JP3412150B2 - ink cartridge - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink cartridge for an ink jet recording apparatus in which an ink jet recording head and an ink cartridge are mounted on a carriage and ink is replenished by replacing the cartridge.

[0002]

2. Description of the Related Art In an ink jet printer of a type in which an ink container is mounted on a carriage having an ink jet recording head, fluctuations in water head pressure due to rocking of ink due to movement of the carriage and printing due to foaming In order to prevent defects, the ink container is divided into two areas, the porous body is housed on the recording head side, and the ink is housed on the other area, as described in European Patent Publication 581531. Something that has been done is proposed. With such a structure, since the ink is supplied to the recording head through the porous body, it is possible to prevent the inconvenience caused by the ink swing.

[0003]

By the way, in the ink jet type recording apparatus, since the ink in the pressure generating chamber is pressurized to generate ink droplets, when the ink contains bubbles, the pressure is lowered and the ink is discharged. Since the ejection performance of droplets also deteriorates, measures have been taken to prevent bubbles from being mixed in the process of injecting ink into the ink cartridge. For example, the ink from which the dissolved air has been removed is injected into the porous body or is injected under reduced pressure. On the other hand, at the time of use, the pressure was reduced in order to keep the dissolved air removed so that the air bubbles that entered when the ink cartridge was installed and the air bubbles remaining in the recording head could be dissolved in the ink and removed. It is carried out in a metal container or wrapped with an air-permeable film. However, if the decompression value in the ink cartridge container is not optimized at the time of manufacturing and assembling the ink cartridge and after that, air bubbles will remain in the ink cartridge, and the ability to dissolve and eliminate the air bubbles remaining in the recording head will be lost. It was found that the above problems, such as chipping, could not be sufficiently solved. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink cartridge capable of reliably eliminating air bubbles and maintaining ink in a quality suitable for printing. Is.

[0004]

In order to solve such a problem, the present invention is suitable for absorbing ink.
Accommodating the multi-porous body was, the comprising: a container body ink supply needle and engaging the ink supply port is provided which communicates with the recording head, a recess for forming the i <br/> ink inlet and vacuum space container
The container body , which comprises a lid that seals the opening of the body,
The inner pressure of the ink container formed by the lid and the lid is reduced to 0 to −300 mmHg, and the ink
The storage container is sealed and stored in a bag made of an air-permeable film , and the space is lower than the internal pressure of the container.
Well maintained.

[0005]

1 and 2 show an embodiment of an ink cartridge, which is a container 1 formed by injection-molding a substantially rectangular parallelepiped polymer material whose opening side is slightly flared. Is divided into a plurality of ink storage chambers 3 by a wall 2, and a porous body 4 made of an elastic material suitable for absorbing and impregnating ink is stored in each storage chamber 3 in a compressed state. An ink supply port 5 that engages with the ink supply needle of the recording head is formed in the. The opening 6 is sealed with a lid 9 having an ink injection hole 7 and an atmosphere communication hole 8.

A convex portion 10 for compressing the porous body 4 is formed in the vicinity of the ink supply port 5, and a concave portion 12 is formed at the upper end thereof to form a vacant chamber 11 having a constant opening area. , A through hole 13 extending from here to the ink supply port 5
Has been drilled. At the outer end of the through hole 13, a packing 16 that is liquid-tightly engaged with the ink supply needle of the recording head is inserted, and can be damaged by the insertion of the ink supply needle, and is made of a low density polyethylene film or the like having low water permeability. It is sealed with an air-permeable film 17. In addition, reference numeral 18 in the figure
The filter material provided so that the recessed part 12 may be covered is shown.

On the other hand, on the surface of the lid body 9, as shown in FIG. 3, a meandering groove 19 having one end communicating with the atmosphere communicating hole 8 and the other end extending to the other side of the lid body 9 is formed. The first film 20 that is prevented from being unintentionally peeled off so as to cover the hatched area in the figure, and the second film 21 that can be easily peeled off by pulling up the tongue piece 21a.
Is attached. In addition, the films 20 and 21 of the groove 19
The region that is not sealed is formed in the lid 9 as a through hole.

FIG. 4 shows an embodiment of the ink injecting apparatus, in which a pedestal 31 for holding the pallet 30 is constructed to be movable up and down as shown by an arrow A by a drive mechanism (not shown). On the other hand, the base 32 is provided with a through hole, the lower surface is formed by the stepped portion 33 on the peripheral surface of the pallet 30, and the upper surface is formed by a lid 34 described later, and an injection chamber 35 is formed. It is connected.

The lid 34 has a through hole 38 formed in a region facing the injection chamber 35, and a piston member 39 which can move up and down as shown by an arrow B in the figure while maintaining an airtight state.
Has been inserted.

The piston member 39 is provided at a position opposed to the ink injection port 7 of the container 1 set in the injection chamber 35 and an air supply device (not shown) so as to face the injection needle 40 and the atmosphere communication port 8 of the container 1. A flow path 41 that communicates is provided. Further, the injection needle 40 is connected to the branch pipe 44 via the flow path 42 and the tube 43.

In this embodiment, the gas-liquid separation unit 45 has its upper and lower ends liquid-tightly fixed to a cylinder 47 so that the hollow fiber bundle 46 serves as a liquid flow path, and the cylinder 47 is connected to a vacuum pump 48. A negative pressure is applied to the outer circumference of the hollow fiber, one end of a cylinder 47 is connected to an ink tank 50 by a tube 49, and the other end is connected to a branch pipe 44 via a stop valve 51.

The measuring pipe 52 includes a cylinder 53 and a piston 5.
4 and the top dead center side is connected to the branch pipe 44 by a tube 55. In the figure, reference numeral 56 is a stop valve, and 57 is a pump for pressure-feeding ink.

When the pallet 30 on which the container 1 on which the respective members have been assembled by the above-described steps is placed reaches the ink injection device and is set below the injection chamber 35, the pedestal 31 is provided.
Rises until it comes into close contact with the lower surface of the base 32.

Next, the piston member 39 is attached to the lid 9 of the container 1.
To a degree where a space can be secured between them, and while the stop valve 51 communicating with the gas-liquid separation unit 45 is closed, the stop valve 56 is opened, and the vacuum pump 37 is operated to operate the injection chamber 35. , The tube 43, and the measuring pipe 52 are depressurized to a predetermined pressure.

When the pressure is reduced to a predetermined pressure, the stop valve 56 is closed, and the stop valve 51 is opened to inject a predetermined amount of the ink 7 into the measuring pipe 52. The member 39 is lowered to the bottom dead center. As a result, the lower end 41a of the flow path 41 is connected to the atmosphere communication port 8, and the injection needle 40 enters from the ink injection port 7 to the vicinity of the bottom surface of the container 1.

Next, when the stop valve 51 is closed to shut off the gas-liquid separation unit 45, the stop valve 56 is opened and the piston 54 of the measuring pipe 52 is pressed to discharge a predetermined amount of ink. A predetermined amount of ink is poured into the container 1.

At this time, since the ink deaerated by the gas-liquid separation unit 45 is injected into the porous body 4,
The ink easily dissolves the gas adsorbed in the pores of the porous body 4 that could not be exhausted in the above-described depressurization step to generate bubbles in the porous body 4 or to leave them, It is uniformly absorbed by the porous body 4.

When the ink injection is completed, the pedestal 31
The container 1 is taken out from the container, and the air-tight film 20 cut to a size that covers the atmosphere communication port 8, the ink injection port 7, and the narrow groove 19 is attached to form a capillary by the narrow groove 19 and the film 20. In this state, when the container 1 is housed in the deaeration chamber and depressurized to about 200 mmHg, the container 1 is depressurized through the narrow groove 19 whose one end is still open. After a predetermined time has passed, the tongue piece 2 for peeling off
An air-permeable film 21 having 1a is attached to the open region of the narrow groove 19 to completely shield the container 1 from the atmosphere.

When the container 1 is depressurized to a pressure lower than -300 mmHg, when minute bubbles remain in the corners of the container 1, especially in the through holes 13, they expand due to depressurization.
It was found that the particles remained in the container as they were, hindering the printing operation. On the other hand, it was found that when the reduced pressure value was increased above -300 mmHg, bubbles did not remain or the size became invisible. That is, the reduced pressure value should preferably be suppressed to -200 mmHg, or at least -300 mmHg.

On the other hand, in the ink cartridge enclosed in the recording apparatus, it is necessary to fill the ink in the flow path such as the pressure generating chamber of the recording head left in the air without leaving bubbles. At the time of filling the recording head with ink, it is desirable that the pressure is lower than the reduced pressure value of the supply product, as described with reference to FIG.
It should be maintained below Hg, more preferably below -250 mmHg.

By the way, a container made of a polymer material or the like and having a structure in which the lid 9 is adhered cannot completely shield air, and therefore, when left in the atmosphere, as shown in FIG. Then, the internal pressure in the container 1 gradually rises. Therefore, the container 1 in which the ink has been completely filled has a bag 60 made of an air-permeable film which is formed as a laminated structure of a polymer material and a metal layer which can be heat-welded within a week at most, as shown in FIG. And a pressure lower than that of the container 1, for example, −
The pressure is reduced to 450 mmHg or less and the opening is sealed by heat welding.

A lid 9 is provided between the bag 60 and the surface of the container 1.
Since the depressurized space is secured by the recess 9a and the gap formed in the container 1, the negative pressure of this space acts on the container 1 and the internal pressure of the container 1 gradually decreases with the passage of time as shown in FIG. As a result, the ability to dissolve bubbles is improved, and the ink cartridge is in a more preferable state. For example, initial-2
The film having a thickness of 00 mmHg or more descends to the vicinity of -300 mmHg, and is then taken out of the bag 60 and the film 2
This internal pressure is maintained until 1 is peeled off.

As described above, the internal pressure is -300 mmH.
By sealing with g or more, air bubbles remaining in the container can be eliminated, or the size can be suppressed to an invisible size. On the other hand, if the bag 60 is housed under a pressure lower than the internal pressure by about 150 mmHg or more, it is observed that even if the bubbles remain in the container, the bubbles disappear with the passage of time. It was also confirmed by experiments that the pressure inside the container 1 also decreased with time as shown in FIG. As a result, the decompression value stored in the bag 60 is lower than the sealing pressure of the container 1 by about 150 mmHg or more, preferably -450.
It is preferable to set the pressure to mmHg or less.

In the ink cartridge included in the recording apparatus, the decompression value is set lower than that of the supplies, and the decompression value of the bag 60 is maintained at -450 mmHg or lower, which is lower than that of the container. The internal pressure will be maintained at about -250 mmHg, which is also suitable for initial filling.

FIG. 7 shows the relationship between the internal pressure of the container and the success rate of initial filling. When the pressure is lower than -240 mmHg, the filling can be reliably completed by only one filling operation.

[0026]

As described above, according to the present invention , the ink pressure can be maintained at a value suitable for eliminating bubbles during the replacement of the ink cartridge for a long period of time, and after the ink is mounted on the recording head. It is possible to maintain the dissolved atmospheric pressure below the saturation value over a long period of time.

[Brief description of drawings]

FIG. 1 is an assembled perspective view showing an embodiment of an ink cartridge of the present invention.

FIG. 2 is a sectional view showing an embodiment of the same ink cartridge as above.

FIG. 3 is a top view showing the structure of the lid of the ink cartridge.

FIG. 4 is a configuration diagram showing an embodiment of an ink injection device.

FIG. 5 is a diagram showing the internal pressure of a container over time.

6A and 6B are diagrams showing a packaging process, respectively.

FIG. 7 is a diagram showing the relationship between the internal pressure of the container and the success rate of initial filling of the recording head.

[Explanation of symbols]

1 container body 4 Porous body 5 Ink supply port 7 Ink inlet 8 atmosphere communication port 9 lid material 9a Recess for forming decompression space 20, 21 Sealing film

Claims (3)

(57) [Claims] 1. A housing the multi-porous body suitable for absorbing ink, a container body an ink supply port is provided to the ink supply needle and engaging in communication with the recording head, Lee ink inlet 及
And an opening of the container body, which is provided with a recess forming a decompression space
The container body and the lid body form
The pressure inside the formed ink container is 0 to minus 3
It is reduced to 00MmHg, and the ink container is sealed by a space in a bag made of temper film barrier Osamu
Are volumes of said space is low rather maintained than the internal pressure of the container
Ink cartridge it is. Wherein said vessel pressure is minus 250mmH
The ink cartridge according to claim 1, which is g or less. Wherein following said bag Gama Inasu 450mmHg
The ink cartridge according to claim 1, which is hermetically sealed under reduced pressure .