JPH07241998A - Ink cartridge for ink jet printer - Google Patents

Abstract

PURPOSE:To prevent air from coming into an ink cartridge on its attachment and detachment where air is liable to intermix with ink, and prevent errors in detection of residual quantity of ink while preventing wastefulness in consumption of ink by providing an exhaust opening to the external wall face in the middle of an ink supply port. CONSTITUTION:In an ink cartridge 10, a tank 13 is filled with a porous material 14 impregnated with ink kept under negatire pressure. An L-shaped capillary tube 16 is provided to an ink reservoir 15 formed to the underside of the ink tank 13. When the ink inside the ink tank 13 is used up, and air comes into the ink reservoir 15, meniscus is formed to the ink surface by the capillary tube 16, and the ink inside the ink reservoir 15 is kept under negative pressure by capillary attraction. An ink supply port 20 to which an ink induction tube 4 can be detachably fitted is formed to the lower end of the ink reservoir 15, and a plug 21 is arranged to the port while an exhaust port 24 opening to the outside is provided.

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 printer which is detachably attached to an ink jet head.

An ink jet head used in an ink jet printer or the like prints by pressurizing ink and ejecting ink droplets from a nozzle having a thin tip. May be absorbed and ink may not be ejected.
Therefore, it is necessary that air bubbles are not mixed in the ink flow path when the ink is ejected.

[0003]

2. Description of the Related Art In a conventional ink jet printer, when it is detected that ink is not ejected from a nozzle, the ink is sucked and exhausted by a so-called purging mechanism that sucks air from the tip side of the nozzle to expel bubbles. Was there.

[0004]

The inclusion of air bubbles in the ink flow path often occurs when air bubbles enter the ink cartridge when the ink cartridge is attached or detached.

Therefore, in order to discharge the bubbles by the purging mechanism, it is necessary to suck out the ink remaining in the head, so that a large amount of ink is wasted. Therefore, the amount of ink that is not effectively used for recording has been extremely large.

Further, some ink cartridges in recent years are provided with electrodes for detecting the remaining amount of ink by electric resistance, and in such a case, when bubbles contact the electrodes of the cartridge, it may cause malfunction. Become.

Therefore, even if the user accidentally removes the ink cartridge, even if the cartridge is re-installed, the remaining amount detection mechanism malfunctions due to the inclusion of air bubbles, and the ink cartridge remains There was a problem that a signal prompting replacement was issued and the printing operation could not be started.

Therefore, it is an object of the present invention to provide an ink cartridge for an ink jet printer which can minimize the entrainment of bubbles when it is attached to or detached from an ink jet head which is highly likely to entrap bubbles in the ink flow path. To do.

[0009]

In order to achieve the above object, the ink cartridge of the ink jet printer of the present invention is detachable from the ink jet head 1 as shown in FIG. 1 for explaining the embodiment. Ink cartridge 10 of the ink jet printer provided in
In, an ink tank portion 13 containing ink to be supplied to the inkjet head 1, and an ink introducing pipe 4 that is provided below the ink tank portion 13 in communication with the ink tank portion 13 and project from the inkjet head 1. Of the ink supply port 20 into and from which the ink supply port 20 is inserted and removed, and a plug body 21 that is movable between a state in which the ink supply port 20 is in close contact with the mouth of the ink tank portion 13 side and a state in which the ink supply port 20 is retracted from the close state. And an urging means 22 for urging the plug body 21 so as to come into close contact with the ink supply port 20, and an exhaust gas having one end opening to an inner wall surface in the middle of the ink supply port 20 and the other end opening to the outside. The holes 24 and 24 are provided.

An ink absorbing member 28 for absorbing the ink may be provided at a position near the outlet of the exhaust hole 24 when the ink cartridge 10 is attached to the ink jet head 1. ,
At least one of the ink introduction tube 4 and the ink supply port 20 is preferably formed of a resilient member.

[0011]

When the ink introduction pipe 4 of the ink jet head 1 is fitted into the ink supply port 20 of the ink cartridge 10, the stopper 21 is pushed up from the base of the ink supply port 20 against the urging force of the urging means 22. The ink introducing tube 4 and the ink tank portion 13 communicate with each other.

In the process of its operation, the ink supply port 2
The air existing in the space between the plug body 21 and the head of the ink introducing tube 4 in 0 is discharged to the outside from the exhaust hole 24 when the ink introducing tube 4 enters, and enters the ink cartridge 10. Do not fit.

By disposing the ink absorbing member 28 near the outlet of the exhaust hole 24, the ink discharged from the exhaust hole 24 mixed with the air is absorbed by the ink absorbing member 28, and the surrounding area is not polluted.

Further, the ink introducing pipe 4 and the ink supply port 20
By forming at least one of them with an elastic member, it is possible to bring them into close contact with each other and prevent ink leakage between the two.

[0015]

Embodiments will be described with reference to the drawings. Figure 2
1 shows an inkjet head 1 provided in a full-color inkjet printer and an ink cartridge 10 that is detachably attached to the inkjet head 1.

The ink jet head 1 is mounted on a carriage 3 which slides along a stay shaft 2,
The four heads of the yellow head 1Y, the magenta head 1M, the cyan head 1C, and the black head 1B are arranged side by side in a row.

Ink introducing pipes 4 for supplying ink to the heads 1Y, 1M, 1C and 1B are provided on the upper end walls of the heads 1Y, 1M, 1C and 1B for the respective colors. As shown in FIG. 3, each ink introduction tube 4 is formed in a cylindrical shape with its upper end blocked in a planar shape, and a plurality of introduction ports 5, which are circumferentially displaced near the upper end, are provided. 5 is drilled.

Returning to FIG. 2, the heads 1Y and 1 for each color are formed.
Corresponding to M, 1C and 1B, ink cartridges 10Y, 10M, 10C and 10B for the respective colors are provided on the upper side thereof so as to be detachable from above. FIG. 2 illustrates a state in which each ink cartridge 10 is slightly separated from the inkjet head 1.

A protrusion 11 is formed on the lower edge of each ink cartridge 10 so as to project laterally to both sides. Correspondingly, a recess 6 is formed on the upper surface of the ink jet head 1.

As a result, when the lower end of the ink cartridge 10 is pressed against the ink jet head 1 from above, the convex portion 11 of the ink cartridge 10 is elastically fitted into the concave portion 6 of the ink jet head 1, whereby the ink cartridge 10 is ejected. It is fixed to the head 1. Removal is the reverse operation.

FIG. 1 is a side sectional view of the portion shown in FIG. 2. On the ink jet head 1 side, a piezoelectric element 8 is arranged along a pressure chamber 7 communicating with the ink introducing tube 4, Ink droplets are ejected from the nozzle 9 at the tip by deforming the piezoelectric element 8 by applying a voltage.
For example, 64 such pressure chambers 7 and nozzles 9 are provided for one ink introduction tube 4.

The ink tank portion 13 of the ink cartridge 10 is filled with a porous body 14 having continuous pores.
Ink is absorbed there and negative pressure is held. The upper end wall of the ink tank portion 13 has a vent hole 12 communicating with the outside.
Are formed.

The ink reservoir 15 formed on the lower side of the ink tank 13 has one end opened to the ink tank 13 and the other end opened laterally in the lower portion of the ink reservoir 15. A character-shaped capillary tube 16 is provided, and the ink tank section 13 and the ink reservoir section 15 are connected to each other by the capillary tube 1.
6 communicate with each other.

When the ink is consumed and the ink in the ink tank portion 13 is exhausted and air enters the ink reservoir portion 15, the ink cannot be held without the capillary tube 16, but the capillary tube 16 forms a meniscus on the ink surface. The ink in the ink reservoir 15 is held under negative pressure by the capillary force.

Electrodes 18 and 19 for detecting the remaining amount of ink are installed in the ink reservoir 15 to detect a change in the electric resistance of the ink caused by the decrease of the ink in the ink reservoir 15. can do.

An ink supply port 20 into which the ink introduction tube 4 of the ink jet head 1 is removably inserted is formed at the lower end of the ink reservoir 15 so that the ink introduction tube 4 can be easily inserted. , The mouth of the ink supply port 20 is
It is chamfered in a taper shape.

The ink supply port 20 and the ink introduction pipe 4
At least one of them is made of an elastic material so that they can be connected airtightly, and the portion on the ink jet head 1 side is on the ink cartridge 10 side so that the airtightness of the connection portion does not deteriorate due to abrasion due to repeated attachment and detachment. A material having a higher hardness than that of the part is used.

At the mouth of the ink reservoir 15 of the ink supply port 20 (that is, the mouth of the ink tank portion 13 side), a plug 21 made of an elastic material is arranged. The stopper 21 is biased in the ink reservoir 15 by a compression coil spring 22 so as to come into close contact with the base of the ink supply port 20, so that the ink does not leak from the ink supply port 20.

However, since the plug 21 is arranged in the ink reservoir 15 so as to be movable in the direction away from the ink supply port 20, the compression coil spring 2 is provided from the ink supply port 20 side.
If the stopper 21 is pushed against the biasing force of 2, the stopper 21 is pushed up and separated from the ink supply port 20, and the ink supply port 2
0 opens.

Therefore, when the ink introducing tube 4 of the ink jet head 1 is inserted into the ink supply port 20, the plug 21 is pushed up by the ink introducing tube 4 and the ink flow path is formed between the ink jet head 1 and the ink tank portion 13. Is formed.

A hardness difference is provided between the ink introducing tube 4 and the plug body 21 so that the adhesion between the ink introducing tube 4 and the plug body 21 is good. Is formed by.

Ink supply port 2 of ink cartridge 10
On the inner wall surface in the middle of 0, one end (inlet) of the exhaust hole 24 is opened adjacent to the mouth on the upper end side where the plug 21 is in close contact, and the other end (outlet) of the exhaust hole 24 is The lower surface of the ink cartridge 10 is open to the outside.

Therefore, as shown in FIG. 4, when the ink introducing pipe 4 is inserted into the ink supplying port 20, it is formed by the upper end surface of the ink introducing pipe 4, the inner wall surface of the ink supplying port 20 and the plug 21. The air remaining in the space is inserted by being pushed out by the ink introduction tube 4 through the exhaust hole 24.

The upper end surface of the ink introducing tube 4 is the plug body 2.
When it hits 1, all the air in the space is exhausted, the inlet of the exhaust hole 24 is blocked by the side surface of the ink introduction tube 4, and the inflow of air via the exhaust hole 24 is prevented.

When the ink cartridge 10 is further pushed into the ink jet head 1 from that state, as shown in FIG.
As shown in FIG. 5, the ink introduction tube 4 resists the urging force of the compression coil spring 22 while the exhaust hole 24 is closed.
Is pushed up, and the introduction port 5 of the ink introduction tube 4 enters the ink reservoir 15. Therefore, at that time, the ink can be supplied from the ink cartridge 10 to the inkjet head 1 without air being mixed into the ink.

When the ink is attached to the ink supply port 20 when the ink cartridge is mounted, the ink may be mixed with the air discharged from the exhaust hole 24 and scattered. Therefore, an ink absorbing member 28 is arranged on the upper surface of the inkjet head 1 so as to face the outlet of the exhaust hole 24.

Therefore, even if the ink is discharged from the outlet of the exhaust hole 24, it is absorbed by the ink absorbing member 28, so that the surrounding area is not polluted. The ink absorbing member 28
May be arranged at an appropriate position near the outlet of the exhaust hole 24 so that the ink discharged from the exhaust hole 24 may come into contact with it.

When the ink cartridge 10 is detached from the ink jet head 1, the stopper 21 is pushed down by the urging force of the compression coil spring 22 as the ink introducing tube 4 is pulled out from the ink supply port 20, and the stopper 21 is pulled down. Is closely attached to the base of the ink supply port 20, the ink supply port 20 is closed. Since the exhaust hole 24 is opened after that, air is not mixed in the ink reservoir 15.

During the operation, the ink introduction tube 4 is attached to the plug body 2.
A little away from the lower end surface of 1, the exhaust hole 24 opens and air enters the ink supply port 20, and the space inside the ink supply port 20 becomes atmospheric pressure.

Therefore, at the moment when the ink introducing pipe 4 is detached from the ink supply port 20, there is no large change in pressure inside the ink supply port 20, and bubbles are not mixed in the ink cartridge 10 and the ink jet head 1.

[0041]

According to the present invention, by providing the exhaust hole which opens on the inner wall surface in the middle of the ink supply port, the invasion of air is prevented at the time of attachment / detachment in which the air in the ink cartridge easily mixes with the ink. Therefore, it is not necessary to remove air bubbles in the ink cartridge by purging, and wasteful consumption of ink is eliminated. Further, since the malfunction of the remaining ink amount detection is eliminated, the ink is normally supplied even if the ink cartridge is once removed and the same ink cartridge is attached again.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment.

FIG. 2 is a perspective view of an example.

FIG. 3 is a partially enlarged perspective view of the embodiment.

FIG. 4 is an operation explanatory diagram of the embodiment.

FIG. 5 is an operation explanatory diagram of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inkjet head 4 Ink introduction tube 10 Ink cartridge 20 Ink supply port 21 Plug 22 Compression coil spring (biasing means) 24 Exhaust hole

Claims (3)

0 [Claims] 1. An ink cartridge (10) for an ink jet printer, which is detachably attached to the ink jet head (1), in which an ink for supplying to the ink jet head (1) is contained. And an ink supply port (20) communicating with the ink tank portion (13) and provided below the ink tank portion (13), into which the ink introduction pipe (4) protruding from the ink jet head (1) is removably fitted. ) And the ink tank portion (1) of the ink supply port (20).
3) A stopper body (21) movable between a state in which it is in close contact with the mouth and a state in which it is retracted from the close state, and the stopper body (21) is in close contact with the ink supply port (20). An urging means (22) for urging and an exhaust hole (24) having one end opening to an inner wall surface in the middle of the ink supply port (20) and the other end opening to the outside are provided. Ink cartridge for inkjet printer. 2. An ink absorbing member (28) for absorbing the ink at a position near the outlet of the exhaust hole (24) when the ink cartridge (10) is attached to the ink jet head (1). ) Is provided, the ink cartridge of the inkjet printer according to claim 1. 3. The ink cartridge for an ink jet printer according to claim 1, wherein at least one of the ink introduction pipe (4) and the ink supply port (20) is formed of a resilient member.