuit 421 is mounted on the wiring board 420 of the print head 22-i. At least a part of the temperature detection circuit 250 of the print head 22-i is the above-mentioned resistor wiring. The line 401 is provided on the print head 22-i.

[0090] In the following description, the print heads 22-1 to 22-n will not be distinguished from one another. The print head 22 receives a clock signal SCK, a latch signal LAT, and a change signal C H, a print data signal SI as print data signals SI1 to SIn, and a drive signal COM. , and the reference voltage signal VBS are input. The temperature detection circuit 250 outputs a head temperature signal TC The following description will be given on the assumption that head temperature signals TC as TC1 to TCn are output.

[0091] The temperature detection circuit 28 detects the temperature of the head unit 20 including the print heads 22-1 to 22-n. The temperature detection circuit 28 then outputs a unit voltage value corresponding to the detected temperature. The temperature detection circuit 28 converts the generated unit temperature signal TH into temperature information. The temperature detection circuit 28 outputs the temperature information to the information output circuit 26 and the control circuit 100. The resistance value of thermistor element changes depending on the temperature change of the board unit 20. can be.

[0092] The temperature information output circuit 26 outputs the temperature information from each of the print heads 22-1 to 22-n. the head temperature signals TC1 to TCn, the unit temperature signal TH output by the temperature detection circuit 28, A temperature information signal TI is generated in response to a temperature acquisition request signal TD output by the control circuit 100. and outputs the temperature information to the control circuit 100. The head temperature signals TC1 to TCn corresponding to the temperature of 2 are acquired, and the acquired head temperature signals TC 1 to TCn, and outputs a temperature information signal TI according to the temperature information signals TC1 to TCn.

[0093] Specifically, the temperature information output circuit 26 receives a temperature acquisition request signal from the control circuit 100. When the head temperature signal TC is selected from the head temperature signals TC1 to TCn according to the signal TD, The temperature information output circuit 26 amplifies the selected head temperature signal TC. The amplified head temperature signal TC is corrected based on the unit temperature signal TH. The temperature information signal TI corresponding to the corrected signal is output to the control circuit 100. The configuration and operation of the power circuit 26 will be described in detail later.

[0094] 4. Signal waveform of drive signal COM and configuration of drive signal selection circuit Next, the configuration and operation of the drive signal selection circuit 200 of the print head 22 will be described. As described above, the drive signal selection circuit 200 of the print head 22 selects the clock based on the clock signal SCK, the print data signal SI, the latch signal LAT, and the change signal CH. By selecting or not selecting the signal waveform included in the drive signal COM, the drive signal VOU T is generated and output to the corresponding piezoelectric element 60. In explaining the operation, first, during the period when ink is ejected onto the medium P, An example of the waveform of the drive signal COM input to the signal selection circuit 200 will now be described. In the following description, the period during which ink is ejected onto the medium P may be referred to as the ejection period. .

[0095] FIG. 8 is a diagram showing an example of the signal waveform of the drive signal COM during the ejection period. As shown in the figure, during the discharge period, the drive signal COM is latched after the latch signal LAT rises. The trapezoidal waveform Adp is placed in the period t1 until the change signal CH rises, and It is placed in the period t2 from when the signal CH rises to when the next change signal CH rises. The trapezoidal waveform Bdp and the latch signal LAT rise after the change signal CH rises. The trapezoidal waveform Cdp is arranged in the period t3 until the predetermined amount The trapezoidal waveform Bdp is a signal waveform that drives the piezoelectric element 60 to eject ink. This is a signal waveform that drives the piezoelectric element 60 so that a smaller amount of ink is ejected than the fixed amount, and is a trapezoidal waveform. The waveform Cdp is a signal waveform that drives the piezoelectric element 60 to such an extent that ink is not ejected. Here, when the trapezoidal waveform Cdp is supplied to the corresponding piezoelectric element 60, the corresponding nozzle opening The ink near the nozzle opening is vibrated to reduce the risk of the ink viscosity increasing near the nozzle opening. This is the signal waveform for

[0096] In addition, the trapezoidal waveforms Adp, Bdp, and Cdp have their respective start and end timings. The voltage value in each waveform is the same as the voltage Vc. , Bdp, and Cdp each start and end at voltage Vc.

[0097] In the following description, when a trapezoidal waveform Adp is supplied to the piezoelectric element 60, the ejection A predetermined amount of ink is called a medium amount, and when a trapezoidal waveform Bdp is supplied to the piezoelectric element 60, In some cases, an amount of ink that is smaller than the predetermined amount to be ejected may be referred to as a small amount. In addition, when a trapezoidal waveform Cdp is supplied to the piezoelectric element 60, the node corresponding to the piezoelectric element 60 The action of vibrating the ink near the nozzle opening to prevent the ink viscosity from increasing is called micro-vibration. The signal waveform of the drive signal COM shown in FIG. 8 is an example and is not intended to be limiting. It is not possible to determine the size of the ink droplets, but rather it is possible to determine the size of the ink droplets depending on the properties of the ink to be ejected and the material of the medium P on which the ink will land. Therefore, various waveform combinations may be used.

[0098] Then, in a cycle tp including periods t1, t2, and t3, the drive signal selection circuit 200 The trapezoidal waveforms Adp, Bdp, and Cdp included in the drive signal COM are selected or not selected. As a result, the drive signal selection circuit 200 selects the drive signal for each of the plurality of nozzles 321 in the period tp. That is, the drive signal selection circuit 200 controls the amount of ink ejected from the peripheral The dot size formed on the medium P during the period tp is controlled. In a period tp including the period, dots of a predetermined size are formed on the medium P. The period tp at which dots are formed corresponds to the dot formation period.

[0099] Next, the signal waveform included in the drive signal COM is selected or deselected to generate the drive signal VO The configuration and operation of the drive signal selection circuit 200 that generates the UT will be described. 9 is a diagram showing the configuration of the drive signal selection circuit 200. As shown in FIG. 0 has a selection control circuit 210 and a plurality of selection circuits 230, the number of which is the same as the number of piezoelectric elements 60. In the following description, it is assumed that the print head 22 has p piezoelectric elements 60. That is, the drive signal selection circuit 200 has p selection circuits 230.

[0100] The selection control circuit 210 receives a clock signal SCK, a print data signal SI, a latch signal LA, The selection control circuit 210 receives the shift register T and the change signal CH. A set of a switch (S / R) 212, a latch circuit 214, and a decoder 216 controls p piezoelectric elements. That is, the drive signal selection circuit 200 is provided corresponding to each of the p systems 60. The signal processing circuit includes a soft register 212, p latch circuits 214, and p decoders 216. .

[0101] The print data signal SI is input to the selection control circuit 210 in synchronization with the clock signal SCK. The print data signal SI is also divided into "large dot LD", "medium dot MD", and "small dot S". 2-bit print data [SIH,S IL] is included in serial corresponding to each of the p piezoelectric elements 60. The print data [SIH, SIL] to be included is p shift levels corresponding to p piezoelectric elements 60. Specifically, p shift registers corresponding to the piezoelectric elements 60 are held in the register 212. The input print data signal S is serially input. I is transferred to the subsequent shift register 212 in sequence in accordance with the clock signal SCK. The print data [SIH, SIL] is then held in the corresponding shift register 212. This causes the clock signal SCK to stop. The data [SIH, SIL] is held in the corresponding shift register 212. A print data signal SI is input to distinguish p shift registers 212. The stages are denoted as stage 1, stage 2, ..., stage p in order from the upstream side.

[0102] Each of the p latch circuits 214 latches the corresponding shift register at the rising edge of the latch signal LAT. The print data [SIH, SIL] held in the register 212 is latched all at once. The print data [SIH, SIL] latched by the latch circuit 214 is sent to the corresponding decoder. 10 is a diagram showing an example of the contents of decoding in the decoder 216. The decoder 216 receives the input signals in each of the periods t1, t2, and t3. It outputs a selection signal S of a logic level specified by the print data [SIH, SIL]. For example, When print data [SIH, SIL]=[1, 0] is input to the decoder 216, The reader 216 sets the logic level of the selection signal S to H, L, L during periods t1, t2, and t3. Output as a level.

[0103] The selection signal S output by the decoder 216 is input to the selection circuit 230. The drive signals 30 are provided in correspondence with the p piezoelectric elements 60. The selection circuit 200 has p selection circuits 230, the same number as the p piezoelectric elements 60. 11 is a diagram showing the configuration of the selection circuit 230. As shown in FIG. 11, the selection circuit 230 The OT circuit includes an inverter 232 and a transfer gate 234 .

[0104] The selection signal S is input to the positive control terminal of the transfer gate 234, which is not marked with a circle. The logic level is inverted by inverter 232 and then The signal is also input to the negative control terminal marked with a circle at the transfer gate 234. The drive signal COM is supplied to the input terminal of the transfer gate 234. When a high level selection signal S is input, the power gate 234 When a low-level selection signal S is input, the input terminal and the output terminal are not conductive. That is, the transfer gate 234 is set to the high level when the logic level of the selection signal S is high. In this case, the signal waveform included in the drive signal COM is output from the output terminal, and the logic level of the selection signal S is When the signal is at a low level, the signal waveform included in the drive signal COM is not output from the output terminal. The drive signal selection circuit 200 includes a transfer gate 23 The signal output to the output terminal of 4 is output as a drive signal VOUT.

[0105] Here, the operation of the drive signal selection circuit 200 will be described with reference to FIG. FIG. 10 is a diagram for explaining the operation of the drive signal selection circuit 200. The print data signal SI is The serial signal is input to the selection control circuit 210 in synchronization with the clock signal SCK. The print data signal SI is synchronized with the clock signal SCK and is supplied to the p piezoelectric elements 60. Then, the clock signal SCK When the input of the signal P stops, the shift register 212 receives the signals P corresponding to each of the p piezoelectric elements 60. The print data signal SI is stored in the shift register. The signals are input in the order corresponding to the p-th, . . . , 2-th, and 1-th stages of the piezoelectric elements 60 of the register 212.

[0106] When the latch signal LAT rises, each of the latch circuits 214 The print data [SIH, SIL] held in the register 212 is latched all at once. LT1, LT2, ..., LTp shown in Figure 12 are shift registers of 1st stage, 2nd stage, ..., pth stage. The print data [SIH, SI] latched by the latch circuit 214 corresponding to the L] is shown.

[0107] The decoder 216 generates the dots specified by the latched print data [SIH, SIL]. In each of the periods t1, t2, and t3, the logic level of the selection signal S is 12. Then, the selection circuit 230 selects the signal output by the decoder 216. The signal waveform included in the drive signal COM is selected or not selected depending on the logic level of the selection signal S. By doing so, the drive signal VOUT is generated.

[0108] Specifically, print data [SIH, SIL]=[1, 1] is input to the decoder 216. When this signal is input, the decoder 216 sets the logic level of the selection signal S to As a result, the selection circuit 230 outputs a trapezoidal waveform signal during the period t1. Adp is selected, and trapezoidal waveform Bdp is selected in period t2, and trapezoidal waveform Bdp is selected in period t3. As a result, the drive signal selection circuit 200 does not select the large dot LD. The inverter outputs a drive signal VOUT.

[0109] When the drive signal VOUT corresponding to the "large dot LD" is supplied to the piezoelectric element 60, during the period A medium amount of ink is ejected during period t1, and a small amount of ink is ejected during period t2. In the period t3, no ink is ejected. When a large amount of ink and a small amount of ink land on the medium P and combine, a "large dot LD" is formed on the medium P. " is formed.

[0110] Also, when print data [SIH, SIL]=[1, 0] is input to the decoder 216, In this case, the decoder 216 sets the logic level of the selection signal S to H during periods t1, t2, and t3. As a result, the selection circuit 230 selects the trapezoidal waveform Adp In the period t2, the trapezoidal waveform Bdp is not selected, and in the period t3, the trapezoidal waveform Cd As a result, the drive signal selection circuit 200 does not select the drive signal p corresponding to the "medium dot MD". The inverter outputs an operating signal VOUT.

[0111] When the drive signal VOUT corresponding to the "medium dot MD" is supplied to the piezoelectric element 60, A medium amount of ink is ejected during period t1, no ink is ejected during period t2, and the expected amount of ink is During the interval t3, no ink is ejected. When the ink droplets land on the medium P, a "medium dot MD" is formed on the medium P.

[0112] Also, when print data [SIH, SIL]=[0, 1] is input to the decoder 216, In this case, the decoder 216 sets the logic level of the selection signal S to L, As a result, the selection circuit 230 selects the trapezoidal waveform Adp during the period t1. In the period t2, the trapezoidal waveform Bdp is selected, and in the period t3, the trapezoidal waveform Cd As a result, the drive signal selection circuit 200 does not select the drive signal p corresponding to the "small dot SD". The inverter outputs an operating signal VOUT.

[0113] When the drive signal VOUT corresponding to the "small dot SD" is supplied to the piezoelectric element 60, during the period During period t1, no ink is ejected, and during period t2, a small amount of ink is ejected. During the interval t3, no ink is ejected. When the droplets land on the medium P, "small dots SD" are formed on the medium P.

[0114] Also, when print data [SIH,SIL]=[0,0] is input to the decoder 216, In this case, the decoder 216 sets the logic level of the selection signal S to L, As a result, the selection circuit 230 selects the trapezoidal waveform Adp during the period t1. is not selected, the trapezoidal waveform Bdp is not selected in the period t2, and the trapezoidal waveform C As a result, the drive signal selection circuit 200 selects the drive signal corresponding to "non-recording ND". Outputs the signal VOUT.

[0115] When the drive signal VOUT corresponding to "non-recording ND" is supplied to the piezoelectric element 60, Ink is not ejected during period t1, ink is not ejected during period t2, and ink is not ejected during period t3. Therefore, no dots are formed on the medium P, which is called "non-printing ND." At this time, the corresponding piezoelectric element 60 receives a drive signal VOUT containing a trapezoidal waveform Cdp. Therefore, the micro vibration is performed. As a result, the opening of the corresponding nozzle 321 This reduces the risk of the ink viscosity increasing in the vicinity of the portion.

[0116] As described above, the drive signal selection circuit 200 selects the drive signal COM output from the drive circuit 50. By selecting or deselecting the signal waveform, the drive signal VOUT is generated and the corresponding piezoelectric element is driven. Therefore, the drive signal VOUT is a signal output from the drive circuit 50. The drive signal contains one of the trapezoidal waveforms Adp, Bdp, or Cdp included in OM. The print head 22 ejects ink based on the drive signal VOUT. It can also be considered that ink is ejected by the nozzle.

[0117] 5. Temperature detection circuit configuration Next, the configuration of the temperature detection circuit 250 will be described. 13 is a diagram showing an example of the configuration of a temperature detection circuit 250. 54. The resistor 254 is connected to the resistor wiring 401 and the measurement lead electrode 393. a, 393b. That is, in the temperature detection circuit 250, at least the resistor 254 It is provided on the print head 22.

[0118] A voltage signal VDD having a constant voltage value is supplied to one end of the resistor 252. The other end of the resistor 254 is connected to a measurement lead electrode 393a The other end of the resistor 254 is electrically connected to the measurement resistor included in the resistor 254. The ground electrode 393b is supplied with a ground potential. The voltage value generated at the connection point between the other end of the resistor 252 and one end of the resistor 254 is used as the head temperature signal. That is, the temperature detection circuit 250 outputs the voltage signal VDD as a voltage signal TC. The voltage signal obtained by dividing the resistance of the resistor wiring 401 and the resistance of the resistor wiring 402 is used as the head temperature signal TC. and output.

[0119] As described above, the resistance value of the resistive wiring 401 is determined by the temperature of the print head 22 and the pressure. The resistance 254 including the resistance wiring 401 changes depending on the temperature of the chamber 312. The resistance wiring 401 functions as a thermistor element whose resistance value changes depending on the temperature. The resistance value changes depending on the temperature of the print head 22 and the temperature of the pressure chamber 312. Therefore, the voltage value of the head temperature signal TC output by the temperature detection circuit 250 is also The temperature of the pressure chamber 312 changes depending on the temperature of the pressure chamber 312. That is, the temperature detection circuit 250 is the temperature of the print head 22, and the voltage value changes depending on the temperature of the pressure chamber 312. A head temperature signal TC is output.

[0120] In the temperature detection circuit 250 of this embodiment, the resistor 252 that divides the voltage signal VDD , 254, the resistor 254 on the low potential side is connected to the resistance wiring 401 and the measurement lead electrode 393a, 393b, the resistor 252 on the high potential side is The temperature sensor may be configured to include the wire 401 and the measurement lead electrodes 393a and 393b. The voltage detection circuit 250 may be configured to include multiple resistive elements in addition to the resistors 252 and 254. good.

[0121] 6. Temperature information output circuit configuration Next, the configuration and operation of the temperature information output circuit 26 will be described. 1 is a diagram showing an example of the configuration of the output circuit 26. The temperature information output circuit 26 receives temperature information from the control circuit 100. Based on the temperature acquisition request signal TD input from the At least one of the head temperature signals TC1 to TCn input from each of the The unit temperature signal TH is input from the circuit 28. Then, the temperature information output circuit The path 26 connects any one of the acquired head temperature signals TC1 to TCn with the unit temperature signal TH and a temperature information signal TI corresponding to the temperature of the print head 22 is generated based on the temperature information signal TI. The signal is output to path 100.

[0122] As shown in FIG. 14, the temperature information output circuit 26 includes a control circuit 500, a multiplexer 5 10. Amplification circuits 520, 550, A / D converters 530, 560, shift registers 540 and a memory circuit 570.

[0123] The multiplexer 510 receives the data output from each of the print heads 22-1 to 22-n. The head temperature signals TC1 to TCn are input to the multiplexer 510. The multiplexer 510 also receives the select signal Sel output by the control circuit 500. According to the input select signal Sel, one of the head temperature signals TC1 to TCn is selected. The selected temperature is selected and output as the selected temperature signal STC.

[0124] The selected temperature signal STC output from the multiplexer 510 is input to the amplifier circuit 520. The amplifier circuit 520 amplifies the voltage value of the input selected temperature signal STC. A width head temperature signal ATC is generated and output.

[0125] The A / D converter 530 receives the amplified head temperature signal ATC output from the amplifier circuit 520. and a clock signal CK1 output by the control circuit 500. -530 synchronizes with the clock signal CK1 and acquires the voltage value of the amplification head temperature signal ATC. The digital signal corresponding to the acquired voltage value is generated and shifted as digital temperature information dtc. That is, the A / D converter 530 outputs the signal to the multiplexer register 540. The head temperature signal TC selected by the sensor 510 is amplified by the amplifier circuit 520. The digital temperature information dtc corresponding to the voltage value of the signal is output by the multiplexer 510. A digital signal corresponding to the temperature of the print head 22 corresponding to the selected head temperature signal TC is output. Temperature information dtc is generated and output to the shift register 540 .

[0126] In the following description, the A / D converter 530 detects the rising edge of the clock signal CK1. The temperature signal ATC of the amplified head inputted at the The following explanation will be given assuming that the temperature information dtc is output to the shift register 540. The inverter 530 amplifies the inputted signal at the falling edge of the clock signal CK1. The temperature signal ATC is converted into a digital signal and the digital temperature information dtc is sent to shift register 5. You can also output to 40.

[0127] The shift register 540 stores the digital temperature information output by the A / D converter 530. dtc and a clock signal CK1 are input. The digital temperature information dtc is acquired sequentially in synchronization with the clock signal CK1. That is, the shift register 540 holds the A / D converter 530. The A / D converter is synchronized with the timing of converting the width head temperature signal ATC into a digital signal. The digital temperature information dtc output by the temperature sensor 530 is sequentially acquired and stored.

[0128] Here, an example of the configuration and operation of the shift register 540 will be described. FIG. 10 is a diagram showing an example of the configuration of a shift register 540.

[0129] As shown in FIG. 15, the shift register 540 includes registers Rg1 to Rgm. The digital temperature information dtc is input to the input terminal of the register Rg1. The output terminal of resistor Rg1 is electrically connected to the input terminal of resistor Rg2. The output terminal of the resistor Rg1 is electrically connected to the input terminal of the resistor Rg2. The input terminal of Rgj (j is any value between 2 and m-1) is connected to the output terminal of register Rg(j-1). The output terminal of the resistor Rgj is electrically connected to the input terminal of the resistor Rg(j+1). The output terminal of the resistor Rgm may be open, and the resistor element The shift register may be electrically connected to the ground potential via a resistor or the like. The registers Rg1 to Rgm included in Star 540 are the input side of the digital temperature information dtc. From the perspective of register Rg1, register Rg2, ..., register Rg(m-1), register The registers are connected in series in the order of Rgm. When there is no need to distinguish between Rg1 to Rgm, they may simply be referred to as registers Rg. That is, the shift register 540 includes m registers Rg connected in series.

[0130] The clock signal CK1 is input to each of the registers Rg1 to Rgm. Each of Rg1 to Rgm is input at the falling edge of the input clock signal CK1. The input clock signal CK1 is input at the rising edge of the clock signal CK1. The information stored in the registers Rg1 to Rgm is output from the output terminal. At the rising edge of the input clock signal CK1, information on the input terminal is acquired. The data is stored at the falling edge of the input clock signal CK1, and the stored data is output from the output terminal. You may output it.

[0131] An example of the operation of the shift register 540 configured as above will be described.

[0132] The A / D converter 530 multiplexes the data at the rising edge of the clock signal CK1. The temperature of the print head 22 corresponding to the head temperature signal TC selected by the controller 510 is This outputs digital temperature information dtc according to the temperature of the input terminal of register Rg1. At the rising edge of the clock signal CK1, the A / D converter 530 outputs The digital temperature information dtc is input. In this, each of the registers Rg1 to Rgm outputs the information it holds from its output terminal. As a result, the information held in register Rg1 is stored at the input terminal of register Rg2. The input terminal of the register Rgj is the information held in the register Rg(j-1). is entered.

[0133] Then, at the falling edge of the clock signal CK1, the registers Rg1 to Rg Each of m holds the information of the input terminal. In this case, the register Rg1 is the A / D The digital temperature information dtc output by the converter 530 is held in the register Rg2. Holds the information output by register Rg1 at the rising edge of the previous clock signal CK1 The register Rgj is the register R at the rising edge of the previous clock signal CK1. The register Rgm holds the information output by g(j-1), and the register Rgm holds the information output by the previous clock signal CK1 The register Rg(m-1) holds the information output at the rising edge of the register Rg(m-1).

[0134] That is, the A / D converter 530 multiplies the signal by 1 every time the clock signal CK1 rises. Printhead 2 corresponding to the head temperature signal TC selected by the multiplexer 510 The shift register 540 outputs digital temperature information dtc according to the temperature of 2. Every time the clock signal CK1 rises, the information held in the registers Rg1 to Rg(n-1) is updated. Then, the clock signal CK1 falls. Each time, the register Rg1 of the shift register 540 receives the signal output by the A / D converter 530. The digital temperature information dtc is acquired and stored, and the information in registers Rg2 to Rgm is Each of these registers acquires and stores information from the input terminal. acquires the digital temperature information dtc input each time the clock signal CK1 rises. , and transfers the stored digital temperature information dtc to the subsequent register Rg. By transmitting this signal, the digital temperature information dt The oldest digital temperature information (dtc) is discarded. This is a so-called FIFO (First In First Out) method, and m digital temperature information dtc is It holds.

[0135] Specifically, the shift register 540 receives the most recent output from the A / D converter 530. The digital temperature information dtc is stored in register Rg1 and is read out every j cycle of the clock signal CK1. The digital temperature information dtc previously output by the A / D converter 530 is stored in the register Rg(j +1), and the A / D converter 530 is held at (m-1) cycles before the clock signal CK1. The output digital temperature information dtc is stored in register Rgm.

[0136] In the following description, the m registers Rg The m pieces of digital temperature information dtc stored in the Then, the m pieces of temperature information dtr stored in the m pieces of registers Rg are distinguished and In this example, the digital temperature information dtc stored in register Rg1 is The digital temperature information dtc stored in the register Rgj is called tr1. The digital temperature information dtc stored in the register Rgm is called trj. It is called trm.

[0137] Returning to FIG. 14, the shift register 540 receives a read request signal output from the control circuit 500. The shift register 540 receives the read request signal Ltc. m pieces of digital temperature information dtc to be held, including m pieces of held temperature information dtr The holding temperature information group Gtc is output to the control circuit 500.

[0138] The amplifier circuit 550 also receives the unit temperature signal TH output by the temperature detection circuit 28. The amplifier circuit 520 amplifies the voltage value of the input unit temperature signal TH. , the amplification unit generates and outputs a temperature signal ATH.

[0139] The A / D converter 560 receives the amplification unit temperature signal AT H and the clock signal CK2 output by the control circuit 500. The counter 560 synchronizes with the clock signal CK2 to calculate the voltage value of the amplification unit temperature signal ATH. The digital temperature information dth is generated based on the acquired voltage value. The A / D converter 560 outputs the clock signal CK At a timing synchronized with the time t2, a digital temperature signal corresponding to the temperature detected by the temperature detection circuit 28 is output. The control circuit 500 generates the degree information dth and outputs it to the control circuit 500.

[0140] The control circuit 500 includes a request analysis unit 501, a clock signal output unit 502, and a temperature information output unit 503. 503, a correction value calculation unit 504, and a memory control unit 505. The control circuit 500 receives the temperature acquisition request signal TD. A select signal Sel according to the signal TD, clock signals CK1 and CK2, and a read request signal Ltc. As a result, the control circuit 500 outputs the temperature information The control circuit 500 controls the operation of various components. The control circuit 500 also includes m pieces of holding temperature information dtr. The control circuit 500 receives the holding temperature information group Gt A temperature information signal TI is generated based on the m pieces of retained temperature information dtr included in the temperature information signal c. The information is output from the information output circuit 26.

[0141] An example of the operation of each component of the control circuit 500 will be described.

[0142] When the request analysis unit 501 receives a temperature acquisition request signal TD input to the control circuit 500, The control circuit 500 analyzes both the select signal and the request signal in accordance with the analysis result of the request analysis unit 501. The read request signal Sel and the read request signal Ltc are generated in response to the analysis result of the request analysis unit 501. At the timing determined by the timing chart, the generated select signal Sel and read request signal Ltc are output. The select signal Sel and the read request signal Ltc output by the control circuit 500 are The temperature information output circuit 26 is operated by supplying the temperature information to a corresponding component of the output circuit 26. .

[0143] The clock signal output unit 502 divides or multiplies the frequency of an oscillation signal output by an oscillation circuit (not shown). By doing so, clock signals CK1 and CK2 are generated and output. The output unit 502 outputs the temperature acquisition request signal TD according to the analysis result of the request analysis unit 501. Whether or not to output the lock signals CK1 and CK2 may be controlled. The clock signals CK1 and CK2 are output continuously regardless of the analysis result of the temperature acquisition request signal TD. This may continue.

[0144] The temperature information output unit 503, based on the read request signal Ltc output by the control circuit 500, The temperature information output unit 503 acquires the input holding temperature information group Gtc. Based on the m pieces of retained temperature information dtr included in the retained temperature information group Gtc, a temperature information signal The control circuit 500 generates the temperature information TI generated by the temperature information output unit 503. The temperature information output unit 503 outputs a signal TI to the control circuit 100. A temperature information signal TI corresponding to the voltage value of the head temperature signal TC output by the head 22, A temperature information signal TI corresponding to the temperature of the print head 22 is generated and output to the control circuit 100. do.

[0145] The correction value calculation unit 504 calculates a correction value for correcting the temperature information signal TI output by the control circuit 500. The correction value calculation unit 504 calculates the correction value Cv, for example, by receiving the correction value Cv from the control circuit 100. At a predetermined timing after the temperature acquisition request signal TD including the request is input, m storage The retained temperature information group Gtc including the retained temperature information dtr and the digital temperature information dth are obtained. Based on the acquired holding temperature information group Gtc and digital temperature information dth, a correction value Cv is calculated. Calculate.

[0146] Specifically, the correction value calculation unit 504 calculates the temperature at a predetermined time after the temperature acquisition request signal TD is input. In timing, m corresponds to the head temperature signal TC1 output by the print head 22-1. A retained temperature information group Gtc including retained temperature information dtr and digital temperature information dth, The temperature information dtr is acquired, and based on the difference between the acquired m pieces of retained temperature information dtr and the digital temperature information dth, Similarly, the correction value calculation unit 5 calculates the correction value Cv corresponding to the print head 22-1. 04 is a signal to the printer at a predetermined timing after the temperature acquisition request signal TD is input. The temperature information dtr includes m pieces of holding temperature information corresponding to the head temperature signal TCi output by the head 22-i. The retention temperature information group Gtc and the digital temperature information dth are acquired, and the acquired m retention temperatures are Based on the difference between the temperature information dtr and the digital temperature information dth, the print head 22-i That is, the correction value calculation unit 504 calculates the corresponding correction value Cv. The correction value calculation unit 5 calculates n correction values ​​Cv corresponding to the respective values ​​-1 to 22-n. Using the correction value Cv calculated by 04, the temperature information output unit 503 outputs the acquired holding temperature information group Correct the m pieces of holding temperature information dtr included in Gtc, and then calculate the corrected m pieces of holding temperature information dt A temperature information signal TI is generated based on r.

[0147] The memory control unit 505 outputs a memory control signal MA for accessing the memory circuit 570. and outputs it to the memory circuit 570, and also outputs it to the memory circuit 570 in response to the memory control signal MA. Specifically, the memory circuit 570 includes: Various information including the n correction values ​​Cv described above is stored in the memory control unit 505. A memory control signal MA for storing information such as the correction value Cv is generated and stored in the memory circuit 570. In addition to outputting the signal, the correction value Cv and other information stored in the memory circuit 570 are read out. The memory control signal MA is generated and output to the memory circuit 570.

[0148] The memory circuit 570 stores various values ​​including the correction value Cv in response to the input memory control signal MA. The information is stored, and the information such as the correction value Cv is read out and stored in a memory containing the read information. The memory circuit 570 outputs a read signal MR to the control circuit 500. It is configured to include non-volatile memory such as flash memory.

[0149] As described above, the temperature information output circuit 26 is a master that selects the head temperature signals TC1 to TCn. A multiplexer 510 and a head temperature signal T selected by the multiplexer 510 C, an amplification circuit for outputting an amplified head temperature signal ATC obtained by amplifying the selected temperature signal STC. The amplifier head temperature signal ATC is sampled at a predetermined sampling rate determined by the clock signal CK1. A / D converter 530 that acquires the temperature every ring cycle and converts it into digital temperature information DTC. The temperature information output circuit 26 outputs a temperature information corresponding to the temperature of the print head 22. The temperature signal TC is acquired at a predetermined sampling period defined by the clock signal CK1. A temperature information signal TI corresponding to the obtained head temperature signal TC is output.

[0150] Here, the temperature information output circuit 26 is preferably configured as, for example, an integrated circuit. This reduces the mounting area of ​​the temperature information output circuit 26 in the head unit 20. As a result, the head unit 20 can be made smaller. The integrated circuit constituting the temperature information output circuit 26 is not limited to one, but may be multiple. Of course, the temperature information output circuit 26 may include multiple circuit elements in addition to the integrated circuit. It may be composed of:

[0151] 7. Temperature detection operation and detection timing in the temperature information output circuit In the liquid ejection device 1 and the head unit 20, ink is ejected from the nozzle 321. The physical properties of ink, such as viscosity, change depending on the temperature. This contributes greatly to the ejection accuracy. The temperature of the ink discharged from the nozzle 321 is the temperature of the pressure chamber 312 The temperature of the ink stored in the liquid ejection device 1 is acquired, and the temperature of the ink stored in the liquid ejection device 1 is acquired. By correcting the various signals that control the operation of the head unit 20, the ink temperature can be adjusted Even in this case, the risk of ink ejection accuracy being reduced is reduced.

[0152] In particular, in the liquid ejection device 1 and the head unit 20 of this embodiment, the print head 22 The temperature detection circuit 250 detects the temperature of the resistor wiring 401 whose resistance value changes depending on the temperature. The resistive wiring 401 is located in the vicinity of the pressure chamber 312, and the pressure chamber 312 is formed The force chamber substrate 310 is formed on a diaphragm 350 that seals the opening on the +Z side surface. The temperature detection circuit 250 detects the temperature of the ink stored in the pressure chamber 312 by detecting the temperature of the ink stored in the pressure chamber 312. This makes it possible to detect the temperature of the ink stored in the pressure chamber 312 more accurately. As a result, the liquid ejection device 1 and the head unit according to this embodiment can be effectively detected. In 20, the liquid ejection device 1 and the head 21 are controlled in accordance with the temperature of the ink stored in the pressure chamber 312. This makes it possible to more appropriately correct the various signals that control the operation of the ink unit 20. Even if the temperature of the ink changes, the ink ejection accuracy is further reduced. It is possible.

[0153] On the other hand, the resistance wiring 401 included in the temperature detection circuit 250 is connected to the pressure chamber in which the ink is stored. However, since the sensor 312 is provided in the vicinity of the sensor 312, the following problems may occur.

[0154] In order to improve the quality of the image formed on the medium P, the print head 22 is provided with several hundred or more The nozzles 321 are arranged at high density. The piezoelectric element 60 has several hundred or more corresponding to several hundred or more nozzles 321, 0 or more piezoelectric elements 60 are arranged at high density on the diaphragm 350. Signal wiring through which the drive signal VOUT supplied to each piezoelectric element 60 in the head 22 propagates. are arranged densely on the diaphragm 350. When the resistive wiring 401 is arranged, the resistive wiring 4 is arranged near the signal wiring through which the drive signal VOUT propagates. 01 is placed, and the noise generated by the change in the voltage value of the drive signal VOUT is If the voltage of the drive signal VOUT changes, If the noise generated as a result of the resistance wiring 401 is contributed to by the resistance wiring 401, the temperature detection circuit including the resistance wiring 401 The accuracy of the head temperature signal TC output by the pressure chamber 312 is reduced. Decreases.

[0155] When the piezoelectric element 60 is driven by the drive signal VOUT, the drive As a result, the vibration plate 350 on which the resistance wiring 401 is arranged is displaced. Accordingly, the impedance of the resistive wiring 401 arranged on the diaphragm 350 may change. If the impedance of the resistive wiring 401 arranged on the diaphragm 350 changes, In this case, the accuracy of the head temperature signal TC output by the temperature detection circuit 250 including the resistance wiring 401 is The temperature of the pressure chamber 312 decreases, and the accuracy of detecting the temperature of the pressure chamber 312 decreases.

[0156] Furthermore, as described above, the print head 22 changes the pressure by changing the volume of the pressure chamber 312. Pressure is applied to the ink contained in the pressure chamber 312, causing the ink to be ejected from the nozzle 321. In the print head 22 having such a structure, the pressure chamber 312 that is generated when ink is ejected The temperature of the ink stored in the pressure chamber 312 may change instantaneously due to the pressure change. The instantaneous temperature change is detected by a temperature detection circuit including the resistance wiring 401. 250 detects the temperature of the head, and the temperature signal TC output by the temperature detection circuit 250 contains noise. If the ink stored in the pressure chamber 312 has a temperature When a temperature change is superimposed on the head temperature signal TC as noise, the temperature detection circuit 250 The accuracy of the output head temperature signal TC decreases, and the accuracy of detecting the temperature of the pressure chamber 312 decreases. .

[0157] To address this problem, in the liquid ejection device 1 of this embodiment, the temperature information output circuit 26 The head temperature signal TC obtained at the appropriate timing is used to calculate the temperature of the print head 22. The temperature information signal TI is generated and output to the control circuit 100. The risk of a decrease in the detection accuracy of the temperature of the pressure chamber 312 detected by the temperature detection circuit 250 is reduced. is doing.

[0158] FIG. 16 is a diagram showing an example of timing for acquiring the temperature of the print head 22. To explain the timing for acquiring the temperature of the print head 22, first, An example of the operation of the ejection device 1 will be explained, and then the timing for acquiring the temperature of the print head 22 will be explained. An example of this will be described.

[0159] As shown in FIG. 16, the liquid ejection device 1 receives a power supply voltage at time t10. When the liquid ejection device 1 is started, the drive circuit 50 outputs the drive signal C The OM starts outputting a signal whose voltage value is constant at voltage Vb.

[0160] In addition, the liquid ejection device 1 is started, and the drive circuit 50 outputs a drive signal having a constant voltage Vb. At time t10 when the output of COM starts, the control circuit 100 selects all the selection circuits 230 A print data signal that controls the logic level of the selection signal S to a high level in order to control the As a result, each of the plurality of piezoelectric elements 60 of the print head 22 This electrode 360 ​​receives a drive signal VOUT based on the drive signal COM output from the drive circuit 50. Then, a drive signal VOUT whose voltage value changes toward the voltage Vb is supplied. When the voltage value of the drive signal COM output by the drive circuit 50 is constant at voltage Vb, the piezoelectric element A drive signal VOUT having a constant voltage value of Vb is supplied to the electrode 360 ​​of the element 60. At this time, it is preferable that the voltage Vb is approximately equal to the voltage value of the reference voltage signal VBS. This reduces the risk of unintended displacement being continuously applied to the piezoelectric element 60, This reduces the risk of abnormalities such as cracks occurring in the material.

[0161] The voltage value of the drive signal VOUT supplied to the electrode 360 ​​of the piezoelectric element 60 is constant at voltage Vb. After this, the control circuit 100 turns off the selection signal . The print data signal SI is output to control the logic level of the selected signal S to the L level. At this time, the voltage value of the electrode 360 ​​of the piezoelectric element 60 is The voltage Vb is maintained by the capacitance component of the piezoelectric element 60. After that, the liquid ejection device 1 The drive circuit 50 continues to output the drive signal COM whose voltage value is constant at voltage Vb. The time it takes for an image information signal containing image data to be input from an external device such as a computer Wait for a period.

[0162] Also, at a predetermined timing during the waiting period when the liquid ejection device 1 waits for the input of the image information signal, In this case, the drive circuit 50 outputs a signal including the micro-vibration waveform obs as the drive signal COM. The micro-vibration waveform obs is a signal waveform whose voltage value starts and ends at voltage Vb. In the same way as the trapezoidal waveform Cdp described above, the ink in the vicinity of the corresponding nozzle opening is vibrated. This is a signal waveform for executing a slight vibration to prevent the ink viscosity from increasing. The shape of such a micro-vibration waveform obs may be the same as the trapezoidal waveform Cdp described above. , may have a shape different from the trapezoidal waveform Cdp.

[0163] In addition, when the drive circuit 50 outputs the drive signal COM including the micro-vibration waveform obs, the control circuit The circuit 100 controls the logic level of the selection signal S to turn on all the selection circuits 230. The print data signal SI is output to control the electrode 3 of the piezoelectric element 60 to the H level. A drive signal VOUT including a micro-vibration waveform obs is supplied to 60. As a result, during the standby period, This reduces the risk of ink sticking to the vicinity of the nozzle 321, and The risk of the ink viscosity increasing in the vicinity is reduced. VOUT is supplied to all the piezoelectric elements 60 of the print head 22. Instead, the voltage may be supplied to only some of the piezoelectric elements 60 in the print head 22 . In addition, the micro-vibration caused by the drive signal VOUT containing the micro-vibration waveform obs occurs during the standby period. It may be executed multiple times.

[0164] At time t20, when an image information signal is input from an external device, the drive circuit 50 The drive circuit starts outputting a signal whose voltage value is constant at voltage Vc as the drive signal COM. At time t20, the circuit 50 starts outputting the drive signal COM, whose voltage value is constant at voltage Vc. The control circuit 100 controls the logic of the selection signal S to turn on all the selection circuits 230. The print data signal SI is output, which controls the processing level to H level. The drive circuit 50 outputs a signal to the electrodes 360 of each of the piezoelectric elements 60 of the head 22. The drive signal VOUT is based on the drive signal COM, and the voltage value changes toward the voltage Vc. Then, the drive signal VOUT output from the drive circuit 50 is supplied. When the voltage value becomes constant at voltage Vc, the voltage value at electrode 360 ​​of piezoelectric element 60 becomes voltage V At c a constant drive signal VOUT is provided.

[0165] The voltage value of the drive signal COM output by the drive circuit 50 is the voltage of the piezoelectric element 60. When the voltage value of the electrode 360 ​​becomes the voltage Vc, the control circuit 100 controls all the selection circuits 230 to A print data signal that controls the logic level of the selection signal S to the L level to control non-conduction. SI is output. As a result, the selection circuit 230 is controlled to be non-conductive. At this time, the piezoelectric element The voltage value of the electrode 360 ​​of the piezoelectric element 60 is maintained at a voltage Vc by the capacitance component of the piezoelectric element 60. .

[0166] Then, after the voltage value of the drive signal COM output by the drive circuit 50 becomes constant at voltage Vc, At time t30, the control circuit 100 controls the carriage 2 carrying the print head 22. Outputs a control signal Ctrl-C to move 1 along the scanning axis toward the forward direction Fw. This causes the carriage 21 to start moving in the forward direction Fw along the scanning axis.

[0167] At time t40 after the carriage 21 starts moving in the forward direction Fw along the scanning axis, The drive circuit 50 outputs a drive signal COM having successive trapezoidal waveforms Adp, Bdp, and Cdp. Then, at a subsequent time t50, the scanning position of the carriage 21 is changed to the position When the image forming area P reaches the printing area, the control circuit 100 receives the input from the external device. A print data signal SI and a clock signal SCK corresponding to the image information signal are input. A change signal CH and a latch signal LAT corresponding to the scanning position of the first scanning line are output. The selection control circuit 210 selects the logic levels corresponding to the plurality of piezoelectric elements 60. The selection circuit 230 outputs a signal S, and the selection circuit 230 outputs a drive signal VOUT based on the drive signal COM. As a result, the desired image is formed on the medium P. In other words, the printing process is executed. Here, the printing area is an area where the print head 22 can eject ink onto the medium P. The area where the ink is ejected is a region where at least a portion of the print head 22 is exposed to the ink. It includes the area located opposite the body P.

[0168] At time t60, when the printing process in the forward direction Fw along the scanning axis is completed, the control The circuit 100 controls all the selection circuits 230 to be non-conductive by changing the logic level of the selection signal S. The selection circuit 230 outputs a print data signal SI that controls the filter to the L level. At this time, the voltage value of the electrode 360 ​​of the piezoelectric element 60 is The voltage Vc is maintained by the capacitance component. At a later time t70, the drive circuit 50 , trapezoidal waveforms Adp, Bdp, Cdp stop outputting the drive signal COM, and the voltage value Start outputting a constant drive signal COM at voltage Vc.

[0169] Then, after the voltage value of the drive signal COM output by the drive circuit 50 becomes constant at voltage Vc, At time t80, when the scanning position of the carriage 21 reaches the stop area, the control circuit 1 00 is a control signal Ct for stopping the carriage 21 carrying the print head 22. rl-C is output, which stops the carriage 21.

[0170] At time t90 after the carriage 21 has stopped, the drive circuit 50 changes its voltage value to voltage V b, the drive circuit 50 starts outputting a constant drive signal COM. At time t90 when the constant drive signal COM starts to be output, the control circuit 100 In order to control the selection circuit 230 to be conductive, the logic level of the selection signal S is controlled to be H level. As a result, the print head 22 outputs a print data signal SI corresponding to the plurality of piezoelectric elements. The electrodes 360 of the elements 60 are connected to the driving circuits 50 in response to the driving signals COM. A drive signal VOUT whose voltage value changes toward voltage Vb is supplied. will be done.

[0171] The voltage value of the drive signal VOUT supplied to the electrode 360 ​​of the piezoelectric element 60 is constant at voltage Vb. After this, the control circuit 100 turns off the selection signal . The print data signal SI is output to control the logic level of the selected signal S to the L level. At this time, the voltage value of the electrode 360 ​​of the piezoelectric element 60 is The voltage Vb is maintained by the capacitance component of the piezoelectric element 60. After that, the liquid ejection device 1 The driving circuit 50 continues to output the driving signal COM with a constant voltage Vb. The process waits until the reversal process for reversing the scanning direction of the ridge 21 is completed.

[0172] Also, at a predetermined time during the waiting period until the reversal process of the scanning direction of the carriage 21 is completed, In this timing, the drive circuit 50 outputs a drive signal COM including a micro-vibration waveform obs. At this time, the control circuit 100 controls all the selection circuits 230 to be conductive. The print data signal SI is output to control the logic level of the pressure signal S to a high level. A drive signal VOUT including a micro-vibration waveform obs is supplied to the electrode 360 ​​of the capacitor 60. As a result, the risk of ink sticking to the vicinity of the nozzle 321 during the standby period is reduced. In addition, the possibility of the ink viscosity increasing in the vicinity of the nozzle 321 is reduced. The drive signal VOUT including bs is supplied to all the piezoelectric elements 60 of the print head 22. The present invention is not limited to the case where only some of the piezoelectric elements 60 of the print head 22 are used. The micro-vibration caused by the drive signal VOUT including the micro-vibration waveform obs may be It may be executed multiple times during the waiting period.

[0173] At time t100, when the reversal process of the scanning direction of the carriage 21 is completed, the drive circuit 50 starts outputting a signal whose voltage value is constant at voltage Vc as the drive signal COM. In addition, at time t In 100, the control circuit 100 controls all the selection circuits 230 to be conductive. The print data signal SI is output to control the logic level of the selection signal S to H level. The electrodes 360 of the plurality of piezoelectric elements 60 of the print head 22 are connected to a drive circuit. The drive signal VOUT based on the drive signal COM output from the circuit 50 has a voltage value of Vc Then, the drive signal VOUT output from the drive circuit 50 changes from When the voltage value of the signal COM becomes constant at the voltage Vc, the electrode 360 ​​of the piezoelectric element 60 receives a voltage A drive signal VOUT having a voltage value of Vc is supplied.

[0174] Then, the control circuit 100 controls all the selection circuits 230 to be non-conductive. , a print data signal SI is output that controls the logic level of the selection signal S to the L level. Therefore, the selection circuit 230 is controlled to be non-conductive. The pressure value is maintained at voltage Vc by the capacitance component of the piezoelectric element 60.

[0175] Then, after the voltage value of the drive signal COM output by the drive circuit 50 becomes constant at voltage Vc, At time t110, the control circuit 100 controls the carriage carrying the print head 22. 21 along the scanning axis toward the reverse direction Rv, This starts the movement of the carriage 21 in the reverse direction Rv along the scanning axis.

[0176] At time t120 after the carriage 21 starts moving in the reverse direction Rv along the scanning axis, The drive circuit 50 outputs a drive signal COM having successive trapezoidal waveforms Adp, Bdp, and Cdp. Then, at a subsequent time t130, the print head 22 is When the scanning position of the carriage 21 reaches the printing area where an image is formed on the medium P, the control The circuit 100 outputs a print data signal SI corresponding to an image information signal input from an external device, and A clock signal SCK, a change signal CH corresponding to the scanning position of the carriage 21, and a latch signal As a result, the selection control circuit 210 outputs the print data signal SI The selection circuit 230 outputs a selection signal S of a logic level according to the drive signal COM. A drive signal VOUT is output, and a desired image is formed on the medium P. , the printing process is executed.

[0177] Here, in the period from time t10 to time t20 shown in FIG. The liquid ejection device 1 waits for an input of an image information signal from an external device. The operation mode in which the image information signal is input from the printer is sometimes called the print processing standby mode. In addition, during the period from time t20 to time t90 shown in FIG. The liquid ejection device 1 executes a printing process based on an image information signal. The operation mode in which the above is performed is sometimes referred to as a print processing mode. During the period from time t90 to time t100, the liquid ejection device 1 moves the carriage 21 in the scanning direction. The carriage 21 waits until the reversal of the scanning direction is completed. The operation mode in which the inversion process is waited for may be referred to as an inversion process wait mode.

[0178] Furthermore, the scanning direction of the carriage 21 is different between time t20 and time t100 shown in FIG. The same process is executed at time t30 and time t110. The same process is performed with only the scanning direction being different. The same process is performed with only the scanning direction of the ridge 21 being different, and the time t50 and the time t130 The same process is performed in the above cases, except that the scanning direction of the carriage 21 is different. The liquid ejection device 1 performs the process from time t20 to time t90 by changing the operation direction of the carriage 21. By repeatedly performing the process while reversing, a desired image is formed on the medium P. For example, the liquid ejection device 1 may be in a print processing standby mode, a print processing mode, and a reverse processing standby mode. By repeating the above steps, a desired image is formed on the medium P.

[0179] In the liquid ejection device 1 of this embodiment that operates as described above, the temperature information output circuit 26 The temperature information output unit 503 included in the control circuit 500 detects the temperature during the detection period Tde shown in FIG. At least one of t1 to Tdet6, a head temperature according to the temperature of the print head 22 is The temperature signal TC is m pieces of temperature information dt held by the shift register 540. Then, the temperature information output unit 503 acquires the retained temperature information group Gtc including r. A temperature information signal TI is generated based on the retained temperature information group Gtc.

[0180] The detection period Tdet1 is a period during the print processing standby mode, and is started at time t10. The drive circuit 50 outputs the drive signal COM whose voltage value fluctuates, and the voltage value changes to voltage Vb After a certain period of time Δt has elapsed since the constant drive signal COM is output, However, just before the drive circuit 50 starts outputting the drive signal COM including the micro-vibration waveform obs, During this detection period Tdet1, the drive circuit 50 detects that the voltage value A constant drive signal COM is output at voltage Vb, and the selection circuit 230 is controlled to be non-conductive. .

[0181] The detection period Tdet2 is a period during the print processing standby mode, during which the drive circuit 50 From the state where the drive signal COM including the dynamic waveform obs is output, the voltage value is a constant drive voltage Vb. After the signal COM is output, the signal starts when a predetermined period Δt has elapsed, and the external device This detection period T At det2, the drive circuit 50 outputs a drive signal COM whose voltage value is constant at voltage Vb. , the selection circuit 230 is controlled to be non-conductive.

[0182] The detection period Tdet3 is a period during the print processing mode, and the drive circuit The circuit 50 outputs the drive signal COM whose voltage value fluctuates, and the voltage value becomes constant at voltage Vc. The pulse signal COM is outputted in a predetermined period of time Δt. The drive circuit 50 starts outputting a drive signal COM having successive trapezoidal waveforms Adp, Bdp, and Cdp. This detection period Tdet3 ends at time t40. The circuit 50 outputs a drive signal COM whose voltage value is constant at voltage Vc, and the selection circuit 230 It is controlled by conduction.

[0183] The detection period Tdet4 is a period during the print processing mode, and the drive circuit When the circuit 50 outputs a drive signal COM having successive trapezoidal waveforms Adp, Bdp, and Cdp, After the voltage value changes from the normal state to the state where a constant drive signal COM is output at voltage Vc, The voltage value of the drive signal COM output by the drive circuit 50 starts when Δt has elapsed. This detection period Td In et4, the drive circuit 50 outputs a drive signal COM having a constant voltage Vc. The selection circuit 230 is controlled to be non-conductive.

[0184] The detection period Tdet5 is a period during the inversion processing standby mode, and is started at time t90. The drive circuit 50 outputs the drive signal COM whose voltage value fluctuates, and the voltage value changes to voltage Vb After a certain period of time Δt has elapsed since the constant drive signal COM is output, However, just before the drive circuit 50 starts outputting the drive signal COM including the micro-vibration waveform obs, During this detection period Tdet5, the drive circuit 50 detects that the voltage value A constant drive signal COM is output at voltage Vb, and the selection circuit 230 is controlled to be non-conductive. .

[0185] The detection period Tdet6 is a period during the inversion process standby mode, during which the drive circuit 50 detects the minute vibration. From the state where the drive signal COM including the dynamic waveform obs is output, the voltage value is a constant drive voltage Vb. After the signal COM is output, the inversion process starts after a predetermined period Δt has elapsed. This detection period Tdet6 ends at time t100 when The drive circuit 50 outputs a drive signal COM having a constant voltage Vb. is controlled to be non-conductive.

[0186] That is, the temperature information output circuit 26 is configured such that the drive circuit 50 outputs a drive signal COM and the selection circuit 230 is controlled to be non-conductive. During one period, a drive signal VOUT whose voltage value fluctuates is supplied to the piezoelectric element 60. In other words, all of the piezoelectric elements 60 in the print head 22 are not driven. a head temperature signal TC corresponding to the temperature of the print head 22 acquired during a period, During this time, the shift register 540 stores m pieces of stored temperature information dtr. Based on the temperature information group Gtc, a temperature information signal T corresponding to the temperature of the corresponding print head 22 is generated. The temperature information output circuit 26 generates a voltage value I and outputs it to the control circuit 100. During the period when the drive signal VOUT, which changes, is not supplied to the piezoelectric element 60, The piezoelectric element 60 is not driven by VOUT, and therefore the vibration plate 350 is not displaced. A head temperature signal TC corresponding to the temperature of the print head 22 is obtained. A temperature information signal TI corresponding to the temperature signal TC is output.

[0187] As a result, the head temperature signal TC acquired by the temperature information output circuit 26 is The propagation of T, the displacement of the vibration plate 350, and the instantaneous temperature of the ink stored in the pressure chamber 312 The possibility of noise caused by temperature changes being superimposed is reduced, and the temperature information output circuit 26 acquires The accuracy of the head temperature signal TC, that is, the accuracy of detecting the temperature of the pressure chamber 312, is improved. As a result, the reliability of the temperature information signal TI output by the temperature information output circuit 26 is improved.

[0188] Here, the temperature information output circuit 26 detects whether the drive signal VOUT, which changes in voltage, is applied to the piezoelectric element 60. is not supplied to the piezoelectric element 60, and the piezoelectric element 60 is not driven by the drive signal VOUT. Therefore, the temperature of the print head 22 obtained during the period when the diaphragm 350 is not displaced is The head temperature signal TC is acquired, and a temperature information signal TI corresponding to the acquired head temperature signal TC is output. Therefore, the temperature information output circuit 26 can generate the temperature information signal TI. The temperature signal TC is generated when a drive signal VOUT, whose voltage value changes, is supplied to the piezoelectric element 60. The head temperature signal TC is obtained during a period in which the vibration plate 350 is not displaced. It is sufficient to use the head temperature signal TC acquired during the above-mentioned detection periods Tdet1 to Tdet6. Therefore, in the following description, it is assumed that the temperature information output circuit 26 outputs the temperature information signal A period during which it is preferable to acquire the head temperature signal TC used to generate the detection signal TI. The periods Tdet1 to Tdet6 are collectively referred to as a detection period Tdet.

[0189] Here, in order to improve the accuracy of detecting the temperature of the print head 22 based on the temperature information signal TI, In this respect, the temperature information output circuit 26 receives as many as possible of the temperature information acquired during the detection period Tdet. It is preferable to generate the temperature information signal TI based on the retained temperature information dtr. Ideally, the temperature information output circuit 26 outputs m pieces of held temperature information d tr is acquired, and m pieces of retention temperature information dtr acquired during the detection period Tdet are acquired. It is preferable to generate the temperature information signal TI based on all of the above.

[0190] However, the detection period Tdet varies depending on the product specifications of the liquid ejection device 1. In addition, it also varies depending on variations in the circuits and configurations that make up the liquid ejection device 1. The shift register 540 of the information output circuit 26 holds m pieces of digital temperature information dtc. The time required to store the temperature information as dtr also varies depending on the variations in the clock signal CK1. Therefore, the temperature information output circuit 26 can hold the temperature information in the shift register 540. All of the m pieces of holding temperature information dtr are acquired during the detection period Tdet, and Based on all of the m pieces of retained temperature information dtr acquired during the period Tdet, the temperature information To realize a configuration for generating the signal TI, it is necessary to consider differences in the specifications of the liquid ejection device 1 and various variations. It is necessary to set a sufficiently long detection period Tdet that takes into account the effects of the weather.

[0191] However, if the detection period Tdet is extended, the liquid ejection device 1 may not be able to eject the desired image onto the medium P. The time required to form an image becomes longer, and the productivity of printed matter produced by the liquid ejection device 1 decreases. Therefore, as in the liquid ejection device 1 and the head unit 20 shown in this embodiment, The vibration detection circuit 250 includes a resistive wiring 401 formed on the diaphragm 350, and the resistive wiring 4 Based on the change in resistance of the print head 22, the temperature of the print head 22 is 2 outputs a head temperature signal TC corresponding to the temperature of the ink stored in the pressure chamber 312 of the The temperature information output circuit 26 acquires and holds the head temperature signal TC at a predetermined cycle. The temperature information dtr corresponding to the plurality of head temperature signals TC is used to When a temperature information signal TI corresponding to the temperature of the head 22 is output, the temperature information signal TI to be output is In order to improve the accuracy of detecting the temperature of the print head 22 based on the The number of samples of the holding temperature information dtr used to calculate the temperature of 22 is set by the liquid discharge device 1 and the head. Based on the detection period Tdet determined by the specifications of the nozzle unit 20, the liquid ejection device 1 and for each head unit 20, preferably for each print head of the liquid ejection device 1. It is required to specify this separately for each code 22.

[0192] The number of samples of the holding temperature information dtr used to calculate the temperature of the print head 22 is For example, during the manufacturing stage of the liquid ejection device 1, the print head 22, and the When the head unit 20 including the sensor is replaced, the sensor data may be measured and stored individually. However, in that case, the number of steps required to manufacture the liquid ejection device 1 will be This may increase the productivity of the liquid ejection device 1 and may also increase the number of printers to be stored. The number of samples of the holding temperature information dtr used to calculate the temperature of the heat head 22 is individually measured, This requires personnel and equipment to store the information, which may increase the cost of the liquid ejection device 1. .

[0193] In the liquid ejection device 1 of this embodiment, the specifications of the liquid ejection device 1 and the head unit 20 are For each detection period Tdet determined by It has a unique configuration that makes it easy to determine the optimal number of samples of temperature information dtr. This reduces the risk of an increase in work hours and reduces the need for new investment in manpower and equipment. The detection period is determined by the specifications of the liquid ejection device 1 and the head unit 20 without For each interval Tdet, the optimum value of the retention temperature information dtr used to calculate the temperature of the print head 22 is calculated. Therefore, it is possible to determine an appropriate number of samples, thereby improving the accuracy of temperature detection.

[0194] In the liquid ejection device 1 of this embodiment, the print head Method for determining the optimal number of samples of the retention temperature information dtr used to calculate the temperature of 22, and determination The method for obtaining the temperature of the print head 22 based on the number of samples taken will now be described. 7 is a method for determining the optimal number of samples of the holding temperature information dtr, and 17 is a diagram showing an example of a method for acquiring the temperature of the print head 22. As shown in FIG. The circuit 100 determines whether a request to adjust the number of samples has occurred (step S100). Therefore, the sample number adjustment request is made by the user of the liquid ejection device 1 or the manufacturer of the liquid ejection device 1. The optimum number of samples of the holding temperature information dtr used to calculate the temperature of the print head 22 is adjusted. , when determining, a request generated by a user's operation, for example, a liquid by the user This may occur during the operation of the liquid ejection device 1, during the manufacturing process of the liquid ejection device 1, or during the print head 2. This may occur automatically when power is first applied after 2 has been replaced.

[0195] When the control circuit 100 determines that a request for adjusting the number of samples has occurred (step S100), Y), the optimum sample of the retained temperature information dtr used to calculate the temperature of the print head 22 The number of samples is adjusted and determined (step S200). If the circuit 100 determines that no sample number adjustment request has occurred (N in step S100), ), or after the sample number determination process in step S200 is completed, the print head It is determined whether a temperature information acquisition request for acquiring the temperature of 22 has occurred (step S300). Here, the temperature information acquisition request may be generated by a request from a user of the liquid ejection device 1. During the period when the liquid ejection device 1 ejects the liquid onto the medium P, the liquid ejection device 1 forms an image. It may also be based on the number of printed surfaces of the medium P formed, the usage time of the liquid ejection device 1, etc. The temperature information acquisition request occurs when the liquid ejection device 1 starts forming an image on the medium P. It may continue while the liquid ejection device 1 is forming an image on the medium P.

[0196] Then, when the control circuit 100 determines that a temperature information acquisition request has occurred (step S3 00 Y), executes temperature information acquisition processing to acquire information on the temperature of the print head 22 ( Step S200). The temperature of the print head 22 acquired by this temperature information acquisition process Depending on the degree, various signals that control the operation of printhead 22 are corrected and adjusted.

[0197] Next, an example of the sample number determination process will be described. As shown in FIG. 18, when the sample number determination process is executed, As an initial setting, "1" is assigned to the variable r and "0" is assigned to the variable q (step S201 After that, the control circuit 100 receives a temperature reading including information requesting execution of the sample number determination process. An acquisition request signal TD is generated and output to the temperature information output circuit 26 (step S202).

[0198] A temperature acquisition request including information requesting the temperature information output circuit 26 to execute a sample number determination process. When the signal TD is input, the control circuit 500 controls the head output of the print head 22-r. The select signal Sel selects the temperature signal TCr. Since the variable r=1, The select signal Sel that selects the head temperature signal TC1 output by the print head 22-1 is The signal is output to the multiplexer 510 (step S203). 540 is a clock signal CK The temperature is acquired at a cycle of 1 and stored as the retained temperature information dtr. That is, the shift register 5 40 is a clock signal that converts the voltage value of the head temperature signal TC1 output by the print head 22-1 into a clock signal. The m pieces of retained temperature information dtr acquired in the period of CK1 are retained.

[0199] Thereafter, a predetermined time period Tdet is included in the detection period for acquiring the temperature of the print head 22-1. At the acquisition timing, the control circuit 500 reads m pixels held by the shift register 540. A read request signal Ltc for reading the retained temperature information dtr is generated and output to the shift register 5. That is, the control circuit 500 outputs the shift register 40 at the acquisition timing. The stored temperature information group Gtc including m pieces of stored temperature information dtr stored in the star 540 is acquired. Then, the control circuit 500 converts the acquired holding temperature information group Gtc into a temperature information signal TI including m pieces of retained temperature information dtr; and outputs it to the control circuit 100.

[0200] The control circuit 100 acquires the holding temperature information group Gtc included in the input temperature information signal TI. The temperature information is acquired and stored as an adjustment temperature information group Gaj (step S205). The adjustment temperature information group Gaj held by the circuit 100 includes (mq) pieces of held temperature information dtr. Since the variable q=0, m pieces of holding temperature information dtr are included. The control circuit 100 stores (mq) pieces of holding temperature information dtr, and stores m pieces of holding temperature information dtr. The maximum value of the temperature information dtr is calculated as the maximum holding temperature information dtr-max and is held (m- q) pieces of holding temperature information dtr, and the minimum value of m pieces of holding temperature information dtr is set as the minimum holding temperature That is, the control circuit 100 calculates the degree information dtr-min. ) pieces of holding temperature information dtr, and since the variable q=0, m pieces of holding temperature information dt Calculate the maximum and minimum holding temperature information dtr-max and dtr-min from r. (Step S206).

[0201] Here, the maximum of (mq) pieces of holding temperature information dtr included in the adjustment temperature information group Gaj is The value is, for example, the maximum value of the temperatures specified by the (mq) pieces of holding temperature information dtr, (mq) pieces of digital temperature information dtc corresponding to (mq) pieces of holding temperature information dtr It may be the maximum value of the specified temperature, and the voltage value of (mq) pieces of retained temperature information dtr The maximum value is (mq) digital values ​​corresponding to (mq) pieces of holding temperature information dtr. Similarly, the maximum voltage value of the temperature information dtc may be included in the temperature information group Gaj for adjustment. The minimum value of the (mq) pieces of holding temperature information dtr included in the (mq) pieces of holding temperature information dtr is, for example, The minimum value of the temperature specified by the temperature information dtr is (mq) pieces of holding temperature information dtr. It may be the minimum value of the temperature specified by the corresponding (mq) digital temperature information dtc. The minimum value of the voltage values ​​of the (mq) pieces of retained temperature information dtr is The minimum voltage value of the (mq) digital temperature information dtc corresponding to the temperature information dtr. It is also possible.

[0202] Then, the control circuit 100 calculates the maximum holding temperature information dtr-max and the minimum holding temperature It is determined whether the difference between the information dtr-min and the predetermined threshold information Tth is equal to or greater than the predetermined threshold information Tth (step Step S207). The control circuit 100 calculates the maximum temperature holding information dtr-max and the minimum temperature holding information dtr-max. When it is determined that the difference between the information dtr-min and the predetermined threshold information Tth is equal to or greater than the predetermined threshold information Tth (step In step S207, the control circuit 100 calculates m holding temperatures included in the adjustment temperature information group Gaj. The retained temperature information dtr corresponding to the oldest digital temperature information dtc in the temperature information dtr is destroyed. That is, the holding temperature information included in the adjustment temperature information group Gaj is discarded (step S208). The number of report dtrs decreases by one.

[0203] Here, in the liquid ejection device 1 of this embodiment, m included in the adjustment temperature information group Gaj The retained temperature information corresponding to the oldest digital temperature information dtc among the retained temperature information dtr dtr is the register Rg1 to Rgm of the shift register 540. - The retained temperature information dtrm corresponds to the digital temperature information dtc retained in Rgm. That is, the control circuit 100 determines the maximum holding temperature information dtr-max and the minimum holding temperature information dtr-max. If it is determined that the difference with the holding temperature information dtr-min is equal to or greater than the predetermined threshold information Tth, In this case (Y in step S207), the (mq) holding temperatures included in the adjustment temperature information group Gaj are Of the temperature information dtr, the digital temperature information dtc stored in the register Rg(mq) is The corresponding holding temperature information dtr(mq) is discarded (step S208). "Discard the temperature information dtr(mq)" means to discard the retained temperature information from the adjustment temperature information group Gaj. It is not limited to erasing information corresponding to dtr(mq), but also includes temperature information group for adjustment Gaj is in a state where it holds information corresponding to the holding temperature information dtr(mq), and This includes cases where the holding temperature information dtr(mq) is not used in the processing.

[0204] The control circuit 100 selects m pieces of holding temperature information dtr included in the adjustment temperature information group Gaj. The oldest digital temperature information DTC is discarded, and the stored temperature information DTR is The number of retained temperature information dtr included in the adjusted temperature information group Gaj is reduced by one. The control circuit 100 adds 1 to the variable q (step S209). is included in the adjustment temperature information group Gaj after discarding the oldest digital temperature information dtc. It is determined whether the number of pieces of holding temperature information dtr is 2 or less. That is, (mq)≦2 Then, the control circuit 100 determines whether the adjustment temperature If it is determined that the number of holding temperature information dtr included in the information group Gaj is not two or less, That is, if (mq)≦2 is not satisfied (N in step S210), the above-mentioned step S205 The process of S209 is executed again.

[0205] That is, the maximum holding temperature of the plurality of holding temperature information dtr included in the adjustment temperature information group Gaj The difference between the temperature information dtr-max and the minimum holding temperature information dtr-min is equal to or exceeds the predetermined threshold information T th (N in step S207), or until it becomes less than ... The adjustment information dtr is kept until the number of pieces of holding temperature information dtr included becomes two or less (Y in step S210). Among the multiple retained temperature information dtr included in the temperature information group Gaj, the oldest acquired The retained temperature information dtr is discarded.

[0206] The control circuit 100 calculates the maximum value of the plurality of pieces of holding temperature information dtr included in the adjustment temperature information group Gaj. The difference between the maximum holding temperature information dtr-max and the minimum holding temperature information dtr-min is equal to or greater than a predetermined threshold. If it is determined that the value is less than the value information Tth (N in step S207), the control circuit 100 At this time, the number of holding temperature information dtr included in the adjustment temperature information group Gaj is (m- q) are the optimum values ​​of the retained temperature information dtr used to calculate the temperature of the print head 22-1. The control circuit 100 then determines that (mq) is the number of samples. The optimum number of samples of the retention temperature information dtr used to calculate the temperature of the node 22-1 is The temperature information output circuit 26 generates a temperature acquisition request signal TD including the temperature information. The control circuit 500 included in the output circuit 26 performs the following operation based on the input temperature acquisition request signal TD: Optimal sample of retained temperature information dtr used to calculate the temperature of print head 22-1 The number (mq) is stored in the memory circuit 570. That is, the control circuit 500 stores the mq) is set as the optimum number of samples corresponding to the print head 22-1, and the memory circuit 570 (step S211).

[0207] On the other hand, the control circuit 100 adjusts the holding temperature information dtr included in the adjustment temperature information group Gaj. If it is determined that the number is two or less (Y in step S210), the control circuit 100 The temperature detection circuit 250 of the print head 22-1 correctly acquires the temperature of the print head 22-1. It is determined that the temperature detection circuit 250 of the print head 22-1 has not reached the specified temperature. The control circuit 100 notifies the user via the line 94. An abnormality in the temperature detection circuit 250 corresponding to 1 is notified (step S212).

[0208] Then, in step S211, the control circuit 500 transfers (mq) to the print head. 22-1, the optimum number of samples is stored in the storage circuit 570, or In step S212, the circuit 100 detects the temperature corresponding to the print head 22-1. After notifying the abnormality of the circuit 250, the control circuit 100 adds 1 to the variable r (step S2 13), the variable q is initialized to 0 (step S214), and the variable r is set to the value of It is determined whether the number is greater than n, which is the total number of print heads 22 that device 1 has (step Step S215). If the control circuit 100 determines that the variable r is not greater than n, (N in step S215), that is, the control circuit 100 determines whether the variable r is valid when the liquid ejection device 1 is enabled. If it is determined that the number of print heads 22 is equal to or less than n, the above-mentioned step S The processes of S203 to S214 are executed again. Holding temperature information used to calculate the temperatures corresponding to the respective heads 22-1 to 22-n The optimum number of dtr samples is determined by the print heads 22-1 to 22- n, and stored in the memory circuit 570.

[0209] On the other hand, if the control circuit 100 determines that the variable r is greater than n (step S21 5 Y), that is, the control circuit 100 determines whether the variable r is a value corresponding to the print head of the liquid ejection device 1. When the total number of print heads 22 exceeds n, the print heads 22-1 to 22-2 of the liquid ejection device 1 are The optimum sample of the holding temperature information dtr used to calculate the temperature corresponding to each of 22-n When the calculation of the number of samples is completed, the sample number determination process ends.

[0210] As described above, in the liquid ejection device 1 of this embodiment, in the sample number determination process, the temperature The information output circuit 26 acquires the signal at each predetermined sampling period defined by the clock signal CK1. A plurality of digital temperature information dtc are stored, and m pieces of digital temperature information dtc are stored; The control circuit 100 receives a plurality of pieces of digital temperature information dtc held by the temperature information output circuit 26. Then, m pieces of digital temperature information dtc are obtained as a temperature information group Gaj for adjustment. The control circuit 100 then adjusts the temperature information signal TI based on the acquired adjustment temperature information group Gaj. The number of samples of the digital temperature information dtc to be used for generation is determined. The number of samples of the digital temperature information dtc determined in step 2 is stored in the temperature information output circuit 26. The data is stored in the memory circuit 570.

[0211] Specifically, when determining the number of samples of the digital temperature information dtc, the control circuit 100: Corresponding to each of the multiple digital temperature information dtc included in the adjustment temperature information group Gaj The temperature information signal TI is generated based on the difference between the maximum and minimum temperatures of the pressure chamber 312. The optimum number of samples of the holding temperature information dtr to be obtained is the number of samples of the printer included in the liquid ejection device 1. Holding temperature information used to calculate the temperatures corresponding to the respective heads 22-1 to 22-n Determine the optimal number of samples for dtr.

[0212] In detail, the control circuit 100 calculates the temperature information for adjustment by calculating the temperature information for adjustment from a plurality of digital temperatures included in the temperature information group Gaj. The difference between the maximum and minimum values ​​of the temperature of the pressure chamber 312 corresponding to each piece of information dtc and a predetermined The control circuit 100 compares the temperature for adjustment with the threshold information Tth, which is a threshold. The pressure chambers 312 corresponding to each of the digital temperature information dtc included in the group Gaj If the difference between the maximum and minimum temperatures is smaller than the threshold information Tth, the adjustment temperature information group G The number of digital temperature information dtc included in aj is used to generate the temperature information signal TI. The optimum number of samples of the holding temperature information dtr is determined and stored in the memory circuit 570. Corresponding to each of the multiple digital temperature information dtc included in the adjustment temperature information group Gaj If the difference between the maximum and minimum temperatures of the pressure chamber 312 is greater than the threshold information Tth, Among the multiple digital temperature information dtc included in the temperature information group Gaj, the one that was acquired the earliest The digital temperature information dtc is discarded from the adjustment temperature information group Gaj, and the adjustment temperature after discarding is The pressure chamber 3 corresponding to each of the digital temperature information dtc included in the temperature information group Gaj The difference between the maximum and minimum values ​​of the 12 temperatures is again compared with the threshold information Tth, which is a predetermined threshold. do.

[0213] The control circuit 100 then calculates the temperature information for adjustment by dividing the temperature information by the digital temperature information included in the temperature information for adjustment Gaj. The difference between the maximum and minimum values ​​of the temperature of the pressure chamber 312 corresponding to each of the information dtc is the threshold information The above comparison is repeated until the temperature information signal TI becomes smaller than Tth. The optimum number of samples of the retention temperature information dtr used for generation is determined. Meanwhile, the control circuit 100 is each of the plurality of digital temperature information dtc included in the adjustment temperature information group Gaj The difference between the maximum and minimum temperatures of the pressure chambers 312 corresponding to the temperature values ​​is greater than the threshold value information Tth. In this case, discard the digital temperature information dtc obtained earliest from the temperature information set Gaj for adjustment. The control circuit 100 then repeatedly discards the adjustment temperature information group Gaj after the discarding. If the number of digital temperature information DTCs included in the It is determined that the temperature of the print head 22 has not been acquired correctly, and An abnormality in the temperature detection circuit 250 is reported.

[0214] Next, an example of the temperature information acquisition process will be described. FIG. 19 shows an example of the temperature information acquisition process. The temperature information acquisition process is performed for the print heads 22-1 to 22-n. The same process is executed for each of the print heads 22-1 to 22-n. Therefore, in the following description, the process performed in response to the print head 22 is As shown in FIG. 19, the temperature information acquisition process is as follows: The control circuit 100 requests execution of a temperature information acquisition process for acquiring the temperature of the print head 22. The process starts by generating a temperature acquisition request signal TD and outputting it to the temperature information output circuit 26. do.

[0215] A temperature acquisition request including information requesting execution of temperature information acquisition processing is sent to the temperature information output circuit 26. When the signal TD is input (step S401), the control circuit 500 controls the print head 22 A select signal Sel that selects the head temperature signal TC output by the multiplexer 510 (Step S402). As a result, the shift register 540 outputs the The head temperature signal TC1 output by the head 22 is acquired at the cycle of the clock signal CK1, and the holding temperature That is, the shift register 540 stores the print head 2 The voltage value of the head temperature signal TCp output by the sensor 2 is acquired at the cycle of the clock signal CK1. The temperature information dtr is stored.

[0216] Thereafter, a predetermined acquisition time period Tdet is included in the detection time period Tdet for acquiring the temperature of the print head 22. At the same timing as step S204 described above, the control circuit 5 00 is used to read out m pieces of temperature information dtr stored in the shift register 540. The control circuit generates a read request signal Ltc and outputs it to the shift register 540. 500 indicates m retained temperatures retained by the shift register 540 at the time of acquisition. A holding temperature information group Gtc including the temperature information dtr is obtained (step S403).

[0217] The control circuit 500 also reads from the memory circuit 570 the optimum print head 22. The control circuit 500 reads out the number of samples (step S404). Among the m pieces of retained temperature information dtr included in the temperature information group Gtc, the one with the latest acquisition timing The temperature information signal TI is generated using the retained temperature information dtr for the number of samples in order from , and output (step S405).

[0218] Specifically, the control circuit 500 reads the information about the print head 22 from the memory circuit 570. When the optimum number of samples corresponding to the temperature is (mq), the control circuit 500 Among the m pieces of retained temperature information dtr included in the temperature information group Gtc, the registers Rg1 to Rg(m -q) stored digital temperature information dt corresponding to the (mq) number of digital temperature information dtc Using r1 to dtr(mq), a temperature information signal TI is generated and output.

[0219] That is, in the temperature information acquisition process, the temperature information output circuit 26 outputs the temperature information signal TI as The timing of outputting the temperature signal is within the detection period Tdet during which the temperature of the print head 22 is acquired. At a predetermined acquisition timing included in the signal, a read request signal Ltc is sent to a shift register 540. By outputting to the At the timing when the read request signal Ltc is output to the shift register 540, The temperature of the print head 22 is acquired at a predetermined timing included in the detection period Tdet. Select the same number of digital temperature information dtc as the number of calculated samples in order of the most recent value. The temperature information output circuit 26 generates a temperature information signal TI using the temperature information dtc. outputs the generated temperature information signal TI.

[0220] Here, the control circuit 500 controls the temperature defined by the holding temperature information dtr1 to dtr(mq). The temperature information signal TI including the maximum and minimum values ​​of the temperature may be generated and output to the control circuit 100. The temperature information according to the average value of the temperatures specified by the retention temperature information dtr1 to dtr(mq) is The control circuit 100 may generate a holding information signal TI and output it to the control circuit 100. By substituting the temperature information dtr1 to dtr(mq) into a predetermined conversion formula or table, The temperature information signal TI may be generated based on the value obtained by the above process and output to the control circuit 100.

[0221] Here, the control circuit 100 is an example of a processor, and the electrode 360 ​​is an example of a first electrode. The electrode 380 is an example of a second electrode, and is aligned along the Z axis in the print head 22. The +Z side of the print head 22 is an example of one side. The −Z side of the print head 22 is an example of the other side, and the resistance wiring 401 is a temperature detection unit. This is an example of the digital temperature information dtc and the protection corresponding to the digital temperature information dtc. The temperature information dtr is an example of temperature information, and the threshold information Tth is an example of a predetermined threshold. In addition, steps S206 to S212 included in the sample number determination process are temperature comparison steps. The control circuit 500 then reads the m number of data bits held by the shift register 540. The timing to output the read request signal Ltc for reading the retained temperature information dtr is the output timing. This is an example of timing.

[0222] 8. Action and Effects In the liquid ejection device 1 and head unit 20 of this embodiment configured as described above, The print head 22 includes an electrode 360, an electrode 380, and a piezoelectric element 370. In the direction along the Z axis where the electrode 380 and the piezoelectric body 370 are stacked, the piezoelectric body 370 A piezoelectric element 60 is located between the electrode 360 ​​and the electrode 380 and is driven by receiving a drive signal COM. and is located on the +Z side, which is one side of the piezoelectric element 60 in the direction along the Z axis, and is located on the +Z side of the piezoelectric element 60. 0, and the vibration plate 350 is deformed in one direction along the Z axis. The volume changes due to the deformation of the diaphragm 350 as the water accumulates. a pressure chamber substrate 310 in which pressure chambers 312 are provided, and a pressure chamber substrate 310 that responds to changes in the volume of the pressure chambers 312. The nozzle 321 that ejects ink by rotating the diaphragm 350 and the other side in the direction along the Z axis are a resistance wiring 401 located on the −Z side, which acquires a temperature corresponding to the temperature of the pressure chamber 312; By including the resistor wiring 401, which acquires the temperature corresponding to the temperature of the pressure chamber 312, the ink It is possible to arrange it near the pressure chamber 312 where the liquid is stored, and as a result, The accuracy of detecting the temperature of the stored ink is improved.

[0223] By using the print head 22 having such a configuration, the detection accuracy of the temperature of the print head 22 is When the temperature is increased, the temperature information output circuit 26 can obtain more digital temperature information dtc. On the other hand, the digital temperature information dt used to calculate the temperature of the print head 22 is preferably If the number of c is increased carelessly, the digital temperature information dtc to be acquired will be propagation of the vibration, the displacement of the vibration plate 350, and the instantaneous temperature of the ink stored in the pressure chamber 312. The possibility of noise due to the change being superimposed increases, and as a result, the temperature of the print head 22 In other words, the accuracy of detecting the temperature of the print head 22 may be reduced. By appropriately setting the number of samples of the digital temperature information DTC, the print head 22 The accuracy of detecting the temperature can be further improved.

[0224] In the liquid ejection device 1 and the head unit 20 of this embodiment, the control circuit 100 controls the temperature The information output circuit 26 acquires all of the digital temperature information dtc that can be held, and Based on all the digital temperature information dtc, the holding temperature can be used to generate the temperature information signal TI. The optimum number of samples of the temperature information dtr is determined. The optimum number of samples for the temperature retention information DTR can be obtained without the need for new personnel or equipment. That is, the liquid ejection device 1 and the head unit 2 of this embodiment can be determined as follows. In this system, the temperature of the print head 22 can be detected with a simple configuration without requiring new equipment or labor. The accuracy can be improved.

[0225] At this time, the control circuit 100 calculates the temperature by dividing the plurality of digital temperature values ​​included in the adjustment temperature information group Gaj. The difference between the maximum and minimum values ​​of the temperature of the pressure chamber 312 corresponding to each of the information dtc is the threshold information. If it is smaller than Tth, the plurality of digital temperature information included in the adjustment temperature information group Gaj The number of dtc is set to the optimum sampling time of the retained temperature information dtr used to generate the temperature information signal TI. The number of digital temperature information dtc included in the adjustment temperature information group Gaj is determined as When the difference between the maximum and minimum temperatures of the corresponding pressure chambers 312 is greater than the threshold information Tth, If it is larger, among the multiple digital temperature information dtc included in the temperature information group Gaj for adjustment, , discard the earliest acquired digital temperature information dtc from the adjustment temperature information group Gaj; Again, for each of the multiple digital temperature information dtc included in the adjustment temperature information group Gaj, The difference between the maximum and minimum temperatures of the corresponding pressure chambers 312 and the threshold information Tth, which is a predetermined threshold value. As a result, the propagation of the drive signal VOUT, the displacement of the diaphragm 350, and the pressure chamber 3 There is a risk of noise being superimposed due to instantaneous temperature changes in the ink stored in 12. This allows the removal of high, old samples and the retention time used to generate the temperature information signal TI. The optimum number of samples of the temperature information dtr can be determined more appropriately.

[0226] Then, the temperature information output circuit 26 acquires the temperature of the print head 22 during the detection period Td The same number of digital samples as the calculated number of samples are taken in order of proximity to the specified acquisition timing included in et. Select the temperature information dtc and use the selected digital temperature information dtc to generate the temperature information signal TI. By generating the electric field, the propagation of the drive signal VOUT, the displacement of the diaphragm 350, and the electric field stored in the pressure chamber 312 are controlled. Noise caused by instantaneous temperature changes in the ink being stored is reduced, The accuracy of detecting the temperature of 22 can be improved.

[0227] Although the embodiments and modifications have been described above, the present invention is not limited to these embodiments. It is possible to implement the invention in various ways without departing from the spirit of the invention. For example, the above embodiments can be combined as appropriate.

[0228] The present invention has substantially the same configuration (for example, function, method and result) as the configuration described in the embodiment. The present invention also includes the following embodiments: The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. A configuration that can achieve the same effect or purpose as the configuration described in the above embodiment. The present invention also includes a configuration in which publicly known technology is added to the configuration described in the embodiment. .

[0229] The following can be derived from the above-described embodiment.

[0230] One aspect of the liquid ejection device is a drive circuit that outputs a drive signal; a print head that receives the drive signal and ejects liquid; A head temperature signal corresponding to the temperature of the print head is acquired at a predetermined sampling period. a temperature information output circuit that outputs a temperature information signal corresponding to the acquired head temperature signal; a processor that controls the printhead and the drive circuitry; Equipped with The print head includes: The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric body, The piezoelectric element is positioned between the first electrode and the second electrode in the stacking direction. a piezoelectric element that receives the drive signal and is driven; The piezoelectric element is positioned on one side of the stacking direction and deformed by driving the piezoelectric element. a diaphragm that The liquid is stored in the cavity, and the cavity is located on one side of the vibration plate in the stacking direction. a pressure chamber substrate provided with a pressure chamber whose volume changes with deformation of the moving plate; a nozzle that ejects liquid in response to a change in the volume of the pressure chamber; a pressure chamber temperature sensor that is located on the other side of the vibration plate in the stacking direction and that responds to the temperature of the pressure chamber; a temperature detection unit that outputs a head temperature signal; and The temperature information output circuit outputs the head temperature signal in multiple steps obtained at each sampling period. Holds temperature information for a number of The processor outputs the plurality of pieces of temperature information held by the temperature information output circuit to a temperature adjustment unit. and adjusting the temperature information signal based on the acquired temperature information group for adjustment. determining the number of samples of the temperature information to be used for generation; The number of samples determined by the processor is stored in the temperature information output circuit. .

[0231] In this liquid ejection device, a temperature detection unit outputs a head temperature signal corresponding to the temperature of the pressure chamber. By being located in the vicinity of the pressure chamber, the temperature of the liquid stored in the pressure chamber can be detected with high accuracy. This can be done.

[0232] In addition, in this liquid ejection device, the temperature information output circuit outputs the head temperature signal at the sampling interval. The processor stores multiple pieces of temperature information acquired for each period, and the temperature information output circuit stores A plurality of pieces of temperature information are acquired as a group of temperature information for adjustment, and based on the acquired group of temperature information for adjustment, The number of samples of temperature information used to generate the temperature information signal is determined based on the temperature information. The number of samples determined by the processor is stored in the temperature information output circuit. The temperature information output circuit outputs the temperature information signal based on all of the plurality of pieces of temperature information that can be held. Determine the optimal number of samples of temperature information to be used for generation. Therefore, new manpower and equipment are required. It is possible to determine the optimum number of samples without requiring a separate sample. The ejection device does not require any new equipment or manpower, and has a simple configuration that allows the temperature of the print head to be controlled. The detection accuracy can be improved.

[0233] In one aspect of the liquid ejection device, The processor adjusts each of the plurality of pieces of temperature information included in the adjustment temperature information group. The number of samples is determined based on the difference between the maximum and minimum values ​​of the temperature of the pressure chamber corresponding to You may do so.

[0234] In one aspect of the liquid ejection device, The processor: the pressure chambers corresponding to the plurality of pieces of temperature information included in the adjustment temperature information group; In the temperature comparison process, the difference between the maximum and minimum temperatures is compared with a predetermined threshold value. the pressure chambers corresponding to the plurality of pieces of temperature information included in the adjustment temperature information group; When the difference between the maximum and minimum values ​​of the temperature is smaller than the predetermined threshold, the adjustment temperature information determining the number of the plurality of pieces of temperature information included in the information group as the number of samples; the pressure chambers corresponding to the plurality of pieces of temperature information included in the adjustment temperature information group; If the difference between the maximum and minimum values ​​of the temperature is greater than the predetermined threshold, The temperature information acquired earliest among the plurality of pieces of temperature information included in the group of pieces of temperature information is used for the adjustment. Alternatively, the temperature information may be discarded from the set of temperature information to be used, and the temperature comparison process may be performed again.

[0235] In this liquid ejection device, the driving signal is transmitted to the piezoelectric element, the vibration plate is displaced, and the liquid stored in the pressure chamber is The sample is taken within a range where noise caused by instantaneous temperature changes in the ink is unlikely to have an effect. The number of samples can be determined, and the print head size can be calculated based on the number of samples. The temperature detection accuracy can be improved.

[0236] In one aspect of the liquid ejection device, In the temperature comparison process, the processor compares the temperature values ​​of the plurality of temperature values ​​included in the adjustment temperature information group. When the number of pieces of temperature information becomes 2 or less, the temperature comparison process is terminated and abnormality information is reported. You may know.

[0237] In one aspect of the liquid ejection device, The temperature information output circuit holds the temperature information signal at the output timing. Among the plurality of pieces of temperature information, the acquired timing is selected in order of proximity to the output timing, The same number of pieces of temperature information as the number of samples are selected, and the temperature information is generated using the selected pieces of temperature information. The temperature information signal may be output.

[0238] In this liquid ejection device, the driving signal is transmitted to the piezoelectric element, the vibration plate is displaced, and the liquid stored in the pressure chamber is The temperature is determined within a range that is unlikely to be affected by noise caused by instantaneous temperature changes in the ink being stored. The print head temperature can be calculated based on the number of samples taken. This can improve the accuracy of detecting the degree of

[0239] In one aspect of the liquid ejection device, The drive circuit may output the drive signal corrected based on the temperature information signal. .

[0240] In this liquid ejection device, the accuracy of detecting the temperature of the print head can be improved. The waveform accuracy of the drive signal corrected based on the temperature of the print head is improved. The ejection accuracy of ink ejected based on the drive signal is also improved.

[0241] In one aspect of the liquid ejection device, The temperature information output circuit an amplifier circuit that amplifies the head temperature signal and outputs an amplified head temperature signal; The amplification head temperature signal is acquired at each sampling period and converted into the temperature information. A / D converter and may include:

[0242] One aspect of the head unit is a print head that receives a drive signal and ejects liquid; A head temperature signal corresponding to the temperature of the print head is acquired at a predetermined sampling period. a temperature information output circuit that outputs a temperature information signal corresponding to the acquired head temperature signal; Equipped with The print head includes: The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric body, The piezoelectric element is positioned between the first electrode and the second electrode in the stacking direction. a piezoelectric element that receives the drive signal and is driven; The piezoelectric element is positioned on one side of the stacking direction and deformed by driving the piezoelectric element. a diaphragm that The liquid is stored in the cavity, and the cavity is located on one side of the vibration plate in the stacking direction. a pressure chamber substrate provided with a pressure chamber whose volume changes with deformation of the moving plate; a nozzle that ejects liquid in response to a change in the volume of the pressure chamber; a pressure chamber temperature sensor that is located on the other side of the vibration plate in the stacking direction and that responds to the temperature of the pressure chamber; a temperature detection unit that outputs a head temperature signal; and The temperature information output circuit outputs the head temperature signal in multiple steps obtained at each sampling period. The number of samples determined based on the number of temperature information is stored.

[0243] In this head unit, a temperature detection section outputs a head temperature signal corresponding to the temperature of the pressure chamber. However, by being located in the vicinity of the pressure chamber, the temperature of the liquid stored in the pressure chamber can be detected with high accuracy. It is possible.

[0244] In addition, in this head unit, the temperature information output circuit samples the head temperature signal. The temperature information signal is generated based on all of the temperature information acquired for each period. The temperature of the print head is calculated based on the number of temperature information samples received. This can improve the accuracy of detecting the temperature of the head.

[0245] In one aspect of the head unit, The number of samples is the maximum value of the temperature of the pressure chamber corresponding to each of the plurality of pieces of temperature information. The value may be determined based on the difference between the value and the minimum value.

[0246] In one aspect of the head unit, The number of samples is the difference between the maximum and minimum values ​​of the temperatures of the pressure chambers corresponding to each of the plurality of pieces of temperature information; In the temperature comparison process, the temperature is compared with a predetermined threshold value. The difference between the maximum value and the minimum value of the temperature of the pressure chamber corresponding to each of the plurality of pieces of temperature information is If the temperature information is smaller than the predetermined threshold, the number of samples is determined as the number of samples. Determined, The difference between the maximum value and the minimum value of the temperature of the pressure chamber corresponding to each of the plurality of pieces of temperature information is If the temperature is greater than the predetermined threshold, the temperature information acquired earliest among the plurality of temperature information is The temperature information may be discarded and the temperature comparison process may be performed again to determine the temperature.

[0247] In this head unit, the number of stored samples determines the propagation and vibration of the drive signal to the piezoelectric element. Noise caused by the displacement of the moving plate and the instantaneous temperature change of the ink stored in the pressure chamber Since this is a range where it is difficult to affect the print head performance, the print head performance calculated based on the number of samples is The temperature detection accuracy can be improved.

[0248] In one aspect of the head unit, The temperature information output circuit holds the temperature information signal at the output timing. Among the plurality of pieces of temperature information, the acquired timing is selected in order of proximity to the output timing, The same number of pieces of temperature information as the number of samples are selected, and the temperature information is generated using the selected pieces of temperature information. The temperature information signal may be output.

[0249] In this head unit, the driving signal is transmitted to the piezoelectric element, the vibration plate is displaced, and the pressure chamber is The temperature is determined within a range that is unlikely to be affected by noise caused by instantaneous temperature changes in the stored ink. The printhead temperature can be calculated based on the number of samples taken. The temperature detection accuracy can be improved.

[0250] In one aspect of the head unit, The drive signal may be corrected based on the temperature information signal.

[0251] In this head unit, the accuracy of detecting the temperature of the print head can be improved. The waveform accuracy of the drive signal corrected based on the temperature of the print head is also improved. The ejection accuracy of the ink ejected based on the above is also improved.

[0252] In one aspect of the head unit, The temperature information output circuit an amplifier circuit that amplifies the head temperature signal and outputs an amplified head temperature signal; The amplification head temperature signal is acquired at each sampling period and converted into the temperature information. A / D converter and may include: [Explanation of symbols]

[0253] 1...liquid ejection device, 10...control unit, 20...head unit, 21...carriage, 22...print head, 26...temperature information output circuit, 28...temperature detection circuit, 30...moving unit 31...carriage motor, 32...endless belt, 40...transport unit, 41...transport Motor, 42...conveyor roller, 50...drive circuit, 52...reference voltage output circuit, 60...piezoelectric Element, 90... ink container, 92... encoder sensor, 94... alarm circuit, 100... control Circuit, 200... drive signal selection circuit, 210... selection control circuit, 212... shift register, 214... latch circuit, 216... decoder, 230... selection circuit, 232... inverter, 234...transfer gate, 250...temperature detection circuit, 252, 254...resistors, 310 ...pressure chamber substrate, 311...partition wall, 312...pressure chamber, 312a, 312b...end portion, 315...connection Plate, 316... nozzle communication passage, 317... first manifold portion, 318... second manifold portion, 319...supply communication passage, 320...nozzle plate, 321...nozzle, 330...protection substrate , 331...holding portion, 332...through hole, 340...case member, 341...accommodating portion, 342...third 3 manifold part, 343... connection port, 344... supply port, 345... compliance board, 346...sealing film, 347...fixed substrate, 348...opening, 349...compliance portion, 3 50...diaphragm, 351...elastic membrane, 352...insulating membrane, 360...electrodes, 360a, 360b ...end portion, 370...piezoelectric body, 370a, 370b...end portion, 371...groove portion, 380...electrode, 3 80a, 380b...end portions, 385...wiring portion, 391...individual lead electrodes, 392...common lead Lead electrodes, 392a, 392b...extension portions, 393, 393a, 393b...measurement lead electrodes , 400... manifold, 401... resistance wiring, 410... active portion, 415... inactive portion, 42 0...wiring board, 421...integrated circuit, 500...control circuit, 501...request analysis unit, 502... Lock signal output unit 503...temperature information output unit 504...correction value calculation unit 505...memory Control unit, 510... multiplexer, 520... amplifier circuit, 530... A / D converter, 540...shift register, 550...amplifier circuit, 560...A / D converter, 570... Memory circuit, P... medium, Rg, Rg1-Rgm... registers

Claims

1. a drive circuit that outputs a drive signal; a print head that receives the drive signal and ejects liquid; A head temperature signal corresponding to the temperature of the print head is acquired at a predetermined sampling period. a temperature information output circuit that outputs a temperature information signal corresponding to the acquired head temperature signal; a processor that controls the printhead and the drive circuitry; Equipped with The print head includes: The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric body, The piezoelectric element is positioned between the first electrode and the second electrode in the stacking direction. a piezoelectric element that receives the drive signal and is driven; The piezoelectric element is positioned on one side of the stacking direction and deformed by driving the piezoelectric element. a diaphragm that The liquid is stored in the cavity, and the cavity is located on one side of the vibration plate in the stacking direction. a pressure chamber substrate provided with a pressure chamber whose volume changes with deformation of the moving plate; a nozzle that ejects liquid in response to a change in the volume of the pressure chamber; a pressure chamber temperature sensor that is located on the other side of the vibration plate in the stacking direction and that responds to the temperature of the pressure chamber; a temperature detection unit that outputs a head temperature signal; and The temperature information output circuit outputs the head temperature signal in multiple steps obtained at each sampling period. Holds temperature information for a number of The processor outputs the plurality of pieces of temperature information held by the temperature information output circuit to a temperature adjustment unit. and adjusting the temperature information signal based on the acquired temperature information group for adjustment. determining the number of samples of the temperature information to be used for generation; The number of samples determined by the processor is stored in the temperature information output circuit. 、 A liquid ejection device characterized by:

2. The processor adjusts each of the plurality of pieces of temperature information included in the adjustment temperature information group. The number of samples is determined based on the difference between the maximum and minimum values ​​of the temperature of the pressure chamber corresponding to do, The liquid ejection device according to claim 1 .

3. The processor: the pressure chambers corresponding to the plurality of pieces of temperature information included in the adjustment temperature information group; In the temperature comparison process, the difference between the maximum and minimum temperatures is compared with a predetermined threshold value. the pressure chambers corresponding to the plurality of pieces of temperature information included in the adjustment temperature information group; When the difference between the maximum and minimum values ​​of the temperature is smaller than the predetermined threshold, the adjustment temperature information determining the number of the plurality of pieces of temperature information included in the information group as the number of samples; the pressure chambers corresponding to the plurality of pieces of temperature information included in the adjustment temperature information group; If the difference between the maximum and minimum values ​​of the temperature is greater than the predetermined threshold, the adjustment temperature information The temperature information acquired earliest among the plurality of pieces of temperature information included in the group of pieces of temperature information is used for the adjustment. the temperature information group is discarded, and the temperature comparison process is performed again.

3. The liquid ejection device according to claim 2.

4. In the temperature comparison process, the processor compares the plurality of temperature information sets included in the adjustment temperature information set. When the number of pieces of temperature information becomes 2 or less, the temperature comparison process is terminated and abnormality information is reported. Know, 4. The liquid ejection device according to claim 3.

5. The temperature information output circuit holds the temperature information signal at the output timing. Among the plurality of pieces of temperature information, the acquired timing is selected in order of proximity to the output timing, The same number of pieces of temperature information as the number of samples are selected, and the temperature information is generated using the selected pieces of temperature information. outputting the temperature information signal; The liquid ejection device according to claim 1 .

6. the drive circuit outputs the drive signal corrected based on the temperature information signal. The liquid ejection device according to claim 1 .

7. The temperature information output circuit an amplifier circuit that amplifies the head temperature signal and outputs an amplified head temperature signal; The amplification head temperature signal is acquired at each sampling period and converted into the temperature information. An A / D converter, Including, The liquid ejection device according to claim 1 .

8. a print head that receives a drive signal and ejects liquid; A head temperature signal corresponding to the temperature of the print head is acquired at a predetermined sampling period. a temperature information output circuit that outputs a temperature information signal corresponding to the acquired head temperature signal; Equipped with The print head includes: The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric body, The piezoelectric element is positioned between the first electrode and the second electrode in the stacking direction. a piezoelectric element that receives the drive signal and is driven; The piezoelectric element is positioned on one side of the stacking direction and deformed by driving the piezoelectric element. a diaphragm that The liquid is stored in the cavity, and the cavity is located on one side of the vibration plate in the stacking direction. a pressure chamber substrate provided with a pressure chamber whose volume changes with deformation of the moving plate; a nozzle that ejects liquid in response to a change in the volume of the pressure chamber; a pressure chamber temperature sensor that is located on the other side of the vibration plate in the stacking direction and that responds to the temperature of the pressure chamber; a temperature detection unit that outputs a head temperature signal; and The temperature information output circuit outputs the head temperature signal in multiple steps obtained at each sampling period. storing the number of samples determined based on the number of temperature information; A head unit characterized by:

9. The number of samples is the maximum value of the temperature of the pressure chamber corresponding to each of the plurality of pieces of temperature information. determined based on the difference between the value and the minimum value, 9. The head unit according to claim 8.

10. The number of samples is the difference between the maximum and minimum values ​​of the temperatures of the pressure chambers corresponding to each of the plurality of pieces of temperature information; In the temperature comparison process, the temperature is compared with a predetermined threshold value. The difference between the maximum value and the minimum value of the temperature of the pressure chamber corresponding to each of the plurality of pieces of temperature information is If the temperature information is smaller than the predetermined threshold, the number of samples is determined as the number of samples. Determined, The difference between the maximum value and the minimum value of the temperature of the pressure chamber corresponding to each of the plurality of pieces of temperature information is If the temperature is greater than the predetermined threshold, the temperature information acquired earliest among the plurality of temperature information is The temperature information is discarded, and the temperature comparison process is performed again.

10. The head unit according to claim 9.

11. The temperature information output circuit holds the temperature information signal at the output timing. Among the plurality of pieces of temperature information, the acquired timing is selected in order of proximity to the output timing, The same number of pieces of temperature information as the number of samples are selected, and the temperature information is generated using the selected pieces of temperature information. outputting the temperature information signal; 9. The head unit according to claim 8.

12. the drive signal is corrected based on the temperature information signal; 9. The head unit according to claim 8.

13. The temperature information output circuit an amplifier circuit that amplifies the head temperature signal and outputs an amplified head temperature signal; The amplification head temperature signal is acquired at each sampling period and converted into the temperature information. An A / D converter, Including, 9. The head unit according to claim 8.

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