Liquid discharge head

Abstract

To release heat of an actuator member without putting a load on a joint part of a contact point, while preventing a wiring member from peeling off from the actuator member.SOLUTION: A head 10 comprises: a flow path member 12; an actuator member 13 arranged on an upper surface 12X of the flow path member 12; a COF 14 including a connection part 141 arranged on an upper surface 13X of the actuator member 13; and a pressing member 21 and a heat releasing member 22 arranged above the connection part 141. The connection part 141 includes a contact point region 14R overlapping in a vertical direction with a contact point region 13R of the actuator member 13, and an outer peripheral region 14S overlapping in the vertical direction with an outer peripheral region 13S of the actuator member 13. The pressing member 21 contacts the outer peripheral region 14S without contacting the contact point region 14R, so as to press the outer peripheral region 14S toward the actuator member 13. The heat releasing member 22 contacts the contact point region 14R without contacting the outer peripheral region 14S.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head that ejects liquid from a nozzle. [Background technology]

[0002] Patent Document 1 discloses a configuration in which a COF (wiring member) is disposed on the upper surface of an actuator (actuator member) and includes a connection portion connected to a contact (first contact) on the upper surface of the actuator, and a pressing member is disposed on the upper surface of the connection portion. The lower surface of the pressing member has an annular pressing portion along the edge of the pressing member and a recess inside the pressing portion. The pressing portion presses the outer periphery of the connection portion, while the recess faces the center of the connection portion with a gap therebetween. The center portion corresponds to the area where the contact of the actuator is disposed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-154473 Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, the pressing member prevents the wiring member from peeling off from the actuator member by the pressing force of the pressing portion, and the recess does not put a load on the joint of the contact point. However, heat from the actuator member is trapped in the recess, and this heat is transferred to the flow path member and further to the liquid in the flow path member, causing a change in the discharge performance of the liquid from the nozzle of the flow path member.

[0005] An object of the present invention is to provide a liquid ejection head that can prevent the wiring member from peeling off from the actuator member, and can release heat from the actuator member without applying a load to the joints of the contacts. [Means for solving the problem]

[0006] a first heat dissipation member disposed above the connection portion and in contact with the second outer periphery but not in contact with the second contact area, the first heat dissipation member having a hardness lower than that of the pressing member; and a second heat dissipation member disposed above the connection portion and in contact with the second outer periphery but not in contact with the second contact area. The first heat dissipation member is disposed above the connection portion and in contact with the second outer periphery but not in contact with the second outer periphery. The first heat dissipation member is disposed above the connection portion and in contact with the second contact area but not in contact with the second outer periphery. The first heat dissipation member has a hardness lower than that of the pressing member. [Effects of the Invention]

[0007] According to the present invention, the pressing member presses the second outer peripheral region of the connection portion toward the actuator member, thereby preventing the wiring member from peeling off from the actuator member. Also, the first heat dissipation member, which has low hardness, comes into contact with the second contact region of the connection portion, thereby allowing heat from the actuator member to be released without applying a load to the contact joint. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view of a printer 100 according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of a head 10 included in a printer 100. FIG. [Figure 3] FIG. 2 is a perspective view of the head 10. [Figure 4] FIG. 2 is a plan view of the head 10. [Figure 5] 5 is a cross-sectional view of the head 10 taken along line VV in FIG. 4. [Figure 6] FIG. 6 is an enlarged view of region VI shown in FIG. 5. [Figure 7] FIG. 2 is an exploded perspective view of a portion of the head 10. [Figure 8] 1 is a schematic diagram showing a connection between water-cooling pipes 24 and 25 provided in a head 10 and a water tank 29. FIG. [Figure 9] 1 is a graph showing temperature changes in an example of the present invention and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment> 1 includes a head 10, which is one embodiment of a "liquid ejection head" according to the present invention. In the following description, the up-down direction is defined based on the state in which the printer 100 is installed for use, the front-rear direction is defined with the downstream side in the transport direction of the paper 9 as the front, and the left-right direction is defined when viewed from the front of the printer 100.

[0010] The printer 100 includes a head 10, a carriage 20 that holds the head 10, a scanning mechanism 30 that moves the carriage 20 and the head 10 left and right, a platen 40 that supports the paper 9 from below, a transport mechanism 50 that transports the paper 9 forward, and a control device 90.

[0011] The scanning mechanism 30 includes a pair of guides 31 and 32 that support the carriage 20, and a belt 33 connected to the carriage 20. The guides 31 and 32 and the belt 33 extend in the left-right direction. When the carriage motor is driven under the control of the control device 90, the belt 33 runs, and the carriage 20 and head 10 move left-right along the guides 31 and 32.

[0012] The platen 40 is disposed below the carriage 20 and the head 10. The paper 9 is supported on the upper surface of the platen 40.

[0013] The transport mechanism 50 has a roller 51 arranged behind the head 10 and a roller 52 arranged in front of the head 10. The head 10, the carriage 20, and the platen 40 are arranged between the roller 51 and the roller 52 in the front-to-rear direction.

[0014] Each of rollers 51 and 52 is made up of a set of rotating members. The set of rotating members includes an upper rotating member arranged above the transport path of paper 9 and a lower rotating member arranged below the transport path of paper 9. The upper rotating member and the lower rotating member are arranged so that their peripheral surfaces are in contact with each other.

[0015] When the conveying motor is driven under the control of the control device 90, the rotating members of the rollers 51 and 52 rotate. As the rotating members of the rollers 51 and 52 rotate while nipping the paper 9, the paper 9 is conveyed forward.

[0016] As shown in FIG. 2, the head 10 includes a flow path member 12 and an actuator member 13.

[0017] A plurality of nozzles 123 open on the lower surface of the flow path member 12. A common flow path 121 communicating with an ink tank and individual flow paths 122 each for each nozzle 123 are formed inside the flow path member 12. The individual flow paths 122 are flow paths that run from the outlet of the common flow path 121 through the pressure chambers 12P to the nozzles 123. A plurality of pressure chambers 12P open on the upper surface 12X of the flow path member 12. The common flow path 121 and the individual flow paths 122 correspond to the "liquid flow paths" of the present invention.

[0018] The actuator member 13 is disposed on the upper surface 12X of the flow path member 12. The actuator member 13 includes a metallic vibration plate 131 disposed on the upper surface 12X of the flow path member 12 so as to cover the plurality of pressure chambers 12P, a piezoelectric layer 132 disposed on the upper surface of the vibration plate 131, and a plurality of individual electrodes 133 disposed on the upper surface of the piezoelectric layer 132 so as to face each of the plurality of pressure chambers 12P.

[0019] The diaphragm 131 and the individual electrodes 133 are electrically connected to the driver ICs 15A and 15B via the COF 14. The driver ICs 15A and 15B are electrically connected to the control device 90. The COF 14 corresponds to the "wiring member" of the present invention. The driver ICs 15A and 15B correspond to the "driving member" of the present invention.

[0020] On the upper surface 13X of the actuator member 13, there are arranged contacts that are arranged on the upper surface of the piezoelectric layer 132 and electrically connected to the vibration plate 131, and contacts 139 that are arranged on the upper surfaces of the individual electrodes 133. The COF 14 has contacts 149 that are electrically connected to the contacts arranged on the upper surface 13X, and signal lines that electrically connect the contacts 149 and the driver ICs 15A and 15B. The contacts 139 correspond to the "first contacts" of the present invention. The contacts 149 correspond to the "second contacts" of the present invention.

[0021] Under the control of the control device 90, the driver ICs 15A and 15B maintain the potential of the diaphragm 131 at ground potential while changing the potential of the individual electrode 133. As a result, the potential of the individual electrode 133 changes between a predetermined drive potential and ground potential. At this time, the actuator 130, which is the portion of the diaphragm 131 and the piezoelectric layer 132 sandwiched between each individual electrode 133 and each pressure chamber 12P, deforms, changing the volume of the pressure chamber 12P. Pressure is applied to the ink in the pressure chamber 12P, causing ink to be ejected from the nozzle 123.

[0022] As shown in FIG. 5, the COF 14 includes a connection portion 141 disposed on the upper surface 13X of the actuator member 13, and two folded portions 142 folded upward from each end of the connection portion 141 in the front-rear direction.

[0023] The connection portion 141 extends in the front-rear and left-right directions parallel to the top surface 13X. As shown in FIG. 5, the top surface 13X includes a contact region 13R in which a plurality of contacts 139 (see FIG. 2) are arranged, and an outer circumferential region 13S surrounding the contact region 13R. The connection portion 141 includes a contact region 14R that overlaps the contact region 13R in the up-down direction, and an outer circumferential region 14S that overlaps the outer circumferential region 13S in the up-down direction. A plurality of contacts 149 (see FIG. 2) are arranged in the contact region 14R. The contact regions 13R and 14R are rectangular, and the outer circumferential regions 13S and 14S are rectangular frame-shaped.

[0024] The contact region 13R corresponds to the "first contact region" of the present invention, and the outer peripheral region 13S corresponds to the "first outer peripheral region" of the present invention. The contact region 14R corresponds to the "second contact region" of the present invention, and the outer peripheral region 14S corresponds to the "second outer peripheral region" of the present invention. The up-down direction corresponds to the "orthogonal direction" of the present invention.

[0025] Each of the two folded portions 142 includes a vertical portion extending upward from the end of the connecting portion 141 and a horizontal portion extending forward or backward from the upper end of the vertical portion toward the center in the front-to-rear direction of the head 10. Of the two folded portions 142, the driver IC 15A is disposed on the upper surface of the horizontal portion of the front folded portion 142, and the driver IC 15B is disposed on the upper surface of the horizontal portion of the rear folded portion 142.

[0026] A frame 19 is disposed around the actuator member 13 on the upper surface 12X of the flow path member 12. The frame 19 is a rectangular frame-shaped member disposed along the periphery of the upper surface 12X. As shown in FIG. 3, four openings 191 are provided on each of the front and rear edges of the frame 19. Each opening 191 communicates with a common flow path 121 of the flow path member 12 and also communicates with an ink tank via a tube. For example, ink in an ink tank flows into the common flow path 121 via the tube and the four front openings 191, and returns to the ink tank via the four rear openings 191 and the tube.

[0027] 5, the actuator member 13 and the COF 14 are disposed within the frame 19. The pressing member 21, the heat dissipation members 22 and 23, the support member 16, and the circuit board 17 are disposed in the space surrounded by the connection portion 141 and the two folded portions 142 of the COF 14. The pressing member 21, the heat dissipation members 22 and 23, the support member 16, and the circuit board 17 are disposed above the connection portion 141. The heat dissipation member 22 corresponds to the "first heat dissipation member" of the present invention, and the heat dissipation member 23 corresponds to the "second heat dissipation member" of the present invention.

[0028] 3 and 4, the flow path member 12 and the frame 19 are rectangular in shape and are elongated in the front-to-rear direction in a plane perpendicular to the up-down direction. The actuator member 13, the pressing member 21, the heat dissipation members 22 and 23, and the support member 16 are also rectangular in shape and are elongated in the front-to-rear direction in a plane perpendicular to the up-down direction.

[0029] As shown in Fig. 7, the pressing member 21 is a plate member having a rectangular frame shape in a plane perpendicular to the up-down direction. As shown in Figs. 5 and 6, the pressing member 21 does not contact the contact area 14R but contacts the outer circumferential area 14S, and presses the outer circumferential area 14S downward toward the actuator member 13. The pressing member 21 may be made of resin, metal, or the like.

[0030] As shown in Fig. 7, the heat dissipation member 22 is a sheet member that is rectangular in a plane perpendicular to the up-down direction. As shown in Figs. 5 and 6, the heat dissipation member 22 is disposed within the frame of the pressing member 21, and is in contact with the contact area 14R but not with the outer circumferential region 14S. The heat dissipation member 22 is made of gel and has a lower hardness than the pressing member 21. The gel is a substance that is intermediate between a solid and a liquid.

[0031] As shown in Fig. 7, the heat dissipation member 23 is a rectangular member in a plane perpendicular to the up-down direction. As shown in Figs. 5 and 6, the heat dissipation member 23 is disposed above the heat dissipation member 22. The lower surface of the heat dissipation member 23 has a central region 23X and a recess 23Y provided in an outer peripheral region surrounding the central region 23X. The central region 23X overlaps the contact regions 13R, 14R in the up-down direction and is in contact with the heat dissipation member 22. The recess 23Y overlaps the outer peripheral regions 13S, 14S in the up-down direction. The pressing member 21 is disposed within the recess 23Y. The heat dissipation member 23 is made of a metal such as copper, graphite, or aluminum.

[0032] 5, two water-cooled pipes 24 are attached to the heat dissipation member 23. The water-cooled pipes 24 correspond to the "first water-cooled pipe" of the present invention.

[0033] 7, the water-cooled pipe 24 has two vertical sections 241 extending in the up-down direction and one horizontal section 242 connecting the two vertical sections 241. The horizontal section 242 extends horizontally and is placed in a groove provided on the upper surface of the heat dissipation member 23 via a heat transfer agent A. The water-cooled pipe 24 is made of a metal such as SUS, copper, or aluminum. The heat transfer agent A is made of, for example, grease and is placed between the water-cooled pipe 24 and the heat dissipation member 23.

[0034] 5, the horizontal portions 242 of the two water-cooling pipes 24 are spaced apart from each other in the front-rear direction and extend in the left-right direction. Three circuit boards 17 are arranged between the two horizontal portions 242 in the front-rear direction.

[0035] The circuit board 17 is disposed above the heat dissipation member 22 in a recess provided on the upper surface of the heat dissipation member 23, and is electrically connected to the COF 14. The two water-cooled pipes 24 overlap the circuit board 17 in the front-to-rear direction and are disposed at positions sandwiching the circuit board 17. The front-to-rear direction corresponds to the "first direction" of the present invention, and the left-to-right direction corresponds to the "second direction" of the present invention.

[0036] 5, the support member 16 is made up of three plates stacked in the vertical direction, and supports three circuit boards 17 on its bottom surface. The support member 16 is disposed between the heat dissipation member 23 and the driver ICs 15A and 15B in the vertical direction.

[0037] A heat dissipation member 18 is disposed above the driver ICs 15A and 15B. The heat dissipation member 18 is in contact with the top surfaces of the two driver ICs 15A and 15B. The heat dissipation member 18 is made of a material with high thermal conductivity, such as metal, and has the function of dissipating heat from the driver ICs 15A and 15B. The heat dissipation member 18 corresponds to the "third heat dissipation member" of the present invention.

[0038] 5, a water-cooled pipe 25 is attached to the heat dissipation member 18. The water-cooled pipe 25 corresponds to the "second water-cooled pipe" of the present invention.

[0039] As shown in Figure 8, the head 10 is equipped with a water tank 29 that communicates with both the water-cooling pipes 24, 25, and a cooler 28. The water tank 29 corresponds to the "water source" of the present invention. The water tank 29 stores water that has been cooled by the cooler 28. The cooling water in the water tank 29 is sent to the water-cooling pipes 24, 25, respectively. The water that has passed through the water-cooling pipes 24, 25 is sent to the cooler 28, where it is cooled, and then stored in the water tank 29.

[0040] FIG. 9 shows the temperature change of the head 10 accompanying the drive of the actuator member 13 in an example of the present invention and a comparative example. In FIG. 9, the solid line shows the analysis results for the example, the dashed line shows the first comparative example, and the dashed line shows the second comparative example. The example is a model similar to this embodiment. The first comparative example is a model in which the pressing member 21 and heat dissipation members 22 and 23 are omitted from this embodiment. The second comparative example is a model in which the pressing member 21 and heat dissipation members 18, 22, and 23 are omitted from this embodiment. It can be seen from FIG. 9 that the example of the present invention is more effective in suppressing the temperature rise of the head 10 than the comparative example.

[0041] As described above, according to this embodiment, as shown in Fig. 5, the pressing member 21 presses the outer peripheral region 14S of the connection portion 141 toward the actuator member 13, thereby preventing the COF 14 from peeling off from the actuator member 13. Furthermore, the heat dissipation member 22, which has low hardness, comes into contact with the contact region 14R of the connection portion 141, thereby allowing heat from the actuator member 13 to be released without applying a load to the joints of the contacts 139, 149 (see Fig. 2).

[0042] The heat dissipation member 22 is made of gel. In this case, the hardness of the heat dissipation member 22 is low, so that the effect of not applying a load to the joints of the contacts 139, 149 (see FIG. 2) can be more reliably achieved.

[0043] A heat dissipation member 23 made of metal is in contact with the heat dissipation member 22 (see FIG. 5). In this case, the heat of the heat dissipation member 22 can be dissipated via the heat dissipation member 23, so that the heat of the actuator member 13 can be dissipated more efficiently.

[0044] The heat dissipation member 23 may be made of copper. Copper has high thermal conductivity and therefore excellent heat dissipation properties, and is easy to process and inexpensive. Furthermore, if the water-cooled pipe 24 is made of stainless steel, copper is compatible with stainless steel and is therefore less susceptible to corrosion or electrolytic corrosion.

[0045] The heat dissipation member 23 may be made of graphite. Graphite has high thermal conductivity and therefore excellent heat dissipation properties, and is easy to process and inexpensive to make.

[0046] A water-cooled pipe 24 is attached to the heat dissipation member 23 (see FIG. 5). In this case, the heat dissipation member 23 is cooled via the water-cooled pipe 24, so that the heat of the heat dissipation member 22, and therefore the heat of the actuator member 13, can be more efficiently dissipated.

[0047] The two water-cooling pipes 24 are arranged so as to overlap the circuit board 17 in the front-rear direction and sandwich the circuit board 17 (see FIG. 5). In this case, the two water-cooling pipes 24 are arranged so as to avoid the circuit board 17, thereby enabling the heat dissipation member 23 to be uniformly heated.

[0048] A heat transfer agent A is disposed between the water-cooled pipe 24 and the heat dissipation member 23 (see FIG. 5). In this case, heat is efficiently transferred from the heat dissipation member 23 to the water-cooled pipe 24, and the heat of the heat dissipation member 22, and therefore the heat of the actuator member 13, can be more efficiently dissipated.

[0049] A water tank 29 is connected to both the water-cooled pipe 24 attached to the heat dissipation member 23 and the water-cooled pipe 25 attached to the heat dissipation member 18 (see FIG. 8). In this case, the water source for the water-cooled pipes 24 and 25 is common, which simplifies the configuration.

[0050] <Modification> Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design modifications are possible within the scope of the claims.

[0051] The flow path member is not limited to a serial type, but may be a line type.

[0052] The object onto which the liquid is ejected from the nozzles is not limited to paper, but may be, for example, cloth, a substrate, a plastic member, or the like.

[0053] The liquid ejected from the nozzles is not limited to ink, but may be any liquid (for example, a treatment liquid that aggregates or precipitates components in the ink, etc.).

[0054] The present invention is not limited to printers, but can also be applied to facsimiles, copiers, multifunction machines, etc. The present invention can also be applied to liquid ejection devices used for purposes other than image recording (for example, liquid ejection devices that eject conductive liquid onto a substrate to form a conductive pattern). [Explanation of symbols]

[0055] 10 heads (liquid ejection heads) 12 Flow path member 121 common flow path (liquid flow path) 122 Individual flow path (liquid flow path) 123 nozzle 12X top 13 Actuator member 139 contact (first contact) 13R Contact area (1st contact area) 13S Outer area (1st outer area) 13X top 14 COF (wiring materials) 141 Connection part 149 contacts (second contacts) 14R Contact area (second contact area) 14S Outer area (2nd outer area) 15A, 15B Driver IC (driving member) 17 Circuit Board 18 heat dissipation member (third heat dissipation member) 21 Pressing member 22 heat dissipation member (first heat dissipation member) 23 heat dissipation member (second heat dissipation member) 24 Water cooling pipe (1st water cooling pipe) 25 Water cooling pipe (second water cooling pipe) 29 Water tank (water source) A heat transfer agent

Claims

1. a flow path member having a liquid flow path including a nozzle; an actuator member for ejecting liquid from the nozzle, the actuator member being disposed on an upper surface of the flow path member and having an upper surface including a first contact area in which a first contact is disposed and a first outer circumferential area surrounding the first contact area; a wiring member including a connection portion arranged on the upper surface of the actuator member, the connection portion overlapping the first contact area in an orthogonal direction perpendicular to the upper surface of the actuator member, the wiring member having a second contact area in which a second contact connected to the first contact is arranged, and a second outer periphery area overlapping the first outer periphery area in the orthogonal direction; a pressing member disposed above the connection portion, not in contact with the second contact area but in contact with the second outer circumferential area, and pressing the second outer circumferential area toward the actuator member; a first heat dissipation member disposed above the connection portion, not in contact with the second outer peripheral region but in contact with the second contact region, the first heat dissipation member having a hardness lower than that of the pressing member; A liquid ejection head comprising:

2. 2. The liquid ejection head according to claim 1, wherein the first heat dissipation member is made of gel.

3. 2. The liquid ejection head according to claim 1, further comprising a second heat dissipation member made of metal, disposed above the first heat dissipation member and in contact with the first heat dissipation member.

4. 4. The liquid ejection head according to claim 3, wherein the metal is copper.

5. 4. The liquid ejection head according to claim 3, wherein the metal is graphite.

6. 4. The liquid ejection head according to claim 3, further comprising a first water cooling pipe attached to the second heat dissipation member.

7. a circuit board disposed above the first heat dissipation member and electrically connected to the wiring member; 7. A liquid ejection head as described in claim 6, characterized in that the two first water cooling pipes are arranged in a position overlapping the circuit board in a first direction parallel to the upper surface of the actuator member and sandwiching the circuit board, and each extend in a second direction parallel to the upper surface of the actuator member and intersecting the first direction.

8. 7. The liquid ejection head according to claim 6, wherein a heat transfer agent is disposed between the first water cooling pipe and the second heat dissipation member.

9. a driving member disposed in a portion of the wiring member other than the connection portion; a third heat dissipation member in contact with the driving member; a second water-cooled pipe attached to the third heat dissipation member; 7. The liquid ejection head according to claim 6, further comprising: a water source communicating with both the first water cooling pipe and the second water cooling pipe.

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