HK1066508B - Ink cartridge - Google Patents

Description

Ink box

The present invention relates to an inkjet recording apparatus, particularly to an ink cartridge for storing ink, which supplies ink to a print head; and a recording unit generally including an ink cartridge and an ink-jet head detachably connected to each other; and an inkjet recording apparatus to which the recording unit is detachably mounted. Hereinafter, the term "record" encompasses the meaning of printing characters, images, and the like on cloth, paper, plastic sheet, or the like.

In several recording apparatuses currently used, a recording head thereof generally records characters, images, and the like on a recording medium such as a sheet of paper, that is, a needle method; thermal recording method; a thermal conversion method; and an ink jet method. Among these methods, the inkjet method is a non-impact printing method which includes the steps of: that is, the ink is ejected and then fixed on the recording medium. Therefore, a recording apparatus using the recording unit printed in this way can perform high-speed, high-density printing. As a result, they are widely used as output terminals as printers of information processing systems such as: copiers, facsimile machines, printers, word processors, workstations, etc., or portable printers as personal computers, mainframe computers, optical disks, or video recording devices, etc.

When the inkjet recording apparatus is used in these systems, the inkjet recording apparatus is designed to be compatible with the respective special functions and operating conditions of these systems. There is a current trend to reduce the size of information handling systems. Therefore, it is required that the recording head and the main body of the ink jet recording apparatus should be miniaturized as much as possible.

Although the need for miniaturization of existing devices has been recognized, there is a need for a recording unit or the like that retains its known capabilities or develops further capabilities. In order to meet these demands, various recording heads and recording apparatuses equipped with these recording heads have been proposed.

An example of which is first described below with reference to fig. 1.

In this figure, the ink jet unit includes an ink jet head 102 and an ink cartridge 101, the ink cartridge 101 serving as an ink tank for storing a liquid, such as ink, which are detachably connected to each other. The ink jet unit is detachably mounted on a carriage 121, and the carriage 121 is movably placed on a guide bar and a lead screw supported on a main frame 122 of the ink jet recording apparatus 120.

Note that the ink ejecting unit is not limited to the above-described structure, and there is an ink ejecting unit in which an ink cartridge and an ink jet head are integrated, for example. When the former type of ink-jet head is used, the ink-jet head is fixed or detachably mounted on a carriage, and the ink cartridge is replaceable.

When the recording head and the ink cartridge are mounted on the carriage as described above, it is necessary to provide a mechanism for the ink cartridge that can generate negative pressure. In the following description, in general, the term "negative pressure" is defined as a value at which the water head pressure of the ink is maintained below atmospheric pressure and sufficient to prevent the ink from leaking from the nozzles of the recording head. As a negative pressure generating mechanism in an ink cartridge, a porous member is used as an ink absorbing member, which can generate surface tension. When a porous member is used, as disclosed in japanese patent application laid-open No. 2-187364, the ink cartridge is structured such that the inlet of the recording head can be pressed into the ink absorbing member of the ink cartridge to increase the utilization rate of the ink, i.e., to reduce the amount of ink remaining in the ink absorbing member.

According to the above-described structure, the surface tension of the porous member can be locally increased by deforming the ink absorbing member around the ink inlet, thereby causing the ink to be guided around the ink inlet and increasing the ink supply amount, thereby reducing the remaining amount of ink in the ink absorbing member.

When using a detachable recording unit (ink jet unit), the user can replace an empty ink cartridge with a new one. Further, it is also possible to replace the recording head or fill an empty ink cartridge with ink for reuse. Further, it is possible for the user to detach the recording head and the ink cartridge without having to separate them. Therefore, it is difficult to predict whether the recording head or the ink cartridge is in a detached or attached state. When the two are detached or connected, a certain amount of air may enter the ink cartridge, so that an ink passage cannot be formed between the recording head and the ink cartridge.

The detachable recording unit disclosed in japanese patent application laid-open No. 2-187364, particularly the recording unit in which an ink absorbing member is pressed into an ink inlet of a recording head to make full use of ink, causes a problem that, as found by the inventors of the present invention, it is difficult for the recording head to obtain ink from the ink cartridge after the ink cartridge is attached to the recording head again before the ink in the ink cartridge is used up.

In general, in such a case, even if the ink jet recovery operation is performed by sucking the ink through the ejection openings of the recording head, the ink cannot be caused to flow back to the recording head, and it is difficult to sufficiently use the ink. The present inventors have analyzed that the largest cause of the above-described troubles is the following problem.

To explain the above reason, one embodiment of an inkjet recording apparatus is shown in fig. 2A and 2B. Fig. 2A shows a connected state of the recording head 2 and the ink cartridge 3, and fig. 2B shows a separated state of the two.

As shown in the drawing, the ink jet unit 4 is constituted by detachably connecting the recording head 2 and the ink cartridge 3 together by a pair of parallel connection claws (not shown).

In the connected state, the ink inlet 40 of the recording head 2 is inserted into a cylindrical connection port 39 serving as an ink supply port. The ink channel 36 is sealed from the environment by an O-ring which seals the joint and is made of ethylene propylene copolymer or the like.

A porous member 37 (i.e., an ink absorbing member such as a sponge block) is stuffed in the ink cartridge 3 to store the ink supplied to the recording head 2. I.e., the porous member has the ability to retain ink.

The water head pressure of the recording head 2 can be maintained at atmospheric pressure or below atmospheric pressure by adjusting the density of the porous member to avoid ink leakage.

In the ink jet recording head having the above-described structure, when the recording head 2 and the ink cartridge 3 are separated, a part of the ink absorbing member near the connection port 39 is directly subjected to the atmospheric pressure. In this case, when the ink absorbing member 37 is deformed back to its original shape, air is introduced into the ink absorbing member 37 to generate bubbles or ink bubbles 38 in the portion of the ink absorbing member 37 near the connection port 39 of the ink cartridge 3.

In this case, when both the recording head 2 and the ink cartridge 3 are reconnected together, the ink absorbing member 37 forms an air area near the connection port 39. Therefore, the air-entrained area makes the ink channel E impossible to form.

Further, when the ink inlet 40 of the recording head 2 is inserted into the ink cartridge 3, air at the ink supply port is pressed into the ink absorbing member, and the compressed air also makes the ink passage E impossible to form.

In these cases, therefore, an undesirable recording state occurs due to a decrease in the ink flow rate or an interruption in the ink passage.

To solve the above-mentioned problems, a mechanism for controlling the air entering into the ink passage has been proposed in some prior art documents, such as that described in Japanese patent application laid-open No. 5-238016. This document discloses a fiber jacket in a projection on a recording headA tube. The inner end of the sleeve communicates with an ink chamber in the recording head, and the outer end of the sleeve contacts an ink absorbing member in the ink cartridge when the recording head is attached to the ink cartridge. According to the above configuration, the sleeve serves as a filter for preventing air from entering the ink chamber of the recording head.

However, in this patent application, no suggestion is made as to whether to solve the problem of air entering the ink cartridge during the process of separating and reconnecting the recording head from the ink cartridge.

There is also the idea of providing a valve to close the ink inlet to prevent air from flowing into the ink channel during disconnection and reconnection. However, mounting a valve member on a recording unit increases the cost and requires more components than a conventional recording unit, and the resulting product is larger in size and inferior in performance. This in turn reduces the advantages of the removable recording head.

In addition to the problem that air easily enters the ink cartridge during the process of separating and reconnecting the recording head, there are other problems to be considered for the ink cartridge in the detachable recording unit:

i) when the recording head is detached, ink leaks from the connection port;

ii) a suitable amount of ink to be supplied from the ink cartridge to the recording head; and

iii) utilization of ink in the cartridge.

The present invention has been made in view of the above problems occurring when a recording head of a detachable recording unit is detached from or attached to an ink cartridge.

It is a first object of the present invention to provide an ink cartridge which is low in cost and high in reliability, prevents ink from leaking therefrom, and stably supplies ink even after a recording head and the ink cartridge are detached and reconnected.

A second object of the present invention is to provide an ink jet recording unit with the above ink cartridge.

A third object of the present invention is to provide an ink jet recording apparatus using the recording unit with the above ink cartridge.

According to a first aspect of the present invention, there is provided an ink cartridge comprising an ink storage portion which is a porous member storing ink, an ink supply portion supplying the ink in the ink storage portion to the outside of the ink cartridge, and an ink guide member provided between the ink storage portion and the ink supply portion, the ink guide member being formed of a bundle of fibers, each of the fibers being parallel to an ink supply direction.

According to a second aspect of the present invention, there is provided an ink cartridge comprising a porous member for storing ink which flows to a recording head through an ink inlet port provided in the recording head.

The ink guide member has a first end in press-contact with the ink inlet and a second end in press-contact with the porous member, and is formed of a bundle of fibers each extending from the second end toward the first end.

According to a third aspect of the present invention, there is provided an ink cartridge comprising a porous member storing ink; an ink supply portion having an outlet for supplying ink to the ink jet head, the outlet also supplying ink to the inlet of the ink jet head; the ink supply portion has an air passage which allows air entering the ink cartridge from the ink supply portion to be discharged from the ink cartridge when the ink inlet is inserted into the ink supply portion.

According to a fourth aspect of the present invention, there is provided an ink jet recording apparatus equipped with a recording unit having a recording head with a plurality of ink ejection ports, wherein the ink cartridge has a porous member for storing ink, and the recording unit has an ink inlet for drawing the ink from the ink cartridge. The ink cartridge further has an ink guide member having one end pressed against the ink inlet and the other end pressed against the ink absorbing member, the ink guide member being made of a bundle of fibers, and the recording unit being detachably mounted on a holder.

According to a fifth aspect of the present invention, there is provided an ink jet recording apparatus comprising an ink jet recording unit having a recording head for ejecting ink and an ink cartridge for storing the ink, and performing recording by ejecting the ink onto a recording medium. The ink cartridge includes an ink absorbing member for holding ink, and an ink guide member disposed between the ink absorbing member and an outlet for supplying ink to the outside, the ink guide member having a surface tension greater than that of the ink absorbing member, while a pressure loss in the ink guide member is only 20mm Hg or less.

According to a sixth aspect of the present invention, there is provided a recording apparatus employing a recording unit having a recording head for performing recording by ejecting ink and an ink cartridge for supplying ink to the recording head, the recording head and the ink cartridge being detachably connected. Wherein the recording head has an ink guide member which is press-fitted to the ink cartridge to receive the supplied ink, the ink cartridge has an ink absorbing member for storing the ink supplied to the recording head, an ink inlet of the recording head is inserted into the ink supply member, and the ink supply member has an outlet formed at a front end of the ink cartridge, so that an ink passage is formed between the ink inlet and the ink absorbing member. One end of the ink guide member is pressed against an ink inlet inserted into the ink supply member, and the other end is pressed against the ink absorbing member. An air passage is provided between the ink guide member and a wall of the ink supply member to discharge air, which has entered the ink cartridge from the ink supply member, out of the ink cartridge when the ink inlet is inserted into the ink supply portion.

According to a seventh aspect of the present invention, there is provided an ink jet recording unit comprising a recording head having a plurality of ejection openings for ejecting ink, and an ink cartridge having a porous member for holding the ink supplied to the recording head. Wherein the recording head has an ink inlet for leading out ink from the ink cartridge, and the ink cartridge further has an ink guide member having one end pressed against the ink inlet and the other end pressed against the ink absorbing member, the ink guide member being made of a bundle of fibers each extending from the porous member toward the ink inlet.

According to an eighth aspect of the present invention, there is provided an ink jet unit in which an ink jet head and an ink cartridge are detachably connected to each other, wherein the ink jet head is for ejecting ink and the ink cartridge is for storing ink supplied to the ink jet head.

Wherein the ink cartridge has an ink absorbing member for holding ink, an ink guide member is provided between the ink absorbing member and an outlet for supplying ink to the outside, the ink guide member has a surface tension greater than that of the ink absorbing member, and a pressure loss in the ink guide member is only 20mm Hg or less, and an ink inlet of the ink jet head is connected to the ink guide member.

According to a ninth aspect of the present invention, there is provided a recording unit comprising a recording head for performing recording by ejecting ink and an ink cartridge for supplying ink to the recording head, which are detachably connected to each other. The ink cartridge has an ink guide member at a rear thereof, the ink guide member being connected to the ink cartridge to receive the supplied ink, the ink guide member having one end connected to an ink inlet inserted into the ink supply member and the other end pressed against the ink absorbing member, the ink cartridge having an ink absorbing member therein for holding the ink to supply the ink to the recording head, the ink inlet of the recording head being inserted into the ink supply portion, the ink supply portion having an outlet formed at a front end of the ink cartridge to form an ink supply passage communicating the ink guide member and the ink absorbing member. There is also an air passage for discharging air, the air passage being located between the ink guide member and a wall of the ink supply member when the ink cartridge is attached to the recording head.

The above and other objects, actions, features and advantages of the present invention will be further understood by reference to the following description of the embodiments in accordance with the accompanying drawings.

FIG. 1 is an isometric view of a prior art ink jet recording unit;

FIG. 2A is a cross-sectional view of a conventional ink jet recording unit in which a recording head is attached to an ink cartridge;

fig. 2B is a sectional view of a conventional ink jet recording unit in which the recording head and the ink cartridge are disassembled;

fig. 3A is a sectional view of an ink jet recording unit according to a first embodiment of the present invention, in which a recording head is separated from an ink cartridge;

fig. 3B is a sectional view of an ink jet recording unit according to a first embodiment of the present invention, in which a recording head is attached to an ink cartridge;

FIG. 4 is an isometric view of an ink guide according to the present invention;

fig. 5 is an enlarged sectional view of a connecting portion of an ink jet recording head and an ink cartridge according to a first embodiment of the present invention;

FIG. 6 is a detail view of the ink guide member shown in FIG. 4;

FIGS. 7A-7D are schematic illustrations of alternative embodiments of ink guides according to the present invention;

FIG. 8A is a cross-sectional view of an ink jet recording head with a valve element, wherein the recording head is attached to an ink cartridge;

FIG. 8B is a cross-sectional view of an ink jet recording head with a valve element, wherein the recording head is separated from the ink cartridge;

fig. 9A is a cross-sectional view of the ink jet recording unit with a valve element shown in fig. 8A, 8B, wherein the recording head is attached to the ink cartridge;

fig. 9B is a circuit diagram for explaining the fluid resistance in the ink jet recording unit with a valve element shown in fig. 9A;

fig. 10A shows the fluid resistance in the ink jet recording unit with a valve element shown in fig. 9A and 9B;

fig. 10B shows the fluid resistance in the ink jet recording unit with the ink guide according to the present invention;

fig. 11A is a graph illustrating the ink supplying capability of the ink jet recording unit with a valve element;

FIG. 11B is a graph illustrating the ink supply capability of an ink jet recording unit with an ink guide according to the present invention;

fig. 12 is a sectional view of an ink jet recording unit according to the present invention, in which a recording head is separated from an ink cartridge;

FIG. 13A is a cross-sectional view of an ink jet recording unit using a filter instead of an ink guide, in which the recording head is separated from the ink cartridge;

FIG. 13B is a cross-sectional view of an ink jet recording unit using a filter instead of an ink guide, in which the recording head is attached to the ink cartridge;

fig. 14A is a sectional view of an ink jet recording unit according to a third embodiment of the present invention, in which a recording head is separated from an ink cartridge;

FIG. 14B is the same as that shown in FIG. 14A except that the recording head is attached to the ink cartridge;

FIG. 14C is a cross-sectional view taken along line C-C of FIG. 14B;

FIG. 15 is an isometric view of an ink guide according to a fourth embodiment of the invention;

fig. 16 is a sectional view of an ink jet recording unit using a filter instead of an ink guide, in which a recording head is attached to an ink cartridge;

fig. 17A is a sectional view of an inkjet recording unit using a filter instead of an ink guide, in which a recording head is separated from an ink cartridge;

fig. 17B is a sectional view of the ink jet recording unit according to the present invention, in which the recording head is in a state of being connected to the ink cartridge;

fig. 17C is a sectional view of an ink jet recording unit according to the present invention, in which a recording head is attached to an ink cartridge;

fig. 18A is a front view of an ink jet recording cartridge according to the present invention in a package bag;

fig. 18B is a side view of the ink jet recording cartridge in a package bag according to the present invention;

fig. 18C is a side view of the ink jet recording cartridge according to the present invention;

fig. 19A is a side view of an ink jet recording cartridge according to the present invention; indicating a condition in which the ink cartridge was just left in an atmospheric environment at a high temperature;

fig. 19B shows a condition in which the ink cartridge is continuously maintained at atmospheric pressure at a high temperature;

FIG. 19C shows a state in which the ink cartridge has just been placed in an atmospheric environment at room temperature after the state shown in FIG. 19B;

FIG. 19D shows the situation after the situation shown in FIG. 19C when the sealing lid on the ink cartridge is opened;

FIG. 20A is a side view of an ink jet recording cartridge according to the present invention, showing the condition when the cartridge is just placed in an atmospheric environment at a high temperature;

fig. 20B shows a condition where the ink cartridge is continuously maintained at atmospheric pressure at a high temperature;

FIG. 20C shows a state in which the ink cartridge has just been placed in an atmospheric environment at room temperature after the state shown in FIG. 20B;

FIG. 20D shows a state in which the seal cover of the ink cartridge port is opened after the state shown in FIG. 20C;

fig. 21A is a top view of an ink jet recording cartridge according to the present invention;

FIG. 21B is a side view of an ink jet recording cartridge according to the present invention;

fig. 21C is a front view (i.e., ink outlet side) of the ink jet recording cartridge according to the present invention;

fig. 21D is a rear view (i.e., vent side) of the ink jet recording cartridge according to the present invention;

FIG. 22A is a cross-sectional view taken along line A-A of FIG. 21A;

FIG. 22B is a cross-sectional view taken along line B-B of FIG. 21B;

FIG. 22C is a cross-sectional view taken along line C-C of FIG. 21C;

FIG. 22D is a cross-sectional view taken along line D-D of FIG. 21D;

FIG. 23 is an enlarged view of an ink guide according to the present invention;

fig. 24 is a sectional view of an ink jet recording unit according to a sixth embodiment of the present invention;

fig. 25 is an enlarged sectional view of a connecting portion of an ink jet recording head and a cap cartridge according to a sixth embodiment of the present invention;

fig. 26 is an isometric view of a color inkjet recording unit according to the invention;

fig. 27 is an isometric view of a color ink jet recording head according to the present invention;

FIG. 28 is an isometric view of a portion of an ink jet printer according to the present invention;

fig. 29 is an isometric view of a personal computer in accordance with the invention.

Several embodiments are described in more detail below with reference to the accompanying drawings.

Example 1

Fig. 3A and 3B are sectional views of an inkjet recording unit 4 as a first embodiment of the present invention. The recording unit 4 includes two parts, i.e., a recording head 2 and an ink cartridge 3, which can be easily attached to each other as shown in fig. 3B and detached from each other as shown in fig. 3A.

The ink jet recording head 2 has a filter 43 at one end of an inlet 45 thereof, the inlet 45 serving as a connection portion to the ink cartridge. The filter 43 has a plurality of holes whose sizes are the same, and the filter 43 can block foreign substances in the ink when the ink cartridge 3 is attached to the recording head 2. The effective pore size of the filter 43 is in the range described below, i.e., the upper limit is such that the maximum effective diameter thereof is sufficient to prevent impurities in the ink from flowing into the recording head, and the pore size is selected depending on the size of the ejection opening formed in the recording head 2 on the other end of the fluid passage. On the other hand, the lower limit of the effective size of the orifices should be chosen depending on the pressure loss in the filter 43 when the ink flow is at its maximum, and its minimum size should be insufficient to affect the operation of the ink-jet printing. The pressure loss depends on the diameter of the fluid channel (i.e., ink channel) in the inlet 45 when the filter 43 is used. According to our experimental results, it is preferable to select the pore diameter of the filter to be 5 to 20 nanometers (μm).

The ink cartridge 3 has a porous member (ink absorbing member) 37 as an ink storage tank for storing ink, and an ink guide member 47 including fibers therein. Reference numeral 48 denotes a vent groove that communicates the inside of the ink cartridge with the atmosphere, and reference numeral 39 denotes an ink supply port that is connected to the ink inlet 45 of the recording head 2.

The ink guide may be used to direct ink in one direction into a device. In the present embodiment, the ink guide member is provided in the ink cartridge so that the ink is guided from the ink absorbing member to the ink supply portion. In this embodiment, the porous member 37 is a sponge-like ink absorbing member which is pressed into the ink absorbing portion of the ink cartridge.

In the drawing, the ink guide member 47 is supported by the support portion 41 of the ink cartridge, and the ink absorbing member is pressed by the inner side of the ink guide member 47 so as to be deformed. This deformation of the ink absorbing member 37 may create a strong surface tension effect at the point of contact, thereby gathering the ink in the vicinity of the ink guide member.

Therefore, the ink can be constantly supplied from the ink absorbing member by the ink guide member without air infiltration into the ink guide member, both when the recording head is detached from the ink cartridge and when a meniscus is formed on the surface of the end of the ink guide member. The end faces the ink inlet 45 of the recording head 2.

When the ink jet recording head 2 is fixed to the ink cartridge to form an ink circuit, the utilization of the ink stored in the ink cartridge can be improved by increasing the flow of the ink flowing into the ink guide and keeping the flow of the ink uninterrupted.

As shown in the present embodiment, in the case where the ink absorbing member 37 is pressed into the ink cartridge 3, the ink guide member 47 pushes the ink absorbing member 37 to deform the ink absorbing member 37 at the pressed portion and the vicinity thereof. Thereby, the ink can be gathered near the ink guide 47.

In the case of an ink absorber having a small compressibility or elastic modulus in the ink cartridge, the ink guide member is preferably press-inserted against the ink absorbing member to generate a deformation large enough to gather the ink at the deformed region.

In the present embodiment, "press-insertion" means that the ink guide member is put into the ink absorbing member by applying a force larger than a pressure generally used.

In general, in order to avoid a reduction in printing quality due to poor supply of ink to ink ejection ports (i.e., nozzles) and ink leakage, recording head ejection ports in an ink jet recording apparatus are maintained at a suitable water head pressure so as to be lower than atmospheric pressure. It is necessary to maintain the ink pressure in the recording head 2 at a lower head pressure than the atmospheric pressure (generally in the range of-150 mm hg to 0mm hg or preferably in the range of-100 to-30 mm hg as compared with the atmospheric pressure). In the present embodiment, the porous member 37 is maintained in a pressure range of 40 to 60 mmHg in order to adjust the state of the ink so as to form a negative pressure.

The ink jet recording head 2 is detachably mounted on the ink cartridge 3 by a pair of coupling means 34 projecting from one end of the ink cartridge 3, the coupling means forming projections parallel to each other for being fixed in recesses (not shown) of the ink jet recording apparatus. The filter member 43 of the ink jet recording head 2 is pressed against the ink guide member 47 of the ink cartridge 3 by applying a predetermined pressure.

The magnitude of the pressure can be easily determined according to the length of the projecting portion of the ink inlet 45 of the recording head 2 and the depth of one supply portion. The depth is the distance from the outer surface of the ink cartridge 3 to one of the contact surfaces of the ink guide 47. The contact surface is for contacting one end of the ink inlet 45 of the recording head 2.

Thus, an ink channel 36 for supplying ink to the inlet of the recording head 2 through the ink guide member 47 is formed by the connection.

According to the configuration of the present invention, since the ink passage formed by the contact between the ink inlet 45 and the ink supply portion 39 is sealed by the O-ring 35 installed at the connecting portion of the recording head 2, the leakage and volatilization of the ink from the contact point can be kept to a minimum.

Fig. 4 shows the structure of the ink guide 47.

The ink guide 47 is a bundle of fibers serving as an ink supply member for supplying ink from the ink cartridge 3 to the recording head 2 when the components are connected to each other, and the ink guide 47 is composed of a plurality of fibers arranged in parallel to the ink supply direction so that ink is supplied in one direction. The ink guide 47 has two regions in the diameter direction (i.e., the direction perpendicular to the ink supply). I.e. it has an outer zone where the supply of ink can be relatively low and an inner zone where the ink guiding capacity is good. The fibers are tightly encapsulated with a binder to form an outer region 52, while in the inner region 51, there is sufficient space between the fibers to allow ink to pass through.

The term "bundle of fibers" refers to a bundle of resin fibers (such as polyester, nylon, polypropylene, polyethylene, cellulose or polyurethane) or a bundle of fibers of other materials (such as metal, wool and coke) or a mixture of materials of these resin fibers and fibers. Further, the phrase "tightly packed fibers" refers to filling a binder or filler material in the spaces between the fibers, and may also refer to fusing the fibers to each other with heat or pressure.

The interior regions may have different sizes of spaces for ink vias, whereby the interior regions may include different sizes of ink vias. That is, one type of ink via diameter is larger than the fiber diameter, while another type of ink via diameter is smaller than the fiber diameter. In this case, the ink can therefore be supplied uniformly through the cross section of the inner region in a direction perpendicular to the ink-guiding direction.

It is preferred to form the fibers from a material such as polyester, nylon, polypropylene, polyethylene, cellulose, and polyurethane because these materials are chemically stable when wetted. One of the criteria used to evaluate the wetting characteristics of a material is its ink contact angle. That is, when the ink contact angle is small, it can be considered as a preferable material. Materials having a large ink contact angle can also be used as ink-guiding materials through hydrophobic treatment. However, this is not recommended from the viewpoints of requiring additional steps, increasing the product cost, and the like.

Alternatively, other materials such as metals, wool, coke, and mixtures of at least two selected from the foregoing materials may be used as the fibrous material.

The ink guide 47 should be provided as a part of the ink passage so that ink can be fed along the passage, and the ink guide 47 should also have a sufficient constant physical strength so as to maintain its shape under the pressure generated by the ink inlet of the recording head. Therefore, it is preferable to process the element into a bundle of fibers.

The upper limit of the fibre thickness for the ink-guide depends on the degree of contact between the ink-guide and the filter at the above-mentioned ink inlet. From this viewpoint, it is preferable to use a fiber having a thickness of 0.05 μm or less. In addition, a lower limit thickness of the fibers for the ink-guiding member of 0.01 μm or more than 0.01mm is preferable because a bundle of fibers can be easily produced at a lower cost. Therefore, in the present embodiment, a polyester fiber having a thickness of 0.03mm is used.

In this embodiment, a resin binder is used to secure a bundle of fibers. The circumferential surface of the fiber bundle and its surroundings are hardened by the use of the binder and thus a hardened zone is formed.

The polyether polyol polyurethane is impregnated as a resin binder into the circumferential surface of the fiber bundle, but is not limited to this, and for example, a melamine binder may be used.

The means for forming the hardened region 52 for fixing the fiber bundle is not limited to the above-described resin binder. Heat or pressure may also be used to fuse the outer circumferential regions of the fiber bundle to form the stiffened region 52. In addition to the stiffening zone, the fiber bundle may also be covered with other materials. Compared to the two different approaches described above, the use of an adhesive is more suitable than the use of a covering approach for the following reasons. In the case of forming the hardened zone, the step of forming the fiber bundle and the step of spreading the binder over the fiber bundle may be performed almost simultaneously. In the case of using the covering means, since the step of covering the fiber bundle with the covering means must be performed under the condition that the fibers are bonded until the covering is uniform and finally uniform physical strength is formed, the process of manufacturing the ink guide member is complicated.

Other methods of bonding the fibers may be used, the problem being that the bonded fiber bundle may be held in the direction of ink supply to the fibers and the shape of the fiber bundle maintained so that the ink passes uniformly through the fiber bundle to achieve a continuous ink supply.

Each fiber in the ink-directing member is aligned in a direction parallel to the direction of ink flow in the member. The surface tension of the formed fiber bundle is higher than that of the porous member. In this case, the surface tension of the porous member includes a force when the porous member is pressed by the ink guide member.

Therefore, when the ink guide 47 is pressed against the ink-filled porous member 37, the ink naturally reaches the top of the ink guide quickly. Since the surface tension of the fiber bundle forms a meniscus, the ink in the top of the ink guide does not leak therethrough.

It is difficult to fix the range of the hardened region in the radial direction of the ink guide because the hardened region is formed by infiltrating the adhesive into the outer region of the ink guide. However, we define a rougher boundary between the hardening zone and the inner zone, within which the adhesive does not penetrate. Comparing these two zones, the ink flows more smoothly through the inner zone than through the hardened zone, because the gaps between the fibers of the hardened zone are filled with resin or the like, while the inner zone is not filled. The inner zone includes a large gap having a diameter larger than the fiber and a small gap having a diameter smaller than the fiber. These gaps are mixed in the inner region to penetrate ink.

Fig. 5 shows a connecting portion between the ink recording head 2 and the ink cartridge 3.

As shown in fig. 5, the contact surface between the filter member 43 of the ink jet recording head and the ink guide member 47 of the ink cartridge 3 satisfies the condition that the contact area of the filter member 43 is smaller than the contact area of the ink guide member 47. Since the region C of the recording head 2 is pressed against the inner region B of the ink guide 47, the condition of the contact surface is determined. The region C serves as an ink passage in the recording head. According to this structure, a uniform pressure contact state can be maintained in the region corresponding to the effective diameter of the seal member.

As a pressure contact condition which can prevent the ink supply amount from decreasing, it is preferable to bring the entire area of one end of the ink inlet port of the recording head into contact with the inner region B of the ink guide member to ensure a contact state therebetween.

The ink actually flows over a contact surface that includes a portion in which the ink inlet of the recording head is in contact with the hardened region of the ink guide. However, the contact surface C preferably does not include this hardened region because it would affect the characteristics of high-speed printing or the like.

Due to manufacturing tolerances, assembly accuracy, or the like, the filter member of the recording head may not be pressed smoothly against the fiber bundle. However, in order to supply ink to the recording head efficiently, the fiber bundle and the filter should be pressed evenly against each other with their ends. Therefore, in order to form a uniform contact surface, the contact surface between the filter member and the ink guide member needs to have sufficient elasticity to compensate for manufacturing errors, assembly accuracy, or the like. From this point of view, it is preferable to press the filter member against the inner region for stable ink supply, as compared with the hardened region.

As described above, the ink guide member 47 has a hardened region having a thickness of about 1mm in the radial direction, which is formed by impregnating the outer circumferential surface of the ink guide member with the adhesive. Therefore, in the present embodiment, a contact position is determined such that the outer circumferential surface of the ink guide member 47 and the outer circumferential surface of the filter member 43 are separated by a distance (i.e., a separation amount in a perpendicular direction to the outer circumferential surface of the filter member in a plane) of 0.5mm or more, preferably 1mm or more, thereby avoiding a press-contact state between the filter member 43 and the hardened region of the ink guide member 47. It is possible to separate them by a distance greater than 0.5mm or less than 1mm, according to practical experience, without affecting their function, but with reduced effective diameter of the filter, it is not effective in high speed printing.

According to the above configuration, when the ink cartridge is separated from the recording head, the ink can be concentrated in the ink supply portion of the ink cartridge, so that the ink absorbing member adjacent to the ink supply portion can prevent the infiltration of air. Therefore, when the ink cartridge is reconnected to the recording head, ink can be smoothly supplied from the ink cartridge to the recording head.

The ink absorbing member has a portion which is deformed by the pressure applied by the fiber bundle, so that it is not necessary to insert the recording head ink inlet into the ink absorbing member to deform it in order to concentrate the ink on a portion of the ink absorbing member. Only the pressure contact state is required for such an ink flow from the ink guide to the ink inlet. Thus, air is not flown into the area around the ink supply portion, and a recording unit having an appropriate ink passage from the ink cartridge to the recording head is provided.

In the case of a high printing speed, a high ink supply speed is required, and at the same time, the ink cartridge 3 is kept at a certain negative pressure. Therefore, the ink flow damping is preferably as small as possible. The ink jet assembly of the present invention solves this problem.

Two points are considered, namely stable ink supply is realized when the recording head is connected; to prevent ink leakage when the recording head is removed, the ink guide member 47 is specifically defined in this embodiment from (i) a state of connection between the recording head and the ink cartridge in which sufficient ink should be constantly supplied to the recording head; (ii) a separated state in which ink leakage from the detached ink cartridge is to be prevented. Therefore, the characteristics of the ink guide member are specifically discussed in accordance with the above-described state.

(separation state)

When the recording head is removed from the ink cartridge, the ink outlet side of the ink guide may be directly exposed to the external environment. Therefore, the ink cartridge should hold the ink without ink leakage when its ink outlet is directed downward or the like. In this embodiment, the ink guide member and the sponge (ink absorbing member) exert the holding force that holds the ink stored in the ink cartridge. That is, the ink guide member and the sponge generate a negative pressure sufficient to hold the ink without causing the ink to leak from the ink supply portion of the ink cartridge due to the surface tension thereof.

In view of achieving continuous ink supply, the surface tension of the ink guide member and the sponge is determined in accordance with the conditions in which the acceleration of the ink flow or the like affected by its own physical conditions, such as the mass and viscosity of the ink when the ink cartridge is moved, are taken into consideration. Therefore, the surface tension of the sponge should preferably be in the range of 40 mm Hg or more, in this embodiment 50 mm Hg. On the other hand, the surface tension of the ink-guiding member is preferably 1.5 times greater than that of the sponge, and is preferably in the range of 85 to 400 mmHg.

In connection with the movement of the ink cartridge, there is a possibility that the ink flow may be accelerated as described above. Therefore, the higher the surface tension of the ink cartridge, the better the ink is retained. However, if the surface tension is too high, a high suction force is required to draw the ink cartridge out of the ink during the re-inking operation. Therefore, the upper limit of the surface tension of the ink cartridge should preferably be 400 mmHg or less. In this embodiment, the ink guide is formed with a surface tension of 200 mm hg.

On the other hand, the ink guide is thus defined. That is, the fibers in the inner region of the ink guide are arranged to leave a fixed space therebetween and have a fixed ink holding force shown by the following formula, which is derived from our experimental results:

h_a＝4.2/ds (1)

in the formula "h_a"represents the surface tension (mm hg) of the ink holding force serving as an ink guide; and "ds" represents the average distance between a fiber and an adjacent fiber in a direction parallel to the cross-sectional plane of the ink guideThe value is obtained.

As mentioned above, the sponge preferably has a surface tension of 40 mm Hg or more, and the ink-directing member has a surface tension "h_aPreferably 200 mm Hg or more, so that the ink can be smoothly supplied from the sponge to the ink guide member. As a result, the value of "ds" according to the formula (1) is preferably less than 0.05 mm.

On the other hand, the surface tension is preferably less than 400mm Hg for the reasons mentioned above. Therefore, the value of "ds" is preferably greater than 0.01 mm.

The diameter Φ d of each fiber of the ink-guiding member should preferably be in the range of 0.01mm to 0.05mm, because if the fiber diameter is too small, it is difficult to manufacture a fiber bundle without high manufacturing costs. If the fiber diameter is too large, the fiber does not have sufficient elasticity for contact with the filter of the recording head.

The fiber density of the ink-guiding member is preferably 100 to 2500 [ roots/mm ] according to the formula shown below²Range of (c):

in the formula:

"ds" denotes the average distance between the fibers as defined above;

"N" represents the density of the fibers [ root/mm²Angle (c); "d" represents the diameter of the fiber.

The distance between the fibers is the average distance between the surfaces of the fibers. That is, the distance is determined by enlarging a cross-sectional view of the fiber bundle and by taking a small number of fiber samples (30 fibers in the present embodiment) and measuring each interval between each fiber and the circumferential surface of the adjacent fiber.

The resulting fiber diameter is the average diameter of the fibers obtained by the steps of enlarging the picture and by taking a small number of fiber samples, calculating the diameter of each fiber at different points and averaging the calculated data.

The axial length of the ink-guiding member, i.e. the length corresponding to each so-called fibre, should preferably be between 2mm and 6 mm. If the ink-guide is too short, it is difficult to manufacture the fiber bundle and some of the fibers inside the fiber bundle are exposed. On the other hand, if the ink guide is too long, it is difficult to form a sufficient flow of ink between the recording head and the ink cartridge in the attached state.

(connection state)

In the case where the recording head is connected to the ink cartridge, in order to feed ink from the ink cartridge to the recording head, the ink flow pressure loss Δ P at one point of the ink guide member at the time of maximum flow velocity_fPreferably 20mm hg or less. This value corresponds to the maximum flow rate for the condition of at least 64 jets in the recording head. If the pressure loss Δ Pf is larger than this value, the print quality may be affected by the difference between the print loads. The pressure loss Δ Pf of the entire system for supplying ink from the ink cartridge to the recording head has a value of 100 mmhg or less.

Under the condition that the pressure loss Δ Pf of the ink guide is in the above range, the size of the ink guide can be determined as follows.

Fig. 6 is a schematic view showing the size of the ink guide member of the present embodiment.

The length "L" of the ink guide 47 is its dimension parallel to the direction of flow of the ink stream flowing at a flow rate U (mm/sec.) the actual diameter D of the ink guide_eGenerally corresponding to the diameter of the ink vias in the ink guide, so the actual diameter De is represented by:

in the formula:

"D" represents the effective diameter of the ink via, [ mm ], which corresponds to the diameter of inner region 51; "d" represents the average diameter of each fiber in inner region 51, [ mm ]; "n" represents the number of fibers.

The above-mentioned length "L" and diameter "De" can also be defined by the following formulas using the above-mentioned pressure loss Δ Pf:

in the formula:

u-W/S, where "S" represents the cross-sectional area of the ink passage, [ mm [ [ mm ]²And "W" represents the flow rate of the ink stream, [ mm ]³Sec ]; "k" represents a damping coefficient of the ink guide having the above-described structure, [ mmAq · sec ], which is about 4.2 × 10^-3(this value is derived from our experimental results).

In this embodiment, the cross-sectional area "W" is at a value corresponding to the maximum and minimum amounts of ink ejected from a series of heads26〔mm³Sec to 512 mm³Sec.

The length "L" may be determined in accordance with the above definition, and may be determined in accordance with the size of the ink cartridge or the amount of ink stored in the sponge. On the other hand, the diameter "De" may also be determined based on the distance "ds" and the effective diameter "D". The effective diameter "D" should preferably be between 1mm and 18mm in accordance with the pressure loss of the filter member of the recording head and the ink flow rate W described above.

Therefore, the ink guide can take any structural size having the above-defined limits, but the various parts of the detailed design for manufacturing the ink cartridge, including the size, volume, etc., are generally determined prior to the ink guide. Therefore, the ink guide should be sized to be insertable into the limited space in the ink cartridge and thus have the desired characteristics.

Table 1 below lists several examples of designs for ink guides under the following conditions. That is, the ink guides are sized as follows: the length L is 6mm, the outer diameter o D' is 6mm, and the effective diameter o D of the thickness excluding the adhesive is 4.8mm, in which case the desired parameters of the ink-guide are as follows: the ink holding power ha is 200 mm hg; the pressure loss Δ Pf at a flow rate W of 42mm/sec is 10 mm Hg or less. In addition, the distance between fibers "ds" derived from "ha" is 0.021 in accordance with the above definition.

TABLE 1

	φd	N	n	De	S	u	ΔPf	Results
									(1)	0.01	1041	18830	0.11	16.6	2.5	5.0	The value of n is preferably large
(2)	0.02	595	10764	0.087	14.7	2.9	9.5	Medium and high grade
									(3)	0.03	385	6757	0.080	13.2	3.2	12.4	Unsuitable for delta Pf > 10
(4)	0.04	269	4863	0.078	12.0	3.5	14.4	Unsuitable for delta Pf > 10
									(5)	0.05	198	3590	0.078	11.0	3.8	15.6	Unsuitable for delta Pf > 10

According to the results shown in Table 1, when the ink guide was made according to the design items (1) and (2), the results of the ink guide satisfied the above conditions. The pressure loss Δ Pf of the design (1) is smaller than that of the design (2), but the design (2) is preferable from the viewpoint of saving the manufacturing cost because the ink guide according to the design (2) has a smaller amount of fibers. The designs (3) to (5) are not suitable for manufacturing the ink guide because the pressure loss Δ Pf is higher than the upper limit value of the above-described required condition by-10 mm hg at the time of the maximum ink flow rate.

According to the above description, the ink guide member should be dimensioned as described above so as to avoid ink leakage in the separated state and to smoothly supply ink from the ink cartridge to the recording head in the connected state. It is worth noting that these properties cannot be obtained by using only materials known to have ink absorption capacity due to surface tension.

After inserting the ink inlet of the recording head into the ink supply portion of the ink cartridge, attention should be paid to the fact that the space between the ink supply portion and the pressure contact point should be filled with ink and the ink passage should be isolated from the outside. In this state, the connection portion may be sealed with an elastic member such as an O-ring. However, air tends to enter into some portion of the ink path during the connection process because the ink inlet port may push air into the interior of the ink cartridge. Therefore, bubbles are generated in the pressure contact area of the sponge and the fluid resistance is increased in the conventional structure, resulting in failure of the recording head to obtain a sufficient amount of ink.

One of the conventional ways to solve this problem is to use a valve mechanism that closes the ink passage when the recording head is removed. In general, in order to avoid generation of air bubbles during connection of the recording head to the ink cartridge, such a valve mechanism is filled with ink. On the other hand, the ink guide of the present invention does not cause the above-described problems.

The ink guide is not limited to a cylindrical shape, but may have various shapes, as in the embodiment shown in fig. 7A-7D.

Each of the ink guides shown in fig. 7A-7D has its own shape that is suitable for directing ink out of the sponge with relatively little resistance, because the sponge-side end of the ink guide has an interior region that is larger than the surface area of the cylindrical member, as shown. Thus, the ink guide having the improved shape can be completely pressed against the sponge 37.

It is necessary here to explain the liquid flow resistance in relation to the structure of the ink cartridge.

In the case of performing high-speed printing, the ink jet recording head 2 must eject a large number of ink droplets per unit time, and the ink cartridge must maintain its negative pressure value constant to meet the requirements of the recording head 302. The flow resistance in the ink path should therefore be less than a maximum.

Fig. 8A and 8B show cross-sectional views of a conventional recording unit as a comparative example of the present invention, in which an ink cartridge 604 is provided with a valve mechanism 614 serving as a portion connected to a recording head 602. In these figures, fig. 8B shows the recording head 602 separated from the ink cartridge 604 and fig. 8A shows both reversibly connected by two hooked steel plates 617 which protrude in parallel from one end of the ink cartridge 604, and the recording head 602 is fixed by inserting them into connection holes (not shown in the figure) located in the recording head 602.

The recording head 602 has an ink inlet 605 inserted into an ink supply portion 611 of the ink cartridge 604 and a filter 603 provided at an end of the ink inlet 605 for preventing inflow of debris. As shown, an O-ring 608 is coaxially fitted over the ink inlet 605, the O-ring 608 sealing off the ink passage from the outside.

The ink cartridge 604 includes an ink absorbing member 609 in which ink can be accommodated. The density of the ink absorbing member 609 can be adjusted to obtain a negative pressure for supplying ink to the ink jet recording head 602.

A mesh filter 613 is provided on the ink supply port side of the ink channel. Pressure is applied to the ink absorbing member 609 to produce a high-density compressed portion in the ink absorbing member 609. Therefore, the compression portion maintains its balance, thereby smoothly guiding the ink from the ink absorbing body to the recording head.

With the valve mechanism 614 functioning downstream of the filter 613 in the ink cartridge 604, when the ink cartridge is separated from the recording head 602, ink leakage from the ink cartridge 604 does not occur.

Fig. 9A shows an ink channel from the ink cartridge 604 having the valve mechanism shown in fig. 8A and 8B to the recording head 602, and fig. 9B is an equivalent circuit corresponding to the ink channel.

In these figures, the ink jet recording head is regarded as a load, the negative pressure of the ink is regarded as a voltage, the ink flow rate is regarded as a current, the ink flow resistance is regarded as a line resistance, and the flow resistance in the ink cartridge 604 is regarded as an internal resistance. Therefore, in order to supply a large amount of ink to the inkjet recording head 602, the flow resistance should be reduced.

Fig. 10A shows the proportions of portions of the flow resistances of the ink jet recording head 602 and the ink cartridge 604 having the valve mechanism as shown in fig. 8A and 8B as comparative examples. Each reference number corresponds to that in fig. 8A and 8B.

Fig. 10B shows the proportions of the portions of the flow resistance of the ink cartridge 3 of the present embodiment. The ink cartridge 3 of the present embodiment does not have the filter 613 and the valve mechanism 614 as in the comparative example. Further, the flow resistance of the ink guide 47 is relatively low, and therefore, the recording head 2 can always receive an appropriate amount of ink during high-speed printing. Each number in the figure corresponds to that in fig. 3.

Fig. 11A and 11B show changes in ink supply capability to the recording head when the valve mechanism of the comparative example (fig. 11A) is used or the ink guide of the present example (fig. 11B) is used.

In these figures, the letter "P" represents an image of a printed pattern including lines and solid areas. And the letter "C" represents an alphabetical printing area and the letter "B" represents a solid image printing area.

During the printing stop, the pressure in the ink channel is almost maintained in the range of-60 mm hg to-80 mm hg with respect to the outside atmospheric pressure due to the surface tension for holding the ink in the ink absorbing member.

According to the measurement result in the printing stop state, the pressure of the ink cartridge having the valve mechanism was about-60 mm hg (fig. 11A), and the pressure of the ink cartridge having the ink guide member was about-80 mm hg with respect to atmospheric air pressure (fig. 11B).

When an image including a portion requiring a large amount of ink (i.e., a solid portion) is printed, as shown in fig. 11A, a pressure loss due to flow resistance is observed in the ink cartridge having the valve mechanism. On the other hand, the ink cartridge according to the present invention does not cause such a trouble, that is, the pressure loss is very small, and thus is suitable for high-speed printing and the like.

Further, it is also noted that the ink cartridge according to the present embodiment can maintain its excellent reliability despite the long-term deactivation. A typical inkjet recording apparatus is liable to generate air bubbles in the ink channels of the inkjet recording unit after being stopped for a long time, resulting in unsatisfactory printing effects. That is, air bubbles will impede the flow of ink to the recording head, resulting in the recording head not being able to print after extended periods of inactivity. If several air bubbles, typically saturated with vapor, are introduced into the ink channel during periods of inactivity, the air bubbles increase in volume due to the dilution of the vapor by the permeation of air into the ink channel through the walls at the external atmospheric pressure. To solve the above problem, it has been proposed to install a timer for calculating the dead time on the head and calculate the time. If the period of deactivation exceeds the above time, the pump is activated to remove air bubbles in the ink.

However, under severe environmental conditions, such as very high temperatures and relatively low temperatures, the size of air bubbles sometimes reaches a limit value within the above period, and these air bubbles prevent the ink from flowing to the recording head, so that the printing capability thereof is degraded. In particular, as shown in fig. 8A, in the case where the valve mechanism 614 is operated when the ink jet recording head 602 is attached to or detached from the ink cartridge 601, air corresponding to the range of valve movement or the like may be introduced from the outside into a certain area of the ink channel. Therefore, under the above circumstances, the valve mechanism causes adverse conditions.

In another aspect, an ink cartridge has an ink guide with an ink contact area. Therefore, a meniscus can be formed in all the ink contact areas, which prevents the inflow of air bubbles when the recording head is separated from the ink cartridge. Further, according to the present invention, the filter of the recording head is in direct pressure contact with the ink guide, thus reducing an area that may allow air infiltration compared to the valve mechanism. Therefore, the ink cartridge of the present invention can remove air at the time of connection to prevent air from being present in the connection portion or in the ink channel.

(example 2)

Fig. 12 is a cross-sectional view of a second embodiment of a recording unit according to the present invention. In this embodiment, the ink guide 47 is provided in the same manner as in embodiment 1 except that the element 47 is slidable in the support portion 41 to be in contact with the filter 43 of the recording head 2 in the direction of the arrow D. The ink guide member 47 is pressed against the ink absorbing member 37 compressed in the ink chamber, and thus the member 47 receives a reaction force directed to the ink supply portion 39. However, as shown in the drawing, the edge of the ink guide 47 stops against the stopper 49.

When the ink inlet 45 of the recording head is inserted into the ink supply portion 39 of the ink cartridge, the ink inlet 45 comes into contact with the ink guide 47. In example 1, the amount of pressure applied by the ink inlet to the ink guide depends on the relationship therebetween. On the other hand, when the ink guide member is provided as a slidable member in example 2, the magnitude of the force depends on the state where the ink inlet is pressed into the ink absorbing member and the sliding distance of the ink guide member when the ink inlet is inserted.

With the above-described structure, when the ink guide is designed and machined to the wrong size in the longitudinal direction, since these dimensional errors can be compensated by sliding the ink guide, the filter and the ink guide are firmly pressed against each other.

Therefore, when the ink guide member 47 is fixed in a non-sliding manner, a gap between the ink inlet and the ink guide member, which is formed by an incomplete connection between the ink inlet and the ink guide member due to a structural defect of the ink guide member (for example, an uneven end surface and an insufficient length due to poor machining accuracy), will obstruct the flow of ink along the ink channel. On the other hand, when the ink guide is too long, the ink inlet generates overpressure on the ink guide, and therefore, the fibers in the ink guide deform and form a region through which ink cannot flow. As a result, the ink cannot be supplied to the recording head sufficiently or stably.

Therefore, when the ink cartridge is repeatedly attached to and detached from the recording head, a stable pressure contact condition is generated according to the sliding mechanism of the ink guide and an inflow of air during the connection is prevented. In addition, since these dimensional errors can be compensated for by sliding the ink guide, the ink guide has an accurate size, and thus, the cost of the product is reduced.

The ink guide should be configured to be slidable by at least 0.1mm or more (i.e., a reduction in the sliding distance) because the filter can be brought into contact with the ink guide by changing the shape of the contact surface of the ink guide, which can be achieved by changing the amount of pressure applied thereto.

However, the elastic deformation causes some troubles in that when the filter is pressed against the ink-receiving member for a long time (several months or several years), the contraction surface of the filter by the ink-guiding member gradually creeps (i.e., plastically deforms), and the force pushing the filter open (i.e., repulsive force) gradually decreases. Thus, the filter and the ink guide member exert force unevenly on each other, and the contraction surface thereof becomes worse, so that air can enter the ink channel and hinder the ink from flowing toward the recording head. As a result, the ink ejection conditions of the recording head deteriorate.

In order to solve the above-described creep phenomenon, the ink guide member is slidably supported in the ink cartridge and is pressed against the filter by an accepting force as a repulsive force of a sponge in the ink cartridge.

Therefore, in order to obtain the required 5g/mm of ink guide member at the contact point²Should have a sliding distance of at least 0.1mm or more in the ink cartridge. It should be noted that it is desirable that the sliding distance be at least 0.1mm or more in view of correcting errors in the dimensions of the ink cartridge or the ink guide member when manufacturing the same.

The upper limit of the slidable distance of the ink guide is 3mm or less, preferably 2mm or less, more preferably 1mm or less. Further, the ink absorbing member has a different elastic modulus from the ink guide member, but is also elastically deformed. Therefore, the upper limit of the slidable distance of the ink absorbing member is 3mm or less, preferably 2mm or less, and most preferably 1mm or less from the viewpoint of preventing the creep phenomenon in which the force trying to push the ink guide member away is gradually reduced in the same manner as the ink guide member.

In the case of using another ink absorbing member having a low compressibility and a low green modulus, the ink guide member is usually press-inserted into the ink absorbing member, and in this case, a lower limit of the slidable distance may also be determined depending on the magnitude of the force applied to the ink absorbing member by the ink guide member.

By "press-fit" is meant that a greater force is applied than by press-contact. Under the pressure-touch condition, the ink guide member is pressed against the ink absorbing member. That is, the ink guide member is pushed into the ink absorbing member and brought into close contact therewith.

As described above, the filter of the ink inlet of the recording head and the slidable ink guide can be better brought into contact with each other than the fixed type because the ink guide can be slid in the direction of inserting the ink inlet into the ink cartridge to be better fitted with each other. Thus, the ink channel from the ink cartridge to the recording head can be formed better, so that air does not easily enter the ink channel, and the ink supply amount is not reduced. Thus, high-quality printing can be achieved.

In order to make the filter of the recording head and the ink guide member contact better, the ink guide member is preferably elastically deformed to some extent, i.e., moved in opposite directions by 1 bar (1 mm in cross section) against the stress²) Reversible size response of stress in the range of 100gf/mm³To 500gf/mm³In the meantime.

Further, it is also noted that the ink cartridge of the present embodiment can produce satisfactory ink supply effects due to its structure after being reconnected to the recording head. That is, the ink guide member is always in press-contact with the sponge body to satisfy the necessity that the ink inlet area of the sponge body in the ink cartridge is always in a state of being compressed by something when the recording head is removed. On the other hand, a recording unit having a structure in which the sponge in the ink cartridge is directly compressed by the recording head cannot maintain a compressive force on the sponge when it is removed, and thus air is introduced into the sponge when the recording head is reconnected to the ink cartridge.

As shown in fig. 13, according to the ink cartridge structure of the present embodiment, the sponge is compressed and supported in the ink cartridge by the inner wall of the ink cartridge. However, the ink guide member is pressed against the ink outlet side of the sponge body with a higher compressive force than the inner wall. The press-contact point is the most deformed portion of the sponge, and thus ink tends to concentrate on the press-contact point.

When a sponge having a relatively low compression state or a low elastic modulus is used in the ink cartridge, it is preferable to press the ink guide into the sponge to ensure the above deformation, thereby concentrating the ink at the press insertion point.

So-called "press-insertion" is the application of a force greater than that applied by a press-touch.

In addition, the ink guide member may have a structure shown in fig. 13 in which the filter 38 is in press contact with the ink absorbing body 37.

More specifically, the inventors of the present invention have devised not only the above-described structure in which the ink adsorbed in the ink absorbing member is concentrated on the ink supply portion side, but also a structure as shown in fig. 13. In this structure, the filter 38 on the connecting portion (ink supply portion) 39 is press-fitted with the ink absorbing member 37, so that the ink is always concentrated on the ink supply portion 39 side.

However, the inventors realized through experiments that the ink jet unit having such a structure has the following problems.

As shown in fig. 13, when the recording head 2 is connected to the ink cartridge 3, the ink channel 36 can be isolated from the outside atmosphere by sealing the connection portion with the O-ring 35. When the ink inlet 45 is inserted into the ink supply portion 39, the O-ring compresses air that forms the interior of a portion of the ink channel 36 toward the mesh filter 38. Thus, air moves toward the mesh filter 38 and then enters the filter. In the mesh filter 38, the air maintains the shape of air bubbles and hinders ink channels or diffusion into the sponge 37 (indicated by arrows or letters a in the drawing). As a result, ink cannot be smoothly supplied from the ink cartridge 3 to the recording head 2 and the printing quality is deteriorated.

The above problems can be effectively solved by using the ink guide of the present invention. That is, the ink guide prevents the movement of air pressed into the ink absorbing member side in the ink cartridge due to its strong surface tension.

However, in order to more effectively prevent the inflow of air, it is preferable that the ink cartridge has the following structure.

(example 3)

The ink jet recording unit of this embodiment of the present invention is described in detail below with reference to fig. 14A to C.

The ink jet recording unit of this embodiment is the same as that of embodiment 1 or 2 except for the air communication channel. The channels are provided in the ink jet cartridge so that the formation of the above-described air layer can be prevented.

Fig. 14A-C are cross-sectional views of the ink jet recording unit, in which fig. 14A shows the recording head 2 removed from the ink cartridge 3; FIG. 14B shows their interconnection; fig. 14C is a partial view taken along line C-C' in fig. 14B.

The ink guide 47 is interposed between an opening (i.e., ink inlet) 391 formed at the front side of the ink cartridge and a sponge (i.e., porous member) 37 fitted inside the ink cartridge 3. The ink guide 47 is supported by a support region 41, which is a sponge-side portion of the inner circumferential surface of the ink supply portion 39. As shown in the drawing, approximately a majority of the ink guide 47 is supported by the support region 41 in the axial direction thereof at the circumferential surface of the ink guide 47.

On the other hand, the remaining circumferential surface portion is exposed to the air in the ink cartridge 3. That is, only one end of the ink guide 47 is in contact with the sponge 37, and the other end is a free end exposed to the outside atmosphere through the ink inlet 391 of the ink cartridge 3. Further, one edge of the free end of the ink guide member 47 is supported by a support plate 49, and the support plate 49 stands on the inner circumferential surface of the boundary between the support area 49 and the ink inlet 391 and projects in the radial direction, so that the ink guide member 47 cannot be drawn out from the ink inlet.

On the inner circumferential surface of the support area 41, a groove 42 is formed in the ink supply direction. These grooves 42 serve as air passages between the ink guides 47 and the support area 41. Further, the inside of the ink cartridge has a plurality of projections (ribs) 3a extending in the ink supply direction. Therefore, the sponge is supported by these ribs 3a, so that a space connected to the groove 42 is formed between the sponge 37 and the inner wall of the ink cartridge 3.

In addition, an air communication port 48 is provided in the rear side wall of the ink cartridge 3, through which the air passage 42 and the above-mentioned space communicate with the outside atmosphere.

Therefore, during the connection of the recording head 2 and the ink cartridge 3, when the ink inlet of the recording head 2 is pressed against the ink guide 47, the air in the space between the ink guide 47 and the connection point is pressed toward the ink guide 47.

In this case, however, air can be discharged to the outside of the ink cartridge 3 through the air passage formed by the groove 42, the above-described space, and the air communication port 48, and it is also noted that the ink is introduced from the sponge 37 to the end of the recording head 2 by the surface tension of the ink guide 47, so no air is introduced into the ink guide 47. It is also noted that since the ink guide has a region stiffened by an adhesive or the like, no ink, air bubbles, mixture of the two, or the like can pass through or past the outer circumferential surface of the ink guide and into the ink passage or ink guide.

Further, at the time of separating the recording head 2 and the ink cartridge 3, the ink guide 47 is released from the pressure of the inlet portion of the recording head 2, and then moved toward the opening 391 of the ink cartridge by the restoring force of the sponge 37, i.e., the force to restore the original state. As shown in the drawing, in the ink cartridge 3, there is formed a support means 49 erected on the inner circumferential surface of the interface between the support area 41 and the ink inlet 391, the support means 49 is protruded in the radial direction to stop the ink guide member 47 so that the ink guide member 47 cannot be protruded from the opening 391, and the edge of the head side end of the ink guide member 47 is uniformly pressed against the support member 49.

Thus, air cannot enter the ink cartridge 3 from the opening. It should be noted that even if the recording head 2 and the ink cartridge 3 are separated, the sponge 37 is pressed against the ink guide 47, so that it is impossible to form an air layer between the contact surfaces thereof.

Therefore, the ink cartridge 3 of the present embodiment is structured such that air can be released to the outside from the ink supply portion through the inner space of the ink cartridge 3, the air communication port 48, and the air passage 42 formed between the ink guide 47 and the support area 41, while the ink guide 47 is in press contact with the sponge 37. Therefore, the ink cartridge 3 of the present embodiment allows air to be uncontrollably introduced into and discharged from it even if its internal pressure with respect to the external atmospheric pressure increases or decreases.

Therefore, the ink cartridge 3 of the present embodiment does not cause troubles such as ink leakage from the opening or the connecting portion, and causes ink to penetrate into the ink channel. Also, the ink cartridge 3 of the present embodiment can introduce air from the outside in accordance with a decrease in the amount of ink due to ink consumption.

(example 4)

The recording unit of the present embodiment is the same as that of embodiment 1, 2 or 3 except that an air passage is provided on the circumferential surface of the ink guide instead of the groove 42 formed in the support portion 41 of the ink cartridge.

Fig. 15 is a cross-sectional view of an ink guide used in the present embodiment.

The ink guide member is comprised of an interior region 51, a bonding region 52 and a plurality of channels 42. Each groove 42 is formed on the circumferential surface of the ink guide. The groove 42 can be easily formed by applying pressure to the circumferential surface formed by the fiber bundle in the step of preparing the fiber bundle.

Thus, since the ink guide member can be manufactured by a simple method and the manufacturing accuracy can be improved, this structure can provide an ink cartridge having better cost efficiency than other embodiments. On the other hand, when the ink cartridge has a groove in a support region on an inner side, it is relatively more difficult to cut or machine the support region.

(example 5)

Fig. 16 shows an ink jet recording unit according to another embodiment of the present invention, in which an ink cartridge has the same structure as any one of the solid fence examples 1 to 4 except that it has two different air passages.

The first air passage is the same as that of embodiment 3, i.e., the first passage includes: a first spaced area formed by a plurality of projections (i.e., ribs) on the inner wall 3a of the ink cartridge 3, which communicates with the outside atmosphere through the air communication port 48; and a second spaced area formed by a groove 42 between the ink guide 47 and the surface of the support area 41.

The second air passage includes a spacing region (i.e., a third spacing region) formed by at least one air communication port 81 (two communication ports are shown in the drawing) opening on the front side toward the recording head. The air communication port 81 opens to an ink supply portion 39 into which the ink inlet 45 of the recording head 2 is inserted.

When the recording head 2 and the ink cartridge 3 are connected, the outer circumferential surface of the ink inlet 45 of the recording head 2 is in contact with the corresponding inner circumferential surface of the ink supply portion 39 of the ink cartridge 3. Also at this time, the protrusion 82 located on the recording head 2 closes the air communication port 81 of the ink cartridge 3.

Therefore, air pressed on the ink guide 47 by the ink inlet 45 of the recording head 2 at this time can be discharged to the outside atmosphere through the first and second air passages. It should be noted that air cannot enter the ink guide 47 and ink cannot flow out from the ink guide 47 to the air passage because the circumferential surface of the ink guide 47 is hardened by the adhesive.

According to the above configuration, the second air passage is in a state of communicating with the outside until the recording head is completely connected with the ink cartridge. On the other hand, after the connection, the second air passage is tightly closed by the protrusion, thereby sealing the connection portion between the recording head and the ink cartridge.

The above ink cartridge has two different air passages, but this is not a limitation, and if the second air passage is sufficient to discharge air to the outside, only the passage may be used on the ink cartridge.

In addition, the second air passage may be formed in the ink cartridge in such a manner that the sponge is compressed by the filter without the conventional valve mechanism or the ink guide of the present invention. By preventing the generation of bubbles at the contact point between the filter and the sponge, it is possible to stably supply ink from the ink cartridge to the recording head. An example of such an ink cartridge is shown in fig. 17A-17C. In the drawings, fig. 17A shows a state before connection, in which the recording head 2 is removed from the ink cartridge 3; fig. 17B shows a state where air is discharged along the connecting route; fig. 17C shows a state after connection.

According to the structure shown in fig. 17A to 17C, air can be discharged from the ink supply portion 39 to the outside. However, the ink cartridge with the ink guide member is preferred because the ink supply stability is better than that of the ink guide member replaced with the filter.

Compared to examples 1 and 2, the ink cartridge with the air passage as described in examples 3 to 5 can be used in a severe environment, for example, can be placed in a wide application area.

The cartridges are typically packaged during shipping using packaging as shown in fig. 18A-18C. Fig. 18A and 18B are an end view and a side view, respectively, of the ink cartridge in a packaged state. Fig. 18C is a sectional view of the ink cartridge in a packaged state to show a condition of safety protection.

The packaging 1625 is an aluminum laminate heat-sealed bag to prevent evaporation of ink during shipping and long-term storage of the cartridge.

In the package 1625, the hole 391 (i.e., the ink outlet) of the ink cartridge 3 is sealed with a sealing tape 1626 to prevent ink from leaking out of the ink cartridge in a harsh environment during transportation. The sealing tape 1626 is attached to the cartridge 3 by heat fusion, but can be easily removed when in use.

Sealing tape 1626 is made of polyethylene, nylon, polyether, aluminum foil, and mixtures thereof. An existing composite laminate film may also be used as the material of the sealing tape 1626.

In addition, it is preferable to use the same material as the ink cartridge 3 in order to establish a good contact at the joint between the sealing tape and the ink cartridge.

The sealing tape 1626 used in the present invention is a multi-laminate sealing tape composed of polypropylene, aluminum, and polyester, depending on the material composed of polypropylene. A gasket for absorbing leaked ink is placed between the sealing tape 1626 and the ink guide 47. One end of the washer 1627 is adhered to the sealing tape 1626 by fusion.

The ink absorbing gasket 1627 serves to absorb ink leaked from the ink guide 47, thereby preventing scattering of a small amount of leaked ink when the sealing tape is peeled off from the ink cartridge.

The material of the ink absorbing washer 1627 may be selected from any material having ink absorbing and retaining properties, such as PVA (polyether polyol polyurethane) polypropylene, polyester, polyethylene, expanded resins such as polyurethane and nylon, and fibrous materials such as paper or cloth.

In an embodiment of the present invention, expanded resin of polypropylene is used for the ink absorbing gasket 1627, which is suitably fused with the sealing tape 1626 by heating. The ink cartridges of examples 1-4 were secured during the ink dispensing process according to the above-described sealing means and tape.

In addition, an extreme increase in the ambient temperature or an extreme decrease in the ambient temperature may occur during the dispensing of the ink cartridge. Changes in these environmental factors sometimes affect the internal conditions of the ink cartridge regardless of the presence of the sealing means. The state of the word effect of the cartridge is explained below with reference to fig. 19A-19D.

In the above figures, fig. 19A shows a state when the ink cartridge is left in the air at a high temperature; fig. 19B shows a state in which the ink cartridge is kept in the air at a high temperature; fig. 19C shows a state when the ink cartridge is left in the air of room temperature after the state shown in fig. 19B, and fig. 19D shows a state when the sealing tape is removed from the ink cartridge after the state shown in fig. 19C.

In the case where the external environment of the ink cartridge changes as shown in fig. 19A, the pressure in the space 1628 between the sealing tape 1626 and the ink guide 47 increases and is greater than the external vapor pressure of the ink cartridge, thereby causing air in the ink cartridge 3 to escape as much as possible into the atmosphere.

In a structure in which the ink guide 47 is in close contact with the ink support area 41 or a narrow space exists therebetween or in a structure in which air is prevented from circulating through a space between the ink guide 47 and the ink support area 41 by the surface tension of the introduced ink, the air enters the ink guide and presses the ink rearward.

The compressed ink is typically subjected to a surface tension force as shown in fig. 19C which forces air to the front edge of the ink guide 47 causing air to gradually escape from the space between the ink guide 47 and the support 41 and, finally, the pressure in the space 1628 is equal to the ambient atmospheric pressure.

When the ambient temperature and atmospheric pressure return to the original conditions, a force is created to introduce air into the above-mentioned space, and thereafter the force acts on the ink in the ink absorbing member 37 made of a porous material for holding the ink. Therefore, the ink leaks from the ink guide 47.

Often, leaked ink can be quickly absorbed by the ink gasket. However, in the event that the cartridge is placed in a harsh environment, a certain amount of ink may remain in space 1628, such that the amount of ink that leaks is greater than the absorption capacity of the ink gasket.

In the case shown in fig. 19D, when the user sealing tape is removed from the ink outlet of the ink cartridge, the ink may be splashed into the air and soil the room.

FIGS. 20A to 20D are explanatory views showing the ink cartridge of example 3, in which an air path 41 is formed for improving the condition shown in FIGS. 19A to 19D.

Fig. 20A shows a state where the ink cartridge is left in the air at a high temperature; fig. 20B shows a state when the ink cartridge is kept in high-temperature air; FIG. 20C shows a state where the ink cartridge is left in air at room temperature after the state shown in FIG. 20B; and fig. 20D is a state where the sealing tape is removed from the ink cartridge after the state shown in fig. 20C.

An ink cartridge is newly designed to discharge air in the space 1628 to the outside atmosphere through an air passage 42 and the inside of the ink cartridge. The air passage 42 is formed between an ink guide 47 for supplying ink and a support area 41 for supporting the ink guide 47.

It will be readily appreciated from the foregoing that air communication between the space and the outside atmosphere can be effected without any restriction, whether by increasing or decreasing the pressure of the air in the space relative to the outside atmosphere. Thus, the occurrence of leakage in the ink cartridge as shown in fig. 19D can be prevented, and therefore, the reliability of ink distribution in the ink cartridge of the present invention is improved.

The excellent performance of the ink cartridges of examples 1 to 5 can be exhibited in a small-sized ink jet recording apparatus, and thus they have a novel structure.

(example 6)

An example of the specific dimensions of the ink cartridge in the present embodiment will be described below.

Fig. 21A to 21D show the appearance of the ink cartridge. In these drawings, fig. 21A is a top plan view, fig. 21B is a side view, fig. 21C is a view from the ink outlet port side, and fig. 21D is a view from the air communication port side.

In addition, FIGS. 22A, 23B, 23C and 22D are cross-sectional views taken along line A-A of FIG. 21A, line B-B of FIG. 21B, line C-C of FIG. 21B and line D-D of FIG. 21B, respectively.

In the present embodiment, the diameter of the support portion 41 for supporting the ink guide is 6.85 mm.

It is preferable to adopt a structure in which the ink guide member is disposed in a central region of a cross-sectional plane perpendicular to a direction in which ink is supplied from the ink cartridge. Thus, the ink guide member is brought into press contact with the central region of the ink absorbing member.

By using the above-described structure, the ink can be moved uniformly toward the ink guide member while the ink guide member guides the ink stored in the ink absorbing member.

As a result, the ink stored in the ink absorbing member is uniformly distributed, and therefore, the ink can be continuously supplied to the recording head during ink supply according to ink consumption, and furthermore, the ink supply efficiency can be improved.

In the present embodiment, the ink cartridge coincides with the center area of the ink absorbing member in the center area, but is not limited to this structure. For example, when the two central regions do not coincide with each other, the ink guide member may be pressed against the central region of the ink absorbing member to obtain the same effect as the present embodiment.

Fig. 23 shows a detailed structure when the shape of the ink guide 47 having a diameter of 6.8mm is not a circle but an ellipse.

One advantage of an oval ink guide is that it is more difficult to fall out of the support area 41 than it is to have a circular shape.

In the present embodiment, each fiber of the ink guide 47 is composed of polyester fiber having a diameter of 0.3 mm. Furthermore, polyether polyol polyurethanes are used as binders for the preparation of fiber bundles.

Fig. 24 is a cross-sectional view of the recording head 2 and the ink cartridge 3 which have been shown in fig. 21A to 21D and fig. 22A to 22D to explain the holding in the connection relationship therebetween by the connection mechanism 37.

Fig. 25 shows a contact position between a filter and an ink guide of an ink inlet according to an embodiment of the present invention. In the present embodiment, the outer circumferential surface of the ink inlet 45 is located in the hardened area a, and the area C where the ink passage is formed is located in the inner area B of the ink guide.

As shown in fig. 24, in the present embodiment, the ink inlet 45 protrudes from the contact surface between the recording head 2 and the ink cartridge by a height of-3.2 mm, and the depth from the contact surface to the ink guide 47 is 2.3 mm. Thus, the ink guide 47 can slide a distance L of 0.9 mm.

Therefore, by pressing the area C on the recording head side where the ink channel 36 is formed against the filter 43 and the inner area B of the ink guide 47 except for the hardened area, the press-contact condition is uniformly formed in the area corresponding to the effective diameter of the filter.

In addition, the pressure-contact state between the filter of the ink inlet and the ink guide member can be adjusted, thereby preventing the occurrence of the creeping phenomenon by making the ink guide member slidable in the inlet direction into which the recording head is inserted. The filter and the ink guide can thus be pressed against one another in a suitable manner.

Thus, the ink passage 36 from the ink cartridge to the recording head can be formed more reliably than in other solutions, so that high-quality printing can be maintained without reducing the ink supply amount in conjunction with air or the like.

In addition to the above, as shown in fig. 22D, the ink cartridge of the present embodiment has an ink guide member provided in a central region of a cross section taken perpendicular to a direction in which ink is drawn out from the ink cartridge. In this case, the filter is pressed against the central region of the ink guide.

With the above configuration, when the ink guide member collects the ink stored in the ink absorbing member, the ink stored in the ink absorbing member can be uniformly moved to the central area.

Therefore, with respect to the ink remaining uniformly distributed in the ink absorbing member, the ink can stably flow to the recording head during ink supply according to the consumption condition of the ink. Thereby improving the efficiency of ink supply.

In the present embodiment, the central region of the ink cartridge and the central region of the ink absorbing member are concentric with each other, and are not limited to this structure. For example, in the case where these regions are not concentric with each other, the center region of the ink guide member can be pressed against the center region of the ink absorbing member, and the same effect as that of the present embodiment can be obtained.

Additionally, a method of refilling an ink cartridge with ink includes the following steps. The air in the ink cartridge is sucked by the air 48; ink is filled into the ink cartridge through the ink outlet, and the ink guide member is placed into the outlet in a pressure-balanced manner.

When the pressure inside the ink cartridge is reduced by the above-described method, air may be sucked through the ink outlet provided with the ink guide member, and then the ink may be filled into the ink cartridge from the air vent.

Another way of refilling can be derived in the same way, for example it comprises the following steps: an orifice is punched in a component of the ink cartridge through which the ink is injected into the ink cartridge with a liquid injector, such as a syringe, in which case the orifice may be sealed with a sealing means, such as a resin.

The connection mechanism for connecting the refill is less complicated than the valve member, i.e. the comparative embodiment with a valve member of embodiment 1. When refilling is required by sucking air or filling ink through the ink outlet, the ink cartridge of the present invention, i.e., the ink cartridge having the ink guide at the ink outlet thereof, can be easily filled with ink.

Therefore, the ink cartridge of the present invention is very popular from the viewpoint of refilling ink into the ink cartridge and from the viewpoint of environmental protection.

Example 7

Needless to say, the ink cartridge of the present invention can be used for an ink jet recording apparatus of any color. Fig. 26 and 27 show one embodiment of an ink cartridge. The recording unit 4 shown in fig. 26 has a recording head 2 and ink cartridges Y, M, C, and Bk, while fig. 27 shows the ink cartridges as viewed from the opposite direction.

As shown in these figures, the Y, M, C, and Bk ink cartridges are each provided with an ink guide 47, so that the recording head 2 receives ink through the ink guide 47.

In fig. 27, the outer end of the ink guide 47 is exposed to the outside atmosphere through an opening connected to the recording head. In this case, ink does not leak even if the opening faces downward.

Example 8

Fig. 28 is an isometric view of a printing mechanism using the ink jet recording unit as described above, which is placed on a personal computer of the present invention, and fig. 29 is an isometric view of the personal computer with the built-in printing mechanism shown in fig. 28.

In fig. 28, only the printing mechanism is derived, in which the ink jet recording unit 4 includes the recording head 2 and the ink cartridge mounted on the carriage 1. An engaging portion is formed at one end of the holder 1, which faces the recording head 2. The engaging portion is slidably engaged with a lead screw 6 rotatably supported by a case frame 5, and the case frame 5 serves as a frame of the body. At the other end of the bracket 1, a guide member (not shown) is provided, which is slidably engaged in a guide rail 7 formed on the box frame 5. In addition, the bracket 1 moves back and forth along an axis with the rotation of the lead screw 6, and the posture is kept stable.

The ink jet recording head 2 is moved synchronously with the above-described carriage 1 moving forward and backward while ejecting ink droplets toward the recording medium 14 to record one line of information. The recording head includes, minute liquid ejection orifices, fluid channels and a thermal energy application portion formed on a part of the fluid channels; the thermal energy generating member for generating heat on the thermal energy acting portion generates thermal energy applied to the ink. Therefore, ejection of ink droplets can be performed by using the thermal energy generated by the thermal energy generating member.

After recording one line of information by sweeping the carriage 1, the recording medium 14, for example, one recording sheet, is moved by a distance corresponding to one line of information, for example, and then the recording unit starts recording the next line. The transfer of the recording medium 14 is performed by a pair of rotatable bodies. It comprises a conveying roller 15 and a gear roller 16 pressed against the conveying roller 15.

To make this more concrete, it will be described in detail below.

The recording medium 14 having an information recordable surface is directed toward the ejection opening of the recording head 2, the recording medium 14 is pressed against the conveying roller 15 by the spur roller, the conveying rotation is driven by the paper feeding motor, and the recording medium is conveyed by a sufficient distance to reach the recording position.

After the recording is completed, the recording medium 14 is pressed against the output roller 19 and is moved out of the apparatus by the rotation of the output roller 19.

The conveying roller 15 and the output roller 19 are both driven by a sheet feeding motor. And the driving force is transmitted through a series of reduction gears 20.

Reference numeral 21 denotes a paper sensor for detecting the presence or absence of the recording medium 14, and reference numeral 22 denotes an image interrupter as a home position sensor which detects that the carriage 1 is in the home position or in the non-home position interrupted or opened by a shuttle 1A. The shuttle 1A is disposed on the carriage 1 and moves together therewith.

The printing mechanism described above is one of the recording head 22 and the ink cartridge 3. Or an ink jet unit in which the above components are incorporated in one unit is mounted on the carriage 1, the output recovery operation is performed by a suction mechanism provided at the home position of the carriage 1. So that a path for supplying ink from the sponge 37 of the ink cartridge 3 to each ink path in the recording head 2 can be formed in an excellent manner.

Fig. 29 is an isometric view of a personal computer with the built-in printing mechanism of fig. 28.

As shown in fig. 10, the personal computer 200 has a notch with an opening cover formed at the deep end of the keyboard portion. Thus, an ink jet printing unit or the like can be detachably set in the slot.

When the ink cartridge 3 or the like needs to be replaced, there are two ways to remove the ink cartridge from the personal computer 200 as shown in the figure. The first method is sufficient to remove the ink cartridge 3 as an integral part of the inkjet recording unit 4, and the other is to remove only the ink cartridge 3 from the personal computer 200.

When the ink jet recording unit 4 is removed as a whole, as shown in the drawing, after the unit 4 is removed from the computer 200, the recording head 2 is removed from the ink cartridge 3, and then, for example, the recording head is attached to a new ink cartridge instead of the old one, and on the other hand, when only the ink cartridge 3 is removed, the ink cartridge may be replaced without removing the recording head 2 from the computer 200.

In addition, one of the methods of refilling an ink cartridge includes the steps of: the air in the ink cartridge is sucked through the air communication port 48; the ink cartridge is filled with ink through the ink inlet, and the ink guide member is disposed at the ink inlet through a pressure balance.

When the pressure inside the ink cartridge is reduced in the above manner, the ink cartridge can be refilled from the air communication port by suction through the ink outlet at which the ink guide member is provided.

Another method of refilling ink is also envisaged, for example, comprising the steps of: a hole is made in the piece of the cartridge and ink is injected into the cartridge through the hole using a liquid syringe. In this case, the hole may be sealed with a sealing means such as resin.

The connecting device connected to the refilling device is less complicated than the valve mechanism of the comparative example as example 1. The ink cartridge having the ink guide member at the ink outlet side according to the present invention can be easily refilled with ink when a step of sucking air or refilling ink through the ink outlet is required.

Therefore, the ink cartridge according to the present invention is most suitable for recording from the viewpoint of refilling the ink cartridge with ink and environmental problems.

Claims (19)

1. An ink cartridge having an ink storage portion with an ink absorbing member for storing ink, an ink supply opening for supplying ink from said ink storage portion to an outside of said ink storage portion, and an air communication port for communicating said ink storage portion with an atmosphere, and being detachably mounted on an ink jet recording head having an ink supply tube, said ink cartridge comprising:

an ink guide member mounted between an ink absorbing member of said ink storing portion and said ink supply opening;

a holder for slidably supporting the ink guide;

a restricting member for preventing the ink guide member from falling out of the ink supply opening to an outside of the ink cartridge.

2. The ink cartridge according to claim 1, characterized in that: the holder has a groove on an inner surface thereof in an ink supply direction.

3. The ink cartridge according to claim 1, characterized in that: the ink guide member has a groove on an outer surface thereof in an ink supply direction.

4. The ink cartridge according to claim 2 or 3, characterized in that: the groove communicates with the air communication port through an internal space of the ink cartridge.

5. The ink cartridge according to claim 1, characterized in that: the ink guide member has a first end portion in contact with the ink absorbing member and a second end portion facing the ink supply opening, and when the ink cartridge is mounted to the ink jet recording head, the second end portion is pressed against the ink supply tube of the ink jet recording head, and the ink guide member is slid toward the side of the ink storing portion accommodating the ink absorbing member.

6. The ink cartridge according to claim 5, characterized in that: the distance that the ink guide slides to the ink storing portion side in a state where the ink cartridge is mounted to the ink jet recording head is in a range of 0.1mm to 3 mm.

7. The ink cartridge according to claim 5, characterized in that: the second end of the ink guide member has an area larger than an area of a filter mounted on an ink supply tube of the ink jet recording head.

8. The ink cartridge according to claim 7, wherein: the ink guide member and the pressure-contact portion of the ink supply tube are positioned inside the holder member so as to be positioned within the circumference of the ink guide member.

9. The ink cartridge according to claim 1, characterized in that: the ink guide includes a fiber bundle and has a hardened region along an outer peripheral surface of the ink guide to hold the fibers together.

10. The ink cartridge according to claim 1, characterized in that: the ink guide includes a fiber bundle, and the fiber bundle is formed by infiltrating an adhesive into an outer peripheral surface of the ink guide.

11. The ink cartridge according to claim 1, characterized in that: the surface tension of the ink guide member is larger than that of the ink absorbing member, and the pressure loss of the ink guide member is 20mmAq or less.

12. The ink cartridge according to claim 1, characterized in that: the surface tension of the ink guide member is in the range of 85mmAq to 400 mmAq.

13. The ink cartridge according to claim 1, characterized in that: the average size of the distance between the fibers in the ink guide is in the range of 0.01mm to 0.05 mm.

14. The ink cartridge according to claim 1, characterized in that: the length of the ink guide member in the ink supply direction is in the range of 2mm to 6 mm.

15. The ink cartridge according to claim 1, characterized in that: the ink-guiding member has a region in which the density of the fibers is 100 to 200 fibers/mm²Within the range of (1).

16. The ink cartridge according to claim 1, characterized in that: the effective diameter of the ink guide member is in the range of 1mm to 18 mm.

17. The ink cartridge according to claim 1, characterized in that: the ink supply opening of the ink cartridge in a housing is sealed by a seal which can be easily removed when the ink cartridge is used.

18. The ink cartridge according to claim 17, wherein: the seal is a laminated aluminum film.

19. The ink cartridge according to claim 1, characterized in that: the ink guide member is formed of a fiber bundle arranged in an ink supply direction.