Patent Grant
9475292
1. Technical Field
The present invention relates to a liquid ejecting head that ejects a liquid from a nozzle and a liquid ejecting apparatus, and particularly to an ink jet-type recording head that ejects ink as the liquid and an ink jet-type recording apparatus.
2. Related Art
As an ink jet-type recording head which is a representative example of a liquid ejecting head that ejects a droplet, there is a recording head which includes a nozzle and a flow path such as a pressure generating chamber communicating with the nozzle, and in which a pressure generator causes pressure in ink in the pressure generating chamber to be changed such that an ink droplet is discharged from the nozzle.
According to the ink jet-type recording head, there has been proposed a recording head in which a so-called compliance section that is formed by a flexible film demarcating a part of a manifold, with which a plurality of pressure generating chambers communicate, and that absorbs pressure fluctuation of a liquid in the manifold by deforming the film (for example, see JP-A-2006-95725).
However, a problem arises in that the film is likely to be deflected during manufacture such as a process in which the films used to form the compliance section adhere, the deflected film is to likely to adhere to another member (cap member) that demarcates a space between the compliance section and the film due to condensation or the like, and the compliance section does not appropriately function.
Particularly, since the film is joined using an adhesive, another problem arises in that adhesive power of the adhesive is likely to be restored due to high-temperature and high-humidity surroundings and the film is likely to adhere to the other member (cap member) with the adhesive.
Further, such problems arise not only in the ink jet-type recording head but also similarly in a liquid ejecting apparatus that ejects a liquid except for the ink.
An advantage of some aspects of the invention is to provide a liquid ejecting head and a liquid ejecting apparatus in which it is possible to prevent a compliance region from adhering to a cap member such that it is possible to reduce malfunction of the compliance region due to the adherence.
Aspect 1
According to an aspect of the invention, there is provided a liquid ejecting head including: a plurality of pressure generating chambers communicating with nozzles through which a liquid is ejected; a manifold communicating with the plurality of pressure generating chambers; a flexible member that has a surface on one side which defines at least a part of a wall of the manifold, that has a surface on the other side, on which an adhesive layer is formed, and that has a compliance region, which is able to perform deflection in response to pressure fluctuation in the manifold, in a region in which the adhesive layer is formed; a compliance space disposed on a side opposite to the manifold through the flexible member; a cap member facing the flexible member through the compliance space; a frame-like member disposed between the flexible member and the cap member; and an island-like member provided between the flexible member and the cap member to be disposed in the compliance region and to be separated from the frame-like member. One surface of the frame-like member on one side facing the flexible member and the other surface thereof on the other side facing the cap member are fixed to the facing members, respectively. Any one surface of one surface of the island-like member on one side facing the flexible member and the other surface thereof on the other side facing the cap member is fixed to the facing member and the other surface is not fixed to the facing member. In a direction in which the flexible member and the cap member face each other, the island-like member is thinner in thickness than the frame-like member.
In this case, the island-like member is provided, and thereby it is possible to prevent the compliance region of the flexible member from coming into contact with and adhering to the cap member and to prevent the compliance region of the flexible member from malfunctioning by adhering to the cap member. In addition, the island-like member is not fixed to one of the flexible member and the cap member, and thereby it is possible for the compliance region to be significantly deformed in deflection toward the inner side of the manifold and it is possible for the compliance region to reliably perform pressure absorption in the manifold. Further, the island-like member is thinner in the thickness than the frame-like member, and thereby it is possible to prevent the compliance region from having a reduced amount of deformation to the cap member side.
Aspect 2
In the liquid ejecting head according to Aspect 1, it is preferable that, in a case where it is assumed that the compliance region is defined in a longitudinal direction and a widthwise direction, the island-like member is disposed to be shifted from the center of the compliance region in the widthwise direction. In this case, it is possible to prevent the deformation of the center position of the compliance region, which has the maximum deformation amount, from being restraint by the island-like member and to prevent the deformation amount of the compliance region from being reduced.
Aspect 3
In the liquid ejecting head according to Aspect 2, it is preferable that a plurality of the island-like members are provided with the center in the widthwise direction interposed therebetween. In this case, the island-like member can reliably prevent the compliance region from adhering to the cap member.
Aspect 4
In the liquid ejecting head according to any one of Aspects 1 to 3, it is preferable that the island-like members are fixed to the flexible member. In this case, it is possible to pull the compliance region to the cap member side due to the weight of the island-like members and it is possible to significantly secure the deformation amount of the compliance region into the manifold.
Aspect 5
In the liquid ejecting head according to Aspect 4, it is preferable that the island-like members are separated from the cap member in a case where the manifold is not filled with a liquid. In this case, it is possible to prevent the island-like member and the cap member from coming into contact with each other during transport or the like and it is possible to prevent the island-like member and the cap member from adhering to each other due to condensation or the like.
Aspect 6
In the liquid ejecting head according to Aspect 4 or 5, it is preferable that a region of the cap member, which faces the island-like member, is subjected to a water repellent treatment. In this case, it is possible to prevent water moisture due to condensation or the like from being attached to the cap member and it is possible to prevent the island-like member and the cap member from adhering to each other due to the water moisture.
Aspect 7
In the liquid ejecting head according to Aspect 6, it is preferable that a region of the cap member, which does not face the island-like member, is not subjected to a water repellent treatment. In this case, it is possible to keep the water moisture in the region of the cap member, which is not subjected to a water repellent treatment and it is possible to further prevent the water moisture from attaching to the region subjected to the water repellent treatment such that it is possible to prevent the island-like member and the cap member from adhering to each other due to the water moisture.
Aspect 8
In the liquid ejecting head according to any one of Aspects 4 to 7, it is preferable that a region of the cap member, which faces the island-like member, is further concave than a region which does not face the island-like member. In this case, it is possible for the island-like member to come into contact with the concave portion of the cap member and it is possible to further deform the compliance region to the cap member side and to increase a deformation amount thereof.
Aspect 9
In the liquid ejecting head according to any one of Aspects 1 to 8, it is preferable that at least a part of a surface of the island-like member on a side, on which the member is not fixed to the facing member, is subjected to a water repellent treatment. In this case, it is possible to prevent the water moisture due to condensation or the like from attaching to the surface on the side on which the island-like member is not fixed and it is possible to prevent the island-like member and the member to which the island-like member is not fixed from adhering to each other due to the water moisture.
Aspect 10
In the liquid ejecting head according to any one of Aspects 1 to 9, it is preferable that a surface of the island-like member on a side, on which the member is not fixed to the facing member, is uneven. In this case, a contact area between the island-like member and the member to which the island-like member is not fixed is reduced, and thus it is possible to prevent the island-like member and the member to which the island-like member is not fixed from adhering to each other.
Aspect 11
In the liquid ejecting head according to any one of Aspects 1 to 10, it is preferable that the frame-like member has a cantilever, the cantilever has at least a part, which is fixed to the flexible member of the compliance region, and has an unfixed region on the distal end side, which is not fixed to the cap member, and the island-like member has the same thickness as the unfixed region of the cantilever. In this case, the cantilever is provided, and thereby the compliance region is unlikely to deform. Therefore, rapid deformation of the compliance region is performed in response to the pressure change in the manifold, and thereby it is possible to prevent variations of the compliance region and it is possible to prevent variation of ejection characteristics of the liquid. In addition, the unfixed region of the cantilever has the same thickness as the island-like member, and thereby it is possible to easily form the cantilever and the island-like member.
Aspect 12
In the liquid ejecting head according to any one of Aspects 1 to 11, it is preferable that the frame-like member and the island-like member are formed of the same material. In this case, it is possible to easily and simultaneously form the frame-like member and the island-like member using the same material.
Aspect 13
According to another aspect of the invention, there is provided a liquid ejecting apparatus including: the liquid ejecting head according to any one of Aspects 1 to 12.
In this case, it is possible to realize the liquid ejecting apparatus in which the compliance region is prevented from adhering and malfunction due to the adhesion of the compliance region is reduced.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, the invention will be described in detail based on embodiments.
As illustrated in the
The flow path formation substrate 10 constituting the head main body 11 can be formed of a metal such as stainless steel or Ni, a ceramic material represented by ZrO2 or Al2O3, a glass-ceramic material, an oxide such as MgO, LaAlO3, or the like. In Embodiment 1, the flow path formation substrate 10 is formed of a silicon single crystal substrate. In the flow path formation substrate 10, pressure generating chambers 12 that are formed through anisotropic etching from one surface side are partitioned by a plurality of diaphragms and are arranged in parallel in a direction in which a plurality of nozzles 21 which eject ink are arranged in parallel. From here on, this direction is referred to as a parallel-arrangement direction of the pressure generating chambers 12 or a first direction X. In addition, in the flow path formation substrate 10, a plurality of rows in which the pressure generating chambers 12 are arranged in parallel in the first direction X are provided and two rows of pressure generating chambers 12 are provided in Embodiment 1. A row-arrangement direction, in which the plurality of rows of pressure generating chambers 12 that are formed in the first direction X are arranged, is referred to as a second direction Y, from here on. Further, a direction which intersects with both the first direction X and the second direction Y is referred to as a third direction Z. In Embodiment 1, the first direction X, the second direction Y, and the third direction Z intersect with one another in the direction orthogonal to each other; however, the directions may intersect with one another in a direction which is not orthogonal to each other.
In addition, in the flow path formation substrate 10, a supply path or the like which has a smaller opening area than the pressure generating chamber 12 and causes flow path resistance to be produced to ink that flows into the pressure generating chamber 12 may be provided on one end side of the pressure generating chamber 12 in the second direction Y.
In addition, in one surface side of the flow path formation substrate 10, the communicating plate 15 and the nozzle plate 20 are stacked in this order. That is, the flow path formation substrate 10 includes the communicating plate 15 provided on one surface of the flow path formation substrate 10 and the nozzle plate 20 that has the nozzle 21 which is provided on the surface side of the communicating plate 15 opposite to the flow path formation substrate 10.
A nozzle communication path 16 through which the pressure generating chamber 12 communicates with the nozzle 21 is provided in the communicating plate 15. The communicating plate 15 has an area larger than the flow path formation substrate 10 and the nozzle plate 20 has an area smaller than the flow path formation substrate 10. The communicating plate 15 is provided, and thereby the nozzle 21 of the nozzle plate 20 is separated from the pressure generating chamber 12. Therefore, ink in the pressure generating chamber 12 is unlikely to be affected by thickening of ink due to evaporation of water moisture which occurs in the ink in the vicinity of the nozzle 21. In addition, since the nozzle plate 20 may be disposed only to cover an opening of the nozzle communication path 16 through which the pressure generating chamber 12 communicates with the nozzle 21, it is possible to relatively decrease the area of the nozzle plate 20 and thus it is possible to reduce cost because the area of the flow path formation substrate 10 can be less than that of the communicating plate 15. Further, in the Embodiment 1, a surface on which the nozzle 21 of the nozzle plate 20 is opened and through which ink droplets are discharged is referred to as a liquid ejection surface 20a.
In addition, a first manifold section 17 and a second manifold section 18 which configure a part of a manifold 100 are provided in the communicating plate 15.
The first manifold section 17 is provided to penetrate through the communicating plate 15 in the thickness direction (a stacking direction of the communicating plate 15 and the flow path formation substrate 10).
In addition, the second manifold section 18 is not provided to penetrate through the communicating plate 15 in the thickness direction but provided to be opened on the nozzle plate 20 side of the communicating plate 15.
Further, an opening shape of the manifold 100 on the nozzle plate 20 side has a longitudinal direction and a widthwise direction in an in-plane direction including the first direction X and the second direction Y. The manifold 100 has the longitudinal direction and the widthwise direction, which means that an aspect ratio of the opening of the manifold 100 on the nozzle plate 20 side is not 1 to 1. In addition, there is no particular limitation to the opening shape of the manifold 100 and, for example, the opening shape may be rectangular, trapezoidal, parallelogrammic, polygonal, elliptical, or the like. In Embodiment 1, since the pressure generating chambers 12 are arranged in parallel in the flow path formation substrate 10 in the first direction X, the manifold 100 which is a common liquid chamber communicating with the pressure generating chambers 12 is provided over the pressure generating chambers 12 arranged in parallel in the first direction X to have a trapezoidal shape which has the longitudinal direction in the first direction X, that is, which is elongated in the first direction X and which has the widthwise direction in the second direction Y, that is, which is short in the second direction Y. Similarly, the opening shape of the manifold 100 on the nozzle plate 20 side is trapezoidal to have the longitudinal direction in the first direction X and to have the widthwise direction in the second direction Y.
Further, a supply communication path 19 that communicates with one end portion of the pressure generating chamber 12 in the second direction Y is provided in the communicating plate 15 individually for each of the pressure generating chambers 12. Through the supply communication path 19, the second manifold section 18 communicates with the pressure generating chamber 12. In other words, in Embodiment 1, as separated flow paths through which the nozzle 21 communicates with the second manifold section 18, the supply communication path 19, the pressure generating chamber 12, and the nozzle communication path 16 are provided.
Such a communicating plate 15 can be formed of a metal such as stainless steel or nickel (Ni), ceramic such as zirconium (Zr), or the like. It is preferable that the communicating plate 15 is formed of a material having the same linear expansion coefficient as the flow path formation substrate 10. In other words, in a case where the communicating plate 15 is formed of a material having the linear expansion coefficient significantly different from that of the flow path formation substrate 10, distortion due to the different linear expansion coefficients between the flow path formation substrate 10 and the communicating plate 15 is produced when the members are heated or cooled. In Embodiment 1, the communicating plate 15 is formed of the same material as the flow path formation substrate 10, that is, a silicon single crystal substrate, and thereby it is possible to prevent an occurrence of distortion due to heat, cracking or peeling due to heat, or the like.
The nozzle 21 that communicates with each of the pressure generating chambers 12 through the nozzle communication path 16 is formed on the nozzle plate 20. In other words, the nozzles 21 eject the same type of liquid (ink) and are arranged in parallel in the first direction X and two rows of the nozzles 21 arranged in parallel in the first direction X are formed in the second direction Y.
Such a nozzle plate 20 can be formed of a metal such as stainless steel (SUS), an organic material such as a polyimide resin, a silicon single crystal substrate, or the like. When the nozzle plate 20 is formed of a silicon single crystal substrate, the nozzle plate 20 has the same linear expansion coefficient as the communicating plate 15. Accordingly, it is possible to prevent an occurrence of distortion due to heating or cooling, cracking or peeling due to heating, or the like.
Meanwhile, a vibration plate 50 is formed on the surface side opposite to the communicating plate 15 of the flow path formation substrate 10. In Embodiment 1, as the vibration plate 50, an elastic film 51 that is provided on the side of the flow path formation substrate 10 and is formed of silicon oxide, and an insulator film 52 that is provided on the elastic film 51 and is formed of zirconium oxide are provided. A liquid flow path such as the pressure generating chamber 12 is formed through anisotropic etching on the flow path formation substrate 10 from one surface side (surface side to which the nozzle plate 20 is joined) and the other surface of the liquid flow path such as the pressure generating chamber 12 is demarcated by the elastic film 51.
In addition, a piezoelectric actuator 300 is configured to include a first electrode 60, a piezoelectric layer 70, and a second electrode 80, which are stacked on the insulator film 52 of the vibration plate 50. Here, the piezoelectric actuator 300 is a portion in which the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are included. In general, any one electrode of the piezoelectric actuator 300 is used as a common electrode and the other electrode and the piezoelectric layer 70 are configured to be patterned for each of the pressure generating chambers 12. Also, the piezoelectric actuator is configured to include one patterned electrode and the piezoelectric layer 70 such that a portion in which piezoelectric strain is produced due to application of a voltage to both electrodes is referred to as a piezoelectric active portion. In Embodiment 1, the first electrode 60 is provided as the common electrode of the piezoelectric actuators 300 and the second electrode 80 is provided as an individual electrode of the piezoelectric actuators 300; however, depending on a drive circuit or wiring, both of the electrodes may be used the other way around. In the above example, since the first electrode 60 is provided to be continuous over a plurality of the pressure generating chambers 12, the first electrode 60 functions as a part of the vibration plate; understandably, the first electrode is not limited thereto. For example, only the first electrode 60 may work as the vibration plate without providing the elastic film 51 and the insulator film 52 described above. In addition, the piezoelectric actuator 300 itself may function as the vibration plate, in practice. Here, in a case where the first electrode 60 is provided immediately on the flow path formation substrate 10, it is preferable that the first electrode 60 is protected using a protective film having insulation properties such that the first electrode 60 and the ink do not conduct to each other. In other words, in Embodiment 1, the configuration, in which the first electrode 60 is provided over the substrate (flow path formation substrate 10) through the vibration plate 50, is described as an example; however, the configuration is not limited thereto, and the first electrode 60 may be provided immediately on the substrate without providing the vibration plate 50. That is, the first electrode 60 may work as the vibration plate. In other words, to be on the substrate means to be immediately on the substrate and a state (above) in which another member is interposed therebetween.
Further, a lead electrode 90 formed of gold (Au) or the like, which is pulled out from the vicinity of an end portion of the second electrode 80 on the side opposite to the supply communication path 19 and extends over the vibration plate 50, is connected to the second electrode 80 which is an individual electrode of the piezoelectric actuator 300. In addition, the protection substrate 30 having the same size as the flow path formation substrate 10 is joined to a surface of the flow path formation substrate 10 on the piezoelectric actuator 300 side which is a pressure generator. The protection substrate 30 has a holding section 31 which is a space that protects the piezoelectric actuator 300.
In addition, the case member 40 which, together with the head main body 11, demarcates the manifold 100 communicating with the plurality of pressure generating chambers 12, is fixed to the head main body 11. The case member 40 has substantially the same shape as the communicating plate 15 described above in a plan view, is joined to the protection substrate 30, and is also joined to the communicating plate 15 described above. Specifically, the case member 40 has a recessed section 41 having a depth on the protection substrate 30 side, with which the flow path formation substrate 10 and the protection substrate 30 are accommodated. The recessed section 41 has an opening area greater than a surface of the protection substrate 30 to which the flow path formation substrate 10 is joined. Also, in a state in which the flow path formation substrate 10 or the like is accommodated in the recessed section 41, an opening surface of the recessed section 41 on the nozzle plate 20 side is sealed by the communicating plate 15. A third manifold section 42 is hereby demarcated by the case member 40 and the head main body 11 on the peripheral section of the flow path formation substrate 10. Also, the first manifold section 17 and the second manifold section 18 provided in the communicating plate 15, and the third manifold section 42 demarcated by the case member 40 and the head main body 11 configure the manifold 100 of Embodiment 1. In other words, the manifold 100 includes the first manifold section 17, the second manifold section 18, and the third manifold section 42. In addition, the manifold 100 of Embodiment 1 is disposed on both outer sides of two rows of pressure generating chambers 12 in the second direction Y, and two manifolds 100 provided on both outer sides of the two rows of pressure generating chambers 12 are separately provided so as not to communicate with each other in the recording head II. In other words, one manifold 100 is provided to communicate with each row (row provided in parallel in the first direction X) of the pressure generating chambers 12 of Embodiment 1.
In addition, a guide path 44, which communicates with the manifold 100 and supplies the ink to the respective manifolds 100, is provided in the case member 40. In addition, a connection port 43, which communicates with a through-hole 32 of the protection substrate 30 and into which a wiring substrate 121 is inserted, is provided in the case member 40.
Further, the wiring substrate 121 inserting into the connection port 43 is connected to the lead electrode 90.
In addition, a drive circuit 120 is provided in the wiring substrate 121.
Further, the two manifolds 100 may communicate with each other on the upstream side of the recording head II, that is, to be more exact, in the upstream flow path which is connected to the guide path 44 communicating with the manifold 100 to be described below.
As a material of the case member 40, for example, a resin, a metal, or the like can be used. Incidentally, the case member 40 can be molded using a resin material, and thereby mass production can be performed at low cost.
In addition, as illustrated in
In other words, the compliance substrate 45 demarcates a part of the manifold 100. Such compliance substrate 45 includes the flexible member 46 formed of a material having flexibility and a frame-like member 47 fixed to a side of the flexible member 46 opposite to the communicating plate 15. The flexible member 46 is formed of a flexible thin film (thin film with a thickness of 20 μm or less which is formed of, for example, polyphenylene sulfide (PPS), aromatic polyamide (aramid), or the like) and the frame-like member 47 is formed of a hard material such as a metal such as stainless steel (SUS) or the like, compared to the flexible member 46. Since a region of the frame-like member 47 which faces the manifold 100 becomes an opening 48 by removing the entire region in the thickness direction, one surface of the manifold 100 becomes the compliance region 49 that is sealed only by the flexible member 46 having flexibility. In other words, the opening 48 is provided in the frame-like member 47, and thereby the compliance space 131 which causes the flexible member 46 to be separated from a cover head 130 which is a cap member and it is possible to deform a part of the flexible member 46 as the compliance region 49 by the compliance space 131. Further, in Embodiment 1, one compliance region 49 is provided corresponding to one manifold 100. In other words, in Embodiment 1, since two manifolds 100 are provided, two compliance regions 49 are provided on both sides in the second direction Y with the nozzle plate 20 interposed.
Further, the flexible member 46 and the frame-like member 47 can be formed by forming an adhesive layer through applying an adhesive over the entire one-side surface of the flexible member 46, then the frame-like member 47 is attached to the one-side surface on which the adhesive of the flexible member 46 is formed. Accordingly, as illustrated in
Here, as illustrated in
In addition, in Embodiment 1, a wall surface of the opening 48 in the widthwise direction, which defines the compliance region 49, is provided at a position facing the manifold 100 in the third direction Z. In other words, in the opening of the surface of the manifold 100, which faces the flexible member 46, the wall surface of the opening in the widthwise direction, which defines the manifold 100, is disposed at a position facing the frame-like member 47 in the third direction Z. Since it is possible to hereby receive, by the frame-like member 47, a load produced when the communicating plate 15 and the flexible member 46 are joined, it is possible to reliably perform the joining between the communicating plate 15 and the flexible member 46. Accordingly, a gap can be formed due to an insufficient load during the joining between the communicating plate 15 and the flexible member 46, and thus it is possible to prevent an occurrence of a defect such as blocking of bubbles.
In addition, as illustrated in
A second exposure opening 132 which exposes the nozzle 21 is provided in the cover head 130. In Embodiment 1, the second exposure opening 132 has a size to expose the nozzle plate 20, that is, an opening having substantially the same size as the first exposure opening 45a of the compliance substrate 45.
In addition, in Embodiment 1, the cover head 130 is provided to have an end portion which is curved from the liquid ejection surface 20a side such that the cover head covers the side surface (surface intersecting with the liquid ejection surface 20a) of the head main body 11.
Such cover head 130 is joined to the side of the compliance substrate 45 opposite to the communicating plate 15 and seals a space on the side of the compliance region 49 opposite to the flow path (manifold 100). In other words, the cover head 130 which is the cap member is provided to cover the compliance regions 49 in a state in which the compliance space 131 is disposed between the compliance regions 49. In this manner, the compliance region 49 is covered with the cover head 130 which is the cap member, and thereby it is possible to prevent the compliance region 49 from being broken even when a recording medium such as paper comes into contact with the compliance region. In addition, the compliance region 49 is prevented from being attached with the ink (liquid), it is possible to wipe off the ink (liquid) attached on the surface of the cover head 130, for example, using a wiper blade or the like, and it is possible to prevent the recording medium from being stained with the ink or the like attached to the cover head 130.
In this manner, the compliance space 131 demarcated between the compliance region 49 and the cover head 130 is opened to the atmosphere on the outside of the recording head II. In Embodiment 1, a through-hole 48a, which penetrates through the frame-like member 47 in the thickness direction, is provided in one side of the respective compliance regions 49 in the first direction X, the through-hole 48a communicates with the opening 48, and thereby the compliance space 131 between the compliance region 49 and the cover head 130 is opened to the atmosphere on the outside through the through-hole 48a. Further, the through-hole 48a communicating with the compliance space 131 between the compliance region 49 and the cover head 130 may be opened to the atmosphere on the liquid ejection surface 20a side, on the side surface side, on the side (case member 40 side) opposite to the liquid ejection surface 20a of the recording head II, or the like. Here, since there is a concern that a defect, such as the ink flowing in from the opening opened to the atmosphere, blocking of an atmosphere open path, or the compliance region 49 attached with the ink, will occurs, it is preferable that the atmosphere open path (not illustrated) communicating with the through-hole 48a is opened to the outside on the side opposite to the liquid ejection surface 20a, that is, on the case member 40 side, and is opened to the atmosphere. Incidentally, in order to open the through-hole 48a to the atmosphere, an atmosphere open path (not illustrated) such as a groove or a through-hole may be provided in a member (a flow path formation substrate 10 or a communicating plate 15) constituting the recording head II and communication with the outside is performed through the atmosphere open path. In Embodiment 1, the through-hole 48a is provided for each compliance region 49, the atmosphere open path (not illustrated) is provided for each through-hole 48a, and each compliance region 49 is separately opened to the atmosphere. It is needless to say that there is no limitation to a method in which the space between the compliance region 49 and the cover head 130 is opened to the atmosphere, and two spaces between the compliance region 49 and the cover head 130 may communicate with each other such that the spaces are opened to the atmosphere through a common atmosphere open path.
Also, as illustrated in
In addition, the island-like member 140 is thinner in thickness than the frame-like member 47 in a direction in which the flexible member 46 faces the cover head 130, that is, in the third direction Z.
Further, the island-like member 140 is disposed with the center thereof in the second direction Y shifted in the second direction Y which is the widthwise direction of the compliance region 49. Specifically, in Embodiment 1, two island-like members 140 are provided on both sides of the center of the compliance region 49 in the second direction Y, respectively. In addition, a plurality of sets of the two island-like members 140 arranged in parallel in the second direction Y are arranged at predetermined intervals in the first direction X which is the longitudinal direction.
In this manner, the island-like members 140 are provided in the compliance space 131 between the compliance region 49 and the cover head 130, and thereby, as illustrated in
In comparison, as illustrated in
Further, in Embodiment 1, as illustrated in
Incidentally, as illustrated in
In such a recording head II, in general, in a print stand-by state in which ejection of an ink droplet is not performed from the nozzle 21, the pressure of the ink in the manifold 100 is regulated to be the negative pressure lower than the pressure on the outside, that is, the atmospheric pressure such that the ink is regulated not to drip from the nozzle 21. Therefore, in Embodiment 1, the ink in the manifold 100 has the negative pressure (with the atmospheric pressure as a reference), and thus the compliance region 49 is deformed in deflection to the side opposite to the cover head 130. Also, in the print stand-by state, the manifold 100 has the negative pressure and, when the ejection of the ink is started, that is, the print is started, the ink in the manifold 100 is consumed and the pressure is further lowered. In Embodiment 1, since the island-like member 140 is provided, and thereby it is possible to pull the compliance region 49 to the cover head 130 side due to the weight of the island-like member 140, it is possible to reliably secure a deformation amount in the manifold 100 and it is possible to absorb the pressure fluctuation of the ink in the manifold 100. Incidentally, when the island-like member 140 is fixed to both the flexible member 46 and the cover head 130, it is not possible for the compliance region 49 of the flexible member 46 to be sufficiently deformed in deflection and it is not possible to absorb the pressure fluctuation of the ink in the manifold 100. In other words, when the island-like member 140 is fixed to both the flexible member 46 and the cover head 130, the complete deflection of the compliance region 49 to the inside of the manifold 100 is likely to be performed immediately after printing is started and it is not possible for the compliance region 49 to absorb the pressure fluctuation due to the consumption of the ink in the manifold 100. Then, the manifold 100 is filled with ink from the upstream side, and thereby the pressure in the manifold 100 temporarily becomes the positive pressure (with the atmospheric pressure as a reference) and the compliance region 49 is deformed in deflection to the cover head 130 side. However, in Embodiment 1, as described above, the island-like member 140 is thinner in thickness than the frame-like member 47, and thereby it is possible to perform expansion of the large volume S1 compared to the volume S2 which can expand the manifold 100 in a case where the island-like member 140 is provided to have the same thickness as the frame-like member 47 and it is possible to perform sufficient expansion of the volume of the manifold 100 while the compliance region 49 is prevented from adhering to the cover head 130. In addition, at this time, since, while the manifold 100 is filled with the ink from the upstream side, the ink in the manifold 100 is consumed by ejecting, a difference in performance of absorbing the pressure fluctuation of the ink in the manifold 100 by the compliance region 49 is produced between immediately after printing is performed and after a certain period of time elapses from the start of the printing, and variations in the ejection characteristics of the ink and, particularly in the weight of the ink droplet are likely to be produced between immediately after the printing is started and during the printing. In addition, when the compliance region 49 is increased to the extent that it is possible to absorb the pressure fluctuation in the manifold 100 in order to control the variations of the ink ejection characteristics, the recording head II is likely to have a large size. In Embodiment 1, one side surface of the island-like member 140 is fixed to the flexible member 46 and the other side surface is not fixed to the cover head 130. In this manner, it is possible for the compliance region 49 to be significantly deformed in deflection in the manifold 100, a compliance function of the compliance region 49 is sufficiently performed, and it is possible to prevent a difference in compliance function of absorbing the pressure fluctuation of the ink in the manifold 100 between immediately after the printing is started and during the printing. Accordingly, it is possible to prevent variations of the ejection characteristics and, particularly, the weight of the ink droplet and it is possible to improve the printing quality. In addition, since the compliance region 49 does not need to be large in size, it is possible to reduce the recording head II in size.
In addition, island-like members 140 are provided, and thereby the deformation of the compliance region 49 of the flexible member 46 to the cover head 130 side is regulated by the island-like member 140 coming into contact with the cover head 130. Therefore, the deformation amount of the compliance region 49 to the inside of the manifold 100 is greater than the deformation amount to the cover head 130 side. Accordingly, in the print stand-by state or during printing, the compliance region 49 significantly deforms in the manifold 100 and it is possible to sufficiently absorb the pressure fluctuation in the manifold 100.
In addition, in Embodiment 1, the island-like members 140 are provided at positions of the compliance region 49, which are shifted from the center in the second direction Y. Therefore, the island-like members 140 do not block the deformation at the center portion in the second direction Y at which the compliance region 49 has a significant deformation amount and it is possible to prevent the deformation amount of the compliance region 49 from being reduced. In other words, as illustrated in
Further, in a case where the pressure in the manifold 100 is the atmospheric pressure, it is preferable that the island-like members 140 are separated from the cover head 130. In other words, when the recording head II is disposed to have the nozzle 21 which faces perpendicularly downward, the compliance region 49 is pulled perpendicularly downward due to the weight of the island-like members 140, it is preferable that the island-like members 140 are provided at positions and with a size at and with which the island-like members do not come into contact with the cover head 130. In a case where the recording head II is transported in a state in which the manifold 100 is not filled with the ink, it is possible to prevent the island-like members 140 from adhering to the cover head 130 due to the condensation. In other words, although the compliance region 49 falls down to the cover head 130 due to the island-like members 140, the island-like members 140 are thinner in the thickness than the frame-like member 47, and thereby it is difficult for the island-like member 140 to come into contact with the cover head 130, and it is possible to prevent the island-like members 140 from adhering to the cover head 130 due to the condensation.
In addition, the island-like member 140 is formed of the same material as the frame-like member 47, and thereby it is possible to easily manufacture the compliance substrate 45 having the flexible member 46, the frame-like member 47, and the island-like member 140. For example, as a manufacturing method of the compliance substrate 45, after a plate-like member which becomes the frame-like member 47, the island-like member 140 is joined to the flexible member 46, the compliance substrate 45 is formed through etching the plate-like member, it is possible to form the frame-like member 47 and the island-like member 140 at the same time, and it is possible to easily manufacture the island-like member.
Further, as illustrated in
In addition, as illustrated in
Further, as illustrated in
Further, a combination, described above, of
In addition, in Embodiment 1, the island-like member 140 is fixed to the flexible member 46 and is not fixed to the cover head 130; however, the configuration is not limited thereto. As illustrated in
As illustrated in the drawings, the same island-like member 140 as in Embodiment 1 described above, and a cantilever 150 are provided in the compliance space 131 between the compliance region 49 and the cover head 130.
The cantilever 150 is provided in the compliance space 131 between the flexible member 46 and the cover head 130 and is provided to be continued from the frame-like member 47 in the second direction Y and to protrude in the compliance space 131. Further, in Embodiment 2, an end side of the cantilever 150, which is continuous to the frame-like member 47, is referred to as a support point side and the end side protruding into the compliance space 131 is referred to as a distal end side. In Embodiment 2, the cantilever is provided to protrude toward the center of the compliance space 131 from the frame-like member 47 on both sides of the compliance space 131 in the second direction Y. In addition, a plurality of the cantilevers 150 are provided to be separated at intervals in the first direction X.
Such cantilever 150 is fixed to at least a part of the flexible member 46 of the compliance region 49 and the distal end side becomes an unfixed region which is not fixed to the cover head 130.
Specifically, an entire surface of the cantilever 150, which faces to the flexible member 46, is fixed to the flexible member 46. In Embodiment 2, since the adhesive layer 46a is provided all over the entire surface of the flexible member 46, the flexible member 46 and the cantilever 150 adhere to each other by the adhesive layer 46a. Further, at least a part of the cantilever 150 may be fixed to the flexible member 46, and the portion where the cantilever 150 is fixed to the flexible member 46 may be the distal end side or the support point side.
In addition, the cantilever 150 has a first notch 151 on the distal end side in a surface of the cantilever 150, which faces the cover head 130. The distal end side is thinner in thickness compared to the support point side of the cantilever 150. Also, the portion at which the first notch 151 of the cantilever 150 is referred to as an unfixed region at which the cantilever is not fixed to the cover head 130 and the portion, at which the first notch 151 of the cantilever 150 is not provided, is fixed to the cover head 130. In other words, when the frame-like member 47 and the cover head 130 adhere to each other using the adhesive, and stray adhesive from between the frame-like member 47 and the cover head 130 is accumulated, by the first notch 151, at the support point side from the first notch 151 and it is possible to suppress the flow of the adhesive to the distal end side from the first notch 151. It is possible to hereby form the unfixed region of the cantilever 150 without variation. Incidentally, the first notch 151 may not be provided and there is a concern that it is difficult to control a flowing-out amount and a flowing position of the adhesive between the frame-like member 47 and the cover head 130 above the cantilever 150 in a case where the first notch 151 is not provided and thus variations in the unfixed region are likely to occur. In Embodiment 2, the distal end side of the first notch 151 provided in the cantilever 150 is thinner and it is possible to suppress the flowing out of the adhesive and to form the unfixed region with ease and high accuracy. Further, an application region and viscosity of the adhesive is adjusted, and thereby it is possible to suppress stray of the adhesive even when the first notch 151 is not provided and it is possible to define the unfixed region. In addition, the support point side from the first notch 151 of the cantilever 150 may be fixed to the cover head 130 or may not be fixed. In Embodiment 2, the support point side from the first notch 151 of the cantilever 150 is fixed to the cover head 130.
Here, since, in the stand-by state in which the ink is not ejected, the pressure in the ink in the manifold 100 becomes the negative pressure (with the atmospheric pressure as the reference), as illustrated in
Also, when the ink is ejected and the pressure in the manifold 100 becomes further the negative pressure, as illustrated in
In comparison, in a case where the cantilever 150 is not provided, as illustrated in
Here, the pressure fluctuation in the manifold 100 when the ejection of the ink is started form a stand-by state, that is, an example of a relationship between the weight of the ink droplet and time is illustrated in
As illustrated in
In comparison, in a case of Example in which the cantilever 150 is provided, the compliance region 49 can absorb the pressure fluctuation in the manifold 100. Therefore, a difference of the ink pressure in the manifold 100 is reduced in T1, T2, and T3 and it is possible to reduce further a difference in the weight of the ink droplet, compared to Comparative Example. Accordingly, the cantilever 150 is provided and thereby it is possible to suppress variations in the weight of the ink droplet to be ejected and it is possible to improve the printing quality.
Incidentally, although it is considered that, the flexible member 46 is formed of a material which is unlikely to deform, for example, the flexible member 46 having a great thickness, or a material which is unlikely to deform without changing the thickness of the flexible member 46, it is not preferable that the flexible member 46 is unlikely to deflect and the compliance performance is likely to deteriorate, the reactivity of the deflected deformation of the compliance region 49 in response to the pressure fluctuation of the ink in the manifold 100 deteriorates and variation in the ejection characteristics of the ink is likely to be occur. In Embodiment 2, the cantilever 150 is provided, using the flexible member 46, it is possible to control the variations in ejection characteristics of the ink droplet without deteriorating the reactivity of the compliance region 49.
In addition, in Embodiment 2, since the distal ends of the cantilevers 150 protruding on both sides in the second direction Y face to be separated in the second direction Y at a predetermined interval, even when the cantilever 150 is provided, it is possible suppress interruption of the deformation of the compliance region 49 of the flexible member 46 to the greatest extent. In other words, in a case where the distal ends of the cantilever 150 protruding on both sides in the second direction Y are connected and not only the cantilever 150 but also the fixed beam (both-end fixed beam) are provided, the deformation of the compliance region 49 is slightly interrupted by the fixed beam, there is a concern that the absorption of the pressure fluctuation is not sufficiently performed by the compliance region 49.
In addition, even when the cantilever 150 is provided, movement of the compliance region to the cover head 130 is regulated by the cantilever 150 when the compliance region 49 of the flexible member 46 moves to the cover head 130 side. Accordingly, the compliance region 49 of the flexible member 46 comes into contact with the cover head 130, and thereby it is possible to prevent the adhering therebetween.
As above, the embodiments of the invention are described; however, a basic configuration of the invention is not limited to the configuration described above.
For example, in Embodiments 1 and 2 described above, an example, in which two manifolds 100 are provided and compliance region 49 is provided for each manifold 100, is described; however, the configuration is not particularly limited thereto, and the manifold 100 which is divided in plurality in the first direction X may be provided.
In addition, in Embodiments 1 and 2 described above, the island-like members 140 are disposed at positions shifted from the center of the compliance region 49 in the second direction Y; however, the configuration is not limited thereto and as illustrated in
Further, in Embodiments 1 and 2 described above, the compliance substrate 45 is provided on the surface side on which the nozzle plate 20 is provided; however, the configuration is not limited thereto and, for example, the compliance substrate 45 may be provided on the side surface orthogonal to the case member 40 side or the liquid ejection surface 20a. In other words, since the cap member is provided to demarcate the compliance space 131 between the compliance substrate 45 and the compliance region 49, the cap member is not limited to the cover head 130 described above, but another member is.
In addition, according to Embodiments 1 and 2 described above, as the pressure generator that causes the pressure change in the pressure generating chamber 12, the thin film type piezoelectric actuator 300 is described; however, the configuration is not particularly limited thereto. For example, it is possible to use a thick film type piezoelectric actuator that is formed by a method of such as attaching green sheets or the like, a longitudinal vibration type piezoelectric actuator in which piezoelectric materials and electrode forming materials are laminated alternately and expand and contract in an axial direction. In addition, as the pressure generator, it is possible to use an actuator in which a heating element is disposed in the pressure generating chamber and bubbles that is produced by heating of the heating element causes liquid droplets to be discharged from the nozzle, a so-called electrostatic actuator in which static electricity is generated between a vibrating plate and an electrode, the vibrating plate is deformed by electrostatic force and thus liquid droplets are discharged from the nozzle.
In addition, the ink jet-type recording head II according to each embodiment configures a part of an ink jet-type recording head unit that includes an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet-type recording apparatus.
In an ink jet-type recording apparatus I illustrated in
Also, a drive force of the drive motor 6 is transmitted to the carriage 3 through a plurality of gears (not illustrated) and a timing belt 7 and thereby the carriage 3 on which the ink jet-type recording head unit 1 is mounted moves along the carriage shaft 5. A transport roller 8 is provided as a transport unit in the apparatus main body 4 and a recording sheet S that is a recording medium such as paper is transported by the transport roller 8. The transport unit that transports the recording sheet S is not limited to the transport roller 8, but may be a belt, drum, or the like.
In the ink jet-type recording apparatus I described above, the ink jet-type recording head II (head unit 1) is mounted on the carriage 3 and moves in a main scanning direction; however, the configuration is not limited thereto. For example, it is possible to apply the invention even to a so-called line-type recording apparatus in which the ink jet-type recording head II is fixed, the recording sheet S such as paper is caused to move only in a sub scanning direction, and thereby printing is performed.
In addition, in the examples described above, the ink jet-type recording apparatus I has a configuration in which the ink cartridge 2 that is a liquid reservoir is mounted on the carriage 3, the configuration is not limited thereto. For example, the liquid reservoir such as an ink tank is fixed to the apparatus main body 4 and the reservoir and the ink jet-type recording head II may be connected through a supply pipe such as a tube. In addition, the liquid reservoir may not be mounted on the ink jet-type recording apparatus.
Further, broad parts of a liquid ejecting head in general are targets of the invention and, for example, the invention can be applied to a recording head such as various ink jet-type recording heads which are used in an image recording apparatus such as a printer, a color-material ejecting head that is used to manufacture a color filter such as a liquid crystal display, an electrode-material ejecting head that is used to produce an electrode, such as an organic EL display or a field emission display (FED), and a bio-organic material ejecting head that is used to manufacture a bio chip.
The present application claims priority to Japanese Patent Application No. 2015-023498 filed on Feb. 9, 2015, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-023498 | Feb 2015 | JP | national |
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| 20030081080 | Moriya | May 2003 | A1 |
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| Number | Date | Country |
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| Number | Date | Country | |
|---|---|---|---|
| 20160229187 A1 | Aug 2016 | US |
