JP2004306393A - Liquid conduction structure interconnecting liquid containing section and liquid using section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform recording stable with a desired density over a long term even when ink containing pigment as a coloring matter is used. <P>SOLUTION: An ink tank 10 and a section 50 for supplying ink from the ink tank to a recording head 20 are fluid conducted through two interconnection passages 53 and 54. Under a state where gas is present in the supply section, ink is moved from the ink tank 10 through one interconnection passage 53 and, at the same time, gas is discharged through the other interconnection passage 54 toward the ink tank 10. Furthermore, a mechanism 30 for introducing outer air in order to sustain the negative pressure in the ink supply system in a preferable state is disposed in the ink tank and its introduction passage is connected with the supply section. Ink is stirred as the gas is discharged or introduced and the density is made uniform. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid communication structure for stably supplying a liquid such as ink to a recording head or a pen as a liquid using unit from an ink tank or the like as a liquid storage unit without waste. . Further, the present invention relates to a liquid supply system using a liquid communication structure and an ink jet recording apparatus using the liquid supply system.
[0002]
[Prior art]
Ink jet recording in which a desired image is formed on a recording medium by applying a liquid ink, for example, as droplets from a fine ejection port provided in a liquid using apparatus, for example, an ink jet recording head, to the recording medium. Since the apparatus has relatively low noise at the time of recording and can form small dots at a high density, the apparatus is used in many printings including color printing in recent years.
[0003]
Until now, inks mainly containing dyes have been used as inks for such ink jet recording. However, recording using an ink containing a dye has relatively poor performance required for applications where light resistance and weather resistance are important, such as recorded materials posted outdoors or recorded materials for which long-term storage is desired. is there. Therefore, in recent years, recording using an ink containing a pigment has been put to practical use instead.
[0004]
However, since the pigment is dispersed rather than dissolved in the solvent, the ink using the pigment inevitably causes sedimentation of the pigment particles as a contained component. Therefore, depending on the use frequency, use interval, number of printed sheets, and the like of the ink jet recording apparatus, the influence of the sedimentation phenomenon of the pigment cannot be ignored in the ink supply system from the ink supply source ink tank to the ink use recording head. There is.
[0005]
For example, if the ink tank is left for a relatively long time in a state where the ink tank is mounted on the ink jet recording apparatus, the pigment particles gradually settle inside the ink tank. As a result, a concentration gradient of pigment particles is generated from the bottom to the top inside the ink tank, and a pigment layer concentration is high and an excessively dark layer is formed at the bottom, while a pigment particle concentration is low and excessive at the top. A pale layer results.
[0006]
Therefore, for example, when ink is supplied from an ink tank configured to lead stored ink from the bottom, ink is first supplied from a layer having a high pigment particle concentration. In the latter period, an extremely light-colored recording will be obtained. That is, there is a problem in that the recorded matter obtained at the beginning of use and at the end of use of the ink tank have a density difference that can be visually observed. This phenomenon is particularly remarkable in color printing in which an image is formed by shading of colors.
[0007]
In order to solve this problem, Patent Literature 1 discloses a method in which a hollow ink supply cylinder is protruded upward from the bottom of the ink storage unit to the inside, and various heights of the top and the outer periphery of the ink supply cylinder are provided. Discloses an ink cartridge for pigment ink in which a plurality of through holes are provided. That is, ink is suctioned not only from the portion near the bottom surface of the ink storage unit but also from a number of locations in the vertical direction in the ink storage unit, and the ink sucked from the number of locations is temporarily removed. By providing a stagnation point and supplying the ink from the stagnation point, the ink in the ink storage unit becomes non-uniform in the height (depth) direction due to long-term storage. The resulting uneven density is reduced.
[0008]
In Patent Document 2, an ink intake tower protrudes upward from the bottom of the ink storage unit to the inside, and a plurality of ink intake ports are formed on an upper side surface of the ink intake tower. An ink cartridge for pigment ink provided is disclosed. In other words, it is described that ink in a good density range can be supplied by configuring so that ink is taken in not from a portion near the bottom surface of the ink storage portion but from an upper portion in the ink storage portion.
[0009]
[Patent Document 1]
JP 2001-270131 A
[0010]
[Patent Document 2]
JP 2001-293880 A
[0011]
[Problems to be solved by the invention]
However, in the technique disclosed in Patent Document 1, ink having a density difference outside the ink supply cylinder is uniformly introduced into the ink supply cylinder, but low-density ink flowing from the upper through hole, that is, light ink is used. Since there is ink of high concentration, that is, heavy ink, which has flowed through the lower through-hole below, the upper and lower convection of the ink is unlikely to occur, and the ink is supplied without being uniformly mixed. Density unevenness may occur even in the region.
[0012]
Further, according to Patent Document 2, it is considered that the pigment particles settled near the bottom surface of the ink storage unit are not led out, so that it is possible to supply the ink in a somewhat favorable concentration range. The effect of a density gradient or a step toward the upper part cannot be completely eliminated, and a density difference may also occur between the early and late stages of recording. Further, there is also a problem that the precipitated pigment component is wasted since it is not led out.
[0013]
The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to stably maintain a desired concentration for a long time even when an ink containing a pigment as a colorant is used. The purpose of the present invention is to make it possible to perform a recorded operation.
[0014]
Another object of the present invention is to provide a liquid supply system having a closed structure with respect to a liquid use part, to eliminate a gas that hinders the liquid use operation and the liquid supply operation, and to reduce the negative pressure in the liquid supply system to a preferable state. The object of the present invention is to enable the liquid in the system to be appropriately stirred with the introduction of outside air for maintenance.
[0015]
[Means for Solving the Problems]
For this purpose, the present invention provides a liquid communication structure that liquid-connects a liquid storage unit that stores a liquid and a liquid use unit that uses the liquid to form a substantially sealed space by being connected to each other. ,
The liquid communication structure includes a plurality of communication paths each communicating the liquid storage section and the liquid use section, and in a state where a gas exists in the liquid use section, the gas communicates with the plurality of communication paths. Through a part, it can be transferred to the liquid storage unit,
A gas introduction path through which a gas can be introduced from the outside into the liquid use unit via a valve mechanism provided integrally with the liquid storage unit and not in fluid communication with the supply of the liquid to the liquid use unit. It is characterized by having.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, some embodiments in which the present invention is applied to an inkjet recording apparatus will be described with reference to the drawings.
[0017]
In this specification, the term “record” refers to not only a case where significant information such as characters and figures are formed, but also a matter that is significant or insignificant, and is also manifested so that humans can perceive it visually. Regardless of whether or not the image, pattern, pattern, or the like is formed on a recording medium widely, or when the recording medium is processed.
[0018]
In addition, the “recording medium” includes not only paper used in general recording apparatuses but also a wide range of materials that can accept ink, such as cloth, plastic films, metal plates, glass, ceramics, wood, and leather. It should be noted that, hereinafter, it is also referred to as “paper” or simply “paper”.
[0019]
In the following embodiments, ink is described as an example of the liquid used in the liquid supply system of the present invention. However, the applicable liquid is not limited to ink, and is applicable to, for example, the inkjet recording field. Needless to say, it includes a processing liquid for the recording medium.
[0020]
(1st Embodiment)
Constitution
FIG. 1 is a schematic sectional view of a liquid supply system according to a first embodiment of the present invention.
[0021]
The ink supply system of the embodiment shown in FIG. 1 generally includes an ink tank 10 as a liquid container, an ink jet recording head (hereinafter, simply referred to as a “recording head”) 20, and an ink supply path communicating between them. And a supply unit 50 to be formed. The supply unit 50 may be integral with the recording head 20 so as to be separable or non-separable. The supply unit 50 is provided on a carriage on which the recording head 20 is mounted. In the above, the ink supply path from the ink tank 10 to the recording head 20 may be closed.
[0022]
The ink tank 10 generally includes two chambers, an ink storage chamber 12 and a valve chamber 30, in which an ink storage space is defined. These two chambers do not directly communicate with each other, but communicate with the supply section 50 through separate connection sections. are doing. The ink (ink-containing ink) to be discharged from the recording head can be stored in the ink storage chamber 12, and is supplied to the recording head along with the discharging operation.
[0023]
In the ink storage chamber 12, a deformable flexible film (sheet member) 11 is provided in a part, and a space for storing ink is defined between this part and the inflexible exterior 15. ing. The inside of the ink storage space forms a substantially closed space except for a connection portion to a supply member provided below. The outer space with respect to the ink storage space as viewed from the sheet member 11, that is, the space above the sheet member 11 in the drawing may be covered with a member having an air communication port.
[0024]
The shape of the central portion of the sheet member 11 of this example is regulated by a pressure plate 14 which is a flat support member, and the peripheral portion thereof is deformable. The central portion of the sheet member 11 is formed in a convex shape in advance, and the side surface shape is substantially trapezoidal. As will be described later, the sheet member 11 is deformed according to a change in the amount of ink in the ink storage space or a change in pressure. At this time, the peripheral portion of the sheet member 11 expands and contracts in a well-balanced manner, and the central portion of the sheet member 11 moves in a vertical direction in the drawing while maintaining a substantially horizontal posture. As described above, since the sheet member 11 is smoothly deformed (moved), no shock is generated due to the deformation, and no abnormal pressure fluctuation occurs in the ink storage space due to the shock.
[0025]
Further, by applying a pressing force for urging the sheet member 11 upward in the drawing via the pressure plate 14 in the ink storage space, the holding force of the meniscus formed in the ink discharge portion of the recording head is balanced. A spring member 40 in the form of a compression spring for generating a negative pressure within a range in which the ink ejection operation of the recording head is possible is provided. At the same time, when the volume of the air in the ink storage chamber fluctuates due to environmental changes (ambient temperature and atmospheric pressure), it is received by the displacement of the spring and the sheet, so that the negative pressure in the chamber does not fluctuate greatly.
[0026]
Although the state of FIG. 1 shows a state in which the ink (ink containing pigment) is almost completely filled in the ink storage space, the spring member 40 is also in a compressed state even in this state, and It is assumed that an appropriate negative pressure is generated in the space. Further, instead of providing a compression spring in the ink storage space, a tension spring is stretched between an appropriate member (for example, a member covering an outer space with respect to the storage space) and the sheet member 11 or the pressure plate 14, thereby forming a tension spring. An appropriate negative pressure may be generated in the ink storage space.
[0027]
The valve chamber 30 is provided with a one-way valve for introducing gas (air) from the outside when the negative pressure in the ink supply path becomes higher than a predetermined value, and for preventing ink leakage from the supply unit 50. Can be The one-way valve is provided with a pressure plate 34 having a communication port 36 and serving as a valve closing member, and a sealing member 37 fixed at a position facing the communication port 36 on the inner wall of the valve chamber housing and capable of sealing the communication port 36. And a sheet member 31 joined to the pressure plate and having the communication port 36 penetrated therethrough. Even in the valve chamber 30, the communication port 13 to the supply unit 50 and the communication port 36 to the atmosphere are substantially excluded. Maintains a closed space. The space in the valve chamber housing on the right side of the figure from the seat member 31 is opened to the atmosphere by the atmosphere communication port 32 and is made equal to the atmospheric pressure.
[0028]
The sheet member 31 is deformable at a peripheral portion other than a portion joined to the pressure plate 34 at a central portion, has a convex central portion, and has a substantially trapezoidal side shape. With such a configuration, the movement of the pressure plate 34 as the valve closing member in the left-right direction in the figure is smoothly performed.
[0029]
Inside the valve chamber 30, a spring member 35 is provided as a valve regulating member for regulating the opening operation of the valve. Also in this case, the spring member 35 is in a slightly compressed state, and the pressure plate 34 is pushed rightward in the drawing by the reaction force of the compression. Due to the expansion and contraction of the spring member 35, the sealing member 37 is brought into close contact with and separated from the communication port 36, thereby providing a function as a valve. Further, gas from the atmosphere communication port 32 to the inside of the valve chamber 30 through the communication port 36 is provided. It has a one-way valve mechanism that allows only introduction.
[0030]
Here, as the seal member 37, any material may be used as long as the communication port 36 is securely sealed. That is, at least a portion that is in contact with the communication port 36 has a shape that maintains flatness with respect to the opening surface, or has a rib that can be in close contact with the periphery of the communication port 36, and further has a tip inside the communication port 36. Any shape may be used as long as it can secure the close contact state, such as a shape having a shape that allows the communication port 36 to enter and close the communication port 36, and the material is not particularly limited. However, since the close contact is achieved by the extension force of the spring member 35, it is easy to follow the sheet member 31 and the pressure plate 34 which move by the action of the extension force, that is, elasticity such as rubber having contractility. It is more preferred to form the sealing member with the body.
[0031]
In the configuration of the ink tank 10, the ink consumption proceeds from the initial state where the ink is sufficiently filled, the negative pressure in the ink storage chamber 12, the force applied by the valve regulating member in the valve chamber 30, and the like. At the moment when the ink pressure is further increased and the negative pressure is further increased from the balanced state, the communication port 36 is opened to cause the inflow of the air, and the supply section is a gas introduction path connected to the valve chamber communication port 13. Each part is designed so that air is taken into the supply part 50 through the communication pipe 59 and further into the ink storage space through the supply part 50. By taking in the air, the volume in the ink storage chamber 10 can be increased conversely because the sheet member 11 or the pressure plate 14 can be displaced upward in the drawing. The communication port 36 is closed by reducing the pressure.
[0032]
Further, even if a change in the surrounding environment of the ink tank, for example, a rise in temperature or a decrease in pressure, occurs, the amount of space between the maximum displacement position below the sheet member 11 or the pressure plate 14 and the initial position is equal to or less than the initial position. Since the expansion of the entrapped air is allowed, in other words, the space corresponding to the volume functions as a buffer area, so that the rise in pressure due to a change in the surrounding environment is reduced, and the ink leaks from the discharge ports. Can be prevented.
[0033]
In addition, since the internal volume of the ink storage space decreases as the liquid is drawn from the initial filling state and the outside air is not introduced until the buffer area is secured, sudden changes in the surrounding environment, vibrations, No ink leakage occurs even if the ink is leaked. Further, since the buffer area is not reserved in advance from the state where the ink is not used, the volume efficiency of the ink container is high, and a compact configuration can be achieved.
[0034]
In the illustrated example, the spring 40 in the ink storage chamber 12 and the spring 35 in the valve chamber 30 are both schematically shown as coil springs, but it is a matter of course that other forms of springs can be used. . In particular, for example, a conical spring may be used, or a leaf spring may be used. Further, when a leaf spring is used, a pair of leaf spring members having a substantially U-shaped cross section may be combined with the U-shaped open ends corresponding to each other.
[0035]
The connection between the recording head 20 and the ink tank 10 is made by inserting the connecting portion 51 of the supply section 50 provided integrally with the recording head in the illustrated example into the ink tank 10. As a result, the two are fluidly connected, and ink can be supplied to the recording head 20. A sealing member 17 made of rubber or the like is attached to the opening on the ink tank side through which the connection portion 51 is inserted. The sealing member 17 is in close contact with the periphery of the connection portion 51 to prevent ink from leaking from the ink tank 10, and The connection between the ink tank 51 and the ink tank 10 is secured. In addition, a slit or the like may be formed in advance in the sealing member 17 at the insertion position in order to facilitate the insertion of the connection portion 51. When the connection portion 51 is not inserted, the slit is closed by the elastic force of the sealing member 17 itself, thereby preventing leakage of ink.
[0036]
The connection portion 51 is a hollow needle-like member whose inside is divided into two parts along the axial direction, and an opening position (hereinafter, referred to as a tank-side opening position) of each of the hollow portions that is positioned on the upper side, that is, in the ink storage chamber 12. Have substantially the same height in the vertical direction, but have a different height at the opening position on the lower side, that is, in the supply unit connected to the head (hereinafter referred to as the head-side opening position). Hereinafter, the flow path (right flow path in the drawing) in which the head side opening position in the supply unit 50 is relatively lower in the vertical direction is the ink flow path 53, and the head side opening position is the upper side in the vertical direction. Is referred to as an air flow path 54, which is mainly used in the process of eliminating bubbles from the supply unit 50, that is, in the process of introducing gas into the ink storage unit. This is because ink is led out to the recording head side, and air is transferred from the air flow path 54 to the ink tank side, and both ink and air are moved in each flow path as described later. is there. That is, the names of these flow paths do not mean that they are dedicated to each fluid.
[0037]
The ink supply path in the supply unit 50 has a cross section that gradually expands from the connection (upstream) side with the ink tank 10 and decreases toward the recording head 20 (downstream). A filter 23 is provided at the maximum enlargement portion of the ink supply path to prevent impurities mixed in the supplied ink from flowing into the recording head 20. The gas-liquid interface in the supply section 50 formed by the stagnation of the gas is larger than the cross-sectional area of the flow paths 53 and 54. By doing so, when the head difference of the ink in the ink tank 10 is applied to the ink in the supply unit 50 through the flow path 53, the pressure of the gas existing in the supply unit 50 is further increased, and It is possible to easily discharge or draw out the gas toward the ink tank 10.
[0038]
The recording head 20 has a predetermined direction (for example, a direction different from the moving direction in the case of a serial recording method in which the recording head 20 is mounted on a member such as a carriage and performs a discharging operation while relatively moving with respect to the recording medium). 2), a plurality of discharge ports, a liquid path communicating with each discharge port, and an element which is disposed in the liquid path and generates energy used for discharging ink. Here, the method of ejecting ink in the recording head, that is, the form of the energy generating element is not particularly limited. For example, an electrothermal converter that generates heat in accordance with energization is used as the element, and the generated thermal energy is used for ink ejection. It may be used for. In this case, the heat generated by the electrothermal transducer causes film boiling in the ink, and the foaming energy at that time allows the ink to be ejected from the ink ejection port. Alternatively, an electromechanical conversion element such as a piezo element that deforms in response to application of a voltage may be used, and ink may be ejected using the mechanical energy.
[0039]
The recording head 20 and the supply unit 50 may be integrated so as to be separable or inseparable, or may be configured separately and connected via a communication path. When integrated, a cartridge that can be attached to and detached from a mounting member (for example, a carriage) in the recording apparatus can be used.
[0040]
Operation when ink tank is installed
A description will be given of an ink stirring operation and the like by taking in gas and transferring ink in an ink tank that has been left still for a relatively long time and in which pigment in ink has settled.
[0041]
FIG. 2 shows a state in which a new ink tank 10 is not mounted on the supply unit 50 or the recording head 20. Here, the ink tank 10 is completely filled with the ink I, a negative pressure is generated by the spring member 40, and the sheet member 11 projects outside the ink tank. Further, the ink I is shown in a state where the ink tank 10 has been allowed to stand for a relatively long period of time, and the pigment as an ink component has settled down to form a layer. In the figure, an example is shown in which the high-density layer a having a high pigment concentration, the medium-density layer b which substantially maintains the original preferable ink concentration, and the low-density layer c having a low pigment concentration are separated into three layers. Ink that separates into two layers, a high-concentration layer with a high pigment concentration and a low-concentration layer with a low pigment concentration, or ink that separates into four or more layers. The present embodiment also exerts the same effect on the obtained ink.
[0042]
On the recording head 20 side, even if the ink tank 10 that has been mounted is empty, recording is performed using the ink remaining in the supply unit 50. Thus, the gas enters and the upper portion of the upstream region of the filter 23 in the supply unit 50 is in a state where gas is accumulated.
[0043]
The pressure balance of each part, the movement of ink and air caused by the pressure balance, and the ink stirring operation will be described with reference to FIGS.
[0044]
FIG. 3 shows a state immediately after the ink tank 10 is mounted on the supply unit 50 from the state of FIG. In FIG. 3, for the sake of explanation, it is assumed that this state is stationary.
[0045]
Consider the pressure of the gas remaining in the upstream region of the filter. Assuming that the pressure of the gas in the ink storage chamber 12 is P and the pressure due to the head difference between the ink interface of the ink storage chamber 12 and the ink interface in the upstream area of the filter is Hs, the pressure of the gas in the upstream area of the filter is P + Hs which is larger than the pressure of the gas by Hs. This is an increase in pressure that occurs because the supply unit 50 or the recording head 20 side has a closed structure.
[0046]
Next, considering the pressure balance at the meniscus position of the head side opening 54h of the air flow passage 54, the pressure acting downward is P + Ha, and the pressure acting upward is the gas pressure P + Hs described above. Therefore, the pressure difference in the up-down direction and the pressure Ma caused by the meniscus and represented by the following equation are balanced.
Ma = 2γcosθa / Ra (1)
Here, γ is the surface tension of the ink, θa is the contact angle of the ink with the air flow path 54, and Ra is the pipe diameter (inner diameter) of the air flow path 54.
[0047]
Therefore, the pressure balance at the position of the head side opening 54h of the air flow path 54 is expressed by the following equation.
P + Hs- (P + Ha) = Ma (2)
Hs−Ha = Ma (3)
That is, the pressure due to the head difference between the meniscus position in the air flow path 54 and the ink interface in the upstream region of the filter and the pressure due to the meniscus in the air flow path are in balance.
[0048]
Therefore, the volume of gas remaining in the upstream region of the filter is large, and
Hs-Ha> Ma (4)
In this case, the gas pressure in the upstream region of the filter is high.
[0049]
Therefore, as shown in FIG. 4, the gas remaining in the upstream region of the filter moves toward the ink storage chamber, while the ink in the high concentration layer a in the ink storage chamber 12 moves to the supply unit 50. Here, the ink in the supply unit 50 has substantially the same density as the ink in the medium density layer b in the ink storage chamber 12, and has a lower specific gravity than the ink in the high density layer a. Therefore, the ink of the high-concentration layer a moves to sink below, and the ink of the supply unit 50 tends to rise, so that the high-concentration ink is diffused into the medium-concentration ink and mixed.
[0050]
Further, as shown in FIG. 5, the meniscus in the air flow path 54 is broken, and the air moves to the ink storage chamber 12 side. Along with this, the ink (high-concentration ink) in the ink storage chamber 12 moves into the supply section 50 via the ink flow path 53 and is diffused and mixed, and the ink level in the supply section 50 also rises. In the ink storage chamber 12, as the introduced air rises, the ink of the high-density layer a having a large specific gravity is pushed up above the region of the medium-density layer b. The ink I is agitated by being pushed up above the area of the layer c. By stirring the ink, the ink concentration in the ink storage chamber 12 is made substantially uniform, so that it is possible to supply ink with a uniform concentration.
[0051]
In the method of supplying the ink in one direction as in Patent Documents 1 and 2 described in the section of the prior art, the phenomenon that the ink of the high-density layer a having a large specific gravity is pushed up to the area of the medium-density layer b or more, similarly to the medium There is no phenomenon that the ink in the density layer b is pushed up more than the area of the low density layer c.
[0052]
Since the volume of the air flow path is very small as compared with the supply section, at the initial stage when the air starts to move, the rise of the ink liquid level in the supply section 50 having a relatively large volume is not so large, The meniscus position of the path 54 moves quickly toward the position of the ink tank side opening 54t. Accordingly, the pressure (Hs-Ha) due to the head difference from the tank-side opening position 54t of the air flow passage 54 to the ink interface position in the upstream region of the filter becomes considerably larger than the pressure due to the meniscus of the air flow passage. Air removal to the ink 12 is promoted, and the agitation force for the ink is also increased.
[0053]
Then, the pressure La due to the head of the air flow path length is given by the following equation.
La <Ma + Ma '(5)
(However, Ma 'is the meniscus pressure formed at the opening position on the air flow path tank side)
In this case, the air is discharged up to the state shown in FIG.
[0054]
In the above, the case where the head side opening 53h of the ink flow path 53 is in contact with the ink as shown in FIG. 3 has been considered. However, the ink consumption further proceeds, and the head side opening 53h of the ink flow path 53 as shown in FIG. Also, a state where the ink is not in contact with the ink in the supply unit 50 will be considered.
[0055]
In FIG. 3, since the head side opening of the ink flow path 53 is in contact with the ink, it is sufficient to consider only the pressure balance at the meniscus position in the air flow path. The meniscus formed on the surface must also be considered.
[0056]
Suppose that it is stationary in the state of FIG. Assuming that the pressure of the gas in the supply unit 50 is P ′ and the pressure of the meniscus formed by the ink flow path 53 is Mi, the pressure balance at each meniscus position of the air flow path 54 and the ink flow path 53 in this state is as follows. Next formula
P '-(P + Ha) = Ma, P'-(P + Hi) = Mi (6)
No fluid exchange occurs between the ink tank and the supply unit. Therefore, in order to perform air removal and ink movement,
P '-(P + Ha)> Ma, P'-(P + Hi) <Mi
It should just be. From these,
P'-P> Ha + Ma, P'-P <Hi + Mi
That is,
Hi + Mi> Ha + Ma
Hi-Ha = H> Ma-Mi (7)
Becomes Therefore, the difference between the pressure difference H due to the water head and the pressure due to the meniscus of the air flow passage 54 and the ink flow passage 53 corresponding to the vertical difference between the head-side opening positions 53h and 54h of the ink flow passage 53 and the air flow passage 54. In this case, it is determined whether or not ink movement occurs and whether or not air is eliminated. Therefore, it is appropriate to adjust the negative pressure in the supply unit by ink ejection or ink suction from the ejection port forming surface side. You can go to
[0057]
Then, the same movement of the ink and the stirring of the ink by the introduction of air occur as described with reference to FIGS. 4 and 5 from the state of FIG.
[0058]
As described above, according to the present embodiment, the inside of the connection part 51 is divided into two to provide two flow paths, and the height of the head-side opening position of each flow path is made different, so that a complicated configuration is achieved. It is possible to stir the ink by quickly transferring the stagnant gas in the upstream region of the filter to the ink tank side without requiring it, and to supply the ink with a uniform concentration.
[0059]
In addition, if a small amount of ink is ejected or the ink is sucked from the ejection port forming side after the ink tank replacement operation, the gas remaining in the supply section is quickly and smoothly transferred to the ink tank side and removed from the supply path. That is, a large amount of ink is not wasted as in the case of removing gas by performing a suction operation from the ejection port side.
[0060]
Operation during recording
As described above, while the ink storage chamber 12 stores ink without having an absorber such as a porous body, the ink storage chamber 12 is connected to the supply unit by two flow paths, and the head side opening position of each flow path is determined. This is an ink stirring operation at the time of mounting the ink tank, which is caused by providing a difference in height. However, the stirring operation according to the present embodiment is not limited to this, and a preferable stirring operation occurs with the consumption of ink during printing after mounting. That is, when the pressure in the ink storage chamber becomes smaller than a predetermined value (when the negative pressure rises to a predetermined value or more) in the process of supplying ink from the ink tank 10 during recording, gas from the outside is actuated by the action of the valve chamber. The stirring operation is performed by being taken into the supply unit and the ink storage chamber.
[0061]
The stirring operation will be described with reference to FIGS. Note that these figures show a state in which a recording operation is not performed for a relatively long time in a state where the ink tank 10 is mounted, and a concentration gradient of the ink is generated in the ink storage chamber 12. Since the above-described stirring operation is performed, the inside of the ink storage chamber 12 has a substantially uniform density distribution in a relatively short period of time after the mounting, so that it is of course possible to supply ink with a uniform density. . In other words, even when the density gradient shown in these figures occurs, the stirring operation accompanying the recording is performed as described below, so that the ink having the uniform density can be supplied stably for a long time.
[0062]
FIG. 7 schematically shows a state in which ink is ejected from the recording head 20 as, for example, droplets. When the ink is ejected, the negative pressure in the recording head 20 or the supply unit 50 increases, breaking the meniscus of the ink formed in the connection unit 51, and moving the ink from the ink tank 10 toward the supply unit 50. Accordingly, the inner volume of the ink storage chamber 12 decreases, and the sheet member 11 is deformed downward while being regulated by the pressure plate 14. Thereby, the spring member 40 is compressed, and the negative pressure in the ink storage chamber 12 is also increased.
[0063]
Here, in the present embodiment, the diameters of the ink flow path 53 and the air flow path 54 are substantially equal to each other, so that the pressure loss in the flow path is large with respect to the negative pressure in the recording head 20 or the supply unit 50. There is no difference, and ink is supplied from each of the flow paths. In the illustrated state where the head side opening 53h of the ink flow path 53 is in contact with the ink, the ink flows from the ink flow path 53 as it is, while bubbles generated in the supply unit 50 or the recording head 20 move to the filter upstream area. , And stay in the region, that is, the upper portion of the supply unit 50 together with the gas that has already remained. In this state, the ink forms a meniscus at the position of the head side opening 54h of the air flow path 54, but drops if the negative pressure in the recording head 20 or the supply unit 50 is high. When a concentration gradient of the ink occurs in the ink storage unit 12 and the inks of each concentration form a layer, the ink of the high concentration layer a is supplied from both the flow paths. The ink in the high-concentration layer a moves to sink below, and the ink in the supply unit 50 tends to rise.
[0064]
In the present embodiment, the connection portion 51 is filled with ink by ink ejection accompanying the printing operation or ink ejection (preliminary ejection) performed as an operation other than the printing operation. This state can be obtained by sealing the outlet forming surface with a cap member and discharging the ink from the discharge port by a suction pump.
[0065]
When ink consumption (ink supply to the recording head) proceeds as shown in FIG. 7 from the initial state of FIG. 1 in which the ink tank 10 is sufficiently filled with ink, the sheet member 11 follows this. Alternatively, the pressure plate 14 is displaced in a direction to reduce the internal volume of the ink storage space, and reaches the position shown in FIG.
[0066]
As the ink consumption further progresses from this state, the pressure in the ink supply system from the ink tank 10 to the recording head 20 decreases (the negative pressure increases) by the reduced amount of ink inside.
[0067]
Then, as shown in FIG. 9, the ink consumption is further continued from the state where the negative pressure in the ink supply system and the force acting by the valve regulating member in the valve chamber 30 are balanced, and the negative pressure further increases. At the moment, the communication port 36 is opened, and the inflow of air occurs. When the ink is introduced into the supply unit 50, the ink in the supply unit 50 is stirred. That is, by the stirring operation in the supply unit 50, the ink density is further uniformed immediately before the ink is supplied to the recording head 20, so that the ink having a good density can be supplied as it is. Further, even when the heavy ink of the high concentration layer a is flowing from the ink tank 10, the heavy ink is stirred by being lifted by the air.
[0068]
Then, air corresponding to the amount introduced into the supply unit 50 is introduced into the ink storage chamber 12 from the supply unit 50 in the same manner as described with reference to FIG. 5, and the stirring operation is performed here as well. In addition, the stirring operation is continuously performed on the ink taken into the supply unit 50 from the ink storage chamber 12.
[0069]
When the negative pressure in the supply unit 50 is reduced by the introduction of the air, the communication port 36 is closed, and the inflow of the atmosphere is stopped.
[0070]
Effects and the like of the first embodiment
As described above, by operating the valve unit 30, a predetermined negative pressure is stably applied to the ink supply system or the recording head 20, and the ejection characteristics of the recording head 20 can be kept good. In addition, by appropriately introducing air into the supply section 50 and the ink storage section 12, the stored ink is efficiently stirred, the density gradient is greatly reduced, and the ink having a substantially uniform density is prolonged. Can be supplied stably.
[0071]
That is, in the case where the ink containing a pigment as a coloring material is used, the air is transferred to the ink storage chamber 12, so that the settled pigment particles are diffused, and the ink can be made into a substantially uniform concentration state. As a result, it is possible to secure the storage stability of the ink and the reliability of the ejection, and it is possible to stably obtain a good printed matter having a long density from the initial recording and having no density difference. Further, since air is introduced through the supply unit at the time of adjusting the negative pressure, agitation is performed even in the immediate vicinity of the recording head 20 and the density can be made more uniform, so that the reliability of ejection can be further improved. . In addition, since the stirring can be performed simultaneously by introducing air for adjusting the negative pressure, it greatly contributes to the simplification of the liquid communication structure.
[0072]
Further, the transfer of the air to the ink storage chamber 12 is not performed only when the ink tank is mounted or the negative pressure is adjusted. Here, in addition to the air that enters when the ink tank is replaced, the air that enters the inside of the ink supply path, the air that enters from the ink ejection port of the print head, or the air that is generated with the ejection operation, The gas dissolved inside the ink may be separated, or the gas may enter from outside by gas permeation through the material constituting the supply path. In the present embodiment, the air that causes a recording failure due to a defective ink supply or clogging of an ejection port due to a mixed bubble is connected by the above-described pressure balance between the ink tank 10 and the supply unit 50. By appropriately transferring the ink into the ink tank 10 via the section 51, the ink can be quickly and smoothly removed from the ink supply path without complicating the structure. In addition, the stirring operation in the ink storage chamber 12 is performed accordingly. In addition, by appropriately introducing gas into the ink tank 10, almost all of the stored ink can be efficiently consumed.
[0073]
Further, the negative pressure adjustment in the present embodiment is performed by opening and closing the communication port 36 in the valve chamber 30. An elastic body such as rubber may be generally used as a seal member for closing the communication port 36, but by providing the valve chamber 30 on the ink tank 30 side as in the present embodiment, the seal member Is sufficient until the ink in the ink tank 10 is consumed, that is, until the ink tank 30 is replaced. That is, when the valve chamber is provided in the supply section 50, if the seal member deteriorates, the supply section or the recording head side must be replaced or repaired. Therefore, it is necessary to provide the seal member or the valve chamber with sufficient durability. However, such a problem can be avoided by providing a valve chamber on the ink tank side as in this embodiment, and higher reliability can be achieved. Can be kept.
[0074]
Further, the air is not directly introduced by connecting the valve chamber 30 to the ink storage section 12, but is supplied into the supply section 50 through the supply section communication pipe 59 inserted into the valve chamber communication port 13. The air is taken into the ink storage space via. Thereby, not only the stirring operation in the supply unit 50 as described above is performed, but also the storage ink that can be generated when the configuration in which the valve chamber 30 is communicated with the ink storage unit 12 and air is directly introduced is adopted. Can be prevented from leaking through the valve chamber.
[0075]
(Other embodiments)
In the first embodiment, the description has been made on the assumption that the ink in the supply unit 50 has substantially the same density as the ink in the middle density layer b in the ink storage chamber 12. This is for the following reason. That is, in the drawings to be referred to, the supply unit 50 or the recording head 20 is drawn large for the sake of explanation. However, in actuality, the internal capacity is small and small as compared with the ink tank 10, and especially the dimension in the height direction is small It is small. Therefore, a remarkable density gradient which may occur in the ink storage chamber 12 is hardly generated in the supply unit or the recording head, and the ink having a good density (medium density) due to the above-described stirring operation is distributed almost uniformly. Because they do.
[0076]
However, if a density gradient also occurs in the supply unit 50 or the recording head 20 when the recording head is left still for a relatively long time, the pigment that has settled due to ink ejection (preliminary ejection) or suction recovery performed as an operation other than the recording operation The recording operation may be performed after forcibly discharging the ink containing many components.
[0077]
In addition, the connection portion 51 can be made to enter a deeper position in the ink storage chamber 12, and a plurality of holes having different heights can be formed on the side portions so that ink ejection or the like can be performed. .
[0078]
Further, in the above-described first embodiment, the connection portion 51 divided into the ink flow passage 53 and the air flow passage 54 is provided, but both the flow passages may be formed in separate connection portions.
[0079]
FIG. 10 is a schematic sectional view of such a liquid supply system. This embodiment is different from the first embodiment in that the air flow path 54 and the ink flow path 53 are located at substantially both ends of the ink storage chamber 12.
[0080]
With this configuration, the same operation and effect as those of the first embodiment can be obtained. In addition, the ink supply from the ink storage chamber 12 to the supply unit 50 and the air introduction from the supply unit 50 to the ink storage chamber 12 By performing the process at both ends of the storage chamber 12, the entire ink storage chamber 12 can be more effectively agitated.
[0081]
(Structural example of inkjet recording device)
FIG. 11 is a diagram illustrating a configuration example of an inkjet recording apparatus to which the present invention can be applied.
[0082]
The recording device 150 of this example is a serial scan type ink jet recording device, and a carriage 153 is guided by guide shafts 151 and 152 movably in the main scanning direction indicated by the arrow A. The carriage 153 is reciprocated in the main scanning direction by a driving force transmission mechanism such as a carriage motor and a belt for transmitting the driving force. In the carriage 153, a liquid supply system 154 including any of the above-described embodiments and a recording head or a supply unit and an ink tank mounted on the carriage and supplying ink is mounted. After the paper P as a recording medium is inserted from an insertion slot 155 provided at the front end of the apparatus, its transport direction is reversed, and then transported by a feed roller 156 in the sub-scanning direction of arrow B. The recording device 150 performs a recording operation of ejecting ink toward a recording area of the sheet P on the platen 157 while moving the recording head in the main scanning direction, and moving the sheet P in the sub-scanning direction by a distance corresponding to the recording width. The image is sequentially recorded on the sheet P by repeating the transport operation of transporting the image to the paper P.
[0083]
Note that, as described above, the recording head may use the thermal energy generated from the electrothermal converter as the energy for ejecting the ink. In such a case, the heat generated by the electrothermal transducer causes film boiling in the ink, and the ink can be ejected from the ink ejection port by the foaming energy at that time. Further, the method of ejecting ink in the recording head is not limited to the method using such an electrothermal transducer, and may be, for example, a method of ejecting ink using a piezoelectric element.
[0084]
A recovery system unit (recovery processing unit) 158 facing the surface of the recording head mounted on the carriage 153 on which the ink ejection ports are formed is provided at the left end in FIG. The recovery system unit 158 is provided with a cap capable of capping the ink discharge port of the recording head, a suction pump capable of introducing a negative pressure into the cap, and the like. By applying the pressure, the ink can be sucked and discharged from the ink discharge port, and a recovery process for maintaining a good ink discharge state of the recording head can be performed. In addition to the image formation, a recovery process (also referred to as a preliminary discharge process) for maintaining a good ink discharge state of the recording head by discharging ink from the ink discharge ports toward the inside of the cap can be performed.
[0085]
(Other)
Note that the configuration of the connection part for smooth gas-liquid exchange between the ink tank and the supply part, particularly the configuration of the ink flow path for smoothly starting the ink movement accompanying the gas transfer, is as described above. However, the present invention is not limited to the configuration in which the head side opening is located at a relatively low position in the vertical direction.
[0086]
Even if the height difference is not provided between the position of the head side opening of the ink flow path and the position of the head side opening of the air flow path, for example, as described above, And one part of the opening on the head side is in contact with the inner wall surface of the supply unit, or a part that forms a fine groove along one flow path is additionally provided. To protrude inward from the supply section, so that a meniscus that applies high pressure is not formed at the head-side opening, whereby ink flows down from the flow path into the supply section. Can be made easier.
[0087]
In addition, the shape of the opening portion is enlarged, the diameter of the flow path is made different, or the state of the inner surface of the flow path is different between the flow paths by appropriately selecting a material or performing a surface treatment. The same effect can be expected by doing so.
[0088]
In addition, instead of providing a connection part having an ink flow path and an air flow path on the recording head side or the ink supply part side, the connection part may be provided on the ink tank side so as to be able to enter the supply part.
[0089]
Also, instead of a connection part in which the inside is divided into two to form two flow paths as in the first embodiment, a separate part that forms each flow path as in the embodiment shown in FIG. 10 is used. It may be a member. Furthermore, the number of channels is not limited to two, and three or more channels may be provided. Also, in the case where the inside is divided into a plurality of portions to form a connection portion that forms a plurality of flow channels, not only the partition between the flow channels is formed linearly but also concentrically as in the above example. Can be used as a connecting portion having a multi-pipe configuration.
[0090]
Further, in the case where the inside is divided into a plurality of sections to form a plurality of flow paths, each flow path is not limited as long as the transfer of gas and the movement of ink do not interfere with each other and hinder smooth and rapid gas-liquid exchange. The road does not have to be completely partitioned.
[0091]
In the above-described embodiments of the ink supply system, basically, any structure is adopted in which the ink is stored or supplied as it is without holding the ink in the absorber or the like, while the movable member (sheet member, pressure plate) And a spring member for urging the negative pressure, the negative pressure generating means is constituted, and the supply system has a closed structure so that an appropriate negative pressure is applied to the recording head.
[0092]
Such a configuration has a higher volumetric efficiency and a higher degree of freedom in ink selection as compared with the conventional configuration in which a negative pressure is generated by the absorber. In addition, the present invention can preferably respond to demands for a higher flow rate and stabilization of ink supply, which are required with the recent increase in printing speed. However, it goes without saying that the present invention can be applied to a configuration in which the absorber is provided in a part of the ink tank.
[0093]
Further, for the purpose of eliminating gas remaining in the supply path, the ink is transferred to the ink tank at the most upstream position farthest from the recording head, and for this purpose, the ink tank is connected to the ink tank through a plurality of flow paths. The ink supply path is connected, and the derivation of ink from the ink tank and the introduction of gas into the ink tank are performed in parallel by utilizing the balance between the two pressures.
[0094]
According to this configuration, the gas remaining in the supply path can be smoothly and promptly removed from the ink tank side without using a complicated device and having a simple structure with a small increase in the number of parts. In addition, the timing of the elimination is naturally performed in accordance with the balance of the pressure when the gas is accumulated to some extent, so that the reliability of the elimination of the gas is high. In addition, such a configuration is advantageous in that, even when a valve mechanism for maintaining a negative pressure by introducing outside air into the ink supply path, that is, the supply unit, is provided, if the amount of introduced gas increases, it is automatically eliminated. This is a configuration that can further contribute to the simplification and cost reduction of the configuration as compared with the case where a negative pressure is generated by the ink tank.
[0095]
Further, since the negative pressure of the ink tank is constantly maintained in the process of removing gas, it is possible to reliably prevent liquid leakage from the ink discharge port of the ink jet recording head. Furthermore, by eliminating gas to the ink tank side, ink consumption can be significantly reduced compared to a method in which gas is eliminated by suctioning ink from the ejection port side of the recording head. This contributes to reducing running costs.
[0096]
In addition, in the case of using an ink tank configured to be detachable with respect to the supply path, conventionally, the supply path is filled with ink to prevent gas from entering the supply path during the replacement operation. In many cases, the ink tank is replaced in a state where the ink is completely consumed, that is, before the ink is completely consumed. However, according to the above configuration, even if gas enters the supply path during the replacement operation, it can be easily removed from the ink tank by installing a new ink tank. This can not only further reduce running costs, but also greatly contribute to environmental problems.
[0097]
Further, in each of the above-described embodiments, the ink tank is disposed at the highest position in a normal use posture, and the supply unit or the recording head is disposed at a low position. This is a very preferable arrangement for performing gas-liquid exchange quickly, smoothly, and with a simple configuration.
[0098]
Depending on the configuration of the ink tank, the gas introduced into the ink tank may be stored anywhere in the ink tank as long as the gas does not return to the ink supply path and the ink supply is not hindered. However, the configuration of the above embodiment in which the ink is stored without being impregnated into the absorber or the like is preferable because the introduced gas is located at the uppermost portion in the ink tank as it is.
[0099]
When the absorber is not present in the ink tank, the volume of the tank itself can be the capacity of the ink. Therefore, it is not necessary to enlarge the ink tank more than necessary, and the shape of the tank is relatively free. It is possible to design.
[0100]
In the above description, a serial type ink jet recording apparatus has been applied as the recording method of the present embodiment, but the present invention and the present embodiment are not limited to this. Further, the present invention and the present embodiment can be applied to a line scanning type recording apparatus instead of a serial type recording apparatus. Further, it goes without saying that a plurality of liquid supply systems can be provided corresponding to the color tone (color, density, etc.) of the ink.
[0101]
In addition, the present invention can be applied not only to an ink jet recording apparatus or system using an ink containing a pigment, but also to an apparatus or system for handling a liquid that is desired to be used in a state where components are uniformly distributed. .
[0102]
Embodiments of the present invention are listed below.
[0103]
[Embodiment 1] A liquid communication structure that liquid-connects a liquid storage unit that stores a liquid and a liquid use unit that uses the liquid to form a substantially closed space by being mutually connected,
The liquid communication structure includes a plurality of communication paths each communicating the liquid storage section and the liquid use section, and in a state where a gas exists in the liquid use section, the gas communicates with the plurality of communication paths. Through a part, it can be transferred to the liquid storage unit,
A gas introduction path through which a gas can be introduced from the outside into the liquid use unit via a valve mechanism provided integrally with the liquid storage unit and not in fluid communication with the supply of the liquid to the liquid use unit. A liquid communication structure comprising:
[0104]
[Embodiment 2] In a state where a gas is present near at least a part of the plurality of communication paths near the liquid use part side, the liquid is transferred from the liquid storage unit through a part of the plurality of communication paths. The liquid communication according to claim 1, wherein the gas is transferred to the liquid storage unit via another part of the plurality of communication paths at the same time that the liquid moves to the use unit. Construction.
[0105]
[Embodiment 3] In a state in which gas is present near at least a part of the plurality of communication paths near the liquid use part, the liquid is transferred from the liquid storage unit through a part of the plurality of communication paths. As the liquid moves to the use section and the gas pressure in the liquid use section increases, the gas is transferred to the liquid storage section through the communication path of another part of the plurality of communication paths. The liquid communication structure according to the second embodiment, wherein the liquid communication structure is transferred.
[0106]
[Embodiment 4] In a posture when a liquid is used, in the vertical direction, the liquid communication structure is located substantially lower than the liquid storage portion, and is further positioned substantially higher than the liquid usage portion. The liquid communication structure according to any one of Embodiments 1 to 3, which is characterized by the following.
[0107]
[Embodiment 5] Using the liquid communication structure according to any one of Embodiments 1 to 4, the liquid can be supplied from the liquid storage unit to the liquid use unit, and the valve included in the liquid storage unit is provided. A liquid supply system capable of introducing outside air from a mechanism to the liquid using section via the gas introduction path.
[0108]
[Sixth Embodiment] A movable member that defines a liquid storage space and that can be displaced in a direction that reduces the internal volume of the storage space with the supply of the liquid to the liquid use unit, while the liquid storage unit defines the liquid storage space. The liquid supply system according to the fifth embodiment, wherein the liquid supply system has at least a part thereof.
[0109]
[Seventh Embodiment] The liquid supply system according to the sixth embodiment, wherein the liquid storage unit includes an urging member for urging the movable member in a direction opposite to the direction of the displacement.
[0110]
[Embodiment 8] The valve mechanism according to any one of Embodiments 5 to 7, wherein the valve mechanism introduces outside air into the liquid use part when the negative pressure in the liquid supply path becomes higher than a predetermined value. Or a liquid supply system.
[0111]
[Ninth Embodiment] The liquid supply system according to the ninth embodiment, wherein the valve mechanism permits the introduction of the outside air into the liquid use part and prevents the movement of the fluid in the opposite direction.
[0112]
[Embodiment 10] The liquid according to any one of Embodiments 5 to 9, wherein the liquid storage section is detachable from the liquid use section via the plurality of communication paths and the liquid gas introduction path. Feeding system.
[0113]
[Embodiment 11] The liquid ejecting apparatus according to any one of Embodiments 5 to 5, wherein the liquid using unit has an ink jet recording head for performing recording by discharging ink as the liquid, and guides the ink to the ink jet recording head. The liquid supply system according to any one of claims 10 to 13.
[0114]
[Embodiment 12] The liquid supply system according to Embodiment 11, wherein the ink is an ink whose contained components can settle.
[0115]
[Thirteenth Embodiment] The liquid supply system according to the twelfth embodiment, wherein the ink is an ink containing a pigment.
[0116]
[Embodiment 14] The liquid supply system according to Embodiment 13, wherein the recording head is integrally configured to be separable.
[0117]
[Embodiment 15] Using the liquid supply system according to any one of Embodiments 11 to 14, the plurality of communication paths are positioned substantially higher than the liquid supply path in the vertical direction in a posture during use. An ink jet recording apparatus for performing recording while holding the liquid supply system such that the liquid storage section is positioned substantially higher than the plurality of communication paths.
[0118]
[Embodiment 16] An ink jet recording head for performing recording by discharging ink as a liquid, wherein the liquid communication structure according to any one of Embodiments 1 to 4 is integrally provided. Recording head.
[0119]
[Embodiment 17] The ink jet recording head according to Embodiment 16, which has a form of a cartridge detachable from the ink jet recording apparatus.
[0120]
[Embodiment 18] The liquid storage portion, which is connected to the liquid communication structure according to any one of Embodiments 1 to 4, and is provided with the valve mechanism in a state of not directly communicating with the fluid, forms the liquid storage section, A liquid tank having a form of a cartridge connectable to the liquid communication structure via the gas introduction path.
[0121]
[Embodiment 19] A cartridge which can be connected to the liquid communication structure of the inkjet recording head according to Embodiment 16 or 17 via the plurality of communication paths and the gas introduction path is provided. And liquid tank.
[0122]
【The invention's effect】
As described above, according to the present invention, in a liquid supply system having a closed structure with respect to a liquid use part, a gas that hinders a liquid use operation and a liquid supply operation can be dispensed with a liquid without complicating the structure. By transferring the air quickly and smoothly from the supply path, and utilizing the transfer performance, to introduce outside air through the liquid supply path side to maintain the negative pressure in the liquid supply system in a favorable state. In addition, the liquid in the system can be agitated as the gas is removed or introduced.
[0123]
In particular, when the present invention is applied to an ink jet recording apparatus, the gas remaining in the ink supply path of the closed structure is smoothly and promptly transferred to the ink tank side, and even when the recording apparatus is actually used, the residual air bubbles are generated. In other words, it is possible to prevent recording problems caused by defective ink supply, clogging of the ejection openings due to mixed bubbles, and the like. Further, by utilizing the transfer performance, external air is introduced from the ink supply path side to maintain the negative pressure in the ink supply system in a preferable state, thereby simplifying the configuration of the ink tank and reducing the cost. be able to. In addition to these, even when using an ink using a pigment as a colorant, the ink can be stirred with the transfer or introduction of gas, so that stable recording can be performed at a desired density over a long period of time. Become.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a liquid supply system according to a first embodiment of the present invention.
FIG. 2 is a diagram for explaining a process of removing gas or stirring the ink when the ink tank is mounted in the first embodiment, and is a schematic cross-sectional view showing a state where a new ink tank is not mounted on a supply unit or a recording head. FIG.
FIG. 3 is a diagram for explaining a gas removal or ink stirring process when an ink tank is mounted in the first embodiment, and is a schematic diagram showing a state at the moment when a new ink tank is mounted from the state of FIG. 2; It is sectional drawing.
4 is a view for explaining a process of removing gas or stirring the ink when the ink tank is mounted in the first embodiment, and is a schematic cross-sectional view showing a state in which ink movement has occurred from the state of FIG. 3; .
FIG. 5 is a diagram for explaining a process of removing gas or stirring the ink when the ink tank is mounted in the first embodiment, and illustrates a state in which the movement of ink and the discharge of gas are simultaneously proceeding from the state of FIG. 4; It is a typical sectional view shown.
FIG. 6 is a schematic cross-sectional view for explaining a gas removal or ink stirring process from different ink storage states in the first embodiment.
FIG. 7 is a diagram for explaining a gas introduction or ink stirring process at the time of recording in the first embodiment, and is a schematic cross-sectional view showing a state where ink in an ink tank is reduced due to ejection of ink. is there.
FIG. 8 is a diagram for explaining a gas introduction or ink stirring process at the time of recording in the first embodiment, and is a schematic cross-sectional view showing a state in which the ink in the ink tank is further reduced by discharging the ink. It is.
FIG. 9 is a schematic cross-sectional view illustrating a state in which an outside air intake operation for adjusting a negative pressure is being performed, illustrating a gas introduction or ink stirring process during printing according to the first embodiment. is there.
FIG. 10 is a schematic sectional view of a liquid supply system according to another embodiment of the present invention.
FIG. 11 is a perspective view illustrating a configuration example of an inkjet recording apparatus to which the present invention can be applied.
[Explanation of symbols]
10 Ink tank
11 Seat members
12 Ink storage room
14 Pressure plate
17 Sealing part
20 Recording head
22 Filter
30 Valve room
31 Valve chamber seat member
34 Valve chamber pressure plate
35 Valve chamber spring member
32,36 communication port
37 Sealing member
40 spring member
50 Supply unit
51 Connection
53 Ink channel
54 Air flow path
59 Supply unit communication pipe
150 inkjet recording device
154 Liquid supply system
153 carriage
158 Recovery unit

Claims (1)

Forming a substantially sealed space by being connected to each other, a liquid storage structure for storing liquid, and a liquid communication structure for liquid communication with a liquid using unit using the liquid,
The liquid communication structure includes a plurality of communication paths each communicating the liquid storage section and the liquid use section, and in a state where a gas exists in the liquid use section, the gas communicates with the plurality of communication paths. Through a part, it can be transferred to the liquid storage unit,
A gas introduction path through which a gas can be introduced from the outside into the liquid use unit via a valve mechanism provided integrally with the liquid storage unit and not in fluid communication with the supply of the liquid to the liquid use unit. A liquid communication structure comprising:

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