JP2012161972A - Liquid jet head and liquid jetting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet head including a compact liquid jetting unit and a wiping member with improved wiping performance, and to provide a liquid jetting apparatus.SOLUTION: The liquid jet head includes: an ink ejecting unit 42 having a conductive nozzle forming surface 48 with a plurality of nozzles 46 opened, and liquid passages communicating with the nozzles respectively; a head case 41 to which the ink ejecting unit is joined; and a conductive cover member 22. The cover member includes a frame part 65 provided with an opening that exposes the nozzle forming surface mounted on the head case, and an abutting part 68 partially projecting toward the inside of the opening from the inner peripheral edge of the opening. The nozzle forming surface and the outer surface of the frame part are flush with each other when the cover member is mounted on the head case while the nozzle forming surface is exposed from the opening and the abutting part abuts on the nozzle forming surface to be made conductive.

Description

  The present invention relates to a liquid ejecting head such as an ink jet recording head, and a liquid ejecting apparatus including the same, and more particularly, to a nozzle forming surface having a nozzle array in which a plurality of nozzles are arranged, and a liquid ejecting head. The present invention relates to a liquid ejecting head including a cover member that protects and grounds a nozzle forming surface, and a liquid ejecting apparatus.

  Examples of the liquid ejecting head that ejects the liquid in the pressure chamber as liquid droplets by causing pressure fluctuations include an ink jet recording head used in an image recording apparatus such as an ink jet recording apparatus (hereinafter simply referred to as a printer). (Hereinafter simply referred to as a recording head), a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL (Electro Luminescence) display, an electrode material ejecting head used for forming an electrode such as an FED (surface emitting display) And a bio-organic substance ejecting head used for manufacturing a biochip (biochemical element). The recording head for the image recording apparatus ejects liquid ink, and the color material ejecting head for the display manufacturing apparatus ejects solutions of R (Red), G (Green), and B (Blue) color materials. The electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and the bioorganic matter ejecting head for the chip manufacturing apparatus ejects a bioorganic solution.

  The liquid ejecting head includes a liquid ejecting unit including a metal nozzle plate having a plurality of nozzles and a liquid channel in which a liquid channel including a pressure chamber communicating with each nozzle is formed. Some include pressure generating means such as a piezoelectric vibrator for causing pressure fluctuation in the liquid in the room, and a resin head case to which the liquid ejecting unit is fixed.

  The liquid ejecting unit is protected by a metal cover member having a frame shape in which an opening for exposing the nozzle of the nozzle plate is opened (see, for example, Patent Document 1). That is, the outer peripheral surface of the liquid ejecting unit is covered with a cover member, and a part of the cover member is an outer peripheral edge on the surface of the nozzle plate (the surface on which liquid is ejected; hereinafter also referred to as a nozzle forming surface). The part is in contact with the cover. With this configuration, it is possible to prevent the recording paper or the like from coming into contact with the liquid ejecting unit. Further, this cover member is grounded, and is brought into contact with the nozzle plate to conduct, for example, damage to the driving IC or the like due to the static electricity generated from the recording paper or the like being transmitted through the nozzle plate, and the liquid and nozzle plate. It is designed to prevent electrification.

JP 2004-284273 A

  In the above liquid ejecting apparatus, the solvent of the liquid is prevented from evaporating from the nozzle of the liquid ejecting head, or the liquid or bubbles thickened from the nozzle are forcibly discharged by applying a negative pressure to the nozzle. Therefore, a cap member for sealing the nozzle forming surface is provided. The cap member is a tray-like member having elasticity, and seals the nozzle forming surface (capping) by bringing the upper edge portion of the opening surface side into contact with the nozzle forming surface side of the liquid ejecting unit. The printer disclosed in Patent Document 1 is configured such that the upper edge portion of the cap member abuts on a portion of the cover member that overlaps the nozzle forming surface. That is, in this configuration, there is a problem that the liquid ejecting unit is increased in size because the cover member is overlapped and the region where the cap member abuts is necessary in the liquid ejecting unit. In this configuration, the outer surface of the cover member (the surface facing the recording paper or the platen during the recording operation) is positioned below the nozzle forming surface by the thickness of the cover member. For this reason, a step is generated between the nozzle forming surface and the cover member, and when the nozzle forming surface is wiped by the wiping member, wiping is left on the stepped portion, or liquid is blown off by an impact when the wiping member gets over the step. There was a risk of it.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting head and a liquid ejecting apparatus capable of reducing the size of the liquid ejecting unit and improving the wiping property by the wiping member. There is.

The liquid ejecting head of the present invention has been proposed to achieve the above object, and has a conductive nozzle forming surface in which a plurality of nozzles from which the liquid is ejected is opened, and the liquid communicating with each nozzle. A liquid jet unit having a flow path;
A head case to which the liquid jet unit is joined;
A cover member having conductivity,
The cover member includes a frame portion having an opening that exposes the nozzle forming surface in an attached state to the head case, and a contact portion that partially protrudes from the inner periphery of the opening toward the opening. Have
The nozzle forming surface and the frame are attached by attaching the cover member to the head case in a state where the nozzle forming surface is exposed from the opening and the contact portion is in contact with and conductive with the nozzle forming surface. The outer surface of the part is aligned on the same surface.

  According to the above configuration, the nozzle forming surface and the outer surface of the frame portion are aligned on the same surface by attaching the cover member to the head case in a state where the contact portion is in contact with and conductive with the nozzle forming surface. The step difference between the nozzle forming surface and the outer surface of the frame portion of the cover member can be reduced as much as possible as compared with the configuration in which the frame portion of the cover member overlaps the peripheral portion of the nozzle forming surface. As a result, the wiping member for wiping the nozzle forming surface can smoothly move the boundary between the nozzle forming surface and the cover member, and the dirt remaining on the nozzle forming surface and the liquid wiped off by the wiping member are repelled. It is possible to prevent malfunctions such as That is, the wiping property by the wiping member is improved. Further, in the liquid ejecting unit, since the frame portion of the cover member is overlapped and the region where the cap member abuts is unnecessary, the liquid ejecting unit can be reduced in size accordingly.

  In the above configuration, it is desirable to employ a configuration in which an adhesive is filled along the entire circumference of the liquid ejecting unit between the inner surface of the frame portion and the head case.

  According to this configuration, the adhesive is filled along the entire circumference of the liquid ejecting unit between the inner surface of the frame portion and the head case, so that the outer peripheral surface of the liquid ejecting unit and the frame portion of the cover member are Since the gap between the inner surface and the head case is sealed with an adhesive, air may flow from between the outer peripheral surface of the liquid ejecting unit and the cover member when the suction process is performed in a capped state by the capping member. This prevents the empty part in the capping member from being negatively positively prevented.

  Further, in the above configuration, the contact portion is formed at each of four corners on the inner peripheral edge of the opening, and the cover member is attached to the head case and is outside the nozzle formation region on the nozzle formation surface. It is desirable to employ a configuration that contacts.

  Further, the outer surface of the contact portion protrudes toward the opposite side of the inner surface of the frame portion from the outer surface of the frame portion, while the inner surface of the contact portion is flush with the outer surface of the frame portion. It is desirable to adopt a configuration aligned with the above.

Further, the liquid ejecting apparatus of the present invention includes any one of the liquid ejecting heads having the above-described configurations,
A cap member capable of sealing the nozzle forming surface of the liquid jet head;
A liquid ejecting apparatus comprising:
The cap member is characterized in that, in a sealed state with respect to the nozzle forming surface, an opening peripheral portion of a surface facing the nozzle forming surface is brought into contact with a frame portion of the cover member.

Further, in the above configuration, a wiping member for wiping the nozzle forming surface of the liquid jet head is provided,
It is desirable that the wiping member adopt a configuration in which the nozzle forming surface and the outer surface of the frame portion are set to dimensions that can be wiped off.

It is a perspective view of a printer. FIG. 3 is an exploded perspective view of a recording head unit. It is a front view of a recording head unit. FIG. 6 is a bottom view of the recording head unit. It is principal part sectional drawing of the AA line in FIG. It is principal part sectional drawing of the BB line in FIG.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following, an ink jet recording apparatus 1 (hereinafter simply referred to as a printer) shown in FIG. 1 is exemplified as the liquid ejecting apparatus.

  The printer 1 shown in FIG. 1 has a cartridge mounting portion 2 to which an ink cartridge 5 storing ink (a kind of liquid in the present invention) is attached, and has a recording head unit 3 (a kind of liquid ejecting head in the present invention). A carriage 4 to be mounted is provided. The carriage 4 is connected to a timing belt 10 installed between the drive pulley 8 and the idle pulley 9 while being supported by the guide rod 6. The drive pulley 8 is joined to the rotating shaft of the pulse motor 11. The operation of the pulse motor 11 causes the carriage 4 to move in the width direction of the recording paper 7 (recording medium or a kind of landing target), that is, main scanning. It is designed to move in the direction. A paper feed roller 12 is disposed below the guide rod 6 in parallel with the guide rod 6. The paper feed roller 12 is configured to be rotated by the driving force from the paper feed motor 13 to convey the recording paper 7 on the platen 14 in the sub-scanning direction.

  A home position serving as a base point for the movement of the recording head unit 3 is located in an end area within the movement range of the carriage 4 and outside the recording area where an image or the like is printed on an ejection target such as recording paper. Is set. On the home position side, a capping mechanism 15 capable of capping (sealing) a nozzle forming surface 48 (see FIG. 4 and the like) of the recording head unit 3 and a wiping mechanism 16 for wiping the nozzle forming surface are mainly used. Adjacent to each other in the scanning direction. The capping mechanism 15 includes a cap member 15 ′ that can seal the nozzle forming surface 48 of the recording head unit 3, that is, the ejection side surface of the nozzle plate 44, and this cap member 15 ′ is positioned at the home position. The recording head unit 3 is configured to be able to advance and retreat with respect to the nozzle formation surface 48. The cap member 15 ′ is a substantially rectangular box in plan view, specifically, a tray-like member opened on the upper surface side that is the side facing the nozzle forming surface 48. For example, the cap member 15 ′ is made of an elastic material such as elastomer or rubber. Have been made. The opening area on the upper surface of the cap member 15 ′ is set to be larger than the area of the nozzle forming surface 48 and slightly smaller than the area of the frame portion 65 of the cover member 22. Further, the sealing empty portion 17 that is an internal space of the cap member 15 'communicates with a suction means such as a suction pump (not shown), and is negatively pressured by operating the suction means in a capped state. It is configured.

  When the carriage 4 is positioned at the home position, the cap member 15 ′ moves upward, and the peripheral edge of the opening of the cap member 15 ′ comes into contact with a frame portion 65 of the head cover 41 described later, thereby sealing the nozzle forming surface 48. The capping state is stopped (see FIGS. 5 and 6). In this capping state, the nozzle forming surface 48 faces the sealing empty portion 17 of the cap member 15 ′, and the opening peripheral edge portion (upper end portion) of the cap member 15 ′ and the outer surface of the frame portion 65 are in close contact with each other. It has become. As a result, evaporation of the ink solvent from the nozzles 46 of the recording head unit 3 is suppressed, and an increase in ink viscosity is suppressed. When the recording process is performed on the recording medium such as the recording paper 7, the capping state of the cap member 15 ′ with respect to the nozzle forming surface 48 is released. Further, during the cleaning process for the purpose of removing thickened ink and bubbles in the internal flow path of the recording head unit 3, the inside of the sealing empty part 17 is made negative by operating the suction means after being in the capping state. Is done. Thereby, ink and bubbles can be forcibly discharged from the nozzle 46.

  A wiping mechanism 16 is provided between the capping mechanism 15 and the recording area (platen 14). The wiping mechanism 16 has a wiper blade 16 '(corresponding to a wiping member in the present invention). The wiping mechanism 16 includes a wiping position where the tip of the wiper blade 16 ′ overlaps with the moving path of the recording head unit 3, and the tip of the blade 16 ′ that is out of the moving path is located on the nozzle forming surface 48 of the recording head unit 3. It is possible to advance and retreat to the retracted position where it does not contact. The wiper blade 16 'is a plate-like member made of an elastic material such as elastomer or rubber. The width of the wiper blade 16 ′ (dimension in the direction orthogonal to the wiping direction) is set to a size that can wipe the nozzle forming surface 48 and the outer surface of the frame portion 65. When wiping the nozzle forming surface 48 of the recording head unit 3, the wiper blade 16 ′ is moved to the wiping position, and the recording head unit 3 and the wiper are in a state where the tip of the wiper blade 16 ′ is in contact with the nozzle forming surface 48. By the relative movement of the blade 16 ′, the wiper blade 16 ′ slides on the nozzle forming surface 48 and the frame portion 65 and wipes ink and the like adhering to the nozzle forming surface 48 and the frame portion 65. Yes.

Next, the recording head unit 3 will be described. 2 is an exploded perspective view of the recording head unit 3, FIG. 3 is a front view of the recording head unit 3, and FIG. 4 is a bottom view of the recording head unit 3. 5 is a cross-sectional view of main parts taken along line AA in FIG. 4, and FIG. 6 is a cross-sectional view of main parts taken along line BB in FIG. 5 and 6 show a state in which the nozzle forming surface 48 is capped by the cap member 15 '.
The recording head unit 3 according to the present embodiment includes an ink introduction unit 19, a head main body 20, a circuit board 21 disposed between the ink introduction unit 19 and the head main body 20, and a cover that protects the head main body 20. And a member 22.

  The ink introduction unit 19 includes an ink introduction member 25 in which a plurality of ink introduction needles 26 are erected, and a base member 27 that forms the bottom of the ink introduction unit 19. Further, between the ink introduction member 25 and the base member 27, an annular seal member 28, a connection flow path member 29 disposed inside the seal member 28, and the connection flow path member 29 and the base member 27 are provided. A plurality of filters 30 mounted between the flow paths are provided.

  A plurality of cartridge arrangement portions 31 on which the ink cartridge 5 is seated are formed on the upper surface of the ink introduction member 25. Each cartridge placement portion 31 is provided with an ink introduction needle 26. In the present embodiment, a total of four ink introduction needles 26 are arranged corresponding to four colors of ink (for example, cyan ink, magenta ink, yellow ink, and black ink). A needle channel (not shown) is formed inside the ink introduction needle 26. One end of the needle channel opens at the tip of the ink introduction needle 26, and the other end communicates with an intermediate channel 33 formed in the connection channel member 29.

  The seal member 28 is an elastic member made of a synthetic resin or the like formed in an annular shape so that the inner surface is along the outer periphery of the connection flow path member 29. The seal member 28 seals the connection portion of each flow path of the ink introduction needle 26, the connection flow path member 29, and the base member 27 to make it liquid-tight.

  The connection flow path member 29 is a flat plate-like member having four intermediate flow paths 33 formed corresponding to the four ink introduction needles 26, respectively. One end of the intermediate flow path 33 communicates with the needle flow path of the ink introduction needle 26, and the other end communicates with the ink supply path 35 of the base member 27 via the filter 30. Here, the filter 30 is mounted between the intermediate flow path 33 of the connection flow path member 29 and the ink supply path 35 of the base member 27, and bubbles and foreign matters mixed in the ink in the flow path are brought to the ink supply path 35 side. It is a member which filters so that it may not be supplied, and four are provided corresponding to four flow paths.

  A connection channel member mounting portion 34 is formed on the upper surface of the base member 27. The connection flow path member 29 is mounted on the connection flow path member mounting portion 34 with the filter 30 interposed. In addition, an ink supply path 35 is formed inside the foundation member 27 so as to penetrate in the height direction of the foundation member. The upper end of the ink supply path 35 opens to the connection flow path member mounting portion 34 and communicates with the intermediate flow path 33 of the connection flow path member 29 via the filter 30, while the lower end of the ink supply path 35 is the head. It communicates with a case channel 58 (described later) formed in the head case 41 of the main body 20. Note that the lower end portion of the ink supply path 35 extends below the lower surface of the base member 27 (on the head main body 20 side), and is inserted into a flow path insertion port 40 of the circuit board 21 described later. Thus, the lower end portion of the ink supply path 35 can be liquid-tightly joined to the case flow path 58 with the circuit board 21 interposed therebetween. Then, the ink introduction unit 19 is formed by joining the base member 27 to the ink introduction member 25 with the seal member 28, the connection flow path member 29, and the filter 30 interposed therebetween. Thereby, the ink introduction flow path 24, the intermediate flow path 33, and the ink supply path 35 communicate with each other in a liquid-tight manner, and the ink in the ink cartridge 5 is supplied to the head main body 20 side through these flow paths.

  An electrical component such as an IC or a resistor is mounted on the circuit board 21, and a connector 36 is formed at one end, and is disposed between the ink introduction unit 19 and the head main body 20. The circuit board 21 is joined to a flexible cable 39 of a vibrator unit 38 to be described later. The connector 36 is connected to the other end of a signal cable (not shown) having one end connected to the control unit of the printer 1. Therefore, a drive signal or the like sent from the control unit of the printer 1 through the signal cable is supplied to the vibrator unit 38 through the circuit board 21 and the flexible cable 39. Further, a passage insertion port 40 penetrating in the thickness direction is formed at a location corresponding to the ink supply passage 35. The lower end of the ink supply path 35 is inserted into the flow path insertion port 40, and the ink supply path 35 and the case flow path 58 of the head case 41 are connected below the circuit board 21.

  Next, the configuration of the head main body 20 will be described in detail. The head main body 20 in this embodiment includes a vibrator unit 38, a head case 41, and an ink ejection unit 42.

  First, the ink ejection unit 42 will be described. The ink ejection unit 42 in this embodiment includes a vibration plate 43, a nozzle plate 44, and a flow path forming substrate 45. These plate members are integrated with an adhesive or the like in a state where the flow path forming substrate 45 is located at the center in the stacking direction. The diaphragm 43 side is joined to the head case 41. The size, ie, area, of the plane of each component plate of the ink ejecting unit 42 (surface parallel to the nozzle forming surface 48 of the nozzle plate 44) is the lower surface (joint surface) of the head case 41 to which the ink ejecting unit 42 is joined. ) Is set smaller than the area. For this reason, when the ink ejecting unit 42 is joined to the lower surface of the head case 41, a step is formed around the ink ejecting unit 42 with the head case 41. As will be described later, an adhesive 72 for fixing the frame portion 65 of the cover member 22 is introduced into the step portion (see FIGS. 5 and 6).

  The diaphragm 43 is a double-structure composite plate material in which a resin film such as PPS (polyphenylene sulfide) is laminated on a metal support plate (not shown) such as stainless steel. The vibration plate 43 seals one opening surface (the surface opposite to the nozzle plate 49) of the flow path forming substrate 45 to partition a part of the pressure chamber 54 and the reservoir (common liquid chamber) 52. ing. Etching is performed on the support plate corresponding to each pressure chamber 54 to remove the portion in an annular shape, and an island portion 55 is formed to which the free end portion of the piezoelectric vibrator 61 is joined. (See FIG. 5). Further, the portion of the vibration plate 43 corresponding to the reservoir 52 is made only of a resin film by removing the support plate by etching processing following the opening shape of the reservoir 52. Further, the diaphragm 43 is formed with an introduction port (not shown) through which the case channel 58 and the reservoir 52 communicate.

  The nozzle plate 44 is a thin plate made of a metal such as stainless steel in which a plurality of nozzles 46 are arranged in a row at a pitch corresponding to the dot formation density. For this reason, the nozzle plate 44 has conductivity. In this embodiment, for example, 180 nozzles 46 are opened in a row, and the nozzle row 47 is configured by these nozzles 46. The lower surface of the nozzle plate 44 (the surface opposite to the surface bonded to the flow path forming substrate 45) is the nozzle forming surface 48 of the present invention. Further, the nozzle plate 44 in the present embodiment is provided with two nozzle rows 47 side by side in the main scanning direction. The number of nozzles 46 constituting the nozzle row 47 and the number of nozzle rows 47 are not limited to those illustrated.

  A liquid repellent film is formed on the nozzle forming surface 48. This liquid repellent film may have a higher insulating property than the material of the nozzle plate 44 in some cases. As will be described later, since it is necessary to more reliably electrically connect the cover member 22 and the nozzle plate 44, the four corners of the nozzle forming surface 48 are in contact with a frame portion 65 described later. In the portion where the portion 68 is in contact, after the liquid repellent film is formed on the entire surface of the nozzle forming surface 47, the liquid repellent film is removed and the base of the nozzle plate 44 is exposed.

  The flow path forming substrate 45 is a plate-like member in which a series of ink flow paths including a reservoir 52, an ink supply port 53, and a pressure chamber 54 are formed. The flow path forming substrate 45 in the present embodiment is produced, for example, by performing an anisotropic etching process on a silicon wafer. The pressure chambers 54 are elongated in a direction perpendicular to the direction in which the nozzles 46 are arranged (nozzle row direction), and are formed in a plurality of rows corresponding to each nozzle 46 in a state of being partitioned by partition walls. ing. Two rows of the pressure chambers 54 are formed side by side in the direction perpendicular to the nozzle rows (main scanning direction during the recording operation) in the flow path forming substrate 45. As described above, the opening surface of each pressure chamber 54 is sealed by the diaphragm 43. The ink supply port 53 is formed as a narrowed portion with a narrow channel width communicating between the pressure chamber 54 and the reservoir 52. The reservoir 52 is an empty portion into which common ink is introduced into the plurality of pressure chambers 54. The reservoir 52 extends partially toward the center of the flow path forming substrate 45 (between the pressure chamber row and the pressure chamber row), and communicates with the case flow path 58 of the head case 41. . For this reason, the reservoir 52 communicates with the ink cartridge 5 through each flow path of the case flow path 58 and the ink introduction unit 19 and also communicates with each corresponding pressure chamber 54 via the ink supply port 53. Accordingly, the reservoir 52 can supply the ink stored in the ink cartridge 5 to each pressure chamber 54.

  The head case 41 is made of, for example, a resin such as an epoxy resin, and is formed from a hollow box-shaped case main body 41a and the upper surface of the case main body 41a from the upper surface of the case main body 41a (the surface on the ink introduction unit 19 side). It is comprised from the plate-shaped part (flange part) 41b extended to the side. As described above, the ink ejection unit 42 is joined to the lower surface of the case main body 41a (the surface opposite to the ink introduction unit 19). In addition, two housing empty portions 57 are formed inside the case main body 41 a, and the transducer units 38 are housed in the respective housing empty portions 57. A case channel 58 penetrating in the height direction of the head case 41 is formed between the housing empty portions 57. The case channel 58 has an upper end communicating with the channel of the ink introduction unit 19 (ink supply channel 35 of the base member 27) and a lower end communicating with the reservoir 52 through the introduction port of the diaphragm 43.

  On the lower surface of the plate-like portion 41b, cover member mounting bosses 59 are projected in a total of four locations, two on each side of the case main body 41a of the head case 41 (see FIG. 4 and the like). The cover member 22 is positioned with respect to the head case 41 by inserting the cover member mounting boss 59 into a fastening hole 70 in the cover member 22 described later. Further, the cover member mounting boss 59 protruding from the fastening hole 70 is crushed (ie, caulked) by applying heat or ultrasonic waves by a caulking horn (not shown). This prevents the cover member 22 from falling off the head case 41. Note that the cover member mounting boss 59 in FIG. 3 is not caulked, and the cover member mounting boss 59 in FIG. 4 is caulked.

  Next, the vibrator unit 38 will be described. The vibrator unit 38 according to this embodiment includes a flexible cable 39, a piezoelectric vibrator group 60 in which a plurality of piezoelectric vibrators 61 are arranged, and a fixed plate 62. The piezoelectric vibrator 61 (a kind of pressure generating means) that constitutes the piezoelectric vibrator group 60 is configured as a longitudinal vibration type piezoelectric vibrator that can expand and contract in the vertical direction. In addition, each piezoelectric vibrator 61 is joined in a so-called cantilever state in which the fixed end portion is joined to the fixed plate 62 so that the free end portion protrudes outward from the tip edge (end surface) of the fixed plate 62. It is fixed. The tip of the free end portion of each piezoelectric vibrator 61 is joined to the island portion 55 of the vibration plate 43 in the ink ejection unit 42. On the other hand, a flexible cable 39 is electrically connected to the fixed end side of each piezoelectric vibrator 61 on the side opposite to the fixed plate 62. A control IC (not shown) for controlling driving of each piezoelectric vibrator 61 and the like is mounted on the surface of the flexible cable 39. The end of the flexible cable 39 opposite to the piezoelectric vibrator 61 is electrically connected to the circuit board 21. In addition, the fixed plate 62 that supports each piezoelectric vibrator 61 is made of a metal plate material having rigidity capable of receiving a reaction force from the piezoelectric vibrator 61. In this embodiment, the thickness is about 1 mm. Made of stainless steel plate. The fixing plate 62 is bonded and fixed to the inner wall of the accommodation space 57.

  In the head main body 20 configured as described above, the tip surface of the piezoelectric vibrator 61 is joined to the island portion 55, so that the volume of the pressure chamber 54 can be increased by expanding and contracting the free end of the piezoelectric vibrator 61. Can be varied. As the volume changes, pressure fluctuations occur in the ink in the pressure chamber 54. The head main body 20 ejects (discharges) ink droplets from the nozzles 46 using the pressure fluctuation.

  The cover member 22 is a member that protects the side surface of the ink ejection unit 42 and the side surface of the head case 41, and is produced by subjecting a conductive plate material such as stainless steel to a drawing process using a press. The cover member 22 in the present embodiment extends along the side surface of the head case 41 in the attached state to the head case 41 from the frame portion 65 disposed on the lower surface of the head case 41 and the four side edges of the frame portion 65. It is comprised by the side wall part 67 extended in the state, respectively. The frame portion 65 is a frame-shaped member having an area that is the same as or slightly larger than the area of the lower surface of the head case 41, and the above-described opening peripheral edge of the cap member 15 ′ is in contact with the frame portion 65 during capping. It is a part (capped part). An opening 66 is formed in the central portion of the frame portion 65. The opening 66 is a rectangular through hole that is slightly larger than the outer shape of the nozzle plate 44. The opening 66 is configured to expose the nozzle formation surface 48 of the ink ejection unit 42 in a state where the cover member 22 is attached to the head case 41.

  At the four corners of the inner peripheral edge of the opening 66 in the frame portion 65, contact portions 68 that partially protrude toward the opening are formed integrally with the frame portion 65, respectively. As shown in FIG. 4, the contact portion 68 in the present embodiment has a size capable of covering a corner portion (portion from which the liquid repellent film has been removed) of the nozzle forming surface 48 disposed in the opening 66. It is a minute protrusion. The contact portion 68 is a region corresponding to the outside of the nozzle formation region on the nozzle formation surface 48 in a state where the cover member 22 is attached to the head case 41, and the nozzle formation surface by the wiper blade 16 ′ described above. It is provided at a position that does not overlap any nozzle 46 on a line in the wiping direction (direction indicated by an arrow in FIG. 4) with respect to 48. Thereby, at the time of wiping, even when the wiper blade 16 ′ gets over the contact portion 68, it is possible to suppress the adhesion of the wiper blade 16 ′ to the region where the nozzle 44 is formed. As a result, it is possible to prevent a decrease in wiping performance of the nozzle formation surface 48 with respect to the nozzle formation region.

  Further, as shown in FIG. 6, the abutting portion 68 is an outer surface of the frame portion 65 (a surface opposite to the inner surface, which is the surface on the head case 41 side), and a surface on which the cap member 15 'is abutted. ) Below (the side opposite to the inner surface). More specifically, the outer surface of the contact portion 68 protrudes downward from the outer surface of the frame portion 65, while the inner surface of the contact portion 68 is aligned with the outer surface of the frame portion 65. Yes. When the cover member 22 is attached to the head case 41, the contact portion 68 contacts the corner portion of the nozzle forming surface 48 of the ink ejection unit 42 that is fixed to the head case 41 in advance, so that the nozzle plate 44 and the cover member 22 are electrically connected, and the mounting position of the cover member 22 with respect to the head case 41 and the nozzle forming surface 48 is defined. As described above, since the inner surface of the contact portion 68 is flush with the outer surface of the frame portion 65, the cover member 22 is in a state where the contact portion 68 is in contact with the corner portion of the nozzle forming surface 48. When attached to the head case 41, the outer surface of the frame portion 65 and the nozzle forming surface 48 of the nozzle plate are aligned on the same surface.

  In the cover member 22, the side wall portions 67 on both sides in the direction orthogonal to the nozzle row (corresponding to the wiping direction) are fastening pieces 69 facing sideways along the plate-like portion 41 b of the head case 41 in the attached state. 2 each, extending a total of 4. The two fastening pieces 69 extending laterally from the same side wall 67 are formed in a state of being bent halfway in such a manner that the tips face each other in a plane parallel to the plate-like portion 41b. A fastening hole 70 through which the cover member mounting boss 59 of the head case 41 is inserted is formed at the distal end of each fastening piece 69 (see FIG. 2). The cover member 22 is attached to the head case 41 and then connected to the ground line. As a result, the cover member 22 is adjusted to the ground potential. Further, the boundary portion between the side wall portion 67 and the frame portion 65 on both sides in the direction orthogonal to the nozzle row is bent relatively gently and has a curved surface R (see FIG. 3). Thereby, when wiping with the wiper blade 16 ', when the wiper blade 16' comes into contact with the bent portion, damage to the wiper blade 16 'is reduced. Further, since the wiper blade 16 ′ can smoothly move toward the nozzle forming surface 48, wiping residue and ink repelling are suppressed.

  In the step of attaching the cover member 22 to the head case 41, the ink ejection unit 42 is pre-joined to the lower surface of the head case 41, and the entire circumference along the outer periphery of the ink ejection unit 42 on the lower surface of the head case 41. The adhesive 72 is applied over the entire area. The adhesive 72 may be applied to the inner surface side of the frame portion 65 of the cover member 22, or between the inner surface of the frame portion 65 and the lower surface of the head case 41 after the cover member 22 is attached to the head case 41. The gap may be filled. Next, the cover member mounting boss 59 of the head case 41 is inserted into the fixing hole 70 of each fixing piece portion 69 of the cover member 22, and the contact portion 68 is formed at the corner portion of the nozzle forming surface 48. The cover member 22 is attached to the head case 41 in the abutting state. As described above, the tip end portion of the cover member mounting boss 59 protruding from the fastening hole 70 is caulked. This prevents the cover member 22 from falling off the head case 41. This eliminates the need for a jig for pressing the cover member 22 toward the head case 41 until the adhesive 72 filled between the frame portion 65 and the lower surface of the head case 41 is cured. When the adhesive 72 is cured, the adhesive 72 seals the seal between the outer peripheral surface of the ink ejection unit 42, the inner surface of the frame portion 65 of the cover member 22, and the lower surface of the head case 41. )

Here, each abutting portion 68 of the cover member 22 abuts on a corner portion of the nozzle forming surface 48, so that the cover member 22 is attached to the head case 41 and the nozzle forming surface 48, particularly on the nozzle forming surface 48. A position perpendicular to the direction is defined. Thereby, as described above, the outer surface of the frame portion 65 and the nozzle forming surface 48 are aligned on the same surface. In addition, the nozzle plate 44 and the cover member 22 are electrically connected via the contact portion 68. Thereby, the nozzle plate 44 can be adjusted to the ground potential.
Further, the cover member mounting boss 59 is inserted into the fixing hole 70 of the fixing piece portion 69, whereby the position of the cover member 22 in the surface direction parallel to the nozzle forming surface 48 is defined. As a result, the nozzle forming surface 48 of the nozzle plate 44 is exposed in the opening 66 of the frame portion 65. In a state where the cover member 22 is positioned and attached to the head case 41, the frame portion 65 is positioned outside the ink ejecting unit 42 in a plane parallel to the nozzle forming surface 48. When the cap member 15 ′ is capped, the opening peripheral edge of the cap member 15 ′ is brought into contact with the outer surface of the frame portion 65. Since the space between the outer peripheral surface of the ink ejection unit 42, the inner surface of the frame portion 65 of the cover member 22, and the lower surface of the head case 41 is sealed with an adhesive 72, when suctioning is performed in a capped state, Air is prevented from flowing in between the outer peripheral surface of the ink ejection unit 42 and the cover member 22. Thereby, the negative pressure in the sealed void 17 can be more reliably reduced. Further, since the adhesive 72 is filled between the inner surface of the frame portion 65 and the lower surface of the head case 41, when the cap member 15 'is pressed against the frame portion 65, the frame portion 65 is deformed. It is suppressed. Thereby, it becomes possible to ensure the airtightness of the sealing empty portion 17 during capping more reliably. In addition, after wiping the frame portion 65 and the nozzle forming surface 48 with the wiper blade 16 ', capping with the cap member 15' while these surfaces are wet can further ensure airtightness. It becomes.

  Thus, the head cover 22 is attached to the head case 41 in a state where the contact portion 68 contacts and conducts at the corner portion of the nozzle forming surface 48 and the nozzle forming surface 48 is exposed to the opening 66, and the frame portion 65. Since the outer surface of the nozzle and the nozzle forming surface 48 are aligned on the same surface, the nozzle forming surface 48 of the nozzle plate 44 and the cover member 22 are compared with the conventional configuration in which the frame portion of the cover member overlaps the peripheral portion of the nozzle forming surface. The level difference between the outer surface of the frame portion 65 can be reduced as much as possible. As a result, the wiper blade 16 ′ at the time of wiping can move smoothly between the boundary between the nozzle plate 44 and the cover member 22. It is possible to prevent problems such as being blown off. That is, the wiping property by the wiping member is improved. Further, since the area where the frame portion 65 of the cover member 22 overlaps and the cap member 15 ′ abuts is not necessary in the ink ejecting unit 42, the ink ejecting unit 42 can be reduced in size accordingly. Further, since the frame portion 65 is positioned outside the ink ejecting unit 42 on a surface parallel to the nozzle forming surface 48, the shape of the cover member 22 is not restricted by the ink ejecting unit 42. For this reason, for example, as described above, a curved surface R can be added to the boundary portion between the side wall portion 67 and the frame portion 65, thereby reducing damage to the wiper blade 16 'during wiping and improving wiping performance. Can be achieved.

  The present invention is not limited to a printer as long as it is a liquid ejecting head including a cover member and a liquid ejecting apparatus equipped with the liquid ejecting head. Various ink jet recording apparatuses such as a plotter, a facsimile machine, and a copying machine, and a recording apparatus The present invention can also be applied to other liquid ejecting apparatuses such as a display manufacturing apparatus, an electrode manufacturing apparatus, and a chip manufacturing apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 3 ... Recording head unit, 15 ... Capping mechanism, 15 '... Cap member, 16 ... Wiping mechanism, 16' ... Wiper blade, 20 ... Head main-body part, 22 ... Cover member, 41 ... Head case, 42 ... Ink ejecting unit, 44 ... nozzle plate, 46 ... nozzle, 47 ... nozzle row, 48 ... nozzle forming surface, 65 ... frame portion, 66 ... opening, 67 ... side wall portion, 68 ... contact portion, 72 ... adhesive

Claims (6)

A liquid ejecting unit having a conductive nozzle forming surface in which a plurality of nozzles from which liquid is ejected is opened, and a liquid flow path communicating with each nozzle;
A head case to which the liquid jet unit is joined;
A cover member having conductivity,
The cover member includes a frame portion having an opening that exposes the nozzle forming surface in an attached state to the head case, and a contact portion that partially protrudes from the inner periphery of the opening toward the opening. Have
The nozzle forming surface and the frame are attached by attaching the cover member to the head case in a state where the nozzle forming surface is exposed from the opening and the contact portion is in contact with and conductive with the nozzle forming surface. A liquid ejecting head, wherein the outer surface of the portion is aligned on the same surface.   The liquid ejecting head according to claim 1, wherein an adhesive is filled along an entire circumference of the liquid ejecting unit between an inner surface of the frame portion and the head case.   The contact portions are formed at four corners on the inner peripheral edge of the opening, and contact the outside of the nozzle formation area on the nozzle formation surface in a state where the cover member is attached to the head case. The liquid ejecting head according to claim 2.   The outer surface of the contact portion protrudes toward the opposite side of the inner surface of the frame portion from the outer surface of the frame portion, while the inner surface of the contact portion is flush with the outer surface of the frame portion. The liquid ejecting head according to claim 1, wherein the liquid ejecting head is provided. The liquid jet head according to any one of claims 1 to 4,
A cap member capable of sealing the nozzle forming surface of the liquid jet head;
A liquid ejecting apparatus comprising:
In the sealed state with respect to the nozzle forming surface, the cap member causes an opening peripheral portion of a surface facing the nozzle forming surface to abut against a frame portion of the cover member. A wiping member for wiping the nozzle forming surface of the liquid jet head;
6. The liquid ejecting apparatus according to claim 5, wherein the wiping member is set to a size capable of wiping the nozzle forming surface and the outer surface of the frame portion.

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