JP5729125B2 - Liquid discharge head and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid discharge head that discharges liquid and a method of manufacturing the same.

  Patent Document 1 describes an ink jet head in which a recess, which is a marker for alignment when an actuator unit is bonded on a plate, is formed across two plates. The concave portion is composed of a through hole formed in the upper plate and a concave bottom portion formed by half etching in the lower plate. When the actuator is stacked on the plate, an image sensor (CCD (Charge Coupled Devices) camera, etc.) is placed in front of the recess, the aperture of the recess is imaged, and the position of the recess is identified based on the image data. . At this time, the bottom surface facing the through-hole is a surface formed by half-etching, and there is a difference in reflectance with respect to incident light from the surface of the plate (the surface of the upper plate and the rolled surface). The hole (opening of the recess) can be identified as a circular pattern. Then, after adjusting the position of the actuator unit relative to the plate based on the position of the recess, the actuator unit is stacked on the plate.

JP 2011-16271 A

  However, in the technique described in Patent Document 1, the position of the light source when imaging the opening of the recess with the image sensor is a position slightly deviated from the front of the recess because the image sensor is arranged directly in front of the recess. Become. Then, in order to identify the opening shape of the recess with high accuracy, the image obtained by imaging at a high magnification shows a shadow near the opening edge of the upper plate in the opening of the recess, so that the opening shape of the recess is accurately identified. become unable. If the opening shape of the recess cannot be accurately identified, the actuator unit with respect to the plate is displaced accordingly, or the opening of the recess itself cannot be identified, and the alignment itself cannot be performed. If the concave portion is imaged at a low magnification, the influence of the shadow is less likely to occur, but the accuracy of identifying the opening shape of the concave portion is lowered. For this reason, displacement of the actuator unit with respect to the plate occurs.

  Accordingly, an object of the present invention is to provide a liquid discharge head capable of accurately identifying the bottom shape of a recess and a method for manufacturing the same.

  The liquid discharge head of the present invention includes a first member and a second member laminated on one surface of the first member. And the said 1st member is formed with the recessed part comprised by the columnar hole which has an opening edge in the said one surface, and the annular hole connected to the said columnar hole through the cyclic | annular opening. In addition, an inner peripheral edge of the annular opening defines a bottom surface of the columnar hole and is included in the opening edge when viewed from the stacking direction of the first member and the second member.

  According to this, the bottom surface of the columnar hole portion defined by the inner peripheral edge of the annular opening is disposed on the inner side of the opening edge as viewed from the stacking direction. For this reason, when the bottom surface is imaged through the opening of the concave portion, a shadow near the opening edge of the first member is hardly reflected on the bottom surface, and the bottom surface shape can be accurately identified. Further, even when an adhesive (adhesive for joining the first member and the second member) is applied to one surface of the first member, even if an excess portion of the adhesive flows into the recess, excessive adhesion is achieved. Since the agent flows into the annular hole portion, the excess adhesive hardly reaches the bottom surface surrounded by the annular opening. For this reason, it becomes difficult for an adhesive to adhere to the said bottom face, and it becomes possible to identify a bottom face shape accurately. Furthermore, the degree of freedom increases also in the position of the light source used when imaging the bottom surface of the columnar hole defined by the inner periphery of the annular opening.

  In the present invention, it is preferable that an outer peripheral edge of the annular opening is disposed at a position overlapping with the opening edge or outside the position when viewed from the stacking direction. As a result, the bottom surface of the columnar hole is only the region defined by the inner periphery of the annular opening. For this reason, the shadow produced when imaging a recessed part becomes easy to be reflected only in an annular hole. Therefore, it becomes easy to identify the opening shape of the recess.

  Moreover, in this invention, it is preferable that the outer periphery of the said annular hole part is arrange | positioned outside the said opening edge edge seeing from the said lamination direction. As a result, the width of the annular hole can be made relatively large. For this reason, even if the adhesive applied to one surface flows into the recess, it becomes difficult to adhere to the bottom surface of the columnar hole.

  Further, in the present invention, the first member is a stacked body of a plurality of plates stacked in the stacking direction, and the concave portion is an outermost layer on which the second member of the plurality of plates is stacked. It is preferable to be formed across two or more plates including the outer layer plate. Thereby, it becomes easy to form a recessed part.

  In the present invention, the outermost layer plate has a through hole forming the columnar hole, and is a surface of a plate adjacent to the outermost layer plate, and the outermost layer plate is laminated. It is preferable that the annular opening is formed at a position facing the through hole on the laminated surface. Thereby, it becomes possible to comprise a recessed part easily. In addition, an annular opening is formed in the laminated surface of the plate adjacent to the outermost layer plate, and the bottom surface is relatively close to the opening of the recess. For this reason, when imaging the bottom face of the columnar hole defined by the inner peripheral edge of the annular opening, it becomes more difficult for a shadow to appear on the bottom face.

  Moreover, in this invention, it is preferable that the bottom face of the said columnar hole part exists in the same plane as the said laminated surface. Thereby, the light from the light source when imaging the bottom surface of the columnar hole defined by the inner periphery of the annular opening is less likely to be irregularly reflected on the bottom surface, and the bottom surface shape can be accurately identified.

  In the present invention, it is preferable that the bottom surface of the columnar hole defined by the inner peripheral edge of the annular opening has a light reflectance different from that of the inner surface of the annular hole. This makes it possible to accurately identify the bottom shape of the columnar hole defined by the inner periphery of the annular opening.

  According to another aspect of the invention, there is provided a method for manufacturing a liquid discharge head, comprising: a first member; and a second member stacked on one surface of the first member. It is a recessed part comprised by the columnar hole part which has an edge, and the annular hole part connected to the said columnar hole part via cyclic | annular opening, Comprising: The inner periphery of the said cyclic | annular opening is a bottom face of the said columnar hole part And forming the recess in the first member as viewed from an orthogonal direction orthogonal to the one surface, and the columnar shape through the opening of the recess. A step of imaging the bottom surface of the hole, a step of aligning the second member with respect to the first member with respect to the direction along the one surface based on the acquired image of the bottom surface, and a position Laminating the combined second member on the one surface; Eteiru.

  Accordingly, the second member can be aligned with the first member based on the bottom surface of the columnar hole defined by the inner peripheral edge of the annular opening.

  In the present invention, in the step of forming the concave portion in the first member, the outer peripheral edge of the annular opening overlaps the opening edge or is located outside the position when viewed from the orthogonal direction. Preferably, the recess is formed in the first member. As a result, the bottom surface of the columnar hole is only the region defined by the inner periphery of the annular opening. For this reason, the shadow produced when imaging a recessed part becomes easy to be reflected only in an annular hole. Therefore, it becomes easy to identify the opening shape of the recess.

  Further, in the present invention, in the step of forming the concave portion in the first member, the outermost layer plate on which the second member is laminated, and the through hole constituting the columnar hole portion is formed. A plurality of outermost layer plates, and a laminated surface on which the outermost layer plates are laminated, the plate having the laminated surface in which the annular opening is formed at a position facing the through hole by the annular hole portion. It is preferable to form the concave portion in the first member by laminating the plates. Accordingly, it is possible to easily form a recess in which the bottom surface of the columnar hole defined by the inner periphery of the annular opening is relatively close to the opening of the recess.

  In the present invention, the step of forming the recess in the first member includes a region defined by an inner peripheral edge of the annular opening, which has a light reflectance different from an inner surface of the annular hole. It is preferable to form a plate having the laminated surface. This makes it possible to accurately identify the bottom shape of the columnar hole defined by the inner periphery of the annular opening.

  According to the liquid ejection head of the present invention, the bottom surface of the columnar hole defined by the inner peripheral edge of the annular opening is disposed on the inner side of the opening edge as viewed from the stacking direction. For this reason, when the bottom surface is imaged through the opening of the concave portion, a shadow near the opening edge of the first member is hardly reflected on the bottom surface, and the bottom surface shape can be accurately identified. Further, even when an adhesive (adhesive for joining the first member and the second member) is applied to one surface of the first member, even if an excess portion of the adhesive flows into the recess, excessive adhesion is achieved. Since the agent flows into the annular hole portion, the excess adhesive hardly reaches the bottom surface surrounded by the annular opening. For this reason, it becomes difficult for an adhesive to adhere to the said bottom face, and it becomes possible to identify a bottom face shape accurately. Furthermore, the degree of freedom increases also in the position of the light source used when imaging the bottom surface of the columnar hole defined by the inner periphery of the annular opening.

1 is a schematic diagram schematically showing an internal configuration of an ink jet printer according to an embodiment of the present invention. FIG. 2 is a plan view of the head body of FIG. 1. It is a top view of one plate which comprises a flow path unit. FIG. 4 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. 3. It is a top view of the other plate which comprises a flow path unit. It is sectional drawing of the flow path unit along the separate ink flow path which connects from a sub manifold flow path to each discharge port. FIG. 7 is an enlarged cross-sectional view of a region indicated by an alternate long and short dash line in FIG. 6. 8 (a) and 8 (b) are enlarged views of the periphery of the recess in FIG. 4, and FIG. 8 (c) is an enlarged view of FIG. 5 around the region overlapping the recess in plan view. It is sectional drawing of the flow path unit around a recessed part, and is sectional drawing along the IX-IX line of Fig.8 (a). It is a flowchart which shows the flow of the manufacturing process of a head main body. It is a perspective view which shows the positional relationship of a flow path unit and an image sensor. It is sectional drawing of the recessed part which concerns on the 1st modification replaced with the recessed part of this embodiment. It is sectional drawing of the recessed part which concerns on the 2nd modification replaced with the recessed part of this embodiment.

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

  First, referring to FIG. 1, a printer 101 having an ink jet head (an ink jet head having a marker for alignment, hereinafter referred to as head 1), which is an embodiment of the liquid discharge head of the present invention. The overall configuration will be described.

  The printer 101 has a rectangular parallelepiped housing 101a. A paper discharge unit 4 is provided on the top of the casing 101a. The internal space of the housing 101a can be divided into spaces A, B, and C in order from the top. In the spaces A and B, a paper transport path from the paper feed unit 101b to the paper discharge unit 4 is formed. In the space A, image formation on the paper P and conveyance of the paper P to the paper discharge unit 4 are performed. In the space B, the paper P is fed to the conveyance path. In the space C, ink is supplied to the head 1 in the space A.

  In the space A, a sheet sensor 8, four heads 1, a transport unit 9, two guide units 10a and 10b for guiding the sheet P, a control device 101p, and the like are arranged. The transport unit 9 includes four flat platens 7 disposed to face each of the four heads 1 and four feed roller pairs 16 disposed along the sheet transport path. It is transported in the direction of the thick arrow (conveyance direction).

  The head 1 has a substantially rectangular parallelepiped shape that is long in the main scanning direction. The heads 1 are arranged at a predetermined pitch in the sub-scanning direction and are supported by the casing 101a via a head holder (not shown). The head holder holds the head 1 so that a predetermined gap suitable for recording is formed between the lower surface of the head 1 and the upper surface 7 a of the platen 7.

  Each head 1 has a head body 2 formed with a plurality of ejection openings 108 (see FIG. 6) for ejecting ink at the lower part. The ejection port 108 is open to the ejection surface 2 a that is the lower surface of the head body 2, and the ink supplied to the head body 2 reaches.

  The two guide parts 10a and 10b are arranged with the transport part 9 in between. The guide unit 10a on the upstream side in the transport direction has three guides 13a and two pairs of feed rollers 14 and 15, and connects a paper feed unit 101b (described later) and the transport unit 9. The sheet P for image formation is conveyed toward the conveyance unit 9. The guide unit 10b on the downstream side in the transport direction has three guides 13b and three feed roller pairs 17 to 19 and connects the transport unit 9 and the paper discharge unit 4. The paper P after image formation is conveyed toward the paper discharge unit 4.

  In the space B, the paper feeding unit 101b is arranged. The paper feed unit 101 b includes a paper feed tray 11 and a paper feed roller 12. Among these, the paper feed tray 11 is detachable from the housing 101a. The paper feed tray 11 is a box that opens upward, and can store a plurality of papers P. The paper feed roller 12 sends out the uppermost paper P in the paper feed tray 11. Here, the sub-scanning direction is a direction parallel to the paper conveyance direction conveyed by the feed roller pairs 15 and 16, and the main scanning direction is a direction parallel to the horizontal plane and orthogonal to the sub-scanning direction.

  In the space C, the cartridge unit 101c is detachably attached to the housing 101a. The cartridge unit 101 c includes a tray 6 and four cartridges 5 accommodated in the tray 6 side by side. The four cartridges 5 contain magenta, cyan, yellow, or black ink. Each cartridge 5 is connected to the head main body 2 via a tube (not shown), and supplies ink of a color corresponding to the head main body 2.

  The control device 101p controls the operation of each part of the printer 101 and controls the operation of the entire printer 101. For example, the control device 101p controls the image forming operation based on image data supplied from an external device (such as a PC connected to the printer 101). Specifically, the control device 101p controls a preparatory operation related to recording, a paper P supply / conveyance / discharge operation, an ink ejection operation synchronized with the conveyance of the paper P, and the like.

  The control device 101p drives a paper feed motor (not shown) for the paper feed roller 12, feed motors (not shown) for the feed roller pairs 14 to 19 and the like based on a recording command received from an external device. The paper P sent out from the paper feed tray 11 is sent to the transport unit 9 by the guide unit 10a on the upstream side. In the transport unit 9, the paper P is sequentially supported and transported by the upper surface 7 a of the platen 7. When the paper P passes directly below each head body 2 in the sub-scanning direction (paper transport direction), ink is sequentially ejected from each ejection surface 2a by the control of the control device 101p, and a color image is formed on the paper P. Is done. The ink ejection operation is performed based on a detection signal from the paper sensor 8 that detects the leading edge of the paper P. The paper P on which the image is formed is discharged from the opening 3 formed in the upper part of the housing 101a to the paper discharge unit 4 by the downstream guide unit 10b.

  Next, the head body 2 will be described below with reference to FIGS. As shown in FIG. 2, the head main body 2 includes eight flow path units 20 and eight actuator units 21 (second members) bonded to the upper surface (one surface) 20 a of the flow path unit 20 (first member). ) Is included. The flow path unit 20 is a flow path forming member in which an ink flow path including a pressure chamber 110 (described later) is formed. The actuator unit 21 includes a plurality of unimorph actuators corresponding to the pressure chambers 110, and selectively applies ejection energy to the ink in the pressure chambers 110.

  The ink flow path of the flow path unit 20 communicates the ink supply port 105b on the upper surface 20a and the discharge port 108 on the lower surface (discharge surface 2a). As shown in FIGS. 2 and 6, the ink flow path includes a manifold flow path 105, a sub-manifold flow path 105a, and an individual ink flow path 132. The manifold channel 105 communicates with the ink supply port 105 b, and the sub-manifold channel 105 a branches off from the manifold channel 105. The individual ink flow path 132 is a flow path from the outlet of the sub-manifold flow path 105a to the discharge port 108. Ink is supplied from the cartridge 5 to the ink supply port 105b.

  As shown in FIG. 6, the flow path unit 20 is a laminated body in which nine metal plates 122 to 130 made of stainless steel are laminated. Among these, a large number of pressure chambers 110 are open on the upper surface 20 a of the uppermost plate 122 (the upper surface of the flow path unit 20). On the other hand, the same number of discharge ports 108 as the pressure chambers 110 are opened on the lower surface (discharge surface 2 a) of the lowermost plate 130. Each pressure chamber 110 is formed corresponding to one discharge port 108.

  On the upper surface (the upper surface of the plate 122) 20a, a plurality of pressure chambers 110 are assembled together to form eight pressure chamber groups 151, as shown in FIG. As shown in FIG. 3, each pressure chamber group 151 occupies a trapezoidal region in plan view. The pressure chamber groups 151 are arranged avoiding the ink supply ports 105b, and are arranged in two rows in a staggered manner along the main scanning direction. Adjacent two pressure chamber groups 151 have their hypotenuses facing each other in parallel, and are arranged with a gap in the sub-scanning direction. The ink supply ports 105b are also arranged in a zigzag pattern in two rows along the main scanning direction. Therefore, each pressure chamber group 151 has a trapezoidal lower bottom portion sandwiched between ink supply ports 105b from both sides in the main scanning direction. Further, as shown in FIG. 4, the two adjacent pressure chamber groups 151 are configured symmetrically with respect to a point Q (point at the tip of the arrow Q) between them. The discharge ports 108 also gather together to form a discharge port group on the discharge surface 2a, like the pressure chamber group 151, and occupy a trapezoidal region.

  Adhesive escape grooves 171 and 172 are further formed on the upper surface 20a by half etching. The escape groove 171 is formed along the upper and lower bases of each pressure chamber group 151. The escape groove 171 includes a plurality of rectangular escape grooves 171a arranged along the main scanning direction, and a linear escape groove 171b that connects the escape grooves 171a to each other. The escape groove 172 is formed along the hypotenuse of each pressure chamber group 151. The escape groove 172 includes a plurality of parallelogram-shaped escape grooves 172a having sides parallel to the oblique sides of the pressure chamber group 151, and linear escape grooves 172b that connect the escape grooves 172a to each other. The relief groove 171 and the relief groove 172 are connected to each other, and thereby the entire pressure chamber group 151 is surrounded. In the present embodiment, the escape groove 172 is formed point-symmetrically with respect to the point Q between the pressure chamber groups 151 as shown in FIG. Similarly, the relief groove 172 not shown in FIG. 4 is symmetrical with respect to the point between the pressure chamber groups 151.

  The escape grooves 171 and 172 restrict the adhesive that enters the pressure chamber 110 in the step of bonding the actuator unit 21 to the upper surface 20a. When the adhesive enters the pressure chamber 110, the characteristics of the ink flow path change, and there is a possibility that the ink discharge characteristics from the discharge port 108 may change. The escape grooves 171 and 172 suppress changes in the ejection characteristics.

  On the upper surface 123a of the plate 123 on which the plates 122 are stacked, as shown in FIGS. 5 and 6, a plurality of channel hole groups 152 including a plurality of channel holes 113 and 114 communicating with the pressure chamber 110 are formed. Yes. The channel hole 113 constitutes an upstream partial channel of the individual ink channel 132 and communicates with the sub-manifold channel 105a. The channel hole 114 forms a downstream partial channel of the individual ink channel 132 and communicates with the ejection port 108. Since the flow path holes 113 and 114 are arranged at positions overlapping the pressure chambers 110 in a plan view, the flow path hole group 152 occupies a trapezoidal area like the pressure chamber group 151, and the pressure chamber group 151. Are arranged in the same way. The plate 123 is also formed with a channel hole 105 c that is a part of the manifold channel 105. Each channel hole 105c communicates with a corresponding ink supply port 105b.

  In addition, as shown in FIG. 6, the remaining plates 124 to 130 are also formed with a large number of flow path holes constituting the ink flow path, similarly to the plates 122 and 123. The plates 122 to 130 are stacked via an adhesive while being aligned with each other, so that these flow path holes communicate with each other, and the manifold flow path 105, the sub-manifold flow path 105a, An ink flow path reaching the ejection port 108 via the individual ink flow path 132 is formed.

  In the flow path unit 20 configured as described above, the flow of ink is as follows. The ink supplied into the flow path unit 20 via the ink supply port 105b flows from the manifold flow path 105 into the sub manifold flow path 105a (FIG. 2). The ink in the sub-manifold flow path 105a is distributed to each individual ink flow path 132 and reaches the discharge port 108 via the aperture 112 and the pressure chamber 110 functioning as a throttle (FIG. 6).

  Next, the actuator unit 21 will be described. As shown in FIG. 2, the eight actuator units 21 are arranged in a zigzag pattern in two rows so as to avoid the ink supply ports 105b. Each actuator unit 21 has the same outer shape as the pressure chamber group 151 and occupies a slightly larger area than the pressure chamber group 151. At this time, the parallel opposing sides of each actuator unit 21 are along the longitudinal direction of the flow path unit 20, and the oblique sides of the adjacent actuator units 21 are superposed along the sub-scanning direction.

  As shown in FIG. 7, the actuator unit 21 is a piezoelectric actuator composed of three piezoelectric layers 141 to 143. Each of the piezoelectric layers 141 to 143 is made of a single sheet having a shape and a size covering the pressure chamber group 151. The lowermost piezoelectric layer 143 has a lower surface fixed to the upper surface 20 a and seals the openings of all the pressure chambers 110 included in the pressure chamber group 151. As shown in FIG. 7, individual electrodes 135 are formed on the upper surface of the piezoelectric layer 141. The individual electrode 135 faces the pressure chamber 110 except for the tip. An individual land 136 is provided at the tip. A common electrode 134 formed on the entire surface of the sheet is interposed between the piezoelectric layer 141 and the lower piezoelectric layer 142. Each of the piezoelectric layers 141 to 143 is made of a lead zirconate titanate (PZT) ceramic having ferroelectricity.

  Here, a driving method of the actuator unit 21 will be described. The outermost piezoelectric layer 141 is polarized in the thickness direction and is sandwiched between two electrodes 134 and 135. The common electrode 134 is at ground potential. When the drive signal is supplied to the individual land 136, the individual electrode 135 has a potential different from that of the common electrode 134, and an electric field is generated between the electrodes. For example, if the polarization direction and the electric field direction are the same, a portion (driving active portion) sandwiched between the electrodes 134 and 135 contracts in a direction (plane direction) orthogonal to the polarization direction, and the lower piezoelectric layer 142 , 143 and a difference in distortion occurs. Due to the difference in strain, the portion sandwiched between the individual electrode 135 and the pressure chamber 110 is deformed into a convex shape (unimorph deformation) toward the pressure chamber 110 side. At this time, ejection energy is applied to the ink in the pressure chamber 110, and an ink droplet is ejected from the ejection port 108.

  In this manner, the portion facing the individual electrode 135 can be selectively deformed and functions as an individual actuator. The actuator unit 21 includes the same number of actuators as the pressure chamber 110.

  Incidentally, the actuator unit 21 is bonded to the upper surface 20 a of the flow path unit 20. Therefore, as shown in FIG. 4, markers (positioning holes: recesses 180 a and 180 b) for positioning the actuator unit 21 are formed on the upper surface 20 a of the flow path unit 20. Hereinafter, the recesses 180a and 180b will be described with reference to FIG. 4, FIG. 5, FIG. 8, and FIG.

  One set of the recesses 180a and 180b is formed for each pressure chamber group 151, and a total of eight sets are formed. As shown in FIG. 4, each concave group is formed at a position sandwiching the pressure chamber group 151 in the main scanning direction. In addition, since the structure of the recessed part 180a and the recessed part 180b is the same, the recessed part 180a is demonstrated and it abbreviate | omits about the detail description of the recessed part 180b.

  As shown in FIG. 9, the recess 180a (180b) includes a columnar hole 181 having a circular opening edge 185a on the upper surface 20a, and an annular hole 182 connected to the columnar hole 181 via an annular opening 183. And is formed across the two plates 122 and 123. Such a split formation method facilitates formation of the recess 180a. Furthermore, even if the concave portion has a more complicated shape, if the concave portion is disassembled into a plurality of simple partial holes and each formed in separate plates, the plates are aligned and stacked. The recess can be easily restored simply by doing. In the present embodiment, a through-hole 185 (described later) is formed in the plate 122, and an annular hole 182 is formed in the plate 123.

  The columnar hole 181 is defined by stacking two plates 122 and 123. The through-hole 185 of the plate 122 has a circular opening edge 185a on the upper surface 20a, and penetrates the plate 122 vertically. A circular region is formed by an annular hole 182 on the upper surface 123 of the plate 123 (lamination surface on which the plates 122 are laminated) 123a. Both plates 122 and 123 are laminated, the opening edge 185a faces the annular hole 182 in plan view, and the circular region becomes the bottom surface 186 of the columnar hole 181. An annular opening 183 is formed along the opening edge 185a in plan view. The annular opening 183 is a belt-like region from the opening edge 185a to the outer peripheral edge of the circular region (the inner peripheral edge 183a of the opening of the annular hole 182). Here, each opening edge 185a is formed at the center of the parallelogram relief groove 172a as shown in FIGS. 8 (a) and 8 (b). As shown in FIG. The point Q is arranged symmetrically with respect to the point Q between 151. In addition, although the opening edge 185a of the through-hole 185 is circular as mentioned above, it is not limited to this.

  As shown in FIGS. 8C and 9, the annular hole 182 is formed on the upper surface 123 a of the plate 123 by half etching. The annular hole part 182 is a belt-like groove part surrounded by an inner peripheral edge 183a and an outer peripheral edge 182b that are concentric in a plan view. In the present embodiment, the inner peripheral edge 183a is the inner peripheral edge of the annular hole 182 itself, and the outer peripheral edge 182b is the outer peripheral edge of the annular hole 182 itself. Therefore, as shown in FIG. 9, the cross section cut in the thickness direction of the plate is a curved surface that expands toward the columnar hole 181 as a whole. The reflectance of the curved surface with respect to light is smaller than the bottom surface 186. Further, with respect to the opening edge 185a in plan view, the inner peripheral edge 183a is disposed on the inner side, and the outer peripheral edge 182b is disposed on the outer side. Since the outer peripheral edge 182b is arranged outside the opening edge 185a, the width of the annular hole 182 can be made relatively large. For this reason, even if the below-mentioned adhesive applied to the upper surface 20a flows into the recesses 180a and 180b, it is difficult to adhere to the bottom surface 186.

  Since the outer peripheral edge 183b of the opening 183 and the opening end edge 185a overlap, the bottom surface of the columnar hole 181 is only the region (bottom surface 186) defined by the inner peripheral edge 183a of the opening 183. For this reason, a shadow (that is, a shadow in the vicinity of the opening edge 185a of the plate 122) generated when imaging the recesses 180a and 180b appears only in the opening 183 (annular hole 182). Therefore, when the image is analyzed, the opening shape of the concave portion 180a is not deformed, and the identification becomes easy.

  As a modification, even when the through hole 185 expands outward as the diameter approaches the upper surface 123a from the upper surface 20a, the outer peripheral edge 183b of the opening 183 is disposed outside the opening edge 185a in plan view. It only has to be done. Even in this case, the same effect as described above can be obtained.

  As another modification, in the above-described embodiment, the annular hole 182 has a curved surface extending toward the columnar hole 181 in the vicinity of the annular opening 183, but is configured with a surface narrowing toward the columnar hole 181. May be. At this time, the inner peripheral edge 183a and the outer peripheral edge 182b that define the annular opening 183 are arranged to be sandwiched between the inner peripheral edge and the outer peripheral edge of the annular hole 182 itself in plan view. In this case, the same effect as described above can be obtained.

  The bottom surface 186 is formed by forming an annular hole 182 on the top surface 123 a of the plate 123, and is a region defined by the inner peripheral edge 183 a of the opening 183. Since the bottom surface 186 is the same rolling surface as the top surface 123a, the light from the light source 195 does not diffusely reflect on the bottom surface 186 when imaging. As a result, the shape of the bottom surface 186 can be accurately identified.

  Further, the plate 122 having the through hole 185 and the plate 123 having the annular hole 182 are laminated to form an annular opening 183 that overlaps the through hole 185 in a plan view, thereby forming the recess 180a. Has been. Thereby, the recessed part 180a can be comprised easily. An annular opening 183 is formed on the upper surface 123a of the plate 123, and the bottom surface 186 is close to the opening 187 of the recess 180a in the stacking direction. For this reason, when the bottom surface 186 is imaged, it is difficult for a shadow to appear on the bottom surface 186.

  The bottom surface 186 is the same rolled surface as the top surface 123a of the plate 123. On the other hand, minute irregularities are formed on the inner surface 182a of the annular hole portion 182 formed by half etching, and the light reflectance is different from that of the bottom surface 186. For this reason, imaging with high contrast is possible between the bottom surface 186 and the annular hole 182 surrounding the bottom surface 186. Therefore, the shape of the bottom surface 186 can be accurately identified. As a modification, the bottom surface 186 may be other than the rolled surface. That is, the bottom surface 186 only needs to have a reflectance different from that of the inner surface 182a, and may be a machined surface or a half-etched surface. In this case, from the viewpoint of being insensitive to shadows generated during imaging, the reflectance of the inner surface 182a on which the shadows are reflected should be smaller than that of the bottom surface 186.

  As described above, the recess 180a has a configuration in which the outer peripheral edge of the bottom surface 186 (that is, the inner peripheral edge 183a of the opening 183) is disposed on the inner side of the opening edge 185a of the concave part 180a in plan view. When the bottom surface 186 is imaged from vertically above, the light source 195 is disposed at a position slightly deviated from the front of the opening 187 of the recess 180a. It appears in the annular hole 182 (opening 183) and does not appear on the bottom surface 186. Therefore, the bottom surface 186 can be accurately identified accurately. By having such recesses 180a and 180b, the inkjet head 1 in which the actuator unit 21 and the flow path unit 20 (particularly, the pressure chamber 110 and the individual actuators in the actuator unit 21) are stacked with high positional accuracy; Become. As a result, the head 1 having uniform ink ejection characteristics is obtained.

  Further, when an adhesive for joining the actuator unit 21 is applied to the upper surface 20 a of the plate 122, the surplus adhesive flows into the annular hole 182 through the annular opening 183. For this reason, it is difficult for excess adhesive to adhere to the bottom surface 186. If the adhesive adheres to the bottom surface 186, the light reflectance differs from the unattached portion, and the shape of the bottom surface 186 cannot be accurately identified. However, in the present invention, since the adhesive hardly adheres to the bottom surface 186, the shape of the bottom surface 186 can be accurately identified. Furthermore, since the bottom surface 186 is inside the opening edge 185a, the bottom surface 186 is not easily affected by the shadow caused by the vicinity of the opening edge 185a. For this reason, the degree of freedom increases in the position of the light source at the time of imaging, and the light source can be shifted from the front side of the recess 180a.

  The escape groove 172a surrounds the recesses 180a and 180b over the entire circumference. Accordingly, it is possible to suppress the surplus portion of the adhesive applied to the upper surface 20a of the plate 122 in order to bond the actuator unit 21 from entering the recesses 180a and 180b.

  As shown in FIGS. 8C and 9, an escape groove 188 that surrounds the annular hole 182 is formed on the upper surface 123 a of the plate 123. Accordingly, when the plates 122 and 123 are bonded to each other, the adhesive is less likely to enter the annular hole 182 (recesses 180a and 180b). For this reason, the excess adhesive between the plates 122 and 123 does not adhere to the bottom surface 186.

  Next, a manufacturing process of the head body 2 having a marker for alignment will be described. FIG. 10 is a flowchart showing the flow of the manufacturing process of the head body 2.

  First, each of the plates 122 to 130 constituting the flow path unit 20 is manufactured. In each plate, a plurality of flow path holes constituting the ink flow path are formed by etching (S1). Next, partial markers are formed on the plate 122 and the plate 123 (S2). At this time, a through hole 185 is formed in the plate 122 by etching as an outer partial marker. In the plate 123, an annular hole 182 is formed by half etching on the upper surface 123a as an inner partial marker. At least the plates 122 and 123 are rolled members made of metal (in this case, stainless steel). Therefore, the etching surface (inner surface 182a) of the annular hole 182 is less smooth than the rolled surfaces of the plates 122 and 123, and has a rough surface. That is, the plate 123 having the upper surface 123a (bottom surface 186) having a reflectance with respect to the light different from the inner surface 182a is formed.

  Here, the reflectance is the ratio of the intensity of light reflected at the reflection angle θ2 to the intensity of light incident at the incident angle θ1 with respect to a certain surface. In the present embodiment, the reflectance is smaller on the inner surface 182a than on the bottom surface 186. The surface roughness of the rolled surface (bottom surface 186) is about Ra = 0.10 μm. On the other hand, the surface roughness of the etched surface (corresponding to the inner surface 182a) is about Ra = 0.32 μm. Light scattering on the etching surface is large on the surface, and the reflected light intensity at the reflection angle θ2 is smaller than that on the rolled surface.

  At the time of imaging, the image sensor 191 is disposed in front of the marker, and the light source 195 is disposed adjacent to the image sensor 191. The image sensor 191 is on a vertical line standing on the marker (a vertical line passing through the center of the opening of the through hole 185). On the other hand, the light source is at a position where the marker is viewed at an angle θ with respect to the perpendicular. The reflectivities in this embodiment are obtained as θ1 = θ and θ2 = 0. In fact, the etched surface is dark and the rolled surface is imaged brightly.

  Next, adhesive relief grooves such as relief grooves 171, 172, 188 are formed on the surfaces of the plates 122, 123, etc. by half etching (S3). It is preferable that a relief groove is also formed in the plate other than the plates 122 and 123 so as to surround the periphery of the opening of the flow path hole. And the flow path unit 20 is produced through alignment, lamination | stacking, and fixation of each plate 122-130 (S4). An epoxy thermosetting adhesive is used to fix the plates 122 to 130. At this time, various flow path holes are aligned, and an ink flow path is configured in the flow path unit 20. At the same time, the partial markers are aligned to form the recesses 180a and 180b. The center of the opening of the through hole 185 overlaps the center of the bottom surface 186 in plan view. That is, the plates 122 and 123 are laminated so that the bottom surface 186 is disposed inside the opening edge 185a in plan view. Thus, the flow path unit 20 in which the concave portions 180a and 180b are simply configured is completed.

  Here, since the annular hole 182 is formed around the bottom surface 186, even if surplus adhesive is generated between the plate 122 and the plate 123 during bonding with the adhesive, the adhesive flows into the annular hole 182. Does not adhere to the bottom surface 186. For this reason, at the time of imaging by the image sensor 191 described later, the adhesive attached to the bottom surface 186 is not imaged, and can be appropriately compared with reference image data described later.

  Next, an adhesive is applied to the upper surface of the flow path unit 20 (S5). The adhesive is an epoxy thermosetting adhesive and adheres the actuator unit 21. Then, the upper surface 20a of the flow path unit 20 is imaged by an image sensor 191 such as a CCD camera (S6). Comparison between imaging near the marker at a low magnification and reference image data (described later) corresponding to the imaging is performed. Prior to imaging by the image sensor 191, the flow path unit 20 is supported on a support base. In addition, a marker (the opening 187 of the recesses 180a and 180b) is arranged in advance so as to be positioned almost in front of the image sensor 191 at the time of imaging.

  At this time, since the light source 195 is displaced from the front of the marker, the shadow near the opening edge 185a is inserted into the recesses 180a and 180b. However, in the present embodiment, the spread of the shadow at the bottom surface portion is configured to be within the annular opening 183. Specifically, the angle at which the light source 195 looks at the marker is θ (see FIG. 11), the thickness of the plate 122 (the distance between the upper surface 20a and the upper surface 123a) is T, and the width of the band-shaped portion of the opening 183 in plan view is w. Then, the relationship of T × tan θ ≦ w is satisfied.

  FIG. 11 is a perspective view showing the positional relationship between the flow path unit 20 and the image sensor 191. The XY coordinates in FIG. 11 are coordinates along the horizontal plane. Image data captured by the image sensor 191 is transmitted to the positioning control device 192. The positioning control device 192 has an image sensor 191 that controls the alignment operation of the actuator unit 21, an image analysis unit 193 that analyzes the captured image, a position adjustment unit 194 that adjusts the position of the actuator unit 21, and the like. doing.

The image sensor 191 is opposed to the flow path unit 20 on the support base at a predetermined interval. The image sensor 191 forms a pair with the light source 195 and captures the marker in front. The light source 195 irradiates the marker at the expected angle θ.
The image analysis unit 193 analyzes the image indicated by the image data from the image sensor 191. By the analysis, a characteristic pattern of the form is extracted from the image data. The image analysis unit 193 stores two types of reference image data in order to determine a marker from the image data. The two types of reference image data correspond to a low-magnification image and a high-magnification image including a marker, and are image data of regions R1 and R2 surrounded by a dashed line in FIGS. The region R1 includes a through hole 185 and an escape groove 172a in plan view. The reference image data in this area can be referred to as a circular shape (corresponding to the through hole 185) enclosed in a parallelogram (corresponding to the escape groove 172a), with the arrangement form of the through holes 185 and the escape groove 172a as characteristic pattern information. It is. Region R2 includes bottom surfaces 186 of recesses 180a and 180b in plan view. The reference image data in this area can be referred to as a circle (corresponding to the bottom surface 186) with the shape of the bottom surface 186 as characteristic pattern information.

  Imaging of the upper surface 20a by the image sensor 191 is performed in two steps, and consists of high-magnification imaging following low-magnification imaging. The image sensor 191 is disposed in front of the recesses 180a and 180b in advance. In low-magnification imaging, the field of view of the image sensor 191 includes a relief groove 172a around the bottom surface 186 at the center. Here, the inner surface of the escape groove 172a and the inner surface 182a of the annular hole 182 are etched surfaces, and have a lower reflectance than other regions (rolled surfaces) and are distinguished from the rolled surfaces with high contrast. The In the present embodiment, as described above, the spread of the shadow near the opening edge 185a stops in the annular opening 183. In addition, this shadow does not affect the identification accuracy, helped by the low magnification and the low reflectivity of the inner surface 182a.

  Thereby, the image sensor 191 can accurately image the through hole 185 and the escape groove 172a. The image analysis unit 193 accurately compares this image data with the reference image data in the region R1 based on characteristic pattern information included in each data. Note that the image analysis unit 193 can perform rotation processing of the reference image data along the XY coordinate plane, and can compare the image data even if the flow path unit 20 is supported by being shifted from the reference direction.

  Here, since the reference image data is composed of the parallelogram pattern information of the escape groove 172a having a larger size in addition to the circular pattern information of the through hole 185, the comparison with the imaging data is easy. Further, as shown in FIG. 4, the escape groove 172a corresponding to the reference image data is larger in size than the other escape grooves 172a arranged on the oblique side portion of the pressure chamber group, and is compared with the imaging data. Makes the comparison more accurate.

  When the image analysis unit 193 determines that there is a portion that closely matches the reference image data corresponding to the region R1, it can be seen that the image sensor 191 is surely opposed to the concave portion 180a or the concave portion 180b. In addition, the image analysis unit 193 stores the rotation angle α of the reference image data viewed as coincident with the image data, and sets the rotation angle of the pressure chamber group 151 from the reference direction on the support base.

  Next, the bottom surface 186 is imaged at a high magnification by the image sensor 191 (S7). The bottom surface 186 at this time is surrounded by the annular hole 182 (annular opening 183), and the shadow near the opening edge 185a does not reach the bottom surface 186.

  In high-magnification imaging, the field of view of the image sensor 191 includes only the bottom 186 surrounded by the annular hole 182 in the center. Since there is no influence of the shadow, the image sensor 191 can accurately image the through hole 185. The image analysis unit 193 accurately compares the image data with the reference image data in the region R2 based on characteristic pattern information included in each data. If the image analysis unit 193 determines that the characteristic patterns of the respective data match, the image analysis unit 193 acquires the position of the center of the bottom surface 186 on the XY coordinate system based on the image data from the image sensor 191. In this manner, the positions of the recesses 180a and 180b are acquired, and the position on the XY coordinate system and the rotation angle θ of the pressure chamber group 151 sandwiched between the recesses 180a and 180b are determined.

  Next, the position adjustment unit 194 adjusts and arranges the position of the actuator unit 21 based on the position coordinates and the rotation angle θ of the pressure chamber group 151 acquired by the image analysis unit 193 (S9). During position adjustment and arrangement, the position adjustment unit 194 drives a jig that supports the actuator unit 21. As shown in FIG. 11, the jig is movable in three directions of X, Y, and θ (directions indicated by white arrows in the figure). The actuator unit 21 is arranged in a predetermined positional relationship with two markers (recesses 180a and 180b) sandwiching the pressure chamber group 151. Thereafter, the actuator unit 21 is joined to the upper surface 20a of the flow path unit 20 via an adhesive (S10). As described above, the acquisition of the position and rotation angle of the pressure chamber group 151 and the alignment and joining of the actuator unit 21 are repeated eight times, whereby all the actuator units 21 are bonded onto the flow path unit 20. In addition, the actuator unit 21 is produced by a process different from the flow path unit 20 (S8).

  As described above, according to the ink jet head 1 according to the present embodiment, the bottom surfaces 186 of the recesses 180a and 180b are arranged inside the opening edges 185a via the annular holes 182 (openings 183) in plan view. Has been. When imaging by the image sensor 191, a shadow near the opening edge 185a is generated due to the positional relationship between the observation point and the light source. However, the spread of the shadow stops in the annular hole 182 and does not reach the bottom surface 186. Therefore, accurate imaging of the bottom surface 186 by the image sensor 191 and accurate comparison of characteristic patterns by the image analysis unit 193 are possible. That is, the XY coordinates and rotation angle of the marker can be acquired accurately.

  According to the method for manufacturing the inkjet head 1, the bottom surface 186 can be accurately identified, and the actuator unit 21 can be disposed at a predetermined position of the flow path unit 20 with the obtained XY coordinates and rotation angle.

  Hereinafter, first and second modified examples of the above-described recesses 180a and 180b will be described. As shown in FIG. 12, the concave portion 280 of the first modified example is the same except that the shape of the annular hole 282 formed in the plate 123 is slightly different from the above-described annular hole 182. That is, the annular hole 282 is slightly smaller than the annular hole 182. And the outer peripheral edge 282b of the annular hole 282 just overlaps the opening edge 185a in the vertical direction. Also in this case, since the bottom surface 186 is disposed inside the opening edge 185a, the same effect as described above can be obtained. In addition, the same effect can be obtained in the same configuration as described above.

  As shown in FIG. 13, the recess 380 of the second modification is configured by adding a plate 322 to the plates 122 and 123. The plate 322 is formed with a truncated cone-shaped through hole 385 and is sandwiched between two plates 122 and 123. The through hole 385 has an opening edge 385a on the upper surface 322a and an opening edge 385b on the lower surface 322b. Each of the opening edges 385a and 385b has a larger diameter at the opening edge 385b. At this time, the opening edge 385a overlaps with the opening edge 185a of the columnar hole 181 and the opening edge 385b overlaps with the outer peripheral edge 182b of the annular hole 182 in plan view. Regarding the opening edge 185a, the outer peripheral edge 182b of the annular hole 182 is located on the outer side and the inner peripheral edge 182a is located on the inner side in plan view. Here, the through-hole 385 can be disassembled into a columnar portion having the same diameter and the same diameter as the columnar hole portion 181 and a hollow truncated cone portion excluding the columnar portion. The columnar hole portion of the recess 380 is constituted by the columnar portion of the columnar hole portion 181 and the through hole 385, and the annular hole portion 382 is constituted by the annular hole portion 182 and the hollow truncated cone portion. In addition, the annular region of the upper surface 123a defined by the opening edge 185a and the bottom surface 186 in plan view and the annular inner surface of the hollow portion of the hollow truncated cone are annular openings 383 of the recess 380, and the columnar holes of the recess 380 And the annular hole 382 are connected. Also in such a recess 380, since the bottom surface 186 is disposed inside the opening edge 185a, the same effect as described above can be obtained. In addition, the same effect can be obtained in the same configuration as described above.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the recesses 180a, 180b, 280, and 380 may be formed across four or more plates. Moreover, the recessed part may be formed in one plate. In this case, what is necessary is just to form the recessed part comprised from the columnar hole part and the annular hole part by machining. Even in this case, the same effect as described above can be obtained.

  In the above-described embodiment, the image sensor 191 captures the recesses 180a and 180b and the vicinity thereof at a low magnification in order to check whether or not the image sensor 191 is opposed in front of the recesses 180a and 180b. When it is known that the image sensor 191 is opposed to the recesses 180a and 180b almost directly in front, the image sensor 191 may image the bottom surface 186 at a high magnification from the beginning.

  The present invention is also applicable to a liquid discharge head that performs recording by discharging a liquid other than ink. Furthermore, the present invention can be applied regardless of the liquid ejection method. For example, although a piezoelectric element is used in this embodiment, a resistance heating method or a capacitance method may be used.

1 Inkjet head (liquid ejection head)
20 Channel unit (first member)
20a Upper surface (one surface)
21 Actuator unit (second member)
122, 123, 322 Plate 123a Upper surface (lamination surface)
180a, 180b, 280, 380 Recess 181 Columnar hole 182, 382 Annular hole 182a Inner surface 182b Outer peripheral edge 183, 383 Opening 183a Inner peripheral edge 183b, 385a Outer peripheral edge 185 Through hole 185a Opening edge 186 Bottom face 187 Opening

Claims (11)

A first member;
A second member laminated on one surface of the first member,
The first member is formed with a recess composed of a columnar hole having an opening edge on the one surface and an annular hole connected to the columnar hole via an annular opening,
An inner peripheral edge of the annular opening defines a bottom surface of the columnar hole and is included in the opening edge as viewed from the stacking direction of the first member and the second member. Liquid discharge head.   2. The liquid ejection head according to claim 1, wherein an outer peripheral edge of the annular opening is disposed at a position overlapping the opening edge or outside the position when viewed from the stacking direction.   3. The liquid discharge head according to claim 1, wherein an outer peripheral edge of the annular hole portion is disposed on an outer side than the opening edge as viewed in the stacking direction. The first member is a stacked body of a plurality of plates stacked in the stacking direction,
The said recessed part is formed ranging over 2 or more plates including the outermost layer plate on which the said 2nd member is laminated | stacked among these several plates, The any one of Claims 1-3 characterized by the above-mentioned. The liquid discharge head according to item. In the outermost layer plate, a through-hole constituting the columnar hole is formed,
The annular opening is formed on a surface of a plate adjacent to the outermost layer plate, on which the outermost layer plate is laminated, at a position facing the through hole. Item 5. The liquid discharge head according to Item 4.   The liquid discharge head according to claim 5, wherein a bottom surface of the columnar hole is in the same plane as the laminated surface.   The bottom surface of the columnar hole defined by the inner peripheral edge of the annular opening has a light reflectance different from that of the inner surface of the annular hole. Liquid discharge head. In a method for manufacturing a liquid ejection head, comprising: a first member; and a second member laminated on one surface of the first member.
A recess formed by a columnar hole having an opening edge on the one surface and an annular hole connected to the columnar hole via an annular opening, wherein the inner periphery of the annular opening is the Defining the bottom surface of the columnar hole and forming the concave portion included in the opening edge as viewed from an orthogonal direction orthogonal to the one surface in the first member;
Imaging the bottom surface of the columnar hole through the opening of the recess;
Aligning the second member with respect to the first member with respect to a direction along the one surface based on the acquired image of the bottom surface;
And a step of laminating the aligned second member on the one surface. In the step of forming the recess in the first member,
The first member is formed with a position where an outer peripheral edge of the annular opening overlaps with the opening edge or the outer side of the position when viewed from the orthogonal direction. Item 9. A method for manufacturing a liquid discharge head according to Item 8. In the step of forming the recess in the first member,
An outermost layer plate on which the second member is laminated, the outermost layer plate having a through-hole forming the columnar hole, and a laminated surface on which the outermost layer plate is laminated, the annular hole The concave portion is formed in the first member by laminating a plurality of plates, including a plate having the laminating surface in which the annular opening is formed at a position facing the through hole by a portion. A method for manufacturing a liquid discharge head according to claim 8 or 9. In the step of forming the recess in the first member,
11. The liquid according to claim 10, wherein the plate has the laminated surface including a region defined by an inner peripheral edge of the annular opening, which has a light reflectance different from an inner surface of the annular hole. Manufacturing method of the discharge head.