JP2011083706A - Printing head and discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet-type printing head which enables a mending of a discharge failure due to damage inflicted to a piezoelectric vibrator and is free from the deterioration of liquid droplet discharging performance even after the mending, as well as a discharge device. <P>SOLUTION: This printing head 1 is of the following structure: each different type of elastic member 5 is arranged on the top of each pressure generating chamber 9 of a printing head 1, and the end part of each different type of piezoelectric vibrator 4 is set in contact with each elastic member 5. In addition, an enclosure 2 for the printing head 1 includes a plurality of fixed plates 3 set in place, and each piezoelectric vibrator 4 is fixedly attached to either one of the fixed plates 3 by a part of the piezoelectric vibrator 4 separated from the elastic member 5. Each fixed plate 3 is constituted in the way that it is individually detachable from an enclosure 2 while the other fixed plate 3 is fixedly attached to the enclosure 2. When a discharge failure occurs due to troubles of some of the piezoelectric vibrators 4, the fixed plate 3 related to the faulty piezoelectric vibrator 4 can be removed from the enclosure 2 and repaired. Since the contact state between the elastic member 5 and the piezoelectric vibrator 4 remains unchanged before and after the repair, the discharge performance does not deteriorate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a print head and a discharge device, and particularly to a printer using a piezoelectric vibrator.

In recent years, inkjet type ejection devices have been used in the manufacture of color filters for liquid crystal display devices and organic EL display devices.
Reference numeral 101 in FIGS. 3A and 3B shows an example of a print head of such a conventional ejection device, and FIG. 3A is a schematic front view for explaining the internal structure. (B) is the schematic side view.

  The print head 101 has a housing 102, a nozzle plate 106, and an elastic plate 105. The casing 102 has a substantially rectangular parallelepiped shape, and has a bottom surface with one surface facing downward. The elastic plate 105 is fixed to the bottom surface of the housing 102 with its face facing upward. The nozzle plate 106 is fixed in such a manner that the surface facing upward is in close contact with the surface facing downward of the elastic plate 105.

A plurality of discharge ports 110 are provided on the surface facing the lower side of the nozzle plate 106, and a plurality of pressure generating chambers 109 are provided in the nozzle plate 106 so as to be separated from each other. Each pressure generation chamber 109 is connected to a different discharge port 110 by a discharge flow path 114.
The surface facing downward of the elastic plate 105 is partially exposed in each pressure generating chamber 109 from the opening of each pressure generating chamber 109 provided on the surface facing upward of the nozzle plate 106.

A plurality of through-holes are provided in the vertical direction so that a concave recess is provided on the side surface of the housing 102 and is connected to the inside of the recess 171 at a position directly above each pressure generation chamber 109 on the bottom surface of the housing 102. 107 is provided. The surface of the elastic plate 105 facing upward is partially exposed inside the recess 171 through each through hole 107.
A plurality of piezoelectric vibrators 104 and a fixed plate 103 are arranged inside the recess 171.
The fixed plate 103 is fixed to the bottom surface of the recess 171.

  Each piezoelectric vibrator 104 has a rod shape, and is arranged in a line in a horizontal direction at a position directly above a different pressure generation chamber 109 with its longitudinal direction parallel to the vertical direction. The lower end of each piezoelectric vibrator 104 is inserted into a different through hole 107 and is in contact with the surface of the elastic plate 105 facing upward. Each piezoelectric vibrator 104 is fixed to the fixed plate 103 at a part spaced from the elastic plate 105.

A common ink chamber 108 is provided inside the housing 102. Each pressure generation chamber 109 is connected to the common ink chamber 108 by a connection channel 115.
An ink tank (not shown) is disposed outside the print head 101, and the ink tank is connected to the common ink chamber 108 by a supply channel 117.

When the discharge liquid is supplied into the common ink chamber 108 from the ink tank in which the discharge liquid is stored, the discharge liquid flows into the pressure generation chambers 109 via the connection flow paths 115, respectively. Each is filled with the discharge liquid.
When a DC voltage is applied to the piezoelectric vibrator 104 in a state where each pressure generation chamber 109 is filled with the discharge liquid, the lower end portion of the piezoelectric vibrator 104 vibrates in the longitudinal direction, and the pressure is passed through the elastic plate 105. A pressing force is applied to the discharge liquid in the generation chamber 109, and the discharge liquid is discharged from the discharge port 110.

In the conventional print head 101 as described above, each piezoelectric vibrator 104 is generally fixed to the casing 102 together with the fixing plate 103 in a non-detachable manner. Accordingly, a part of the plurality of piezoelectric vibrators 104 may be damaged due to unforeseen circumstances such as when the ejected liquid accidentally enters the head or an excessive input voltage is applied to the piezoelectric vibrator 104. When the discharge and the discharge of the discharge liquid are partially impossible, the print head 101 is usually recovered by a method of discarding and replacing it with a new one.
However, with this method, even when only one of the plurality of piezoelectric vibrators 104 is damaged, the print head 101 is discarded, and there is a problem that the cost burden is large.

Japanese Patent No. 3675436

  The present invention was created in order to solve the above-described disadvantages of the prior art. The purpose of the present invention is to perform ink jet printing capable of repairing a discharge failure due to damage to a piezoelectric vibrator and not deteriorating the droplet discharge performance after the repair. To provide a head and an ejection device.

In order to solve the above problems, the present invention provides a head main body, a nozzle plate fixed to the head main body and having a plurality of pressure generating chambers formed therein, and each of the pressure generating chambers formed in the nozzle plate. A vibrating portion provided so as to close each of the openings, a plurality of piezoelectric vibrators that are in contact with the vibrating portion from the outside of the nozzle plate, and formed on the nozzle plate and connected to each of the pressure generating chambers. A plurality of discharge ports, and a fixed plate is fixed to the head body, and each of the piezoelectric vibrators is fixed to the fixed plate at a part spaced apart from the vibrating portion, The fixed plate is a print head configured to be detachable from the head body together with the plurality of piezoelectric vibrators fixed to the fixed plate.
The present invention provides a head body, a nozzle plate fixed to the head body and having a plurality of pressure generation chambers formed therein, and an opening of each pressure generation chamber formed in the nozzle plate. A plurality of piezoelectric vibrators that are in contact with the vibration part from the outside of the nozzle plate, a plurality of discharge ports that are formed in the nozzle plate and are connected to the pressure generation chambers, respectively. A plurality of fixed plates are fixed to the head main body, and each of the piezoelectric vibrators is fixed to any one of the fixed plates at a part spaced apart from the vibrating portion. The plate is configured to be detachable separately from the head body together with the plurality of piezoelectric vibrators fixed to the fixing plate in a state where the other fixing plate is fixed to the head body. It was a printing head.
The present invention is a printing head, wherein a part of each piezoelectric vibrator spaced apart from the vibrating portion is fixed to the fixing plate via an adhesive layer, and a lower end of each piezoelectric vibrator is directly attached to the vibrating portion. A bonded print head.
The present invention is the printing head, wherein the vibration part is made of resin, and an end portion of each piezoelectric vibrator is buried in and in contact with the vibration part within a range not exceeding the thickness of the vibration part. Print head.
This invention is a print head, Comprising: The said vibration part is a print head whose hardness measured by the type A durometer hardness test is 35 or more.
The present invention is a print head, wherein the nozzle plate is fixed to a plate-like portion provided in the head body, and the vibration portion is a print head fixed to the plate-like portion.
The present invention is the printing head, wherein a portion of the plate-like portion facing the opening of each pressure generating chamber is provided with a through hole portion, and the periphery of the vibrating portion is bonded to the inner periphery of the through hole portion. Print head.
The present invention is a print head, wherein the through hole portion includes a plurality of through holes, the vibration portion includes a plurality of elastic members, and ends of the piezoelectric vibrators are bonded to the different elastic members. The periphery of each of the elastic members is a print head bonded to the inner periphery of the different through hole.
The present invention is an ejection apparatus, comprising: the print head; and a substrate stage configured to be horizontally movable relative to the print head, and the ejection liquid ejected from the print head is applied to the substrate stage. It is the discharge device comprised so that it might land on the surface of the mounted discharge target object.

The present invention is a print head, wherein a discharge liquid is supplied from the ink chamber to each pressure generation chamber, the elastic member comes into contact with the discharge liquid, and when the piezoelectric vibrator vibrates, the elastic member passes through the elastic member. The print head is configured such that vibration is transmitted to the discharge liquid in the pressure generation chamber, and the discharge liquid to which the vibration is transmitted is discharged from the discharge port.
The test method for the type A durometer hardness test is defined in JIS K6253: 2006.

Since each piezoelectric vibrator is configured to be individually detachable from the housing every predetermined number, it is possible to repair the ejection failure of the print head due to partial damage of the piezoelectric vibrator at a low cost.
Since the mounting state of the fixing plate and the contact state between the piezoelectric vibrator and the elastic member do not change before and after the repair, the ejection failure of the print head can be repaired without deteriorating the ejection performance.

Three-dimensional view of a discharge device according to the present invention (A) Schematic front view of printing head according to the present invention (b) Schematic side view (A) Schematic front view of conventional print head (b) Schematic side view (A)-(f) The figure for demonstrating the assembly process of the print head which is this invention The figure for demonstrating the assembly process of a print head in case a vibration part is comprised with one elastic board. (A) Schematic front view of the print head when the vibration part is composed of one elastic plate (b) Schematic side view

An example of the structure of the ejection device according to the present invention will be described.
FIG. 1 shows a three-dimensional view of the ejection device 50.
The discharge device 50 includes a pedestal 51, a substrate stage 53, and the print head 1.
The surface facing upward of the pedestal 51 is leveled, and two linear main rails 52a and 52b parallel to each other are provided on the surface.

The substrate stage 53 is arranged on the main rails 52a and 52b so as to be laid on both rails. Main rail upper moving mechanisms 61a and 61b are provided on portions of the surface facing the lower side of the substrate stage 53 that face the main rails 52a and 52b, respectively. Each of the main rail upper moving mechanisms 61a and 61b is provided with a motor, and is configured to reciprocate the substrate stage 53 along the longitudinal direction of the main rails 52a and 52b when receiving a control signal from the control device 65.
A substrate holding surface 58 is provided on the surface facing the upper side of the substrate stage 53, and is configured to be able to hold a substrate which is a discharge target by vacuum suction or the like.

At a position higher than the substrate stage 53 on the pedestal 51, a rod-shaped bridge 54 is arranged so that its longitudinal direction is vertical and horizontal with the longitudinal direction of the main rails 52a, 52b.
Both ends of the bridge 54 are fixed to upper ends of columns 55a and 55b provided on the outer sides of the two main rails 52a and 52b on the pedestal 51, respectively.

The print head 1 is disposed on the side surface of the bridge 54 at a position higher than the substrate stage 53 on the pedestal 51.
The side surface of the bridge 54 facing the print head 1 is provided with a linear sub rail 56 along the longitudinal direction thereof. 62 is provided. The sub-rail moving mechanism 62 includes a motor, and is configured to be able to reciprocate the print head 1 along the longitudinal direction of the sub-rail 56 when receiving a control signal from the control device 65.

  Accordingly, the print head 1 is moved back and forth along the longitudinal direction of the sub rail 56 while moving the substrate stage 53 along the longitudinal direction of the main rails 52 a and 52 b and passing below the bridge 54. 1 can be positioned above a desired position on the substrate stage 53, and when the discharge liquid is discharged from the print head 1 in this state, the discharge target placed on the substrate holding surface 58 of the substrate stage 53 The discharged liquid can be landed at a desired position on the object surface.

  The moving mechanism in the ejection device 50 of the present invention is not limited to the above structure as long as the print head 1 is configured to be relatively horizontally movable on the substrate stage 53, and the substrate stage stationary with respect to the pedestal 51. The print head 1 may be configured to be movable in two directions that are horizontal and perpendicular to each other above 53, and the substrate stage 53 is horizontally and perpendicular to each other below the print head 1 that is stationary with respect to the pedestal 51. It may be configured to be movable in the direction.

2A is a schematic front view for explaining the internal structure of the print head 1, and FIG. 2B is a schematic side view thereof.
The print head 1 includes a housing (head body) 2, a nozzle plate 6, and a plurality of pressure generation modules 70.

The housing 2 has a substantially rectangular parallelepiped shape, and the nozzle plate 6 has a substantially rectangular flat plate shape. The housing 2 has a bottom surface with one surface facing downward, and the nozzle plate 6 is fixed to the bottom surface of the housing 2.
A plurality of discharge ports 10 are provided on the surface facing the lower side of the nozzle plate 6, and a plurality of pressure generating chambers 9 are provided in the nozzle plate 6 so as to be separated from each other. Each pressure generation chamber 9 is connected to a different discharge port 10 by a discharge flow path 14.

A concave recess 71 is provided on a side surface of the housing 2, and a plate-like portion 29 having two surfaces formed from a side surface below the recess 71 and a bottom surface of the housing 2 is formed on the bottom of the housing 2. ing.
The plate-like portion 29 is provided with a through hole portion in the vertical direction.
Here, the through-hole portion is composed of the same number of through-holes 7 as the pressure generating chambers 9, and each through-hole 7 is relative to the opening of the different pressure generating chamber 9 formed on the surface facing the upper side of the nozzle plate 6. As shown, the same arrangement as the opening and the same center-to-center distance are provided.

Vibrating portions are provided so as to be partially exposed in the pressure generating chambers 9 from the openings of the pressure generating chambers 9 formed on the upper surface of the nozzle plate 6.
Here, the vibration part is composed of the same number of elastic members 5 as the pressure generating chambers 9, and each elastic member 5 is disposed in a different through hole 7.
The vibrating portion of the present invention is not limited to the above-described configuration, and is constituted by a single elastic plate, and the elastic plate is provided between the bottom surface of the plate-like portion 29 and the surface facing the nozzle plate 6. May be.

FIG. 6A shows a schematic front view for explaining the internal structure of the print head 1 in the case where the vibration part is composed of one elastic plate, and FIG. 6B shows the schematic side view thereof. Yes. Reference numeral 28 denotes an elastic plate.
Each pressure generating module 70 is arranged inside the recess 71 of the housing 2. Each pressure generating module 70 includes a fixed plate 3 and a plurality of piezoelectric vibrators 4.

Each fixing plate 3 is fixed to the bottom surface of the recess 71.
Each piezoelectric vibrator 4 has a rod shape, and is arranged in a line in the horizontal direction at a position directly above the different pressure generation chambers 9 with the longitudinal direction parallel to the vertical direction. The lower end of each piezoelectric vibrator 4 is in contact with the elastic member 5 through different through holes 7.
Here, each elastic member 5 is made of resin, and the lower end of each piezoelectric vibrator 4 is buried in and in contact with each elastic member 5 within a range not exceeding the thickness of each elastic member 5. The periphery is bonded to the inner periphery of each through hole 7.

The contact state between each piezoelectric vibrator 4 and the vibrating portion of the present invention is not limited to the configuration in which the piezoelectric vibrator 4 and the vibrating portion are directly bonded as described above, and each piezoelectric vibrator 4 and the vibrating portion are bonded via an adhesive or the like. It may be. Reference numeral 27 in FIGS. 6A and 6B denotes an adhesive.
Each piezoelectric vibrator 4 is fixed to a different fixing plate 3 at a part spaced apart from the elastic member 5. A notch is formed below the fixed portion of each fixed plate 3, and the lower end of each piezoelectric vibrator 4 and the fixed plate 3 are separated from each other.

A first electrode layer 24 is provided on one side surface of each piezoelectric vibrator 4, and a second electrode layer 23 is provided on a side surface opposite to the first electrode layer 24 so as to be insulated from the first electrode layer 24. .
When a DC voltage is applied between the first electrode layer 24 and the second electrode layer 23, the lower end of the piezoelectric vibrator 4 that is not fixed to the fixing plate 3 is either expanded or contracted in the longitudinal direction. The shape is changed, and a pressing force can be applied to the pressure generating chamber 9 via the elastic member 5.

The vibration part preferably has a hardness measured by a type A durometer hardness test of 35 or more.
The vibration part needs to be resistant to the solvent of the discharged liquid, and when the vibration part is composed of a resin elastic member 5, examples of desirable materials include silicone-based materials used for sealing and potting. The pasty rubber material.
In the case where the vibration part of the present invention is composed of a single elastic plate 28, examples of desirable materials for the elastic plate 28 include thin metal foils and organic polymer films.

The print head 1 of the present invention is not limited to a structure in which a plurality of fixing plates 3 are provided, but a structure in which a single fixing plate 3 is provided, and each piezoelectric vibrator 4 is fixed to the fixing plate 3. But you can.
The assembly process of the print head 1 as described above will be described with reference to FIGS. 4A to 4C are side views of the print head 1 in each process, and FIGS. 4D to 4F are views of the housing 2 in each process of FIGS. 4A to 4C. The top view which looked up at the bottom from the bottom is shown.

4A and 4D show a state before the print head 1 is assembled. The print head 1 is separated into a housing 2, a nozzle plate 6, and a plurality of pressure generation modules 70.
As described above, when the bottom surface of the housing 2 is fixed to the upper surface of the nozzle plate 6 on the plate-like portion 29 at the bottom of the housing 2, the upper openings of the different pressure generation chambers 9 are respectively A plurality of through holes 7 are provided so as to communicate with each other.

The structure of each pressure generation module 70 will be described.
Each fixing plate 3 has a substantially rectangular flat plate shape, and one end is directed downward. One surface of each fixing plate 3 is formed flat. The other surface has a notch formed in the lower part, and the thickness of the notch is made thinner than the thickness above the notch.
An adhesive layer 25 is disposed above the notch of each fixing plate 3.
The upper part of the side surface of each piezoelectric vibrator 4 on which the first electrode layer 24 is provided is fixed to one of the fixing plates 3 via an adhesive layer 25. At this time, the lower end of each piezoelectric vibrator 4 protrudes downward from the lower end of the fixed plate 3.

  First, as shown in FIGS. 4B and 4E, the lower ends of the piezoelectric vibrators 4 are inserted into the different through holes 7 so that each pressure generating module 70 is placed inside the recess 71. Move to. Each pressure generating module 70 is stationary by positioning so that the convex portion provided at the upper end of each fixing plate 3 fits into the concave portion provided on the side wall above the depression 71 (front of FIG. 2A). (See diagram). At this time, the lower ends of the piezoelectric vibrators 4 inserted inside the different through holes 7 are within the range of the lengths of the through holes 7 and do not protrude from the bottom surface of the housing 2. It is stationary. The flat surface of each fixing plate 3 is in contact with the bottom surface of the recess 71, and the lower end of each fixing plate 3 is in contact with the side surface below the recess 71.

The upper part of each fixing plate 3 is screwed to a predetermined position of the housing 2 by a main screw 42 (see the front view of FIG. 2A).
A gap 16 is formed between the notch of each fixed plate 3 and the lower portion of the piezoelectric vibrator 4 fixed to the fixed plate 3.
The holding plates 11 longer than the length of the rows of the piezoelectric vibrators 4 are arranged in the gaps 16 and both ends of the holding plates 11 are screwed to predetermined positions of the housing 2 by the sub screws 41 (FIG. 2A). See the front view).

  A concave portion is provided on a surface of each fixing plate 3 facing the pressing plate 11, and a convex portion is provided on a surface of the pressing plate 11 facing each fixing plate 3. When both end portions of the pressing plate 11 are screwed to predetermined positions of the housing 2, the convex portions of the pressing plate 11 are configured to fit into the concave portions of the fixing plates 3.

  In this manner, each fixing plate 3 is aligned with a predetermined positional relationship relative to the housing 2 and fixed. The adhesive layer 25 and the fixing plate 3 are conductive, and the first electrode layer 24 of each piezoelectric vibrator 4 is electrically connected to the housing 2 via the adhesive layer 25 and the fixing plate 3. Connected to.

  Next, when the vibration part is composed of the elastic member 5 made of resin, a peeling film in which a liquid resin having adhesive properties is uniformly applied to the surface is passed through the plate-like part 29 from below the housing 2. When the resin surface of the release film is pressed against the portion where the hole 7 is provided, the resin at the portion facing each through hole 7 is pushed into each through hole 7. At this time, the lower end of the piezoelectric vibrator 4 inserted inside each through-hole 7 is positioned so as not to protrude from the bottom surface of the housing 2, so that it does not penetrate through the resin and faces downward. It is not exposed on the surface.

Next, when the resin is cured, the lower end of the piezoelectric vibrator 4 is bonded to the pressed resin in a state where it is buried within a range not exceeding the thickness of the resin, and the periphery of the pressed resin is the inner circumference of each through hole 7. The through holes 7 are tightly closed with resin.
When the release film is peeled off from the housing 2, one elastic member 5 is formed in each through hole 7 as shown in FIGS. 4 (c) and 4 (f). The elastic members 5 are separated from each other.

  When the vibration part of the present invention is constituted by a single elastic plate 28, the elastic plate 28 having the adhesive 27 applied on the surface is attached to the surface of the adhesive 27 as shown in the schematic side view of FIG. 5. Is pressed against the bottom surface of the housing 2 and the elastic plate 28 is adhered to the bottom surface of the housing 2 via the adhesive 27 to form a vibrating portion. The lower end of each piezoelectric vibrator 4 is bonded to the elastic plate 28 by an adhesive 27 pushed into each through hole 7.

Next, the circuit board 21 provided with a plurality of circuit electrodes 22 on one surface is disposed in the vicinity of the opening of the recess 71, and each circuit electrode 22 is brought into contact with the second electrode layer 23 of the piezoelectric vibrator 4 different from each other. Connect.
The circuit board 21 is connected to a control device (not shown), and is configured to electrically connect one circuit electrode 22 selected by the control signal and its own input terminal when receiving a control signal from the control device. Yes.
The input terminal of the circuit board 21 and the housing 2 are connected to different output terminals of a DC power supply 69 arranged outside the housing 2 (see FIG. 2).

When a DC voltage is applied between the circuit board 21 and the housing 2 from the DC power source 69 with one circuit electrode 22 selected on the circuit board 21 by the control signal, the selected circuit electrode 22 A direct current voltage is applied to the piezoelectric vibrator 4 in contact therewith.
A common ink chamber 8 is provided inside the housing 2, and an ink tank connection port 18 is provided on the side surface of the housing 2. The inside of the common ink chamber 8 is connected to an ink tank connection port 18 by a supply channel 17. The bottom wall of the common ink chamber 8 is not provided, and the inside of the common ink chamber 8 is exposed on the bottom surface of the housing 2.

  Next, as shown in FIG. 2 (b), the opening at the top of each pressure generating chamber 9 and the different through-holes 7 on the bottom surface of the housing 2 face each other, and the inside of each pressure generating chamber 9 is connected by a connection channel 15. In a state where the nozzle plate 6 and the housing 2 are aligned so as to be connected to the common ink chamber 8, the surface facing the upper side of the nozzle plate 6 is fixed to the bottom surface of the housing 2. In this way, the print head 1 is assembled.

Here, a common ink chamber 8 common to each pressure generating chamber 9 is provided inside the housing 2, but the present invention is not limited to this, and a separate ink chamber is provided in each pressure generating chamber 9. It may be provided.
The ink tank connection port 18 is connected to an ink tank 57 disposed outside the print head 1.
The discharge liquid is stored in the ink tank 57, and when the discharge liquid is supplied from the ink tank 57 into the common ink chamber 8, the discharge liquid passes through the connection channel 15 and enters each pressure generation chamber 9. Inflow (see FIG. 1).

The discharge liquid that has flowed into the pressure generating chamber 9 reaches the discharge port 10 through the discharge flow path 14, but the back pressure of the discharge liquid at the discharge port 10 balances with the downward force due to the weight of the discharge liquid, and the discharge liquid As long as no other downward force is added, the discharge liquid is not discharged from the discharge port 10, and thus the state in which the discharge liquid is filled in the pressure generation chamber 9 is maintained.
The discharge liquid filled in each pressure generating chamber 9 comes into contact with the elastic member 5.

  When a DC voltage is applied to one piezoelectric vibrator 4 selected by the control device in a state where the discharge liquid is filled in each pressure generating chamber 9, the lower end of the piezoelectric vibrator 4 vibrates and the lower end thereof is The bonded elastic member 5 vibrates and a pressing force is applied to the discharge liquid in the pressure generation chamber 9 that comes into contact with the elastic member 5, and the discharge liquid is externally supplied from the discharge port 10 connected to the pressure generation chamber 9. Discharged.

Since each fixing plate 3 is fixed to the housing 2 by the mounting structure as described above, it is configured to be detachable from the housing 2 separately.
Accordingly, when one piezoelectric vibrator 4 of the print head 1 is damaged, only one piece of the plurality of fixed plates 3 on which the damaged piezoelectric vibrator 4 is fixed can be replaced without replacing the entire print head 1. Can be removed from the housing 2 together with the plurality of piezoelectric vibrators 4 fixed thereto, and the other fixing plate 3 can be repaired while being fixed to the housing 2.

  In the case where the vibration part is composed of a resin elastic member 5, the elastic member 5 has an upwardly facing surface bonded to the lower end of each piezoelectric vibrator 4, and at the same time, the periphery is on the inner periphery of each through-hole 7. Since the predetermined fixing plate 3 is detached from the housing 2 separately, the elastic member 5 bonded to each lower end of the plurality of piezoelectric vibrators 4 fixed to the fixing plate 3 is destroyed. Is done. However, after separating the nozzle plate 6 from the bottom surface of the housing 2, it is possible to remove the elastic member 5 destroyed from the inside of each through hole 7, and then recreate the elastic member 5 by the method described above. .

  When the vibrating portion of the present invention is configured by a single elastic plate 28, when the predetermined fixing plate 3 is removed from the housing 2, the elastic plate 28 is located between the bottom surface of the housing 2 and the nozzle plate 6. It remains adhered to. After separating the nozzle plate 6 from the bottom surface of the housing 2, the elastic plate 28 is separated from the bottom surface of the housing 2. The adhesive 27 remaining from the bottom surface of the housing 2 is removed, and then the adhesive 27 is newly applied to the surface of a new elastic plate 28. Thereafter, the vibration portion made of one elastic plate 28 is formed by the method described above. It can be recreated.

When the vibration part is composed of the resin elastic member 5, the elastic member 5 and the piezoelectric member 5 can be formed as long as the thickness of the elastic member 5 and the buried length of the end portion of the piezoelectric vibrator 4 in the elastic member 5 do not change before and after the repair. Since the contact state with the vibrator 4 is the same before and after the repair, the ejection performance does not change before and after the repair.
Adhesion between each fixed plate 3 and each piezoelectric vibrator 4 is performed by using a not-shown sticking jig that is considered so that the positional relationship between the casing 2, each fixed plate 3 and each piezoelectric vibrator 4 does not change. To do. Since the relative positional relationship of the piezoelectric vibrator 4 with respect to the housing 2 does not change, a change in ejection performance due to restoration does not occur.

The end portions of the piezoelectric vibrators 4 are buried in the elastic member 5 having a predetermined thickness with a predetermined embedment length, and bonded in a state of being in direct contact without using an adhesive, whereby the contact state between the two is changed. It becomes uniform, and there is no difference in the pressing force applied to the discharge liquid from each piezoelectric vibrator 4 via the elastic member 5. Accordingly, there is no variation in the discharge amount from each discharge port 10 due to the difference in pressing force.
Further, since the elastic member 5 that contacts the end of each piezoelectric vibrator 4 is separated for each piezoelectric vibrator 4, vibration generated in the piezoelectric vibrator 4 to which a voltage is applied comes into contact with this. Although it propagates only to the elastic member 5, it does not propagate to the other elastic members 5, and the problem of crosstalk that discharge liquid is discharged from the other discharge ports 10 by vibration propagation through the elastic member 5 does not occur.

The length at which the end of the piezoelectric vibrator 4 is buried in the elastic member 5 affects the discharge performance of the discharge liquid.
As an example, the print head 1 as described above was manufactured by setting the buried length of the tip of the piezoelectric vibrator 4 to 0.48 mm with respect to the thickness of the elastic member 5 of 0.50 mm.
At this time, discharge performance with an average speed of 4 m / s and an average discharge amount of 40 pl per drop with respect to an input voltage of 50 V was obtained.

1 …… Print head 2 …… Case (head body)
3 ... Fixed plate 4 ... Piezoelectric vibrator 5 ... Elastic member 6 ... Nozzle plate 7 ... Through hole 8 ... Ink chamber 9 ... Pressure generating chamber 10 ... Discharge port 29 ... Plate-like portion 50 ... ... Discharge device 53 ... Substrate stage

Claims (9)

The head body,
A nozzle plate fixed to the head body and having a plurality of pressure generating chambers formed therein;
A vibration part provided to block the opening of each pressure generating chamber formed in the nozzle plate;
A plurality of piezoelectric vibrators in contact with the vibration part from the outside of the nozzle plate;
A plurality of discharge ports formed in the nozzle plate and connected to the pressure generation chambers;
A print head comprising:
A fixing plate is fixed to the head body,
Each of the piezoelectric vibrators is fixed to the fixing plate at a part spaced apart from the vibrating part,
The print head is configured such that the fixed plate is detachable from the head body together with the plurality of piezoelectric vibrators fixed to the fixed plate. The head body,
A nozzle plate fixed to the head body and having a plurality of pressure generating chambers formed therein;
A vibration part provided to block the opening of each pressure generating chamber formed in the nozzle plate;
A plurality of piezoelectric vibrators in contact with the vibration part from the outside of the nozzle plate;
A plurality of discharge ports formed in the nozzle plate and connected to the pressure generation chambers;
A print head comprising:
A plurality of fixing plates are fixed to the head body,
Each of the piezoelectric vibrators is fixed to any one of the fixed plates at a part spaced apart from the vibrating part,
Each of the fixing plates is configured to be detachable separately from the head body together with the plurality of piezoelectric vibrators fixed to the fixing plate in a state where the other fixing plates are fixed to the head body. Print head. A part of each piezoelectric vibrator spaced apart from the vibrating portion is fixed to the fixing plate via an adhesive layer,
The print head according to claim 1, wherein a lower end of each piezoelectric vibrator is directly bonded to the vibrating portion.   4. The vibration part according to claim 1, wherein the vibration part is made of resin, and an end part of each piezoelectric vibrator is buried in and in contact with the vibration part within a range not exceeding the thickness of the vibration part. A print head according to claim 1.   The print head according to any one of claims 1 to 4, wherein the vibration portion has a hardness measured by a type A durometer hardness test of 35 or more. The nozzle plate is fixed to a plate-like portion provided in the head body,
The print head according to claim 1, wherein the vibration part is fixed to the plate-like part. A through-hole portion is provided in a portion facing the opening of each pressure generation chamber of the plate-like portion,
The print head according to claim 6, wherein a periphery of the vibrating portion is bonded to an inner periphery of the through-hole portion. The through hole portion is composed of a plurality of through holes,
The vibrating part is composed of a plurality of elastic members,
The print head according to claim 7, wherein end portions of the piezoelectric vibrators are bonded to the different elastic members, and the circumferences of the elastic members are bonded to inner peripheries of the different through holes. A print head according to any one of claims 1 to 8,
A substrate stage configured to be horizontally movable relative to the print head;
Have
An ejection device configured to cause ejection liquid ejected from the print head to land on the surface of an ejection object placed on the substrate stage.

Images