This application is based on Japanese Patent Application Nos. 11-153060 (1999) filed May 31, 1999, 11-153062 (1999) filed May 31, 1999, 11-153063 (1999) filed May 31, 1999, 11-153064 (1999) filed May 31, 1999, and 2000-117063 filed Apr. 18, 2000, the contents of which are incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to an ink tank, an ink-jet cartridge, an ink-supplying apparatus, an ink-jet printing apparatus, a method for supplying ink, an ink-jet printing head and a printing apparatus.
2. Description of the Related Art
(First Prior Art)
Heretofore, a serial-scanning type printing apparatus has been known as an example of the ink-jet printing apparatus. This kind of the printing apparatus exchangeably carries a printing head as a printing means and an ink tank as an ink container on the carriage which is capable of movement in the direction of main-scanning perpendicular to the direction of sub-scanning (i.e., the direction of moving a printing medium such as a piece of paper). As for this kind of the printing system, images are sequentially printed on a printing medium by repeating the movement of the carriage on which the printing head and the ink tank are mounted in the direction of main-scanning and the movement of the printing medium in the direction of sub-scanning.
The serial-scanning type printing apparatus is able to print an image on a large sized printing medium (e.g., A1, A0 size) by enlarging the migration width of the carriage. In this case, however, the ink storage capacity of the ink tank should be increased for using a great volume of ink to print an image on the surface of a large-sized printing, so that the whole weight of the carriage is increased in proportion to the capacity of the ink. In addition, an inertial force in the movement of the carriage is also proportionally increased. For moving the carriage at a high speed against the inertial force, there is the need for installing a driving motor with a large amount of electric power for driving the carriage in high power, resulting in the problem of increasing the price of the printing apparatus in its entirety. In addition, as the total weight of the carriage is increased, there is another problem that the printing apparatus oscillates greatly as a whole by the counterforce contrary to the force for deaccelerating the carriage to zero against the inertial force when the carriage returns at a returning point of its reciprocating motion in the main-scanning direction. Therefore, it was difficult for speeding up the travel speed of the carriage.
For reducing the weight of the carriage, on the other hand, the capacity of the ink tank may be lessened. In this case, however, the frequency of replacing the ink tank rises and thus there is a high possibility of replacing the ink tank with the new one in the middle of the printing movement.
One of the solutions to solve the problem about such a replacement of the ink tank is proposed in Japanese Patent Application Laying-open 9-24698 (1997). In this prior art document, a deformable ink container is connected to a printing head. The deformable ink container can be connected to an auxiliary ink container as necessary for supplying ink from the latter to the former. The deformable ink container comprises a bag that stores ink under the negative pressure enough to restrain the leakage of ink from the ink-eject port. Therefore, ink can be supplied from the auxiliary ink container to the deformable ink container by an effect of such a negative pressure.
The bag used in the deformable ink container is a flexible one enough to reduce its capacity in proportion to become flat, depending on the volume of ink ejected from the printing head (i.e., the usage of ink in the bag). When the volume of the bag is decreased to less than the fixed volume, a supply opening of the deformable ink container is opened to establish connection with the auxiliary ink container. As a result, ink is supplied into the bag of the deformable ink container from the auxiliary ink container by the negative pressure of the inside of the bag. When the ink capacity of the bag reaches to a maximum level, the negative pressure in the bag becomes zero and the supply of the ink is automatically stopped. According to such a prior art, therefore, the supply of ink can be automatically stopped by using the negative pressure without requiring the control using a pressure sensor, a volume detection sensor, and so on.
By the way, the upper limit of the negative pressure in the deformable ink container can be determined by its balance with the force of ejecting ink from the printing head. If the negative pressure becomes too high, the force of ejecting ink from the printing head is decreased by an effect of the negative pressure. Therefore, the negative pressure must be decided within the scope of the best ink-eject conditions in the printing head. In addition, a head location of ink in the auxiliary ink container must be configured so that it is lower than that of ink in the deformable ink container. If the deference between those heads is too large, ink cannot be supplied any more even if the negative pressure in the deformable ink container is defined so as to correspond to the conditions of ink-eject of the printing head.
As for the prior art, therefore, it is provided with the special device to configure a position of the auxiliary ink container in the vertical direction with respect to the deformable ink container. As for being provided with such a device, however, the problems of upsizing and cost up of the printing apparatus may be caused. If air enters into an ink flow path that connects between the auxiliary ink container and the deformable ink container from a part of the path at the time of ink supply, the entering air moves into the bag of the deformable ink container and then reduces the ink capacity of the deformable ink container by a large amount. Furthermore, the deformable ink container is filled with air if a large amount of the air is entered into the bag, so that there is a problem that a further supply of ink cannot be made. Still furthermore, the deformable ink container comprises an elastic container part that forms a bag and a movable part such as a spring that inflate the bag to a predetermined volume. Thus, there are further problems of the limitation of downsizing, complicated and heavy-weighted structure, and the rise in production cost.
(Second Prior Art)
Heretofore, a serial-scanning type printing apparatus has been known as an example of the ink-jet printing apparatus. This kind of the printing apparatus exchangeably carries a printing head as a printing means and an ink tank as an ink container on the carriage which is capable of movement in the direction of main-scanning perpendicular to the direction of sub-scanning (i.e., the direction of moving a printing medium such as a piece of paper). The printing head and the ink tank are connected each other by an ink path. As for this kind of the printing system, images are sequentially printed on a printing medium by repeating the movement of the carriage on which the printing head and the ink tank are mounted in the direction of main-scanning and the movement of the printing medium in the direction of sub-scanning.
On the other hand, a method for supplying ink to the ink tank of the ink-jet printing apparatus may be of the supply of ink through the application of pressure to the ink or the sucking of ink through the induction of negative pressure in the ink tank.
By the way, if the method for sucking of the ink into the ink tank is used as a method for supplying ink to the ink tank being connected to the printing head, there is the possibility of sucking ink in the printing head into the ink tank by an effect of the negative pressure to be introduced into the ink tank at the time of supplying ink under suction. If the ink in the printing head is introduced into the ink tank, a meniscus of ink to be formed on each of ink eject ports of the printing head is broken down and air enters into the printing head through the ink eject port. As a result, the supply of ink under suction cannot be performed as the negative pressure in the ink tank is reduced.
(Third Prior Art)
Heretofore, a printing apparatus that performs the printing using a printing material such as ink have been widely available. In recent years, in particular, a serial-scan type ink-jet printing apparatus is rapidly becoming in widespread use. Such an ink-jet printing apparatus comprises a carriage on which a printing head and an ink tank are mounted. The printing head ejects ink onto a printing medium to print an image thereon while the carriage moves directly above the printing medium in the main-scanning direction.
According to the configuration of such a printing apparatus, an empty ink tank must be replaced with the new one to continue its printing movement when the ink stored in the ink tank is exhausted. If the printing movement is continued long or performed on a larger-sized printing medium, a larger amount of ink may be consumed. In this case, therefore, the ink tank must be exchanged frequently, so that the printing movement in progress is suspended every time the ink tank is replaced with the new one. Such a replacement work is very troublesome.
As a consequence, there is another printing apparatus having a supplementary ink tank for automatically refilling ink when the ink tank mounted on the carriage becomes empty. The supplementary ink tank is connected to the ink tank on the carriage through a tube or the like. Ink can be supplemented from the supplementary ink tank to the ink tank on the carriage when the amount of ink stored in the ink tank decreases to a predetermined level. Therefore, the user may only replace the supplementary ink tank with the new one.
The conventional supplementary ink tank generally comprises an ink bag for storing ink and a case for encasing the ink bag.
The ink bag may be formed as the joining of two thin films by welding their opposite sides together or by any of other conventional techniques. Each of the thin films is generally in the shape of a rectangular, and also a part of one joining side of the rectangular is shaped like a cylinder as a protrusion being connected to a cylindrically shaped withdrawal member made of plastic or the like. Thus, the ink bag can be fixed in the inside of the case by putting the withdrawal member into an ink output opening of the case.
A main body of the printing apparatus has a hollow tube that has an external diameter enough to be inserted into the withdrawal member. If the supplementary ink tank is inserted into the predetermined position in the printing apparatus, the hollow tube fits into the withdrawal member of the ink bag and then the connection between the supplementary ink tank and the hollow tube is accomplished. Consequently, the ink tank on the carriage is able to receive ink passing through the hollow tube.
Alternatively, the supplementary ink tank may be prepared by welding thin films so that the ink bag itself has a cylindrical protrusion without installing any withdrawal means on the ink bag. In this case, the insertion of a needle-like tip of the tube into the protrusion of the ink bag allows the connection between the protrusion and the hollow tube for forming an ink passage.
However, the above conventional supplementary ink tank has the following programs.
That is, if a part of the ink bag is formed as a protrusion, the process of shaping the ink bag is complicated and the cost of production is increased.
Furthermore, if the ink passage between the withdrawal member and the hollow tube is not securely formed, leakage of ink might occur from the loosely connected portion. For automatically connecting them to make an ink passage at the time of mounting the supplementary ink tank, the supplementary ink tank must be precisely connected to the hollow tube so that a center of the withdrawal member coincides with an extension line of a center of the hollow tube. In this case, however, it is difficult to keep such an ink-passage connection consistently because there is a possibility that the hollow tube is curved by putting in and out the supplementary ink tank over and over again.
It is a first object of the present invention is to provide an ink tank, an ink-jet cartridge, an ink-supplying apparatus, an ink-jet printing apparatus, and a method for supplying ink, where ink can be reliably supplied to the ink tank by a simplified configuration of an ink passage to achieve both the size and weight reductions of the printing apparatus and to increase the reliability thereof.
It is a second object of the present invention is to provide an ink tank, an ink-jet cartridge, an ink-supplying apparatus, an ink-jet printing apparatus, and a method for supplying ink, where ink can be smoothly supplied during an extended period of time.
It is a third object of the present invention is to provide an ink-jet printing apparatus, an ink-supplying apparatus, and a method for supplying ink, where ink can be reliably supplied to the ink tank by a simplified configuration of an ink passage to achieve both the size and weight reductions of the printing apparatus and to increase the reliability thereof.
It is a fourth object of the present invention is to provide an ink tank, an ink-jet printing head, an ink-jet cartridge, and an ink-jet printing apparatus, where ink can be reliably supplied to the ink tank by preventing the entry of ink or air from the ink-jet printing head connected to the ink tank when ink is supplied to the ink tank under suction caused by the induction of negative pressure in the ink tank.
It is a fifth objet of the present invention is to provide an ink tank and a printing apparatus, where the ink tank has a main body that can be easily shaped like a bag and connected to an ink passage at the time of mounting the ink tank on the printing apparatus.
In the first aspect of the present invention, there is provided an ink tank capable of introducing ink into the ink tank through an inlet by a negative pressure introduced into the ink tank through a suction port, comprising gas-liquid separating means which is provided at the suction port and which permits gas to pass but inhibits ink from passing.
In the second aspect of the present invention, there is provided an ink-jet cartridge comprising an ink tank according to the first aspect, and an ink-jet printing head which is able to eject ink introduced from the ink tank.
In the third aspect of the present invention, there is provided an ink-supplying device for supplying ink to an ink tank according to the first aspect or an ink tank of an ink- jet cartridge according to the second aspect, comprising ink-supplying means for supplying ink stored in a main ink tank into the ink tank through the inlet, and negative-pressure loading means for loading negative pressure caused by a suction pump into the ink tank through the suction port.
In the fourth aspect of the present invention, there is provided an ink-supplying device for supplying ink to an ink tank according to the first aspect or an ink tank of an ink-jet cartridge according to the second aspect, comprising ink-supplying means for supplying ink stored in a main ink tank into the ink tank through the inlet, negative-pressure loading means for loading negative pressure caused by a suction pump into the ink tank through the suction port, and capping means capable of capping an ink eject port of the printing head by a cap member.
In the fifth aspect of the present invention, there is provided an ink-jet printing apparatus, comprising a mounting portion on which an ink tank according to the first aspect and an ink-jet printing head are mountable, where the ink-jet printing is able to eject ink supplied from the ink tank, and transfer means which performs the relative movements of the ink-jet printing head and a printing medium.
In the sixth aspect of the present invention, there is provided an ink-jet printing apparatus, comprising a mounting portion on which an ink-jet cartridge according to the second aspect is mountable, and transfer means for relatively moving the ink-jet cartridge and a printing medium.
In the seventh aspect of the present invention, there is provided a method for supplying ink to an ink tank according to the first aspect and an ink tank of an ink cartridge according to the second aspect, comprising the steps of supplying ink into the ink tank from the inlet by loading negative pressure into the ink tank from the suction port through the gas-liquid separating means, and stopping the load of negative pressure into the ink tank from the suction port.
In the eighth aspect of the present invention, there is provided an ink-jet printing apparatus, comprising a mounting portion on which an ink tank according to the first aspect and an ink-jet printing head are mountable, where the ink-jet printing is able to eject ink supplied from the ink tank, transfer means which performs the relative movements of the ink-jet printing head and a printing medium, and means for forming ink meniscus on the ink eject port by the recovery process which discharges ink from the ink eject port of the ink-jet printing head under suction before supplying of ink to the ink tank.
In the ninth aspect of the present invention, there is provided an ink-jet printing apparatus for printing an image on a printing medium employing an ink-jet printing head capable of ejecting ink supplied from an ink tank, comprising negative-pressure loading means which is able to introduce negative pressure into the ink tank, ink-supplying means for supplying ink into the ink tank using the negative pressure in the ink tank, gas-liquid separating means which lies in a negative-pressure loading passage between the ink tank and the negative-pressure loading means and which permits gas to pass but inhibits ink from passing, and disrupting means capable of disrupting a midcourse portion of the negative-pressure loading passage between the ink tank and the gas-liquid separating means.
In the tenth aspect of the present invention, there is provided an ink-supplying device, comprising negative-pressure loading means which is able to introduce negative pressure into an ink tank, ink-supplying means for supplying ink into the ink tank using the negative pressure in the ink tank, gas-liquid separating means which lies in a negative-pressure loading passage between the ink tank and the negative-pressure loading means and which permits gas to pass but inhibits ink from passing, and disrupting means capable of disrupting a midcourse portion of the negative-pressure loading passage between the ink tank and the gas-liquid separating means.
In the eleventh aspect of the present invention, there is provided a method for supplying ink to an ink tank, comprising gas-liquid separating means which lies in a negative-pressure loading passage between the ink tank and the negative-pressure loading means and which permits gas to pass but inhibits ink from passing, and disrupting means for disrupting a midcourse portion of the negative-pressure loading passage between the ink tank and the gas-liquid separating means, the method comprising the steps of loading negative pressure into the ink tank through the negative-pressure loading passage, supplying ink into the ink tank using negative pressure in the ink tank, stopping the loading of negative pressure into the ink tank by the gas-liquid separating means when ink touches the gas-liquid separating means, and disrupting the midcourse portion by the disrupting means except when ink is supplied into the ink tank.
In the twelfth aspect of the present invention, there is provided an ink tank which has an ink-supplying port for supplying ink into an ink-jet printing head, and which is capable of introducing ink into the ink tank by negative pressure introduced into the ink tank, comprising a valve provided at the ink-supplying port, which closes the ink-supplying port by negative pressure higher than a predetermined level in the ink tank.
In the thirteenth aspect of the present invention, there is provided an ink-jet printing head capable of ejecting ink supplied from an ink tank through an ink supplying port, comprising a valve provided at a connecting port connected to the ink-supplying port, which closes the ink-supplying port by negative pressure higher than a predetermined level in the ink tank.
In the fourteenth aspect of the present invention, there is provided an ink-jet cartridge comprising an ink tank according to the twelfth aspect, and an ink-jet printing head capable of ejecting ink supplied from an ink tank through an ink-supplying port.
In the fifteenth aspect of the present invention, there is provided an ink-jet cartridge comprising an ink-jet printing head according to the thirteenth aspect, and an ink tank capable of supplying ink into the inkjet printing head through the connecting port.
In the sixteenth aspect of the present invention, there is provided an ink-jet printing apparatus comprising a tank mounting portion on which an ink tank according to the twelfth aspect is mountable, a head mounting portion on which an ink-jet printing head capable of ejecting ink supplied from the ink tank is mountable, and moving means for relatively moving the ink-jet printing head and a printing medium.
In the seventeenth aspect of the present invention, there is provided an ink-jet printing apparatus comprising a head mounting portion on which an ink-jet printing head according to the thirteenth aspect is mountable, a tank mounting portion on which an ink tank capable of supplying ink to the ink-jet printing head is mountable, and moving means for relatively moving the ink-jet printing head and a printing medium.
In the eighteenth aspect of the present invention, there is provided an ink tank having a bag-like tank body which is made of a sheet of a thin film that is folded down in one side to form a folding part, and which is capable of storing ink, wherein the folding part forms a connecting portion capable of connecting between the inside and the outside of the tank body by means of a hollow conduit that is able to penetrate the folding part.
In the nineteenth aspect of the present invention, there is provided a printing apparatus capable of printing of an image using ink in the tank body, comprising a tank mounting portion on which an ink tank according to the eighteenth aspect is mountable, wherein a hollow conduit that is able to penetrate the connecting portion of the tank body and is provided at the tank mounting portion.
The present invention is configured such that the supply of ink under suction can be automatically stopped using the function of a gas-permeable member, so that the supply of ink to the ink tank can be performed by a simple structure with reliability. This offers an advantage of being able to achieve both the size and weight reductions of the printing apparatus and an improved reliability thereof.
The present invention is also configured such that the formation of ink meniscus on an ink eject port of the printing head is performed by draining the ink from the printing head being connected to the ink tank under suction, before the supply of ink to the ink tank under suction is performed. This offers an advantage of being able to achieve the supply of ink to the ink tank under suction with reliability.
The present invention is configured such that a porous material with an oil repellent finish is used as the gas-permeable member to be functioned as a gas-liquid separate means. The gas-permeable member repels ink enough. This offers an advantage of being able to achieve the supply of ink smoothly over an extended period of time with reliability in addition to improve the durability of the gas-permeable member.
The present invention is configured such that the gas-liquid separate means is not connected to the inside of the ink tank except when the supply of ink is performed. This offers an advantage of being able to prevent that the performance of the gas-liquid separate means is decreased by exposing the gas-liquid separate means to ink for a long time.
The present invention is configured such that a valve is provided in an ink-supplying path between the ink tank and the ink-jet printing head and closed when the inside of the ink tank becomes a predetermined level of negative pressure. This offers an advantage of being able to achieve the supply of ink under suction with reliability by preventing the entry of ink or air from the ink-jet printing head to be connected to the ink tank.
The present invention is configured that the main body of the ink tank is shaped like a bag which is good enough for communicating the inside of a main body of the ink tank with the outside through a hollow tube by passing the hollow tube through a curved portion of a thin film that forms the bag-shaped main body of the ink tank. This offers an advantage of being able to achieve the cost reduction of manufacturing the ink tank as the bag-shaped main body of the ink tank is formed with ease.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.