JP2007076138A - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet head in which peeling and cracking are suppressed regardless of temperature environment.
SOLUTION: A plurality of flow path forming substrates 201 in which pressure generation chambers 203 are formed and a plurality of nozzle plates 208 each having a plurality of nozzles 207 for discharging liquid in the pressure generation chambers 203 by driving piezoelectric elements 212. A liquid ejecting head main body 200, a fixing plate 300 that is bonded to the nozzle plate 208 to fix the plurality of liquid ejecting head main bodies 200, and a head case 222 that covers the plurality of liquid ejecting head main bodies 200. Even if the liquid ejecting head main body 200 is configured by fixing the reinforcing member 500 that suppresses deformation of the main body 200 across the fixing plate 300 and the head case 222 and laminating and bonding members having different linear expansion coefficients. Suppresses peeling and cracking regardless of the environment.
[Selection] Figure 6

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that discharge liquid droplets from nozzles formed in a nozzle plate, and in particular, a part of a pressure generating chamber that communicates with the nozzle is configured by a diaphragm, The present invention relates to an ink jet recording head and an ink jet recording apparatus in which ink droplets are ejected from nozzles by displacement of a piezoelectric element provided on the head.

  Conventionally, a liquid ejecting head that ejects liquid droplets from a nozzle by applying pressure to the liquid by a piezoelectric element or a heat generating element is known, and a typical example thereof is ink jet recording that ejects ink droplets. Head. As such an ink jet recording head, for example, a nozzle plate (manufactured by SUS), a reservoir forming substrate, and a compliance forming substrate (sheet) are bonded to a flow path forming substrate mainly made of silicon (Si), and the head main body is It is configured. A plurality of head main bodies are bonded and fixed to a joining member (fixing plate), and a head case (manufactured by SUS) is bonded to the head main body (see, for example, Patent Document 1).

  In such a liquid jet head, a flow path forming substrate and a reservoir forming substrate mainly made of silicon (Si) are bonded to a head case mainly made of SUS via a sheet. Since the head case and nozzle plate are made of SUS and have a large coefficient of linear expansion compared to silicon (Si), the stress that peels from the outer periphery when placed in a lower temperature environment than the temperature during pressure bonding (room temperature) Will occur. For this reason, the present condition is that it is necessary to manage adhesion conditions etc. so that peeling and a crack may not arise between layers with weak adhesion.

JP 2005-96419 A

  The present invention has been made in view of the above situation, and even if a member of a material having a different linear expansion coefficient is laminated and bonded to form a head body, it is possible to prevent peeling and cracking regardless of the temperature environment. An object is to provide a liquid ejecting head.

  In addition, the present invention has been made in view of the above situation, and even if a member of a material having a different linear expansion coefficient is laminated and bonded to form a head body, it is possible to prevent peeling and cracking regardless of the temperature environment. An object of the present invention is to provide a liquid ejecting apparatus including the liquid ejecting head.

In order to achieve the above object, a first aspect of the present invention includes: a flow path forming substrate in which a pressure generating chamber is formed; and a plurality of nozzles that discharge liquid in the pressure generating chamber by driving the pressure generating element. A plurality of head bodies each provided with a nozzle plate, a joining member that is bonded to the nozzle plate and fixes the plurality of head bodies, and a cover that covers the plurality of head bodies, In the liquid ejecting head, a reinforcing member for suppressing deformation is fixed over the joining member and the cover.
In the first aspect, since the reinforcing member is fixed over the joining member and the cover, the reinforcing member receives the stress applied to the constituent members having different linear expansion coefficients of the head body which are laminated and bonded even if the temperature changes. It is possible to suppress peeling and cracking.

According to a second aspect of the present invention, in the liquid jet head according to the first aspect, the reinforcing member is made of silicon.
In the second aspect, a silicon reinforcing member can be used.

According to a third aspect of the present invention, in the second aspect, the nozzle plate forming a part of the head body and the nozzle plate formed on a surface opposite to the liquid ejection surface of the nozzle plate. A reservoir that is formed on a surface of the flow path forming substrate opposite to the surface on which the nozzle plate is formed and that constitutes a part of a reservoir that serves as a common ink chamber for each pressure generating chamber And a compliance substrate that is bonded on a surface of the protective substrate opposite to the surface to which the flow path forming substrate is bonded to absorb the pressure change in the reservoir. In the liquid ejecting head, the thickness dimension of the reinforcing member is larger than the thickness dimension of the laminated structure.
In the third aspect, sufficient rigidity can be ensured by using a silicon reinforcing member.

According to a fourth aspect of the present invention, in the liquid jet head according to the first aspect, the reinforcing member is made of zirconia.
In the fourth aspect, a highly rigid reinforcing member can be used.

According to a fifth aspect of the present invention, in the liquid jet head according to any one of the first to fourth aspects, the reinforcing member is disposed so as to surround the periphery of the head body.
In the fifth aspect, stress can be applied to the periphery of the head body.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the joining member covers the plurality of head bodies and is fixed to a cartridge case to which a liquid supply unit is respectively attached. The liquid ejecting head is a cover head.
In the sixth aspect, the cover head can be used to receive stress.

According to a seventh aspect of the present invention, in the liquid ejecting head according to any one of the first to fifth aspects, the joining member is a fixing plate that positions the plurality of head bodies relative to each other. is there.
In the seventh aspect, the fixing plate can be used to receive stress.
As a preferred mode, by providing positioning protrusions or the like on the reinforcing member, it is possible to position and hold a plurality of head bodies.

According to an eighth aspect of the present invention for achieving the above object, there is provided a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to seventh aspects.
According to an eighth aspect, there is provided a liquid jet head capable of receiving stress on a structural member having a different linear expansion coefficient that is laminated and bonded to the head body by a reinforcing member even when a temperature change occurs, and capable of suppressing peeling and cracking. The liquid ejecting apparatus can be provided.

  The liquid ejecting head of the present invention is a liquid ejecting head in which peeling and cracking are suppressed regardless of the temperature environment even when the members of the materials having different linear expansion coefficients are laminated and bonded to form the head main body. be able to.

  In addition, the liquid ejecting apparatus of the present invention is a liquid ejecting head in which peeling and cracking are suppressed regardless of the temperature environment even when members of materials having different linear expansion coefficients are laminated and bonded to form a head body. It can be set as the liquid ejecting apparatus provided with.

  FIG. 1 is an exploded perspective view of an ink jet recording head as a liquid ejecting head according to an embodiment of the present invention, and FIG. 2 is an ink jet recording head as a liquid ejecting head according to an embodiment of the present invention. 3 is an assembled perspective view, FIG. 3 is a cross-sectional view of the main part of an ink jet recording head as a liquid jet head according to an embodiment of the present invention, FIG. 4 is an exploded perspective view of the ink jet recording head main body, and FIG. FIG. 6 is a cross-sectional view of the main part of the recording head main body, FIG. 7 is a plan view of the reinforcing member, FIG. 8 is an external view of the reinforcing member, and FIG. FIG. 10 shows the appearance of the reinforcing member applied in FIG. 9, and FIG. 11 shows the main part of the recording head main body when the reinforcing member according to another embodiment is applied. Show the cross section That. Further, FIG. 12 shows a schematic state of a recording apparatus as a liquid ejecting apparatus.

The configuration of the ink jet recording head will be described with reference to FIGS.
The illustrated ink jet recording head 1 (liquid ejecting head: hereinafter referred to as a recording head) includes a cartridge case 100, an ink jet recording head main body 200 (hereinafter referred to as a recording head main body), a fixing plate 300 as a joining member, And a cover head 400. The cartridge case 100 includes a cartridge mounting portion 101 to which an ink cartridge (not shown) that is an ink supply means (liquid supply means) is mounted. The bottom surface of the cartridge case 100 is provided with a plurality of ink communication paths 102 having one end opened to each cartridge mounting portion 101 and the other end opened to the recording head main body 200 side. Further, an ink supply needle 103 to be inserted into the ink cartridge is fixed to the opening portion of the ink communication path 102 of the cartridge mounting portion 101.

  A plurality of (four in the illustrated example) recording head main bodies 200 (recording head units) positioned at predetermined intervals are fixed to the bottom surface side of the cartridge case 100. The four recording head main bodies 200 of the recording head unit are provided corresponding to the inks of the respective colors, and the four recording head main bodies 200 are positioned relative to each other by being bonded and fixed to a fixing plate 300. The recording head unit is provided on the bottom side of the cartridge case 100 in such a positioned state.

The configuration of the recording head main body 200 will be described with reference to FIGS.
As shown in the figure, the flow path forming substrate 201 constituting the recording head main body 200 is made of, for example, a silicon single crystal substrate, and an elastic film 202 made of silicon dioxide previously formed by thermal oxidation is formed on one surface thereof. ing. A plurality of pressure generation chambers 203 are formed in the flow path forming substrate 201, and the pressure generation chambers 203 are formed by anisotropic etching from the other surface side. For example, the flow path forming substrate 201 has two rows in which the pressure generation chambers 203 are arranged in the width direction. In addition, a communication portion 205 constituting the reservoir 204 is formed on the outer side in the longitudinal direction of the pressure generation chamber 203 in each row. The communication portion 205 communicates with a reservoir portion provided on a protective substrate, which will be described later. This is a common ink chamber for the chamber 203. The communication unit 205 is in communication with one end in the longitudinal direction of each pressure generation chamber 203 via the ink supply path 206.

  Further, a nozzle plate 208 having a nozzle 207 drilled is fixed to the opening surface side of the flow path forming substrate 201 with an adhesive, a heat welding film, or the like. The nozzle plate 208 is made of, for example, a conductive material such as a metal material (for example, stainless steel: SUS).

  On the other hand, a piezoelectric element 212, which is an example of a pressure generating element that discharges ink in the pressure generating chamber 203, is formed on the elastic film 202 formed on the surface of the flow path forming substrate 201. The piezoelectric element 212 includes, for example, a lower electrode film (not shown) made of a metal material such as platinum or iridium, a piezoelectric layer (not shown) made of lead zirconate titanate (PZT), for example, and iridium, for example. An upper electrode film (not shown) made of a metal material such as

  Further, on the flow path forming substrate 201 on which such a piezoelectric element 212 is formed, a protective substrate having a piezoelectric element holding portion 213 capable of securing a space that does not hinder its movement in a region facing the piezoelectric element 212. 214 is joined. Further, as described above, the protective substrate 214 is formed with a reservoir portion 215 that constitutes a reservoir 204 that communicates with the communication portion 205 of the flow path forming substrate 201 and serves as a common ink chamber for the pressure generating chambers 203. Yes.

A driving IC 216 for driving each piezoelectric element 212 is mounted on the protective substrate 214. Each terminal of the drive IC 216 is connected to a lead electrode drawn from the individual electrode of each piezoelectric element 212 via a bonding wire or the like, although not shown. Then, an external wiring 217 such as a flexible printed cable (FPC) as shown in FIG. 1 is connected to each terminal of the driving IC 216, and various signals such as a print signal are supplied through the external wiring 217. It has become.

  A compliance substrate 218 is bonded to a region corresponding to the reservoir 204 on the protective substrate 214. The compliance substrate 218 is provided with a flexible portion 219 having a smaller thickness than other regions in a region corresponding to the reservoir 204, and a pressure change in the reservoir 204 deforms the flexible portion 219. It has come to be absorbed. Further, the compliance substrate 218 is formed with an ink introduction port 220 communicating with the reservoir 204.

  A head case 222 provided with an ink supply communication path 221 that communicates with the ink introduction port 220 and communicates with the ink communication path 102 of the cartridge case 100 is joined to the compliance substrate 218. Ink is supplied into the reservoir 204 through the ink communication path 102, the ink supply communication path 221, and the ink introduction port 220. The head case 222 is provided with a drive IC holding part 223 that penetrates in the thickness direction in a region facing the drive IC 216. Although not shown, each drive IC 216 is placed in the drive IC holding part 223. Potting agent is filled so as to cover.

  The recording head main body 200 fills the interior from the reservoir 204 to the nozzle 207 with ink, and then applies a voltage to each piezoelectric element 212 corresponding to the pressure generating chamber 203 in accordance with a recording signal from the driving IC 216 to The ink droplets are ejected from the nozzles 207 by applying a pressure to the ink in each pressure generating chamber 203 by bending and deforming the 202 and the piezoelectric element 212.

  As shown in FIG. 6, the recording head main body 200 is bonded and fixed to the fixing plate 300 while being positioned with a predetermined interval. Since the fixed plate 300 is made of a flat plate having no large ribs, the four recording head bodies 200 can be easily assembled. The fixing plate 300 is provided with an exposure opening 301 as an opening for exposing the nozzle 207 corresponding to each recording head main body 200, and the fixing plate 300 is bonded to the peripheral portion of the nozzle plate 208 constituting each recording head main body 200. It is joined through the agent.

  On the other hand, as shown in FIGS. 6 to 8, a reinforcing member 500 made of silicon is attached to the fixing plate 300 and the head case 222. The reinforcing member 500 includes a box-shaped portion 501 arranged in a state surrounded by a gap around one recording head main body 200, and has a shape in which the box-shaped portions 501 are continuously provided. The reinforcing member 500 is formed by, for example, etching. As shown in FIG. 6, the dimension L1 in the thickness direction of the reinforcing member 500 is set to be larger than the laminated thickness dimension L2 of the nozzle plate 208, the protective substrate 214, and the compliance substrate 218.

  Since the reinforcing member 500 is bonded and fixed across the fixing plate 300 and the head case 222 of the recording head main body 200, the stress can be suppressed even if peeling stress acts on the nozzle plate 208, the protective substrate 214, and the compliance substrate 218. it can. That is, it peels off from the outer peripheral portion when placed in a lower temperature environment than the temperature (normal temperature) at the time of pressure bonding of the nozzle plate 208, the protective substrate 214 and the compliance substrate 218, which has a large linear expansion coefficient with respect to silicon (Si). Even if a stress occurs, the reinforcing member 500 can suppress the stress.

  The dimension L1 in the thickness direction of the reinforcing member 500 is larger than the thickness dimension L2 of the laminated structure of the nozzle plate 208, the flow path forming substrate 201, the protective substrate 214, and the compliance substrate 218 constituting a part of the head body 200. Since the dimensions are set, even the silicon reinforcing member 500 can sufficiently suppress the peeling stress.

  Accordingly, it is possible to prevent delamination of the nozzle plate 208, the protective substrate 214, and the compliance substrate 218 regardless of the temperature environment, and it is possible to prevent the occurrence of cracks at corners and the like.

  In addition, after positioning protrusions are provided on the reinforcing member 500 and the reinforcing member 500 is disposed at a predetermined position with respect to the fixing plate 300 or the like, the positioning of the head body with respect to the fixing plate 300 is performed using the positioning protrusions or the like. It is also possible to do so.

An example of another shape of the reinforcing member will be described based on FIGS. 9 and 10.
In the illustrated reinforcing member 600, H-shaped steel members each having a long plate portion 601 continuous in the longitudinal direction of the recording head main body 200 and a short plate portion 602 intermittent in the width direction are continuously arranged. . The reinforcing member 600 is also made of silicon, and the dimension in the thickness direction is set to be larger than the laminated thickness dimension L2 of the nozzle plate 208, the protective substrate 214, and the compliance substrate 218. For this reason, even if peeling stress acts on the nozzle plate 208, the protective substrate 214, and the compliance substrate 218, the peeling stress can be sufficiently suppressed.

  Therefore, by using the reinforcing members 500 and 600, the liquid in which peeling or cracking is suppressed regardless of the temperature environment even when the head body is configured by laminating and bonding members of materials having different linear expansion coefficients. An ejection head can be obtained.

A recording head body to which a reinforcing member according to another embodiment is applied will be described with reference to FIG.
The basic configuration of the illustrated recording head main body is the same as that shown in FIG. The reinforcing member 700 provided in the recording head main body shown in FIG. 11 is formed of zirconia (ZrO ₂ ), and the dimension L1 in the thickness direction is the laminated thickness of the nozzle plate 208, the protective substrate 214, and the compliance substrate 218. It is set to the same dimension as the dimension L2. Since zirconia (ZrO ₂ ) has high hardness and excellent toughness, even if the dimension L1 in the thickness direction is set to be the same as the laminated thickness dimension L2 of the nozzle plate 208, the protective substrate 214 and the compliance substrate 218, the peeling stress Can be suppressed. For this reason, it is possible to obtain a liquid jet head in which peeling and cracking are suppressed without increasing the size of the reinforcing member 700.

  The recording head main body 200 provided with the reinforcing member 500 or the reinforcing member 600 or the reinforcing member 700 described above is fixed to a fixed plate 300, and a cover is provided around the four recording head main bodies 200 fixed to the fixed plate 300. A head 400 is provided, and the four recording head bodies 200 are protected from ink or the like by the cover head 400. The cover head 400 has an opening 401 corresponding to the exposed opening 301 of the fixed plate 300.

  Note that the shape of the reinforcing member is not limited to the shape of the illustrated example described above, and L-shaped ones are arranged alternately and continuously so as to surround the recording head main body 200. It is possible to apply things.

  As shown in FIGS. 1 to 3, the cover head 400 has a flange portion 402 at an end portion, and the flange portion 402 is provided with a through hole 403. A protrusion 104 is provided on the surface of the cartridge case 100 on the recording head main body 200 side. The through hole 403 of the cover head 400 is fitted into the protrusion 104 and the tip of the protrusion 104 is heated and caulked to cover the cartridge case 100. The head 400 is fixed to the cartridge case 100.

  The material of the cover head 400 is not particularly limited, and a conductive material such as a metal material may be used, for example, similarly to the nozzle plate 208 and the like. When the cover head 400 is formed using a conductive material, the fixing plate 300 and the cover head 400 can be electrically connected and the cover head 400 can be grounded. Further, in the case of such a configuration, it is desirable to bond the cover head 400 and the fixing plate 300 with an adhesive, similarly to the bonding between the nozzle plate 208 and the fixing plate 300.

  In addition, it is also possible to apply the cover head 400 without using the fixing plate 300 as a joining member, and fix the reinforcing member 500 or the reinforcing member 600 or the reinforcing member 700 across the cover head 400 and the head case 222. . In this case, the peeling stress is suppressed between the cover head 400 and the head case 222, and the recording head main body 200 is protected from ink or the like. In this case, since the distance between each nozzle 207 of the nozzle plate 208 and the recording medium can be shortened, the flying distance of the ink droplets can be shortened and the ink droplets can be surely made to fly to the recording medium, thereby improving the print quality. be able to.

The recording head 1 described above is mounted on an ink jet recording apparatus as a liquid ejecting apparatus. The outline of the ink jet recording apparatus will be described with reference to FIG.
As shown in the figure, the recording heads 1A and 1B having the recording head main body are detachably provided with cartridges 2A and 2B constituting ink supply means, and the recording heads 1A and 1B are mounted on the carriage 3. A carriage shaft 5 is attached to the apparatus main body 4, and a carriage 3 on which the recording heads 1A and 1B are mounted is provided on the carriage shaft 5 so as to be movable in the axial direction. The driving force of the drive motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, and the carriage 3 on which the recording head 1 is mounted is moved along the carriage shaft 5. On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8.

  In the above-described embodiment, the flexural vibration type piezoelectric element is exemplified as the pressure generating element that applies pressure to the liquid in the pressure generating chamber 203. However, the pressure generating element is not particularly limited. It may be a longitudinal vibration type piezoelectric element in which electrode layers and electrode forming materials are alternately laminated to expand and contract in the axial direction, or a heating element or the like.

  In the above-described embodiment, the ink jet recording head that discharges ink droplets is described as an example of the liquid ejecting head. However, the present invention can be widely applied to all liquid ejecting heads. For example, as a liquid ejecting head, for forming a recording head used in an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an FED (surface emitting display). An electrode material ejecting head used, a bioorganic matter ejecting head used for biochip production, or the like can be applied.

2 is an exploded perspective view of an ink jet recording head. FIG. FIG. 2 is an assembled perspective view of an ink jet recording head. It is principal part sectional drawing of an inkjet recording head. 2 is an exploded perspective view of an ink jet recording head main body. FIG. FIG. 3 is a cross-sectional view of a recording head body. FIG. 3 is a cross-sectional view illustrating a main part of a recording head main body. It is a top view of a reinforcing member. It is an external view of a reinforcing member. It is a top view of a head body at the time of applying a reinforcing member of another shape. It is an external view of a reinforcing member. FIG. 3 is a cross-sectional view illustrating a main part of a recording head main body. It is the schematic of a recording device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head, 100 Cartridge case, 200 Recording head main body, 300 Fixing plate, 301 Opening, 400 Cover head, 500, 600, 700 Reinforcing member

Claims (8)

A plurality of head bodies each including a flow path forming substrate in which a pressure generating chamber is formed, a nozzle plate in which a plurality of nozzles for discharging liquid in the pressure generating chamber are formed by driving the pressure generating element, and the nozzle plate A bonding member that is bonded to and fixes the plurality of head bodies, and a cover that covers the plurality of head bodies,
A liquid ejecting head, wherein a reinforcing member for suppressing deformation of the head main body due to heat is fixed across the joining member and the cover. In claim 1,
The liquid ejecting head according to claim 1, wherein the reinforcing member is made of silicon. In claim 2,
The nozzle plate constituting a part of the head body;
The flow path forming substrate formed on the surface opposite to the liquid discharge surface of the nozzle plate;
Protection formed on a surface of the flow path forming substrate opposite to the surface on which the nozzle plate is formed, and forming a reservoir portion that constitutes a part of a reservoir serving as a common ink chamber for each pressure generating chamber A substrate,
The reinforcing substrate is bonded to the surface opposite to the surface to which the flow path forming substrate is bonded, and the compliance substrate absorbs the pressure change in the reservoir, so that the reinforcement is more than the thickness dimension of the laminated structure. A liquid ejecting head having a large thickness dimension of a member. In claim 1,
The liquid ejecting head according to claim 1, wherein the reinforcing member is made of zirconia. In any one of Claims 1-4,
The liquid ejecting head according to claim 1, wherein the reinforcing member is disposed so as to surround a periphery of the head main body. In any one of Claims 1-5,
The liquid ejecting head according to claim 1, wherein the joining member is a cover head that covers the plurality of head main bodies and is fixed to a cartridge case to which a liquid supply unit is mounted. In any one of Claims 1-5,
The liquid ejecting head according to claim 1, wherein the joining member is a fixing plate that positions the plurality of head bodies relative to each other. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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