Liquid ejecting head and liquid ejecting apparatus

Abstract

The present application provides a liquid ejecting head and a liquid ejecting apparatus capable of detecting whether the pressure of a meniscus of a nozzle is within a normal range while suppressing an increase in cost and an increase in size. The apparatus includes: a plurality of nozzles that eject a liquid; a plurality of pressure chambers that apply pressure to the liquid for ejecting the liquid from the plurality of nozzles, respectively, the plurality of pressure chambers being arranged in the first direction; a first liquid chamber disposed in a first direction with respect to the first pressure chamber, the first pressure chamber being located at an end of the plurality of pressure chambers in the first direction; a first vibration plate defining a part of the first liquid chamber; and a manifold connected to the plurality of pressure chambers and the first liquid chamber in common, the liquid ejecting head having a strain gauge corresponding to the first diaphragm for acquiring the pressure in the first liquid chamber.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device for ejecting liquid from a nozzle, and in particular, to an inkjet recording head and an inkjet recording device for ejecting ink as a liquid. Background Technology

[0002] Liquid jetting devices, such as inkjet printers and plotters, are characterized by liquid jetting heads that can eject liquids such as ink stored in containers or cans as droplets.

[0003] For example, the liquid injection head disclosed in Patent Document 1 includes a nozzle for injecting liquid, a pressure chamber connected to the nozzle, and pressure detectors individually provided for each of the multiple pressure chambers. The pressure detectors can measure the pressure of the liquid (meniscus) near the pressure chamber.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2007-261285

[0005] In this existing technology, pressure detectors are provided for each pressure chamber individually, thus enabling the detection of whether the pressure at the meniscus of each nozzle is properly maintained within the meniscus pressure resistance range. However, detecting the pressure at the meniscus near all pressure chambers individually increases costs and requires a larger liquid injection head. The goal is to detect whether the pressure at the meniscus of the nozzles within the liquid injection head is within the normal range, while minimizing cost increases and size increases. Summary of the Invention

[0006] The present invention, which addresses the aforementioned technical problems, relates to a liquid injection head, characterized by comprising: a plurality of nozzles for injecting liquid; a plurality of pressure chambers for imparting pressure to the liquid for injecting liquid from the plurality of nozzles respectively, wherein the plurality of pressure chambers are arranged in a first direction; a first liquid chamber disposed in the first direction relative to the first pressure chamber, wherein the first pressure chamber is located at an end of the plurality of pressure chambers in the first direction; a first vibrating plate defining a portion of the first liquid chamber; and a first common liquid chamber communicatively connected to the plurality of pressure chambers and the first liquid chamber, wherein the liquid injection head has a first detection element corresponding to the first vibrating plate for acquiring the pressure within the first liquid chamber.

[0007] Furthermore, other aspects of the present invention relate to a liquid injection device, characterized in that it comprises: a liquid injection head of the above-described manner; and a pressure acquisition unit that acquires the pressure of the first liquid chamber based on the resistance value of the first detection element. Attached Figure Description

[0008] Figure 1This is a diagram showing the outline configuration of the liquid injection device according to Embodiment 1.

[0009] Figure 2 This is a block diagram of the liquid injection device according to Embodiment 1.

[0010] Figure 3 This is an exploded perspective view of the liquid injection head involved in Embodiment 1.

[0011] Figure 4 This is a cross-sectional view of the liquid injection head according to Embodiment 1.

[0012] Figure 5 This is an exploded perspective view of the head chip involved in Implementation Method 1.

[0013] Figure 6 This is a top view of the head chip involved in Embodiment 1.

[0014] Figure 7 It is involved in Implementation Method 1 Figure 6 A-A' profile.

[0015] Figure 8 It is involved in Implementation Method 1 Figure 6 The cross-sectional view along line B-B'.

[0016] Figure 9 This is a top view showing the flow path of the head chip according to Embodiment 1.

[0017] Figure 10 This is a diagram showing an example of the strain gauge and pressure detection unit according to Embodiment 1.

[0018] Figure 11 This is a cross-sectional view of the head chip involved in a variation of embodiment 1.

[0019] Figure 12 This is a top view showing the flow path of the head chip involved in Variation 2 of Embodiment 1.

[0020] Figure 13 This is a diagram showing an example of a strain gauge and pressure detection unit involved in a variation 3 of Embodiment 1.

[0021] Figure 14 This is a block diagram of the liquid injection device involved in Variation 6 of Embodiment 1.

[0022] Figure 15 This is a top view showing the flow path of the head chip according to Embodiment 2.

[0023] Figure 16 It is involved in implementation method 2. Figure 15 The cross-sectional view along the C-C' line.

[0024] Figure 17 It is involved in implementation method 2. Figure 15 The cross-sectional view of the D-D' line.

[0025] Explanation of reference numerals in the attached figures

[0026] Hc…head chip, 1…liquid jetting device, 2…liquid jetting head, 10…flow path forming substrate, 12, 12L, 12R…pressure chamber, 12A…first pressure chamber, 12B…second pressure chamber, 15…connecting plate, 20…nozzle plate, 21…nozzle, 21D…dummy nozzle, 43…outlet, 44…inlet, 45…flexible substrate, 50…vibrating plate, 50A…first vibrating plate, 50B…second vibrating plate, 60…first electrode, 61…piezoelectric layer, 62…second electrode, 70, 70A, 70B…strain gauge, 71…detection circuit, 72…pressure… Force acquisition unit, 75…first resistive element, 76…second resistive element, 77…third resistive element, 81, 81L, 81R…first liquid chamber, 81D…first dummy liquid chamber, 82…second liquid chamber, 91…individual lead electrode, 92…common lead electrode, 100…manifold, 100A…supply-side manifold, 100B…recovery-side manifold, 110…wiring assembly, 111…drive signal selection circuit, 131…first individual flow path, 132…second individual flow path, 200…flow path assembly, 210…relay board, 220…cover head, 300…piezoelectric actuator. Detailed Implementation

[0027] The present invention will now be described in detail based on embodiments. However, the following description illustrates one aspect of the invention, which can be modified arbitrarily within the scope of the invention. In the figures, the same reference numerals indicate the same parts, and descriptions are omitted where appropriate. Furthermore, in the figures, X, Y, and Z represent three mutually orthogonal spatial axes. In this specification, the directions along these axes will be designated as the X direction, Y direction, and Z direction. The direction in which the arrows point in each figure will be designated as the positive (+) direction, and the opposite direction of the arrows will be designated as the negative (-) direction. Furthermore, the Z direction represents the vertical direction, the +Z direction represents vertically downward, and the -Z direction represents vertically upward. Moreover, the directions of the three spatial axes, which are not limited to positive and negative directions, will be designated as the X-axis direction, Y-axis direction, and Z-axis direction for explanation.

[0028] (Implementation Method 1)

[0029] Figure 1 This is a diagram showing the general configuration of the liquid injection device 1 of the present invention.

[0030] As shown in the figure, the liquid jetting device 1 is a serial printer as described below: it has a liquid jetting head 2, which conveys the medium S in the X-axis direction, and while the liquid jetting head 2 reciprocates in the Y-axis direction, it jets liquid from the liquid jetting head 2 toward the medium S in the +Z direction, thereby performing printing. It should be noted that, as the medium S, in addition to recording paper, any material such as resin film or cloth can be used.

[0031] The liquid injection device 1 includes a liquid injection head 2, a liquid storage section 3, a control unit 4, a conveying mechanism 5 for delivering the medium S, and a moving mechanism 6.

[0032] The liquid jet head 2 sprays an example of liquid supplied from the liquid storage section 3, namely ink, as ink droplets in the +Z direction.

[0033] The liquid storage section 3 stores the ink ejected from the liquid jet head 2. Examples of liquid storage sections 3 include, for instance, a detachable box within the liquid jetting device 1, a bag-shaped ink packet formed of a flexible film, or an ink refill container. It should be noted that, although not specifically illustrated, the liquid storage section 3 may, for example, store multiple types of ink with different colors and compositions separately. Furthermore, the liquid storage section 3 may also consist of a main tank and a secondary tank. It can also be configured such that the secondary tank is connected to the liquid jet head 2, and the ink consumed by the ink ejected from the liquid jet head 2 is replenished from the main tank to the secondary tank. Alternatively, the ink can circulate between the liquid storage section 3 and the liquid jet head 2.

[0034] The control unit 4 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage device such as semiconductor memory. Furthermore, the control unit 4 also includes a power supply device for supplying power from an external power source, such as a commercial power supply, to the various elements of the liquid injection device 1. The control unit 4 is electrically connected to the liquid injection head 2 via external wiring (not shown). The control unit 4 comprehensively controls the various elements of the liquid injection device 1 by executing a program stored in the storage device through a control device.

[0035] The conveying mechanism 5 conveys the medium S in the X-axis direction, for example, by having a conveying roller 5a that rotates by a conveying motor, which is controlled and driven by the control unit 4.

[0036] The moving mechanism 6 is a mechanism for reciprocating the liquid injection head 2 in the Y-axis direction. It includes a holder 6a, which serves as a carriage for holding the liquid injection head 2, and a conveyor belt 6b, which is an annular belt mounted along the Y-axis direction. The control unit 4 rotates the conveyor belt 6b by controlling the drive of a conveyor motor (not shown), causing the liquid injection head 2 and the holder 6a fixed to the conveyor belt 6b to reciprocate together in the Y-axis direction.

[0037] The liquid injection head 2 performs an injection action under the control of the control unit 4. This injection action is performed by injecting liquid from multiple nozzles 21 (see reference). Figure 4 The ink supplied from the liquid storage unit 3 is sprayed as ink droplets in the +Z direction. The spraying action of the liquid spray head 2 is performed in parallel with the transport of the medium S based on the transport mechanism 5 and the reciprocating movement of the liquid spray head 2 based on the moving mechanism 6, thereby coating the medium S with ink, i.e., printing.

[0038] Figure 2 This is a block diagram of the liquid injection device 1. (For example...) Figure 2 As shown, the liquid injection device 1 includes a control unit 4, a conveying mechanism 5, a moving mechanism 6, and a liquid injection head 2. The control unit 4 includes a control unit 120, a storage unit 121, and a drive signal generation circuit 122. The liquid injection head 2 includes a drive signal selection circuit 111, multiple piezoelectric actuators 300, a pressure acquisition unit 72, a detection circuit 71, and a strain gauge 70.

[0039] The control unit 120 includes one or more processing circuits, such as a CPU or FPGA. The control unit 120 generates signals for controlling the operation of each part of the liquid jetting device 1. The control unit 120 controls the ink ejection operation of the liquid jetting head 2.

[0040] The control unit 120 generates a printed signal SI, a waveform specification signal dCom, and a timing signal PTS. The printed signal SI is a digital signal used to specify the type of operation of the liquid injection head 2. The printed signal SI also specifies whether a drive signal Com is supplied to the piezoelectric actuator 300. The waveform specification signal dCom is a digital signal that specifies the waveform of the drive signal Com. The drive signal Com is an analog signal used to drive the piezoelectric actuator 300. The timing signal PTS is a signal that specifies the timing for generating the drive signal Com.

[0041] Storage unit 121 includes one or more storage circuits such as a semiconductor memory. Storage unit 121 stores printed data Img supplied from the host computer. Storage unit 121 stores the control program of liquid injection device 1.

[0042] The drive signal generation circuit 122 includes a DA conversion circuit. The drive signal generation circuit 122 generates a drive signal Com having a waveform defined by the waveform specification signal dCom. The drive signal generation circuit 122 outputs the drive signal Com each time it receives a timing signal PTS.

[0043] The drive signal selection circuit 111 switches whether to supply the drive signal Com to each piezoelectric actuator 300 based on the printed signal SI. The drive signal selection circuit 111 selects the piezoelectric actuator 300 to which the drive signal Com is supplied based on the printed signal SI, the latch signal LAT, and the change signal CH supplied from the control unit 4. The latch signal LAT specifies the latching timing of the printed data Img. The change signal CH specifies the selection timing of the drive pulses included in the drive signal Com.

[0044] The pressure acquisition unit 72 acquires the pressure of the first liquid chamber 81 and the second liquid chamber 82 (described later) based on the resistance value of the strain gauge 70 in the detection circuit 71.

[0045] Figure 3 This is an exploded 3D view of the liquid jet nozzle. Figure 4 This is a cross-sectional view of the liquid injection head. The directions of the liquid injection head 2 are described based on the directions when the liquid injection head 2 is mounted on the liquid injection device 1, namely the X-axis direction, Y-axis direction, and Z-axis direction. The liquid injection head 2 of this embodiment includes multiple head chips Hc, a flow path component 200, a relay substrate 210, and a cover 220.

[0046] The flow path component 200 includes a first flow path component 201 having a first flow path 401, a second flow path component 202 having a second flow path 402, and a sealing component 203 connecting the first flow path 401 and the second flow path 402 in a liquid-tight state. The first flow path component 201, the sealing component 203, and the second flow path component 202 are stacked in the +Z direction in this order.

[0047] In this embodiment, the first flow path component 201 is constructed by stacking three components in the Z-axis direction. The first flow path component 201 has a connecting portion 204 that connects to a liquid storage section 3 containing liquid. In this embodiment, the connecting portion 204 is configured to protrude cylindrically in the Z-direction on the Z-direction surface of the first flow path component 201. The liquid storage section 3 can be directly connected to the connecting portion 204 or connected to the connecting portion 204 via a supply pipe such as a hose. Inside the connecting portion 204 is a first flow path 401 for supplying liquid from the liquid storage section 3. The first flow path 401 is constructed by a flow path extending in the Z-axis direction and a flow path extending along the stacking interface of the stacked components. Furthermore, a liquid storage section 401a with an inner diameter larger than other areas is provided midway through the first flow path 401, and a filter 401b is provided inside the liquid storage section 401a. Furthermore, in this embodiment, a first flow path component 201 includes eight connecting portions 204 and eight independent first flow paths 401.

[0048] The second flow path component 202 has a plurality of second flow paths 402, which are respectively connected to the ends of the plurality of first flow paths 401 opposite to the connecting portion 204. That is, in this embodiment, one second flow path component 202 has eight independent second flow paths 402. The first flow paths 401 and the second flow paths 402 are liquid-tightly connected via a sealing component 203. The sealing component 203 can be made of a material that is resistant to liquid and elastically deformable relative to the liquid used by the liquid injection head 2, such as rubber, elastomer, etc. A connecting flow path 403 is provided in such a sealing component 203, which extends through in the Z-axis direction, and the first flow paths 401 and the second flow paths 402 are connected via the connecting flow path 403. That is, in the flow path component 200, eight flow paths 400, each having a first flow path 401, a second flow path 402, and a connecting flow path 403, are independently provided.

[0049] Multiple head chips Hc are held on the surface of the second flow path component 202 facing the +Z direction. Specifically, the second flow path component 202 has a receiving portion 208, which has a concave shape with an opening on the surface facing the +Z direction, and the head chips Hc are received within the receiving portion 208. In the liquid injection head 2 of this embodiment, multiple head chips Hc are held; in this embodiment, as an example, four head chips Hc are held. Furthermore, in this embodiment, the four head chips Hc are arranged side by side in the Y-axis direction with the same position relative to the X-axis direction.

[0050] It should be noted that, in this embodiment, an example is shown where a common receiving portion 208 is provided for all head chips Hc, but it is not particularly limited to this. For example, the receiving portion 208 may also be provided independently for each head chip Hc, or it may be provided independently for each group of two or more head chips Hc.

[0051] The second flow path 402 is connected to each of the inlet ports 44 of such a head chip Hc.

[0052] The second flow path component 202 is provided with wiring through holes 205 for wiring components 110 of each head chip Hc to be inserted. In this embodiment, one wiring through hole 205 is provided for each head chip Hc. That is, in this embodiment, a total of four wiring through holes 205 are provided for the four head chips Hc. The wiring components 110 of the head chips Hc are led out to the -Z direction facing side of the second flow path component 202 through the wiring through holes 205.

[0053] Furthermore, in the Z-axis direction, between the second flow path component 202 and the sealing component 203, a relay substrate 210 is provided for wiring components 110 that commonly connect multiple head chips Hc. The relay substrate 210 is made of a rigid substrate without flexibility, and wiring, electronic components, etc. (not shown) are mounted on it. In this embodiment, as an electronic component, a connector 211 (not shown) connected to an external wiring disposed outside the liquid injection head 2 is shown. In addition, printing signals, etc., for controlling the head chips Hc are input to the relay substrate 210 from the external wiring via the connector 211, and supplied from the relay substrate 210 to each head chip Hc. It should be noted that an external wiring opening 206 for inserting the external wiring connected to the connector 211 is provided on the side wall of the flow path component 200 opposite to the connector 211. The external wiring is connected to the connector 211 of the relay substrate 210 disposed inside the flow path component 200 via the external wiring opening 206.

[0054] The relay substrate 210 is provided with wiring through-holes 212 for leading the wiring component 110 of the head chip Hc to the surface facing the -Z direction. There is one wiring through-hole 212 for each head chip Hc, and a total of four are provided.

[0055] Furthermore, a protrusion insertion hole 213 extending through the Z-axis direction is provided on the relay substrate 210. On the surface of the second flow path component 202 facing the -Z direction, a protrusion 207 is provided protruding in the -Z direction and having a second flow path 402 disposed inside. The protrusion 207 is inserted through the protrusion insertion hole 213 to the -Z direction side of the relay substrate 210 and connected to the connecting flow path 403.

[0056] A cover 220 is fixed to the surface of the flow path component 200 facing the +Z direction. The cover 220 defines the space for the receiving portion 208 that houses the head chip Hc. In this embodiment, the cover 220 is large enough to cover four head chips Hc. The cover 220 is a common component fixed to the surface of the four head chips Hc facing the +Z direction. Furthermore, the cover 220 has an exposure opening 221 independently provided for each head chip Hc, exposing the nozzle 21 of the head chip Hc in the +Z direction. Ink is ejected from the nozzle 21 in the +Z direction, and the nozzle 21 is exposed from the exposure opening 221.

[0057] use Figures 5 to 10 The head chip Hc is explained. Figure 5 This is an exploded 3D view of the head chip Hc. Figure 6 This is a top view of the head chip Hc. Figure 7 yes Figure 6 A-A' profile. Figure 8 yes Figure 6 The cross-sectional view along line B-B'. Figure 9 This is a top view showing the flow path of the head chip Hc. Figure 10 This is a diagram showing an example of a strain gauge and pressure sensing unit. It should be noted that... Figure 6 The illustrations of the protective substrate 30, housing component 40, connecting plate 15, and flexible substrate 45 in the head chip Hc are omitted. Line A-A' is parallel to the Y-axis and passes through the liquid-ejecting nozzle 21 and its connected pressure chamber 12. Line B-B' is parallel to the Y-axis and passes through the strain gauge 70 and its corresponding first liquid chamber 81. Furthermore, in... Figure 9 For simplicity, the first separate flow path 131 including the first liquid chamber 81 and the first separate flow path 131 including the second liquid chamber 82 are each represented as one, and the second separate flow path 132 including the pressure chamber 12 is represented as six.

[0058] The head chip Hc includes a nozzle plate 20 with multiple nozzles 21, a flow path forming substrate 10, a connecting plate 15, a protective substrate 30, a housing component 40, a piezoelectric actuator 300, and a wiring component 110.

[0059] The flow path forming substrate 10 is made of, for example, a silicon substrate. On the flow path forming substrate 10, a plurality of pressure chambers 12 are arranged along the X-axis direction. The plurality of pressure chambers 12 are arranged in a straight line along the X-axis direction with the same position relative to the Y-axis direction. Two pressure chambers 12 adjacent to each other in the X-axis direction are separated by a partition wall (not shown). Furthermore, in this embodiment, two rows of pressure chambers 12 are provided in the Y-axis direction and arranged side-by-side along the X-axis direction. These two rows of pressure chambers are staggered by half the distance between the pressure chambers 12 in the X-axis direction, i.e., a so-called half-pitch. That is, all the pressure chambers 12 in the two rows of pressure chambers are arranged in an alternating manner along the X-axis direction.

[0060] The pressure chamber 12 located at the -X direction end, which is one of the X-axis directions, is referred to as the first pressure chamber 12A. In the head chip Hc of this embodiment, there are two rows of pressure chambers 12 arranged side by side in the X-axis direction; therefore, there are two first pressure chambers 12A. The pressure chamber 12 located at the +X direction end, which is the other of the X-axis directions, is referred to as the second pressure chamber 12B. Like the first pressure chambers 12A, there are also two second pressure chambers 12B.

[0061] A connecting plate 15 and a nozzle plate 20 are sequentially stacked on the surface of the flow path forming substrate 10 facing the +Z direction. A vibrating plate 50 and a piezoelectric actuator 300 are sequentially stacked on the surface of the flow path forming substrate 10 facing the -Z direction.

[0062] The connecting plate 15 is composed of a plate-shaped component that is engaged with the surface of the flow path forming substrate 10 facing the +Z direction.

[0063] A nozzle communication path 16 is provided on the connecting plate 15, connecting the pressure chamber 12 and the nozzle 21. Furthermore, a first manifold portion 17 and a second manifold portion 18, forming part of a manifold 100, are provided on the connecting plate 15. This manifold 100 is a common liquid chamber that is commonly connected to multiple pressure chambers 12. The first manifold portion 17 is configured to penetrate the connecting plate 15 in the Z-axis direction. The second manifold portion 18 is configured not to penetrate the connecting plate 15 in the Z-axis direction, but to open on a surface facing the +Z direction. Moreover, a supply communication path 19, independent of each pressure chamber 12, is provided on the connecting plate 15, communicating with the pressure chamber 12. The supply communication path 19 connects the second manifold portion 18 and the pressure chamber 12, supplying ink from the manifold 100 to the pressure chamber 12. Such a connecting plate 15 can be made of silicon substrates, glass substrates, SOI substrates, various ceramic substrates, stainless steel substrates, and other metal substrates.

[0064] The nozzle plate 20 and the connecting plate 15 are joined on the opposite side of the flow path forming substrate 10, i.e., the surface facing the +Z direction. A plurality of nozzles 21 are formed on the nozzle plate 20, communicating with each pressure chamber 12 via nozzle connecting paths 16. In this embodiment, the plurality of nozzles 21 are arranged in a row along the X-axis direction. Furthermore, in this embodiment, the nozzle rows L, in which the nozzles 21 are arranged side-by-side along the X-axis direction, are separated into two rows in the Y-axis direction. In this embodiment, the two rows of nozzle rows L are referred to sequentially as nozzle row La and nozzle row Lb in the +Y direction. Thereafter, without distinguishing between nozzle rows La and Lb, they are simply referred to as nozzle row L. The nozzle rows La and Lb are arranged with half the distance between the nozzles 21 in the X-axis direction, i.e., a so-called half-pitch. That is, all the nozzles 21 in the nozzle rows La and Lb are arranged in an alternating pattern along the X-axis direction.

[0065] As such a nozzle plate 20, it is possible to use metal substrates such as silicon substrates, glass substrates, SOI substrates, various ceramic substrates, and stainless steel substrates, as well as organic materials such as polyimide resin.

[0066] In this embodiment, the vibrating plate 50 has an elastic film 51 made of silicon oxide disposed on the flow path forming substrate 10 side, and an insulating film 52 made of zirconium oxide disposed on the -Z direction-oriented surface of the elastic film 51. It should be noted that the vibrating plate 50 may be composed only of the elastic film 51, or only of the insulating film 52, or may have other films in addition to the elastic film 51 and the insulating film 52.

[0067] The piezoelectric actuator 300 includes a first electrode 60, a piezoelectric layer 61, and a second electrode 62 sequentially stacked on the vibrating plate 50 in the -Z direction. Such a piezoelectric actuator 300 is also called a piezoelectric element, referring to the portion including the first electrode 60, the piezoelectric layer 61, and the second electrode 62. Furthermore, the portion of the piezoelectric layer 61 that undergoes piezoelectric deformation when a voltage is applied between the first electrode 60 and the second electrode 62 is called the active portion 310. That is, the active portion 310 refers to the portion of the piezoelectric layer 61 sandwiched between the first electrode 60 and the second electrode 62. In this embodiment, an active portion 310 is formed corresponding to each pressure chamber 12. These multiple active portions 310 are "driving elements" that cause pressure changes in the ink within the pressure chamber 12. Generally, the electrode of any one of the active portions 310 is configured as a separate electrode independent for each active portion 310, while the electrode of the other is configured as a common electrode common to multiple active portions 310. In this embodiment, the first electrode 60 is divided into individual electrodes constituting each active portion 310, and the second electrode 62 is continuously disposed across multiple active portions 310 to form a common electrode constituting multiple active portions 310. Of course, the first electrode 60 may also constitute a common electrode, and the second electrode 62 may constitute an individual electrode.

[0068] The piezoelectric layer 61 is, for example, made of a piezoelectric material composed of a composite oxide with a perovskite structure as shown in the general formula ABO3.

[0069] Individual lead electrodes 91 are drawn from the first electrode 60 as lead-out wiring. Furthermore, a common lead electrode 92 is drawn from the second electrode 62 as lead-out wiring. The ends of these individual lead electrodes 91 and the common lead electrode 92 opposite to the ends connected to the piezoelectric actuator 300 are connected to a wiring component 110 made of a flexible substrate. The wiring component 110 is equipped with a drive signal selection circuit 111 having multiple switching elements, which select whether to supply a drive signal Com for driving each of the active parts 310 to each active part 310. That is, in this embodiment, the wiring component 110 is a COF (Chip On Film). It should be noted that the drive signal selection circuit 111 may not be provided in the wiring component 110. That is, the wiring component 110 may also be an FFC (Flexible Flat Cable), FPC (Flexible Printed Circuits), etc.

[0070] A protective substrate 30, approximately the same size as the flow path forming substrate 10, is bonded to the surface of the flow path forming substrate 10 facing the -Z direction. The protective substrate 30 has a receiving portion 31 that serves as a space for protecting the piezoelectric actuators 300. The receiving portions 31 are independently provided for each row of piezoelectric actuators 300 arranged in the X-axis direction, and two are arranged in the Y-axis direction. Furthermore, a through-hole 32 is provided on the protective substrate 30, which extends in the Z-axis direction between the two receiving portions 31 arranged in the Y-axis direction. The ends of individual lead electrodes 91 and common lead electrodes 92, which are led out from the electrodes of the piezoelectric actuators 300, extend out of the through-hole 32, and are electrically connected to the wiring component 110 within the through-hole 32. Such a protective substrate 30, for example, is made of a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates, similar to the flow path forming substrate 10.

[0071] A housing component 40 is fixed to the protective substrate 30. This housing component 40, together with the flow path forming substrate 10, defines a manifold 100 communicating with a plurality of pressure chambers 12. In top view, the housing component 40 has approximately the same shape as the aforementioned connecting plate 15, and engages with both the protective substrate 30 and the connecting plate 15. This housing component 40 has a recess 41 on the protective substrate 30 side, the depth of which accommodates both the flow path forming substrate 10 and the protective substrate 30. Furthermore, a third manifold portion 42 communicating with the first manifold portion 17 of the connecting plate 15 is provided in the housing component 40.

[0072] The manifold 100 of this embodiment is constituted by a first manifold portion 17 and a second manifold portion 18 provided on the connecting plate 15, and a third manifold portion 42 provided on the housing member 40. The manifold 100 is an example of a first common liquid chamber that is commonly connected to a plurality of pressure chambers 12, and a first liquid chamber 81 and a second liquid chamber 82 described later. Looking towards... Figure 9 In the top view shown in the +Z direction, the manifold 100 is formed such that its width becomes narrower as it moves towards the +X direction, -X direction, and Y-axis direction.

[0073] Furthermore, manifolds 100 are provided for each nozzle row La, Lb, meaning there are a total of two. Therefore, different liquids can be ejected from nozzle rows La, Lb. Additionally, an inlet 44 is provided in the housing component 40, which communicates with the manifolds 100 and is used to supply ink to each manifold 100. Furthermore, a connection port 40a is provided in the housing component 40, which communicates with the through hole 32 of the protective substrate 30 and through which a wiring component 110 is inserted. The wiring component 110 is led out to the -Z direction facing side of the liquid injection head 2 via the connection port 40a. The housing component 40 can be made of metal, resin, or other materials.

[0074] When to Figure 9 When viewed in the +Z direction, the inlet 44 is positioned between the first pressure chamber 12A and the second pressure chamber 12B in the X-axis direction. In this embodiment, the inlet 44 is positioned at the middle of the manifold 100 in the X-axis direction. The middle of the manifold 100 refers to any position of the second part when the various parts after the three-way branch pipe 100 in the X-axis direction are designated as the first part, the second part, and the third part from the -X direction toward the +X direction.

[0075] Furthermore, a flexible substrate 45 is provided on the +Z direction side of the openings of the first manifold portion 17 and the second manifold portion 18 of the connecting plate 15. This flexible substrate 45 seals the +Z direction side openings of the first manifold portion 17 and the second manifold portion 18. In this embodiment, such a flexible substrate 45 includes a sealing film 46 made of a flexible thin film and a fixing substrate 47 made of a rigid material such as metal. Since the area of ​​the fixing substrate 47 opposite the manifold 100 becomes an opening 48 completely removed in the thickness direction, one surface of the manifold 100 becomes a flexible portion 49, which is a flexible portion sealed only by the flexible sealing film 46. The +Z direction facing surface of the fixing substrate 47 is fixed to the -Z direction facing surface of the cover head 220 by adhesive or the like.

[0076] In this head chip Hc, liquid flows from the inlet 44 through the manifold 100 to the nozzle 21, filling the flow path with ink. Then, based on a signal from the drive signal selection circuit 111, voltage is applied to each active part 310 corresponding to the pressure chamber 12, causing the vibrating plate 50 and the piezoelectric actuator 300 to flex and deform together. This increases the pressure of the liquid within the pressure chamber 12, ejecting droplets from the designated nozzle 21.

[0077] In addition, such as Figure 6 , Figure 8 , Figure 9 As shown, the head chip Hc has a first liquid chamber 81, a second liquid chamber 82, and strain gauges 70 respectively disposed in the first liquid chamber 81 and the second liquid chamber 82.

[0078] Specifically, a first liquid chamber 81 and a second liquid chamber 82 are formed on the flow path forming substrate 10. The first pressure chamber 12A of the first liquid chamber 81 is disposed in the -X direction relative to the end of the plurality of pressure chambers 12 located in the -X direction. The second pressure chamber 12B of the second liquid chamber 82 is disposed in the +X direction relative to the end of the plurality of pressure chambers 12 located in the +X direction. In this embodiment, there are two rows of the plurality of pressure chambers 12 arranged side by side in the X-axis direction; therefore, two of each of the first liquid chamber 81 and the second liquid chamber 82 are provided.

[0079] The first liquid chamber 81 is spaced at the same interval as the pressure chamber 12 in the X-axis direction, and is arranged from the first pressure chamber 12A towards the -X direction, forming a configuration that, when viewed from... Figure 6 The shape shown in the +Z direction from above is approximately the same as that of the pressure chamber 12. However, the first liquid chamber 81 may not have the same spacing as the pressure chambers 12 in the X-axis direction. Furthermore, the first liquid chamber 81 is connected to the supply communication path 19 of the communication plate 15, and the first liquid chamber 81 and the manifold 100 are connected via the supply communication path 19.

[0080] The second liquid chamber 82 is spaced at the same interval as the pressure chamber 12 in the X-axis direction, and is arranged from the second pressure chamber 12B in the +X direction, forming a configuration that, when viewed from... Figure 6 The shape shown in the +Z direction from above is approximately the same as that of the pressure chamber 12. However, the second liquid chamber 82 may not have the same spacing as the pressure chambers 12 in the X-axis direction. Like the first liquid chamber 81, the second liquid chamber 82 is connected to the manifold 100 via the supply connection path 19. It should be noted that in this embodiment, neither the first liquid chamber 81 nor the second liquid chamber 82 is connected to the nozzle connection path 16 and is not connected to the nozzle 21 for injecting liquid.

[0081] Thus, a first separate flow path 131 and a second separate flow path 132 are formed by the flow paths formed on the flow path forming substrate 10 and the connecting plate 15. The first separate flow path 131 refers to the flow path connected to the manifold 100 and including the first liquid chamber 81. In this embodiment, the first separate flow path 131 is composed of the second manifold portion 18, the supply connecting path 19, and the first liquid chamber 81. In addition, the second liquid chamber 82 located on the opposite side of the first liquid chamber 81 in the X-axis direction also constitutes the first separate flow path. That is, the flow path connected to the manifold 100 and including the second manifold portion 18, the supply connecting path 19, and the second liquid chamber 82 is also the first separate flow path 131.

[0082] The second separate flow path 132 refers to the flow path described below: connected to the manifold 100, connected to a plurality of nozzles 21, and including a plurality of pressure chambers 12. In this embodiment, the second separate flow path 132 is composed of a second manifold section 18, a supply connection path 19, pressure chambers 12, and nozzle connection path 16.

[0083] In this embodiment, when looking towards Figure 9 In the top-view observation along the +Z direction shown, the width of the first individual flow path 131 in the Y-axis direction is equal to the width of the second individual flow path 132 in the Y-axis direction. Of course, the widths of the first individual flow path 131 and the second individual flow path 132 in the Y-axis direction can also be different.

[0084] Furthermore, in both the first separate flow path 131 and the second separate flow path 132, the portion connecting to the manifold 100 is reduced in size. Specifically, as... Figure 9 As shown, the second manifold section 18 comprises a narrowing section 18a connected to the manifold 100 with a constant width in the X-axis direction, an increasing section 18b whose width gradually increases from the narrowing section 18a toward the supply connection path 19 in the X-axis direction, and a constant width section 18c whose width remains constant from the increasing section 18b toward the supply connection path 19 in the X-axis direction. The width of the narrowing section 18a in the X-axis direction is narrower than the width of the constant width section 18c in the X-axis direction.

[0085] Thus, both the first separate flow path 131 and the second separate flow path 132 have a reduced portion 18a in the X-axis direction of the flow path, but this configuration is not limited to this. For example, it is preferable not to provide the reduced portion 18a on the first separate flow path 131 including the first liquid chamber 81. That is, it is preferable that the width of the first separate flow path 131 in the X-axis direction remains constant. The reduced width of the first liquid chamber 81 due to the reduced portion 18a can improve the sensing accuracy of the pressure in the first liquid chamber 81.

[0086] In the first liquid chamber 81 and the second liquid chamber 82, the openings on the -Z direction side of the through holes formed in the flow path forming substrate 10 in the Z-axis direction are defined by the vibrating plate 50. That is, a portion of the first liquid chamber 81 and the second liquid chamber 82 is defined by the vibrating plate 50. The portion of the vibrating plate 50 that defines the +Z direction surface as part of the first liquid chamber 81 is referred to as the first vibrating plate 50A. The portion of the vibrating plate 50 that defines the +Z direction surface as part of the second liquid chamber 82 is referred to as the second vibrating plate 50B.

[0087] In this embodiment, such as Figure 6 As shown, the width W1 of the first vibrating plate 50A in the X-axis direction is greater than the width W2 of the vibrating plate 50 in the X-axis direction, and the vibrating plate 50 defines a surface in the +Z direction that is part of the first pressure chamber 12A. Similarly, regarding the second vibrating plate 50B, the width W3 in the X-axis direction is greater than the width W4 of the vibrating plate 50 in the X-axis direction, and the vibrating plate 50 defines a surface in the +Z direction that is part of the second pressure chamber 12B.

[0088] In addition, regarding the first vibrating plate 50A, look towards Figure 6 The shape shown in the +Z direction is rectangular, but it is not limited to this shape. For example, it can also be a parallelogram shape, or a so-called rounded rectangle (also known as a track shape) with the two ends of the long side forming semicircles, or it can be a polygon. In addition, the aspect ratio of the rectangle inscribed in the first vibrating plate 50A is preferably 0.8 to 1.2.

[0089] A strain gauge 70 is provided on the surface of the first vibrating plate 50A opposite to the side of the first liquid chamber 81. The strain gauge 70 is formed of metal, polycrystalline silicon, or semiconductor silicon. Examples of metals include NiCr, Pt, CuNi, and CrN. In this embodiment, the strain gauge 70 is formed by repeatedly extending and retracting the metal in the X-axis direction. However, the method of forming the strain gauge 70 is not limited to extending and retracting the metal in the X-axis direction. It should be noted that the strain gauge 70 is provided corresponding to the first vibrating plate 50A that defines the first liquid chamber 81, but not corresponding to each pressure chamber 12. A strain gauge 70 is also provided on the surface of the second vibrating plate 50B opposite to the side of the second liquid chamber 82.

[0090] The pressure in the first liquid chamber 81 and the second liquid chamber 82 is detected by utilizing the property that the electrical resistance of metals, semiconductors, etc., changes due to deformation. The pressure in the first liquid chamber 81 and the second liquid chamber 82 refers to the pressure exerted by the liquid filling the first liquid chamber 81 and the second liquid chamber 82 on the first vibrating plate 50A and the second vibrating plate 50B. This pressure can be considered the same as the pressure formed on the meniscus of the nozzle 21. When an external force is applied to the strain gauge 70 via the first vibrating plate 50A and the second vibrating plate 50B according to the pressure in the first liquid chamber 81 and the second liquid chamber 82, a stress corresponding to this external force is applied to the strain gauge 70. As a result, deformation occurs in the strain gauge 70, and the resistance value changes. By using this resistance value, the pressure in the first liquid chamber 81 and the second liquid chamber 82 can be detected.

[0091] Thus, by using strain gauge 70 to detect the pressure of the first liquid chamber 81, the pressure of the first liquid chamber 81 can be obtained even when the liquid pressure does not change. Examples of situations where the liquid pressure does not change include when the liquid is merely circulating without being ejected from nozzle 21, or when the liquid is not flowing. However, even in such situations where no liquid is being ejected, the pressure value of the first liquid chamber 81 can be measured. It should be noted that, as a method for detecting the pressure of the first liquid chamber 81 without using strain gauge 70, for example, residual vibration generated after liquid ejection can be detected via piezoelectric actuator 300, and the liquid pressure can be measured based on the signal of this residual vibration. However, in this method, the pressure change of the liquid can only be obtained at the instant the piezoelectric element deforms.

[0092] It should be noted that the strain gauge 70 is formed on the first vibrating plate 50A, but this is not a limitation. For example, other layers may be stacked on the vibrating plate 50, and the strain gauge 70 may be formed on these layers. That is, the first vibrating plate refers to a component consisting of layers that function as a vibrating plate. Specifically, it may be a configuration consisting only of the vibrating plate 50, or it may include the vibrating plate 50 and a first electrode 60 stacked thereon, a configuration including a piezoelectric layer 61, and a configuration including a second electrode 62. When the strain gauge is placed on the first vibrating plate including the first electrode 60, the piezoelectric layer 61, and the second electrode 62, electrical insulation is achieved.

[0093] Furthermore, an example is shown where only the strain gauge 70 is provided on the first vibrating plate 50A; however, this configuration is not limited to this. For example, the piezoelectric actuator 300 may be formed on one part of the first vibrating plate 50A, and the strain gauge 70 may be provided on another part thereof.

[0094] Furthermore, the vibrating plate 50 corresponding to the first pressure chamber 12A is not separate from the first vibrating plate 50A and is formed from a single continuous component. Similarly, the second vibrating plate 50B is also formed from a single continuous component with the vibrating plate 50. Thus, the first vibrating plate 50A and the second vibrating plate 50B, as well as the vibrating plate 50 that operates with the piezoelectric actuator 300, are formed from the same component. Therefore, the first vibrating plate 50A and the second vibrating plate 50B can be manufactured using the same process as the vibrating plate 50 that operates with the piezoelectric actuator 300, achieving cost reduction. Of course, the first vibrating plate 50A and the second vibrating plate 50B can also be manufactured as separate components from the vibrating plate 50 that operates with the piezoelectric actuator 300. Furthermore, the first vibrating plate 50A can be made thinner than the vibrating plate 50 that operates with the piezoelectric actuator 300, or it can be made from a more deformable material. Therefore, the first vibrating plate 50A is more deformable, and thus, the pressure of the first liquid chamber 81 can be detected with greater accuracy.

[0095] Specifically, the detection circuit 71 is located on the head chip Hc, and the detection circuit 71 acquires the output voltage based on the resistance value of the strain gauge 70. Figure 10 An example of the detection circuit 71 is shown.

[0096] In addition to the strain gauge 70 mentioned above, the detection circuit 71 also includes a first resistive element 75, a second resistive element 76, and a third resistive element 77. The strain gauge 70, the first resistive element 75, the second resistive element 76, and the third resistive element 77 constitute a Wheatstone bridge circuit. One end of the strain gauge 70 is connected to the first resistive element 75, and the other end is connected to the third resistive element 77. Furthermore, the first resistive element 75 is connected to the second resistive element 76, and the second resistive element 76 is connected to the third resistive element 77. The detection circuit 71 is connected to a power supply (not shown) that applies voltage to points In1 and In2. When the resistance value of the strain gauge 70 changes, a voltage difference is generated at points Out1 and Out2.

[0097] It should be noted that, in Figure 10 In this example, a detection circuit 71 is configured relative to a strain gauge 70. For example... Figure 6 As shown, four strain gauges 70 are provided in the head chip Hc, therefore, four detection circuits 71 are also provided. This allows for either a detection circuit 71 to be provided for each strain gauge 70, or a single detection circuit 71 to be shared among multiple strain gauges 70. For example, the strain gauges 70 corresponding to the first vibrating plate 50A and the second vibrating plate 50B can be connected to a single detection circuit 71. In this case, instead of... Figure 10 The second resistive element 76 shown can be connected to the strain gauge 70.

[0098] Preferably, the first resistive element 75 to the third resistive element 77 are in the same temperature environment as the strain gauge 70, and are located in a position where no pressure is applied. Furthermore, the resistance values ​​of both the strain gauge 70 and the first resistive elements 75 to 77 are the same when no pressure is applied. Therefore, the first resistive element 75 to 77 are preferably adjacent to the strain gauge 70 in the -X direction, and are positioned on the same vibrating plate 50 as the strain gauge 70, with the same pattern. If they are formed with the same pattern on the same vibrating plate 50, the difference in manufacturing deviation between the first resistive element 75 to 77 and the strain gauge 70 can be reduced.

[0099] The In1, In2, Out1, and Out2 points of the detection circuit 71 are electrically connected to the wiring component 110 (see reference). Figure 6A pressure acquisition unit 72 is provided in the wiring component 110. The pressure acquisition unit 72 performs the function of acquiring the pressure of the first liquid chamber 81 and the second liquid chamber based on the resistance value of the strain gauge 70. In this embodiment, it is installed as an electronic circuit provided in the wiring component 110. The pressure acquisition unit 72 acquires the output voltage e of the detection circuit 71 and calculates the deformation of the strain gauge 70. The relationship between the output voltage e, the deformation, and the pressure of the first liquid chamber 81 and the second liquid chamber 82 is pre-stored in the storage unit 121. Therefore, the pressure of the first liquid chamber 81 and the second liquid chamber 82 can be calculated based on the output voltage e based on the resistance value.

[0100] The liquid injection head 2 described above includes: a plurality of nozzles 21 for injecting liquid; a plurality of pressure chambers 12 for imparting pressure to the liquid injected from the plurality of nozzles 21 respectively, and the plurality of pressure chambers 12 are arranged in the X-axis direction; a first liquid chamber 81 disposed in the -X direction relative to the first pressure chamber 12A located at the -X end of the plurality of pressure chambers 12; a first vibrating plate 50A defining a portion of the first liquid chamber 81; and a manifold 100 co-located with the plurality of pressure chambers 12 and the first liquid chamber 81. The liquid injection head 2 has a strain gauge 70 for acquiring the pressure in the first liquid chamber 81 corresponding to the first vibrating plate 50A.

[0101] In such a liquid injection head 2, for example, when the pressure of the liquid filling the entire nozzle 21 decreases due to clogging of the filter 401b, the pressure loss of the liquid near the first pressure chamber 12A located at one end in the X-axis direction, which is the parallel arrangement direction of the nozzles 21, is particularly large, and there is a high risk of damage to the meniscus formed in the nozzle 21. This is because: Figure 9 As shown, the first pressure chamber 12A is far from the inlet 44, and its pressure loss is relatively greater than that of the liquid near the other pressure chambers 12. Moreover, in this embodiment, the width of the manifold 100 in the Y-axis direction narrows from the inlet 44 toward the +X and -X directions, therefore, the pressure loss of the first pressure chamber 12A is relatively greater than that of the liquid near the other pressure chambers 12.

[0102] If the pressure near the first pressure chamber 12A at the -X end of the plurality of pressure chambers 12 is appropriate, then for the other pressure chambers 12, since the pressure is above that pressure, it is not necessary to measure the pressure. In other words, in order to prevent damage to the liquid surface in all nozzles 21, it is only necessary to measure the pressure near the first pressure chamber 12A, where the pressure loss is particularly large, and it is not necessary to measure the pressure near the other pressure chambers 12.

[0103] As described above, the liquid injection head 2 of this embodiment only needs to measure the pressure of the first liquid chamber 81, which has a particularly large pressure loss. Therefore, a strain gauge 70 is provided corresponding to the first liquid chamber 81. This avoids increasing the cost of the liquid injection head 2 and its size compared to a configuration where strain gauges 70 are individually provided in all pressure chambers 12 to measure pressure, and also prevents damage to the meniscus in all nozzles 21. Specifically, a pressure threshold is preset within a range smaller than the meniscus's pressure resistance. If the pressure value detected based on the resistance value of the strain gauge 70 exceeds the threshold, a warning is issued urging abnormal sensing, head replacement, filter replacement, etc., thereby preventing damage to the meniscus. This suppresses the inability to perform normal liquid injection due to meniscus damage, prevents air bubbles from entering the nozzle, and inhibits the inability to perform normal injection. It should be noted that, as another specific method, a pressure threshold is preset within a range greater than the meniscus's pressure resistance. If the detected pressure value exceeds the threshold, a warning is issued urging abnormal sensing of the self-sealing valve, thereby preventing damage to the meniscus. This also helps to prevent the normal jetting of liquid due to the disruption of the meniscus.

[0104] It should be noted that "-X direction" is equivalent to "first direction". "Strain gauge 70" is equivalent to "first detection element". "Manifold 100" is equivalent to "first common liquid chamber". "First detection element corresponding to the first vibrating plate" refers to the strain gauge 70 installed on the surface opposite to the surface of the first liquid chamber 81 that defines the first vibrating plate 50A. Furthermore, when viewed in the +Z direction, which is the direction of liquid injection, the strain gauge 70, the first liquid chamber 81, and the first vibrating plate 50A overlap. In this way, the first detection element is installed in a manner corresponding to the first vibrating plate, thereby avoiding contact with the liquid. Therefore, the first detection element is not limited to an element with liquid resistance.

[0105] For example, the first sensing element is not limited to strain gauge 70; piezoelectric elements and electrostatic capacitive sensors can also be used. When a piezoelectric element is used as the first sensing element, the pressure of the first liquid chamber 81 can be detected as described below.

[0106] A piezoelectric element is disposed on the first vibrating plate 50A as the first detection element. The piezoelectric element has the same configuration as the piezoelectric actuator 300, therefore, detailed description is omitted. The electrostatic capacitance is obtained based on the voltage applied to the piezoelectric element disposed on the first vibrating plate 50A, and the pressure of the first liquid chamber 81 is detected based on this electrostatic capacitance.

[0107] The electrostatic capacitance changes in response to the pressure in the first liquid chamber 81. Specifically, when the pressure in the first liquid chamber 81 changes, the first vibrating plate 50A deforms in response to this pressure change. When the first vibrating plate 50A deforms, stress is applied to the piezoelectric element disposed on it. This stress causes a change in the polarization state of the piezoelectric element. This change in polarization manifests as a change in the dielectric constant of the piezoelectric element, thereby causing a change in the electrostatic capacitance. Therefore, the electrostatic capacitance changes in response to changes in the pressure in the first liquid chamber 81.

[0108] The electrostatic capacitance of the piezoelectric element is correlated with the pressure of the first liquid chamber 81; therefore, the pressure of the first liquid chamber 81 can be sensed based on the electrostatic capacitance using the piezoelectric element. Furthermore, the aforementioned pressure acquisition unit 72 acquires the electrostatic capacitance of the piezoelectric element based on the voltage applied to it, and acquires the pressure of the first liquid chamber 81 based on the electrostatic capacitance. Thus, the pressure of the first liquid chamber 81 can be sensed using the piezoelectric element as the first detection element and the pressure acquisition unit 72 based on the electrostatic capacitance.

[0109] When a capacitive sensor is used as the first detection element, the pressure of the first liquid chamber 81 can be detected as follows. The capacitive sensor is provided as the first detection element corresponding to the first vibrating plate 50A. The capacitive sensor has a movable electrode and a fixed electrode. The movable electrode is disposed on the surface of the first vibrating plate 50A opposite to the side of the second liquid chamber 82, and the fixed electrode is disposed in the plane of the protective substrate 30 in the +Z direction opposite to the movable electrode. Corresponding to the pressure in the first liquid chamber 81, the first vibrating plate 50A deforms, and with the deformation of the first vibrating plate 50A, the position of the movable electrode changes. On the other hand, the position of the fixed electrode does not change; therefore, corresponding to the pressure in the first liquid chamber 81, the distance between the movable electrode and the fixed electrode in the Z-axis direction changes. Furthermore, due to the change in the distance between the movable electrode and the fixed electrode, the electrostatic capacitance of the movable electrode and the fixed electrode changes. Therefore, corresponding to the change in the pressure in the first liquid chamber 81, the electrostatic capacitance changes. Therefore, similar to the case of a piezoelectric element, the pressure of the first liquid chamber 81 can be detected based on the electrostatic capacitance obtained by the capacitive sensor.

[0110] The liquid injection head 2 of this embodiment has a pressure acquisition unit 72 that acquires the pressure of the first liquid chamber 81 based on the resistance value of the strain gauge 70.

[0111] The liquid injection head 2 of this embodiment also has an inlet 44 for introducing liquid into the manifold 100. The plurality of pressure chambers 12 have a second pressure chamber 12B located at the end opposite to the -X direction, i.e., the +X direction. When viewed in the +Z direction (injecting liquid into the plurality of nozzles 21), the inlet 44 is positioned between the first pressure chamber 12A and the second pressure chamber 12B in the -X direction. In such a liquid injection head 2, compared to a case where the inlet 44 is positioned further outward than the pressure chamber 12 in the X-axis direction, neither the first pressure chamber 12A nor the second pressure chamber 12B is significantly further away from the inlet 44 than the other. In other words, the pressure loss in the first pressure chamber 12A and the second pressure chamber 12B at both ends is the same, eliminating pressure chambers 12 with significantly large pressure losses. It should be noted that "+X direction" is equivalent to "second direction," and "+Z direction" is equivalent to "injection direction."

[0112] The liquid injection head 2 of this embodiment further includes: a second liquid chamber 82, disposed in the +X direction relative to the second pressure chamber 12B and connected to the manifold 100, the second pressure chamber 12B being located at the end of the plurality of pressure chambers 12 in the opposite direction to the -X direction, i.e., the +X direction; a second vibrating plate 50B, defining a portion of the second liquid chamber 82; and a strain gauge 70, corresponding to the second vibrating plate 50B, for acquiring the pressure within the second liquid chamber 82. Such a liquid injection head 2 can detect pressure in both the first liquid chamber 81 and the second liquid chamber 82. For example... Figure 10 As shown, when a detection circuit 71 is provided for the strain gauge 70, anomalies in the menisci of the nozzles 21 at both ends can be sensed individually. Furthermore, when the strain gauge 70 corresponding to the first vibrating plate 50A and the strain gauge 70 corresponding to the second vibrating plate 50B are connected to a common detection circuit 71, the average pressure value of the nozzles 21 at both ends can be sensed. It should be noted that the "strain gauge 70 corresponding to the second vibrating plate 50B for acquiring the pressure within the second liquid chamber 82" is equivalent to the "second detection element".

[0113] The liquid injection head 2 of this embodiment does not have a piezoelectric actuator 300 corresponding to the first liquid chamber 81, but has multiple piezoelectric actuators 300 that apply pressure to multiple pressure chambers 12. That is, only a strain gauge 70 is provided in the first liquid chamber 81, and no piezoelectric actuator 300 is provided. With such a liquid injection head 2, the first vibrating plate 50A is not obstructed by the piezoelectric actuator 300, and therefore can be easily deformed. The first vibrating plate 50A is easily deformed due to the pressure of the liquid, therefore, the pressure of the first liquid chamber 81 can be detected with greater accuracy.

[0114] In the liquid injection head 2 of this embodiment, the width W1 of the first vibrating plate 50A in the -X direction is greater than the width W2 of the vibrating plate 50 in the -X direction that defines a portion of the first pressure chamber 12A.

[0115] The liquid injection head 2 of this embodiment has multiple individual flow paths connected to the manifold 100. Each individual flow path includes: multiple second individual flow paths 132, each communicating with multiple nozzles 21 and each including multiple pressure chambers; and a first individual flow path 131 including a first liquid chamber 81. The width of the first individual flow path 131 in the Y-axis direction, which intersects the -X direction and the +Z direction (the injection direction of the liquid), is equal to the width of the second individual flow path 132 in the Y-axis direction. It should be noted that "Y-axis direction" is equivalent to "third direction". Furthermore, in this embodiment, the widths of the first individual flow path 131 and the second individual flow path 132 in the Y-axis direction can be equal or different.

[0116] (Modification 1 of Implementation Method 1)

[0117] use Figure 11 A variation of Embodiment 1 is shown. The liquid injection head 2 in Variation 1 differs from the liquid injection head 2 in Embodiment 1 in that: the first liquid chamber 81 is connected to the dummy nozzle 21D; and a piezoelectric actuator 300 is formed on the first vibrating plate 50A in addition to the strain gauge 70. In Variation 1, the first liquid chamber 81 is referred to as the first dummy liquid chamber 81D.

[0118] Specifically, in the first dummy liquid chamber 81D, a strain gauge 70 is disposed on a portion of the first vibrating plate 50A that defines the first dummy liquid chamber 81D, and a piezoelectric actuator 300 is formed on another portion thereof. The strain gauge 70 is not limited to being disposed on the first vibrating plate 50A; for example, it may also be stacked on the piezoelectric actuator 300 in the +Z direction.

[0119] In addition, the first dummy liquid chamber 81D and Figure 7 The pressure chamber 12 shown is similarly connected to the nozzle communication path 16 formed on the connecting plate 15. The nozzle communication path 16 is connected to the dummy nozzle 21D formed on the nozzle plate 20. The dummy nozzle 21D is a nozzle that does not contribute to printing. It does not contribute to printing because it sprays liquid as a rinsing agent to prevent thickening, but does not spray droplets used to directly form an image on the medium.

[0120] The liquid injection head 2 involved in this variation 1 achieves the same effect as in embodiment 1. Furthermore, since the first dummy liquid chamber 81D is connected to the dummy nozzle 21D which does not contribute to printing, liquid can easily fill the flow path from the manifold 100 to the supply connection path 19, the first dummy liquid chamber 81D, the nozzle connection path 16, and the dummy nozzle 21D. This results in good liquid filling of the flow path; therefore, for example, when performing the initial liquid filling process in a state where the flow path is not filled with liquid, liquid can be well filled into the first dummy liquid chamber 81D and the dummy nozzle 21D without leaving air bubbles or the like.

[0121] It should be noted that, in the liquid injection head 2 with the first dummy liquid chamber 81D, it is preferable to use one with... Figure 9 The first separate flow path 131 of the reduced section 18a as shown. This is because the above-mentioned rinsing can be performed appropriately.

[0122] In Embodiment 1, the first liquid chamber 81 is not connected to the nozzle 21, which does not contribute to printing. However, it is preferable to provide a dummy nozzle 21D as in Modification 1, and to install a piezoelectric actuator 300 in the first dummy liquid chamber 81D. Furthermore, it is desirable to perform regular cleaning and rinsing of the dummy nozzle 21D, just like the other nozzles 21. This prevents liquid thickening in the first dummy liquid chamber 81D.

[0123] (Modification 2 of Implementation Method 1)

[0124] use Figure 12 A variation of Embodiment 1 is shown. The liquid injection head 2 in Variation 2 differs from the liquid injection head 2 in Embodiment 1 in that a strain gauge 70 is provided at one end in the X-axis direction, and the position of the inlet 44 is different.

[0125] Specifically, strain gauge 70 and first vibrating plate 50A defining the first liquid chamber 81 (refer to...) Figure 6 The corresponding settings are as follows. Furthermore, the distance from the inlet 44 to the first pressure chamber 12A is greater than the distance from the inlet 44 to the second pressure chamber 12B. The distance from the inlet 44 to the first pressure chamber 12A is the shortest distance guiding the flow path from the inlet 44 to the first pressure chamber 12A. The same applies to the distance from the inlet 44 to the second pressure chamber 12B.

[0126] In the case of the liquid injection head 2 of this modified example 2, where a strain gauge 70 is installed in one location, it is placed in the first liquid chamber 81 located at the end furthest from the inlet 44. The pressure loss is greater the further away from the inlet 44, therefore, the pressure in the first liquid chamber 81, located at a position with greater pressure loss, can be detected. Furthermore, since there is only one strain gauge 70, the cost of the liquid injection head 2 can be reduced and its size can be miniaturized compared to a configuration in which strain gauges 70 are installed at both ends in the X-axis direction.

[0127] It should be noted that, in Figure 12 In this configuration, the inlet 44 is positioned further inward than the plurality of pressure chambers 12 in the X-axis direction. That is, the inlet 44 is positioned further in the +X direction than the first pressure chamber 12A located in the -X direction, and further in the -X direction than the second pressure chamber 12B located in the +X direction. The inlet 44 is not limited to this configuration; it can also be positioned further outward than the plurality of pressure chambers 12 in the X-axis direction. That is, the inlet 44 can also be positioned further in the -X direction than the first pressure chamber 12A, or further in the +X direction than the second pressure chamber 12B.

[0128] (Modification 3 of Implementation Method 1)

[0129] use Figure 13 The following is a variation of Embodiment 1: Modification 3. The difference between the liquid injection head 2 in Modification 3 and the liquid injection head 2 in Embodiment 1 is that two strain gauges 70 are provided on the first vibrating plate 50A, and the two strain gauges 70 are connected to a detection circuit 71.

[0130] Specifically, the liquid injection head 2 has a connection with the first vibrating plate 50A (see reference). Figure 6 Corresponding to this, it is used to obtain the first liquid chamber 81 (refer to...). Figure 6Strain gauges 70A and 70B are used to measure the pressure within the device. When strain gauges 70A and 70B show the same resistance change, that is, when both strain gauges 70A and 70B are positioned in a stretched or compressed state, in the detection circuit 71, strain gauge 70A is connected to the first resistive element 75 and the third resistive element 77, replacing the second resistive element 76; strain gauge 70B is also connected to the first resistive element 75 and the third resistive element 77. These strain gauges 70A, 70B, the first resistive element 75, and the third resistive element 77 constitute a Wheatstone bridge circuit. It should be noted that when strain gauges 70A and 70B show different resistance changes, that is, when one strain gauge is stretched while the other is compressed, strain gauge 70B and the first resistive element 75 are replaced. That is, strain gauge 70A is connected to the third resistive element 77 and strain gauge 70B, and strain gauge 70B is connected to the first resistive element 75 and strain gauge 70A.

[0131] As in the liquid jet head 2 of this modified example 3, a detection circuit 71 has two strain gauges 70 disposed on a first vibrating plate 50A. The pressure acquisition unit 72, which acquires the pressure of the first liquid chamber 81 based on the resistance value obtained by the detection circuit 71 with these two strain gauges 70, improves the detection accuracy of the pressure of the first liquid chamber 81 compared to a pressure acquisition unit 72 based on the resistance value of the detection circuit 71 with only one strain gauge 70. It should be noted that "strain gauge 70A" corresponds to "first detection element," and "strain gauge 70B" corresponds to "second detection element."

[0132] It should be noted that, although not specifically illustrated, four strain gauges 70 can also be installed on the first vibrating plate 50A. Additionally, Figure 13 The first resistive element 75 and the third resistive element 77 shown are replaced with strain gauges 70. That is, four strain gauges 70 can also be used to form a Wheatstone bridge circuit and serve as the detection circuit 71. In this way, by setting four strain gauges 70 on the first vibrating plate 50A to form the detection circuit 71, the pressure of the first liquid chamber 81 can be detected with even higher accuracy.

[0133] (Modification 4 of Implementation Method 1)

[0134] In implementation method 1, such as Figure 7 As shown, the head chip Hc has two rows of nozzles, La and Lb, arranged side-by-side in the X-axis direction, and two manifolds 100 are arranged corresponding to them. Additionally, as... Figure 6As shown, four strain gauges 70 are installed on the -X side of the first pressure chamber 12A, which corresponds to each nozzle array La and Lb, and on the +X side, which corresponds to the second pressure chamber 12B.

[0135] In variation example 4, although not specifically illustrated, observation reveals... Figure 6 In a top-view observation along the +Z direction as shown, the strain gauges 70 are arranged symmetrically at points. For example, the strain gauges 70 are positioned on a first vibrating plate 50A that defines a first liquid chamber 81, which is located further to the -X direction than the first pressure chamber 12A on the -Y direction side. Furthermore, the strain gauges 70 are positioned on a second vibrating plate 50B that defines a second liquid chamber 82, which is located further to the +X direction than the second pressure chamber 12B on the +Y direction side.

[0136] In the liquid injection head 2 involved in this modified example 4, since strain gauges 70 are not installed on the first vibrating plate 50A on the +Y direction side and the second vibrating plate 50B on the -Y direction side, wiring leading from the strain gauges 70 can be arranged in these spaces, thus simplifying the wiring arrangement. Therefore, with Figure 6 Compared to the configuration of four strain gauges 70 shown, the size of the liquid jet head 2 can be reduced. Furthermore, when the liquid jet head 2 ejects liquid in a direction other than the +Z direction, such as during vertical printing, a pressure difference is generated between the first liquid chamber 81 and the second liquid chamber 82. This pressure difference can be obtained by measuring the difference in pressure values ​​detected by the strain gauges 70 located at the +X and -X directions respectively. Since this pressure difference corresponds to the angle between the direction of liquid jet ejection from the liquid jet head 2 and the horizontal plane, the angle (or posture) of the liquid jet head 2 can be detected based on the pressure difference.

[0137] (Variation 5 of Implementation Method 1)

[0138] In variation example 4, when looking towards Figure 6 In the +Z direction shown, two strain gauges 70 are arranged symmetrically at a point. However, in modified example 5, they are arranged symmetrically with respect to the X-axis direction, which is the arrangement direction of the pressure chambers 12.

[0139] Specifically, although not specifically illustrated, a strain gauge 70 is disposed on a first vibrating plate 50A defining a first liquid chamber 81, which is located further towards the -X direction than the first pressure chamber 12A on the -Y direction side. Similarly, a strain gauge 70 is disposed on a first vibrating plate 50A defining a first liquid chamber 81, which is located further towards the -X direction than the first pressure chamber 12A on the +Y direction side. In this modified example 5, the liquid injection head 2 does not have a strain gauge 70 disposed on a second vibrating plate 50B defining a second liquid chamber 82; therefore, the size of the head chip Hc in the X-axis direction can be miniaturized.

[0140] (Modification 6 of Implementation Method 1)

[0141] In Embodiment 1, the pressure acquisition unit 72 is provided in the wiring component 110 of the liquid injection head 2, but it is not limited to this configuration. Figure 14 This is a block diagram of the liquid injection device 1 according to Modification 6. The liquid injection device 1 according to Modification 6 includes a liquid injection head 2 and a pressure acquisition unit 72. The pressure acquisition unit 72 is not provided in the liquid injection head 2 but is provided in the liquid injection device 1. For example, the pressure acquisition unit 72 is provided as part of the control unit 4 of the liquid injection device 1. In this case, the head chip Hc has a strain gauge 70 and a detection circuit 71, and the output voltage e detected by the detection circuit 71 is transmitted to the pressure acquisition unit 72 of the control unit 4 via the wiring component 110, the relay board 210, etc. Even with this configuration, the same operating effect is achieved as that of the liquid injection device 1 with the liquid injection head 2 of Embodiment 1.

[0142] (Implementation Method 2)

[0143] This invention can also be applied to so-called circulating liquid jet head 2. Figure 15 This is a top view showing the flow path of the head chip according to Embodiment 2. Figure 16 yes Figure 15 The cross-sectional view along the C-C' line. Figure 17 yes Figure 15 A cross-sectional view along line D-D'. In Figure 15 In this drawing, the vibrating plate 50 and the piezoelectric actuator 300 are omitted from the illustration. It should be noted that the same reference numerals are used for the same components as in Embodiment 1, and repeated descriptions are omitted.

[0144] The head chip Hc has a first separate flow path 131 and a second separate flow path 132. In this embodiment, when looking at... Figure 15 In the +Z direction shown, the first separate flow path 131 and the second separate flow path 132 extend in the Y-axis direction and are spaced apart in the X-axis direction.

[0145] The head chip Hc has a supply manifold 100A for supplying liquid to a plurality of nozzles 21 and a recovery manifold 100B for recovering liquid that has not been ejected from the plurality of nozzles 21.

[0146] The head chip Hc is provided with an inlet 44 communicating with the supply manifold 100A and an outlet 43 communicating with the recovery manifold 100B. Liquid is introduced into the inlet 44 from the liquid storage section 3 provided in the liquid injection device 1. The outlet 43 is connected to the liquid storage section 3, and liquid is recovered from the outlet 43 to the liquid storage section 3.

[0147] Liquid is supplied from the inlet 44 to the supply manifold 100A of the head chip Hc. The liquid from the supply manifold 100A is supplied to the first separate flow path 131 and the second separate flow path 132, and the liquid supplied to the second separate flow path 132 is ejected from each nozzle 21. Liquid supplied to the second separate flow path 132 that is not ejected from the nozzles 21 is discharged to the recovery manifold 100B. On the other hand, no nozzles 21 are provided on the first separate flow path 131. Therefore, liquid flows sequentially through the supply manifold 100A, the first separate flow path 131, and the recovery manifold 100B.

[0148] The configuration of the head chip Hc will be described in more detail. A plurality of pressure chambers 12R and 12L, corresponding to each nozzle 21, are provided on the flow path forming substrate 10. The pressure chambers 12R and 12L are configured to penetrate the flow path forming substrate 10 in the Z direction, which is the thickness direction. In this embodiment, a second individual flow path 132 includes one pressure chamber 12R and one pressure chamber 12L. The pressure chamber 12R is disposed near the supply-side manifold 100A, and the pressure chamber 12L is disposed near the recovery-side manifold 100B.

[0149] A vibrating plate 50 and a piezoelectric actuator 300 are formed on the -Z direction side of the flow path forming substrate 10. The piezoelectric actuator 300 is disposed on the vibrating plate 50 at a position corresponding to the pressure chambers 12R and 12L.

[0150] On the connecting plate 15, as flow paths constituting the second separate flow path 132, there are first connecting flow paths 33A, 33B, 33C, and second connecting flow paths 34A, 34B, 34C, and 34D.

[0151] The first connecting flow path 33A opens on the +Z direction side of the connecting plate 15 and extends in the Y-axis direction, with one end of it connected to the supply side manifold 100A.

[0152] The first connecting flow path 33B opens on the +Z direction side of the connecting plate 15 and extends in the Y-axis direction, connecting with the nozzle 21.

[0153] The first connecting flow path 33C opens on the +Z direction side of the connecting plate 15 and extends in the Y-axis direction, with one end of it connected to the recovery side manifold 100B.

[0154] The second connecting flow path 34A passes through the connecting plate 15 in the Z-axis direction, connecting the first connecting flow path 33A and the pressure chamber 12R.

[0155] The second connecting flow path 34B passes through the connecting plate 15 in the Z-axis direction, connecting the pressure chamber 12R and the first connecting flow path 33B.

[0156] The second connecting flow path 34C passes through the connecting plate 15 in the Z-axis direction, connecting the first connecting flow path 33B and the pressure chamber 12L.

[0157] The second connecting flow path 34D passes through the connecting plate 15 in the Z-axis direction, connecting the pressure chamber 12L and the first connecting flow path 33C.

[0158] The openings on the +Z direction side of the first connecting flow paths 33A, 33B, 33C, 34A, 34B, 34C, and 34D are sealed by the flexible substrate 45 to form flow paths. Thus, the second separate flow path 132 of this embodiment is composed of the first connecting flow path 33A, the second connecting flow path 34A, the pressure chamber 12R, the second connecting flow path 34B, the first connecting flow path 33B, the second connecting flow path 34C, the pressure chamber 12L, the second connecting flow path 34D, and the first connecting flow path 33C.

[0159] On the other hand, the first separate flow path 131 has the same configuration as the second separate flow path 132, but it differs from the second separate flow path 132 in that it is not connected to the nozzle 21. Furthermore, the first separate flow path 131 differs from the second separate flow path 132 in that it has a first liquid chamber 81R and a first liquid chamber 81L instead of pressure chambers 12R and 12L. That is, the first separate flow path 131 of this embodiment is composed of a first connecting flow path 33A, a second connecting flow path 34A, a first liquid chamber 81, a second connecting flow path 34B, a first connecting flow path 33B, a second connecting flow path 34C, a first liquid chamber 81L, a second connecting flow path 34D, and a first connecting flow path 33C.

[0160] A strain gauge 70 is provided corresponding to the first vibrating plate 50A that defines the first liquid chamber 81R. In this embodiment, the strain gauge 70 is not provided in the first liquid chamber 81L; however, a strain gauge 70 may be provided corresponding to the first liquid chamber 81L. Furthermore, although not specifically illustrated, a detection circuit may be provided on the vibrating plate 50 to detect the pressure in the first liquid chamber 81L in the same manner as in Embodiment 1.

[0161] The liquid injection head 2 described in Embodiment 2 above includes: a plurality of second separate flow paths 132 for supplying liquid from a supply-side manifold 100A, the plurality of second separate flow paths 132 being respectively connected to a plurality of nozzles 21 and including each of the plurality of pressure chambers 12; and a first separate flow path 131 including a recovery-side manifold 100B for recovering liquid not sprayed from the plurality of nozzles 21 from the plurality of second separate flow paths 132, and a first liquid chamber 81R, the first separate flow path 131 being connected to the supply-side manifold 100A and the recovery-side manifold 100B.

[0162] In this liquid jet head 2, the pressure in the multiple pressure chambers 12 does not vary significantly, whether it is the pressure chamber 12 located at the end in the X-axis direction or the pressure chamber located at the center. Therefore, it can be said that in order to prevent damage to the meniscus in all nozzles 21, the pressure can be measured near any pressure chamber 12. Thus, in the liquid jet head 2 of this embodiment, the strain gauge 70 is only provided on the first vibrating plate 50A that defines the first liquid chamber 81R, so that the pressure in only the first liquid chamber 81R is measured. As a result, compared with the configuration of providing strain gauges 70 to measure the pressure in each of the pressure chambers 12, it is possible to suppress the increase in cost and size of the liquid jet head 2, and to prevent damage to the meniscus in all nozzles 21.

[0163] Furthermore, among the multiple pressure chambers 12 arranged side-by-side in the X-axis direction, the first liquid chamber 81R is positioned further towards the -X direction than the first pressure chamber 12A located at the end in the -X direction, and the strain gauge 70 is disposed in this first liquid chamber 81R. Thus, compared to the case where the first liquid chamber 81R is positioned outside the end, for example, between adjacent first pressure chambers 12A in the X-axis direction, the nozzles 21 can be arranged at equal intervals and with high density.

[0164] Furthermore, in the liquid injection head 2 of this embodiment, the liquid is circulated, thus preventing the liquid in the first liquid chamber 81R from becoming viscous and accurately detecting the pressure.

[0165] It should be noted that "supply-side manifold 100A" corresponds to "first common liquid chamber" and "recovery-side manifold 100B" corresponds to "second common liquid chamber". In addition, no nozzle 21 is provided in the first separate flow path 131, but a dummy nozzle may be provided in the same way as in the variation 1 of embodiment 1.

[0166] (Other implementation methods)

[0167] The various embodiments of the present invention have been described above; however, the basic structure of the present invention is not limited to the above-described structure.

[0168] Furthermore, in the embodiments described above, a thin-film piezoelectric actuator 300 and an active part 310 were used as the driving element for generating pressure changes in the pressure chamber 12. However, this is not a limitation. For example, a thick-film piezoelectric actuator formed by bonding a printed circuit board or similar method, or a longitudinal vibration type piezoelectric actuator in which piezoelectric material and electrode forming material are alternately stacked and stretched axially, can be used as the driving element. In addition, an electrostatic actuator can be used, in which a heating element is disposed in the pressure chamber 12 and droplets are ejected from the nozzle 21 by bubbles generated by the heating element. This electrostatic actuator generates static electricity between the vibrating plate and the electrode, and the vibrating plate is deformed by the electrostatic force, thus ejecting droplets from the nozzle 21.

[0169] Furthermore, in the liquid jetting device 1 described above, the liquid jetting head 2 is shown to move in the main scanning direction, which is the Y-axis direction. However, it is not particularly limited to this. For example, the present invention can also be applied to a so-called line printer in which the liquid jetting head 2 is fixed and the medium S moves only in the secondary scanning direction, which is the X-axis direction, for printing.

[0170] Furthermore, this invention broadly encompasses all liquid jetting devices equipped with a jetting section. Examples of jetting sections include various inkjet printing heads used in image recording devices such as printers, and pigment jetting heads used in manufacturing color filters for liquid crystal displays. Additionally, examples of jetting sections include electrode material jetting heads used for forming electrodes in organic EL displays and FED (field emission display) devices, and biological organic matter jetting heads used in biochip manufacturing; these types of jetting sections can also be applied to liquid jetting devices equipped with such jetting sections.

[0171] (Note)

[0172] Based on the examples shown above, for instance, the following structure has been understood.

[0173] The liquid jet head according to preferred embodiment 1 includes: a plurality of nozzles for jetting liquid; a plurality of pressure chambers for applying pressure to the liquid for jetting liquid from the plurality of nozzles respectively, the plurality of pressure chambers being arranged in a first direction; a first liquid chamber disposed in the first direction relative to the end of the plurality of pressure chambers located in the first direction; a first vibrating plate defining a portion of the first liquid chamber; and a first common liquid chamber communicatively connected to the plurality of pressure chambers and the first liquid chamber. The liquid jet head has a first detection element corresponding to the first vibrating plate for acquiring the pressure within the first liquid chamber. Therefore, compared to a configuration where a first detection element is individually provided in each pressure chamber to measure pressure, damage to the meniscus can be prevented in all nozzles without increasing the cost or size of the liquid jet head. Specifically, before the meniscus is damaged, if the pressure value detected based on the resistance value of the first detection element exceeds a threshold value set within a range less than the meniscus's pressure resistance, a warning is issued urging abnormal sensing or replacement of the liquid jet head, filter, etc. This improves the quality of the liquid jet head. Specifically, it can suppress the inability to spray liquid normally due to the disruption of the meniscus, and prevent air bubbles from entering the nozzle, thus preventing the inability to spray normally.

[0174] In embodiment 2, which is a specific example of embodiment 1, a pressure acquisition unit is included, which acquires the pressure of the first liquid chamber based on the resistance value of the first detection element. Therefore, the pressure of the first liquid chamber can be acquired even when the liquid pressure does not change. Examples of situations where the liquid pressure does not change include when the liquid is merely circulating and not being ejected from the nozzle. Even in such cases where no liquid is being ejected, the pressure value of the first liquid chamber can be measured.

[0175] In Method 3, a specific example of Method 1, the first liquid chamber is a first dummy liquid chamber connected to a dummy nozzle that does not contribute to printing. As a result, since the liquid fills the first dummy liquid chamber well, for example, when the initial filling process of filling liquid is performed in a state where the first dummy liquid chamber is not filled with liquid, the liquid can be filled well without leaving air bubbles in the first dummy liquid chamber or the dummy nozzle.

[0176] In embodiment 4, a specific example of embodiment 1, the method further includes: an inlet for introducing liquid into the first common liquid chamber; the plurality of pressure chambers having a second pressure chamber located at the end opposite to the first direction, i.e., the second direction; and the distance from the inlet to the first pressure chamber being greater than the distance from the inlet to the second pressure chamber. Thus, when the first detection element is located in one place in the liquid injection head, it is located in the first liquid chamber located away from the inlet. Since the pressure loss is greater further away from the inlet, it is possible to detect the pressure in the first liquid chamber where the pressure loss is greater.

[0177] In embodiment 5, a specific example of embodiment 1, an inlet is further provided for introducing liquid into the first common liquid chamber. The plurality of pressure chambers each have a second pressure chamber located at the end in the opposite direction to the first direction, i.e., the second direction. When viewed in the injection direction of the liquid being injected into the plurality of nozzles, the inlet is positioned between the first and second pressure chambers in the first direction. Therefore, compared to a case where the inlet is positioned further outward than the pressure chambers in the first direction, the pressure chamber of either the first or second pressure chamber is not significantly farther from the inlet than the other. In other words, the pressure loss in the first and second pressure chambers at both ends is the same, eliminating pressure chambers with significantly large pressure losses.

[0178] In embodiment 6, which is a specific example of embodiment 2, a second detection element corresponding to the first vibrating plate is further included for acquiring the pressure in the first liquid chamber. The pressure acquisition unit also acquires the pressure in the first liquid chamber based on the resistance value of the second detection element. Since the pressure acquisition unit acquires the pressure in the first liquid chamber based on both the first and second detection elements, the detection accuracy of the pressure in the first liquid chamber can be improved compared to a pressure acquisition unit that acquires the pressure in the first liquid chamber based on the resistance value of a single first detection element.

[0179] In embodiment 7, a specific example of embodiment 1, the following are further included: a second liquid chamber disposed in the second direction relative to the second pressure chamber and connected to the first common liquid chamber, the second pressure chamber being located in the opposite direction to the first direction of the plurality of pressure chambers, i.e., at the end of the second direction; a second vibrating plate defining a portion of the second liquid chamber; and a second detection element corresponding to the second vibrating plate for acquiring the pressure within the second liquid chamber. Thus, pressure can be detected within both the first and second liquid chambers.

[0180] In embodiment 8, which is a specific example of embodiment 1, there is no piezoelectric element corresponding to the first liquid chamber, but rather multiple piezoelectric elements that apply pressure to the plurality of pressure chambers. Therefore, since the first vibrating plate is not obstructed by the piezoelectric elements, it can be easily deformed. Because the first vibrating plate is easily deformed due to the pressure of the liquid, the pressure of the first liquid chamber can be detected with greater accuracy.

[0181] In embodiment 9, which is a specific example of embodiment 1, the width of the first vibrating plate in the first direction is greater than the width of the vibrating plate in the first direction that defines a portion of the first pressure chamber.

[0182] In embodiment 10, which is a specific example of embodiment 9, a plurality of separate flow paths are provided that are connected to the first common liquid chamber. The plurality of separate flow paths include: a plurality of second separate flow paths that are respectively connected to the plurality of nozzles and respectively include the plurality of pressure chambers; and a first separate flow path that includes the first liquid chamber, wherein the width of the third direction of the first separate flow path intersecting the first direction and the injection direction of the injected liquid is equal to the width of the third direction of the second separate flow path.

[0183] In embodiment 11, a specific example of embodiment 1, the method includes: a plurality of second separate flow paths from which liquid is supplied from the first common liquid chamber; each of the plurality of second separate flow paths communicating with the plurality of nozzles and each including the plurality of pressure chambers; a second common liquid chamber for recovering liquid not ejected from the plurality of nozzles from the plurality of second separate flow paths; and a first separate flow path including the first liquid chamber and connecting the first common liquid chamber and the second common liquid chamber. Therefore, compared to a configuration that provides a first detection element for measuring pressure in each of the pressure chambers, it is possible to suppress the increase in cost and size of the liquid jet head, and to prevent damage to the menisci in all nozzles. Furthermore, in the plurality of pressure chambers, a first liquid chamber is provided further in the first direction than the first pressure chamber located at the end in the first direction, and the first detection element is provided in this first liquid chamber, thereby allowing for a more evenly spaced and densely arranged arrangement of nozzles contributing to printing compared to the case where the element is provided outside the end. Furthermore, in the liquid injection head, the liquid circulates from the first common liquid chamber to the second common liquid chamber, thus preventing the liquid in the first liquid chamber from becoming viscous and enabling accurate pressure detection.

[0184] The liquid injection device according to the preferred embodiment 12 includes: a liquid injection head of embodiment 1; and a pressure acquisition unit that acquires the pressure of the first liquid chamber based on the resistance value of the first detection element.

[0185] The pressure acquisition unit can be located in the liquid injection device, rather than in the liquid injection head. This simplifies the structure of the liquid injection head.

Claims

1. A liquid injection head, characterized in that, have: Multiple nozzles spray liquid; Multiple pressure chambers are provided to impart pressure to a liquid for ejecting the liquid from the multiple nozzles, and the multiple pressure chambers are arranged in a first direction; A first liquid chamber is disposed in the first direction relative to a first pressure chamber, the first pressure chamber being located at the end of the plurality of pressure chambers in the first direction; The first vibrating plate delineates a portion of the first liquid chamber; as well as The first common liquid chamber is connected in a common manner to the plurality of pressure chambers and the first liquid chamber. The liquid injection head has a first detection element corresponding to the first vibrating plate for obtaining the pressure in the first liquid chamber.

2. The liquid injection head according to claim 1, characterized in that, The liquid injection head has a pressure acquisition section, which acquires the pressure of the first liquid chamber based on the resistance value of the first detection element.

3. The liquid injection head according to claim 2, characterized in that, The liquid injection head also has a second detection element, which corresponds to the first vibrating plate, and is used to acquire the pressure in the first liquid chamber. The pressure acquisition unit also acquires the pressure of the first liquid chamber based on the resistance value of the second detection element.

4. The liquid injection head according to claim 1, characterized in that, The first liquid chamber is a first dummy liquid chamber connected to a dummy nozzle that does not contribute to printing.

5. The liquid injection head according to claim 1, characterized in that, The liquid injection head also has an inlet for introducing liquid into the first common liquid chamber. The plurality of pressure chambers have a second pressure chamber located at an end in a second direction opposite to the first direction. The distance from the inlet to the first pressure chamber is greater than the distance from the inlet to the second pressure chamber.

6. The liquid injection head according to claim 1, characterized in that, The liquid injection head also has an inlet for introducing liquid into the first common liquid chamber. The plurality of pressure chambers have a second pressure chamber located at an end in a second direction opposite to the first direction. When viewed in the direction of liquid injection into the plurality of nozzles, the inlet is positioned between the first pressure chamber and the second pressure chamber in the first direction.

7. The liquid injection head according to claim 1, characterized in that, The liquid injection head also has: The second liquid chamber is disposed in the second direction relative to the second pressure chamber located at the end of the plurality of pressure chambers in the second direction which is the opposite direction to the first direction, and is connected to the first common liquid chamber. The second vibrating plate demarcates a portion of the second liquid chamber; as well as The second detection element, corresponding to the second vibrating plate, is used to obtain the pressure in the second liquid chamber.

8. The liquid injection head according to claim 1, characterized in that, The liquid jet head does not have a piezoelectric element corresponding to the first liquid chamber, but has multiple piezoelectric elements that apply pressure to the multiple pressure chambers.

9. The liquid injection head according to claim 1, characterized in that, The width of the first vibrating plate in the first direction is greater than the width of the vibrating plate in the first direction that defines a portion of the first pressure chamber.

10. The liquid injection head according to claim 9, characterized in that, The liquid injection head has multiple individual flow paths connected to the first common liquid chamber. The multiple individual flow paths have: Multiple second separate flow paths are respectively connected to the multiple nozzles and each includes the multiple pressure chambers; as well as The first separate flow path includes the first liquid chamber. The width of the first separate flow path in the third direction, which intersects the first direction and the jetting direction of the liquid, is equal to the width of the second separate flow path in the third direction.

11. The liquid injection head according to claim 1, characterized in that, The liquid injection head includes: Multiple second separate flow paths are supplied with liquid from the first common liquid chamber, and the multiple second separate flow paths are respectively connected to the multiple nozzles and each includes the multiple pressure chambers; A second common liquid chamber is used to recover liquid that was not ejected from the plurality of nozzles from the plurality of second individual flow paths; as well as The first separate flow path includes the first liquid chamber and connects the first common liquid chamber and the second common liquid chamber.

12. A liquid injection device, characterized in that, have: The liquid injection head according to any one of claims 1, 4 to 11; and The pressure acquisition unit acquires the pressure of the first liquid chamber based on the resistance value of the first detection element.

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