Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
1997-08-04
2001-10-23
Le, N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
Reexamination Certificate
active
06305794
ABSTRACT:
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a liquid container for supplying liquid to an external recording element such as pens and ink ejection portion which use negative pressure, an ink jet cartridge integrally having the container and an ink jet recording head, and a manufacturing method of the container.
A container for accommodating liquid is known wherein the liquid is supplied out of the container while maintaining a negative pressure within the container. Such a container performs appropriate liquid supply for the liquid using portion such as a nib or tip of a pen or recording head connected to the container, by the negative pressure produced by the container per se.
Various liquid accommodating containers of this type are used, but the usable ranges thereof are rather limited. One of the reasons for this is that there has not been a one which is easy to manufacture and which is a simple in structure. For example, in the field of the ink jet recording requiring a proper negative pressure property, a container having a sponge therein as a generation source for the negative pressure or a bladder-like container having a spring providing force against an inward deformation due to the consumption of the ink, as disclosed in Japanese Laid Open Patent Application No. SHO-56-67269, Japanese Laid Open Patent Application No. HEI-6-226993, for example. U.S. Pat. No. 4,509,062 discloses an ink accommodation portion of rubber having a conical configuration with a rounded top having a smaller thickness than the other portion. The round thinner portion of the circular cone portion provides a portion which displaces and deforms earlier than the other portion. These examples have been put into practice, and are satisfactory at present.
However, the negative pressure generating mechanisms described above is relatively expensive, and therefore, does not suit for the writing devices such as markers, plotters having writing tips. The use of the complicated negative pressure generating mechanism is not desirable since it result in bulkiness of the writing device. In writing devices, the use is made with a felt capable of generating a negative pressure and of introducing the air from the tip to permit supply of the ink thereto. The main problem of this type of the gas-liquid exchange structure for the ink supply is the ink leakage at the tip. In order to solve this problem, an ink retaining mechanism has been proposed wherein a great number of fins are formed at predetermined intervals between the tip and the liquid accommodating container extending in a direction perpendicular to the ink supply direction, for the purpose of preventing the ink leakage by retaining the ink which is going to leak upon the ambient condition change or the like. However, such a mechanism results in a relatively large amount of non-usable ink remaining in the container. The ink supplying system of such writing devices, generally uses an open type, which leads to evaporation of the ink, with the result of reduction of the usable amount of the ink. Therefore, ink evaporation suppression by using substantial sealed type is desirable.
The description will be made briefly about the substantially sealed type in the ink jet recording. When a negative pressure generation source is not used in an ink supplying system, the ink is supplied using the level difference relative to the ink using portion (ink ejection head), that is, the static head difference. This does not require any special condition in the ink accommodation portion, and therefore, a simple ink accommodation bladder is used in many cases.
However, In order to use a closed system, the ink supply path has to extend between the ink accommodation bladder to the ink using portion (ink ejection head) thereabove with the result that long ink supply tube is required, so that system is bulky. In order to reduce or eliminate the static head difference Of the ink supply path, an ink container capable of providing the ink ejection head with a negative pressure, has been proposed and put into practice. Here, a term “ink jet cartridge” is used to cover a unified head and ink container.
The ink jet cartridge is further classified into a type wherein the recording head and the ink accommodating portion are always unified, and a type wherein the recording means and the ink accommodating portion are separable, and are separately mountable to the recording device, but are unified in use.
In either structure, the connecting portion of the ink accommodating portion relative to the recording means is provided at a position lower than the center of the ink accommodating portion in order to increase the usage efficiency of ink accommodated in the ink accommodating portion. In order to stably maintain the ink and to prevent the ink leakage from the ejection portion such as a nozzle in the recording means, the ink accommodating portion in the ink jet cartridge is given a function of generating a back pressure against the ink flow to the recording means. The back pressure is called “negative pressure”, since it provides negative pressure relative to the ambient pressure at the ejection outlet portion.
In order to produce the negative pressure, the use may be made with capillary force of a porous material or member. The ink container using the method, comprises a porous material such as a sponge contained and preferably compressed in the entirety of the ink container, and an air vent for introducing air thereinto to facilitate the ink supply during the printing.
However, when the porous material is used as an ink retaining member, the ink accommodation efficiency per unit volume is low. In order to provide a solution to this problem, the porous material is contained in only a part of the ink container rather than in the entirety of the ink container in a proposal. With such a structure, the ink accommodation efficiency and ink retaining performance per unit volume is larger than the structure having the porous material in the entirety of the ink container.
From the standpoint of improving the ink accommodation efficiency, the bladder-like container using or not using the spring, or the ink accommodating container of rubber is usable.
Such an ink container is widely used now. However, further improvement is desired.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the present invention to further improve an ink accommodation efficiency.
It is a further object of the present invention to provide a container made of simple parts.
It is a further object of the present invention to provide a container which can be recycled.
According to an aspect of the present invention, there is provided a liquid container, comprising a generally prism-like casing having a substantial air vent and having a corner portion formed by extensions of three sides of the prism configuration; an inner shell for containing liquid therein, said inner shell having outside equivalent or similar to inside of said casing; a liquid supply portion for supplying the liquid to outside from said liquid containing portion; a pinch-off portion where said inner shell is pinched by said casing; an integral portion where a maximum area side of said inner shell is integral with a side of said inner shell opposite therefrom.
According to another aspect of the present invention, there is provided a liquid container, comprising: a generally prism-like casing having a substantial air vent and having a corner portion formed by extensions of three sides of the prism configuration; an inner shell for containing liquid therein, said inner shell having outside equivalent or similar to inside of said casing; a liquid supply portion for supplying the liquid to outside from said liquid containing portion; a pinch-off portion where said inner shell is pinched by said casing; wherein said casing and said inner shell have respective maximum area sides which do not have said liquid supply portion or said pinch-off portion; a deformation confinement member provided on said maximum area side of said i
Matsumoto Hidehisa
Mihara Hiroaki
Sasaki Toshiaki
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Le N.
Nghiem Michael
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