JP2005119033A - Liquid ejector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejecting apparatus using a valve unit having high airtightness and excellent pressure resistance without peeling of members.
SOLUTION: A first film member 39 forming a liquid supply chamber 40 is composed of a film having a three-layer structure including a first protective film layer, a first intermediate layer, and a first inner layer from the outside. The second film member 47 forming the pressure chamber 48 is composed of a film having a three-layer structure including a second protective film layer, a second intermediate layer, and a second inner layer from the outside. The first and second inner layers of the first and second film members 39 and 47 are made of the same material polypropylene so that the coefficient of thermal expansion of the unit case 31 is the same. The first and second inner layers are thermocompression bonded to the unit case 31 to form the liquid supply chamber 40 and the pressure chamber 48, respectively.
[Selection] Figure 7

Description

  The present invention relates to a liquid ejecting apparatus using a valve unit having high airtightness and excellent pressure resistance.

  As a liquid ejecting apparatus, an ink jet printer that performs printing by ejecting ink from nozzles is known. This type of printer includes means for moving the recording paper in the sub-scanning direction, a carriage that reciprocates in the main scanning direction, and a recording head that is mounted on the carriage and ejects ink from the nozzles toward the recording paper. Then, while reciprocating the carriage, ink is ejected from the nozzles of the recording head to print on the recording paper.

  By the way, since this type of printer used for business use consumes a large amount of ink, an ink cartridge storing a large amount of ink is required. When the ink cartridge storing a large amount of ink is mounted on the carriage, the carriage becomes heavy and an excessive load is applied to the carriage motor. For this reason, an off-carriage printer in which an ink cartridge is disposed at a location away from the carriage is known. In an off-carriage printer, an ink cartridge and a recording head mounted on the carriage are connected by a flexible supply tube, and ink is supplied from the ink cartridge to the recording head via the supply tube.

  Also, the ink used in the recording head needs to be shielded from the outside air due to its nature. Examples of the member that comes into contact with ink include a recording head, an ink supply tube that serves as an ink flow path, and a valve unit. These members are required to have gas barrier properties, have no chemical effect on ink properties, and have low moisture permeability. However, it is difficult to form a member that satisfies these requirements with a single member. For example, when the ink supply tube is formed of a resin material having excellent flexibility, the moisture permeability and the nitrogen permeability are high, so that it is not suitable as a member for containing ink. On the contrary, if the moisture permeability and nitrogen permeability are lowered, the rigidity is excellent, but flexibility cannot be expected. Thus, some ink supply tubes are composed of a plurality of members in order to satisfy these requirements (for example, see Patent Document 1). In this tube, the inner surface portion that comes into contact with ink is formed of a resin material, and the outer surface of the resin material is formed of a metal thin film in order to enhance gas barrier properties. Furthermore, in order to improve the corrosion resistance of the metal thin film, the outer surface of the metal thin film is covered with a resin material.

On the other hand, in the valve unit, as the amount of ink in the pressure chamber formed in the valve unit decreases, the member forming the pressure chamber is displaced, and this displacement presses and releases the movable valve to release the pressure chamber from the liquid supply chamber. Ink supply and non-supply to the printer are switched. For this reason, the member forming a part of the pressure chamber is soft so that the negative pressure state can be sensed efficiently, has no chemical effect on the ink properties, and further has a water permeability. The material is required to be low and excellent in gas barrier properties.
Japanese Patent Laid-Open No. 10-250096

By the way, although the member comprised as mentioned above can satisfy a certain amount of requirements (flexibility, gas barrier property), when used for a member constituting a part of the pressure chamber, If it is under severe conditions, problems will occur. Here, a member having a resin material is thermocompression bonded to the side surface of the pressure chamber and the side surface of the liquid supply chamber forming the valve unit. If an appropriate material is not selected, the pressure applied to the pressure chamber and the liquid supply chamber causes the surface of the resin material corresponding to the side surface of the pressure chamber and the side surface of the liquid supply chamber to peel off or from a plurality of resin materials. There may be a case where the configured members are separated. This is due to the difference in coefficient of thermal expansion between the members constituting the pressure chamber and the liquid supply chamber and the resin material of the unit case. If the thermal expansion coefficient of the resin material that constitutes the member is the same, it is considered that peeling will not occur, but in practice, a material that satisfies the requirements and has the same thermal expansion coefficient should be specified. It is difficult.

  The present invention has been made paying attention to the technical problem described above, and is to provide a liquid ejecting apparatus using a valve unit having high airtightness and excellent pressure resistance without peeling off members. .

  The liquid ejecting apparatus of the present invention includes a liquid supply chamber and a pressure chamber formed by thermocompression bonding of a film member to a unit case to close a recess provided in the unit case, and a space between the liquid supply chamber and the pressure chamber. The liquid supplied from the liquid container to the liquid supply chamber is introduced into the pressure chamber by operating the open / close valve based on the state of the pressure chamber. In the liquid ejecting apparatus including the valve unit that supplies the liquid introduced to the liquid ejecting head, the film member is formed of a material having the same thermal expansion coefficient as that of the unit case.

  According to this invention, since the film member and the unit case have the same coefficient of thermal expansion, when the film member is thermocompression bonded to the unit case, the film member and the unit case expand and contract at the same coefficient of thermal expansion. Therefore, no extreme stress is applied to one member after thermocompression bonding. Accordingly, the film member has an adhesive structure that is very difficult to peel off from the unit case.

In this liquid ejecting apparatus, the film member is formed of the same material as the unit case.
According to this invention, since the film member and the unit case are made of the same material, the coefficient of thermal expansion is the same. Therefore, when the film member is bonded to the unit case by thermocompression bonding, the film member and the unit case have the same coefficient of thermal expansion. Since it expands and contracts, extreme stress is not applied to one member after thermocompression bonding. Accordingly, the film member has an adhesive structure that is very difficult to peel off from the unit case.

  In this liquid ejecting apparatus, the film member has a multilayer structure having at least a protective film layer, an intermediate layer, and an inner layer that is thermocompression bonded to the unit case, and the inner layer has the same thermal expansion coefficient as the unit case. Formed of the material.

According to this invention, the film member can make use of each feature in each layer, and the degree of freedom of design is widened compared to a member formed from a single material.
In the liquid ejecting apparatus, the unit case is polypropylene.

  According to this invention, since it is the polypropylene excellent in workability, manufacture is easy. Moreover, since it is excellent in chemical resistance, the liquid can be stored without affecting the liquid. Furthermore, since the polypropylene is lighter than the metal material, the pressure chamber and the liquid supply chamber can be formed without increasing the valve unit.

In this liquid ejecting apparatus, the film member forming the liquid supply chamber includes a protective film layer formed of polyethylene terephthalate, an intermediate layer formed of aluminum foil, and an inner layer formed of polypropylene. .

  According to this invention, since the protective film layer is formed of polyethylene terephthalate, the intermediate layer and the inner layer are protected. In addition, since the intermediate layer is formed of an aluminum foil having excellent gas barrier properties and zero moisture permeability, the airtightness in the liquid supply chamber is improved. Moreover, since aluminum foil is excellent in rigidity, the strength of the liquid supply chamber can be improved.

  In this liquid ejecting apparatus, the film member forming the pressure chamber includes a protective film layer formed of polyethylene terephthalate, an intermediate layer formed of a silica vapor deposition film or an alumina vapor deposition film, and an inner layer formed of polypropylene. Consists of

  According to this invention, since the protective film layer is formed of polyethylene terephthalate, the intermediate layer and the inner layer can be protected. In addition, since the intermediate layer is formed of an alumina vapor deposition film or a silica vapor deposition film having excellent gas barrier properties and low moisture permeability, the hermeticity in the pressure chamber is improved. Since the inner layer is formed of polypropylene having excellent flexibility, it is easy to sense a pressure change in the pressure chamber.

In this liquid ejecting apparatus, the inner layer of the film member made of polypropylene has a thickness of 20 microns or more.
According to this invention, since the inner layer has a thickness of 20 microns or more, it can be easily processed by thermocompression bonding.

In this liquid ejecting apparatus, the protective film layer made of polyethylene terephthalate has a thickness of 6 microns or more.
According to the present invention, since the polyethylene terephthalate forming the protective film layer has a thickness of 6 microns or more, the intermediate layer and the inner layer can be protected.

In this liquid ejecting apparatus, the intermediate layer made of the aluminum foil has a thickness of 5 microns or more.
According to the present invention, since the aluminum foil forming the intermediate layer has a thickness of 5 microns or more, pinholes that are likely to occur during the formation of the aluminum foil can be almost eliminated, and the moisture permeability can be lowered.

  Hereinafter, an ink jet printer that embodies the liquid ejecting apparatus according to the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic plan view of a main part of an ink jet printer according to the present embodiment.

  As shown in FIG. 1, an ink jet printer 11 (hereinafter simply referred to as a printer) serving as a liquid ejecting apparatus includes a substantially rectangular parallelepiped frame 12 having an upper opening in a substantially rectangular case (not shown). It is installed.

  The frame 12 is provided with a platen 13, a guide shaft 14, a carriage 15, a recording head 16 as a liquid ejecting head, a valve unit 17, an ink cartridge 18 as a liquid container, and a pressure pump 19. In the present embodiment, the longitudinal direction of the printer 11 is referred to as a main scanning direction. A direction orthogonal to the main scanning direction is referred to as a sub-scanning direction.

A platen 13 is disposed on the frame 12 along the main scanning direction. Platen 13
Supports a recording medium fed through a paper feeding means (not shown). The recording medium is conveyed in the sub-scanning direction by the paper feeding means and is guided to the upper surface of the platen 13.

  The frame 12 supports a driving pulley 20 and a driven pulley 21. A carriage motor 22, which is a reversible motor supported by the frame 12, is drivingly connected to the driving pulley 20. A timing belt 23 is hooked on the driving pulley 20 and the driven pulley 21, and the carriage 15 is fixed to the timing belt 23.

  The guide shaft 14 is formed in a rod shape, is laid on the frame 12 in a direction parallel to the platen 13, that is, in the main scanning direction, and supports the carriage 15 so as to be reciprocally movable in the main scanning direction. The carriage 15 is drivably coupled to the carriage motor 22 via the timing belt 23, and the carriage 15 is driven via the timing belt 23 to reciprocate along the guide shaft 14, that is, in the main scanning direction.

  The carriage 15 includes four ink supply valve units 17B, 17C, 17M, and 17Y corresponding to ink colors (black, cyan, magenta, and yellow) for supplying ink as a liquid to the recording head 16. It is installed. In the following description, the four ink supply valve units 17 may be represented simply as “valve units 17”.

  The flexible ink supply tubes 25 constituting the ink supply path are connected to the valve unit 17 from the corresponding ink cartridges 18 mounted on the cartridge holder 24 arranged on the right side of the frame 12. Each color ink is supplied via each. The valve unit 17 supplies the temporarily stored ink to the recording head 16 with the pressure adjusted. Details of the valve unit 17 will be described later.

  The recording head 16 is provided at a position facing the platen 13 of the carriage 15 and includes a plurality of nozzles (not shown) for ejecting ink toward the platen 13 side. The recording head 16 includes a filter, an ink supply pipe, a piezoelectric vibrator, and a flow path unit (not shown). The recording head 16 causes the ink supplied from the valve unit 17 to be ejected as ink droplets from the nozzles by expanding and contracting the pressure chambers by the piezoelectric vibrator.

  A capping unit 26 is provided in a non-printing area below the recording head 16 and on the left side of the cartridge holder 24. The capping means 26 is formed in a bottomed shape, and an upper opening thereof capping the recording head 16. The capping unit 26 prevents the ink from evaporating by sealing the nozzles of the recording head 16 during non-recording.

  Further, the bottom portion of the capping means 26 is communicated with a suction tube (not shown), and a suction pump is disposed in the middle of the suction tube. Then, by driving the suction pump with the capping unit 26 sealing the nozzles of the recording head 16, a so-called cleaning operation is performed in which ink is forcibly sucked from the recording head 16 to the capping unit 26 side. It has become. Then, the ink sucked by the suction pump is collected in the waste liquid collection box.

On the other hand, a wiping member 27 in which an elastic material such as rubber is formed in a strip shape is disposed adjacent to the printing area side of the capping means 26, and the wiping member 27 is placed horizontally on the moving path of the recording head 16 as necessary. The nozzle is advanced so that the nozzle forming surface can be wiped and cleaned.

  The pressurizing pump 19 is fixed to the frame 12 at a position above the ink cartridge 18. As shown in FIG. 2, the pressure pump 19 is connected to the ink cartridge 18 via an air supply tube 28 that constitutes an air flow path, and sucks the atmosphere to supply the pressurized air into the ink cartridge 18. Is done. An ink pack 29 is accommodated in the ink cartridge 18, and the ink pack 29 communicates with the ink supply valve unit 17 via an ink supply tube 25.

  The ink pack 29 is formed of a material having flexibility and gas barrier properties, and is formed of, for example, an aluminum laminate film in which an outer layer is sandwiched between a nylon film and an inner layer is sandwiched between polyethylene films. The ink in the ink pack 29 is sealed in a deaerated state.

  The ink supply tube 25 is formed with a double structure in which, for example, an inner layer made of a flexible member such as polyethylene resin having excellent chemical resistance is covered with vinyl chloride, a metal film, etc. having excellent hermetic barrier properties as an outer layer. ing.

  Therefore, when pressurized air is supplied from the pressurizing pump 19 into the ink cartridge 18, the ink pack 29 is elastically deformed by a pressure difference between the inside and outside of the ink pack 29. That is, the ink pack 29 is crushed by the pressurized air, and each ink stored in the ink pack 29 is supplied to the valve unit 17 via the ink supply tube 25.

Next, the valve unit 17 will be described with reference to FIGS.
3 and 4 are perspective views of the recording head 16 and the valve unit 17, and FIGS. 5 and 6 are side views of the valve unit 17. 7 is a cross-sectional view of the valve unit 17, and FIGS. 8 to 10 are enlarged cross-sectional views of the main part of the valve unit 17. FIG. 3 and 4, for convenience of explanation, only two valve units 17 are mounted on the top of the recording head 16, and the remaining two are omitted. .

  As shown in FIGS. 3 and 4, the valve unit 17 includes a unit case 31 formed of a resin material in a substantially circular flat shape, and the ink supply tube 25 is connected to a connection portion 32 formed at one end thereof. It is connected. Further, as shown in FIG. 3, an ink outlet 33 is formed at the other end. The ink outlet 33 is connected to the recording head 16 via an annular connecting member 34 and a plate-like head support 35. It is connected to the.

  The unit case 31 is lightweight because it is mounted on the carriage 15 to be driven, and the unit case 31 is made of a material having excellent workability and mechanical characteristics since complicated processing is formed. Required. Furthermore, it is important that the ink properties are not affected chemically because the ink is contained, and that the material has a low water permeability and gas permeability. Therefore, in this embodiment, the unit case 31 is formed of polypropylene that is excellent in lightness, mechanical properties, workability, and chemical resistance.

As shown in FIGS. 3, 5 and 7, a substantially cylindrical first recess 36 is formed on one side surface 31 a of the unit case 31. Further, as shown in FIGS. 3 and 5, a groove 37 is formed on one side surface 31 a so as to draw a “<” shape from the first recess 36 toward the connecting portion 32. The end of the groove 37 communicates with a hole 38 formed in the connecting portion 32. Further, a flexible film-like first film member 39 is attached to the one side surface 31a by thermocompression bonding so as to close the first recess 36 and the groove 37. The first recess 36 and the first film member 39 form a substantially cylindrical liquid supply chamber 40, and the groove 37 and the first film member 39 form an ink introduction path 41. . Accordingly, the ink flowing from the ink supply tube 25 flows into the liquid supply chamber 40 via the hole 38 of the connection portion 32 and the ink introduction path 41.

  The first film member 39 has a pressure resistance that can withstand the pressure applied to the ink stored in the liquid supply chamber 40, has no chemical effect on the ink properties, and further has a moisture permeability and gas permeability. It is important that the material is low. Therefore, as shown in FIG. 8, the first film member 39 is composed of a film having a three-layer structure. The first film member 39 includes a first protective film layer S1, a first intermediate layer S2, and a first inner layer S3 in order from the outside.

  The first protective film layer S1 has a light weight and is a resin material that protects the first intermediate layer S2 and the first inner layer S3, and is formed of polyethylene terephthalate in the present embodiment. The thickness of the first protective film layer S1 is 6 microns or more, which is a thickness that can protect the first intermediate layer S2 and the first inner layer S3.

  The first intermediate layer S2 is desirably a material that is light in weight, low in gas permeability and moisture permeability, and can ensure a certain level of rigidity. Here, an amorphous alloy that easily forms a thin film and secures a gas barrier property can be used, but it is preferable to use an aluminum foil of a metal material for the first intermediate layer S2 in consideration of manufacturing cost. In addition, as the aluminum foil is formed thinner, pin-all is more likely to occur. Therefore, the thickness of the first intermediate layer S2 is 5 microns or more that can eliminate almost all pinholes that are likely to occur when forming the aluminum foil.

  It is important that the first inner layer S3 does not have a chemical effect on the ink properties because it touches the ink, and that the first inner layer S3 has high adhesion to the unit case 31 to withstand the pressure applied to the ink. In order to increase the adhesiveness to the unit case 31 (hard to peel off), it is only necessary that the thermal expansion coefficient of the resin material forming the unit case 31 is the same. Therefore, the first inner layer S3 is made of polypropylene which is the same material as the unit case 31 made of polypropylene. Further, the thickness of the first inner layer S3 is not too thin and is not less than 20 microns because of the ease of processing by thermocompression bonding. The first film member 39 composed of these layers S1, S2 and S3 is preliminarily thermocompression bonded with the contact surface of each layer through an adhesive. After the first film member 39 is formed, the first inner layer S3 is thermocompression bonded to the unit case 31 with the side surface 31a of the unit case 31 corresponding to one side 31a.

  Further, as shown in FIGS. 5 and 7, a spring seat 42 having an outer diameter slightly smaller than the inner diameter of the liquid supply chamber 40 is provided on the surface of the first film member 39 on the liquid supply chamber 40 side. The liquid supply chamber 40 is attached so as to be concentric. The spring seat 42 is provided with an annular step 43 on the surface opposite to the first film member 39. The spring seat 42 may be attached to the first film member 39 by thermocompression bonding, or may be attached by an adhesive or a double-sided adhesive tape.

  Further, as shown in FIGS. 6 and 7, a second recess 44 having a substantially truncated cone shape is formed on the other side surface 31 b of the unit case 31. The second recess 44 is provided so as to be positioned concentrically while having a larger diameter than the first recess 36.

Further, a groove 45 is formed on the other side surface 31 b of the unit case 31 from the end of the second recess 44 toward the ink outlet 33, and the end of the groove 45 is the ink outlet 33. Communicating with a hole 46 formed in the. Furthermore, a flexible film-like second film member 47 is attached to the other side surface 31b by thermocompression bonding so as to close the second recess 44 and the groove 45. A pressure chamber 48 having a substantially truncated cone shape is formed by the second recess 44 and the second film member 47, and an ink outlet path 49 is formed by the groove 45 and the second film member 47. Yes. Therefore, the ink described later in the pressure chamber 48 is discharged to the recording head 16 through the ink outlet passage 49 and the hole 46 of the ink outlet portion 33.

  The second film member 47 is soft so that the negative pressure state of the pressure chamber 48 can be sensed efficiently, has no chemical effect on the ink properties, and further has moisture permeability and gas permeability. It is important that the material is low-grade. Therefore, as shown in FIG. 9, the second film member 47 has a three-layer structure. The second film member 47 includes a second protective film layer S4, a second intermediate layer S5, and a second inner layer S6 in order from the outside.

  The second protective film layer S4 is light in weight, can deposit the second intermediate layer S5, and is desirably a material that protects the second intermediate layer S5 and the second inner layer S6. It is. Therefore, the second protective film layer S4 is formed of polyethylene terephthalate in the present embodiment. The thickness of the second protective film layer S4 is 6 microns or more, which is a thickness that can protect the second intermediate layer S5 and the second inner layer S6.

  The second intermediate layer S5 is light in weight, and is desirably bonded to the second inner layer S6 with an adhesive and is a material having low gas permeability and moisture permeability. Therefore, in the present embodiment, the second intermediate layer S5 is formed on the second protective film layer S4 as an alumina vapor deposition film. The thickness of the second intermediate layer S5 is about 500 angstroms.

  The second inner layer S6 is soft so that a negative pressure state can be sensed efficiently, has no chemical effect on the ink properties, and has an adhesive property with the unit case 31 to withstand the pressure applied to the ink. It is important to be high (hard to peel off). Therefore, the second inner layer S6 is made of polypropylene, which is the same material as the unit case 31 made of polypropylene. Further, the thickness of the second inner layer S6 is set to 20 microns or more without being too thin because it is easy to detect a pressure change in the pressure chamber 48 and is easily processed by thermocompression bonding. The second film member 47 composed of each of these layers S4, S5 and S6 is bonded to the second inner layer S6 in advance with the second protective film layer S4 formed by vapor deposition of the second intermediate layer S5. It is thermocompression bonded through the agent. Then, the second film member 47 is thermocompression bonded to the unit case 31 with the second inner layer S6 corresponding to the other side surface 31b of the unit case 31.

  As shown in FIG. 7, a partition wall 50 is formed between the liquid supply chamber 40 and the pressure chamber 48 of the unit case 31 so as to partition the liquid supply chamber 40 and the pressure chamber 48. Is formed with a support hole 51 that constitutes an on-off valve that allows the liquid supply chamber 40 and the pressure chamber 48 to communicate with each other. A movable valve 52 constituting an on-off valve is slidably inserted and supported in the support hole 51. Specifically, the movable valve 52 includes a cylindrical rod member 53 and a disk-shaped plate member 54 formed integrally with the rod member 53. The outer diameter of the plate-like member 54 is larger than the outer diameter of the rod member 53, and only the rod member 53 of the movable valve 52 is slidably inserted and supported in the support hole 51. Yes.

In the support hole 51 formed in the partition wall 50, four notch grooves 51a are formed at equal intervals, as shown in the enlarged view of FIG. Therefore, in a state where the rod member 53 is inserted and supported in the support hole 51, the four ink flow paths 51b are formed by the rod member 53 and the notch groove 51a. As shown in FIG. 7, the plate-like member 54 is located in the liquid supply chamber 40, and the plate-like member 54 has an annular step portion 54 a on the surface on the liquid supply chamber 40 side. Is formed. The stepped portion 43 of the spring receiving seat 42 and the stepped portion 54a of the plate-like member 54 are provided with a coil-shaped seal spring 55. By the action of the seal spring 55, the spring receiving seat 42 and the plate-like member are disposed. It is biased in a direction away from 54.

  On the other hand, as shown in FIGS. 7 and 10, a rubber seal member 56 formed in an annular shape so as to surround the support hole 51 is attached to the partition wall 50 on the liquid supply chamber 40 side by thermocompression bonding or the like. ing. Accordingly, the plate-like member 54 in the movable valve 52 is brought into contact with the seal member 56 by the biasing force of the seal spring 55. The seal member 56 may be an O-ring or the like, but an elastomer resin or the like may be integrally formed with the unit case 31 by two-color molding. When the plate-like member 54 and the seal member 56 are separated from each other against the urging force of the seal spring 55, the ink flow path 51b is opened. As a result, the ink in the liquid supply chamber 40 is introduced into the pressure chamber 48 via the ink flow path 51b. On the contrary, when the plate-like member 54 and the seal member 56 are brought into contact with each other by the biasing force of the seal spring 55, the ink flow path 51b is closed. As a result, the introduction of ink from the liquid supply chamber 40 to the pressure chamber 48 through the ink flow path 51b is blocked.

  On the other hand, a pressure receiving plate 57 formed of a material harder than that of the second film member 47 is attached to the surface of the second film member 47 opposite to the pressure chamber 48. The pressure receiving plate 57 preferably has an outer diameter smaller than the inner diameter of the pressure chamber 48 and is made of a lightweight synthetic resin material such as polyethylene or polypropylene. The pressure receiving plate 57 may be attached in advance to the second film member 47 by thermocompression bonding, or may be attached by an adhesive or a double-sided adhesive tape.

  When the ink is ejected from the recording head 16 and the pressure in the pressure chamber 48 decreases, the second film member 47 (pressure receiving plate 57) bends to the bottom surface side of the second recess 44, as shown in FIG. As shown, the rod member 53 of the movable valve 52 is pressed toward the liquid supply chamber 40 against the biasing force of the seal spring 55. As a result, the ink channel 51b is opened, and the ink in the liquid supply chamber 40 is introduced into the pressure chamber 48 via the ink channel 51b. When the pressure chamber 48 is filled with ink from the liquid supply chamber 40, the second film member 47 (pressure receiving plate 57) returns to its original state as shown in FIG. It will be in the state separated from. Then, the plate-like member 54 of the movable valve 52 and the seal member 56 are brought into contact with each other by the urging force of the seal spring 55, and the ink flow path 51b is closed, and ink is introduced from the liquid supply chamber 40 to the pressure chamber 48. Is cut off.

Next, the characteristics of the valve unit 17 provided in the printer 11 configured as described above will be described below.
(1) In the present embodiment, the liquid supply chamber 40 and the ink introduction path 41 are formed in a three-layer structure including a first protective film layer S1, a first intermediate layer S2, and a first inner layer S3 in order from the outside. A first film member 39 having a shape was formed by thermocompression bonding to one side surface 31 a of the unit case 31. The material of the first inner layer S3 of the first film member 39 that is directly bonded (thermocompression bonded) to the one side surface 31a of the unit case 31 is formed of the same material as the unit case 31.

  Accordingly, since the same material, that is, the coefficient of thermal expansion is the same, the first inner layer S3 and the unit case 31 expand and contract at the same coefficient of thermal expansion when thermocompression bonded. No stress is applied. Therefore, the first film member 39 has an adhesive structure that is very difficult to peel off from the one side surface 31 a of the unit case 31. In addition, since the same material is used, the material is easily available and the manufacturing cost can be reduced.

Further, the first intermediate layer S2 constituting the first film member 39 was formed of an aluminum foil having no gas permeability and no moisture permeability. Therefore, it is possible to suppress changes in ink properties, viscosity, and the like due to evaporation of moisture in the ink supplied to the liquid supply chamber 40 and the ink introduction path 41.

  Further, the first protective film layer S1 constituting the first film member 39 was formed of polyethylene terephthalate. Therefore, there is no fear of damaging the first intermediate layer S2 or the first inner layer S3.

  (2) In the present embodiment, the pressure chamber 48 and the ink outlet passage 49 are formed in a film shape having a three-layer structure of the second protective film layer S4, the second intermediate layer S5, and the second inner layer S6 in order from the outside. The second film member 47 was formed by thermocompression bonding to the other side surface 31 b of the unit case 31. The material of the second inner layer S6 of the second film member 47 that is directly bonded (thermocompression bonded) to the other side surface 31b of the unit case 31 is formed of the same material as the unit case 31.

  Accordingly, since the same material, that is, the coefficient of thermal expansion is the same, the second inner layer S6 and the unit case 31 expand and contract at the same coefficient of thermal expansion when thermocompression bonded. No stress is applied. Therefore, the second film member 47 has an adhesive structure that is very difficult to peel off from the other side surface 31 b of the unit case 31. In addition, since the same material is used, the material is easily available and the manufacturing cost can be reduced.

  Further, the second intermediate layer S5 constituting the second film member 47 was formed of an alumina vapor deposition film. Therefore, the second inner layer S6 made of soft polypropylene can be easily displaced even by a small negative pressure. Moreover, since the alumina vapor deposition film has low gas permeability and moisture permeability, it is possible to suppress changes in ink properties and viscosity due to moisture evaporation of the ink supplied to the pressure chamber 48 and the ink outlet passage 49. it can.

  (3) In this embodiment, polypropylene is used for the unit case 31, the first film member 39, and the second film member 47. Since this polypropylene does not generate harmful gases such as chlorine gas or dioxin during combustion, it does not harm the environment.

  (4) In the present embodiment, when the liquid supply chamber 40 and the pressure chamber 48 are formed on the unit case 31, the first film member 39 and the second film member 47 are each thermocompression bonded to the unit case 31. Adhere to. Therefore, the sealing performance can be improved with a simple configuration as compared with the configuration in which the liquid supply chamber 40 and the pressure chamber 48 are mechanically sealed.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the first intermediate layer S2 of the first film member 39 on the liquid supply chamber 40 side is formed of aluminum foil. Alternatively, the first intermediate layer S2 may be formed of an alumina vapor deposition film or a silica vapor deposition film. And you may adhere | attach the 1st protective film layer S1 in which the alumina vapor deposition film or the silica vapor deposition film was formed on the 1st inner layer S3 with an adhesive agent.

  In the above embodiment, the first protective film layer S1 of the first film member 39 on the liquid supply chamber 40 side is formed of polyethylene terephthalate. Instead, the first protective film layer S1 may be formed of polyamide. Thereby, in addition to the gas barrier property by the aluminum foil of the first intermediate layer S2, the gas barrier property is improved because polyamide is also excellent in the gas barrier property.

In the above embodiment, the second intermediate layer S5 of the second film member 47 is an alumina vapor deposition film. However, instead of this, a silica vapor deposition film may be used, or an alumina vapor deposition film and a silica vapor deposition film are bonded. The combined layer may be used as the second intermediate layer S5. A similar gas barrier property can be obtained even in such a configuration.

  In the above embodiment, the first and second inner layers S3 and S6 of the first and second film members 39 and 47 are made of the same material as the unit case 31, but the coefficient of thermal expansion of the unit case 31 is the same. Or you may implement using the material which has the expansion coefficient close | similar to it. Also in this case, the first and second film members 39 and 47 are firmly bonded to the unit case 31.

FIG. 2 is a plan view for explaining the overall configuration of the printer according to the embodiment. FIG. 4 is a schematic diagram for explaining ink supply in the present embodiment. The perspective view which looked at the valve unit and the recording head from one side of the valve unit. The perspective view similarly seen from the other side of the valve unit. The side view which looked at the ink supply valve unit from one side. Similarly, the side view seen from the other side. It is sectional drawing of the valve unit in this embodiment, (a) shows a time when a movable valve is a closed state, (b) shows a time when a movable valve is an open state. The principal part expanded sectional view of a valve unit. The principal part expanded sectional view of a valve unit. The principal part expanded sectional view of a valve unit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Inkjet printer as a liquid ejecting apparatus, 16 ... Recording head as a liquid ejecting head, 17 ... Valve unit, 18 ... Ink cartridge as a liquid container, 31 ... Unit case, 36 ... First recess, 39 ... 1st film member, 40 ... liquid supply chamber, 44 ... 2nd recessed part, 47 ... 2nd film member, 48 ... pressure chamber, 51 ... support hole which comprises on-off valve, 52 ... movable which comprises on-off valve Valve, S1 ... first protective film layer, S2 ... first intermediate layer, S3 ... first inner layer, S4 ... second protective film layer, S5 ... second intermediate layer, S6 ... second inner layer.

Claims (9)

A liquid supply chamber and a pressure chamber formed by thermocompression bonding of a film member to the unit case to close a recess provided in the unit case, and an opening / closing valve provided between the liquid supply chamber and the pressure chamber are provided. Then, the liquid supplied from the liquid container to the liquid supply chamber is introduced into the pressure chamber by operating the on-off valve based on the state of the pressure chamber, and the liquid introduced into the pressure chamber is ejected to the liquid. In a liquid ejecting apparatus including a valve unit that supplies a head,
The liquid ejecting apparatus according to claim 1, wherein the film member is formed of a material having the same thermal expansion coefficient as that of the unit case. The liquid ejecting apparatus according to claim 1,
The liquid ejecting apparatus, wherein the film member is formed of the same material as the unit case. The liquid ejecting apparatus according to claim 1 or 2,
The film member has a multilayer structure having at least a protective film layer, an intermediate layer, and an inner layer that is thermocompression bonded to the unit case, and the inner layer is formed of a material having the same thermal expansion coefficient as the unit case. A liquid ejecting apparatus. The liquid ejecting apparatus according to any one of claims 1 to 3,
The liquid ejecting apparatus according to claim 1, wherein the unit case is made of polypropylene. The liquid ejecting apparatus according to claim 3 or 4,
The film member forming the liquid supply chamber includes a protective film layer formed of polyethylene terephthalate, an intermediate layer formed of aluminum foil, and an inner layer formed of polypropylene. Injection device. The liquid ejecting apparatus according to claim 3 or 4,
The film member forming the pressure chamber is composed of a protective film layer formed of polyethylene terephthalate, an intermediate layer formed of a silica deposited film or an alumina deposited film, and an inner layer formed of polypropylene. A liquid ejecting apparatus. The liquid ejecting apparatus according to claim 5 or 6,
The liquid ejecting apparatus according to claim 1, wherein the inner layer of the film member made of polypropylene has a thickness of 20 microns or more. The liquid ejecting apparatus according to claim 5 or 6,
The protective film layer made of polyethylene terephthalate has a thickness of 6 microns or more. The liquid ejecting apparatus according to claim 5,
The liquid ejecting apparatus according to claim 1, wherein the intermediate layer made of the aluminum foil has a thickness of 5 microns or more.

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