Note: Descriptions are shown in the official language in which they were submitted.
CA 022~301~ 1998-11-24
--1--
INK CONTAINER, INK JET HEAD HAVING INK CONTAINER,
INK JET APPARATUS HAVING INK CONTAINER, AND
MANUFACTURING METHOD FOR INK CONTAINER
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to an ink
container, in which fiber is placed as an ink
retaining member for retaining ink, an ink jet
apparatus employing such an ink container, and a
manufacturing method for such an ink container.
As for a conventional ink container (whether
it is integrated with a recording head, or it is
exchangeable independently from the head) having been
put to practical use for ink-based recording, there is
a type of ink container filled with a single or a
plurality of sponge pieces.
The sponge piece is placed in the ink
container to prevent the ink from leaking out of a
liquid ejecting portion such as a nozzle provided in a
recording means. More specifically, it is placed
there to use the capillary force peculiar to porous
material such as sponge; the capillary force is used
as back pressure for impeding the ink low directed
toward the recording means. This back pressure
creates negative pressure, relative to the atmospheric
pressure, in the ejecting portion, and hereinafter, it
will be referred to as "negative pressure".
CA 022~301~ 1998-11-24
Generally speaking the diameter of a sponge
pore falls within a range of 80 - 200 ~m, and the
sponge material itself occupies a substantial portion
of the internal volume of the container. Therefore,
as long as the sponge is present within the ink
container, little can be expected from an attempt made
to increase the amount of the ink, relative to the
internal volume of a given ink container, that is, an
attempt made to improve the space usage efficiency for
the ink container.
Further, even when an effort is made to
modify the structure of the ink container so that the
amount of the ink, which otherwise ends up being left
unused in the ink container, is reduced, the capillary
force or the like of the sponge places an inherent
limit to the reduction.
The porous material employed as the ink
retaining member is formed in advance in a
predetermined shape; therefore, when it is compressed
into the ink container, the contour of the porous
material does not perfectly conform to the internal
surface of the ink container, leaving gaps between the
two, which is liable to fail to create the capillary
force expected there. Further, urethane form, a
typical porous material, is not compatible with
certain types of ink, which limits the number of ink
choices to be stored in the ink container.
CA 022~301~ 1998-11-24
--3--
Therefore, the inventors of the present
invention made a proposal in a Japanese Laid-Open
Patent Application No. 34353/1990 in which the ink
supplying efficiency was improved by rendering smaller
the sponge pore diameter adjacent to the ink supplying
port than in the middle of the ink container. The
inventors of the present invention disclosed another
invention in a Japanese Laid-Open Patent Application
No. 8405/1993, in which a bundle off parallelly bound
straight strands of fiber was disposed next to the ink
supplying port, which was effective for improving the
ink supplying efficiency and reducing the amount of
the unusable ink.
There are fiber-based structures other than
those described above: for example, the structures
disclosed in Japanese Laid-Open Patent Application
Nos. 96742/1993 and 104735/1993, in which the
direction of the ink movement was changed. In the
former invention, a bundle of fiber strands is
disposed in contact with the sponge piece, in such a
manner than when the ink container is in use, the
bundle of fiber strands extends from the bottommost
portion to the ink supply port disposed above,
whereby the amount of the unusable ink which otherwise
ends up remaining in the bottom portion of the ink
container is reduced. In the latter invention, the
entire internal space of the ink container is filled
CA 022~301~ 1998-11-24
with sponge, and a bundle of fiber strands is disposed
within a portion projecting from the ink container,
wherein this bundle of fiber strands constitutes an
ink supply passage for supplying the ink to the sponge
disposed adjacent to the filter of a recording head.
As described above, the main stream
inventions regarding the internal structure of an ink
container presumes the presence of the sponge;
therefore, they have not reduced substantially the
amount of the ink retained unusably in the sponge or
have not solved the problem that the ink capacity of
the ink container is reduced by the presence of the
sponge.
On the other hand, a Japanese Laid-Open
Patent Application No. 79882/1994 discloses a
structure in which strands of fiber extending
vertically (in the direction of the gravity) are
disposed within the ink container to occupy no more
than 20 % of the internal space of the container so
that the ink capacity of the ink container is
substantially increased, and also, the ink supplying
efficiency is improved. However, in this invention,
only a small amount of straight fiber, or the strands
of fiber, are arranged merely in one direction.
This Laid-Open Patent Application No.
79882/1994 also discloses a modification, in which
nr -~ove,~ fabric of polyester, polypropylene, or the
CA 022~301~ 1998-11-24
--5--
like is filled in layers in the ink container. This
modification is not different from the original in
that it suffers from the problems of the conventional
ink container.
Through extensive studies of the inventions
described in the foregoing, the inventors of the
present invention discovered that the structures
disclosed in these inventions barely provided an ink
retaining capability, and the strands of fiber
collected together in a manner of being bundled as the
ink was filled. As a result, the ink was concentrated
around the ink supply port, deteriorating the
efficiency with which the ink was fed out of the ink
container, and also, it was impossible to create
stably the negative pressure, which was an important
factor in the field of ink jet recording.
SUMMARY OF THE INVENTION
The primary object of the present invention
is to solve new problems, that is, the insufficient
ink delivery, the ink leak, and the like, which are
created due to the reduction in the overall ink
retaining capability of an ink container, resulting
from the decrease of the intervals among the strands
of fiber employed as the ink retaining material, which
occurs while the ink is filled.
Another object of the present invention is to
CA 022~301~ 1998-11-24
provide an ink container in which the ink retaining
capacity is increased by means of improving the
arrangement of the fiber that occupies the internal
space of the ink container, wherein this fiber strand
arrangement relates to the way the fiber strands
contact the internal walls of the ink container, and
the way the fiber strands contact each other.
During the making of the present invention,
attention was given to a different view point: there
is an ink flowability difference between the inner
portion of the ink container and the portion next to
the container wall. In other words, the relationship
between the ink flowability, and the material for the
ink container internal wall and fiber strand, which
had not been studied formerly, was studied. As a
result, the present invention could provide a
preferably relationship among the properties of the
ink (in particular, pigment-based ink) to be used and
the fiber material.
On the other hand, the studies by the
inventors of the present invention disclosed that as
the influence from the fiber itself, there were
changes in properties related to the fiber strand
diameter. Thus, the second object of the present
invention is to provide an ink container in which this
properties change is effectively applied.
Being guided by this second object, the
CA 022~301~ 1998-11-24
present invention provides a preferable ink container,
in which a fibrous member constituted of fiber strands
with preferable properties in placed across, and in
contact with, a filter disposed on the head or
container side, more preferably, an ink container, in
which a preferable relationship is provided between
the diameter of the fiber strands occupying the major
portion of the internal volume of the ink container,
and the diameter of the fiber strand occupying the ink
supply port side (head side), that is, the outward
side, of the internal space of the ink container; and
an ink container, in which the resistance of the fiber
itself constituting the major portion of the ink flow
resistance can be eased.
Another object of the present invention is to
provide an ink container manufacturing method, in
which a type of fiber strand, which is compatible, in
terms of shelf life, with the ink to be used, and is
placeable, as the ink retaining member, in the
container main body, in such a manner that does not
limit the choices of usable ink, can be employed, and
simply placed in the container main body.
In order to realize such a manufacturing
method, the present invention proposes such a
structure in which a region containing the fibrous
material is provided at least on the ink supplying
side of the ink container, wherein the fiber strand
CA 022~301~ 1998-11-24
--8--
within the fibrous material is deformed within the
limit of the elasticity of the fiber material, and is
caused to extend in various directions so as to form
complex multiple intersections.
With the presence of the above described
structure, that is, the presence of the multiple fiber
strand intersections and the elastic deformation of
the fiber strand, it is possible to prevent the gap
between the adjacent fiber strand portions, or fiber
stands, from being reduced by the properties of the
ink as the ink is filled.
The present invention also proposes an ink
container structure in which a region containing the
fibrous material is provided at least on the ink
supply side, wherein the material for the container
wall and the material for the fiber strand satisfy the
same requirements.
According to the structure described above,
the properties of the container wall can be matched
with the ink flowability within the fibrous member
placed in the ink container; therefore, it is possible
to prevent such a phenomenon that occurred in the past
that is, the phenomenon that the ink flow along the
container wall became excessively different from the
ink flow within the center portion of the container,
disturbing thereby the flow of the ink or air, and as
a result, the amount of the ink left unused increased,
CA 022~301~ 1998-11-24
or the ink consumption fluctuated.
Also, the present invention proposes, as the
manufacturing method for the ink container comprising
the container main body filled with the fibrous member
capable of retaining the ink, to guide the fiber
strand into the container main body as the fiber
strand is continuously produced using a fiber strand
manufacturing apparatus. With the employment of this
method, the fiber and ink container can be
manufactured through a continuous operation, making it
possible to eliminate the storage facility or the like
for the fiber.
The present invention proposes, as another
manufacturing method for the ink container comprising
the container main body containing the fibrous member
capable of retaining the ink, a method in which the
fiber strand is formed in advance into a belt of
fibrous aggregate, and then, the thus formed belt of
the fibrous aggregate is folded into the container
main body. With the employment of this proposals, it
is possible to place reliably the fibrous member in
the container main body while preventing the fiber
strand from scattering.
Further, the present invention proposes to
place in the container main body a predetermined
number of fibrous aggregate pieces constituted of the
aforementioned aggregated fiber strand. In this case,
CA 022~301~ 1998-11-24
--10--
their number is varied depending on the type of the
ink container in order to match the ink container
type.
The present invention also proposes, as a
form of the fiber strand arrangement in the container
main body, to pack in advance the fiber strand in an
ink-permeable pouch, and then, place a predetermined
number of the pouches filled with the fiber stand in
the container main body. When this method in
employed, the fiber strand can be reliably placed in
the container main body within being scattered.
It should be noted here that using the
polyolefinic material as the fiber strand material is
more preferable; in this case, it is possible to give
the fiber strand compatibility, in terms of shelf
life, with various types of ink, for example, alkaline
ink, and also, to stabilize the structure of the
fibrous aggregate using the thermoplastic properties
of the material.
It is also preferable to place two or more
types of fiber strands, which are different in
external diameter or sectional configuration; in this
case, it is possible to give the fiber strand an
optimum ink retaining capability correspondent to its
position within the container main body.
Further, as another manufacturing method for
an ink container comprising the container main body
CA 022~301~ 1998-11-24
containing the fibrous member capable of retaining the
ink, the ink may be placed in the container main body
before the fiber strand is placed therein. Such a
manufacturing method allows some flexibility in the
order of the manufacturing steps.
Further, the present invention proposes, as
another method for the ink container, to increase,
when the ink is placed in the container main body, the
amount of the ink solvent by the amount equivalent to
the amount of the ink solvent that is expected to
evaporate while the ink is placed in the container
main body.
In this case, the ink solvent may be placed
in the container main body before the fiber strand is
placed in the container main body.
With the employment of such a manufacturing
method, it is possible to prevent the ink from being
denatured, to adjust the fiber strand arrangement, in
the ink solvent, and to improve the wettability of the
fiber strand surface to the ink.
These and other objects, features and
advantages of the present invention will become more
apparent upon a consideration of the following
description of the preferred embodiments of the present
invention taken in conjunction with the accompanying
drawings.
CA 022~301~ 1998-11-24
--12--
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic perspective view of
an embodiment of ink cartridge in accordance with the
present invention, depicting its structure.
Figure 2 is a perspective view depicting how
the ink cartridge illustrated in Figure 1 and an ink
jet head are connected.
Figures 3(a) an 3(b) are structural sectional
views of different types of fiber strands in
accordance with the present invention.
Figure 4 is an explanatory view that
describes the dimensional relation between the volume
of the fibrous member in accordance with the present
invention and that of the ink cartridge or container.
Figure 5 is a schematic perspective view of
another embodiment of ink container in accordance with
the present invention.
Figure 6 is a schematic perspective view of
another embodiment of ink container in accordance
with the present invention.
Figure 7 is a perspective view of the ink
container in accordance with the present invention, and
shows the relationship between the measurements of the
ink container and the length of the fiber strand.
Figure 8 is a schematic drawing that
describes how the ink container functions when it
employs two types of fiber strands with a different
CA 022~301~ 1998-11-24
diameter.
Figure 9 is a schematic drawing that
describes how the ink container functions when it
employs a negative pressure generating member other
than the one employed in the ink container illustrated
in Figure 8.
Figures 10 (a - h) are sectional views of the
various fiber strands in accordance with the present
invention.
Figure 11 is a sectional view of another ink
cartridge employing the fiber strand in accordance with
the present invention as the negative pressure
generating member.
Figure 12 is a perspective view of a typical
ink jet recording apparatus employing the ink
cartridge illustrated in Figure 11.
Figure 13 is an explanatory drawing that
depicts the function of a plurality of complexly
intersecting fiber strands in accordance with present
invention~
Figure 14 is a sectional view of an ink
container manufactured according to the first
embodiment of ink container manufacturing method in
accordance with the present invention.
Figure 15 is a schematic drawing that
describes the ink container manufacturing steps of the
first embodiment of the ink container manufacturing
CA 022~301~ 1998-11-24
method in accordance with the present invention.
Figure 16 is a schematic drawing that
describes an ink container manufacturing steps of the
second embodiment of ink container manufacturing method
in accordance ~ith the present invention.
Figure 17 is a schematic drawing that
describes an ink container manufacturing steps of the
third embodiment of ink container manufacturing method
in accordance with the present invention.
Figure 18 is a schematic drawing that
descries an ink container manufacturing steps of the
fourth embodiment of ink container manufacturing method
in accordance with the present invention.
Figure 19 is a schematic drawing that
describes an ink container manufacturing steps of the
fifth embodiment of ink container manufacturing method
in accordance with the present invention.
Figure 20 is a schematic drawing that
describes an ink container manufacturing steps of the
sixth embodiment of ink container manufacturing method
in accordance with the present invention.
Figure 21 is a schematic drawing that
describes an ink container manufacturing steps of the
seventh embodiment of ink container manufacturing
method in accordance with the present invention.
Figure 22 is a schematic drawing that
describes an ink container manufacturing steps of the
CA 022~301~ 1998-11-24
eighth embodiment of ink container manufacturing method
in accordance with the present invention.
Figure 23 is a schematic drawing that
describes an ink container manufacturing steps of the
ninth embodiment of ink container manufacturing method
in accordance with the present invention.
Figure 24 is a schematic drawing that
describes an ink container manufacturing steps of the
tenth embodiment of ink container manufacturing method
in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, the embodiments of the present
invention will be described with reference to the
drawings.
Figure 1 is a schematic perspective view of
the first embodiment of the ink container in
accordance with the present invention, and Figure 2 is
a partially cutaway perspective view that depicts how
the ink container illustrated in Figure 1 is connected
to an ink jet head.
The ink containers illustrated in these
drawings are of a cartridge type, that is, a
replaceable type that can be installed into, or
removed from, an ink jet apparatus. A cartridge 1 is
filled with fiber (fibrous material) as a negative
pressure generating material. The fibrous member 4 is
CA 022~301~ 1998-11-24
--16--
constituted of a large number of polypropylene fiber
strands, which are 100 ~m in diameter and several
centimeters to 10 cm in length, being filled in the
internal space of the ink container so as to intersect
with each other three-dimensionally while forming
random curvatures. The amount of the fiber strands
filled in the cartridge 1 having an internal volume of
400 cc is approximately four grams. The fibrous
member 4 may be constituted of a single strand of
fiber long enough to fill the internal space of the
ink container by itself, or a plurality of fiber
strands.
The filling ratio of the fibrous material in
accordance with the present invention, relative to the
internal space in which the fibrous material is to be
filled, is optional as long as it effects a plurality
of fiber strand intersections, but it is preferable to
be no less than 10 % and no more than 35 ~, more
preferably, no less than 15 % and no more than 25 %.
This is because these preferable ranges afford a
preferable ratio between the internal space fillable
with the ink and the amount of the consumable ink
therefrom.
A container 11 constituting the casing of the
ink cartridge 1 is formed of polypropylene, which is
the same material used for the fibrous member 4. One
of the walls of the container 11 is provided with an
CA 022~301~ 1998-11-24
ink supply passage 8. One of the openings of the ink
passage 8 faced outward, and the other end faces
inward and is fitted with a filter 8A. The filter 8A
is in contact with the fibrous member 4, maintaining a
proper contact pressure. Another wall of the
container 11, which is on the opposite side of the
wall in which the ink supply passage 8 is provided,
constitutes the lid 2 of the container 11. This lid 2
is provided with an air vent 7.
The container 11 is substantially rectangular
as shown in Figure 1 or 2, and comprises an ink supply
passage and the like. On the other hand, the fibrous
member 4 to be filled within the container 11 does not
have a rigid form. In other words, the fiber strands
constituting the fibrous member 4 are not arranged to
follow a certain rule, for example, to be bundled in a
certain way. Instead, they are randomly arranged.
This random arrangement is not only advantageous in
terms of the ink retaining performance and ink
delivery performance, which will be described later,
but also make it easier for the fiber strands to
conform to the contour of the internal space of the
container 11. Therefore, the fibrous member 4 can be
easily placed within the ink cartridge 1, without
leaving any gap. After the fibrous member 4 is placed
within the ink cartridge 1, the lid 2 constituting a
part of the container is attached using ultrasonic
CA 022~301~ 1998-11-24
-18-
welding, whereby a preferable degree of density can be
given to the fibrous member 4.
Referring to Figure 2, the ink cartridge 1 is
connected to an ink jet head 12 with the use of an ink
supply tube 14. In other words, the supply tube 14 is
inserted into the supply passage 8 of the cartridge 1.
This connection occurs on the carriage (unillustrated)
of an ink jet apparatus.
The following experiment was carried out
using the ink cartridge described above.
Black ink was injected into the ink cartridge
1, and the ink cartridge 1 was rotated in every
direction without plugging the openings. No ink
leaked out of the ink supply passage 8 are air vent 7,
which were the open portions of the ink cartridge 1.
This proved that when the ink was retained by the
fiber, the capillary force or the like could be
generated to retain the ink.
In addition, a piece of silicon tube was
inserted through the ink supply passage 8, and the ink
was continuously sucked at a flow rate of 2 g/min will
it became impossible to suck out any more ink. Then,
the amount of the ink remaining within the ink
cartridge, that is, the amount of the ink which could
not be sucked out, was measured. It was 7.7 g. For
the purpose of comparison, the same sucking test was
carried out using an ink cartridge, in which, in place
CA 022~301~ 1998-11-24
--19--
of the fibrous member 4, a piece of urethane foam
(well-known material) having a volume of 160 cc and 35
cells per inch (cell was had been treated using the
explosion method) had been compressed in the cartridge
as the negative pressure generating member of this
embodiment. The remaining amount of the ink was
substantially the same. Those tests proved that the
ink could be supplied in response to the ink
consumption which occurred as the recording was made,
and the ink flow was not interrupted within the ink
passage in the early stage of the ink consumption.
It is understandable from the experiments
described above that the ink cartridge comprising the
fibrous member 4 of this embodiment displays such ink
retaining performance and ink supplying performance
that are equal to those of the conventional ink
cartridge comprising the urethane foam piece.
An ink cartridge, in which strands or fiber
are flexibly arranged to intersect with each other as
they are in the ink cartridge in accordance with the
present invention, functions at least equally to the
conventional ones as described above. Such ink
cartridge enjoys the following two specific advantages
whether it comprises this structure or not.
The first advantage is related to the shelf
life of the ink container when used with the ink that
contains pigment, or the ink with high pH. In other
CA 022~301~ 1998-11-24
-20-
words, when the polyurethane fiber of the first
embodiment of the present invention is used as the
negative pressure generating member, the amount of the
ink solute, which deposits while an ink cartridge
filled with the pigment ink is stored for a long
period of time, is extremely small, and also, the
deterioration of the negative pressure generating
member is extremely small, in comparison to when the
urethane foam is used as the conventional negative
pressure generating member. Therefore, the cartridge
comprising the polyure-th~n~ fiber strand as the
negative pressure generat-ing member can withstand
practical usage.
As for another example of the first
advantage, it can be pointed that the deterioration
of the polyurethane is extremely small when used with
the ink with a high pH, for example, no less than pH
10, or the ink with a low pH, for example, no more
than pH 3.
When the inventors of the present invention
measured the diameter of the ink particle, which
serves as an index for the aforementioned deposition,
at 60 ~C, involving a case in which the ink cartridge
was filled with only the ink, a case in which it is
filled with the ink and urethane foam, and a case in
which it is filled with the ink and polyurethane
fiber. The results are a~ follows.
CA 022~30l~ l998-ll-24
--21--
Period 2 weeks 2 months
ink only 0.093 (~m) 0.093 (~m)
urethane foam 0.112 0.359
polypropylene fibers 0.093 0.118
As is evident from the results of the
measurement described above, the polypropylene fiber
is compatible with the pigment ink, and therefore, is
preferable as the negative pressure generating member
of the ink cartridge for storing the pigment ink.
As for the second advantage of the structure
in accordance with the present invention,
polypropylene, which is in the form of fiber, is a
material suitable for recycling. In particular, when
the container portion of the cartridge is also made of
the same material as the fibrous portion as it is in
the aforementioned embodiment, recycling steps can be
simplified.
For example, fiber (lO0 ~m in diameter) can
be obtained from a used ink cartridge comprising
integrally the fiber and container by a melt-spinning
machine after heating it to approximately 80 ~C to
evaporate the remaining ink components, though the
color of the fiber obtainable through this recycling
method is going to be black.
An ink cartridge was produced by filling the
fibrous material thus obtained into the container in
CA 022~301~ 1998-11-24
the same manner as described before, and was evaluated
using the same method as described before. The amount
of the remaining ink was 7.9 g, which was
substantially the same as that obtained using the
fiber made of Yirgin (pre-recycling) polypropylene.
Therefore, it is easily understandable that the ink
cartridge in accordance with the present invention is
easily recyclable.
Further, resin chips produced by heating a
used ink cartridge of the same type comprising the
fiber and container portions to approximately 180 ~C
after evaporating the residual ink components can be
formed into an ink cartridge container and lid using a
molding apparatus.
The recycling process can be carried out
using nothing but discarded ink cartridges as
described above, but it is also possible to mix them,
at an optional ratio, with resin which has not been
used for forming fiber or the like.
As for the material to be used to form the
ink cartridge in accordance with the present
invention, any material usable for forming both the
container and fiber portions is acceptable. As for
the organic material, there are aramid, vinylon,
acrylic, polyester, polyethylene, polypropylene,
carbon. As for the nonorganic material, there are
boron, glass (silica), alumina, and zirconia. As for
CA 022~301~ 1998-11-24
-23-
the metallic material, there are tungsten molybdenum,
steel, stainless steel, beryllium, titanium, aluminum,
magnesium, and amorphous (Fe-Si-B group).
From the standpoint of ease of the initial
molding, the organic or metallic material is
preferable, wherein the organic material is more
preferable in consideration of ease of handling.
Further, from the standpoint of recycling,
thermoplastic organic resins are further preferable
since they can be easily recycled without going
through such steps as cracking or refining.
As for further preferable thermoplastic
resins, there are polyethylene, polyvinyl chloride,
polystyrene, acrylonitrile, polypropylene, polyamide,
polyacetal, polyethyleneterephthalate, polybutylene-
terephthalate, polycarbonate, polyphenylene oxide,
polyphenylene sulfide, polyether sulfon, polyether
keton, polyether imide, polyamide imide, polysulfon,
nylon, polyimide, and the like, as well as complex or
denatured forms of these materials.
However, as stated before, when an emphasis
is placed on the storage stability of the ink for an
ink jet, olefinic resins such as polyethylene or
polypropylene are particularly preferable.
Figures 3(a) and 3(b) show approximate
sections of the fibers composed of different material.
It is optional to mix additives at a ratio that does
CA 022~301~ 1998-11-24
--~24--
not exceed the amount of the aforementioned resin.
In order for the fiber strands composed of
the material selected from the list given above to
function as the preferable negative pressure
generating member suitable for the ink cartridge, it
is preferable for the strands to intersect randomly
with each other at multiple points within the ink
cartridge as described previously. When the fiber
strands are filled in the ink cartridge in an orderly
manner like parallelly bundled fiber strands, the gaps
among the fiber strands are reduced. As a result, the
amount of the ink fillable within the ink cartridge is
reduced. In other words, the amount of the usable ink
relative to the internal volume of the container is
reduced.
Figure 4 depicts the relationship between the
volume of the fibrous member 4 and the volume of the
container ll before the former is filled into the
latter.
As will be evident from this drawing, as the
fibrous member 4 is filled into the container 11, it
is slightly compressed since the volume of the
container 11 is slightly smaller than that of the
fibrous member 4. As a result, a force proportional
to the degree of compression is generated within the
fibrous member 4 due to the elasticity of the fibrous
member 4.
CA 022~301~ 1998-11-24
--25--
The following points should be noted here.
In order for the above described first and second
advantages to be effectively displayed, it is
preferable that after the negative pressure generating
member is filled into the cartridge, the volume of the
fibrous member 4 is not reduced by the physical
external force generated due to the vibration of the
ink cartridge or the impact applied thereupon. More
specifically, when the diameter of the fiber strand is
extremely small, the overall volume of the fibrous
member is reduced as the ink permeates between the
fiber strands and causes the fiber strands to lump
together. As the fiber strands within the fibrous
member lump together, the volume of the fibrous member
is sometimes reduced to a point where it fails to fill
up satisfactorily the internal space of the ink
cartridge, or shifts within the cartridge, preventing
the ink from being swiftly supplied. It is guessed
that this lumping is caused by the following reasons:
as the ink makes contact with the fiber strands, the
adjacent fiber strands are pulled closer to each other
due to the surface tension of the ink permeating
between them, whereby the gaps between them are
reduced to decrease the overall volume of the fibrous
member. As a result, the fibrous member, the volume
of which has reduced below the internal volume of the
ink cartridge, shifts within the ink cartridge,
CA 022~301~ 1998-11-24
sometimes breaking the contact between the ink supply
passage and filter, which results in a situation in
which the ink cannot be supplied swiftly as described
above.
As will be evident from the above
description, it is preferable that the structure of
the ink cartridge is such that the volume of the
fibrous member within the ink cartridge does not
decrease after the fiber strands come in contact with
the ink.
In order to create such a str.ucture, it is
preferable for the fiber strands of the fibrous member
4 to intersect each other at multiple points as shown
in Figure 13. This is because the forces, which are
generated by the surface tension of the ink or the
like and work to move the fiber strands in the
directions of arrow marks in the drawing when the
fibrous member 4 comes in contact with the ink, cancel
each other due to the presence of the multiple
intersections, whereby the fibrous member is prevented
from contacting.
In addition to the structure described above,
there is another preferable structure, in which
fibrous material having rigidity strong enough to
resist the surface tension of the ink to be used is
employed, or the fiber strand diameter is increased so
that the fiber strands become rigid enough to resist
CA 022~301~ 1998-11-24
-27-
the surface tension of the ink to be used. Further,
it is preferable to select the fiber material
depending on the ink to be used. It is also
preferable to determine the amount of the fiber filled
into the cartridge depending on the ink to be used.
As to means for causing the fiber strands to
intersect at multiple points as described above, there
is a method in which the fiber strands are bundled,
and this bundle of fiber strands is teased several
times in the direction parallel to the direction of
the strands using an apparatus having comb-like teeth.
There is also a-method in which the bundled
fiber strands are cut to an optional length, and then,
are stirred up using a stirring device.
As for another means, there is a method in
which a negative pressure generating member having an
apparent volume larger than the internal volume of the
cartridge container is placed in the cartridge
container, and then, is compressed by the cartridge
lid or the like with a sufficient pressure.
As one of the preferable means, there is a
method in which the negative pressure generating
member is constituted of a certain type of fiber
strand, the surface layer of which is composed of
resin having a relatively low melting point as shown
in Figure 3, and the points of intersection are welded
by heating the fibrous member at a temperature higher
CA 022~301~ 1998-11-24
--28--
than the melting point of the external resin layer of
the fiber strand and lower than the melting point of
the core portion of the fiber strand to stabilize the
positional arrangement of the fiber strand portions
intersecting each other at multiple points.
Because of the reasons described above, and
since the amount of the fiber to be filled in the
cartridge varies depending on the internal volume and
configuration of the ink cartridge, the structure of
the negative pressure generating member, and the like
factor, it is impossible to specify simply the
diameter of the fiber strand for the negative pressure
generating member to be used in the embodiments of the
present invention, and also, to specify simply the
amount of the fiber strands to be filled in the
cartridge. However, in consideration of the fact
that the generation of the negative pressure is
dependent on the gap between the adjacent fiber
strands, it is evident that when the gap is
excessively large, the negative pressure is reduced to
allow the ink to leak out of the ink cartridge, and
contrarily, when it is excessively small, the negative
pressure is increased too high to allow the ink to be
supplied from the ink cartridge to the ink jet head.
Thus, the fiber strand diameter is preferred to be in
a range of 5 ~m - 1 mm: more preferably, lO ~m - 0.5
mm; and most preferably, 15 ~m - 45 ~m, though such
CA 022~301~ 1998-11-24
--29--
preference depends on the internal volume of the ink
cartridge and/or the amount of the fiber strands to be
filled in the ink cartridge.
As for the preferable diameter range of the
fiber strands intersecting each other at multiple
points, relative to the location at which each fiber
strand is disposed, it is preferred to be within a
range of 20 - 40 ~m if the fiber strand is disposed
near the ink supply port, and to be no less than 40 ~m
if it is disposed in other areas. The more preferable
diameter range for the strand disposed in the other
areas is 50 - lOO ~m.
There is no particular restriction concerning
the filling of the fiber strands into the ink
cartridge, but it is preferable to press the fiber
strands at least in one direction by the lid or the
like, as described before, in order to prevent the
fiber strands from shifting within the ink cartridge.
Further, in consideration of the fact that when a gap,
which is larger than the gap between the adjacent
fiber strands, is created where the fibrous member 4
contacts the filter 8A of the ink supply passage, it
is possible for the ink supply from the ink cartridge
to the ink jet head to be interrupted; therefore, it
is more preferable that the fiber strands are pressed
toward the filter of the ink supply passage.
Figures 5 and 6 are schematic views of other
CA 022~301~ 1998-11-24
--30--
embodiments of ink cartridge in accordance with the
present invention.
Referring to Figure 5, the density is varied
so as to increase toward the ink supply passage 8 by
means of disposing fiber strands with a smaller
diameter 4b adjacent to the surface of the filter 8A
of the ink supply passage 8, and fiber strands with a
relatively larger diameter 4a in the other areas, in a
compressing manner. With this arrangement, the ink
within the ink cartridge is likely to concentrate
toward the ink supply passage 8, being less likely to
be left unused.
Figure 6 is a schematic view of one of the
embodiments of ink cartridge in accordance with the
present invention, in which the smaller diameter fiber
strand 4b is disposed along the internal surface of
the container portion 11 of the cartridge, in such a
manner as to form a sort of an envelop, and the larger
diameter fiber strand 4a is disposed in such a manner
as to be enclosed within the envelop.
In this cartridge, the fiber strand 4b
disposed along the internal wall surface serves to
generate the negative pressure of the ink cartridge,
whereas the fiber strand 4a disposed within the pouch
of the fiber strand 4b generates a relatively low
negative pressure to increase the ink usage
efficiency. In other words, the negative pressure
CA 022~301~ 1998-11-24
generated by the fiber strand 4a is lower than that of
the fiber strand 4b; therefore, the fiber strand 4a
displays less ink retaining capability, and a smaller
amount of the ink will remain unused therein. As is
evident from this description, the functions can be
easily separated in this cartridge.
It should be noted here that the technology
for providing the negative pressure generating member
with the density gradient as described above has been
known with regard to the conventional ink container
comprising the urethane foam or the like. In the case
of the urethane foam, the density distribution within
the negative pressure generating member is controlled
using the following two means: (1) before the foam
material is inserted into the cartridge, its
configuration is changed (including the method of
cutting notches in the foam material), so that the
compression ratio varies within the foam material
after the insertion, and (2) projections or the like
are provided within the ink cartridge to control the
density distribution of the negative pressure
generating member. In the case of (1), a foam
material piece having an unusual (complicated)
configuration is to be inserted into the ink
cartridge, which is liable to cause the inserted foam
material piece to wrinkle, wherein the wrinkle
occurring at an unexpected location sometimes
CA 022~301~ 1998-11-24
--32--
deteriorates the performance of the ink cartridge.
Further, the foam material piece must be
processed to be formed into the unusual (complicated)
configuration, which sometimes increases the
manufacturing cost. In the case of ( 2 ), the foam
material may be in a simple form, for example,
rectangular, but since it is quite common that the
projections are provided within the ink cartridge, the
internal volume of the ink cartridge is reduced; in
other words, the ink capacity of the cartridge is
decreased, resulting in the reduction of ink usage
efficiency.
On the contrary, in the case of the negative
pressure generating member used in the present
invention, it is possible to give the negative
pressure generating member the density gradient as
described above by means of simply mixing the fiber
strands having a different diameter and/or a shape.
Therefore, in the case of the present invention,
disposing mixedly within the ink cartridge a number of
fiber strands with a different diameter as the
negative pressure generating member creates a
preferable structure for improving the performance of
the ink cartridge.
Here, the technical concept of using fibrous
material as the negative pressure generating member,
which runs through the preceding embodiments, can be
CA 022~301~ 1998-11-24
summarized as follows.
Firstly, the fiber strand constituting the
fibrous member is regulated to a predetermined length,
whereby the fibrous member filled into the ink
container is deformed within an elastically deformable
range, so that the fiber strands therein intersect
each other at multiple points.
For example, referring to Figure 7, let it be
assumed that the length, width, and height of the
substantially rectangular ink cartridge 1 are L, N and
M, and the diagonal line of the surface containing M
and N is 1. The preferable range for the length of
the fiber strand constituting the fibrous member is to
be no less than 1. The more preferable range is to be
no less than the length of the diagonal line F of the
rectangular parallelepiped. When such a requirement
is satisfied, each of the fiber strands filled in the
cartridge 1 is deformed within the elastically
deformable range to intersect with others at multiple
points.
Secondary, fibrous material pieces, each of
which is constituted of fiber strands having a
different diameter from those of the other fibrous
material pieces, are disposed at predetermined points
within the ink cartridge 1.
For example, referring to Figure 8, the
fibrous material piece 4b constituted of the fiber
CA 022~301~ 1998-11-24
strands with a relatively small diameter is disposed
adjacent to the filter 8A of the ink supply passage 8
so as to make contact therewith, and the fibrous
material piece 4a constituted of the fiber strands
with a diameter larger than that of the strands
constituting the fibrous material piece 4b is filled
so as to surround the fibrous material piece 4b and
fill the rest of the internal space of the ink
cartridge. With this arrangement, the flow resistance
of the filter, which conventionally constituted the
major portion of the flow resistance through the ink
supply passage from the ink container to the ink jet
head, is reduced, whereby the ink supply performance
is enhanced, and at the same time, the deterioration
of the ink retaining capability of the ink container
can be prevented.
To describe more specifically, the following
table is given.
Table 1
Filter line Container
(resistance)
CONV. 12 - 15 ~m Sponge line approx. 90 ~m
Fibers 4b Fibers 4a
EMB. 20 ~m
Dia. 25 - 40 ~m Dia. 50 - 100 ~m
CA 022~301~ 1998-11-24
In comparison with the conventional
arrangement the filter diameter is increased to reduce
its flow resistance, which constitutes the major
portion of the flow resistance when the ink is
supplied. With this arrangement, the overall ink
delivery resistance is reduced. Also, the fibrous
material composed of the fiber strands with a smaller
diameter is disposed adjacent to the filter;
therefore, it is possible to concentrate the ink
toward the ink supply passage, and at the same time,
prevent the ink from leaking from the filter or ink
supply passage.
Figure 9 depicts another embodiment of the
present invention, to which the second technical
concept is applied when a different type of negative
pressure generating member is employed.
In Figure 9, an alphanumeric reference 40a
designates a piece of felt composed of fiber strands
with a relatively large diameter, and 40 b designates
a piece of felt composed of fiber strands with a
diameter smaller than that of the felt 40a. This
embodiment does not give the fiber strands as much
freedom as the embodiments described before, but since
the relative diameter of the fiber strand is reduced
toward the supply port side, it enjoys such advantages
that the flowability of the ink within the ink
container is improved; and that the internal space
CA 022~301~ 1998-11-24
--36--
fillable with the ink is increased relative to the
space filled with the fibrous material, while reducing
the amount of the unusable amount of the ink within
the ink container. Further, since the felt 40b
composed of the finer fiber strands is placed in
contact with the fiber 8A, the diameter of the filter
8A can be rendered larger in this embodiment than in
the cartridge with the conventional structure.
In the descriptions of the preceding
embodiments, nothing has been mentioned about the ribs
to be provided within the ink cartridge for
introducing the atmospheric air or for the like
purposes. Such ribs may be provided, and when
provided, it is essential that there is a proper
amount of contact at least between the filter of the
ink supply passage and the fibrous material.
Figures lO(a) - lO(h) are sectional views
depicting the sections of various fiber strands that
constitute the fibrous member 4 in the different
embodiments of the present invention.
The sectional configuration of the fiber
strand may be in any of the configurations depicted in
these drawings. In particular, however, in order to
increase the volume of the void within the cartridge
filled with the fibrous material, the fiber strands
having a sectional configuration with ridges and
valleys as shown in Figures lO(f) - lO(h), and those
CA 022~301~ 1998-11-24
~-37-
having a hollow structure-as shown in Figures lO(e)
and lO(g), are more preferable. Further, in the cases
of the fiber strands having one of the sectional
configurations depicted in Figures lO(e) - lO(h), even
when they become parallelly bundled, the volume of the
void that functions in a predetermined manner as the
negative pressure generating member is not reduced,
which makes them preferable.
Figure 11 is a sectional view of another
example of ink cartridge, in which the fibrous member
embodied in accordance with the present invention is
employed as the negative-pressure generating member.
The ink cartridge 1 of this embodiment
illustrated in Figure 9 comprises an ink supply
passage 8 where it is connected to an ink jet
recording head 12, a negative pressure generating
member accommodating portion 53 for accommodating the
fibrous member 4 as the negative pressure generating
member, and an ink storing portion 56 which is
disposed next to the negative pressure generating
member accommodating portion 53 with the interposition
of a rib 54, and is connected thereto through a
connecting portion 57 provided at the bottom portion
55 of the ink cartridge.
In Figure 11, a reference numeral 7
designates an air vent for allowing the interior of
the negative pressure generating member accommodating
CA 022~301~ 1998-11-24
-~38-
portion 53 to be in communication with the atmosphere;
59, a rib for improving the strength of the ink
storing portion 56; 60, an opening through which the
ink is filled into the ink container cartridge; and a
reference numeral 61 designates a sealing member for
sealing the opening 60. The rib 54 is provided with a
groove 54A for carrying out the gas-liquid exchange
between the ink within the ink storing portion and the
atmospheric air to be introduced into the negative
pressure generating member accommodating portion
through the air vent 58. With the presence of this
structure, the ink within the negative pressure
generating member accommodating portion is first
consumed, and then, the ink within the ink storing
portion 56 is consumed after the ink level within this
portion 53 drops to the groove 54A, and the
aforementioned gas-liquid exchange begins to allow the
ink in the ink storing portion 56 to be supplied to
the portion 53 side through the connecting portion 57.
Figure 12 is a perspective view of an ink jet
recording apparatus as a printer usable with the ink
cartridge illustrated in Figure 10.
In Figure 12, a reference numeral 101
designates a printer; 102, a control panel provided in
the frontal portion of the top surface of the housing
of the printer 101; 103, a sheet feeder cassette to be
installed through the frontal opening of the
CA 022~301~ 1998-11-24
-39-
aforementioned housing; 104, a sheet of paper
(recording medium) fed out of the sheet feeder
cassette 103; and a reference numeral 105 designates a
tray for holding the sheets of paper discharged
through the sheet conveying passage within the
aforementioned printer 101. The member designated by
a reference numeral 106 is a main assembly cover
having an L-shaped sectional configuration. This main
assembly cover 106 covers an opening 107 provided in
the right front portion of the housing, and is
rotatively attached to the inward facing surfaces of
the opening 107 using hinges 108. Within the housing,
a carriage 110 supported with guides or the like
(unillustrated) is disposed. The carriage 110 is
reciprocative in the direction of the width of the
sheet passed through the sheet conveying path, that
is, in the direction parallel to the longitudinal
direction of the aforementioned guides or the like.
The carriage 110 of this embodiment generally
comprises a stage llOa supplied horizontally with the
guides or the like, an opening (unillustrated), which
is formed in this stage llOa adjacent to the guides
and in which the ink jet head is mounted, a cartridge
garage llOb for accommodating the ink cartridges lY,
lM, lC and lBk mounted on the stage llOa located in
front of this opening, and a cartridge holder llOc for
preventing the cartridges mounted in this garage llOb
CA 022~301~ 1998-11-24
--40--
from dropping out.
The aforementioned stage llOa is slidably
supported, at the rear portion, with the
aforementioned guides, and its front end portion is
resting on an unillustrated guide plate. This guide
plate may double as a sheet pressing member for
preventing the sheet conveyed through the
aforementioned sheet conveying path from lifting up,
or as a member capable of functioning to lift the
stage from the guides in response to the thickness of
the sheet, in the manner of a cantilever.
As for the openi-ng of the stage llOa, an ink
jet head (unillustrated) is mounted thereon, with its
ink ejecting orifices facing downward.
The cartridge garage llOb is provided with a
through hole extending in the front-rear direction for
accommodating four ink cartridges lY, lM, lC and lBk
all together, and also, with an engagement notch,
which is located in each of the outward facing lateral
surfaces and is engaged with the engagement claw of
the cartridge holder llOc.
At the front end portion of the stage llOa,
the cartridge holder llOc is rotatively attached with
the hinge 116. The distance from the front surface of
the garage llOb to the hinge 116 is determined in
consideration of the distance the cartridges lY, lM,
lC and lBk project from the front end of the garage
CA 022~30l~ l998-ll-24
--41--
llOb when they are placed within the garage llOb, and
the like measurement. The cartridge holder llOc is in
the form of a substantially rectangular plate. The
cartridge holder llOc is provided with a pair of
engaging claws llOe, which project from the
correspondent corners located away from the corners
fixed with the aforementioned hinge 116, in the
direction perpendicular to the surface of the plate
portion of the cartridge holder llOc. The plate
portion of the cartridge holder llOc is provided with
an accommodating hole 120, which accommodates the tab
portions of the cartridges lY, lM, lC and lBk. This
accommodating hole 120 has a size and a shape that
match the tabs, and is positioned to correspond with
the tab positions.
As is evident from the descriptions given
above, according to the present invention, when the
fibrous material is employed as the negative pressure
generating member in the ink cartridge, the narrowing
of the gap between the adjacent fiber strands can be
prevented while the ink is filled into the cartridge
may result in the insufficient ink delivery, ink leak,
and the like, which occur as the reduced distance
between the adjacent fiber strands deteriorates the
ink retaining capability of the cartridge, but the
narrowing can be prevented.
Also, an ink container suitable for the
CA 022~301~ 1998-11-24
-42-
change of the specific ink properties due to the fiber
strand diameter, can be provided.
It is also possible to provide an ink
container, in which the diameter of the fiber strand
within the con~ainer is preferably regulated, and the
flow resistance of the filter itself that creates the
dynamic resistance to the ink movement can be eased.
Next, a manufacturing method for the ink
container will be described.
First, the first embodiment of the ink
container manufacturing method in accordance with the
present invention will be described with reference to
Figures 14 and 15. Figure 14 is a sectional view of a
finished ink container, and Figure 15 describes the
manufacturing steps for the ink container.
In Figure 14, the main body 210 of the ink
container is formed by joining a container 211 and a
lid 212. The ink and a fibrous member F capable of
retaining the ink are contained in the container main
body 210. The container main body 210 is provided
with an ink supply port 211A and an air vent 212A.
From the ink supply port 211A, a cone-shaped
projection 211B projects into the container main body
210, and the inward tip of the cone-shaped projection
211B is provided with a filter 213. The ink container
of this embodiment is usable as an ink cartridge to be
replaceably mounted on, for example, the recording
CA 022~301~ 1998-11-24
-~43-
head of an ink jet recording-apparatus.
Such an ink container is manufactured through
the steps illustrated in Figures 15(a), 15(b), 15(c)
and 15(d).
To begin with, a long continuous strand of
fiber F produced continuously with a fiber producing
apparatus 220 is placed into the container 211 as
shown in Figure 15(a).
The fiber producing apparatus 20 produces a
continuous strand of, for example, polyolefinic
polypropylene fiber, wherein the continuous strands of
polypropylene fiber F is produced by means of
extruding the melted fiber material within a furnace
221 from a spinning nozzle 222.
The continuous fiber strand F extruded from
this fiber producing apparatus is temporarily rested
between rollers 231 and 232, and then, is sent out
into the guide hole 35A of a feeding guide 35 by a
pair of feeding rollers 233 and 234, so as to be
introduced into the container 211. While the fiber
strand F is introduced into the container 211, the
container 211 is reciprocated in the horizontal
direction (direction of an arrow mark A), and the
feeding guide 35 is reciprocated in the direction
perpendicular to the surface of Figure 15, so that the
fiber strand F is accumulated substantially evenly in
the container 211. It should be noted here that a
CA 022~301~ 1998-11-24
number of continuous fibe-r strands F produced
simultaneously by the fiber producing apparatus 220
may be introduced into a single container 211, and
also, that a number of such fiber strands may be
introduced after being twisted together.
After the fiber strand F is accumulated in
the container 211 by a predetermined length, the
feeding rollers 233 and 234 are stopped, and a pair of
blades 236 and 237 are moved in the directions of
arrow marks B1 and B2, respectively, to cut the fiber
strand F by pinching it between them (Figure 15(b)).
Meanwhile, the fiber strand F being extruded from the
fiber producing apparatus 220 is rested between the
rollers 231 and 232. The amount of the rested fiber
strand F can be adjusted by means of controlling the
rotation of the rollers 231 and 232.
Next, the lid 212 is closed, as illustrated
in Figure 15(c), onto the container 211 in which the
fiber strand F has been accumulated, and then, the
container 211 and lid 212 are joined, as shown in
Figure 15(d), to form the container main body 210,
using ultrasonic waves or the like. It should be
noted here the the accumulated fiber strand F bulging
above the container 211 is preferred to be pressed
down into the container 211 with a pressing member,
compressed air, or the like.
When both the container 211 and lid 212 are
CA 022~301~ 1998-11-24
--45--
formed of thermally fusible resin, they can be easily
joined by thermal welding. Further, when the
container 211 and 212 are formed of the same thermally
fusible resin (for example, polypropylene) as the
fiber strand F, the joint can be properly sealed even
if the fiber strand F is pinched between the joining
surfaces, since the joining surfaces are thermally
welded together with the pinched fiber strand. in
addition, after the ink container is used, in other
words, after the ink in the ink container is
completely consumed, there is no need for separating
the fiber strand F as the ink retaining member from
the container main body 210, and they can be processed
together (for example, melted together at a
lS temperature higher than the boiling point of the
stored ink) to be recycled.
The ink may be stored in the container 211
either before or after joining the container 211 and
lid 212, wherein the ink is absorbed into and retained
between the gaps created between the adjacent portions
of the fiber strand F due to the capillary force
generated there. For example, the ink may be stored
into the container main body 210 through the ink
supply port 211A (Figure 14) or an unillustrated ink
injecting port after the container main body 210 is
completed by joining the container 211 and lid 212.
It is also acceptable to store the ink into the
CA 022~301~ 1998-11-24
--46--
container 211 during the operation for guiding the
fiber strand F into the container 211, before the
beginning of the operation, or immediately after the
end of the operation. It should be noted here that
when-the ink is stored before joining the container
211 and lid 212, the ink supply port is kept sealed as
needed.
When the fiber strand F is placed into the
container 211 after the ink is stored, it must be
taken into consideration that the solvent of the ink
might evaporate due to the heat possessed by the fiber
strand F; therefore, it is preferable to increase in
advance the amount of the solvent in the ink by the
amount estimated to evaporate while the ink is stored
lS into the container 211. For example, when it is
estimated that 20 ~ of the solvent of the ink is
evaporated by the heat of the fiber strand F, all that
is necessary is to reduce the ink density by means of
increasing in advance the amount of the ink solvent by
the correspondent amount. it is also acceptable to
store the ink in the following manner: the ink
solvent is stored in advance in the container 211;
next, the fiber strand F is placed; and finally, the
ink solute is stored with or without the solvent so as
for the resultant ink to have the optimum density. In
this case, not only the fiber strand F is cooled by
the ink solvent stored in advance in the container
CA 022~301~ 1998-11-24
--47--
211, being stabilized within the solvent in terms of
positional arrangement, but also, the surface of the
fiber strand F becomes more wettable, or more
compatible, with the ink.
The ink container completed through the steps
of placing the fiber strand F and the ink in the
container main body 210 as described above is used as
the ink cartridge, which is mounted in, for example,
an ink jet recording apparatus, with its ink supply
10 port 211A (Figure 14) being connected to the recording
head.
During usage, that is, during the recording
operation in which ink is ejected from the ink
ejecting orifices of the recording head, the ink
retained by the fiber strand F is supplied to the
recording head through the ink supply port 211A;
within the container main body 210, the ink is
delivered to the ink supply port 21lA by the apparent
negative pressure generated by the fiber strand F.
When the recording operation is not going on, the ink
is prevented from leaking by the ink retaining
capability of the fiber strand F.
Since the fiber strand F is a continuous long
strand, the amount of waste particles or chips, which
are liable to be generated at the cut surface of the
fiber strand F, can be minimized; therefore, the
filter 213 (Figure 14) is prevented from being clogged
CA 022~301~ 1998-11-24
-48-
with such refuse. In other words, the clogging of the
filter 213, which his liable to occur when the fiber
strands F having been cut relatively short are
employed, can be avoided.
As for the material suitable for forming both
the container main body 210 and fiber strand F, it is
preferable to use the organic or metallic material,
in consideration of ease of the initial formation
thereof (before recycling), wherein from the
standpoint of handling, the organic material is more
preferable. When recyclability is taken into
consideration, the thermoplastic resins, which can be
easily recycled without going through the processing
steps such as cracking or refining, are far more
preferable. Further, when an emphasis is placed on
the stability of the material (compatibility with the
ink for ink jet recording during an extended storage
period), olefinic resins such as polyethylene or
polypropylene are particularly preferable.
It has been already stated that in order for
the fiber strand F composed of a material selected
from among the aforementioned choices of material to
function properly as a preferable ink retaining member
during ink jet recording, the fiber strand F is
preferred to intersect randomly with itself at
multiple points within the container main body 210.
Contrarily, when the fiber strand F is placed in the
CA 022~301~ 1998-11-24
--49--
container main body 210 in an orderly manner like
being parallelly bundled, the void within the
container main body 210 is reduce; in other words, the
space fillable with the ink is reduced. As a result,
the ink capacity of the container main body 210
relative to the internal volume thereof is reduced.
As for the sectional configuration of the
fiber strand F, any configuration is acceptable.
However, in order to increase the volume of the void
within the cartridge filled with the fiber strand F,
the fiber strand F with the sectional configuration
having the ridges and valleys at the periphery, or the
hollow one, is preferable.
It is not possible to specify generally the
diameter and amount of the fiber strand F to be filled
in the container main body 210 since they vary
depending on the internal volume and configuration of
the container main body 210. However, in
consideration of the fact that the generation of the
negative pressure is dependent on the gap between the
adjacent portions of the fiber strand F, it is evident
that when the gap is excessively large, the negative
pressure is reduced, allowing the ink to leak out of
the container main body 210, and contrarily, when it
is excessively small, the negative pressure is
increased too high to allow the ink to be supplied
from the container main body 210 to the recording
CA 022~301~ 1998-11-24
--50--
head. Thus the diameter of the fiber strand F is
preferred to be in a range of 5 ~m - 1 mm, more
preferably, 10 ~m - 0.5 ~m, though such preference
depends on the internal volume of the container main
body 210 and/or the amount of the fiber strand F to be
filled thereinto.
In order to prevent the fiber strand F from
shifting within the container main body 210, it is
preferable to press the fiber strand F at least in one
direction by the lid 2 or the like. Further, when a
large gap is generated between the adjacent portions
of the fiber strand F, at the location where the fiber
strand F contacts the ink supply port 211A, it is
possible for the ink supply from the container main
body 210 to the recording head to be interrupted;
therefore, it is more preferable that the fiber strand
F is pressed toward the ink supply port 211A.
Further, the fiber strand F may be cut to a
predetermined length with the blades 236 and 237 while
the fiber strand F is introduced into the container
211 as shown in Figure 15(a). In this case, the only
control a controlling means 238 of the blades 236 and
237 has to execute is to operate the blades 236 and
237 each time the fiber strand F is delivered by a
predetermined distance by the feeding rollers 233 and
234. It is preferable that the length by which the
fiber strand F is cut is larger than the length of the
CA 022~301~ 1998-11-24
--51--
diagonal line Ll of the container main body 210
(Figure 14). With such an arrangement, the cut fiber
strand F is bent in the container main body 210,
whereby the cut fiber strands F are caused to
intersect with each other in a tangly manner so as to
provide sufficient ink retaining capability. More
specifically, the fiber strand F is cut to a length of
10 cm. Further, when it is intended to give the fiber
strand density a gradient within the container main
body 210 as will be described later, the length by
which the fiber strand is cut may be changed
corresponding to where the cut fiber strand is
disposed within the container main body 210. When the
continuous fiber strand F is placed within the
container 211 without being cut, all that is necessary
is to input the wanted length L2 (for example, 1 m) of
a single continuous fiber strand F in the controlling
means 238.
Figure 16 is an explanatory drawing for
describing the second embodiment of the manufacturing
steps for the ink container in accordance with the
present invention. The container main body 210 in
this drawing comprises a container 211 and a lid 212
as the one in the aforementioned embodiment
illustrated in Figure 14 does.
In this embodiment, the fiber strand F is
formed into a long belt of fibrous aggregate Fl, and
CA 022~301~ 1998-11-24
then, the fibrous aggregate belt Fl is folded into the
container 211. For example, when thermally fusible
polyolefinic resin such as polypropylene is used as
the material for the fiber strand F, the fiber strand
F is first aggregated, and then, the surface portion
of thus formed fibrous aggregate is heated to weld the
complex intersections of the fiber strand F, so that
the fiber strand F is formed into a stable belt of
fibrous aggregate Fl. As for the form of the fiber
strand aggregation within the aggregate Fl, it may be
such that one or several long strands of.fiber
randomly intersect at multiple points; that a large
number of short fiber strands (several centimeters)
randomly intersect at multiple points; that a large
number of long fiber strands are bundled so as to
extend in the longitudinal direction of the aggregate
F1; or the like form. The sectional configuration of
the belt of the aggregate Fl is optional; for example,
it may be rectangular. In other words, it may be
optionally selected depending on the configuration or
the like of the container main body 210.
When such an aggregate F1 is placed in the
container 211, it is first folded into a hollow guide
member 241 as illustrated in Figure 16(a). More
specifically, while the aggregate F1 is fed downward
of the drawing by a pair of feeding rollers 242 and
243, through the guiding hole 244a of a feeding guide
CA 022~301~ 1998-11-24
- 53 -
244, being guided into the guide member 241, the
feeding guide 244 iS reciprocated in the direction of
an arrow mark C in the same drawing, so that the
aggregate F1 is folded. It is desirable that at the
moment of each folding, an external force is imparted
on the fold-back portion of the aggregate Fl by an
unillustrated auxiliary means, so that the aggregate
F1 is reliably folded not the guide member 241. As
for the auxiliary means, a pressing means or
compressed air may be used to press the aggregate F1
in the folding direction or downward.
After the aggregate F1 long enough to fill up
the container main body 210 iS folded into the guide
member 241, the rollers 242 and 243 are stopped as
shown in Figure 16(c), and at the same time, a pair of
blades 245 and 246 are moved in the direction of arrow
marks Dl and D2, respectively, to cut the aggregate Fl
between the two blades. Within the guide member 241,
a holding portion 241A iS provided, which is
structured as a portion of the guide member 241, that
is, a portion where the internal diameter of the guide
member 241 iS slightly reduced, or as a projection
disposed on the internal peripheral surface of the
guide member 241, SO as to help to compress the
aggregate Fl and hold it. Instead, the holding
portion 241A may be replaced with a cap closing the
downward opening of the guide member 241. In any
CA 022~301~ 1998-11-24
-54-
case, what counts is the capability to hold the
aggregate Fl within the guide member 241.
Next, the guide member 241 and container 211
are put together in alignment as shown in Figure
16(c3, and then, the aggregate Fl within the guide
member 241 is pushed down into the container 211, with
a pressing member 247. Thereafter, the container 211
and lid 212 are joined as they were in the preceding
embodiment (Figures 16(e) and 16(f)). The placement
of the ink into the container main body may be either
before or after joining the two components.
Figure 17 is an explanatory drawing that
describes the steps of the third embodiment of ink
container manufacturing method in accordance with the
present invention. This embodiment is different from
the second embodiment in that the fiber strand F is
formed into a plate-shaped fibrous aggregate F2. The
configuration of the plate of the fibrous aggregate F2
is optional, and is selected to match the
configuration of the container main body 210.
This aggregate F2 is stocked in the stocker
248 (Figure 17(a)). When placed into the container
211, it is first pushed down into the guide member
241, being held there, as illustrated in Figure 17(b),
and then, is moved into the container 211 with a
pressing member 247. Thereafter, the container 211
and lid 212 are joined together in the same manner as
CA 022~301~ 1998-11-24
- 55 -
the preceding embodiments (Figures 17(c3 and 17(f)).
Also in this case, the placement of the ink may be
either before or after joining the two components.
Figure 18 is an explanatory drawing that
describes the steps of the fourth embodiment of the
ink container manufacturing method in accordance with
the present invention. In this embodiment, the fiber
strand F is placed in a pouch 251 in advance, and
then, the pouch 251 filled with the fiber strand F is
placed in the container 211. The pouch 251, which is
in the form of net or is provided with numerous pores,
allows the ink to permeate through it. As for the
material of the pouch 251, the same material as those
for the fiber strand F and container main body 210 may
be used. For example, when the pouch 251 iS composed
of thermally fusible resin, it can be sealed using the
thermal welding. As for the arrangement of the fiber
strand F in the pouch 251, it may be such that one or
several long strands of fiber randomly intersect with
each other at multiple points; that a large number of
short strands of fiber (several centimeters long)
intersect with each other at multiple points; a large
number of long strands of fiber are bundled together;
or the like arrangement.
The pouch 251 containing the fiber strand F
is stocked in the stocker 252 in advance (Figure
18(a)), and when it is necessary to be placed in the
CA 022~30l~ l998-ll-24
- 56 -
container 211, it is pushed down to be dropped into
the container 211 (Figure 18(b)). At this time, the
container 211 iS horizontally moved to shift
sequentially the landing point of the pouch 251 in the
container 211, SO that the dropped pouches 251 are
substantially evenly distributed in the container 211.
Further, the container 211 may be vibrated in the
horizontal and/or vertical direction to pack more
tightly the pouches 251. It is also possible to
vibrate and/or move the stocker 252 in order to drop
evenly the pouches 251 into the container 211.
The number of the pouches 251 to be dropped
into a single container 211 iS determined in advance
on the basis of the sizes of the container 211 and
pouch 251, packing density of the fiber strand F in
the pouch 251, or the like factor. After an
appropriate number of the pouches 251 are dropped into
the container 211, the container 211 and lid 212 are
joined in the same manner as they were in the
preceding embodiments (Figures 18(c) and 18(d)). The
ink is placed in the container 211 either before or
after joining the two components.
Figure 19 is an explanatory drawing that
describes the steps of the fifth embodiment of the ink
container manufacturing method in accordance with the
present invention. This embodiment is different from
the aforementioned second embodiment in that the fiber
CA 022~301~ 1998-11-24
-57-
strand F is placed in the container 211-without being
first fixed in the guide member 241. Further, in this
embodiment, the bottom portion of the guide member 241
is fitted into the container 211 (Figures l9(a) and
l9(b)), and then, the fiber strand F is pushed
downward into the container 211, with a pressing
member 247, as shown in Figure l9(c)). Around the
bottom edge of the pressing member 247, a projection
247A is provided, which projects downward and pressed
harder the portion of the fiber strand F facing the
projection 247A, preventing thereby the fiber strand F
from being pinched between the joining surfaces of the
container 211 and lid 212, as shown in Figure l9(d).
After the fiber strand F is moved into the container
211, the container 211 and lid 212 are joined as they
were in the preceding embodiments. The ink may be
placed either before or after joining the two
components.
As for the arrangement of the fiber strand F
in the guide member 241, that is, the arrangement in
which the fiber strand F is subsequently placed in the
container main body 210, it may be such that one or
several long strands of fiber randomly intersect at
multiple points; that a large number of short fiber
strands (several centimeters long) randomly intersect
at multiple points; that a large number of long fiber
strands are bundled so as to extend in the
CA 022~301~ 1998-11-24
--58--
longitudinal direction of the fibrous aggregate Fl; or
the like arrangement.
It is not mandatory that the guide member 241
is provided with the holding portion 241. For
example, the fiber strand F may be guided down into
the container 211 after the bottom portion of the
guide member 241 is fitted into the container 211 as
illustrated in Figure l9(b). In this case, the
internal space of the guide member 241 serves as the
guiding path for the fiber strand F.
Figure 20 is an explanatory drawing that
describes the steps of the sixth embodiment of the ink
container manufacturing method in accordance with the
present invention. Also in this embodiment, the
pouches 251 are used as they were in the fourth
embodiment illustrated in Figure 18, except that there
are two types of pouches in this embodiment: those
containing the fiber strand FA with a smaller diameter
and those containing the fiber strand FB containing
the fiber strand with a larger diameter. After the
pouches 2 5 1 are dropped into the container 211, the
lid 212 is joined with the container 211 as it was in
the fourth embodiment, wherein the pouch 251
containing the smaller diameter fiber strand FA is
disposed so as to face the ink supply port 211A. Such
an arrangement is realized in the following manner;
after a pouch 251 containing the smaller diameter
CA 022~301~ 1998-11-24
-59-
fiber strand FA is disposed on the filter 213 as
illustrated in Figure 20(a), pouches 251 containing
the larger diameter fiber strand FB are deposited
(Figure 20(b)), and then, the lid 212 is joined
(Figure 20(c)).
The ink retaining capability (generation of
apparent negative pressure) of the fiber strand F,
which is given by the capillary phenomenon, is
proportional to the size of the gap between the
adjacent portions of the fiber strand F; in the case
of the smaller diameter fiber strand FA; the gap
between the adjacent portions of the fiber strand F is
small, which makes the ink retaining capability
stronger, whereas, in the case of the larger diameter
fiber strand FB, the gap is larger, which makes the
ink retaining capability weaker. Such ink retaining
capability varies depending on not only the external
diameter of the fiber strand, but also, the sectional
configuration thereof; therefore, the combination of
the fiber strands FA and FB may be replaced with a
combination of fiber strands different in the
sectional configuration.
When the fiber density in the container main
body 210 is increased toward the ink supply port 21lA,
it is easier for the ink within the container main
body 210 to collect toward the ink supply port 211A,
which reduces the amount of the ink left unused.
CA 022~301~ 1998-11-24
--60--
Further, the projection 211B projecting inward from
the ink supply port 211 functions to compress the
fiber strand FA, increasing further the density
thereof.
What is important in this case is for the
pouch 251 filled with the smaller diameter fiber
strand FA to be disposed to face the ink supply port
211A. When it is placed in the container 211 at the
same time as the other pouches, or when the structure
of the container 211 is such that when the pouch 251
is placed in the container 211, the ink supply port
211A comes to be situated at the top, it may be placed
after the other pouches 251 are deposited. Further,
it is also acceptable to prepare three or more types
of pouches, each containing a fiber strand F of a
different diameter, which are placed in the container
210, sequentially or at the same time, in such a
manner as to increase the fiber strand density toward
the ink supply port 21lA in the container main body.
Figure 21 is an explanatory drawing that
describes the steps of the seventh embodiment of the
ink container manufacturing method in accordance with
the present invention. In this emboqiment~ a fiber
strand FB, which is equivalent to the fiber strand FB
in the sixth embodiment described above, is placed in
the container 211 without being packed in the pouch
251. As for the placing method of the fiber strand
CA 022~301~ 1998-11-24
FB, the one employed in the first or fifth embodiment
may be employed. Further, two or more different types
of fiber strands may be placed, as the fiber strand
FB, in the container 211, so that the fiber density is
increased toward the ink supply port 211A. Also, the
fiber strand FB may be placed in the container 211
without being packed in the pouch 251, using the same
method as the aforementioned first or fifth
embodiment; in this case, it may be placed in such a
manner that the fiber strands FA and FB are aggregated
into the form matching the internal configuration of
the container 211, and the fibrous aggregate thus
formed is placed in the container 211, wherein the
aggregate can be stabilized by means of welding the
fiber portions at multiple points at which the fiber
portions exposed at the surface intersect with each
other.
Figure 22 is a sectional view of an ink
container that describes the eighth embodiment of the
ink container manufacturing method in accordance with
the present invention. In this embodiment, the
fibrous aggregate is formed in such a manner that the
aggregate of the larger diameter fiber strand is
enclosed within the aggregate of the smaller diameter
fiber strand FB, and then, the fibrous aggregate thus
formed is placed in the container 211. This fibrous
aggregate can be also stabilized by means of welding
CA 022~301~ 1998-11-24
-62-
the fiber strand portions exposed at the surface of
the aggregate at multiple points at which the fiber
strand portions intersect each other. As for the
placing method for the aggregate, the method employed
in the fifth embodiment (Figure 19), for example, may
be employed. In the ink container of this embodiment,
the apparent negative pressure is primarily generated
by the smaller diameter fiber strand FA disposed along
the internal wall surface of the container main body
210, whereas the larger diameter fiber strand FB
positioned within the smaller diameter fiber strand FA
generates a smaller amount of the apparent negative
pressure, which results in weaker ink retaining
capability, but reduces the ratio of the ink left
unused.
Figure 23 is an explanatory drawing that
describes the steps of the ninth embodiment of the ink
container manufacturing method in accordance with the
present invention. In this embodiment, the pouches
251, in which the fiber strand F is packed in the same
manner as the fourth embodiment illustrated in Figure
18, are deposited in the container 211 while the
container 211 iS continuously or intermittently moved
in the direction of an arrow mark G by a conveyer belt
270. Then, the lid 212 is joined with the container
211. Therefore, a number of stockers 252 are arranged
in the direction of the path of the container 211,
CA 022~301~ 1998-11-24
--63--
wherein the pouch 251 is-dropped form each of the
stockers 252 into the container 211, to be disposed at
a predetermined location within the container 211.
Figure 24 is an explanatory drawing that
describes the steps of the tenth embodiment of the ink
container manufacturing method in accordance with the
present invention. In this embodiment, a pouch 251
containing the smaller diameter fiber strand FA and a
pouch 251 container the larger diameter fiber strand
FB are dropped into the container 211 placed on a
conveyer belt 270, from stockers 252-1 and 252-2,
respectively, in the same manner as the sixth
embodiment illustrated in Figure 20, and then, the lid
212 is joined with the container 211. The pouch 251
containing the smaller diameter fiber strand FA is
dropped into the container 211 so as to face an
unillustrated ink supply port.
As described above, in the case of the ink
container manufacturing method in accordance with the
present invention, the fiber strand is led into the
container main body as it is continuously produced;
therefore, the fiber strand and ink container can be
manufactured through a continuous operation, which
makes it possible to eliminate the storage facility
for the fiber strands, or the like.
Further, in this ink container manufacturing
method, the continuous fiber strand is led into the
CA 022~301~ 1998-11-24
--64--
container main body after being temporarily rested;
therefore, the ink container can be manufactured
without interrupting the continuous production of the
fiber strand.
Further, when the ink container is
manufactured through such a procedure that the fiber
strand is formed into a belt of fibrous aggregate, and
then, this belt of fibrous aggregate is folded into
the container main body, the fiber strand is prevented
from scattering; therefore, it can be reliably placed
in the container.
In addition, when the ink container is
manufacture through such a procedure that the
aggregate of fiber strand is produced in advance, and
then, a predetermined number of these aggregate pieces
are placed in the container main body, not only can
the fiber strand be reliably placed in the container
main body while preventing it from being scattered,
but also, the number of the aggregate pieces to be
placed in the container main body can be changed,
depending on the type of the ink container; therefore,
this method is applicable to various ink containers.
When the ink container is manufactured
through another procedure in which the fiber strand is
packed in a pouch, and then, this pouch containing the
fiber strand is placed in the container main body, the
fiber strand can be reliably placed in the container
CA 022~301~ 1998-11-24
--65--
while preventing the scattering of the fiber strand.
When the ink container is manufactured
through such a procedure that the fiber strand is led
into the container main body through the guiding path
of the guide member, the fiber strand can be smoothly
and reliably placed in the container while preventing
it from being scattered.
When the ink container is manufactured
through another procedure in which the fiber strand is
placed in the container main body after the fiber
strand is once held in the guide member to regulate
the aggregating form of the fiber strand, the fiber
strand can be reliably and smoothly placed in the
container.
When the polyolefinic material is used as the
material for the fiber strand, it is possible to give
the ink container compatibility with various types of
ink, for example, alkaline ink, and also, to stabilize
the structure of the fiber strand aggregate using the
thermally fusible properties of the material.
Further, when two or more types of fiber
strands different in external diameter or sectional
configuration are employed as the fiber strands to be
placed in the container main body, the ink retaining
capability of the fiber strand can be established to
be optimal for their position within the ink container
main body.
CA 022~301~ 1998-11-24
--66--
When the ink container is manufactured
through such a procedure that the ink is placed in the
container main body before the fiber strand is placed
therein, a certain degree of flexibility is afforded
in the ink container manufacturing process, wherein
the ink can be prevented from being denatured, by
means of increasing the amount of the solvent in the
ink by the amount equivalent to the amount of the
solvent that evaporates when the fiber strand is
placed in the container.
Further, when the fiber strand is placed in
the container after the ink solvent is placed in the
container main body, it is possible to improve, in the
ink solvent, the arrangement in which the fiber strand
is placed in the container, and also, to improve the
wettability of the fiber strand surface to the ink.
While the invention has been described with
reference to the structures disclosed herein, it is
not confined to the details set forth and this
application is intended to cover such modifications or
changes as may come within the purposes of the
improvements or the scope of the following claims.
