JPH1044460A - Liquid container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform gas-liquid exchange between the ink in an ink containing section and the atmosphere well by introducing the atmosphere forcibly into a communication passage at the time of ink supply using an atmosphere introduction passage by disposing a negative pressure generating member in a passage coupling an atmosphere communicating section with the upper end of the atmosphere introduction passage. SOLUTION: When an ink jet recorder is operated, an ink suction force is generated in an ink tank 1. Consequently, an ink 9 is sucked from an ink containing section 6 and passed through a gap 8, between the end B of rib and the bottom 11 of ink cartridge, for communicating the ink containing section 6 with a negative pressure generating member containing section 4 to the negative pressure generating member containing section 4 thence sucked through a negative pressure generating member 3 into a joint member 7 and fed to an ink jet recording head. Since the negative pressure generating member containing section 4 is opened through an atmosphere communication port 13 to the atmosphere, the air passes through the negative pressure generating member 3 and enters the ink containing section 6 through the gap 8 between the rib end B and the ink cartridge bottom 11. Consequently, the ink in the ink containing section is exchanged with the atmosphere quickly in safety at the time of supplying ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid container for storing a liquid to be supplied to a liquid ejecting head, and more particularly to a liquid container having a structure capable of providing a stable negative pressure to the liquid ejecting head.

[0002]

2. Description of the Related Art Conventionally, a liquid container (hereinafter, also referred to as an ink tank) for supplying a liquid (hereinafter, also referred to as ink) to a liquid ejecting head (hereinafter, also referred to as a recording head) for an ink jet recording apparatus. Are roughly classified into the following two.

[0003] One is a method in which an ink tank is built in the main body of an ink jet recording apparatus, and an ink supply pipe or the like is fed from the ink tank into the main body and connected to a recording head to supply ink.

In this method, the ink supply system becomes large, and it is difficult to reduce the size and cost of the apparatus main body. In addition, the ink in the supply system is easily cut off, and the ejection recovery system (mechanism) for improving the ejection reliability becomes large-scale, and it is difficult not only to reduce the size and cost of the device but also to recover the ink. The required ink consumption is also large, which leads to a problem of waste ink treatment and, consequently, an increase in running cost.

[0005] However, a method for maintaining a stable meniscus in the ink discharge section of the recording head can be achieved by mounting the ink tank below the position of the recording head, which is simple and stable. The generated negative pressure is generated at the ink discharge port of the recording head.

The second is an ink in which an absorber is housed as a negative pressure generating member in the entire ink tank, the ink is held by the absorber, and a stable meniscus is maintained at the ink discharge port of the recording head. There is a tank. This all-absorber ink tank system holds ink slightly smaller than the maximum amount of ink that the absorber can hold, and generates a meniscus inside the absorber on the side of the atmosphere communication section, so that a predetermined amount of ink is supplied to the ink supply section. Since the internal negative pressure is generated, the print head is adjusted by adjusting the capillary force of the ink tank in consideration of the ink head difference between the meniscus inside the absorber on the side of the atmosphere communication part and the discharge part of the print head. It is possible to maintain a stable meniscus in the ejection section of the above, and it is possible to eject a stable ink. However, in the conventionally known all-absorber ink tank method, the amount of ink that can be held (ink holding ratio) with respect to the ink tank volume is small, and when the ink tank scans with the print head in opposition to the printing paper, This has been a problem to be solved by reducing the size of the recording apparatus main body and the running cost. In particular, miniaturization is an important factor in an ink jet recording apparatus of a variable printing attitude, and a system that can generate a stable internal negative pressure and has a high ink holding ratio is required.

On the other hand, JP-A-56-67269 and JP-A-59-98857 disclose a spring bag ink tank system using an ink bag biased by a spring in an ink tank. . The spring bag method is excellent in that the internal negative pressure in the ink supply unit is generated stably using the spring force.However, there are restrictions on the spring shape to obtain a predetermined internal negative pressure, There are many problems that the process of fixing the bag is slightly complicated and the manufacturing cost is high, and the ink holding ratio is small in a thin ink tank.

Japanese Patent Application Laid-Open No. 02-214666 discloses a divided ink chamber ink tank system in which an ink tank is divided into a plurality of ink chambers, and the ink chambers are communicated with each other through pores capable of generating a negative pressure. . The divided ink chamber system disclosed in the present disclosure is a system in which an internal negative pressure in an ink supply unit is generated by capillary force of pores that connect ink chambers to each other. The divided ink chamber method is advantageous in terms of manufacturing cost because the configuration of the ink tank can be simplified as compared with the spring bag method, and is advantageous in that there are few mechanical restrictions on the shape of the ink tank. However, in the divided ink chamber system disclosed in the above-mentioned disclosure, if the holding posture of the ink tank is changed, depending on the remaining amount of ink, there may be a state in which ink is not present in the pores, and the internal negative pressure due to the pores becomes unstable and ink leakage occurs. May occur, which greatly restricts the handling of the ink tank.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the technical problems in various ink tank forms as described above. Excellent ink retention ratio, no ink leakage against environmental changes, stable negative pressure characteristics, stable ink supply to the recording head without affecting the ink ejection characteristics It is intended to realize a form of an ink tank that performs the following.

[0010]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and comprises an air communication portion communicating with the atmosphere, and a liquid supply portion for supplying a liquid to a liquid jet head. A negative pressure generating member storage chamber in which a negative pressure generating member is stored, and a liquid that communicates with the negative pressure generating member storage chamber via a communication passage and is substantially sealed except for the communication passage. A liquid storage container for a liquid ejecting head, comprising: a storage chamber; and a wall extending upward from the communication path of the negative pressure generation member storage chamber, wherein a liquid is stored in the negative pressure generation member during a process of consuming the liquid. The air introduction path through which air can be introduced into the liquid storage chamber for enabling gas-liquid exchange in the communication path while maintaining the liquid level above the communication path is lower than the negative pressure of the wall. The side surface of the generating member storage chamber side is connected to the communication path The negative pressure generating member has a gap between the negative pressure generating member and the wall by being formed so that the negative pressure generating member is interposed in a path connecting the air communication portion and an upper end of the air introduction path. It is characterized by having.

[0011] The air introduction path is formed by providing a rib on the wall.

[0012] The air introduction path is formed by providing a groove in the wall.

The liquid supply section and the atmosphere communication section are sealed by one member during distribution.

The liquid container is made of a material whose interior is visible.

Further, a liquid contributing to image formation is stored in the liquid storage container.

The negative pressure generating member is a sponge that has not been subjected to a thermal compression process, and the sponge that has not been subjected to the thermal compression process is compressed and stored in the negative pressure generating member storage chamber.

The negative pressure generating member is a sponge subjected to a thermal compression process.

[0018] Thus, by forcibly introducing air into the communication path during ink supply using the air introduction path, the meniscus in the communication path can be stably and promptly broken, and the ink in the ink storage section can be removed. Gas-liquid exchange is performed satisfactorily.

[0019]

FIG. 1 is a cross-sectional view showing a state in which a recording head, an ink tank, and a carriage of an ink jet recording apparatus according to the present invention are connected. The recording head 20 in this embodiment is of a bubble jet type that performs recording using an electric heat exchanger that generates thermal energy for causing film boiling to occur in ink in response to an electric signal. In FIG. 1, the main components of the recording head 20 are all arranged by being bonded or pressed onto the head base plate 111 with the positioning projections 111-1 and 111-2 provided on the head base plate 111 as a positioning reference. Here, the in-plane vertical direction in FIG. 1 is positioned by the head positioning portion 104 of the carriage HC and the projection 111-2. Further, in the vertical direction of the cross-sectional view of FIG. 1, a part of the protrusion 111-2 protrudes so as to cover the head positioning portion 104, and a notch (not shown) of the protrusion 111-2 and the head positioning portion 104 are formed. Positioned. The heater board 113 includes a plurality of electrothermal transducers (discharge heaters) arranged in a plurality of rows on an Si substrate, and electrical wires such as aluminum for supplying power to the heaters formed by a film forming technique. Flexible board (hereinafter, referred to as a head flexible board) having a wiring that has a pad for receiving an electric signal from
It is called "head PCB". ) 105 are connected by wire bonding so that the respective wirings correspond to each other. Replaceable ink tank 1 through a partition or a channel for dividing each of the plurality of ink channels corresponding to the discharge heater.
A grooved top plate 112 in which a common liquid chamber for introducing ink from the nozzle and supplied to the ink flow path and an orifice forming a plurality of discharge ports is integrally molded with polysulfone or the like is pressed against the heater board 113 with a spring (not shown) and sealed. The ink ejection portion is formed by press-fixing and sealing using a stopper.

The flow path 115 which is connected and sealed to the groove top plate 112
In the present embodiment, is penetrated to the opposite side of the head base plate 111 through a hole provided in the head PCB 113 and the head base plate 111 so that the head base plate 111 can be connected to the replacement ink tank 1. Adhesively fixed. In addition, a filter 25 is provided at an end of the flow path 115 on the side to be connected to the ink tank 1 to prevent dust or unwanted bubbles from flowing into the ejection section.

The replacement ink tank is coupled to the recording head 20 by an engagement guide and pressurizing means 103, and is mechanically brought into contact with the filter 25 provided at the end of the flow path 115 by the ink absorber of the ink supply unit. A bond is made.
After coupling, the recording head suction recovery pump 50 of the recording apparatus main body
15 and the like, the ink is combined by forcibly supplying and filling the recording head 20 with ink from the replacement ink tank 1.

In this embodiment, the recording head 20 and the replacement ink tank 1 are connected when engaged by the pressing means, and the recording head 20 and the carriage HC are mechanically and electrically connected in the same direction. Therefore, the positioning of the pad on the head PCB 105 and the head drive electrode 102 is also ensured.

In this embodiment, the ring seal is formed of a somewhat thick elastic ring so that the joint portion with the outer wall of the replacement ink tank can be widened so as to allow backlash of the ink supply portion.

As described above, in the present embodiment, the replacement ink tank 1 and the recording head 20 are sufficiently coupled to each other, and then the replacement ink tank is urged. In addition, the recording head and the replacement ink tank are simply connected outside the main body and then mounted on the carriage, so that the replacement operation can be facilitated. In this embodiment,
Since the electrical connection between the carriage (printer main unit) and the printhead is also made at the same time, the operability when replacing the printhead and the replacement ink tank is good, but the electrical connection is made by a separate connector connection method. Then, it is also possible to increase the degree of freedom in the configuration for further assuring the positioning of the recording head and the coupling with the replacement ink tank.

Here, in order to explain the arrangement and operation of the recording head in the ink jet recording apparatus according to the present embodiment, the operation of the recording apparatus will be described with reference to FIG. In FIG. 4, the recording medium P is
000 using a paper holding plate 5002 in the carriage moving direction.
000. The carriage HC is fitted with a carriage moving pin in its spiral groove 5004 and supported and engaged by a lead screw 5005 that operates as a drive source by rotating itself and a slider 5003 arranged in parallel with the lead screw, and the plan is performed. It reciprocates right and left along the recording surface of the recording medium P guided on the ten roller 5000. The rotation of the lead screw 5005 is controlled via the drive transmission gears 5011 and 5009 in conjunction with the forward / reverse rotation of the drive motor. Reference numerals 5007 and 5008 denote home position detecting means for confirming the presence of the carriage lever 5006 in this region by photocouplers and switching the rotation direction of the motor 5013.

The image recording signal is sent to the recording head in a timely manner with respect to the movement of the carriage on which the recording head is mounted, and performs recording by discharging ink droplets at predetermined positions.
Reference numeral 5016 denotes a member for supporting a cap member 5022 for capping the front surface of the recording head. Reference numeral 5015 denotes suction means for suctioning the inside of the cap, and performs suction recovery of the recording head through an opening 5023 in the cap. Reference numeral 5017 denotes a cleaning blade. Reference numeral 5019 denotes a member that allows the blade to move in the front-rear direction. These members are supported by a main body support plate 5018. It is needless to say that the suction means, the blade, and the like need not be in this form, and well-known ones can be applied. Reference numeral 5012 denotes a lever for determining the timing of the suction recovery operation. The lever 5012 moves with the movement of the cam 5020 engaging with the carriage, and the driving force from the driving motor is controlled by known transmission means such as clutch switching. Is done. These recovery means are configured such that when the carriage comes to the home position side area, desired processing can be performed at predetermined positions at the corresponding positions by the action of the lead screw 5005.

Now, an embodiment of the ink tank of the present invention will be described in detail.

First, the configuration and operation principle of the ink tank which is the basis of the present invention will be described.

(Construction) As shown in FIG. 2, the main body of the ink tank has an opening 2 for connecting to an ink jet recording head, and a negative pressure generating member accommodating portion 4 accommodating a negative pressure generating member 3 and the negative pressure generating member accommodating portion 4. An ink container 6 for storing ink 9 which is adjacent to the negative pressure generating member container via the rib 5 and communicates via the gap 8 in the ink tank bottom 11;

(Principle of Operation (1)) FIG. 2 shows an ink tank 1 according to the present invention.
FIG. 7 is a schematic cross-sectional view when a joint member 7 for supplying the pressure is inserted and comes into pressure contact with the negative pressure generating member 3 so that the ink jet recording apparatus can be operated. Incidentally, a filter 25 may be provided at the end of the joint member 7 in order to remove dust in the ink tank.

When the ink jet recording apparatus is operated, ink is discharged from the orifice of the ink jet recording head 20, and an ink suction force is generated in the ink tank 1. The ink 9 passes from the ink container 6 to the rib end B and the bottom 11 of the ink cartridge due to the suction force, and passes through the gap 8 communicating the ink container 6 and the negative pressure generating member container 4. It is drawn into the joint member 7 through the negative pressure generating member 3 and supplied to the ink jet recording head 20 into the negative pressure generating member housing section 4. As a result, the pressure inside the ink container 6 that is closed except for the gap 8 decreases,
A pressure difference is generated between the ink containing section 6 and the negative pressure generating member containing section 4. When the recording is continued, the pressure difference continues to rise, but the air passes through the negative pressure generating member 3 and the rib end B because the negative pressure generating member accommodating portion 4 is open to the atmosphere through the air communication hole 13. The ink enters the ink container 6 through the gap 8 with the bottom 11 of the ink cartridge. At this point, the pressure difference between the ink storage section 6 and the negative pressure generating member storage section 4 is eliminated. This operation is repeated during ink jet recording, and a certain negative pressure is obtained in the ink cartridge. In addition, the ink 9 in the ink container 6 can be used almost entirely except for the ink 9 attached to the wall surface in the ink container 6, so that the ink use efficiency is improved.

(Operating Principle (2)) A simple model for explaining the operating principle of the present ink tank based on the operating principle (1) of the present ink tank described above is shown in FIG. (2) will be described.

In FIG. 10, the ink container 106 includes
It corresponds to the ink storage section 6 and contains ink. 10
Reference numerals 2, 103-1 and 103-2 denote capillary tubes schematically representing the negative pressure generating member 3 from a functional aspect, and generate a negative pressure in the ink tank by the force of the meniscus. 107
Corresponds to a joint member 7 and is connected to an ink jet recording head (not shown). This area corresponds to an ink supply unit that supplies ink from an ink tank. Flow Q occurs.

This figure corresponds to a state in which the ink storage section and the negative pressure generating member are sufficiently filled with ink, a state in which the ink can be supplied in the negative pressure generation member, and a state in which the ink is slightly consumed from the ink storage section. Then, the head pressure at the orifice of the recording head and the decompression state in the ink container 106,
103-1 and 103-2 are in a state where the capillary forces are balanced. When ink is supplied from the ink supply unit, 1
The heights of the capillary tubes 03-1 and 103-2 hardly change, and the ink is consumed from the ink storage unit 106 through the space 108 corresponding to the gap 8. Ink storage unit 10 at that time
Due to the increase in the negative pressure in Step 6, the meniscus of the capillary of 102 is displaced into a bubble shape, and the meniscus is broken, so that the atmosphere becomes bubbles and the ink storage unit 106
Is taken in. Thereby, 103-1 and 103-2
Without changing the height of the capillary tube, that is, with almost no change in the ink distribution in the negative pressure generating member, and maintaining the balance of the internal pressure substantially, by the amount of ink supplied,
From 06, ink is consumed.

That is, when ink is supplied from the ink supply unit by the amount of ink Q, the change in the volume is 10%.
In the second capillary, a displacement of the meniscus occurs as a displacement of the meniscus, and the change in the surface energy of the meniscus at that time increases the negative pressure of the ink supply unit as a pressure loss. When the bubbles and ink are finally exchanged, the meniscus also returns to its original state, and the internal pressure of the ink supply unit is maintained at a predetermined internal pressure by the capillary force of 102.

FIG. 11 shows how the internal pressure in the ink supply section of the ink tank according to the present embodiment changes according to the ink supply amount (consumption amount). Initial state (Fig. 14)
Then, as described above, the supply of ink from the negative pressure generating member housing section starts. In other words, the ink present in the negative pressure generating member accommodating portion is supplied until the meniscus is formed in the lower end portion of the ink chamber wall, that is, the gap portion 8, so that the ink is supplied in the same manner as the conventional all-absorber type ink tank. The internal pressure of the ink supply unit is generated by the balance between the capillary force on the ink upper surface (gas-liquid interface) of the compressed ink absorber in the pressure generating member housing and the head pressure of the ink itself. A state in which the ink in the negative pressure generating member accommodating portion decreases along with the ink supply (consumption) and a gas-liquid interface is formed at the lower end of the ink chamber as described above (FIG. 15).
Then, the ink supply from the ink storage section starts, the internal pressure of the ink supply section is maintained by the capillary force of the compressed ink absorber near the lower end of the ink chamber, and the ink is supplied from the ink storage section. Maintains a substantially constant internal pressure. When the ink is further consumed and the ink in the ink storage section is almost consumed and the ink liquid level in the ink storage section becomes lower than the lower end of the ink chamber wall (FIG. 16), the air is supplied to the ink storage section at a stretch, and the ink storage section is supplied. Is completely communicated with the atmosphere, and a small amount of ink remaining in the ink storage unit is absorbed by the compressed ink absorber in the negative pressure generation member storage unit, and the amount of ink in the negative pressure generation member storage unit increases. The internal pressure of the ink supply unit slightly changes in the positive direction by the amount that the gas-liquid interface slightly increases. Further, when the ink is consumed, the ink in the negative pressure generating member accommodating section starts to be consumed again. However, when the air goes down from the ink supply section to the gas-liquid interface, the air starts to be supplied to the recording head, and the ink supply is limited (FIG. 17). ,
The ink tank needs to be replaced.

According to the study by the present inventor, when the head is connected to the print head, suction recovery is performed by the suction means of the printing apparatus main body.
By removing bubbles in the ink flow path generated at the time of combining and allowing some ink to flow out of the ink tank,
It is possible to maintain a stable ink internal pressure from the beginning, and even if the ink in the negative pressure generating member accommodating section is consumed at the initial stage and immediately before replacement, there is no problem in the recording characteristics during the stable ink supply period shown in FIG. No good recording was performed.

According to the mechanism described above, it has been found that there are the following important points in order to supply ink.

It is stable in the immediate vicinity of the gap 8,
That is, a meniscus between the ink and the atmosphere needs to be formed. Otherwise, in order to displace the meniscus and move it to the ink storage unit, ink must be supplied until the internal pressure of the ink supply unit becomes a considerably large negative pressure. Then, driving at a high frequency becomes difficult, which is disadvantageous for performing high-speed printing.

FIG. 11 shows the relationship between the internal pressure in the ink supply section of the ink tank and the ink supply amount (consumption amount).
And a so-called static negative pressure in a state where ink is not supplied, and a so-called dynamic negative pressure in a state where ink is supplied.

In this figure, the difference between the dynamic negative pressure and the static negative pressure is the pressure loss when the ink is supplied, and the negative pressure generated at the time of meniscus displacement described above makes up a large ratio.

Therefore, the point of the present invention is to promptly break the meniscus in this portion, and the means for that is to provide an air introduction path for forcibly introducing the air into the vicinity of the gap 8. Some examples are given below.

<Embodiment 1> FIG. 3 shows a first embodiment of the present invention, which will be described in detail with reference to FIG. The negative pressure generating member 3 of the ink tank is an absorbent such as urethane foam. When the absorber 3 is delivered to the negative pressure generating member housing 4, the rib 5 of the negative pressure generating member housing 4 and the absorber 5 3
Between the rib end portion B and the bottom portion 11 of the ink tank, the air introduction passage 14 extends to the vicinity of the gap 8 between the rib end portion B and the ink tank bottom 11. Has become. And it communicates with the atmosphere through the atmosphere communication port. For this reason, when the ink 9 starts to be supplied from the ink supply unit 2, a certain amount of ink is consumed from the absorber 3, and when the internal pressure of the ink supply unit 2 reaches a predetermined negative pressure,
An ink surface as shown in FIG. 3 is formed in the absorber 3 stably, and a meniscus is formed between the ink and the atmosphere near the gap 8. When this state is reached, the meniscus can be immediately broken at the gap 8 by the subsequent supply of the ink 9, and as a result, the ink loss can be stably performed without making the pressure loss ΔP too large. Therefore, high-speed printing is possible with good ejection stability.

At the time of non-printing, the capillary force of the negative pressure generating member itself (or the meniscus force at the interface between the ink and the negative pressure generating member) and the like are developed, and the leakage of the ink from the ink jet recording head is suppressed.

In order to use the ink tank 1 of the present invention in a color ink jet recording apparatus, inks of each color (for example, four colors of black, yellow, magenta, and cyan) are stored in individual ink tanks and used. Can be. Also, an ink tank may be formed by integrating individual ink cartridges, or a replaceable ink cartridge for frequently used black ink and a replaceable ink cartridge in which other color ink integrated replaceable cartridges are separated. good. These combinations are arbitrary according to the ink jet device.

Hereinafter, the present invention will be described in more detail.

In the ink tank according to the present invention, in order to control the negative pressure in the ink jet recording head, not only the selection, shape and size of the negative pressure generating member 3 but also the shape and size of the rib end B and the rib end B And size of the gap 8 between the ink container and the bottom 11 of the ink tank, the volume ratio of the negative pressure generating member housing 4 and the ink housing 6, the amount of insertion of the joint member 7 into the ink tank, the shape and the size, and the filter 25. It is preferable to optimize the shape, size, roughness of the surface, surface tension of the ink, and the like.

As the negative pressure generating member 3 used in the present invention, a conventionally known member can be used as long as it has the ability to hold the ink even by its own weight of liquid (ink) and slight vibration. . For example, a cotton-like body in which fibers are meshed into a net, a porous body having communication holes, and the like can be given. A sponge such as a polyurethane foam whose ink holding power and negative pressure generation are easily adjusted is preferable. In particular, a foam is preferable because it can be adjusted to a desired porosity during foam production. If the foam density is further adjusted by performing a heat compression treatment on the foam, decomposition products are generated by heating, which may change the physical properties of the ink and adversely affect the recording quality. Required. Also, in order to manufacture an ink cartridge corresponding to various ink jet recording apparatuses, a foam having a corresponding porous density is required, but it has a specific number of cells (the number of holes per inch) that is not subjected to thermal compression. It is preferable that the foam material is cut into a desired size, and the foam material is compressed and inserted into the negative pressure generating member accommodating portion 4 to adjust the porosity and the capillary force.

(Environmental Change in Inkjet Recording Apparatus) In an ink cartridge (ink tank) having a closed ink container 6, an external environmental change (temperature rise, or With respect to the pressure drop, the ink 9 remaining in the ink containing section 6 is pushed out of the ink containing section 6 by the air expansion of the ink containing section (there is also the expansion of the ink). May cause ink leakage. However, in the ink cartridge according to the present invention, the air expansion volume (including a small amount of ink expansion) of the closed system ink storage unit 6 according to the worst-cased environmental condition is predicted, and the ink storage unit 6 associated therewith is estimated. It is preferable that the negative pressure generating member accommodating section 4 previously has the amount of ink movement from the ink. In addition, the installation position of the atmosphere communication hole 13 is as follows.
Although there is no particular designation as long as it is above the joint opening as the ink supply port 2 on the side of the negative pressure generating member accommodating portion 4, in order to separate the flow of ink in the negative pressure generating member 3 from the joint opening when the environment changes. , Preferably far from the joint opening. The number, shape, size, and the like of the air communication holes 13 can be arbitrarily set in consideration of the evaporation of the ink.

(Distribution of the ink cartridge alone) When distributing the ink cartridge alone, the joint opening and / or the air communication hole 13 should be sealed with a sealing material or the like to prepare for evaporation of ink and air expansion in the ink cartridge. Is preferred. As a sealing material, a composite of a single layer barrier and several layers of a plastic film, which are called a barrier material in the field of packaging, and a composite material of these and a reinforcing material such as paper and cloth, or an aluminum foil. It is preferred to use. It is more preferable that the material similar to the material of the ink cartridge body is used as the adhesive layer of the barrier material and the hermeticity is increased by welding with heat or the like.

Further, in order to suppress the evaporation of ink from the ink cartridge or the inflow of air from the outside atmosphere, a packaging form in which the air inside the packaging material is degassed after the ink cartridge is inserted and then sealed. It is effective.
As the packaging material, it is preferable to select a barrier material as in the above-mentioned sealing material, in consideration of gas permeability and liquid permeability.

By selecting the above-described packaging form, the physical distribution of the ink cartridge alone becomes very reliable without ink leakage or the like.

(Manufacturing method) The material of the ink cartridge body may be any material conventionally used for a molded product, but a material which does not affect the ink for ink jet or a member which is treated so as not to affect the ink. You need to choose from. It is also necessary to consider the productivity of the ink cartridge. For example, the ink cartridge body is divided into an ink cartridge bottom portion 11 and an upper portion thereof, which are integrally molded with a resin material. After the negative pressure generating member 3 is inserted, the ink cartridge bottom portion 11 and the upper portion are welded. Thus, the ink cartridge body can be manufactured. If a transparent or translucent resin material is selected, the ink in the ink container can be visually recognized from the outside of the ink cartridge, so that the time for replacing the ink cartridge can be visually determined. Further, in order to facilitate welding of the sealing material or the like, it is preferable to provide a convex portion as shown in the figure. Furthermore, it is also preferable in terms of design that the outer surface of the ink cartridge body is subjected to processing such as embossing.

For filling the ink, any of a pressurizing method and a depressurizing method can be used. It is preferable to provide an ink filling port in any one of the tank main bodies for filling the ink, because it does not contaminate the other ink cartridge openings. The ink filling port after ink filling is preferably plugged with plastic or a metal material.

Various modifications can be made to the configuration and shape of the ink cartridge without departing from the scope of the present invention.

(Others) The present ink tank (cartridge) may be used as a replaceable type, or may be integrated with a recording head.

When used as a replaceable type, it is preferable to automatically detect the replaceable tank by the main body or perform a recovery operation such as suction by the user himself.

Needless to say, as shown in FIG. 18, Bk (black) 1a and C (cyan) 1
The ink cartridge may be used as an ink-jet printer that performs recording by combining four color exchange ink tanks of b, M (magenta) 1c, and Y (yellow) 1d.

<Comparative Example> Here, a comparative example in the present embodiment will be described while showing how the internal pressure in the ink supply section of the ink tank changes according to the ink supply amount.

In the ink tank, no air introduction path is provided, and an absorber having a substantially uniform pore size distribution is built in the negative pressure generating member accommodating portion.

In the initial state, the ink container is almost completely filled with ink as shown in FIG. 14, and the negative pressure generating member container is also filled with some ink. When the ink supply is started from this state, first, the ink is supplied from the negative pressure generating member accommodating portion, so that the capillary force on the ink upper surface (gas-liquid interface) of the absorber in the negative pressure generating member accommodating portion and the ink itself. The internal pressure of the ink supply unit is generated due to the balance with the water head pressure, but as the ink supply progresses, the upper surface of the ink descends, so the negative pressure increases almost linearly with the height. I will do it. The state shown in FIG. Unless the state where a gas-liquid interface (meniscus) is formed in the gap, which is the lower end of the ink chamber, along with the ink supply, the negative pressure of the ink supply part increases steadily.

By the time the meniscus is formed in the gap, the ink level in the absorbent body drops considerably, and in some cases, the liquid level drops below the joint with the head. I will.

In this case, the atmosphere is taken into the recording head, and the ejection becomes unstable, resulting in non-ejection.

Even if this is not the case, the internal pressure of the ink supply unit exceeds a certain negative pressure determined by the pore size of the absorber in the gap as shown in FIG.
It may be even larger. This is because the absorber is slightly compressed around its inner wall by the inner wall of the negative pressure generating member housing part, but since there is no wall in the gap, it is not compressed. Since it is slightly smaller, it is considered that the state is just like the model shown in FIG.

This figure shows a state where the ink has been consumed from the negative pressure generating member accommodating portion to some extent. When ink is further supplied from this state, the pore size of the absorber becomes R ₂ , R _2
3, the meniscus of the largest part of R ₄ in R ₄ is R
_3, as compared with the portion of R ₄ greatly displaced moves and subsequently come to near the gap portion, since the sudden meniscus force is weakened, to move the meniscus to the ink container side, that the meniscus is broken Then, the atmosphere is taken into the ink container. At this time, not only from the portion of R _2, it is consumed little ink from part of R _3, R _4.
At this time, the pressure loss ΔP during the movement of the meniscus becomes relatively large.

However, the meniscus once broken also forms a meniscus again at a position close to the original position due to the momentum at the time of return, so that the pressure loss remains high for a while.

[0067] Then, the meniscus is stabilized at the portion of the pore size R ₁ of the gap portion, repeating the same, once the meniscus gap portion is stabilized, bubbles until the negative pressure determined by the pore size R ₁ of the clearance Enters the ink storage section and stabilizes.

The state up to this point is the state shown in FIG. 13-b, in which ink is consumed from both the ink container and the absorber. As described above, if the air introduction path is not set, the internal pressure in the ink supply unit is not stabilized as described above, and the pressure loss ΔP at the time of ink supply becomes large, so that the ejection characteristics deteriorate and high-speed printing becomes difficult. There are cases.

<Embodiment 2> FIG. 5 shows another embodiment.

In this embodiment, two ribs 61 are provided inside the negative pressure generating member accommodating portion 4 of the rib 5.
The rib 61 extends from the ceiling of the ink tank to the vicinity of the gap 8. A portion sandwiched between the ribs and the absorber 3 becomes the air introduction path 14.

The lower end A of the rib 61 is
The gap 8 can be covered with the absorber 3 simply by inserting the rectangular parallelepiped absorber 3 into the negative pressure generating member accommodating portion 4 by positioning the lower portion B above the lower end B of the upper portion. Therefore, the air introduction path 14 which is simple and stable is formed in the gap 8
It is possible to adopt a configuration for guiding to a very close vicinity of. still,
Between the contact point of the ceiling portion of the rib 61 and the air communication hole 13,
The absorber 3 is interposed.

When printing was performed using this ink tank, the ink was supplied by printing, and quickly, as shown in FIG.
The ink surface and the meniscus as shown in Fig. 1 are formed, and the crispness and the replacement of the bubble and the ink by the meniscus rupture are performed, so that the ink supply with a small pressure loss can be performed, and the high-speed printing can be stably performed. It is now possible to do it.

<Embodiment 3> FIG. 6 shows another configuration of the air introduction passage 14. The number of the ribs 71 similar to the rib 61 in the embodiment 2 is further increased, and the number of the air introduction passages 14 is increased. The rib 71 is also provided on the ceiling of the negative pressure generating member accommodating portion. The absorber 3 is interposed between the end of the rib 71 provided on the ceiling and the air communication hole 13.

As a result, it is possible to stably secure the plurality of air introduction paths 14 from the air communication port 13 to the vicinity of the gap 8, and to supply ink with a small pressure loss as in the first and second embodiments. As a result, high-speed printing can be stably performed.

Even if the air communication hole 13 is provided at a position distant from the gap 8, air can be introduced smoothly.

<Embodiment 4> FIG. 7 shows another embodiment.

In this embodiment, similarly to the second and third embodiments, the air introduction path 14 is formed by providing the ribs 81 on the ribs 5. Asymmetrical configuration, the negative pressure generating member accommodating portion 4 passes from the ink accommodating portion 6 through the gap 8.
The flow path of the air flowing into the ink container 6 through the gap 8 from the air introduction path 14, which is generated complementarily to the flow of the ink 9, flows through the center line A. On the other hand, by making them independent, there is an effect of reducing the pressure loss for replacement.

As a result, the pressure loss ΔP for replacing the ink and the air bubble is reduced to about half.

As a result, it is possible to more stably eject ink from the recording head.

<Embodiment 5> FIG. 8 shows another modification of the rib 91.

In the second to fourth embodiments, the upper end of the rib 91 extends to the upper side of the inner wall of the negative pressure generating member housing portion.
In the present embodiment, it is assumed that the length does not extend to that and is short.

This prevents the upper portion of the absorber from being compressed by the ribs 91, prevents the risk of meniscus force being generated in the compressed portion, and makes the control of the negative pressure more stable. can do.

More specifically, in the initial ink tank in which the ink is consumed, the ink level in the absorber, which is the negative pressure generating member 3, changes from the ink level in the absorber to the stable ink level. Try to consume ink. In other words, if the premature gas-liquid exchange through the air introduction passage 14 is promoted, the ink is consumed from the ink storage unit 6 and the consumption of the ink from the absorber 3 is reduced. At the time of the change, the amount of ink that can be transferred from the ink storage unit 6 to the negative pressure generating member storage unit 4 is limited, so that the buffer effect against the ink leakage of the absorber 3 is reduced by half. . Therefore,
In the present embodiment, the air introduction path 14 is provided so that the ink is introduced into the air after the ink has been consumed to some extent in the absorber 3, and the ink liquid level in the absorber 3 is controlled.
Increased buffer effect against ink leakage.

In addition, it is possible to stably maintain the ink liquid level in the absorber 3 near the air introduction path 14, and to maintain a substantially constant negative pressure while the ink 9 in the ink containing section 6 is consumed. Pressure (head difference). Thus, the negative pressure on the head can be stabilized, and the ejection of ink from the ejection port can be stabilized.

<Embodiment 6> FIG. 9 shows another embodiment.

In this embodiment, the air introduction path 14 is formed by providing a groove 100 in a rib.

The distortion of the compressibility of the absorber 3 accommodated in the negative pressure generating member accommodating portion 4 is reduced, so that the negative pressure can be easily controlled, so that the ink can be supplied stably.

<Embodiment 7> Another embodiment will be described with reference to FIG.

The construction is almost the same as that of the sixth embodiment, except that the air introduction path 14 extends to the lower end B of the rib.
That is, it has an outstanding configuration.

As in the case of the fifth and sixth embodiments, the ink liquid level in the absorber 3 in the initial ink tank where the ink is consumed is changed from the ink liquid level in which the height of the upper end portion C of the air introduction path 14 is stable. Until the process shifts to, the ink in the absorber is consumed, and thereafter the ink 9 in the ink storage section 6 is consumed while performing gas-liquid exchange through the air introduction path 14. Since the lower end B of the rib is penetrated, the behavior can be considered as a model as shown in FIG.

Hereinafter, a detailed description will be given using a model.

When the absorber 3, which is a negative pressure generating member, is schematically represented from a functional point of view, it is considered to be a capillary tube as shown in FIG. 20, and the air introduction path 14 extends from the upper end portion C to the rib lower end B. Therefore, it is considered that the air introduction passage 14 is connected to the capillary again from the upper end portion C to the upper side.

As described above, the ink level in the absorber 3 is at a certain height in the initial ink tank where the ink is consumed, but gradually increases as the ink is consumed. Then, the liquid level decreases, and accordingly, the internal pressure (negative pressure) in the ink supply unit 6 gradually increases.

When the ink is consumed up to the height of the upper end portion C, which is the upper end of the air introduction path 14, the ink liquid surface forms a meniscus at the position D in the capillary. When the ink is further received and consumed, the ink liquid level, that is, the meniscus is lowered again. Since the ink in the path 14 will be consumed, the ink in the ink storage section will be consumed at this position thereafter. That is, gas-liquid exchange is performed. Accordingly, during ink consumption, the ink liquid level is stabilized at the position C slightly below the height of the upper end portion C, so that the internal pressure in the ink supply unit 6 enters the stable region. When the ink supply is stopped, the meniscus in the capillary returns from the position E to the position D again, and is stabilized.

As described above, the ink liquid level in the absorber 3 reciprocates between D and E until all the ink in the ink container 6 is consumed.

Then, since the ink in the absorber 3 is consumed thereafter, the internal pressure (negative pressure) of the ink supply unit 2 increases again, and the ink runs out.

The internal pressure in the ink supply unit 6 is determined by the capillary force of the absorber 3 (that is, the height corresponding to the height at which the absorber can absorb ink). Because the difference is obtained as
Considering that it is necessary to set the height of the ink supply unit 2 higher than that of the ink supply unit 2, it is necessary to reduce the pore size of the absorber 3 to some extent.

The reason why the height of the upper end portion C is set higher than that of the ink supply unit 2 is obvious. If the ink liquid level is lower than that of the ink supply unit 2, the air is taken in and the ejection failure occurs. This is to prevent it.

On the contrary, it is not good to make the height too high.
That is, this is because there is less room for a buffer when ink overflows from the ink storage unit 6 to the absorber 3 due to a change in internal pressure in the ink tank due to a change in environment. So C
The volume of the absorber 3 above the height is set to about half of the volume of the ink container 6.

The mechanism described above will be described more simply.

That is, assuming that the absorber 3 has a uniform density, the internal pressure (negative pressure) in the ink supply unit 2 can be absorbed from the capillary force of the absorber 3, that is, the height of the ink supply unit 2. from the height H _1, it is the determined by the difference or H ₁ -H ₂ height H ₂ already ink from the height of the ink supply portion 2 is sucked up.

That is, for example, if the force for pulling up the ink in the absorber 3 is H ₁ = 60 mm and the height of the portion C from the ink supply section 2 to the air introduction path 14 is H ₂ = 15 mm, the ink supply section internal pressure H ₁ -H ₂ = 60mm-15m
m and 45 mmAq.

Therefore, in the initial stage, as the ink 9 is consumed from the absorber 3, the internal pressure (negative pressure) decreases almost linearly as the liquid level decreases.

By using the ink tank having the above-described structure, it is possible to supply ink at a stable negative pressure.

Further, since the structure of the ink tank itself can be easily formed by using a mold or the like, it is possible to manufacture a large amount of the ink tank at low cost.

Next, when the ink is further consumed and the liquid level in the absorber 3 reaches the position of the air introduction path 14, that is, the position of the upper end portion C, that is, when the ink liquid level becomes the state of E in FIG. Since the ink in the air introduction passage 14 cannot maintain the meniscus, the ink is absorbed by the absorber 3 to form an air passage, and gas-liquid exchange is performed at a stretch by introducing the air.
The ink level absorbed by the absorber 3 causes the liquid level of the absorber 3 to rise again, so that the liquid level becomes D, and the gas-liquid exchange stops. In this state, there is no ink in the air introduction passage 14 already, and the absorber 3 on the air introduction passage 14 drawn as a model diagram simply functions as a valve. Here, the upper end portion C of the atmosphere introduction path 14 and the atmosphere communication hole 1
3, a negative pressure generating member is interposed.

Therefore, if the ink is consumed again in this state, the liquid level of the absorber 3 is slightly lowered and the valve is opened. When the ink consumption ends, the liquid level of the absorber 3 rises due to the capillary force of the absorber, but when it reaches the position D, the gas-liquid exchange is stopped. The surface will be stable.

As described above, the ink level is adjusted to the air introduction path 14.
, That is, the height of the upper end portion C, and the capillary force of the absorber 3, that is, the ink pulling height is adjusted in advance, so that the internal pressure of the ink supply unit 2 can be easily adjusted. It becomes possible to control.

Further, in order to hold ink overflowing from the ink storage section to the absorber side due to a change in pressure in the ink tank due to a change in environment, the capillary force of the absorber, that is, the ink pulling height is increased. By doing so, the ink 9 overflows from the ink tank and the ink supply unit 2
Prevents the pressure from becoming positive.

[0110]

As described above, according to the present invention,
When the ink is supplied, the ink in the ink container and the atmosphere can be stably and quickly gas-liquid exchanged,
As a result, it has become possible to stably control the internal pressure in the ink supply unit, and to achieve high-speed printing with good ejection stability in the recording head.

In addition, it has become possible to provide an ink tank that does not cause ink leakage even when the pressure inside the ink tank changes due to a change in the external environment.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a connection between a head and an ink tank.

FIG. 2 is a schematic diagram showing another example of a head and a tank according to the present invention.

FIG. 3 is a schematic view showing an example of a tank according to the present invention.

FIG. 4 is a perspective view schematically showing a recording apparatus.

FIG. 5 is a schematic view showing an example of an ink tank according to the present invention.

FIG. 6 is a schematic view showing another example of the ink tank according to the present invention.

FIG. 7 is a schematic diagram showing still another example of the ink tank according to the present invention.

FIG. 8 is a schematic view showing another example of the ink tank according to the present invention.

FIG. 9 is a schematic view showing still another example of the ink tank according to the present invention.

FIG. 10 is a diagram showing a model of an ink supply state according to the present invention.

FIG. 11 is a characteristic diagram showing a state of an internal pressure change in an ink supply unit according to the present invention.

FIG. 12 is a diagram showing a model of a state of ink supply in a comparative example.

FIG. 13 is a characteristic diagram illustrating a state of an internal pressure change in an ink supply unit in a comparative example.

FIG. 14 is a diagram illustrating an initial state in which ink is filled in an ink tank.

FIG. 15 is a diagram showing a state in which a gas-liquid interface has begun to be formed.

FIG. 16 is a diagram illustrating the vicinity of the end of ink supply.

FIG. 17 is a diagram illustrating a state where ink is supplied.

FIG. 18 is a perspective view showing a form in which four heads are integrated and an individual tank can be attached.

FIG. 19 is a schematic view showing still another example of the ink tank according to the present invention.

FIG. 20 is a diagram showing a model of an ink supply state according to the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiromitsu Hirabayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Shigetasu Nagoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Kyano (72) Inventor Hitoshi Sugimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masaya Uezuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Miyuki Matsubara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Fumihiro Goto 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] A negative pressure generating member storage chamber including an atmospheric communication portion communicating with the atmosphere, a liquid supply portion for supplying a liquid to a liquid ejecting head, and a negative pressure generating member stored therein; A liquid storage chamber that communicates with the pressure generating member storage chamber via the communication path and is substantially sealed except for the communication path; and a wall extending upward from the communication path of the negative pressure generation member storage chamber. A liquid storage container for a liquid ejecting head, comprising: By forming an air introduction path through which air can be introduced into the liquid storage chamber to enable liquid exchange, the side surface of the wall on the negative pressure generating member storage chamber side is directed from the upper end of the wall to the communication path. Having a gap between the negative pressure generating member and the wall A liquid container, wherein the negative pressure generating member is interposed in a path connecting the air communication section and an upper end of the air introduction path. 2. The liquid container according to claim 1, wherein the air introduction path is formed by providing a rib on the wall. 3. The liquid container according to claim 1, wherein the air introduction path is formed by providing a groove in the wall. 4. The liquid supply section and the atmosphere communication section,
2. The liquid container according to claim 1, wherein a single member is sealed during distribution. 5. The liquid storage container according to claim 1, wherein the liquid storage container is made of a material whose inside is visible. 6. The liquid container according to claim 1, wherein a liquid contributing to image formation is stored in the liquid container. 7. The negative pressure generating member is a sponge that has not been subjected to a thermal compression process, and the sponge that has not been subjected to the thermal compression process is compressed and stored in the negative pressure generating member storage chamber. The liquid container according to claim 1, wherein 8. The liquid container according to claim 1, wherein the negative pressure generating member is a sponge subjected to a thermal compression process.