JP7135848B2 - Actuator, Liquid Ejection Head, Liquid Ejection Unit, and Apparatus for Ejecting Liquid - Google Patents

Description

The present invention relates to an actuator, a liquid ejection head, a liquid ejection unit, and an apparatus for ejecting liquid.

2. Description of the Related Art Conventionally, an actuator is known that has a plate-like portion forming one inner wall surface of a space formed within a substrate. For example, a liquid ejection head of an inkjet recording apparatus includes an actuator having a pressurized liquid chamber, which is a space formed in a substrate. It has a nozzle plate formed with nozzle holes for ejecting the liquid in the pressurized liquid chamber, and a vibrating plate which is a plate-like portion forming an inner wall surface on the opposite side of the nozzle plate with the liquid chamber interposed therebetween. An electromechanical conversion element is provided on the surface of the diaphragm opposite to the pressurized liquid chamber. A structure suitable for measuring the dimension inside the pressurized liquid chamber is also known.

For example, in Patent Document 1, a diaphragm that is opaque to visible light is provided, a space having a shape similar to the pressurized liquid chamber is formed at the end of the pressurized liquid chamber for measurement, and the space is used as the diaphragm. describes a liquid ejection head provided with a partition plate transparent to visible light at a location corresponding to . It is said that the width of the vibrating plate in the pressurized liquid chamber can be measured by visible light through this partition plate.

However, in the liquid ejection head of Patent Document 1, when the vibration plate, which is the plate-like portion, is opaque, there remains a problem that the original length of the pressurized liquid chamber itself cannot be measured.

In order to solve the above-described problems, the present invention provides an actuator having a space formed in a substrate, wherein most of the plate-like portion forming one inner wall surface of the space is made of a material that does not transmit light of a specific wavelength. At least two portions of the plate-like portion corresponding to the periphery of the space are made of a material that transmits the light of the specific wavelength.

ADVANTAGE OF THE INVENTION According to this invention, the outstanding effect that the length of the space itself which an actuator has can be measured even when a plate-shaped part is opaque is exhibited.

FIG. 2 is a partially broken perspective view showing the internal configuration of the liquid ejection head according to the embodiment; FIG. 2 is a bottom view showing the internal structure of the liquid ejection head; Sectional drawing of AA' of FIG. Sectional drawing of BB' of FIG. FIG. 4 is an explanatory diagram of a method for manufacturing the same liquid ejection head; FIG. 4 is an explanatory diagram of length measurement of the same liquid ejection head. FIG. 4 is an explanatory diagram of an example of a specific method for detecting edges of a pressurized liquid chamber; FIG. 11 is an explanatory diagram of a forward tapered shape in which the wall surface of the pressurized liquid chamber is inclined so that the bottom side is narrower than the piezoelectric element side; FIG. 10 is an explanatory view of a case of a reverse tapered wall surface in which the pressurized liquid chamber is inclined so that the width of the pressurized liquid chamber is narrower on the piezoelectric element side than on the bottom side; Explanatory drawing of the example which formed the through-hole as a structure which can be measured. Sectional drawing of the liquid ejection head in other embodiment. FIG. 5 is a cross-sectional view of a liquid ejection head according to still another embodiment; Explanatory drawing of a modification. Explanatory drawing of another modification. Explanatory drawing of another modification. FIG. 4 is a perspective view of a liquid ejection head according to still another embodiment; 1 is a perspective view showing an example of an inkjet recording apparatus according to an embodiment; FIG. FIG. 18 is a side view showing an example of a mechanical section of the inkjet recording apparatus of FIG. 17; FIG. 4 is an explanatory plan view of a main part showing an example of a liquid ejection unit; FIG. 11 is a plan view of a main portion showing another example of the liquid ejection unit; FIG. 11 is a front explanatory view showing still another example of the liquid ejection unit;

[Embodiment 1]
An embodiment in which the present invention is applied to a liquid ejection head of an inkjet recording apparatus as an image forming apparatus that ejects liquid will be described below.

FIG. 1 is a perspective view of a liquid ejection head portion having a subframe substrate and piezoelectric actuators of the present invention, FIG. 2 is a bottom view showing two piezoelectric actuators, and FIG. , and FIG. 4 is a BB' cross-sectional view of FIG.

As shown in the figure, the liquid ejection head section 1 is of a side shooter type that ejects liquid droplets from nozzle holes 6 provided on the substrate surface, and includes an actuator substrate 100, a subframe substrate 200, and a nozzle substrate 300.

The actuator substrate 100 includes a piezoelectric element 2 that generates liquid ejection energy and a vibration plate 3 . Also, a pressurized liquid chamber partition wall 4, a pressurized liquid chamber 5, a fluid resistance portion 7, and a common liquid chamber 8 are formed. Each pressurized liquid chamber 5 is partitioned by a pressurized liquid chamber partition wall 4 . A passivation film 50 is formed for the purpose of protecting the lead wiring layer (see FIGS. 3 and 4).

A subframe substrate 200 is provided on the actuator substrate 100 . A gap 67 (counterbore) is formed so that the liquid supply port 66 for supplying liquid from the outside, the common liquid supply path 9, and the vibration plate 3 can flex (see FIGS. 3 and 4). The subframe substrate 200 constitutes a gap-forming substrate. Further, since the gap 67 covers the piezoelectric element 2, the subframe substrate 200 is also called a protective substrate.

The nozzle substrate 300 has nozzle holes 6 formed at positions corresponding to the individual pressurized liquid chambers 5 . By bonding the actuator substrate 100, the subframe substrate 200, and the nozzle substrate 300, the liquid ejection head section 1 is formed.

Here, an actuator section 68, which is a feature of the present invention, is applied. The actuator section 68, which is a feature of the present invention, may be a dummy bit that is not driven.
As shown in FIGS. 1, 2, 3 and 4, the actuator substrate 100 is arranged on the side facing the pressurized liquid chamber 5 with the vibrating plate 3 forming a partial wall surface of the pressurized liquid chamber 5 and the vibrating plate 3 interposed therebetween. A piezoelectric element 2 is formed. This piezoelectric element 2 is formed from a common electrode 10 , individual electrodes 11 and a piezoelectric body 12 . Further, the vibration plate 3 also forms a partial wall surface of the fluid resistance portion 7 that continues to the pressurized liquid chamber. A through hole is formed at a location corresponding to the common liquid chamber 8 , so that ink, which is a liquid, can be supplied from the outside to the common liquid chamber 8 through the common liquid supply path 9 of the subframe substrate 200 . .

In the liquid ejection head section 1 formed in this manner, the recording liquid is ejected based on the image data from the control section in a state in which each pressurized liquid chamber 5 is filled with a liquid, for example, a recording liquid (ink). A pulse voltage is applied to the individual electrode 11 corresponding to the nozzle hole 6 for which the cleaning is desired. For example, an oscillation circuit applies a pulse voltage of 20 V through a connection hole formed in the lead wiring and the interlayer insulating film 45 . By applying this voltage pulse, the piezoelectric body 12 itself shrinks in the direction parallel to the diaphragm 3 due to the electrostrictive effect, and the diaphragm 3 bends in the direction of the pressurized liquid chamber 5 . As a result, the pressure in the pressurized liquid chamber 5 rises sharply, and the recording liquid is ejected from the nozzle hole 6 communicating with the pressurized liquid chamber 5 . Next, after the application of the pulse voltage, the shrunk piezoelectric body 12 returns to its original position, so that the flexed diaphragm 3 returns to its original position, and the pressure in the pressurized liquid chamber 5 is lower than that in the common liquid chamber 8 . becomes. With this negative pressure, ink supplied from the outside through the liquid supply port 66 is supplied from the common liquid supply path 9 and the common liquid chamber 8 to the pressurized liquid chamber 5 via the fluid resistance portion 7 . By repeating this, droplets can be continuously ejected to form an image on a recording medium (paper) arranged facing the liquid ejection head.

In this embodiment, visible light transmission processed regions 15 (in the illustrated example, six locations per pressurized liquid chamber 5) are provided for forming visible light transmission regions indicated by broken lines in FIG. As shown in FIG. 4, the working region 15 for transmitting visible light has a vibrating plate impermeable to visible light 21 (described later) that constitutes the vibration plate 3 at other pressurized liquid chambers (see FIG. 3). The active layer Si 16) and the common electrode 10 do not exist, and only the visible light transmissive film 20 (Box layer SiO ₂ 17, which will be described later) is provided. In the range overlapping the pressurized liquid chamber 5 in the visible light transmission processing region 15, visible light is emitted from the pressurized liquid chamber of the actuator substrate 100 to the piezoelectric element side, and from the piezoelectric element side of the actuator substrate 100 to the pressurized liquid chamber. Light can pass through. In addition, the processing area 15 for visible light transmission is formed so as to include the inner surface position of the partition wall 4 in the diaphragm 3 in the width direction of the pressurized liquid chamber 5 (the boundary position in the width direction of the pressurized liquid chamber). is set. In the illustrated example, the processing areas 15 for visible light transmission at the four corners include boundary positions in the longitudinal direction. As a result, the hatched area in the drawing, which overlaps with the pressurized liquid chamber 5, in the visible light transmission processing area 15 becomes a visible light transmission area 15'.

FIG. 5 is an explanatory diagram of the manufacturing process. Actually, patterns corresponding to a plurality of chips are formed on a wafer, but here, two bits of the actuator section 68 of the actuator substrate 100 including the present invention will be described.
(a) An SOI substrate (for example, a plate thickness of 400 μm) with a plane orientation of (110) is used as the actuator substrate 100 , and the active layer Si 16 and the box layer SiO ₂ 17 are used as the later diaphragm 3 . Since the active layer Si does not transmit visible light, the active layer Si 16 in the visible light transmitting processed region 15 is etched by a lithography method so that the width of the pressurized liquid chamber can be measured by edge detection using transmitted visible light. Remove. The Si etching at this time is performed by etching with an ICP etcher using, for example, the Bosch method, thereby removing the active layer Si of the processing region 15 for visible light transmission without substantially etching the underlying Box layer SiO ₂ 17. can be done.

Here, the film thickness of the active layer Si 16 has a function of obtaining the rigidity of the vibration plate 3 so that droplets can be optimally ejected, and is arbitrarily set within the range of 1 μm to 20 μm. The reason why the active layer Si 16 of the SOI substrate is used for the diaphragm is that the film thickness tolerance can be set to about ±0.2 μm regardless of the thickness of the diaphragm. It is superior to the laminated film of Therefore, it is possible to obtain a highly accurate actuator with little variation between bits. Also, the film thickness of the box layer SiO ₂ 17 may be arbitrarily set from 70 nm to 1 μm because it is necessary to function as a stopper layer during etching for forming the pressurized liquid chamber 5 to be formed later. . Here, the active layer Si 16 of the SOI wafer is used as the diaphragm 3. However, even if a diaphragm material that does not transmit visible light, such as a polysilicon film, is used, the width of the pressurized liquid chamber can be determined by transmitting visible light. For the measurement, the processing area 15 for transmitting visible light should be opened.

(b) Next, in order to obtain adhesion with the common electrode 10, a SiO ₂ film is formed as a thermal oxide film 51 on the active layer Si 16 to a thickness of 70 nm to 1 μm.
(c) Next, as the common electrode 10, for example, TiO ₂ as an adhesion layer and Pt as an electrode are deposited by sputtering to a thickness of 50 nm and 120 nm, respectively. The TiO ₂ film may be formed by forming Ti by sputtering and then oxidizing Ti by RTA in an oxygen atmosphere to obtain TiO ₂ .

Next, PZT is deposited as the piezoelectric body 12 by, for example, spin coating in a plurality of times, and finally deposited to a thickness of 2 μm. Next, a Pt individual electrode 11 is formed by sputtering to a thickness of, for example, 70 nm. Here, the film formation method of the piezoelectric body 12 is not limited to the spin coating method, and may be formed by, for example, a sputtering method, an ion plating method, an aerosol method, a sol-gel method, an inkjet method, or the like.

Then, the individual electrode 11, the piezoelectric body 12, and the common electrode 10 are patterned by a litho-etching method in order to form the piezoelectric element 2 at a position corresponding to the pressurized liquid chamber 5 to be formed later. After that, the common electrode 10 is patterned by a lithography method. At this time, the common electrode 10 layer, which will become the common liquid chamber 8 later, is also patterned.

(d) Next, an interlayer insulating film 45 is formed to insulate the common electrode 10 and the piezoelectric body 12 from lead wires to be formed later. The interlayer insulating film 45 is a SiO ₂ film formed by plasma CVD, for example. The interlayer insulating film 45 may be a film other than SiO ₂ by the plasma CVD method as long as it is a film that does not affect the piezoelectric body 12 or the electrode material and has insulating properties.

Next, connection holes for connecting the individual electrodes 11 and the lead wires are formed by a litho-etching method. When the common electrode 10 is also connected to the lead-out wiring, a connection hole is formed in the same manner.

Next, as a lead wiring, for example, TiN/Al films are formed to a thickness of 30 nm/1 μm by sputtering. TiN is applied as a barrier layer to prevent direct contact between Pt, which is the material of the individual electrode 11 or the common electrode 10, and Al, which is the material of the lead wiring, at the bottom of the connection hole. This is to prevent film peeling or the like from occurring due to stress due to volume change, which is caused by alloying due to thermal history in the subsequent steps, when in direct contact.

Next, as a passivation film 50, a silicon nitride film is deposited to a thickness of 700 nm by plasma CVD, for example. After that, the lead wiring pad portion of the lead wire, the actuator portion 68, and the common liquid supply path 9 portion are also opened by the litho-etching method.
Next, the vibrating plate 3 is removed by the litho-etching method at the common liquid chamber flow path 9 and the portion that will later become the common liquid chamber 8 .

(e) Next, the subframe substrate 200 having the liquid supply ports 66 and the gaps 67 corresponding to the positions of the actuator portions 68 is bonded to the actuator substrate 100 via the bonding portion 48 with an adhesive. The adhesive is applied to the subframe substrate 200 side to a thickness of about 1 to 4 μm by a general thin film transfer device.

Next, in order to form the pressurizing liquid chamber 5, the common liquid chamber 8, and the fluid resistance section 7, the actuator substrate 100 is polished by a known technique so as to have a desired thickness t (for example, a thickness of 80 μm). do. Etching or the like may be used instead of the polishing method.

Next, the pressurized liquid chamber 5, the common liquid chamber 8, and the partition wall portions other than the fluid resistance portion 7 are covered with a resist by a litho method. After that, anisotropic wet etching is performed with an alkaline solution (KOH solution or TMHA solution) to form the pressurized liquid chamber 5, the common liquid chamber 8, and the fluid resistance portion 7. FIG. The pressurized liquid chamber 5, the common liquid chamber 8, and the fluid resistance portion 7 may be formed by dry etching using an ICP etcher other than anisotropic etching using an alkaline solution.
Next, a nozzle substrate 300 having nozzle holes 6 at positions corresponding to the separately formed pressurized liquid chambers 5 is joined. As described above, the liquid ejection head section 1 is completed.

Since the processing dimensional accuracy of the pressurized liquid chamber is important, the dimensions of the liquid chamber bottom (piezoelectric element side) and upper portion are measured with an optical measuring device. The dimensions of the bottom side are measured by irradiating transmitted light from the upper side (pressurized liquid chamber side) and measuring through a vibration plate that transmits visible light from the bottom side (piezoelectric element side). However, it is difficult to detect the underlying pattern edge (here, the bottom of the pressurized liquid chamber) through a material that does not transmit visible light (for example, single crystal Si). If it is a material that transmits infrared light, it is possible to measure the width dimension of the pressurized liquid chamber 5 by transmitting the infrared light and detecting the edge of the base. However, since infrared light has a longer wavelength than visible light, the resolution is lower than that of visible light, and a resolution of 1 μm or less cannot be obtained. Also, if the material does not transmit visible light or infrared light, it is completely impossible to measure the dimensions.

Therefore, this embodiment is characterized in that the width dimension of the pressurized liquid chamber can be measured with transmitted visible light with high measurement accuracy by providing the minimum required visible light transmission region 15'. In other words, by forming the minimum required visible light transmitting region 15' in the actuator section 68, visible light is transmitted and the edge of the pressurized liquid chamber 5 can be visually recognized, so that the width of the pressurized liquid chamber 5 can be measured. becomes.

As shown in FIG. 6(b), visible light cannot be transmitted through the Pt layer of the common electrode 10 and the active layer Si 16 of the film constituting the diaphragm 3 where there is no visible light transmission region 15'. The edge of the pressurized liquid chamber 5 reflects the visible light incident from the side opposite to the piezoelectric element section on the surface of the common electrode 10 layer, and the edge of the pressurized liquid chamber 5 cannot be visually recognized. On the other hand, as shown in FIG. 6(a), since only the box layer SiO ₂ 17 of the diaphragm 3 is present in the visible light transmission region, visible light is transmitted, and the edge of the pressurized liquid chamber 5 is I can confirm. By providing the visible light transmission region 15' in this way, the width dimension that greatly affects the actuator characteristics of the bottom of the pressurized liquid chamber 5 can be measured regardless of the cross-sectional shape (taper, reverse taper) of the pressurized liquid chamber partition wall 4. becomes. Further, when the actuator function does not have to be provided, for example, if the pattern is used for dimension measurement, the structure without the piezoelectric element 2 may be used.

FIG. 7 is an explanatory diagram of an example of a specific method for detecting the edge of the pressurized liquid chamber. When the range including the two visible light transmission regions 15' indicated by X in FIG. 7(a) is viewed with a microscope, an image I corresponding to the two visible light transmission regions 15' is displayed as shown in FIG. 7(b). detected. Since the outer edges E1 and E2 of each of the two images I correspond to the edges of the liquid chamber, the liquid chamber width W can be measured by measuring the distance between the edges E1 and E2 of the images.

Note that the arrows shown in FIG. 6A are obtained by irradiating visible light from the bottom of the pressurized liquid chamber opposite to the piezoelectric element side and detecting the light transmitted from the piezoelectric element side. It shows the case of measuring the width dimension of the bottom of the pressure fluid chamber on the side of the piezoelectric element. Conversely, when measuring the width of the bottom of the pressurized liquid chamber on the side opposite to the piezoelectric element side, visible light is irradiated from the bottom of the liquid chamber on the side opposite to the piezoelectric element side of the pressurized liquid chamber. , measured from the same side. In this way, since the transmitted light is emitted from the bottom of the pressurized liquid chamber opposite to the piezoelectric element portion, the length is measured before the nozzle substrate 300 is joined.

If the taper angle of the section of the pressurized liquid chamber is other than 90°, it is desirable that the visible light incident side and the length measurement side are arranged as follows.
FIG. 8 is an explanatory diagram of a forward taper shape in which the wall surface is inclined so that the width of the pressurized liquid chamber is narrower on the bottom side than on the piezoelectric element side. As shown in FIG. 8A, when measuring the width W1 of the pressurized liquid chamber on the piezoelectric element side, visible light is irradiated from the piezoelectric element side of the pressurized liquid chamber and observed from the same side. is preferred. Further, as shown in FIG. 8B, when measuring the width W2 on the bottom side of the pressurized liquid chamber, it is possible to irradiate visible light from the bottom side of the pressurized liquid chamber and observe from the same side. preferable.

FIG. 9 is an explanatory diagram of a case where the pressurized liquid chamber has an inverse tapered shape in which the wall surface is inclined so that the width on the piezoelectric element side is narrower than that on the bottom side. As shown in FIG. 9A, when measuring the width W1 of the pressurized liquid chamber on the piezoelectric element side, it is possible to irradiate and observe visible light from both the piezoelectric element side and the bottom side. It is preferable to irradiate visible light from the bottom side and observe from the piezoelectric element side. As shown in FIG. 9B, in measuring the width W2 on the bottom side of the pressurized liquid chamber, it is preferable to irradiate visible light from the bottom side and observe from the same side.

In the example of the manufacturing method described with reference to FIG. 5, the subframe substrate 200 is joined when the pressurized liquid chamber 5 is formed. Therefore, the portion of the subframe substrate 200 corresponding to the visible light transmitting region 15' is formed so as to be dimensionally measurable. FIG. 10 is an explanatory diagram of an example in which a through hole 201 is formed as a measurable structure. When a through-hole is formed as a measurable structure in this way, it is closed by a plate forming a common liquid chamber which is further joined on the subframe substrate 200 . Unlike the manufacturing method described using FIG. In the case of performing measurement), the subframe substrate 200 does not require a special structure for enabling the dimension measurement.

[Embodiment 2]
FIG. 11 is a cross-sectional view of a liquid ejection head according to another embodiment. The liquid ejection head according to this embodiment is the same as that of the first embodiment except that the material of the visible light transmission region 15' is different. That is, in Embodiment 1, the visible light transmitting region 15' is only a thin box layer _SiO2 single layer, and the _SiO2 film itself has a compressive stress. Buckling may occur. If the visible light transmission region 15' is buckled, in the worst case, the film of the visible light transmission region 15' is torn, causing a problem, and the quality of the actuator and the liquid ejection head is significantly deteriorated. In order to prevent such buckling, the second embodiment provides a tensile stress film that transmits visible light, thereby preventing buckling and improving the reliability of the actuator. and

In the second embodiment, by forming the visible light transmitting tensile stress film 44 before forming the interlayer insulating film 45, visible light is transmitted onto the box layer SiO ₂ 17 which is the compressive stress film of the visible light transmitting region 15′. A permeable tensile stress film 44 is laminated. Specifically, the visible light transmissive tensile stress film 44 is made of a material that has tensile _stress and transmits visible light, such as _{Al2O3 , Si3N5} , and _ZrO2 . These films are formed by, for example, a sputtering method or an ALD film forming method. As described above, in the second embodiment, unlike the first embodiment, the visible light transmitting region 15' is less likely to buckle and the visible light transmitting region is formed. becomes possible.

[Embodiment 3]
FIG. 12 is a cross-sectional view of a liquid ejection head according to still another embodiment (Embodiment 3).
This Embodiment 3 has a configuration in which all the constituent films of the visible light transmission region 15' are removed. Other points are the same as those of the first and second embodiments. As a result, the edge of the pressurized liquid chamber partition 4 does not have a film material in the visible light transmission region 15' and is not affected by the permeable film at all. Compared with the first and second modes, the most accurate dimension measurement is possible.

However, since there is no constituent film in the visible light transmission region, a dedicated pattern (dummy pattern) is used only for dimension measurement. Since liquid is not supplied to the dummy pattern, liquid leakage does not occur even if the film material does not exist in part of the liquid chamber. In practice, it is necessary to arrange this dedicated pattern in a region where there is no functional influence as a liquid ejection head.
In addition, in any of the first, second, and third embodiments, the visible light transmission processing region 15 is formed as shown in (B), (C), or (D) in addition to (A) as shown in FIG. It can be placed in place. Both are set so that the pressurized liquid chamber partition edge can be visually recognized at least in the width direction. FIGS. 13A and 13D show a configuration in which the vertical and horizontal dimensions of the pressurized liquid chamber 5 can be measured. Moreover, in the case of a dummy pattern, the piezoelectric element 2 may or may not be present.

FIG. 14 is a bottom view showing an example of locations where dummy patterns are formed.
A dummy liquid chamber 5A was formed at the end of the row of the original pressurized liquid chambers 5, and a processed area 15 for transmitting visible light similar to that of the first embodiment was formed in this liquid chamber 5A.

FIG. 15 is a bottom view showing another example of formation locations of dummy patterns. A dummy liquid chamber 5A is formed at the end of the line of the original pressurized liquid chambers 5, and a common liquid chamber 8 is formed therefrom. The chamber was extended while maintaining the width of the pressurized fluid chamber to the longitudinal position where the pressure was applied. Then, a processed region 15 for transmitting visible light was formed in the extended portion.

Although each of the above embodiments is an example of using visible light for length measurement, the present invention is not limited to this. For example, infrared light can be used for measurement depending on the required resolution, and in that case, the visible light transmission processing area is formed so as to transmit the light used for measurement.

[Embodiment 4]
FIG. 16 is a perspective view of an ink cartridge 105 integrally provided with the liquid ejection head section 1 according to Embodiments 1 to 4 and containing ink as a liquid. The ink cartridge 105 is formed by integrating the liquid ejection head portion 1 having the nozzles 6 and the like and an ink tank 105a for supplying ink to the liquid ejection head portion 1. As shown in FIG. Thus, in the case where the ink tank 105a is one part of the integrated liquid ejection head, the yield and reliability of the ink cartridge 105 can be improved by increasing the accuracy, density, and reliability of the actuator part. Therefore, the cost of the ink cartridge 105 can be reduced.

[Embodiment 5]
Next, an example of an inkjet recording apparatus, which is a device for ejecting liquid and which includes the liquid ejection head section 1 according to Embodiments 1 to 4, will be described.
17 is a perspective view showing an example of the inkjet recording apparatus according to the embodiment, and FIG. 18 is a side view showing an example of the mechanical section of the inkjet recording apparatus of FIG. 17. As shown in FIG.
The inkjet printing apparatus of this embodiment includes a carriage movable in the main scanning direction inside a printing apparatus main body 91, a liquid ejection head (printing head) 104 having the liquid ejection head section 1 mounted on the carriage, and the liquid ejection head 104. The printing mechanism unit 92 and the like, which are composed of ink cartridges and the like for supplying ink to the printer, are housed therein.

A paper feed cassette (or a paper feed tray) 94 capable of stacking a large number of sheets of paper 93 can be detachably attached to the lower portion of the recording apparatus main body 91 from the front side, and the paper 93 can be manually fed. A manual feed tray 95 for feeding paper can be folded down. Then, the paper 93 fed from the paper feed cassette 94 or the manual feed tray 95 is taken in, and after a desired image is recorded by the printing mechanism section 92, the paper is discharged to the paper discharge tray 96 mounted on the rear side.

The printing mechanism unit 92 holds a carriage 103 slidably in the main scanning direction with a main guide rod 101 and a sub guide rod 102 which are guide members that extend horizontally between left and right side plates. A carriage 103 has liquid ejection heads (recording heads) 104 for ejecting ink droplets of respective colors of yellow (Y), cyan (C), magenta (M), and black (Bk). They are arranged in a direction intersecting the scanning direction. It is mounted with the ink droplet ejection direction directed downward. In addition, each ink cartridge 105 for supplying ink of each color to the liquid ejection head 104 is exchangeably mounted on the carriage 103 .

The ink cartridge 105 has an air port communicating with the atmosphere at the top, a supply port at the bottom for supplying ink to the liquid ejection head 104, and a porous body filled with ink inside. The capillary force of the porous body maintains the ink supplied to the liquid ejection head 104 at a slight negative pressure. Further, although the liquid ejection heads 104 for each color are used as the liquid ejection heads here, one liquid ejection head having nozzles for ejecting ink droplets for each color may be used.

Here, the carriage 103 has its rear side (downstream side in the paper transport direction) slidably fitted on the main guide rod 101 and its front side (upstream side in the paper transport direction) slidably mounted on the secondary guide rod 102 . It is location. In order to move and scan the carriage 103 in the main scanning direction, a timing belt 110 is stretched between a driving pulley 108 and a driven pulley 109 which are rotationally driven by a main scanning motor 107 . The timing belt 110 is fixed to the carriage 103 , and the carriage 103 is reciprocally driven by forward and reverse rotation of the main scanning motor 107 .

Next, a mechanism for conveying the paper 93 set in the paper feed cassette 94 to the lower side of the liquid ejection head 104 will be described. First, a paper feed roller 111 and a friction pad 112 for separating and feeding the paper 93 from the paper feed cassette 94, a guide member 113 for guiding the paper 93, and a transport roller 114 for inverting and transporting the fed paper 93 are provided. have. A conveying roller 115 that is pressed against the peripheral surface of the conveying roller 114 and a tip roller 116 that regulates the delivery angle of the paper 93 from the conveying roller 114 are provided. The conveying roller 114 is rotationally driven by a sub-scanning motor 117 via a gear train.

A print receiving member 119 is provided as a paper guide member for guiding the paper 93 fed from the transport roller 114 below the liquid ejection head 104 so as to correspond to the moving range of the carriage 103 in the main scanning direction. A conveying roller 121 and a spur 122 that are rotationally driven for sending out the sheet 93 in the sheet discharging direction are provided downstream of the print receiving member 119 in the sheet conveying direction. Furthermore, there are disposed a paper discharge roller 123 and a spur 124 for sending the paper 93 to the paper discharge tray 96, and guide members 125 and 126 forming a paper discharge path.

During recording, the carriage 103 is moved and the liquid ejection head 104 is driven in accordance with an image signal to eject ink onto the stationary paper 93 to record one line. Record the next line. Upon receiving a recording end signal or a signal indicating that the trailing edge of the paper 93 has reached the recording area, the recording operation is terminated and the paper 93 is discharged.

In addition, a recovery device 127 for recovering ejection defects of the liquid ejection head 104 is arranged at a position outside the printing area on the right end side in the moving direction of the carriage 103 . The recovery device 127 has capping means, suction means and cleaning means. During standby for printing, the carriage 103 is moved toward the recovery device 127 and capped the liquid ejection head 104 by the capping means to keep the ejection openings in a moist state, thereby preventing ejection failure due to ink drying. In addition, by ejecting ink that is not related to printing during printing, etc., the ink viscosity of all ejection ports is made constant, and stable ejection performance is maintained.

In the event of an ejection failure or the like, the ejection port (nozzle) of the liquid ejection head 104 is sealed with capping means, and ink and air bubbles are sucked out from the ejection port through a tube with suction means. As a result, the ink, dust, etc. adhering to the ejection port surface are removed by the cleaning means, and the ejection failure is recovered. Also, the sucked ink is discharged to a waste ink reservoir provided at the bottom of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir.

The inkjet recording apparatus of this embodiment includes a liquid ejection head 104 having the liquid ejection head section 1 of any one of the first to third embodiments described above. Therefore, the electromechanical conversion element of the liquid ejection head 104 can maintain good ink ejection characteristics, and stable ink ejection can be performed.

In this specification, a "device that ejects liquid" is a device that includes a liquid ejection head or a liquid ejection unit, drives the liquid ejection head, and ejects liquid. Devices that eject liquid include not only devices that can eject liquid onto an object to which liquid can adhere, but also devices that eject liquid into air or liquid.

The "liquid ejecting device" can include means for feeding, transporting, and ejecting an object to which liquid can adhere, as well as a pre-processing device, a post-processing device, and the like.

For example, as a "device that ejects liquid", an image forming device that ejects ink to form an image on paper, and powder is formed in layers to form a three-dimensional object (three-dimensional object). There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that ejects a modeling liquid onto a formed powder layer. There is also an apparatus that discharges a liquid resist for patterning in patterning processing.

Further, the "apparatus for ejecting liquid" is not limited to one that visualizes significant images such as characters and figures with the ejected liquid. For example, it includes those that form patterns that have no meaning per se, and those that form three-dimensional images.

The aforementioned "substance to which a liquid can adhere" means a substance to which a liquid can adhere at least temporarily, such as a substance to which a liquid adheres and adheres, a substance which adheres and permeates, and the like. Specific examples include media such as recording media such as paper, recording paper, recording paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, and unless otherwise specified, includes anything that has liquid on it.

The materials of the above-mentioned "things to which liquids can adhere" include paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, and textiles for clothing. However, it is sufficient if it can be attached.

In addition, the “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be discharged from the liquid discharge head, but the viscosity is 30 [mPa s] at normal temperature and pressure, or by heating or cooling. It is preferable to be as follows. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional-imparting materials such as polymerizable compounds, resins, and surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium. , edible materials such as natural pigments, and the like. These can be used, for example, as inkjet inks, surface treatment liquids, constituent elements of electronic elements and light emitting elements, liquids for forming electronic circuit resist patterns, material liquids for three-dimensional modeling, and the like. Specifically, the "liquid" includes inks, treatment liquids, DNA samples, resists, pattern materials, binders, modeling liquids, or solutions and dispersions containing amino acids, proteins, and calcium.

Further, the ``device for ejecting liquid'' includes a device in which a liquid ejection head and an object to which liquid can be adhered move relatively, but is not limited to this. Specific examples include a serial type apparatus in which the liquid ejection head is moved and a line type apparatus in which the liquid ejection head is not moved.

In addition, as a "liquid ejecting device", there are other processing liquid coating devices that eject processing liquid onto the paper in order to apply the processing liquid to the surface of the paper for the purpose of modifying the surface of the paper, raw materials is dispersed in a solution, and sprays a composition liquid through a nozzle to granulate fine particles of the raw material.

A "liquid ejection unit" is a combination of functional parts and mechanisms integrated with a liquid ejection head, and is a collection of parts related to ejection of liquid. For example, the "liquid ejection unit" includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance/recovery mechanism, and a main scanning movement mechanism with a liquid ejection head.

Here, integration means, for example, that the liquid ejection head and functional parts or mechanisms are fixed to each other by fastening, adhesion, or engagement, or that one is held movably with respect to the other. include. Also, the liquid ejection head, the functional parts, and the mechanism may be configured to be detachable from each other.

For example, as a liquid ejection unit, as shown in FIG. 19, there is a liquid ejection unit 440 in which a liquid ejection head 104 and a head tank 441 are integrated. In addition, there is one in which the liquid ejection head 104 and the head tank 441 are integrated by being connected to each other by a tube or the like. Here, a unit including a filter can be added between the head tank 441 and the liquid ejection head 104 of these liquid ejection units.

Further, there is a liquid ejection unit in which a liquid ejection head and a carriage are integrated.

Further, as a liquid ejection unit, there is one in which the liquid ejection head is movably held by a guide member constituting a part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated. Further, as shown in FIG. 20, there is a liquid ejection unit in which the liquid ejection head 104, the carriage 103, and the main scanning movement mechanisms 107 to 109 are integrated.

There is also a liquid ejection unit in which the liquid ejection head, the carriage, and the maintenance and recovery mechanism are integrated by fixing a cap member, which is a part of the maintenance and recovery mechanism, to a carriage to which the liquid ejection head is attached. .

Also, as a liquid ejection unit, as shown in FIG. 21, a tube is connected to the liquid ejection head 104 to which the head tank or flow path part 444 is attached, and the liquid ejection head and the supply mechanism are integrated. There is

It is assumed that the main scanning movement mechanism also includes a single guide member. Also, the supply mechanism includes the tube unit and the loading unit unit.

Further, the terms used in the present application, such as image formation, recording, printing, printing, printing, modeling, etc., are synonymous.

What has been described above is only an example, and the present invention has specific effects in each of the following aspects.
(Aspect 1)
In an actuator such as an actuator substrate 100 having a plate-like portion such as a vibration plate 3 forming one inner wall surface of a space such as a pressurized liquid chamber 5 formed in the substrate, the plate-like portion emits light of a specific wavelength. It includes a material that does not transmit light and a material that transmits light of a specific wavelength, and portions corresponding to at least two of the peripheral edges of the space in this plate-like portion have, for example, the specific wavelength at both ends in the width direction. It is characterized by being made of a material that transmits light. According to this, as described in the above embodiment, the positions of the peripheral edges of the space located at the two locations are confirmed using light of a specific wavelength that can pass through the transmission region at the ends of the space to be measured. Therefore, it is possible to accurately measure the distance between the rims located at the two locations.

(Aspect 2)
In Aspect 1 above, the nozzle 6, the pressurized liquid chamber 5 as the space communicating with the nozzle, the diaphragm 3 as the plate-like portion constituting a part of the inner wall surface of the pressurized liquid chamber, An electromechanical conversion element such as a piezoelectric element 2 is provided on the opposite side of the vibration plate to the pressurized liquid chamber side, and the electromechanical conversion element is provided at locations corresponding to the two locations. Electrodes of mechanical transducers are not provided. According to this, it is possible to accurately measure the processing dimensions of the pressurized liquid chamber, so that it is possible to guarantee good liquid ejection performance.

(Aspect 3)
In the actuator of mode 2, the diaphragm has a Si layer and a SiO ₂ layer, and the portions corresponding to the two portions are composed of the SiO ₂ layer. Therefore, the liquid in the pressurized liquid chamber does not permeate, and the liquid discharge function can be exhibited satisfactorily.

(Aspect 4)
The SiO ₂ layer forming the locations corresponding to the two locations has a tensile stress film that transmits the light of the specific wavelength. According to this, this region does not buckle, and a highly reliable actuator can be obtained.

(Aspect 5)
In the actuator of aspect 4, the tensile stress film is a film made of any one of Al ₂ O ₃ , Si ₃ N ₅ and ZrO ₂ , or a film formed by laminating two or more layers of each film made of any one of them. be. According to this, by applying a relatively inexpensive material, it is possible to realize a highly reliable actuator while suppressing the cost.

(Aspect 6)
In the actuator according to any one of aspects 1 to 5, a gap forming substrate having a gap allowing deformation of the plate-like portion is bonded to the substrate on which the actuator is formed, Through-holes are formed at locations corresponding to the two locations on the gap-forming substrate.

(Aspect 7)
An actuator having a substrate in which a pressurized liquid chamber to which a liquid ejected from a nozzle is supplied, and a vibration plate forming one inner wall surface of the pressurized liquid chamber,
A dummy chamber to which the liquid is not supplied is formed in the substrate, and the width of the dummy chamber is the same as the width of the pressurized liquid chamber. The location is characterized by no walls.

(Aspect 8)
A liquid ejection head that ejects liquid by the actuator according to any one of modes 1 to 7. According to this, the ejection performance can be stabilized.

(Aspect 9)
A liquid ejection unit comprising the liquid ejection head according to aspect 8. According to this, the ejection performance can be stabilized.

(Mode 10)
In the liquid ejection unit according to aspect 9, a head tank for storing liquid to be supplied to the liquid ejection head, a carriage for mounting the liquid ejection head, a supply mechanism for supplying the liquid to the liquid ejection head, and a liquid ejection head. At least one of a maintenance and recovery mechanism for performing maintenance and recovery and a main scanning movement mechanism for moving the liquid ejection head in the main scanning direction is integrated with the liquid ejection head. According to this, the ejection performance can be stabilized.

(Aspect 11)
A device for ejecting liquid, comprising the liquid ejection head according to aspect 8 or the liquid ejection unit according to aspect 9 or 10. According to this, the ejection performance can be stabilized.

Reference Signs List 1: Liquid ejection head 2: Piezoelectric element 3: Vibration plate 4: Pressurized liquid chamber partition wall 5: Pressurized liquid chamber 6: Nozzle hole 7: Fluid resistance portion 8: Common liquid chamber 9: Common liquid supply path 10: Common Electrode 11 : Individual electrode 12 : Piezoelectric body 15 : Visible light transmission processing region 15 ′ : Visible light transmission region 44 : Visible light transmission tensile stress film 45 : Interlayer insulating film 48 : Joint 50 : Passivation film 66 : Liquid supply port 67 : Gap 68 : Actuator section 70 : Actuator substrate 80 : Subframe substrate 90 : Nozzle substrate 91 : Recording device body 92 : Printing mechanism 93 : Paper 94 : Paper feed cassette 95 : Manual feed tray 96 : Paper discharge tray 100 : Actuator substrate 101 : Main guide rod 102 : Sub guide rod 103 : Carriage 104 : Liquid discharge head (recording head)
105: Ink cartridge 107: Main scanning motor (main scanning movement mechanism)
108: drive pulley (main scanning movement mechanism)
109: driven pulley (main scanning movement mechanism)
110 : Timing belt 111 : Paper feed roller 112 : Friction pad 113 : Guide member 114 : Conveying roller 115 : Conveying roller 116 : Tip roller 117 : Sub-scanning motor 119 : Print receiving member 121 : Conveying roller 122 : Spur 123 : Exhaust Paper roller 124 : Spur 125 : Guide member 126 : Guide member 127 : Recovery device 200 : Subframe substrate 300 : Nozzle substrate 440 : Liquid ejection unit 441 : Head tank 444 : Flow path parts

JP 2012-196829 A

Claims (11)

In an actuator having a plate-like portion forming one inner wall surface of a space formed within a substrate,
The plate-shaped portion includes a material that does not transmit light of a specific wavelength and a material that transmits light of a specific wavelength,
The actuator is characterized in that portions of the plate-shaped portion corresponding to at least two of the peripheral edges of the space are made of a material that transmits the light of the specific wavelength. The actuator of claim 1, wherein
a nozzle, a pressurized liquid chamber as the space communicating with the nozzle, a vibration plate as the plate-like portion forming part of the inner wall surface of the pressurized liquid chamber, and the pressurized liquid in the vibration plate and an electromechanical conversion element provided on the side opposite to the chamber side, and electrodes of the electromechanical conversion element are not provided at locations corresponding to the two locations on the electromechanical conversion element. actuator. The actuator of claim 2, wherein
The diaphragm has a Si layer and a _SiO2 layer,
An actuator, wherein a portion corresponding to the two portions is composed of a SiO ₂ layer. The actuator of claim 3, wherein
The actuator according to claim 1, wherein the SiO ₂ layer forming the locations corresponding to the two locations is provided with a tensile stress film that transmits the light of the specific wavelength. 5. The actuator of claim 4,
The tensile stress film is a film made of any one of Al ₂ O ₃ , Si ₃ N ₅ , and ZrO ₂ , or a film formed by laminating two or more layers of each film made of any one of them. actuator. The actuator according to any one of claims 1 to 5,
On the substrate on which the actuator is formed, a gap forming substrate having a gap for allowing deformation of the plate-like portion is bonded. are formed with through-holes respectively. An actuator having a substrate in which a pressurized liquid chamber to which a liquid ejected from a nozzle is supplied, and a vibration plate forming one inner wall surface of the pressurized liquid chamber,
A dummy chamber to which the liquid is not supplied is formed in the substrate, and the width of the dummy chamber is the same as the width of the pressurized liquid chamber,
The actuator according to claim 1, wherein the dummy chamber has no wall surface at least at two locations on the periphery in the width direction. A liquid ejection head that ejects a liquid using the actuator according to any one of claims 1 to 7. A liquid ejection unit comprising the liquid ejection head according to claim 8 . In the liquid ejection unit according to claim 9,
a head tank for storing the liquid to be supplied to the liquid ejection head, a carriage for mounting the liquid ejection head, a supply mechanism for supplying the liquid to the liquid ejection head, a maintenance and recovery mechanism for maintaining and recovering the liquid ejection head, and the liquid A liquid ejection unit comprising: at least one main scanning movement mechanism for moving an ejection head in a main scanning direction; and the liquid ejection head. 11. A device for ejecting liquid, comprising the liquid ejection head according to claim 8 or the liquid ejection unit according to claim 9 or 10.

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