Patent Grant
11981136
The present application is based on, and claims priority from JP Application Serial Number 2021-049385, filed Mar. 24, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus.
In general, a liquid ejecting apparatus such as an ink jet printer is provided with a liquid ejecting head ejecting a liquid such as ink as droplets. The liquid ejecting head may be provided with a heater heating a liquid as in, for example, the ink jet head described in JP-A-2010-76176.
The print head described in JP-A-2010-76176 includes a flow path body having a liquid flow path, a head main body where a liquid is ejected from the flow path body, and two sheet-shaped heaters. Here, the flow path body is interposed between the head main body and the heater and the heat from the heater is transferred to the head main body via the flow path body.
In the print head described in JP-A-2010-76176, the flow path body is interposed between the head main body and the heater, and thus the distance between the head main body and the heater increases in accordance with the thickness of the flow path body. Accordingly, in the print head described in JP-A-2010-76176, a temperature gradient is likely to occur between the heater and the head main body. As a result, it is difficult to manage the temperature of the head main body with high accuracy.
In order to solve the above problems, a liquid ejecting head according to an aspect of the present disclosure includes: a plurality of head chips having a nozzle surface provided with a liquid ejecting nozzle; a thermally conductive holder holding the plurality of head chips; a thermally conductive flow path structure provided with a flow path of a liquid supplied to the plurality of head chips; and a planar heater disposed between the holder and the flow path structure and along a direction parallel to the nozzle surface, in which the heater overlaps the plurality of head chips in a plan view.
A liquid ejecting apparatus according to another aspect of the present disclosure includes: the liquid ejecting head of the above aspect; and a liquid storage portion where a liquid supplied to the liquid ejecting head is stored.
Hereinafter, preferred embodiments according to the present disclosure will be described with reference to the accompanying drawings. In the drawings, the dimensions and scale of each portion are appropriately different from the actual ones and some parts are schematically illustrated for easy understanding. In addition, the scope of the present disclosure is not limited to these forms unless it is stated in the following description that the present disclosure is particularly limited.
In the following description, mutually intersecting X, Y, and Z axes are appropriately used for convenience. In addition, in the following description, one direction along the X axis is an X1 direction and the direction opposite to the X1 direction is an X2 direction. Likewise, Y1 and Y2 directions are opposite to each other along the Y axis. In addition, Z1 and Z2 directions are opposite to each other along the Z axis. In addition, viewing in the Z axis direction may be simply referred to as “plan view”. The Y or Y2 direction is an example of “first direction”. The X1 or X2 direction is an example of “second direction”.
Here, typically, the Z axis is a vertical axis and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z axis may not be vertical. Although the X, Y, and Z axes are typically orthogonal to each other, the axes are not limited thereto and may intersect at an angle ranging, for example, from 80° to 100°.
As illustrated in
The liquid storage portion 10 is an ink storage container. Examples of a specific aspect of the liquid storage portion 10 include a cartridge that can be attached to and detached from the liquid ejecting apparatus 100, a bag-shaped ink pack formed of a flexible film, and a container such as an ink-replenishable ink tank.
The liquid storage portion 10 has a plurality of containers (not illustrated) where different types of inks are stored. The inks stored in the containers are not particularly limited, examples thereof include cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and a treatment liquid, and combinations of two or more of these are used. The composition of the ink is not particularly limited, and the ink may be, for example, a water-based ink in which a coloring material such as a dye and a pigment is dissolved in a water-based solvent, a solvent-based ink in which a coloring material is dissolved in an organic solvent, or an ultraviolet-curable ink.
Exemplified in the present embodiment is a configuration in which four different types of inks are used. The inks have different colors such as cyan, magenta, yellow, and black.
The control unit 20 controls the operation of each element of the liquid ejecting apparatus 100. For example, the control unit 20 includes a processing circuit such as a central processing unit (CPU) and a field programmable gate array (FPGA) and a storage circuit such as a semiconductor memory. The control unit 20 outputs a drive signal D and a control signal S toward the liquid ejecting head 50. The drive signal D includes a drive pulse driving the drive element of the liquid ejecting head 50. The control signal S specifies whether or not to supply the drive signal D to the drive element.
The transport mechanism 30 transports the medium M in a transport direction DM, which is the Y1 direction, under the control of the control unit 20. The moving mechanism 40 reciprocates the liquid ejecting head 50 in the X1 and X2 directions under the control of the control unit 20. In the example illustrated in
The liquid ejecting head 50 has a plurality of head chips 54 as will be described later. Under the control of the control unit 20, the liquid ejecting head 50 ejects the ink supplied from the liquid storage portion 10 from each of a plurality of nozzles of the head chips 54 toward the medium M in the Z2 direction (ejection direction). This ejection is performed in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid ejecting head 50 by the moving mechanism 40. As a result, a predetermined ink-based image is formed on the surface of the medium M.
The liquid storage portion 10 may be coupled to the liquid ejecting head 50 via a circulation mechanism. The circulation mechanism supplies ink to the liquid ejecting head 50 and collects the ink discharged from the liquid ejecting head 50 for resupply to the liquid ejecting head 50. As a result of the operation of the circulation mechanism, an increase in ink viscosity can be suppressed and air bubble retention in ink can be reduced.
Here, the support body 41 is provided with an opening 41a and a plurality of screw holes 41b. In the present embodiment, the support body 41 has a substantially box shape having a plate-shaped bottom portion and the opening 41a and the screw holes 41b are provided in, for example, the bottom portion. The liquid ejecting head 50 is fixed to the support body 41 by screwing using the screw holes 41b with the liquid ejecting head 50 inserted in the opening 41a. As described above, the liquid ejecting head 50 is attached with respect to the support body 41.
In the example illustrated in
As illustrated in
The heat transfer member 57 is an example of “second heat transfer member”. In addition, each of the head chips 54_1 to 54_4 is the head chip 54 illustrated in
Provided in the flow path structure 51 is a flow path for supplying the ink stored in the liquid storage portion 10 to the four head chips 54. The flow path structure 51 has a flow path member 51a and eight coupling pipes 51b.
The flow path member 51a is provided with four supply flow paths (not illustrated) provided for each of the four types of inks and four discharge flow paths (not illustrated) provided for each of the four types of inks. Each of the four supply flow paths has one introduction port where ink is supplied and two discharge ports where ink is discharged. Each of the four discharge flow paths has two introduction ports where ink is supplied and one discharge port where ink is discharged. Each of the introduction ports of the supply flow paths and the discharge ports of the discharge flow paths is provided on the surface of the flow path member 51a that faces the Z1 direction. On the other hand, each of the discharge ports of the supply flow paths and the introduction ports of the discharge flow paths is provided on the surface of the flow path member 51a that faces the Z2 direction.
In addition, the flow path member 51a is provided with a plurality of wiring holes 51c. A wiring substrate 54i (described later) of the head chip 54 is passed through each of the wiring holes 51c toward the substrate unit 52. As for the side surface of the flow path member 51a, notched parts are provided at two points in the circumferential direction. Disposed in the space resulting from the part is, for example, a component such as wiring (not illustrated) coupling the heater 56 and the substrate unit 52. In addition, the flow path member 51a is provided with a hole (not illustrated) and fixing with respect to the holder 53 is performed by screwing using the hole.
The flow path member 51a is configured by a laminate (not illustrated) in which a plurality of substrates are laminated in the direction along the Z axis. The respective substrates are appropriately provided with grooves and holes for the supply and discharge flow paths described above. The substrates are mutually joined by means of, for example, an adhesive, brazing, welding, or screwing. If necessary, a sheet-shaped seal member made of a rubber material or the like may be appropriately disposed between the substrates. In addition, the number, thickness, and so on of the substrates that constitute the flow path member 51a are determined in accordance with an aspect such as the shapes of the supply and discharge flow paths and are any not particularly limited.
It is preferable that a material that is satisfactory in terms of thermal conductivity is used as the constituent material of each of the substrates, and preferable examples thereof include a metal material (e.g. stainless steel, titanium, and magnesium alloy) and a ceramics material (e.g. silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria) having a thermal conductivity of 10.0 W/m·K or more at room temperature (20° C.). By configuring the flow path member 51a using such a metal or ceramics material, the ink in the flow path member 51a can be efficiently heated by the heat from the heater 56.
Each of the eight coupling pipes 51b is a pipe body protruding from the surface of the flow path member 51a that faces the Z1 direction. The eight coupling pipes 51b correspond to the four supply flow paths and the four discharge flow paths described above and are coupled to the introduction ports of the supply flow paths or the discharge ports of the discharge flow paths that correspond. Although the constituent material of each coupling pipe 51b is not particularly limited, it is preferable to use a metal material (e.g. stainless steel, titanium, and magnesium alloy) or a ceramics material (e.g. silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria).
Of the eight coupling pipes 51b, the four that correspond to the four supply flow paths described above are coupled to the liquid storage portion 10 so as to receive the supply of different types of inks. Of the eight coupling pipes 51b, the four that correspond to the four discharge flow paths are used by being coupled to, for example, a discharge container for discharging ink on a predetermined occasion such as when the liquid ejecting head 50 is initially filled with ink or a sub-tank disposed between the liquid storage portion 10 and the liquid ejecting head 50 and capable of holding a liquid. On normal occasions such as printing, the four coupling pipes 51b that correspond to the four discharge flow paths are blocked by a sealing body such as a cap. When the liquid storage portion 10 is coupled to the liquid ejecting head 50 via the circulation mechanism, the four coupling pipes 51b that correspond to the four discharge flow paths are normally coupled to the ink collection flow path of the circulation mechanism.
The substrate unit 52 is an assembly having a mounting component for electrically coupling the liquid ejecting head 50 to the control unit 20. The substrate unit 52 has a circuit substrate 52a, a connector 52b, and a support plate 52c.
The circuit substrate 52a is a printed wiring substrate such as a rigid wiring substrate having wiring for electrically coupling each head chip 54 and the connector 52b. The circuit substrate 52a is disposed on the flow path structure 51 via the support plate 52c, and the connector 52b is installed on the surface of the circuit substrate 52a that faces the Z1 direction.
The connector 52b is a coupling component for electrically coupling the liquid ejecting head 50 and the control unit 20. The support plate 52c is a plate-shaped member for attaching the circuit substrate 52a with respect to the flow path structure 51. The circuit substrate 52a is mounted on one surface of the support plate 52c, and the circuit substrate 52a is fixed by screwing or the like with respect to the support plate 52c. The other surface of the support plate 52c is in contact with the flow path structure 51. The support plate 52c is fixed to the flow path structure 51 by screwing or the like in that state.
Here, the support plate 52c has not only a function of supporting the circuit substrate 52a as described above but also a function of ensuring electrical insulation between the circuit substrate 52a and the flow path structure 51 and providing heat insulation between the heater 56 and the circuit substrate 52a. From the viewpoint of suitably exhibiting these functions, it is preferable that the constituent material of the support plate 52c is a material excellent in terms of electrical and thermal insulation. Specifically, it is preferable that the material is, for example, a resin material such as modified polyphenylene ether resin (e.g. Zylon), polyphenylene sulfide resin, and polypropylene resin. Zylon is a registered trademark. In addition, the constituent material of the support plate 52c may include a fiber base material (e.g. glass fiber), a filler (e.g. alumina particles), or the like in addition to the resin material.
The holder 53 is a structure accommodating and supporting the four head chips 54. It is preferable that a material that is satisfactory in terms of thermal conductivity is used as the constituent material of the holder 53, and preferable examples thereof include a metal material (e.g. stainless steel, titanium, and magnesium alloy) and a ceramics material (e.g. silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria) having a thermal conductivity of 10.0 W/m·K or more at room temperature (20° C.). By configuring the holder 53 using such a metal or ceramics material, the heat from the heater 56 can be efficiently transferred to each head chip 54 via the holder 53.
The holder 53 has a substantially tray shape and has a recess 53a, a plurality of ink holes 53b, a plurality of wiring holes 53c, a plurality of recesses 53d, a plurality of screw holes 53i, and a plurality of screw holes 53k. The recess 53a is open toward the Z1 direction and is a space where the laminate of the flow path member 51a, the heater 56, and the heat transfer member 57 is disposed. Each of the ink holes 53b is a flow path allowing ink to flow between the head chip 54 and the flow path structure 51. The wiring substrate 54i of the head chip 54 is passed through each of the wiring holes 53c toward the substrate unit 52. Each of the recesses 53d is open toward the Z2 direction and is a space where the head chip 54 is disposed. The screw holes 53i are screw holes for screwing the holder 53 with respect to the support body 41. The screw holes 53k are screw holes for screwing the cover 58 with respect to the holder 53. Details of the holder 53 will be described later with reference to
Each head chip 54 ejects ink. Each head chip 54 has a plurality of nozzles ejecting a first ink and a plurality of nozzles ejecting a second ink, which is different in type from the first ink. Here, the first and second inks are two of the four types of inks described above. For example, two of the four types of inks are respectively used as the first and second inks for the head chip 54_1 and the head chip 54_2. The other two are respectively used for the head chip 54_3 and the head chip 54_4. Each head chip 54 is provided with the wiring substrate 54i. In
The fixing plate 55 is a plate-shaped member to which the four head chips 54 and the holder 53 are fixed. Specifically, the fixing plate 55 is disposed with the four head chips 54 sandwiched between the fixing plate 55 and the holder 53 and each head chip 54 and the holder 53 are fixed by means of an adhesive or the like.
The fixing plate 55 is provided with a plurality of opening portions 55a exposing a nozzle surface FN of the four head chips 54. In the example illustrated in
The fixing plate 55 has a rectangular or substantially rectangular outer shape in a plan view. Here, “substantially rectangular” is a concept including a shape that can be regarded as a substantially rectangular shape and a shape that is similar to a rectangle. The shape that can be regarded as a substantially rectangular shape can be obtained by, for example, performing chamfering such as C chamfering and R chamfering on the four corners of a rectangle. The shape similar to a rectangle is, for example, an octagon including four sides along the rectangle and four sides shorter than each of the four sides. The opening portion 55a may be shared by two or more head chips 54. When the opening portions 55a are individually provided for each head chip 54, the area of contact between the fixing plate 55 and each head chip 54 can be increased with ease, and thus heat can be efficiently transferred from the holder 53 to each head chip 54.
The heater 56 is a planar heater disposed between the flow path structure 51 and the holder 53. The heater 56 is, for example, a film heater having an insulating film and a thin film-shaped heat-generating resistor. The film is made of a resin material such as polyimide and polyethylene terephthalate (PET). The heat-generating resistor is patterned on the film and is made of a metal material such as stainless steel, copper, and a nickel alloy. In addition, the heater 56 may be a planar heater such as a ceramic heater and a silicone rubber heater in which a heating element is sandwiched between silicone rubber and silicone rubber containing glass fibers.
The heater 56 is provided with a plurality of holes 56a and a plurality of holes 56b. Each of the holes 56a is a hole through which the wiring substrate 54i of the head chip 54 and a flow path pipe 531 formed in the holder 53 are passed. The ink hole 53b formed in the flow path pipe 531 is a part of the flow path that allows ink to flow between the head chip 54 and the flow path structure 51. The flow path pipe 531 protrudes in the Z1 direction from, for example, the upper surface of the holder 53 facing the Z1 direction (first surface F1 to be described later). The tip of the flow path pipe 531 on the Z1 direction side is bonded to the lower surface of the flow path structure 51 facing the Z2 direction. As a result, the ink hole 53b is liquid-tightly sealed in relation to the flow path in the flow path structure 51. Each of the holes 56b is a hole for screwing the heater 56 with respect to the holder 53. Details of the shape of the heater 56 in a plan view will be described later with reference to
The heat transfer member 57, which has thermal conductivity, is a plate-shaped member disposed between the flow path structure 51 and the heater 56. The heat transfer member 57 has a function of transferring heat in each of the thickness and plane directions. By means of this function, the heat from the heater 56 is efficiently transferred to the flow path structure 51 via the heat transfer member 57. Here, the heating unevenness of the flow path structure 51 attributable to the heat generation distribution of the heater 56 is reduced by means of the plane-direction heat transfer of the heat transfer member 57.
The heat transfer member 57 is made of, for example, a metal material or a thermally conductive material such as ceramics (e.g. silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria). Examples of the metal material include stainless steel, aluminum, titanium, and a magnesium alloy. The heat transfer member 57 is preferably a material having a high level of thermal conductivity with respect to the flow path structure 51 and the holder 53. By providing the heat transfer member 57 having a high level of thermal conductivity as described above, the heat from the heater 56 can be easily moved in the direction parallel to the nozzle surface FN. As a result, the heat from the heater 56 can be uniformly and efficiently transferred to the flow path structure 51, which is an object of heating, via the heat transfer member 57.
The heat transfer member 57 is provided with a plurality of holes 57a, a plurality of wiring holes 57b, and a plurality of holes 57c. The flow path pipe 531 is inserted through each of the holes 57a. The wiring substrate 54i of the head chip 54 is passed through each of the wiring holes 57b toward the substrate unit 52. The holes 57c are holes for screwing the heat transfer member 57 with respect to the holder 53. In the present embodiment, two of the holes 57c are used so that the heater 56 and the heat transfer member 57 are fixed to the holder 53 by being tightened together. Details of the shape of the heat transfer member 57 in a plan view will be described later with reference to
The cover 58 is a box-shaped member accommodating the substrate unit 52. The cover 58 is made of, for example, a resin material such as modified polyphenylene ether resin, polyphenylene sulfide resin, and polypropylene resin as in the case of the support plate 52c described above.
The cover 58 is provided with eight through holes 58a and an opening portion 58b. The eight through holes 58a correspond to the eight coupling pipes 51b of the flow path structure 51, and the corresponding coupling pipe 51b is inserted into each through hole 58a. The connector 52b is passed through the opening portion 58b from the inside to the outside of the cover 58.
The head chip 54 has a substantially symmetrical configuration in the direction along the X axis. However, the positions of the nozzles N in the first row L1 and the nozzles N in the second row L2 in the direction along the Y axis may be the same as or different from each other. Exemplified in
As illustrated in
The flow path substrate 54a and the pressure chamber substrate 54b are laminated in this order in the Z1 direction and form a flow path for ink supply to the nozzles N. The diaphragm 54e, the piezoelectric elements 54f, the protective plate 54g, the case 54h, the wiring substrate 54i, and the drive circuit 54j are installed in the region that is positioned in the Z1 direction beyond the laminate of the flow path substrate 54a and the pressure chamber substrate 54b. The nozzle plate 54c and the vibration absorber 54d are installed in the region that is positioned in the Z2 direction beyond the laminate. Schematically, each element of the head chip 54 is a plate-shaped member that is elongated in the Y direction. The elements are joined together by means of, for example, an adhesive. Hereinafter, the elements of the head chip 54 will be described in order.
The nozzle plate 54c is a plate-shaped member provided with the respective nozzles N in the first row L1 and the second row L2. Each of the nozzles N is a through hole through which ink is passed. Here, the surface of the nozzle plate 54c that faces the Z2 direction is the nozzle surface FN. In other words, the normal direction of the nozzle surface FN is the direction of the normal vector of the nozzle surface FN and is the Z2 direction (ejection direction). The nozzle plate 54c is manufactured by, for example, processing a silicon single crystal substrate by a semiconductor manufacturing technique using a processing technique such as dry etching and wet etching. Alternatively, another known method and another known material may be appropriately used in manufacturing the nozzle plate 54c. The cross-sectional shape of the nozzle is typically circular, the shape is not limited thereto, and the shape may be a non-circular shape such as polygonal and elliptical shapes.
The flow path substrate 54a is provided with a space R1, a plurality of supply flow paths Ra, and a plurality of communication flow paths Na for each of the first row L1 and the second row L2. The space R1 is an elongated opening extending in the direction along the Y axis in a plan view in the direction along the Z axis. Each of the supply flow path Ra and the communication flow path Na is a through hole formed for each nozzle N. Each supply flow path Ra communicates with the space R1.
The pressure chamber substrate 54b is a plate-shaped member provided with a plurality of pressure chambers C called cavities for each of the first row L1 and the second row L2. The pressure chambers C are arranged in the direction along the Y axis. Each pressure chamber C is an elongated space formed for each nozzle N and extending in the direction along the X axis in a plan view. As in the case of the nozzle plate 54c described above, each of the flow path substrate 54a and the pressure chamber substrate 54b is manufactured by, for example, processing a silicon single crystal substrate by a semiconductor manufacturing technique. Alternatively, another known method and another known material may be appropriately used in manufacturing each of the flow path substrate 54a and the pressure chamber substrate 54b.
The pressure chamber C is a space positioned between the flow path substrate 54a and the diaphragm 54e. The pressure chambers C are arranged in the direction along the Y axis for each of the first row L1 and the second row L2. In addition, the pressure chamber C communicates with each of the communication flow path Na and the supply flow path Ra. Accordingly, the pressure chamber C communicates with the nozzle N via the communication flow path Na and communicates with the space R1 via the supply flow path Ra.
The diaphragm 54e is disposed on the surface of the pressure chamber substrate 54b that faces the Z1 direction. The diaphragm 54e is a plate-shaped member that is capable of elastically vibrating. The diaphragm 54e has, for example, a first layer and a second layer, which are laminated in the Z1 direction in this order. The first layer is, for example, an elastic film made of silicon oxide (SiO2). The elastic film is formed by, for example, thermally oxidizing one surface of a silicon single crystal substrate. The second layer is, for example, an insulating film made of zirconium oxide (ZrO2). The insulating film is formed by, for example, forming a zirconium layer by a sputtering method and thermally oxidizing the layer. The diaphragm 54e is not limited to the configuration resulting from the lamination of the first and second layers. For example, the diaphragm 54e may be configured by a single layer or three or more layers.
On the surface of the diaphragm 54e that faces the Z1 direction, the piezoelectric elements 54f mutually corresponding to the nozzles N are disposed as drive elements for each of the first row L1 and the second row L2. Each piezoelectric element 54f is a passive element deformed by drive signal supply. Each piezoelectric element 54f has an elongated shape extending in the direction along the X axis in a plan view. The piezoelectric elements 54f are arranged in the direction along the Y axis so as to correspond to the pressure chambers C. The piezoelectric element 54f overlaps the pressure chamber C in a plan view.
Each piezoelectric element 54f has a first electrode (not illustrated), a piezoelectric layer (not illustrated), and a second electrode (not illustrated), which are laminated in the Z1 direction in this order. One of the first and second electrodes is an individual electrode disposed so as to be mutually separated for each piezoelectric element 54f, and a drive signal is applied to the electrode. The other of the first and second electrodes is a band-shaped common electrode extending in the direction along the Y axis so as to be continuous over the piezoelectric elements 54f, and a predetermined reference potential is supplied to the electrode. Examples of the metal material of the electrodes include metal materials such as platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu). One of the materials can be used alone or two or more can be used in combination in the form of an alloy, lamination, or the like. The piezoelectric layer is made of a piezoelectric material such as lead zirconate titanate (Pb (Zr, Ti) O3). The piezoelectric layer forms, for example, a band shape extending in the direction along the Y axis so as to be continuous over the piezoelectric elements 54f. Alternatively, the piezoelectric layer may be integrated over the piezoelectric elements 54f. As for the piezoelectric layer in this case, a through hole penetrating the piezoelectric layer is provided, so as to extend in the direction along the X axis, in the region that corresponds in a plan view to the gap between the pressure chambers C adjacent to each other. When the diaphragm 54e vibrates in conjunction with the above deformation of the piezoelectric element 54f, the pressure in the pressure chamber C fluctuates and ink is ejected from the nozzle N as a result. A heat-generating element heating the ink in the pressure chamber C may replace the piezoelectric element 54f as a drive element.
The protective plate 54g is a plate-shaped member installed on the surface of the diaphragm 54e that faces the Z1 direction, protects the piezoelectric elements 54f, and reinforces the mechanical strength of the diaphragm 54e. Here, the piezoelectric elements 54f are accommodated between the protective plate 54g and the diaphragm 54e. The protective plate 54g is made of, for example, a resin material.
The case 54h is a case for storing ink supplied to the pressure chambers C. The case 54h is made of, for example, a resin material. The case 54h is provided with a space R2 for each of the first row L1 and the second row L2. The space R2 communicates with the space R1 and functions together with the space R1 as a reservoir R storing ink supplied to the pressure chambers C. The case 54h is provided with an introduction port IO for ink supply to each reservoir R. The ink in each reservoir R is supplied to the pressure chamber C via each supply flow path Ra.
The vibration absorber 54d is also called a compliance substrate, is a flexible resin film constituting the wall surface of the reservoir R, and absorbs the pressure fluctuation of the ink in the reservoir R. The vibration absorber 54d may be a metallic and flexible thin plate. The surface of the vibration absorber 54d that faces the Z1 direction is joined to the flow path substrate 54a by means of, for example, an adhesive. A frame body 54k is joined to the surface of the vibration absorber 54d that faces the Z2 direction by means of, for example, an adhesive. The frame body 54k is a frame-shaped member that is along the outer periphery of the vibration absorber 54d and comes into contact with the fixing plate 55. Here, the frame body 54k is made of a metal material such as stainless steel, aluminum, titanium, and a magnesium alloy. By configuring the frame body 54k by means of a metal material as described above, the heat from the heater 56 can be suitably transferred to the ink in the head chip 54 via the holder 53 and the fixing plate 55. In
The wiring substrate 54i, which is mounted on the surface of the diaphragm 54e that faces the Z1 direction, is a mounting component for electrically coupling the control unit 20 and the head chip 54. The wiring substrate 54i is a flexible wiring substrate such as a chip on film (COF), a flexible printed circuit (FPC), and a flexible flat cable (FFC). The drive circuit 54j for drive voltage supply to each piezoelectric element 54f is mounted on the wiring substrate 54i of the present embodiment. The drive circuit 54j performs switching based on the control signal S as to whether or not to supply at least a part of the waveform in the drive signal D as a drive pulse.
The bottom portion 5a has a substantially plate shape extending in a direction orthogonal to the Z axis and constitutes the bottom surface of the recess 53a. Here, the bottom portion 5a is divided into a holding portion 5a1 and a coupling portion 5a2 disposed so as to surround the outer periphery of the holding portion 5a1 and thinner than the holding portion 5a1.
The holding portion 5a1 has the four recesses 53d described above and holds the four head chips 54. Each head chip 54 is accommodated in the space that is surrounded between each recess 53d and the fixing plate 55. In addition, as illustrated in
The heat receiving portion 5a11 has a plate shape having the first surface F1 and a second surface F2 extending in a direction orthogonal to the Z axis and constitutes the bottom surfaces of the recess 53d and the recess 53h. The first surface F1, which faces the Z1 direction, is a heat receiving surface receiving the heat from the heater 56. The flow path structure 51 is placed on the first surface F1 via the heater 56 and the heat transfer member 57 described above. The second surface F2 faces the Z2 direction and constitutes the bottom surfaces of the recess 53d and the recess 53h.
In the example illustrated in
The holes 53e are used in positioning the head chip 54 with respect to the holder 53 by inserting a protrusion (not illustrated) provided on the head chip 54. The holes 53f are holes for inserting positioning pins used in positioning the flow path structure 51, the heater 56, and the heat transfer member 57. The screw holes 53g are used in screwing the heat transfer member 57. The screw holes 53g are used in screwing the flow path structure 51.
The side wall portion 5a12 protrudes in the Z2 direction from the heat receiving portion 5a11 and constitutes the side surfaces of the recess 53d and the recess 53h. The coupling portion 5a2 is coupled to the end of the side wall portion 5a12 in the Z2 direction. Here, when viewed in the direction along the Z axis, the shape of the side wall portion 5a12 is the shape of the heat receiving portion 5a11 from which the shapes of the recesses 53d and the recesses 53h are removed. In other words, the side wall portion 5a12 that is viewed in the direction along the Z axis includes a partition wall between the adjacent recesses 53d, a partition wall between the adjacent recesses 53d and 53h, and an outer peripheral wall surrounding the recesses 53d and the recesses 53h.
The coupling portion 5a2 is disposed so as to surround the holding portion 5a1 when viewed in the direction along the Z axis. The coupling portion 5a2 has a plate shape extending from the side wall portion 5a12 in a direction orthogonal to the Z axis and couples the side wall portion 5a12 and the outer wall portion 5b over the entire circumference. The coupling portion 5a2 may have a shape having a defective part or may be configured by a plurality of parts arranged at intervals in the circumferential direction.
The outer wall portion 5b, which constitutes the side surface of the recess 53a described above, has a frame shape extending in the Z1 direction over the entire circumference from the peripheral edge of the bottom portion 5a.
The flange portion 5c has a plate shape protruding outward in a direction orthogonal to the Z axis from the end of the outer wall portion 5b in the Z1 direction. In this manner, the outer peripheral edge of the coupling portion 5a2 of the bottom portion 5a is coupled via the outer wall portion 5b to the inner peripheral edge of the flange portion 5c. In the example illustrated in
As illustrated in
As illustrated in
Specifically, the head chip 54_1, the head chip 54_2, the head chip 54_3, and the head chip 54_4 are arranged in this order in the X1 direction. The head chip 54_1 and the head chip 54_3 are disposed at positions misaligned in the Y1 direction with respect to the head chip 54_2 and the head chip 54_4. Here, the head chip 54_1 and the head chip 54_3 are disposed side by side in the direction along the X axis such that the mutual positions in the direction along the Y axis are aligned. Likewise, the head chip 54_2 and the head chip 54_4 are disposed side by side in the direction along the X axis such that the mutual positions in the direction along the Y axis are aligned. In addition, in a plan view, each head chip 54 has a rectangular or substantially rectangular shape extending in the direction along the Y axis.
In
The outer edge OE1 of the holding portion 5a1 has a part positioned inside the rectangle VS and a part positioned outside the rectangle VS.
Here, when the four sides of the rectangle VS are a first side E1, a second side E2, a third side E3, and a fourth side E4, the head chip 54_1 is in contact with the first side E1 and the third side E3 in a plan view. The head chip 54_2 is in contact with the second side E2 in a plan view. The head chip 54_3 is in contact with the third side E3 in a plan view. The head chip 54_4 is in contact with the second side E2 and the fourth side E4 in a plan view.
The first side E1 is one of the four sides of the rectangle VS. The second side E2 is coupled to one end of the first side E1, which is one of the four sides of the rectangle VS. The third side E3 is coupled to the other end of the first side E1, which is one of the four sides of the rectangle VS. The fourth side E4 is the side of the rectangle VS other than the first side E1, the second side E2, and the third side E3.
A first region RE1 surrounded by the first side E1, the second side E2, the head chip 54_1, and the head chip 54_2 in a plan view is divided into a first inside part RE1a and a first outside part RE1b by the outer edge OE1. The first inside part RE1a is the part of the first region RE1 that is positioned inside the outer edge OE1. The first outside part RE1b is the part of the first region RE1 that is positioned outside the outer edge OE1. The first region RE1, which is rectangular, is surrounded by the first side E1, the second side E2, a straight line along the short side that is one of the two short sides of the head chip 54_1 and closer to the head chip 54_2, and a straight line along the long side that is one of the two long sides of the head chip 54_2 and closer to the head chip 54_1 in a plan view.
Here, the first side E1 has a first part PA1 defining the first region RE1. The first part PA1 is one of the four sides constituting the rectangular first region RE1 and belongs to the first side E1. The second side E2 has a second part PA2 defining the first region RE1. The second part PA2 is one of the four sides constituting the rectangular first region RE1 and belongs to the second side E2. In a plan view, the outer edge OE1 of the holding portion 5a1 intersects with both the first part PA1 and the second part PA2.
In a plan view, an intersection IPa between the outer edge OE1 of the holding portion 5a1 and the first part PA1 is positioned closer to the head chip 54_1 than a midpoint MP1 of the first part PA1 and an intersection IPb between the outer edge OE1 of the holding portion 5a1 and the second part PA2 is positioned closer to the head chip 54_2 than a midpoint MP2 of the second part PA2. In the example illustrated in
Further, a center CP of the first region RE1 is positioned outside the outer edge OE1 of the holding portion 5a1 in a plan view. In other words, the center CP of the first region RE1 is not included inside the outer edge OE1 of the holding portion 5a1. In the example illustrated in
As in the case of the first region RE1 described above, a second region RE2 surrounded by the third side E3, the fourth side E4, the head chip 54_3, and the head chip 54_4 in a plan view is divided into a second inside part RE2a and a second outside part RE2b by the outer edge OE1. The second inside part RE2a is positioned inside the outer edge OE1. The second outside part RE2b is positioned outside the outer edge OE1. The second region RE2, which is rectangular, is surrounded by the third side E3, the fourth side E4, a straight line along the long side that is one of the two long sides of the head chip 54_3 and closer to the head chip 54_4, and a straight line along the short side that is one of the two short sides of the head chip 54_4 and closer to the head chip 54_3 in a plan view.
As illustrated in
In
In a plan view, the first region RE1 is divided into a first inside part RE1c and a first outside part RE1d by the outer edge OE2. The first inside part RE1c is the part of the first region RE1 that is positioned inside the outer edge OE2. The first outside part RE1d is the part of the first region RE1 that is positioned outside the outer edge OE2. As described above, the outer edge OE2 in the present embodiment is schematically identical in shape to the outer edge OE1 of the holding portion 5a1. Accordingly, the first inside part RE1c is substantially identical to the first inside part RE1a and the first outside part RE1d is substantially identical to the first outside part RE1b.
In a plan view, the outer edge OE2 of the heater 56 includes the head chips 54 and intersects with both the first part PA1 and the second part PA2. In addition, in a plan view, an intersection IPc between the outer edge OE2 of the heater 56 and the first part PA1 is positioned closer to the head chip 54_1 than the midpoint MP1 of the first part PA1 and an intersection IPd between the outer edge OE2 of the heater 56 and the second part PA2 is positioned closer to the head chip 54_2 than the midpoint MP2 of the second part PA2. In the example illustrated in
The center CP of the first region RE1 is positioned outside the outer edge OE2 in a plan view. In other words, the center CP of the first region RE1 is not included inside the outer edge OE2 of the heater 56. In the example illustrated in
As in the case of the first region RE1, the second region RE2 is divided into a second inside part RE2c and a second outside part RE2d by the outer edge OE2 in a plan view. The second inside part RE2c is positioned inside the outer edge OE2. The second outside part RE2d is positioned outside the outer edge OE2. In the present embodiment, the second inside part RE2c is substantially identical to the second inside part RE2a and the second outside part RE2d is substantially identical to the second outside part RE2b.
In a plan view, the heat transfer member 57 indicated by a dashed line in
Here, the plan-view shape of the heat transfer member 57 is substantially identical to the plan-view shape of the flow path structure 51. Accordingly, in a plan view, the flow path structure 51 overlaps at least a part of each of the first outside part RE1d and the second outside part RE2d. Likewise, although not illustrated, the flow path structure 51 overlaps at least a part of each of the first outside part RE1b and the second outside part RE2b illustrated in
As described above, the support body 41 is provided with the opening 41a into which the outer wall portion 5b is inserted. The flange portion 5c has an attachment surface 5c1 facing the Z2 direction, which is the normal direction of the nozzle surface FN. The holder 53 is attached to the support body 41 in a state where the outer wall portion 5b is inserted in the opening 41a with the outer wall portion 5b and the support body 41 having a gap d1 therebetween and the attachment surface 5c1 is in contact with the support body 41.
As described above, the heater 56 heats each head chip 54 by transferring heat to each head chip 54 through the transfer path H1.
The heat from the heater 56 is partially transferred to the support body 41 via the holder 53. In other words, some of the heat from the heater 56 escapes to the support body 41 via the holder 53 without being used for heating each head chip 54. This heat escape results in not only a decline in the efficiency of the heating of each head chip 54 by the heater 56 but also a variation in the temperature distribution in each head chip 54 or between the head chips 54.
In order to reduce the heat escape, the holder 53 has a configuration for increasing the thermal resistance in the transfer path H2 of the heat from the heater 56 to the support body 41. Specifically, in the holder 53, the heat receiving portion 5a11 and the flange portion 5c are coupled via the side wall portion 5a12, the coupling portion 5a2, and the outer wall portion 5b as described above.
The transfer path H2 is a path where heat is transferred to the heat receiving portion 5a11, the side wall portion 5a12, the coupling portion 5a2, the outer wall portion 5b, and the flange portion 5c in this order. Each of the coupling portion 5a2 and the flange portion 5c extends in a direction intersecting with the Z axis whereas each of the side wall portion 5a12 and the outer wall portion 5b extends in the direction along the Z axis. Accordingly, the transfer path H2 is bent or curved at two or more points between the heat receiving portion 5a11 and the flange portion 5c when viewed in a cross section as illustrated in
Here, the outer peripheral surface of the side wall portion 5a12 is disposed with a gap d3 formed over the entire area with respect to the inner peripheral surface of the outer wall portion 5b. Accordingly, the heat transfer from the side wall portion 5a12 to the outer wall portion 5b passes through the coupling portion 5a2 without being directly performed therebetween. In addition, the flow path structure 51 is disposed with the gap d2 formed between the flow path structure 51 and the outer wall portion 5b. Accordingly, the heat transfer from the heat receiving portion 5a11 to the outer wall portion 5b does not pass through the flow path structure 51.
As described above, the liquid ejecting head 50 includes the head chips 54, the thermally conductive holder 53, the thermally conductive flow path structure 51, and the planar heater 56. Each of the head chips 54 has the nozzle surface FN provided with the nozzle N ejecting ink, which is an example of “liquid”. The holder 53 holds the head chips 54. The flow path structure 51 is provided with a flow path of the ink that is supplied to the head chips 54. The heater 56 is disposed between the holder 53 and the flow path structure 51 and is along the direction that is parallel to the nozzle surface FN. In addition, the heater 56 overlaps the head chips 54 in a plan view.
In the liquid ejecting head 50, the heater 56 is disposed between the holder 53 and the flow path structure 51. Accordingly, the heat from the heater 56 can be efficiently transferred to each of the holder 53 and the flow path structure 51 as compared with the configuration of the related art in which the flow path structure 51 is interposed between the heater 56 and the holder 53. As a result, it is possible to reduce the temperature difference between the holder 53 and the flow path structure 51 and, by extension, the temperature difference between the head chip 54 and the flow path structure 51. In addition, the heater 56 has a planar shape along the direction parallel to the nozzle surface and overlaps the head chips 54 in a plan view. Accordingly, the heat from the heater 56 can be efficiently transferred to each of the head chips 54 as compared with a configuration in which the heater 56 overlaps only some of the head chips 54 in a plan view. As a result, the temperature difference between the head chips 54 can be reduced. From the above, it is possible to manage the temperature of the head chip 54 with high accuracy by controlling the temperature of the heater 56.
As described above, the holder 53 in the present embodiment has the holding portion 5a1 holding the head chips 54. The holding portion 5a1 includes the head chips 54 in a plan view. Accordingly, the heat from the heater 56 can be transferred to the head chips 54 via the single holding portion 5a1. As a result, there is no need to provide the heater 56 for each head chip 54 and the heater 56 can be installed with ease.
Each of the head chips 54 is elongated along the direction along the Y axis. In addition, the head chips 54 include the head chip 54_1 as an example of “first head chip” and the head chip 54_2 as an example of “second head chip”. The head chip 54_1 and the head chip 54_2 are adjacent to each other. Here, the head chips being adjacent to each other means the positional relationship between the head chips 54 and a configuration other than the head chip 54 (for example, corresponding to the side wall portion 5a12 of the holder 53 in the present embodiment) may be interposed between the head chips 54. In addition, the head chip 54_1 and the head chip 54_3 are disposed to be offset from each other in the direction along the X axis and at the same position pertaining to the direction along the Y axis such that the end portion of the head chip 54_2 in the Y1 direction is interposed. However, in terms of positional relationship, the head chip 54_1 and the head chip 54_3 face each other in the direction along the X axis by at least half of the dimension of the head chip 54 pertaining to the direction along the Y axis. Accordingly, it can be said that the head chip 54_1 and head chip 54_3 are also adjacent to each other. The head chip 54_1 and the head chip 54_2 are disposed to be offset from each other in both the direction along the Y axis and the direction along the X axis. When the first and second directions are two directions intersecting with each other along the nozzle surface FN, the direction along the Y axis is an example of “first direction” and the direction along the X axis is an example of “second direction”.
Here, the head chip 54_1 is in contact with the first side E1 and the third side E3 of the virtual rectangle VS in a plan view and the head chip 54_2 is in contact with the second side E2 in a plan view. The first region RE1 surrounded by the first side E1, the second side E2, the head chip 54_1, and the head chip 54_2 in a plan view includes the first outside part RE1b positioned outside the outer edge OE1 of the holding portion 5a1. The outer edge OE1 is the outer edge of the side wall portion 5a12 in a plan view.
As described above, the rectangle VS circumscribes the aggregate of the head chips 54 of the liquid ejecting head 50 in a plan view. The first side E1 is one of the four sides of the rectangle VS. The second side E2 is coupled to one end of the first side E1, which is one of the four sides of the rectangle VS. The third side E3 is coupled to the other end of the first side E1, which is one of the four sides of the rectangle VS.
The first outside part RE1b lacks the holding portion 5a1 and lacks the head chip 54. Accordingly, the presence of the first outside part RE1b means reducing a useless part other than the part of the holding portion 5a1 that should be heated. Accordingly, it is possible to reduce the heat from the heater 56 escaping to the useless part. As a result, the head chip 54 can be efficiently heated by the heater 56. This is also advantageous in that the area or power consumption of the heater 56 can be reduced.
As described above, the holder 53 is provided with the ink holes 53b and the ink holes 53b constitute a flow path of the ink that is supplied to the head chips 54. Accordingly, from the viewpoint of increasing the ink resistance of the holder 53 and efficiently transferring the heat from the heater 56 to the ink in the ink hole 53b via the holder 53, it is preferable that the holder 53 is made of stainless steel or ceramics.
In a plan view, the first region RE1 includes the first outside part RE1d, which does not overlap the heater 56. Accordingly, the area of the heater 56 can be reduced. The first outside part RE1d lacks the head chip 54_1 and lacks the head chip 54_2, and thus useless heat generation of the heater 56 can be reduced. As a result, the head chip 54 can be efficiently heated by the heater 56.
As described above, the liquid ejecting head 50 further includes the heat transfer member 57 as an example of “second heat transfer member”. The heat transfer member 57 is disposed between the heater 56 and the flow path structure 51, is higher in thermal conductivity than the flow path structure 51, and is, for example, aluminum. In a plan view, each of the heat transfer member 57 and the flow path structure 51 overlaps the first outside part RE1b. Since the flow path structure 51 is at the first outside part RE1b, the degree of freedom can be increased in routing the flow path in the flow path structure 51. In addition, since the heat transfer member 57 is disposed between the heater 56 and the flow path structure 51, the heat from the heater 56 can be transferred to the flow path structure 51 after being spread in the plane direction by the second heat transfer member. In particular, even with the flow path structure 51 at a part of the first outside part RE1b, the heat transfer member 57 is also at the first outside part RE1b, and thus the heat from the heater 56 can be transferred to the part via the heat transfer member 57. As a result, it is possible to reduce a variation in the temperature distribution of the flow path structure 51 attributable to the heater 56.
As described above, from the viewpoint of increasing the ink resistance of the flow path structure 51 and efficiently transferring the heat from the heater 56 to the ink in the flow path structure 51, it is preferable that the flow path structure 51 is made of stainless steel or ceramics.
In the present embodiment, the head chips 54 include the head chip 54_3 as an example of “third head chip” and the head chip 54_4 as an example of “fourth head chip”. The head chip 54_3 and the head chip 54_4 are disposed to be offset from each other in both the direction along the Y axis and the direction along the X axis.
Here, when the fourth side E4 is the side of the virtual rectangle VS other than the first side E1, the second side E2, and the third side E3, the head chip 54_3 is in contact with the third side E3 in a plan view and the head chip 54_4 is in contact with the second side E2 and the fourth side E4 in a plan view. The second region RE2 surrounded by the third side E3, the fourth side E4, the head chip 54_3, and the head chip 54_4 in a plan view includes the second outside part RE2b positioned outside the outer edge OE1 of the holding portion 5a1.
As in the case of the first outside part RE1b, the second outside part RE2b lacks the holding portion 5a1 and lacks the head chip 54. Accordingly, the presence of the second outside part RE2b means reducing a useless part other than the part of the holding portion 5a1 that should be heated. Accordingly, it is possible to reduce the heat from the heater 56 escaping to the useless part. As a result, the head chip 54 can be efficiently heated by the heater 56. This is also advantageous in that the area or power consumption of the heater 56 can be reduced.
The area of the first outside part RE1b is preferably 25% or more of the area of the first region RE1 and more preferably 50% or more and 90% or less of the area of the first region RE1. By the area of the first outside part RE1b being within this range, the above useless part of the holding portion 5a1 can be suitably reduced. Assuming that the area of the first outside part RE1b is too small, the power consumption of the heater 56 tends to increase and the temperature distribution in each head chip 54 or between the head chips 54 tends to vary. Assuming that the area of the first outside part RE1b is too large, it is difficult to ensure a wall thickness that is necessary for the holding portion 5a1. In addition, the area of the second outside part RE2b is preferably 25% or more of the area of the second region RE2 as in the case of the relationship between the area of the first outside part RE1b and the first region RE1.
As described above, the heater 56 overlaps the head chips 54 in a plan view. In a plan view, the first region RE1 includes the first outside part RE1d positioned outside the outer edge OE2 of the heater 56.
The first outside part RE1d lacks the heater 56 and lacks the head chip 54. Accordingly, the presence of the first outside part RE1d means reducing the unnecessary part of the heater 56. Accordingly, it is possible to reduce a variation in the temperature distribution in each head chip 54 or between the head chips 54 attributable to heat generation at the unnecessary part. This is also advantageous in that the area or power consumption of the heater 56 can be reduced.
In a plan view, each of the heat transfer member 57 and the flow path structure 51 overlaps the first outside part RE1d. Since the flow path structure 51 is at the first outside part RE1d, the degree of freedom can be increased in routing the flow path in the flow path structure 51. In addition, even with the flow path structure 51 at a part of the first outside part RE1d, the heat transfer member 57 is also at the first outside part RE1d, and thus the heat from the heater 56 can be transferred to the part via the heat transfer member 57. As a result, it is possible to reduce a variation in the temperature distribution of the flow path structure 51 attributable to the heater 56. This is particularly useful in a configuration in which a part of the flow path in the flow path structure 51 overlaps the first outside part RE1d in a plan view.
As described above, in a plan view, the second region RE2 includes the second outside part RE2d positioned outside the outer edge OE2 of the heater 56.
As in the case of the first outside part RE1d, the second outside part RE2d lacks the heater 56 and lacks the head chip 54. Accordingly, the presence of the second outside part RE2d means reducing the unnecessary part of the heater 56. Accordingly, it is possible to reduce a variation in the temperature distribution in each head chip 54 or between the head chips 54 attributable to heat generation at the unnecessary part. This is also advantageous in that the area or power consumption of the heater 56 can be reduced.
The area of the first outside part RE1d is preferably 25% or more of the area of the first region RE1 and more preferably 50% or more and 90% or less of the area of the first region RE1. By the area of the first outside part RE1d being within this range, the unnecessary part of the heater 56 can be suitably reduced. Assuming that the area of the first outside part RE1d is too small, the power consumption of the heater 56 tends to increase and the temperature distribution in each head chip 54 or between the head chips 54 tends to vary. Assuming that the area of the first outside part RE1d is too large, it is difficult to uniformly transfer the heat from the heater 56 to the holding portion 5a1 depending on, for example, the size of the holding portion 5a1. Also in this respect, the temperature distribution in each head chip 54 or between the head chips 54 tends to vary. In addition, the area of the second outside part RE2d is preferably 25% or more of the area of the second region RE2 as in the case of the relationship between the area of the first outside part RE1d and the first region RE1.
As described above, the liquid ejecting head 50 is supported by the support body 41. Here, the holder 53 has not only the holding portion 5a1 but also the flange portion 5c coming into contact with the support body 41 at a position apart from the holding portion 5a1. The heater 56 heats the holding portion 5a1. The holding portion 5a1 has the heat receiving portion 5a11, which receives the heat from the heater 56.
As for the transfer path H2, the shortest path of the heat transferred through the holder 53 from the heat receiving portion 5a11 to the flange portion 5c is bent or curved at two or more points. Here, being bent or curved means, for example, a state where the length of the side wall portion 5a12 along the transfer path H2 (that is, the length of the side wall portion 5a12 pertaining to the direction along the Z axis) and the length of the coupling portion 5a2 along the transfer path H2 (that is, the length of the coupling portion 5a2 pertaining to the direction along the Y axis) respectively exceed the thickness of the side wall portion 5a12 in the thickness direction (direction along the Y axis) and the thickness of the coupling portion 5a2 in the thickness direction (direction along the Z axis) in the case of being bent or curved between the side wall portion 5a12 and the coupling portion 5a2 as in the present embodiment. The same applies to being bent or curved between the coupling portion 5a2 and the outer wall portion 5b and a case of being bent or curved at parts other than the parts. “Shortest path from the heat receiving portion 5a11 to the flange portion 5c” does not include the path of the heat that moves in the heat receiving portion 5a11 and the flange portion 5c. More specifically, “shortest path from the heat receiving portion 5a11 to the flange portion 5c” is a part of the shortest path that is through the holder 53 from any position of the heat receiving portion 5a11 to the position of contact between the flange portion 5c and the support body 41 and the part does not include the path of the heat that moves in the heat receiving portion 5a11 and the flange portion 5c. Accordingly, the thermal resistance of the shortest path can be increased as compared with a configuration in which the shortest path from the heat receiving portion 5a11 to the flange portion 5c is in a straight line and a configuration in which the thickness of the coupling portion 5a2 is increased such that the surface of the coupling portion 5a2 facing the Z1 direction coincides with the first surface F1. Accordingly, it is possible to make it difficult for the heat from the heater 56 to be dissipated to the support body 41 via the flange portion 5c. As a result, the head chip 54 can be efficiently heated by the heater 56.
As described above, the heater 56 is disposed at a position that is in the direction (Z1 direction) opposite to the normal direction of the nozzle surface FN (Z2 direction) with respect to the holding portion 5a1. The holding portion 5a1 further has the side wall portion 5a12 extending in the normal direction (Z2 direction) from the heat receiving portion 5a11. The heat receiving portion 5a11 and the side wall portion 5a12 form the recess 53d, which is an example of “space” accommodating the head chip 54. Accordingly, the head chip 54, the holder 53, and the heater 56 can be easily assembled so as to be laminated in this order.
The holder 53 further has the outer wall portion 5b coupled to the flange portion 5c and surrounding the side wall portion 5a12 when viewed in the normal direction and the coupling portion 5a2 coupling the side wall portion 5a12 and the outer wall portion 5b. The coupling portion 5a2 extends in a direction intersecting with the normal direction, and each of the side wall portion 5a12 and the outer wall portion 5b extends from the coupling portion 5a2 in the direction opposite to the normal direction.
In this manner, the holder 53 has the holding portion 5a1 holding the head chip 54, the flange portion 5c coming into contact with the support body 41 at a position apart from the holding portion 5a1, the outer wall portion 5b coupled to the flange portion 5c and surrounding the holding portion 5a1 when viewed in the normal direction of the nozzle surface FN, and the coupling portion 5a2 coupling the holding portion 5a1 and the outer wall portion 5b. The holding portion 5a1 protrudes from the coupling portion 5a2 in the direction opposite to the normal direction, and the outer wall portion 5b extends from the coupling portion 5a2 toward the flange portion 5c in the direction opposite to the normal direction.
By the holder 53 being configured as described above, the shortest path that constitutes the transfer path H2 and is from the heat receiving portion 5a11 to the flange portion 5c has a point bent or curved by the coupling between the side wall portion 5a12 and the coupling portion 5a2 and a point bent or curved by the coupling between the outer wall portion 5b and the coupling portion 5a2. In other words, in the shortest path that constitutes the transfer path H2 and is from the heat receiving portion 5a11 to the flange portion 5c, the heat transfer direction in the side wall portion 5a12 and the heat transfer direction in the outer wall portion 5b are opposite to each other.
As described above, the outer wall portion 5b surrounds the holding portion 5a1 at a distance from the holding portion 5a1 in a plan view. Accordingly, it is possible to easily realize the transfer path H2, which is bent or curved at two or more points as described above between the heat receiving portion 5a11 and the flange portion 5c.
As described above, the flange portion 5c is disposed at a position in the direction opposite to the normal direction of the nozzle surface FN beyond the heat receiving portion 5a11. Accordingly, the length of the outer wall portion 5d pertaining to the direction along the Z axis can be increased and the thermal resistance of the transfer path H2 can be increased.
As described above, the heat receiving portion 5a11 has the first surface F1 and the second surface F2 facing directions opposite to each other. Here, the first surface F1 is a heat receiving surface receiving the heat from the heater 56. The head chip 54 has the case 54h provided with an ink flow path. The case 54h is fixed to the second surface F2 and is made of a material lower in thermal conductivity than the holder 53. By the constituent material of the case 54h being lower in thermal conductivity than the holder 53 as described above, it is possible to reduce heat dissipation from the ink in the head chip 54. Here, it is difficult to transfer the heat from the heat receiving portion 5a11 to the case 54h. As a result, the heat moves with relative ease through the holder 53 in the direction toward the support body 41. Accordingly, when the case 54h is used, it is particularly useful to make it difficult to dissipate heat from the support body 41 as described above.
As described above, the flow path structure 51 is disposed at a position in the direction opposite to the normal direction of the nozzle surface FN with respect to the holding portion 5a1 and the heater 56 is disposed between the holding portion 5a1 and the flow path structure 51. The flow path structure 51 is disposed at a distance from the outer wall portion 5b. Accordingly, it is possible to reduce direct heat dissipation from the flow path structure 51 to the outer wall portion 5b.
As described above, the outer peripheral surface of the side wall portion 5a12 is disposed at a distance over the entire area with respect to the inner peripheral surface of the outer wall portion 5b when viewed in the normal direction of the nozzle surface FN. Accordingly, it is possible to reduce direct heat dissipation from the side wall portion 5a12 to the outer wall portion 5b.
As described above, the flange portion 5c surrounds the outer wall portion 5b over the entire circumference when viewed in the normal direction of the nozzle surface FN. Accordingly, the flange portion 5c is capable of preventing the mist resulting from ink ejection at the head chip 54 from wrapping around vertically above the support body 41 from the nozzle surface FN. As for the flange portion 5c, the heat of the heater 56 may be dissipated to the support body 41 from the entire circumference of the flange portion 5c surrounding the outer wall portion 5b. However, the outer peripheral surface of the side wall portion 5a12 that is viewed in the normal direction of the nozzle surface FN is disposed at a distance over the entire area with respect to the inner peripheral surface of the outer wall portion 5b as described above, and thus it is possible to reduce direct heat dissipation from the side wall portion 5a12 to the outer wall portion 5b.
Hereinafter, a second embodiment of the present disclosure will be described. Elements in the form exemplified below that are identical in action and function to those of the first embodiment are denoted by the same reference numerals as those used in the description of the first embodiment with detailed description thereof omitted as appropriate.
As illustrated in
The temperature of the head chip 54 can be managed with high accuracy in the second as well as first embodiment. In the example illustrated in
The plan-view shape of the heater 56 is not limited thereto. For example, the shape may be the same as the plan-view shape of the flow path structure 51 or the heat transfer member 57. In other words, in a plan view, each of the heater 56 and the flow path structure 51 may overlap the first outside part RE1b. In this case, it is possible to reduce a variation in the temperature distribution of the flow path structure 51 even with the heat transfer member 57 absent between the heater 56 and the flow path structure 51.
Hereinafter, a third embodiment of the present disclosure will be described. Elements in the form exemplified below that are identical in action and function to those of the first embodiment are denoted by the same reference numerals as those used in the description of the first embodiment with detailed description thereof omitted as appropriate.
The outer wall portion 5d couples the outer peripheral edge of the coupling portion 5a2 of the bottom portion 5a and the inner peripheral edge of the flange portion 5c. Here, the outer wall portion 5d has a first wall portion 5d1, a first plate portion 5d2, a second wall portion 5d3, a second plate portion 5d4, and a third wall portion 5d5.
The first wall portion 5d1 has a tubular shape extending in the Z1 direction from the coupling portion 5a2. The first plate portion 5d2 has a plate shape extending from the first wall portion 5d1 in a direction orthogonal to the Z axis so as to approach the holding portion 5a1. The second wall portion 5d3 has a tubular shape extending in the Z1 direction from the first plate portion 5d2. The second plate portion 5d4 has a plate shape extending from the second wall portion 5d3 in a direction orthogonal to the Z axis so as to be away from the holding portion 5a1. The third wall portion 5d5 has a tubular shape extending in the Z1 direction from the second plate portion 5d4.
The temperature of the head chip 54 can be managed with high accuracy in the third as well as first embodiment. In the present embodiment, the bottom portion 5a and the flange portion 5c are coupled via the outer wall portion 5d, and thus the transfer path H2 of the heat from the heater 56 to the support body 41 is bent or curved at six or more points. The regions surrounded by the two-dot chain lines in
The forms exemplified above can be variously modified. Exemplified below are specific aspects of modification applicable to the forms described above. Any two or more aspects selected from the following examples can be appropriately merged to the extent that the aspects are not mutually contradictory.
In the form described above, the plan-view shape of the holding portion 5a1 is non-rectangular in accordance with the disposition of the four head chips 54. The plan-view shape of the holding portion 5a1 is not limited to the above form. For example, the shape may be a rectangular or substantially rectangular shape.
In the form described above, the plan-view shape of the heater 56 is non-rectangular in accordance with the disposition of the four head chips 54. The plan-view shape of the heater 56 is not limited to the above form. For example, the shape may be a rectangular or substantially rectangular shape.
In the form described above, a configuration using one heat transfer member 57 is exemplified. However, the present disclosure is not limited thereto. For example, a form in which the first embodiment and the second embodiment are combined may be used. In other words, the heat transfer member 57 may be disposed between the heater 56 and the holder 53 and between the heater 56 and the flow path structure 51.
An elastic sheet may be disposed between the holder 53 and the flow path structure 51, which are rigid bodies. An elastomer or the like can be adopted as the elastic sheet. For example, it is desirable to select a thermally conductive sheet higher in thermal conductivity than the resin material constituting the case 54h of the head chip 54. It is preferable to use a material having a thermal conductivity of 1.0 W/m·K or more as the elastic and thermally conductive sheet higher in thermal conductivity than the resin material. Specifically, an acrylic or silicon-based sheet, a material in which a metal material such as silicon, stainless steel, aluminum, titanium, and a magnesium alloy is dispersed in an elastomer, a composite material in which an elastic material such as an elastomer contains a filler such as a carbon-based filler such as a carbon fiber-based filler, a ceramic oxide such as silica and alumina, and a ceramic nitride such as silicon nitride and boron nitride, or the like is suitable as the thermally conductive sheet. By filling the gap between the holder 53 and the flow path structure 51 with an elastic material as described above, it is possible to enhance adhesiveness between the heat transfer member 57 and the heater 56 and an object of heating such as the holder 53 and the flow path structure 51 and efficiently transfer the heat from the heater 56 to the heating object even in the event of a manufacturing error in the thickness dimension of the holder 53 or the flow path structure 51 pertaining to the direction along the Z axis.
“Outer edge OE2 of the heater 56” in the above embodiment may be read as the outer edge of the region of formation of the heat-generating resistor of the heater 56.
In a plan view, the heater 56 may not overlap the first outside part RE1b. In this configuration, the area of the heater 56 can be reduced. In addition, the first outside part RE1b lacks the head chip 54_1, the head chip 54_2, and the holding portion 5a1, and thus the heater 56 does not overlap the first outside part RE1b in a plan view and useless heat generation of the heater 56 can be further reduced.
Exemplified in the above form is a configuration in which the liquid ejecting head 50 has four head chips 54. However, the present disclosure is not limited thereto, and the number may be two, three, or five or more. In the above form, the head chips 54 are staggered along the longitudinal direction of the head chips 54. However, the present disclosure is not limited thereto. The head chips 54 may be staggered along the lateral direction of the head chips 54.
Although the serial liquid ejecting apparatus 100 in which the support body 41 supporting the liquid ejecting head 50 reciprocates is exemplified in the above form, the present disclosure is also applicable to a line-type liquid ejecting apparatus in which the nozzles N are distributed over the entire width of the medium M. In other words, the support body supporting the liquid ejecting head 50 is not limited to a serial carriage and may be a structure supporting the liquid ejecting head 50 in a line-type liquid ejecting apparatus. In this case, a plurality of the liquid ejecting heads 50 are, for example, disposed side by side in the width direction of the medium M and the liquid ejecting heads 50 are collectively supported by one support body.
The liquid ejecting apparatus exemplified in the above form can be adopted in various types of equipment such as a facsimile machine and a copier as well as dedicated printing equipment. However, the use of the liquid ejecting apparatus is not limited to printing. For example, a liquid ejecting apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming a color filter of a display device such as a liquid crystal display panel. In addition, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming an electrode or wiring of a wiring substrate. In addition, a liquid ejecting apparatus that ejects a solution of a living body-related organic substance is used as, for example, a biochip manufacturing apparatus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-049385 | Mar 2021 | JP | national |
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| Number | Date | Country | |
|---|---|---|---|
| 20220305788 A1 | Sep 2022 | US |
