JP3261802B2 - Inkjet 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 cartridge, and more particularly to an ink-jet cartridge in which a recording head for ejecting ink to record an image on a recording medium and a tank for supplying ink to the head are integrated. About.

[0002]

2. Description of the Related Art Heretofore, there has been known an ink-jet cartridge of this type having a porous body in a tank portion communicating with the atmosphere at an atmosphere communication portion. This is to adjust the capillary force to a desired value by changing the characteristics of the porous body, the compression ratio, and the like as parameters, to stably supply the ink to the recording head while holding the ink, JP-A-63-87242 discloses a thermal ink-jet pen in which ink is stored in a porous medium of polyurethane foam (foam).

[0003]

In the above-described conventional ink jet cartridge, a porous body is inserted into a tank portion, and ink is stored therein. For this reason, the inside of the tank is filled with the porous body, and the amount of ink that can be stored in the porous body is about 50% of the tank capacity. In other words, by using a porous material, this method of stably supplying ink can store only a small amount of ink, and has a drawback that efficiency is poor.

[0004]

According to the present invention, there is provided an ink jet cartridge having a recording head for discharging ink and a tank for storing ink to be discharged, wherein the tank communicates with the atmosphere through an atmosphere communicating portion. By doing so, in an ink jet cartridge that can supply ink in the tank unit to the recording head unit, a small chamber is provided in the atmosphere communication part of the tank unit, and an air layer and a liquid layer are formed in this small chamber. A pressure adjusting unit is provided between the liquid layer and the atmosphere, which is separated by a filter that allows the air to pass through but does not allow the liquid to pass therethrough.The pressure adjusting unit further includes: It is constituted by having a second filter that allows air to pass therethrough but does not allow liquid in a small chamber to pass therethrough, and an air communication stop having a through hole only in a central portion in the liquid layer.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention. FIG. 1 (a) shows an overall view, and FIG. 1 (b) shows a partially enlarged view. The main body 1 includes a storage unit 2 for storing ink, a through hole 5 through which ink flows, a recording head unit 6 outside the through hole 5, and a pressure adjustment unit 20 indicated by a wavy circle. The ink 2 is normally stored in the storage unit 2.
FIG. 1B is an enlarged view of the pressure adjustment unit 20 and the pressure adjustment unit 2.
0 and the body have a hole 2 with a diameter such that the capillary force works moderately
It communicates with 1. The lower surface of the pressure adjusting section 20 is separated from the outside by a filter B24 made of a substance having a polymer structure that allows gas to pass therethrough but does not allow liquid to pass therethrough, or another structure having an equivalent function. A liquid (preferably pure) 23 is held inside the pressure adjusting unit 20, but is not filled, and has an appropriate air chamber 22 at an upper portion thereof.

When the discharged ink 7 is sequentially discharged from the storage unit 2, a storage space 4 is formed in the storage unit 2. At this time, as the discharge ink 7 discharges, the pressure in the storage section 2 becomes lower in the storage section 2, and a discharge failure occurs in the ink jet cartridge having no pressure adjusting section 20. However, in the embodiment of FIG. When the negative pressure in the storage section 2 exceeds the capillary force of the hole 21, the ink in the hole 21 is drawn into the storage section 2, and the air in the air chamber 22 is drawn into the storage section 2. Then, the outside air is newly replenished into the air chamber 22 through the filter B24 by the amount of the drawn air. By these series of operations, the storage section 2 and the air chamber 22
Is always maintained at a constant negative pressure. Again,
Without the air chamber 22, the hole 21 would be filled with liquid both above and below, and no capillary force would be generated. If there is no liquid 23, when the ink jet cartridge is turned upside down, the storage space 4 comes into contact with the outside air and the negative pressure cannot be maintained. In addition, the holes 21 are always in contact with the outside air whose conditions change, and there is a possibility that the ink may dry or its physical properties may change. That is, the best condition is that the hole 21 is always in contact with the air chamber 22 and the liquid 23 is always interposed between the hole 21 and the filter B24.

Incidentally, in the embodiment of FIG.
Assumes a square shape, but this shape is not limited as long as the above conditions are not deviated.

The pressure adjusting section 20 shown in FIG. 1 further includes a filter C25 and an air communication stopper 26.

The function of the embodiment shown in FIG. 1 will be described below. Normally, the cartridge operates in the state as shown in FIG. 1B unless the use of the cartridge is specified by design. FIGS. 2A and 2B show a state in which the pressure adjusting unit 20 is inclined by 60 degrees and 90 degrees, respectively. Here, by providing the filter C25 and the air communication stopper 26 as in the pressure adjusting unit 20, FIG.
2B, the hole 21 always generates a capillary force even when the ink jet cartridge is inclined. Thereby, even if the ink jet cartridge is inclined, the pressure is kept at an appropriate level, and stable printing is performed.

It is to be noted that the atmosphere communication stopper 2 shown in FIGS.
The shape of No. 6 is an example, and the shape is not limited as long as the same function can be performed.

[0012]

As described above, according to the present invention, by not having a porous body in the tank portion and having a pressure adjusting portion in the air communication portion, it is possible to store more ink, and furthermore, the inside of the tank portion can be stored. Since the pressure is kept constant, it is possible to stably supply ink to the recording head. In addition, by providing the pressure adjusting section with a structure that allows the pressure to be adjusted even in an angled state, there is an effect that printing is always performed stably even when the ink jet cartridge is inclined.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 1 (a) is an overall view, and FIG. 1 (b) is a partially enlarged view.

FIG. 2 is a view showing a state in which the embodiment of FIG. 1 is inclined at 60 degrees and 90 degrees.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Storage part 3 Ink 5 Through-hole 6 Recording head 7 Discharge ink 20 Pressure adjustment part 21 Hole 22 Air chamber 23 Liquid 24 Filter B 25 Filter C 26 Air communication stop

Claims (1)

(57) [Claims] An ink jet recording apparatus includes: a recording head for discharging ink; and a tank for storing ink to be discharged. The tank communicates with the atmosphere through an atmosphere communicating part having a hole. In the ink jet cartridge capable of supplying the ink to the recording head section, a small chamber is provided in the atmosphere communication section of the tank section, and an air layer and a liquid layer are formed in the small chamber, and between the liquid layer and the atmosphere. A pressure regulating section partitioned by a filter that allows air to pass through but does not allow the liquid to pass through, the hole is in contact with a layer of air in the small chamber, and the hole is provided between the hole and the filter. A layer of liquid in the small chamber is interposed, and a second filter that allows air to pass through the layer of air in the small chamber but does not allow liquid in the small chamber to pass through the pressure adjusting section; Inside has a through hole in the center Ink jet cartridge and having an atmosphere communication stop.