JP3797246B2 - Inkjet printer head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a piezoelectric type ink jet printer head.
[0002]
[Prior art]
  2. Description of the Related Art In an on-demand type piezoelectric ink jet printer head of the prior art, an ink jet head unit (hereinafter simply referred to as a head unit) in which nozzle rows are arranged in a direction orthogonal to the printing direction is provided for each nozzle of a plurality of nozzles. A cavity plate having a pressure chamber formed therein, a common ink chamber (manifold chamber) for supplying ink to the plurality of pressure chambers, and a drive unit of the pressure chamber provided on the back side of the cavity plate. As a method of fixing the head unit to the bottom plate of the head holder, the present applicant has previously filed a patent application as a method for fixing the head unit to the bottom plate of the head holder. In 2000-260616, the bottom plate of the head holder Adhesive pour holes exposed on the side edges of the head unit and the back surface of the protective cover are drilled, and a plurality of head units are arranged in parallel on the lower surface side of the bottom plate. It has been proposed that a head unit and a protective cover are bonded and fixed to the bottom plate while an agent such as a UV adhesive is dropped, and the periphery of the protective cover is bonded and fixed to the bottom plate with a sealant.
[0003]
  By the way, the inkjet printer head needs to fix the position of the inkjet nozzle with respect to the head holder and fix the head unit in order to improve the printing accuracy. Therefore, as described above, a plurality of ink jet printer heads on the lower surface side of the bottom plate. The head units are arranged in parallel, and a UV adhesive is dropped from the upper surface side of the bottom plate through the adhesive pouring hole, and from the upper surface side of the bottom plate to the UV adhesive through the adhesive pouring hole. It was solidified in a short time by irradiation with ultraviolet rays.
[0004]
[Problems to be solved by the invention]
  However, when the ultraviolet rays are irradiated from the upper surface side of the bottom plate toward the adhesive pouring hole, the lower surface side of the bottom plate and the back surface side (back surface side) of the head unit at the outer peripheral portion from the adhesive pouring hole. Ultraviolet rays do not reach the flowing out UV adhesive, and the uncured portion of the UV adhesive remains.
[0005]
  Such an uncured portion of the UV adhesive is the head unit.Back (back)If the piezoelectric actuator or the flexible flat cable is in contact with the piezoelectric actuator, the insulation of the uncured portion is low. Therefore, a weak current flows from the piezoelectric actuator or the flexible flat cable through the uncured portion during use of the inkjet. There was a problem of leakage and electrical short circuit accidents.
[0006]
  In order not to generate such an uncured portion, there are problems that it takes a long time to irradiate ultraviolet rays and the manufacturing cost increases. Further, the solidified (adhered) part of the head unit or protective cover with the UV adhesive and the bottom plate of the head holder is partial, and the other part is sealed with a sealant such as silicone so that the ink does not enter. However, if there is a contact part (mixed part) between this sealing agent and the non-solidified UV adhesive, it is impossible to achieve curing of the UV adhesive by UV irradiation or solidification of the sealing agent at that part, The problem of electrical short-circuit accidents such as the above and the occurrence of imperfect seals cannot be solved.
[0007]
  The present invention has been made to solve the above-described conventional problems, and the uncured portion of the photo-curing adhesive diffuses and leaks out to the portion of the back surface of the head unit 6 where light such as ultraviolet rays does not reach. It is a technical problem to provide an ink jet printer head that solves the above problems by providing means for preventing the uncured portion of the photo-curing adhesive from directly contacting the electrically conductive portion. It is what.
[0008]
[0009]
[0010]
[0011]
[Means for Solving the Problems]
  In order to achieve the technical problem, the invention according to claim 1 has a plurality of nozzles arranged in a line on the front surface.And the actuator was placed on the back sideIn the ink jet printer head in which the head unit is fixed to the bottom plate of the head holder via a photo-curing adhesive, the bottom plate is provided with an adhesive pouring hole facing the back surface of the side edge of the head unit. Near the outer periphery of the adhesive pouring hole in the bottom plateAnd between the adhesive pouring hole and the actuatorThe portion is formed in a proximity portion having a small gap with respect to the back surface of the head unit, and the photocurable adhesive from the adhesive pouring hole is applied to the proximity surface on the lower surface of the bottom plate or the back surface of the head unit. A reservoir groove is formed to prevent diffusion and leakage from the head to the back side of the head unit.
[0012]
  AndClaim 2The invention described inClaim 1In the ink jet printer head described in (1), the pool groove is formed to be recessed in one or a plurality of strips substantially in parallel with the direction in which the nozzle row extends.
[0013]
[0014]
[0015]
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present inventionReference examples andEmbodiments will be described with reference to the drawings. FIG. 1 is a color ink jet printer which is one embodiment of the ink jet recording apparatus of the present invention.ShowFIGS. 2 to 4 are perspective views of a piezoelectric ink jet printer head according to an embodiment of the present invention, and FIG.
[0017]
  A color inkjet printer 100 according to the present invention includes an ink cartridge 61 filled with, for example, four color inks of cyan, magenta, yellow, and black, and an inkjet head unit for printing on a sheet (recording medium) 62. An ink jet printer head 63 having 6 (hereinafter simply referred to as a head unit), a carriage 64 on which the ink cartridge 61 and the ink jet printer head 63 are mounted, and the carriage 64 reciprocates in a direction perpendicular to the transport direction of the paper 62. A drive unit 65 to be moved, a platen roller 66 extending in the reciprocating direction of the carriage 64 and arranged to face the head unit 6, and a purge device 67 are provided.
[0018]
  The drive unit 65 is disposed at the lower end portion of the carriage 64 and extends in parallel with the platen roller 66, the guide plate 72 disposed at the upper end portion of the carriage 64 and extending in parallel with the carriage shaft 71, and the carriage shaft 71. And two guide pulleys 73 and 74 disposed at both ends of the carriage shaft 71 and a timing belt 75 wound around the pulleys 73 and 74.
[0019]
  A carriage 64 joined to the timing belt 75 is supported by the carriage shaft 71 and the guide plate 72 by a driving force from one pulley 73 that rotates in accordance with the driving of the motor 76 and can linearly reciprocate.
[0020]
  A sheet 62 conveyed in the direction of an arrow from a sheet feeding unit (not shown) is introduced between the platen roller 66 and the head unit 6 and predetermined printing is performed by ink ejected from the head unit 6 as described later. Thereafter, the paper is discharged.
[0021]
  The purge device 67 is provided on the side of the platen roller 66 and is disposed so as to face the head unit 6 when the printer head 63 is at the reset position. The purge device 67 includes a purge cap 81 that abuts against an opening surface of the nozzle so as to cover a plurality of nozzles 11 a described later of the head unit 6, a pump 82 and a cam 83, and an ink storage portion 84. Yes. When the printer head 63 is at the reset position, the head unit 6 is recovered by sucking the defective ink containing bubbles and the like accumulated inside the head unit 6 by the pump 82 by driving the cam 83. Yes. The sucked defective ink is stored in the ink storage section 84.
[0022]
  A wiper member 86 is disposed adjacent to the purge device 67 at a position on the platen roller 66 side in the purge device 67. The wiper member 86 is formed in a spatula shape, and wipes the nozzle forming surface of the head unit 6 as the carriage 64 moves. When wiping the nozzle formation surface, the wiper member 86 protrudes upward, and when the nozzle formation surface is not wiped, it retracts downward.
[0023]
  The cap 85 covers the plurality of nozzles 11a of the head unit 6 mounted on the carriage 64 that is returned to the reset position when printing is completed in order to prevent ink from drying.
[0024]
  Of the inkjet printer head 63Embodiment2 and 3, the head holder 1, the two head units 6 and 6 arranged in parallel on the lower surface side of the bottom plate 5, and the nozzle row on the surface of each head unit 6 are exposed. Opened windows 44 a and 44 a are provided on the lower plate 44 b, and are constituted by a surface of the head units 6 and 6 and a box-shaped protective cover 44 fixed to the head holder 1.
[0025]
  EmbodimentAs shown in FIGS. 2 to 5, the head holder 1 is an injection molded product of a synthetic resin material such as polypropylene or polypropylene, and is formed in a substantially box shape with an open top surface (see FIG. 3). This open portion has a mounting portion 3 to which four ink cartridges 61 as ink supply sources can be detachably mounted from above, and one side portion of the mounting portion 3 has an ink for each ink cartridge 61. Ink supply passages 4a, 4b, 4c, and 4d that can be connected to a discharge portion (not shown) are formed so as to communicate with the lower surface of the bottom plate 5 of the head holder 1 (see FIG. 3). A rubber packing (not shown) is provided on the outer periphery of each ink supply passage 4a, 4b, 4c, 4d so that each ink cartridge 61 can be in close contact with the ink discharge portion.
[0026]
  The bottom plate 5 is used for disposing the head unit 6 and is formed horizontally so as to protrude one step from the lower surface (the upper surface side in FIG. 4) of the head holder 1. On the bottom surface side of the bottom plate 5, two support portions 8 and 8 are formed for supporting two head units 6 described later in parallel. A plurality of adhesive pouring holes 9 a and 9 b for fixing the head unit 6 with the UV adhesive 7 are formed in each support portion 8 so as to penetrate to the mounting portion 3 side. The plurality of adhesive pouring holes 9a and 9b are formed at locations where the long side portions of the head unit 6 are fixed at appropriate intervals. In the embodiment, the adhesive pouring hole 9a at a position where one side (long side) of the two support portions 8 and 8 is adjacent is formed wide so as to straddle the back surfaces of the two head units 6 and 6 arranged side by side. Has been.
[0027]
  As shown in FIG. 4, an opening 50 communicating with each of the ink supply passages 4a, 4b, 4c, and 4d is provided at one side portion of each of the support portions 8. A substantially annular fitting groove 46 is recessed so as to surround the outer periphery of each opening 50. Each fitting groove 46 is fitted with a ring-shaped packing 47 having a good sealing property such as soft rubber.
[0028]
  When each head unit 6 is fixed to the lower surface of the bottom plate 5 with UV adhesive 7 as will be described later, the tip of the packing 47 is the outer periphery of the ink supply port 19a (see FIG. 12) in the head unit 6. And the contact portion with the ink supply port 19a is sealed to prevent ink leakage.
[0029]
  Before that, first, the details of the head unit 6 and its components will be described. As shown in FIGS. 12 to 15, the head unit 6 has a laminated cavity plate 10 made of a plurality of metal plates and an adhesive or an adhesive sheet 41 (see FIG. 15) for the cavity plate 10. A plate-type piezoelectric actuator 20 that is bonded and laminated via a flexible flat cable 40 that is lap-joined on the upper surface for electrical connection with an external device.
[0030]
  Further, as will be described later, the ink supplied from the ink cartridge 61 thereabove is provided on the upper surface of the ink supply port 19a formed on one end of the uppermost base plate 14 on the back surface side of the head unit 6. A filter 29 for dust removal is fixed in advance with an adhesive (see FIGS. 12 and 13). When the cavity plate 10 is assembled to the head holder 1, the ink supply port 19 a presses the periphery thereof against the packing 47.
[0031]
  The cavity plate 10 is configured as shown in FIGS. That is, the nozzle plate 11, the two manifold plates 12, the spacer plate 13, and the base plate 14 each have a structure in which five thin metal plates are overlapped and bonded with an adhesive, and in the embodiment, each plate excluding the nozzle plate 11. Is made of 42% nickel alloy steel sheet and has a thickness of about 50 μm to 150 μm.
[0032]
  The nozzle plate 11 is bonded to the lower manifold plate 12, and a large number of through passages 17 communicating with the nozzle 11a are formed in the first direction (long side direction) of each of the upper and lower manifold plates 12 and the spacer plate 13. It is provided at a constant pitch in a zigzag array in two rows. In addition, ink passages 12 a and 12 b are formed in the two manifold plates 12 so as to extend along both sides of the row of the through holes 17. However, the ink passage 12b in the lower manifold plate 12 is recessed so as to open only to the upper side of the manifold plate 12 (see FIG. 12). The ink passages 12 a and 12 b are sealed by stacking the spacer plate 13 on the upper manifold plate 12.
[0033]
  The base plate 14 is provided with a plurality of narrow pressure chambers 16 extending in a second direction (short side direction) perpendicular to the center line along the long side (first direction). Has been. And when the parallel longitudinal reference lines 14a and 14b are set on both the left and right sides of the center line, the tip 16a of the pressure chamber 16 on the left side of the center line is located on the right longitudinal reference line 14a, Conversely, the tip 16a of the pressure chamber 16 on the right side of the longitudinal center line is positioned on the left longitudinal reference line 14b, and the tips 16a of the left and right pressure chambers 16 are alternately arranged. The pressure chambers 16 are alternately arranged so that every other pressure chamber 16 extends in the opposite direction.
[0034]
  The front end 16a of each pressure chamber 16 communicates with the spacer plate 13 and both manifold plates 12 through through passages 17, 17, 17 that are similarly drilled in a staggered arrangement. On the other hand, the other end 16 b of each pressure chamber 16 communicates with the ink passages 12 a and 12 b in both the manifold plates 12 through through holes 18 drilled in the left and right side portions of the spacer plate 13. As shown in FIGS. 14 and 15, the other end 16 b of each pressure chamber 16 is recessed so as to open only on the lower surface side of the base plate 14.
[0035]
  As a result, ink that has flowed into the ink passages 12a and 12b from the ink supply ports 19a and 19b formed in one end of the base plate 14 and the spacer plate 13 passes through the through holes 18 from the ink passage 12a. After being distributed in each pressure chamber 16, the pressure chamber 16 passes through the through passages 17, 17, 17 and reaches the nozzle 11 a corresponding to the pressure chamber 16 ( (See FIGS. 13 and 15).
[0036]
  On the other hand, as shown in FIG. 15, the piezoelectric actuator 20 has a structure in which a plurality of piezoelectric sheets 21 are laminated. As described in JP-A-4-341851, the piezoelectric actuator 20 has the lowest stage. On the upper surface (wide surface) of the piezoelectric sheet 21 and the odd-numbered piezoelectric sheet 21 counted upward, narrow individual electrodes (not shown) are formed for each of the pressure chambers 16 in the cavity plate 10. Has been. A common electrode (not shown) common to the plurality of pressure chambers 16 is formed on the upper surface (wide surface) of the even-numbered piezoelectric sheet 21 from the bottom. On the upper surface of the uppermost top sheet, along the edge of the long side, the surface electrode 30 electrically connected to each of the individual electrodes, and the surface electrode 30 electrically A connected surface electrode 31 is provided (see FIG. 12).
[0037]
  In the plate-type piezoelectric actuator 20 having such a configuration, the individual electrodes in the piezoelectric actuator 20 correspond to the pressure chambers 16 in the cavity plate 10 with respect to the cavity plate 10. Laminated and fixed. Further, when the flexible flat cable 40 is pressed against the upper surface of the piezoelectric actuator 20, various wiring patterns (not shown) in the flexible flat cable 40 become the surface electrodes 30, 31. Electrically joined to the
[0038]
  In this configuration, by applying a voltage between any individual electrode of the individual electrodes in the piezoelectric actuator 20 and the common electrode, the piezoelectric sheet is piezoelectrically applied to a portion corresponding to the individual electrode to which the voltage is applied. Due to the distortion in the stacking direction caused by this, the internal volume of the pressure chamber 16 corresponding to each individual electrode is reduced by this distortion, so that the ink in the pressure chamber 16 is ejected from the nozzle 11a in the form of droplets. Then (see FIG. 15), predetermined printing is performed.
[0039]
  Next, the method of fixing the head unit 6 to the head holder 1 and the viscosity of a photo-curing adhesive used for the fixing, for example, a modified acrylic resin-based adhesive as an adhesive having a fast curing property upon irradiation with ultraviolet rays. A means for preventing the occurrence of an uncured portion of the UV adhesive 7 or preventing the uncured portion of the UV adhesive 7 from diffusing and leaking to a portion of the back surface of the head unit 6 where ultraviolet rays do not reach will be described. .
[0040]
  A means for preventing the uncured portion of the UV adhesive 7 from diffusing and leaking to the back of the head unit 6 where ultraviolet rays do not reach.Reference exampleIs an outer peripheral side of the adhesive pouring holes 9a and 9b, and an adhesive member is interposed between the bottom surface of the bottom plate 5 facing the back surface of the head unit 6 and the back surface of the head unit 6. The UV adhesive 7 is configured to be prevented from leaking greatly to the back side of the head unit 6 from the agent flow holes 9a and 9b.
[0041]
  ThatFirst reference example3 and FIG. 5, the back surface of the cavity plate 10 among the back surfaces of each head unit 6, along the vicinity of the left and right long sides of the cavity plate 10 outside the piezoelectric actuator 20. This is a protrusion 90 made of an elastic member such as a rubber material. The bases of the projecting bodies 90, 90 are fixed to the back surface of the cavity plate 10 with an adhesive (not shown) such as an epoxy resin.
[0042]
  The two head units 6 and 6 and the protective cover 44 arranged in parallel as described above are simultaneously fixed to the bottom plate 5 of the head holder 1 with the UV adhesive 7, or the protective cover 44 is used later. It may be fixed.
[0043]
  A method for fixing the head unit 6 to the head holder 1 will be described. As shown in FIG. 13, for example, two positioning holes 54 a and 54 a that are separated in the extending direction of the row of nozzles 11 a of the nozzle plate 11 are formed in advance.
[0044]
  First, the lower plate 44b of the protective cover 44 is set on the upper surface of the flat jig, and the two nozzle plates 11 are exposed from the opening windows 44a and 44a formed in the lower plate 44b of the protective cover 44. And positioning holes 54a, 54a in the nozzle plates 11 are fitted into positioning pins (not shown) protruding from the upper surface of the jig. In this case, the thickness of the lower plate 44 b of the protective cover 44 is preferably slightly thicker than the nozzle plate 11.
[0045]
  In this manner, the heads 6 and 6 are set so that the distance between the rows of the nozzles 11a is constant and parallel. The head holder 1 is put on them, the head units 6 and 6 are made to correspond to the predetermined positions of the support portions 8 and 8, and then the adhesive is poured into the adhesive pouring holes 9a and 9b from the upper surface of the bottom plate 5, that is, the mounting portion 3 side. The UV adhesive 7 is poured, and immediately after that, the UV adhesive 7 is rapidly cured by irradiating ultraviolet rays from the upper surface of the bottom plate 5 toward the inside of the adhesive casting holes 9a and 9b. The position is fixed at once.
[0046]
  In that case, the tip (upper end) of the protrusion 90 in each head unit 6 is pressed against the proximity portion 5a that is the outer periphery of the adhesive flow holes 9a and 9b and is close to the back surface of the cavity plate 10 from the bottom plate 5. Therefore, on the back surface side of the cavity plate 10, the side edge of the long side of the piezoelectric actuator 20 with respect to the adhesive flow holes 9 a and 9 b is blocked by the proximity portion 5 a and the protrusions 90. Therefore, it is possible to reliably prevent large diffusion / leakage such that the viscous UV adhesive 7 injected into each of the adhesive flow holes 9a and 9b approaches the side edge of the piezoelectric actuator 20 on the back side of the head unit 6. it can. As a result, there are no places where the ultraviolet rays irradiated from the upper surface side of the bottom plate 5 through the adhesive pouring holes 9a and 9b are difficult to hit, and the occurrence of uncured portions of the UV adhesive 7 can be prevented. Accordingly, it is possible to eliminate the disadvantage that an uncured portion of the UV adhesive 7 comes into contact with a portion such as the piezoelectric actuator 20 having conductivity and an electrical short circuit accident occurs.
[0047]
  The front surface of each head unit 6 and the back surface of the lower plate 44b of the protective cover 44 may be bonded and fixed in advance with an adhesive (not shown), or only the protective cover 44 may be bonded and fixed later. . Further, as shown in FIG. 5, sealing agents 55a and 55b such as silicone are injected between the inner surface of the four circumferences of the box-shaped protective cover 44 and the stepped portion of the bottom plate 5 of the head holder 1 for sealing. Ink is prevented from entering the gap between the head unit 6 and the protective cover 44 during printing or wiping by the wiper member 86.
[0048]
  The second shown in FIGS.Reference exampleThen, the elastic members are ring bodies 91a and 91b made of an elastic body surrounding the outer peripheral portions of the adhesive flow holes 9a and 9b. On the other hand, on the lower surface of the bottom plate 5, cylindrical portions 92a and 92b which are outer peripheral portions of the respective adhesive pouring holes 9a and 9b are integrally formed to project, and the ring bodies 91a and 92b are respectively formed on the cylindrical portions 92a and 92b. 91b is previously fitted. Next, the firstReference exampleSimilarly, when the head unit 6 and the protective cover 44 are set on the jig, the tips of the ring bodies 91a and 91b are pressed against the back surface of the head unit 6 as shown in FIG.The aboveSince the piezoelectric actuator 20 is blocked by the ring bodies 91a and 91b with respect to the adhesive flow holes 9a and 9b, the UV adhesive 7 having a viscosity injected into the adhesive flow holes 9a and 9b is used as a head unit. It is possible to reliably prevent large diffusion / leakage that approaches the piezoelectric actuator 20 on the back surface side of 6 and to prevent the uncured portion of the UV adhesive 7 from coming into contact with the electrical element portion.Reference exampleIt has almost the same effect. Other configuration is firstReference exampleBecause it is almost the same as the same parts
(Configuration) is given the same reference numeral, and detailed description is omitted.
[0049]
  Shown in FIG.EmbodimentThen, on the back surface of the cavity plate 11 in each head unit 6 and closer to the outer periphery than the outer peripheral edge (long side edge in the embodiment) of the piezoelectric actuator 20, the position of the adhesive flow holes 9a, 9b Also, one or more recess grooves 93 for blocking the flow of the UV adhesive 7 are formed on the outer peripheral side. The side surface external electrode 94 formed in the stacking direction (thickness direction) of the outer peripheral edge (long side edge in the embodiment) of the piezoelectric actuator 20 is the same as the configuration shown in Japanese Patent Laid-Open No. 2001-246744. Further, the individual and common electrodes inside the piezoelectric actuator 20 and the surface electrodes 30 and 31 are electrically connected to each other, and the back surface of the cavity plate 10 having conductivity such as metal, the side surface external electrode 94, Insulating grooves 95 are formed in the back surface of the cavity plate 10 so as to have a space between the lower end of the side external electrode 94 and a space.
[0050]
  On the other hand, of the lower surface of the bottom plate 5, a proximity portion 5a protruding downward from the vicinity of the outer periphery of the adhesive pouring holes 9a, 9b is formed, and the back surface of the head unit 6 (cavity plate 10 in the embodiment) is formed. Reduce the gaplikeIt is approaching and the said accumulation groove | channel 93 is arrange | positioned so that the said proximity part 5a may be faced. It is desirable that the gap between the cavity plate 10 and the proximity portion 5 a is smaller than the thickness of the piezoelectric actuator 20 in order to prevent the UV adhesive 7 from approaching the piezoelectric actuator 20.
[0051]
  With this configuration, the viscous UV adhesive 7 injected from the adhesive pouring holes 9a and 9b is accumulated in one or more accumulation grooves 93 in the proximity portion 5a. In this case, it is possible to reliably prevent large diffusion / leakage such that the uncured portion of the UV adhesive 7 approaches the side edge of the piezoelectric actuator 20.Reference exampleIt has almost the same effect. Further, since the accumulation groove 93 is located in the vicinity of the outer periphery of the adhesive flow holes 9a and 9b, the UV adhesive 7 accumulated in the accumulation groove 93 is easily exposed to ultraviolet rays, and the curing can be promoted. Generation of uncured portions of the adhesive 7 can be made difficult to occur. Other configuration is firstReference exampleBecause it is almost the same as the same parts
(Configuration) is given the same reference numeral, and detailed description is omitted.
[0052]
  Shown in FIG. 10 (a) and FIG. 10 (b)Reference examplesThen, using the insulating groove (concave groove) 95 for preventing the back surface of the cavity plate 10 and the side surface external electrode 94 from being in direct contact as shown in the above embodiment, at least the adhesive flow hole 9a. , 9b is covered with an electrically insulating material 96 so as to cover all of the side surface external electrodes 94 (including the side surface of the piezoelectric actuator 20) in a portion close to the outer periphery of 9b.Reference exampleThen, an electrically insulating thermosetting epoxy resin adhesive is applied to the side external electrode 94 at a portion near the outer periphery of the adhesive flow holes 9a, 9b including the side surface of the piezoelectric actuator 20 from the insulating groove (concave groove) 95. It is applied so as to cover everything, and is cured by heating.
[0053]
  With this configuration, even if the UV adhesive 7 injected from the adhesive flow holes 9a and 9b approaches the side surface of the piezoelectric actuator 20 from the proximity portion 5a, the side external electrode 94 is formed by the electrically insulating material 96. Can be electrically shielded from the UV adhesive 7. If there is no electrical insulating material 96 in the insulating groove (concave groove) 95, the UV adhesive 7 flows into the insulating groove 95 and becomes uncured. An insulation distance between the cavity plate 10 and the cavity plate 10 via the UV adhesive 7 is a depth of the insulating groove 95 of 50 μm. However, when the electrically insulating material 96 is applied in the insulating groove (concave groove) 95, even if the UV adhesive 7 flows on the electrically insulating material 96, the gap between the side external electrode 94 and the conductive cavity plate 10 is reduced. The insulation distance through the UV adhesive 7 can be about 200 μm between the side external electrode 94 and the outer edge of the insulating groove 95 (the position farthest from the side external electrode 94). That is, even when the application amount of the electrical insulating material 96 is small and the side external electrode 94 cannot be sufficiently covered, the UV adhesive 7 between the side external electrode 94 and the conductive cavity plate 10 is interposed. All the insulation distances can be made sufficiently large. In addition, since the gap between the cavity plate 10 and the proximity portion 5 a is sufficiently smaller than the thickness of the piezoelectric actuator 20, the UV adhesive 7 reaches the upper portion of the piezoelectric actuator 20 even when the amount of the electrically insulating material 96 is small. Nothing will happen. With these configurations, even if the uncured portion of the UV adhesive 7 approaches the side edge of the piezoelectric actuator 20, current leakage and the like can be reliably prevented,First reference exampleIt has almost the same effect. Other configuration is firstReference exampleBecause it is almost the same as the same parts
(Configuration) is given the same reference numeral, and detailed description is omitted.
[0054]
  As shown in FIG.Reference exampleThen, in the vicinity of the side edge of the piezoelectric actuator 20 and close to the adhesive flow holes 9a, 9b, a through hole 98 penetrating vertically is formed, and the lower end of the through hole 98 is the cavity plate. 10 is formed so as to communicate with an insulating groove (concave groove) 95 on the back surface.
[0055]
  After fixing the head unit 6 and the head holder 1 with the UV adhesive 7 poured from the adhesive casting holes 9 a and 9 b, a sealing agent 97 such as an electrically insulating silicone resin is applied between the protective cover 44 and the head holder 1. The filling between the piezoelectric actuator 20 and the flexible flat cable 40 and the head holder 1 is the same as in the other embodiments, but in the case of the present embodiment, the piezoelectric actuator 20, the flexible flat cable 40 and the head. The sealing agent 97 filled with the holder 1 flows into the insulating groove (concave groove) 95 through the through hole 98 (see FIG. 11) of the piezoelectric actuator 20 and approaches the side edge of the piezoelectric actuator 20. The tip of the uncured portion of the UV adhesive 7 is pushed up from below and away from the side edge of the piezoelectric actuator 20. Also in this case, since the gap between the cavity plate 10 and the proximity portion 5 a is sufficiently smaller than the thickness of the piezoelectric actuator 20, the tip of the uncured portion of the UV adhesive 7 is separated from the side edge of the piezoelectric actuator 20 by the sealing agent 97. It becomes easy to keep away. Accordingly, it is possible to prevent the uncured portion of the UV adhesive 7 from coming into contact with the electrical element portion such as the piezoelectric actuator 20 and to prevent an accident such as an electrical short circuit due to ink leakage later. And it can be surely prevented.
[0056]
  For example, by disposing the flow holes 9a and 9b in the vicinity of the four corners of the rectangular head unit 6 in plan view, when the UV adhesive 7 is solidified, the head unit 6 is displaced due to shrinkage distortion of the adhesive. Can be reduced as much as possible. If the pouring holes 9a are formed so as to extend across the adjacent sides of the head units 6 and 6 arranged in parallel, the UV adhesive 7 is filled in one pouring hole 9a, and two UV irradiations are applied. Units 6 and 6 can be solidified at the same time, which can contribute to shortening the working time and greatly improving the production efficiency. Also, eachReference examples andThe configuration of the embodiment exhibits a further excellent effect by combining with each other.
[0057]
  The number of the head units 6 to be arranged in parallel can be arbitrarily configured as 2 to 4, and the cavity plate 10 in the head unit 6 may be a ceramic material in addition to a metal material. Furthermore, the drive means of the ink jet printer of the present invention may be other types of the plate-like piezoelectric actuator 20 described above, or the vibration plate covering the back surface of the pressure chamber is vibrated by static electricity to inject ink into the nozzle 11a. It is also possible to have a configuration in which the liquid is discharged from the liquid.
[0058]
[0059]
[0060]
[0061]
【The invention's effect】
  As described above, the invention described in claim 1It has a plurality of nozzles arranged in a row on the frontAnd the actuator was placed on the back sideIn the ink jet printer head in which the head unit is fixed to the bottom plate of the head holder via a photo-curing adhesive, the bottom plate is provided with an adhesive pouring hole facing the back surface of the side edge of the head unit. Near the outer periphery of the adhesive pouring hole in the bottom plateAnd a portion between the adhesive pouring hole and the actuatorIt is formed in a proximity portion with a small gap with respect to the back surface of the head unit, and a photocurable adhesive from the adhesive flow hole is formed on the bottom surface of the bottom plate or the back surface of the head unit in the proximity portion from the proximity portion. A reservoir groove for preventing diffusion and leakage to the back side of the head unit is formed.
[0062]
  According to this configuration, the photo-curing adhesive injected from the adhesive pouring hole once accumulates in the accumulation groove, so that a large amount of diffusion leaks from the adjacent portion with a small gap to the back side of the head unit with a large gap. As a result, the uncured portion of the photo-curing adhesive has conductivity on the back side of the head unit.Of the actuatorIt is possible to effectively prevent contact with the portion, and since the pool groove is in the vicinity of the outer periphery of the adhesive pouring hole, light such as ultraviolet rays is irradiated to the photocurable adhesive collected in the pool groove. It becomes easy to hit, the curing can be promoted, and the curing that the generation of the uncured portion of the photo-curing adhesive can be made difficult is also achieved.
[0063]
  Claim 2The invention described inClaim 1In the ink jet printer head described in the above, the reservoir groove is formed in one or a plurality of recesses substantially parallel to the direction in which the nozzle rows extend, and the conductive portion on the back side of the head unit is The presence of one or more stagnant grooves parallel to the multiple locations along the direction in which the nozzle rows extend effectively prevents contact and generation of the uncured portion of the photo-curing adhesive. it can.
[0064]
[0065]
[0066]
[0067]
[0068]
[0069]
[Brief description of the drawings]
FIG. 1 is a perspective view of an ink jet printer to which the present invention is applied.
FIG. 2 is a perspective view of the inkjet printer head with the nozzle side facing up.
[Fig. 3]EmbodimentIt is a disassembled perspective view of the components of the inkjet printer head in FIG.
[Fig. 4]EmbodimentFIG. 5 is an exploded perspective view of components of the ink jet printer head viewed from above the head holder in FIG.
FIG. 5Reference exampleFIG.
FIG. 6Reference exampleFIG. 5 is an exploded perspective view of components of the ink jet printer head viewed from above the head holder in FIG.
FIG. 7Reference exampleIt is a principal part enlarged plan view in FIG.
FIG. 8Reference exampleFIG.
FIG. 9EmbodimentIt is a principal part expanded sectional view in FIG.
FIG. 10 (a)Reference exampleThe principal part sectional drawing in FIG. 1, (b) is the further expanded sectional side sectional view.
FIG. 11Reference exampleIt is a principal part expanded sectional view in FIG.
FIG. 12 is a perspective view of each component of the head unit.
FIG. 13 is a perspective view of each component of the cavity plate.
FIG. 14 is a partially enlarged perspective view of a cavity plate.
FIG. 15 is an enlarged side sectional view of the head unit.
[Explanation of symbols]
    1 Head holder
    5 Bottom plate
    5a Proximity
    6 Head unit
    7 UV adhesive
    8 Supporting part
  9a, 9b Adhesive pouring hole
  10 Cavity plate
  11 Nozzle plate
  11a nozzle
  20 Piezoelectric actuator
  40 Flexible cable
  44 Protective cover
  44a Open window
  90 ridges
  91a, 91b Ring body
  92a, 92b cylinder
  93 Reservoir
  95 Groove (insulation groove)
  96 Electrical insulating materials
  97 Sealant

Claims (2)

In an inkjet printer head formed by fixing a head unit having a plurality of nozzles arranged in a row on the front surface and an actuator arranged on the back surface to the bottom plate of the head holder via a photocurable adhesive,
The bottom plate is provided with an adhesive pouring hole facing the back surface of the side edge of the head unit,
A portion of the bottom plate near the outer periphery of the adhesive pouring hole and between the adhesive pouring hole and the actuator is formed in an adjacent portion having a small gap with respect to the back surface of the head unit. In the lower surface of the bottom plate or the back surface of the head unit, a ditch groove is formed to prevent the photo-curing adhesive from the adhesive flow hole from diffusing and leaking from the proximity portion to the back surface side of the head unit. An inkjet printer head characterized by the above. 2. The ink jet printer head according to claim 1 , wherein the reservoir groove is formed to be recessed in one or a plurality of strips substantially in parallel with a direction in which the nozzle row extends.

Images