JP3832541B2 - Head unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a head unit mounted on an ink jet recording apparatus that discharges and prints ink droplets supplied from an ink cartridge.
[0002]
[Prior art]
In general, in a head unit including an ink jet recording head, ink is supplied from an ink cartridge filled with ink to an ink jet head through an ink supply needle and a flow path inserted into the ink cartridge. Is ejected from the nozzle by driving a piezoelectric element or the like.
[0003]
For example, as shown in FIG. 9, a frame 101 constituting a conventional head unit 100 defines an ink cartridge storage chamber 102 that is mounted on a carriage of a printer and stores an ink cartridge (not shown). A head case 103 having an ink flow path communicating with the ink cartridge is joined to the surface of the frame opposite to the ink cartridge housing chamber 102. The recording head main body 104 for discharging the ink is fixed. An ink supply needle 105 to be inserted into the ink cartridge is provided on the bottom surface of the frame 101 on the ink cartridge storage chamber 102 side. Ink is supplied to the recording head main body 104 through 103a. A circuit board 106 on which a drive circuit is mounted is fixed between the head case 101 and the printhead main body 104, and the printhead main body 104 is driven by this drive circuit to discharge ink.
[0004]
Further, in such a head unit 100, the frame 101 and the head case 103 are fixed via a seal member 107 that seals the periphery of the ink flow path 103a, whereby the ink from the connection part of the ink flow path is fixed. Prevents leakage.
[0005]
[Problems to be solved by the invention]
However, in such a conventional head unit 100, when the frame 101 and the head case 103 are joined via the seal member 107, the seal member 107 is deformed and the periphery of the ink flow path is not completely sealed. There is a problem that ink leaks from this portion. For example, when the seal member 107 that seals each ink flow path 103a is integrally formed, deformation that is uneven in the thickness direction occurs in the longitudinal direction, and particularly, the end portion is turned up and the seal is insufficient. There is a problem of becoming.
[0006]
Further, the frame 101 and the head case 103 are fixed by, for example, fastening with screws, but the number of fastenings needs to be minimized by design, and the position thereof is also limited. Therefore, when moving the head by scanning the carriage or replacing the ink cartridge, the frame 101 moves with the fastening position as a fulcrum when a load is applied, and the frame 101 and the head case 103 are That is, there is a problem in that a gap is formed in the connection portion of the ink flow path 103a and ink leakage occurs.
[0007]
In view of such circumstances, it is an object of the present invention to provide a head unit that can improve the sealing performance of a connection portion of an ink flow path and prevent ink leakage.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention for solving the above problems, a recording head main body having a pressure generating chamber communicating with a nozzle opening for discharging ink, and the ink supply port fixed to the ink supply port side of the recording head main body A head unit comprising: a head case having an ink flow path communicating with the head; and an ink supply means holding member that holds the ink supply means and is fixed to a side of the head case opposite to the recording head main body via a seal member A plurality of projecting portions each of which opens the ink flow path is provided on the seal member side of the head case, and the seal member has a shape covering the plurality of projecting portions, and the plurality of projecting portions are Receiving portions that receive the sealing members and prevent deformation of the end portions of the sealing members in the thickness direction on the outer sides of the substantially polygonal vertices to be connected are the protruding portions. In the head unit, characterized in that are integrally provided.
[0009]
In the first aspect, the seal member is prevented from being deformed by the receiving portion, the sealability of the connecting portion between the head case and the ink supply means holding member is improved, and ink leakage can be prevented.
[0010]
According to a second aspect of the present invention, in the first aspect, the seal unit has a shape that integrally covers the plurality of protrusions.
[0011]
In the second aspect, the plurality of protrusions are reliably covered by the integrally formed sealing member, the sealing performance of the connection portion between the head case and the ink supply means holding member is further improved, and ink leakage is reliably ensured. Can be prevented.
[0012]
According to a third aspect of the present invention, in the first or second aspect, the opening end surface of the ink flow path that comes into contact with the seal member has an R shape.
[0013]
In the third aspect, the opening end of the ink flow path and the seal member are in line contact, and the sealing performance is improved.
[0014]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the printed circuit board is disposed between the protrusions to prevent deformation of the seal member. is there.
[0015]
In the fourth aspect, the printed circuit board prevents the seal member from being deformed, and the sealing performance of the connection portion between the head case and the ink supply unit holding member is improved.
[0016]
According to a fifth aspect of the present invention, in any one of the first to third aspects, a slit portion for positioning is formed at a peripheral edge of a portion corresponding to the protruding portion of the seal member and positioned in the thickness direction. In the head unit, a rib that is fitted to the slit portion protrudes radially outward from the protruding portion.
[0017]
In the fifth aspect, the seal member can be easily and reliably positioned.
[0018]
According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the connection between the head case and the ink supply unit holding member is fastened by at least two fastening mechanisms projecting at least one of them. It is in the head unit characterized by this.
[0019]
In the sixth aspect, the head case and the ink supply means holding member are securely fixed.
[0020]
According to a seventh aspect of the present invention, in the sixth aspect, the at least one opposing surface of the head case and the ink supply unit holding member protrudes from the other portion and contacts the other opposing surface. A head unit characterized in that at least two contact portions for positioning the head case and the ink supply means holding member are provided so as to sandwich the fastening mechanism in a direction intersecting with the direction in which the fastening mechanisms are arranged. is there.
[0021]
In the seventh aspect, the relative positional relationship between the head case and the ink supply means holding member is determined by the abutting portion, and the sealing performance at these joint portions is improved.
[0022]
According to an eighth aspect of the present invention, in the seventh aspect, at least one of the fastening mechanisms is provided with a positioning portion that performs relative positioning of the head case and the ink supply unit holding member. The head unit is characterized in that the plurality of contact portions are arranged at the positions of the substantially polygonal apexes.
[0023]
In the eighth aspect, the relative position between the head case and the ink supply means holding member is reliably determined by the positioning portion and the abutting portion that are disposed at the substantially triangular limited position.
[0024]
According to a ninth aspect of the present invention, in the eighth aspect, the plurality of projecting portions are disposed within the substantially polygonal range connecting the plurality of contact portions and the positioning portion. It is in the head unit.
[0025]
In the ninth aspect, the sealing performance of the connecting portion between the head case and the ink supply means holding member is further improved, and the ink flow paths are reliably connected.
[0026]
A tenth aspect of the present invention is the head unit according to any one of the seventh to ninth aspects, wherein an arrangement direction of the plurality of contact portions is a direction in which the head unit is scanned. .
[0027]
In the tenth aspect, ink leakage when scanning the ink jet recording head can be prevented.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments.
[0029]
FIG. 1 is a perspective view of a head unit according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view showing the main part thereof, and FIG. 3 is a perspective view of a head case.
[0030]
As shown in FIGS. 1 and 2, the head unit 10 according to an embodiment of the present invention has an ink cartridge storage chamber 11 that is mounted on a carriage of a printer and stores an ink cartridge as ink supply means (not shown). A cartridge case 12 as an ink supply means holding member, a head case 14 provided on the lower surface side of the ink cartridge case 12 via an ink supply path substrate 13, and a piezoelectric element provided on the lower surface side of the head case 14 by driving a piezoelectric element. And a recording head main body 15 that ejects ink. An ink supply needle 16 to be inserted for each color of the ink cartridge is fixed to the bottom surface portion of the cartridge case 12 on the ink cartridge housing chamber 11 side.
[0031]
The ink supply path substrate 13 provided on the lower side of the cartridge case 12 includes a plurality of, for example, two inks corresponding to black ink in this embodiment, yellow, magenta, and the like. A total of five ink supply paths 17A to 17E, one for each color of cyan, are provided.
[0032]
The head case 14 has ink flow paths 18A to 18E connected to the ink supply paths 17A to 17E of the ink supply path substrate 13, and these ink flow paths are provided on the ink supply path substrate 13 side of the head case 14. A plurality of projecting portions 19A to 19E are provided to open 18A to 18E, respectively.
[0033]
For example, in the present embodiment, ribs 21 extending in a direction substantially perpendicular to the arrangement direction of the protrusions 19A to 19E are provided on a part of the periphery of the protrusions 19 in order to position a seal member 20 described later. (See FIG. 3). Note that the rib 21 only needs to be formed so that the seal member can be reliably positioned. In the present embodiment, the rib 21 is provided on the protrusions 19A to 19C and 19E. Since the distance from the portion 19E is short, positioning can be performed without providing a rib. Furthermore, the receiving part 22 which prevents a deformation | transformation of the longitudinal direction both ends of the sealing member 20 is provided in the outer side of the protrusions 19A and 19E located in the both ends of these protrusions 19A-19E.
[0034]
In addition, as will be described in detail later, in the present embodiment, a through hole 23 for positioning and fixing the head case 14 is located substantially at the center of both ends in a direction orthogonal to the direction in which the protrusions 19A to 19E are arranged. Are formed respectively.
[0035]
The seal member 20 is for sealing the periphery of the connection portion between the ink supply path 17 and the ink flow path 18, and through holes 24 are formed corresponding to the respective ink flow paths 18 as shown in FIG. 4. The head case 14 has a shape that integrally covers the plurality of protrusions 19A to 19E. Further, ribs 25 projecting in the thickness direction are formed at portions corresponding to the periphery of the projecting portions 19A to 19C and 19E of the seal member 20, and are fitted to the outer peripheral surfaces of the projecting portions 19A to 19C and 19E. A concavity 26 to be joined is defined. In addition, a slit portion 27 is formed on a part of the rib 25 so as to correspond to the ribs 21 of the protrusions 19A to 19C and 19E described above.
[0036]
Then, the ink flow path 18 of the head case 14 and the ink supply path 17 of the ink supply path substrate 13 are connected via such a seal member 20. That is, the head case 14 is brought into contact with the ink supply paths 17A to 17E of the ink supply substrate 13 through the seal member 40 at the tip surfaces of the protrusions 19A to 19E. A path 18 is connected.
[0037]
Here, both end portions of the seal member 20 are prevented from being deformed in the thickness direction by the receiving portions 22 of the head case 14, and the sealing performance of the connection portion between the ink supply path 17 and the ink flow path 18 is improved. ing. That is, the seal member is deformed when sandwiched between the ink supply path substrate 13 and the head case 14, but is not deformed in the thickness direction. There is no gap in the connecting part. Further, as shown in FIG. 3, a circuit board 28 for driving the recording head main body 15 is disposed between the projecting portions 19 of the head case 14. Also, deformation in the thickness direction is prevented. As a result, ink leakage at the connecting portion between the ink supply path 17 and the ink flow path 18 is reliably prevented.
[0038]
Although the shape of the front end surface of such a protrusion 19 is not particularly limited, for example, it is preferable to have a substantially R shape. Thereby, the protrusion 19 and the seal member 20 are in line contact, and the sealing performance is improved. .
[0039]
At this time, the seal member 20 is reliably positioned at a predetermined position by fitting the rib 21 of the head case 14 into the slit portion 27. In addition, although rib is not provided in protrusion part 19D by the relationship of the space, the through-hole 23 corresponding to protrusion part 19D is also positioned by positioning of protrusion part 19C and 19E and the slit part 27. FIG.
[0040]
In the present embodiment, the seal member 20 is integrally formed. However, the present invention is not limited to this. For example, a plurality of seal members may be provided corresponding to the protruding portions. Even in this case, the same effect as described above can be obtained by providing the protrusions integrally with the protrusions that prevent the deformation of the end of the seal member.
[0041]
Further, the arrangement of the protrusions 19 is not particularly limited, and may be arranged in a polygonal shape such as a substantially triangular shape as shown in FIG. At this time, if the receiving portions 22 for preventing the deformation of the end portions of the seal member 20 are integrally provided on the outer sides of the apexes connecting the protruding portions 19, the same effects as described above can be obtained.
[0042]
Further, as will be described in detail below, the head case 14 is positioned and fixed by the positioning portion 31 and the abutting portion 32, so that the protruding portion 19 can be positioned in any position. It is preferable to arrange within the range of a substantially polygon that connects 32, whereby the ink flow path can be more reliably communicated.
[0043]
As described above, the head case 14 is provided on the ink supply path substrate 13 via the seal member 20, but actually, the head case 14 is fixed to the cartridge case 12 by fastening a fastening mechanism, for example, a screw in this embodiment. Has been. Hereinafter, the fixing structure will be described.
[0044]
In the present embodiment, as shown in FIG. 6, the cartridge case 12 is provided with two fastening bosses 29 </ b> A and 29 </ b> B that sandwich the ink supply path substrate 13 in the width direction at the center in the width direction on the lower surface side. . The fastening bosses 29 </ b> A and 29 </ b> B are for fastening screws for fixing the head case 14. Further, ribs 30A and 30B for increasing the strength of the fastening bosses 29A and 29B and positioning the head case 14 are attached to both sides of the two fastening bosses 29A and 29B, respectively. In the present embodiment, the ribs 30 </ b> A provided on one fastening boss 29 </ b> A serve as a positioning portion 31 for positioning the head case 14. That is, the rib 30A provided on the fastening boss 29A is formed at a predetermined height, and comes into contact with the head case 14 so as to keep the distance between the cartridge head 11 and the head case 14 constant. . Further, the rib 30B provided on the other fastening boss 29B is formed slightly lower than the rib 30A and does not come into contact with the head case 14. Further, on both sides of the fastening boss 29B, there are provided contact portions 32 having substantially the same height as the positioning portion 31 and positioning the head case 14.
[0045]
Accordingly, the head case 14 is fitted with the fastening boss 29 of the cartridge case 12 in the through hole 23 provided at the center of both ends thereof, and abuts on the three points of the positioning portion 31 and the two abutment portions 32. And is fixed to the cartridge case 12 by fastening a screw to the fastening boss 29 of the cartridge case.
[0046]
At this time, in the present embodiment, since the positioning portion 31 and the two contact portions 32 are provided so as to correspond to the vertices of the substantially equilateral triangle, the relative position between the head case 14 and the cartridge case 12 is determined. Can be determined reliably.
[0047]
In the present embodiment, the head case 14 is positioned at the three points of the positioning portion 31 and the two contact portions 32. However, the present invention is not limited to this, and for example, by providing a contact portion. Needless to say, the head case 14 may be positioned by contacting the head case 14 at four or more points.
[0048]
As described above, in the present embodiment, the head case 14 is positioned and fixed at at least three points, that is, the head case 14 is fixed by the fastening bosses 29 arranged in the direction intersecting the scanning direction and arranged in the scanning direction. Since the position of the cartridge case 12 and the head case 14 is held at a predetermined position by the positioning portion 31 and the contact portion 32, the cartridge case even if the heavy ink cartridge is shaken during the scanning of the head. The relative position between the head case 14 and the head case 14 is securely held, and no ink leakage occurs.
[0049]
As described above, the cartridge case 12 and the head case 14 are fixed so that the ink supply path 17 and the ink flow path 18 are securely connected, and the head case 14 and the recording head main body 15 are fixed. After the head unit is formed, it is mounted on the carriage of the ink jet recording apparatus.
[0050]
Here, an example of a recording head main body used in such a head unit is shown.
[0051]
FIG. 7 shows an example of an ink jet recording head which is a head body having a longitudinal vibration type piezoelectric element. As shown in the figure, the spacer 31 has a plurality of pressure generating chambers 32 arranged in parallel, and on both sides of the spacer 31, a nozzle plate 34 having nozzle openings 33 corresponding to the pressure generating chambers 32, a vibration plate 35, and the like. It is sealed by. In addition, the spacer 31 is formed with a reservoir 37 that serves as a common ink chamber for the plurality of pressure generating chambers 32 and is communicated with each pressure generating chamber 32 through the ink supply port 36. An ink cartridge (not shown) is connected.
[0052]
On the other hand, the tip of the piezoelectric element 38 is in contact with the area corresponding to each pressure generating chamber 32 on the opposite side of the diaphragm 35 from the pressure generating chamber 32. These piezoelectric elements 38 are stacked by sandwiching piezoelectric materials 39 and electrode forming materials 40 and 41 alternately in the vertical direction, and an inactive region that does not contribute to vibration is fixed to the fixed substrate 42. The fixed substrate 42, the diaphragm 35, the spacer 31, and the nozzle plate 34 are integrally fixed via a base 43.
[0053]
In the ink jet recording head configured as described above, the ink is supplied to the reservoir 37 via the ink flow path communicating with the ink cartridge, and is distributed to each pressure generating chamber 32 via the ink supply path 36. Actually, the piezoelectric element 38 is contracted by applying a voltage to the piezoelectric element 38. As a result, the diaphragm is pulled up together with the piezoelectric element 38 to expand the volume of the pressure generating chamber 38, and ink is drawn into the pressure generating chamber 38. Then, after filling the interior up to the nozzle 33 with ink, the voltage applied to the electrode forming materials 40 and 41 of the piezoelectric element 38 is released according to the recording signal from the drive circuit, and the piezoelectric element 28 is expanded. Return to the original state. As a result, the vibration plate 35 is also displaced and returns to the original state, so that the pressure generating chamber 32 is contracted, the internal pressure is increased, and ink droplets are ejected from the nozzle 33.
[0054]
In this embodiment, the piezoelectric vibration type ink jet recording head has been described as an example of the recording head main body. However, the present invention is not limited to this. For example, various structures such as a bubble jet ink jet recording head can be used. Needless to say, the present invention can be applied to an ink jet recording head.
[0055]
In addition, the ink jet recording heads of these embodiments constitute a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and are mounted on the ink jet recording apparatus. FIG. 8 is a schematic view showing an example of the ink jet recording apparatus.
[0056]
As shown in FIG. 8, in the head units 61A and 61B having the ink jet recording head, the cartridges 62A and 62B constituting the ink supply means are detachably provided as described above, and the recording head units 61A and 61B are mounted. The carriage 63 is provided on a carriage shaft 65 attached to the apparatus main body 64 so as to be movable in the axial direction. For example, the recording head units 61A and 61B eject a black ink composition and a color ink composition, respectively.
[0057]
Then, the driving force of the driving motor 66 is transmitted to the carriage 68 via a plurality of gears and timing belt 67 (not shown), so that the carriage 63 on which the recording head units 61A and 61B are mounted is moved along the carriage shaft 65. The On the other hand, the apparatus main body 64 is provided with a platen 68 along the carriage 63. The platen 68 can be rotated by a driving force of a paper feed motor (not shown), and a recording sheet S that is a recording medium such as paper fed by a paper feed roller is wound around the platen 68 and conveyed. It has become so.
[0058]
【The invention's effect】
As described above, in the present invention, since the receiving portions for preventing the deformation of the seal member are provided on both sides of the protruding portion where the ink flow path opens, the sealing performance of the connection portion of the ink flow path can be improved. it can. In addition, since the head case and the cartridge case are positioned at at least three points, the cartridge case does not tilt when the head is scanned, and the sealing performance can be further improved. Ink leakage from the connecting portion can be prevented.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a head unit according to an embodiment of the invention.
FIG. 2 is a cross-sectional view showing a main part of a head unit according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a head case according to an embodiment of the present invention.
4A and 4B are a plan view and a cross-sectional view showing a seal member according to an embodiment of the present invention.
FIG. 5 is a plan view showing another example of the arrangement of the protrusions according to the embodiment of the present invention.
FIG. 6 is a perspective view showing a cartridge case according to an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a recording head body according to an embodiment of the invention.
FIG. 8 is a schematic view of an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 9 is a perspective view of a head unit according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Head unit 12 Cartridge case 13 Ink supply path board | substrate 14 Head case 15 Recording head main body 16 Ink supply needle 17 Ink supply path 18 Ink flow path 19 Projection part 20 Seal member 21 Rib 22 Receiving part 27 Slit part 31 Positioning part 32 Contact Part

Claims (10)

A recording head main body having a pressure generating chamber communicating with a nozzle opening for discharging ink; a head case having an ink flow path fixed to the ink supply port side of the recording head main body and communicating with the ink supply port; In a head unit comprising: an ink supply means holding member that holds means and is fixed to a side of the head case opposite to the recording head main body via a seal member;
The head case is provided with a plurality of protrusions that open the ink flow paths on the seal member side, and the seal member has a shape that covers the plurality of protrusions, and is an approximate connection between the plurality of protrusions. The head is characterized in that a receiving portion for receiving the sealing member and preventing deformation of the end portion of the sealing member in the thickness direction is provided integrally with the projecting portion outside the apex of the polygon. unit.   The head unit according to claim 1, wherein the seal member has a shape that integrally covers the plurality of protrusions.   3. The head unit according to claim 1, wherein an opening end surface of the ink flow path in contact with the seal member has an R shape.   The head unit according to claim 1, wherein a printed circuit board is disposed between the protrusions to prevent the seal member from being deformed.   A rib that protrudes in the thickness direction and forms a slit portion for positioning is provided on a peripheral edge of a portion corresponding to the protrusion portion of the seal member, and the slit portion is fitted with the slit portion. The head unit according to any one of claims 1 to 3, wherein a mating rib is provided projecting radially outward.   5. The head unit according to claim 1, wherein the connection between the head case and the ink supply unit holding member is fastened by at least two fastening mechanisms at least one of which protrudes.   At least one of the opposing surfaces of the head case and the ink supply means holding member protrudes from the other portion and abuts against the other opposing surface to position the head case and the ink supply means holding member. The head unit according to claim 6, wherein two abutting portions are provided with the fastening mechanism sandwiched in a direction intersecting with an arrangement direction of the fastening mechanisms.   At least one of the fastening mechanisms is provided with a positioning portion for performing relative positioning between the head case and the ink supply means holding member, and the positioning portions and the plurality of contact portions are arranged at substantially polygonal vertex positions. The head unit according to claim 7, wherein the head unit is formed.   9. The head unit according to claim 8, wherein the plurality of projecting portions are arranged within a range of the substantially polygonal shape connecting the plurality of contact portions and the positioning portion.   The head unit according to claim 7, wherein an arrangement direction of the plurality of contact portions is a direction in which the head unit is scanned.

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