JP2001171139A - Liquid tank and liquid supply method, ink-jet recording apparatus using the same and ink supply method of ink- jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink tank of an ink-jet recording apparatus and an ink supply method whereby ink can be filled in a liquid feed tube by an internal pressure in the ink tank generated by reducing the ink tank and further, ink can be supplied to the vicinity of a printing head or a nozzle. SOLUTION: When the ink tank 11 is coupled to the liquid feed tube 7, a storage capacity in the ink tank 11 is reduced by bellows 11c and moreover a communication opening to the outside air is closed by a check valve, thereby increasing the internal pressure in the ink tank 11. A liquid in the coupled liquid feed tube 7 is pressed out by the increased internal pressure to supply the ink in the ink tank 11 to the vicinity of a discharge opening of the liquid feed tube 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid tank and a liquid supply method, in which a liquid supply tube is connected to a liquid tank containing a liquid, and the liquid is supplied by the liquid supply tube. To an ink jet recording apparatus and an ink supply method for the ink jet recording apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus that performs printing using ink, such as an ink jet recording apparatus used as an output device of a computer or a workstation, a predetermined liquid stored in a liquid tank such as an ink tank is used. Is supplied from a liquid tank through a liquid feeding tube.

For example, in the above-described image forming apparatus, an ink tank serving as a liquid tank is installed such that the liquid level of the ink in the ink tank is located below the print head, and the ink is discharged from the print head. The negative pressure of the ink is maintained by the surface tension of the nozzle of the print head caused by the consumption of the ink. When ink is consumed by printing and the ink in the ink tank runs out, it is replaced with a new ink tank filled with ink.However, when replacing with the new ink tank, there is no ink in the liquid feed tube, That is, a state in which air remains in the liquid sending tube occurs. For this reason, even if a new ink tank filled with ink is installed, the ink will not be supplied to the print head through the liquid feeding tube, and printing cannot be performed immediately.

Therefore, conventionally, when replacing the ink tank, the connection of the liquid supply tube to the print head is disconnected, and a syringe is attached to the connection of the liquid supply tube to suction the inside of the liquid supply tube. It is necessary to extract the air and ink in the nozzle and the liquid feed tube by sucking the ink from the discharge side of the nozzle of the print head.

[0005]

However, as described above, when the connection between the print head and the liquid supply tube is removed by removing the air from the liquid supply tube when replacing the ink tank, the liquid supply tube is not filled. The ink remaining on the inner wall of the tube and adhering to the inner wall of the tube may be dripped, thereby often contaminating the apparatus. Further, in order to suck the ink to the print head, a lot of time is spent on the ink, and an inefficient operation is required. As described above, some of the liquid tanks for ink or the like in the related art become very inconvenient to handle.

Accordingly, the present invention is directed to a liquid tank and a liquid supply method capable of filling a liquid supply tube with ink by a pressure generated in the liquid tank and further supplying the ink to a predetermined portion such as a print head. And an ink jet recording apparatus using the same and an ink supply method for the ink jet recording apparatus.

[0007]

According to a first aspect of the present invention, there is provided a liquid tank which is connected to a liquid feed tube and stores a liquid fed by the liquid feed tube. Storage volume changing means for changing the storage volume of the liquid in the tank, a communication port for communicating the inside of the tank with outside air, and a valve means for opening and closing the communication port by a pressure difference between the inside of the tank and the outside air. Have.

[0008] According to the second aspect of the present invention, the first aspect is provided.
Is formed by a bellows-like member provided at least in a part of the tank body.

According to a third aspect of the present invention, in a liquid supply method for connecting a liquid tank containing a liquid to a liquid feed tube and feeding the liquid by the liquid feed tube, the liquid tank is connected to the liquid feed tube. When connecting to the liquid tank, the internal volume in the liquid tank is reduced to increase the internal pressure in the liquid tank, and the fluid in the connected liquid sending tube is pushed out by the increased internal pressure to push out the fluid in the liquid tank. Liquid is supplied to the vicinity of the discharge port of the liquid sending tube.

According to a fourth aspect of the present invention, there is provided an ink jet recording apparatus for performing printing by sending ink from an ink tank and discharging the ink droplets in accordance with print data, wherein the ink tank is installed. The liquid tank according to claim 1 or 2 is provided as an ink tank to be installed in the ink tank installation section, the installation section being provided.

According to a fifth aspect of the present invention, the ink tank mounting portion according to the fourth aspect includes a locking member for stopping the expansion of the ink tank having a reduced ink storage volume in the tank.

According to a sixth aspect of the present invention, there is provided an ink supply method for an ink jet recording apparatus for performing printing by sending ink from an ink tank and discharging the ink droplets in accordance with print data. Is used.

According to the first aspect of the present invention, when the storage volume of the liquid in the tank is reduced, the communication port is closed by the valve means, thereby increasing the inside of the tank. The liquid is sent through the liquid sending tube by the internal pressure.

According to the second aspect of the present invention, the liquid storage volume in the tank can be easily reduced.

According to the fourth aspect of the present invention, when replacing the ink tank, when the ink storage volume in the ink tank is reduced, the communication port is closed by the valve means and the inside of the ink tank rises. The ink is supplied to the print head via the liquid supply tube by the internal pressure of the ink.

According to the fifth aspect of the present invention, since the locking member regulates the ink tank so as not to expand, the pressure in the ink tank is maintained at a high pressure.

Further, according to the invention described in claim 6,
An ink jet recording apparatus with good workability when replacing an ink tank is realized.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an inkjet printer (hereinafter simply referred to as a printer) as an example of a suitable image forming apparatus to which the present invention is applied.

A carriage 2 provided in the printer 1 shown in FIG. 1 is supported by a guide shaft 5 located above a platen 4 via a slide bearing (not shown) so as to be reciprocally movable. The guide shaft 5 is driven by a driving force of a carriage motor and a belt (not shown).
Along the arrow R and L directions (main scanning direction) in the figure. A print head 3 as a recording unit is mounted on the carriage 2, and the print head 3 is reciprocated in the directions of arrows R and L in FIG. Configuration has been made.

The print head 3 is provided with an ink discharge hole (not shown) for discharging ink, and is connected to a liquid feed tube 7 for supplying ink from an ink tank 11 described later. The ink supplied from the ink tank 11 is ejected from the ink ejection holes of the print head 3 in accordance with the print data, and the recording medium 6 conveyed under the print head 3 in the sub-scanning direction. Printing is performed on the top.

At one end of the printer 1 in the width direction, a substantially box-shaped ink tank installation section 9 for holding the ink tank 11 is provided. The height position of the ink tank installation section 9 is adjusted so that the ink liquid level in the ink tank 11 mounted on the ink tank installation section 9 is lower than the above-described ink ejection hole of the print head 3. Have been.

The end opening of the ink tank installation section 9 is
The ink tank 11 is formed as an ink tank insertion opening 9a, and the ink tank 11 is inserted and removed in the width direction through the ink tank insertion opening 9a.
The mounting posture of the ink tank 11 mounted in the box-shaped ink tank mounting section 9 is maintained by being restricted by the opening shape of the ink tank mounting section 9.

As shown in FIGS. 2 and 3, one end of the liquid feed tube 7 is provided at a lower side of an upright wall portion 9b which constitutes a rear bottom surface of the ink tank installation portion 9. Are connected to each other. The joint portion 10 is provided with a joint wall portion 10a in which the lower side portion of the rear-side standing wall portion 9b is made thinner, and a packing 10b made of, for example, butyl rubber is attached to the inside of the joint wall portion 10a. It is attached. The joint wall 10a and the packing 10
At a substantially central portion of b, a stainless steel pipe 8 is mounted so as to penetrate.

The inner portion 8a of the pipe 8 protruding toward the inside of the ink tank mounting portion 9 has a substantially needle shape, and the pipe 8 protruding toward the outside of the ink tank mounting portion 9 is formed. The outer portion 8b is connected to a liquid sending tube 7 for sending ink to the print head 3.

On the other hand, as shown in FIGS. 4 to 7, the ink tank 11 installed in the ink tank installation section 9 is made of a box-shaped member made of an elastic material such as a polypropylene material. At the rear end of the tank 11, an ink tank joint 11b made of butyl rubber, which is arranged to face the joint 10 of the ink tank installation part 9, is formed in a convex shape. The ink tank joining section 11b is inserted and mounted in the joint section 10 of the ink tank installation section 9.

When the ink tank 11 is inserted and installed in the ink tank installation section 9, the needle-shaped end 8a of the pipe 8 provided on the joint section 10 side is used.
Is inserted from the ink tank joining portion 11b on the ink tank 11 side and is inserted into the ink tank 11,
Accordingly, the ink in the ink tank 11 is supplied to the print head 3 via the pipe 8 and the liquid supply tube 7 connected to the ink tank 11.

Further, a bellows 11c is formed in a part of the main body of the ink tank 11 as a storage volume changing means for making the main body of the ink tank 11 extendable.
The bellows 11c is connected to the ink tank joint 11b described above.
Are formed so as to have an expansion / contraction action in a direction substantially perpendicular to a surface into which the pipe 8 is inserted, that is, a direction in which the ink tank 11 is inserted into and removed from the ink tank installation portion 9.
By the expansion and contraction of the bellows 11c, the ink tank 11
The configuration is such that the ink storage volume in the inside changes.

On the other hand, a communication port 11d for communicating the inside of the ink tank 11 with the outside air is formed through the upper surface of the ink tank 11 in the drawing. A check valve 12 made of a plate-like member is mounted on the inside so as to open and close the communication port 11d. The check valve 12 is attached so as to close the communication port 11d from the inside of the ink tank 11 via a leaf spring-like member 12a.
It is configured to open outside air only from the inside of the ink tank 11 in the direction that guides outside air into the ink tank 11 from 1d. When the pressure inside the ink tank 11 is higher than the outside air pressure, the communication port 11d is closed. When the pressure inside the ink tank 11 is lower than the outside air pressure, the communication port 11d is opened.

Then, when replacing the ink tank 11, that is, by removing the used ink tank 11 from the ink tank installation section 9, a new ink tank 11 configured as described above is inserted as shown in FIG. Printer 1
When inserting the ink tank 11 into the ink tank installation part 9, the end face 11a of the ink tank 11 opposite to the part where the ink tank joining part 11b is provided is pressed in the direction The ink tank 11 is inserted into the ink tank installation section 9. Joint part 10
After the needle-shaped tip portion of the pipe 8 provided in the above comes in contact with the ink tank joint portion 11b made of butyl rubber, the end surface 11a is further pushed in, as shown in FIG.
The needle-shaped tip of the pipe 8 is connected to the ink tank joint 11.
Accordingly, the inner passage of the pipe 8 communicates with the ink in the ink tank 11 via the liquid feed tube 7.

Next, after the ink tank joining portion 11b on the ink tank 11 side and the joint portion 10 on the ink tank installation portion 9 are brought into close contact with each other, the end surface 11a of the ink tank 11 is further pushed in, whereby the ink tank 1 is pressed.
The bellows 11c provided in one main body contracts. As a result, the pressure in the ink tank 11 increases, and the communication port 11d disposed above the ink tank 11 is closed by the check valve 12, so that the pressure in the ink tank 11 rapidly increases.

The bellows 11c of the ink tank 11 contracts to the state shown in FIG. 7, but at this time, the front end portion (left end portion in the figure) of the bottom surface 9c constituting the ink tank installation portion 9 That is, a substantially rectangular flat plate-shaped locking member 9d is formed at the lower edge portion of the above-described ink tank insertion opening 9a so as to contact the end surface 11a of the ink tank 11 contracted as described above. Have been. By mounting the ink tank 11 such that the end surface 11a of the ink tank 11 inserted into the ink tank mounting section 9 is brought into contact with the inner surface of the locking member 9d, the ink tank 11 is securely inserted into the ink tank mounting section 9. Fixed.

The ink tank 11 configured as described above
In the case, when the ink storage volume in the ink tank 11 is reduced, the communication port 11d is closed by the check valve 12, whereby the ink is printed through the liquid sending tube 7 by the increased internal pressure in the ink tank 11. The liquid is sent toward the head 3.

At this time, the volume changing means includes a bellows-like member 11 provided at least in a part of the main body of the ink tank 11.
c, the volume of ink stored in the ink tank 11 can be easily reduced.

At this time, the compressed ink tank 11 is brought into contact with the locking member 9d on the ink tank installation portion 9 side, so that the bellows portion 11c of the ink tank 11 is prevented from extending in the expanding direction. Therefore, the ink tank 11 is maintained in a contracted state. Therefore, when the ink container 1 is inserted into the ink tank installation section 9, the ink storage volume is reduced and the ink tank 1 is raised.
The pressure in 1 is maintained at the high pressure state as it is. When the pressure in the ink tank 10 rises, the ink in the ink tank 10 passes through the pipe 8 while pushing out the air and ink remaining in the liquid sending tube 7, and further pushes the liquid sending tube 5. Then, the ink is supplied to the vicinity of the print head 3 or to a nozzle orifice (not shown) of the print head 3.

When the ink supplied to the print head 3 is consumed by being printed on the recording medium 6 by the print head 3, the ink is consumed from the ink tank 11 by the capillary action of the nozzle. Is supplied via At this time, since the internal pressure of the ink tank 10 has been reduced by the supply of ink, the check valve 1
2, the inside of the ink tank 11 communicates with the atmosphere through the communication port 11d, and the internal pressure of the ink tank 11 rises and is maintained at the same pressure as the atmospheric pressure.

As described above, by using an ink tank in which a part of the ink tank 11 can be contracted by an external force, the pressure in the ink tank 11 can be increased. The ink can be quickly supplied to the nozzle orifice portion of the print head 3. Therefore, when replacing the ink tank 11, it is necessary to draw air in the tube 5 from the nozzle portion of the print head 3 by a pump or the like, or to remove the print head 3 and the tube 5 and to bleed the air with a syringe or the like as in the related art. As a result, the complexity of replacement of the ink tank 11 is greatly reduced.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above embodiments, and it is needless to say that various changes can be made without departing from the gist of the present invention. Nor. For example, in the above-described embodiment, the present invention is applied to the ink tank of the ink jet printer, but the present invention can be similarly applied to other various liquid tanks.

Further, the valve means and the storage volume changing means are not limited to the above-described embodiment, but may have various configurations.

[0039]

As described above, according to the first aspect of the present invention, there is provided a liquid tank which is connected to a liquid sending tube and stores the liquid sent by the liquid sending tube. A storage volume changing means for changing a storage volume, a communication port for communicating the inside of the tank with the outside air, and a valve means for opening and closing the communication port by a pressure difference between the inside of the tank and the outside air. Because
When the storage volume of the liquid in the tank is reduced, the communication port is closed by the valve means, and the liquid can be sent through the liquid sending tube due to the increased internal pressure in the tank, making it easy and clean. To supply liquid.

According to the second aspect of the present invention, since the volume changing means of the first aspect is formed by a bellows-shaped member provided at least in a part of the tank body, the liquid storage in the tank is achieved. The volume can be easily reduced.

According to a third aspect of the present invention, there is provided a liquid supply method for connecting a liquid tank containing a liquid to a liquid feed tube and feeding the liquid by the liquid feed tube.
When connecting the liquid tank to the liquid sending tube, the internal volume in the liquid tank is reduced by increasing the internal pressure in the liquid tank, and the fluid in the connected liquid sending tube is increased by the increased internal pressure. The liquid in the liquid tank can be extruded and supplied to the vicinity of the discharge port of the liquid sending tube.

According to a fourth aspect of the present invention, there is provided an ink jet recording apparatus which performs printing by sending ink from an ink tank and ejecting the ink droplets in accordance with print data. Since the liquid tank according to claim 1 or 2 is provided as an ink tank to be installed in the ink tank installation section, the ink tank is installed in the ink tank installation section.
When the storage volume of the ink in the ink tank is reduced, the communication port is closed by the valve means, and the ink is sent to the print head via the liquid sending tube by the increased internal pressure in the ink tank. it can.

According to a fifth aspect of the present invention, the ink tank mounting portion according to the fourth aspect includes a locking member for stopping the expansion of the ink tank having a reduced ink storage volume in the tank. Since it is configured, the locking member regulates the ink tank so that it does not expand,
The pressure in the ink tank can be maintained at a high pressure.

According to a sixth aspect of the present invention, there is provided an ink supply method for an ink jet recording apparatus for performing printing by sending ink from an ink tank and discharging the ink droplets in accordance with print data. Because the liquid supply method according to item 3 is used,
An ink jet recording apparatus with good workability when replacing an ink tank can be realized.

[Brief description of the drawings]

FIG. 1 is an external perspective explanatory view showing an embodiment of the overall structure of an ink jet recording apparatus according to the present invention.

FIG. 2 is an explanatory longitudinal sectional view corresponding to a portion indicated by line II in FIG. 1;

3 is a partially enlarged cross-sectional view corresponding to a portion indicated by III in FIG.

FIG. 4 is an explanatory longitudinal sectional view corresponding to FIG. 2, showing an initial stage of installing an ink tank in the inkjet recording apparatus shown in FIG. 1;

FIG. 5 is a partially enlarged sectional explanatory view corresponding to a portion indicated by IV in FIG. 4;

FIG. 6 is an explanatory longitudinal sectional view corresponding to FIG. 2 and showing a state of the next stage of FIG. 4 in which an ink tank is installed in the ink jet recording apparatus.

7 is an explanatory longitudinal sectional view corresponding to FIG. 2 and showing a state of the next stage of FIG. 6 in which an ink tank is installed in the ink jet recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet recording apparatus 7 Liquid feed tube 9 Ink tank installation part 9d Locking member 11 Ink tank 11c Bellows 11d Communication port 12 Check valve

Claims (6)

[Claims] 1. A liquid tank to which a liquid feeding tube is connected and for storing a liquid to be fed through the liquid feeding tube, wherein a storage volume of the liquid in the liquid tank is shrunk.
Storage volume changing means for extending, a communication port for communicating the inside of the liquid tank with the outside air, and closing the communication port when the pressure on the inside of the liquid tank is higher than the outside air pressure, and closing the inside of the liquid tank Valve means for opening the communication port when the pressure of the liquid is lower than the outside air pressure, and reducing the storage volume of the liquid in the liquid tank by the storage volume changing means, thereby closing the valve means to increase the pressure. A liquid tank, wherein the liquid is supplied through the liquid supply tube by an internal pressure in the liquid tank. 2. A liquid tank, wherein the volume changing means according to claim 1 is formed by a bellows-shaped member provided at least in a part of the tank body. 3. A liquid supply method in which a liquid supply tube is connected to a liquid tank containing a liquid, and the liquid is supplied through the liquid supply tube. The internal pressure in the liquid tank is increased by reducing the internal volume in the liquid tank, and the fluid in the connected liquid sending tube is pushed out by the increased internal pressure to send the liquid in the liquid tank to the liquid tank. A liquid supply method characterized in that the liquid is supplied to the vicinity of a discharge port of a liquid tube. 4. An ink jet recording apparatus configured to perform printing by sending ink from an ink tank and ejecting the ink droplets from a head unit in accordance with print data, wherein the ink tank is installed. An ink jet recording apparatus comprising an installation section, wherein the liquid tank according to claim 1 or 2 is used as an ink tank installed in the ink tank installation section. 5. The ink jet recording apparatus according to claim 4, wherein the ink tank installation section includes a locking member for stopping the expansion of the ink tank in which the storage volume of the ink in the tank is reduced. 6. The ink supply method for an ink jet recording apparatus according to claim 3, wherein ink is supplied from an ink tank and printing is performed by discharging the ink droplets in accordance with print data. An ink supply method for an ink jet recording apparatus, comprising using a supply method.