JP2009172778A - Droplet discharge head, droplet discharge apparatus, and recording apparatus - Google Patents

Abstract

Provided is a droplet discharge head that can ensure high assembly accuracy and can inspect relative positional accuracy between components after joining the components.
A droplet discharge head 10 in which two second members 14 are joined to a first joining surface 27 of a first member 15 in parallel with each other. The second joining surfaces 28 of both the second members 14 are provided with a stepped portion 18 that is concave in the joining direction, and the stepped portion 18 is used for position adjustment with respect to the first member 15 so as to be related to the opposing side surface 14a. An alignment mark 21 is provided as a reference, and at least one of the second members 14 is in contact with the second joint surface 28 while the second members 14 are in parallel with the first joint surface 27. An opening 20 is formed in the outer wall surface 16 for communicating the stepped portion 18 to the outside of the second member 14 on the outer wall surface side located in a direction orthogonal to the parallel direction of the second members 14 in the direction along Has been.
[Selection] Figure 2

Description

  The present invention is, for example, a droplet discharge head for discharging droplets for image recording, and in particular, at least two second members are bonded in parallel to the first bonding surface of the first member. The present invention relates to a droplet discharge head, and a droplet discharge device and a recording device on which the droplet discharge head is mounted.

  In recent years, recording apparatuses (liquids) such as printers, facsimiles, and copiers that record an image using an ink jet type droplet discharge head that prints on paper by discharging ink droplets (droplets) onto the paper. The number of droplet discharge devices is increasing. Various droplet discharge heads having various structures are known. A plurality of nozzles for discharging ink droplets, a flow path plate for forming a liquid chamber corresponding to each nozzle, a liquid Actuators corresponding to the respective nozzles for applying ejection energy to the ink in the chamber, and each actuator is selectively driven to eject ink droplets corresponding to the recording signal from the nozzles. Some form an image with ink droplets. As the actuator, an electromechanical conversion element that converts electrical energy into mechanical displacement, a heating resistor, or the like is used.

  In this droplet discharge head, in order to perform high-quality recording at high density, the positions of the constituent micro parts, that is, the nozzle plate, flow path plate, piezoelectric element, etc., are adjusted and joined with high accuracy. It needs to be assembled. In particular, in recent years, since further downsizing of the droplet discharge head has been demanded, each constituent micro component is further miniaturized. Therefore, in assembling the droplet discharge head, for example, very high accuracy (for example, ± 10 μm or so) is required.

  In order to achieve an appropriate positional relationship between the liquid chambers of the flow path plate and the actuator (heater in this example) in order to achieve such high assembly accuracy, the rightmost end of the steps that can be made behind the actuator in the Y-axis direction. The position of the liquid chamber is detected by an observation system using image processing to make the step located at the reference position (so-called alignment mark) for adjusting the position of the actuator, and then the position of the reference liquid chamber is observed under the same observation system. An alignment method using image processing that adjusts the position of the flow path plate so as to match the alignment mark has been proposed (see, for example, Patent Document 1).

  However, in this method, it is necessary to detect the position of the alignment mark set on the member (the rightmost step in the above example). For this reason, there is a possibility that the adhesive for shielding the alignment mark and the position of the alignment mark cannot be detected. Even if the adhesive does not completely shield the alignment mark, it is necessary to grasp the contour position of the alignment mark in a scene where higher accuracy is required. As a result, the position of the alignment mark may not be detected with high accuracy.

  For this reason, the present applicant has formed a concave shape in the joining direction on the joining surface of one member (in this example, a piezoelectric element as an actuator) of the two members to be joined in contact with each other. A droplet discharge head having a structure in which a step portion (separated from the above member) is provided and an alignment mark is formed on the step portion has been proposed in the invention already filed (see, for example, Patent Document 2). In the droplet discharge head having this configuration, since the alignment mark is provided at a position recessed with respect to the bonding surface to which the adhesive is applied, the adhesive applied to the bonding surface is prevented from adhering to the alignment mark. Therefore, the position of the alignment mark can be detected with high accuracy. The state of alignment (alignment) in the droplet discharge head having this configuration will be described with reference to FIGS.

  In the example shown in FIGS. 17 to 19, two piezoelectric elements 3 as actuators provided on the substrate 2, a vibration plate 4 in which a displacement portion (not shown) is joined to the piezoelectric elements 3, and a liquid chamber A flow path plate 5 for forming 5a, and a nozzle plate (not shown) joined on the flow path plate 5 so that each nozzle (not shown) corresponds to a displacement portion of the vibration plate 4. In the droplet discharge head 1, the relative position adjustment between the piezoelectric elements 3 provided on the substrate 2 and the diaphragm 4 to which the flow path plate 5 is bonded is shown.

  Both piezoelectric elements 3 have a long plate shape, and the above-described step portion 6 and alignment mark 7 are provided in the vicinity of both ends viewed in the extending direction. The step portion 6 and the alignment mark 7 have a groove shape extending in the width direction of both piezoelectric elements 3.

  The vibration plate 4 is provided with a position detection hole 4a which is a through hole as a position detection mark for adjusting the relative position of the piezoelectric element 3 and the vibration plate 4 with the alignment mark 7 as a reference. The flow path plate 5 is provided with an observation hole 5a that is a through hole for observing the position detection hole 4a and the alignment mark 7.

  In the relative position adjustment between the piezoelectric elements 3 and the diaphragm 4, the position detection hole 4 a and the alignment mark 7 are relative to each other through the observation hole 5 a using the mark detection device 8 that is an observation optical system. The relative positions of the two piezoelectric elements 3 and the diaphragm 4 are adjusted so that the mutual positional relation is appropriate, whereby the positions of the two piezoelectric elements 3 and the diaphragm 4 are observed. Can be combined. Here, the position detection hole 4a is a relative position with respect to the position near the side surface of the piezoelectric element 3 facing the other side of the other piezoelectric element 3 in the grooved alignment mark 7. It is set to adjust the relationship. In other words, the relative position of the diaphragm 4 is set with reference to an intermediate (hereinafter referred to as “inside”) side between the two piezoelectric elements 3 facing each other. This is based on the outer side surface of either one of the piezoelectric elements 3, due to processing errors of both the piezoelectric elements 3 themselves, mounting errors of the piezoelectric elements 3 on the substrate 2, and the like. Even when the relative position with respect to the plate 4 is adjusted, various errors are accumulated as the distance from the reference position becomes larger. Although the positional deviation of the vibration plate 4 in the droplet ejection head 1 may be increased, the positional deviation of the vibration plate 4 in the droplet ejection head 1 can be reduced when the inner side is used as a reference. At this time, the illumination device 9 is used for the observation of the alignment mark 7 by the mark detection device 8.

  This illumination device 9 is not a coaxial epi-illumination, but an oblique illumination that illuminates the periphery of the alignment mark 7 from the side of both piezoelectric elements 3 (so as to advance between both piezoelectric elements 3 and the diaphragm 4). It is said that. This is because if the coaxial epi-illumination is used, it is possible to clearly obtain the contour shape of the position detection hole 4a, but there is a possibility that sufficient brightness cannot be obtained around the alignment mark 7. As this cause, it is conceivable that the periphery of the alignment mark 7 is illuminated only with the light that has passed through the position detection hole 4a. In particular, when illumination is performed to observe the alignment mark 7 provided on the piezoelectric element 3 as in this example, the intensity of the reflected light is generally reduced in the piezoelectric element 3 generally formed of ceramics. There is a high possibility that sufficient brightness cannot be obtained in the vicinity of the mark 7. For this reason, the illumination device 9 is oblique illumination.

In this device, the position detection hole 4a and the alignment mark 7 are passed through the observation hole 5a using the mark detection device 8 in a state where both the piezoelectric elements 3 and the vibration plate 4 face each other while maintaining a predetermined distance. The relative positional relationship between the piezoelectric elements 3 and the diaphragm 4 is adjusted so that the mutual positional relationship is appropriate. After this adjustment, both the piezoelectric elements 3 and the diaphragm 4 are brought into contact with each other with pressure while maintaining the positional relationship, and the adhesive applied to the joint surfaces of the two piezoelectric elements 3 is thermally cured, The piezoelectric element 3 and the diaphragm 4 are joined. Thereby, both the piezoelectric elements 3 and the diaphragm 4 can be joined in an appropriate positional relationship.
JP 2001-63073 A JP 2003-305851 A

  However, in the droplet discharge head 1 described above, after the positional relationship between the piezoelectric elements 3 and the diaphragm 4 is adjusted in a state where the piezoelectric elements 3 and the diaphragm 4 are separated from each other by a predetermined interval, the piezoelectric elements 3 and the diaphragm 4 are adjusted. Since the element 3 and the diaphragm 4 are brought into contact with each other and pressurized, and the adhesive applied to the joint surfaces of the two piezoelectric elements 3 is thermally cured, for example, both in the process of being brought into contact with the surface and applying pressure. There is a possibility that the positional relationship between the piezoelectric element 3 and the diaphragm 4 is shifted.

  Here, in the method described above, since the illumination device 9 is obliquely illuminated, after the two piezoelectric elements 3 and the diaphragm 4 are brought into surface contact with each other, the illumination device 9 surrounds the periphery of the alignment mark 7. Since it becomes impossible to illuminate (see FIG. 19), the positional relationship between the two piezoelectric elements 3 and the diaphragm 4 cannot be adjusted. At this time, it is conceivable that the illumination device 9 illuminates between the two piezoelectric elements 3 arranged in parallel. However, since the two piezoelectric elements 3 are arranged in parallel at a very close position, With illumination, it is very difficult to obtain sufficient brightness around the alignment mark 7.

  For this reason, in the droplet discharge head 1, although an assembly accuracy of several tens of μm (for example, about ± 10 μm) can be ensured, several μm (for example, about ± 1 μm) due to the influence of an error caused in the process of being pressed against the surface. The following assembly accuracy cannot be achieved. Further, with this droplet discharge head 1, it becomes impossible to inspect the relative positional accuracy between the parts after joining.

  The present invention has been made in view of the above problems, and can ensure high assembly accuracy and can inspect relative positional accuracy between components after joining between components. An object of the present invention is to provide a droplet discharge head.

  In order to solve the above problem, the invention according to claim 1 relates to droplet discharge, and at least two second members are in contact with each other with respect to the same first joint surface of the first member while being parallel to each other. A droplet discharge head that is bonded to the first bonding surface by an adhesive, and a stepped portion that is concave in the bonding direction is provided on the second bonding surface that is in surface contact with the first bonding surface in the second members. As a reference for position adjustment with respect to the first member in the direction along the first joint surface, the step portion is related to opposite side surfaces facing each other when the second members are arranged in parallel. The alignment mark is provided, and at least one of the second members is along the second joint surface in a state where the second members are in surface contact with the first joint surface in parallel. Said second members in the direction Opening for communicating the stepped portion on the outer side of the second member at the outer end wall surface positioned in the direction perpendicular to the parallel direction, characterized in that it is formed in the outer end wall.

  The invention according to claim 2 is the liquid droplet ejection head according to claim 1, wherein the second member provided with the opening is arranged such that the outer end wall surface provided with the opening is arranged in parallel. As the second member approaches the alignment member, the step is inclined with respect to the parallel direction so as to approach the alignment mark, and the stepped portion extends in the parallel direction on the second joint surface of the second member. The opening is defined by one side wall surface defining the groove shape being cut out by the outer end wall surface.

  The invention according to claim 3 is the droplet discharge head according to claim 2, wherein the alignment mark extends along a parallel direction on a step surface facing the first joint surface in the step portion. The present invention is characterized in that at least one of a pair of side wall surfaces defining the groove shape is provided on the step surface so as to communicate with the opposite side surface while presenting an existing groove shape.

  The invention according to claim 4 is the droplet discharge head according to claim 2 or claim 3, wherein the stepped portion has only a part of one side wall surface defining the groove shape by the outer end wall surface. It is characterized by being cut out.

  The invention according to claim 5 is the droplet discharge head according to claim 3 or claim 4, wherein the second member provided with the opening is an extension of the alignment mark having a groove-like opposing side surface. It is characterized by being orthogonal to the current direction.

  The invention according to claim 6 is the droplet discharge head according to any one of claims 1 to 5, wherein the second members are piezoelectric elements for applying discharge energy to the droplet. It is characterized in that it is divided by a plurality of parallel slits so as to form a plurality of channels for discharging droplets in parallel, and the parallel direction coincides with the extending direction of each slit.

  According to a seventh aspect of the invention, there is provided a liquid droplet ejection apparatus on which the liquid droplet ejection head according to any one of the first to sixth aspects is mounted.

  According to an eighth aspect of the present invention, there is provided a recording apparatus on which the liquid droplet ejection head according to any one of the first to sixth aspects is mounted.

  In the droplet discharge head according to the present invention, since the outer end wall surface of at least one of the two second members arranged in parallel is opened, both the second members are in surface contact with the first joint surface. Even in such a state, it is possible to obtain sufficient brightness around the alignment mark by oblique illumination through the opening. For this reason, in this droplet discharge head, it is possible to ensure high assembly accuracy and to inspect the relative positional accuracy between components after joining the components. For this reason, this droplet discharge head has very good droplet discharge characteristics even when it is miniaturized.

  In addition to the above-described configuration, the second member provided with the opening is arranged so that the outer end wall surface provided with the opening approaches the alignment mark as the other second member arranged in parallel approaches. The step portion is inclined with respect to the parallel direction, and the stepped portion has a groove shape extending along the parallel direction on the second joint surface of the second member, and one side wall surface defining the groove shape is the If the opening is defined by being cut out by the outer end wall surface, the stepped portion is formed by performing groove processing so as to cross the outer end wall surface inclined in the parallel direction to the second joint surface of the second member. If formed, the stepped portion and the opening communicating with the stepped portion can be provided by one processing. For this reason, production efficiency can be improved.

  In addition to the above-described configuration, the alignment mark has a pair of grooves defining the groove shape while exhibiting a groove shape extending along the parallel direction on the step surface facing the first joint surface in the step portion. If at least one of the side wall surfaces is provided on the step surface so as to communicate with the opposite side surface, the step portion and the alignment mark can be formed using the same equipment for groove processing. So production efficiency can be increased.

  In addition to the above-described configuration, when the step portion has only a part of one side wall surface defining the groove shape cut out by the outer end wall surface, the outer end wall surface of the step portion in the second member On the side, the outer end wall portion that defines the side wall surface that defines the remaining groove shape and the outer end wall surface remains, and a part of the second joint surface is defined by the outer end wall portion. Therefore, the second joint surface of the outer end wall portion can be brought into surface contact with the first joint surface of the first member. This can improve the bonding strength between the first member and both second members, and can also be used for temporary bonding between the first member and both second members.

  In addition to the configuration described above, the extending direction of the second member provided with the opening is orthogonal to each other when the opposing side surface is orthogonal to the extending direction of the groove-shaped alignment mark. The first member and the second member in the direction along the surface including the extending direction of the groove-shaped alignment mark out of the surfaces orthogonal to the opposing side surface by utilizing the groove-shaped alignment mark and the opposing side surface The relative positional relationship can be adjusted appropriately and easily.

  In addition to the above-described configuration, each of the second members is a piezoelectric element for imparting ejection energy to the droplet, and a plurality of parallel members are formed in parallel to form a plurality of channels for ejecting the droplet. If it is divided by the slits and the parallel direction is aligned with the extending direction of each slit, the periphery of the alignment mark can be appropriately illuminated, so the piezoelectric element with low reflected light intensity is provided. Even alignment marks can be observed appropriately.

  In particular, when the stepped portion has a groove shape extending along the parallel direction, the slit and the stepped portion can be formed using the same equipment for groove processing, so that the production efficiency is increased. Can do.

  In addition, when the stepped portion and the alignment mark have a groove shape extending along the parallel direction, the slit, the stepped portion, and the alignment mark can be formed using the same equipment for groove processing. , Can increase production efficiency.

  When the droplet discharge device is equipped with the droplet discharge head having the above-described configuration, the droplet discharge capable of discharging high-quality droplets at high density even when miniaturized. An apparatus can be provided.

  When the recording apparatus is equipped with the droplet discharge head having the above-described configuration, it is possible to provide a recording apparatus capable of high-quality recording at high density even when the recording apparatus is miniaturized. .

  Embodiments of a droplet discharge head according to the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory view schematically showing the structure of the main part of a droplet discharge head 10 according to the present invention, and FIG. 2 is a schematic exploded perspective view for explaining the droplet discharge head 10. . Here, in the following description, when viewing FIG. 1 from the front, the left-right direction is the X-axis direction, the direction orthogonal to the paper surface is the Y-axis direction, and the up-down direction is the Z-axis direction. 3 is a top view showing the drive unit 11 (piezoelectric element 14) viewed from the upper surface side along the Z-axis direction, and FIG. 4 is a diaphragm 15 viewed from the upper surface side along the Z-axis direction. 5 is a top view showing the flow path plate 23 viewed from the upper surface side along the Z-axis direction, and FIG. 6 is a nozzle plate viewed from the upper surface side along the Z-axis direction. FIG.

  In this embodiment, the droplet discharge head 10 is a PZT type print head, and includes a drive unit 11 and a liquid chamber unit 12 as shown in FIGS.

  The drive unit 11 is configured by arranging long piezoelectric elements 14 as actuators in two rows on a substrate 13 and bonding them with an adhesive. Both the piezoelectric elements 14 are arranged along the X-axis direction, and are arranged in parallel in the Y-axis direction. In this embodiment, the piezoelectric element 14 is used as an actuator for the droplet discharge head 10 which is a PZT type print head. However, as the actuator of the droplet discharge head, other electromechanical conversion elements or heat generation are used. An electrothermal conversion element such as a resistor can also be used.

  The piezoelectric element 14 is, for example, a laminated piezoelectric element having 10 or more layers, and a lower surface bonded to the substrate 13 and an upper surface bonded to the vibration plate 15 (second bonding surface 28 described later) are upper bottoms along the X-axis direction. The columnar shape extends along the XY plane while exhibiting an equal trapezoidal shape having a lower base and extending in the Z-axis direction. The lower surface and the upper surface are set so that the opposing side surface 14a facing the other piezoelectric element 14 arranged in parallel is shortened. For this reason, the pair of outer wall end faces 16 positioned in the X-axis direction in each piezoelectric element 14 are arranged in the Y-axis direction (Y−) which is a parallel direction so as to approach each other as the other piezoelectric element 14 arranged in parallel is approached. (Z plane) and tilted with respect to the Y-axis direction (YZ plane) so as to approach an alignment mark 21 (to be described later) as the other piezoelectric element 14 arranged in parallel is approached. It will be. Hereinafter, in the outer wall end surface 16, a direction orthogonal to the Z-axis direction (along the surface) is referred to as an outer wall end surface extending direction.

  In the piezoelectric element 14, a plurality of slits 17 extending along the Y-Z direction while extending along the YZ plane using, for example, a dicing saw or the like are provided in the upper half of the piezoelectric element 14. It is divided into a plurality of drive units 14b and a plurality of support columns 14c. Each drive portion 14b is a location for applying a drive pulse (ejection energy) for causing the ink in the liquid chamber 25, which will be described later, to drop and fly, to the ink, and each column portion 14c is a location that supports the liquid chamber unit 12. Become. In FIGS. 3, 12, 13, and 18, the state of being divided into each drive unit and each column unit is omitted for easy understanding.

  Further, both the piezoelectric elements 14 are provided with a groove-like stepped portion 18 in the vicinity (both ends) of both outer wall end faces 16, and an alignment groove 19 is provided on a stepped surface 18 a serving as a bottom surface of the groove-like stepped portion 18. Yes. The groove-shaped step portion 18 has a predetermined depth dimension in the Z-axis direction and a predetermined width dimension in the X-axis direction, and the upper surface (second bonding surface 28 described later) of the piezoelectric element 14 is in the Y-axis direction. Like the plurality of slits 17, it is formed in the upper half portion of the piezoelectric element 14 so as to cross a part of the outer wall end surface 16 when viewed in the extending direction of the outer wall end surface. For this reason, the groove-shaped stepped portion 18 is formed on the YZ plane and a step surface 18a that is a bottom surface positioned below the upper surface (second bonding surface 28 described later) of the piezoelectric element 14 along the XY plane. Two side wall surfaces 18 b and 18 c are provided along the same, and a part of the side wall surface 18 b located on both ends thereof is cut out by the outer wall end surface 16. In other words, a part of the outer wall end surface 16 is cut away by processing to form the groove-shaped stepped portion 18, and thereby the groove-shaped stepped portion 18 is formed at a position near the alignment mark 21 described later. A communication opening 20 is formed. As will be described later, the opening 20 emits light from a direction substantially along the XY plane on the outer wall end surface 16 side so as to enable appropriate observation of the alignment mark 21 (illumination device described later in this embodiment). (Irradiation light from 31) is provided to secure a light guide path to the alignment mark 21, so that the periphery of the alignment mark 21 can be illuminated with a desired light amount by this irradiation light. What is necessary is just to be set as a size dimension. The size of the opening 20 includes an inclination angle of the outer wall end surface 16 with respect to the Y-axis direction (YZ plane), a width dimension of the groove-shaped step portion 18, and a position where the groove-shaped step portion 18 crosses the outer wall end surface 16. Can be easily adjusted by appropriately setting. Here, the direction substantially along the XY plane means that the first member (the diaphragm 15 as described later in this embodiment) and the second member (both piezoelectric elements 14 as described later in this embodiment). An angle range in which the periphery of the alignment mark 21 can be illuminated with illumination light passing through the opening 20 in a state where the surface is in contact.

  The alignment groove 19 provided in the groove-shaped step portion 18 is formed on the step surface 18a using, for example, a dicing saw like the plurality of slits 17, and extends in the Y-axis direction along the YZ plane. Has been extended to pass. The alignment groove 19 is provided so as not to cross the outer wall end surface 16, in other words, the both side surfaces defining the groove shape are not cut out by the outer wall end surface 16. Therefore, the alignment groove 19 opens the opposing side surface 14a so as to be orthogonal to the opposing side surface 14a extending in the X-axis direction (see FIG. 10 and the like). As will be described later, the alignment groove 19 (both side surfaces thereof) extending in the Y-axis direction and the opposite side surface 14a orthogonal thereto constitute an alignment mark 21 (see FIG. 10, FIG. 11, etc.). .

  Further, in both piezoelectric elements 14, the groove-shaped stepped portion 18 extending in the Y-axis direction crosses a part of the outer wall end surface 16 inclined with respect to the YZ plane as viewed in the extending direction of the outer wall end surface. Thus, the outer wall end 22 remaining at both ends is provided. The outer wall end portion 22 defines the remaining portion of the side wall surface 18b while defining the remaining portion of the outer wall end surface 16 viewed in the extending direction of the outer wall end surface, and the upper surfaces of the plurality of driving portions 14b and the plurality of support column portions 14c. An upper surface (temporary bonding surface 29 described later) located on the same plane as (second bonding surface 28 described later) is defined. The liquid chamber unit 12 (its vibration plate 15) is brought into surface contact with and joined to the upper surfaces of the piezoelectric elements 14, that is, the upper surfaces of the plurality of drive units 14b, the plurality of support columns 14c, and the outer wall end portion 22. .

  The plurality of slits 17, the pair of groove-shaped step portions 18, and the alignment groove 19 described above are formed by joining the two piezoelectric elements 14 having a trapezoidal cross section in a suitable position on the substrate 13. Groove processing is performed. For this reason, between the two piezoelectric elements 14 arranged in parallel, the plurality of slits 17, the pair of groove-shaped step portions 18, and the alignment groove 19 are symmetric with respect to the XZ plane.

  The liquid chamber unit 12 includes a vibration plate 15, a flow path plate 23, and a nozzle plate 24. As shown in FIGS. 2 and 4, the diaphragm 15 has a flat plate shape as a whole, and has a displacement portion (not shown) for transmitting the vibration of the drive portion 14 b of the drive unit 11 to a liquid chamber 25 described later. Then, the displacement portion is brought into contact with the upper surface (second bonding surface 28 described later) of the piezoelectric element 14 so as to appropriately correspond to the driving portion 14b. Further, the diaphragm 15 penetrates to serve as a reference for positioning with respect to the flow path plate 23 and a pair of diaphragm side counter flow path positioning holes 15a that are penetrated so as to serve as a reference for positioning with respect to the piezoelectric element 14 (drive unit 11). A pair of diaphragm side paired piezoelectric element positioning holes 15b. A flow path plate 23 is joined to the diaphragm 15.

  As shown in FIGS. 2 and 5, the flow path plate 23 has a flat plate shape as a whole, and has a plurality of liquid chambers 25 extending in the Y-axis direction and arranged in parallel in the X-axis direction, A pair of flow path plate side counter diaphragm positioning recesses 23a (see FIG. 1) that are concave to serve as a reference, and a pair of flow path plate side versus nozzle plate that are concave to serve as a positioning reference for the nozzle plate 24. It has a positioning recess 23b, a pair of flow path plate side observation holes 23c penetrated for observation of the diaphragm side piezoelectric element positioning hole 15b and the alignment mark 21 (see FIG. 10, FIG. 11, etc.). In the flow path plate 23, each liquid chamber 25 appropriately corresponds to a displacement portion (not shown) of the vibration plate 15 in order to transmit vibration (discharge energy) of the drive portion 14 b of the drive unit 11 to the ink in the liquid chamber 25. In this way, the diaphragm 15 is joined via an adhesive. A nozzle plate 24 is joined to the flow path plate 23.

  2 and 6, the nozzle plate 24 has a flat plate shape as a whole and is formed so as to be aligned in the X-axis direction. And a pair of nozzle plate side counter flow channel positioning holes 24a that are penetrated so as to be a reference for positioning with respect to 23. This nozzle plate 24 is joined to the flow path plate 23 via an adhesive so that each nozzle hole 26 corresponds appropriately to each liquid chamber 25 of the flow path plate 23.

  In this droplet discharge head 10, ink is supplied to the liquid chamber unit 12 by an ink supply mechanism (not shown) and supplied to the liquid chamber 25. In the liquid droplet ejection head 10, in this state, the drive unit 14 b of the piezoelectric element 14 of the drive unit 11 is selectively driven appropriately so that vibration (discharge energy) of the drive unit 14 b is generated in the liquid chamber unit 12. The ink is applied to the ink in the liquid chamber 25 through the vibration plate 15, and ink droplets are ejected from the nozzle hole 26. In the liquid droplet ejection head 10, in order to appropriately eject ink droplets, it is necessary that the components are aligned with each other with high accuracy and bonded. Next, position adjustment when assembling the droplet discharge head 10 will be described.

  First, the position adjustment (joining) between the vibration plate 15 and the flow path plate 23 in the liquid chamber unit 12 will be described. The position adjustment between the nozzle plate 24 and the flow path plate 23 will be described with reference to the vibration plate 15 and the flow path plate 23. The description is omitted because it is similar to the joining.

  In the present embodiment, as described above, the diaphragm 15 is provided with the pair of diaphragm side counter flow channel positioning holes 15a, and the channel plate 23 has a pair of channel plate side counter diaphragm positioning recesses. 23a is provided, and position adjustment between the diaphragm 15 and the flow path plate 23 is performed by a two-field detection method. As shown in FIG. 7, when the diaphragm 15 is arranged on the flow path plate 23 at a predetermined interval, both the flow path plate side counter vibration plate positioning recesses 23a are interposed via the both vibration plate side counter flow path positioning holes 15a. Can be observed (hereinafter referred to as an observation position). In this two visual field detection method, as shown in FIG. 8, images I at two observation positions are acquired so that each diaphragm side counter flow channel positioning hole 15a is entirely contained on the screen. In FIG. 8, the pair of diaphragm side piezoelectric element positioning holes 15b is omitted for easy understanding.

  In both images I, the center position 15b of the pair of diaphragm side counter flow channel positioning holes 15a is detected from the analysis of the image, and the center position of both diaphragm side counter flow channel positioning holes 15a is detected from these two center positions 15b. (Center reference position of diaphragm 15) (Cs = xs, ys, θs (where θs is the inclination of the straight line connecting the two center positions 15b with respect to the X-axis direction)). Further, in both images I, the center position 23d of the pair of channel plate side pair nozzle plate positioning recesses 23b is detected from the analysis of the image, and the two channel positions 23d of the both channel plate side pair nozzle plate positioning recesses 23b are detected. A center position (center reference position of the flow path plate 23) (Cr = xr, yr, θr (where θr is an inclination of the straight line connecting the two center positions 23d with respect to the X-axis direction)) is obtained. Thereafter, an error amount between the center positions of the diaphragm 15 and the flow path plate 23 is calculated by the following expression (1) so that both the center positions are matched.

(Δxu, Δyu, Δθu) = (xs, ys, θs) − (xr, yr, θr) (1)
Based on the calculated (Δxu, Δyu, Δθu), the position (x, y, θ) of the flow path plate 23 is corrected with the diaphragm 15 as a reference. As described above, the vibration plate 15 and the flow channel plate 23 are formed using the vibration plate side flow passage plate positioning holes 15a and the vibration plate side flow passage plate positioning holes 15a located in the vicinity of both ends as viewed in the X-axis direction. Since the position adjustment is performed, the influence of the component error is distributed to both of them based on the center position viewed in the X-axis direction, so that the positions of the diaphragm 15 and the flow path plate 23 are adjusted with higher accuracy. be able to. Note that the position of the diaphragm 15 may be corrected based on the flow path plate 23. After this position correction is completed, the surfaces are brought into contact with each other in the direction in which the distance between them becomes shorter (Z-axis direction), and pressure bonding is performed.

  The positional deviation that may occur at the time of this pressure bonding or when the diaphragm 15 and the flow path plate 23 are brought into close contact with each other, even after the diaphragm 15 and the flow path plate 23 are in surface contact with each other. Since it is possible to observe both the flow path plate side paired diaphragm positioning recesses 23a via the gap, it can be corrected. As a method of correcting the position while applying pressure, there are both a step pressurizing method in which pressure is applied stepwise and the position is appropriately corrected accordingly, and a continuous pressurizing method in which continuous pressurization is applied and the position is appropriately corrected accordingly. Although there is a method, an optimal method may be selected as appropriate from the relationship between target accuracy and tact (in this case, time required for alignment or time required for assembling the droplet discharge head 10). In order to shorten the tact time, in the step pressurization method, the number of steps may be reduced to correct the position, and in the continuous pressurization method, the continuous load change speed may be increased. Also, when aiming for high accuracy, increase the number of pressurization steps and position correction in the step pressurization method, and in the continuous pressurization method, slow the continuous load change speed so that there is no correction delay. It is sufficient to correct the position. After the load and the mutual positional accuracy reach the standard value, the diaphragm 15 and the flow path plate 23 are temporarily fixed with a UV adhesive or the like. Thus, the diaphragm 15 to which the flow path plate 23 is bonded is bonded to both the piezoelectric elements 14 of the drive unit 11. This will be described below.

  FIG. 9 is an explanatory view schematically showing how the piezoelectric elements 14 of the drive unit 11 are aligned with the diaphragm 15 to which the flow path plate 23 is joined. A state in which the diaphragm 15 is opposed to the diaphragm 15 at a predetermined interval is shown, and (b) shows a state in which both the piezoelectric elements 14 and the diaphragm 15 are in contact with each other. FIG. 10 is a perspective view schematically showing the periphery of the alignment mark 21 in the piezoelectric element 14. In FIG. 9, only the piezoelectric element 14 on the back side in the front view of the two piezoelectric elements 14 is shown for easy understanding.

  Here, since the two piezoelectric elements 14 are joined to the vibration plate 15, the vibration plate 15 corresponds to the first member, and both the piezoelectric elements 14 correspond to the second member. In the following description, the lower surface of the diaphragm 15 as the first member (the surface located on the lower side when FIG. 9 is viewed from the front) is referred to as the first bonding surface 27. The upper surface of 14b and each support | pillar part 14c is called the 2nd joining surface 28, and the upper surface of the outer wall edge part 22 is called the temporary joining surface 29. FIG.

  When performing this alignment, as shown to Fig.9 (a), the mark detection apparatus 30 and the illuminating device 31 are used. Although not shown, the mark detection device 30 can acquire an image to be observed through an observation optical system in which the optical axis direction is the Z-axis direction. The illumination device 31 illuminates the periphery of the alignment mark 21 from the side of the two piezoelectric elements 14 (so as to advance between the two piezoelectric elements 14 and the diaphragm 15), as described in the prior art. Oblique lighting. Thereby, the alignment mark 21 is appropriately observed in the image acquired by the mark detection device 30, that is, the contour position between the alignment groove 19 (both side surfaces thereof) and the opposite side surface 14a orthogonal thereto is grasped with extremely high accuracy. It is possible to do.

  First, the bonding adhesive 32 is applied to the second bonding surfaces 28 of the two piezoelectric elements 14 of the drive unit 11 and the first bonding surface 27 of the vibration plate 15 to which the flow path plate 23 is bonded. After applying the temporary adhesive 33 to the temporary bonding surfaces 29 of the two piezoelectric elements 14, both the piezoelectric elements 14 and the diaphragm 15 are opposed to each other with a predetermined interval. Here, the bonding adhesive 32 is an adhesive for finally bonding both the piezoelectric elements 14 and the diaphragm 15. In this embodiment, a bonding adhesive that is cured by applying heat is used. . The temporary adhesive 33 is an adhesive for maintaining the state in which both the piezoelectric elements 14 and the diaphragm 15 are adjusted in position and in surface contact with each other. In this embodiment, a UV adhesive is used. Yes. The bonding adhesive 32 and the temporary adhesive 33 adhere to the edge portion of the groove-shaped step portion 18 (the upper end position of the side wall surfaces 18b and 18c), but do not adhere to the step surface 18a of the groove-shaped step portion 18. Therefore, it does not adhere to the alignment groove 19 and the edge portion between the stepped surface 18a and the opposing side surface 14a. For this reason, proper observation of the alignment mark 21 is prevented from being hindered due to adhesion of the bonding adhesive 32 and the temporary adhesive 33.

  In this state, both the piezoelectric element 14 and the piezoelectric element positioning hole 15b and the alignment mark 21 are observed through the both flow path plate side observation holes 23c and using the mark detection device 30 and the illumination device 31. Alignment with the diaphragm 15 is performed. This will be described with reference to FIG. FIG. 11 schematically shows the diaphragm-side piezoelectric element positioning hole 15b and the alignment mark 21 in the image acquired by the mark detection device 30, and (a) is based on one piezoelectric element 14 as a reference. (B) is based on two piezoelectric elements 14 arranged in parallel.

  First, the image acquired by the mark detection device 30 is analyzed to detect the center position 15c of both diaphragm side paired piezoelectric element positioning holes 15b. Thereafter, similar to that described with reference to FIG. 8, although not shown, the center position of both diaphragm-side paired piezoelectric element positioning holes 15b (center reference position of the piezoelectric element 14) is obtained from both center positions 15c.

  Next, in the method using one piezoelectric element 14 as a reference, the center position 21a of the alignment mark 21 is detected by analyzing the image acquired by the mark detection device 30, as shown in FIG. The center position 21 a is obtained from the contour positions (edges) on both side surfaces of the alignment groove 19 to obtain the groove center line ld of the alignment groove 19, and from the contour position (edge) of the opposing side surface 14 a orthogonal to the alignment groove 19. Is obtained from the intersection of the edge line le and the groove center line ld. Thereafter, as shown in FIG. 8, although not shown, the center positions of both alignment marks 21 (center reference positions of both piezoelectric elements 14) are obtained from both center positions 21a.

  Thereafter, the error amount between the center position of both diaphragm side paired piezoelectric element positioning holes 15b and the center position of both alignment marks 21 is calculated in the same manner as in equation (1), and both piezoelectric elements are matched so that both center positions match. 14 (drive unit 11) is used as a reference to correct the position of the diaphragm 15. Note that the position of both piezoelectric elements 14 (drive unit 11) may be corrected with respect to the diaphragm 15. After this position correction is completed, the surfaces are brought into contact with each other in the direction (Z-axis direction) in which the distance between them is shortened, and pressure bonding is performed (see FIG. 9B).

  Here, in the liquid droplet ejection head 10 according to the present invention, the positional deviation that may occur at the time of this pressure bonding or close to each other is after the two piezoelectric elements 14 and the diaphragm 15 are brought into surface contact. Even if it exists, since both the flow-path board side counter-diaphragm positioning recessed part 23a can be observed through both the vibration-plate-side counter flow path positioning holes 15a, it can correct | amend. As shown in FIGS. 9B and 10, as described above, in the piezoelectric element 14 of the droplet discharge head 10, the groove-shaped step portion 18 provided with the alignment groove 19 has the alignment groove 19. Since the opening 20 provided in the outer wall end face 16 is communicated to the outside of the piezoelectric element 14 in the X-axis direction, the irradiation light from the illuminating device 31 is emitted from the opening 20 and the groove-shaped step portion 18. This is because the periphery of the alignment groove 19, that is, the alignment mark 21 can be irradiated.

  As the method of correcting the position while applying pressure, there are both the method of step pressurization and the method of continuous pressurization, as described with reference to FIG. 8, but the target accuracy and tact (in this case, alignment) The optimum method may be selected as appropriate from the relationship of the time required for assembly or the time required for assembling the droplet discharge head 10. After the load and the positional accuracy of each other reach the standard value, both the piezoelectric elements 14 and the diaphragm 15 are temporarily fixed by the temporary adhesive 33 applied to the temporary bonding surface 29 that is the upper surface of the outer wall end portion 22. Therefore, the positional relationship between the two piezoelectric elements 14 and the diaphragm 15 is reliably maintained. Thereafter, the two piezoelectric elements 14 and the diaphragm 15 are finally bonded by the bonding adhesive 32 applied to the first bonding surface 27 when heat is applied.

  Further, in the method based on the two piezoelectric elements 14 arranged in parallel, as shown in FIG. 11B, the image acquired by the mark detection device 30 is analyzed, and the centers of the opposed alignment marks 21 are analyzed. The position 21a ′ is detected. The center position 21a ′ is obtained by obtaining the groove center line ld of the alignment groove 19 from the contour positions (edges) on both side surfaces of the alignment grooves 19 of the two piezoelectric elements 14, and both orthogonal to the alignment grooves 19 of the two piezoelectric elements 14. From the contour position (edge) of the opposing side surface 14a, the edge center line le 'of both opposing side surfaces 14a is obtained and obtained from the intersection of the edge center line le' and the groove center line ld. Here, as described above, since the alignment groove 19 is symmetrical with respect to the XZ plane between the two piezoelectric elements 14 arranged in parallel, the groove center line ld is obtained based on the one alignment groove 19. However, the same result can be obtained even if it is obtained based on both alignment grooves 19. In the method based on the two piezoelectric elements 14 arranged in parallel, the error can be distributed to both the upper and lower sides from the intermediate position of the two piezoelectric elements 14, that is, both sides sandwiching the XZ plane as viewed in the Y-axis direction. Thus, the position adjustment between the piezoelectric elements 14 and the diaphragm 15 can be performed with higher accuracy.

  As described above, in the droplet discharge head 10 according to the present invention, the groove-shaped stepped portion 18 provided with the alignment mark 21 is formed on the both outer wall end faces 16 of the piezoelectric element 14 in the vicinity of the alignment mark 21 in the X-axis direction. Since the opening 20 is provided to communicate with the outside of the piezoelectric element 14 as seen in FIG. 1, the illumination device is obliquely illuminated even when both the piezoelectric elements 14 and the diaphragm 15 are in surface contact with each other. 31 can illuminate the periphery of the alignment mark 21, so that both the piezoelectric elements 14 and the diaphragm 15 can be joined in a state in which the position is adjusted with higher accuracy, and both the piezoelectric elements 14 and the diaphragm 15 can be joined. Even after the two are joined, the relative positional accuracy between the parts can be inspected.

  In the droplet discharge head 10, a plurality of slits 17 extending in the Y-axis direction, a pair of groove-shaped step portions 18, and an alignment groove 19 are provided for the piezoelectric element 14 having a trapezoidal cross section. Thus, the opening 20 communicating with the groove-shaped step portion 18 in the piezoelectric element 14 can be formed on both outer wall end surfaces 16. Therefore, the manufacturing process of the piezoelectric element 14 and thus the droplet discharge head 10 can be simplified, and the manufacturing cost of the piezoelectric element 14 and thus the droplet discharge head 10 can be suppressed.

  Further, in the droplet discharge head 10, the opening 20 formed in the both outer wall end surfaces 16 by the groove-shaped step portion 18 opens over the entire outer wall end surface 16 (as viewed in the extending direction of the outer wall end surface 16 of the outer wall end surface 16). Since the outer wall end 22 remaining at both ends is provided, the upper surface of the outer wall end 22 is suitable for use as the temporary bonding surface 29. This is because the temporary bonding surface 29 is separated from the first bonding surface 27 (the upper surface of each driving portion 14b and each column portion 14c) of the diaphragm 15 to which the bonding adhesive 32 is applied by the groove-shaped step portion 18. Therefore, the temporary adhesive 33 and the bonding adhesive 32 can be prevented from being mixed. Further, the upper surface of the outer wall end portion 22 can be used to increase the bonding strength between the piezoelectric elements 14 and the diaphragm 15 by applying the bonding adhesive 32.

  Therefore, according to the liquid droplet ejection head 10 according to the present invention, it is possible to ensure high assembly accuracy, and even between the two piezoelectric elements 14 and the diaphragm 15, even between the parts concerned. Inspection of relative positional accuracy can be performed. Therefore, even when the droplet discharge head 10 is miniaturized, it is possible to discharge high-quality droplets at high density, in other words, it has extremely good droplet discharge characteristics.

  In the above-described embodiment, both piezoelectric elements 14 are set to have a trapezoidal column shape in cross section and the opposite side surfaces facing each other have short sides, but extend in the Y-axis direction. The extending direction of the groove-shaped step portion 18 and the extending direction of the outer wall end surface 16 of the outer wall end surface 16 are inclined with respect to each other so that the opening 20 can be formed in the outer wall end surface 16 when the groove-shaped step portion 18 is formed. However, the present invention is not limited to the above-described embodiment. For example, as shown in FIG. 12, both the piezoelectric elements 14 'can be formed in a columnar shape having a parallelogram in cross section. In this case, both the piezoelectric elements 14 'may be set so that both outer wall end faces 16 are parallel as shown in FIG. 12, and both outer wall end faces 16 are set to be symmetric with respect to the XZ plane. May be. In this way, when the columnar piezoelectric element 14 ′ has a parallelogram cross section, the direction of cutting the piezoelectric element that is the base for forming the outer wall end face 16 can be unified, so that the columnar piezoelectric element (14 ′ ) Can be made simpler.

  Further, in the above-described embodiment, the outer wall end surface 16 of the piezoelectric element 14 is inclined with respect to the YZ plane, and the outer wall end surface 16 is traversed when forming the groove-shaped stepped portion 18 extending in the Y-axis direction. However, the opening formed on the outer wall end surface is irradiated light from the direction substantially along the XY plane on the outer wall end surface 16 side (irradiated light from the illumination device 31 in this embodiment). The groove-shaped stepped portion 18 may be communicated with the outside of the piezoelectric element 14 so as to secure a light guide path to the alignment mark 21 and is not limited to the above-described embodiment. However, since the opening 20 can be formed at the same time by forming the groove-shaped step portion 18, it is desirable to have the configuration as in the above-described embodiment.

  Furthermore, in the above-described embodiment, the remaining outer wall end portions 22 are provided at both ends of the piezoelectric element 14, but irradiation light from the direction substantially along the XY plane on the outer wall end surface 16 side (this embodiment) In the example, an opening that communicates the groove-shaped step portion 18 with the outside of the piezoelectric element 14 may be formed on the end face of the outer wall so as to secure a light guide path to the alignment mark 21 (light irradiated from the illumination device 31). This can be eliminated.

  In the embodiment described above, the vibration plate 15 and the piezoelectric element 14 are joined before the nozzle plate 24 is joined to the flow path plate 23. However, the liquid chamber unit is formed by joining the nozzle plate 24 to the flow path plate 23. After forming 12, the piezoelectric element 14 may be bonded to the diaphragm 15 of the liquid chamber unit 12. In this case, it is necessary to form a through hole in the nozzle plate 24 that enables observation of both the diaphragm side counter-piezoelectric element positioning holes 15b and the alignment mark 21 while communicating with both the flow path plate side observation holes 23c.

  In the above-described embodiment, the two piezoelectric elements 14 are arranged in parallel. However, the groove-shaped stepped portion 18 is formed on the outer wall end face by forming an opening communicating with the outside of the piezoelectric element 14. Two or more piezoelectric elements may be arranged in parallel, as long as a special effect can be obtained in securing the light guide path.

  In the embodiment described above, the alignment mark 21 is constituted by the alignment groove 19 (both side surfaces thereof) and the opposing side surface 14a orthogonal thereto, but the position adjustment with respect to the diaphragm 15 in the direction along the first joint surface 27 is performed. It is only necessary to be provided so as to relate to the opposing side surface 14a of the two piezoelectric elements 14, and is not limited to the above-described embodiment.

  In the above-described embodiment, the example in which the two piezoelectric elements 14 as the second member are joined in parallel while being in surface contact with the first joining surface 27 of the diaphragm 15 as the first member is described. Any member may be used as long as at least two second members are bonded to the same first bonding surface of the member by an adhesive so as to be in surface contact with each other while being parallel to each other, and is not limited to the above-described embodiment. .

  Another example of the droplet discharge head according to the present invention is shown in FIG. In the drive unit 110 of the droplet discharge head 100 in FIG. 13, two elongated piezoelectric elements 140 are provided on the substrate 13. Both piezoelectric elements 140 are provided with outer wall end surfaces 16 in which groove-shaped step portions 18, alignment grooves 19, and openings 20 are formed in the vicinity of both ends as in the piezoelectric element 14 of the above-described embodiment. The difference from the piezoelectric element 14 of the above-described embodiment is that both the piezoelectric elements 140 are bonded to an appropriate position on the substrate 13 and then are divided into five by the dividing grooves 34 provided so as to extend in the Y-axis direction. The line head is divided into piezoelectric element portions 140a (the piezoelectric element portions 140a located at both ends are provided with the outer wall end face 16 in which the groove-shaped step portion 18, the alignment groove 19 and the opening 20 are formed). It constitutes. Although not shown, each piezoelectric element portion 140a is provided with a plurality of slits similarly to the piezoelectric element 14 of the above-described embodiment. In each piezoelectric element portion 140a, a plurality of slits are provided by the plurality of slits. A drive unit and a plurality of support columns are formed.

  Next, an example of an image recording apparatus equipped with the droplet discharge head 100 according to the present invention will be described. FIG. 14 is an explanatory diagram schematically showing the internal structure of the image recording apparatus 50 on which the droplet discharge head 100 is mounted. The image recording apparatus 50 is a line-type printer equipped with a line-type droplet discharge head 100 (line head) having a nozzle row having a length equal to or larger than the print area width of a recording medium, and includes black (Bk), magenta ( M), four droplet discharge heads 100 corresponding to four colors of cyan (C) and yellow (Y) (one corresponding to black is 100 Bk, magenta is 100 M, cyan is 100 C, and yellow is 100 M) Is shown). Corresponding to each droplet discharge head 100, a maintenance mechanism device 51 is provided. The maintenance mechanism device 51 performs a head maintenance operation such as a purge process and a wiping process, and the apparatus moves to a position facing the head nozzle surface during the head maintenance operation.

  The image recording apparatus 50 is fed with recording paper 53 from a paper feed tray 52. The sheet feeding tray 52 is configured by attaching a feeding rotating body 55 and a pressure plate 56 for feeding a recording sheet 53 to a base member 54. The pressure plate 56 is swingable about a rotation shaft 57 attached to the base member 54, and is urged toward the feeding rotating body 55 by a pressure plate spring 58. Although not shown, a separation pad made of a material having a large coefficient of friction such as an artificial leather is provided at a position of the pressure plate 56 facing the feeding rotating body 55, although illustration is omitted. . Further, although not shown in the drawing, the paper feed tray 52 is provided with a release cam that releases the contact between the pressure plate 56 and the feeding rotating body 55.

  In the sheet feeding tray 52, the release cam pushes the pressure plate 56 down to a predetermined position in the standby state, whereby the contact between the pressure plate 56 and the feeding rotating body 55 is released. In this state, when the driving force of the conveying roller 59 is transmitted to the feeding rotating body 55 and the release cam (not shown) by a gear or the like, the release cam moves away from the pressure plate 56 and the pressure plate 56 rises. Then, the feeding rotator 55 and the recording paper 53 come into contact with each other, the recording paper 53 is picked up as the feeding rotator 55 rotates, and feeding is started while being separated one by one by a separation claw (not shown). Is done.

  The feeding rotating body 55 is rotated to feed the recording paper 53 into the platen 60. The recording paper 53 fed by the feed rotating body 55 passes between the first guide 61 and the second guide 62 and is guided to the transport roller 59. The transport roller 59 and the pinch roller 63 allow the platen 53 to be fed. Up to 60. Thereafter, the paper feed tray 52 is again in a standby state in which the contact between the recording paper 53 and the feed rotating body 55 is released, and the driving force from the transport roller 59 is cut off. Further, the image recording apparatus 50 is provided with a manual feed tray 64 and a feeding rotating body 65 for the manual feed tray 64. The recording paper 53 placed on the manual feed tray 64 is fed by the feeding rotating body 65 and conveyed to the conveying roller 59.

  The recording paper 53 conveyed to the platen 60 is passed under each droplet discharge head 100. Here, the paper conveyance speed and the droplet discharge timing are determined based on a signal controlled by an electric circuit (not shown), and a desired image can be formed. The recording sheet 53 on which an image is recorded is sandwiched between a discharge roller 66 and a spur 67, conveyed, and discharged to a discharge tray 68.

  Next, an example of an image recording apparatus equipped with the droplet discharge head 10 according to the present invention will be described. FIG. 15 is a perspective view schematically showing an internal structure for explaining an image recording apparatus 50 ′ on which the droplet discharge head 10 is mounted. FIG. 16 is an image recording apparatus 50 on which the droplet discharge head 10 is mounted. It is explanatory drawing which shows typically the internal structure for demonstrating '.

  The image recording apparatus 50 ′ is configured by storing a printing mechanism 71 inside a recording apparatus main body 70. The print mechanism unit 71 includes a carriage 72 that can move in the main scanning direction, a droplet discharge head 10 mounted on the carriage 72, an ink cartridge 73 that supplies ink to the droplet discharge head 10, and the like. The image recording apparatus 50 ′ is provided with a paper feed cassette 74 (or a paper feed tray) below the recording apparatus main body 70. The paper feed cassette 74 can be loaded with a large number of recording papers 53 and can be detachably mounted from the front side (left side as viewed in front of FIG. 16). Further, the image recording apparatus 50 'is provided with a manual feed tray 75 that can be turned over. The recording paper 53 fed from the paper feed cassette 74 or the manual feed tray 75 is taken into the recording apparatus main body 70, and after a required image is recorded by the printing mechanism unit 71, a paper discharge tray mounted on the rear side. The paper is discharged to 76.

  In the printing mechanism section 71, the carriage 72 is moved in the main scanning direction (direction perpendicular to the paper surface of FIG. 16) by a main guide rod 77 and a sub guide rod 78 which are guide members horizontally mounted on left and right side plates (not shown). It is slidably held. The carriage 72 is slidably fitted to the main guide rod 77 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 78 on the front side (downstream side in the paper conveyance direction). ing. In the printing mechanism portion 71, a timing belt 82 is stretched between a driving pulley 80 and a driven pulley 81 that are rotationally driven by a main scanning motor 79 to move and scan the carriage 72 in the main scanning direction. The belt 82 is fixed to the carriage 72. For this reason, when the main scanning motor 79 is driven to rotate forward and backward, the carriage 72 is reciprocated along the main scanning direction.

  The carriage 72 is provided with four droplet discharge heads 10 for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection head 10 is provided such that the direction of arrangement of the plurality of nozzle holes 26 (see FIG. 2 and the like) intersects the main scanning direction and the ink droplet ejection direction is downward. In addition, each ink cartridge 73 for supplying ink of each color to each droplet discharge head 10 is replaceably mounted on the carriage 72.

  Although not shown, the ink cartridge 73 is provided with an air port communicating with the air at the upper side, and a supply port for supplying ink to each droplet discharge head 10 at the lower side. The filled porous body is accommodated. The ink cartridge 73 is configured to maintain the ink supplied to each droplet discharge head 10 at a slight negative pressure by the capillary force of the porous body. In this example, the droplet discharge heads 10 are provided corresponding to the respective colors as the recording heads, but one recording head having nozzles for discharging the ink droplets of the respective colors may be used. In addition, as a recording head, instead of the droplet discharge head 10 which is the above-described PZT printing head, a bubble type that generates air bubbles by a heating resistor and pressurizes ink, or a diaphragm that forms an ink flow path wall surface And an electrostatic type that pressurizes the ink by displacing the diaphragm with an electrostatic force between the electrode and the electrode opposed thereto.

  Further, in the printing mechanism unit 71, a feeding roller for separating and feeding the recording paper 53 from the paper feeding cassette 74 in order to convey the recording paper 53 set in the paper feeding cassette 74 to the lower side of the droplet discharge head 10. 83, a friction pad 84, a guide member 85 for guiding the recording paper 53, a conveying roller 86 for reversing and conveying the fed recording paper 53, and a conveying roller 87 pressed against the peripheral surface of the conveying roller 86. A leading end roller 88 that defines the feeding angle of the recording paper 53 from the conveying roller 86 is provided. The transport roller 86 is rotationally driven by a sub-scanning motor 89 through a gear train (not shown).

  Further, the print mechanism 71 is a paper guide member that guides the recording paper 53 fed from the transport roller 86 corresponding to the movement range of the carriage 72 in the main scanning direction on the lower side of the recording liquid droplet ejection head 10. A printing receiving member 89 is provided. A conveyance roller 90 and a spur 91 that are rotationally driven to send the recording paper 53 in the paper discharge direction are provided on the downstream side of the printing receiving member 89 in the paper conveyance direction. A paper discharge roller 92 and a spur 93 that are fed to the paper discharge tray 76 and guide members 94 and 95 that form a paper discharge path are provided.

  In the image recording apparatus 50 ′, during recording, the recording liquid droplet ejection head 10 is driven according to the image signal while moving the carriage 72, so that ink is ejected onto the stopped recording paper 53 and one line is recorded. The image (including characters) is recorded, and after the recording paper 53 is conveyed by a predetermined amount, the next line is recorded. In the image recording apparatus 50 ′, when the recording end signal or the signal that the trailing edge of the recording paper 53 reaches the recording area is received, the recording operation is completed and the recording paper 53 is discharged.

  Further, the image recording apparatus 50 ′ is provided with a recovery device 96 for recovering the ejection failure of the droplet ejection head 10 at a position outside the recording area on the right end side in the movement direction of the carriage 72. Although not shown, the recovery device 96 includes a cap unit, a suction unit, and a cleaning unit. In the image recording apparatus 50 ', the carriage 72 is moved to the recovery device 96 side during printing standby, and each droplet discharge head 10 is capped by cap means (not shown). For this reason, each nozzle hole 26 (see FIG. 2 and the like) of each droplet discharge head 10 is kept in a wet state, and discharge failure due to ink drying is prevented. Further, in the image recording apparatus 50 ′, even when the recording is in progress, the carriage 72 is appropriately moved to the recovery device 96, and ink that is not related to recording is recovered from each nozzle hole 26 of each droplet discharge head 10. It is supposed that it discharges toward 96. Thereby, in each droplet discharge head 10, the ink viscosity of all the nozzle holes 26 is made constant, and the stable discharge performance is maintained. Further, in the image recording apparatus 50 ′, when a discharge failure occurs, the carriage 72 is moved to the recovery device 96 side, and the cap means (not shown) of the recovery device 96 is used for each droplet discharge head 10. Each nozzle hole 26 is sealed, and in this state, the inside of the cap means of the recovery device 96 is set to a negative pressure by the suction means communicated through the tube. Thereby, in each droplet discharge head 10, bubbles and the like are sucked out from the nozzle holes 26 together with the ink. Thereafter, ink, dust, etc. adhering to the surface of each nozzle hole 26 are removed by a cleaning means (not shown) of the recovery device 96. Thereby, the ejection failure is recovered. The ink sucked at this time is discharged to a waste ink reservoir provided at the lower portion of the recording apparatus main body 70, although not shown, and is absorbed and held by an ink absorber inside the waste ink reservoir.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to this specific configuration, and design changes that do not depart from the spirit of the present invention are included in the technical scope of the present invention.

It is explanatory drawing which shows roughly the structure of the principal part of the droplet discharge head which concerns on this invention. It is a schematic exploded perspective view for description of a droplet discharge head. It is a top view which shows the drive unit (piezoelectric element) seen from the upper surface side along the Z-axis direction. It is a top view which shows the diaphragm seen from the upper surface side along the Z-axis direction. It is a top view which shows the flow-path board seen from the upper surface side along the Z-axis direction. It is a top view which shows the nozzle plate seen from the upper surface side along the Z-axis direction. It is explanatory drawing which shows the mode of position alignment with a diaphragm and a flow-path board. It is explanatory drawing for demonstrating the method of position alignment with a diaphragm and a flow-path board. It is explanatory drawing which shows a mode that alignment with both the piezoelectric elements of a drive unit, and the diaphragm with which the flow-path board was joined, (a) is a predetermined space | interval with both piezoelectric elements and a diaphragm. (B) shows a state in which both piezoelectric elements and the diaphragm are brought into contact with each other. It is a perspective view which shows typically the periphery of the alignment mark in a piezoelectric element. FIG. 2 schematically shows a diaphragm side piezoelectric element positioning hole and an alignment mark in an image acquired by a mark detection device, (a) is based on one piezoelectric element, (b) This is based on two piezoelectric elements arranged in parallel. It is a top view similar to FIG. 3 which shows the piezoelectric element of another example. It is a top view similar to FIG. 3 which shows the drive unit (piezoelectric element) of the droplet discharge head of another example. FIG. 14 is an explanatory view schematically showing an internal structure of the image recording apparatus on which the droplet discharge head of FIG. 13 is mounted. FIG. 13 is a perspective view schematically showing an internal structure for explaining an image recording apparatus on which the droplet discharge head of FIGS. 1 to 12 is mounted. FIG. 13 is an explanatory view schematically showing an internal structure for explaining an image recording apparatus on which the droplet discharge head of FIGS. 1 to 12 is mounted. It is explanatory drawing which shows the structure of the principal part in order to demonstrate the conventional droplet discharge head. It is a top view which shows the piezoelectric element of the conventional droplet discharge head seen from the upper surface side along the Z-axis direction. It is a perspective view which shows typically the periphery of the alignment mark in the piezoelectric element of the conventional droplet discharge head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Droplet discharge head 14 Piezoelectric element 14a (as a 2nd member) Opposite side surface 15 Diaphragm 16 (As a 1st member) Outer end wall surface 17 Slit 18 Groove-shaped step part 18a (Step part) Step side 18b side Wall surface 18c Side wall surface 19 Alignment groove 20 Opening 21 Alignment mark 27 First joint surface 28 Second joint surface 50, 50 'Image recording apparatus

Claims (8)

A droplet discharge head related to droplet discharge, wherein at least two second members are bonded to an identical first bonding surface of the first member by an adhesive so as to be in surface contact with each other in parallel,
The second joint surface that is in surface contact with the first joint surface in both the second members is provided with a stepped portion that is concave in the joining direction,
Alignment as a reference for position adjustment with respect to the first member in the direction along the first joint surface so that the step portion is related to the opposite side surfaces facing each other when the second members are arranged in parallel. Mark is provided,
At least one of the second members has the second members in a direction along the second joint surface in a state where the second members are in surface contact with the first joint surface in parallel. The droplet discharge is characterized in that an opening for communicating the stepped portion with the outside of the second member is formed in the outer end wall surface on the outer end wall surface located in a direction orthogonal to the parallel direction of head. The second member provided with the opening is inclined with respect to the parallel direction such that the outer end wall surface provided with the opening approaches the alignment mark as the other second member arranged in parallel approaches. ,
The step portion has a groove shape extending along the parallel direction on the second joint surface of the second member, and one side wall surface defining the groove shape is notched by the outer end wall surface. The droplet discharge head according to claim 1, wherein the opening is defined by:   The alignment mark has a groove shape extending along a parallel direction on a step surface facing the first joint surface in the step portion, and at least one of a pair of side wall surfaces defining the groove shape is the The droplet discharge head according to claim 2, wherein the droplet discharge head is provided on the step surface so as to communicate with the opposite side surface.   4. The droplet discharge head according to claim 2, wherein in the stepped portion, only a part of one side wall surface defining a groove shape is cut out by the outer end wall surface. 5.   5. The droplet according to claim 3, wherein the second member provided with the opening has the opposed side surface orthogonal to the extending direction of the groove-shaped alignment mark. Discharge head.   The second members are piezoelectric elements for imparting ejection energy to the droplet, and are divided by a plurality of parallel slits to form a plurality of channels for ejecting the droplet in parallel. 6. The liquid droplet ejection head according to claim 1, wherein the first and second slits coincide with the extending direction of each of the slits.   A liquid droplet ejection apparatus comprising the liquid droplet ejection head according to claim 1. A recording apparatus on which the droplet discharge head according to claim 1 is mounted.

Images