Liquid discharge head and recording device

Abstract

This liquid discharge head comprises a head body (9) that has a discharge hole, a heat sink (11) that has a flow path (13), and a heat insulation member (15) that is interposed between the head body (9) and the heat sink (11).

Description

Liquid ejection head and recording device

[0001] The present disclosure relates to a liquid ejection head such as an inkjet head, and a recording apparatus having the liquid ejection head.

[0002] Among liquid ejection heads (e.g., inkjet heads) that eject liquid (e.g., ink) toward a recording medium (e.g., paper), those having a heat sink are known (see, for example, Patent Document 1 below). In Patent Document 1, the liquid ejection head includes a generally plate-shaped head main body that ejects liquid from its bottom surface and a generally rectangular parallelepiped housing that covers the back (top) surface of the head main body. A drive IC (Integrated Circuit) that inputs drive signals to the head main body is housed inside the housing. Openings are formed on two side surfaces of the housing, and heat sinks are disposed to cover the openings. The heat sink is made of metal, with the drive IC pressed against its inner surface and the outer surface exposed to the outside of the housing. This allows the heat sink to contribute to heat dissipation from the drive IC.

[0003] The liquid ejection head of Patent Document 2 listed below has a flow path member for cooling a driving IC. The flow path member is a plate-like member that stands above a long head chip that ejects liquid from its underside. The flow path member also has a flow path that supplies liquid to the head chip. Along the flow path, multiple driving ICs are stacked on the wall surface of the flow path member via heat transfer plates. Members called manifolds are arranged on both ends of the head chip, and the flow path member is connected to the head chip via the manifolds. Note that in Patent Document 2, the materials of the flow path member, heat transfer plate, and manifold are unknown.

[0004] JP 2023-25267 A JP 2023-90296 A

[0005] A liquid ejection head according to one aspect of the present disclosure includes a head body having ejection holes, a heat sink having a flow path, and a heat insulating member interposed between the head body and the heat sink.

[0006] A recording apparatus according to an aspect of the present disclosure includes the liquid ejection head.

[0007] 1. A side view of a recording apparatus according to an embodiment. A plan view of the recording apparatus of FIG. 1. A perspective view of a liquid ejection head of the recording apparatus of FIG. 1. An exploded perspective view of the liquid ejection head of FIG. 3. A cross-sectional view taken along line V-V of FIG. 3. An exploded perspective view of the head body of the liquid ejection head of FIG. 3. A cross-sectional view taken along line VII-VII of FIG. 6. A side view showing the flow path of the heat sink in the liquid ejection head of FIG. 3. A perspective view showing a heat insulating member of the liquid ejection head of FIG. 3. An enlarged view of region X in FIG. 5. A cross-sectional view taken along line XI-XI of FIG. 9. A perspective view of a liquid ejection head according to another example. A cross-sectional view showing the heat insulating member and its periphery of the liquid ejection head of FIG. 11. A diagram for explaining image quality in printing using a liquid ejection head according to a comparative example.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings used in the following description are schematic. Therefore, for example, the dimensional ratios in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional ratios may not match between drawings. Certain shapes and / or dimensions may be exaggerated, and details may be omitted. However, the above does not deny that the actual shapes and / or dimensions may be as shown in the drawings, or that features of shapes and / or dimensions may be extracted from the drawings.

[0009] For convenience, the drawings are illustrated with a Cartesian coordinate system D1D2D3, and terms such as D1 direction, D2 direction, and D3 direction are used. As will be understood from the description below, the term D1 direction may be replaced with the term "longitudinal direction of the head" and / or the direction perpendicular to the direction of relative movement between the head and the recording medium. The term D2 direction may be replaced with the term "transverse direction of the head" and / or the direction of the relative movement. The term D3 direction may be replaced with the term "normal direction" to the ejection surface or back surface of the head main body. The liquid ejection head and recording apparatus according to the embodiment may be used in any orientation. However, for convenience, terms may be used assuming that the +D3 side is upward.

[0010] (Overview of the embodiment) Figure 3 is a perspective view mainly showing a head 3 (an example of a liquid ejection head) according to the embodiment. The head 3 performs recording (printing), for example, on a recording medium (see print paper P in Figure 1, described later) facing the lower surface (ejection surface 5) of the head 3. Specifically, a plurality of ejection holes 7 (see Figure 7, described later) are opened in the ejection surface 5 of the head 3. Ink droplets (an example of liquid droplets) are ejected from the plurality of ejection holes 7. As a result, a plurality of dots that form an image are formed on the recording medium.

[0011] Fig. 5 is a cross-sectional view taken along line VV in Fig. 3. As shown in Fig. 3 and Fig. 5, the head 3 has, for example, a head main body 9 that constitutes the ejection surface 5, and at least one heat sink 11 (two in the illustrated example) that contributes to heat dissipation from the head 3 (more strictly, electronic components (described later) included in the head 3).

[0012] In the illustrated example, the head body 9 is, for example, a generally plate-shaped member (in other words, a shape in which the thickness is smaller than the length and width; the same applies below) with the D3 direction as its thickness direction. The heat sink 11 is a generally plate-shaped member facing the D2 direction on the back surface (top surface) of the head body 9. The heat sink 11 has a flow path 13 ( FIG. 5 ) through which a coolant (e.g., water) flows.

[0013] A heat insulating member 15 is interposed between the head main body 9 and the heat sink 11. The heat insulating member 15 is, for example, bonded to the head main body 9 and the heat sink 11, thereby bonding the head main body 9 and the heat sink 11. For example, the head main body 9 and the heat sink 11 are not in contact with each other.

[0014] In the above configuration, the heat sink 11 has the flow passages 13, which improves the cooling effect of the electronic components compared to a configuration in which the heat sink 11 is simply a plate. Therefore, for example, the electrical load on the electronic components can be increased. As a result, for example, the frequency at which ink droplets are ejected from the head body 9 can be increased, thereby improving printing speed.

[0015] On the other hand, if the cooling capacity of the heat sink 11 becomes high, an unintended cooling effect occurs in the portion of the head body 9 that is joined to the heat sink 11. As a result, for example, a deviation in the temperature distribution occurs in the head body 9. This deviation in the temperature distribution causes, for example, uneven viscosity of ink within the head body 9, which in turn causes variations in the ejection characteristics from the multiple ejection holes 7.

[0016] However, by interposing the heat insulating member 15 between the heat sink 11 and the head main body 9, the above-mentioned inconvenience is eliminated. The above-mentioned inconvenience (in other words, the problem) is less likely to occur in a heat sink 11 that does not have a flow path 13. From another perspective, the heat insulating member 15 provides advantageous effects when combined with the flow path 13. Note that, unlike the description of the embodiment, when extracting an invention from this disclosure that does not require the flow path 13, the heat insulating member 15 does not have to be combined with the flow path 13.

[0017] In the embodiment, unlike the illustrated example, the heat sink 11 and the head main body 9 may be in direct contact with each other over a relatively small area at the position where the heat insulating member 15 is not disposed. Also, the heat insulating member 15 may not contribute to joining the head main body 9 and the heat sink 11. Even in these cases, the heat insulating member 15 reduces the contact area between the heat sink 11 and the head main body 9, thereby still achieving the above-mentioned effect.

[0018] The above is an overview of the embodiment. Below, the details of the embodiment will be explained roughly in the following order: 1. Printer in general (FIGS. 1 and 2) 2. Overall configuration of the head (FIGS. 3 to 5) 3. Head body (FIGS. 3 to 7) 3.1. Front part 3.1.1. Flow path member 3.1.2. Actuator board 3.2. Back part 4. Heat sink (FIGS. 3 to 5 and 8) 5. Heat insulating member (FIGS. 3 to 5 and 9 to 11) 5.1. General 5.2. Base 5.3. Rib 5.4. Material 6. Other examples of head (FIGS. 12 and 13) 7. Experimental example (FIG. 14) 8. Summary of the embodiment

[0019] The description of the heat sink 11 in Section 4 includes a description of the positional relationship between the flow path 13 and the driving IC 37 (described later), and a description of the joining between the heat sink 11 and the head cover 25 (described later). The description of the heat insulating member 15 in Section 5 includes a description of the joining between the heat insulating member 15 and other members (such as the heat sink 11), and a description of the relationship between the thermal conductivity of the heat insulating member 15 and the thermal conductivity of other members.

[0020] (1. Printer in General) Fig. 1 is a side view of a printer 1 having a head 3. Fig. 2 is a plan view of the printer 1.

[0021] The configuration of the printer 1 may be various, for example, a known configuration, except for the configuration related to the heat sink 11 and the heat insulating member 15. The printer 1 illustrated in Figures 1 and 2 is merely an example. Below, the printer 1 as a whole will be briefly described using the printer 1 illustrated in Figures 1 and 2 as an example.

[0022] The printer 1 forms an image on the printing paper P by ejecting ink droplets downward from heads 3 located above the printing paper P. Specifically, as shown in Figure 2, one head unit 17 is made up of five heads 3. In each head unit 17, the five heads 3 are arranged in a staggered pattern so that there are no gaps in the D1 direction when viewed in the D2 direction. The printable range of each head unit 17 roughly spans the width of the printing paper P (in the D1 direction). An image is then formed by the heads 3 ejecting ink droplets while the printing paper P is passing below the heads 3.

[0023] As can be seen from the above, the printer 1 is configured as a so-called line printer. However, the printer 1 is not limited to a line printer. For example, the printer 1 may be a serial printer. In a serial printer, for example, the operation of moving the head (head unit) in a direction intersecting the transport direction of the print paper P and the transport of the print paper P are performed alternately. For convenience, the explanation of the embodiments may be given assuming a line printer without any particular mention.

[0024] The printer 1 has a total of four head units 17. The four head units 17 are arranged, for example, in the transport direction of the printing paper P. The five heads 3 in each head unit 17 correspond to ink of the same color. The four head units 17 correspond to ink of different colors (four color inks). The four color inks are, for example, magenta (M), yellow (Y), cyan (C), and black (K). This allows the printer 1 to function as a color printer.

[0025] Unlike the above description, the printer 1 may print in a single color, or conversely, may print in more than four colors. In other words, the number of colors is arbitrary. Two or more head units 17 may correspond to one color. Conversely, one head unit 17 may correspond to two or more colors, for example, by having one head 3 correspond to two or more colors. The number of heads 3 included in one head unit 17 is arbitrary, and may be one. As can be understood from the above, the number of heads 3 included in the printer 1 is arbitrary.

[0026] There is no particular limitation on the configuration for fixing the plurality of heads 3 to each other in each head unit 17. 1 and 2 show, as an example, a frame 21 having an opening (not shown) that exposes the ejection surface 5 of the head 3 downward.

[0027] The printer 1 prints on, for example, roll paper as printing paper P. However, the printing paper P may also be sheet paper. The size of the printing paper P is also arbitrary. For example, the size of the printing paper P may be small like a receipt, a size commonly used in offices, or large like a poster.

[0028] The transport device 19 for transporting the printing paper P may have any configuration. Figures 1 and 2 show an example of a configuration in which the printing paper P is transported by rotating rollers that sandwich the printing paper P. Other configurations include, for example, a configuration in which the printing paper P is transported by transporting a belt that adsorbs the printing paper P, and a configuration in which the printing paper P is transported by rotating a drum wrapped around the printing paper P. In a broader concept, the transport device 19 is a moving unit that moves the head (3) and the recording medium (P) relative to each other.

[0029] As schematically shown in FIG. 3 , the printer 1 has an ink supply system 89 that supplies ink to the head 3. The ink supply system 89 may have any configuration. For example, the ink supply system 89 may have an ink tank 91 that stores ink and an ink pump 93 that delivers ink from the ink tank 91 to the head 3. The ink tank 91 may be replaceable, in which case the ink tank 91 may not be considered a component of the printer 1. The ink pump 93 is not limited to a pump that is generally considered to be a pump, and may, for example, apply pressure to the ink tank 91. The ink supply system 89 may have a configuration that recovers ink from the head 3 (in other words, a configuration that circulates ink).

[0030] As schematically shown in FIG. 3 , the printer 1 has a refrigerant supply system 95 that supplies a refrigerant (e.g., water) to the head 3. The refrigerant supply system 95 may be defined to include a component that recovers the refrigerant. The refrigerant supply system 95 may have any configuration. For example, the refrigerant supply system 95 may have a refrigerant tank 97 that stores the refrigerant and a pump 99 that sends the refrigerant from the refrigerant tank 97 to the head 3. The refrigerant that has exchanged heat with the head 3 may be returned to the refrigerant tank 97 (as in the illustrated example), or may not be returned (for example, it may be discarded). The refrigerant supply system 95 may be configured by equipment in a factory, etc., in which case the refrigerant supply system 95 may not be considered a component of the printer 1. The printer 1 or the factory, etc., may or may not have a heat pump for cooling the refrigerant.

[0031] The coolant is, for example, water. However, the coolant may be a liquid other than water (for example, antifreeze) or a gas (for example, air). Furthermore, the ink ejected from the head 3 may be used as the coolant. In this case, unlike the illustrated example, for example, the coolant supply system 95 may be eliminated, and the flow path 13 of the heat sink 11 may be directly or indirectly connected to the flow path of the head main body 9 (for more details, see the top port 85 described later). Then, ink may be supplied from the ink supply system 89 to the flow path 13 of the heat sink 11, and the ink that has absorbed heat in the heat sink 11 may be supplied to the head main body 9.

[0032] In addition to the above components, the printer 1 may have various other components. Although not specifically shown, examples are given below. Controller: For example, controls the head 3, the transport device 19, the ink supply system 89, and the refrigerant supply system 95. Drying device: For example, promotes the drying of the ink. Application device: For example, applies a transparent coating agent evenly to the printing paper P. Cleaning device: For example, cleans the head 3. Note that the printer 1 may use the head 3 to apply a coating agent in addition to, or instead of, printing with colored ink.

[0033] (2. Overall Configuration of Head) The configuration of the head 3 may be various, for example, a known configuration, excluding the configuration related to the heat sink 11 and the heat insulating member 15. Below, the components of the head 3 in the illustrated example are listed, and then the components other than the head main body 9, the heat sink 11, and the heat insulating member 15 are briefly described.

[0034] As shown in FIG. 3 , the head 3 may include the following components in addition to the head main body 9, heat sink 11, and heat insulating member 15: Head cover 25: For example, together with the heat sink 11, this constitutes the housing 23 of the head 3. Connector 27: For example, this electrically connects the head 3 to other components (such as the controller) within the printer 1. Ink pipe 29: For example, this connects the head main body 9 to the ink supply system 89. This may be considered a component of the ink supply system 89 rather than a component of the head 3. Connection part 31: For example, this connects the flow path 13 of the heat sink 11 to the coolant supply system 95. This may be considered a component of the coolant supply system 95 rather than a component of the head 3. Communication pipe 33: For example, this connects the flow paths 13 of the two heat sinks 11. This may be considered a component of the coolant supply system 95 rather than a component of the head 3. Positioning fixture 35: For example, this positions the head 3 relative to the frame 21. This may be considered a component of the head 3.

[0035] 4 is an exploded perspective view of the head 3. As shown in this figure, the head 3 may further include the following components: Drive IC 37: For example, generates a drive signal to be input to the head main body 9. Flexible Printed Circuits (FPC) 39: For example, transmits a signal related to the drive IC 37. Lower surface heater 41 and upper surface heater 43: For example, heats the head main body 9 (in a broader concept, performs temperature adjustment). Pressing member 45: For example, presses the drive IC 37 against the heat sink 11. Circuit board 47: For example, has various electric circuits connected to the drive IC 37.

[0036] 4 and 5, the head main body 9 has the following components: Front part 49: For example, this constitutes the ejection surface 5. Back part 51: For example, this constitutes the back surface of the head main body 9 (the surface on the +D3 side).

[0037] The housing 23 has, for example, a generally rectangular parallelepiped shape with an open bottom. The head cover 25 forms the top surface and both side surfaces in the D1 direction out of the five surfaces of the housing 23. The two heat sinks 11 form the remaining two surfaces. The head cover 25 may be made of any material. For example, the material may be metal or resin. The metal may be, for example, aluminum or an aluminum alloy.

[0038] As described above, the head 3 has an electrical configuration for driving the head main body 9, which includes the drive IC 37, FPC 39, circuit board 47, and connector 27. A signal input from a controller (not shown) to the connector 27 is input to the drive IC 37 via the circuit board 47 and FPC 39 in this order. The drive IC 37 generates a drive signal based on the input signal. This drive signal is input to the head main body 9 via the FPC 39. The drive signal is, for example, a pulse signal having an electric potential of an appropriate magnitude.

[0039] Specific aspects (number, position, configuration, etc.) of the FPC 39 are arbitrary. In the example of Figures 4 and 5, the head 3 has two FPCs 39 arranged approximately symmetrically with respect to a plane of symmetry (not shown) parallel to the D1-D3 plane.

[0040] Each FPC 39 is, for example, a single-sided plate having a conductor pattern only on one surface (hereinafter referred to as the "first surface"). The first surface of the FPC 39 in the edge region faces and is electrically connected to the upper surface of the front part 49. The FPC 39 extends outward in the D2 direction of the housing 23 in the edge region, and then bends to extend upward to the opposite side of the first surface. The upward-extending portion faces the first surface to the inner surface of the heat sink 11. A driving IC 37 is mounted on the region of the first surface facing the inner surface of the heat sink 11.

[0041] Unlike the illustrated example, for example, one FPC 39 may be provided, with the central region connected to the front part 49 and the end regions extending upward. Also, the FPC 39 may be a double-sided board having conductor patterns on both sides.

[0042] The specific aspects (number, position, configuration, etc.) of the driver ICs 37 are arbitrary. In the examples of Figures 4 and 5, a plurality of driver ICs 37 (five in the example of Figure 4) are arranged in a row in the D1 direction on the first surface of each FPC 39. In other words, the plurality of driver ICs 37 are arranged at the same positions as each other in the D3 direction. The driver ICs 37 are generally rectangular parallelepipeds with a longitudinal direction, and are mounted with the longitudinal direction oriented along the D1 direction. Unlike the illustrated example, for example, the driver ICs 37 may be mounted on both sides of the FPC 39, which is configured as a double-sided plate.

[0043] The pressing member 45 has, for example, a support portion 45a that is generally U-shaped when viewed in the D1 direction and an elastic member 45b located on the outer side of the U-shape. The pressing member 45 presses the driving IC 37 via the FPC 39 using the elastic member 45b, thereby pressing the driving IC 37 against the heat sink 11. The force pressing the driving IC 37 may be obtained by the restoring force of the support portion 45a and / or the elastic member 45b. The material of the support portion 45a and the elastic member 45b is arbitrary. For example, the thermal conductivity of these materials may be higher or lower than that of the heat insulating member 15.

[0044] 4 and 5, the lower surface heater 41 is, for example, in the form of a sheet that overlaps the lower surface of the back part 51. The upper surface heater 43 is, for example, in the form of a sheet that overlaps the upper surface of the back part 51. These heaters contribute, for example, to increasing the temperature of the ink and reducing the viscosity of the ink. These heaters generate heat by receiving power via, for example, a circuit board 47 (and are controlled from another perspective). The target temperature may be a temperature within the range of room temperature (5°C or higher and 35°C or lower), or may be a temperature higher than room temperature.

[0045] 3 and 4, two ink pipes 29 are provided. The two ink pipes 29 may, for example, both be used to supply ink of the same color to the head body 9. Alternatively, the two ink pipes 29 may supply ink of different colors. Furthermore, one ink pipe 29 may be used to supply ink, and the other ink pipe 29 may be used to collect ink.

[0046] As can be understood from the above, the head body 9 may be of a circulation type that circulates ink, or may not be of a circulation type. For convenience, in the description of the embodiments, the head body 9 may be described on the assumption that it is not of a circulation type unless otherwise specified.

[0047] An upper surface port 85 ( FIG. 4 ) through which the head main body 9 receives ink opens in an area of ​​the upper surface of the back part 51 that is located outside the housing 23. Consequently, the ink pipe 29 connected to the upper surface port 85 is located outside the housing 23. Unlike the example shown in the figure, the upper surface port 85 may open in an area that is covered by the housing 23. And the ink pipe 29 may be inserted into the housing 23 from the top surface of the housing 23.

[0048] The connecting part 31 is, for example, a member that connects the flow path 13 of the heat sink 11 to a pipe (including the communicating pipe 33), and its specific configuration is arbitrary. The pipe (including the communicating pipe 33) may be flexible or inflexible. The specific role of the communicating pipe 33 will be described in the description of the heat sink 11.

[0049] (3. Head Body) As described above, the head body 9 has a front part 49 and a back part 51. The front part 49 has an ejection surface 5 and directly contributes to the ejection of ink droplets. The back part 51, for example, contributes to the supply of ink to the front part 49 (supply and recovery in the case of a circulation type), contributes to improving the strength of the head body 9, and / or contributes to fixing the head body 9 to the frame 21. The front part 49 and the back part 51 may be joined, for example, by an adhesive (for example, a thermosetting resin) not shown that is interposed between the upper surface of the former and the lower surface of the latter.

[0050] (3.1. Front Part) As shown in Fig. 4, the front part 49 is generally plate-shaped. Its planar shape is, for example, generally rectangular with the D1 direction as the longitudinal direction. As shown in Fig. 5, the front part 49 has a flow path member 53 having a flow path (including the ejection holes 7) through which ink flows, and an actuator substrate 55 that applies pressure to the ink to eject it.

[0051] (3.1.1. Flow Path Member) FIG. 6 is an exploded perspective view of the head main body 9. The flow path member 53 is a generally plate-shaped member. The flow path member 53 has at least one port 57 (eight in the illustrated example), at least one common flow path 59 (four in the illustrated example), and a plurality of individual flow paths 61 (only some of which are shown) as flow paths. Each individual flow path 61 has an ejection hole 7 ( FIG. 7 ). Ink flows through the port 57, the common flow path 59, and the individual flow path 61 in that order, and is ejected from the ejection hole 7.

[0052] The port 57 opens to the back surface (top surface) of the flow path member 53. A plurality of common flow paths 59 extend from the port 57 along the ejection surface 5 inside the flow path member 53, and also extend parallel to one another. A plurality of individual flow paths 61 are arranged along each common flow path 59 and over substantially the entire length of the common flow path 59. However, for convenience, only some of the individual flow paths 61 (and further only pressure chambers 67, which are part of each individual flow path 61, as described below) are shown in Figure 6. Furthermore, the individual flow paths 61 should be shown by dotted lines, just like the common flow path 59, but because they are small compared to the size of the figure, they are shown by solid lines for convenience.

[0053] The number of common flow channels 59 and the direction in which they extend are arbitrary, and the number of ports 57 and their opening positions are also arbitrary. In the example of FIG. 6 , the common flow channels 59 extend along (for example, parallel to) the longitudinal direction (direction D1) of the flow channel member 53. From another perspective, the multiple common flow channels 59 include two or more common flow channels 59 that are at different distances from the long side of the flow channel member 53. The ports 57 are connected to both ends of the common flow channel 59. From another perspective, the ports 57 are located on the short side of the flow channel member 53 with respect to the common flow channels 59 (or, from another perspective, the actuator substrate 55). Ink flows from both ends of the common flow channel 59 toward the center.

[0054] Examples other than those shown in the drawings include: the direction in which the multiple common flow paths 59 extend may be the D2 direction instead of the D1 direction, or may be inclined at an angle of 45° or less with respect to the D1 direction or the D2 direction; one or more common flow paths 59 extending along the D1 direction may be arranged in the D1 direction; the multiple common flow paths 59 may merge at one or both ends to form a manifold-like flow path; that is, the multiple common flow paths 59 may not be independent of each other within the flow path member 53; the port 57 may be located on the long side of the flow path member 53 relative to the common flow path 59 (and / or the actuator substrate 55); the port 57 may be connected to only one end of the common flow path 59, rather than to both ends. Ink may flow from one end of the common flow path 59 to the other end.

[0055] The plurality of ejection holes 7 (from another perspective, the plurality of individual flow paths 61) are arranged in one or more rows (for example, two or four rows) along each common flow path 59, and the plurality of common flow paths 59 are arranged in parallel with each other, so that they are arranged in multiple rows (in other words, two-dimensionally) on the ejection surface 5. This improves the resolution of the printed image (as will be described later with reference to FIG. 14 ). The ejection holes 7 may also be arranged in a single row.

[0056] Fig. 7 is a cross-sectional view of the front part 49 taken along line VII-VII in Fig. 6. This figure shows an area roughly corresponding to one common flow path 59 (its cross section) and one individual flow path 61 (its longitudinal section).

[0057] The flow path member 53 is formed, for example, by stacking a plurality of plates 63. The plates 63 have a plurality of voids (e.g., through holes and recesses) that form the flow path. The thickness and number of the plurality of plates 63 may be set appropriately depending on the shape of the flow path, etc. The plurality of plates 63 may be formed from an appropriate material. For example, the plurality of plates 63 are formed from metal or resin. The thickness of the plates 63 is, for example, 10 μm or more and 300 μm or less. The plates 63 are fixed to each other, for example, by an adhesive (e.g., a thermosetting resin) interposed between the plates 63 (not shown).

[0058] Each individual flow path 61 has, for example, in this order from the common flow path 59 side, a communication path 65, a pressure chamber 67, a descender 69, and an ejection hole 7. When pressure is applied to the pressure chamber 67 by an actuator 71 (described later) provided on the actuator substrate 55, ink in the descender 69 is pushed toward the ejection hole 7, and ink droplets are ejected from the ejection hole 7. The pressure chamber 67 is then replenished with ink from the common flow path 59 via the communication path 65. The specific shape and dimensions of each of these parts are arbitrary.

[0059] (3.1.2. Actuator Substrate) The number, shape, and dimensions of the actuator substrates 55 are arbitrary. In the example of FIG. 6, one actuator substrate 55 is provided having an area that covers all of the pressure chambers 67. The shape of the actuator substrate 55 is generally rectangular with four sides parallel to the four sides of the flow path member 53, and the longitudinal direction is also the same as the longitudinal direction of the flow path member 53. Unlike the example shown in the figure, for example, multiple actuator substrates 55 may be arranged in the longitudinal direction of the flow path member 53.

[0060] As indicated by the reference numerals in Fig. 7, the actuator substrate 55 has an actuator 71 provided for each pressure chamber 67. The actuator 71 is, for example, a piezoelectric type that applies pressure to ink by mechanical distortion of a piezoelectric body. The piezoelectric actuator is, for example, a so-called unimorph type. However, the actuator 71 may also be configured by another type of piezoelectric actuator, such as a bimorph type.

[0061] The unimorph actuator 71 has, for example, in this order from the flow path member 53 side, a vibration plate 73, a common electrode 75, a piezoelectric layer 77, and an individual electrode 79. The vibration plate 73, the common electrode 75, and the piezoelectric layer 77 extend, for example, over substantially the entire actuator substrate 55. That is, they are provided in common to a plurality of pressure chambers 67. An individual electrode 79 is provided for each pressure chamber 67. The individual electrode 79 has a main body portion 79a that overlaps the pressure chamber 67, and an extraction electrode 79b that is extracted from the main body portion 79a and to which a drive signal is input. The main body portion 79a has substantially the same shape and dimensions as the pressure chamber 67. The specific material and thickness of each layer are arbitrary.

[0062] At least the portion of the piezoelectric layer 77 that is sandwiched between the main body portion 79 a of the individual electrode 79 and the common electrode 75 is polarized in the thickness direction. Therefore, for example, when an electric field (voltage) is applied in the polarization direction of the piezoelectric layer 77 by the main body portion 79 a and the common electrode 75, the piezoelectric layer 77 contracts in a direction along the layer. This contraction is regulated by the vibration plate 73. As a result, the actuator 71 is flexed and deformed so as to be convex toward the pressure chamber 67. When an electric field (voltage) is applied in the opposite direction to the above by the main body portion 79 a and the common electrode 75, the actuator 71 is flexed and deformed in the direction opposite to the pressure chamber 67. By utilizing this flexural deformation, the volume of the pressure chamber 67 can be changed, and pressure can be applied to the ink in the pressure chamber 67.

[0063] The FPC 39 is disposed such that an area on one end thereof faces the actuator substrate 55, and pads (not shown) located on the surface of this area are connected to the extraction electrodes 79b. A drive signal generated by the driver IC 37 is input to the extraction electrodes 79b via the FPC 39. The actuator substrate 55 also has a connection electrode (not shown) connected to the common electrode 75 at an appropriate position (for example, outside the area where the multiple pressure chambers 67 are arranged). The FPC 39 has pads (not shown) connected to the connection electrode. A constant potential (for example, a reference potential) is applied to the common electrode 75 from the FPC 39.

[0064] 4 and 6, the back part 51 is, for example, a substantially plate-shaped member. Its planar shape is, for example, a substantially rectangular shape having four sides parallel to the four sides of the front part 49 and whose longitudinal direction coincides with the longitudinal direction of the front part 49. As shown in Fig. 6, the back part 51 has, for example, a substantially rectangular main body 51a and a flange 51b protruding outward from an upper region of the outer circumferential surface (side surface) of the main body 51a.

[0065] The main body part 51a has a lower surface that is joined to the back surface (upper surface) of the flow path member 53. A recess 81 (FIG. 6) is formed on the lower surface of the main body part 51a to avoid contact with the actuator substrate 55. Its planar shape and dimensions are, for example, slightly larger than those of the actuator substrate 55. In other words, the back part 51 and the flow path member 53 are joined to each other in a frame-shaped region in a plan view.

[0066] A bottom port 83 ( FIG. 6 ) that connects to the port 57 of the flow path member 53 opens on the bottom surface of the main body 51 a. One bottom port 83 has a size that spans, for example, the size of multiple ports 57 (four in the example of FIG. 6 ). Unlike the example shown in the figure, the bottom port 83 and the port 57 may be provided in a one-to-one correspondence. As described above, the position of the port 57 is arbitrary, and the position of the bottom port 83 may also be provided in an arbitrary position depending on the position of the port 57.

[0067] 4, an upper surface port 85 opens on the upper surface of the back part 51 (the back surface of the head main body 9). The upper surface port 85 is connected to the lower surface port 83 via a flow path (not shown) inside the back part 51. Ink flows sequentially through the upper surface port 85, the flow path (not shown), and the lower surface port 83, and is supplied to the port 57. The upper surface port 85 may open on the upper surface of the main body 51a, or may open on the upper surface of the flange 51b.

[0068] 4 and 6, the main body 51a is provided with a slit 87. The slit 87 penetrates the main body 51a in the D3 direction and extends in the D1 direction in a region that overlaps with the recess 81 when viewed in the D3 direction. As shown in FIG. 5, the FPC 39 is inserted through the slit 87.

[0069] For example, when the lower part of the main body 51a is inserted into the opening of the frame 21, the flange 51b engages with the frame 21 and contributes to fixing the head 3 to the frame 21. The flange 51b also contributes to expanding the area of ​​the back surface of the head main body 9. This increases the bonding area with the heat insulating member 15 and increases the degree of freedom in arranging the top surface port 85, for example.

[0070] The specific dimensions of each part are arbitrary. For example, the wall of the recess 81 in the main body 51a may be thicker or taller. Either the bottom surface (+D3 side) of the recess 81 or the lower surface of the flange 51b may be located lower. The flange 51b may be thicker or wider.

[0071] The shape of the back part 51 may be a shape other than the above. For example, the flange 51b may not be provided. Furthermore, the flange 51b may not be provided around the entire periphery, but may be provided only on the short sides or only on the long sides. The main body 51a may have a portion that protrudes above the flange 51b, and the slit 87 may be opened in that portion.

[0072] Although not specifically shown, the back part 51 may be configured by stacking a plurality of plates, similar to the flow path member 53. In this regard, the description of the flow path member 53 may be applied to the back part 51.

[0073] (4. Heat Sink) The shape and dimensions of the heat sink 11 and the flow path 13 are arbitrary. In the examples of Figures 3 to 5, the heat sink 11 is a generally rectangular plate. The rectangle of the heat sink 11 may be a square or a rectangle (other than a square), and the longitudinal direction of the rectangle may be either direction D1 or direction D3 (the former in the illustrated example).

[0074] 8 is a view of the heat sink 11 as seen from the inside of the housing 23. In this figure, an example of the flow path 13 is indicated by a dotted line, and a driving IC 37 is also shown. In more detail, this figure shows the +D2 side of the two heat sinks 11, but the -D2 side is basically the same as in FIG.

[0075] The flow path 13 illustrated in Fig. 8 has a central flow path 13a extending in the D1 direction and two end flow paths 13b extending in the D3 direction. The central flow path 13a penetrates the heat sink 11 in the D1 direction, and both ends of the central flow path 13a are blocked by appropriate blocking members (see Figs. 3 and 4; reference numerals omitted). The two end flow paths 13b each extend from the upper surface of the heat sink 11 to the central flow path 13a, connecting one end of the central flow path 13a to the outside of the heat sink 11. The refrigerant is supplied to the upper end of one end flow path 13b, flows through the one end flow path 13b, the central flow path 13a, and the other end flow path 13b in this order, and is discharged from the upper end of the other end flow path 13b.

[0076] Examples of the path of the flow path 13 other than the illustrated example are given below. For example, the flow path 13 may have multiple central flow paths 13a extending parallel to each other between two end flow paths 13b. Furthermore, the flow path 13 may have a meandering portion extending in the D1 direction while reciprocating in the D3 direction, or a meandering portion extending in the D3 direction while reciprocating in the D1 direction. The multiple central flow paths 13a or the meandering portion may extend over the entire heat sink 11 or over a partial region (e.g., a region obtained by dividing the heat sink 11 into two or three equal parts in the D3 direction). As can be understood from the illustrated example and the other examples described above, the flow path 13 may cool the heat sink 11 locally or globally. For convenience, the description of the embodiments may be based on the illustrated example without any special mention.

[0077] 3 and 4, the upper opening of the end flow passage 13b on the +D1 side of one heat sink 11 (see the position of the connecting part 31; the same applies below) and the upper opening of the end flow passage 13b on the +D1 side of the other heat sink 11 are connected by a communicating pipe 33. The refrigerant is supplied to the upper opening of the end flow passage 13b on the -D1 side of one heat sink 11, flows sequentially through the flow passage 13 of the one heat sink 11, the communicating pipe 33, and the other heat sink 11, and is discharged from the upper opening of the end flow passage 13b on the -D1 side of the other heat sink 11.

[0078] As shown in Figure 8, when the heat sink 11 is viewed through its normal direction, the multiple driver ICs 37 are arranged along the central flow path 13a so as to overlap the central flow path 13a. However, the two do not have to overlap. Furthermore, the -D1 end of the -D1-side driver IC 37 among the multiple driver ICs 37 may be located on the +D1 side of the -D1-side end flow path 13b in terms of its position in the D1 direction, or may overlap (in the illustrated example), or may be located on the -D1 side. The same applies to the +D1-side end of the +D1-side driver IC 37.

[0079] The overlap between the driving IC 37 and the central flow path 13a when viewed in the D2 direction only needs to be at least a portion of the driving IC 37 and a portion of the central flow path 13a, and the size of the overlap is also arbitrary. For example, the length of the driving IC 37 in the D3 direction may be within the length of the central flow path 13a in the D3 direction, or conversely, the length of the central flow path 13a in the D3 direction may be within the length of the driving IC 37 in the D3 direction. The two may overlap each other just enough in the D3 direction, or they may overlap partially but extend beyond each other in the D3 direction. Furthermore, for example, at least half or at least two-thirds of the length of the driving IC 37 in the D3 direction may overlap the central flow path 13a.

[0080] The position of the central flow passage 13a in the direction D3 is arbitrary. For example, the central flow passage 13a is positioned downward within the heat sink 11. Specifically, the central flow passage 13a may be located in the lowest region when the height of the heat sink 11 (the length from the bottom surface to the top surface) is divided into two, three, or four equal parts. By positioning the central flow passage 13a downward, for example, in a configuration in which the driving IC 37 overlaps the central flow passage 13a, the position of the driving IC 37 overlapping the central flow passage 13a can be relatively lowered, making it easier to secure space above the central flow passage 13a within the housing 23 (or, from another perspective, to reduce the height of the housing 23). On the other hand, the influence of the flow passage 13 on the temperature of the head body 9 is increased, increasing the likelihood of the aforementioned inconveniences occurring. As a result, the usefulness of the heat insulating member 15 is enhanced.

[0081] The positions of the end flow paths 13b in the D1 direction are arbitrary. For example, the two end flow paths 13b are positioned on opposite sides of the heat sink 11 in the D1 direction. Specifically, for example, the distance (shortest distance) between the end flow paths 13b and the side surface of the heat sink 11 extending in the D3 direction may be 1 / 10 or less of the length of the heat sink 11 in the D1 direction. By positioning the two end flow paths 13b on opposite sides, for example, the likelihood of refrigerant stagnation at both ends of the central flow path 13a is reduced. Furthermore, it is easy to arrange the drive ICs 37 at both ends so that they do not protrude outside the end flow paths 13b in the D1 direction (toward the ends of the central flow path 13a). In other words, it is easy to arrange the entire drive ICs 37 at both ends in an area where the likelihood of refrigerant stagnation is low.

[0082] The cross-sectional shape and dimensions of the flow path 13 are arbitrary. For example, the cross-sectional shape may be circular (example in FIG. 5 ) or rectangular. The cross-sectional shape and dimensions of the flow path 13 may be constant (example shown) or variable in the flow path direction, except for unique portions such as the ends. Furthermore, as can be understood from the above description of the overlap between the driving IC 37 and the central flow path 13a, the diameter of the flow path 13 when viewed in the normal direction of the heat sink 11 (for example, the maximum length in the D3 direction of the central flow path 13a) may be smaller, equal to, or larger than the length of the driving IC 37 in the D3 direction. The cross-sectional shapes and areas of the central flow path 13a and the end flow paths 13b may be the same (example shown) or different, except for unique portions such as the ends.

[0083] The heat sink 11 may be formed as a single unit from the same material, or may be formed by combining a plurality of members. The manufacturing method thereof may also be arbitrary.

[0084] For example, the heat sink 11 may be constructed by forming the flow passages 13 in a metal plate by cutting. More specifically, for example, holes that become the flow passages 13 are drilled in the flow passage direction using a rotary tool (e.g., a drill). Alternatively, for example, the heat sink 11 may be cast by filling a metal material into a cavity of a mold that includes a core that forms the flow passages 13. After the metal material has solidified, the core may be withdrawn in the flow passage direction.

[0085] In the manufacturing method using cutting or casting as described above, the heat sink 11 can be integrally formed from the same material. The heat sink 11 in the illustrated example is assumed to be manufactured using the manufacturing method described above, with each portion (13a and 13b) of the flow passage 13 being linear, and both ends of the central flow passage 13a reaching the side surfaces on the +D1 side and / or the -D1 side (both in the illustrated example) of the heat sink 11. These ends are then blocked.

[0086] Furthermore, for example, the heat sink 11 may be constructed by laminating a second plate to a first plate having a recess (groove) that becomes the flow path 13 on its main surface (the surface on the +D2 side or the -D2 side) so as to close the recess. The first plate may be constructed by forming the recess by cutting, or by filling a mold with a molding material. The heat sink 11 may also be constructed by stacking multiple (three or more) plates, like the front part 49.

[0087] In this manufacturing method in which two or more plates (members) are combined, there is a high degree of freedom in the shape of the flow path 13 (it does not have to be linear). Note that all of the two or more plates may be made of metal (from another perspective, a material with high thermal conductivity), or only some of the plates (for example, the plate between the driver IC 37 and the flow path 13) may be made of metal.

[0088] The joining position and joining method between the heat sink 11 and the head cover 25 are arbitrary. For example, as shown in Fig. 5 , two heat sinks 11 may be fastened together with the head cover 25 sandwiched between them by a bolt BT1 inserted through the two heat sinks 11 and a nut NT1 threaded onto the bolt BT1. Then, the two heat sinks 11 may tighten the head cover 25 as they are fastened together, thereby joining the heat sink 11 and the head cover 25.

[0089] In the above embodiment, as shown in Fig. 4, the head cover 25 may have flanges (reference numerals omitted) on the edges of the top and side surfaces that come into surface contact with the inner surface of the heat sink 11. As shown in Figs. 4 and 5, the flanges provided on the edges of the top surface may have holes (reference numerals omitted) through which the bolts BT1 are inserted. Furthermore, the heat sink 11 may have recesses (reference numerals omitted) that accommodate at least a portion of the bolt heads of the bolts BT1 or the nuts NT1.

[0090] As indicated by the reference numerals in FIG. 8 , the hole in the heat sink 11 through which the bolt BT1 is inserted and / or the surrounding area thereof can be considered to be the fixing portion 11a of the heat sink 11 relative to the head cover 25. Alternatively, the upper edge portion of the heat sink 11 may be considered to be the fixing portion 11a. As will be described later, the heat sink 11 is joined to the heat insulating member 15 at a fixing portion 11b (hole and / or the surrounding area) located at its lower portion. Alternatively, the lower edge portion of the heat sink 11 may be considered to be the fixing portion 11b. Therefore, the driver IC 37 can be said to be located between the fixing portion 11a and the fixing portion 11b.

[0091] (5. Heat Insulating Member) (5.1. General) The heat insulating member 15 may be made of any material, shape, size, etc., as long as it is interposed between the head body 9 and the heat sink 11 and can reduce the transfer of heat between them, as compared to a configuration in which the head body 9 and the heat sink 11 are in direct contact with each other. An example of the heat insulating member 15 shown in the drawings will be described below.

[0092] 9 is a perspective view of the heat insulating member 15. The heat insulating member 15 is formed integrally as a whole from the same material (e.g., resin), for example. The heat insulating member 15 is generally frame-shaped (has a frame-shaped portion 15a). A more specific shape of the frame-shaped portion 15a corresponds to the shape of the lower edge of the housing 23, and in the illustrated example, is a rectangle with the longitudinal direction in the D1 direction.

[0093] The frame-shaped portion 15a has a frame-shaped base 15b and a first rib 15c standing on the base 15b. The base 15b is placed, for example, on the back surface of the head body 9. The first rib 15c contributes, for example, to improving the strength of the frame-shaped portion 15a and / or joining the heat insulating member 15 and the heat sink 11.

[0094] Unlike the illustrated example, the frame-shaped portion 15a may not have the first rib 15c. For example, the cross section of the frame-shaped portion 15a may be rectangular over approximately the entire circumference. This rectangle may be square or rectangular (excluding square). The rectangle may have a larger width (horizontal length) or height (vertical length). Furthermore, the frame-shaped portion 15a may have a shape that is partially interrupted rather than extending continuously around the entire circumference when viewed in the D3 direction. Furthermore, the heat insulating member 15 may have a shape that is difficult to perceive as a frame.

[0095] (5.2. Base) The base 15b may have a width (length from the inner periphery to the outer periphery) greater than its thickness (length in the D3 direction) (although this does not have to be the case). The ratio is arbitrary, and for example, the width is at least twice the thickness. The width and / or thickness of the base 15b may or may not be constant around the entire periphery.

[0096] The base 15b may (but does not have to) have a second rib 15g that is shorter than the first rib 15c. The second rib 15g contributes to, for example, improving the strength of the base 15b. The position of the second rib 15g and the shape when viewed in the D3 direction are arbitrary. Figure 9 illustrates an example of a second rib 15g extending in the D1 direction and a second rib 15g extending in the D2 direction on the short side of the base 15b.

[0097] A hole 15d may be formed in the short side of the base 15b, through which a screw (see FIG. 4, reference numeral omitted) that joins the heat insulating member 15 and the head main body 9 is inserted. The screw may be inserted into the hole 15d from above and threaded into a female screw (see FIG. 4, reference numeral omitted) that opens on the top surface of the back part 51. The hole 15d may be provided on the long side of the heat insulating member 15 in addition to or instead of the short side.

[0098] The end of the pressing member 45 (more specifically, the portion of the support portion 45a facing the back surface of the head body 9) may overlap the short side of the base 15b. The screw may be inserted through a hole in the pressing member 45 (see FIG. 4; reference numerals omitted) in addition to the heat insulating member 15. That is, the heat insulating member 15 and the pressing member 45 may be fastened together. However, the pressing member 45 may be fixed only to the heat insulating member 15 without being fixed directly to the head body 9, or may be fixed to the head body 9 separately from the heat insulating member 15.

[0099] From another perspective, the pressing member 45 (more specifically, the portion of the support portion 45a facing the back surface of the head main body 9) may be supported at both ends by the short sides of the heat insulating member 15. In other words, the pressing member 45 may be floating above the top surface of the head main body 9 (strictly speaking, the top heater 43 in the example of FIG. 4) except for both ends (see also FIG. 5). This reduces the likelihood that the driving IC 37 and the head main body 9 will thermally affect each other via the pressing member 45, for example. However, the pressing member 45 may overlap the top surface of the head main body 9.

[0100] The lower surface of the base 15b may have a region that is flush over the entire periphery of the frame shape (this region may be the entire lower surface). The back surface of the head main body 9 may have a flush region that faces the above-mentioned flush region of the base 15b over the entire periphery. In this case, for example, the sealing between the heat insulating member 15 and the head main body 9 is improved over the entire periphery of the frame-shaped portion 15a. However, the lower surface of the base 15b and / or the back surface of the head main body 9 do not have to be flush. For example, there may be a gap between the lower surface of the base 15b and the back surface of the head main body 9.

[0101] Although not specifically shown, an adhesive (e.g., a thermosetting resin) may be interposed between the lower surface of the base 15b and the back surface of the head body 9. This adhesive may, for example, contribute to joining the heat insulating member 15 and the head body 9 and / or sealing the space between them. As understood from the above, the heat insulating member 15 and the head body 9 may be fixed together using screws and an adhesive. However, they may also be fixed together using only screws or only an adhesive. The space between the heat insulating member 15 and the head body 9 may be sealed using a packing (e.g., an O-ring) interposed between them instead of or in addition to an adhesive.

[0102] (5.3. Ribs) As shown in Fig. 9, the first rib 15c extends, for example, along the long side of the base 15b and protrudes from the base 15b toward the +D3 side. The length by which the first rib 15c extends along the long side of the base 15b is arbitrary, and for example, the first rib 15c extends over 80% or more, 90% or more, or the entire length of the long side of the base 15b. The height of the first rib 15c (the amount of protrusion from the base 15b) is, for example, greater than the thickness (in the D2 direction) of the first rib 15c (although this does not have to be the case). The ratio is arbitrary, and for example, the height is at least twice the thickness.

[0103] The relationship between the height (D3 direction) and thickness (D2 direction) of the first rib 15c and the width (direction from the inner periphery to the outer periphery) and thickness (D3 direction) of the base 15b is arbitrary as long as the thickness of the first rib 15c is smaller than the width of the long side of the base 15b. Furthermore, the position of the first rib 15c within the width of the long side of the base 15b is also arbitrary. In the illustrated example, the first rib 15c is located in the central region when the width of the long side of the base 15b (ignoring the chamfered corners in the cross section) is divided into three equal parts. Unlike the illustrated example, the first rib 15c may be provided on the edge of the inner or outer periphery of the base 15b. The thickness of the first rib 15c is, for example, 1 / 3 or 1 / 4 or less of the width of the long side of the base 15b.

[0104] The first rib 15c may have a third rib 15h on the wall surface facing the inside of the housing 23 or on the wall surface opposite thereto. The third rib 15h contributes to, for example, improving the strength of the first rib 15c. Furthermore, the third rib 15h on the wall surface facing the inside of the frame-shaped portion 15a may contribute to positioning of components located on the inside. Similarly, the third rib 15h on the wall surface facing the outside of the frame-shaped portion 15a may contribute to positioning of components located on the outside. Figure 9 illustrates an example of the third rib 15h extending in the D3 direction on the inner wall surface.

[0105] The first rib 15c has, for example, a pocket 15e for accommodating the nut NT2 on a wall surface facing the inside of the frame-shaped portion 15a. The nut NT2 contributes to joining the heat sink 11 and the heat insulating member 15 together.

[0106] FIG. 10 is an enlarged view of region X in FIG. 5 . FIG. 11 is a cross-sectional view similar to FIG. 10 . However, FIG. 11 is slightly different in position in the D1 direction from FIG. 10 . Specifically, FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 9 (the position of pocket 15e). In the following description, for convenience, the inside of frame portion 15a (or housing 23) may be simply referred to as the "inside," and the outside of frame portion 15a (or housing 23) may be simply referred to as the "outside." Furthermore, with respect to the heat sink 11, first rib 15c, etc., the surfaces facing inward may be referred to as the "inner surface," and the surfaces facing outward may be referred to as the "outer surface."

[0107] As shown in Figures 5, 10, and 11, the inner surface of the lower portion of the heat sink 11 and the outer surface of the first rib 15c are overlapped with each other. Then, as shown in Figure 11, a bolt BT2 is inserted from the outside through a hole (reference numeral omitted) in the heat sink 11 and a hole 15f in the first rib 15c, and is threaded into a nut NT2. This joins the heat sink 11 and the heat insulating member 15. The number and positions of the bolts BT2 and nuts NT2 are arbitrary. As can be seen from the position of the pocket 15e in Figure 9, in the illustrated example, two sets of bolts BT2 and nuts NT2 are provided on both sides in the D1 direction for one first rib 15c (one heat sink 11).

[0108] The pocket 15e, for example, contributes to facilitating the screwing operation. For example, the nut NT2 can be placed near the first rib 15c in advance before various operations, including the screwing operation. Furthermore, the nut NT2 is fitted into the pocket 15e, thereby preventing rotation. In other words, a robot or an operator does not need to hold the nut NT2 to restrict rotation during screwing. Furthermore, screwing can be performed even when the inside of the heat sink 11 is closed (for example, when the heat insulating member 15 is fixed to the head main body 9 and the head cover 25 is fixed to the heat sink 11). The specific shape and dimensions of the pocket 15e are arbitrary.

[0109] As shown in Figures 10 and 11, the heat sink 11 has a cross section in which a corner between the inner surface and the bottom surface is cut away to form a recess 11c (see also Figure 4). From another perspective, the portion of the heat sink 11 facing the first rib 15c is made thinner from the inside. As a result, for example, as shown in Figure 11, the top of the first rib 15c can be abutted against the bottom surface of the heat sink 11 within the recess 11c, thereby positioning the heat sink 11 in the D3 direction relative to the heat insulating member 15. Also, for example, the position of the outer surface of the heat sink 11 can be shifted inward, thereby reducing the size of the housing 23 in the D2 direction.

[0110] 10 and 11 , the portion of the first rib 15c at the position of the pocket 15e is slightly higher than the portion at other positions. Only the former portion abuts against the underside of the heat sink 11 within the recess 11c. Unlike the example shown in the figure, almost the entire first rib 15c may abut against the underside of the heat sink 11. Alternatively, the entire first rib 15c (including the portion of the pocket 15e) may not abut against the underside of the heat sink 11. The first rib 15c may abut against the underside of the heat sink 11 at some positions excluding the position of the pocket 15e.

[0111] Because the heat sink 11 is supported by the first rib 15c via the bolt BT2 and / or the top of the first rib 15c, the lower surface of the heat sink 11 (excluding the recess 11c) may be raised above the upper surface of the base 15b (although it does not have to be raised above the upper surface of the base 15b). That is, the lower surface of the heat sink 11 faces a portion (base 15b) supporting the lower part of the first rib 15c across a gap 101. This gap 101 (and gas (e.g., air) present in the gap 101) contributes to, for example, thermal insulation between the heat sink 11 and the insulating member 15. Unlike the illustrated example, the portion supporting the lower part of the first rib 15c that faces the lower surface of the heat sink 11 across the gap 101 may be the head main body 9 instead of the base 15b. For example, in the illustrated example, the portion of the base 15b outside the first rib 15c may be eliminated.

[0112] In an embodiment in which the recess 11c is provided, the outer surface of the heat sink 11 may be located outside the outer surface of the heat insulating member 15 (base 15b) and / or the outer surface of the head body 9 (examples in FIGS. 10 and 11), may be coincident with them, or may be located inside them. When they are not coincident, the degree of difference in position is also arbitrary. The difference in position between the outer surface of the heat sink 11 and the outer surface of the heat insulating member 15 and / or the outer surface of the head body 9 may be, for example, 1 / 10 or less of the thickness of the heat sink 11 (including the case where there is no difference).

[0113] The dimensions of the recess 11c are arbitrary. For example, the length of the recess 11c in the D1 direction may be any length as long as it is equal to or greater than the length of the first rib 15c in the D1 direction (i.e., a length that can accommodate the first rib 15c). For example, the length of the recess 11c in the D1 direction may be approximately the same as the length of the first rib 15c in the D1 direction (e.g., the former is between 1 and 1.2 times the latter). Furthermore, the length of the recess 11c in the D2 direction may be between 1 / 3 and 2 / 3 of the thickness of the heat sink 11 (approximately 1 / 2 in the illustrated example). Furthermore, the length of the recess 11c in the D3 direction may be smaller than, equal to, or larger than the height (length in the D3 direction) of the first rib 15c (at the position of the pocket 15e or another position). In addition, in a configuration in which the top of the first rib 15c is abutted against the underside of the heat sink 11 within the recess 11c to form the gap 101, the length of the recess 11c in the D3 direction is greater than the height of the abutted portion of the first rib 15c.

[0114] For example, the outer surface of the first rib 15c does not have the third rib 15h described above. Furthermore, no rib is provided on the inner surface of the heat sink 11 within the recess 11c. Therefore, the outer surface of the first rib 15c and the inner surface of the heat sink 11 within the recess 11c are in surface contact with each other. In this case, for example, the sealing performance between the heat insulating member 15 and the heat sink 11 can be improved. However, ribs (protrusions, in a broader sense) may be provided on the outer surface of the first rib 15c and / or the inner surface of the heat sink 11. In this case, for example, the contact area between the heat sink 11 and the heat insulating member 15 is reduced, thereby reducing the likelihood of heat transfer between the heat sink 11 and the heat insulating member 15.

[0115] Unlike the illustrated example, the recess 11c may not be provided. From another perspective, for example, the entire thickness of the heat sink 11 may be located outside the first rib 15c. Furthermore, the heat sink 11 may be located inside the first rib 15c rather than outside the first rib 15c. In this case, the recess 11c may or may not be formed on the outer surface of the lower part of the heat sink 11. As described above, the first rib 15c may be located on the outer edge of the base 15b. In this case, the recess 11c may not be formed and the entire thickness of the heat sink 11 may be located outside the first rib 15c, so that the lower surface of the heat sink 11 and the upper surface of the base 15b (and further the back surface of the head main body 9) do not face each other.

[0116] The pocket 15e does not have to be provided. Furthermore, the bolt BT2 and the nut NT2 may be positioned on the outside and the bolt BT2 on the inside, as opposed to the illustrated example. However, this typically reduces workability. The nut NT2 may be unnecessary. For example, the bolt BT2 inserted into the heat sink 11 may be threaded into a female thread provided in the heat insulating member 15 (first rib 15c), or the bolt BT2 inserted into the heat insulating member 15 may be threaded into a female thread provided in the heat sink 11. However, using a metal nut NT2 (and a metal bolt BT2) provides higher fastening reliability than forming a female thread in the heat insulating member 15 made of resin.

[0117] The heat insulating member 15 and the heat sink 11 may be joined by other methods instead of or in addition to the bolts BT2. For example, the two may be fixed to each other by an adhesive (e.g., a thermosetting resin).

[0118] (5.4. Material) The material of the heat insulating member 15 has a lower thermal conductivity than, for example, the materials of the head body 9 and the heat sink 11 (either the entire head body 9 or the portion where they face each other). This can mitigate heat transfer between the head body 9 and the heat sink 11 compared to when they are in direct contact with each other.

[0119] For example, the rear surface of the head body 9 and the lower surface of the heat sink 11 may be made of metal, while the heat insulating member 15 may be made of resin. Typically, the thermal conductivity of resin is lower than that of metal.

[0120] The specific types of metal and resin in the above embodiment are also arbitrary. Examples are given below.

[0121] The material of the plate 63 of the front part 49 and the plate (not shown) of the back part 51 (the material of the back surface of the head body 9) is, for example, stainless steel. From another perspective, the thermal conductivity of the material is, for example, 10 W / m°C or more and 40 W / m°C or less.

[0122] The material of the heat sink 11 is, for example, aluminum or an aluminum alloy. From another perspective, the thermal conductivity of the material is, for example, 200 W / m·°C or more and 300 W / m·°C or less. The description of the material of the heat sink 11 (including the description below) may be applied to the material of the head cover 25.

[0123] The material of the heat insulating member 15 is, for example, PPS (Polyphenylenesulfide) resin. From another perspective, the thermal conductivity of the material is, for example, 0.5 W / m·°C or more and 2 W / m·°C or less.

[0124] The thermal conductivity of typical resins is less than 0.5 W / m°C. Here, a specific type of resin for the heat insulating member 15 is selected so that the linear expansion coefficient of the heat insulating member 15 approaches the linear expansion coefficient of the material of the head main body 9 and / or the heat sink 11. As a result, the thermal conductivity of the heat insulating member 15 is high considering that the material is resin.

[0125] For example, the linear expansion coefficient of the material of the plate of the head body 9 is 0.5×10 －６ Above 2.0 x 10 －６ (1 / °C). The linear expansion coefficient of the material of the heat sink 11 is 2.0 x 10 －５ Above 3.0 x 10 －５ (1 / °C). The linear expansion coefficient of the material of the heat insulating member 15 is 1.0 x 10 －５ Above 4.0 x 10 －５ (1 / °C).

[0126] (6. Other Examples of Head) Fig. 12 is a perspective view for explaining a head 203 according to another example, and corresponds to Fig. 3. Fig. 13 is a cross-sectional view for explaining the head 203, and corresponds to Fig. 11.

[0127] The head 203 differs from the head 3 only in that a sealing resin 103 ( FIG. 13 ) is disposed therein. In FIG. 12 , the region R1 where the sealing resin 103 is disposed (not the sealing resin 103 itself) is indicated by hatching. The sealing resin 103 is disposed from the exterior side so as to seal the boundary formed by the heat sink 11, the head cover 25, and the heat insulating member 15, which is visible from the exterior. The sealing resin 103 is also disposed in the holes (or, from another perspective, the through holes through which the bolts BT1 and BT2 are inserted) that accommodate the bolt heads of the bolts BT1 and BT2 and the nuts NT1 and NT2. The sealing resin 103 contributes to improving the airtightness of the housing 23, for example.

[0128] 13, the sealing resin 103 is also disposed in the gap 101 between the lower surface of the heat sink 11 and the upper surface of the base 15b. In the example shown, the sealing resin 103 fills the entire gap 101, and no space exists where gas exists. However, for example, the sealing resin 103 may be filled in the outer portion of the gap 101, leaving a space in the inner portion of the gap 101.

[0129] The sealing resin 103 may be made of any material, such as a thermosetting resin. The thermal conductivity of the sealing resin 103 is lower than that of the heat sink 11 and the plate of the head body 9, for example. The thermal conductivity of the sealing resin 103 may be lower than, equal to, or higher than that of the heat insulating member 15. As described above, the material of the heat insulating member 15 may be selected to have a higher thermal conductivity than general resins, taking into account the linear expansion coefficient. In such a case, the thermal conductivity of the sealing resin 103 is likely to be lower than that of the heat insulating member 15.

[0130] (7. Experimental Example) As described in the outline of the embodiment, the heat sink 11 having the flow path 13 affects the ink droplet ejection characteristics of the head body 9 due to an unintended cooling effect. An example of this is shown below.

[0131] 14 is a diagram illustrating the image quality when printing with a head according to a comparative example. The head according to the comparative example basically differs from head 3 only in that it does not have a heat insulating member 15. In other words, the lower surface of the heat sink 11 having the flow passages 13 directly overlaps the back surface of the head main body 9. Note that the description of the arrangement of the multiple ejection holes 7 in the head according to the comparative example described below may be applied to the head 3 (and 203) according to the embodiment.

[0132] The upper diagram in Fig. 14 is a planar perspective view of a portion of the ejection surface 5 of a head according to a comparative example. The ejection holes 7, for example, form multiple rows (14 rows in the illustrated example) of ejection hole rows NR (only one row is labeled with a reference symbol). Each ejection hole row NR has ejection holes 7 arranged in the D1 direction or in a direction inclined toward the D1 direction. When the multiple ejection hole rows NR are viewed in the D2 direction, the ejection holes 7 of each ejection hole row NR are arranged so as to be positioned between the ejection holes 7 of other ejection hole rows NR.

[0133] When printing is performed while moving the print paper P and the head relatively in the direction D2, by adjusting the ejection timing of ink droplets from the plurality of ejection hole rows NR, it is possible to make ink droplets from the plurality of ejection hole rows NR land at the same position in the direction D2 on the print paper P. At this time, the ejection holes 7 of the plurality of ejection hole rows NR are positioned at different positions in the direction D1, so an image is printed at a pitch that is smaller than the pitch of the ejection holes 7 within each ejection hole row NR.

[0134] The above-described printing can be achieved by various arrangement patterns of the plurality of ejection holes 7. In the illustrated example, when the plurality of ejection holes 7 are viewed in the D2 direction, the ejection holes 7 are arranged in the following order from the -D1 side: a plurality of consecutive rows (four rows) of ejection holes 7 on the +D2 side; a plurality of consecutive rows (six rows) of ejection holes 7 on the center side in the D2 direction; and a plurality of consecutive rows (four rows) of ejection holes 7 on the -D2 side. Furthermore, this pattern is repeated.

[0135] The above combination of three numbers in four rows, six rows, and four rows may be changed to other combinations of numbers. For example, each number may be any number equal to or greater than one. Instead of three numbers, one number, two numbers, or four or more numbers may be used. The combination of numbers may vary within one head (it does not have to be the same pattern repeated). The sum of the three numbers (total number of ejection hole rows NR) is arbitrary.

[0136] The middle and bottom figures in Figure 14 are photographs showing the results of printing on printing paper P using a head of a comparative example. More specifically, in this example, it is intended to draw straight lines parallel to the direction D1. Note that the arrangement pattern of the ejection holes 7 in the top figure in Figure 14 is for the sake of convenience of explanation, and does not strictly match the arrangement pattern of the ejection holes 7 of the head that performed the printing shown in the middle and bottom photographs in Figure 14 (although they do generally match).

[0137] The middle photograph in Figure 14 shows the case where no refrigerant was flowing through the flow path 13 of the heat sink 11. The bottom photograph in Figure 14 shows the case where a refrigerant was flowing through the flow path 13 of the heat sink 11. The refrigerant was water at 15°C. The printing paper P was moving toward the +D2 side relative to the head.

[0138] When the refrigerant is not flowing, the dots formed by the ink droplets ejected from the ejection holes 7 are aligned roughly in a line in the D1 direction. On the other hand, when the refrigerant is flowing, the dots formed by the ink droplets ejected from the ejection holes 7 located at the ends on the +D2 and -D2 sides are shifted toward the -D2 side relative to the other dots. The reason for this is as follows.

[0139] 3 to 5, if the heat insulating member 15 is not provided, the lower surface of the heat sink 11 overlaps the vicinity of the edges on the +D2 side and the -D2 side of the rear surface of the head main body 9. Also, as shown in FIGS. 5 and 6, the back part 51 that forms the rear surface of the head main body 9 overlaps the vicinity of the outer edge of the rear surface of the flow path member 53 that forms the ejection surface 5. Therefore, the flow path member 53 is more susceptible to the cooling action of the heat sink 11 closer to the outer edge. As a result, a temperature distribution bias occurs in the flow path member 53, such that the temperature decreases closer to the outer edge.

[0140] As a result of the above, the temperature of the ink in the flow path member 53 decreases toward the outer edge of the flow path member 53, and therefore the viscosity increases. As a result, ink droplets ejected from ejection holes 7 located on the outer edge of the flow path member 53 experience a delay in ejection timing and / or a decrease in ejection speed compared to the other ejection holes 7. As a result, as shown in the lower photograph of Figure 14, the dots formed by the ejection hole rows NR located at the ends on the -D2 and +D2 sides are shifted in the opposite direction to the transport direction of the printing paper P.

[0141] 6, the above-described deviation is likely to be large when multiple common flow paths 59 extending parallel to one another extend in the direction D1 or in a direction inclined toward the direction D1. This is because it is not expected that the flow of ink in the direction D2 will alleviate the imbalance in the temperature distribution in the direction D2. Of course, even if the common flow path 59 extends in the direction D2, there is not necessarily a flow of ink large enough to alleviate the imbalance in the temperature distribution, so the deviation can be large.

[0142] In the above, attention was focused on the bias in the temperature distribution in the D2 direction in the flow path member 53. However, in the flow path member 53, bias in the temperature distribution in the D1 direction also occurs. The reason for this is, for example, that the back part 51 overlaps the outer periphery of the back surface of the flow path member 53 (i.e., overlaps with the ends on the -D1 side and the +D1 side). This also causes dot misalignment. However, in the inventor's experiments, the impact of bias in the temperature distribution in the D1 direction was smaller than the impact of bias in the temperature distribution in the D2 direction.

[0143] By providing the heat insulating member 15 as in the embodiment, the amount of dot misalignment described above can be reduced. For example, when intending to print a straight line parallel to the D1 direction, the amount of misalignment is defined as the distance between a straight line (imaginary line) parallel to the D1 direction that contacts the dot furthest to the +D2 side from the +D2 side, and a straight line (imaginary line) parallel to the D1 direction that contacts the dot furthest to the -D2 side from the -D2 side. In the inventor's experiment, when the heat insulating member 15 was provided, the amount of misalignment was reduced by approximately 7 μm compared to when the heat insulating member 15 was not provided (when the refrigerant was water at 15°C).

[0144] (8. Summary of the embodiment) Below, some configurations of the recording device and head according to the embodiment will be extracted and their effects will be described. Below, the reference numerals of the head 3 will be mainly used, but the same applies to the head 203.

[0145] The liquid ejection head (head 3) according to the embodiment has a head body 9, a heat sink 11, and a heat insulating member 15. The head body 9 has ejection holes 7. The heat sink 11 has a flow path 13. The heat insulating member 15 is interposed between the head body 9 and the heat sink 11. Furthermore, the recording apparatus (printer 1) according to the embodiment has such a head 3.

[0146] Therefore, for example, as described in the overview of the embodiment and as described with reference to Fig. 14, the likelihood that the unintended cooling action of the heat sink 11 will affect the temperature of the head body 9 is reduced. As a result, for example, the likelihood that the image quality of the printed image will be degraded is reduced.

[0147] The head 3 may further include a drive IC 37 located on the surface of the heat sink 11 .

[0148] In this case, for example, the heat sink 11 having the flow path 13 can quickly cool the driving IC 37. As a result, for example, the driving IC 37 can be made to perform a high-load operation that increases the temperature of the driving IC 37. For example, printing can be performed at a high frequency, thereby improving the printing speed.

[0149] The heat insulating member 15 may have a frame-shaped portion 15a that overlaps the back surface of the head body 9 on the side opposite the ejection holes 7 and has a frame shape when viewed in a normal direction to the back surface. The frame-shaped portion 15a may have a first rib 15c (an example of a rib) that protrudes along the normal direction (for example, parallel to the normal direction) and extends along the circumferential direction of the frame shape (for an appropriate length of one circumference or less).

[0150] In this case, for example, by making the heat insulating member 15 frame-shaped, it is possible to reduce the contact area between the heat insulating member 15 and the head body 9. As a result, the likelihood of heat being transferred between the heat sink 11 and the head body 9 via the heat insulating member 15 is reduced. In other words, the heat insulating effect is improved. Furthermore, by making the heat insulating member 15 have the first rib 15c, it is possible to ensure rigidity even when the heat insulating member 15 is frame-shaped.

[0151] The heat insulating member 15 may have a first rib 15c (an example of a rib) that protrudes from a portion (base 15b) that overlaps with the back surface of the head body 9 on the opposite side from the ejection surface toward the side facing the back surface. The heat sink 11 may be joined to the heat insulating member 15 by joining the wall surface of the first rib 15c.

[0152] In this case, for example, heat from the heat sink 11 is transmitted horizontally between the heat sink 11 and the first rib 15c, then downward along the first rib 15c, and then to the back surface of the head body 9. This heat path is longer than the heat path along which heat from the heat sink 11 is transmitted to the base 15b in a configuration in which the heat sink 11 is joined to the upper surface of the base 15b (this configuration may also be included in the present disclosure). The formation of such a path improves the heat insulating effect.

[0153] The lower surface of the heat sink 11 and the portion supporting the first rib 15c (the base 15b in the illustrated example) may face each other with a gap 101 therebetween.

[0154] In this case, for example, the gap 101 insulates the heat sink 11 from the base 15b, improving the heat insulating effect. In other words, a thermal shortcut from the lower surface of the heat sink 11 to the upper surface of the base 15b is unlikely to occur.

[0155] The head 203 may have a sealing resin 103 in the gap 101 .

[0156] In this case, for example, the sealing resin 103 insulates the area between the lower surface of the heat sink 11 and the heat insulating member 15, improving the heat insulating effect. In addition, by applying the sealing resin, the sealing performance of the head 203 is also improved.

[0157] The head 3 may further include a head cover 25 that covers the heat insulating member 15 and is joined to the heat sink 11 .

[0158] In this case, for example, the heat of the heat sink 11 can escape to the head cover 25. As a result, the heat of the heat sink 11 is less likely to be transmitted to the heat insulating member 15, and therefore is less likely to be transmitted to the head body 9 via the heat insulating member 15. As a result, the thermal insulation between the heat sink 11 and the head body 9 is improved.

[0159] The driving IC 37 may be located between a fixing portion 11 a of the heat sink 11 to the head cover 25 and a fixing portion 11 b of the heat sink 11 to the heat insulating member 15 .

[0160] In this case, for example, the heat sink 11 can be fixed to the head cover 25 and the heat insulating member 15 on both sides of the drive IC 37 in a predetermined direction (direction D3 in the illustrated example). This improves the reliability of the positioning of the heat sink 11 relative to the drive IC 37, and ultimately improves the adhesion between the drive IC 37 and the heat sink 11. As a result, the heat dissipation performance of the drive IC 37 is improved.

[0161] When viewed in the normal direction of the heat sink 11, the flow path 13 and the driving IC 37 may overlap (at least partially).

[0162] In this case, for example, the three-dimensional distance between the flow path 13 and the driving IC 37 is short, so that heat can be efficiently exchanged between the refrigerant flowing through the flow path 13 and the driving IC 37. In other words, heat can be efficiently dissipated from the driving IC 37.

[0163] The head 3 may further include a pressing member 45. The pressing member 45 may be located on the opposite side of the head body 9 from the ejection holes 7, and may press the driving IC 37 against the heat sink 11. In addition, both ends of the pressing member 45 that face the head body 9 may be supported by the heat insulating member 15, and the portion between the ends may be floating above the head body 9.

[0164] In this case, for example, by pressing the driving IC 37 against the heat sink 11, heat can be effectively dissipated from the driving IC 37 to the heat sink 11. Furthermore, because the driving IC 37 is floating from the pressing member 45 to the head body 9, it is possible to reduce the likelihood of heat being transferred from the driving IC 37 to the head body 9 via the pressing member 45. Because the heat insulating member 15 also serves as a member for floating the pressing member 45, the number of components can be reduced.

[0165] The head 3 may further include a drive IC 37 located on the opposite side of the head body 9 from the ejection holes 7, and a housing 23 that covers the head body 9 from the opposite side of the ejection holes 7 and houses the drive IC 37. Two heat sinks 11 may face each other and form two side surfaces of the housing 23.

[0166] That is, the flow path 13 may be provided in the housing 23. In this case, for example, by providing the flow path 13 in the housing 23, the influence of the temperature outside the housing 23 on the temperature inside the housing 23 can be reduced by controlling the temperature using the flow path 13. As a result, for example, it is easier to maintain a constant temperature not only for the drive IC 37 but also for the head main body 9 or other electronic components, and ultimately the operation of the head 3 is stabilized.

[0167] The flow path 13 may not communicate with the discharge hole 7 .

[0168] That is, the coolant flowing through the flow path 13 and the liquid (ink) supplied to the ejection holes 7 may be separate entities. In this case, for example, a coolant with a lower temperature than the ink can be used, facilitating heat dissipation from the drive IC 37. Furthermore, when ink is used as the coolant, changes in the amount of heat transferred from the drive IC 37 to the ink change the temperature (and therefore the viscosity) of the ink, which changes the ejection characteristics of the ink droplets, but the likelihood of such a problem occurring is low.

[0169] In the above embodiment, the printer 1 is an example of a recording apparatus, and the heads 3 and 203 are each an example of a liquid ejection head.

[0170] The technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0171] The recording device may be a plotter. The recording device may be a handheld printer that is held and moved by a user and moves relative to the recording medium. The recording device may be one in which the recording medium and the head are moved relative to each other by moving the head using a robot or the like.

[0172] The recording medium is not limited to paper, and may be, for example, cloth, wood, tile, a printed wiring board (more specifically, an insulating layer on which a conductive pattern is printed), or a car body.

[0173] The head may be used for purposes other than recording devices. For example, the head may be used to prepare chemicals. Specifically, the head may eject a predetermined amount of liquid chemical or a liquid containing a chemical toward a reaction vessel or the like.

[0174] As can be understood from the examples of the recording medium and the like given above, the liquid is not limited to ink, but may be, for example, paint or a conductive material printed on a printed wiring board.

[0175] The pressure applying unit for applying pressure to the flow path (liquid) to eject the liquid is not limited to a piezoelectric type. For example, the pressure applying unit may be a thermal type pressure applying unit that applies pressure to the liquid by heating the liquid to generate bubbles.

[0176] The flow path member is not limited to one formed by stacking plates made of metal or resin, and may be formed, for example, by a micro-electro-mechanical system (MEMS). The MEMS may include not only the flow path member but also the pressure unit.

[0177] From this disclosure, an invention may be extracted that does not require the head to have a heat sink, the head to have a heat insulating member, and / or the heat sink to have a flow path.

[0178] 1... printer (recording apparatus), 3... head (liquid ejection head), 5... ejection surface, 7... ejection holes, 9... head body, 11... heat sink, 13... flow path, 15... heat insulating member.

Claims

1. A liquid ejection head comprising: a head body having an ejection hole; a heat sink having a flow path; and a heat insulating member interposed between the head body and the heat sink.

2. The liquid ejection head according to claim 1, further comprising a drive IC located on the surface of the heat sink.

3. A liquid ejection head as described in claim 1 or 2, wherein the heat insulating member overlaps the rear surface of the head body on the opposite side to the ejection holes and has a frame-shaped portion which is frame-shaped when viewed in a normal direction to the rear surface, and the frame-shaped portion has ribs which protrude in the normal direction and extend circumferentially around the frame shape.

4. A liquid ejection head as described in any one of claims 1 to 3, wherein the insulating member has a rib that protrudes from a portion that overlaps with the rear surface of the head body on the opposite side from the ejection holes toward the side facing the rear surface, and the heat sink is joined to the insulating member by bonding to the wall surface of the rib.

5. The liquid ejection head according to claim 4, wherein the lower surface of the heat sink and the portion supporting the rib face each other with a gap therebetween.

6. The liquid ejection head according to claim 5, further comprising a sealing resin in the gap.

7. The liquid ejection head according to any one of claims 1 to 6, further comprising a head cover which covers said heat insulating member and is joined to said heat sink.

8. A liquid ejection head as described in claim 7, further comprising a drive IC located on the surface of the heat sink, the drive IC being located between a fixed portion of the heat sink to the head cover and a fixed portion of the heat sink to the insulating member.

9. The liquid ejection head according to claim 8, wherein the flow path and the driving IC overlap when viewed in a normal direction of the heat sink.

10. A liquid ejection head as described in claim 2, or any one of claims 3 to 9 which directly or indirectly cite claim 2, further comprising a pressing member located on the opposite side of the head body from the ejection holes and pressing the drive IC against the heat sink, wherein both ends of the pressing member which faces the head body are supported by the heat insulating member and the portion between the both ends is spaced apart from the head body.

11. A liquid ejection head as described in any one of claims 1 to 10, further comprising: a drive IC located on the opposite side of the head body from the ejection holes; and a housing that covers the head body from the opposite side of the ejection holes and contains the drive IC, wherein the two heat sinks face each other and form two side surfaces of the housing.

12. The liquid ejection head according to any one of claims 1 to 11, wherein the flow path does not communicate with the ejection hole.

13. A recording apparatus comprising a liquid ejection head according to any one of claims 1 to 12.