JP2002361892A - Ink supply unit, recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fill each pressure liquid chamber with ink uniformly and stably while shortening the filling time even if the number of nozzles is increased. SOLUTION: An ink supply channel 18 interconnecting an ink reservoir tank 2 and a common liquid chamber 15 comprises a master channel 20 being coupled with the ink reservoir tank 2 and 2M (M=1-i) systems of slave channel 21 being coupled with the common liquid chamber 15. The 2M (M=1-i) systems of slave channel 21 are formed by repeating the operation for branching the master channel 20 into two systems of slave channel 21 mirror symmetric to a plane including an axis obtained by connecting the center of cross-section of the master channels 20. A channel of constant length is formed from the branch part of a new master channel 20 to the forward end part being coupled with the common liquid chamber 15 and ink is supplied from the ink supply channel 18 to the common liquid chamber 15 while being distributed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply apparatus for supplying ink to a recording head of an ink jet recording apparatus, a recording head, and an ink jet recording apparatus.

[0002]

2. Description of the Related Art Recording head 3 of an ink jet recording apparatus
Has a plurality of pressurized liquid chambers 13 having nozzles 12 as shown in a plan sectional view of FIG. 12A and a side sectional view of FIG. The ink in the pressurized liquid chamber 13 is ejected from the nozzle 12 by changing the pressure of the ink, and printing is performed on recording paper or the like. The pressurized liquid chamber 12 is filled with ink from a common liquid chamber 15 via a fluid resistance path 16. The common liquid chamber 15 is provided with one connection hole 19 connected to the ink supply flow path 18 between the ink reservoir tank 2 and the common liquid chamber 15 through the ink supply flow path 18 and the connection hole 19 from the ink reservoir tank 2. Is supplied to the ink.

When the ink reservoir tank 2 is replaced, if air bubbles enter the ink supply flow path 18 connecting the common liquid chamber 15, the fluid resistance partially increases and the supply of ink to the common liquid chamber 15 is hindered. In addition, as described in Japanese Patent Application Laid-Open No. 9-207354, for example, an ink discharge path for branching the ink supply flow path 18 and discharging bubbles to the outside is provided, as shown in Japanese Patent Application Laid-Open No. 9-207354. The switching section of the branch section is switched to remove bubbles in the ink supply flow path 18 to keep the ink flow constant.

[0004]

When filling the plurality of pressurized liquid chambers 13 with the ink supplied to the common liquid chamber 15,
It is desirable to fill each pressurized liquid chamber 13 with ink evenly. However, as described above, if one connection hole 19 for connecting to the ink reservoir tank 2 is provided in the common liquid chamber 15 and ink is supplied from the ink reservoir tank 2 to the common liquid chamber 15, The time at which the ink flowing into the liquid chamber 15 reaches the plurality of pressurized liquid chambers 13 from the common liquid chamber 15 is not constant, and the time at which the ink reaches the pressurized liquid chamber 13 located at a position away from the connection hole 19. Is the connection hole 19
It is later than the time when the ink reaches the pressurized liquid chamber 13 close to the pressure. This ink arrival time difference increases as the number of pressurized liquid chambers 13 increases, and there is a disadvantage that the ink filling conditions for each pressurized liquid chamber 13 are different.

After the ink is saturated in each of the fluid resistance paths 16 and the pressurized liquid chamber 13, the supply of the ink to the common liquid chamber 15 is continued for a certain period of time. 12 to be discharged. This pressurized liquid chamber 1
In the step of discharging bubbles remaining in the third liquid chamber 3, the common liquid chamber 15
The flow velocity of the ink flowing in the inside decreases as the distance from the connection hole 19 increases. For this reason, the flow rate of the ink flowing into the pressurized liquid chamber 13 distant from the connection hole 19 is also reduced, and there is a disadvantage that the discharge performance of the bubbles in the pressurized liquid chamber 13 is reduced.

In recent years, high-density recording and high-speed printing have been demanded.
To cope with this, the number of nozzles 12, that is, the number of pressurized liquid chambers 13 tends to increase. Thus, the pressurized liquid chamber 1
As the number of 3 increases, the time for filling each pressurized liquid chamber 13 with ink becomes longer, and in some cases, there is a possibility that a pressurized liquid chamber in which the ink cannot be reliably filled may occur, and the above-mentioned disadvantages become significant. .

According to the present invention, there is provided an ink supply system capable of uniformly and stably filling each pressurized liquid chamber with ink even if the number of nozzles is increased, and shortening the filling time. It is an object of the present invention to provide an apparatus, a recording head capable of ejecting ink from each nozzle with stable ejection characteristics, and an ink jet recording apparatus.

[0008]

An ink supply device according to the present invention comprises a plurality of pressurized liquid chambers, pressure applying means, and a common liquid chamber for filling the pressurized liquid chamber with ink via a fluid resistance path. An ink reservoir for storing a common liquid chamber of a recording head for storing ink on the recording head by applying a volume change to the ink in the pressurized liquid chamber by the pressure applying means and ejecting the ink in the pressurized liquid chamber from a nozzle to print on recording paper or the like In an ink supply device provided between the ink reservoir tank and the ink reservoir tank to supply ink from the ink reservoir tank to the common liquid chamber, an ink supply flow path communicating the ink reservoir tank with the common liquid chamber is provided in a main stream connected to the ink reservoir tank. And the 2M system connected to the common liquid chamber (M =
1M to 1M), and the 2M-system (M = 1 to i) child flow paths are mirror-image-symmetric with respect to a plane including an axis obtained by connecting the flow path cross-sectional centers of the parent flow paths. It is constituted by repeating branching into two sub-flow paths, and the flow path length from the branch part of the main flow path to the leading end connected to the common liquid chamber is formed to be constant.

The cross-sectional area S2 of the two sub-flow paths branched from the main flow path of the ink supply flow path satisfies the relationship of 2 · S2 ≦ S1 with respect to the cross-sectional area S1 of the main flow path. It is preferable that the cross-sectional area Sn of the two sub-flow paths branched from the sub-path satisfy the relationship of 2 · Sn ≦ S (n−1) with respect to the cross-sectional area S (n−1) of the sub-flow path before branching.

It is desirable that each branch of the ink supply flow path is formed with a smooth curved surface.

Further, the shape of the ink outlet for the common liquid chamber of the ink supply flow path is formed to be widened in the direction in which the ink flows, and the spread angle θ is determined by setting the number of pressurized liquid chambers to N and the common liquid chamber to the common liquid chamber. When the number of connected sub flow paths is M, the pitch of the pressurized liquid chamber corresponding to 1 bit is W, and the shortest distance from the ink outlet to the position where the fluid resistance path is provided is L, θ> It is desirable to satisfy the relationship of tan ^-1 {(N * W / M / 2) / L}.

It is preferable that the ink supply channel is formed by forming a groove in the photosensitive film. In addition, it is preferable to form a sub flow path that is sequentially branched from the main flow path by forming grooves in different photosensitive films, and stack and bond the grooved photosensitive films to form an ink supply flow path.

A groove forming a part of the parent flow path is provided in the photosensitive film having a groove forming a child flow path branched from the parent flow path so as to communicate with the groove forming the child flow path. It is preferable that a photosensitive film having a groove forming a sub flow path branching from the flow path be provided so as to communicate with a groove forming a sub flow path branching a groove forming a part of the previous sub flow path.

Further, a reinforcing plate composed of one or a plurality of high-rigidity members is arranged between the plurality of photosensitive films to be laminated,
It is preferable that the reinforcing plate is provided with through holes communicating with the grooves of the upper and lower photosensitive films.

A recording head according to the present invention is characterized in that a part of the wall surface of the common liquid chamber is constituted by the ink supply device.

An ink jet recording apparatus according to the present invention is characterized in that it has a recording head which forms a part of a wall surface of a common liquid chamber by an ink supply device, and an ink reservoir tank connected to the ink supply device.

[0017]

FIG. 1 is a block diagram of an ink jet printer according to the present invention. As shown in the figure, the ink jet printer 1 has four ink reservoir tanks 2 containing inks of respective colors of cyan C, magenta M, yellow Y and black Bk, and a plurality of nozzles. Four recording heads 3 to which ink is supplied, a carriage 4 on which the ink reservoir tank 2 and the recording head 3 are mounted, and a paper feed tray 5 for storing recording paper
a, 5b, paper feed trays 5a, 5b,
And a discharge roller 10 for discharging the printed recording paper to a paper output tray 9. When printing the image data sent from the host device on the recording paper, the carriage 4 scans along the carriage guide roller 11 while the nozzles of the recording head 3 print on the recording paper sent to the printing unit 7 by the transport rollers 8. And ejects ink according to the image data to record characters and images.

The recording head 3 has a plurality of pressurized liquid chambers 13 having nozzles 12 as shown in a plan sectional view of FIG. 2A and a side sectional view of FIG. The ink in the pressurized liquid chamber 13 is ejected from the nozzles 12 by changing the pressure of the ink in the pressurized liquid chamber 13 to print on recording paper or the like. The pressurized liquid chamber 12 is filled with ink from a common liquid chamber 15 via a fluid resistance path 16. The common liquid chamber 15 has 2M (M = 1 to i) connection holes 19, such as two or four, connected to the ink supply flow path 18 between the ink reservoir tank 2 and the common liquid chamber 15.
Are provided at equal intervals, and ink is supplied from the ink reservoir tank 2 to the common liquid chamber 15 through the ink supply flow path 18 and the connection hole 19.

As shown in FIG. 3, an ink supply flow path 18 connecting the ink reservoir tank 2 and the common liquid chamber 15 of the recording head 3 has a main flow path 20 connected to the ink reservoir tank 2 and a main flow path 20. It has a sub flow path 21 branched from the path 20 and connected to the common liquid chamber 15. The sub flow path 21 is formed according to the number of connection holes 19 provided in the common liquid chamber 15 as shown in FIG.
As shown in (2), two sub-flow paths 21a obtained by branching the main flow path 20 once, or as shown in (b). There are provided 2M sub-channels (M = 1 to i) such as four sub-channels 21b obtained by further branching the two sub-channels 21a into two sub-channels. The two or four sub flow paths 182 are provided mirror-symmetrically with respect to a plane including an axis obtained by connecting the center of the flow path cross section of the main flow path 20. The length of the flow path up to the distal end connected to the connection hole 19 of the chamber 15 is formed to be constant. Also, as shown in FIG.
The cross-sectional area S2 of the two sub-flow paths 21a obtained by branching the main flow path 20 once is 2 · S2 with respect to the cross-sectional area S1 of the main flow path 20.
<S1. In addition, two branched sub flow paths 2
The cross-sectional area S3 of the four sub-channels 21b obtained by branching 1a into two sub-systems is 2 · S3 ≦ the cross-sectional area S2 of the sub-channel 21.
There is a relationship of S2.

As described above, the sub flow paths 21 a and 21 b are provided symmetrically with respect to the main flow path 20, and the flow path from the branch portion of the main flow path 20 to the leading end connected to the connection hole 19 of the common liquid chamber 15 is provided. By making the length constant and the cross-sectional area of each of the sub flow paths 21a and 21b constant, the fluid resistance of each of the sub flow paths 21a and 21b can be made constant. The flow rate and the flow rate of the ink flowing into each of the 15 connection holes 19 can be made constant, and the ink having a constant flow rate and a constant flow rate can be dispersed and supplied to the common liquid chamber 15.

For example, as shown in FIG. 5, the main flow path 20 is branched into three sub-flow paths 21 so that each sub-flow path 21a
In order to keep the fluid resistance of the
It is necessary to change the flow path length or the cross-sectional area from the branch portion 1a to the front end connected to the connection hole 19 of the common liquid chamber 15, and the structure of the ink supply flow path 18 becomes complicated.
By providing a and 21b symmetrically with respect to the main flow path 20, the fluid resistance of each of the sub flow paths 21a and 21b can be made constant with a simple structure.

The cross-sectional area S2 of the two sub-flow paths 21a obtained by branching the main flow path 20 once is changed to the cross-sectional area S1 of the main flow path 20.
The relationship of 2 · S2 ≦ S1 is satisfied, and the two sub-channels 21a are divided into two sub-channels 21a.
b with respect to the cross-sectional area S2 of the sub flow path 21
By setting the relationship of 2 · S3 ≦ S2, each sub flow path 21
The ink can flow without decreasing the flow velocity of the ink flowing through the main flow path 20 at a and 21b, and the ink can be supplied to the common liquid chamber 15 at substantially the same flow velocity as the initial flow velocity flowing through the main flow path 20. As a result, the efficiency of ink supply to the common liquid chamber 15 can be improved.

Further, since the ink is supplied to the common liquid chamber 15 at a constant flow rate and a constant flow rate from the connection holes 19 provided at a constant interval, a multi-bit pressurized liquid is formed for high-density recording and high-speed printing. Even if the number of the chambers 13 increases, the connection holes 1
There is no large difference in the distance from the pressure chamber 9 to each of the pressurized liquid chambers 13, and the flow rate, the inflow pressure, and the arrival time of the ink supplied to the common liquid chamber 15 and reaching each of the pressurized liquid chambers 13 are made substantially constant. Accordingly, the amount of ink to be filled in each pressurized liquid chamber 13 can be made substantially uniform, and the uneven filling of the pressurized liquid chamber 13 can be reduced.

In order to further increase the efficiency of ink supply to the supply liquid chamber 15, the main flow path 20 and each sub flow path 21
By performing the water-repellent treatment on the inner walls of the a and 21b, the fluid resistance of the ink supply channel 18 can be further reduced.
Also, as shown in FIG. 6, by forming each branch portion of the ink supply flow path 18 with a smooth curved surface, the density of stream lines of the ink flowing in the ink supply flow path 18 is made uniform, and the flow of the ink is stopped. And vortices can be prevented from occurring, and bubbles can be prevented from increasing in each branch portion to increase the fluid resistance, and the ink can be stably supplied from the ink supply channel 18 to the common liquid chamber 15. Can be supplied.

In order to fill the pressurized liquid chambers 13 with the ink distributed and supplied from the ink supply flow path 18 to the common liquid chambers 15 almost uniformly, the common liquid chambers 15 are filled. It is necessary to appropriately determine the shape of the ink outlet of each sub flow path 21 connected to each connection hole 19. Therefore, when the number of the pressurized liquid chambers 13 is N and the number of the sub flow paths 21 connected to the common liquid chamber 15 is M, the number M of the sub flow paths 21 connected to the common liquid chamber 15 is added. The number of the pressure liquid chambers 13 is made smaller than the number N, and as shown in FIG. 7, the shape of the ink outlet 22 of each sub flow path 21 is expanded in the direction in which the ink flows out, and the pressure liquid chamber corresponding to 1 bit is formed. 13 pitch and is W, the shortest distance from the ink outlet port 22 to a position where fluid resistance path 16 is provided when is L, the divergence angle theta of the ink outlet port ^{22, θ> tan -1 {(} N * W / M / 2) / L｝.

That is, the number M of the sub-flow paths 21 connected to the common liquid chamber 15 is equal to or larger than the number N of the pressurized liquid chambers 13, and one or more ink outlets 22 are provided in each pressurized liquid chamber 13. Although the ink dispersion supply effect is saturated and the configuration becomes complicated, the number M of the sub flow paths 21 connected to the common liquid chamber 15 is reduced by the pressure liquid chamber 13 to prevent this adverse effect. Is preferably smaller than the number N. Also, the spread angle θ of the ink outlet 22
Is regulated as described above, the ink can radially flow out from the ink outlet 22 and can be evenly sent to the inlet of the fluid resistance path 16 connected to each pressurized liquid chamber 13.

Further, in order to prevent air bubbles from entering the ink supply flow path 18, a filter is provided in the ink reservoir tank 2 of the ink supply flow path 18, or a master flow path 20 is provided.
May be provided with a branch path for opening to the atmosphere.

Next, a description will be given of a method of manufacturing an ink supply apparatus having the ink supply flow path 18 having four sub-flow paths 21b branched from the main flow path 20.

As shown in FIG. 8, for example, the ink supply device 23 includes a top plate 30 and three flow path plates 31, 32, 33.
And a bottom plate 34. A connection hole 35 connected to the ink reservoir tank 2 is provided through the top plate 30, and a straight parent flow channel 36 connected to the connection hole 35 of the top plate 30 is provided through the flow passage plate 31. Have been. A U-shaped first branch groove 37 whose center communicates with the parent flow channel 36 is formed in the flow channel plate 32.
The flow path plate 33 is provided with two second branch grooves 38, each having a central portion communicating with the tip of the first branch groove 37, and the bottom plate 34 is provided with a second branch groove 38. The four connection holes 39 communicating with the tip of the branch groove 38 and connecting to the common liquid chamber 15 are provided at equal intervals.

Usually, the pressurized liquid chamber 13 and the common liquid chamber 15 of the recording head 3 are formed by etching a single crystal silicon substrate. The direction of the plane obtained by etching the silicon substrate is defined by the crystal plane orientation. This single-crystal silicon substrate is divided into a top plate 30 and flow path plates 31, 32, 33.
When the connection hole 35, the branch grooves 37, 38, and the connection hole 39 are formed by etching using the base plate 34 and the bottom plate 34, it is difficult to form all the inner wall surfaces with a continuous smooth surface. Therefore, the top plate 30, the flow path plates 31, 32, 33 and the bottom plate 3
A photosensitive film is used for 4 and the inner walls of the connection hole 35, the branch grooves 37 and 38, and the connection hole 39 are made smooth by performing hole processing and groove processing. Further, by forming the connection holes 35 and the like by hole processing and groove processing using a photosensitive film, the connection holes 35 and the like can be easily processed.

The top plate 30, the flow plates 31, 32, 33 and the bottom plate 34 are laminated and joined to form the main flow channel groove 36.
Constitutes the main flow path 20 and the first branch groove 37 forms the sub flow path 21.
a, and the ink supply flow path 18 can be formed three-dimensionally by forming the sub flow path 21 b with the second branch groove 38. Further, since the photosensitive film has good bonding property with silicon, the bottom plate 40 of the ink supply device 23 can be easily bonded to the substrate having the common liquid chamber 15 of the recording head 3.

In the above description, each flow path plate 31, 32, 33
Although the case in which the photosensitive film is formed of a single photosensitive film has been described, a plurality of photosensitive films are bonded to each other in accordance with the cross-sectional area of the parent flow path 20 and the secondary flow paths 21a and 21, and each flow path plate 31,
32 and 33 are preferably formed.

The parent channel groove 36 formed in the channel plate 31
The width of the first branch groove 37 formed in the flow path plate 32 is made smaller than the groove width of the first branch groove 37 formed in the flow path plate 32.
By making the groove width of the second branch groove 38 formed in the flow path plate 33 smaller than that of the flow path plate 33, the cross-sectional area S2 of the two sub-flow paths 21a is made larger than the cross-sectional area S1 of the main flow path 20. , 2 ・ S
The relationship of 2 ≦ S1 is satisfied, and the cross-sectional area S3 of the four sub-flow paths 21b that is obtained by dividing the two sub-flow paths 21a into two sub-systems.
With respect to the cross-sectional area S2 of the sub flow path 21, 2 · S3 ≦ S2
And the flow path plates 31, 3
When the photosensitive films are expanded and contracted, the position of the first branch groove 37 with respect to the parent flow channel 36 is shifted or the position of the second branch groove 38 with respect to the first branch groove 37 is changed. Even if it is shifted, the cross-sectional area of each communication portion does not need to be changed.

Further, an ink supply device 23 having an ink supply flow path 18 provided with two sub-flow paths 21a branched from the main flow path 20 can be manufactured in the same manner.

In the above-described manufacturing method, the main flow channel groove 36 forming the main flow channel 20 is formed in the flow channel plate 31, and the first branch groove 37 forming the sub flow channel 21a is formed in the flow channel plate 32. However, as shown in FIG. 9, the flow path plate 32
A second main channel groove 40 communicating with the main channel groove 36 of the channel plate 31 and a first branch groove 37 having a smaller groove width than the second main channel groove 40 may be formed. By forming the second parent flow channel 40 and the first branch groove 37 in the flow channel plate 32 in this manner, the top plate 30, the flow channel plates 31, 32, and the bottom plate 34 are stacked to form an ink supply device. When it is formed, it is possible to prevent a positional shift from occurring in the branch portion between the parent flow channel 20 and the child flow channel 21a, and to make the flow characteristics of the ink flowing through the two systems of the child flow channels 31a uniform.

Further, as shown in FIG.
6 and the flow path plate 32 having the second main flow path groove 40 and the first branch groove 37, the main flow path groove 36 and the second main flow path groove 40 are formed. A reinforcing plate 42 having a communication hole 41 communicating therewith may be provided. By providing the reinforcing plate 42 in this manner, it is possible to increase the rigidity of the ink supply device 23, prevent deformation due to external force, and supply ink with stable flow characteristics. Further, by making the flow path cross-sectional area of the communication hole 41 of the reinforcing plate 42 larger than the flow path cross-sectional area of the communication portion between the parent flow groove 36 and the second parent flow groove 40, the flow path plate 31
And the reinforcing plate 41 and the flow path plate 32 can be prevented from being affected by a positional shift when stacked, and the flow characteristics of the main flow path 20 can be stabilized.

In the ink jet printer 1, the case where the ink supply device 23 is manufactured separately from the recording head 3 and the ink supply device 23 is connected to the common liquid chamber 15 of the recording head 3 has been described. As shown in (c), one surface of the inner wall surface of the common liquid chamber 15 of the recording head 3 may be constituted by the ink supply device 23. In this manner, by forming one of the inner wall surfaces of the common liquid chamber 15 with the ink supply device 23 made of a photosensitive film having low rigidity,
The ink supply device 23 can function as a damper, and absorbs pressure fluctuations transmitted from the pressurized liquid chamber 13 to the common liquid chamber 15 when ink is ejected from the nozzles 12 to reduce the pressure between the pressurized liquid chambers 13. Mutual interference can be suppressed.

When the number of sub-flow paths 21 of the ink supply device 23 which forms one inner wall surface of the common liquid chamber 15 increases, the thickness of the ink supply device 23 also increases,
3 becomes stronger. In such a case, FIG.
As shown in (c), by reducing the thickness of the region 24 where the ink supply channel 18 of the ink supply device 23 is not provided, the damper function can be reliably exhibited.

Further, when the top plate of the common liquid chamber 15 is constituted by the ink supply device 23, as shown in FIG. The surface is formed by an inclined surface 25 inclined at a fixed angle with respect to the ink supply device 23, and the outflow direction of the ink flowing out from the ink outlet 22 is defined by the inclined surface 25 by the fluid resistance path 16.
When the pressure is changed to the side, the pressurized liquid chamber 13 can be efficiently filled with ink. In this case, the inclined surface 25 can be easily formed by cutting out the silicon substrate forming the common liquid chamber 15 into the (100) plane crystal orientation and performing anisotropic etching to form the common liquid chamber 15. it can.

[0040]

As described above, according to the present invention, the ink supply flow path communicating the ink reservoir tank with the common liquid chamber is provided with a main flow path connected to the ink reservoir tank and a 2M flow path connected to the common liquid chamber. The sub-channels of the 2M system (M = 1 to i) are formed with respect to a plane including an axis obtained by connecting the cross-sectional centers of the parent channels. The ink supply is made by repeating the process of branching into two mirror image symmetric sub-channels and forming a constant flow path length from the branch part of the parent flow path to the tip end connected to the common liquid chamber. The ink can be dispersed and supplied from the channel to the common liquid chamber.

Further, each sub flow path is provided symmetrically with respect to the main flow path, and the flow path length from the branch portion of the main flow path to the leading end connected to the common liquid chamber is made constant. The flow resistance and the flow rate of the ink flowing into the common liquid chamber from the ink supply flow path can be made constant, and the ink having a constant flow rate and a constant flow rate can be dispersed in the common liquid chamber. Can be supplied.

In addition, since the ink is dispersed in the common liquid chamber at regular intervals and the ink is supplied at a constant flow rate and a constant flow rate, the number of bits is increased for high-density recording and high-speed printing. Even if the number increases, the flow rate, inflow pressure, and arrival time of the ink supplied to the common liquid chamber and reaching each pressurized liquid chamber can be made substantially constant, and the amount of ink filled in each pressurized liquid chamber And the unevenness of filling of the pressurized liquid chamber can be reduced.

Further, the cross-sectional area S2 of the two sub-flow paths branched from the main flow path of the ink supply flow path is equal to the cross-sectional area S of the main flow path.
The relationship of 2 · S2 ≦ S1 with respect to 1 is satisfied, and the cross-sectional area Sn of the two sub-flow paths branched from the sub-flow path is smaller than the cross-sectional area S (n−1) of the pre-branch sub-flow path. 2 · Sn ≦ S (n−
By satisfying the relationship of 1), it is possible to flow ink without decreasing the flow velocity of the ink flowing through the parent flow path in each child flow path, and it is almost the same as the initial flow velocity flowing through the parent flow path in the common liquid chamber. By supplying ink at a flow rate, the efficiency of supplying ink to the common liquid chamber can be improved.

Further, by forming each branch portion of the ink supply flow path with a smooth curved surface, the fluid resistance of the ink supply flow path can be further reduced, and the flow of ink flowing through the ink supply flow path can be reduced. Since vortices can be prevented from occurring, and bubbles are prevented from staying in each branch and increasing the fluid resistance, it is possible to stably supply ink from the ink supply channel to the common liquid chamber. it can

Further, the shape of the ink outlet for the common liquid chamber of the ink supply flow path is formed to be widened in the direction in which the ink flows out. When the number of connected sub flow paths is M, the pitch of the pressurized liquid chamber corresponding to 1 bit is W, and the shortest distance from the ink outlet to the position where the fluid resistance path is provided is L, θ> By satisfying the relationship of tan ^-1 {(N * W / M / 2) / L}, the ink is radially discharged from the ink outlet, and the ink is supplied to the inlet of the fluid resistance path connected to each pressurized liquid chamber. Can be sent evenly.

Further, by forming the ink supply channel by forming a groove in the photosensitive film, the fluid resistance of the ink supply channel can be reduced with a simple configuration.

Further, the main flow path and the sub flow path that is sequentially branched are formed by forming grooves in different photosensitive films, and the grooved photosensitive films are laminated and joined to form an ink supply flow path. Thereby, the ink supply flow path can be easily formed three-dimensionally.

A groove forming a part of the parent flow path is provided in the photosensitive film having a groove forming a child flow path branched from the parent flow path so as to communicate with the groove forming the child flow path. By providing the photosensitive film having a groove forming a sub flow path branching from the flow path in communication with the groove forming the sub flow path branching the groove forming a part of the previous sub flow path, the photosensitive film It is possible to prevent displacement of the ink supply flow path when the films are laminated and joined, and it is possible to supply ink stably.

Further, a reinforcing plate made of one or more high-rigidity members is disposed between the plurality of photosensitive films to be laminated,
By providing the reinforcing plate with through holes communicating with the grooves of the upper and lower photosensitive films, the rigidity of the ink supply device can be increased to prevent deformation due to external force, and ink can be supplied with a stable flow rate characteristic.

Further, by forming a part of the wall surface of the common liquid chamber of the recording head by this ink supply device, the ink supply device can function as a damper, and when the ink is ejected from the nozzles, the pressurized liquid is supplied. By absorbing the pressure fluctuation transmitted from the chamber to the common liquid chamber, mutual interference between the pressurized liquid chambers can be suppressed, and ink can be ejected with stable ejection characteristics.

Further, the ink jet recording apparatus has a recording head which forms a part of the wall surface of the common liquid chamber by the ink supply device, and an ink reservoir tank connected to the ink supply device, so that high-density recording and high-speed recording are possible. Even if the number of bits is increased for printing and the number of pressurized liquid chambers is increased, ink can be ejected with stable ejection characteristics and high-quality recording can be stably performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ink jet printer of the present invention.

FIG. 2 is a configuration diagram of a recording head.

FIG. 3 is a layout diagram of an ink supply channel.

FIG. 4 is a perspective view showing a sectional area of an ink supply channel.

FIG. 5 is a layout diagram of another ink supply channel.

FIG. 6 is a layout diagram showing a shape of a branch portion of an ink supply channel.

FIG. 7 is an explanatory diagram illustrating a shape of an ink outlet of an ink supply channel.

FIG. 8 is an exploded perspective view illustrating a configuration of an ink supply device.

FIG. 9 is an exploded perspective view showing a second configuration of the ink supply device.

FIG. 10 is an exploded perspective view showing a third configuration of the ink supply device.

FIG. 11 is a cross-sectional view illustrating a configuration of a recording head having an ink supply device.

FIG. 12 is a configuration diagram of a conventional recording head.

[Explanation of symbols]

1; inkjet printer, 2; ink reservoir tank, 3; recording head, 12; nozzle, 13;
14; pressure applying means, 15; common liquid chamber, 16; fluid resistance path, 18; ink supply flow path, 19; connection hole, 20; parent flow path, 21;

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuyuki Okada 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2C056 EA26 KB15 KC05 KC30

Claims (11)

[Claims] 1. A pressurizing liquid chamber comprising a plurality of pressurized liquid chambers, a pressure applying means, and a common liquid chamber for filling the pressurized liquid chamber with ink through a fluid resistance path. Provided between the common liquid chamber of the recording head that prints on recording paper by ejecting ink in the pressurized liquid chamber from the nozzle by giving a volume change to the ink reservoir tank and the common ink reservoir tank In an ink supply device that supplies ink to the liquid chamber, an ink supply flow path that communicates the ink reservoir tank and the common liquid chamber includes a main flow path connected to the ink reservoir tank,
And a 2M system (M = 1 to i) sub flow path connected to the common liquid chamber, and the 2M system (M = 1 to i) sub flow path connects the flow path cross-sectional centers of the parent flow paths. It is configured by repeating branching into two sub-flow paths mirror-symmetric to the plane including the obtained axis, and the flow path length from the branch part of the main flow path to the tip connected to the common liquid chamber is constant. An ink supply device characterized by being formed in a. 2. A sectional area S2 of two sub-flow paths branched from a main flow path of the ink supply flow path satisfies a relation of 2 · S2 ≦ S1 with respect to a cross-sectional area S1 of the main flow path. The cross-sectional area Sn of the two sub-channels branched from the road satisfies the relationship of 2 · Sn ≦ S (n−1) with respect to the cross-sectional area S (n−1) of the sub-channel before branching. The ink supply device according to claim 1. 3. The ink supply device according to claim 1, wherein each branch portion of the ink supply flow path is formed with a smooth curved surface. 4. An ink outlet for the common liquid chamber of the ink supply flow path is formed so as to expand in a direction in which ink flows out. Where M is the number of child flow paths connected to the liquid pressure and W is the pitch of the pressurized liquid chamber corresponding to one bit, and L is the shortest distance from the ink outlet to the position where the fluid resistance path is provided. The ink supply device according to claim 1, wherein the relationship satisfies the following relationship:> tan− ¹ {(N * W / M / 2) / L}. 5. The ink supply device according to claim 1, wherein the ink supply flow path is formed by forming a groove in a photosensitive film. 6. A sub flow path which is sequentially branched from the main flow path is formed by forming grooves in different photosensitive films.
6. The ink supply device according to claim 5, wherein the grooved photosensitive films are laminated and joined to form an ink supply passage. 7. A photosensitive film having a groove forming a sub flow path branched from the main flow path, a groove forming a part of the main flow path is provided so as to communicate with the groove forming the sub flow path. 6. The photosensitive film having a groove forming a sub flow path branching from the sub flow path, and provided in communication with a groove forming a sub flow path branching a groove forming a part of the preceding sub flow path. The ink supply device according to claim 1. 8. A reinforcing plate made of one or more high-rigidity members is disposed between the plurality of photosensitive films to be laminated, and the reinforcing plate is provided with through holes communicating with the grooves of the upper and lower photosensitive films. The ink supply device according to claim 5, 6 or 7. 9. A pressurized liquid chamber having a plurality of pressurized liquid chambers, a pressure applying means, and a common liquid chamber for filling the pressurized liquid chamber with ink via a fluid resistance path, wherein the pressure applying means supplies ink to the pressurized liquid chamber. 9. A recording head which applies a volume change to ink and ejects ink in a pressurized liquid chamber from a nozzle to print on recording paper or the like, wherein the ink supply device according to claim 5 uses one of the wall surfaces of the common liquid chamber. A recording head, comprising a unit. 10. An ink jet recording apparatus comprising the ink supply device according to claim 1. Description: 11. An ink jet recording apparatus comprising: the recording head according to claim 9; and an ink reservoir tank connected to the ink supply device.