JP5088509B2 - Liquid discharge head - Google Patents

Description

  The present invention relates to an actuator and a liquid discharge head provided with a drive circuit unit that supplies a drive signal to the actuator.

  In a head having an actuator for ejecting liquid from an ejection port and a drive circuit unit for driving the actuator, there is one that performs heat dissipation from a circuit as disclosed in Patent Document 1. In Patent Document 1, heat generated from a plurality of driver ICs is released from a heat pipe to a heat receiving block. The heat receiving block is in contact with the ink supply path and the ink return path, and heat generated from the driver IC is transmitted to the ink in the ink flow path through the heat receiving block.

Japanese Patent Laying-Open No. 2007-1035 (FIGS. 13 and 14)

  The ejection characteristics of the liquid (ink) ejected from the head vary depending on the temperature. Therefore, it is conceivable to heat the head using heat generated from the drive circuit unit in order to make the ink suitable for ejection. In this regard, according to the above literature, heat is transferred from a plurality of driver ICs to the ink in the ink flow path through the heat receiving block.

  However, according to the above document, the ink flow path is formed inside the tube-shaped ink flow path extending linearly along one direction. On the other hand, for example, when the liquid flow paths are distributed along the plane inside the flow path body, it is difficult to uniformly transfer the heat from the driver IC to the liquid in the liquid flow path.

  An object of the present invention is to provide a liquid discharge head in which heat generated from a drive circuit unit is easily transmitted to a liquid flow path evenly.

The liquid discharge head according to the present invention includes a discharge port that discharges a liquid, a flow channel body in which a liquid flow channel that supplies liquid to the discharge port is formed, and discharge energy that discharges liquid from the discharge port An actuator applied to the liquid in the flow path, a plurality of drive circuit units for supplying a drive signal to the actuator, and a contact member that is thermally coupled to the plurality of drive circuit units and contacts the flow path body with which, before Symbol liquid flow path includes a distribution area distributed along a plane within said channel member, said abutment member, said one plane in which the flow path of the liquid is not formed And the one or a plurality of projecting portions projecting from the flat plate toward the channel body. part is viewed from a direction perpendicular to said one plane It is distributed in a range overlapping with the distribution region.

  According to the liquid ejection head of the present invention, the abutting portion of the abutting member with the flow path body is distributed along the surface in a range overlapping the liquid flow path. For this reason, it is easy to transmit the heat from the plurality of drive circuit units evenly to the liquid flow paths distributed along the surface via the contact member.

In addition, since the projecting portion comes into contact with the flow path body, heat is easily transferred selectively to a desired position of the flow path body.

  Further, in the present invention, the formation region of the one or more protrusions is distributed in a range overlapping with the distribution region as viewed from a direction orthogonal to the one plane, and does not overlap with the liquid channel. It is preferable that it is not arranged at the position. According to this, since the protrusion is not disposed at a position that does not overlap with the liquid flow path, heat can be appropriately transferred to the range where the liquid flow path is formed in the flow path body.

In the present invention, a plurality of the protrusions having the same shape and size are provided, and the plurality of protrusions per unit area when the channel body is viewed from a direction orthogonal to the one plane. It is preferable that the larger the volume of the liquid channel existing in the unit, the larger the number of the projecting portions in contact with the channel body per unit area. According to this, since the protrusion part is formed so that the position where the liquid flow path is large, the protrusion part is appropriately arranged at a position where a lot of heat should be transmitted. In the present invention, it is preferable that the protruding portion has a size and a shape that overlap with the liquid flow channel when the flow channel body is viewed from a direction orthogonal to the one plane. According to this, since the protruding portion has a size and shape overlapping with the liquid channel, heat from the drive circuit unit can be appropriately transmitted to the liquid channel.

  In the present invention, it is preferable that the contact member has a protruding plate protruding from the flat plate in a direction intersecting the one plane, and the drive circuit unit is in contact with the protruding plate. According to this, the drive circuit unit can be arranged at a position separated from the contact portion with the flow path body in the contact member.

In the present invention, it is preferable that a plurality of the protruding plates corresponding to the plurality of driving circuit units are provided. According to this, since the protruding plate is provided for each drive circuit unit, the heat from the drive circuit unit can be led to the contact portion with the flow path body in the contact member without wasting heat. . In the present invention, it is preferable that the plurality of protruding plates are arranged in a staggered pattern at equal intervals along the longitudinal direction at both ends in the short direction of the contact member. According to this, the heat from a plurality of drive circuit units can be uniformly transmitted to the flow path body via the protruding plate.

Further, in the present invention, a notch is formed in an end portion of the flat plate, and a portion adjacent to the notch in the end portion of the flat plate is bent in a direction intersecting the one plane, and It is preferable that it is a protruding plate. According to this, the contact member can be easily formed. In the present invention, it is preferable that the protruding plate is formed between two adjacent cutouts. According to this, the heat of the drive circuit unit can be appropriately transmitted in a desired direction without diffusing.

Further, in the present invention, the flow path body is constituted by a stacked body in which a plurality of flat plate members extending along the one plane are stacked, and the liquid flow path is formed of the plurality of flat plate members. It may be formed along at least one of the planes. In the present invention, the flat plate of the contact member is sandwiched between the flow passage body that is a laminate of the plurality of flat plate members made of metal and the resin flow passage body that communicates with the flow passage body. It may be.

  Moreover, in this invention, it is preferable that the said contact member is comprised from the material whose heat conductivity is larger than the material used for the said flow path body. According to this, it is easy to transfer the heat from the drive circuit unit to the flow path body.

  According to the liquid ejection head of the present invention, the abutting portion of the abutting member with the flow path body is distributed along the surface in a range overlapping the liquid flow path. For this reason, it is easy to transmit the heat from the plurality of drive circuit units evenly to the liquid flow paths distributed along the surface via the contact member.

1 is a longitudinal sectional view showing an internal configuration of an ink jet printer including an ink jet head according to an embodiment of the present invention. It is a disassembled perspective view of the inkjet head of FIG. It is a longitudinal cross-sectional view along the surface orthogonal to the main scanning direction of the inkjet head of FIG. FIG. 2 is a schematic diagram of an ink circulation mechanism including a longitudinal section along a plane orthogonal to the sub-scanning direction of the inkjet head of FIG. 1. FIG. 5A is a bottom view of a soaking plate included in the inkjet head of FIG. FIG. 5B is a front view of the soaking plate. FIG. 5C is a plan view in which the uppermost metal plate is removed from the laminate included in the inkjet head. FIG. 3 is a plan view of the head body of FIG. 2. FIG. 7 is an enlarged view of a portion straddling two adjacent actuator units 21 in FIG. 6. It is sectional drawing of the flow-path unit along the VIII-VIII line shown in FIG. FIG. 9A is an enlarged cross-sectional view of a region indicated by a one-dot chain line in FIG. FIG. 9B is a plan view of the individual electrode. FIG. 2 is a block diagram illustrating a control system of the ink jet printer of FIG. 1. It is a top view which shows the modification of a laminated body. It is a perspective view which shows the modification of a heat equalizing plate.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing an internal configuration of an ink jet printer including an ink jet head according to an embodiment of the present invention. As shown in FIG. 1, the ink jet printer 101 has a rectangular parallelepiped casing 101a. In the casing 101a, four inkjet heads 1 (hereinafter referred to as heads 1) that discharge magenta, cyan, yellow, and black ink, respectively, and a transport mechanism 16 are arranged. A control unit 100 that controls the operation of the head 1, the transport mechanism 16, and the like is attached to the inner surface of the top plate of the housing 101 a. Below the transport mechanism 16, a paper feed unit 101b that can be attached to and detached from the housing 101a is disposed. An ink tank unit 101c that can be attached to and detached from the housing 101a is disposed below the paper supply unit 101b.

  A paper transport path is formed along the thick arrow shown in FIG. 1 inside the ink jet printer 101, and the paper P is transported from the paper supply unit 101 b toward the paper discharge unit 15. The paper feed unit 101 b includes a paper feed tray 11 and a paper feed roller 12. The paper feed tray 11 has a box shape opened upward, and stores a plurality of paper sheets P in a stacked state. The paper feed roller 12 sends out the paper P at the uppermost position of the paper feed tray 11. The fed paper P is guided to the transport mechanism 16 while being guided by the guides 13 a and 13 b and sandwiched by the feed roller pair 14.

  The transport mechanism 16 includes two belt rollers 6 and 7, a transport belt 8, a tension roller 10, and a platen 18. The conveyor belt 8 is an endless belt wound around the rollers 6 and 7. The tension roller 10 is biased downward in contact with the inner peripheral surface of the lower loop of the conveyor belt 8 and applies tension to the conveyor belt 8. The platen 18 is disposed in a region surrounded by the conveyor belt 8 and supports the conveyor belt 8 at a position facing the head 1 so that the conveyor belt 8 does not bend downward. The belt roller 7 is a driving roller, and rotates in the clockwise direction in FIG. 1 when a driving force is applied to the shaft thereof from the conveying motor 19. The belt roller 6 is a driven roller, and rotates in the clockwise direction in FIG. 1 when the conveyor belt 8 travels as the belt roller 7 rotates. The driving force of the transport motor 19 is transmitted to the belt roller 7 via a plurality of gears.

  The outer peripheral surface 8a of the conveyance belt 8 has adhesiveness by being subjected to silicone treatment (formation of a silicone resin layer). A nip roller 4 is disposed at a position facing the belt roller 6. The nip roller 4 presses the paper P sent out from the paper supply unit 101 b against the outer peripheral surface 8 a of the transport belt 8. The paper P pressed against the outer peripheral surface 8a is transported in the paper transport direction (rightward in FIG. 1 and in the sub-scanning direction) while being held on the outer peripheral surface 8a by the adhesive force.

  A peeling plate 5 is provided at a position facing the belt roller 7. The peeling plate 5 peels the paper P from the outer peripheral surface 8a. The peeled paper P is guided by the guides 29a and 29b and conveyed while being sandwiched between the two pairs of feed rollers 28. Then, the paper P is discharged from a discharge port 22 formed in the upper part of the housing 101a to a paper discharge recess (paper discharge unit) 15 provided on the upper surface of the housing 101a (top plate).

  The four heads 1 eject inks of different colors (magenta, yellow, cyan, black). These four heads 1 have a substantially rectangular parallelepiped shape elongated in the main scanning direction. Further, the four heads 1 are fixed side by side along the conveyance direction A of the paper P. That is, the printer 101 is a line type printer, and the conveyance direction A and the main scanning direction are orthogonal to each other.

  The bottom surface of the head 1 is an ejection surface 2a on which a plurality of ejection ports 108 (see FIG. 5) for ejecting ink are formed. When the conveyed paper P passes just below the four heads 1, the inks of the respective colors are sequentially ejected from the ejection ports 108 toward the upper surface of the paper P. Thereby, a desired color image is formed on the upper surface of the paper P, that is, the printing surface.

  Each head 1 is connected to an ink tank 17 in the ink tank unit 101c. The four ink tanks 17 store different colors of ink. Ink is supplied from each ink tank 17 to the head 1 via a tube (see FIG. 4).

  FIG. 2 is an exploded perspective view of the head 1, and FIG. 3 is a longitudinal sectional view along a plane orthogonal to the main scanning direction of the head 1. FIG. 4 is a schematic diagram of the ink circulation mechanism including a vertical cross section along a plane orthogonal to the sub-scanning direction of the head 1. In addition, illustration of the board | substrate 80 is abbreviate | omitted in FIG.

  As shown in FIGS. 2 to 4, the head 1 includes a head body 33 in which a plurality of ejection ports 108 (see FIG. 6) for ejecting ink are formed, and a reservoir unit 30 that supplies ink to the head body 33. Have. The reservoir unit 30 is stacked on the head body 33, and an ink supply port 51 and an ink discharge port 52 are formed on the upper surface of the reservoir unit 30. In the present embodiment, the reservoir unit 30 and the head main body 33 constitute the flow path body of the present invention.

  In this embodiment, an ink circulation mechanism that supplies ink to the head 1 and circulates ink inside and outside the head 1 is connected. The ink circulation mechanism is for discharging air mixed in the ink flow path by circulating ink inside and outside the head 1.

  The ink circulation mechanism includes a pump 25 that sucks ink from the ink tank 17 and supplies the ink to the head 1, and a sub tank 26 that separates air from the ink. Further, the ink circulation mechanism connects the ink tube 27 a that connects the pump 25 and the ink supply port 51, the ink tube 27 b that connects the ink discharge port 52 and the inlet of the sub tank 26, and the outlet of the sub tank 26 and the pump 25. Ink tube 27c is included. An opening / closing valve 24a is inserted in the ink tube 27c, and circulation can be started and stopped. Further, an exhaust tube 27d having an open / close valve 24b inserted therein is connected to the upper portion of the sub tank 26 so that the air in the sub tank 26 can be released to the atmosphere. An open / close valve 24 c is also interposed between the ink tank 17 and the pump 25. The pump 25 and the on-off valves 24 a to 24 c are controlled by the control unit 100.

  The reservoir unit 30 includes a filter unit 41 that is integrally molded with resin, and a stacked body 40 in which a plurality of metal plates 42 to 45 are stacked. The filter unit 41 and the laminated body 40 are opposed to each other with gaps 1a and 1b formed along the main scanning direction. In the filter unit 41, ink flow paths 61 to 67 are formed, and in the stacked body 40, ink flow paths including through holes 42a and 43a are formed.

  A connection portion 41a is formed below the filter unit 41 with the stacked body 40 protruding toward the stacked body 40, and the ink flow path on the filter unit 41 side and the ink on the stacked body 40 side are connected via the connecting portion 41a. The flow paths are connected to each other. In the present embodiment, the connection portion 41 a is provided at a substantially central portion with respect to the main scanning direction of the filter unit 41. The gap 1a and the gap 1b are arranged on both sides in the main scanning direction with the connecting portion 41a interposed therebetween, and have substantially the same length. The connecting portion 41a is joined to the upper surface of the stacked body 40 while penetrating through a through-hole 70a described later formed in the vicinity of the center portion of the soaking plate 70 in the up-down direction.

  In the filter unit 41, as shown in FIG. 4, an ink flow path 61 communicating with the ink supply port 51 at the upper end is formed. When ink is supplied from the ink tube 27 a, the ink flows into the ink flow path 61 through the ink supply port 51. The ink flow path 61 extends substantially vertically downward at the left end of the filter unit 41 in FIG. The lower end of the ink flow path 61 communicates with the left end of the ink flow path 62 in FIG. The ink flow path 62 extends from the communication position with the ink flow path 61 to the vicinity of the connection portion 41a along the gap 1a. The ink flow path 62 is opened in the lower surface of the filter unit 41, and the opening is sealed with a damper film 54 which is a resin thin film. The damper film 54 absorbs and attenuates ink vibration by being displaced according to ink vibration.

  The ink flow path 63 is disposed above the ink flow path 62 so as to face the ink flow path 62. Between the ink flow paths 62 and 63, a filter 53 having a plurality of minute through holes for filtering ink is provided. A region of the ink flow paths 62 and 63 that includes the filter 53 and faces the filter 53 in the vertical direction forms a filter chamber. When the ink in the ink flow path 62 passes through the filter 53 and flows into the ink flow path 63, the foreign matter is removed from the ink.

  The ink flow path 63 extends along the main scanning direction and opens on the upper surface of the filter unit 41. The opening of the ink flow path 63 is sealed with a damper film 56 which is a resin thin film. The damper film 56 functions in the same manner as the damper film 54 with respect to ink vibration. The ink flow path 63 communicates with the upper end of the ink flow path 64 in the vicinity of the center of the filter unit 41. The ink flow path 64 extends substantially vertically downward from the communication position with the ink flow path 63, and communicates with the ink flow path on the stacked body 40 side through the connection portion 41a.

  The ink flow path 65 is formed in the connecting portion 41 a as a flow path different from the ink flow path 64, and communicates with the ink flow path on the stacked body 40 side at a position different from the ink flow path 64. The ink flow path 65 extends upward in the connection portion 41a, and communicates with the ink flow path 66 in the vicinity of the base portion of the connection portion 41a. The ink flow path 66 extends to the lower side of the ink discharge port 52 along the main scanning direction. The ink flow path 66 is opened on the lower surface of the filter unit 41, and the opening is sealed with a damper film 55 which is a resin thin film. The damper film 55 functions in the same manner as the damper film 54 with respect to ink vibration. The ink channel 66 communicates with the ink channel 67 below the ink discharge port 52. The ink flow path 67 extends substantially vertically upward from the ink flow path 66 to the ink discharge port 52, and communicates with the ink discharge port 52.

  Next, the configuration of the stacked body 40 will be described. The laminated body 40 is obtained by laminating metal plates 42 to 45 each having holes and recesses formed therein so that the holes and the recesses communicate with each other to form an ink flow path. Each metal plate is a flat plate member extending horizontally and has a horizontal surface.

  The metal plate 42 is formed with a through hole 42 a communicating with the ink flow path 64 on the filter unit 41 side and a through hole 42 b communicating with the ink flow path 65. The through holes 42a and 42b penetrate the plate 42 in the stacking direction of the stacked body at a position overlapping the ink flow paths 64 and 65 in plan view.

  Through holes 43 a and 43 b are formed in the plate 43. As shown in FIG. 5C, which is a plan view of the laminate 40 with the plate 42 removed, the through-hole 43a has a rectangular planar shape that is roughly long in the main scanning direction, and the right end portion 43c. However, it is tapered toward the vicinity of the center of the plate 43. The through hole 43a communicates with the through hole 42a in the vicinity of the tip of the right end portion 43c. The through-hole 43b also has a rectangular planar shape that is long in the main scanning direction, and the left end 43d is tapered toward the center of the plate 43. The through hole 43b communicates with the through hole 42b near the tip of the left end portion 43d.

  The plate 44 is formed with a recess 44a that opens on the lower surface thereof. The recess 44a has a rectangular planar shape that is long in the main scanning direction, and includes a region in which the through holes 43a and 43b are formed in plan view, as indicated by a broken line in FIG. It is out. As shown in FIGS. 4 and 5C, a through hole 44b is formed at the left end of the recess 44a. The through hole 44b communicates with the left end of the through hole 43a. A through hole 44c is formed at the right end of the recess 44a. The through hole 44c communicates with the right end of the through hole 43b. The opening of the concave portion 44a is blocked by the plate 45, thereby forming an ink flow path that allows the through hole 44b and the through hole 44c to communicate with each other.

  The plate 45 is formed with a plurality of through holes 45a communicating with the recesses 44a. The through holes 45a are arranged at an interval from each other in the main scanning direction. The through hole 45a communicates with an ink flow path in the head main body 33 described later. Further, a gap 45b extending from one end in the sub-scanning direction to the vicinity of the other end is formed between the plate 45 and the head body 33 (see FIG. 3). On the upper surface of the head main body 33, an actuator unit 21 described later is attached to a region facing the gap 45b. The actuator unit 21 is stacked on the head main body 33 by the gap 45b, and the reservoir unit 30 is stacked with the actuator unit 21 interposed therebetween.

  As described above, the plates 42 to 45 of the laminated body 40 are formed with a plurality of through holes and recesses, and these communicate with each other, whereby the through holes 43a, 44b, the recesses 44a, the through holes 44c, An ink flow path is formed through 43b to the through hole 42b. In the reservoir unit 30 as a whole, the ink flow path on the laminated body 40 side and the ink flow path on the filter unit 41 side communicate with each other, so that the ink flow paths 61 to 64 and the ink on the laminated body 40 side from the ink supply port 51. A supply / discharge channel that reaches the ink discharge port 52 via the channels and the ink channels 65 to 67 is formed. Further, a plurality of branch channels consisting of through holes 45 a branch from the supply / discharge channel, and these branch channels are directed toward the head body 33.

  Next, the operation of the ink circulation mechanism will be described. When ink is first introduced into the head 1, the supply / discharge passage is filled with ink by driving the pump 25 with the open / close valve 24 a closed and the open / close valves 24 b, 24 c open. Let Thereafter, the on-off valve 24a is opened, the on-off valve 24b is closed, and the pump 25 is driven strongly by the control unit 100, whereby ink flows into the head body 33 through the through hole 45a. Make it. As a result, the inside of the head 1 is filled with ink from the ink tank 17.

  When supplying ink to the head 1 while circulating the ink, the control unit 100 opens the on-off valve 24a, opens the on-off valve 24b, and opens the on-off valve 24c. Then, the pump 25 is driven. As a result, the ink from the ink tank 17 is supplied to the head 1 through the ink tube 27 a and the ink supply port 51. At the same time, the ink from the head 1 flows into the sub tank 26 through the ink discharge port 52 and the ink tube 27b. In the sub tank 26, air separates from the ink and moves upward, and is released to the atmosphere via the exhaust tube 27d.

  In the meantime, in the head 1, as shown by the one-dot chain line in FIG. 4, the ink flowing from the ink supply port 51 passes through the supply / discharge passage formed in the filter unit 41 and the laminated body 40 to the ink discharge port 52. It flows toward. When this state is maintained for a predetermined period, the supply / discharge flow path in the reservoir unit 30 is filled with new ink from the ink tank 17. At this time, it is preferable to drive the pump 25 to such an extent that ink does not flow into the head body 33 through the through hole 45a. Thereby, destruction of the meniscus formed at the ejection port 108 on the head main body 33 side is suppressed.

  When forming the ink circulation flow, the control unit 100 drives the pump 25 with the on-off valve 24a opened, the on-off valve 24b closed, and the on-off valve 24c closed. . As a result, the ink from the sub tank 26 is supplied to the head 1 through the ink tube 27 a and the ink supply port 51. Then, the ink that has flowed into the head 1 flows into the sub tank 26 through the ink discharge port 52 and the ink tube 27b through the supply / discharge flow path in the reservoir unit 30. The ink in the sub tank 26 flows again into the head 1 through the ink tube 27c, the pump 25, and the ink tube 27a.

  By the way, in order to appropriately eject the ink from the head 1, it is preferable to maintain the temperature of the ink within an appropriate range. In the present embodiment, a heating mechanism for bringing the ink in the head 1 to an appropriate temperature is provided. Hereinafter, the ink heating mechanism will be described.

  Between the filter unit 41 and the laminated body 40, as shown in FIG.2 and FIG.3, the metal heat equalizing plate 70 (contact member) is installed horizontally. The soaking plate 70 is not formed with an ink flow path, and is a member different from the filter unit 41 and the laminate 40. The material of the soaking plate 70 is made of a material having a higher thermal conductivity than that of the material constituting the laminate 40, for example, aluminum. As shown in FIGS. 2 and 5A, the heat equalizing plate 70 has a substantially rectangular shape substantially the same size as the metal plate 42 in a plan view. Near the center of the heat equalizing plate 70, a through hole 70a into which the connecting portion 41a is inserted is formed. As shown in FIG. 4, the substantially left half of the heat equalizing plate 70 is disposed in the gap 1a, and the substantially right half of the heat equalizing plate 70 is disposed in the gap 1b.

  Eight protruding plates 71 protruding upward are fixed to both ends of the heat equalizing plate 70 in the sub-scanning direction. Of these, the four protruding plates 71 are arranged at equal intervals along the main scanning direction at one end of the soaking plate 70, and the remaining four plates are along the main scanning direction at the other end of the soaking plate 70. They are arranged at equal intervals. Further, as shown in FIG. 5B, the eight protruding plates 71 are arranged in a staggered manner at regular intervals along the main scanning direction without overlapping each other in a front view. Each protruding plate 71 has a structure in which a notch 70b is formed at an end portion of a flat plate member that becomes the heat equalizing plate 70, and a portion sandwiched between the two notches 70b is bent upward. The region sandwiched between the notches 70b is connected to the region where the protrusion 72 is formed. The protruding plate 71 has a surface along a plane orthogonal to the sub-scanning direction.

  A plurality of projecting portions 72 projecting downward are formed on the lower surface of the heat equalizing plate 70. The lower surface of the projecting portion 72 extends horizontally, and both are in close contact with the upper surface of the stacked body 40. In addition, the protrusion part 72 may be joined to the laminated body 40 via the adhesive which has thermal conductivity, and may be contact | abutted directly to the laminated body 40 not via an adhesive agent. About half of these protrusions 72 are distributed in the left half of the heat equalizing plate 70 in FIG. 5A, and the remaining half are distributed in the right half.

  The protrusions 72 are distributed according to the ink flow path formation region such as the through holes 43a and 43b disposed below the heat equalizing plate 70. For example, the number of protrusions 72 is changed according to the volume of the ink flow path formed in the stacked body 40 per unit area in plan view. As shown in FIG. 5C, the protrusion 72 distributed in the left half of the heat equalizing plate 70 overlaps the formation region of the through hole 43a in plan view. These protrusions 72 are arranged in a matrix so that the number per unit area is substantially equal in the left region R1. On the other hand, in the region R2 including the right end portion 43c of the through hole 43a, the number per unit area is arranged so as to approach the right end portion 43c.

  Moreover, the protrusion part 72 distributed in the right half of the soaking plate 70 has overlapped with the formation area of the through-hole 43b. These protrusions 72 are arranged in a matrix so that the number per unit area is substantially uniform in the right region R4. On the other hand, in the region R3 including the left end portion 43d of the through hole 43b, the number per unit area decreases as the distance from the left end portion 43d approaches.

  In the present embodiment, the protrusion 72 is not disposed in a region where the ink flow path such as the through holes 43a and 43b is not formed in a plan view.

  As shown in FIG. 3, a driver IC 73 (drive circuit unit) is fixed to the outer surface of each protruding plate 71 in the sub-scanning direction. That is, the head 1 is provided with eight driver ICs 73 as many as the protruding plates 71. The driver IC 73 has a drive circuit that supplies a drive signal to an actuator unit 21 described later. The driver IC 73 has a substantially rectangular parallelepiped shape, and one surface along a plane is joined to the protruding plate 71 via a heat conductive adhesive. The driver IC 73 may be fixed to the protruding plate 71 through another member such as an elastic member having thermal conductivity.

  The driver IC 73 is mounted on a COF (Chip On Film) 48 that is a flat flexible substrate. The COF 48 is connected to a connecting portion provided on the opposite side of the protruding plate 71 in the driver IC 73. One end of the COF 48 is drawn upward from the driver IC 73 along the side surfaces of the protruding plate 71 and the filter unit 41, and is connected to a connector 81 installed on the substrate 80. The other end of the COF 48 is drawn downward along the side surfaces of the protruding plate 71 and the laminated body 40 from the driver IC 73 and drawn into a gap 45b formed between the metal plate 45 and the head body 33. The actuator unit 21 is connected. A signal line is provided in the COF 48, and a signal is transmitted from the substrate 80 to the driver IC 73 and from the driver IC 73 to the actuator unit 21 through the signal line.

  With the above configuration, when heat is generated from the electronic circuit or the like of the driver IC 73, the heat is transmitted to the protruding plate 71, and the laminated body 40 in contact with the protruding portion 72 through the horizontal portion of the heat equalizing plate 70. Communicated. Therefore, the heat in the driver IC 73 can be used to heat the ink in the stacked body 40.

  In this embodiment, all the driver ICs 73 are fixed to a soaking plate 70 that is an integral metal member, and a plurality of projecting portions 72 are distributed along the lower surface of the soaking plate 70 so as to contact the laminated body 40. Yes. For this reason, even if there is unevenness in heat generation for each driver IC 73, heat is transmitted evenly in the process of reaching the protrusions 72 through the heat transmitted through the heat equalizing plate 70. Heat is uniformly transmitted to the laminate 40 without unevenness.

  Moreover, since the protrusion part 72 which protruded below contact | abuts on the upper surface of the laminated body 40, it is easy to selectively transfer heat to the desired position on the upper surface of the laminated body 40. In the present embodiment, since the protrusion 72 is disposed only at a position overlapping the through holes 43a and 43b formed in the stacked body 40 in plan view, heat is directly transmitted to the ink in the through holes 43a and 43b. Cheap.

  Furthermore, the number of the protrusions 72 is adjusted according to the formation region of the through holes 43a and 43b. For example, in the laminated body 40, the volume of the ink flow path formed in the region R1 is larger than that of the ink flow path formed in the region R2 per unit area in plan view. In the region R1, the width of the through hole 43 is uniform. Therefore, in the region R1, the ink flow path is uniformly larger than that in the region R2, and the amount of ink existing in the region R1 is larger, so that more protrusions 72 are uniformly arranged than in the region R2, and more heat is transferred. It is configured to be. On the other hand, in the region R2, the ink flow path is small, and the closer to the right end portion 43c, the smaller the width of the through hole 43, the less the ink inside. Accordingly, the number of protrusions 72 is reduced as the distance from the right end 43c is approached, and heat having a magnitude corresponding to the amount of ink is transmitted.

  The number of the protrusions 72 may be determined more strictly according to the volume of the ink flow path existing in the region having the unit area in the plan view of the stacked body 40. For example, in FIG. 5C, when an arbitrary columnar portion T1 penetrating the laminate 40 in the vertical direction and having a unit area on the bottom surface is taken, the larger the volume of the ink flow path existing in T1, the more T1 You may make it the number of the protrusion parts 72 per unit area which contact | abut to increase.

  Hereinafter, the head main body 33 provided in the lower part of the head 1 will be described. FIG. 6 is a plan view of the head body 33. FIG. 7 is an enlarged view of a portion straddling two adjacent actuator units 21 in FIG. FIG. 8 is a partial cross-sectional view of the flow path unit 9 along the line VIII-VIII shown in FIG. FIGS. 9A and 9B are an enlarged cross-sectional view of a region indicated by a one-dot chain line in FIG. 8 and a plan view of an individual electrode. In FIG. 7, the aperture 112 to be drawn with a broken line is drawn with a solid line for easy understanding of the drawing.

  As shown in FIG. 6, the head body 33 includes a flow path unit 9 and eight actuator units 21 fixed to the upper surface 9 a of the flow path unit 9. As shown in FIG. 6, the flow path unit 9 has an ink flow path including a pressure chamber 110 and the like that are holes formed in the upper surface 9a. The actuator unit 21 has a trapezoidal planar shape. The actuator unit 21 includes a plurality of actuators corresponding to the pressure chambers 110, and has a function of selectively giving ejection energy to the ink in the pressure chambers 110.

  The flow path unit 9 has a rectangular parallelepiped shape that has substantially the same planar shape as the stacked body 40. A total of 18 ink supply ports 105b are opened on the upper surface 9a of the flow path unit 9 corresponding to the openings of the ink flow paths on the laminated body 40 (plate 45) side. A manifold channel 105 communicating with the ink supply port 105 b and a sub-manifold channel 105 a branched from the manifold channel 105 are formed inside the channel unit 9. The manifold channel 105 extends along the oblique side of the trapezoid of the actuator unit 21 in plan view. Below the actuator unit 21, four sub-manifold channels 105a extend along the main scanning direction. These four sub-manifold channels 105a branch from the manifold channel 105 on one oblique side of the actuator unit 21, extend along the main scanning direction, and merge with another manifold channel 105 on the other oblique side. ing. As shown in FIGS. 7 and 8, a discharge surface 2a in which a large number of discharge ports 108 are arranged in a matrix is formed on the lower surface of the flow path unit 9.

  The pressure chambers 110 are arranged along the longitudinal direction (main scanning direction) of the flow path unit 9, thereby forming a plurality of pressure chamber rows composed of the plurality of pressure chambers 110 on the upper surface 9 a of the flow path unit 9. ing. The number of pressure chambers 110 included in each pressure chamber row corresponds to the outer shape (trapezoidal shape) of an actuator unit 21 described later, from the long side (lower base side) to the short side (upper base side). It arrange | positions so that it may decrease gradually toward it. The discharge port 108 is also arranged in the same manner. However, the plurality of discharge port arrays formed by arranging the discharge ports 108 are all arranged parallel to the sub-manifold channel 105a while avoiding this in a plan view.

  As shown in FIG. 8, the flow path unit 9 includes nine metal plates 122 to 130 made of stainless steel. By laminating these plates 122 to 130 in alignment with each other, a discharge port is provided in the flow path unit 9 from the manifold flow path 105 to the sub manifold flow path 105a and from the outlet of the sub manifold flow path 105a through the pressure chamber 110. A large number of individual ink flow paths 132 to 108 are formed.

  The ink flow in the flow path unit 9 will be described. As shown in FIGS. 6 to 8, the ink supplied from the laminated body 40 into the flow path unit 9 through the ink supply port 105b is branched from the manifold flow path 105 to the sub-manifold flow path 105a. The ink in the sub-manifold channel 105a flows into each individual ink channel 132 and reaches the ejection port 108 via the aperture 112 and the pressure chamber 110 functioning as a throttle.

  Next, the actuator unit 21 will be described. As shown in FIG. 6, each of the eight actuator units 21 has a trapezoidal planar shape, and is arranged in a staggered manner so as to avoid the ink supply ports 105b. Furthermore, the parallel opposing sides of each actuator unit 21 are along the longitudinal direction of the flow path unit 9, and the oblique sides of the adjacent actuator units 21 overlap each other in the width direction (sub-scanning direction) of the flow path unit 9. Yes.

  As shown in FIG. 9A, the actuator unit 21 includes three piezoelectric sheets 141 to 143 made of a lead zirconate titanate (PZT) ceramic material having ferroelectricity. Each of the piezoelectric sheets 141 to 143 is composed of a single sheet having a shape and size straddling the plurality of pressure chambers 110. The lower surface of the lowermost piezoelectric sheet 143 is a fixed surface that is fixed to the flow path unit 9. The upper surface of the uppermost piezoelectric sheet 141 is a bonding surface to which the COF 50 is bonded. An individual electrode 135 is formed at a position facing the pressure chamber 110 on the joint surface. A common electrode 134 formed on the entire surface of the sheet is interposed between the uppermost piezoelectric sheet 141 and the lower piezoelectric sheet 142. As illustrated in FIG. 9B, the individual electrode 135 has a substantially rhombic planar shape similar to the pressure chamber 110. In plan view, most of the individual electrodes 135 are in the region of the pressure chamber 110. One of the acute corners of the substantially rhomboid individual electrode 135 extends outside the pressure chamber 110, and an individual bump 136 that protrudes from the upper surface of the piezoelectric sheet 141 while being electrically connected to the individual electrode 135 is provided at the tip thereof. ing. Note that individual bumps for common electrodes are also formed on the upper surface of the piezoelectric sheet 141. The common electrode 134 is electrically connected to the individual bumps through a conductor in a through hole formed in the piezoelectric sheet 141.

  The common electrode 134 is equally grounded in the region corresponding to all the pressure chambers 110. On the other hand, the individual electrode 135 is electrically connected to each output terminal of the driver IC 73 via the COF 50, and a drive signal from the driver IC 73 is selectively supplied.

  The piezoelectric sheet 141 is polarized in the thickness direction. When an electric field is applied to the piezoelectric sheet 141 in the polarization direction by setting the individual electrode 135 to a potential different from that of the common electrode 134, the electric field application portion corresponding to the individual electrode 135 functions as an active portion that is distorted by the piezoelectric effect. In other words, a plurality of actuators corresponding to the number of pressure chambers 110 are built in the actuator unit 21, and each portion sandwiched between the individual electrodes 135 and the pressure chambers 110 functions as an individual actuator. For example, if the polarization direction and the electric field application direction are the same, the active portion contracts in a direction (plane direction) orthogonal to the polarization direction. As described above, the actuator unit 21 uses the upper one piezoelectric sheet 141 away from the pressure chamber 110 as a layer including the active portion, and deactivates the lower two piezoelectric sheets 142 and 143 close to the pressure chamber 110. It is a so-called unimorph type actuator made into a layer. Note that the inactive layer does not spontaneously distort when an electric field is applied. As shown in FIG. 9A, since the piezoelectric sheets 141 to 143 are fixed to the upper surface of the plate 122 that partitions the pressure chamber 110, the electric field application portion of the piezoelectric sheet 141 and the piezoelectric sheets 142 and 143 below the electric field application portion. If there is a difference in the strain in the plane direction, the entire piezoelectric sheets 141 to 143 are deformed so as to be convex toward the pressure chamber 110 (unimorph deformation). At this time, ejection energy is given to the ink in the pressure chamber 110.

  FIG. 10 is a block diagram illustrating a control system of the printer 101. As shown in FIG. 10, a print command is input from the control unit 100 to the substrate 80 of the head 1. The board 80 transmits print data to the driver IC 73 through the COF 48 based on the print command from the control unit 100. The driver IC 73 generates a drive signal based on the print data from the substrate 80 and supplies it to the individual electrode 35 of the actuator unit 21 through the COF 48. This drive signal is a voltage signal that causes the actuator unit 21 to undergo unimorph deformation as described above. When a drive signal is supplied to the individual electrode 35, ejection energy is applied to the ink in the pressure chamber 110 due to deformation of the actuator unit 21, and ink is ejected from the ejection port 108. The print command transmitted to the substrate 80 by the control unit 100 is adjusted so that a desired image is formed on the print paper P by the ink from the ejection port 108.

  According to the present embodiment described above, the heat from the plurality of driver ICs 73 can be uniformly transmitted to the stacked body 40 via the heat equalizing plate 70.

  In particular, when the internal ink flow path is spread along a plane as in the laminate 40 of the present embodiment, it is difficult to uniformly transfer heat from the driver IC 73 to the ink in the ink flow path. On the other hand, on the lower surface of the heat equalizing plate 70 of the present embodiment, a plurality of protrusions 72 are distributed along the lower surface so as to overlap the through holes 43a and 43b extending along the plane in a plan view. Therefore, the heat from the driver IC 73 can be uniformly transmitted to the ink in the ink flow path via these protrusions 72.

  In the present embodiment, a protruding plate 71 protruding upward from the horizontal portion of the heat equalizing plate 70 is provided, and a driver IC 73 is fixed to each protruding plate 71. As a result, even if the driver IC 73 is disposed apart from the protruding portion 72 that is the contact portion of the laminated body 40, the heat equalizing plate 70 and the laminated body 40 are appropriately thermally coupled via the heat equalizing plate 70. be able to. Further, the heat from the driver IC 73 can be led to the protruding portion 72 through each protruding plate 71 without waste.

  Further, two notches 70 b are formed so as to sandwich the protruding plate 71, and a region sandwiched between these notches 70 b is connected to a region where the protruding portion 72 is formed. For this reason, the heat from the driver IC 73 can be appropriately transmitted from the protruding plate 71 toward the protruding portion 72 without diffusing.

<Modification>
The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the means for solving the problem. It is possible.

  In the above-described embodiment, the through holes 43a and 43b extend in the laminated body 40 along a plane. However, the present invention is not limited to this, and can be applied to any case where the flow paths are distributed along the plane inside the flow path body. FIG. 11 is a plan view of the flow path body 240 in which the ink flow path 205 is formed. The ink flow path 205 is composed of a plurality of linear ink flow paths arranged in parallel. Even if the plurality of ink flow paths have communication paths in the stacking direction, the ink flow path 205 is generally planar. Distributed. As described above, even when the ink flow path itself does not spread along the plane, the ink flow is formed even when the entire ink flow path is distributed along the plane by forming a plurality of ink flow paths. It is difficult to transfer heat uniformly to the ink in the path. Therefore, even in such a configuration, the heat from the driver IC 73 is transferred to the flow path body 240 through the heat equalizing plate having the plurality of projections 172 distributed in a plane in a range overlapping with the formation area of the ink flow path 205. By transmitting, the present invention can be applied.

  In the above-described embodiment, the plurality of protrusions 72 are distributed according to the shape of the ink flow path on the laminated body 40 side, so that heat is uniformly transmitted to the ink in the ink flow path. . However, as shown in the soaking plate 270 of FIG. 12, a protruding portion 272 having a shape corresponding to the shape of the ink flow path on the laminated body 40 side may be provided. The protrusion 272 has a size and a shape that exactly overlaps the through hole 43a that is an ink flow path on the laminated body 40 side in a plan view. Also in this case, the contact portion between the protruding portion 272 and the stacked body 40 is distributed only in a range where it overlaps the through hole 43a, so that the heat from the driver IC 73 is appropriately transmitted to the ink in the ink flow path. The

  In the above-described embodiment, the soaking plate 72 is provided with the projecting portion 72 and brought into contact with the laminated body 40. However, the projecting portion 72 is not provided, and the flat surface on the lower surface of the soaking plate is provided on the laminated body 40. You may make it contact | abut directly. In this case, a silicon grease layer or a thermally conductive silicon sheet is formed between the soaking plate 70 and the laminated body 40 in a pattern corresponding to the distribution state so that heat is transferred according to the distribution state of the ink flow path. A thermally conductive resin layer may be formed.

  In this embodiment, the actuator is a piezoelectric type, but it can also be applied to an electrostatic type or a resistance heating type.

1 Inkjet head (head)
30 Reservoir unit 33 Head main body 70 Heat equalizing plate 71 Protruding plate 72 Protruding portion 73 Driver IC
100 Control Unit 101 Inkjet Printer (Printer)

Claims (12)

A discharge port that discharges the liquid, and a flow path body in which a liquid flow path that supplies the liquid to the discharge port is formed;
An actuator for applying discharge energy for discharging liquid from the discharge port to the liquid in the liquid channel;
A plurality of drive circuit units for supplying drive signals to the actuator;
A contact member that is thermally coupled to the plurality of drive circuit units and contacts the flow path body ;
Before SL liquid flow path includes a distribution area distributed along a plane within said channel member,
The contact member is
A flat plate along the one plane in which no liquid flow path is formed, and a contact portion that contacts the flow path body, and one or a plurality of protrusions that protrude from the flat plate toward the flow path body And the one or more protrusions are distributed in a range overlapping with the distribution region when viewed from a direction orthogonal to the one plane. A plurality of the protrusions having the same shape and size are provided,
The plurality of protrusions are
When the channel body is viewed from the direction perpendicular to the one plane, the larger the volume of the liquid channel existing per unit area, the larger the number of the projecting portions per unit area that abut on the channel body. The liquid discharge head according to claim 1 . The formation region of the one or more protrusions is distributed in a range overlapping with the distribution region when viewed from a direction orthogonal to the one plane, and is not disposed at a position not overlapping with the liquid flow path. The liquid discharge head according to claim 1 , wherein the liquid discharge head is provided. The protrusion is
  2. The liquid discharge head according to claim 1, wherein the liquid discharge head has a size and a shape overlapping with the liquid flow path when the flow path body is viewed from a direction orthogonal to the one plane. The contact member has a protruding plate protruding from the flat plate in a direction intersecting the one plane;
The driving circuit unit, a liquid discharge head according to any one of claims 1-4, characterized in that in contact with the projecting plate.   The liquid ejection head according to claim 5, wherein a plurality of the protruding plates corresponding to the plurality of driving circuit units are provided. The plurality of protruding plates are:
  The liquid discharge head according to claim 6, wherein the abutting members are arranged in a staggered pattern at equal intervals along the longitudinal direction at both ends in the short direction. A notch is formed at the end of the flat plate,
Portion adjacent to the cutout in said end portion of said flat plate, any one of the claims 5-7, characterized in that has a said projecting plate bent in the direction intersecting the one plane The liquid discharge head described in 1. The liquid ejection head according to claim 8, wherein the protruding plate is formed by being sandwiched between two adjacent cutouts. The flow path body is composed of a laminated body in which a plurality of flat plate members extending along the one plane are laminated,
The liquid flow path, the liquid discharge head according to any one of claims 1 to 9, characterized in that it is formed along at least the one plane to one of the plurality of flat plate members. The flat plate of the contact member is sandwiched between the flow passage body that is a laminate of the plurality of flat plate members made of metal and a resin flow passage body that communicates with the flow passage body. The liquid discharge head according to claim 10. It said abutment member, the liquid discharge head according to any one of claims 1 to 11, characterized in that it is composed of a material having larger thermal conductivity than the material used in the channel body .

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