Liquid ejection device and sub-carriage

Abstract

The present invention provides a liquid injection device for suppressing temperature unevenness within a liquid injection head and a secondary slide. The liquid injection device (1) comprises: a first liquid injection head (12) that injects liquid; a secondary slide (21) that holds the first liquid injection head (12); and a slide (5) that holds the secondary slide (21). The secondary slide (5) comprises: a first component (24) that is thermally conductive and holds the first liquid injection head (12); and a heating part (38) disposed on the first component (24). The first liquid injection head (12) has first sidewall portions (13a, 13b) opposite to the first component (24). The heating part (38) is arranged such that, when viewed along the injection direction of the liquid injected from the first liquid injection head (12), it sandwiches the first component (24) between itself and the first sidewall portions (13a, 13b).

Description

Technical Field

[0001] This invention relates to a liquid injection device and a secondary carriage. Background Technology

[0002] A liquid ejection device includes: a liquid ejection head having a supply channel component; and a heater for heating ink within the liquid ejection head. Patent Document 1 discloses a liquid ejection head in which a heater for heating ink is disposed on the side of the supply channel component.

[0003] Because the heater described in Patent Document 1 is directly fixed to the side of the liquid jet head, the distance from the heater to the flow channel inside the liquid jet head is relatively short. Therefore, the heat from the heater is difficult to move in the in-plane direction of the side of the liquid jet head to which the heater is fixed, thus easily causing temperature deviations within the liquid jet head. In a liquid jet head with the heater directly fixed in this way, uneven temperature may occur within the liquid jet head.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-199638 Summary of the Invention

[0005] One aspect of the present invention relates to a liquid injection device comprising: a first liquid injection head that injects liquid; a secondary carriage that holds the first liquid injection head; and a carriage that holds the secondary carriage. The secondary carriage has a first component and a heating element. The first component is thermally conductive and holds the first liquid injection head, and the heating element is disposed on the first component. The first liquid injection head has a first sidewall portion opposite to the first component. The heating element is arranged such that it sandwiches the first component between itself and the first sidewall portion when viewed along the injection direction of the liquid injected from the first liquid injection head.

[0006] One aspect of the present invention relates to a secondary carriage that holds and holds a head of a liquid jetting device on the carriage of the liquid jetting device. The secondary carriage includes: a frame that surrounds the side wall portion of the head when viewed along the jetting direction of the liquid jetting from the head and has thermal conductivity; and a heating portion disposed on the outer peripheral surface of the frame. Attached Figure Description

[0007] Figure 1 This is a schematic diagram illustrating the liquid injection device involved in the embodiment.

[0008] Figure 2 This is a 3D exploded view of the head unit.

[0009] Figure 3 A bottom view showing the liquid jet head held on the subcarriage.

[0010] Figure 4 A top view showing the liquid jet head held on the sub-carriage.

[0011] Figure 5 A side view showing the liquid jet head held on the subcarriage.

[0012] Figure 6 An exploded perspective view of a liquid jet nozzle.

[0013] Figure 7 A schematic diagram showing the flow path of ink in a liquid jetting device.

[0014] Figure 8 This is a cross-sectional view of the chip head.

[0015] Figure 9 This is a sectional view of the frame of the secondary carriage, showing the section intersecting the Z-axis direction.

[0016] Figure 10 To show the sectional view of the subcarriage, and to show along... Figure 9 The cross section of line XX in the diagram.

[0017] Figure 11 A cross-sectional view showing the main parts of the secondary carriage in an enlarged format.

[0018] Figure 12 This is a cross-sectional view showing the connection between the sub-carriage and the carriage, and it shows the connection along... Figure 9 The cross section of line XII-XII in the middle.

[0019] Figure 13 This is a cross-sectional view showing the fixing part between the sub-carriage and the carriage, and showing the section along... Figure 9 The cross section of line XIII-XIII in the middle.

[0020] Figure 14 This is an exploded perspective view of the secondary carriage.

[0021] Figure 15 A perspective view showing a heater mounted on the outer periphery of the frame of the subcarriage. Detailed Implementation

[0022] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. However, the dimensions and scales of the various parts in the drawings are appropriately different from the actual situation. Furthermore, since the embodiments described below are preferred examples of the present invention, various technically preferred limitations have been added; however, unless otherwise stated in the following description, the scope of the present invention is not limited to these embodiments.

[0023] In the following description, the three intersecting directions are sometimes referred to as the X-axis direction, Y-axis direction, and Z-axis direction. The X-axis direction includes the X1 direction and X2 direction, which are opposite directions to each other. The Y-axis direction includes the Y1 direction and Y2 direction, which are opposite directions to each other. The Z-axis direction includes the Z1 direction and Z2 direction, which are opposite directions to each other. The Z1 direction is a downward direction, and the Z2 direction is an upward direction. The Z1 direction is an example of a jet direction. The Y-axis direction is an example of a first direction. The X-axis direction is an example of a second direction. Furthermore, in this specification, the terms "up" and "down" are used. "Up" and "down" correspond to the "up" and "down" of the normal operating state where the nozzle of the liquid jetting device 1 is at the bottom.

[0024] The X-axis, Y-axis, and Z-axis are orthogonal. Although the Z-axis is usually along the vertical direction, it can also be a direction other than vertical.

[0025] Figure 1 This is a schematic diagram illustrating the liquid jetting apparatus 1 according to the first embodiment. The liquid jetting apparatus 1 is an inkjet printing apparatus that jets ink, an example of a "liquid," in the form of droplets onto a medium PA. The liquid jetting apparatus 1 is a serial printing apparatus. The liquid jetting apparatus 1 includes a plurality of liquid jetting heads 10. The liquid jetting heads 10 jet ink toward the medium PA while moving in the width direction of the medium PA. The medium PA is typically printing paper. However, the medium PA is not limited to printing paper; for example, it can be any printing material such as resin film or fabric.

[0026] like Figure 1 As shown, the liquid jetting device 1 includes a liquid container 2 for storing ink. Examples of specific types of liquid container 2 include a box that can be detached from the liquid jetting device 1, a bag-shaped ink pouch formed of a flexible film, and an ink canister for refilling ink. Furthermore, the type of ink stored in the liquid container 2 is arbitrary. The liquid container 2 is one example of a liquid storage unit.

[0027] The liquid container 2 includes a first liquid container 2a and a second liquid container 2b. The first liquid container 2a stores a first ink. The second liquid container 2b stores a second ink of a different type than the first ink. For example, the first ink and the second ink may be inks of different colors. Alternatively, the first ink and the second ink may be inks of the same type. Furthermore, the composition of the ink is not particularly limited; for example, it may be an aqueous ink obtained by dissolving color materials such as dyes or pigments in an aqueous solute, a solvent-based ink obtained by dissolving color materials in an organic solvent, or an ultraviolet-curable ink. The ink may also be a resin-based solvent ink. The liquid spraying device 1 can use high-viscosity liquids at room temperature.

[0028] The liquid injection device 1 includes a control unit 3, a medium conveying mechanism 4, a carriage 5, and a carriage conveying mechanism 6. The control unit 3 controls the operation of each component of the liquid injection device 1. The control unit 3 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory. Various programs and data are stored in this storage circuit. The processing circuit executes the program and appropriately uses the data to achieve various controls.

[0029] The media conveying mechanism 4 is controlled by the control unit 3 and conveys the media PA along the conveying direction DM. The media conveying mechanism 4 includes a conveying roller for conveying the media PA and a motor for rotating the conveying roller. In addition, the media conveying mechanism 4 is not limited to a structure using a conveying roller. For example, it can also be a structure using a roller or a seamless belt to convey the media PA in a state where it is attracted to the outer peripheral surface by electrostatic force or the like.

[0030] The carriage conveyor 6 is controlled by the control unit 3, which causes the head unit 20 to reciprocate in the X-axis direction. The carriage conveyor 6 may also include, for example, a seamless belt mounted on multiple rollers separated in the X-axis direction. Alternatively, the liquid container 2 may be a structure mounted on the carriage 5 and conveyed together with multiple liquid injection heads 10.

[0031] Figure 2 This is an exploded perspective view of head unit 20. Figure 3 This is a bottom view showing the liquid injection head 10 and the auxiliary carriage 21. Figure 4 This is a top view showing the liquid injection head 10 and the auxiliary carriage 21. Figure 5This is a side view showing the liquid injection head 10 and the auxiliary carriage 21. The liquid injection device 1 includes a head unit 20. The head unit 20 includes a liquid injection head 10, an auxiliary carriage 21, and a carriage 5. The auxiliary carriage 21 holds a plurality of liquid injection heads 10. The carriage 5 holds the auxiliary carriage 21.

[0032] Figure 6 This is an exploded perspective view of the liquid injection head 10. (See attached image.) Figure 6 As shown, the liquid jet head 10 includes a fixing plate 11, a plurality of head chips 12 on which nozzles N are provided, a retainer 13 for holding the fixing plate 11 and the head chips 12, a flow channel structure 14 forming an ink flow channel, a relay substrate 15 disposed on the upper part of the flow channel structure 14, a connector 16 disposed on the relay substrate 15, and an upper cover 17.

[0033] The fixing plate 11 forms the bottom surface of the liquid injection head 10. An opening 11a is formed on the fixing plate 11 to expose the nozzle N of the head chip 12. The nozzle N is illustrated in... Figure 3 as well as Figure 8 middle.

[0034] like Figure 3 as well as Figure 6 As shown, multiple head chips 12 are disposed at the bottom of the liquid injection head 10. The multiple head chips 12 are held by a holder 13. Multiple nozzles N for injecting liquid are provided on the head chips 12. Figure 3 The nozzles N shown are arranged in the Y-axis direction to form nozzle row 18.

[0035] like Figure 6 As shown, the flow channel structure 14 is disposed on the holder 13. Flow channels for ink flow are formed in the flow channel structure 14. The flow channel structure 14 includes a plurality of flow channel substrates 19. The plurality of flow channel substrates 19 are stacked in their thickness direction. Grooves and openings are formed, for example, on the flow channel substrates 19. Flow channels are formed through these grooves and openings.

[0036] The flow channel structure 14 is provided with an ink supply port 14a for introducing ink into the interior of the flow channel structure 14 and an ink discharge port 14b for discharging ink from the flow channel structure 14. Therefore, an ink circulation method that circulates ink can be used in the liquid jetting device 1, but it is also possible to avoid using an ink circulation method by using only the ink supply port 14a and not the ink discharge port 14b.

[0037] The relay substrate 15 covers the upper part of the central portion of the flow channel structure 14 in the Y-axis direction. Multiple electrical wirings are provided on the relay substrate 15. The head chip 12 is electrically connected to the electrical wirings provided on the relay substrate 15.

[0038] Connector 16 extends upward from relay substrate 15. Connector 16 is electrically connected to external electrical components of liquid injection head 10. Head chip 12 is electrically connected to control unit 3 via connector 16.

[0039] The plurality of liquid injection heads 10 include liquid injection head 10A and liquid injection head 10B. Liquid injection heads 10A and 10B are arranged adjacent to each other in the X-axis direction. Liquid injection head 10A is an example of a first liquid injection head, and liquid injection head 10B is an example of a second liquid injection head. The first liquid injection head can also be liquid injection head 10B, and the second liquid injection head can also be liquid injection head 10A.

[0040] like Figure 4 As shown, liquid injection heads 10A and 10B include a plurality of head chips 12. The plurality of head chips 12 includes head chip 12A and head chip 12B. Head chips 12A and head chip 12B are adjacent to each other. Head chips 12A and 12B are each elongated in the Y-axis direction and are offset in the X-axis direction and in the Y-axis direction intersecting the X-axis direction. Head chip 12A is offset in the X1 direction and the Y2 direction compared to head chip 12B.

[0041] like Figure 6 As shown, the upper cover 17 abuts against the Z2 direction surface of the retainer 13 at its Z1 direction end, and houses the flow channel structure 14, the relay substrate 15, and the connector 16 between the upper cover 17 and the Z2 direction surface of the retainer 13. On the upper surface of the upper cover 17 on the Z2 direction side, there are wiring openings 17a for inserting external wiring components into the connector 16, and openings 17b and 17c for connecting the ink supply port 14a and the ink discharge port 14b to external flow channel components such as pipes.

[0042] like Figure 4As shown, in a top view observed along the injection direction, the liquid injection head 10 has a central portion 81 and protrusions 82 and 83. When viewed along the Z-axis, protrusion 82 extends from the central portion 81 in the Y2 direction. Protrusion 83 extends from the central portion 81 in the Y1 direction when viewed along the Z-axis. Protrusion 82 overlaps with the Y2-direction end of head chip 12A when viewed along the Z-axis. Protrusion 83 overlaps with the Y1-direction end of head chip 12B when viewed along the Z-axis. The central portion 81 includes the Y1-direction end of head chip 12A and the Y2-direction end of head chip 12B. The central portion 81 includes at least a portion of head chip 12A and at least a portion of head chip 12B. The dimensions of each of the protrusions 82 and 83 in the X-axis direction are less than half the dimension of the central portion 81 in the X-axis direction. The protrusion 82 is located in the X1 direction relative to the centerline passing through the center of the central portion 81 and along the Y-axis, and the protrusion 83 is located in the X2 direction relative to the centerline. The shape of the liquid injection head 10 can also be, for example, that of the holder 13.

[0043] Figure 7 This is a schematic diagram showing the ink flow channel 30 of the liquid jetting device 1. Figure 7 The image shows a flow channel 30 for the flow of an ink. Furthermore, in... Figure 7 The diagram illustrates the flow of ink within the flow channel 30 when an ink circulation system is employed. The ink flow channel 30 is configured separately for each type of ink. A liquid container 2, a pump 31, filters 32 and 33, and a common liquid chamber 41 are connected to the flow channel 30. The flow channel 30 has a supply flow channel 35 and a recovery flow channel 36. The supply flow channel 35 supplies ink from the liquid container 2 to the common liquid chamber 41. The recovery flow channel 36 recovers ink from the common liquid chamber 41 back to the liquid container 2. The liquid jetting device 1 includes heaters 37 and 38 for heating the ink. The heater 37 heats the ink flowing in the supply flow channel 35. The heater 38 is disposed in the auxiliary carriage 21 and heats the ink within the head chip 12. For details regarding the heater 38, please refer to [reference needed]. Figures 11-15 This will be discussed later.

[0044] Pump 31 is connected downstream of liquid container 2 and transfers the ink stored in liquid container 2. Heater 37 is connected downstream of pump 31 and heats the ink to a predetermined temperature. Alternatively, the structure can be configured such that heater 37 heats the ink stored in liquid container 2. By adjusting the temperature of the ink, the viscosity of the ink can be adjusted. These components—liquid container 2, pump 31, and heater 37—are disposed outside liquid jet head 10. Liquid container 2, pump 31, and heater 37 can also be mounted on carriage 5, for example. Figure 5As shown, heater 37 is positioned in the Z2 direction of liquid injection head 10. Filter 32 is positioned in the Z2 direction of heater 37. Filter 32 removes foreign matter and air bubbles mixed into the ink.

[0045] like Figure 7 As shown, ink flows in the supply channel 35 and passes through the ink supply port 14a, being introduced into the internal channels of the channel structure 14. The internal channels of the channel structure 14 are branched into multiple branches, thereby connecting to multiple head chips 12. A common liquid chamber 41 is provided in the head chip 12. The ink introduced into the head chip 12 is stored in the common liquid chamber 41. A portion of the ink stored in the common liquid chamber 41 is ejected from the nozzle N.

[0046] Filter 33 is disposed upstream of common liquid chamber 41 in the flow channel inside flow channel structure 14. Ink passing through filter 33 is supplied to common liquid chamber 41. Filter 33 removes foreign matter and air bubbles mixed into the ink.

[0047] Ink remaining in the common liquid chamber 41 that is not ejected from nozzle N is recycled back to the liquid container 2. Ink discharged from the common liquid chamber 41 flows in the flow channels inside the flow channel structure 14 and passes through the ink discharge port 14b, and is discharged to the outside of the flow channel structure 14. Ink discharged from the ink discharge port 14b flows in the recovery flow channel 36 and is recycled back to the liquid container 2. Ink is circulated in this way.

[0048] Figure 8 This is a cross-sectional view showing the head chip 12. (Example) Figure 8 As shown, the head chip 12 includes a common liquid chamber 41, a relay flow channel 42, a pressure chamber 43, a connecting flow channel 44, a piezoelectric actuator 45, and a nozzle N. Furthermore, the head chip 12 has a nozzle plate 51, a malleable substrate 53, a connecting plate 54, a pressure chamber forming plate 55, a vibrating plate 56, a protective substrate 57, and a housing 58.

[0049] The nozzle plate 51 extends in the Y-axis direction and has a predetermined length. Multiple nozzles N are formed on the nozzle plate 51. Each nozzle N is a through hole extending through the thickness of the nozzle plate 51. The multiple nozzles N are arranged in a nozzle array 18 in the Y-axis direction. The multiple nozzle arrays 18 are separated in the X-axis direction.

[0050] A portion of a common liquid chamber 41, a relay flow channel 42, and a connecting flow channel 44 are formed in the connecting plate 54. A portion of the common liquid chamber 41 in the Z1 direction is formed in the connecting plate 54. The connecting flow channel 44 communicates with nozzles N. Multiple connecting flow channels 44 are connected to multiple nozzles N respectively. A nozzle plate 51 is disposed in the Z1 direction of the connecting plate 54. Nozzles N are respectively disposed in the Z1 direction of the connecting flow channels 44. The connecting plate 54 is made of a metal such as silicon or stainless steel.

[0051] A malleable substrate 53 is disposed in the Z1 direction of the connecting plate 54. The malleable substrate 53 is formed to cover the relay channel 42 and the common liquid chamber 41. The malleable substrate 53 is supported on the fixed plate 11 via a support plate 52. The support plate 52 is formed to surround the common liquid chamber 41 and the relay channel 42 when viewed from the Z-axis direction. The support plate 52 is made of a metal such as stainless steel. In the Z-axis direction, gaps are formed between the common liquid chamber 41 and the fixed plate 11, and between the relay channel 42 and the fixed plate 11. The malleable substrate 53 is made of a flexible component such as a resin film or a metal sheet, and is deformed in the Z1 and Z2 directions in a manner that approaches and moves away from the fixed plate 11, thereby mitigating pressure fluctuations of the ink in the common liquid chamber 41. In addition, even when the malleable substrate 53 is formed of resin, since the thermal resistance is very small if it is a thin film, it hardly hinders heat conduction.

[0052] A pressure chamber forming plate 55 is disposed in the Z2 direction of the connecting plate 54. Multiple pressure chambers 43 are formed in the pressure chamber forming plate 55. Each pressure chamber 43 is formed for a specific nozzle N. The pressure chambers 43 communicate with the relay flow channel 42 and the connecting flow channel 44.

[0053] A vibrating plate 56 is disposed in the Z2 direction of the pressure chamber forming plate 55. The vibrating plate 56 forms the wall surface of the pressure chamber 43 in the Z2 direction. A plurality of piezoelectric actuators 45 are disposed on the surface of the vibrating plate 56 in the Z2 direction. The plurality of piezoelectric actuators 45 are respectively arranged in a manner corresponding to the plurality of pressure chambers 43. The piezoelectric actuator 45 includes a plurality of electrodes and a piezoelectric layer disposed between the electrodes.

[0054] A protective substrate 57 is disposed in the Z2 direction of the vibrating plate 56. The protective substrate 57 covers a plurality of piezoelectric actuators 45. The protective substrate 57 reinforces the vibrating plate 56 and protects the plurality of piezoelectric actuators 45.

[0055] A portion of a common liquid chamber 41 is formed within the housing 58. A portion of the common liquid chamber 41 in the Z2 direction is formed within the housing 58, and a portion in the Z1 direction is formed within the connecting plate 54. Furthermore, a supply port 46 and a discharge port 47 are formed within the housing 58. The supply port 46 and the discharge port 47 are separated in the Y-axis direction. The discharge port 47 is located in… Figure 7 It is shown in the middle.

[0056] like Figure 8 As shown, ink flows through the supply port 46 into the common liquid chamber 41. The ink in the common liquid chamber 41 flows through the relay channel 42 into the pressure chamber 43. The ink in the pressure chamber 43 flows through the connecting channel 44 and is ejected from the nozzle N.

[0057] The head chip 12 has a COF60. COF is short for Chip on Film. The COF60 has a flexible wiring substrate 61 and a driving circuit 62. The flexible wiring substrate 61 is a flexible wiring substrate. The flexible wiring substrate 61 is, for example, an FPC. The flexible wiring substrate 61 can also be, for example, an FFC. FPC is short for Flexible Printed Circuit. FFC is short for Flexible Flat Cable.

[0058] The piezoelectric actuator 45 is electrically connected to the flexible wiring substrate 61 via lead electrodes (not shown). The drive circuit 62 is electrically connected to the flexible wiring substrate 61. The flexible wiring substrate 61 and... Figure 1 The control unit 3 shown is electrically connected.

[0059] The piezoelectric actuator 45 is electrically connected to the control unit 3. The piezoelectric actuator 45 is controlled and driven by the control unit 3. The piezoelectric actuator 45 deforms the wall of the pressure chamber 43, thereby changing the volume within the pressure chamber 43. As a result, the piezoelectric actuator 45 ejects ink from the pressure chamber 43 from the nozzle N. Alternatively, the liquid injection head 10 may have a structure that includes other driving elements such as a heating element instead of the piezoelectric actuator 45.

[0060] like Figure 6 as well as Figure 8 As shown, the retainer 13 has sidewall portions 13a and 13b configured to cover the sides of the head chip 12. Sidewall portions 13a and 13b are an example of a first sidewall portion. The thickness direction of sidewall portion 13a is along the X-axis. The thickness direction of sidewall portion 13b is along the Y-axis. Figure 8 As shown, the sidewall portion 13a is disposed on the outer side of the head chip 12 in the X-axis direction. The fixing plate 11 is mounted on the sidewall portions 13a and 13b of the retainer 13. Figure 3As shown, when viewed along the Z-axis, the sidewall portions 13a and 13b are configured to surround the head chip 12.

[0061] The sidewall portions 13a and 13b may also be formed of metal, for example. They may also be formed of stainless steel or titanium, for example. They may also be formed of thermally conductive ceramic, or other thermally conductive materials. Since the sidewall portions 13a and 13b are components of the liquid injection head 10, ink may adhere to them; therefore, from the viewpoint of liquid resistance, they are preferably formed of stainless steel, titanium, or ceramic. Additionally, a flow channel for ink flow may be formed in the sidewall portions 13a and 13b. In this case, when the sidewall portions 13a and 13b are formed of stainless steel, titanium, or ceramic, they are particularly preferred from the viewpoint of liquid resistance. Furthermore, "thermally conductive" means, for example, that the thermal conductivity at room temperature is 10.0 W / m·K or higher. Room temperature is, for example, 15°C or higher and 25°C or lower.

[0062] In addition, such as Figure 2 As shown, the cage 13 has a flange 13d. When viewed along the Z-axis, the flange 13d extends outward compared to the sidewall portions 13a and 13b. When viewed along the Z-axis, the flange 13d is arranged to overlap with the sub-carriage 21. The flange 13d is integrally formed with the sidewall portions 13a and 13b. The flange 13d can also be separately formed from the sidewall portions 13a and 13b. The sidewall portions 13a and 13b and the flange 13d can be made of the same material or different materials. As described later, the sidewall portions 13a and 13b, the flange 13d, and the sub-carriage 21 can transfer heat to each other. Alternatively, the cage 13 can also be formed of a non-thermally conductive resin.

[0063] like Figure 2 as well as Figure 5 As shown, the liquid injection head 10 is held on the sub-carrier 21 and mounted on the carriage 5. The carriage 5 can be a support body that supports the sub-carrier 21. The carriage 5 is, for example, plate-shaped. An opening 5a is formed on the carriage 5, exposing the sub-carrier 21. In the Y-axis direction, sub-carrier support portions 5b are formed on both sides of the opening 5a. The sub-carrier support portions 5b can be, for example, stepped surfaces. The carriage 5 is, for example, made of metal. Preferably, the carriage 5 is made of a metal with high rigidity and conductivity. In such a carriage 5, grounding and rigidity can be ensured. The carriage 5 can be made of metal materials such as aluminum, stainless steel, and magnesium. Alternatively, the carriage 5 can also be made of other materials such as resin.

[0064] Figure 9 This is a cross-sectional view of the frame 22 of the sub-carriage 21, showing the section intersecting the Z-axis direction. Figure 10To show the cross-sectional view of the sub-carriage 21, and to illustrate along... Figure 9 The cross section of line XX in the diagram. Figure 11 A cross-sectional view showing the main parts of the secondary carriage 21 in an enlarged manner. Figure 12 This is a cross-sectional view showing the connection between the auxiliary carriage 21 and the carriage 5, and it is along... Figure 9 A sectional view of line XII-XII in the diagram. Figure 13 This is a cross-sectional view showing the fixing part between the auxiliary carriage 21 and the carriage 5, and it is along... Figure 9 A cross-sectional view of line XIII-XIII in the diagram. Figure 14 This is an exploded perspective view of the secondary carriage 21. (See attached image.) Figures 9-14 As shown, the sub-carriage 21 includes a block 24, a heater 38, and a cover 25. The block 24 has a frame 22 and a base 23. The block 24 is formed, for example, of metal or thermally conductive ceramic. The block 24 may also be formed of an alloy containing at least one of aluminum, copper, silver, and gold. The block 24 is an example of a first component. The heater 38 is an example of a heating element. The cover 25 is an example of a second component. The frame 22 is an example of a first frame.

[0065] like Figure 9 As shown, the frame 22 is formed to surround the liquid injection head 10 when viewed along the Z-axis. The base portion 23 holds the liquid injection head 10. The base portion 23 may also hold the liquid injection head 10 via other portions. A portion of the retainer 13 of the liquid injection head 10 may also be disposed in the Z2 direction of the frame 22. For example, the flange 13d of the retainer 13 may also be disposed in the Z2 direction of the frame 22. For example, the liquid injection head 10 may be held on the frame 22 by distributing the base portion 23 in the Z2 direction of the frame 22 and distributing a portion of the liquid injection head 10 in the Z2 direction of the base portion 23. Furthermore, a stepped surface for holding the liquid injection head 10 may be formed on the frame 22. Additionally, the frame 22 may include a portion formed to protrude in the Z2 direction compared to the base portion 23; in this structure, the liquid injection head 10 may also be held by the Z2-direction end of the frame 22. When viewed along the Z-axis, a head chip 12 is disposed on the inner side of the frame 22.

[0066] Frame 22 may be made of stainless steel, for example. Frame 22 may also be made of other metals.

[0067] The base portion 23 is, for example, plate-shaped. The thickness direction of the base portion 23 is along the Z-axis. When viewed along the Z-axis, the base portion 23 extends outward compared to the frame 22. The base portion 23 is positioned relative to the frame 22 in the Z2 direction. Figure 12 as well as Figure 13As shown, the base portion 23 extends in the Y2 direction compared to the frame 22. When viewed along the Z-axis, the base portion 23 is arranged to overlap with the sub-carriage support portion 5b of the carriage 5. The end of the base portion 23 is positioned in the Z2 direction of the sub-carriage support portion 5b.

[0068] like Figure 13 As shown, the block 24 can also be fastened relative to the carriage 5 via a resin bushing 72 and a metal screw 73. The bushing 72 includes a cylindrical portion with a through hole for inserting the screw 73. A female thread 74 for mounting the screw 73 is formed on the carriage 5. The bushing 72 has an insertion portion 72a that is pressed into a hole 23a formed in the base portion 23, and a flange portion 72b that extends outward compared to the insertion portion 72a when viewed along the Z-axis. The flange portion 72b is a portion sandwiched between the head of the screw 73 and the Z2-oriented surface of the base portion 23. Furthermore, through the contact portion 29, which will be described in detail later, the Z1-oriented surface of the base portion 23 and the Z2-oriented surface of the sub-carriage support portion 5b are spaced apart and opposed. Therefore, heat transfer from the base portion 23 to the sub-carriage support portion 5b via heat conduction is suppressed. The screw 73 can be made of a metal with high hardness, such as iron, stainless steel, or brass. The screw 73 can also be made of aluminum or titanium. The bushing 72 can be made of a resin material with high heat resistance. The bushing 72 is made of a resin material with heat resistance and a thermal conductivity of less than 1.0 W / m·K. The bushing 72 is made of PEEK, but can also be made of other resin materials. PEEK is an abbreviation for polyetheretherketone resin. Alternatively, the bushing 72 can also be made of ceramic with heat resistance and a thermal conductivity of less than 10.0 W / m·K at room temperature. The bushing 72 is located between the screw 73 and the base portion 23, and the screw 73 and the base portion 23 do not contact each other. Therefore, heat transfer from the base portion 23 to the carriage 5 via the screw 73 is suppressed.

[0069] The frame 22 and the base portion 23 are integrally formed. Alternatively, the frame 22 and the base portion 23 can be formed separately. The separately formed frame 22 and the base portion 23 can also be joined together.

[0070] like Figures 11-13 As shown, the frame 22 is opposite to the sidewalls 13a and 13b of the holder 13 of the liquid injection head 10. Figure 11 As shown, the side wall portion 13a of the cage 13 is opposite to the frame 22 in the X-axis direction. Figure 12 as well as Figure 13As shown, the sidewall portion 13b of the retainer 13 is opposite to the frame 22 in the Y-axis direction. When viewed along the X-axis and Y-axis directions, the frame 22 and the sidewall portions 13a and 13b are arranged in an overlapping manner. When viewed along the Z-axis direction, the heater 38 is arranged with the frame 22 in between the sidewall portions 13a and 13b. In other words, a portion of the block 24 is disposed between the heater 38 and the sidewall portions 13a and 13b. The frame 22 and the heater 38 do not need to be in direct contact, as long as the heat from the heater 38 can be transferred to the frame 22. Specifically, it is sufficient that an insulating component with a thermal conductivity of less than 1.0 W / m·K at room temperature is placed between the heater 38 and the frame 22. However, even if an insulating component is sandwiched between the heater 38 and the frame 22, as long as the insulating component is a thin structure such as an adhesive or film, the thermal resistance will be very small and can be ignored, so the heat from the heater 38 can be transferred to the frame 22. Similarly, the frame 22 and the side walls 13a and 13b do not need to be in direct contact, as long as heat can be transferred from the frame 22 to the side walls 13a and 13b.

[0071] Figure 15 This is a perspective view of heater 38. Figures 9-15 The heater 38 shown is a thin-film heater. The heater 38 heats up through resistance. The resistive element of the heater 38 can be, for example, copper or stainless steel. When viewed along the Z-axis, the heater 38 is arranged in a frame 22 surrounding the fixing plate 11 of the liquid injection head 10 and the sub-carriage 21. The thickness direction of the heater 38 is along the thickness direction of the sidewall portions 13a and 13b and the thickness direction of the frame 22. Figure 10 as well as Figure 11 In the cross-section shown, the thickness direction of heater 38 is along the X-axis.

[0072] The inner peripheral surface 38a of the heater 38 can also be connected to the outer peripheral surface 22b of the frame 22. The heater 38 can also be fixed to the outer peripheral surface 22b using heat-dissipating paste. Figure 12 as well as Figure 13 In the cross-section shown, the thickness direction of heater 38 is along the Y-axis. Figure 9 The heater 38 is illustrated with a double-dotted line. The heater 38 is formed in the form of a frame 22 surrounding the sub-carriage 21. When viewed along the Z-axis, a fixing plate 11 and a nozzle plate 51 are disposed inside the frame 22. The bottom surface 11b of the fixing plate 11 facing the Z1 direction and the nozzle surface 51a of the nozzle plate 51 facing the Z1 direction are examples of the spray surfaces of the liquid injection head 10.

[0073] Figures 9-14 The cover 25 shown is configured to cover the heater 38. (As shown) Figures 10-14 As shown, the cover 25 has a first portion 26 and a second portion 27. The first portion 26 is plate-shaped. The thickness direction of the first portion 26 is along the thickness direction of the heater 38. When viewed along the Z-axis, the first portion 26 is arranged to surround the heater 38. The length of the first portion 26 in the Z-axis direction is longer than the length of the heater 38 in the Z-axis direction. Figure 10 as well as Figure 11 In the cross-section shown, the thickness direction of the first portion 26 is along the X-axis. Figure 12 as well as Figure 13 In the cross-section shown, the thickness direction of the first portion 26 is along the Y-axis. A gap G1 is formed between the outer peripheral surface 38b of the heater 38 and the inner peripheral surface 26a of the first portion 26. When viewed along the Z-axis, the first portion 26 of the cover 25 is positioned relative to the heater 38, spaced apart by the gap G1, and surrounds the heater 38. The gap G1 is an example of a first gap.

[0074] The second portion 27 of the cover 25 is configured to cover the surface 22c of the frame 22 located at its Z1-direction end. The Z1-direction surface 22c of the frame 22 is an example of the end of the first frame in the spray direction. The surface 22c and the second portion 27 are bonded together with an adhesive (not shown). A recess 22d is formed on the surface 22c, which is recessed in the Z2-direction and functions to receive excess adhesive between the surface 22c and the second portion 27. The second portion 27 extends toward the frame 22 from the Z1-direction end of the first portion 26. The second portion 27 is plate-shaped. The thickness direction of the second portion 27 is along the Z-axis. The second portion 27 covers the surface of the block 24 located at its Z1-direction end.

[0075] Here, the thermal conductivity of the cover 25 is lower than that of the block 24. Furthermore, in the sub-carriage 21, since the bottom of the block 24 is covered by the second part 27 of the cover 25, the block 24 is not exposed in the Z1 direction. This suppresses heat dissipation from the block 24 heated by the heater 38. Because the cover 25 covers both the block 24 and the heater 38, neither the block 24 nor the heater 38 is exposed in the Z1 direction. Therefore, the adhesion of ink ejected from the nozzle surface 51a and ink mist separated from the ink to the block 24 and the heater 38 is suppressed. Moreover, if the second part 27 is made of stainless steel or ceramic with high liquid resistance, the block 24 and the heater 38 can be protected from ink contamination; and aluminum with high thermal conductivity can be used for the block 24. As a result, the sub-carriage 21 achieves improved ink resistance and improved thermal conductivity of the block 24.

[0076] Furthermore, by covering the block 24 with the cover 25, the surface area of ​​the block 24 exposed to the surrounding air can be reduced, thus suppressing convective heat transfer caused by the relative airflow during the transport of the auxiliary carriage 21. This, in turn, suppresses heat dissipation from the block 24 heated by the heater 38.

[0077] The sidewalls 13a and 13b and the flange 13d of the retainer 13 of the liquid injection head 10 are thermally conductive. The sidewalls 13a and 13b of the retainer 13 are in thermal contact with the block 24 of the auxiliary carriage 21. "Temperature contact" means that heat can be transferred between the sidewalls 13a and the block 24. Specifically, this includes cases where the sidewalls 13a and 13b and the flange 13d are integrally formed of a thermally conductive material, and cases where they are composed of multiple thermally conductive separate parts. The flange 13d of the retainer 13 is in contact with the base portion 23. The heat of the block 24 is transferred to the sidewalls 13a and 13b via the flange 13d. As indicated by arrows H1 and H2, a portion of the heat of the block 24 is transferred to the sidewalls 13a and 13b through thermal conductivity.

[0078] As indicated by arrow H3, a portion of the heat from block 24 is transferred to sidewalls 13a and 13b via radiation and conduction generated by the internal movement of heat within the air in gap G2 (described later). Specifically, a portion of the heat from frame 22 is transferred to sidewalls 13a and 13b via radiation and conduction generated by the internal movement of heat within the air in gap G2.

[0079] The thermal conductivity of the block 24 is higher than that of the sidewalls 13a and 13b. Furthermore, as mentioned above, the thermal conductivity of the cover 25 is lower than that of the block 24. Moreover, the thermal conductivity of the cover 25 is lower than that of the sidewalls 13a and 13b. When the cover 25 is made of ceramic, the thermal conductivity of the ceramic can be less than 10.0 W / m·K, for example, at room temperature. The room temperature can be, for example, 15°C or higher and 25°C or lower. The thermal conductivity of the cover 25 can also be less than 5.0 W / m·K, for example, or less than 1.0 W / m·K. When the cover 25 is made of resin, the thermal conductivity of the resin can also be less than 1.0 W / m·K, for example, at room temperature. For example, if the sidewalls 13a and 13b are formed of stainless steel or titanium, the cover 25 can also be formed of ceramic or resin with a lower thermal conductivity than that of the sidewalls 13a and 13b.

[0080] When viewed along the Z-axis, a gap G2 is formed between the frame 22 and the side wall portion 13b. Gap G2 is an example of a second gap. Gap G2 is the gap between the inner circumferential surface 22a of the frame 22 and the outer circumferential surface 13c of the side wall portion 13b. When viewed along the Z-axis, gap G1 is larger than gap G2. Gap G1 can be, for example, 0.75 mm or more, or 1.00 mm or more. Gap G2 can be greater than 0.00 mm and less than 0.15 mm. Gap G2 can also be, for example, larger than 0.15 mm. When gap G2 is larger than 0.15 mm, a heat transfer sheet with a thermal conductivity of 1.0 W / m·K or more at room temperature can be placed in gap G2. When the gap G2 is 0.15 mm or less, heat can be transferred from the frame 22 to the side wall 13b through radiation and conduction generated by the movement of air within the gap G2, thus eliminating the need for a heat transfer fin. This reduces the possibility of deterioration in the alignment accuracy of the liquid injection head 10 relative to the sub-carriage 21 caused by placing a heat transfer fin within the gap G2. Furthermore, when the gap G1 is 0.75 mm or more, heat transfer from the heating section 38 to the first part 26 of the cover 25 via the gap G1 can be suppressed through radiation and conduction of heat transferred through the air within the gap G1.

[0081] The first portion 26 of the cover 25, when viewed along the Z-axis, is positioned between the inner peripheral surface 5c of the opening 5a of the carriage 5 and the frame 22. When viewed along the Z-axis, a gap G3 is formed between the outer peripheral surface 26b of the first portion 26 of the cover 25 and the inner peripheral surface 5c of the opening 5a of the carriage 5. Gap G3 is larger than gap G2. Gap G3 is an example of a third gap. In the head unit 20, by making gap G3 larger than gap G2, heat dissipation from the first portion 26 of the cover 25 to the carriage 5 can be suppressed.

[0082] like Figure 12As shown, the sub-carriage 21 has an abutment portion 29 that protrudes from the base portion 23 toward the carriage 5 and abuts against the carriage 5. The thermal conductivity of the abutment portion 29 is lower than that of the side wall portion 13b. The thermal conductivity of the abutment portion 29 at room temperature can be, for example, less than 10.0 W / m·K. The thermal conductivity of the abutment portion 29 at room temperature can be less than 5.0 W / m·K or less than 1.0 W / m·K. The abutment portion 29 is disposed on the Z2 direction side of the sub-carriage support portion 5b of the carriage 5. The abutment portion 29 protrudes from the base portion 23 in the Z1 direction and abuts against the sub-carriage support portion 5b. The abutment portion 29 can also be formed, for example, by a ceramic made of zirconium oxide. The thermal conductivity of zirconium oxide at room temperature is, for example, 3.0 W / m·K. When the abutment portion 29 is formed of a ceramic material made of zirconium oxide, the strength of the abutment portion 29 can be ensured, and the thermal conductivity can be kept low. Furthermore, by using a ceramic material made of zirconium oxide, the flatness of the surface of the abutment portion 29 that contacts the sub-carriage support portion 5b can be improved. However, the abutment portion 29 is not limited to being formed of ceramic; it can also be formed of other materials. For example, the abutment portion 29 can also be formed of a resin material.

[0083] like Figure 10 As shown, the nozzle surface 51a of the nozzle plate 51 of the head chip 12 may also be located closer to the Z1 direction than the Z1 direction surface 27b of the second part 27 of the cover 25. The nozzle surface 51a is the Z1 direction surface of the nozzle plate 51. The nozzle surface 51a is an example of an ejection surface on which the nozzle N is formed. The surface 27b of the cover 25 is an example of the end of the sub-carriage 21 in the ejection direction. Alternatively, the ejection surface may include both the nozzle surface 51a and the bottom surface 11b of the fixing plate 11. When the ejection surface is located closer to the Z1 direction than the Z1 direction surface 27b of the sub-carriage 21, for example, when a wiping action is performed during maintenance, the adhesion of ink to the sub-carriage 21 can be suppressed. The adhesion of ink to the block 24 of the sub-carriage 21 can be suppressed, thereby protecting the block 24.

[0084] like Figure 1 , Figure 9 as well as Figure 10 As shown, the secondary carriage 21 can hold multiple liquid injection heads 10. The block 24 of the secondary carriage 21 holds the liquid injection heads 10A and 10B. Figure 9 , Figure 10 as well as Figure 13 As shown, heater 38 is a surface heater surrounding liquid injection heads 10A and 10B.

[0085] In the sub-carriage 21, since both liquid injection heads 10A and 10B are surrounded by a single heater 38, it is unnecessary to separately install heaters to surround the liquid injection heads 10A and 10B. Therefore, the sub-carriage 21 facilitates easy manufacturing and reduces costs. In the sub-carriage 21, the surface heater can be, for example, a thin-film heater, a silicone rubber heater, or a space heater.

[0086] Next, the common part 22C of frame 22 will be explained. For example... Figure 9 As shown, frame 22 includes frame 22A and frame 22B. Frame 22A surrounds the sidewalls 13a and 13b of the retainer 13A of the liquid injection head 10A when viewed along the Z-axis. Frame 22B surrounds the sidewalls 13a and 13b of the retainer 13B of the liquid injection head 10B when viewed along the Z-axis. Frames 22A and 22B share at least a common portion 22C between the liquid injection head 10A and the liquid injection head 10B.

[0087] The heater 38 is disposed along the outer periphery of the frame 22. The outer periphery of the frame 22 does not include the common portion 22C. Additionally, in Figure 15 In the diagram, the common portion 22C is shown using imaginary lines. When viewed along the Z-axis, the heater 38 is formed in a manner that surrounds the entire circumference of the sidewall portions 13a and 13b, excluding the common portion 22C. Here, "surrounding the entire circumference of the sidewall portions 13a and 13b" means that the heater 38 surrounds more than 70% of the entire circumference of the sidewall portions 13a and 13b. Furthermore, more preferably, as shown... Figure 13As shown, the heater 38 is formed to surround more than 90% of the entire circumference of the sidewall portions 13a and 13b. The heater 38 may also be configured to correspond to at least a portion of each sidewall portion 13a extending in the Y-axis direction. The heater 38 may also be configured to correspond to at least a portion of each sidewall portion 13b extending in the X-axis direction. A portion of the heater 38 is configured to overlap with the sidewall portion 13a when viewed along the X1 direction. A portion of the heater 38 is configured to overlap with the sidewall portion 13a when viewed along the X2 direction. A portion of the heater 38 is configured to overlap with the sidewall portion 13b when viewed along the Y1 direction. A portion of the heater 38 is configured to overlap with the sidewall portion 13b when viewed along the Y2 direction. The heater 38 is configured to overlap with at least a portion of the frame 22 in all four directions: X1, X2, Y1, and Y2. Alternatively, the heater 38 can be configured so that it does not overlap with the frame 22 in all four directions: X1, X2, Y1, and Y2. In short, the goal is to reduce temperature unevenness at the frame 22, thereby suppressing temperature unevenness at the head chip 12.

[0088] The connecting portion 38d, which connects the heater 38 and the terminal 71a, is connected to the short side portion 38e of the heater 38. Preferably, the connecting portion 38d is connected to a portion of the heater 38 other than the long side portion 38f. The long side portion 38f is, for example, the portion that extends the longest in the Y-axis direction. The short side portion 38e may also be a portion shorter than the long side portion 38f in the Y-axis direction. Furthermore, the short side portion 38e is configured in... Figure 4 The X2 direction side of the end of the head chip 12A in the Y2 direction of the liquid injection head 10B shown.

[0089] Next, the fixing of the cover 25 and the block 24 will be explained. For example... Figure 9 as well as Figure 10 As shown, the cover 25 has a third portion 28, which, when viewed along the Z-axis, is positioned between frames 22A and 22B and does not overlap with the common portion 22C. Figure 10 As shown, the third part 28 is connected to the Z2-direction end of the first part 26. The third part 28 is plate-shaped, and its thickness direction is along the Z-axis. The third part 28 and the base portion 23 of the block 24 are fixed together. For example, the third part 28 and the base portion 23 are fixed together using screws 28a.

[0090] In the sub-carriage 21, when viewed along the Z-axis, screws 28a are positioned at the overlap with the third part 28 to fix the block 24 and the cover 25 together, thus allowing for efficient and flexible use of the space in the base portion 23. The sub-carriage 21 also helps to prevent the base portion 23 from becoming too large.

[0091] Next, the configuration of connector 71 for heater 38 will be explained. For example... Figure 4 as well as Figure 5 As shown, the head unit 20 includes a connector 71 for the heater 38. The connector 71 is a connector for connecting the heater 38 and electrical wiring for supplying power to the heater 38. The connector 71 includes a terminal 71a that is electrically connected to the thin-film heater 38, and a housing 71b that covers the terminal 71a.

[0092] like Figure 4 As shown, connector 71 is positioned in the Y2 direction of the head chip 12B of the liquid injection head 10B and in the X2 direction of the head chip 12A of the liquid injection head 10B. When viewed along the Z-axis, connector 71 is positioned to not overlap with the liquid injection heads 10A and 10B. Connector 71 is held on the base portion 23 of the sub-carrier 21. Figure 9 As shown, an opening 23b is formed on the base portion 23 for inserting the terminal 71a. The terminal 71a passes through the opening 23b and extends out in the Z2 direction of the base portion 23.

[0093] Next, refer to Figures 11-13 The heat transfer path in head unit 20 will be explained. The frame 22 of block 24 is heated by heater 38. The frame 22 and base 23 of block 24 are heated to approximately the same temperature. The heat from the frame 22 is transferred to the side walls 13a and 13b of the retainer 13 by radiation and conduction generated by the movement of heat in the air of gap G2. The heat from the base 23 is transferred to the flange 13d of the retainer 13 by conduction. The heat from the flange 13d is transferred to the side walls 13a and 13b by conduction. The heat from the side walls 13a and 13b is transferred to the fixing plate 11. Figure 8 As shown, the heat from the fixed plate 11 is transferred to the connecting plate 54. Since the plastic substrate 53 is thinner and has lower thermal resistance compared to the fixed plate 11, and since the support plate 52 in this embodiment is made of a thermally conductive metal, heat transfer from the fixed plate 11 to the connecting plate 54 is not hindered. The heat from the connecting plate 54 heats the ink within the flow channels of the connecting plate 54. Therefore, the ink within the liquid injection head 10 can be heated in the sub-carriage 21.

[0094] For example, in the liquid ejector head 10 of this embodiment, the amount of ink in the common liquid chamber 41 is greater in the Y-axis direction at the central portion 81 than at the protrusion 82 (as an end in the Y2 direction) and the protrusion 83 (as an end in the Y1 direction). This is because, as Figure 4 As shown, when viewed along the X-axis, the two head chips 12 overlap at the central portion 81. Therefore, in the Y-axis direction, the central portion 81 is more difficult to heat than the protruding portions 82 and 83, which are the ends in the Y-axis direction. Here, for example, we envision a structure in which the heater 38 is directly fixed to the side walls 13a and 13b of the liquid injection head 10 (hereinafter referred to as the "comparative example"). In the comparative example, the heat from the heater 38 is transferred to the flow channel of the connecting plate 54 via the side walls 13a and 13b and the fixing plate 11. In the comparative example, since the distance from the heater 38 to the common liquid chamber 41 is shorter, it is difficult to move the heat of the heater 38 in the in-plane direction of the heater 38, for example, in the Y-axis direction. Therefore, the temperature near the central portion 81 in the liquid jet head 10, where the amount of ink in the common liquid chamber 41 is relatively large and difficult to heat, is lower than the temperature near the protrusions 82 and 83, where the amount of ink in the common liquid chamber 41 is relatively small and easy to heat compared to the central portion 81. As a result, a temperature deviation occurs in the Y-axis direction of the liquid jet head 10.

[0095] In contrast, according to the liquid injection device 1 of this embodiment, since a frame 22 with a higher thermal conductivity than the sidewalls 13a and 13b is disposed between the heater 38 and the sidewalls 13a and 13b when viewed along the Z-axis, the heat from the heater 38 can be transferred to the sidewalls 13a and 13b via the frame 22. That is, compared to the comparative example, the distance from the heater 38 to the flow channel, such as the common liquid chamber 41, within the liquid injection head 10 is longer, making it easier for the heat from the heater 38 to move in the in-plane direction of the heater 38 via the frame 22. Therefore, the heat from the heater 38 is transferred to the liquid injection head 10 in a manner that is dispersed through the frame 22. Thus, the heat in the portions of the heater 38 located near the protrusions 82 and 83 can move towards the central portion 81 by moving within the frame 22. In other words, by positioning the frame 22 between the liquid injection head 10 and the heater 38, temperature deviations within the liquid injection head 10 can be suppressed. In addition, such as Figure 11 As shown, preferably, the direction of the frame 22 perpendicular to the in-plane direction of the heater 38 (in... Figure 11The thickness of the sidewall 13a in the X-axis direction is greater than the thickness of the sidewall 13a in the direction perpendicular to the in-plane direction of the heater 38. In this structure, since the distance from the heater 38 to the liquid injection head 10 can be extended, the heat from the heater 38 can be more dispersed in the in-plane direction of the heater 38, thereby transferring heat to the liquid injection head 10. The same applies to the portion of the frame 22 opposite to the sidewall 13b.

[0096] Furthermore, since the frame 22 is configured to surround the sidewall portions 13a and 13b, the area around the sidewall portions 13a and 13b can be maintained at a substantially uniform temperature. This allows for the maintenance of a substantially uniform temperature in the sidewall portions 13a and 13b, and suppresses temperature unevenness in the head chip 12 held on the holder 13. As a result, the liquid jetting device 1 can appropriately heat the ink within the head chip 12. In the liquid jetting device 1, because the ink within the head chip 12 is appropriately heated, the viscosity of the ink can be appropriately maintained, thereby allowing the ink to be ejected from the liquid jetting head 10.

[0097] In the secondary carriage 21, when viewed along the Z-axis, the heater 38 is covered by the cover 25. An air layer as a gap G1 is formed between the heater 38 and the cover 25. This reduces heat loss from the heater 38 and frame 22 to the cover 25 due to radiation and heat conduction within the air in the gap G1. Furthermore, since the thermal conductivity of the cover 25 is lower than that of the block 24, heat from the heater 38 is easily transferred to the block 24 through thermal conduction, but is difficult to transfer to the cover 25. This suppresses heat loss from the heater 38 and allows for appropriate heating of the block 24.

[0098] Furthermore, in the sub-carriage 21, the gap G1 is larger than the gap G2. In the sub-carriage 21, since the gap G2 between the frame 22 and the sidewalls 13a and 13b becomes narrower, the thermal resistance caused by the air in the gap G2 can be reduced, and heat can be appropriately transferred from the frame 22 to the sidewalls 13a and 13b through radiation and conduction generated by the movement of heat in the air within the gap G2. Furthermore, the gap G1 becomes a closed space surrounded by the block 24 and the cover 25, with minimal airflow to the outside. In this embodiment, the gap G1 communicates with the outside only through the opening 23b. This suppresses heat loss caused by convective heat transfer. Although airflow relative to the sub-carriage 21 occurs due to the movement of the carriage 5, airflow is difficult to generate within the air layer in the gap G1, and the heater 38 and the block 24 are protected by the cover 25; therefore, heat loss from the heater 38 and the block 24 is suppressed.

[0099] Furthermore, the block 24 and the carriage 5 are partially connected by a conductive component (not shown). For example, any metal can be used as the conductive component. Since the fixing plate 11, the retainer 13, the block 24, and the carriage 5 constituting the head unit 20 are all conductive, the head unit 20 can be grounded to the ground on the main body side of the liquid injection device 1 via the fixing plate 11, the retainer 13, the block 24, the conductive component, and the carriage 5. Therefore, in the head unit 20, the effects of noise emitted from the liquid injection head 10 or the electronic components of the liquid injection device 1, as well as static electricity generated from the dielectric PA, can be suppressed.

[0100] In the head unit 20, an abutment portion 29 is disposed between the block 24 and the carriage 5. Since the thermal conductivity of the abutment portion 29 is lower than that of the block 24, heat dissipation from the block 24 to the carriage 5 via the abutment portion 29 can be suppressed in the head unit 20. Furthermore, the abutment portion 29 is shaped to protrude from the base portion 23 of the block 24. As a result, the contact area between the sub-carriage 21 and the carriage 5 can be reduced, thus appropriately achieving both ensuring the flatness for mounting the sub-carriage 21 onto the carriage 5 and suppressing heat dissipation from the sub-carriage 21 to the carriage 5.

[0101] Furthermore, the secondary carriage 21 may also be equipped with a temperature sensor to measure the temperature of the block 24. The temperature sensor is electrically connected to the control unit 3. The control unit 3 can control the heat generated by the heater 38 based on the temperature of the block 24 detected by the temperature sensor.

[0102] Furthermore, the foregoing embodiments are merely representative examples of the present invention. The present invention is not limited to the foregoing embodiments, and various modifications and additions can be made without departing from the spirit of the present invention.

[0103] Although stainless steel, titanium, or thermally conductive ceramics are exemplified as materials for the sidewall portions 13a and 13b in the above embodiments, the materials for the sidewall portions 13a and 13b are not limited to these materials and may be other materials. For example, the materials for the sidewall portions 13a and 13b may also be ceramics with a thermal conductivity of less than 10.0 W / m·K at room temperature or thermally insulating resins.

[0104] Although in the above embodiment, the carriage 5 is configured to have, for example, a sub-carriage 21, the carriage 5 may also have a configuration with two or more sub-carriages 21.

[0105] Although in the above embodiments, the secondary carriage 2 is configured to have, for example, two liquid injection heads 10, the secondary carriage 21 can be configured to have one liquid injection head 10 or to have three or more liquid injection heads 10.

[0106] Although in the above embodiment, the liquid injection head 10 is configured to have, for example, two head chips 12, the liquid injection head 10 may have a structure with one head chip 12 or a structure with three or more head chips 12. The frame 22 is not limited to a frame configured to surround two head chips 12. The frame 22 may be configured to surround one head chip 12 or a frame configured to surround three or more head chips 12. In addition, when the liquid injection head 10 has three or more head chips 12 and the head chips 12 are staggered along the Y-axis direction, the central portion 81 is a portion that overlaps with at least a portion of each of the head chips 12, the protrusion 82 is a portion that overlaps with the Y2 direction end of the head chip 12 located in the Y2 direction, and the protrusion 83 is a portion that overlaps with the Y1 direction end of the head chip 12 located in the Y1 direction.

[0107] Although the above embodiments describe a case where gap G3 is larger than gap G2, head unit 20 is not limited to a head unit where gap G3 is larger than gap G2. Gap G3 can be the same size as gap G1 or gap G2, or it can be smaller than gap G2.

[0108] Although in the above embodiments, the plurality of head chips 12 are configured offset in the Y-axis direction, the plurality of head chips 12 are not limited to being configured offset in the Y-axis direction.

[0109] Although in the above embodiment, the heater 38 is arranged to surround the plurality of liquid injection heads 10 when viewed along the Z-axis, a heater 38 may also be provided for each liquid injection head 10. Furthermore, the position of the connector 71 is not limited to the position in the X2 direction of the head chip 12A; it may be positioned in the Y2 direction of the head chip 12A, or between the liquid injection heads 10A and 10B without overlapping the common portion 22C, or at other positions.

[0110] Although the above embodiment illustrates a case where the thermal conductivity of the cover 25 is less than that of the block 24, the thermal conductivity of the cover 25 may also be approximately the same as that of the block 24.

[0111] Although the above embodiment illustrates a case where the thermal conductivity of the block 24 is higher than that of the sidewalls 13a and 13b, the thermal conductivity of the block 24 may also be approximately the same as that of the sidewalls 13a and 13b.

[0112] Although the above embodiment exemplifies a liquid jetting device 1 in which the carriage 5 equipped with the liquid jetting head 10 reciprocates in the width direction of the medium PA in a serial manner, the present invention can also be applied to a row-type liquid jetting device having a row-type head in which the liquid jetting heads 10 are arranged side by side in a predetermined direction.

[0113] The liquid jetting apparatus exemplified in the foregoing manner can be used not only in printing equipment but also in various other devices such as fax machines and copiers. However, the applications of the liquid jetting apparatus are not limited to printing. For example, a liquid jetting apparatus that jets a solution of color material is used as a manufacturing apparatus for color filters in display devices such as liquid crystal display panels. Furthermore, a liquid jetting apparatus that jets a solution of conductive material is used as a manufacturing apparatus for wiring or electrodes in wiring substrates. Additionally, a liquid jetting apparatus that jets a solution of organic matter related to living organisms is used, for example, as a manufacturing apparatus for biochips.

[0114] Symbol Explanation

[0115] 1…Liquid injection device; 5…Carriage; 5a…Carriage opening; 10, 10A, 10B…Liquid injection heads (first liquid injection head, second liquid injection head); 12, 12A, 12B…Head chip (first head chip, second head chip); 13a, 13b…Side wall portion (first side wall portion, second side wall portion); 13c…Outer peripheral surface of the side wall portion (outer peripheral surface of the first side wall portion); 20…Head unit; 21…Sub-carriage; 22, 22A, 22B…Frame (first frame, second frame); 22C…Common part; 22a…Frame 22c…Inner peripheral surface (inner peripheral surface of the first frame); 23…End of the frame (end of the first frame in the spray direction); 24…Base portion; 25…Block (first component); 26…Cover (second component); 27…Abutting portion; 38…Heater (heating portion); 51a…Nozzle surface (spray surface); 72…Bushing; G1…Gap (first gap); G2…Gap (second gap); G3…Gap (third gap); N…Nozzle; X…X-axis direction (second direction); Y…Y-axis direction (first direction); Z…Z-axis direction (spray direction).

Claims

1. A liquid injection device, comprising: A first liquid injection head has an injection surface with a nozzle on which liquid is injected; A secondary carriage having a first component and a heating element, the first component being thermally conductive and holding the first liquid injection head, the heating element being disposed on the first component; The carriage, which holds the sub-carriage. The first liquid injection head has a first sidewall portion opposite to the first component. The heating element, when viewed along the spray direction of the liquid ejected from the first liquid nozzle, is configured such that it sandwiches the first component between itself and the first sidewall portion, and is configured to surround the spray surface of the first liquid nozzle and the first sidewall portion. The secondary carriage has a second component that, when viewed along the spray direction, is positioned relative to the heating element, spaced apart by a first gap, and surrounds the heating element. The first component has a first frame that, when viewed along the spray direction, surrounds the spray surface of the first liquid spray head and the first sidewall portion. The heating element is disposed on the first frame. When observed along the spray direction, the first gap is greater than the second gap between the inner circumferential surface of the first frame and the outer circumferential surface of the first sidewall.

2. The liquid injection device as claimed in claim 1, wherein, The first sidewall portion is thermally conductive and in thermal contact with the first component.

3. The liquid injection device as described in claim 1 or 2, wherein, The thermal conductivity of the first component is higher than that of the first sidewall.

4. The liquid injection device as claimed in claim 1, wherein, The thermal conductivity of the second component is lower than that of the first component.

5. The liquid injection device as described in claim 1 or 4, wherein, The thermal conductivity of the first component is higher than that of the first sidewall portion. The thermal conductivity of the second component is lower than that of the first sidewall.

6. The liquid injection device as claimed in claim 1, wherein, The first component has a first frame that, when viewed along the spray direction, surrounds the spray surface of the first liquid spray head and the first sidewall portion. The heating element is disposed on the first frame. When viewed in a direction opposite to the spray direction, the second component covers the end of the first frame in the spray direction.

7. The liquid injection device as claimed in claim 1, wherein, The first gap is 0.75mm or more. The second gap is greater than 0.00 mm and less than 0.15 mm.

8. The liquid injection device as claimed in claim 1 or 7, wherein, The carriage is made of metal. An opening is formed on the carriage for the insertion of the sub-carriage. The second component, when viewed along the spray direction, is positioned between the inner circumferential surface of the carriage opening and the first component. When observed along the spray direction, the third gap between the inner circumferential surface of the carriage opening and the outer circumferential surface of the first portion of the second component is greater than the second gap. The first part is plate-shaped. The thickness direction of the first part is along the thickness direction of the heating part. When viewed along the jetting direction, the first portion is configured to surround the heating element.

9. The liquid injection device as claimed in claim 1, wherein, The carriage is made of metal. The first sidewall portion is thermally conductive and in thermal contact with the first component. The first component has a base portion for holding the first liquid injection head. The secondary carriage has an abutment portion that protrudes from the base portion toward the carriage and contacts the carriage. The thermal conductivity of the contact portion is lower than that of the first sidewall portion.

10. The liquid injection device as claimed in claim 1, wherein, The first liquid injection head has an injection surface with a nozzle formed for injecting liquid. The spray surface is located in the spray direction relative to the end of the secondary carriage in the spray direction.

11. The liquid injection device as claimed in claim 1, wherein, It also includes a second liquid injection head, which has a second sidewall portion opposite to the first component. The first component of the sub-carriage holds the first liquid injection head and the second liquid injection head. The heating element is a planar heater that surrounds both the first sidewall and the second sidewall.

12. The liquid injection device as claimed in claim 11, wherein, The first component has a first frame and a second frame. When viewed along the spray direction, the first frame surrounds the first sidewall portion, and the second frame surrounds the second sidewall portion. The first liquid injection head and the second liquid injection head are arranged adjacent to each other. The first frame and the second frame have at least a common portion between the first liquid injection head and the second liquid injection head. The heating element is disposed along the outer periphery of the first frame and the second frame.

13. The liquid injection device as claimed in claim 12, wherein, The secondary carriage has a second component that, when viewed along the spray direction, is positioned relative to the heating element, spaced apart by a first gap, and surrounds the heating element. When viewed along the spray direction, the first component and the second component are fixed to each other at a portion between the first frame and the second frame that does not overlap with the common portion.

14. The liquid injection device as claimed in claim 1, wherein, It also includes a connector, which is electrically connected to the heating element. The first liquid injection head includes a first head chip and a second head chip held on the first sidewall portion. The first head chip and the second head chip are both elongated strips in a first direction. The first head chip and the second head chip are arranged adjacently and offset in the first direction and in a second direction intersecting the first direction. The connector is positioned at the first direction of the first head chip and at the second direction of the second head chip, and is held on the sub-carrier.

15. The liquid injection device as claimed in claim 1, wherein, The first sidewall is made of stainless steel, titanium, or thermally conductive ceramic. The first component of the subcarriage comprises at least one of aluminum, copper, silver, and gold.

16. The liquid injection device as claimed in claim 1, wherein, The first component of the subcarriage is fastened relative to the carriage by a resin bushing and by metal screws.

17. A secondary carriage, which is a secondary carriage included in the liquid injection device according to claim 1, the secondary carriage holding a liquid injection head for injecting liquid and being held on the carriage of the liquid injection device, the secondary carriage comprising: A frame that, when viewed along the jetting direction of the liquid ejected from the liquid nozzle, surrounds the sidewall portion of the liquid nozzle and has thermal conductivity; The heating element is disposed on the outer peripheral surface of the frame.

18. A liquid injection device, comprising: The first liquid injection head sprays liquid; A secondary carriage having a first component and a heating element, the first component being thermally conductive and holding the first liquid injection head, the heating element being disposed on the first component; The carriage, which holds the sub-carriage. The first liquid injection head has a first sidewall portion opposite to the first component. The heating element is configured such that, when viewed along the jetting direction of the liquid ejected from the first liquid jet head, it sandwiches the first component between itself and the first sidewall portion. The carriage is made of metal. The first sidewall portion is thermally conductive and in thermal contact with the first component. The first component has a base portion for holding the first liquid injection head. The secondary carriage has an abutment portion that protrudes from the base portion toward the carriage and contacts the carriage. The thermal conductivity of the contact portion is lower than that of the first sidewall portion.

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