JP2003237104A - Liquid ejector and its liquid supplying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the cost by decreasing the number of components and eliminating the need for intricate control. <P>SOLUTION: The liquid ejector comprises a head 6 for ejecting liquid drops in correspondence with ejection data, a main tank 9 and a subtank 7 for supplying liquid to the ejection head 6, and a pump 21 for supplying an air pressure to the main tank 9 and generating a liquid flow to the subtank 7. A ventilation passage 100 for supplying an air pressure is provided between the air pressurizing pump 21 and the main tank 9 and a thin hole 100a opening into the atmosphere through a vent pipe 101 is made in the way of the ventilation passage 100. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejecting apparatus having two main and sub tanks for supplying a liquid to an ejecting head and a liquid supplying method in this apparatus.

[0002]

2. Description of the Related Art An ink jet type recording apparatus as an example of a liquid ejecting apparatus is generally mounted on a carriage,
An ejecting head that moves in the width direction of the recording sheet as a target to eject ink droplets as a droplet, and a paper feeding unit that relatively moves the recording sheet in a direction orthogonal to the moving direction of the ejecting head are provided. I have it.

In such an ink jet recording apparatus, printing on a recording sheet is performed by ejecting ink droplets from an ejection head based on print data as ejection data.

On the carriage, for example, black,
Equipped with an ejection head capable of ejecting yellow, cyan, and magenta inks, not only text printing with black ink but also full-color printing is possible by changing the ejection ratio of each ink.

Therefore, an ink cartridge as a liquid cartridge for supplying each ink to the ejection head is provided in the recording apparatus.

In a normal ink jet recording apparatus, each ink cartridge storing each ink is placed on a carriage and moves together with the carriage.

On the other hand, in a recording apparatus of this type provided for office or business use, a large-capacity ink cartridge is arranged outside the carriage in order to accommodate a relatively large amount of printing.

Further, there is provided a recording apparatus of a type in which a main tank as an ink cartridge is loaded in a cartridge holder arranged on the apparatus main body side. Then, a sub-tank is arranged on the carriage on which the ejection head is mounted, and ink is supplied from each main tank to each sub-tank via an ink supply tube (ink path) as a liquid supply tube. Ink is supplied from each sub tank to the ejection head.

In such a recording apparatus, in order to improve throughput, ink is sequentially supplied from each main tank to each sub-tank while printing is performed, and ink is supplied from each sub-tank to each ejection head. Functions that provide stable supply are required.

As means for satisfying such a function, for example, by pressurizing an ink pack as a liquid pack in the main tank with air, an ink flow is generated from the main tank to the subtank, and the subtank is formed in the subtank. A configuration capable of supplying ink is preferably adopted. In this case, it is important that an excessive pressure is not applied to the ink pack in the main tank.

Therefore, an ink jet type recording apparatus having a liquid supply system as shown in FIG. 5 has been conventionally used, and the pressure supplied to the ink pack at the time of ink supply from the main tank to the sub tank can be adjusted. Be seen.

A liquid supply system of this ink jet recording apparatus will be described with reference to FIG.

In the figure, reference numeral 21 indicates an air pressure pump. The air pressurized by the air pressurizing pump 21 is supplied to the pressure adjusting valve 22 and further the pressure detector 23.
It is configured to be supplied to each main tank 9 (only one is shown) via each.

The pressure adjusting valve 22 is the air pressure pump 2
It has a function of keeping the air pressure applied to each main tank 9 within a predetermined range by opening the valve when the air pressure pressurized by 1 reaches a predetermined value or more.

Further, the pressure detector 23 functions to detect the air pressure pressurized by the air pressure pump 21 and control the drive of the air pressure pump 21.

With this configuration, each main tank 9 (ink pack 24) receives a pressure from the pressurized air, and an ink flow of a predetermined pressure is generated from each main tank 9 to each sub tank. .

The ink pressurized in each main tank 9 is supplied to each sub tank via each ink supply valve 26 and each ink supply tube 10.

[0018]

By the way, in such a liquid ejecting apparatus, the pressure supplied from the air pressure pump 21 into the main tank 9 is adjusted by the pressure adjusting valve 2.
2 and the pressure detector 23 are performed as follows.

That is, when the pressure detector 23 detects that the air pressure pressurized by the air pressure pump 21 reaches a predetermined pressure, the drive of the air pressure pump 21 is stopped. Further, when the pressure detector 23 detects that the air pressure has become equal to or lower than the predetermined pressure, the air pressure pump 21 is driven.

Therefore, in the above-mentioned liquid ejecting apparatus, not only the number of parts is increased, but also complicated control is required for the pressure adjustment, which causes a problem that the cost is increased.

The present invention has been made in order to solve such a technical problem, and can reduce the number of parts and eliminate the complicated control conventionally required for pressure adjustment. It is an object of the present invention to provide a liquid ejecting apparatus and a liquid supply method in the apparatus, which can realize cost reduction.

[0022]

A liquid ejecting apparatus according to the present invention, which has been made to achieve the above object, ejects a liquid droplet corresponding to ejection data, and supplies a liquid to the ejecting head. A main and sub two tanks for doing so, and an air pressurizing pump for generating a liquid flow to the sub tank by supplying air pressure to the main tank of these two tanks,
A ventilation passage for supplying the air pressure is provided between the air pressure pump and the main tank, and a pore opening to the atmosphere is provided in the middle of the ventilation passage.

With this structure, when the air pressure is supplied from the air pressure pump into the ventilation passage, the main tank receives the air pressure, and the liquid is supplied from the main tank to the sub tank accordingly. At this time, the air pressure supplied from the air pressure pump to the main tank is adjusted by causing a part of the air pressure to flow out into the atmosphere from the pores of the ventilation passage.

In this case, the air pressure corresponding to the supply amount of the air pressure supplied from the air pressure pump into the ventilation passage flows out from the pores into the atmosphere.

Therefore, the pressure adjusting valve and the pressure detector, which are conventionally required for adjusting the air pressure supplied from the air pressure pump to the main tank, are unnecessary.

Therefore, the number of parts can be reduced, and the complicated control conventionally required for pressure adjustment can be dispensed with, and the cost can be reduced.

Here, the main tank has a liquid pack made of a flexible member for containing a liquid and a closed container for containing the liquid pack, and the air is provided between the closed container and the liquid pack. It is desirable to form a pressure chamber into which the air pressure from the pressurizing pump can be introduced.

With this configuration, the liquid is supplied from the main tank to the sub tank by supplying air pressure from the air pressure pump to the pressure chamber in the closed container to pressurize the liquid pack. .

Further, it is desirable that the pores be slits.

With this structure, when the air pressure is supplied from the air pressure pump to the main tank, a part of the air pressure is discharged into the atmosphere through the slit of the ventilation passage.

Further, it is desirable that an atmosphere open passage having a flow passage resistance larger than that of the ventilation passage is connected to the pores.

Further, it is desirable that the atmosphere open path is a ventilation pipe, and that the ventilation pipe is formed of a flexible tube or a metal pipe.

It is also possible to employ a structure in which the atmosphere open path is formed by a base having a groove and a seal member for sealing the groove of the base.

Further, it is preferable that the base is made of a plastic plate and the sealing member is made of a plastic film.

With this structure, a part of the air pressure supplied from the air pressure pump into the ventilation passage flows out of the pores into the atmosphere through the atmosphere opening passage in accordance with the supply amount,
The pressure can be adjusted effectively.

Therefore, the air pressure flowing from the ventilation passage to the pores and the atmosphere opening passage is throttled, and the pressure of the air pressure supplied from the air pressure pump into the ventilation passage is effectively adjusted.

On the other hand, the liquid supply method in the liquid ejecting apparatus according to the present invention comprises an ejection head for ejecting droplets corresponding to ejection data, two main and sub tanks for supplying liquid to the ejection head. A liquid supply method in a liquid ejecting apparatus, comprising: an air pressure pump for supplying air pressure to a main tank of these two tanks to generate a liquid flow to the sub tank. In supplying the liquid to the, the air pressure is supplied from the air pressurizing pump to the air passage to the main tank, and a part of the air pressure is let out to the atmosphere from the pores provided in advance in the air passage. It is characterized by

According to such a method, when the air pressure is supplied from the air pressure pump into the ventilation passage, the main tank receives the air pressure, and accordingly, the liquid is supplied from the main tank to the sub tank. At this time, the air pressure supplied from the air pressure pump to the main tank is adjusted by causing a part of the air pressure to flow out into the atmosphere from the pores of the ventilation passage.

Therefore, the pressure adjusting valve and the pressure detector, which are conventionally required for adjusting the air pressure supplied from the air pressure pump to the main tank, are unnecessary.

Therefore, the number of parts can be reduced, and the complicated control conventionally required for the pressure adjustment can be dispensed with, and the liquid ejecting apparatus can be obtained at a low cost.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION An ink jet recording apparatus as a liquid ejecting apparatus according to the present invention and a liquid supply method in this apparatus will be described based on the embodiments shown in the drawings.

First, regarding the ink jet type recording apparatus,
This will be described with reference to FIG. FIG. 1 is a plan view showing the basic configuration of an ink jet recording apparatus.

A carriage indicated by reference numeral 1 in the drawing is guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2 and is a main scan in the longitudinal direction of the paper feeding member 5, that is, the width direction of the recording paper. It is configured to reciprocate in the direction. Although not shown in FIG. 1, an ink jet type ejection head 6 (shown in FIG. 2) is mounted on the surface of the carriage 1 facing the paper feed member 5.

The carriage 1 has sub-tanks 7a to 7d for supplying ink to the ejection head 6.
Is installed.

Four sub-tanks 7a to 7d are provided corresponding to each of the black, yellow, magenta and cyan inks in order to temporarily store the respective inks therein. Then, in each of these sub tanks 7a to 7d, from the main tanks 9a to 9d as ink cartridges loaded in the cartridge holder 8 arranged in the apparatus main body, the ink supply tubes 10, 10, ... .. is configured to be supplied with the respective inks.

The main tanks 9a to 9d as the above-mentioned ink cartridges receive the air pressure from the air pressurizing pump 21, respectively.
Therefore, an ink flow with a predetermined pressure is generated in each of the sub tanks 7a to 7d.

On the other hand, capping means 11 is arranged in a non-printing area (home position) on the moving path of the carriage 1. This capping means 11
A cap member 11a formed of a flexible material such as rubber capable of sealing the nozzle forming surface of the ejection head 6 is disposed on the upper surface of the cap member 11a.

When the carriage 1 moves to the home position, the cap member 11a seals the nozzle forming surface of the jet head.

The cap member 11a functions as a lid that seals the nozzle forming surface of the jet head 6 and prevents the nozzle openings from drying during the rest period of the recording apparatus. Although not shown in the drawing, one end of a tube of a suction pump (tube pump) is connected to the cap member 11a, and a negative pressure by the suction pump is applied to the ejection head 6 to cause the ejection head 6 to operate. A cleaning operation for sucking and discharging the ink from is executed.

A wiping member 12 made of an elastic material such as rubber is arranged adjacent to the printing area side of the capping means 11, and the nozzle forming surface of the ejection head 6 can be wiped and cleaned as necessary. Is configured.

FIG. 2 schematically shows the structure of the ink supply system mounted on the recording apparatus shown in FIG. 1. In FIG. 2, the corresponding parts of the ink supply system are designated by the same reference numerals. Will be explained together. In FIG. 2, the same members as those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 2, the outer case (closed container) 9A of the main tank 9 accommodates an ink pack 24 made of a flexible material for containing ink. A pressure chamber 25 is formed between the closed container 9A and the ink pack 24, and pressurized air from the air pressure pump 21 is supplied into the pressure chamber 25 through the ventilation passage 100. Is configured.

The ventilation passage 100 is made of a metal pipe and is connected to the air pressure pump 21 and the main tank 9. A pore 100a formed of a through hole is provided on the road wall in the middle of the air passage 100. A vent pipe 101 as an atmosphere open path is integrally provided at the outer peripheral edge of the pore 100a. The pores 100a are configured to open to the atmosphere via the ventilation pipe 101.

The pores 100a are provided in the ventilation passage 1
No. 00 has a flow path resistance greater than that of a circular opening. That is, the pores 100
The diameter of a is set to be smaller than the diameter of the air passage 100. The diameter of the ventilation pipe 101 is set to be the same as the diameter of the pore 100a. As a result, part of the air pressure supplied from the air pressure pump 21 to the pressure chamber 25 of the main tank 9 is passed from the pores 100a of the ventilation passage 100 to the ventilation pipe 101, and further to the ventilation pipe 101.
It is designed to be discharged into the atmosphere and adjusted.

With this configuration, each main tank 9a-9
Each of the ink packs 24 housed in d (representatively represented by reference numeral 9 in FIG. 2) receives a constant pressure from the pressurized air and is transferred from each main tank 9a to 9d to each sub tank 7a to 7d. On the other hand, an ink flow with a predetermined pressure is generated.

The ink pressurized in each of the main tanks 9a to 9d passes through each ink supply valve 26 and each ink supply tube 10 to each sub-tank 7a to 7d mounted on the carriage 1 (see FIG. 2 is representatively shown by the code | symbol 7).

Further, the ink supply valve 26 is opened and closed according to the ink level in the sub tank 7 by an ink amount detecting means (not shown). As a result, the ink is supplied intermittently from the main tank 9 to the sub tanks 7, and the ink in each sub tank 7 is always stored in a certain range.

Ink is supplied from each of the sub-tanks 7 to the ejection head 6 through the opening / closing valve 35 and the ink supply tube 36. Therefore, based on the print data supplied to the actuator (not shown) of the ejection head 6, ink droplets are ejected from the nozzle openings 6a formed on the nozzle formation surface of the ejection head 6.

Next, an ink supply method in the ink jet recording apparatus according to this embodiment will be described with reference to FIG.

This ink supply method uses the air pressure pump 21.
Is supplied to the inside of the ventilation path 100 from the inside.

In this case, from the air pressure pump 1 to the ventilation passage 1
When the air pressure is supplied to 00, the main tank 9 receives the air pressure, and accordingly, the ink is supplied from the main tank 9 to the sub tank 7 through the ink supply valve 26 and the ink supply tube 10. At this time, the air pressure supplied from the air pressure pump 21 to the main tank 9 is adjusted by causing a part of the air pressure to flow from the pores 100a of the ventilation passage 100 to the ventilation pipe 101 and further to the atmosphere from the ventilation pipe 101. .

Here, the pores 100a in the present embodiment.
The function of the ventilation pipe 101 will be described.

These pores 100a and ventilation pipe 101
When the air pressure is supplied from the air pressure pump 21 into the ventilation passage 100, the function is exhibited.

That is, as the air pressure (air amount) is supplied from the air pressure pump 21 into the ventilation passage 100, a part thereof is introduced into the pores 100a and the ventilation pipe 101. At this time, the air pressure supplied from the air pressure pump 21 into the ventilation passage 100 is adjusted by causing a part of the air pressure to flow out into the atmosphere from the pores 100a of the ventilation passage 100.

In this case, the outflow of air pressure from the pores 100a into the atmosphere is carried out in accordance with the amount of air pressure supplied from the air pressure pump 21 into the ventilation passage 100. That is, while the supply amount of the air pressure from the air pressurizing pump 21 is small, a relatively small supply amount of the air pressure flows out of the pores 100 a into the atmosphere through the ventilation pipe 101. Further, when the supply amount of the air pressure from the air pressurizing pump 21 increases, a relatively large supply amount of the air pressure is supplied from the pores 100a to the ventilation pipe 101.
Through the air into the atmosphere.

Therefore, the pressure adjusting valve and the pressure detector, which are conventionally required for adjusting the air pressure supplied from the air pressure pump 21 to the main tank 9, are unnecessary.

Therefore, in this embodiment, the number of parts can be reduced, and the complicated control conventionally required for pressure adjustment can be eliminated.
The cost can be reduced.

In the present embodiment, the case where the atmosphere open path is the ventilation pipe 101 has been described, but the present invention is not limited to this, and as shown in FIGS. 3 and 4A to 4C. It can be anything. FIG. 3 is a perspective view showing a main part of the ink jet recording apparatus according to the second embodiment of the present invention. 4A to 4C are a front view, a plan view and a side view showing the main part of the ink jet recording apparatus according to the second embodiment of the present invention.

The atmosphere opening passage 201 shown in FIGS. 3 and 4A to 4C is composed of a base 202 and a seal member (not shown), and is connected to the ventilation passage 100.

The base 202 is formed of a plastic plate. In this base 202, the pores 100 are
A concave groove 202a communicating with a is provided. The concave groove 202a is formed by a meandering groove having a flow passage resistance larger than that of the ventilation passage 100. As a result, a part of the air pressure supplied from the air pressure pump 21 into the ventilation passage 100 flows out into the atmosphere from the pores 100a through the concave grooves 202a in accordance with the supply amount, and the pressure adjustment is made more effective. It can be carried out.

The seal member (not shown) is formed of a plastic film that seals the groove 202a.

Further, in the above embodiment, the ventilation passage 1
00 and the ventilation pipe 101 are formed of a metal pipe, the present invention is not limited to this.
The material is not particularly limited, such as being formed by a flexible tube, and the case where the pore 100a is a round opening has been described, but the present invention is not limited to this, and for example, a slit is used. It may be present, and the shape of the opening is not particularly limited.

Furthermore, in the above-described embodiment, an ink jet recording apparatus (printing apparatus including fax, copier, etc.) which ejects ink has been described as the liquid ejecting apparatus, but it is a liquid ejecting apparatus which ejects other liquids. May be. For example, a liquid ejecting apparatus that ejects a liquid such as an electrode material or a coloring material that is used for manufacturing a liquid crystal display, an EL display, an FED (surface emitting display), or the like, or a liquid ejecting apparatus that ejects a bioorganic substance used for biochip manufacturing It may be a sample injection device as a precision pipette.

[0074]

As is apparent from the above description, according to the liquid ejecting apparatus and the liquid supply method in this apparatus according to the present invention, the number of parts can be reduced, and
The complicated control conventionally required for pressure adjustment can be dispensed with, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing an ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing an ink supply system from a main tank to an ejection head in the recording apparatus shown in FIG.

FIG. 3 is a perspective view showing a main part of an ink jet recording apparatus according to a second embodiment of the invention.

4A to 4C are a front view, a plan view and a side view showing a main part of an ink jet recording apparatus according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram shown for explaining an ink supply system from a main tank to a sub tank in a conventional recording apparatus.

[Explanation of symbols]

1 Carriage 6 Jet Head 7 (7a, 7b, 7c, 7d) Sub Tank 8 Cartridge Holder 9 (9a, 9b, 9c, 9d) Main Tank (Ink Cartridge) 10 Ink Supply Tube 21 Air Pressurizing Pump 24 Ink Pack 25 Pressure Chamber 26 Ink supply valve 100 Ventilation path 100a Pore 101 Ventilation tube

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[Procedure amendment]

[Submission date] December 12, 2002 (2002.12.
12)

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 5]

[Figure 4]

Claims (10)

[Claims] 1. An ejection head for ejecting liquid droplets corresponding to ejection data, two main and sub tanks for supplying liquid to the ejection head, and an air pressure for supplying air pressure to the main tank of these two tanks. An air pressurizing pump for generating a liquid flow to the sub tank is provided, and a vent passage for supplying the air pressure is provided between the air pressurizing pump and the main tank. The liquid ejecting apparatus is characterized in that a fine hole that is open to the atmosphere is provided in the. 2. The main tank has a liquid pack made of a flexible member for containing a liquid and a closed container for containing the liquid pack, and the air supply is provided between the closed container and the liquid pack. The liquid ejecting apparatus according to claim 1, wherein a pressure chamber capable of introducing air pressure from the pressure pump is formed. 3. The liquid ejecting apparatus according to claim 1, wherein the fine holes are slits. 4. The atmosphere opening passage having a flow passage resistance larger than the flow passage resistance of the ventilation passage is connected to the pores. Liquid ejector. 5. The liquid ejecting apparatus according to claim 4, wherein the atmosphere open path is a ventilation pipe. 6. The liquid ejecting apparatus according to claim 5, wherein the ventilation pipe is formed of a flexible tube. 7. The liquid ejecting apparatus according to claim 5, wherein the ventilation pipe is formed of a metal pipe. 8. The liquid ejecting apparatus according to claim 4, wherein the atmosphere opening path is formed by a base having a groove and a seal member that seals the groove of the base. . 9. The liquid ejecting apparatus according to claim 8, wherein the base is formed of a plastic plate, and the sealing member is formed of a plastic film. 10. An ejection head for ejecting liquid droplets corresponding to ejection data, two main and sub tanks for supplying liquid to the ejection head, and an air pressure is supplied to the main tank of these two tanks. A liquid supply method in a liquid injection device comprising an air pressure pump for generating a liquid flow to a sub tank, wherein when supplying liquid from the main tank to the sub tank, from the air pressure pump A liquid supply method in a liquid ejecting apparatus, characterized in that air pressure is supplied to an air passage leading to the main tank, and part of this air pressure is made to flow out into the atmosphere from pores provided in advance in the air passage.