JPH08267777A - Ink jet recording device - Google Patents

Abstract

PURPOSE: To provide an inexpensive ink jet recording device of high ink filling efficiency in an ink jet recording device in which a recording head section for jetting ink and an ink tank are constituted removably from a device main body. CONSTITUTION: An air valve section 9 for controlling the pressure (negative pressure) in an ink tank 6 is provided on a head section 40, and an air valve section 9 is intruded into the ink tank 6 by mounting the ink tank 6 on the head section 40. As the air valve section 9 for which high dimension accuracy is essential is not required in the ink tank 6 by the above arrangement, the diposable ink tank 6 can be constituted by a material of low cost.

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 apparatus in which a head portion holding a recording head for ejecting ink and an ink tank are detachably attached to an apparatus main body.

[0002]

2. Description of the Related Art An ink jet recording system is adopted as one of printing systems in recording devices such as printers, fax machines, copying machines and printing machines.

An ink jet recording apparatus using this ink jet recording system drives a recording head based on image data to eject ink droplets from an ink ejection port provided on the front surface of the recording head (ink or the like). It is configured to form an image composed of the dot pattern.

The above ink jet recording apparatus is suitable for color printing. In the case of color printing, a plurality of ink colors (for example, cyan, magenta, yellow and black) are used, and a plurality of recording heads corresponding to these ink colors. Is recorded using.

The inks of a plurality of colors used in the above-mentioned ink jet recording apparatus are accommodated in separate ink tanks, and when the ink is exhausted, only the ink tanks of the necessary colors are replaced. There is.

The structure of the ink tank is roughly classified into an "open type" in which the inside of the ink tank communicates with the atmosphere.
A so-called sponge type in which a water absorbing member such as polyurethane foam is filled is often used as an example of the "open type", which is divided into a "sealed type" in which an ink tank is sealed. The disadvantage of this sponge type is that the sponge inserted in the ink tank occupies the volume and the filling amount of the ink is reduced accordingly, resulting in a large ink tank.

Since the size of the ink tank occupies an important weight in order to reduce the size of the ink jet recording apparatus, it is necessary to improve the ink filling efficiency of the ink tank. As a means for this, there is one in which the ink tank is made "closed type" and a pressure adjusting member (air valve) for alleviating the negative pressure that increases with the consumption of ink is attached.

[0008]

However, in the closed type ink tank of the color ink jet recording apparatus as described above, if the negative pressure in the ink tank becomes too large, the ink cannot be supplied to the recording head, and vice versa. Further, if the negative pressure in the ink tank becomes too small, ink may leak from the ejection port of the recording head, or the meniscus of the ejection port may be convex, resulting in deterioration of print quality. In order to control the negative pressure in the ink tank in order to solve this problem, a pressure adjusting member with high dimensional accuracy is required, so a molding resin with high dimensional accuracy (eg PE
The ink tank must be composed of S etc.). Therefore, even if the recording head unit and the ink tank can be separated to reduce the running cost, the ink tank becomes expensive, and as a result, the running cost cannot be reduced.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, according to the present invention, by mounting an ink tank on the head portion, the pressure in the ink tank provided in the head portion is adjusted so as to enter the ink tank. A pressure adjusting member for adjusting is provided. Similarly, by mounting the ink tank on the head portion, a pressure adjusting member provided on the head portion is provided so as to come into pressure contact with the ink tank.

[0010]

According to the present invention, because of the above-described structure, the pressure adjusting member composed of highly accurate parts for controlling the negative pressure in the ink tank is not provided in the ink tank which is a disposable part. Can be cheaper.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a head portion and an ink tank of the inkjet recording apparatus according to an embodiment of the present invention. 1 and 2, the carriage 1 is guided by the shaft 2 and reciprocates in the longitudinal direction of the platen 3. A head unit 40 holding a recording head 4 is detachably attached to the carriage 1.
A plurality of nozzle plates 5 are provided on the front surface of the recording head 4,
Each nozzle plate 5 is formed with a plurality of ink ejection openings (not shown). An ink heating means such as a heater or an electrode is provided inside the recording head 4, and air bubbles are generated in the ink by driving the ink heating means based on the image data. An ink droplet is ejected from an ink ejection port provided on the front surface to form an image having an ink dot pattern on a recording medium.

The carriage 1 has ink tanks 6 (6BK, 6C, 6M, 6) corresponding to the respective colors of the recording head 4.
Y) is attached and fixed. Ink tank 6 (6B
K, 6C, 6M, 6Y), for example, inks of respective colors of black, cyan, magenta, and yellow are stored, and are supplied to the recording head 4 as needed.

A flow passage portion 7 for ink from the ink tank 6 is formed in the head portion 40, and the ink flow passage portion 7 is formed.
A filter 8 for trapping dust and air bubbles is attached to the tip of the. The filter 8 is intricately meshed with a stainless wire material so that the filtration particle size is about 10 microns. The ink tank 6 is provided near the flow path portion 7.
An air valve portion 9 for controlling the negative pressure inside is formed.

The ink tank 6 is inexpensive, has good moldability, and is formed of a polyolefin resin such as polypropylene having excellent impact resistance and ink resistance. Therefore, there is a drawback that dimensional accuracy due to molding is difficult to obtain. Case 6a and lid 6b
Is adhered and sealed by a method such as ultrasonic welding.

The housing 6a has a hole 16 through which the flow path portion 7 enters and a hole 26 through which the air valve portion 9 enters. A porous member 36 and a valve member 46 are provided in the hole 16 into which the flow path portion 7 enters and the hole 26 into which the air valve portion 9 enters so that ink in the ink tank 6 does not leak. When the ink tank 6 is attached to the head portion 40, the flow path portion 7 enters the hole 16 and is brought into pressure contact with the porous member 36, so that the ink is guided to the flow path portion 7. At the same time, the air valve portion 9 enters the hole 26, and the valve member 46
By pushing into the ink tank 6, the air valve portion 9 enters the ink tank 6.

A fine hole (not shown) is opened at the tip of the air valve portion 9. As ink in the ink tank 6 is consumed, the negative pressure in the ink tank 6 increases, but The atmospheric pressure penetrates according to the diameter, and alleviates the increase in the negative pressure in the ink tank 6.

Since the purpose of the air valve portion 9 is not to penetrate into the ink tank 6, if the fine holes at the tip of the air valve portion 9 and the inside of the ink tank 6 communicate with each other, the same effect can be obtained by pressing them. Is obtained.

[0018]

As described above, according to the present invention, the pressure adjusting member formed of highly accurate parts for controlling the negative pressure in the ink tank is not provided in the ink tank which is a disposable part. In addition, the ink tank can be made inexpensive and the running cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a head unit and an ink tank of an inkjet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1 Carriage 2 Shaft 3 Platen 4 Recording Head 5 Nozzle Plate 6 Ink Tank 6a Case 6b Lid 7 Flow Path 8 Filter 9 Air Valve 16 Hole 26 Hole 36 Porous Member 40 Head 46 Valve Member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichizo Otsubo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. An ink jet recording apparatus in which a head section for holding a recording head for ejecting ink and an ink tank for storing ink to be supplied to the recording head are configured to be detachable from a main body of the apparatus. An ink jet recording apparatus, comprising: a pressure adjusting member that adjusts a pressure inside the ink tank, which is provided in the head portion so that the tank is attached to the head portion so as to enter the ink tank. 2. The ink jet recording apparatus according to claim 1, wherein the pressure adjusting member is an air valve that allows atmospheric pressure to enter the ink tank when the pressure in the ink tank becomes lower than a predetermined pressure. . 3. An ink jet recording apparatus in which a head section for holding a recording head for ejecting ink and an ink tank for storing ink to be supplied to the recording head are detachably configured from an apparatus main body. An ink jet recording apparatus, comprising: a pressure adjusting member that adjusts a pressure in the ink tank, which is provided in the head portion so as to be in pressure contact with the ink tank by mounting the tank on the head portion. 4. The ink jet recording apparatus according to claim 3, wherein the pressure adjusting member is an air valve that allows atmospheric pressure to enter the ink tank when the pressure in the ink tank becomes lower than a predetermined pressure. .