JP3714150B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of ink jet recording apparatuses.
[0002]
[Prior art]
An ink jet recording apparatus such as a conventional ink jet printer has a plurality of nozzles opened to the outside, a plurality of pressure chambers for supplying ink to the nozzle corresponding to each of the nozzles, and ink from an ink supply source. An ink jet comprising: a common ink chamber that distributes to a plurality of pressure chambers via ink supply holes; and an actuator that includes a plurality of pressure generating units that apply pressure to the pressure chambers to eject ink corresponding to each of the pressure chambers. The head includes a head and a cap that comes into contact with the nozzle opening surface of the inkjet head so as to cover the plurality of nozzles.
[0003]
In such a configuration, the common ink chamber is formed into a member such that the central portion thereof extends linearly in a row direction formed by a plurality of nozzles, for example, as shown in FIG. It was located in a plane parallel to the surface formed by the common ink chamber, and was positioned so as not to overlap the common ink chamber in a direction perpendicular to the surface. The reason for positioning the cap in this way is that the ink jet head can withstand the capping pressure.
[0004]
[Problems to be solved by the invention]
However, in general, since the position where the cap comes is shifted in a direction where the common ink chamber is located due to assembly displacement or the like, it is necessary to allow a certain margin for capping (A portion shown in FIG. 12: hereinafter referred to as “capping margin”). . Therefore, in order to consider such a capping margin, it is necessary to move the common ink chamber to the outside of the member (a direction perpendicular to the row direction formed by the plurality of nozzles and away from the plurality of nozzles). However, when the external dimensions of the inkjet head are reduced, there is a problem that the volume of the common ink chamber cannot be secured.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus that can solve the above-described problems and can reduce the size of an ink jet head while ensuring the volume of a common ink chamber.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, an inkjet recording apparatus according to claim 1 includes a nozzle plate having a plurality of nozzles that are open to the outside, and a plurality of nozzles for supplying ink to the nozzles corresponding to each of the nozzles. A base plate having a pressure chamber, and a manifold plate having a common ink chamber that is located between the base plate and the nozzle plate and distributes the ink from an ink supply source to the plurality of pressure chambers through ink supply holes. the inkjet head Ru provided by laminating an actuator, the comprising a plurality of pressure generating section that gives a pressure for ejecting the ink corresponding to each of the pressure chamber to the pressure chamber, so as to cover the plurality of nozzles And a cap that abuts against an opening surface of the nozzle of the inkjet head. In Kujetto recording apparatus, the common ink chamber in the ink-jet head, in the nozzle opening surface side of the plurality of pressure chambers, the overlap plurality of a portion of the pressure chamber in the stacking direction and the plurality nozzles The common ink chamber has a protrusion that protrudes from the wall surface in a direction parallel to the nozzle opening surface and is positioned in the vicinity of the position where the cap abuts. Is a scaffold for receiving the cap.
[0007]
According to the ink jet recording apparatus of the first aspect, the common ink chamber has a protrusion that protrudes from the wall surface in a direction parallel to the nozzle opening surface and that is located in the vicinity of the position where the cap abuts. And since the said projection part becomes a scaffold which receives a cap, even if it provides a common ink chamber in the position close enough to a nozzle row | line | column, it can be set as the structure which can endure a capping pressure. Therefore, it is possible to reduce the size of the inkjet head while securing the volume of the common ink chamber.
[0008]
The ink jet recording apparatus according to claim 2, wherein, in order to solve the problem, in the ink jet recording apparatus according to claim 1, the protrusion is streamlined with respect to an ink flow direction in the common ink chamber. It is characterized by being.
[0009]
According to the ink jet recording apparatus of the second aspect, since the protrusion is streamlined with respect to the ink flow direction in the common ink chamber, the ink can flow smoothly in the common ink chamber.
[0010]
In order to solve the above-described problem, in the ink jet recording apparatus according to claim 1 or 2, the ink jet recording apparatus according to claim 1 or 2 includes two common ink chambers across a row formed by the plurality of nozzles. The protrusions are symmetric with respect to a row formed by the plurality of nozzles.
[0011]
According to the ink jet recording apparatus of the third aspect, there are two common ink chambers across the row formed by the plurality of nozzles, and the protrusions are symmetrically arranged across the row formed by the plurality of nozzles. The part can be a stable cap scaffold.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.
[0013]
FIG. 1 is a perspective view showing an embodiment of a color ink jet printer as an ink jet recording apparatus of the present invention. In FIG. 1, the color inkjet printer 100 includes an ink cartridge 61 filled with, for example, four color inks of cyan, magenta, yellow, and black, and a piezoelectric inkjet head 6 for printing on paper 62. A head unit 63; a carriage 64 on which the ink cartridge 61 and the head unit 63 are mounted; a drive unit 65 that reciprocates the carriage 64 in a linear direction; and a piezoelectric inkjet head 6 that extends in the reciprocating direction of the carriage 64; A platen roller 66 and a purge device 67 that are arranged to face each other are provided.
[0014]
The drive unit 65 includes a carriage shaft 71 disposed at the lower end portion of the carriage 64 and extending in parallel with the pteran roller 66; a guide plate 72 disposed at the upper end portion of the carriage 64 and extending in parallel with the carriage shaft 71; Two pulleys 73 and 74 disposed between both ends of the carriage shaft 71 and the plate 72 are joined to an endless belt 75 spanned between the pulleys 73 and 74.
[0015]
When one pulley 73 is rotated in the forward and reverse directions by driving the motor 76, the carriage 64 joined to the endless belt 75 is moved along with the forward and reverse rotation of the pulley 73, and the carriage shaft 71 and the guide plate 72. And is reciprocated in a linear direction.
[0016]
The paper 62 is fed from a paper feed cassette (not shown) provided on the side of the ink jet printer 100, introduced between the piezoelectric ink jet head 6 and the platen roller 66, and discharged from the piezoelectric ink jet head 6. The predetermined printing is performed with the ink to be discharged, and then the paper is discharged. In FIG. 1, the paper feed mechanism and paper discharge mechanism for the paper 62 are not shown.
[0017]
The purge device 67 is provided on the side of the platen roller 66 and is disposed so as to face the piezoelectric inkjet head 6 when the head unit 63 is at the reset position. The purge device 67 includes a cap 81 that abuts against an opening surface of the nozzle so as to cover a plurality of nozzles to be described later of the piezoelectric inkjet head 6, a pump 82 and a cam 83, and an ink storage portion 84. When the head unit 63 is at the reset position, the nozzle of the piezoelectric ink jet head 6 is covered with the cap 81, and defective ink containing bubbles and the like accumulated inside the piezoelectric ink jet head 6 is pumped by driving the cam 83. The piezoelectric ink-jet head 6 is recovered by being suctioned by 82. As a result, it is possible to prevent ejection failure due to ink retention or bubble growth at the time of initial ink introduction. The sucked defective ink is stored in the ink storage unit 84.
[0018]
2, 3, and 4 are perspective views of the head unit 63. FIG. 5 is a bottom view of the head unit 63.
[0019]
As shown in FIG. 4, the head unit 63 mounted on the carriage 64 that runs along the paper 62 is formed in a substantially box shape with the upper surface open, and four ink cartridges 61 are detachably mounted from above. An ink supply passage 4a, 4b, 4c, 4d that can be connected to an ink discharge portion (not shown) of each ink cartridge 61 is provided at one side portion 3a of the mounting portion 3 in the head unit 63. The bottom plate 5 communicates with the lower surface of the bottom plate 5. Note that a rubber packing (not shown) is provided on the upper surface of one side portion 3a of the mounting portion 3 so as to be in close contact with an ink discharge portion (not shown) of each ink cartridge 61. .
[0020]
The bottom plate 5 is formed in a horizontal shape so as to protrude downward from the mounting portion 3, and as shown in FIGS. 3 and 5, two piezoelectric inkjet heads 6 are arranged in parallel on the lower surface side of the bottom plate 5. The two support portions 8 for arranging them are formed in a stepped shape. Each support portion 8 is formed with a plurality of cavities 9 a and 9 b for fixing with a UV adhesive so as to penetrate vertically.
[0021]
FIG. 6 is a perspective view of the piezoelectric inkjet head 6. FIG. 7 shows a cross-sectional view of the piezoelectric inkjet head 6. As shown in FIGS. 6 and 7, the piezoelectric inkjet head 6 includes a plurality of stacked cavity plates 10 and a plate type that is bonded to and stacked on the cavity plates 10 via an adhesive or an adhesive sheet. In order to make electrical connection between the piezoelectric actuator 20 and the upper surface of the piezoelectric actuator 20 and an external device, a flexible flat cable 40 is laminated and bonded with an adhesive, and is opened on the lower surface side of the lowermost cavity plate 10. Ink is ejected downward from the nozzle 15.
[0022]
FIG. 8 is an exploded perspective view of the cavity plate 10. FIG. 9 is an exploded perspective view of the cavity plate 10. As shown in FIG. 8, the cavity plate 10 has a structure in which five thin metal plates of a nozzle plate 11, two manifold plates 12, a spacer plate 13 and a base plate 14 are laminated and bonded together with an adhesive. is there. In the present embodiment, each of these plates 11 to 14 is made of 42% nickel alloy steel plate (42 alloy) and has a thickness of about 50 μm to 150 μm. Each of these plates 11 to 14 is not limited to metal, and may be formed of resin, for example.
[0023]
As shown in FIG. 9, a plurality of narrow pressure chambers 16 extending in a direction orthogonal to the longitudinal center lines 14a and 14b are formed in the base plate 14 in a staggered arrangement. The base plate 14 is provided with a throttle portion 16 d connected to each pressure chamber 16. Further, an ink supply hole 16b connected to the throttle portion 16d is formed. Each ink supply hole 16 b communicates with the common ink chamber 12 a in the manifold plate 12 through each ink supply hole 18 formed in both the left and right portions of the spacer plate 13. Here, the cross-sectional area perpendicular to the direction in which the ink flows in each throttle portion 16 d is smaller than the cross-sectional area in each pressure chamber 16. This is because the flow path resistance is increased by reducing the cross-sectional area of the throttle portion 16d.
[0024]
One end portion 16 a of each pressure chamber 16 has through holes 17 having a small diameter formed in the staggered arrangement of nozzles 15 in the nozzle plate 11 and similarly formed in the staggered arrangement of the spacer plate 13 and the two manifold plates 12. Communicated through.
[0025]
The base plate 14 and the spacer plate 13 are provided with ink supply holes 19b and 19a for supplying ink from the ink cartridge to the common ink chamber 12a in the manifold plate 12, respectively.
[0026]
As shown in FIG. 8, the two manifold plates 12 have two common ink chambers across a row formed by a plurality of nozzles 15 in the nozzle plate 11. The common ink chambers 12 a and 12 b are located in a plane parallel to the surface formed by the plurality of pressure chambers 16 in the base plate 14, and are closer to the opening surfaces of the plurality of nozzles 15 in the nozzle plate 11 than the plurality of pressure chambers 16. In addition, two manifold plates 12 are formed so as to extend long in the row direction formed by the plurality of nozzles 15.
[0027]
Further, the common ink chambers 12a and 12b have shapes in which their cross-sectional areas decrease at a constant rate in the direction away from the ink supply holes 19a and 19b at the ends (C portion) away from the ink supply holes 19a and 19b. is there. This is to make it easier to discharge residual bubbles that tend to collect at the end portions (C portion) of the common ink chambers 12a and 12b.
[0028]
Further, the common ink chambers 12a and 12b have protrusions 50 that protrude from the wall surfaces in a direction parallel to the opening surfaces of the plurality of nozzles 15 and that are located in the vicinity of the position where the cap 81 contacts. Although three protrusions 50 are shown in each common ink chamber 12a, 12b, only one protrusion 50 may be provided.
[0029]
FIG. 10 shows an enlarged view of the manifold plate 12 shown in FIG. As shown in FIG. 10, the common ink chambers 12 a and 12 b are present at positions where the capping margin is not taken into consideration with respect to the cap 81. Further, the protrusions 50 of the common ink chambers 12 a and 12 b exist symmetrically across the row formed by the plurality of nozzles 15 in the nozzle plate 11. When the head unit 63 is at the reset position, that is, when the cap 81 abuts against the opening surface of the nozzle 15 so as to cover the plurality of nozzles 15 in the nozzle plate 11, the protrusion 50 is provided in the cap 81. It will be a scaffold to receive.
[0030]
That is, the example of FIG. 10 shows a state in which the cap 81 is not displaced, but as described above, the cap 81 exists symmetrically across the row formed by the plurality of nozzles 15 due to assembly displacement or the like. The protrusion 50 serves as a scaffold for the cap 81 when it shifts to either the common ink chamber 12 a or 12 b. Therefore, the piezoelectric inkjet head 6 can be configured to withstand capping without considering the capping margin. In addition, since the protrusion 50 exists symmetrically across the rows formed by the plurality of nozzles 15 in the nozzle plate 11, the common ink chambers 12 a and 12 b exist symmetrically across the rows formed by the plurality of nozzles 15. Regardless of which of these, it becomes a stable scaffold.
[0031]
Further, as shown in FIG. 10, the shape of the protrusion 50 is streamlined with respect to the ink flow direction in the common ink chambers 12a and 12b. As a result, ink can flow smoothly in the common ink chambers 12a and 12b. Note that the protrusions 50 are only partially provided in the common ink chambers 12a and 12b, so that the volumes of the common ink chambers 12a and 12b can be sufficiently secured.
[0032]
The common ink chambers 12 a and 12 b are sealed by stacking the nozzle plate 11 and the spacer plate 13 on the two manifold plates 12.
[0033]
In the nozzle plate 11, a plurality of ink ejection nozzles 15 having a minute diameter (in this embodiment, about 25 μm) are spaced at a minute pitch P along the center lines 11 a and 11 b in the longitudinal direction of the nozzle plate 11. It is drilled in a staggered arrangement.
[0034]
With the configuration of the cavity plate 10 described above, the ink that has flowed into the common ink chambers 12a and 12b from the ink supply holes 19a and 19b formed at one end of the base plate 14 and the spacer plate 13 is transferred from the common ink chamber 12a to each ink. The ink is distributed to the pressure chambers 16 through the supply holes 18, the ink supply holes 16b, and the throttle portions 16d. Then, ink flows in the direction of the one end portion 16 a of each pressure chamber 16, passes through each through hole 17, and reaches the nozzle 15 corresponding to each pressure chamber 16.
[0035]
FIG. 11 is an exploded perspective view of the piezoelectric actuator 20. As shown in FIG. 11, the piezoelectric actuator 20 has a structure in which two piezoelectric sheets 21 and 22 and one insulating sheet 23 are laminated. On the upper surface of the lowermost piezoelectric sheet 21, a plurality of narrow drive electrodes 24 corresponding to the respective pressure chambers 16 in the cavity plate 10 are provided in a staggered arrangement. Further, one end 24 a of each drive electrode 24 is formed so as to be exposed on the left and right side surfaces 20 c orthogonal to the front and back surfaces 20 a and 20 b of the piezoelectric actuator 20.
[0036]
A common electrode 25 common to the plurality of pressure chambers 16 is provided on the upper surface of the piezoelectric sheet 22 at the next stage. Similarly to the one end portion 24a of each drive electrode 24, the one end portion 25a of the common electrode 25 is also formed so as to be exposed on the left and right side surfaces 20c. Each region in the piezoelectric sheet 22 sandwiched between each drive electrode 24 and the common electrode 25 becomes a pressure generating portion corresponding to each pressure chamber 16.
[0037]
On the upper surface of the uppermost insulating sheet 23, a surface electrode 26 for each of the drive electrodes 24 and a surface electrode 27 for the common electrode 25 are provided so as to be aligned along the left and right side surfaces 20c.
[0038]
The left and right side surfaces 20c are provided with a first recessed groove 30 at one end 24a of each drive electrode 24 and a second recessed groove 31 at one end 25a of the common electrode 25 so as to extend in the stacking direction. ing. As shown in FIG. 7, a side electrode 32 that electrically connects each drive electrode 24 and each surface electrode 26 is provided in each first recess groove 30, and a common electrode is provided in each second recess groove 31. Side electrodes 33 that electrically connect the electrode 25 and the surface electrode 27 are respectively formed. The electrodes 28 and 29 are discarded patterns.
[0039]
The cavity plate 10 and the piezoelectric actuator 20 configured as described above are stacked such that each pressure chamber 16 in the cavity plate 10 and the drive electrode 24 in the piezoelectric actuator 20 correspond to each other. Further, when the flexible flat cable 40 is pressed against the upper surface 20 a of the piezoelectric actuator 20, various wiring patterns (not shown) in the flexible flat cable 40 are electrically connected to the surface electrodes 26 and 27. Are joined together.
[0040]
In the configuration as described above, when the paper 62 is fed from a paper feed cassette (not shown) and introduced between the piezoelectric ink-jet head 6 and the platen roller 66, the carriage 64 is driven by the motor 76 to move the guide plate. Along the line 72, the position is moved from the reset position to a predetermined position.
[0041]
Then, by applying a voltage between any drive electrode 24 of each drive electrode 24 of the piezoelectric actuator 20 in the piezoelectric inkjet head 6 and the common electrode 25, the drive electrode to which the voltage is applied in the piezoelectric sheet 22. In the portion 24, that is, the pressure generating portion, distortion in the stacking direction due to piezoelectricity occurs. Then, the internal volume of the pressure chamber 16 corresponding to each drive electrode 24 is reduced by the pressure due to this distortion, so that the ink in the pressure chamber 16 is ejected from the nozzle 15 in the form of droplets, and the paper Predetermined printing on 23 is performed. Thus, the carriage 64 is reciprocated in the linear direction along the guide plate 72, and printing on the paper 23 is performed. When this is completed, the head unit 63 mounted on the carriage 64 returns to the reset position. The plurality of nozzles 16 of the piezoelectric inkjet head 6 are covered with the cap 81.
[0042]
As described above, according to the color ink jet printer 100 according to the present embodiment, the positions where the common ink chambers 12a and 12b protrude from the wall surfaces in the direction parallel to the opening surfaces of the plurality of nozzles 15 and the cap 81 contacts. Therefore, even if the cap 81 is displaced when the head unit 63 is in the reset position, the projection 50 serves as a scaffold for receiving the cap 81. Without considering the margin, the piezoelectric inkjet head 6 can be structured to withstand the capping pressure. Therefore, the piezoelectric inkjet head 6 can be reduced in size.
[0043]
The common ink chambers 12a and 12b in the manifold plate 12 according to the present embodiment can be formed by etching. However, when the manifold plate 12 is formed using resin, the common ink chambers 12a and 12b can be formed by pressing, shaping, or the like.
[0044]
Further, the shape and number of the protrusions 50 in the above embodiment are not limited to those shown in FIG. 11, and various improvements and modifications can be made without departing from the spirit of the present invention.
[0045]
In the above-described embodiment, the piezoelectric type is used for the pressure generating part in the piezoelectric actuator 20, but the present invention is not limited to this, and an electrostatic pressure generating part or the like may be used. .
[0046]
【The invention's effect】
As described above, according to the ink jet recording apparatus of the first aspect, the common ink chamber has the protruding portion that protrudes from the wall surface in the direction parallel to the nozzle opening surface and that is located near the position where the cap contacts. Since the protrusion is a scaffold for receiving the cap, the ink jet head can withstand the capping pressure even if the common ink chamber is provided at a position sufficiently close to the nozzle row. Therefore, it is possible to reduce the size of the inkjet head while securing the volume of the common ink chamber.
[0047]
According to the ink jet recording apparatus of the second aspect, since the protrusion is configured to be streamlined with respect to the ink flow direction in the common ink chamber, the ink can flow smoothly in the common ink chamber. .
[0048]
According to the ink jet recording apparatus of the third aspect, the common ink chamber is configured so that there are two across the row formed by the plurality of nozzles, and the protrusions are arranged symmetrically across the row formed by the plurality of nozzles. Therefore, the projection can be a stable cap scaffold.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a color ink jet printer as an ink jet recording apparatus of the present invention.
FIG. 2 is a perspective view with the nozzle side of the head unit facing up.
FIG. 3 is an exploded perspective view of components of the head unit.
FIG. 4 is an exploded perspective view of the components of the head unit as viewed from above the color inkjet printer.
FIG. 5 is a bottom view of the head unit as seen from the bottom surface side.
FIG. 6 is a perspective view of each component of the piezoelectric inkjet head.
FIG. 7 is a cross-sectional view of a piezoelectric inkjet head.
FIG. 8 is an exploded perspective view of a cavity plate.
FIG. 9 is an exploded enlarged perspective view of a cavity plate.
FIG. 10 is an enlarged top view of the manifold plate shown in FIG.
FIG. 11 is an exploded enlarged perspective view of a piezoelectric actuator.
FIG. 12 is an enlarged top view of a conventional manifold plate.
[Explanation of symbols]
4a, 4b, 4c, 4d Ink supply passage 5 Bottom plate 6 Piezoelectric inkjet head 10 Cavity plate 11 Nozzle plate 12 Manifold plate 12a, 12b Common ink chamber 13 Spacer plate 14 Base plate 15 Nozzle 16 Pressure chamber 16d Restriction section 18, 19b, 19a Ink supply hole 20 Piezoelectric actuator 21, 22 Piezoelectric sheet 23 Insulating sheet 24 Drive electrode 25 Common electrode 26, 27 Surface electrode 30, 31 Recessed groove 32, 33 Side electrode 40 Flexible flat cable 50 Projection 61 Ink cartridge 62 Paper 63 Head unit 64 Carriage 65 Drive unit 66 Platen roller 67 Purge device 71 Carriage shaft 72 Guide plate 73, 74 Pulley 75 Endless belt 76 Mo 81 cap 82 pump 83 cam 84 the ink reservoir 100 color ink jet printer

Claims (3)

A nozzle plate having a plurality of nozzles opened to the outside, a base plate having a plurality of pressure chambers for supplying ink to the nozzle corresponding to each of the nozzles, and a position between the base plate and the nozzle plate A manifold plate having a common ink chamber that distributes the ink from an ink supply source to the plurality of pressure chambers via an ink supply hole, and a pressure for ejecting the ink corresponding to each of the pressure chambers. the inkjet head and the actuator, the Ru includes by laminating with a plurality of pressure generating section that gives to the pressure chamber,
In an inkjet recording apparatus comprising: a cap that abuts against an opening surface of the nozzle of the inkjet head so as to cover the plurality of nozzles;
The common ink chamber in the inkjet head is substantially parallel to a row formed by the plurality of nozzles , overlapping a part of the plurality of pressure chambers in the stacking direction on the nozzle opening surface side of the plurality of pressure chambers. Located in
The common ink chamber has a protruding portion that protrudes from the wall surface in a direction parallel to the nozzle opening surface and is located in the vicinity of the position where the cap abuts, and the protruding portion serves as a scaffold for receiving the cap. An ink jet recording apparatus.   The inkjet recording apparatus according to claim 1, wherein the protrusion is streamlined with respect to an ink flow direction in the common ink chamber.   3. The common ink chamber includes two common ink chambers across a row formed by the plurality of nozzles, and the protrusions are symmetrically disposed across the row formed by the plurality of nozzles. Inkjet recording apparatus.

Images