JP2004284293A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head capable of preventing banding due to bi-directional printing and of surely supplying ink to an ink supply passage. <P>SOLUTION: Ink outlets and ink inlets 48 are provided at both ends of each of discrete fluid passage plate 52 and a head case 21 in the width direction (sub-scanning direction; direction of arrow B) to be arranged in the order of the ink outlets and the ink inlets 48C, 48M, 48Y, 48Y, 48M, 48C along a main scanning direction (direction of arrow A) of the recording head 11, and then the inks are supplied to the ink supply holes of the respective heads 12. The superposing of ink droplets to be ejected is made to be in the order of C, M, Y, Y, M, and C, and then the orders of ink droplets to be superposed are the same between inward movement and outward movement of the recording head so that the banding can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording head that performs printing by discharging color ink droplets onto a surface to be printed.
[0002]
[Prior art]
A so-called ink jet recording apparatus that discharges liquid or molten solid ink from nozzles, slits, porous films, etc., and prints on printing materials such as paper, cloth, film, etc. has various advantages such as small size, low cost, quietness, etc. There is. For this reason, recently, a large number of ink jet recording apparatuses for recording on report paper, copy paper, and the like are commercially available, and occupy a large position in the field of recording apparatuses.
[0003]
Above all, a piezo ink jet system that ejects ink droplets by changing the pressure in a pressure chamber using a piezoelectric element, and a thermal ink jet system that ejects ink droplets by expanding ink by the action of thermal energy, high-speed printing, It has many advantages such as high resolution.
[0004]
In these inkjet recording apparatuses, when an ink droplet is ejected from a nozzle in an inkjet recording head, the ink droplet adheres to the periphery of the nozzle, and ink leakage occurs due to an overshoot phenomenon in which the ink swells from the nozzle.
[0005]
For this reason, the ink ejection direction may be inclined, or the diameter and speed of the ink droplet may vary, which significantly reduces the printing performance of the ink jet recording head. In order to prevent ink droplets from adhering around the nozzles, a water-repellent film is applied to the nozzle surface.
[0006]
On the other hand, in an ink jet recording apparatus, improvement of recording speed in color printing is an important theme. As a method of improving the recording speed, in addition to increasing the length of the recording head, generally, the recording (driving) frequency of the recording head is improved, and bidirectional printing is performed.
[0007]
Compared with one-way printing, bi-directional printing is a method which is advantageous in terms of cost as a total system because required energy is dispersed when obtaining the same throughput.
[0008]
Here, in the case of bi-directional printing, the order of color ejection is Y (yellow) → M (magenta) → C (cyan) in the forward scan, and C (cyan) → M (magenta) → Y (yellow) in the backward scan. ). In the forward scan and the backward scan, the order in which the colors are applied is reversed, so that the color appearance is different, and there is a problem that so-called banding occurs as a printing result.
[0009]
For this reason, it is necessary to set the color arrangement of the print heads to Y, M, C, C, M, Y so that the driving order of each color is the same in both the forward scan and the backward scan.
[0010]
In Patent Literature 1, as shown in FIGS. 19 and 20, the ink supply unit 200 includes ink tanks 202Y, 202M, 202C, and 202B for Y (yellow), M (magenta), C (cyan), and B (black). It is composed of
[0011]
On the other hand, in the head case 204 accommodating the ink supply unit 200, a supply path 206 for each color is provided at the center of a direction perpendicular to the main scanning direction of the recording head 208 (hereinafter, referred to as “sub-scanning direction”: arrow direction). The ink in the ink tanks 202Y, 202M, 202C, and 202B is supplied respectively.
[0012]
The ink supplied from the supply path 206 passes through the individual ink supply paths 212Y, 212M, 212C, and 212B from the ink supply units 210Y, 210M, 210C, and 210B of the head 209 as a flow path plate constituting the recording head 208. It is configured to pass through and supply to the ejection units 214C, 214M, 214Y, 214B.
[0013]
However, when the supply path 206 is provided at the center of the recording head 208 in the sub-scanning direction, as shown in FIGS. In a suction operation of covering the nozzle 216 with the suction cap 218 and sucking ink into the nozzle 216, the amount of deflection of the head 209 is greatest at the center of the head 209.
[0014]
For this reason, in the connection part connecting the supply path 206 and the head 209, the force for separating the supply path 206 and the head 209 acts greatly, and the connection part may be peeled off. Accordingly, a case where ink is not supplied to the ink supply units 210Y, 210M, 210C, and 210B of the head 209 may occur.
[0015]
[Patent Document 1]
JP-A-2002-86730
[0016]
[Problems to be solved by the invention]
The present invention has been made in consideration of the above-described circumstances, and has as its object to provide an ink jet recording head that can prevent banding due to bidirectional printing and can reliably supply ink to an ink supply path.
[0017]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a flow path plate in which a plurality of nozzle groups arranged so that the overlapping order of ink droplets ejected in the forward scan and the backward scan are the same, A head case having an introduction port for holding and supplying ink to the flow path plate, an individual ink flow path attached to the head case and supplying ink to the introduction port, and provided in the individual ink flow path And a common supply port through which ink is supplied from the ink tank, wherein the introduction port is provided at both ends of the head case along a direction orthogonal to the main scanning direction of the inkjet recording head. The individual ink flow path is arranged, and among the common supply ports provided for each color, a first color individual ink supply path to which ink is supplied from a central first color common supply port. The first color individual ink supply path is formed on the same plane as the first color individual ink supply path, and ink is supplied from a second color common supply path outside the first color common supply port. A second color individual ink supply path extending outside of the first color common ink supply path, and a third color common ink supply path formed outside the first color common supply port and formed on the same plane as the second color individual ink supply path. And a third color individual ink supply path to which ink is supplied and which goes around the outside of the second color individual ink supply path.
[0018]
According to the first aspect of the present invention, for example, two sets of ink jet recording heads for each color are mounted on the head case so that the overlapping order of the ink droplets ejected in the forward scan and the backward scan of the ink jet print head is the same. I do.
[0019]
In this way, by making the overlapping order of the ink droplets ejected in the forward scan and the backward scan of the inkjet recording head the same, it is possible to prevent banding due to bidirectional printing.
[0020]
In addition, inlets for supplying ink to the flow path plate are provided at both ends of the head case along a direction (sub-scanning direction) orthogonal to the main scanning direction of the inkjet recording head. When the inlet is located at the center of the head case in the sub-scanning direction, the amount of flexure of the flow path plate in the recovery operation at the time of non-ejection and the suction operation of sucking ink in the nozzle when replacing the ink tank is The central part of the channel plate is the largest.
[0021]
For this reason, in the connecting part connecting the inlet and the flow path plate, a force for separating the inlet and the flow path plate is large, and the connecting part may be peeled off. Therefore, there may be a case where the ink is not supplied from the inlet of the head case to the ink supply port of the flow path plate.
[0022]
On the other hand, at both ends of the flow path plate, there is almost no amount of bending of the flow path plate, so that there is almost no force for separating the inlet from the flow path plate. Therefore, there is no possibility that the connection portion is peeled off, and the ink can be reliably supplied from the inlet of the head case to the ink supply port of the flow path plate.
[0023]
In addition, the head case is provided with an individual ink channel for supplying ink to the inlet, and the individual ink channel is provided with a common supply port through which ink is supplied from an ink tank.
[0024]
Here, the individual ink flow path is constituted by a first color individual ink supply path, a second color individual ink supply path, and a third color individual ink supply path, and the first color individual ink supply path is provided. The path is a supply path for supplying ink from the central first color common supply port among the common supply ports provided for each color.
[0025]
Further, the second color individual ink supply path is formed on the same plane as the first color individual ink supply path, and ink is supplied from outside the common supply port of the first color to form the first color individual ink supply path. The supply path goes around the outside of the supply path.
[0026]
Further, the third color individual ink supply path is formed on the same plane as the second color individual ink supply path, and ink is supplied from outside the common supply port of the first color to form the second color individual ink supply path. The supply path goes around the outside of the supply path.
[0027]
That is, the individual ink flow path is composed of the individual ink supply path of the first color, the individual ink supply path of the second color, and the individual ink supply path of the third color. , The second color individual ink supply path, and the third color individual ink supply path are provided so as not to cross each other.
[0028]
Thus, by providing the individual ink flow paths for three colors on the same plane, the individual ink flow paths are made thinner than in the case where the individual ink flow paths are provided for each plane corresponding to each color. can do. Also, the number of parts is small and the structure is simple.
[0029]
According to a second aspect of the present invention, the individual ink flow path is configured such that ink is supplied from a central first color common supply port among common supply ports provided for each color. And a second color individual ink formed on a different plane from the first color individual ink supply path and supplied with ink from a second color common supply path outside the first color common supply port. A supply path and a third color common supply path formed on a different plane from the first color individual ink supply path and the second color individual ink supply path and outside the first color common supply port. An ink jet recording head comprising: a third color individual ink supply path to which ink is supplied.
[0030]
According to the second aspect of the present invention, the individual ink flow path includes a first color individual ink supply path, a second color individual ink supply path, and a third color individual ink supply path. The individual ink supply path for one color is a supply path for supplying ink from the central common supply port among the common supply ports provided for each color.
[0031]
Further, the second color individual ink flow path is formed on a plane different from the first color individual ink supply path, and ink is supplied from the second color common supply path outside the first color common supply port. Supply route. Further, the third color individual ink flow path is formed on a different plane from the first color individual ink supply path and the second color individual ink supply path, and the third color outside the first color common supply port is formed. Is a supply path for supplying ink from the common supply path.
[0032]
That is, the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path are provided on different planes. In a case where three individual ink flow paths are provided on the same plane, the second color individual ink supply path is turned outside the first color individual ink supply path, and the second color individual ink supply path is turned outside the second color individual ink supply path. By rotating the third color individual ink supply path, the respective supply paths can be prevented from intersecting with each other.
[0033]
However, since the individual ink supply path for the second color and the individual ink supply path for the third color are formed outside the outlet through which the ink is introduced to the flow path plate, the individual ink flow path of the individual ink flow path is formed. The area becomes large.
[0034]
On the other hand, if the individual ink supply path for the first color, the individual ink supply path for the second color, and the individual ink supply path for the third color are provided on different planes, respectively, Therefore, the area of the individual ink flow path can be reduced, and the size of the ink jet recording head can be reduced.
[0035]
According to a third aspect of the present invention, the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path have a common supply port for each color and an introduction port for each color. Up to the same flow path length.
[0036]
According to the third aspect of the present invention, the flow from the common supply port of each color of the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path to the introduction port of each color. The road length is the same. By making the flow path length from the common supply port to the introduction port of each color the same, the time required from the common supply port to the introduction port is made substantially the same for each color, and the difference between the ink characteristics of each color is reduced.
[0037]
According to a fourth aspect of the present invention, the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path are provided with the central first color common supply port as an intersection. It is characterized in that the ink supply paths intersect when viewed through.
[0038]
According to the fourth aspect of the present invention, when the individual ink supply path for the first color, the individual ink supply path for the second color, and the individual ink supply path for the third color are viewed through, the common supply of the central first color is performed. The mouth intersects at the intersection.
[0039]
The invention according to claim 5 is characterized in that the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path are formed as straight lines. .
[0040]
According to the fifth aspect of the invention, the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path are formed by straight lines. When the individual ink supply path is meandering, stagnation occurs in the individual ink flow path, and the flow resistance increases.
[0041]
For this reason, by making the individual ink flow paths straight, stagnation portions can be eliminated and flow resistance can be reduced. In addition, since scale (red) is easily formed in the stagnation portion and causes clogging of the individual ink flow path, the clogging can be prevented by making the individual ink flow path straight.
[0042]
According to a sixth aspect of the present invention, the individual ink supply path for the first color, the individual ink supply path for the second color, and the individual ink supply path for the third color are formed on different planes to store ink. It is characterized by a possible ink pool.
[0043]
According to the sixth aspect of the present invention, the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path are formed on different planes, so that the ink can be stored. Has a pool.
[0044]
The individual ink supply path is formed by welding a pair of ribs facing each other on a plane to form a side wall of the individual ink supply path and closing the opening of the side wall with another plane. In the case of an ink pool for storing ink, the shape of the rib is simplified, so that the processing time is shortened and the cost can be reduced. Further, since the shape is simple, the defect rate due to poor welding can be reduced, and the yield can be improved.
[0045]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an inkjet recording apparatus 10 including a recording head according to an embodiment of the present invention. The inkjet recording apparatus 10 is provided with a carriage 15 that is moved by a main scanning mechanism 13 in the main scanning direction (the direction of arrow A).
[0046]
The recording head 11 is fixed to the carriage 15 as shown in FIGS. 2 and 3 (FIG. 2 is an explanatory diagram showing the positional relationship between the carriage 15 and the recording head 11). When moved in the main scanning direction, the head 12 as a flow path plate constituting the recording head 11 is conveyed in the sub-scanning direction (direction of arrow B) by the sub-scanning mechanism 17 (see FIG. 1) according to image information. Ink droplets are ejected onto the recording paper P to record an image on the entire surface of the recording paper P.
[0047]
Here, an outline of the head 12 will be described.
[0048]
As shown in FIGS. 4 and 5, the head 12 has a total of seven substantially rectangular plates including a nozzle plate 24, an ink pool plate 26, supply path plates 30 and 32, a pressure generation chamber plate 34, and a vibration plate 36. Are aligned and laminated, and joined by joining means such as an adhesive.
[0049]
The nozzle plate 24 is provided with a nozzle 24A for discharging ink, and the ink pool plate 26 is provided with a wall portion 28 projecting therein. The communication hole 16 communicating with the nozzle 24A is formed in the wall portion 28. Is formed. Further, supply holes 30A and 32A are formed in the supply path plates 30 and 32, respectively.
[0050]
The nozzle 24A, the communication hole 16, and the supply holes 30A and 32A communicate with the ink pool plate 26 and the supply path plates 30 and 32 being stacked, and are connected to the pressure generation chamber 14 formed in the pressure generation chamber plate 34. ing.
[0051]
On the other hand, an ink pool 20 is formed in the ink pool plate 26 between the wall portions 28, and the ink pool 20 is provided with ink from an ink inlet 48 of the head case 21 (see FIG. 3). The ink supplied via the supply port 50 (see FIG. 6) is stored.
[0052]
An opening 22 is formed in the supply path plate 30 so as to be connected to the ink pool 20. Further, a supply groove 18 is formed in the supply path plate 32, and the ink pool 20 and the pressure generating chamber 14 are communicated with the ink pool plate 26 and the supply path plates 30, 32 being stacked.
[0053]
A vibration plate 36 is laminated on the pressure generating chamber plate 34, and a single-plate type piezoelectric element 38 as a pressure generating means is mounted on the vibration plate 36 corresponding to the pressure generating chamber 14. It is connected to the flexible wiring board 42 via the solder 40.
[0054]
With such a configuration, when the driving voltage waveform is applied to the piezoelectric element 38, the vibration plate 36 bends and deforms together with the piezoelectric element 38 to pressurize the ink in the pressure generating chamber 14 and eject ink droplets from the nozzles 24A.
[0055]
Here, a water-repellent film (not shown) is formed on the surface (front surface) of the nozzle plate 24 on the side where the ink is ejected, and this water-repellent film prevents ink leakage around the nozzle 24A and the like. The ink droplet ejected from 24A is always ejected perpendicular to the nozzle plate 24.
[0056]
The material of the nozzle plate 24 is polyimide, and the material of the ink pool plate 26 and the supply path plates 30 and 32 is SUS.
[0057]
Next, the gist and operation of the inkjet recording head according to the first embodiment of the present invention will be described.
[0058]
As shown in FIGS. 2 and 3, the head case 21 has a box shape, and the head 12 is fixed to a lower end of the head case 21. On the other hand, a flange portion 21 </ b> A is formed at the upper end of the head case 21. The flange portion 21A protrudes outward from the peripheral wall of the head case 21, and is fixed in a state in which it contacts the peripheral portion of the insertion port 15A formed on the bottom surface of the carriage 15.
[0059]
On the upper surface of the flange portion 21A, an individual ink flow path plate 52 for guiding ink of each color to an ink inlet 48 (described later) formed in the head case 21 is fixed.
[0060]
Above the individual ink flow path plate 52, the ink tank 54C, the ink tank 54M, and the ink tank 54Y (C indicates cyan, M indicates magenta, and Y indicates yellow. The same applies to the following description). The common supply port 56C, the common supply port 56M corresponding to the ink tank 54C, the ink tank 54M, and the ink tank 54Y are arranged on the upper surface of the individual ink flow path plate 52 in the direction (arrow A direction). The supply port 56Y is formed along the main scanning direction.
[0061]
In the individual ink flow path plate 52, an individual ink supply path 58Y, an individual ink supply path 58M, and an individual ink supply path 58C through which each ink passes are provided, respectively, and a common supply port 56C, a common supply port 56M, a common supply port The ink supplied from the port 56Y is individually passed (described later).
[0062]
7A to 7C (note that FIG. 7A is a plan view, FIG. 7B is a front view, and FIG. 7C is a right side view). 8) and FIG. 8, an ink outlet 60 through which ink is drawn from the individual ink supply path 58Y, the individual ink supply path 58M, and the individual ink supply path 58C is provided.
[0063]
The ink outlets 60 are provided at both ends of the individual ink flow path plate 52 in the width direction (sub-scanning direction of the recording head 11: arrow B direction) along the main scanning direction of the recording head 11 (arrow A direction). The ink outlet port 60C, the ink outlet port 60M, the ink outlet port 60Y, the ink outlet port 60Y, the ink outlet port 60M, and the ink outlet port 60C are provided in this order, and the ink that has passed through the individual ink supply paths 58C, 58M, and 58Y is provided. Derived respectively.
[0064]
On the other hand, as shown in FIGS. 3 and 7, inside the peripheral wall of the head case 21, there are an ink outlet 60C, an ink outlet 60M, an ink outlet 60Y, an ink outlet 60Y, an ink outlet 60M, and an ink outlet. An ink inlet 48C, an ink inlet 48M, an ink inlet 48Y, an ink inlet 48Y, an ink inlet 48M, and an ink inlet 48C are provided corresponding to 60C, respectively.
[0065]
As shown in FIG. 6, from the ink inlet 48C, the ink inlet 48M, the ink inlet 48Y, the ink inlet 48Y, the ink inlet 48M, and the ink inlet 48C, the corresponding heads 12C, 12M, and 12Y are respectively provided. The ink is supplied to the ink supply port 50C, the ink supply port 50M, the ink supply port 50Y, the ink supply port 50Y, the ink supply port 50M, and the ink supply port 50C of the heads 12Y, 12M, and 12C.
[0066]
As a result, the overlapping order of the ejected ink droplets becomes C, M, Y, Y, M, and C, so that the overlapping order of the ink droplets in the forward scan and the backward scan of the recording head 11 is the same, and so-called banding is performed. It is preventing.
[0067]
In the present embodiment, as shown in FIG. 3, the ink inlets 48C, 48M, and 48Y are set at positions corresponding to both ends of the recording head 11 in the sub-scanning direction (direction of arrow B) in the main scanning direction (arrow A). Direction).
[0068]
For example, when the ink introduction ports 48C, 48M, and 48Y are provided at positions corresponding to the center of the recording head 11 in the sub-scanning direction, as shown in FIG. The amount of deflection of the recording head 208 (corresponding to the recording head 11) is greatest at the center of the recording head 208.
[0069]
For this reason, the connecting portion 220 that connects the supply path 206 (corresponding to the ink introduction ports 48C, 48M, and 48Y) and the print head 208 has a large force for separating the supply path 206 and the print head 208, and the connection section There is a risk that the 220 will be peeled off.
[0070]
On the other hand, both ends of the recording head 208 hardly bend. For this reason, as shown in FIGS. 9A and 9B, by providing the ink introduction ports 48 at positions corresponding to both ends of the recording head 11 in the sub-scanning direction, the ink introduction ports 48 are provided in the suction operation. There is hardly any force separating the head 12 from the head 12. Therefore, there is no possibility that the connection portion 49 is peeled off, and the ink can be reliably supplied from the ink introduction port 48 to the ink supply port 50 (see FIG. 6) of the head 12.
[0071]
On the other hand, as shown in FIG. 8, the individual ink supply path 58Y, the individual ink supply path 58M, and the individual ink supply path 58C are formed on the same plane 53 so as not to cross each other.
[0072]
Specifically, as shown in FIG. 3, the ink tank 54Y is disposed between the ink tank 54C and the ink tank 54M, and the common supply port 56Y is provided between the common supply port 56C and the common supply port 56M.
[0073]
Then, the individual ink supply path 58Y is formed in a U-shape, disposed at the center of the individual ink flow path plate 52, and supplies Y ink from the common supply port 56Y to the four ink outlet ports 60Y. The ink is guided.
[0074]
Further, the individual ink supply path 58M is formed in a U-shape, supplies M ink from the outside of the common supply port 56Y, turns to the outside of the individual ink supply path 58Y, and supplies four inks from the common supply port 56M. Each ink is guided to the outlet 60M.
[0075]
Further, the individual ink supply path 58C is formed in a U-shape, C ink is supplied from outside the common supply port 56Y, and the C ink is turned to the outside of the individual ink supply path 58M. Each ink is guided to the outlet 60C.
[0076]
Thus, by providing the individual ink supply paths 58Y, 58M, 58C for each color on the same plane 53, compared with the case where the individual ink supply paths 58Y, 58M, 58C are provided for each plane corresponding to each color. Thus, the thickness of the individual ink channel plate 52 can be reduced. Also, the number of parts is small and the structure is simple.
[0077]
Next, the gist and operation of the ink jet recording head according to the second embodiment of the present invention will be described. The description of the same contents as those in the first embodiment is omitted.
[0078]
As shown in FIGS. 10A to 10C (FIG. 10A is a plan view, FIG. 10B is a front view, and FIG. 10C is a right side view) and FIG. 62C is provided on the plane 64, the individual ink supply path 62M is provided on the plane 66, and the individual ink supply path 62Y is provided on the plane 68.
[0079]
As shown in FIGS. 7 and 8, when the individual ink supply paths 58C, 58M, and 58Y are provided on the same plane 53, the individual ink supply paths 58M are turned outside the individual ink supply paths 58Y, and By turning the individual ink supply paths 58C to the outside of the 58M, the individual ink supply paths 58C, 58M, 58Y can be prevented from intersecting with each other, but a part of the individual ink supply paths 58M, 58C It will be formed outside the outlets 60M and 60C.
[0080]
On the other hand, in the present embodiment, as shown in FIG. 11, the individual ink supply paths 62C, 62M, and 62Y are provided on different planes 64, 66, and 68, respectively. The individual ink supply paths 62C, 62M, and 62Y can be formed in the area of. Therefore, the area of the individual ink flow path plate 72 can be reduced, and the size of the recording head 11 (see FIG. 3) can be reduced.
[0081]
Next, the gist and operation of the ink jet recording head according to the third embodiment of the present invention will be described. The description of the same contents as in the second embodiment is omitted.
[0082]
As shown in FIGS. 12A to 12C (FIG. 12A is a plan view, FIG. 12B is a front view, and FIG. 12C is a right side view) and FIG. Are arranged at substantially the center of the individual ink flow path plate 76, the common supply port 74Y is arranged on the near side of the drawing, and the common supply port 74M is arranged on the back side of the drawing. The flow path lengths from the common supply ports 74C, 74M, and 74Y to the ink outlet ports 78C, 78M, and 78Y are the same.
[0083]
Here, in the individual ink supply passage 79M, the common supply port 74M is connected to the ink outlet port 78M on the near side in the drawing. ₁ Ink supply path up to 79M ₁ And ink supply port 78M on the back side of the drawing from ₂ Ink supply path up to 79M ₂ Are different (79M ₁ > 79M ₂ ).
[0084]
In the individual ink supply path 79Y, the ink supply port 78Y on the near side in the drawing is connected to the common supply port 74Y. ₁ Supply path 79Y up to ₁ From the common supply port 74Y to the ink outlet port 78Y on the back side of the drawing. ₂ Supply path 79Y up to ₂ Are different (79Y ₁ <79Y ₂ ).
[0085]
Therefore, the ink supply path 79Y ₁ And ink supply path 79M ₂ Meandering, and the ink supply path 79Y ₂ Alternatively, the ink supply path 79M ₁ To absorb the difference in distance. Thereby, the lengths of the respective flow paths from the common supply ports 74C, 74M, 74Y to the ink outlet ports 78C, 78M, 78Y are made substantially the same.
[0086]
In this way, by making the lengths of the respective flow paths substantially the same, the ink supply ports 78C, 78M (78M) from the common supply ports 74C, 74M, 74Y. ₁ , 78M ₂ ), 78Y (78Y ₁ , 78Y ₂ ) Can be made substantially the same for each color, and the difference in ink characteristics can be reduced.
[0087]
Next, the gist and operation of the inkjet recording head according to the fourth embodiment of the present invention will be described. The description of the same contents as in the third embodiment is omitted.
[0088]
14A to 14C (FIG. 14A is a plan view, FIG. 14B is a front view, and FIG. 14C is a right side view). When the supply path 80C, the individual ink supply path 80M, and the individual ink supply path 80Y are seen through, the individual ink supply path 80C is set at the intersection of the common supply port 84C arranged at the center of the individual ink flow path plate 82. ₁ And individual ink supply path 80C ₂ , Individual ink supply path 80M ₁ And individual ink supply path 80M ₂ , Individual ink supply path 80Y ₁ And individual ink supply path 80Y ₂ And cross each other.
[0089]
Accordingly, in the individual ink supply paths 80C, 80M, and 80Y, the respective flow path lengths from the common supply ports 84C, 84M, and 84Y to the ink outlet ports 86C, 86M, and 86Y are made equal, and the individual ink supply paths 80C ₁ , 80C ₂ , Individual ink supply path 80M ₁ , 80M ₂ , Individual ink supply path 80Y ₁ , 80Y ₂ Can be formed in a straight line.
[0090]
As shown in FIG. 12A, the ink supply path 79Y ₁ And ink supply path 79M ₂ Is meandered, the ink supply path 79Y ₁ And ink supply path 79M ₂ Inside, stagnation portions 88 are formed, and flow resistance increases.
[0091]
Therefore, even if the flow path lengths are the same, the passage time differs between a flow path formed in a straight line and a flow path formed in a meandering manner. Therefore, as shown in FIG. 14, by setting the individual ink supply paths 80C, 80M, and 80Y to be straight, the stagnation portion can be eliminated, the flow resistance can be reduced, and the respective passage times can be made substantially the same.
[0092]
Further, scale is easily formed in the stagnation portion 88 (see FIG. 12A), which may cause clogging of the individual ink supply passages 80M and 80Y. Therefore, the individual ink supply passages 80C, 80M and 80Y are linearly formed. By doing so, the clogging can be prevented.
[0093]
Next, the gist and operation of the inkjet recording head according to the fifth embodiment of the present invention will be described. The description of the same contents as in the second embodiment is omitted.
[0094]
As shown in FIGS. 16A to 16C (FIG. 14A is a plan view, FIG. 14B is a front view, and FIG. 14C is a right side view) and FIG. An individual ink pool 92Y is provided, an individual ink pool 92M is provided on a plane 94, and an individual ink pool 92C is provided on a plane 96.
[0095]
As shown in FIG. 18, the individual ink supply path 98 is formed by welding a pair of ribs 98A on a plane 100 to form side walls of the individual ink supply path 98 and closing the opening 98B of the rib 98A with another plane 102. However, as shown in FIG. 17, when the individual ink supply paths are the individual ink pools 92Y, 92M, and 92C for storing the ink, the shape of the rib is simplified, so that the processing time is shortened, and the cost is reduced. Down can be planned. Further, since the shape is simple, the defect rate due to poor welding can be reduced, and the yield can be improved.
[0096]
In the present embodiment, the droplet is ejected by the pressure generated by the deformation of the piezoelectric actuator. However, an electromechanical transducer using an electrostatic force or a magnetic force, or a device for generating a pressure using a boiling phenomenon is used. Energy for discharging the droplet may be obtained by using another pressure generating means such as an electrothermal conversion element.
[0097]
Further, as the piezoelectric actuator, in addition to the single-plate type piezoelectric actuator used in the present embodiment, another type of actuator such as a vertical vibration type laminated piezoelectric actuator may be used.
[0098]
Further, in the present embodiment, the flow path is formed by laminating a plurality of plates, but the configuration, material, and the like of the plates are not limited to the above-described embodiments. For example, the present invention is similarly applicable to a head in which a flow path is integrally formed using a material such as ceramics, glass, resin, or silicon.
[0099]
Further, in the present embodiment, an ink jet recording head and an ink jet recording apparatus for recording characters and images by ejecting ink droplets on the recording paper P have been described as an example. However, the present invention is not limited to this. That is, the recording medium is not limited to paper, and the ejected liquid is not limited to ink.
[0100]
For example, it is necessary to discharge ink on a polymer film or glass to create a color filter for display, or to form a bump for component mounting by discharging molten solder onto a substrate. The present invention can be applied to the general droplet ejecting apparatus used for the present invention.
[0101]
【The invention's effect】
According to the first aspect of the present invention, the overlapping order of the ink droplets ejected in the forward scan and the backward scan of the ink jet recording head is made the same to prevent banding by bidirectional printing. can do. In addition, by providing inlets at both ends of the head case along a direction (sub-scanning direction) orthogonal to the main scanning direction of the inkjet recording head, the connection between the inlet and the flow path plate is pulled during the suction operation. There is no possibility of peeling, and the ink can be reliably supplied from the introduction port to the ink supply port of the flow path plate.
[0102]
Furthermore, by providing individual ink flow paths for three colors on the same plane, the individual ink flow paths can be made thinner than when individual ink flow paths are provided for each plane corresponding to each color. Can be. Also, the number of parts is small and the structure is simple.
[0103]
According to the second aspect of the invention, when the first color individual ink supply path, the second color individual ink supply path, and the third color individual ink supply path are provided on different planes, respectively, Since each supply path can be formed in the inner area, the area of the individual ink flow path can be reduced, and the size of the inkjet recording head can be reduced.
[0104]
According to the third aspect of the invention, by making the flow path length from the common supply port to the introduction port of each color the same, the time required from the common supply port to the introduction port is made substantially the same for each color, and the ink characteristics of each color are changed. To reduce the difference.
[0105]
According to the fourth aspect of the present invention, when the individual ink supply path for the first color, the individual ink supply path for the second color, and the individual ink supply path for the third color are viewed through, the common supply of the central first color is performed. The mouth intersects at the intersection.
[0106]
According to the fifth aspect of the invention, since the individual ink flow paths are straight, the stagnation portion can be eliminated, and the flow resistance can be reduced. In addition, since scale (red) is easily formed in the stagnation portion and causes clogging of the individual ink flow path, the clogging can be prevented by making the individual ink flow path straight.
[0107]
According to the sixth aspect of the invention, since the individual ink supply path is an ink pool for storing ink, the processing time can be shortened, and the cost can be reduced. Further, since the shape of the ink pool is simple, the defect rate due to poor welding can be reduced, and the yield can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an inkjet recording apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an arrangement of a recording head and a carriage according to the first embodiment of the present invention.
FIG. 3 is a perspective view showing a head case and an individual flow path plate constituting the recording head according to the first embodiment of the present invention.
FIG. 4 is a perspective view showing a head constituting the recording head according to the embodiment of the present invention.
FIG. 5 is a cross-sectional view illustrating a head constituting the recording head according to the embodiment of the invention.
FIG. 6 is a plan view showing a head constituting the recording head according to the embodiment of the present invention.
FIG. 7A is a plan view, FIG. 7B is a front view, and FIG. 7C is a right side view showing an individual flow path plate constituting the recording head according to the first embodiment of the present invention.
FIG. 8 is an exploded perspective view showing the individual flow channel plate of FIG. 7;
FIGS. 9A and 9B show a state in which the head constituting the recording head according to the embodiment of the present invention is being sucked.
FIG. 10A is a plan view, FIG. 10B is a front view, and FIG. 10C is a right side view showing an individual flow path plate constituting the recording head according to the second embodiment of the present invention.
FIG. 11 is an exploded perspective view showing the individual flow channel plate of FIG.
12A is a plan view, FIG. 12B is a front view, and FIG. 12C is a right side view showing an individual flow path plate constituting a recording head according to a third embodiment of the present invention.
FIG. 13 is an exploded perspective view showing the individual flow channel plate of FIG.
14A is a plan view, FIG. 14B is a front view, and FIG. 14C is a right side view showing an individual channel plate constituting a recording head according to a fourth embodiment of the present invention.
FIG. 15 is an exploded perspective view showing the individual flow channel plate of FIG.
16A is a plan view, FIG. 16B is a front view, and FIG. 16C is a right side view showing an individual flow path plate constituting a recording head according to a fifth embodiment of the present invention.
FIG. 17 is an exploded perspective view showing the individual flow channel plate of FIG.
FIG. 18 is an explanatory view showing a procedure for manufacturing an individual flow path plate.
FIG. 19 is an exploded perspective view showing a conventional recording head and an ink tank.
FIG. 20 is a plan view showing a head constituting a conventional recording head.
FIGS. 21A and 21B show a state in which a conventional head is sucked.
[Explanation of symbols]
10 Inkjet recording device
11 Recording head
12 heads (recording head, flow path plate)
21 Head case (recording head)
52 Individual ink channel plate (recording head, individual ink channel)
56C common supply port (recording head, first color common supply path)
56M common supply port (recording head, second color common supply path)
56Y common supply port (print head, third color common supply path)
58Y individual ink supply path (first color individual ink supply path)
58M individual ink supply path (second color individual ink supply path)
58C individual ink supply path (third color individual ink supply path)
62Y individual ink supply path (first color individual ink supply path)
62M individual ink supply path (second color individual ink supply path)
62C Individual ink supply path (third color individual ink supply path)
72 Individual ink channel plate (recording head, individual ink channel)
74C common supply port (recording head, first color common supply path)
74M common supply port (print head, second color common supply path)
74Y common supply port (recording head, third color common supply path)
76 Individual ink channel plate (recording head, individual ink channel)
79C Individual ink supply path (first color individual ink supply path)
79M individual ink supply path (second color individual ink supply path)
79Y individual ink supply path (third color individual ink supply path)
80C Individual ink supply path (first color individual ink supply path)
80M individual ink supply path (second color individual ink supply path)
80Y individual ink supply path (third color individual ink supply path)
82 Individual ink channel plate (recording head, individual ink channel)
84C common supply port (recording head, first color common supply path)
84M common supply port (recording head, second color common supply path)
84Y common supply port (recording head, third color common supply path)
92Y individual ink pool
92M individual ink pool
92C Individual ink pool

Claims (6)

A flow path plate formed with a plurality of nozzle groups arranged so that the overlapping order of the ink droplets ejected in the forward scan and the backward scan is the same,
A head case holding the flow path plate, and having an inlet for supplying ink to the flow path plate,
An individual ink flow path attached to the head case and supplying ink to the introduction port,
A common supply port provided in the individual ink flow path and supplied with ink from an ink tank;
In an ink jet recording head having
The introduction ports are arranged at both ends of the head case along a direction orthogonal to the main scanning direction of the inkjet recording head,
The individual ink flow path,
A first color individual ink supply path to which ink is supplied from a central first color common supply port among common supply ports provided for each color;
The first color individual ink supply path is formed on the same plane as the first color individual ink supply path, and ink is supplied from a second color common supply port outside the first color common supply port. A second color individual ink supply path that goes around the outside of the
The second color individual ink supply path is formed on the same plane as the second color individual ink supply path, and is supplied with ink from a third color common supply path outside the first color common supply port. A third color individual ink supply path around the outside of the
An ink jet recording head comprising: A flow path plate formed with a plurality of nozzle groups arranged so that the overlapping order of the ink droplets ejected in the forward scan and the backward scan is the same,
A head case holding the flow path plate, and having an inlet for supplying ink to the flow path plate,
An individual ink flow path attached to the head case and supplying ink to the introduction port,
A common supply port provided in the individual ink flow path and supplied with ink from an ink tank;
In an ink jet recording head having
The introduction ports are arranged at both ends of the head case along a direction orthogonal to the main scanning direction of the inkjet recording head,
The individual ink flow path,
A first color individual ink supply path to which ink is supplied from a central first color common supply port among common supply ports provided for each color;
A second color individual ink supply path formed on a different plane from the first color individual ink supply path and supplied with ink from a second color common supply path outside the first color common supply port; ,
The ink is supplied from a third color common supply path formed on a plane different from the first color individual ink supply path and the second color individual ink supply path and outside the first color common supply port. A third color individual ink supply path;
An ink jet recording head comprising: The first ink channel, the second ink channel, and the third ink channel have the same channel length from the common supply port of each color to the introduction port of each color. 3. The ink jet recording head according to claim 2, wherein: When the central first supply port of the first color is an intersection, the individual ink supply path of the first color, the individual ink supply path of the second color, and the individual ink supply path of the third color are viewed through. The inkjet recording head according to claim 2, wherein the inkjet recording heads intersect. The inkjet according to claim 3, wherein the individual ink supply path for the first color, the individual ink supply path for the second color, and the individual ink supply path for the third color are formed in a straight line. Recording head. The individual ink supply path for the first color, the individual ink supply path for the second color, and the individual ink supply path for the third color are formed on different planes to form an ink pool capable of storing ink. 3. The ink jet recording head according to claim 2, wherein:

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