JP2010012650A - Head unit and liquid ejector equipped with this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head unit which can suppress occurrence of jamming, and to provide a liquid ejector equipped with this. <P>SOLUTION: A cover 70 covering a side surface of the upstream side of an inkjet head 1 keeps a bottom surface 71 arranged on the same height as that of an ink ejection surface 2a. The cover 70 has a contact surface 72 formed on the inner surface 81, an inclined surface 73 formed on the outer surface 82, and a fixing part 78 which fixes the cover 70 to the inkjet head 1. When the cover 70 is fixed to the inkjet head 1, the inkjet head 1 presses the inner surface 81 of the cover 70 in a direction to be away from the upstream side surface at a position more distanced from the ink ejection surface 2a than from the fixing part 78 so that the contact surface 72 is excited in a direction to approach the upstream side surface of the inkjet head 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a head unit in which a cover is fixed to a liquid discharge head that discharges liquid, and a liquid discharge apparatus including the head unit.

  Patent Document 1 describes an ink jet head including a flow path unit having a nozzle plate in a lowermost layer on which nozzles for ejecting ink are formed. In this ink jet head, the nozzle plate is formed with a plurality of projecting portions extending outward in both end portions in the sub-scanning direction. The projecting portion is bent toward the flow channel unit, and the base portion has a predetermined R shape. For this reason, the front end of the paper can easily enter a position facing the nozzle plate, and the front end of the paper can be restrained from being caught on the side surface of the inkjet head.

JP 2003-311953 A

  However, in the ink jet head described in Patent Document 1, the protruding portion of the nozzle plate protrudes more outward than the other plates constituting the flow path unit, so that the protruding portion is formed during the head manufacturing process. When an external force is applied to the projecting portion, the nozzle plate and other plates adjacent to the nozzle plate are separated from each other, and the head is likely to be damaged.

  In order to prevent breakage and jamming of these heads, it is conceivable to incline the outer peripheral side wall of the flow path unit without forming a protruding portion on the nozzle plate. In this case, as the plurality of plates constituting the flow path unit are moved away from the nozzle plate, the planar shape is gradually increased, and the flow path unit has an outer peripheral side wall that is inclined over the entire circumference. By laminating these plates, a flow path unit having an inclined outer peripheral side wall can be formed. However, even if the outer peripheral side wall is macroscopically inclined, it is microscopically stepped, so the leading edge of the paper is at the corner formed by the nozzle plate and the nozzle plate and other adjacent plates. It will get caught and jammed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a head unit capable of suppressing the occurrence of a jam and a liquid ejection apparatus including the head unit.

  The head unit A of the present invention has a discharge surface for discharging a liquid, covers a liquid discharge head having one direction as a longitudinal direction, and a side surface along the longitudinal direction of the liquid discharge head. And a cover fixed to the discharge head. The cover has one end at the same height as the discharge surface in a direction orthogonal to the discharge surface, and a fixing portion fixed to the liquid discharge head at a portion separated from the discharge surface, In one end, an abutting region that abuts the side surface is formed on the inner surface side facing the side surface, and an inclined region that is inclined with respect to the ejection surface is formed on the outer surface side opposite to the side surface. The ejection head presses the inner surface of the cover in a direction away from the side surface at a position farther from the ejection surface than the fixed portion so that the contact area is biased in a direction approaching the side surface. To do.

  According to this, since the cover having the inclined region is fixed to the liquid discharge head, it is possible to suppress the jamming due to the recording medium being caught on the side surface of the liquid discharge head. Further, when the inner surface of the cover is pressed, the contact area contacts the side surface of the liquid discharge head. For this reason, there is no gap between the contact area of the cover and the side surface of the liquid discharge head, and there is no need to separately provide a seal member for filling the gap, and the liquid that has entered the gap falls unexpectedly and the recording medium It is possible to suppress soiling.

  In this invention, it is preferable that the said inclination area | region has the length more than the said discharge surface regarding the said longitudinal direction. Thereby, it becomes possible to suppress jam more.

  Moreover, in this invention, it is preferable that the said inclination area | region has the height more than the distance from the said discharge surface to the said fixed part regarding the said orthogonal direction. Thereby, it becomes possible to suppress jam more.

  In the present invention, it is preferable that the liquid discharge head has a heat sink attached to the side surface, and an opening is formed in the cover at a position facing the heat sink. As a result, even if a heat sink is attached to the side surface of the liquid ejection head, since the opening is formed in the cover, the heat dissipation performance by the heat sink does not deteriorate.

  Further, at this time, the liquid discharge head includes a plurality of driver ICs, along which the heat generated when the liquid is discharged from the discharge surface is discharged by the heat sink, and the opening of the cover is You may form corresponding to the arrangement position of driver IC. As a result, the heat sink can effectively dissipate the heat of the driver IC.

  At this time, a cantilever beam that can be bent and deformed in a direction away from the side surface by being pressed by the heat sink may be formed at the opening edge of the cover. As a result, the cantilever bends when the cover is fixed to the liquid discharge head, so that the cover can be reliably brought into contact with the liquid discharge head.

  In the present invention, a hook protruding from the side surface is formed at a position facing the fixed portion of the liquid discharge head, and the hook penetrating in the thickness direction of the cover is fitted into the fixed portion. It is preferable to have a through portion. This facilitates fixing of the cover to the liquid discharge head.

  At this time, a plurality of the hooks and the through portions may be formed in the longitudinal direction. As a result, the cover can be securely fixed to the liquid discharge head.

  In the present invention, the cover is preferably made of metal. Thereby, since a cover consists of metal, heat can be effectively taken from a heat sink. Therefore, the heat dissipation performance by the heat sink is improved.

  In the present invention, the cover is preferably made of a synthetic resin. This reduces the cost of the cover.

  In another aspect, the head unit B of the present invention has a discharge surface for discharging liquid and a plurality of driver ICs for generating a signal for discharging liquid from the discharge surface, and one direction is a longitudinal direction. Covering the liquid discharge head and the side surface along the longitudinal direction of the liquid discharge head, covering the side surface along the longitudinal direction of the heat sink, and the heat sink sandwiching the plurality of driver ICs between the side surface, And a cover fixed to the liquid discharge head. The cover has the heat sink sandwiched between a side surface of the liquid discharge head, and a plurality of openings are formed at positions facing the driver IC, and the end in the direction orthogonal to the discharge surface. One end of which the edge is the same height as the discharge surface, a fixed portion that is fixed to the liquid discharge head away from the discharge surface, and is pressed away from the discharge surface than the fixed portion from the side surface of the heat sink. Each end of the cover has an abutting area in contact with the side surface on the inner surface facing the side surface of the liquid discharge head, and on the outer surface opposite to the inner surface. An inclined region including an inclined surface inclined with respect to the discharge surface is formed.

  According to this, since the cover having the inclined region is fixed to the liquid discharge head, it is possible to suppress the jamming due to the recording medium being caught on the side surface of the liquid discharge head. In addition, when the pressing portion is pressed from the side surface of the heat sink, the contact region contacts the side surface of the liquid discharge head. For this reason, there is no gap between the contact area of the cover and the side surface of the liquid discharge head, and there is no need to separately provide a seal member for filling the gap, and the liquid that has entered the gap falls unexpectedly and the recording medium It is possible to suppress soiling. Further, the heat sink can effectively dissipate the heat of the driver IC by the plurality of openings formed in the cover.

  In the present invention, the cover is made of a synthetic resin, is disposed via a gap with the heat sink, and the inclined surface of the inclined region is formed by a plurality of ribs that protrude outward from the outer surface. preferable. Thereby, since the cover is arranged via the gap with the heat sink, the heat dissipation by the heat sink is not hindered even if the cover is made of synthetic resin. Moreover, since the inclined surface is formed by a plurality of ribs protruding from the outer surface, the strength of the cover is improved.

  The liquid ejection apparatus according to the present invention includes a recording medium conveyance mechanism, a conveyance direction of the recording medium by the conveyance mechanism, and the longitudinal direction of the liquid ejection head orthogonal to each other, and the cover of the liquid ejection head with respect to the conveyance direction. The head unit A or the head unit B is fixed so as to be positioned upstream.

  According to this, since the cover is disposed upstream of the liquid discharge head, it is possible to suppress the jamming due to the recording medium conveyed being caught on the upstream side surface of the liquid discharge head. Further, when the inner surface (or pressing portion) of the cover is pressed, the contact area contacts the side surface of the liquid ejection head. For this reason, there is no gap between the contact area of the cover and the side surface of the liquid discharge head, and there is no need to separately provide a seal member for filling the gap, and the liquid that has entered the gap falls unexpectedly and the recording medium It is possible to suppress soiling.

  According to the head unit A of the present invention, since the cover having the inclined region is fixed to the liquid discharge head, it is possible to prevent the recording medium from being caught by the side surface of the liquid discharge head. Further, when the inner surface of the cover is pressed, the contact area contacts the side surface of the liquid discharge head. For this reason, there is no gap between the contact area of the cover and the side surface of the liquid discharge head, and there is no need to separately provide a seal member for filling the gap, and the liquid that has entered the gap falls unexpectedly and the recording medium It is possible to suppress soiling.

  According to the head unit B of the present invention, since the cover having the inclined region is fixed to the liquid discharge head, it is possible to prevent the recording medium from being caught by the side surface of the liquid discharge head. In addition, when the pressing portion is pressed from the side surface of the heat sink, the contact region contacts the side surface of the liquid discharge head. For this reason, there is no gap between the contact area of the cover and the side surface of the liquid discharge head, and there is no need to separately provide a seal member for filling the gap, and the liquid that has entered the gap falls unexpectedly and the recording medium It is possible to suppress soiling. Further, the heat sink can effectively dissipate the heat of the driver IC by the plurality of openings formed in the cover.

  According to the liquid ejection apparatus of the present invention, since the cover is disposed upstream of the liquid ejection head, it is possible to suppress the jamming due to the conveyed recording medium being caught on the upstream side surface of the liquid ejection head. Further, when the inner surface (or pressing portion) of the cover is pressed, the contact area contacts the side surface of the liquid ejection head. For this reason, there is no gap between the contact area of the cover and the side surface of the liquid discharge head, and there is no need to separately provide a seal member for filling the gap, and the liquid that has entered the gap falls unexpectedly and the recording medium It is possible to suppress soiling.

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

  FIG. 1 is a schematic side view showing an overall configuration of an ink jet printer according to a first embodiment of the present invention. As shown in FIG. 1, the ink jet printer 101 is a color ink jet printer having four head units 3. The inkjet printer 101 includes a paper feeding unit 111 on the right side in the drawing and a paper discharge unit 112 on the left side in the drawing. The head unit 3 includes an inkjet head 1 that ejects ink, and a cover 70 that covers the upstream side surface of the inkjet head 1 in the paper transport direction (the direction from right to left in the drawing). .

  Inside the ink jet printer 101, a paper transport path is formed through which the paper P, which is a recording medium, is transported from the paper feed unit 111 toward the paper discharge unit 112. A pair of feed rollers 105a and 105b that pinch and convey the sheet are disposed immediately downstream of the sheet feeding unit 111. The pair of feed rollers 105a and 105b feed the paper P from the paper feeding unit 111 to the left in the drawing. In an intermediate portion of the sheet conveyance path, two belt rollers 106 and 107, an endless conveyance belt 108 wound around the rollers 106 and 107, and an area surrounded by the conveyance belt 108 A belt conveyance mechanism 113 including a platen 115 disposed at a position facing the head unit 3 is provided.

  The platen 115 supports the conveyance belt 108 so that the conveyance belt 108 does not bend downward in a region facing the head unit 3. A nip roller 104 is disposed at a position facing the belt roller 107. The nip roller 104 presses the sheet P fed from the sheet feeding unit 111 by the feed rollers 105 a and 105 b against the outer peripheral surface 108 a of the transport belt 108.

  A conveyance motor 108 is driven by rotating a belt roller 106 by a conveyance motor (not shown). As a result, the conveyance belt 108 conveys the paper P pressed against the outer peripheral surface 108 a by the nip roller 104 toward the paper discharge unit 112 while being adhesively held.

  A peeling mechanism 114 is provided immediately downstream of the conveyance belt 108 along the sheet conveyance path. The peeling mechanism 114 is configured to peel the paper P adhered to the outer peripheral surface 108a of the conveying belt 108 from the outer peripheral surface 108a and to send it toward the paper discharge unit 112 on the left side in the drawing.

  The inkjet heads 1 of the four head units 3 eject inks of different colors (magenta, yellow, cyan, black). Four head units 3 are fixed side by side along the paper conveyance direction (sub-scanning direction). That is, the ink jet printer 101 is a line printer. Each of the four inkjet heads 1 has a head body 2 at the lower end thereof. The head main body 2 has an elongated rectangular parallelepiped shape that is elongated in a direction (main scanning direction) orthogonal to the paper transport direction. In addition, the bottom surface of the head main body 2 is an ink ejection surface 2a facing the outer peripheral surface 108a. When the paper P transported by the transport belt 108 passes immediately below the four head bodies 2, the ink of each color is ejected from the nozzles formed on the ink ejection surface 2a toward the upper surface of the paper P, that is, the printing surface. By discharging, a desired color image is formed on the printing surface of the paper P.

  Next, the head unit 3 will be described in detail. Since the four head units 3 have the same configuration, only one head unit 3 will be described. FIG. 2 is a schematic perspective view of the inkjet head shown in FIG. FIG. 3 is a perspective view showing an internal configuration of the inkjet head shown in FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV shown in FIG.

  First, the inkjet head 1 constituting the head unit 3 will be described. As shown in FIGS. 2 to 4, the inkjet head 1 has a substantially rectangular parallelepiped shape in which one direction is a longitudinal direction (main scanning direction). The ink jet head 1 has a head body 2 having a flow path unit 4 and an actuator unit 20, and an ink reservoir 50 that supplies ink to the flow path unit 4. Further, the inkjet head 1 has a head cover 11 disposed on the ink reservoir 50, and the ink reservoir 50 and the control board 17 are disposed in the internal space thereof.

  An opening 11a is formed on the side surface of the head cover 11 along the main scanning direction. The opening 11 a is formed by cutting out a part of this side surface, and extends from the lower end of the side surface to the vicinity of the center of the side surface along the vertical direction of the head cover 11. The opening 11a has a rectangular shape, and its long side is parallel to the main scanning direction. The short side of the opening 11a is parallel to the vertical direction. Inside the head cover 11, a heat sink 13 is disposed so as to close the opening 11a. In the present embodiment, the flat protrusion 14 formed on the heat sink 13 is exposed from the head cover 11 through the opening 11a. In the inkjet head 1, the gap between the members is filled with a seal member (not shown) so that the space surrounded by the head cover 11, the heat sink 13, the reservoir base 52, and the flow path unit 4 becomes a sealed space. ing.

  Inside the flow path unit 4, a flow path including a common ink chamber and a large number of individual ink flow paths from the common ink chamber to the nozzle through the pressure chamber is formed. On the upper surface of the flow path unit 4, four actuator units 20 that can selectively apply ejection energy to the ink in a number of pressure chambers are attached in order to eject ink droplets from the nozzles.

  The actuator unit 20 is a unimorph type actuator including a piezoelectric layer sandwiched between a large number of individual electrodes and a common electrode disposed so as to face the pressure chamber. In the present embodiment, individual electrodes are formed on the surface of the actuator unit 20. The piezoelectric layer is made of a lead zirconate titanate (PZT) ceramic material having ferroelectricity. Further, the individual electrode and the common electrode are made of a metal material such as an Ag-Pd system. The individual electrode is electrically connected to the corresponding wiring 16a of the FPC 16 through a land made of gold containing glass frit. Then, a predetermined voltage pulse (driving signal for ejecting ink) generated by the driver IC 15 is supplied to the individual electrode via the wiring 16a, so that a region corresponding to the individual electrode of the actuator unit 20 is deformed. The volume of the pressure chamber facing the region changes. As a result, a pressure wave (discharge energy) is generated in the ink in the pressure chamber, and ink droplets are discharged from the corresponding nozzles.

  The control board 17 controls the actuator unit 20 and is fixed above the ink reservoir 50 as shown in FIGS. Four connectors 17 a are fixed to the upper surface of the control board 17. The connector 17a is electrically connected to various processors and storage devices constructed on the control board 17.

  The drive control unit constructed by the processor and the storage device generates droplet data for driving the actuator unit 20. Print data is transmitted to the drive control unit from a host device (for example, a host computer). The print data is data in which a color density value (tone value) and a continuous number of times of pixels of this density are combined corresponding to each pixel of each color component constituting the color image. When receiving the print data, the drive control unit identifies the corresponding droplet data (the waveform of the drive signal for ejecting the ink droplets) from the color density value, duplicates the continuous number of times, and stores the predetermined data in the storage device. Are sequentially stored in the storage area. This waveform is stored as a data table in another storage area of the storage device.

  In the present embodiment, the drive control unit generates droplet data for each nozzle arranged at regular intervals in the main scanning direction (each pixel row arranged in the sub-scanning direction formed by each nozzle). Furthermore, the drive control unit sequentially outputs droplet data to the driver IC 15 for each printing cycle for forming one pixel. During this printing cycle, the driver IC 15 outputs a drive signal corresponding to the droplet data to the actuator unit 20. The drive signal is a signal amplified by the driver IC 15 based on the droplet data. The driver IC 15 generates heat by outputting a drive signal (driving the actuator unit 20).

  One end of the FPC 16 is electrically connected to the side surface of each connector 17a. The FPC 16 is a flexible sheet-like member, on which a plurality of wirings 16a are formed and a driver IC 15 is mounted. On the other hand, the other end (terminal of the wiring 16 a) of the FPC 16 is electrically connected to the individual electrode of the actuator unit 20 in the recess 53 a of the ink reservoir 50.

  The concave portion 53 a has a sandwich structure in which the actuator unit 20 is sandwiched between the ink reservoir 50 and the flow path unit 4, and is formed to secure a space for arranging the actuator unit 20 between the ink reservoir 50 and the flow path unit 4. It is a gap.

  The driver ICs 15 are IC chips that drive the actuator unit 20 and are arranged two by two along the side surface of the ink reservoir 50 as shown in FIG. Further, as shown in FIG. 4, the driver IC 15 is biased against the heat sink 13 together with the FPC 16 by a sponge 18 provided on the side surface of the ink reservoir 50 at a position facing the flat protrusion 14 of the heat sink 13. .

  As shown in FIG. 2, the heat sink 13 has a substantially rectangular shape having a longitudinal direction in the main scanning direction, and is a metallic plate-like member such as aluminum or stainless steel. The heat sink 13 is formed with a flat protrusion 14 and a plurality of protrusions 13 a to be inserted into the flow path unit 4. The flat protrusion 14 is formed at a portion facing the side surface of the upper reservoir 51 (described later) of the heat sink 13 and protrudes from the opening 11. The protruding portion, that is, the tip is flat and has a rectangular shape that is long in the main scanning direction. The flat protrusion 14 is formed by, for example, pressing a metal flat plate. As described above, since the flat protrusion 14 is formed on the heat sink 13, the surface area of the heat sink 13 is increased and the rigidity is increased.

  A heat radiating sheet 19 is attached to the inner surface of the flat protrusion 14 at a position facing the driver IC 15. The driver IC 15 is in close contact with the heat sink 13 via the heat dissipation sheet 19, and the driver IC 15 and the heat sink 13 are thermally coupled. Thereby, the heat generated in the driver IC 15 is dissipated through the heat sink 13.

  The plurality of protrusions 13a protrude downward from the lower end of the heat sink 13, and are spaced apart from each other along the main scanning direction. The width of the upper surface of the flow path unit 4 is larger than the width of the lower surface of the ink reservoir 50. The ink reservoir 50 is arranged in the center in the sub-scanning direction (width direction) of the flow path unit 4. Accordingly, there is a region that does not face the lower surface of the ink reservoir 50 in the vicinity of both ends in the sub-scanning direction of the flow path unit 4. In these regions, five recesses 4a are respectively formed. These recesses 4a are formed at positions corresponding to the plurality of protrusions 13a. Further, the recess 4a is formed in a size and shape so as to be fitted to the protrusion 13a of the heat sink 13. The heat sink 13 is erected from the flow path unit 4 by fitting the protrusions 13a into the recesses 4a. Further, as shown in FIG. 4, the upper portion of the heat sink 13 is in contact with the inner side surface of the head cover 11 to fix the head cover 11.

  Similar to the head body 2, the ink reservoir 50 has a rectangular shape in plan view, and its long side is parallel to the main scanning direction. The ink reservoir 50 includes an upper reservoir 51, a reservoir base 52, and a lower reservoir 53 in order toward the flow path unit 4.

  An ink flow path 54 is formed inside the upper reservoir 51. The ink flow path 54 communicates with the ink supply valve 12 (see FIG. 2) and communicates with the flow path unit 4 via an ink flow path (not shown) formed in the reservoir base 52 and the lower reservoir 53. . A part of the lower surface of the ink flow path 54 is made of a flexible film 55. The lower surface of the film 55 faces the reservoir base 52 via a predetermined gap, and is disposed so as to be able to be displaced corresponding to this gap. For this reason, when the film 55 vibrates, the shock due to the pressure wave generated in the ink filled in the ink flow path 54 is absorbed. A filter 56 having a plurality of fine holes is disposed in the ink flow path 54.

  As shown in FIG. 4, the lower reservoir 53 is joined to the flow path unit 4, but a concave portion 53 a is partially formed on the boundary surface between them. The recesses 53 a are arranged corresponding to the actuator units 20, respectively, and the actuator unit 20 is attached to the surface of the flow path unit 4 in a gap created by the recesses 53 a. Thus, the ink supplied from the ink supply valve 12 flows into the flow path unit 4 through the ink flow path 54 formed in the ink reservoir 50. The ink passes through the filter 56 provided in the ink flow path 54 before reaching the flow path unit 4. At that time, impurities in the ink are filtered by the filter 56.

  As shown in FIGS. 3 and 4, three hooks 57 to 59 are formed on the upstream side surface of the lower reservoir 53 in the paper conveyance direction (sub-scanning direction). These hooks 57 to 59 are arranged apart from each other at a predetermined interval in the main scanning direction. The hooks 57 to 59 have an L-shape that protrudes outward from the upstream side surface of the lower reservoir 53 and is bent in parallel with the lower reservoir 53 from there in the main scanning direction. Of these hooks 57 to 59, the hook 58 provided at the center in the main scanning direction protrudes from a position recessed by one step from the other two hooks 57 and 59. As shown in FIG. 3, the base 58a is formed so that the tip of the hook 58 is located at the same position as the tips of the other two hooks 57 and 59 in the sub-scanning direction. As shown in FIG. 2, when the heat sink 13 is attached to the side surface of the inkjet head 1, the base portion 58 a protrudes from the tip portion from the hole 13 b formed in the heat sink 13. A gap between the base 58a and the hole 13a of the heat sink 13 is filled with a seal member (not shown).

  Next, the cover 70 fixed to the inkjet head 1 will be described. 5A is a side view of the cover 70, and FIG. 5B is a cross-sectional view taken along the line VV in FIG. 5A.

  As shown in FIG. 5, the cover 70 is a plate-like member that is long in the main scanning direction, and the length in the main scanning direction is the same as that of the ink ejection surface 2a. Further, as shown in FIG. 4, when the cover 70 is fixed to the inkjet head 1, the lower surface 71 at the lower end (one end: end edge) thereof is disposed at the same height as the ink ejection surface 2a. The height of the cover 70 is such that it covers the upstream side surface of the inkjet head 1 from the center to the lower end.

  As shown in FIGS. 4 and 5, a contact surface (contact region) 72 that is continuous with the lower surface 71 and contacts the upstream side surface is formed on the inner surface 81 of the cover 70 that faces the upstream side surface of the inkjet head 1. Has been. On the other hand, the outer surface 82 on the opposite side of the inner surface 81 of the cover 70 is formed with an inclined surface (inclined region) 73 that is continuous with the lower surface 71 and inclined with respect to the ink ejection surface 2a. The lower surface 71, the contact surface 72, and the inclined surface 73 are formed at the lower end portion (one end portion) of the cover 70. In the present embodiment, the lower end portion is a range from the lower surface 71 to the upper end of the inclined surface 73 with respect to the vertical direction (substantially the same range as the range from the lower surface 71 to the fixing portions 77 to 79).

  The inclined surface 73 is formed over the entire main scanning direction of the cover 70 as shown in FIG. That is, it has the same length as the ink discharge surface 2a. By forming the inclined surface 73 as described above, for example, even when the sheet P with the curled front end is conveyed to the region facing the ink discharge surface 2a, the front end is a region facing the ink discharge surface 2a. Can guide you smoothly. In addition, since the inclined surface 73 has the same length as the ink ejection surface 2a in the main scanning direction, the paper P can be guided more reliably to the region facing the ink ejection surface 2a, and the jam can be further improved. Can be suppressed.

  The inclined surface 73 has an upper end disposed at the lower ends of fixing portions 77 to 79 described later. That is, the inclined surface 73 has the same height as the distance from the ink ejection surface 2a to the fixing portions 77 to 79 in the vertical direction. As a result, even when, for example, a sheet P with a large front end is curled is conveyed to a region facing the ink ejection surface 2a, the front end of the sheet P and the inclined surface 73 come into contact with each other and can smoothly guide the front end. it can. Therefore, jam can be further suppressed.

  As shown in FIG. 5A, the cover 70 is formed with three fixing portions 77 to 79 that are fixed to the inkjet head 1. These fixing portions 77 to 79 are formed at positions facing the hooks 57 to 59 when the cover 70 is fixed to the inkjet head 1. The fixing portions 77 to 79 are formed on the through portions 77a, 78a, and 79a penetrating in the thickness direction (sub-scanning direction) of the cover 70 and the outer surface 82 of the cover 70, and extend from the through portions 77a to 79a along the main scanning direction. It has extended grooves 77b, 78b, 79b. The through portions 77a and 78a have openings that are slightly larger than the front end surfaces of the corresponding hooks 57 and 58. The penetrating portion 79a is cut out at one side wall in the main scanning direction.

  In this configuration, the hooks 57 to 59 are fitted into the through portions 77a to 79a, and then the cover 70 is slid so that the tip portions of the hooks 57 to 59 move toward the grooves 77b to 79b. Protrusions 77c and 79c projecting downward are formed on the upper walls of the grooves 77b and 79b among the three grooves 77b, 78b and 79b, as shown in FIG. When the cover 70 slides, the protrusions 77 c and 79 c mesh with the tip portions of the hooks 57 and 59, whereby the fixing portions 77 to 79 of the cover 70 are fixed to the inkjet head 1. As shown in FIG. 4, the cover 70 is disposed with the heat sink 13 sandwiched between the side surface of the ink reservoir 50 and the heat sink 13.

  Thus, since the hooks 57 to 59 are formed on the inkjet head 1 and the fixing portions 77 to 79 including the through portions 77 a to 79 a and the grooves 77 b to 79 b are formed on the cover 70, the cover 70 is attached to the inkjet head 1. Can be fixed easily. Note that the fixing portions 77 to 79 may not have the grooves 77b to 79b. In this case, when the cover 70 is fixed to the inkjet head 1, the tip portions of the hooks 57 to 59 only protrude from the outer surface 81. Further, since the hooks 57 to 59 and the fixing portions 77 to 79 are provided in three in the main scanning direction, the cover 70 is difficult to come off from the inkjet head 1 and can be fixed securely. Further, when the cover 70 is fixed to the inkjet head 1, the projections 77c and 79c and the hooks 57 and 59 are engaged with each other, so that the cover 70 is difficult to move in the main scanning direction and the cover 70 is separated from the hooks 57 to 59. It becomes difficult to drop off. Furthermore, one end of the cover 70 can be aligned at the same height as the ink ejection surface 2a over the entire longitudinal direction.

  The cover 70 is made of a synthetic resin. Thus, by being comprised from a synthetic resin, it becomes possible to form the cover 70 easily and the manufacturing cost of the cover 70 becomes low. In this embodiment, the cover 70 is made of synthetic resin, but may be made of the same metal as the heat sink 13. In this case, heat in the vicinity of the flat protrusion 14 of the heat sink 13 can be taken away, so heat is taken away from the heat sink 13 indirectly. Therefore, the heat dissipation performance by the heat sink 13 is improved.

  As shown in FIG. 5, the cover 70 has five openings 75 arranged along the main scanning direction. As shown in FIG. 4, the opening 75 is formed in a region that is disposed above the fixing portions 77 to 79 and faces the flat protrusion 14. Further, the openings 75 are arranged so as to be disposed at positions facing the driver IC 15 when the cover 70 is fixed to the inkjet head 1. Specifically, when the cover 70 is fixed to the inkjet head 1, the second opening 75 from the left in FIG. 5 is disposed at a position facing the driver IC 15 on the left in FIG. The opening 75 is disposed at a position facing the driver IC 15 on the right side in FIG.

  Since the opening 75 is formed in the cover 70 in this way, the heat dissipation performance by the heat sink 13 does not deteriorate. Further, since the opening 75 is formed corresponding to the arrangement position of the driver IC 15, the heat sink 13 can effectively dissipate the heat of the driver IC 15.

  Each opening 75 is formed with a cantilever 76 extending upward from the center of the lower end of the opening edge as shown in FIG. The thickness of the cantilever 76 is formed to be thinner than the thickness of the other part of the cover 70. A protruding portion 76 a that protrudes toward the inner surface 81 side is formed at the upper end portion of the cantilever beam 76. As shown in FIG. 5B, the front end surface 76b (a part of the inner surface 81) of the protruding portion 76a protrudes most in the sub-scanning direction on the inner surface 81, and the fixing portions 77 to 79 in the vertical direction. It is further away from the ink ejection surface 2a.

  With this configuration, when the cover 70 is fixed to the inkjet head 1, as shown in FIG. 4, the tip surface (pressing portion) 76 b of the protruding portion 76 a comes into contact with the flat protruding portion 14. The cantilever 76 is bent in a direction away from the flat protrusion 14 when the front end surface 76b is pressed from the flat protrusion 14 (in other words, the flat protrusion 14 is pressed against the front end surface 76b). Since the cantilever 76 is thus bent, the cover 70 can be easily fixed to the inkjet head 1. In addition, manufacturing variations can be absorbed, and the contact surface 72 of the cover 70 can be reliably contacted with the side surface of the inkjet head 1. Then, the pressing force that bends the cantilever beam 76 is transmitted to the contact surface 72 as the rotational force of the cover 70 around the fixing portions 77 to 79. As a result, the contact surface 72 is biased in a direction approaching the upstream side surface of the inkjet head 1 (flow path unit 4), and is brought into close contact with the upstream side surface. For this reason, there is almost no gap between the contact surface 72 of the cover 70 and the upstream side surface of the inkjet head 1.

  On the other hand, as shown in FIG. 4, the cover 70 is separated from the heat sink 13 at a portion above the contact surface 72 except for the tip surface 76 b of the protrusion 76 a. In particular, a large gap is formed in the portion of the heat sink 13 that faces the flat protrusion 14. Thereby, the heat dissipation of the heat sink 13 is improved.

  As described above, according to the ink jet printer 101 of the present embodiment, the cover 70 having the inclined surface 73 is fixed upstream in the paper transport direction of the ink jet head 1, so that the paper P is caught on the upstream side surface of the ink jet head 1. It is possible to suppress the occurrence of jam. Further, when the front end surface 76b of the cover 70 is pressed, the contact surface 72 comes into close contact with the upstream side surface of the inkjet head 1, and no gap is generated between them. Therefore, it is not necessary to separately provide a seal member for filling the gap, and it is possible to prevent the ink that has entered the gap from dropping unexpectedly and soiling the paper P. Even if the cover 70 is made of synthetic resin, the cover 70 is disposed with a gap from the heat sink 13, so that heat dissipation of the heat sink 13 is not hindered.

  Next, the head unit 203 according to the second embodiment of the present invention will be described below. FIG. 6 is a side view of the cover of the head unit according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view of a main part of a head unit according to the second embodiment of the present invention. The head unit 203 according to the present embodiment is substantially the same as the head unit 3 of the first embodiment except that the portion constituting the inclined surface 273 of the cover 270 is slightly different from the cover 70 of the first embodiment. In addition, about the same thing as 1st Embodiment, the same code | symbol is shown and description is abbreviate | omitted.

  As shown in FIGS. 6 and 7, the outer surface 282 of the cover 270 of the present embodiment is formed with a protrusion 284 a at the lower end thereof, the lower end being continuous with the lower surface 71 and extending over the entire length in the longitudinal direction of the cover 270. Has been. The protrusion 284a has an inclined surface 273a that protrudes from the outer surface 282 and is inclined with respect to the ink ejection surface 2a. In the present embodiment, the inclined surface 273a is a curved surface with a small curvature. Further, a plurality of ribs 284b arranged at predetermined intervals along the main scanning direction are formed at the lower end portion of the outer surface 282. The ribs 284b are formed to protrude outward from the outer surface 282, and have an inclined surface 273b that is inclined with respect to the ink ejection surface 2a. The inclined surface 273b is a curved surface having a small curvature following the inclined surface 273a. The rib 284 b has a lower end continuous with the lower surface 71 and the upper end extends to the lower end edge of the opening 75, similar to the protrusion 284 a. In the portion of the rib 284b that overlaps the protruding portion 284a, the inclined surface 273b of the rib 284b is continuous with the inclined surface 273a of the protruding portion 284a without distinction. An inclined region 274 is formed by the inclined surface 273a of the protrusion 284a and the inclined surface 273b of the rib 284b. The inclined region 274 has substantially the same length as the ink ejection surface 2a in the main scanning direction.

  The ribs 284b are arranged at an interval shorter than the width in the direction orthogonal to the sheet conveyance direction of the sheet P conveyed to the region facing the ink ejection surface 2a. As described above, since the inclined region 274 is configured by the plurality of ribs 284b, the strength of the cover 270 itself is improved as compared with the first embodiment. In addition, the same effect can be acquired in the structure similar to 1st Embodiment.

  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, in each embodiment, the tip surface 76 b is pressed against the flat protrusion 14, but if the contact surface 72 that is the contact region is urged to the upstream side surface of the inkjet head 1, the cover 70. , 270, the inkjet head 1 may be pressing somewhere on the inner surface 81. Further, the cantilever 76 may not be formed. In this case, the inner surfaces of the upper ends of the covers 70 and 270 are partially brought into contact with either the side surface of the inkjet head 1 or the side surface of the heat sink 13, and the contact surface 72 is urged toward the upstream side surface of the inkjet head 1. That's fine.

  Further, the inclined area formed by the inclined surfaces 73, 273a, 273b may be longer or shorter than the ink discharge surface 2a in the main scanning direction. Further, the height of the inclined region may be lower or higher than the distance from the ink ejection surface 2a to the fixing portions 77 to 79 in the vertical direction. Further, the opening 75 formed in the covers 70 and 270 may not face the driver IC 15, and the opening 75 itself may not be formed. The covers 70 and 270 and the inkjet head 1 may be fixed with a configuration other than the hooks 57 to 59 and the fixing portions 77 to 79. In addition, the inkjet printer 101 according to the first embodiment has four head units 3, but if the head unit 3 is arranged on the most upstream side in the paper conveyance direction, the remaining three are inkjet heads. There may be. In addition, although the inclined surfaces 273a and 273b are curved surfaces, they may be flat surfaces like the inclined surface 73. On the contrary, the flat inclined surface 73 may be formed as a curved surface having a small curvature in the same manner as the inclined surface 273a.

  In addition, each of the above-described embodiments is an example in which the present invention is applied to a head unit that ejects ink from nozzles and an inkjet printer having the head unit. However, the applicable object of the present invention is such a head unit and inkjet printer. Not limited. For example, a conductive paste is discharged to form a fine wiring pattern on the substrate, an organic light emitter is discharged to the substrate to form a high-definition display, or an optical resin is discharged to the substrate. The present invention can be applied to a head unit having a liquid discharge head and a cover for forming a microelectronic device such as an optical waveguide, and various liquid discharge apparatuses having the head unit.

1 is a schematic side view showing an overall configuration of an inkjet printer according to a first embodiment of the present invention. It is a schematic perspective view of the inkjet head shown in FIG. FIG. 3 is a perspective view showing an internal configuration of the ink jet head shown in FIG. 2. It is sectional drawing along the IV-IV line shown in FIG. (A) is a side view of a cover, (b) is sectional drawing along the VV line of Fig.5 (a). It is a side view of the cover of the head unit by 2nd Embodiment of this invention. It is principal part sectional drawing of the head unit by 2nd Embodiment of this invention.

Explanation of symbols

1 Inkjet head (liquid ejection head)
2a Ink ejection surface 3 Head unit 13 Heat sink 15 Driver IC
57 to 59 Hooks 70, 270 Cover 71 Lower surface 72 Contact surface (contact region)
73 Inclined surface (inclined area)
75 Opening 76 Cantilever 76b Tip surface (pressing part)
77-79 fixed part 77a-79a penetrating part 81 inner surface 82,282 outer surface 101 inkjet printer (liquid ejecting apparatus)
113 Belt conveying mechanism 273a, 273b Inclined surface 274 Inclined region 284a Protruding portion 284b Rib

Claims (13)

A liquid discharge head having a discharge surface for discharging liquid and having one direction as a longitudinal direction;
Covering a side surface along the longitudinal direction of the liquid discharge head, and a cover fixed to the liquid discharge head,
The cover has one end at the same height as the discharge surface with respect to a direction orthogonal to the discharge surface, and a fixing portion fixed to the liquid discharge head at a portion separated from the discharge surface. A contact region that contacts the side surface is formed on the inner surface facing the side surface, and an inclined region that is inclined with respect to the discharge surface is formed on the outer surface opposite to the side surface, respectively.
The liquid discharge head is a direction in which the inner surface of the cover is separated from the discharge surface at a position farther from the discharge surface than the fixed portion so that the contact area is biased in a direction approaching the side surface. A head unit that is pressed against the head unit.   The head unit according to claim 1, wherein the inclined region has a length equal to or longer than the ejection surface in the longitudinal direction.   3. The head unit according to claim 1, wherein the inclined region has a height greater than or equal to a distance from the ejection surface to the fixed portion with respect to the orthogonal direction. The liquid discharge head has a heat sink attached to the side surface;
The head unit according to claim 1, wherein an opening is formed in the cover at a position facing the heat sink. In the liquid discharge head, a plurality of driver ICs are arranged along the side surface, and heat generated when the liquid is discharged from the discharge surface is released by the heat sink.
The head unit according to claim 4, wherein the opening of the cover is formed corresponding to an arrangement position of the driver IC.   6. The head unit according to claim 4, wherein a cantilever beam that can be bent and deformed in a direction away from the side surface when pressed by the heat sink is formed at an opening edge of the cover. A hook protruding from the side surface is formed at a position facing the fixed portion of the liquid ejection head,
The head unit according to any one of claims 1 to 6, wherein the fixing portion includes a penetrating portion into which the hook penetrating in the thickness direction of the cover is fitted.   The head unit according to claim 7, wherein a plurality of the hooks and the through portions are formed in the longitudinal direction.   The head unit according to claim 1, wherein the cover is made of metal.   The head unit according to claim 1, wherein the cover is made of a synthetic resin. A liquid discharge head having a discharge surface for discharging the liquid and a plurality of driver ICs for generating a signal for discharging the liquid from the discharge surface and having one direction as a longitudinal direction; and a longitudinal direction of the liquid discharge head A heat sink covering the side surface and sandwiching the plurality of driver ICs between the side surface, a side surface along the longitudinal direction of the heat sink and a cover fixed to the liquid ejection head,
The cover has the heat sink sandwiched between a side surface of the liquid discharge head, a plurality of openings are formed at positions facing the driver IC, and an edge is formed in a direction perpendicular to the discharge surface. One end of the same height as the discharge surface, a fixed portion that is fixed to the liquid discharge head away from the discharge surface, and a pressure that is pressed away from the discharge surface than the fixed portion from the side surface of the heat sink Each with
One end of the cover has an abutting region that abuts the side surface on the inner surface facing the side surface of the liquid ejection head, and an outer surface opposite to the inner surface is inclined with respect to the ejection surface. A head unit comprising an inclined region including a surface. The cover is made of a synthetic resin, and is disposed via the heat sink and a gap.
The head unit according to claim 11, wherein the inclined surface of the inclined region is formed by a plurality of ribs formed to protrude outward from the outer surface. A recording medium transport mechanism;
12. The fixing device according to claim 1 or 11, wherein the transport direction of the recording medium by the transport mechanism and the longitudinal direction of the liquid discharge head are orthogonal to each other and the cover is positioned upstream of the liquid discharge head with respect to the transport direction. A liquid ejecting apparatus comprising: the head unit described above.

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