The present invention relates to an ink cartridge to be coupled to a device using ink.
Conventionally, ink cartridges have been widely used in devices using ink. An example of such devices, an inkjet printing device has been known. The inkjet printing device typically includes an inkjet head, which has an ink nozzle. The ink nozzle is driven to eject ink drops toward recording medium such as a piece of paper to form images and characters thereon. Typically, the ink cartridge includes an ink reservoir, and the ink accommodated in the reservoir is supplied to the inkjet head.
The exchangeable ink cartridge is advantageous in that when the printer runs out of the ink, only by replacing the old cartridge with a new cartridge. Therefore, the exchangeable ink cartridge is widely employed.
A typical structure of the ink cartridge is configured such that an ink reservoir is formed inside a housing of the cartridge, and an opening formed on the housing. The reservoir is connected with a communication path, and the opening is sealed with a stopper such as a rubber stopper.
The device, to which the ink cartridge is to be coupled, is formed with an ink cartridge bay, where a hollow needle is projected at a position corresponding to the rubber stopper. When the ink cartridge is coupled to the cartridge bay, the hollow needle penetrates through the rubber stopper so that the ink can be sucked via the communication path and the hollow needle and supplied to the device.
In a case of an inkjet printer, the hollow needle is connected with an inkjet head through an ink feed tube so that the ink is supplied from the ink cartridge to the inkjet head.
If air or impurities invade inside the reservoir, bubbles of the air and/or the impurities are supplied to the device together with the ink, which may cause trouble. For example, if the device is an inkjet printer, and if the bubbles are supplied to the printer, some dots may not be formed since drops of ink is not jetted due to the bubbles. The impurities supplied to the printer may block up the ink nozzles.
Therefore, a structure which is capable of preventing the air and impurities from invading in the device when the ink is supplied from the replaceable ink cartridge to the device is desired.
However, in view of manufacturing such an ink cartridge, it is desired that an operation for filling the reservoir with the ink is relatively easy. Further, once the reservoir is filled with the ink, invasion of the air and/or impurities should be blocked without fail.
In view of the requirements described above, the present invention is advantageous in that it provides an ink cartridge, which includes a housing defining a body of the cartridge, an ink reservoir accommodated in the housing, an opening formed on the housing, the opening communicating the ink reservoir through a fluid path, a stop to be tightly fitted in the opening, the stop having elasticity, the stop being configured such that a hollow needle can be penetrated therethrough, a hole formed by penetration of the hollow needle being closed by the elasticity of the stop after removal of the hollow needle, and a valve structure provided to a part of the stop, the valve structure selectively opens and closes the communication between the opening and the ink reservoir.
With this configuration, the ink can be supplied to the ink reservoir easily through the hollow needle. After the ink supply is completed, the valve structure is closed so that the ink does not flow from the ink reservoir to the opening and/or bubbles of the air and impurities do not enter from the opening to the ink reservoir. It should be noted that the stop also has a sealing effect to block the communication between both sides thereof.
Optionally, the valve structure may be configured to selectively open and close the communication between the opening and the ink reservoir depending on a positional condition of the stop.
In some embodiments, the positional condition includes a position along an axis of the stop. Alternatively, the positional condition may include a rotational position of the stop.
In one embodiment, the fluid path communicates with the opening at a decentered position of a bottom surface the opening.
In a particular case, the valve structure may include a protrusion that is protruded from a bottom surface of the stop at a position corresponding to the decentered position where the opening communicates with the fluid path. With this configuration, the protrusion is fitted in the fluid path when the stop is located at a predetermined position, and the protrusion is spaced from the fluid path when the stop is located at another position, along the axial direction thereof.
Further optionally, the valve structure may be configured to be opened when the stop is located at a first position where the stop is inserted intermediately in the opening, and closed when the stop is located at a second position where the stop is deeply inserted in the opening.
In one embodiment, a position where the fluid path communicates with the opening is located on an inner side surface of the opening. In this case, the communication between the fluid path and the opening is opened when the stop is located at the first position, and an outer side surface of the stop closes the communication between the fluid path and the opening when the stop is located at the second position.
Still optionally, the valve structure may include a protrusion that is protruded from a bottom surface of the stop at a position corresponding to the position where the opening communicates with the fluid path. The protrusion is fitted in the fluid path when the stop is fully or deeply inserted in the opening, the protrusion being spaced from the fluid path when the stop is located at an intermediate position along the axial direction thereof.
In some embodiments, the protrusion is located at a central portion of the bottom surface of the stop, and the fluid path communicates with the opening at a central portion of the bottom surface of the opening.
Preferably, the protrusion is formed to be slightly larger than a portion of the fluid path where the protrusion is fitted in, and the protrusion is compressed when fitted in the fluid path. Generally, when the protrusion is compressed, it is hardened. Thus, the above configuration improves the sealing effect.
In one embodiment, the protrusion has a conical shape. Alternatively, the protrusion may have a cylindrical shape. It may be possible to utilize various modifications of the shape of the protrusion.
In a particular case, the stop may include a barrel member and a closing wall defined inside the barrel member. The closing wall blocks a communication between both sides of the barrel member. In one embodiment, a thickness of the closing wall along the axis of the stop is smaller than a length of the barrel member along the axis of the stop. Of course, it is possible that the stop has a shape of solid cylinder.
Optionally, the protrusion is formed on an end of the barrel member. Corresponding to this configuration, a portion where the fluid path communicates with the opening is decentered and corresponding to a portion where the protrusion is formed on the end of the barrel member.
According to another aspect of the invention, there is provided an ink cartridge, which is provided with a housing defining a body of the cartridge, an ink reservoir accommodated in the housing, a first opening formed on the housing, the first opening communicating the ink reservoir through a first fluid path, a second opening formed on the housing, the second opening communicating the ink reservoir through a second fluid path.
The cartridge is further provided with a first stop to be fitted in the first opening, the first stop having elasticity, the first stop being configured such that a needle can be penetrated therethrough, a hole formed by penetration of the hollow needle being closed by the elasticity of the first stop after removal of the needle, a second stop to be fitted in the second opening, the second stop having elasticity, the second stop being configured such that a needle can be penetrated therethrough, a hole formed by penetration of the hollow needle being closed by the elasticity of the second stop after removal of the needle, a one-way valve provided between the first opening and the first fluid path, the one-way valve allowing a flow of fluid only in a direction from the ink reservoir to the first opening, the air inside the ink reservoir being evacuated through the first opening, a valve structure provided to a part of the second stop, the valve structure selectively opens and closes the communication between the second opening and the ink reservoir through the second fluid path.
Optionally, the ink cartridge may further include a connection member that connects end portions of the first stop and the second stop, the first stop, the second stop and the connection member forming an integral stop.
Further, a groove may be formed between the first opening and the second opening. The groove is preferably configured such that the connection member is fitted in the groove. A surface of the housing where the first and second opening formed may be substantially planar when the first stop and the second stop are fully inserted in the first opening and the second opening, respectively, and the connection member is fitted in the groove.
Still optionally, the ink cartridge may include a protection film, which is adhered on the surface where the first opening and the second opening are formed to cover the first opening and the second opening with the first stop, the second stop and the connection member fitted in the first opening, the second opening and the groove, respectively.
Furthermore, opposing end portions of the protection film may be bent toward the housing to define bent portions, and the housing may be formed with grooves capable of receiving the bent portions. With this configuration, the bent portions can be accommodated in the grooves when the protection film is adhered on the surface where the first opening and the second opening are formed.
According to a further aspect of the invention, there Is provided a method of filling an ink in an ink reservoir accommodated in an ink cartridge, the ink cartridge including a housing defining a body of the cartridge, an opening being formed on the housing, the opening communicating the ink reservoir through a fluid path, a stop to be fitted In the opening being provided, the stop having elasticity, the stop being configured such that a hollow needle can be penetrated therethrough, a hole formed by penetration of the hollow needle being closed by the elasticity of the stop after removal of the hollow needle, a valve structure being provided to a part of the stop, the valve structure selectively opens and closes the communication between the opening and the ink reservoir depending on a location of the stop. The method includes locating the stop at a position where the valve structure is opened, penetrating a hollow needle, supplying the ink to the ink reservoir through the hollow needle, removing the hollow needle from the stop, and locating the stop at a position where the valve structure Is closed.