JP2022177434A - Liquid jet head and liquid jet device - Google Patents

Abstract

To heat a liquid of a liquid jet head with a heater efficiently without any waste.SOLUTION: A liquid jet head includes: a planar heater having a first surface and a second surface opposite to the first surface; a first member disposed on the first surface and having a first passage for supplying liquid to nozzles for jetting the liquid; and a second member disposed on the second surface. The first passage extends along the first surface. The heater has: a first area; and a second area having an amount of heat generated per unit time smaller than an amount of heat generated per unit time in the first area. The first member overlaps on the first area and does not overlap the second area in a plan view viewed in a thickness direction of the heater. The second member overlaps both of the first area and the second area in the plan view.SELECTED DRAWING: Figure 4

Description

The present invention relates to a liquid ejecting head and a liquid ejecting apparatus.

2. Description of the Related Art A liquid ejecting apparatus typified by an inkjet printer is generally provided with a liquid ejecting head that ejects liquid such as ink as droplets. A liquid jet head may be provided with a heater for heating the liquid, for example, as in the ink jet head described in Japanese Patent Application Laid-Open No. 2002-200012.

JP 2010-143109 A

Patent Document 1 does not disclose the distribution of the amount of heat generated by the heater per unit time. Here, it is desired to efficiently heat the liquid by the heater without waste.

In order to solve the above problems, a liquid jet head according to a preferred aspect of the present invention provides a planar heater having a first surface and a second surface opposite to the first surface; A first member disposed on a first surface and having a first flow path for supplying liquid to a nozzle for ejecting liquid; and a second member disposed on the second surface; The first flow path extends along the first surface, and the heater includes a first region and a second heater having a smaller heat generation amount per unit time than that of the first region. and a region, wherein the first member overlaps with the first region and does not overlap with the second region when viewed in plan view in the thickness direction of the heater, and the second member comprises the It overlaps both the first region and the second region in plan view.

A liquid jet head according to another preferred aspect of the present invention is a planar heater having a first surface and a second surface opposite to the first surface, and disposed on the first surface. a first member having a first flow path for supplying liquid to nozzles for ejecting liquid; and a second flow path disposed on the second surface for supplying liquid to nozzles for ejecting liquid. a second member having a channel, each of said first channel and said second channel extending along said first surface or said second surface, said heater being connected to said first region; and a second region having a smaller heat generation amount per unit time than that of the first region, and occupying the first region in plan view in the thickness direction of the heater. The ratio of the area of one channel is larger than the ratio of the area of the first channel occupying the second region in the plan view.

A liquid ejecting apparatus according to a preferred aspect of the present invention includes the liquid ejecting head according to any one of the aspects described above, and a control section that controls driving of the heater.

1 is a schematic diagram showing a configuration example of a liquid ejecting apparatus according to a first embodiment; FIG. 1 is a plan view of a liquid jet head according to a first embodiment; FIG. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2; FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2; 4 is a cross-sectional view showing an example of a head chip; FIG. FIG. 4 is a diagram for explaining heat generation distribution of a heater in the first embodiment; 8 is a plan view of a liquid jet head according to a second embodiment; FIG. FIG. 8 is a cross-sectional view taken along line BB in FIG. 7; FIG. 11 is a plan view of a liquid jet head according to a third embodiment; FIG. 11 is a plan view of a liquid jet head according to a fourth embodiment; FIG. 11 is a cross-sectional view of a liquid jet head according to a fourth embodiment; It is a figure for demonstrating heat_generation|fever distribution of the heater in 4th Embodiment. It is a figure for demonstrating heat_generation|fever distribution of the heater in 5th Embodiment. FIG. 10 is a diagram for explaining the heat generation distribution of the heater in Modification 1; FIG. 11 is a cross-sectional view of a liquid jet head according to Modification 2;

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings are appropriately different from the actual ones, and some parts are shown schematically for easy understanding. Moreover, the scope of the present invention is not limited to these forms unless there is a description to the effect that the present invention is particularly limited in the following description.

For the sake of convenience, the following description will be made using the mutually intersecting X-axis, Y-axis, and Z-axis as appropriate. Also, in the following description, one direction along the X axis is the X1 direction, and the opposite direction to the X1 direction is the X2 direction. Similarly, opposite directions along the Y-axis are the Y1 direction and the Y2 direction. Also, directions opposite to each other along the Z axis are the Z1 direction and the Z2 direction. Also, viewing in the Z-axis direction may be simply referred to as "plan view".

Here, typically, the Z axis is the vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z-axis does not have to be a vertical axis. The X-axis, Y-axis, and Z-axis are typically orthogonal to each other, but are not limited to this, and may intersect at an angle within the range of 80° or more and 100° or less, for example.

1. First Embodiment 1-1. Schematic Configuration of Liquid Ejecting Apparatus FIG. 1 is a schematic diagram showing a configuration example of a liquid ejecting apparatus 100 according to a first embodiment. The liquid ejecting apparatus 100 is an inkjet printing apparatus that ejects ink, which is an example of a “liquid,” onto the medium M as droplets. The medium M is typically printing paper. It should be noted that the medium M is not limited to printing paper, and may be a print target made of any material such as a resin film or fabric, for example.

As shown in FIG. 1 , the liquid ejecting apparatus 100 has a liquid reservoir 10 , a control unit 20 , a transport mechanism 30 , a moving mechanism 40 and a liquid ejecting head 50 .

The liquid storage section 10 is a container that stores ink. Specific aspects of the liquid reservoir 10 include, for example, a cartridge detachable from the liquid ejecting apparatus 100, a bag-shaped ink pack formed of a flexible film, and an ink tank capable of replenishing ink. container.

The ink stored in the liquid reservoir 10 is not particularly limited, but examples thereof include cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and treatment liquid. The composition of the ink is not particularly limited. For example, it may be a water-based ink in which a coloring material such as a dye or pigment is dissolved in a water-based solvent, or a solvent-based ink in which a coloring material is dissolved in an organic solvent. UV curable ink may be used. Also, the liquid storage section 10 may have a plurality of containers that store inks of different types.

The control unit 20 controls operations of each element of the liquid ejecting apparatus 100 . For example, the control unit 20 includes a processing circuit such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array) and a memory circuit such as a semiconductor memory. The control unit 20 outputs the drive signal D and the control signal S toward the liquid jet head 50 . The drive signal D is a signal including drive pulses for driving the drive elements of the liquid jet head 50 . The control signal S is a signal that specifies whether or not to supply the drive signal D to the drive element. Also, the control unit 20 is an example of a "control section" and controls the driving of the heater 54, which will be described later.

The transport mechanism 30 transports the medium M in the transport direction DM, which is the Y1 direction, under the control of the control unit 20 . The moving mechanism 40 reciprocates the liquid jet head 50 in the X1 direction and the X2 direction under the control of the control unit 20 . In the example shown in FIG. 1, the moving mechanism 40 has a substantially box-shaped support 41 called a carriage that accommodates the liquid jet head 50, and a transport belt 42 to which the support 41 is fixed. The support 41 supports the liquid jet head 50 and is made of a metal material. Note that the liquid reservoir 10 described above may be mounted on the support 41 in addition to the liquid jet head 50 .

The liquid jet head 50 has a plurality of head chips 51, and under the control of the control unit 20, the ink supplied from the liquid reservoir 10 is ejected from each of the plurality of nozzles of each head chip 51 onto the medium M. and jet in the Z2 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 jet head 50 by the moving mechanism 40 , thereby forming a predetermined image of ink on the surface of the medium M. FIG.

Note that the liquid reservoir 10 may be connected to the liquid jet head 50 via a circulation mechanism. The circulation mechanism is a mechanism that supplies ink to the liquid ejecting head 50 and recovers ink discharged from the liquid ejecting head 50 for resupply to the liquid ejecting head 50 . By operating the circulation mechanism, it is possible to suppress an increase in the viscosity of the ink and reduce the retention of air bubbles in the ink.

1-2. Configuration of Liquid Jet Head FIG. 2 is a plan view of the liquid jet head 50 according to the first embodiment. FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 is a cross-sectional view taken along the line BB in FIG. 2. FIG. 2 to 4, each part of the liquid jet head 50 is simply shown for convenience. Also, in FIG. 2, illustration of a cover 56, which will be described later, is omitted.

As shown in FIGS. 2 to 4, the liquid jet head 50 has two head chips 51_1 and 51_2, a holder 52, a fixing plate 53, a heater 54, a first member 55, and a cover 56. . Here, the heater 54 has a first surface F1 and a second surface F2 opposite to the first surface F1. is placed on top of Also, an assembly composed of the two head chips 51_1 and 51_2, the holder 52, and the fixing plate 53 constitutes the second member 5 that is to be heated by the heater 54 and is arranged on the second surface F2. Each part of the liquid jet head 50 will be sequentially described below.

Each of the head chips 51_1 and 51_2 is the head chip 51 shown in FIG. 1 and has a shape extending in the direction along the Y-axis. In the example shown in FIG. 2, the head chip 51_1 and the head chip 51_2 are arranged side by side in the direction along the X-axis so as to align their positions in the direction along the Y-axis. 2 to 4, among the constituent elements of the head chip 51, the reservoir R, which is an example of the "second flow path", is shown for convenience. Moreover, hereinafter, each of these chips may be referred to as a head chip 51 without distinguishing between the head chips 51_1 and 51_2. The structure of the head chip 51 will be detailed later with reference to FIG.

In this embodiment, the types of ink ejected by the head chip 51_1 and the head chip 51_2 are the same. This is because the number of first flow paths SC provided in the first member 55, which will be described later, is one. However, when the number of first flow paths SC included in the first member 55, which will be described later, is two or more, two or more types of ink can be supplied toward the head chip 51. Different types of ink may be ejected from the chip 51_2.

Also, the arrangement of the head chips 51_1 and 51_2 is not limited to the example shown in FIG. And the posture of the head chip 51_2 may be inclined with respect to the X-axis or the Y-axis.

The holder 52 is a structure that accommodates and supports the two head chips 51 . As a constituent material of the holder 52, it is preferable to use a material having good thermal conductivity. Metal materials such as magnesium alloys, or ceramic materials such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet and yttria are preferably used. By constructing the holder 52 using such a metal material or ceramic material, the heat from the heater 54 can be efficiently transmitted to each head chip 51 via the holder 52 .

The holder 52 has a substantially plate shape extending in a direction orthogonal to the Z-axis. The holder 52 is provided with two holes 52a, a recess 52b and a recess 52c. Each of the two holes 52a penetrates the holder 52 in the direction along the Z-axis, and the head chip 51 is arranged in each hole 52a. The holder 52 of this embodiment indirectly supports the two head chips 51 via the fixing plate 53 . The head chip 51 may be fixed to at least a part of the wall surface defining the hole 52 a of the holder 52 so that the holder 52 directly supports the head chip 51 . The concave portion 52b is provided on the surface of the holder 52 facing the Z2 direction, and the fixing plate 53 is arranged in the concave portion 52b. The concave portion 52c is provided on the surface of the holder 52 facing the Z1 direction, and the heater 54 is arranged in the concave portion 52c.

In the example shown in FIG. 2, the holder 52 has a rectangular shape in plan view. In addition, the shape of the holder 52 is not limited to the example shown in FIG. 2, and is arbitrary. For example, the holder 52 may have a recess opening in the Z2 direction instead of the hole 52a. The recess may accommodate at least part of the head chip 51, and the head chip 5 may be supported by the bottom surface of the recess facing the Z2 direction. Further, a channel for supplying ink to the head chip 51 and an opening through which a wiring substrate 51i described later is inserted may be formed on the bottom surface of the recess.

The fixing plate 53 is a plate-like member for fixing the two head chips 51 to the holder 52 . Specifically, the fixing plate 53 is fixed to each of the head chips 51 and the holder 52 with an adhesive agent or the like while sandwiching the two head chips 51 between the fixing plate 53 and the heater 54 .

The fixing plate 53 is provided with two openings 53 a through which the nozzle surfaces FN of the two head chips 51 are exposed. The fixing plate 53 is made of, for example, a metal material such as stainless steel, titanium, magnesium alloy, or the like, and has a function of transferring heat from the holder 52 to each head chip 51 . In addition, the fixed plate 53 has conductivity. Therefore, the fixed plate 53 is grounded through the holder 52 and the support 41, and also functions as an electrostatic shield to prevent static electricity from the medium M. Note that the fixing plate 53 may be configured by stacking a plurality of plate-like members made of a metal material.

The fixing plate 53 may have one opening shared by the two head chips 51 instead of the two openings 53a. However, in the configuration in which the openings 53 a are individually provided for each head chip 51 , the contact area between the fixing plate 53 and each head chip 51 can be easily increased. can be transmitted.

The head chips 51_1 and 51_2, the holder 52, and the fixing plate 53 described above constitute the second member 5. From the viewpoint of efficiently transmitting the heat from the heater 54 to the ink in the second member 5, the second member 5 preferably contains a material having a thermal conductivity of 10.0 W/m·k or more. That is, it is preferable that the thermal conductivity of the material forming part or all of at least one of the head chips 51_1 and 51_2, the holder 52, and the fixing plate 53 is 10.0 W/m·k or more.

The first member 55 is a structure having a first channel SC for supplying the ink stored in the liquid storage section 10 to the two head chips 51 . The area of the first member 55 in plan view is smaller than the area of the second member 5 described above in plan view. That is, the area of the second member 5 is larger than the area of the first member 55 in plan view. Here, the first flow path SC overlaps the reservoir R in plan view.

The first channel SC communicates with the reservoir R and supplies the reservoir R with ink. In the example shown in FIG. 2, the first flow path SC has a common flow path SCa and four branch flow paths SCb. The common flow path SCa extends in the direction along the X-axis, and an inlet 55a for receiving ink from the liquid reservoir 10 is provided in the center of the common flow path SCa in the longitudinal direction. The common flow path SCa transfers the ink from the inlet 55a in each of the X1 direction and the X2 direction. The four branch flow paths SCb extend in the Y1 direction from the common flow path SCa, and transfer the ink from the common flow path SCa in the Y1 direction. A discharge port 55b is provided at the end of each branch channel SCb in the Y1 direction. The outlet 55b communicates with an inlet IH of the head chip 51, which will be described later. As described above, the first flow path SC distributes ink to a plurality of reservoirs R. As shown in FIG.

Although not shown, the first member 55 is composed of, for example, a laminate obtained by laminating a plurality of substrates in the direction along the Z-axis. Each of the plurality of substrates is appropriately provided with grooves and holes for the above-described first channel SC. The plurality of substrates are bonded together by, for example, adhesive, brazing, welding or screwing. As the constituent material of each of the plurality of substrates, it is preferable to use a material with good thermal conductivity. Metallic materials such as steel, titanium and magnesium alloys, or ceramic materials such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet and yttria are preferably used. By configuring the first member 55 using such a metal material or ceramic material, the heat from the heater 54 can efficiently heat the ink in the first flow path SC. A sheet-shaped sealing member made of a rubber material or the like may be appropriately arranged between the plurality of substrates, if necessary. Further, the number, thickness, etc. of the substrates constituting the first member 55 are determined according to aspects such as the shape of the first flow path SC, and are not particularly limited, and are arbitrary.

The heater 54 is a planar heater disposed between the first member 55 and the second member 5 and having a first surface F1 and a second surface F2. The area of the heater 54 is smaller than the area of the second member 5 in plan view. That is, the area of the second member 5 is larger than the area of the heater 54 in plan view. The first surface F1 faces the Z1 direction, and the first member 55 overlaps a part of the first surface F1 in plan view. In the present embodiment, the portion of the first surface F1 other than the portion faces the space inside the liquid jet head 50, which is the space inside the cover 56 in the present embodiment. In this way, the first surface F1 faces the space over at least part of the second region RE2, which will be described later in detail. Note that in the present embodiment, the first surface F1 faces the space over the entire second region RE2. The second surface F2 faces the Z2 direction, and the second member 5 overlaps the entire area of the second surface F2 in plan view.

The heater 54 is, for example, a film heater having a thin-film base, an insulating film, and a heating resistor sandwiched between the base and the film. The base material is made of, for example, a resin material such as polyimide or PET (polyethylene terephthalate). The film is made of, for example, a resin material such as polyimide or PET (polyethylene terephthalate). The heating resistor is a heating wire patterned on the base material, and is made of a metal material such as stainless steel, copper, or nickel alloy. Alternatively, the heater 54 may be a planar heater such as a silicone rubber heater in which a heating resistor is sandwiched between silicone rubbers containing glass fibers, or a ceramic heater. The heating resistor is a heating resistor 54b described later. The heating resistor 54b will be described later in detail with reference to FIG.

The heater 54 is provided with a plurality of holes 54a. Each of the plurality of holes 54a is a hole through which a flow path for supplying ink from the first member 55 to the head chip 51 passes.

The heater 54 is thermally connected to each of the first member 55 and the second member 5 . “Thermal connection” means satisfying any of the following conditions a, b, or c. Condition a: Two members are in direct physical contact. Condition b: Two members are arranged with a gap of 100 μm or less. Condition c: Two members are physically connected via another member having a thermal conductivity of 1.0 W/m·K or more at room temperature (20° C.). Heat transfer grease, adhesive, or the like may exist between the two members under each condition. In this case, the adhesive preferably contains a thermally conductive filler or the like from the viewpoint of enhancing thermal conductivity.

In the example shown in FIGS. 3 and 4, the first surface F1 of the heater 54 contacts the first member 55, and the second surface F2 of the heater 54 contacts each head chip 51 and holder 52, respectively. Moreover, as shown in FIG. 2, the heater 54 is provided over a range including the head chip 51_1 and the head chip 51_2 in plan view. Here, the heater 54 has a first region RE1 and a second region RE2 having different heat generation amounts per unit time so as to efficiently heat the first member 55 and the second member 5 .

The first region RE1 is a region overlapping both the first member 55 and the second member 5 in plan view. In the example shown in FIG. 2, the outer shape of the first region RE1 in plan view is substantially equal to the outer shape of the first member 55 in plan view. Note that the outer shape of the first region RE1 in plan view is determined according to the outer shape of the first member 55 in plan view, etc., and is not limited to the example shown in FIG. It may differ from the outer shape. In this case, for example, the outer edge of the first region RE1 is included in the outer edge of the first member 55 in plan view.

The second region RE2 is a region that overlaps the second member 5 without overlapping the first member 55 in plan view. In the example shown in FIG. 2, the second region RE2 is a region of the heater 54 excluding the first region RE1, and the outline of the second region RE2 is rectangular in plan view. The outer shape of the second region RE2 in plan view is determined according to the outer shape of the first member 55 and the second member 5 in plan view, etc., and is not limited to the example shown in FIG.

As can be understood from the above, since both the first member 55 and the second member 5 overlap the first region RE1 in plan view, the heat from the first region RE1 is transferred to the first member 55 and the second member 5. directly to both On the other hand, although the second member 5 overlaps the second region RE2 in plan view, the first member 55 does not overlap, so the heat from the second region RE2 is directly transmitted only to the second member 5. be. Thus, the second region RE2 has fewer objects to be heated than the first region RE1.

Therefore, the heat capacity of the portion corresponding to the first region RE1 of the heating target composed of the first member 55 and the second member 5 is larger than the heat capacity of the portion corresponding to the second region RE2. Therefore, in order to reduce the temperature difference between these portions, the amount of heat generated per unit time of the first region RE1 is larger than the amount of heat generated per unit time of the second region RE2.

Here, the first region RE1 overlaps both the first channel SC and the reservoir R in plan view, and the second region RE2 overlaps only the reservoir R in plan view. In addition, the proportion of the area of the first flow path SC that occupies the first region RE1 in plan view is greater than the proportion of the area of the first flow channel SC that occupies the second region RE2 in plan view. In addition, the proportion of the area of the first flow path SC and the reservoir R occupying the first region RE1 in plan view is greater than the proportion of the area of the first flow channel SC and the reservoir R occupying the second region RE2 in plan view. .

It should be noted that the “proportion of the area of the first flow path SC occupying the first region RE1 in plan view” refers to the ratio of the area of the first flow channel SC in plan view to the area of the first region RE1 in plan view. This is the area ratio of the portion overlapping RE1. Similarly, the “proportion of the area of the first flow path SC occupying the second region RE2 in plan view” refers to the ratio of the area of the first flow channel SC in plan view to the area of the second region RE2 in plan view. This is the area ratio of the portion overlapping the region RE2. "Ratio of the area of the first flow channel SC and the reservoir R occupying the first region RE1 in plan view" means the ratio of the area of the first flow channel SC in plan view to the area of the first region RE1 in plan view. It is the ratio of the total area of the area of the portion overlapping the region RE1 and the area of the portion of the reservoir R overlapping the first region RE1 in plan view. "Ratio of the area of the first flow path SC and the reservoir R occupying the second region RE2 in plan view" is the ratio of the area of the first flow channel SC in plan view to the area of the second region RE2 in plan view. It is the ratio of the total area of the area of the portion overlapping the region RE2 and the area of the portion of the reservoir R overlapping the second region RE2 in plan view.

The cover 56 is a box-shaped or tray-shaped member having a recess 56 a forming a space for housing the heater 54 and the first member 55 between itself and the holder 52 . The cover 56 is made of, for example, a resin material such as modified polyphenylene ether resin, polyphenylene sulfide resin, or polypropylene resin.

The cover 56 is provided with a hole 56b. The hole 56b is a hole through which a flow path for supplying ink from the liquid reservoir 10 to the first member 55 passes.

1-3. Configuration of Head Chip FIG. 5 is a cross-sectional view showing an example of the head chip 51 . As shown in FIG. 5, the head chip 51 has a plurality of nozzles N arranged along the Y-axis. The plurality of nozzles N are divided into a first row L1 and a second row L2 that are spaced apart from each other in the direction along the X-axis. Each of the first row L1 and the second row L2 is a set of a plurality of nozzles N linearly arranged in the direction along the Y-axis.

The head chips 51 are substantially symmetrical to each other in the direction along the X-axis. However, the positions of the plurality of nozzles N in the first row L1 and the plurality of nozzles N in the second row L2 in the direction along the Y-axis may be the same or different. FIG. 5 illustrates a configuration in which the positions of the plurality of nozzles N in the first row L1 and the plurality of nozzles N in the second row L2 match each other in the Y-axis direction.

As shown in FIG. 5, the head chip 51 includes a channel substrate 51a, a pressure chamber substrate 51b, a nozzle plate 51c, a vibration absorber 51d, a vibration plate 51e, a plurality of piezoelectric elements 51f, a protection plate 51g, a case 51h, and a wiring substrate 51i. and a drive circuit 51j.

The channel substrate 51a and the pressure chamber substrate 51b are stacked in this order in the Z1 direction and form channels for supplying ink to the plurality of nozzles N. As shown in FIG. A vibrating plate 51e, a plurality of piezoelectric elements 51f, a protection plate 51g, a case 51h, a wiring board 51i, and a driving circuit 51j are located in a region located in the Z1 direction from the laminate composed of the flow path substrate 51a and the pressure chamber substrate 51b. Installed. On the other hand, a nozzle plate 51c and a vibration absorber 51d are installed in a region located in the Z2 direction from the laminate. Each element of the head chip 51 is generally a plate-like member elongated in the Y direction, and is bonded to each other with an adhesive, for example. Each element of the head chip 51 will be described in order below.

The nozzle plate 51c is a plate-like member provided with a plurality of nozzles N for each of the first row L1 and the second row L2. Each of the plurality of nozzles N is a through hole through which ink passes. Here, the surface facing the Z2 direction of the nozzle plate 51c is the nozzle surface FN. The nozzle plate 51c is manufactured, for example, by processing a silicon single crystal substrate by a semiconductor manufacturing technique using a processing technique such as dry etching or wet etching. However, other known methods and materials may be used as appropriate for manufacturing the nozzle plate 51c. In addition, the cross-sectional shape of the nozzle is typically circular, but is not limited to this, and may be non-circular such as polygonal or elliptical.

The channel substrate 51a is provided with a space R1, a plurality of supply channels Ra, and a plurality of communication channels 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 along the Z-axis. Each of the supply channel Ra and the communication channel Na is a through hole formed for each nozzle N. As shown in FIG. Each supply channel Ra communicates with the space R1.

The pressure chamber substrate 51b is a plate-like member provided with a plurality of pressure chambers C called cavities for each of the first row L1 and the second row L2. A plurality of pressure chambers C are arranged in a 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 plan view. The flow path substrate 51a and the pressure chamber substrate 51b are each manufactured by processing a silicon single crystal substrate by semiconductor manufacturing technology, for example, in the same manner as the nozzle plate 51c described above. However, other known methods and materials may be appropriately used for manufacturing the flow path substrate 51a and the pressure chamber substrate 51b. The channel substrate 51a is preferably made of a material having a thermal conductivity of 10.0 W/m·k or more, and may be made of stainless steel other than a silicon single crystal substrate.

The pressure chamber C is a space located between the channel substrate 51a and the vibration plate 51e. A plurality of pressure chambers C are arranged in the direction along the Y-axis for each of the first row L1 and the second row L2. Further, the pressure chamber C communicates with each of the communication channel Na and the supply channel Ra. Therefore, the pressure chamber C communicates with the nozzle N via the communication channel Na and communicates with the space R1 via the supply channel Ra.

A vibration plate 51e is arranged on the surface of the pressure chamber substrate 51b facing the Z1 direction. The diaphragm 51e is a plate-like member that can vibrate elastically. The diaphragm 51e has, for example, a first layer and a second layer, which are laminated in this order in the Z1 direction. The first layer is, for example, an elastic film made of silicon oxide (SiO ₂ ). The elastic film is formed, for example, by thermally oxidizing one surface of a silicon single crystal substrate. The second layer is an insulating film made of, for example, zirconium oxide (ZrO ₂ ). The insulating film is formed, for example, by forming a zirconium layer by sputtering and thermally oxidizing the layer. Note that the diaphragm 51e is not limited to the lamination of the first layer and the second layer described above, and may be composed of a single layer, or may be composed of three or more layers, for example.

A plurality of piezoelectric elements 51f corresponding to the nozzles N are arranged as drive elements for each of the first row L1 and the second row L2 on the surface of the vibration plate 51e facing the Z1 direction. Each piezoelectric element 51f is a passive element that deforms when supplied with a drive signal. Each piezoelectric element 51f has an elongated shape extending in the direction along the X-axis in plan view. The plurality of piezoelectric elements 51f are arranged in the direction along the Y-axis so as to correspond to the plurality of pressure chambers C. As shown in FIG. The piezoelectric element 51f overlaps the pressure chamber C in plan view.

Each piezoelectric element 51f has a first electrode, a piezoelectric layer, and a second electrode (not shown), which are stacked in this order in the Z1 direction. One electrode of the first electrode and the second electrode is an individual electrode arranged apart from each other for each piezoelectric element 51f, and a drive signal is applied to the one electrode. The other electrode of the first electrode and the second electrode is a strip-shaped common electrode that extends in the direction along the Y-axis so as to be continuous across the plurality of piezoelectric elements 51f. is supplied. Examples of metal materials for these electrodes include metal materials such as platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu). They can be used singly or in combination of two or more 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). Eggplant. However, the piezoelectric layer may be integrated over the plurality of piezoelectric elements 51f. In this case, the piezoelectric layer is provided with a through hole extending in the direction along the X-axis and penetrating the piezoelectric layer in a region corresponding to the gap between the pressure chambers C adjacent to each other in plan view. When the vibration plate 51e vibrates in association with the deformation of the piezoelectric element 51f, the pressure in the pressure chamber C fluctuates, and ink is ejected from the nozzle N. As the driving element, a heating element for heating the ink in the pressure chamber C may be used instead of the piezoelectric element 51f.

The protection plate 51g is a plate-like member installed on the surface of the diaphragm 51e facing the Z1 direction, and protects the plurality of piezoelectric elements 51f and reinforces the mechanical strength of the diaphragm 51e. Here, a plurality of piezoelectric elements 51f are accommodated between the protection plate 51g and the vibration plate 51e. The protective plate 51g is made of, for example, a resin material.

The case 51h is a case for storing the ink supplied to the pressure chambers C. As shown in FIG. The case 51h is made of, for example, a resin material. Note that the case 51h may be made of a metal material or ceramics having a thermal conductivity of 10.0 W/m·k or more. A space R2 is provided in the case 51h for each of the first row L1 and the second row L2. The space R2 is a space that communicates with the aforementioned space R1, and functions as a reservoir R that stores ink supplied to the plurality of pressure chambers C together with the space R1. The reservoir R is an example of a "second flow path". An inlet IH for supplying ink to each reservoir R is provided in the case 51h. Ink in each reservoir R is supplied to the pressure chamber C through each supply channel Ra.

The vibration absorber 51d, also called a compliance substrate, is a flexible resin film forming a wall surface of the reservoir R and absorbs pressure fluctuations of the ink inside the reservoir R. FIG. Note that the vibration absorber 51d may be a flexible thin plate made of metal. A surface facing the Z1 direction of the vibration absorber 51d is joined to the flow channel substrate 51a with an adhesive or the like. On the other hand, the frame 51k is joined to the Z2-direction surface of the vibration absorber 51d with an adhesive or the like. The frame 51k is a frame-shaped member along the outer periphery of the vibration absorber 51d, and contacts the fixed plate 53 described above. Here, the frame 51k is made of a metal material such as stainless steel, aluminum, titanium, magnesium alloy, or the like. By forming the frame body 51 k from a metal material in this manner, the heat from the heater 54 can be suitably transmitted to the ink in the head chip 51 via the holder 52 and the fixing plate 53 .

In FIG. 5, a heat transfer path H1 from the heater 54 to the head chip 51 is schematically shown by a dashed arrow. Although part of the transmission path H1 includes the vibration absorber 51d, since the thickness of the vibration absorber 51d is extremely thin, the thermal resistance of the vibration absorber 51d in the transmission path H1 is very small.

The wiring board 51i is mounted on the surface of the diaphragm 51e facing the Z1 direction, and is a mounting component for electrically connecting the control unit 20 and the head chip 51. FIG. The wiring board 51i is, for example, a flexible wiring board such as COF (Chip On Film), FPC (Flexible Printed Circuit), or FFC (Flexible Flat Cable). A drive circuit 51j for supplying a drive voltage to each piezoelectric element 51f is mounted on the wiring board 51i of the present embodiment. The drive circuit 51j is a circuit that switches, based on the control signal S, whether or not to supply at least part of the waveform included in the drive signal D as a drive pulse.

1-4. Heat Generation Distribution of Heater FIG. 6 is a diagram for explaining the heat generation distribution of the heater 54 in the first embodiment. In FIG. 6, for the sake of convenience, the first region RE1 and the second region RE2 are shown in different shades of gray scale.

In this embodiment, the heater 54 has a heating resistor 54b, and the heating resistor 54b has a first portion 54b1 provided in the first region RE1 and a second portion 54b2 provided in the second region RE2. , has Note that FIG. 6 schematically shows the shape of the heating resistor 54b.

The first portion 54b1 is arranged to extend substantially over the entire first region RE1. In the example shown in FIG. 6, the first portion 54b1 has a meandering shape extending in the direction along the X-axis while meandering in the direction along the Y-axis. That is, the first portion 54b1 is folded back multiple times. Note that the shape and arrangement of the first portion 54b1 are not limited to the example shown in FIG.

The second portion 54b2 is arranged to extend over substantially the entire second region RE2. In the example shown in FIG. 6, the second portion 54b2 has a meandering shape extending in the direction along the X-axis while meandering in the direction along the Y-axis. That is, the second portion 54b2 is folded back multiple times. Note that the shape and arrangement of the second portion 54b2 are not limited to the example shown in FIG.

In the present embodiment, the second portion 54b2 is electrically connected in series with the first portion 54b1, and the amount of heat generated per unit area of the first region RE1 is greater than the amount of heat generated per unit area of the second region RE2. is configured to be large. That is, the electrical resistance per unit area of the first portion 54b1 in the first region RE1 is configured to be higher than the electrical resistance per unit area of the second portion 54b2 in the second region RE2. Specifically, the cross-sectional area of the first portion 54b1 is smaller than the cross-sectional area of the second portion 54b2, and the length of the first portion 54b1 per unit area in the first region RE1 is equal to the unit area in the second region RE2. At least one of: being longer than the length of the second portion 54b2, and that the electrical resistivity of the material forming the first portion 54b1 is higher than the electrical resistivity of the material forming the second portion 54b2. By satisfying , the electrical resistance per unit area of the first portion 54b1 in the first region RE1 is configured to be higher than the electrical resistance per unit area of the second portion 54b2 in the second region RE2. In order to make the length of the first portion 54b1 per unit area in the first region RE1 longer than the length of the second portion 54b2 per unit area in the second region RE2, The interval between the matching portions may be narrower than the interval between the folded back portions of the second portion 54b2.

The heating resistor 54b described above generates heat by being supplied with electric power under the control of the control unit 20 described above. In this embodiment, the control unit 20 controls power supply to the heating resistor 54b based on the detection result of the temperature sensor (not shown) so that the temperature detected by the temperature sensor reaches a predetermined temperature. The temperature sensor is, for example, a thermistor or a thermocouple and is arranged on the second member 5 .

1-5. Summary of First Embodiment The liquid jet head 50 described above includes the planar heater 54 , the first member 55 , and the second member 5 as described above. The heater 54 has a first surface F1 and a second surface F2 opposite to the first surface F1. The first member 55 is arranged on the first surface F1 and has a first flow path SC for supplying ink to the nozzles N that eject ink, which is an example of "liquid." The second member 5 is arranged on the second surface F2. Note that "one of two objects is placed on top of the other" does not only mean that the two objects are in contact with each other, but also that another object is interposed between the two objects. This concept also includes cases where

Here, the first flow path SC extends along the first surface F1. The heater 54 has a first region RE1 and a second region RE2 that generates less heat per unit time than the first region RE1. The first member 55 overlaps the first region RE1 and does not overlap the second region RE2 in plan view in the thickness direction of the heater 54 . The second member 5 overlaps both the first region RE1 and the second region RE2 in plan view.

In the liquid jet head 50 described above, the first member 55 and the second member 5 are objects to be heated by the heater 54 . Here, both the first member 55 and the second member 5 overlap in the first region RE1 in plan view. On the other hand, the second member 5 overlaps the second region RE2 without overlapping the first member 55 in plan view. Therefore, of the object to be heated, the heat capacity of the portion corresponding to the first region RE1 is larger than the heat capacity of the portion corresponding to the second region RE2. In addition, since the temperature of the ink supplied to the first flow path SC is normally lower than the temperature of the first member 55, the temperature of the first member 55 tends to decrease.

Therefore, by making the amount of heat generated per unit time of the first region RE1 larger than the amount of heat generated per unit time of the second region RE2, compared to the configuration in which the amount of heat generated per unit time of the heater 54 is uniform, The temperature difference between the portions corresponding to the first region RE1 and the second region RE2 to be heated can be reduced. In other words, by making the amount of heat generated per unit time of the first region RE1 larger than the amount of heat generated per unit time of the second region RE2, the excessive temperature rise of the portion corresponding to the second region RE2 to be heated can be prevented. While preventing this, the portion corresponding to the first region RE1 to be heated can be heated to a desired temperature. As described above, the ink of the liquid jet head 50 can be efficiently heated by the heater 54 without waste.

As described above, the first member 55 is preferably made of a material having a thermal conductivity of 10.0 W/m·k or higher. In this case, the ink in the first flow path SC can be efficiently heated by the heater 54 .

Further, as described above, the second member 5 has the reservoir R, which is an example of the "second flow path". The reservoir R is a channel for supplying ink to the nozzles N and extends along the second surface F2. In this way, in the configuration in which the second member 5 has the reservoir R, the ink in the reservoir R can be efficiently heated by the heater 54 .

Furthermore, as described above, the area of the second member 5 is larger than the area of the first member 55 in plan view. Therefore, even if the entire area of the first member 55 overlaps the second member 5 in plan view, the first member 55 does not overlap the second region RE2 in plan view, but overlaps the first region RE1. can be superimposed on both the first region RE1 and the second region RE2 in plan view. As a result, the weight of the liquid jet head 50 can be reduced. Moreover, when another component other than the first member 55 is arranged in the space in the Z1 direction with respect to the second region RE2, the space can be effectively used. Further, if the outer shape of the cover 56 is reduced so as to reduce the space in the Z1 direction with respect to the second region RE2, the size of the liquid jet head 50 can be reduced.

Also, the first flow path SC distributes the ink to a plurality of reservoirs R as described above. In such a distribution configuration, by making the area of the second member 5 larger than the area of the first member 55 in plan view, it is possible to reduce the wasteful portions of the first member 55 and the second member 5. can.

Furthermore, as described above, the area of the second member 5 is larger than the area of the heater 54 in plan view. Therefore, the entire area of the second member 5 can be overlapped with the heater 54 in plan view. As a result, the heat from the heater 54 is prevented from being wasted without passing through either the first member 55 or the second member 5 .

Further, as described above, the proportion of the area of the first flow path SC that occupies the first region RE1 in plan view is greater than the proportion of the area of the first flow channel SC that occupies the second region RE2 in plan view. In the configuration in which the first flow path SC is provided in this way, the temperature of the portion corresponding to the first region RE1 among the objects to be heated is more likely to decrease than the portion corresponding to the second region RE2. Therefore, making the amount of heat generated per unit time of the first region RE1 larger than the amount of heat generated per unit time of the second region RE2 means that the heat generated between the portions corresponding to the first region RE1 and the second region RE2 to be heated is reduced. It is useful for reducing the temperature difference between

Furthermore, as described above, the ratio of the area of the first flow path SC and the reservoir R occupying the first region RE1 in plan view is the area of the first flow channel SC and the reservoir R occupying the second region RE2 in plan view. greater than the proportion of When the temperature of the liquid supplied to the reservoir R is lower than the temperature of the second member 5, the portion of the second member 5 corresponding to the first region RE1 has a higher temperature than the portion corresponding to the second region RE2. easy to decline. Therefore, making the amount of heat generated per unit time of the first region RE1 larger than the amount of heat generated per unit time of the second region RE2 means that the heat generated between the portions corresponding to the first region RE1 and the second region RE2 to be heated is reduced. It is useful for reducing the temperature difference between

Here, the first region RE1 overlaps both the first channel SC and the reservoir R in plan view, and the second region RE2 overlaps only the reservoir R in plan view. Also, the first channel SC and the reservoir R communicate with each other, and ink is supplied to the reservoir R from the first channel SC. Since the first channel SC and the reservoir R communicate with each other in this manner, the liquid in the first channel SC can be supplied to the reservoir R after being heated by the heat from the heater 54 . Also, the liquid in the reservoir R can be supplied to the nozzle N after being further heated by the heat from the heater 54 . Therefore, the liquid sufficiently heated by the heat from the heater 54 can be supplied to the nozzle N.

Moreover, as described above, the second member 5 preferably contains a material having a thermal conductivity of 10.0 W/m·k or more. In this case, the ink in the reservoir R can be efficiently heated by the heater 54 .

Furthermore, as described above, the first flow path SC and the reservoir R overlap each other in plan view. Also, the second region RE2 overlaps the reservoir R in plan view.

In addition, as described above, the first surface F1 faces the space over at least part of the second region RE2. Since the space is a closed space surrounded by the cover 56 and air (gas) with low thermal conductivity exists, it has heat insulation. Therefore, heat is not easily dissipated from the portion of the heater 54 facing the space. Therefore, making the amount of heat generated per unit time of the first region RE1 larger than the amount of heat generated per unit time of the second region RE2 means that the heat generated between the portions corresponding to the first region RE1 and the second region RE2 to be heated is reduced. It is useful for reducing the temperature difference between

Moreover, as described above, the heater 54 has the heating resistor 54b. The heating resistor 54b is integrally provided over the first region RE1 and the second region RE2. Therefore, the number of terminals provided in the heater 54 can be reduced compared to the configuration in which the heating resistors 54b are separately provided for each of the first region RE1 and the second region RE2. As a result, the number of parts constituting the liquid jet head 50 can be reduced.

Here, in the present embodiment, as described above, the heating resistor 54b is electrically connected in series to the first portion 54b1 provided in the first region RE1 and the first portion 54b1, and is connected in series to the second region RE2. and a second portion 54b2 provided. In addition, the electrical resistance per unit area of the first portion 54b1 in the first region RE1 is configured to be higher than the electrical resistance per unit area of the second portion 54b2 in the second region RE2. Therefore, the amount of heat generated per unit area of the first region RE1 can be made larger than the amount of heat generated per unit area of the second region RE2. As a result, even if the calorific value of the first region RE1 and the calorific value of the second region 54b2 are not controlled by separate control systems, the calorific value per unit time of the first region RE1 can be adjusted to the calorific value per unit time of the second region RE2. can be larger than

2. 2nd Embodiment Hereinafter, 2nd Embodiment of this invention is described. In the embodiments exemplified below, the reference numerals used in the description of the first embodiment are used for the elements having the same actions and functions as those of the first embodiment, and the detailed description of each element is appropriately omitted.

FIG. 7 is a plan view of a liquid jet head 50A according to the second embodiment. 8 is a cross-sectional view taken along the line BB in FIG. 7. FIG. The liquid jet head 50A is the same as the liquid jet head 50 of the first embodiment except that it has a first member 55A instead of the first member 55. As shown in FIG.

The first member 55A is the same as the first member 55 except that the outer shape in plan view is different. The outer shape of the first member 55A in plan view is equal to the outer shape of the heater 54 in plan view. Therefore, both the first member 55A and the second member 5 overlap each of the first region RE1 and the second region RE2 in plan view.

According to the second embodiment described above, the ink of the liquid jet head 50A can be efficiently heated without waste by the heater 54, as in the first embodiment described above. Also in the present embodiment, as in the first embodiment, the ratio of the area of the first flow path SC that occupies the first region RE1 in plan view is the same as that of the first flow channel SC that occupies the second region RE2 in plan view. Greater than area percentage. Therefore, making the amount of heat generated per unit time in the first region RE1 larger than the amount of heat generated in the second region RE2 per unit time is useful for uniformly heating the first member 55A and the second member 5 by the heater 54. is useful in

3. 3rd Embodiment Hereinafter, 3rd Embodiment of this invention is described. In the embodiments exemplified below, the reference numerals used in the description of the first embodiment are used for the elements having the same actions and functions as those of the first embodiment, and the detailed description of each element is appropriately omitted.

FIG. 9 is a plan view of a liquid jet head 50B according to the third embodiment. The liquid jet head 50B is the same as the liquid jet head 50 of the first embodiment described above, except that the arrangement of the head chips 51_1 and 51_2 and the related configuration are different. Here, the liquid jet head 50 is the same as the liquid jet head 50 except that the heater 54, the first member 55 and the second member 5 are replaced with a heater 54B, a first member 55B and a second member 5B.

The second member 5B is the same as the second member 5, except for the arrangement of the head chips 51_1 and 51_2. In this embodiment, the head chip 51_1 and the head chip 51_2 are arranged to be shifted in the direction along the Y-axis.

In the head chip 51 of this embodiment, the introduction port IH is provided at a position near one end in the longitudinal direction of the head chip 51 . The head chip 51_1 and the head chip 51_2 are arranged so that the inlet IH of the head chip 51_1 and the inlet IH of the head chip 51_2 are aligned in the direction along the X axis, and are offset from each other in the direction along the Y axis. . Here, in the reservoir R of the head chip 51_1, the ink from the inlet IH is transferred in the Y2 direction. On the other hand, in the reservoir R of the head chip 51_2, the ink from the inlet IH is transferred in the Y1 direction.

The first flow channel SC of the first member 55B has a common flow channel SCc and a distribution flow channel SCd. The common channel SCc extends in the direction along the Y-axis, and an inlet 55a for receiving ink from the liquid reservoir 10 is provided at the end of the common channel SCc in the Y2 direction. The common flow path SCc transfers the ink from the inlet 55a in the Y1 direction. The distribution channel SCd extends in the X1 direction and the X2 direction from the common channel SCc, and transfers the ink from the common channel SCc in the X1 direction and the X2 direction. The distribution channel SCd is provided with four outlets 55b arranged in the direction along the X-axis.

The heater 54B is a planar heater arranged between the first member 55B and the second member 5B. Here, the heater 54B overlaps the entire area of the first member 55B in plan view. In the example shown in FIG. 9, the outer shape of the heater 54B in plan view is equal to the outer shape of the first member 55B in plan view, and their outer edges match each other in plan view.

Each of the first region RE1 and the second region RE2 of the heater 54B overlaps both the first member 55B and the second member 5B in plan view. In addition, the first region RE1 overlaps the reservoir R of the head chip 51_1 and the common channel SCc of the first channel SC in plan view. On the other hand, the second region RE2 overlaps the reservoir R of the head chip 51_2 without overlapping the common flow path SCc in plan view. Note that the heater 54B is divided into a first region RE1 and a second region RE2 with a center line LC along the distribution channel SCd as a boundary in plan view.

According to the third embodiment described above, as in the first embodiment described above, the amount of heat generated per unit time in the first region RE1 is made larger than the amount of heat generated per unit time in the second region RE2, so that the liquid is ejected. The ink in the head 50B can be efficiently heated by the heater 54 without waste. Further, in the present embodiment, the direction of ink flowing through the common flow path SCc, the direction of ink flowing through the reservoir R of the head chip 51_1, and the direction of ink flowing through the reservoir R of the head chip 51_2 are all aligned with each other on the Y axis. , the size of the liquid jet head 50B can be reduced compared to a configuration in which these directions are not parallel to each other. Furthermore, since the direction of ink flowing through the reservoir R of the head chip 51_1 is opposite to the direction of ink flowing through the reservoir R of the head chip 51_2, the common flow channel SCc that occupies most of the first flow channel SC is a flat surface. It visually overlaps the first region RE1. That is, the ink supplied to the reservoir R of the head chip 51_1 and the ink supplied to the reservoir R of the head chip 51_2 are ink heated by the first region RE1 of the heater 54B. Here, for example, the direction of ink flowing through the reservoir R of the head chip 51_1 in the liquid jet head 50B of the present embodiment is the Y1 direction, not the Y2 direction, and the inlet IH of the head chip 51_1 is the end of the reservoir R in the Y2 direction. Consider a comparative example located in the section. In this comparative example, the ratio of the common flow path SCc to the first flow path SC is smaller than that of the present embodiment, and the ratio of the distribution flow path SCd to the first flow path SC is the same as that of the present embodiment. become larger in comparison. As a result, the part for supplying to the reservoir R of the head chip 51_1 in the first channel SC overlapping the first region RE1 in plan view becomes the head portion of the first channel SC overlapping the first region RE1 in plan view. Since the ink is smaller than the portion of the chip 51_2 for supplying to the reservoir R, there is a difference between the temperature of the ink when it is supplied to the head chip 51_1 and the temperature of the ink when it is supplied to the head chip 51_2. On the other hand, in the present embodiment, most of the first flow path SC is the common flow path SCc. It is possible to suppress the difference between the temperature of the ink to be supplied.

4. Fourth Embodiment A fourth embodiment of the present invention will be described below. In the embodiments exemplified below, the reference numerals used in the description of the first embodiment are used for the elements having the same actions and functions as those of the first embodiment, and the detailed description of each element is appropriately omitted.

FIG. 10 is a plan view of a liquid jet head 50C according to the fourth embodiment. The liquid jet head 50C has four head chips 51_1 to 51_4. The head chip 51_1, head chip 51_2, head chip 51_3, and head chip 51_4 are arranged in this order in the X2 direction. However, the head chips 51_1 and 51_3 are arranged at positions shifted in the Y2 direction with respect to the head chips 51_2 and 51_4. Here, the head chip 51_1 and the head chip 51_3 are arranged side by side in the direction along the X-axis so as to align their positions in the direction along the Y-axis. Similarly, the head chip 51_2 and the head chip 51_4 are arranged side by side in the direction along the X-axis so as to be aligned with each other in the direction along the Y-axis. Note that the head chip 51_1, the head chip 51_2, the head chip 51_3, and the head chip 51_4 may be referred to as the head chip 51 hereinafter.

In FIG. 10, the direction of ink flow in the reservoir R of each head chip 51 is indicated by an arrow. Although not shown, the reservoir R of this embodiment is provided with an ink introduction port at one end and an ink discharge port at the other end. Here, ink is transferred in the Y2 direction in each of the reservoirs R of the head chips 51_1 and 51_3. On the other hand, ink is transferred in the Y1 direction in each of the reservoirs R of the head chips 51_2 and 51_4.

FIG. 11 is a cross-sectional view of a liquid jet head 50C according to the fourth embodiment. FIG. 11 schematically shows the configuration of the liquid jet head 50C. As shown in FIG. 11, the liquid jet head 50C has a heater 54C, a first member 55C, and a channel member 57 in addition to the four head chips 51_1 to 51_4 described above. Here, the first member 55C, the heater 54C, the channel member 57, and the four head chips 51 are arranged in this order in the Z2 direction. The heater 54C has a first surface F1 facing the Z1 direction and a second surface F2 facing the Z2 direction, and the first member 55C is arranged on the first surface F1. Then, an assembly composed of the channel member 57 and the four head chips 51 constitutes the second member 5C arranged on the second surface F2.

The first member 55C has four first channels SC for supplying ink to the four head chips 51_1 to 51_4. On the other hand, the channel member 57 has four third channels DC for discharging ink from the four head chips 51_1 to 51_4 to the outside. In addition to the first flow path SC, the first member 55C is provided with a flow path for discharging ink from the third flow path DC. Further, the channel member 57 is provided with a channel for supplying ink from the first channel SC to the head chip 51 in addition to the third channel DC.

FIG. 12 is a diagram for explaining the heat generation distribution of the heater 54C in the fourth embodiment. In FIG. 12, in addition to the outer shape of the heater 54C, the first flow path SC is indicated by a solid line, and the third flow path DC is indicated by a two-dot chain line.

As shown in FIG. 12, in plan view, the ratio of the area of the first flow path SC occupying the first region RE1 of the heater 54C is higher than the ratio of the area of the first flow channel SC occupying the second region RE2 of the heater 54C. is also big. On the other hand, in plan view, the proportion of the area of the third flow path DC occupying the first region RE1 of the heater 54C is smaller than the proportion of the area of the third flow channel DC occupying the second region RE2 of the heater 54C.

According to the fourth embodiment described above, as in the first embodiment described above, the amount of heat generated per unit time in the first region RE1 is made larger than the amount of heat generated per unit time in the second region RE2. The ink in the head 50C can be efficiently heated by the heater 54 without waste.

5. Fifth Embodiment A fifth embodiment of the present invention will be described below. In the embodiments exemplified below, the reference numerals used in the description of the first embodiment are used for the elements having the same actions and functions as those of the first embodiment, and the detailed description of each element is appropriately omitted.

FIG. 13 is a diagram for explaining the heat generation distribution of the heater 54D in the fifth embodiment. This embodiment is the same as the above-described fourth embodiment except that a heater 54D is used instead of the heater 54C. The heater 54D is the same as the heater 54C of the fourth embodiment described above, except that the heat generation distribution is different.

The heater 54D has a first region RE1, a second region RE2, and a third region RE3. Here, the first region RE1 is a region between the second region RE2 and the third region RE3. Here, the amount of heat generated per unit time of the third region is smaller than the amount of heat generated per unit time of the first region RE1. However, from the viewpoint of uniformly heating the first member 55C and the flow path member 57, the amount of heat generated per unit time of the third region RE3 is preferably larger than the amount of heat generated per unit time of the second region RE2.

According to the fifth embodiment as well, the amount of heat generated per unit time in the first region RE1 is greater than the amount of heat generated per unit time in the second region RE2. can be efficiently heated without

6. Modifications The forms illustrated above can be modified in various ways. Specific modified aspects that can be applied to the above-described modes are exemplified below. Two or more aspects arbitrarily selected from the following examples can be combined as appropriate within a mutually consistent range.

6-1. Modification 1
14A and 14B are diagrams for explaining the heat generation distribution of the heater 54E in Modification 1. FIG. The heater 54E is the same as the heater 54 of the first embodiment except that it has a heating resistor 54c instead of the heating resistor 54b. The heating resistor 54c is similar to the heating resistor 54b except that the first portion 54b1 and the second portion 54b2 are electrically connected in parallel.

That is, the heating resistor 54c has a first portion 54b1 provided in the first region RE1 and a second portion 54b2 electrically connected in parallel to the first portion 54b1 and provided in the second region RE2. The first portion 54b1 and the second portion 54b2 are configured such that the amount of heat generated per unit area of the first region RE1 is larger than the amount of heat generated per unit area of the second region RE2. That is, the electrical resistance per unit area of the first portion 54b1 in the first region RE1 is configured to be smaller than the electrical resistance per unit area of the second portion 54b2 in the second region RE2.

Specifically, the cross-sectional area of the first portion 54b1 is larger than the cross-sectional area of the second portion 54b2, and the length of the first portion 54b1 per unit area in the first region RE1 is equal to the unit area in the second region RE2. At least one of: being shorter than the length of the second portion 54b2; and that the electrical resistivity of the material forming the first portion 54b1 is lower than that of the material forming the second portion 54b2. is satisfied, the electric resistance per unit area of the first portion 54b1 in the first region RE1 is lower than the electric resistance per unit area of the second portion 54b2 in the second region RE2. In order to make the length of the first portion 54b1 per unit area in the first region RE1 shorter than the length of the second portion 54b2 per unit area in the second region RE2, The interval between the matching portions may be made wider than the interval between the folded back portions of the second portion 54b2. Therefore, the amount of heat generated per unit area of the first region RE1 can be made larger than the amount of heat generated per unit area of the second region RE2. As a result, even if the calorific value of the first region RE1 and the calorific value of the second region 54b2 are not controlled by separate control systems, the calorific value per unit time of the first region RE1 can be adjusted to the calorific value per unit time of the second region RE2. can be larger than

According to Modification 1 as well, by making the amount of heat generated per unit time in the first region RE1 larger than the amount of heat generated per unit time in the second region RE2, the ink of the liquid jet head 50 is efficiently discharged by the heater 54E. Efficient heating.

6-2. Modification 2
FIG. 15 is a cross-sectional view corresponding to FIG. 4, and is a cross-sectional view of the liquid jet head 50F according to Modification 2. As shown in FIG. The liquid jet head 50</b>F is the same as the liquid jet head 50 of the first embodiment except that it includes a heat insulating member 58 .

The heat insulating member 58 is a member made of a material such as a resin material having a thermal conductivity of less than 1.0 W/m·k. The heat insulating member 58 has a plate shape with a thickness direction in the Z-axis direction. Note that the shape of the heat insulating member 58 is arbitrary. A heat insulating member 58 is arranged in the space inside the liquid jet head 50 , which is the space inside the cover 56 in this embodiment. That is, the first surface F1 is in contact with the heat insulating member 58 over at least part of the second region RE2. In this modification, the entire second region RE2 of the first surface F1 is in contact with the heat insulating member 58 .

In this case as well, the portion of the heater 54 in contact with the heat insulating member 58 is difficult to dissipate heat. , to reduce the temperature difference between the portions corresponding to the first region RE1 and the second region RE2 to be heated. Note that the heat insulating member 58 may be integrated with the cover 56 .

6-3. Modification 3
Although the configuration in which the number of head chips 51 included in the liquid jet head is 2 or 4 is exemplified in the above embodiment, the number is not limited to this configuration, and the number may be 1, 3, or 5 or more. It's okay.

6-4. Modification 4
In the above embodiment, the serial liquid ejecting apparatus 100 in which the support 41 that supports the liquid ejecting head 50 reciprocates is exemplified. The present invention can also be applied to That is, the support that supports the liquid jet head 50 is not limited to a serial carriage, and may be a structure that supports the liquid jet head 50 in a line system. In this case, for example, a plurality of liquid jet heads 50 are arranged side by side in the width direction of the medium M, and the plurality of liquid jet heads 50 are collectively supported by one support.

6-5. Modification 5
The liquid ejecting apparatus exemplified in the above embodiments can be employed in various types of equipment such as facsimile machines and copiers, in addition to equipment dedicated to printing. However, the application of the liquid ejecting apparatus is not limited to printing. For example, a liquid ejecting apparatus that ejects a colorant solution is used as a manufacturing apparatus for forming a color filter for a display device such as a liquid crystal display panel. Also, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes of a wiring board. Further, a liquid ejecting apparatus that ejects a solution of an organic matter related to living organisms is used as a manufacturing apparatus for manufacturing biochips, for example.

5 Second member 5B Second member 5C Second member 10 Liquid reservoir 20 Control unit 30 Conveying mechanism 40 Moving mechanism 41 Support 42 Conveying belt 50 Liquid jet head 50A Liquid jet head 50B Liquid jet head 50C Liquid jet head 51 Head chip 51_1 Head chip 51_2 Head chip 51_3 Head chip 51_4 Head chip 51a Flow path substrate 51b Pressure chamber substrate 51c Nozzle plate 51d Vibration absorber 51e Vibration plate 51f Piezoelectric element 51g Protection plate 51h Case 51i Wiring substrate 51j Drive circuit 51k Frame 52 Holder 52B Holder 52a Hole 52b Recess 52c Recess 53 Fixed plate 53a Opening 54 Heater 54B Heater 54C Heater 54D Heater 54E Heater 54a Hole 54b Heating resistor 54b1 First part 54b2 Second part 54c Heating resistor 55 First member 55A First member 55B First member 55C First member 55a Introduction port 55b Discharge port 56 Cover 56a Recessed portion 56b Hole 57 Flow path member 58 Thermal insulation member 100 Liquid injection device C Pressure chamber D... drive signal, DC... third flow path, DM... conveying direction, F1... first surface, F2... second surface, FN... nozzle surface, H1... transmission path, IH... inlet, L1... first row, L2...Second row, LC...Center line, M...Medium, N...Nozzle, Na...Communicating channel, R...Reservoir (second channel), R1...Space, R2...Space, RE1...First region, RE2 Second area RE3 Third area Ra Supply channel S Control signal SC First channel SCa Common channel SCb Branch channel SCc Common channel SCd Distribution flow path.

Claims (20)

a planar heater having a first surface and a second surface opposite to the first surface;
a first member disposed on the first surface and having a first flow path for supplying liquid to nozzles for ejecting liquid;
a second member disposed on the second surface;
The first flow path extends along the first surface,
The heater has a first region and a second region having a smaller amount of heat generated per unit time than the first region,
The first member overlaps the first region and does not overlap the second region in a plan view seen in the thickness direction of the heater,
The second member overlaps both the first region and the second region in plan view,
A liquid jet head characterized by: The first member is made of a material having a thermal conductivity of 10.0 W / m · k or more,
The liquid jet head according to claim 1 . the second member has at least one second flow path for supplying liquid to a nozzle for ejecting liquid;
the second flow path extends along the second surface;
3. The liquid jet head according to claim 1. The area of the second member is larger than the area of the first member in plan view,
4. The liquid jet head according to claim 3. the at least one second flow path includes a plurality of second flow paths;
the first channel distributes liquid to the plurality of second channels;
5. The liquid jet head according to claim 4. The area of the second member is larger than the area of the heater in the plan view,
6. The liquid jet head according to claim 4 or 5. The ratio of the area of the first flow channel that occupies the first region in the plan view is greater than the ratio of the area of the first flow channel that occupies the second region in the plan view,
The liquid jet head according to any one of claims 4 to 6. The second member contains a material having a thermal conductivity of 10.0 W/m·k or more,
The liquid jet head according to any one of claims 4 to 7. the first channel and the at least one second channel overlap each other in the plan view;
The liquid jet head according to any one of claims 4 to 8. The second region overlaps the at least one second flow channel in plan view,
The liquid jet head according to any one of claims 4 to 8. the first surface faces space over at least a portion of the second region;
The liquid jet head according to any one of claims 4 to 10. The first surface contacts the insulating member over at least a portion of the second region.
The liquid jet head according to any one of claims 4 to 10. a planar heater having a first surface and a second surface opposite to the first surface;
a first member disposed on the first surface and having a first flow path for supplying liquid to nozzles for ejecting liquid;
a second member disposed on the second surface and having a second flow path for supplying liquid to a nozzle for ejecting liquid;
each of the first flow path and the second flow path extends along the first surface or the second surface;
The heater has a first region and a second region having a smaller amount of heat generated per unit time than the first region,
The proportion of the area of the first flow path that occupies the first region in plan view in the thickness direction of the heater is greater than the proportion of the area of the first flow channel that occupies the second region in plan view. ,
A liquid jet head characterized by: The ratio of the areas of the first flow channel and the second flow channel that occupy the first region in the plan view is the ratio of the areas of the first flow channel and the second flow channel that occupy the second region in the plan view. greater than the proportion of the area,
The liquid jet head according to claim 13. the first region overlaps both the first channel and the second channel in plan view;
The second region overlaps only the second flow channel in plan view,
The liquid jet head according to claim 13 or 14. the first flow path and the second flow path communicate with each other;
liquid is supplied from the first channel to the second channel;
The liquid jet head according to any one of claims 13 to 14. The heater has a heating resistor integrally provided over the first region and the second region,
The liquid jet head according to any one of claims 1 to 16. The heating resistor has a first portion provided in the first region and a second portion electrically connected in series to the first portion and provided in the second region,
The electrical resistance of the first portion per unit area in the first region is greater than the electrical resistance of the second portion per unit area in the second region.
The liquid jet head according to claim 17. The heating resistor has a first portion provided in the first region and a second portion electrically connected in parallel to the first portion and provided in the second region,
The electrical resistance of the first portion per unit area in the first region is lower than the electrical resistance of the second portion per unit area in the second region.
The liquid jet head according to claim 17. a liquid jet head according to any one of claims 1 to 19;
A control unit that controls driving of the heater,
A liquid injection device characterized by:

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