JP2812110B2 - Inkjet recording 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 jet recording cartridge, and more particularly to an ink jet recording cartridge in which an ink tank for storing ink and a print head for discharging ink from the ink tank are integrated.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording cartridge of this type has a structure in which ink is stored in a foam (foam) material packed in an ink tank, as disclosed in Japanese Patent Application Laid-Open No. 63-87242. The inside of the recording cartridge is maintained at a constant negative pressure by the capillary force generated by the foam material, and the ink is held.

[0003]

This conventional ink jet recording cartridge has a poor volumetric efficiency because the ink is stored in a foam material, and the amount of the ink is limited.

[0004]

According to the present invention, there is provided an ink jet recording cartridge comprising: an ink tank for storing ink; a print head for discharging the ink from the ink tank; a surface in contact with gas inside the ink tank; Pressure adjusting means having a surface in contact with gas outside the ink tank, a first filter which allows gas to pass through each of the surfaces but does not allow liquid to pass, and a small amount of liquid is mounted inside the container while confining a small amount of air bubbles; A pressure control means is provided, comprising one connected to the pressure adjusting means by a capillary and the other connected to outside air and an overflow connected by a capillary.

In the ink jet recording cartridge according to the present invention, the pressure control means may allow gas to pass through the ink tank but not liquid so that the cartridge is not covered with the ink even if the cartridge is placed in an arbitrary direction. It is characterized in that it is isolated by a second filter or the like.

Further, in the ink jet recording cartridge according to the present invention, the pressure adjusting means may be configured such that even when the cartridge is placed in an arbitrary direction, the small amount of air bubbles in the pressure adjusting means may cause the gas and the outside air to remain in the cartridge. It is characterized by a shape that does not connect

Further, the ink jet recording cartridge according to the present invention is characterized in that the shape of the cartridge is such that the second filter cannot be placed so as to be closed by the ink.

[0008]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the present invention. FIG.
Referring to FIG. 1, the cartridge 1 includes an ink tank 2 for storing the ink 4, a print head 3 for discharging the ink 4 from the ink tank 2, a pressure control unit 5 including a pressure adjustment chamber 6 and an overflow reservoir 7, and have.

FIG. 2 is a detailed view of the pressure control section 5. FIG.
Referring to FIG. 2 and FIG. 2, the pressure adjustment chamber 6 allows gas attached to the surface in contact with the gas inside the ink tank 2 to pass through but not liquid, for example, polytetrafluoroethylene (P).
A filter (A) 8 made of ET) and a filter (B) 9 that allows gas attached to the surface in contact with the outside air to pass through but does not allow liquid to pass through, such that a small amount of liquid 10 such as pure water forms small bubbles 11. The structure is confined. Overflow pool 7
One is connected to the pressure adjusting chamber 6 by a capillary hole (A) 12 having a diameter capable of generating a capillary force, and the other is a capillary hole (B) having a diameter capable of generating a capillary force.
13 is connected to the outside air. In addition, the pressure control unit 5 controls the filter (A) regardless of how the cartridge 1 is placed.
In order to prevent the surface 8 from being covered with the ink 4, a filter (C) 14 that allows gas to pass through but not liquid is isolated from the ink tank 2.

FIG. 3 is a diagram showing an operation state of the pressure control unit 5. Referring to FIG. 1, FIG. 2 and FIG. 3, when the ink is held, the gas inside the ink tank 2 is released by the capillary force generated in the capillary hole (A) 12 connecting the pressure adjusting chamber 6 and the overflow reservoir 7. The ink 4 is held at the negative pressure (FIG. 3A). At the time of ink ejection, the ink 4 in the ink tank 2 is consumed by being ejected from the print head 3, and the negative pressure of the gas inside the ink tank 2 increases. When the negative pressure becomes larger than the capillary force generated in the capillary hole (A) 12, bubbles 11 are generated from the capillary hole (A) 12 by the pressure adjusting chamber 6.
(FIG. 3B). At the same time, the ink tank 2 includes the filter (A) 8 and the filter (C) 14.
Through the capillary hole (A) 12 and into the pressure adjusting chamber 6, the outside air is sent by the amount of the air bubbles 11 and is maintained at a constant negative pressure. When the internal gas in the ink tank 2 expands in volume due to a temperature change or a rise in altitude and the pressure becomes larger than the outside air, the liquid 10 displaced by the internal gas in the ink tank 2 and the bubbles 11 in the pressure adjusting chamber 6 expands in volume. Flows into the overflow reservoir 7, and as shown in FIG. 3C, the gas inside the ink tank 2 and the outside air are connected by the gas, so that the expanded gas is released to the outside and the volume expansion is eliminated. When the volume expansion is eliminated, the state is returned to the state at the time of holding the ink as shown in FIG.

FIG. 4 is a comparison diagram of the cross-sectional shape of the pressure adjusting chamber 6. When the pressure adjustment chamber 6 has a cylindrical shape as shown in FIG.
When the ink tank 2 is placed as described above, the gas inside the ink tank 2 and the outside air are connected by the air bubbles 11 in the pressure adjustment chamber 6, and the inside of the ink tank 2 becomes the same pressure as the outside air, and the ink 4 leaks from the print head 3. Therefore, if the pressure adjustment chamber 6 is formed in a conical shape as shown in FIG. 4B, even if the cartridge 1 is placed as shown in FIG.
Accordingly, the gas inside the ink tank 2 and the outside air are not connected, and the inside of the ink tank 2 is kept at a negative pressure. Further, as shown in FIG. 4B, the bubble 11 is always on the filter (A) 8 side so as to be in contact with the gas inside the ink tank 2, so that when the gas inside the ink tank 2 expands in volume, the bubble 11 is also the same. As a result, the gas inside the ink tank 2 and the outside air are easily connected by the gas.

FIG. 5 is a comparison diagram based on the outer shape of the cartridge 1. Referring to FIGS. 2 and 5, if the outer shape of the cartridge 1 as shown in FIG.
When the cartridge 1 is placed as shown in FIG. 5A during storage, the filter (C) 14 is covered with the ink 4, so that when the gas inside the ink tank 2 expands in volume, the expanded gas is used as the pressure control unit 5. As a result, the ink cannot escape to the outside, and the ink 4 remaining in the print head 3 is pushed out. Therefore, as shown in FIG.
By making the surface to be placed as shown in FIG. 5 (A) into a dome shape or a cone instead of a plane, a shape which cannot be placed as shown in FIG. 5 (A) is obtained.

[0013]

As described above, according to the present invention,
By having a pressure control unit inside the cartridge, the gas inside the cartridge can always be maintained at a negative pressure without using a foam material, so that more ink can be used with the same volume compared to a method using a foam material. Can be held.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a detailed view of a pressure control unit of the embodiment.

FIG. 3 is a diagram illustrating an operation state of a pressure control unit according to the embodiment.

FIG. 4 is a comparison diagram of the shape of the pressure adjustment chamber of this embodiment.

FIG. 5 is a comparison diagram based on the outer shape of the cartridge of this embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cartridge 2 Ink tank 3 Print head 4 Ink 5 Pressure control part 6 Pressure regulation room 7 Overflow pool 8 Filter (A) 9 Filter (B) 10 Liquid 11 Bubbles 12 Capillary hole (A) 13 Capillary hole (B) 14 Filter ( C)

Claims (4)

(57) [Claims] An ink tank for storing ink; a print head for ejecting the ink from the ink tank; and a surface in contact with gas inside the ink tank and a surface in contact with gas outside the ink tank. A first filter that allows gas to pass through each surface but does not allow liquid to pass through, and a small amount of liquid inside the first filter and a pressure adjusting unit attached while trapping a small amount of air bubbles; An ink jet recording cartridge, comprising: pressure control means including an outside air and an overflow reservoir connected by a capillary tube. 2. The pressure control means according to claim 1, wherein said ink tank allows gas to pass therethrough but does not allow liquid to pass therethrough so that said cartridge is not covered with said ink even when said cartridge is placed in an arbitrary direction.
2. The ink jet recording cartridge according to claim 1, wherein the cartridge is isolated by a filter or the like. 3. The pressure adjusting means has a shape such that even when the cartridge is placed in an arbitrary direction, the small amount of bubbles in the pressure adjusting means do not connect the gas in the cartridge to the outside air. The ink jet recording cartridge according to claim 1, wherein: 4. The ink jet recording cartridge according to claim 1, wherein the shape of the cartridge is such that the second filter cannot be placed so as to be closed by the ink.