JP6276103B2 - Liquid discharge head and recording apparatus - Google Patents

Description

  The present invention relates to a liquid discharge head that discharges liquid and a recording apparatus using the same.

  In recent years, printing apparatuses using an ink jet recording method, such as an ink jet printer or an ink jet plotter, are not only printers for general consumers, but also, for example, the formation of electronic circuits or the manufacture of color filters for liquid crystal displays, organic EL display It is also widely used for industrial applications such as manufacturing.

  In such an ink jet printing apparatus, a liquid discharge head for discharging liquid is mounted as a print head, and the liquid discharge head is provided on a head main body having a plurality of discharge holes and on the head main body. And a heater IC electrically connected to the head body and supplying electricity to the head body from the outside, and a driver IC mounted on the flexible board (for example, Patent Document 1).

JP 2010-046969 A

  In recent years, an increase in printing speed has been demanded, and a driving frequency for driving a liquid discharge head has been increased. As a result, the driver IC emits high-temperature heat, so that the adhesion force of the heater provided in the head main body is reduced, and the heater may peel off from the head main body. When the heater peels from the head main body, the liquid flowing through the head main body cannot be maintained at a constant temperature, and there is a possibility that the liquid discharged from the discharge holes may vary in discharge.

The liquid ejection head of the present invention is electrically connected to the head body having a plurality of ejection holes, a heater provided on the head body, and the head body, and supplies electricity to the head body from the outside. It comprises a flexible substrate for a driver IC mounted on the flexible substrate, a heat radiator for radiating heat of the driver IC, and a pressing member for pressing the heater to the head body cage said pressing member, you are pressing the driver IC to the radiator.
The liquid discharge head according to the present invention includes a head main body having a plurality of discharge holes, a heater provided on the head main body, and the head main body electrically connected to the head main body from the outside. A flexible substrate for supplying, a driver IC mounted on the flexible substrate, a pressing member for pressing the heater against the head body, and a temperature measuring element provided on the head body. The pressing member presses the temperature measuring element against the head body.

  The recording apparatus of the present invention includes the liquid discharge head described above, a transport unit that transports a recording medium to the liquid discharge head, and a control unit that controls driving of the head body. .

  According to the liquid discharge head of the present invention, it is possible to reduce the possibility that the adhesion force of the heater provided in the head main body is reduced, and to reduce the possibility that the liquid discharged from the discharge holes may vary in discharge. Can do.

1 is a schematic configuration diagram of a printer according to a first embodiment of the present invention. FIG. 2 is a plan view of a head body that constitutes the liquid ejection head of FIG. 1. FIG. 3 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. 2, and is a diagram in which a part of the structure is omitted for explanation. FIG. 3 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. 2, and is a diagram in which a part of the structure is omitted for explanation. It is a longitudinal cross-sectional view along the II line | wire of FIG. FIG. 2 is a perspective view of the liquid ejection head in FIG. 1. It is a longitudinal cross-sectional view along the II-II line of FIG. 1A and 1B show a head main body, a heater, and a pressing member that constitute the liquid discharge head of FIG. 1, wherein (a) is an exploded perspective view and (b) is a plan view. FIG. 9 is a longitudinal sectional view showing a liquid ejection head according to a second embodiment of the present invention and corresponding to FIG. 7. 9A and 9B show a head main body, a heater, a heat insulating material, and a pressing member that constitute the liquid discharge head of FIG. 9, wherein FIG. 9A is an exploded perspective view, and FIG. 9B is a plan view. The head main body which comprises the liquid discharge head which concerns on the 3rd Embodiment of this invention, a heater, a heat insulating material, and a press member are shown, (a) is a disassembled perspective view, (b) is a top view. It is. (A) is an enlarged plan view showing a part thereof enlarged, and (b) is a cross-sectional view taken along line III-III shown in FIG. 12 (a). The head main body which comprises the liquid discharge head which concerns on the 4th Embodiment of this invention, a heater, a heat insulating material, and a press member are shown, (a) is an enlarged plan view which expands and shows a part, (B) is the IV-IV sectional view taken on the line shown to Fig.13 (a). FIG. 9 shows a liquid discharge head according to a fifth embodiment of the present invention, and is a longitudinal sectional view corresponding to FIG. 7. The head main body which comprises the liquid discharge head which concerns on the 6th Embodiment of this invention, a heater, a heat insulating material, and a press member are shown, (a) is a disassembled perspective view, (b) is a part. It is an enlarged plan view shown enlarged.

<First Embodiment>
FIG. 1 is a schematic configuration diagram of a color ink jet printer which is a recording apparatus including a liquid discharge head according to an embodiment of the present invention. This color inkjet printer 1 (hereinafter referred to as printer 1) has four liquid ejection heads 2. These liquid discharge heads 2 are arranged along the conveyance direction of the printing paper P, and the liquid discharge heads 2 fixed to the printer 1 have an elongated shape extending in the direction from the front to the back in FIG. ing. This long direction is sometimes called the longitudinal direction.

  In the printer 1, a paper feed unit 114, a transport unit 120, and a paper receiver 116 are sequentially provided along the transport path of the printing paper P. Further, the printer 1 is provided with a control unit 100 for controlling the operation of each part of the printer 1 such as the liquid ejection head 2 or the paper feed unit 114.

  The paper supply unit 114 includes a paper storage case 115 that can store a plurality of printing papers P, and a paper supply roller 145. The paper feed roller 145 can send out the uppermost print paper P among the print papers P stacked and stored in the paper storage case 115 one by one.

  Two pairs of feed rollers 118 a, 118 b, 119 a, and 119 b are arranged between the paper feed unit 114 and the transport unit 120 along the transport path of the printing paper P. The printing paper P sent out from the paper supply unit 114 is guided by these feed rollers 118 a, 118 b, 119 a, and 119 b and further sent out to the transport unit 120.

  The transport unit 120 includes an endless transport belt 111 and two belt rollers 106 and 107. The conveyor belt 111 is wound around belt rollers 106 and 107. The conveyor belt 111 is adjusted to such a length that it is stretched with a predetermined tension when it is wound around the two belt rollers 106 and 107. As a result, the conveyor belt 111 is stretched without slack along two parallel planes that include the common tangent lines of the two belt rollers 106 and 107, respectively. Of these two planes, the plane closer to the liquid ejection head 2 is a transport surface 127 that transports the printing paper P.

  As shown in FIG. 1, a conveyance motor 174 is connected to the belt roller 106. The transport motor 174 can rotate the belt roller 106 in the direction of arrow A. The belt roller 107 can rotate in conjunction with the transport belt 111. Therefore, the conveyance belt 111 moves along the direction of arrow A by driving the conveyance motor 174 and rotating the belt roller 106.

  In the vicinity of the belt roller 107, a nip roller 138 and a nip receiving roller 139 are arranged so as to sandwich the conveyance belt 111. The nip roller 138 is urged downward by a spring (not shown). A nip receiving roller 139 below the nip roller 138 receives the nip roller 138 biased downward via the conveying belt 111. The nip roller 138 is rotatably installed and rotates in conjunction with the transport belt 111.

  The printing paper P sent out from the paper supply unit 114 to the transport unit 120 is sandwiched between the nip roller 138 and the transport belt 111. As a result, the printing paper P is pressed against the transport surface 127 of the transport belt 111 and is fixed on the transport surface 127. The printing paper P is transported in the direction in which the liquid ejection head 2 is installed according to the rotation of the transport belt 111. The outer peripheral surface 113 of the conveyor belt 111 may be treated with adhesive silicon rubber. Thereby, the printing paper P can be securely fixed to the transport surface 127.

  The liquid discharge head 2 has a head body 2a at the lower end. The lower surface of the head body 2a is a discharge hole surface 4-1, in which a large number of discharge holes for discharging liquid are provided.

  Liquid droplets (ink) of the same color are ejected from the ejection holes 8 provided in one liquid ejection head 2. Each liquid discharge head 2 is supplied with liquid from an external liquid tank (not shown). The discharge hole 8 of each liquid discharge head 2 is open to the discharge hole surface 4-1, and is in one direction (a direction parallel to the print paper P and perpendicular to the transport direction of the print paper P. Since it is arranged at equal intervals in the (longitudinal direction), it is possible to print without gaps in one direction. The colors of the liquid ejected from each liquid ejection head 2 are, for example, magenta (M), yellow (Y), cyan (C), and black (K), respectively. Each liquid ejection head 2 is arranged with a slight gap between the lower surface of the head main body 2 a and the transport surface 127 of the transport belt 111.

  The printing paper P transported by the transport belt 111 passes through the gap between the liquid ejection head 2 and the transport belt 111. At that time, droplets are ejected from the head main body 2 a constituting the liquid ejection head 2 toward the upper surface of the printing paper P. As a result, a color image based on the image data stored by the control unit 100 is formed on the upper surface of the printing paper P.

A separation plate 140 and two pairs of feed rollers 121a, 121b, 122a, and 122b are disposed between the transport unit 120 and the paper receiver 116. The printing paper P on which the color image is printed is conveyed to the peeling plate 140 by the conveying belt 111. At this time, the printing paper P is peeled from the transport surface 127 by the right end of the peeling plate 140. The printing paper P is sent out to the paper receiving unit 116 by the feed rollers 121a, 121b, 122a, 122b. In this way, the printed printing paper P is sequentially sent to the paper receiving unit 116 and stacked on the paper receiving unit 116.

  Note that a paper surface sensor 133 is installed between the liquid ejection head 2 and the nip roller 138 that are the most upstream in the transport direction of the printing paper P. The paper surface sensor 133 includes a light emitting element and a light receiving element, and can detect the leading end position of the printing paper P on the transport path. The detection result by the paper surface sensor 133 is sent to the control unit 100. The control unit 100 can control the liquid ejection head 2 or the conveyance motor 174 so that the conveyance of the printing paper P and the image printing are synchronized with each other based on the detection result sent from the paper surface sensor 133.

  Next, the liquid discharge head 2 of the present invention will be described with reference to FIGS.

FIG. 6 is a perspective view of the liquid discharge head 2 of FIG. FIG. 7 is a longitudinal sectional view taken along line II-II of the liquid discharge head 2 of FIG. In FIG. 7, the internal structure of the flow path such as the flow path member 4 is omitted. FIG. 8 is an exploded perspective view and a plan view showing the head main body 2a, the heater 81, the heat insulating material 83, and the pressing member 96.

  The liquid discharge head 2 includes a head main body 2a, a connection substrate 80, a circuit substrate 82, a flexible substrate 60, a driver IC (Integrated Circuit) 55, and a housing 90.

  As shown in FIG. 7, the head body 2 a includes a flow path member 4, a piezoelectric actuator substrate 21 provided on the upper surface of the flow path member 4, and a reservoir 40 for supplying liquid to the flow path member 4. ing. A housing 90 is provided on the head main body 2a via a frame 92. The head body 2a may not include the reservoir 40 and the housing 90.

  The casing 90 can be formed of a metal or an alloy, and has a rectangular parallelepiped shape. The casing 90 is configured by a casing main body 90a that forms side surfaces on both ends in the longitudinal direction of the liquid discharge head 2, a casing side plate 90b that is attached to the casing main body 90a, and a top plate portion 90c. The top plate portion 90c has a hole 90d so that a signal can be input via the external connector 80a of the connection board 80.

  Between the housing 90 and the reservoir 40, a frame 92 having an opening 92c at the center on a flat plate is provided. As shown in FIG. 8, the frame body 92 includes a pair of long sides 92a, a pair of short sides 92b, and an opening 92c formed by the pair of long sides 92a and the pair of short sides 92b.

  The housing body 90a has a top plate portion 90c and a housing side plate 90b attached from the side by screws or the like. At this time, the driver IC 55 that has been previously pushed outward from the attachment position of the housing side plate 90b is pressed against the housing side plate 90b. An opening formed by the frame body 92, the reservoir 40, and the flow path member 4 below the frame body 92 is closed by attaching the side plate 94 with screws or the like. Between the above members, resin or the like is applied and cured as necessary, so that liquid mist does not easily enter the inside of the housing 90.

The reservoir 40 is provided with a reservoir channel. One end of the reservoir channel is opened to the outside of the liquid discharge head 2 as a liquid supply hole 40a. The reservoir 40 is connected at both ends in the longitudinal direction of the flow path member 4, and the reservoir flow path is connected to the opening 5 a of the manifold 5. That is, the liquid supplied from the liquid supply hole 40 a enters the reservoir flow path, branches inside, and is supplied to both ends of the manifold 5.

  Further, a part of the inner wall of the reservoir channel is a damper made of an elastically deformable material. Since the damper can be deformed in a direction facing the surface opposite to the reservoir flow path, the volume of the reservoir flow path can be changed by elastically deforming the damper. Therefore, the liquid can be stably supplied when the liquid discharge amount suddenly increases. In addition, it is preferable to provide a filter in the reservoir flow path so that foreign matter contained in the liquid does not easily enter the flow path member 4 and can suppress non-ejection caused by clogging of foreign matter.

  The connection board 80 is arranged on the upper part of the housing 90, and is mounted with an external connector 80a connected to external wiring and an internal connector 80b connected to the circuit board 82, for flowing electricity. A wiring 80c is provided. A portion of the external connector 80a protrudes from the opening 90d of the housing 90, and is configured to be easily connected to the outside. The internal connector 80b is electrically connected to the wiring 80c and is surface-mounted on the connection board 80.

The reservoir 40 includes a pressing member 96 partially having a heat insulating member 98 and a guide frame 84 for fixing a circuit board 82 for processing a drive signal for discharging liquid from the housing 90a and the head body 2a. It is fixed. Thereby, the pressing member 9 is applied to the head main body 2a.
6 will be fixed.

  A drive signal sent from the control unit 100 (see FIG. 1) via a signal cable (not shown) is sent to the external connector 80a, the connection board 80, the internal connector 80b, the circuit board 82, the flexible board 60, and the flexible board 60. A liquid droplet is ejected by being supplied to the mounted driver IC 55, driving a displacement element 30 of a piezoelectric actuator substrate 21 described later, and pressurizing the liquid inside the flow path member 4.

  The driver IC 55 generates heat when driven. Since the driver IC 55 is pressed to the inside of the housing 90 by deflecting the pressing member 96, the heat generated in the driver IC 55 is transmitted to the housing 90. And it spreads quickly to the whole housing 90, and is thermally radiated outside. If the driver IC 55 is flip-chip mounted and the surface opposite to the surface on which the electrodes are disposed is brought into contact with the housing 90, heat can be easily transmitted. In order to promote heat dissipation, it is preferable that the casing side plate 90b has an uneven outer surface.

The heat insulating member 98 makes it difficult for heat to be transmitted to the pressing member 96. Accordingly, heat is hardly transmitted to the reservoir 40 via the pressing member 96, and heat is hardly transmitted to the head body 2a. By forming the heat insulating member 98 with an elastic material, the driver IC 55 can be easily pressed against the metal housing 90.

  Further, a heat conductive material may be filled between the driver IC 55 and the housing 90. When the thermal conductive material is filled, the contact area is increased by the thermal conductive material, so that the thermal conductivity can be further increased. The thermal conductive material is made of grease having high thermal conductivity or high thermal conductivity. A resin containing a filler containing The resin may have a certain degree of viscosity or may be cured.

  The guide frame 84 has a pair of measuring plate portions extending in the vertical direction when viewed in a longitudinal section, and a connecting portion connecting the pair of measuring plate portions. A circuit board 82 is provided in each of the pair of measuring plates, and the circuit board 82 is held and fixed to the guide frame 84 in a standing state.

The pressing member 96 is a member for pressing the driver IC 55 to the inside of the housing 90. As shown in FIG. 7, the driver IC 55 is pressed to the inside of the housing 90 via the heat insulating member 98. Yes.

  The flexible substrate 60 is electrically connected to each displacement element 30 serving as a pressure unit provided on the piezoelectric actuator substrate 21 in order to supply a signal. As shown in FIG. 2, two flexible substrates 60 are connected to the piezoelectric actuator substrate 21. The electrode of the wiring formed in the flexible substrate 60 that is electrically connected to the piezoelectric actuator substrate 21 is arranged in a rectangular shape in the connection region 60 c of the one end portion of the flexible substrate 60 with the piezoelectric actuator substrate 21. Yes. The two flexible substrates 60 are connected such that their ends come to the center of the piezoelectric actuator substrate 21 in the short direction. The two flexible substrates 60 extend from the central portion in the short direction toward the long side of the piezoelectric actuator substrate 21.

  The head main body 2a, the frame body 92, the heater 81, and the pressing member 96 which comprise the liquid discharge head 2 are demonstrated using FIG. In FIG. 8, the illustration of the flexible substrate 60 is omitted.

  The heater 81 is disposed on the reservoir 40 and is provided to bring the temperature of the liquid flowing through the head body 2a close to a constant level. In plan view, it is arranged inside the opening 92c of the frame body 92, and is arranged in a state of being separated from the frame body 92 by a predetermined distance. A flexible substrate (not shown) is inserted between the frame body 92 and the heater 81. The heater 81 and the reservoir 40 may be bonded with an adhesive (not shown) or a double-sided tape (not shown).

  As the heater 81, it is preferable to use a film heater in order to suppress an increase in the thickness direction. Although not shown, the heater 81 has a resistance wiring inside, and a heat generating portion 281b (see FIG. 12) that generates heat, and a lead electrode 281a (see FIG. 12) for electrically connecting the resistance wiring and the outside. 12).

  The pressing member 96 includes a flat plate portion 96a provided on the heater 81 and a pair of protruding portions 96b provided adjacent to the long side 92a of the frame body 92 and protruding upward from the flat plate portion 96a. I have. The pressing member 96 includes a corner portion 96d formed by the flat plate portion 96a and the protruding portion 96b.

  The flat plate portion 96a and the protruding portion 96b are provided so as to extend in the longitudinal direction, and both ends of the flat plate portion 96a are provided up to the short side 92b of the frame body 92, and through the frame body 92, The reservoir 40 is connected by screws or the like. Thereby, the pressing member 96 is connected to the reservoir 40 in a state where the heater 81 is pressed.

  As shown in FIG. 7, the flat plate portion 96 a is provided on the heater 81, and the pressing member 96 is connected to the reservoir 40. Therefore, the pressing member 96 can press the heater 81 against the reservoir 40, and presses the heater 81 against the head body 2a.

  Further, the protruding portion 96b extends upward to a position where the driver IC 55 provided on the flexible substrate 60 is provided. Accordingly, the driver IC 55 is configured to be pressed inside the housing 90 by the protruding portion 96 b of the pressing member 96.

Here, in recent years, printing apparatuses are required to increase the printing speed, and the driving frequency supplied to the driver IC tends to increase as the printing speed increases. When the drive frequency supplied to the driver IC increases, the driver IC, flexible substrate, circuit board, and connection substrate become high temperature, the adhesion between the heater and the reservoir decreases, and the heater may peel from the head body. . Even when the heater and the head main body are bonded with an adhesive or a double-sided tape, the adhesive force of the adhesive or the double-sided tape may be reduced by the heat of the driver IC, and may be peeled off from the reservoir. Accordingly, the temperature of the liquid flowing through the head body cannot be maintained at a constant temperature, and there is a possibility that the ejection speed or the ejection amount varies. That is, there may be variations in the ejection characteristics of the ejection holes.

  On the other hand, the liquid ejection head 2 includes a pressing member 96 for pressing the heater 81 against the reservoir 40. Thereby, the heater 81 is pressed against the head main body 2a, and the adhesion between the heater 81 and the head main body 2a can be improved. As a result, the heater 81 can warm the liquid flowing through the head main body 2a, and the possibility that the variation in the ejection characteristics of the ejection holes 8 (see FIG. 5) of the liquid ejection head 2 becomes large can be reduced. In particular, since the reservoir 40 holds a large amount of liquid, the discharge characteristics at each discharge height 8 of the liquid discharge head 2 can be made close to uniform by keeping the temperature of the liquid inside the reservoir 40 uniform. .

  Although an example in which the head main body 2a is provided on the reservoir 40 has been shown, the present invention is not limited to this. For example, the heater 81 may be provided on the piezoelectric actuator substrate 21 of the head body 2a, and the pressing member 96 may be provided on the heater 81 so as to press the heater 81 against the piezoelectric actuator substrate 21. With such a configuration, the liquid flowing through the flow path member 4 can be warmed by the heater 81, and the discharge characteristics of the liquid discharge head 2 can be stabilized.

  Further, the heater 81 and the pressing member 96 may be provided on the flow path member 4. With such a configuration, the liquid flowing through the flow path member 4 can be warmed by the heater 81, and the discharge characteristics of the liquid discharge head 2 can be stabilized.

  Further, the flow path member 4 of the head main body 2a may vibrate in the thickness direction or in the width direction as the liquid is discharged. In this case, when the pressing member 96 is provided so as to press the heater 81 against the piezoelectric actuator substrate 21 or the flow path member 4, the pressing member 96 can inhibit the deformation of the flow path member 4, and the vibration of the head body 2 a can be suppressed. Can be suppressed.

  The liquid ejection head 2 further includes a housing 90 for radiating heat from the driver IC 55, and the pressing member 96 presses the driver IC 55 against the housing 90. More specifically, the pressing member 96 presses the driver IC 55 against the housing side plate 90b of the housing 90. Therefore, the heat generated in the driver IC 55 is transmitted from the housing side plate 90b to the entire housing 90. Accordingly, the heat of the driver IC 55 spreads quickly to the housing 90 and is radiated to the outside, so that the driver IC 55 can be radiated. As a result, the heat of the driver IC 11 is hardly transmitted to the heater 81, and the adhesion between the heater 81 and the head body 2a can be improved.

  In addition, although the example using the housing | casing 90 was shown as a heat radiator for radiating the heat | fever of driver IC55, it is not limited to this. For example, the heat radiator may be formed of a metal or alloy plate such as aluminum, iron, or copper.

  Further, in the liquid discharge head 2, the pressing member 96 includes a flat plate portion 96a positioned on the head body 2a and a protruding portion 96b protruding above the flat plate portion 96a. The flat plate portion 96a heads the heater 81. The main body 2 a is pressed, and the protrusion 96 b presses the driver IC 55 against the housing 90.

  As a result, when the protrusion 96b is deformed toward the guide frame 84 due to the reaction caused by pressing the driver IC 55, the flat plate portion 96a is deformed into a convex shape toward the lower side, and the heater 81 is added to the reservoir 40. Can be pressed. As a result, the adhesion between the heater 81 and the head body 2a can be further improved.

  Further, when the flat plate portion 96a is deformed upward by a reaction due to the pressing of the reservoir 40, the projecting portion 96b is deformed toward the driver IC 55, and the driver IC 55 is attached to the housing 90. Can be pressed. Thereby, the heat dissipation of the driver IC 55 can be improved, and the amount of heat transmitted to the heater 91 can be reduced. As a result, the adhesion between the heater 81 and the head body 2a can be further improved.

  FIG. 2 is a plan view of the head main body 2a. FIG. 3 is an enlarged view of a region surrounded by a one-dot chain line in FIG. 2, and is a plan view in which a part of the structure is omitted for explanation. 4 is an enlarged view of a region surrounded by a one-dot chain line in FIG. 2, and is a diagram in which a part of the structure different from FIG. 3 is omitted for explanation. In FIGS. 3 and 4, for easy understanding of the drawings, the squeezing 6, the discharge hole 8, the pressurizing chamber 10, and the like to be drawn by broken lines below the piezoelectric actuator substrate 21 are drawn by solid lines. Further, the discharge hole 8 in FIG. 4 is drawn larger than the actual diameter for easy understanding of the position. FIG. 5 is a longitudinal sectional view taken along the line II of FIG.

  The head body 2 a has one piezoelectric actuator substrate 21 including a flat plate-like flow path member 4 and a displacement element 30 connected on the flow path member 4. The planar shape of the piezoelectric actuator substrate 21 is rectangular, and is arranged on the upper surface of the flow path member 4 so that the long side of the rectangle is along the longitudinal direction of the flow path member 4.

  Two manifolds 5 are formed inside the flow path member 4. The manifold 5 has an elongated shape that extends from one end side in the longitudinal direction of the flow path member 4 to the other end side, and the manifold opening 5a that opens to the upper surface of the flow path member 4 at both ends. Is formed. By supplying the liquid from both ends of the manifold 5 to the flow path member 4, it is possible to prevent the liquid from being insufficiently supplied. Further, as compared with the case where the liquid is supplied from one end of the manifold 5, the difference in the pressure loss generated when the liquid flows through the manifold 5 can be reduced to about half, so that the variation in the discharge characteristics can be reduced.

  In the manifold 5, at least a central portion in the length direction, which is a region connected to the pressurizing chamber 10, is partitioned by a partition wall 15 provided at an interval in the width direction. The partition wall 15 has the same height as the manifold 5 in the central portion in the length direction, which is a region connected to the pressurizing chamber 10, and completely separates the manifold 5 into a plurality of sub-manifolds 5b. By doing so, it is possible to provide the discharge hole 8 and a descender connected from the discharge hole 8 to the pressurizing chamber 10 so as to overlap with the partition wall 15 when seen in a plan view.

  In FIG. 2, the whole of the manifold 5 excluding both ends is partitioned by a partition wall 15. The whole may be partitioned by the partition 15 including both ends. In that case, if only the vicinity of the opening 5a opened on the upper surface of the flow path member 4 is not partitioned and a partition wall is provided from the opening 5a in the depth direction of the flow path member 4, the reservoir Connection with 40 becomes easy.

The portion of the manifold 5 divided into a plurality of parts may be referred to as a sub-manifold 5b. In this embodiment, two manifolds 5 are provided independently, and openings 5a are provided at both ends. One manifold 5 is provided with seven partition walls 15 and divided into eight sub-manifolds 5b. The width of the sub-manifold 5b is larger than the width of the partition wall 15, so that a large amount of liquid can flow through the sub-manifold 5b. In addition, the length of the seven partition walls 15 becomes longer as they are closer to the center in the width direction. At both ends of the manifold 5, the ends of the partition walls 15 are closer to the ends of the manifold 5 as the partition walls 15 are closer to the center in the width direction. It ’s close. As a result, the flow resistance generated by the outer wall of the manifold 5 and the flow resistance generated by the partition wall 15 are balanced, and the individual supply flow that is the portion connected to the pressurizing chamber 10 in each sub-manifold 5b. The pressure difference of the liquid at the end of the region where the channel 14 is formed can be reduced. Since the pressure difference in the individual supply channel 14 leads to a pressure difference applied to the liquid in the pressurizing chamber 10, the discharge variation can be reduced if the pressure difference in the individual supply channel 14 is reduced.

  The flow path member 4 is formed by two-dimensionally expanding a plurality of pressurizing chambers 10. The pressurizing chamber 10 is a hollow region having a substantially rhombic planar shape having two sharp corners and two obtuse corners with rounded corners.

  The pressurizing chamber 10 is connected to one sub-manifold 5b through an individual supply channel 14. Along with one sub-manifold 5b, two rows of pressurizing chambers 11 which are rows of pressurizing chambers 10 connected to the sub-manifold 5b are provided, one on each side of the sub-manifold 5b. Yes. Accordingly, 16 rows of pressurizing chambers 11 are provided for one manifold 5, and 32 rows of pressurizing chamber rows 11 are provided in the entire head body 2a. The intervals in the longitudinal direction of the pressurizing chambers 10 in the respective pressurizing chamber rows 11 are the same, for example, 37.5 dpi.

  A dummy pressurizing chamber 16 is provided at the end of each pressurizing chamber row 11. The dummy pressurizing chamber 16 is connected to the manifold 5 but is not connected to the discharge hole 8. A dummy pressurizing chamber row in which dummy pressurizing chambers 16 are arranged in a straight line is provided outside the 32 pressurizing chamber rows 11. The dummy pressurizing chamber 16 is not connected to either the manifold 5 or the discharge hole 8. By these dummy pressurizing chambers, the structure (rigidity) around the pressurizing chamber 10 that is one inward from the end is close to the structure (rigidity) of the other pressurizing chambers 10, thereby reducing the difference in liquid ejection characteristics. it can. In addition, since the influence of the surrounding structure difference has a large influence on the pressurizing chambers 10 adjacent to each other in the length direction, the dummy pressurizing chambers are provided at both ends in the length direction. Since the influence in the width direction is relatively small, it is provided only on the side closer to the end of the head body 2a. Thereby, the width | variety of the head main body 2a can be made small.

  The pressurizing chambers 10 connected to one manifold 5 are arranged at substantially equal intervals on the rows and on the columns along the row direction which is the longitudinal direction of the liquid discharge head 2 and the column direction which is the short direction. Has been placed. The row direction is the same direction as the diagonal line connecting the obtuse angle portions of the rhombus-shaped pressurizing chamber 10, and the column direction is the same direction as the diagonal line connecting the acute angle portions of the rhombus-shaped pressurization chamber 10. That is, the rhombus-shaped diagonal line of the pressurizing chamber 10 is not in an angle with the rows and columns. By arranging the pressurizing chambers 10 in a lattice shape and arranging the rhombic pressurizing chambers 10 having such angles, crosstalk can be reduced.

  This is because the corners face each other in both the row direction and the column direction with respect to one pressurizing chamber 10, so that the flow path member is more than the case where the sides face each other. This is because it is difficult for vibration to be transmitted through 4. In this case, the obtuse angled portions are opposed to each other in the longitudinal direction, so that the pressurizing chamber 10 can be arranged with a higher density in the longitudinal direction, thereby increasing the density of the discharge holes 8 in the longitudinal direction. This is because the liquid ejection head 2 with a resolution can be obtained. If the intervals between the pressurizing chambers 10 on the rows and columns are equal, the crosstalk can be reduced by eliminating the narrower intervals than others, but the intervals may differ by about ± 20%.

When the pressurizing chambers 10 are arranged in a grid pattern and the piezoelectric actuator substrate 21 is formed in a rectangular shape having outer sides along rows and columns, the piezoelectric actuator substrate 21 is formed on the pressurizing chamber 10 from the outer sides. Since the individual electrodes 25 are arranged at equal distances, the piezoelectric actuator substrate 21 can be hardly deformed when the individual electrodes 25 are formed. When the piezoelectric actuator substrate 21 and the flow path member 4 are joined, if this deformation is large, stress may be applied to the displacement element 30 near the outer side, resulting in variations in displacement characteristics. However, by reducing the deformation, The variation can be reduced. In addition, since the dummy pressurizing chamber row of the dummy pressurizing chamber 16 is provided outside the pressurizing chamber row 11 closest to the outer side, the influence of deformation can be made less susceptible. The pressurizing chambers 10 belonging to the pressurizing chamber row 11 are arranged at equal intervals, and the individual electrodes 25 corresponding to the pressurizing chamber rows 11 are also arranged at equal intervals. The pressurizing chamber rows 11 are arranged at equal intervals in the short direction, and the rows of individual electrodes 25 corresponding to the pressurizing chamber rows 11 are also arranged at equal intervals in the short direction. Thereby, it is possible to eliminate a portion where the influence of the crosstalk becomes particularly large.

  When the flow path member 4 is viewed in plan, the pressurizing chamber 10 belonging to one pressurizing chamber row 11 is overlapped with the pressurizing chamber 10 belonging to the adjacent pressurizing chamber row 11 in the longitudinal direction of the liquid ejection head 2. By arranging so as not to become crosstalk, crosstalk can be suppressed. On the other hand, when the distance between the pressurizing chamber rows 11 is increased, the width of the liquid discharge head 2 is increased. Therefore, the accuracy of the installation angle of the liquid discharge head 2 with respect to the printer 1 or when using a plurality of liquid discharge heads 2 The influence of the relative position accuracy of the liquid discharge head 2 on the printing result is increased. Therefore, by making the width of the partition wall 15 smaller than that of the sub-manifold 5b, the influence of the accuracy on the printing result can be reduced.

  The pressurizing chambers 10 connected to one sub-manifold 5 b constitute two pressurizing chamber rows 11, and the discharge holes 8 connected to the pressurizing chambers 10 belonging to one pressurizing chamber row 11 are One discharge hole row 9 is configured. The discharge holes 8 connected to the pressurizing chambers 10 belonging to the two pressurizing chamber rows 11 are opened on different sides of the sub manifold 5b. In FIG. 4, the partition wall 15 is provided with two rows of discharge holes 9. The discharge holes 8 belonging to each of the discharge hole rows 9 are connected to the sub-manifold 5 b on the side close to the discharge holes 8 in the pressurizing chamber 10. Are connected through. If the discharge hole 8 connected to the adjacent sub-manifold 5b via the pressurizing chamber row 11 and the liquid discharge head 2 do not overlap in the longitudinal direction, the pressurizing chamber 10 and the discharge hole 8 are connected. Since crosstalk between the flow paths can be suppressed, the crosstalk can be further reduced. If the entire flow path connecting the pressurizing chamber 10 and the discharge hole 8 is arranged so as not to overlap in the longitudinal direction of the liquid discharge head 2, the crosstalk can be further reduced.

  In addition, the width of the liquid discharge head 2 can be reduced by arranging the pressurizing chamber 10 and the sub-manifold 5b so as to overlap each other in plan view. When the ratio of the overlapping area to the area of the pressurizing chamber 10 is 80% or more, and further 90% or more, the width of the liquid discharge head 2 can be further reduced. Further, the bottom surface of the pressurizing chamber 10 where the pressurizing chamber 10 and the sub-manifold 5b overlap is less rigid than the case where the pressurizing chamber 10 and the sub-manifold 5b do not overlap. There is a risk of variation. By making the ratio of the area of the pressurizing chamber 10 overlapping the sub-manifold 5b to the area of the entire pressurizing chamber 10 substantially the same in each pressurizing chamber 10, the rigidity of the bottom surface constituting the pressurizing chamber 10 is increased. Variations in ejection characteristics due to changes can be reduced. Here, “substantially the same” means that the difference in area ratio is 10% or less, particularly 5% or less.

A plurality of pressurizing chambers are formed by a plurality of pressurizing chambers 10 connected to one manifold 5. Since there are two manifolds 5, there are two pressurizing chamber groups. The arrangement of the pressurizing chambers 10 related to ejection in each pressurizing chamber group is the same, and is arranged to be translated in the lateral direction. These pressurizing chambers 10 are arranged over substantially the entire surface of the upper surface of the flow path member 4 in a region facing the piezoelectric actuator substrate 21, although there are portions where the gaps are slightly wide, such as between the pressurizing chamber groups. . In other words, the pressurizing chamber group formed by these pressurizing chambers 10 occupies a region having substantially the same size and shape as the piezoelectric actuator substrate 21. Further, the opening of each pressurizing chamber 10 is closed by bonding the piezoelectric actuator substrate 21 to the upper surface of the flow path member 4.

  A descender connected to the discharge hole 8 opened in the discharge hole surface 4-1 on the lower surface of the flow path member 4 extends from a corner portion of the pressurizing chamber 10 facing the corner portion where the individual supply flow path 14 is connected. ing. The descender extends in a direction away from the pressurizing chamber 10 in plan view. More specifically, the pressurizing chamber 10 extends away from the direction along the long diagonal line while being shifted to the left and right with respect to that direction. As a result, the discharge chambers 8 can be arranged at an interval of 1200 dpi as a whole, while the pressurization chambers 10 are arranged in a lattice shape in which the intervals in the respective pressurization chamber rows 11 are 37.5 dpi.

  Individual electrodes 25 are formed at positions facing the pressurizing chambers 10 on the upper surface of the piezoelectric actuator substrate 21. The individual electrode 25 includes an individual electrode body 25a that is slightly smaller than the pressurizing chamber 10 and has a shape substantially similar to the pressurizing chamber 10, and an extraction electrode 25b that is extracted from the individual electrode body 25a. In the same manner as the pressurizing chamber 10, the individual electrode 25 constitutes an individual electrode row and an individual electrode group. One end of the extraction electrode 25b is connected to the individual electrode main body 25a, and the other end passes through the acute angle portion 10a of the pressurization chamber 10, and outside the pressurization chamber 10, two acute angle portions of the pressurization chamber 10 are provided. 10a is drawn to a region that does not overlap with the extended row of diagonal lines connecting 10a. Thereby, crosstalk can be reduced. The shape of the extraction electrode 25b will be described in detail later.

  A common electrode surface electrode 28 is formed on the upper surface of the piezoelectric actuator substrate 21 and is electrically connected to the common electrode 24 via a via hole. The common electrode surface electrodes 28 are formed in two rows along the longitudinal direction at the central portion of the piezoelectric actuator substrate 21 in the lateral direction, and are formed in one row along the lateral direction near the end in the longitudinal direction. ing. Although the illustrated common electrode surface electrode 28 is intermittently formed on a straight line, it may be formed continuously on a straight line.

  The piezoelectric actuator substrate 21 is formed by laminating and firing a piezoelectric ceramic layer 21a having a via hole, a common electrode 24, and a piezoelectric ceramic layer 21b, as will be described later, and then forming individual electrodes 25 and a common electrode surface electrode 28 in the same process. It is preferable to do this. The positional variation between the individual electrode 25 and the pressurizing chamber 10 greatly affects the ejection characteristics, and if the individual electrode 25 is formed and then fired, the piezoelectric actuator substrate 21 may be warped. When the substrate 21 is joined to the flow path member 4, stress is applied to the piezoelectric actuator substrate 21, and the displacement may vary due to the influence. Therefore, the individual electrode 25 is formed after firing. Similarly, the surface electrode 28 for the common electrode may be warped, and if the surface electrode 28 is formed at the same time as the individual electrode 25, the positional accuracy becomes higher and the process can be simplified. The surface electrode 28 is formed in the same process.

  Such a positional variation of via holes due to firing shrinkage that may occur when firing the piezoelectric actuator substrate 21 mainly occurs in the longitudinal direction of the piezoelectric actuator substrate 21, and therefore, a manifold having an even number of common electrode surface electrodes 28. 5, in other words, it is provided at the center in the short direction of the piezoelectric actuator substrate 21, and the common electrode surface electrode 28 has a long shape in the longitudinal direction of the piezoelectric actuator substrate 21. In addition, it is possible to prevent the via hole and the common electrode surface electrode 28 from being electrically connected due to misalignment.

Two flexible substrates 60 are arranged and bonded to the piezoelectric actuator substrate 21 from the two long sides of the piezoelectric actuator substrate 21 toward the center. At that time, the connection electrode 26 and the common electrode connection electrode (not shown) are formed and connected on the extraction electrode 25b and the common electrode surface electrode 28 of the piezoelectric actuator substrate 21a, respectively, so that the connection is easy. Become. At that time, if the area of the common electrode surface electrode 28 and the common electrode connection electrode is made larger than the area of the connection electrode 26, the end of the flexible substrate 60 (the front end and the end in the longitudinal direction of the piezoelectric actuator substrate 21). Since the connection can be made stronger by the connection on the common electrode surface electrode 28, the flexible substrate 60 can be hardly peeled off from the end.

  Further, the discharge hole 8 is arranged at a position avoiding the area facing the manifold 5 arranged on the lower surface side of the flow path member 4. Further, the discharge hole 8 is disposed in a region facing the piezoelectric actuator substrate 21 on the lower surface side of the flow path member 4. These discharge holes 8 occupy a region having substantially the same size and shape as the piezoelectric actuator substrate 21 as one group, and the displacement elements 30 of the corresponding piezoelectric actuator substrate 21 are displaced from the discharge holes 8. Droplets can be ejected.

  The flow path member 4 included in the head main body 2a has a laminated structure in which a plurality of plates are laminated. These plates are a cavity plate 4a, a base plate 4b, an aperture plate 4c, a supply plate 4d, manifold plates 4e to j, a cover plate 4k, and a nozzle plate 4l in order from the upper surface of the flow path member 4. A number of holes are formed in these plates. Since the thickness of each plate is about 10 to 300 μm, the formation accuracy of the holes to be formed can be increased. Each plate is aligned and laminated so that these holes communicate with each other to form the individual flow path 12 and the manifold 5. In the head main body 2a, the pressurizing chamber 10 is on the upper surface of the flow path member 4, the manifold 5 is on the inner lower surface side, the discharge holes 8 are on the lower surface, and the parts constituting the individual flow path 12 are close to each other in different positions. The manifold 5 and the discharge hole 8 are connected via the pressurizing chamber 10.

  The holes formed in each plate will be described. These holes include the following. The first is the pressurizing chamber 10 formed in the cavity plate 4a. Second, there is a communication hole that constitutes an individual supply channel 14 that is connected from one end of the pressurizing chamber 10 to the manifold 5. This communication hole is formed in each plate from the base plate 4b (specifically, the inlet of the pressurizing chamber 10) to the supply plate 4c (specifically, the outlet of the manifold 5). The individual supply flow path 14 includes a squeeze 6 that is formed in the aperture plate 4c and is a portion where the cross-sectional area of the flow path is small.

  Third, there is a communication hole constituting a flow path communicating from the other end of the pressurizing chamber 10 to the discharge hole 8, and this communication hole is referred to as a descender (partial flow path) in the following description. The descender is formed on each plate from the base plate 4b (specifically, the outlet of the pressurizing chamber 10) to the nozzle plate 4l (specifically, the discharge hole 8). The hole of the nozzle plate 41 is opened as a discharge hole 8 having a diameter of 10 to 40 μm, for example, which is open to the outside of the flow path member 4, and the diameter increases toward the inside. . Fourthly, communication holes constituting the manifold 5. The communication holes are formed in the manifold plates 4e to 4j. Holes are formed in the manifold plates 4e to 4j so that the partition walls 15 remain so as to constitute the sub-manifold 5b. The partition 15 in each manifold plate 4e-j cannot be held when the entire portion to be the manifold 5 is made a hole, so the partition 15 is connected to the outer periphery of each manifold plate 4e-j with a half-etched tab. To be.

The first to fourth communication holes are connected to each other to form an individual flow path 12 from the liquid inflow port (outlet of the manifold 5) to the discharge hole 8 from the manifold 5. The liquid supplied to the manifold 5 is discharged from the discharge hole 8 through the following path. First, from the manifold 5, it enters the individual supply flow path 14 and reaches one end of the throttle 6. Next, it proceeds horizontally along the extending direction of the restriction 6 and reaches the other end of the restriction 6. From there, it reaches one end of the pressurizing chamber 10 upward. Furthermore, it progresses horizontally along the extending direction of the pressurizing chamber 10 and reaches the other end of the pressurizing chamber 10. While moving little by little in the horizontal direction from there, it proceeds mainly downward and proceeds to the discharge hole 8 opened in the lower surface.

  The piezoelectric actuator substrate 21 has a laminated structure composed of two piezoelectric ceramic layers 21a and 21b which are piezoelectric bodies. Each of these piezoelectric ceramic layers 21a and 21b has a thickness of about 20 μm. The thickness from the lower surface of the piezoelectric ceramic layer 21a of the piezoelectric actuator substrate 21 to the upper surface of the piezoelectric ceramic layer 21b is about 40 μm. Both of the piezoelectric ceramic layers 21 a and 21 b extend so as to straddle the plurality of pressure chambers 10. These piezoelectric ceramic layers 21a and 21b are made of, for example, a lead zirconate titanate (PZT) ceramic material having ferroelectricity.

  The piezoelectric actuator substrate 21 includes a common electrode 24 made of a metal material such as Ag—Pd and an individual electrode 25 made of a metal material such as Au. As described above, the individual electrode 25 includes the individual electrode main body 25a disposed at the position facing the pressurizing chamber 10 on the upper surface of the piezoelectric actuator substrate 21, and the extraction electrode 25b extracted therefrom. A connection electrode 26 is formed at a portion of one end of the extraction electrode 25 b that is extracted outside the region facing the pressurizing chamber 10. The connection electrode 26 is made of, for example, silver-palladium containing glass frit, and has a convex shape with a thickness of about 15 μm. Further, the connection electrode 26 is electrically joined to an electrode provided on the flexible substrate 60. Although details will be described later, a drive signal is supplied to the individual electrode 25 from the control unit 100 (FIG. 1) through the flexible substrate 60. The drive signal is supplied in a constant cycle in synchronization with the conveyance speed of the print medium P.

  The common electrode 24 is formed over substantially the entire surface in the region between the piezoelectric ceramic layer 21a and the piezoelectric ceramic layer 21b. That is, the common electrode 24 extends so as to cover all the pressurizing chambers 10 in the region facing the piezoelectric actuator substrate 21. The thickness of the common electrode 24 is about 2 μm. The common electrode 24 is connected to the common electrode surface electrode 28 formed at a position avoiding the electrode group composed of the individual electrodes 25 on the piezoelectric ceramic layer 21b through a via hole formed in the piezoelectric ceramic layer 21b. Grounded and held at ground potential. The common electrode surface electrode 28 is connected to another electrode on the flexible substrate 60 in the same manner as the large number of individual electrodes 25.

  As will be described later, when a predetermined drive signal is selectively supplied to the individual electrode 25, the volume of the pressurizing chamber 10 corresponding to the individual electrode 25 changes, and the liquid in the pressurizing chamber 10 is pressurized. Is added. As a result, droplets are discharged from the corresponding liquid discharge ports 8 through the individual flow paths 12. That is, the portion of the piezoelectric actuator substrate 21 that faces each pressurizing chamber 10 corresponds to the individual displacement element 30 corresponding to each pressurizing chamber 10 and the liquid discharge port 8. That is, a displacement element 30, which is a piezoelectric actuator having a unit structure as shown in FIG. 5, is added to each pressurizing chamber 10 in a laminate composed of two piezoelectric ceramic layers 21 a and 21 b. The piezoelectric actuator substrate 21 includes a plurality of displacement elements 30 as pressurizing portions. The diaphragm 21a is located directly above the pressure chamber 10, is formed by a common electrode 24, a piezoelectric ceramic layer 21b, and individual electrodes 25. Yes. In the present embodiment, the amount of liquid ejected from the liquid ejection port 8 by one ejection operation is about 1.5 to 4.5 pl (picoliter).

The large number of individual electrodes 25 are individually electrically connected to the control unit 100 via the flexible substrate 60 and wiring so that the potential can be individually controlled. When an electric field is applied to the piezoelectric ceramic layer 21b in the polarization direction by setting the individual electrode 25 to a potential different from that of the common electrode 24, a portion to which the electric field is applied functions as an active portion that is distorted by the piezoelectric effect. In this configuration, when the control unit 100 sets the individual electrode 25 to a predetermined positive or negative potential with respect to the common electrode 24 so that the electric field and the polarization are in the same direction, a portion sandwiched between the electrodes of the piezoelectric ceramic layer 21b. (Active part) contracts in the surface direction. On the other hand, the piezoelectric ceramic layer 21a, which is an inactive layer, is not affected by an electric field, so that it does not spontaneously shrink and tries to restrict deformation of the active portion. As a result, there is a difference in strain in the polarization direction between the piezoelectric ceramic layer 21b and the piezoelectric ceramic layer 21a, and the piezoelectric ceramic layer 21b is deformed so as to protrude toward the pressurizing chamber 10 (unimorph deformation).

In an actual driving procedure in the present embodiment, the individual electrode 25 is set to a potential higher than the common electrode 24 (hereinafter referred to as a high potential) in advance, and the individual electrode 25 is temporarily set to the same potential as the common electrode 24 every time there is a discharge request. (Hereinafter referred to as a low potential), and then set to a high potential again at a predetermined timing. As a result, the piezoelectric ceramic layers 21a and 21b return to their original shapes at the timing when the individual electrode 25 becomes low potential, and the volume of the pressurizing chamber 10 increases compared to the initial state (the state where the potentials of both electrodes are different). To do. At this time, a negative pressure is applied to the pressurizing chamber 10 and the liquid is sucked into the pressurizing chamber 10 from the manifold 5 side. After that, at the timing when the individual electrode 25 is set to a high potential again, the piezoelectric ceramic layers 21 a and 21 b are deformed so as to protrude toward the pressurizing chamber 10, and the pressure in the pressurizing chamber 10 is reduced by the volume reduction of the pressurizing chamber 10. The pressure becomes positive and the pressure on the liquid rises, and droplets are ejected. That is, in order to discharge the droplet, a drive signal including a pulse based on a high potential is supplied to the individual electrode 25. The ideal pulse width is AL (Acoustic Length), which is the length of time during which the pressure wave propagates from the orifice 6 to the discharge hole 8. According to this, when the inside of the pressurizing chamber 10 is reversed from the negative pressure state to the positive pressure state, both pressures are combined, and the liquid droplets can be discharged at a stronger pressure.

  In gradation printing, gradation expression is performed by the number of droplets ejected continuously from the ejection holes 8, that is, the droplet amount (volume) adjusted by the number of droplet ejections. For this reason, the number of droplet discharges corresponding to the designated gradation expression is continuously performed from the discharge holes 8 corresponding to the designated dot region. In general, when liquid ejection is performed continuously, it is preferable that the interval between pulses supplied to eject liquid droplets is AL. As a result, the period of the residual pressure wave of the pressure generated when discharging the previously discharged liquid droplet coincides with the pressure wave of the pressure generated when discharging the liquid droplet discharged later, and these are superimposed. Thus, the pressure for discharging the droplet can be amplified.

<Second Embodiment>
The liquid ejection head 102 will be described with reference to FIGS. The liquid discharge head 102 is different from the liquid discharge head 2 in that a heat insulating material 83 is disposed between the heater 81 and the pressing member 96, and the other points are the same and will not be described. In addition, about the same member, the same code | symbol is attached | subjected and it is the same below.

  The heat insulating material 83 is provided on the heater 81 and is disposed between the heater 81 and the pressing member 96. In plan view, the heat insulating material 83 has substantially the same shape as the heater 81, and the heat insulating material 83 is provided over the entire surface of the heater 81. The heat insulating material 83 is disposed inside the opening 92c of the frame body 92 in plan view, and is disposed in a state of being separated from the frame body 92 by a predetermined distance.

  Therefore, in the liquid discharge head 2, the head main body 2a, the heater 81, the heat insulating material 83, and the pressing member 96 are arranged in this order, and the pressing member 96 presses the heater 81 against the head main body 2a via the heat insulating material 83. ing.

As the heat insulating material 83, a sponge body having a high foaming rate can be used, and for example, a melamine sheet can be used. By setting the thickness of the heat insulating material 83 to 2 to 5 mm,
While being able to insulate, it can suppress that the liquid discharge head 2 enlarges.

  In the liquid discharge head 2, a heat insulating material 83 is disposed between the heater 81 and the pressing member 96, and the pressing member 96 presses the heater 81 against the head body 2 a via the heat insulating material 83. That is, the liquid ejection head 2 is configured such that the head main body 2a, the heater 81, the heat insulating material 83, and the pressing member 96 are arranged in this order, and the pressing member 96 also presses the heat insulating material 83. Accordingly, the heater 81 can be pressed via the heat insulating material 83, and the possibility that the adhesion between the heater 81 and the reservoir 40 is reduced can be reduced. Therefore, the liquid discharge head 2 can warm the liquid flowing through the reservoir 40 by the heater 81, and can reduce the possibility that the discharge characteristics of each discharge hole 8 (see FIG. 5) vary greatly.

  Thus, when the pressing member 96 presses the reservoir 40 in a state where the flat plate portion 96 a is inclined with respect to the upper surface of the reservoir 40 by pressing the heater 81 through the heat insulating material 83. However, when the heat insulating material 83 is elastically deformed, the pressing member 96 can be pressed uniformly against the heater 81. Thereby, the possibility that the reservoir 40 and the heater 81 are locally peeled can be reduced, and the adhesion between the reservoir 40 and the heater 81 can be improved.

  Further, since the liquid ejection head 2 is provided with the heat insulating material 83 between the head main body 2a and the pressing member 96, the possibility that the heat inside the housing 90 is transmitted to the head main body 2a is reduced. Can do. In particular, in the liquid discharge head 2, the temperature of the driver IC 55 increases with high-speed printing, and the inside of the housing 90 may become high temperature. The possibility of high temperatures can be reduced.

  As shown in FIGS. 9 and 10, the liquid discharge head 2 is disposed so that the heat insulating material 83 covers a corner portion 96 d formed by the flat plate portion 96 a and the protruding portion 96 b. Therefore, the possibility that the heater 81 is damaged by the contact between the corner portion 96d and the heater 81 can be reduced.

  In particular, when the pressing member 96 is deformed when the casing 90 (see FIG. 6) or the reservoir 40 is pressed, the corner portion 96d may be displaced and the heater 81 may be damaged. The heat insulating material 83 functions to protect the heater 81, and the possibility that the heater 81 is damaged can be reduced.

  The sum of the thickness of the heater 81 and the thickness of the heat insulating material 83 is preferably larger than the thickness of the frame 92. Accordingly, when the pressing member 96 is connected to the reservoir 40 via the frame 92, the heat insulating material 83 is compressed in the thickness direction, and the heat insulating material 83 can apply a pressing force to the heater 81. Therefore, the pressing member 96 can press the heat insulating material 83 more.

  The pressing member 96 preferably presses the entire surface of the heater 81 through the heat insulating material 83. Thereby, the possibility that the adhesion between the heater 81 and the head main body 2a is reduced over the entire surface of the heater 81 can be reduced.

  The heater 81 and the heat insulating material 83 are preferably disposed inside the opening 92 c of the frame 92. Furthermore, it is preferable that a space surrounded by the heater 81, the frame body 92, and the pressing member 96 is filled with a heat insulating material 83. Thereby, it is possible to reduce the possibility that the heater 81 is displaced while reducing the decrease in the adhesion force of the heater 81.

  Note that the space surrounded by the heater 81, the frame body 92, and the pressing member 96 is filled with the heat insulating material 83 means that the space surrounded by the heater 81, the frame body 92, and the pressing member 96 is filled with the heat insulating material 83. This is a concept that includes not only the case where the openings are disposed without gaps but also the case where the planar view area of the heat insulating material 83 occupies 90% or more of the planar view area of the opening 92c.

  Further, in order to suppress the displacement of the heat insulating material 83, the long side 92a and the short side 92b of the frame body 92 may be provided with convex portions that project toward the center portion of the opening 92c in plan view. Thereby, when the heat insulating material 83 is disposed in the opening 92c of the frame 92, the heat insulating material 83 can be easily positioned. Further, by making the arrangement of the heat insulating material 83 accurate, it is possible to suppress the displacement of the heat insulating material 83 and to apply a pressing force uniformly to the heater 81.

  Moreover, it is preferable that the heat insulating material 83 is formed of an elastic member having elasticity. Thereby, the heater 81 can be pressed with a constant pressing force. In addition to the heat insulating material 83, an elastic member may be disposed between the heater 81 and the pressing member 96. Thereby, the heater 81 can be further pressed through the heat insulating material 83. Further, the elastic member may be disposed between the heat insulating material 83 and the frame body 92. Thereby, positioning of the heat insulating material 83 can be facilitated.

  Further, a heat conducting member may be provided between the heater 81 and the heat insulating material 83. Thereby, the heat of the heater 81 to the reservoir 40 can be made close to uniform. As the heat conducting member, for example, a metal foil such as an aluminum foil can be used. For example, the metal foil can be disposed over the entire area between the heater 81 and the heat insulating material 83.

<Third Embodiment>
The liquid discharge head 202 will be described with reference to FIGS. The liquid discharge head 202 is different from the liquid discharge head 102 in the shapes of the heater 281, the heat insulating material 283, and the pressing member 296, and the other points are the same, and thus the description thereof is omitted.

  As shown in FIGS. 11B, 12A, and 12B, the heater 281 includes a lead electrode 281a and a heat generating portion 281b. The lead electrode 281a is drawn to the outside and is electrically connected to a power source provided outside. The heat generating portion 281b is configured by wiring formed of a material having a high electric resistance value. The heat generating portion 281b is formed over substantially the entire surface of the heater 281 and is electrically connected to the lead electrode 281a. Therefore, when a voltage is applied to the lead electrode 281a, the heat generating portion 281b generates heat.

  The heat insulating material 283 is configured such that one end in the longitudinal direction is shorter than the heater 281 in a plan view. The pressing member 296 is provided with a notch 296 c on one end side of the heat insulating material 283. And as shown in FIG.11 (b), the opening is formed by the notch part 296c of the press member 296. FIG. The lead electrode 281a of the heater 281 is drawn out from this opening. And the heat insulating material 283 is arrange | positioned in a part of opening in planar view.

  As shown in FIG. 12B, the heater 281 has a heat generating portion 281b provided on the head main body 2a, and the lead electrode 281a is drawn out so as to be adjacent to the short side 92b of the frame 92. . The heat insulating material 283 is provided over the entire surface of the heat generating portion 281b of the heater 281 and one end of the heat insulating material 283 is in contact with the lead electrode 281a. Therefore, as shown in FIG. 12B, the lead electrode 281 a has a structure that is sandwiched between the heat insulating material 283 and the frame 92.

As described above, in the liquid discharge head 202, the lead electrode 281a of the heater 281 is drawn from the opening formed by the pressing member 296 and the frame body 92, and the heat insulating material 283 is formed in a part of the opening in a plan view. Is provided. As a result, the lead electrode 281a is fixed by the heat insulating material 283 and the frame body 92, and the lead electrode 281a repeats contact with the frame body 92 even when vibration occurs when the liquid discharge head 2 is conveyed. The possibility can be reduced, and the possibility that the lead electrode 281a is disconnected can be reduced.

  Further, since the liquid discharge head 202 is fixed to the head main body 2a in a state where the pressing member 296 presses the heat insulating material 283, the heat insulating material 283 is compressed by the pressing force applied to the pressing member 296, and the frame The lead electrode 281 a can be pressed against the body 92. That is, the pressing member 296 can be fixed to the head body 2 a and the lead electrode 281 a can be fixed to the frame body 92.

  Note that the length of the heat insulating material 283 in the longitudinal direction and the length of the heater 281 in the longitudinal direction may be substantially the same, and one end of the heat insulating material 283 on the side where the lead electrode 281a is drawn out may be bent upward. In this way, by bending one end of the heat insulating material 283 upward, the heat insulating material 283 can be disposed between the notch 296c of the pressing member 96 and the lead electrode 281a, and the lead electrode 281a is disconnected. The possibility can be reduced. Further, the opening formed by the notch 296c is filled with the heat insulating material 283, and the heat insulating property can be improved.

<Fourth Embodiment>
The liquid discharge head 302 will be described with reference to FIG. The liquid discharge head 302 is different from the liquid discharge head 202 in the shape of the heat insulating material 383, and the other points are the same, and thus the description thereof is omitted.

  The heat insulating material 383 includes a hole 383a and a flat portion 383b. The hole 383a is provided at one end in the longitudinal direction, and is arranged so that the hole 383a and the notch 296c of the pressing member 296 overlap each other.

  As shown in FIG. 13B, the lead electrode 281a of the heater 281 is inserted into the hole 383a. In the opening formed by the frame body 92 and the pressing member 296, a part of the flat portion 383b of the heat insulating material 383 is disposed.

  The liquid ejection head 302 includes a hole 383a through which the heat insulating material 383 is inserted through the lead electrode 281a. The lead electrode 281 a is inserted through the hole 383 a, and the heat insulating material 383 is pressed by the pressing member 296.

  For this reason, even when the hole 383a is formed larger than the diameter of the lead electrode 281a, the heat insulating material 383 to which the pressing force is applied is deformed to act to fill the gap between the hole 383a and the lead electrode 281a. Thereby, the gap between the hole 383a and the lead electrode 281a can be filled with the heat insulating material 383, and the heat insulating property between the head main body 2a and the pressing member 296 can be improved. That is, by making the hole 383a larger than the lead electrode 281a, the liquid discharge head 2 can be easily assembled, and the heat insulation between the head body 2a and the pressing member 296 can be improved.

  In addition, the lead electrode 281a is pressed against the pressing member 296 and the frame body 92 via the heat insulating material 383, thereby reducing the possibility of disconnection due to contact with the pressing member 296 and the frame body 92. it can. In addition, since the lead electrode 281a is inserted into the hole 383a of the heat insulating material 383, the heater 281 and the heat insulating material 383 can be easily aligned.

  Although an example in which one hole 383a is provided is shown, when there are a plurality of lead electrodes 281a, a plurality of holes 383a may be provided, or a plurality of lead electrodes 281a may be inserted into one hole 383a.

<Fifth Embodiment>
The liquid discharge head 402 will be described with reference to FIG. The liquid discharge head 402 is different from the liquid discharge head 102 in the shape of the heat insulating material 483, and the other points are the same, and thus the description thereof is omitted.

  The liquid ejection head 402 has a configuration in which the planar view width of the heat insulating material 483 is larger than the planar view width of the opening 92 c of the frame 92. Note that the planar view width of the heat insulating material 483 is larger than the planar view width of the opening 92c of the frame body 92 in a state where the heat insulating material 483 is not disposed inside the opening 92c of the frame body 92. This means that the planar view width is larger than the planar view width of the opening 92 c of the frame 92.

  As shown in FIG. 14, an opening is formed by the frame body 92 and the pressing member 96, and the flexible substrate 60 is drawn upward from the opening formed by the frame body 92 and the pressing member 96. . The flexible substrate 60 is pressed against the frame body 92 by a heat insulating material 483.

  Thereby, in the liquid discharge head 402, the flexible substrate 60 is sandwiched between the frame body 92 and the heat insulating material 483, and the flexible substrate 60 is erected in the vicinity of the frame body 92. Therefore, it becomes easy to arrange the pressing member 96, and the assembly of the liquid ejection head 2 can be facilitated.

  In addition, since the liquid ejection head 402 has a configuration in which the planar view width of the heat insulating material 483 is larger than the planar view width of the opening 92c of the frame 92, when the heat insulating material 483 is accommodated in the opening 92c, the opening is formed. It functions to press the flexible substrate 60 inserted through the 92c toward the long side 92a of the frame 92. Therefore, it becomes easy to arrange the pressing member 96, and the assembly of the liquid ejection head 2 can be facilitated.

  Further, since the planar view width of the heat insulating material 483 is larger than the planar view width of the opening 92c of the frame 92, the corner portion 96d formed by the flat plate portion 96a of the pressing member 96 and the protruding portion 96b. A heat insulating material 483 can be provided so as to cover the surface. Thereby, the possibility that the flexible substrate 60 contacts the corner portion 96d can be reduced, and the possibility that the wiring formed inside the flexible substrate 60 is disconnected can be reduced.

  The liquid ejection head 2 can be assembled as follows, for example.

  First, the side plate 94 and the frame 92 are screwed to the reservoir 40 of the head body 2a. At that time, the flexible substrate 60 connected to the piezoelectric actuator substrate 21 is inserted so as to pass inside the side plate 94 and the frame body 92. Next, the heater 81 is disposed in the opening 92 c of the frame 92, and the heat insulating material 483 is disposed so as to cover the entire surface of the heater 81. At this time, the flexible substrate 60 is erected by being pressed against the frame body 92 by the heat insulating material 483. Then, the pressing member 96 is disposed on the heat insulating material 483 and fixed to the reservoir 40 with screws while pressing the heat insulating material 483. Thereafter, the guide frame 84, the circuit board 82, and the connection board 80 are arranged, the flexible board 60 is fitted into the connector 82a of the circuit board 82, and finally the housing body 90a is covered.

  As described above, the liquid discharge head 2 is erected in a state where the flexible substrate 60 is in contact with the frame body 92, and handling properties at the time of manufacturing can be improved.

<Sixth Embodiment>
The liquid discharge head 502 will be described with reference to FIG. The liquid discharge head 502 further includes a temperature measuring element 584, and the shape of the heater 581 is different from that of the liquid discharge head 202, and the other points are the same.

  The heater 581 includes a lead electrode 521a, a flat portion 521b, and a notch 521c. The cutout portion 521c is formed in the flat portion 521b and is disposed at the center portion in the longitudinal direction. The notch 521c is provided so as to penetrate the flat part 521b. A temperature measuring element 584 is disposed in the notch 521c.

  The temperature measuring element 584 has a function of measuring the temperature of the head main body 2a, and includes a lead electrode 584a, an element portion 584b, and a wiring portion 584c. The element portion 584b is disposed inside the notch 521c and is provided on the head main body 2a. Therefore, the periphery of the element portion 584b is surrounded by the heater 581.

  The lead electrode 584a of the temperature measuring element 584 is drawn out so as to be adjacent to the lead electrode 581a of the heater 581. Therefore, the lead electrodes 581a and 584a can be pulled out together. The wiring portion 584c electrically connects the lead electrode 584a and the element portion 584b. The control unit 100 (see FIG. 1) drives the heater 281 based on the temperature detected by the element unit 584b to uniformly control the temperature of the liquid flowing through the head main body 2a.

  As the temperature measuring element 584, for example, a thermocouple or a thermistor can be exemplified.

  The liquid discharge head 502 includes a temperature measuring element 584 provided on the head main body 2a, and the pressing member 296 presses the temperature measuring element 584 against the head main body 2a. Thereby, the temperature measuring element 584 is pressed against the head main body 2a, and the adhesion between the temperature measuring element 584 and the head main body 2a can be improved. As a result, the temperature measuring element 584 can accurately detect the temperature of the liquid flowing through the head main body 2a, and the temperature of the liquid flowing through the head main body 2a can be controlled uniformly. Therefore, it is possible to reduce the possibility that the variation in the ejection characteristics of each ejection hole 8 (see FIG. 5) of the liquid ejection head 2 becomes large.

  The element portion 584b is disposed inside the notch 521c and is provided on the head main body 2a. Therefore, the periphery of the element portion 584b is surrounded by the heater 581. Therefore, the environment of the heater 581 around the element portion 584b can be made constant, and accurate temperature detection can be performed.

  In addition, although the example which forms the notch part 581c in the heater 581 and accommodates the element part 584 in the notch part 581c was shown, it is not limited to this. A temperature measuring element 584 may be disposed on the heater 581.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, although the printer 100 using the liquid discharge head 2 according to the first embodiment is shown, the present invention is not limited to this, and the liquid discharge heads 102, 202, 302, 402, 502 are used for the printer 100. Also good. Further, the liquid discharge heads 2, 102, 202, 302, 402, 50
2 may be combined.

  In the present specification, the displacement element 30 using piezoelectric deformation is shown as the pressurizing unit. However, the displacement element 30 is not limited to this, and any other element that can pressurize the liquid in the liquid pressurizing chamber 10 may be used. For example, the liquid in the liquid pressurizing chamber 10 may be heated and boiled to generate pressure, or MEM (Micro Electro Mechanical Systems) may be used.

  Moreover, although the example which provided the circuit board 82 and the connection board | substrate 80 in the inside of the housing | casing 90 was shown, it does not necessarily need to provide. For example, a structure in which the flexible substrate 60 is pulled out to the opening 90d of the housing 90 may be directly connected to the outside.

  Moreover, although the example which comprised the press member 96 by the flat plate part 96a and the protrusion part 96b was shown, it is not limited to this. For example, it may have a curved portion curved toward the heat insulating material 83 instead of the flat plate portion 96a. In this case, the pressing force for pressing the heat insulating material 83 can be increased, and the possibility that the heater 81 is peeled can be reduced.

  In the present embodiment, the liquid ejection head 2 including the frame body 92 has been described. However, the frame body 92 may not be necessarily provided. Moreover, although the example which penetrates the flexible substrate 60 from the opening formed by the frame 92 and the press member 96 was shown, even if the flexible substrate 60 penetrates between the outer side of the frame 92, and the housing | casing 90. Good.

DESCRIPTION OF SYMBOLS 1 ... Printer 2 ... Liquid discharge head 2a ... Head main body 4 ... Channel member 4a-1 ... (of channel member) 5 ... Manifold 5 ... Manifold 5a .. (manifold) opening 5b ... sub-manifold 6 ... squeezing 8 ... discharge hole 9 ... discharge hole array 10 ... pressure chamber 11 ... pressure chamber array 12 ... Individual flow path 14 ... Individual supply flow path 15 ... Partition 21 ... Piezoelectric actuator substrate 30 ... Displacement element (pressurizing part)
32 ... Individual channel 34 ... Common electrode 35 ... Individual electrode 36 ... Connection electrode 40 ... Reservoir 40a ... (Reservoir) liquid supply hole 55 ... Driver IC
60 ... flexible substrate 80 ... connection substrate 80a ... external connector 80b ... (connecting substrate) internal connector 80c ... (connection substrate) wiring 81 ... heater 82 ... Circuit board 82a ... (Circuit board) connector 83 ... Heat insulation 84 ... Guide frame 90 ... Frame 92 ... Frame body 94 ... Side plate 96 ... Pressing member 98 ... Insulating members

Claims (10)

A head body having a plurality of ejection holes;
A heater provided on the head body;
A flexible substrate electrically connected to the head body and for supplying electricity to the head body from the outside;
A driver IC mounted on the flexible substrate;
A radiator for dissipating the heat of the driver IC;
A pressing member for pressing the heater against the head body ,
The pressing member, the liquid discharge head is characterized that you have to press the driver IC to the radiator. A head body having a plurality of ejection holes;
A heater provided on the head body;
A flexible substrate electrically connected to the head body and for supplying electricity to the head body from the outside ;
A driver IC mounted on the flexible substrate;
A pressing member for pressing the heater against the head body;
Equipped with a temperature measuring element which is provided on said head main body,
A liquid discharge head in which the pressing member, characterized in that the temperature measuring element is pressed against the head body. A heat radiator for dissipating heat from the driver IC;
The liquid ejection head according to claim 2 , wherein the pressing member presses the driver IC against the heat radiating body. A heat insulating material is disposed between the heater and the pressing member;
The liquid ejection head according to claim 1, wherein the pressing member presses the heater against the head body via the heat insulating material. A frame surrounding the heat insulating material and the pressing member;
From the opening formed by the pressing member and the frame, the lead electrode of the heater is drawn out,
The liquid discharge head according to claim 4, wherein the heat insulating material is provided in a part of the opening in a plan view. The flexible substrate is drawn from the opening;
The liquid ejection head according to claim 5, wherein the heat insulating material presses the flexible substrate against the frame body.   The liquid ejection head according to claim 6, wherein a planar view width of the heat insulating material is larger than a planar view width of the opening of the frame body. The pressing member includes a flat plate portion positioned on the head main body, and a protruding portion protruding upward from the flat plate portion,
8. The liquid ejection head according to claim 3, wherein the flat plate portion presses the heater against the head body, and the protruding portion presses the driver IC against the heat radiating body. The pressing member includes a flat plate portion positioned on the head main body, and a protruding portion protruding upward from the flat plate portion,
The liquid discharge head according to claim 4, wherein the heat insulating material is disposed so as to cover a corner portion formed by the flat plate portion and the protruding portion. A liquid ejection head according to any one of claims 1 to 9,
A transport unit for transporting a recording medium to the liquid discharge head;
And a control unit that controls driving of the head body.