JP2002205414A - ink cartridge - Google Patents

Abstract

(57) [Problem] To provide an ink cartridge that does not use a porous body, to stably and reliably supply ink contained in a container to a recording head. SOLUTION: A container 1 containing ink, an ink supply hole 2 for supplying ink to the outside, and a through hole communicating the inside of the container with the atmosphere are provided, and a membrane valve 11 is provided in the ventilation portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink cartridge suitable for being mounted on a carriage on which an ink jet recording head is mounted.

[0002]

2. Description of the Related Art An ink jet printer applies an ink jet recording head for applying pressure to a pressure generating chamber communicating with a common ink chamber and a nozzle opening to discharge ink droplets from the nozzle opening, and supplies ink to the recording head. An ink cartridge is mounted on a carriage, and ink droplets are ejected onto recording paper in accordance with print data while the carriage reciprocates.

[0003] Incidentally, since the nozzle opening of the recording head is located at a position lower than the ink level of the ink cartridge, a water head pressure acts on the nozzle opening. Therefore, a porous body is usually accommodated in the ink cartridge. The pressure of the ink cartridge is configured to be slightly lower than that of the nozzle opening due to the surface tension of the porous body, and measures are taken to prevent the ink from seeping out from the nozzle opening.

However, as the consumption of ink progresses and the amount of ink absorbed by the porous body decreases, the surface tension of the porous body increases, and the supply of ink to the recording head tends to be delayed. There is a problem that the ink cannot be completely consumed. In addition, since the amount of ink that can be stored in the cartridge is reduced by the substantial volume of the porous body, there is a problem that the ink cartridge becomes large.

In order to solve such a problem, for example, as shown in Japanese Patent Application Laid-Open No. 7-68782, a valve structure which is opened when an ink jet printer main body is mounted is provided at an air opening portion above an ink cartridge. In addition, an ink cartridge for an ink jet recording head has been proposed in which an ink supply unit is provided with a valve structure using an ink holder whose volume changes depending on the amount of ink.

[0006]

According to this, since it is not necessary to accommodate the porous body in the cartridge, it is possible to increase the substantial ink accommodation amount of the ink tank. In this case, there is a problem that the volume change of the ink holding member cannot catch up with the demand, the required amount of ink cannot be supplied to the ink jet recording head, and the print quality may be deteriorated.

On the other hand, the valve structure of the air opening portion is always open when the ink jet printer is mounted on an ink jet printer.
When the attitude of the ink jet printer is changed while the ink cartridge is mounted, the ink flows out of the ink cartridge, and there is a problem that the user's hands and clothes are contaminated.

Further, since two valve structures are provided in one ink cartridge, the ink cartridge has a complicated mechanism, and the number of parts increases, so that the assemblability decreases and the cost increases. There is a problem that occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to increase the efficiency of use in an ink cartridge and prevent the ink from flowing out due to a change in posture when mounted on an ink jet printer. Another object of the present invention is to provide an ink cartridge having a relatively simple structure.

[0010]

In order to solve such a problem, the present invention is characterized in that a membrane valve which is opened by a negative pressure equal to or lower than a predetermined value is provided in an air vent of an ink cartridge. It is.

[0011]

In the normal state, the membrane valve is closed. When the ink is consumed by the ink discharge from the recording head, the amount of ink decreases, and when the pressure inside the ink cartridge becomes lower than a certain negative pressure, the membrane valve is set to the atmospheric pressure. It becomes an open state by receiving a pressure difference between the ink cartridge and the pressure inside the ink cartridge, and is closed again when the atmospheric pressure is taken into the ink cartridge and the negative pressure disappears. Since the membrane valve is normally closed, the interior of the ink cartridge is a closed space, preventing ink from bleeding from the head nozzles, and also preventing ink from flowing out of the air opening hole due to a change in the attitude of the ink jet printer body. Is prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 denotes a container constituting an ink cartridge main body. An ink through hole 4 through which ink in the container is discharged and an ink supply hole 2 into which an ink supply needle of a recording head is inserted are provided on the bottom surface 1a of the container. Is formed. Ink supply hole 2
A rubber or polymer elastomer having durability against ink so that a seal can be taken between the ink supply hole 2 and the ink supply needle when the ink supply needle communicating with the recording head (not shown) is inserted. Is inserted. When the ink supply needle of the recording head is inserted into the ink supply hole 2, the outer periphery of the ink supply needle comes into close contact with the through hole 3 a of the seal member 3 and is sealed.

The upper surface 6 of the ink cartridge is provided with an air opening hole 7.

Reference numeral 11 denotes a membrane valve made of an elastic material such as rubber or polymer elastomer having durability to ink. The membrane valve 11 is in close contact with the membrane valve support member 13, and the gap is sealed. Further, the membrane valve support member 13 is airtightly joined to the joining portion 9 inside the ink cartridge by vibration welding or ultrasonic welding.

The membrane valve support member 13 is mounted so as to be offset upward from the ink cartridge, whereby a membrane reaction force is generated in the membrane valve 11, and the membrane valve seal portion 10 is attached to the atmosphere seal portion 8 of the ink cartridge. Membrane valve 1
1 is closed. In this embodiment, the membrane valve seal portion 10 is formed so as to be convex from the membrane portion 11a so as to easily adhere to the atmosphere seal portion 8 of the ink cartridge.

Reference numeral 5 denotes ink, which is stored in the container 1 in a liquid state.

A through hole 1 provided at the center of the membrane valve 11
Reference numeral 2 denotes a flow path for taking in air into the ink cartridge by communicating with the atmosphere opening hole 7 when the membrane valve 11 is opened as shown in FIG.

FIG. 3 shows another embodiment of the present invention. In this embodiment, the seal portion 10 of the membrane valve 11 is pressed against the atmosphere seal portion 8 by a coil spring 21. On the back surface of the membrane valve seal portion 10, a convex portion 11b extending around the through hole 12 is formed.
Is inserted at one end. A coil spring support member 22 is mounted on the outer periphery of the membrane valve support member 13 by a method such as press fitting. A recess 22a is provided at the center of the coil spring support member 22 so that the other end of the coil spring 21 is inserted, and a through hole 22b is provided at the center of the recess 22a. The through hole 22b communicates with the atmosphere opening hole 7 and the membrane valve through hole 12 when the membrane valve 11 is in the open state.

The dimensions of the coil spring 21 and the dimensions of the coil spring supporting member 22 are designed so that the coil spring 21 presses the membrane valve projection 11b with an appropriate pressure.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the seal portion 10 of the membrane valve 11 is pressed against the atmosphere seal portion 8 by a leaf spring 31. A leaf spring support member 32 is mounted on the outer periphery of the membrane valve support member 13, and a leaf spring 31 is mounted on the leaf spring support member 32. A through hole 31 a is provided in the center of the leaf spring 31. The through hole 31a communicates with the atmosphere opening hole 7 and the membrane valve through hole 12 when the membrane valve 11 is open. On the back surface of the membrane valve seal portion 10, a convex portion 11 b extending around the through hole 12 is formed so that the leaf spring 31 pushes the central portion of the membrane valve 11.
The dimensions of the leaf spring 31 and the dimensions of the leaf spring support member are designed so that the leaf spring 31 presses the membrane valve convex portion 11b with an appropriate pressure.

In general, an ink cartridge for an ink-jet printer is circulated in a vacuum-packed state in order to suppress a change in physical properties of the ink in the ink cartridge. Therefore, there is a problem that the ink stored in the ink cartridge easily leaks to the outside due to pressure. In the ink cartridge of the present invention, when a negative pressure is applied to the outside of the ink cartridge by the vacuum packing, the pressure acts in the direction in which the membrane valve in the atmosphere opening section is closed, so that the ink does not easily leak to the outside of the ink cartridge. There is an advantage that.

[0023]

In the present invention as described above,
A structure in which a membrane valve that opens with a negative pressure equal to or less than a certain value and communicates with the atmosphere is provided on the upper surface of the ink cartridge. When the pressure becomes lower than the negative pressure, the membrane valve is opened by receiving a pressure difference between the atmospheric pressure and the pressure inside the ink cartridge, so that a required amount of ink can be supplied to the recording head.

Since the membrane valve is normally closed, the interior of the ink cartridge is a closed space, preventing ink from bleeding from the head nozzles, and furthermore, from the air opening hole due to a change in the attitude of the ink jet printer main body. Ink leakage is also prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an entire embodiment of the present invention.

FIG. 2 is a view showing an open state of a membrane valve in the embodiment of FIG.

FIG. 3 is a sectional view of a membrane valve according to another embodiment of the present invention.

FIG. 4 is a sectional view of a membrane valve according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 1a Bottom of container 2 Ink supply hole 3 Seal member 4 Ink hole 5 Ink 6 Ink cartridge upper surface 7 Atmosphere opening hole 8 Ink cartridge atmosphere seal portion 9 Joining portion 10 Membrane valve seal portion 11 Membrane valve 11a Membrane portion 11b Protrusion portion REFERENCE SIGNS LIST 12 Membrane valve through hole 13 Membrane valve support member 21 Coil spring 22 Coil spring support member 22a Coil spring support member recess 22b Coil spring support member through hole 31 Leaf spring 31a Leaf spring through hole 32 Leaf spring support member

Claims (6)

[Claims] 1. An ink cartridge comprising a container containing ink, an ink supply hole for supplying ink to the outside, and a through hole communicating the inside of the container with the atmosphere, and a membrane valve provided in the vent. 2. The ink cartridge according to claim 1, wherein said membrane valve is made of an elastic material having durability against ink. 3. The ink cartridge according to claim 2, wherein the elastic material is a rubber or a polymer elastomer. 4. The ink cartridge according to claim 1, further comprising pressing means for pressing a through hole formed in said membrane valve against a cartridge seal portion. 5. The ink cartridge according to claim 1, wherein said pressing means is a coil spring. 6. The ink cartridge according to claim 1, wherein said pressing means is a leaf spring having a through hole.