DE9321138U1 - An ink jet recording apparatus using a recording unit having an ink cartridge having an ink induction element - Google Patents

Description

Inkjet recording device using

a recording unit with an ink cartridge, which

has an ink inducing element

The present invention relates to an inkjet recording device/ more precisely, an ink cartridge (hereinafter also referred to as an ink tank) for storing ink to be supplied to an inkjet head, a recording unit in which the ink cartridge and the inkjet head are integrated, which are detachably connected to one another, and the inkjet recording device, to which the recording unit can be detachably mounted. In the following description, the term "recording" covers the printing of letters, images or the like on textile material, paper, plastic films or the like.

Various types of recording devices have been proposed, on which a recording head is mounted, which operates according to one of the following methods: dot writing method, thermal recording method, thermal transfer method and ink jet method. The recording head records letters, images

or the like on a recording medium/such as paper. Among these methods, the ink jet recording method is one of the non-impact methods and comprises the steps of ejecting ink droplets and depositing these ink droplets on the recording medium. Therefore, a recording device using a recording unit operating according to this method can perform high-speed and high-density recording. Such devices have therefore been used as printers or as output terminals of an information processing system, i.e., for example, copying machines, facsimile machines, printing machines, word processors, work stations or the like, or they have been used as mobile or portable printers of personal computers, host computers, optical disks or video equipment or the like.

When an ink jet recording device is used in these systems, the ink jet recording device is designed to meet the respective specific functions and conditions of these systems. Miniaturization of the size of the information processing system is one of the major demands today. Therefore, the recording unit and the main body of the ink jet recording device using this unit must also be miniaturized.

While such miniaturization is carried out on an actual apparatus basis, the recording unit etc. must retain the function that has been conventionally known from the unit or must have additional functions. In order to meet these requirements, various recording units and various recording

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devices have been proposed in which such a unit is mounted.

One of these embodiments is first explained in connection with Figure &eeacgr;- .

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

It is to be understood that the ink jet unit is not limited to the embodiment described above. For example, there is also an ink jet unit having an ink cartridge integrally connected to the ink jet head. When the former type of ink jet head is used, the ink cartridge is designed to be replaceable, while the ink jet head is fixed or detachably mounted on the carriage.

When the recording head (ink jet head) and the ink cartridge are mounted on the carriage as described above, it is necessary to provide the ink cartridge with a mechanism that generates a negative pressure. In the following description, "a negative pressure" is generally defined as a condition in which the water column pressure of the ink is maintained at a value that is sufficiently lower than the atmospheric pressure to prevent leakage of ink from

the nozzles of the recording head. As a negative pressure generating mechanism provided in the ink cartridge, a porous member is used as an ink absorbing member, which generates a capillary force of the porous member. When using such a porous member, as described in, for example, Japanese Patent Application Laid-Open No. 2-187364, the ink cartridge has such a structure that the ink inlet portion of the recording head is pressurized into the ink absorber of the ink cartridge to increase the efficiency of ink consumption, that is, to reduce the residual amount of ink in the ink absorber.

According to the above-described construction, the capillary force of the porous member can be locally increased by deforming the ink absorber at a part around the ink inlet portion, thereby inducing the ink into the vicinity of the ink inlet portion. In this way, the ink supply is promoted so that the residual amount of the ink in the ink absorber decreases.

In the case of the detachable type recording unit (ink jet unit), there is a possibility that the user replaces the empty ink cartridge with a new one. There is also a possibility that the recording head can be replaced with a new head or the empty ink cartridge can be reused. There is also a possibility that the user separates the parts more than necessary. Therefore, it is difficult to predict the situation in which the recording head or the ink cartridge is detached and attached. At the stage of separation or attachment, a certain amount of air may enter the ink cartridge.

trone and prevent an ink path from being formed between the recording head and the ink cartridge.

The detachable type recording unit as described in, for example, Japanese Patent Application Laid-Open No. 2-187364 has the following problems, particularly in the case where the ink inlet portion of the recording head is press-fitted into the ink absorber to effectively utilize the ink. It has been found that the recording head has difficulty in absorbing the ink from the ink cartridge after the ink cartridge is connected to the recording head and before the ink cartridge is used up.

In this situation, the flow of ink to the recording head often cannot be restored by an ejection recovery operation in which ink is sucked out of the ejection port of the recording head, so that it is difficult to completely use up the ink. It has been found that the biggest cause of these problems in the above situation is the reason described below.

Figures 2A and 2B show one of the embodiments of the ink jet recording apparatus for explaining this reason. Figure 2A shows the connected state of a recording head 2 and an ink cartridge 3, while Figure 2B shows the detached state of these two components.

As the figures show, an ink jet unit 4 is manufactured by connecting the recording head 2 via a pair of

by parallel connecting claws {not shown) is detachably connected to the ink cartridge 3.

At the joint, the ink inlet portion 40 of the recording head 2 is inserted into a cylindrical joint portion 39 used as an ink supply portion. The ink path 36 can be isolated from the outside atmosphere by an O-ring 35 which seals the joint portion and is made of ethylene-propylene rubber or the like.

The porous member (i.e., an ink absorber such as a sponge material) 37 occupies the interior of the ink cartridge 3 to store ink supplied to the recording head 2. The porous member has the ability to hold the ink.

The density of the porous member is adjusted, and the water column pressure of the recording head 2 is adjusted to be lower than the atmospheric pressure to prevent ink leakage.

In the ink jet recording head of the above-described embodiment, a part of the ink absorber adjacent to the connecting portion 39 is directly exposed to the external atmosphere when the recording head 2 and the ink cartridge 3 are in the detached state. In this case, the ink absorber 37 induces air while the deformed ink absorber 37 returns to its original shape, so that the part of the ink absorber 37 adjacent to the connecting portion 39 of the ink cartridge 3 can be filled with air bubbles or ink 38 containing bubbles when the

The recording head 2 and the ink cartridge 3 are separated from each other.

When the recording head 2 is reconnected to the cartridge 3, the ink absorber 37 forms an air region in the part adjacent to the ink supply section 39. This air region prevents an ink path E from being formed.

Furthermore, when the ink inlet portion 40 of the recording head 2 is inserted into the ink cartridge 3, the air in the ink supply portion may be compressed into the ink absorber, and this compressed air also prevents the formation of the ink path E.

Therefore, under these conditions, an undesirable recording state may be generated due to a reduced ink flow or the interrupted ink path.

In order to solve the problems described above, mechanical devices for controlling the inflow of air into the ink path have been proposed in various documents, for example, in Japanese Patent Application Publication No. 5-238016. This document discloses a fiber sleeve in a portion protruding from the recording head. An inner end of the sleeve communicates with the ink chamber of the head, while an outer end thereof comes into contact with an ink absorber of the ink reservoir when the recording head is connected to the ink reservoir. According to the construction described above, the sleeve functions as a filter and prevents air from being induced into the chamber of the recording head.

However, this document does not contain any proposal regarding the solution of the problem that air enters the ink cartridge during the execution of the separation and reconnection of the recording head and the ink cartridge.

There is also a thought of arranging a valve mechanism for closing the ink outlet to prevent air from flowing into the ink path during separation and reconnection. However, compared with a conventional recording unit, a method for manufacturing a recording unit provided with such a valve mechanism involves higher production costs and more parts. In addition, the resulting product is larger in size and has poor performance. This reduces the advantages of such a movable type of recording unit.

In addition to the problem that air can easily enter the ink cartridge during the separation and reconnection of the recording head and the ink cartridge, the following points must also be considered with such a detachable type of recording unit:

(i) Ink leaks from the ink connection portion when the recording head is removed;

(ii) the appropriate amount of ink supplied from the

Ink cartridge to recording head plays a role; and

(iii) the efficiency in terms of consumption of the ink stored in the ink cartridge must be taken into account.

The present invention can therefore solve a variety of the problems described above that occur in a detachable recording unit in which the recording head is detached from or connected to the ink cartridge.

The present invention aims to provide an ink cartridge with low cost and high reliability that prevents ink leakage and ensures a stable ink supply after a recording head and an ink cartridge are separated and connected.

Furthermore, according to the invention, an ink jet recording unit is to be created which has the ink cartridge described above.

Furthermore, an ink jet recording device is to be provided in which the above-described recording unit with ink cartridge is used.

According to the first aspect of the present invention, there is provided an ink cartridge having an ink storage portion with a porous member for storing the ink and an ink supply portion for supplying ink from the ink storage portion to the outside of the ink cartridge, comprising:

an ink inducing element disposed between the ink storage section and the ink supply section

and is formed as a fiber bundle, each fiber being arranged parallel to the ink supply direction.

According to the second aspect of the present invention, there is provided an ink cartridge having a porous member for storing ink to be supplied to a recording head through an ink inlet portion of the recording head, the ink cartridge comprising:

an ink inducing member having a first end portion brought into pressure contact with the ink inlet portion and a second end portion brought into pressure contact with the porous member, the ink inducing member being formed as a fiber bundle of which each fiber is directed from the second end portion to the first end portion.

According to the third aspect of the present innovation, an ink cartridge is provided which comprises:

a porous member for storing ink; and an ink supply portion having an outlet used for supplying ink to an ink jet head and into which an ink inlet portion of the ink jet head is inserted, the ink supply portion having an air path for allowing air introduced into the ink cartridge from the ink supply portion to escape to the outside of the ink cartridge when the ink inlet portion is inserted into the ink supply portion.

According to the fourth aspect of the present invention, there is provided an ink jet recording apparatus, in which a recording unit having a recording head with a plurality of ejection openings

and an ink cartridge having a porous member for storing ink, wherein the recording unit has an ink inlet portion for leading ink from the ink cartridge, and the ink cartridge has an ink inducing member, one end of which is in pressure contact with the ink inlet portion and the other end with the ink absorber, and wherein the ink inducing member consists of a fiber bundle and a carriage is provided for detachably mounting the recording unit.

According to the fifth aspect of the 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 ink, the recording unit performing recording by ejecting ink onto a recording medium, the ink cartridge having an ink absorber for holding ink and an ink inducing member disposed between the ink absorber and an outlet for supplying ink to the outside, the capillary force of the ink inducing member being higher than that of the ink absorber and the pressure loss of the ink inducing member being 20 mmAq or less.

According to the sixth aspect of the present invention, there is provided an ink jet recording apparatus using a recording unit having a recording head for 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 to each other, the recording head having an ink inducing element,

which is in pressure contact with the ink cartridge and serves to receive the supplied ink, and wherein the ink cartridge comprises an ink absorber for storing the ink to be supplied to the recording head, an ink supply section into which an ink inlet of the recording head is inserted and which has an outlet formed at the front end of the ink cartridge to form an ink path connecting the ink inlet to the ink absorber, an ink inducing member having one end in pressure contact with the ink inlet inserted into the ink supply section and another end in pressure contact with the ink absorber, and an air supply path arranged between the ink inducing member and a wall of the ink supply section and serving to allow air introduced into the ink cartridge from the ink supply section to escape to the outside of the ink cartridge when the ink inlet section is inserted into the ink supply section.

According to the 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 ink to be supplied to the recording head, the recording head having an ink inlet for supplying ink from the ink cartridge, and the ink cartridge having an ink inducing member having one end in pressure contact with the ink inlet and another end in pressure contact with the ink absorber, the ink inducing member being composed of a fiber bundle in which each fiber is directed from the porous member to the ink inlet portion.

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

the ink cartridge comprises an ink absorber for holding stored ink and an ink inducing element disposed between the ink absorber and an outlet for supplying ink to the outside, wherein the capillary force of the ink inducing element is higher than that of the ink absorber and the pressure loss of the ink inducing element is 20 mmAq or less, and wherein an ink inlet of the ink jet head is in contact with the ink inducing element.

According to the ninth aspect of the present invention, there is provided a recording unit in which a recording head for recording by ejecting ink and an ink cartridge for supplying ink to the recording head are detachably connected to each other, the recording head having an ink inducing portion which is in contact with the ink cartridge and serves to receive the supplied ink, one end of the ink inducing element is in contact with the ink inlet inserted into the ink supply portion and another end of the ink inducing element is in pressure contact with the ink absorber, and the ink cartridge having an ink absorber for storing the ink to be supplied to the recording head and an ink supply portion into which an ink inlet of the recording head is inserted and which has an outlet formed at a front end of the ink cartridge to form an ink supply path which the ink inducing

decorative element with the ink absorber, and a
to form an air path for allowing air to escape to the outside, said air path being arranged between the ink inducing element and a wall of the ink supply section when the recording head is connected to the ink cartridge.

The innovation is described in detail below using examples of implementation in conjunction with the drawing. Shown are:

figure

Figure 2A Figure 2B Figure 3A

Figure 3B is a perspective view of an ink jet recording unit of the prior art;

a cross-section through a conventional inkjet recording unit, wherein a recording head is connected to an ink cartridge;

a cross-section through a conventional ink jet recording unit , with a recording head removed from an ink cartridge;

a cross-section through an ink jet recording unit according to the first embodiment of the present innovation, wherein a recording head is removed from an ink cartridge;

a cross section through an inkjet drawing unit according to the first embodiment of the present

15

Innovation in which the recording head is removed from the ink cartridge;

Figure &eeacgr; a perspective view of an ink inducing element according to the present

ing innovation;

Figure 5 is a greatly enlarged sectional view of a connecting portion of the ink jet recording head and the

Ink cartridge according to the first embodiment of the innovation;

Figure 6 is a detailed view of the ink inducing element of Figure *7;

the figures

7A-7D are schematic representations of a modified embodiment of the ink inducing element according to the present

Innovation;

Figure 8A shows a cross section through an inkjet recording unit with a valve mechanism,"wherein a recording

voltage head is connected to an ink cartridge;

Figure 8B shows a cross section through an ink jet recording unit with a

Valve mechanism with the recording head removed from the ink cartridge ;

Figure 9A is a cross-sectional view of the ink jet recording unit with the valve mechanism of Figures 8A-8B, with the recording head connected to the ink cartridge;

Figure 9B is a circuit diagram for explaining the flow resistance occurring in the recording unit with valve mechanism shown in Figure 9A;

Figure 1OA is a diagram for explaining the flow resistance of the ink jet recording unit shown in Figures 9A and 9B with the valve

valve mechanism occurs;

Figure 10B is a diagram for explaining the flow resistance occurring in the ink jet recording unit,

which has the ink inducing element according to the present innovation;

Figure llA is a graphical representation to explain the ability of supplying

Ink of the inkjet recording unit, which can be seen with the valve mechanism;

Figure HB is a graph for explaining the ink supply capability of the ink jet recording unit having the ink inducing element according to the present invention;

Figure 12 shows a cross section through an ink jet recording unit according to the present invention, wherein a recording head is connected to an ink cartridge

is separated;

Figure 13A shows a cross section through an ink

Jet recording unit in which a filter is used instead of the ink inducing element.

ment and wherein the recording head is connected to the ink cartridge;

Figure 13B shows a cross section through an ink

jet recording unit in which a filter is used instead of the ink inducing element and in which the recording head is removed from the ink cartridge;

Figure 14A shows a cross section through an ink jet recording unit according to the third embodiment of the present invention, wherein the recording

head is removed from the ink cartridge;

Figure 14B is a cross-section through the ink jet recording unit, where the

Recording head is connected to the ink cartridge;

• · * · ff · 9 «ff·· #

Figure 14C is a partial view taken in a direction along line C-C in Figure 14B;

Figure 15 is a perspective view of an ink inducing element according to the fourth

Embodiment of the present innovation ;

Figure 16 shows a cross section through an ink jet recording unit, in which a

filter is used instead of the ink inducing element and the recording head is connected to the ink cartridge;
15

Figure 17A shows a cross section through an ink

jet recording unit in which a filter is used instead of the ink inducing element and the recording head is separated from the ink cartridge

is removed;

Figure 17B shows a cross section through an ink jet recording unit according to the present invention, wherein the

drawing head in the phase of connection with the ink cartridge is shown ;

Figure 17C shows a cross section through an ink

jet recording unit according to the present invention, wherein the recording head is connected to the ink cartridge;

Figure 18A Figure 18B

a front view of the ink cartridge for inkjet recording in a package according to the present innovation;

a side view of the ink cartridge for inkjet recording in a package according to the present innovation;

Figure 18C a side view of the ink cartridge

for ink-jet recording according to the present innovation;

Figure 19A

a side view of the ink cartridge for ink jet recording according to the present invention, showing a state at the time of placing the ink cartridge in a high temperature atmosphere;

Figure 19B shows a state where the ink cartridge is kept in the atmosphere at high temperature;

Figure 19C shows a state at the time when the ink cartridge is kept in an atmosphere at room temperature after the state of Figure 19B;

Figure 19D shows a state in which the sealing tape is removed after the state of Figure

2OC removed from the ink cartridge
becomes;

Figure 2OA a side view of the ink cartridge
for ink jet recording according to the present invention, wherein a state
at the time when the ink cartridge is placed in an atmosphere
is placed at a high temperature;

Figure 20B shows a state in which the ink cartridge is kept at a high temperature in the atmosphere;
15

Figure 20C shows a state at the time when the ink cartridge is placed in an atmosphere at room temperature after the state of Figure 20B;
20

Figure 2OD a state in which the sealing tape
is removed from the ink cartridge according to the state of Figure 2OC;

Figure 2IA a top view of an ink cartridge

for inkjet recording in accordance with the present innovation;

Figure 2IB is a side view of an ink cartridge for inkjet recording according to the

present innovation;

Figure 2IC is a front view (i.e. ink outlet side) of an ink cartridge for ink

Beam recording according to the present innovation;

Figure 2ID is a rear view (i.e. air opening side) of an ink cartridge for ink

beam recording according to the present innovation;

Figure 22A is a section along line A-A in Figure 2IA;

Figure 22B is a section along line B-B in Figure 2IB;

Figure 22C is a section along line C-C in Figure 2 IC;

Figure 22D is a section along line DD in Figure 2ID;
20

Figure 23 is a greatly enlarged view of the ink inducing element according to the present invention;

Figure 24 shows a cross section through an ink

beam recording unit according to the sixth embodiment of the present innovation;

Figure 25 is a greatly enlarged sectional view

a connecting portion of the ink jet recording head and the ink cartridge according to the sixth embodiment of the present invention;

Figure 26 is a perspective view of a

Color ink jet recording head according to the present innovation; 5

Figure 27 is a perspective view of the color ink jet recording head according to the present invention;

Figure 28 is a perspective view of a tin-

jet printing mechanism according to the present innovation; and

Figure 29 is a perspective view of a PC according to the present innovation.

The present innovation is described in detail below in conjunction with the attached drawings, which show various preferred embodiments of the innovation.

<Embodiment 1>

Figures 3A and 3B show cross-sectional views of an ink jet recording unit 4 which is a first embodiment of the present invention. The recording unit 4 consists of two parts, namely a recording head 2 and an ink cartridge 3, which can be easily connected to each other as shown in Figure 3B and which can also be easily separated from each other as shown in Figure 3A.

The ink jet recording head 2 has a filter 43 at one end of an ink inlet portion 45 which functions as a connecting portion with the ink cartridge 3. The filter 43 has a plurality of pores having a constant pore size and serves to trap dirt particles in an ink flow when the recording head is connected to the ink cartridge 3. The pore size of the filter 43 is in the range defined below. The upper limit of the effective pore size is defined as the maximum effective diameter of the pore for preventing the dirt particles from flowing into the recording heads, which depends on the size of the nozzles formed at the other end of the liquid passage in the recording head 2. On the other hand, the lower limit of the effective pore size depends on the pressure loss of the filter 43 at the maximum ink flow rate and is defined as the minimum effective diameter of the pore which is insufficient to adversely affect an ink printing operation. The pressure loss depends on the diameter of the liquid channel (i.e., an ink path) in the ink inlet section 45 where the filter 43 is arranged, so that according to the experiments of the inventors, it is preferable to set the effective diameter of the empty pore of the filter in a range of 5-20 μm.

The ink cartridge 3 has a porous member (ink absorber) 37 as an ink reservoir for storing ink and an ink inducing member 47 made of fiber members. Reference numeral 48 denotes an air communication port for communicating the interior of the ink cartridge with atmospheric air, and reference numeral 49 denotes an ink supply portion for communicating with an ink inlet portion 45 of the recording head 2.

The ink inducing member can be used for inducing ink in one direction in a device. In this embodiment, the ink inducing member is suitably disposed in the ink cartridge so that ink is induced from the ink absorber to the ink supply portion. In this embodiment, the porous member 37 is an ink absorber, such as a sponge, compressed in the ink storage portion of the cartridge.

As shown in the figures, the ink inducing member 47 is supported by the cartridge support portion 41, and an inner surface of the ink inducing member 47 is pressed against the ink absorber 37 to deform it. By deforming the ink absorber 37 in this way, a higher capillary action is achieved at the contact point, thereby centering the ink in the vicinity of the ink inducing member.

Therefore, air cannot enter the ink inducing member 47 because the ink inducing member is capable of maintaining a constant supply of ink from the ink absorber whenever the recording head is detached from the ink cartridge. Furthermore, a meniscus can also be formed on a surface of the ink inducing member facing the ink inlet portion 45 of the recording head.

The efficiency of using the ink stored in the ink cartridge can be improved by improving the flow of the ink into the ink inducing element and maintaining it without interruption when an ink path is formed by attaching the ink jet recording head 2 to the ink cartridge 3.

r\C *

When the ink absorber 37 in the ink cartridge 3 is compressed as in the present embodiment, the ink inducing member 47 pressurizes the ink absorber 37 so that the compressed portion and the vicinity of the ink absorber 37 are strained. The ink can thus be centered in the vicinity of the ink inducing member 47.

When a low compressibility or a low elastic modulus of the ink absorber is used in the ink cartridge, the ink inducing element is preferably inserted into the ink absorber under pressure to achieve a deformation large enough to concentrate the ink in the deformed portion.

In this embodiment, the term "pressurized insertion" means that the ink inducing element is inserted into the ink absorber by applying a force greater than the compression force normally used.

Generally speaking, the ink ejection openings of the recording head of the ink jet recording apparatus are maintained at an appropriate water column pressure lower than atmospheric pressure in order to prevent the printing quality from being deteriorated by a low ink supply to the ink ejection openings (i.e. nozzles) and by ink leakage therefrom. It is necessary to maintain the pressure of the ink in the recording head 2 at a pressure lower than atmospheric pressure (usually in a range of -150 mm water column to 0 mm water column, preferably in a range of 100 mm water column to -30 mm water column compared to

Atmospheric pressure). In this embodiment, the porous member 37 is maintained at a pressure in a range of 40 mm - 60 mm water column to regulate the state of the ink so that a negative pressure occurs. 5

The ink jet recording head 2 is detachably fixed to the ink cartridge 3 by means of a pair of connectors 34. The connectors 34 project from one end of the ink cartridge 3 and form parallel projections which engage in recesses (not shown) of the ink jet recording device. A filter 43 of the ink jet recording head 2 is pressed onto the ink inducing element 47 of the ink cartridge 3 by applying predetermined pressing forces.

The pressing forces depend on the length of the protruding part of the ink inlet section 45 of the recording head 2 and the depth of the supply section, which is defined by the distance from an outer surface of the ink cartridge 3 to a contact surface of the ink inducing element 47 which is brought into contact with one end of the ink inlet section 45 of the recording head 2.

The connection therefore forms an ink path 36 for supplying ink to an inlet of the recording head 2 through the ink inducing element 47.

By the construction of the present embodiment, the leakage of ink and the evaporation of ink from the contact point can be minimized because the ink channel formed by the contact between the ink inlet portion 45 and the ink supply portion 39 is formed by an O-

&bull; m

·

Ring 35 is sealed, which is arranged at a connecting portion of the recording head 2.

Figure V shows the construction of the ink inducer element 47 described above.

The ink inducing member 47 is a bundle of fibers designed as an ink supply member for supplying the ink from the ink cartridge 3 to the recording head 2 when they are connected to each other. The member is made of a plurality of fibers arranged parallel to the ink supply direction to supply the ink in one direction. The ink inducing member 47 has two regions in the diametrical direction (i.e., a direction perpendicular to the ink supply direction). In other words, it has an outer peripheral region having a comparatively poor ability to supply the ink and an inner region having a comparatively excellent ability to induce the ink. The outer peripheral region 52 is formed by applying a binder to fix the fibers so that they form a closed package, while the inner region 51 is formed so that a space is provided between the fibers which is large enough to allow ink to pass through.

The term "fiber bundle" means a bundle of fibrous resin, such as polyester, nylon, polypropylene, polyethylene, cellulose and polyurethane, or a bundle of other fibrous materials, such as metal, grass and carbon, or a bundle of a fibrous mixture of these resins and materials. The term "fixing the fibers so that they form a close packing" means that the space between the fibers is filled with binding agents.

agent or filling material or that the fibers are fused together by heat or pressure.

The inner region may have different sized spaces as ink paths, so that ink paths of different sizes may be present. One type of ink path has a diameter larger than that of the fiber, while the other type has a diameter smaller than that of the fiber. In this case, therefore, the ink can be uniformly passed through a cross-sectional area of the inner region in a direction perpendicular to the ink induction direction.

Preferably, each fiber is made of a material such as polyester, nylon, polypropylene, polyethylene, cellulose and polyurethane that is chemically resistant and can be easily moistened. One of the standards for evaluating the moistening ability of the material is the so-called ink contact angle. In other words, the material can be classified as good if the ink contact angle is relatively small. It is also possible to use material with a large ink contact angle as an ink inducing material by subjecting the material to a hydrophilic treatment. However, since this causes additional steps that increase the cost of the product, among other things, this cannot be recommended.

Furthermore, other materials such as metal, grass, carbon, and mixtures of at least two of the materials described above can be used as fiber materials.

The ink inducing element 47 should be arranged as part of an ink path to guide the ink along that path and should be provided with sufficient physical strength to maintain its shape against the compressive force applied from the ink inlet of the recording head. It is therefore preferred to form the element as a fiber bundle.

The upper limit of the thickness of the fiber for the ink inducing element depends on the degree of contact between the ink inducing element and the filter at the above-described ink inlet portion. In view of this fact, it is preferable to use a fiber having a thickness of 0.05 mm or less. Furthermore, it is preferable that the lower limit of the thickness of the fiber for the ink inducing element is 0.01 mm or more in order to easily manufacture the fiber bundle at a low cost. In this embodiment, therefore, a polyester fiber having a thickness of 0.03 mm is used.

In this embodiment, a resin binder is used as a means for fixing the fiber bundle. The peripheral surface and its vicinity of the bundle are hardened by the binder to form a hardened portion.

Polyurethane of polyester polyol is used as a resin binder to penetrate the peripheral surface of the bundle. However, the invention is not limited to such a substance. A melamine resin binder can also be used if it is adapted to the object.

&bull; * · 1 I

The means for forming the hard portion 52 for fixing the fiber bundle is not limited to the resin binders described above. The hard portion 52 may also be formed by fusing an outer peripheral portion of the bundle by applying heat or pressure. In place of the hard portion, it is also possible to cover the fiber bundle with other material. Comparing the two different means described above, the binder is more suitable than the covering means for the following reasons. In the formation of the hard portion, the step of forming the fiber bundle and the step of passing the binder through the bundle can be carried out almost at the same time. When using the covering means, the process for producing the ink inducing element may become complicated because a step of covering the bundle with the covering means should be carried out in the state in which the fibers are bundled until they are uniformly covered in order to uniformize their physical strength.

It is also possible to use other methods for bundling the fibers if the products thus manufactured maintain a direction for supplying the ink along the fibers and a certain shape of the fiber bundle so that the ink can penetrate the bundle evenly and thus be supplied in a constant manner.

Each fiber in the ink inducing element is aligned in a direction parallel to the ink flow in the element. The capillary pressure to be built up by the bundle is set to a higher value than that of the porous element. This

also applies to the case where the porous element is compressed by the ink inducing element.

In this way, the ink quickly reaches the tip of the ink inducing element because the ink inducing element 47 is pressed against the porous member 37 that has absorbed the ink. The ink in the tip of the ink inducing element does not leak because a meniscus is formed by the capillary force of the bundle of fibers.

It is difficult to determine the extent of the hard region in the radial direction of the ink inducing element because the hard region is formed by permeation of the binder through the outer peripheral surface of the element. However, a rough boundary line is defined between the hard region and an inner region into which the binder has not penetrated. Comparing these two regions, the ink permeates through the inner region more smoothly than through the hard region because gaps between the fibers of the hard region are filled with the resin or the like, while otherwise they are not. The inner region has large gaps with large diameters compared to the diameter of the fiber and small gaps with smaller diameters compared to the diameter of the fiber. These gaps are mixed in the inner region to allow the ink to pass through.

Figure 5 shows a connecting portion between the ink recording head 2 and the ink cartridge 3. 30

The contact area between the filter 43 of the ink jet recording head and the ink inducing element of the ink cartridge 3 must satisfy the condition that the contact area of the filter 43 is smaller than that of the ink

ink inducing element 47 as shown in Figure 5. This condition of the contact area is set to press a region C of the recording head 2 against the inner region B of the ink inducing element 47. The region C is provided as an ink path in the recording head. According to this construction, it is possible to maintain a uniform pressure contact state at a region corresponding to the effective diameter of the filter.

In order to achieve a more preferable pressure contact state and prevent a decrease in the amount of ink supplied, the entire area of one end of the ink inlet portion of the recording head should be brought into contact with the inner area B of the ink inducing element to ensure their contact.

The ink penetrates through the contact surface including the portion where the ink inlet portion of the recording head is in contact with the hard portion of the ink inducing element. However, it is preferred that the contact surface C does not include this hard portion, since this adversely affects the properties for performing high-speed printing, etc.

Due to mechanical tolerances, assembly accuracy tolerances, etc., the filter of the recording head may be pressed unevenly against the fiber bundle. However, in order to achieve effective ink supply to the recording head, the fiber bundle and the filter should be pressed evenly against each other without forming wrinkles at the contact ends. Therefore, the contact area between the filter and the ink inducing element must be

flexible" enough to compensate for these mechanical tolerances, assembly tolerances, etc. and to achieve a uniform contact surface. It is therefore preferred to press the filter against the inner area and not against the hard area in order to ensure a consistent ink supply.

As described above, the ink inducing member 47 has a hard portion having a thickness of about 1 mm in the radial direction formed by permeating the binder through the outer peripheral surface of the member. In this embodiment, therefore, a contact position is set to separate the outer peripheral surface of the ink inducing member 47 and the outer peripheral surface of the filter 43 by a distance (i.e., a separation amount in the direction of a line normal to the outer peripheral surface of the filter in a plane) of 0.5 mm or more, preferably 1 mm or more, to avoid a pressure contact state between the filter 43 and the hard portion of the ink inducing member. However, as determined by experiments, it is also possible to separate these members by a distance of more than 0.5 mm or less than 1 mm without the members losing their functions. However, this will produce unsatisfactory results when printing at high speeds, as the effective diameter of the filter will be reduced.

With the above-described construction, the ink can be concentrated at the ink supply portion of the ink cartridge when it is separated from the recording head, so that the ink absorber adjacent to the ink supply portion is prevented from inducing or sucking air. Therefore, the ink can be smoothly discharged from the ink cartridge.

tron to the recording head when they are reconnected.

The ink absorber has a portion which is deformed by the pressure applied by the fiber bundle, so that it is not necessary to insert the ink inlet portion of the recording head into the ink absorber to deform a part of the absorber and concentrate the ink thereon. Only a pressure contact state is required to allow the ink to flow from the ink inducing element to the ink inlet portion. Consequently, no inflow of air can be caused into the area around the ink supply portion, thereby providing the recording unit with a proper ink path from the ink cartridge to the recording head.

When printing is performed at a relatively high speed, the ink supply rate must be high while the ink cartridge 3 maintains a certain negative pressure. It is therefore preferable to make the ink flow resistance as small as possible. The present ink jet unit solves this problem.

In order to realize both the stable supply of ink at the time of connection to the recording head and the prevention of ink leakage at the time of removal of the recording head, the ink inducing element 47 is defined below in detail based on two different states, i.e. (i) a connection state between the recording head and the ink cartridge in which a sufficient amount of ink should be constantly supplied to the recording head and (ii) a disconnected state in which the prevention of ink leakage from the removed ink cartridge.

Therefore, the characteristics of the ink inducing element will be explained in detail in connection with the above-described conditions.

(Separated state)

When the recording head is removed from the ink cartridge, the ink outlet side of the ink inducing element may be directly exposed to the external atmosphere. Therefore, the ink cartridge should hold the ink without causing ink leakage when its ink outlet surfaces face downward or the like. In this embodiment, the ink inducing element and the sponge (ink absorber) are responsible for maintaining the ink holding force against the force of the ink stored in the ink cartridge. In other words, the ink inducing element and the sponge must generate a certain negative pressure large enough to hold the ink without causing ink to leak from the ink supply portion of the ink cartridge due to capillary forces.

The capillary forces of the ink inducing element and the sponge are defined to cause a constant ink supply as described below, taking into account an acceleration of the ink flow or the like caused by physical conditions of the ink, such as the mass of the ink and the degree of ink vibration during movement of the ink cartridge. The capillary force of the sponge should therefore preferably be in a range of 40 mm water column or more, and is 50 mm water column in the present embodiment. On the other hand, the capillary force for the ink inducing element should preferably be 1.5

times as large as that of the sponge and preferably in a range of 85 mm to 400 mm water column.

Considering the movement of the ink cartridge, there is a possibility of causing acceleration of the ink flow as mentioned above. Therefore, the larger the capillary force of the ink cartridge is, the better the ink can be held. However, if it is too high, a high suction pressure is required in an ejection recovery process to draw the ink out of the ink cartridge. Therefore, the upper limit of the capillary force of the ink cartridge should preferably be 400 mm H2O or less. In the present embodiment, the ink induction is such that the capillary force is 200 mm.

Alternatively, the ink inducing element can be defined as follows. The fibers in the inner region of the ink inducing element are arranged to leave a constant clearance between the fibers and to exert a constant ink holding force, as explained by the following equation which was obtained from test results.

ha τζ 4.2/ds (1)

where "ha" represents the capillary force (mm water column) as the ink holding force of the ink inducing element and "ds" represents the average of each distance between one fiber and the adjacent fiber in a direction parallel to the cross-sectional plane of the ink guiding element.

As described above, the capillary force of the sponge should preferably be 40 mm water column or more.

while the capillary force of the ink inducing element "ha" should preferably be 200 mm H2O or more in order to smoothly guide the ink from the sponge to the ink inducing element. Therefore, the value of "ds" is preferably less than 0/05 mm according to equation (1) .

On the other hand, the capillary force should preferably be below 400 mm water column for the reason described above. The value of "ds" is therefore preferably above 0.01 mm.

The diameter φα of each fiber inducing element should preferably be in a range of 0.01 mm to 0.05 mm, because if it is too small, the fiber bundle is difficult to manufacture at high cost. On the other hand, if it is too large, the fiber does not have sufficient flexibility to contact the filter of the recording head.

The density N of the fibers of the ink inducing element should preferably be in a range of 100 to 2,500 (number/ mmr) according to the following equation:

ds = YTl/N) -d (2)

where "ds" is the average distance between the fibers defined above, "N" is the density of the fibers (number/mm^) and "d" is the diameter of the fiber. 30

The interfiber distance is an average distance between the fiber surfaces. In other words, the distance is measured by taking a cross-sectional view of the bundle of fibers from a magnified image

is selected, various fibers (30 fibers in the present embodiment) are selected, and each clearance between a circumferential surface of one fiber and a circumferential surface of the next fiber is measured. 5

The diameter of the fiber is obtained as the average diameter of the fibers obtained by using magnified images, selecting several fibers, calculating the diameter of each fiber at different points and averaging the obtained calculation data.

The axial length (which generally corresponds to the length of each fiber) of the ink inducer element should preferably be in a range of 2 mm to 6 mm. If the ink inducer element is too short, it may be difficult to manufacture the fiber bundle and some fibers on the inside of the bundle may come out. On the other hand, if the ink inducer element is too long, it is difficult to obtain a sufficient ink flow in the connection state between the recording head and the ink cartridge.

(connection state)

When the recording head is connected to the ink cartridge, as regards the ink supply from the cartridge to the recording head, the pressure loss ^Pf of the ink flow at a point of the ink inducer element at the maximum throughput should preferably be 20 mm H2O or less. This value corresponds to the maximum throughput under the condition that the recording head has at least 64 ejection openings. When the pressure loss ^Pf of the ink flow at a point of the ink inducer element at the maximum throughput should preferably be 20 mm H2O or less. This value corresponds to the maximum throughput under the condition that the recording head has at least 64 ejection openings.

If the pressure loss £Pf is higher than this value, the print quality may be adversely affected depending on a difference between the individual printing types. The pressure loss APf of the entire ink supply system from the ink cartridge to the recording head is 100 mm water column or less.

Assuming that the ink inducing element is subjected to a pressure loss 4Pf in the range described above, the dimensions of the ink inducing element can be defined as follows:

Figure 6 is a schematic view showing dimensions of the ink inducing element of the present embodiment.

The length "L" of the ink inducing element 47 is defined as a size thereof in a direction parallel to the ink stream flowing at a rate U (mm/sec). The actual diameter De of the ink inducing element generally corresponds to a diameter of an ink path in the inducing element. Therefore, the actual diameter De is defined by the following equation:

1

De = (D ² -nd ² ) ... (3)

n«d

where:

"D" is the effective diameter (mm) of the ink path, with the diameter of the ink path corresponding to the diameter of the inner region 51, "d" is the average diameter (mm) of each fiber in the inner region 51, and "n" is the number of these fibers.

The length "L" and diameter "De" as described above can also be defined by the following equation using the pressure loss APf described above:

APf = K. u · .... (4)

De ²

where:

u = W/S, where "S" is the cross-sectional area (mm ) of the ink path and "W" is the throughput (mnr/sec) of the ink stream, and

"K" is a resistance coefficient (mm water column -sea) which takes a value of about 4.2 × 10~ ³ (this value was determined from an experimental result) when the ink inducing element has the construction described above.

In this embodiment, the cross-sectional area "W" is in a range of 26 (mm ³ /sec) to 512 (mirr/sec) depending on the maximum and minimum ink ejection amounts of a series head.

The length "L" can be determined depending on the definition described above or on the size of the ink cartridges or the amount of ink to be stored in the sponge. The diameter "De" can be determined depending on the distance "ds" and the effective diameter "D". The effective diameter "D" should preferably be determined depending on the pressure loss of the filter of the recording head and the

Ink throughput W can be in a range of 1 mm to 18 mm.

The ink inducing element can therefore have any dimensions, taking into account the definition limits described above. Generally speaking, however, all parts of a detailed plan for manufacturing the ink cartridge, including its dimensions, volume, etc., are determined before those of the ink inducing element. Therefore, the dimensions of the ink inducing element should be determined so that it fits into a limited space in the ink cartridge and also has the required properties.

Table 1 below shows various embodiments of the ink inducing element construction under the following conditions. The ink inducing element has the following dimensions: a length L of 6 mm, an outer diameter OD' of 6 mm and an effective diameter OD excluding the thickness of the binder of 4.8 mm. The required properties of the ink guide element are: ink holding force ha 200 mm water column and pressure loss δPf at a flow rate W of 42 inm/sec 10 mm water column or less. The distance "ds" between the fibers is 0.021, the value "ha" having the definition described above.

(1) 0.01 1041

0.02 595 0.03 385

De Table S ,6 1 2 U &eegr; , 16 ,7 2 ,5 18830 , 11 14 ,2 3 ,9 10764 , 087 13 ,2 6757 080

Decision 5.0 favorable

large N 9.5 optimal 2.4 unsuitable

(4) 0.04 269 4863 0.078 12.0 3.5 14.4 inappropriate

<jPf>10

(5) 0.05 198 3590 0.078 11.0 3.8 15.6 inappropriate

According to the results shown in Table 1, when the ink inducing element has the constructions (1) and (2), it satisfies the conditions described above. The pressure loss Pf of the construction (1) is lower than that of the construction (2). However, in order to reduce the cost of the product, construction (2) is preferably used because the element according to the construction (2) has a smaller number of fibers. The constructions (3-5) are not preferred for producing the ink inducing element because the pressure loss Pf at the maximum flow rate of the ink is higher than 10 mm of water column and is thus at the upper limit of the required condition described above.

As explained above, the dimensions of the ink inducing element should be determined as described above in order to prevent leakage of ink in the separated state and to smoothly supply the ink from the ink cartridge to the recording head in the connected state. These characteristics cannot be achieved.

by simply using the well-known material that can absorb ink through its capillary force.

After inserting the ink inlet portion of the recording head into the ink supply portion of the ink cartridge, the space between the ink supply portion and the pressure contact point should be filled with ink and the ink path should be isolated from the external atmosphere. In this case, an elastic member such as an O-ring may be used to make the connection portion airtight. However, air easily enters a part of the ink path during the connection period because the ink inlet portion pushes the air into the inside of the ink cartridge.

Consequently, in a conventional structure, air bubbles are generated in the pressure contact area of the sponge and the flow resistance is greatly increased, resulting in the recording head not being able to obtain a sufficient amount of ink.

One of the conventional means for solving this problem is, for example, a valve mechanism responsive to the closing of the ink path when the recording head is removed. Generally speaking, the valve mechanism is saturated with ink to prevent the generation of air bubbles during reconnection of the recording head to the ink cartridge. However, the ink inducing element of the present invention does not cause the above-described problem.

The ink inducing element is not limited to a columnar shape. It may also have other shapes, such as the embodiment shown in Figures 7A-7D.

44 ·"

Each of the ink inducing members shown in Figures 7A-7D is formed to have its own shape suitable for introducing the ink from the sponge with a comparatively small resistance because, as shown in the figures, the sponge-side end of the ink inducing member has the inner portion having a larger surface area compared with a columnar member. Therefore, the ink inducing member having the modified shape can be intensively brought into pressure contact with the sponge 37.

It is necessary at this point to explain the flow resistance of the ink cartridge in connection with its design.

When performing high-speed printing, the ink jet recording head 2 must eject a quantity of ink droplets per unit time, and the ink cartridge must keep its negative pressure at a constant value in order to meet the requirements of the head 302. Therefore, the flow resistance in the ink path should be reduced as soon as possible.

Figures 8A and 8B show a cross-sectional view of a conventional recording unit in comparison with the present invention, wherein an ink cartridge 604 has a valve mechanism 614 provided at a portion to be connected to a recording head 602. In these figures, Figure 8B shows the separated state of the recording head 602 from the ink cartridge 604, while Figure 8A shows the connected state via two hook plates 617 projecting in parallel from one end of the ink cartridge 604 to fix the recording head 602.

JJ-

recording head 602 by inserting them into connecting holes (not shown) formed in the recording head 602.

The recording head 602 has an ink inlet portion 605 to be inserted into an ink supply portion 611 of the ink cartridge 604, and a filter 603 provided at one end of the ink inlet portion 605 to prevent the inflow of dirt. As shown in the figures, an O-ring 608 is coaxially disposed around the ink inlet portion 605. The O-ring 608 seals the ink path from the outside.

The ink cartridge 604 has an ink absorber 609 capable of holding ink therein. The density of the ink absorber 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 path and pressurizes the ink absorber so that a compressed portion with high density is obtained in the absorber 609. Therefore, the compressed portion maintains its balance to guide the ink from the ink absorber to the recording head in a smooth manner.

Due to the valve mechanism 614 acting on the downstream end of the filter 613 in the cartridge 604, no ink leaks from the ink cartridge 604 when the ink cartridge is separated from the recording head 602.

Figure 9A shows an ink path from the ink cartridge 604, which includes the valve mechanism shown in Figures 8A and 8B.

mus, to the recording head 602, while Figure 9B shows an equivalent electrical circuit corresponding to this ink path.

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

Figure 10A shows the proportion of each part of the flow resistance of the ink jet recording head 602 and the ink cartridge 604 having the valve mechanism of the comparative example shown in Figures 8A and 8B. Each reference numeral corresponds to that of Figures 8A and 8B.

Figure 10B shows the proportion of each part 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 of the comparative example. Furthermore, the flow resistance of the ink inducing element 47 is comparatively small, so that the recording head 2 is able to obtain an appropriate amount of ink constantly during the period of high-speed printing. Each reference numeral corresponds to that of Figure 3.

Figures HA and HB show a variation of the ink supply to the recording head when the valve mechanism

* mm mm m #« ·«

of the comparative example {Figure HA) or the ink inducing element of the present example (Figure HB) is used.

In these figures, "P" shows an image of a print pattern having line and solid areas. "C" denotes the line area of the image, while "B" represents the solid area of the image.

During a rest period of the printing process, the pressure in the ink path is kept almost in a range of -60 mm to -80 mm water column against the pressure of the outside atmosphere via a capillary force, which is responsible for keeping the ink in the ink absorber.

According to the results of the measurement in the resting state, the ink cartridge equipped with the valve mechanism is under a pressure of about - 60 mm water column (Figure HA), while the ink cartridge equipped with the ink inducing element is under a pressure of about - 80 mm .. water column (Figure HB) compared to atmospheric pressure.

During printing of a pattern having a portion requiring a large amount of ink (i.e., full portion), a pressure loss due to flow resistance is observed in the ink cartridge having the valve mechanism as shown in Figure 11A. On the other hand, the ink cartridge according to the present invention does not cause such problems, i.e., the amount of pressure loss is extremely small, so that this cartridge is suitable for high-speed printing and the like.

&bull; .»· on &phgr; &bgr;» ««

Furthermore, it is found that the ink cartridge according to the present embodiment is capable of maintaining its excellent reliability despite a rest period for a long period or after such a rest period. On the other hand, in a conventional ink jet recording apparatus, after a rest period for a long period, air bubbles are easily generated in the ink path of the ink jet recording unit, and these air bubbles are responsible for insufficient results in printing. In other words, the air bubbles may block the flow of ink to the recording head so that the recording head cannot perform the printing process after the long rest period. If some air bubbles, which are normally filled with saturated vapor, are introduced into the ink path during the rest period, the volume of the air bubbles increases because the air penetrates into the ink path through the wall and dilutes the amount of vapor through an osmotic effect of the outside atmosphere. To solve these problems, it has been proposed to mount a timer for counting the period of post-rest time on the ink jet recording head and count this time. When the operation time is longer than the period described above, pumping is started to remove the air bubbles with the ink.

However, occasionally the air bubbles grow within the above-described period under poor environmental conditions, such as extremely high temperature and low relative humidity. These grown air bubbles interrupt the flow of ink to the recording head, resulting in poor printing.

Particularly, when the valve mechanism 614 is driven when connecting or disconnecting the ink jet recording head 602 and the ink cartridge 601 as shown in Figure 8A, air from the outside may be introduced into a certain area of the ink path. The valve mechanism therefore encounters adverse conditions under the environmental conditions described above.

According to the invention, the ink cartridge has the ink inducing element having an ink contact area. A meniscus can therefore be formed over the entire ink contact area, which is responsible for preventing the inflow of air bubbles when the recording head and the ink cartridge are separated. Furthermore, according to the invention, the filter of the recording head is brought into direct pressure contact with the ink inducing element, so that a possible area that could allow the ingress of air is reduced compared with the valve mechanism. The ink cartridge of the present invention therefore makes it possible to remove air at the joint to prevent the occurrence of air in the joint portion or in the ink path.

< Embodiment 2 >

Figure 12 is a cross-sectional view of a second embodiment of the recording unit according to the present invention. In this embodiment, an ink inducing member 47 is provided in the same manner as in Embodiment 1, except that the member 47 can slide in a holder portion 41 to contact the filter 43 of the recording head 2 in the direction of arrow D. The ink inducing member

47 is pressed against the ink absorber 37 compressed in the ink chamber. The member 47 thus receives the reaction force directed to the ink supply section 39. However, as shown in this figure, an edge of the ink inducing member 47 strikes against a stopper 49.

When the ink inlet portion 45 of the recording head 2 is inserted into the ink supply portion 39 of the ink cartridge 3, the ink inlet portion 45 contacts the ink inducing member 47. In the embodiment 1, the magnitude of the force for pressing the ink inlet portion against the ink inducing member depends on the relationship between these members. However, in the embodiment 2 in which the ink inducing member is formed as a sliding member, the magnitude of the force depends on the state of pressing the ink inlet portion into the ink absorber and a sliding distance of the ink inducing member by inserting the ink inlet portion.

With the above construction, the filter and the ink inducing element are in stable pressure contact with each other even if the ink inducing element is provided with incorrect dimensions in the longitudinal direction, since these dimensional errors can be compensated by sliding the ink inducing element.

When the ink inducing member 47 is fixed without sliding movement, there is a possibility that the ink flow along the ink path is interrupted by gaps between the ink inlet section and the ink inducing member. These gaps may be caused by inaccurate connection due to design problems of the ink inducing member, such as uneven

end face and a short length thereof, which are due to poor machining accuracy. On the other hand, if the ink inducing _member is formed too long, an overpressure of the ink inlet portion against the ink inducing member occurs, so that the fibers in the ink inducing member are deformed and a local area is formed through which the ink cannot flow. As a result, the recording head receives insufficient or inconsistent ink supply.

Therefore, according to the sliding mechanism of the ink inducing member, it is possible to establish a stable pressure contact state and further prevent the inflow of air during the connection phase of attaching and detaching the ink cartridge with respect to the recording head, time and again. Furthermore, since these dimensional errors can be compensated by the sliding of the ink inducing member, the cost of the product can be reduced. Therefore, it is not necessary to manufacture the ink inducing member precisely.

The ink inducing element should be arranged so that it can slide at least 0.1 mm or more (lower limit of sliding distance) because the filter can be brought into contact with the ink inducing element by changing the shape of the contact surface of the ink inducing element by changing the amount of pressure to be applied thereto.

However, the elastic deformation creates some problems. If the filter is pressed against the ink inducing element for a long time (i.e., several months or several years), the contractive surface of the ink inducing element with respect to the filter may be subjected to creep (i.e., plastic deformation), so

that the force pushing the filter away (repulsive force) has been gradually reduced. Consequently, the filter and the ink inducing element do not exert uniform forces against each other, and their contraction areas become poor, so that air may be introduced into the ink path and interrupt the flow of ink to the recording head. Consequently, the ink ejection state of the recording head becomes poor.

To solve the creep phenomenon described above, the ink inducing element is slidably mounted in the ink cartridge and is pressed against the filter by absorbing the recoil force of the sponge in the ink cartridge.

Therefore, the ink inducing member should have a sliding distance of at least 0.1 ra or more in the ink cartridge in order to obtain the required pressure of 5 g/mnr (experimentally determined value) at the pressure contact point. It is understood that the sliding distance of at least 0.1 mm or more is a preferable condition in order to make correction of a dimensional error of manufacture of the ink cartridge or the ink inducing member.

The upper limit of the sliding distance of the ink inducing member is 3 mm or less, preferably 2 mm or less, most preferably 1 mm or less. In addition, the elastic modulus of the ink absorber is different from that of the ink inducing member, but is also elastically deformed. Therefore, the upper limit of the sliding distance of the ink absorber is 3 mm or less, preferably 2 mm or less, most preferably 1 mm or less, in order to prevent the creep phenomenon.

53

degree in which the force pushing the ink inducing element away is gradually reduced in the same way as that of the ink inducing element.

When another type of ink absorber is used which is characterized by a low compression ratio and a low elastic modulus, the ink inducing member is generally inserted into the ink absorber under pressure. In this case, too, a lower limit of the sliding distance is set depending on the magnitude of the force exerted by the ink inducing member on the ink absorber.

The term "press-insertion" can be defined as applying a force greater than that of the pressure-contact state in which the ink inducing element is pressed against the ink absorber. In other words, the ink inducing element is pressed into the ink absorber to make close contact therebetween.

As described above, since the ink inducing element can slide in the insertion direction of the ink inlet portion into the ink cartridge to achieve preferential fitting, the filter of the ink inlet portion of the recording head and the slidably formed ink inducing element can be brought into more perfect contact with each other as compared with the fixed type. The ink path can therefore be formed more perfectly from the ink cartridge to the recording head, and air is more difficult to enter the ink path, so that the amount of ink supplied cannot be reduced. High-quality printing can therefore be achieved.

In order to establish a suitable contact between the filter of the recording head and the ink inducing element, it is preferred that the ink inducing element has a certain degree of elastic strain, ie, a reversible dimensional response to strains corresponding to a force for moving a rod (1 mm ² in cross-sectional area) by 1 mm in the backward direction, which corresponds to a range of 100 gf/mm^ to 500 gf/mm^.

Moreover, the ink cartridge of the present embodiment also provides satisfactory results in terms of ink supply after reconnection to the recording head, owing to its construction. In other words, the ink inducing element is in a state of pressure contact with the sponge at all times to meet the requirement that an ink outlet portion of the sponge in the ink cartridge must always be in a compressed state when the recording head is removed. A recording head in which the sponge of the ink cartridge is directly compressed by the recording head cannot maintain this compression force against the sponge in the removed state, so that air may enter the sponge when the recording head is reconnected to the ink cartridge.

In the construction of the ink cartridge of the present embodiment, the sponge is stored in the ink cartridge compressed by the inner wall thereof, as shown in Figure 12. However, the ink outlet side of the sponge is press-contacted by the ink inducing element with a higher compression force than that by the inner wall. The press-contact point is the most deformed

section of the sponge so that the ink in the sponge tends to concentrate at the printing contact point.

When a sponge having a comparatively lower degree of compression in the cartridge or having a comparatively lower elastic modulus is used, it is preferable to insert the ink inducing element into the sponge under pressure in order to ensure the above-mentioned deformation and to concentrate the ink at the pressure insertion point.

The term "pressurized insertion" can be defined as applying a force greater than that of the pressure contact condition.
15

It is also possible to replace the ink inducing element with the structure shown in Figure 13, in which a filter 38 is in pressure contact with the ink absorber 37.

More specifically, not only the above-described structure in which the ink held in the ink absorber is held on the side of the ink supply section, but also the structure shown in Fig. 13 is formed. In this structure, a filter 38 at the connecting section 39 (ink supply section) is in pressure contact with the ink absorber 37 so that the ink is always centered on the side of the ink supply section 39.

However, through an experiment, the inventors found that an ink jet unit having such a construction has the following problems.

As shown in Figure 13, the ink path 36 is isolated from the outside atmosphere by sealing the connecting portion during connection of the recording head 2 to the ink cartridge 3 via the O-ring 35. When the ink inlet portion 45 is inserted into the ink supply portion 39, the O-ring pressurizes the air in an inner portion formed as part of the ink path 36 toward the mesh filter 38. Therefore, the air moves to the mesh filter 38 and then enters the filter 38. In the filter 38, the air remains in the form of air bubbles and interrupts the ink path or disperses into the sponge 37 (indicated by arrows and a letter A in the figure). As a result, the ink is poorly supplied from the ink cartridge 3 to the recording head 2, so that the printing quality is deteriorated.

This kind of problems can be effectively solved by using the ink inducing element of the present invention. In other words, the ink inducing element stops the movement of the air so that it cannot be pressed into the ink absorbing side of the ink cartridge by the comparatively large capillary force of the ink inducing element.

However, it is preferable to design the ink cartridge in the manner described below in order to stop the inflow of air even more perfectly.

< Embodiment 3 >

An ink jet recording unit of the present embodiment of the invention will now be described in detail in conjunction with Figures 14A-14C.

The ink jet recording unit of the present embodiment is the same as Embodiment 1 or 2, except that an air communication path is formed in the ink jet cartridge to further prevent the formation of the above-described air layer.

Figures 14A-14C are cross-sectional views of the ink jet recording unit, wherein Figure 14A shows a recording head 2 removed from the ink cartridge 3, Figure 14B shows both elements in a connected state, and Figure 14C is a partial view taken in the direction of line CC in Figure 14B.

The ink inducing member 47 is arranged between an opening (i.e., an ink outlet) 391 formed on the front side of the ink cartridge 3 and a sponge (i.e., a porous member) 37 provided inside the ink cartridge 3. The ink inducing member 47 is supported by a support portion 41 which is the sponge-side part of the inner peripheral surface of the ink supply section 39. As shown in the figure, about half of the ink inducing member 47 is supported by the support portion 41 on the peripheral surface of the member 47 in the axial direction thereof.

The remaining part of the peripheral surface is freely exposed to the air in the ink cartridge 3. In other words, only one end of the ink inducing member 47 is in contact with the sponge 37, while the other end is free and exposed to the external atmosphere through the ink outlet 39 of the ink cartridge 3. Further, an edge of the free end of the ink inducing member 47 is supported by a bearing plate 49 which is provided on the inner peripheral surface.

the boundary between the bearing area 49 and the ink outlet 391 in the diametrical direction. The ink inducing element 47 can therefore not protrude from the ink outlet.

In the inner peripheral surface of the bearing portion 41, grooves 42 are formed in the ink supply direction. These grooves 42 serve as air communication paths between the ink inducing element 47 and the bearing portion 41. In addition, the inside of the ink cartridge has a plurality of projections (ribs) 3a which are elongated in the ink supply direction. Therefore, the sponge 37 is supported by these ribs 3a so that a clearance is formed between the sponge 37 and the inner wall of the ink cartridge 3, which clearance communicates with the grooves 42.

Furthermore, an air communication opening 48 is formed in the rear wall of the ink cartridge 3, through which the air paths 42 and the above-described free space are communicated with the outside atmosphere.

Therefore, during the connection of the recording head 2 and the ink cartridge 3, the air present in the clearance between the ink inducing member 47 and the connection point is pressed toward the ink inducing member 47 when the ink inlet portion of the recording head 2 is pressed against the ink inducing member 47.

In this case, however, the air can escape to the outside of the ink cartridge 3 by penetrating through the air communication path formed by the grooves 42, the above-described clearance and the air communication hole 48. The air cannot penetrate into the ink inducing member 47 because the ink is drawn from the sponge 37 into the ink cartridge 3 by the capillary force of the ink inducing member.

end of the recording head 2. The ink, air bubbles, a mixture thereof or the like cannot enter the ink path or the ink inducing element by penetrating the outer peripheral surface of the ink inducing element, since the element has a portion hardened by the binder resin or the like.

At the time of separating the recording head 2 and the ink cartridge 3, the ink inducing member 47 is relaxed from the pressing force of the inlet portion of the recording head 2 and then moves toward the opening 391 of the ink cartridge by the restoring force with which the sponge 37 restores its original shape. As shown in the figure, in the ink cartridge 3, a bearing means 49 is formed in the form of a plate which stands on the inner peripheral surface of a boundary between the bearing portion 41 and the ink outlet opening 391 in the diametrical direction. Thus, the ink inducing member 47 cannot protrude from the opening 391 because it abuts against the bearing means 49 and the edge of the head-side end of the ink inducing member 47 is brought into uniform pressing contact with the bearing means 49.

Therefore, the air cannot enter the ink cartridge 2 through the opening. The sponge 37 is brought into pressure contact with the ink inducing member 47 even when the recording head 2 and the ink cartridge 3 are separated from each other, so that there is no possibility of an air layer being formed between their contact surfaces.

The ink cartridge 3 of the present embodiment is therefore designed so that the air from the ink supply port

": &Ggr;: &iacgr;

sclinitt is released to the outside via the interior of the ink cartridge 3 through the air communication hole 48 and the air path 42 formed between the ink inducing member 47 and the bearing portion 41 while the ink inducing member 47 is in pressure contact with the sponge 37. Therefore, in the ink cartridge 3 of the present embodiment, the air can enter and exit without any control even when the internal pressure increases or decreases with respect to the external atmospheric pressure.

Therefore, in the ink cartridge 3 of the present embodiment, no problems such as leakage of ink from the opening or the connecting portion and intrusion of ink into the ink path arise. Moreover, in the ink cartridge 3 of the present embodiment, the air can be introduced from the outside depending on a decrease in the amount of ink due to ink consumption.

< Embodiment 4 >

This recording unit of the present embodiment is the same as Embodiments 1, 2 or 3, except that an air path is formed in the peripheral surface of the ink inducing element instead of the grooves 42 formed in the bearing portion 41 of the ink cartridge.

Figure 15 is a cross-sectional view of the ink inducing element used in the recording unit of the present embodiment.

The ink inducing element consists of an inner region 51, a binder region 52 and a plurality of

of grooves 42. Each groove 42 is formed on a peripheral surface of the element. The groove 42 can be easily manufactured by pressing the peripheral surface of a fiber bundle during the manufacturing steps of the bundle.

This type of construction is preferred in order to produce a particularly inexpensive ink cartridge as compared with the other embodiments, since both the manufacturing process and the manufacturing accuracy can be improved. In the ink cartridge having the grooves in the bearing area of its inner side, cutting or machining the bearing area is more difficult.

< Embodiment 5 >

Figure 16 shows an ink jet recording unit in which the ink cartridge has the same construction as in Embodiments 1 to 4, except that two different air paths are formed. ■

The first air path corresponds to that of embodiment 3.

In other words, the first air path is composed of: a first space portion formed by a plurality of the projections (i.e., ribs) 3a on the inner wall of the ink cartridge 3 and communicated with the outside atmosphere via the air communication port 48, and a second space portion formed by the grooves between the ink inducing member 47 and the surface of the bearing portion 41.

The second air path consists of a spaced portion (i.e., a third spaced portion) formed by at least one air communication port 81 (two ports are shown in the figure) opening at the front side opposite to the recording head. The air communication port 81 leads to a part of the ink supply section 39 into which the ink inlet section 45 of the recording head 2 is inserted.

When connecting the recording head 2 to the ink cartridge 3, the outer peripheral surface of the ink inlet portion 45 of the recording head 2 is brought into contact with a corresponding inner peripheral surface of the ink supply portion 39 of the ink cartridge 3. At this time, the projections 82 on the recording head 2 also close the air communication holes 81 of the ink cartridge 3.

Therefore, at this time, the air pressed against the ink inducing element 47 from the ink inlet section 45 of the recording head 2 can escape to the outside atmosphere via the first and second air communication paths. The air cannot enter the ink inducing element 47 and the ink cannot flow out from the ink inducing element 47 to the air paths either, since the surface of the ink inducing element 47 is hardened by the binder.

Furthermore, in the above-described construction, the second air path is in a state of communicating with the external atmosphere until the recording head is completely connected to the ink cartridge. After the connection, the second air path is tightly closed by the projection so that the connection

connection section between the recording head and the ink cartridge is perfectly sealed.

The ink cartridge described above has two different air paths. However, it is not limited to this. It is also possible to use an ink cartridge with only the second air path if this is sufficient to allow the air to escape sufficiently to the outside atmosphere.

Furthermore, the second air path can be formed in the ink cartridge by compressing the sponge by means of the filter, i.e., without the conventional valve mechanism or the ink inducing element of the present invention. A stable supply of ink from the ink cartridge to the recording head is ensured by preventing the generation of air bubbles at the pressure contact point between the filter and the sponge. An embodiment of such an ink cartridge is shown in Figs. 17A-17C. In these figures, 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 in which air escapes during connection, and Fig. 17C shows a state after connection.

Therefore, in the construction shown in Figs. 17A-17C, the air can escape from the ink supply section 39 to the outside atmosphere. However, the ink cartridge with the ink inducing element is recommended over the cartridge with the filter in order to supply the ink more stably.

Compared with Embodiments 1 and 2, the ink cartridges of Embodiments 3-5 having the described air paths can withstand bad environmental conditions, so that the ink cartridge can be arranged or assigned in a wide area.

When distributed, the ink cartridge is typically packaged in a box as shown in Figures 18A-18C. Figures 18A and 18B are an end view and a side view of the ink cartridge in the box.

Figure 18C is a side cutaway view of the ink cartridge in the packaging to illustrate safe storage.

The 1625 packaging is a heat-sealed bag made of an aluminum laminate to prevent evaporation of the ink during distribution or storage of the ink cartridge over a long period of time.

In the package 1625, an opening (i.e., an ink outlet) 391 of the ink cartridge 3 is sealed by a sealing tape 1626 to prevent ink leakage from the cartridge under bad environmental conditions during distribution. The sealing tape 1626 is bonded to the ink cartridge 3 by heat-melting, but can be easily peeled off when the cartridge 3 is used.

The sealing tape 162 6 is made of polyethylene, nylon, polyether, polypropylene, aluminum foil and mixtures thereof. It is also possible to use a complex laminate film as the material of the sealing tape 1626.

It is preferred to use the same material as for the ink cartridge 3 to obtain a good contact at the sealing point between the sealing tape and the ink cartridge.
5

The sealing tape 1626 used in the present invention is made of laminated layers of polypropylene, aluminum and polyester. A pad 1627 for absorbing leaking ink is located between the sealing tape 1626 and the ink inducing element 47. One end of the pad 1627 is heat-sealed to the sealing tape 1626.

The ink absorption pad 1627 serves to absorb the ink leaking from the ink inducing member 47 to prevent the small amount of leaking ink from scattering when the sealing tape is peeled off from the ink cartridge.

The material for the ink absorption pad 1627 can be selected from any materials that can absorb and hold the ink, for example, expanded resins such as PVA (polyvinyl alcohol), polypropylene, polyester, polyethylene, polyurethane and nylon, and fiber materials such as paper and textile materials.

In the present embodiment, an expanded polypropylene resin is used for the ink absorption pad 1627, which is suitably heat-fused to the sealing tape 1626. With the packaging and the sealing tape described above, the ink cartridges of Embodiments 1-4 can be safely stored during distribution.

Furthermore, there is a possibility that the ambient temperature is extremely increased or extremely decreased during distribution of the ink cartridge. These environmental changes sometimes affect the internal state of the ink cartridge regardless of the presence of the package. These states of the ink cartridge are explained in conjunction with Figures 19A-19D.

Figure 19A shows a state in which the ink cartridge is placed in a high temperature atmosphere. Figure 19B shows a state in which the ink cartridge is kept in this high temperature atmosphere. Figure 19C shows a state in which the ink cartridge is placed in a room temperature atmosphere after the state of Figure 19B. Finally, Figure 19D shows a state in which the sealing tape has been removed from the ink cartridge after the state of Figure 19C.

When the external environment of the ink cartridge is changed, as shown in Figure 19A, the pressure in the space 1628 between the sealing tape 1626 and the ink inducing member 47 increases and becomes greater than the pressure of the external atmosphere of the ink cartridge, causing the air in the ink cartridge 3 to try to escape to the external atmosphere.

In a structure in which the ink inducing element 47 is in close contact with the bearing portion 41 or in which there is a narrow space therebetween or in which the passage of air through the space between the ink inducing element 47 and the bearing portion 41 is prevented due to surface tension caused by the ink, the air penetrates into the ink inducing element 47.

ment and pressurizes the ink in a backward direction.

The pressurized ink is always subjected to a capillary force which pushes the air to the front of the ink inducing element 47 as shown in Figure 19C, so that the air gradually escapes from the space between the ink inducing element 47 and the bearing device 41 and the pressure of the space 1628 is finally equalized to the pressure of the outside atmosphere.

When the ambient temperature and atmospheric pressure return to normal, a force is generated to introduce the air into the space, and this force then acts on the ink in the ink absorber 37 made of the porous material to hold the ink. Therefore, the ink leaks out of the ink inducing element 47.

In general, the leaked ink can be quickly absorbed by the ink pad. A certain amount of ink

However, it may remain in space 1628 if the ink cartridge is in a problematic environment so that the amount of leaked ink is greater than the absorption capacity of the ink pad. 25

In such a case, the ink is scattered in the air and causes contamination when the user pulls off the sealing tape from the ink outlet portion of the ink cartridge as shown in Figure 19D. 30

Figures 20A-20D show the ink cartridge of Embodiment 3 in which an air path 42 is formed to improve the state shown in Figures 19A-19D.

&bull; *

·

Figure 2OA shows a state when the ink cartridge is placed in a high temperature atmosphere, Figure 2OB shows a state in which the ink cartridge is kept in the high temperature atmosphere, Figure 2OC shows a state at the time of placing the ink cartridge in a room temperature atmosphere after the state of Figure 2OB, and Figure 2OD shows a state in which the sealing tape has been removed from the ink cartridge after the state of Figure 2OC.

The ink cartridge is designed so that the air in the space 1628 can escape to the outside atmosphere both through an air path 42 and through an inner part of the ink cartridge. The air path 42 is formed between the ink inducing element 47 for supplying the ink and the storage area 41 for storing the ink inducing element 47.

As can be easily understood from the above description, the movement of the air between the above-described space and the outside atmosphere is carried out without any restriction, regardless of the increase or decrease of the relative pressure of the air in the space with respect to the outside atmosphere. Consequently, the leakage of the ink in the ink cartridge shown in Fig. 19D is prevented from occurring. Thus, the ink cartridge of the present invention has improved reliability for sale.

The ink cartridges of embodiments 1-5 have excellent properties due to their innovative designs.

which are particularly noticeable in a small-sized inkjet recording device.

< Embodiment 6 > 5

In this embodiment, an example of specific dimensions of the ink cartridge is explained below.

Figures 21A-21D show the external appearance of the ink cartridge. Of these figures, Figure 2IA is a plan view, Figure 2IB is a side view, Figure 2IC is a view from the ink outlet side, and Figure 2ID is a view from the air connection port side.

Figures 22A, 23B, 23C and 22D are sectional views taken along line A-A in Figure 2IA, B-B in Figure 2IB, C-C in Figure 2IB and D-D in Figure 2IB.

In this embodiment, a bearing portion 41 for supporting the ink inducing element has a diameter of 6.85 mm.

It is preferable to realize the construction in which the ink inducing element is arranged in a middle area

a cross-sectional plane perpendicular to the direction of ink supply from the ink cartridge. Therefore, the ink inducing element can be in pressure contact with a central portion of the ink absorber. 30

Using the above-described construction, the ink can be smoothly moved to the ink inducing element when the ink inducing element induces the ink stored in the ink absorber.

As a result, the ink remaining in the ink absorber is evenly distributed. Therefore, the ink can be constantly supplied to the recording head during the ink supply period depending on the ink consumption. Furthermore, the ink supply efficiency can be improved.

In this embodiment, the central portion of the ink cartridge and the central portion of the ink absorber coincide. However, the innovation is not limited to this configuration. For example, if these portions do not coincide, the ink inducing element may be in pressure contact with the central portion of the ink absorber to achieve the same effects as in the present embodiment.

Figure 23 shows a detailed embodiment of the ink inducing element 47 with a diameter of 6.8 mm not in a circular shape but in the shape of an ellipse.

Compared to the circular shape, the advantage of an elliptically shaped ink inducing element is that it is more difficult for it to fall out of the bearing area 41.

In this embodiment, each fiber of the inducing element 47 is made of polyester with a diameter of 0.3 mm. Polyurethane of polyester polyol is used as a binder for making the fiber bundle.

Figure 24 is a cross-sectional view of the recording head 2 and the ink cartridge 3 already shown in Figures 21A-21D and 22A-22D to show their connection.

ation state maintained by the connection mechanism 37.

Figure 25 shows the contact position between the filter of the ink inlet portion and the ink inducing element according to the present embodiment. In the present embodiment, the outer peripheral surface of the ink inlet portion 45 is provided at a hardened region A, while a region C for forming an ink path is arranged in an inner region B of the ink inducing element.

As shown in Figure 24, the ink inlet portion 45 protrudes with a height of 3.2 mm from a contact surface between the recording head 2 and the ink cartridge, while the depth from the contact surface to the ink inducing element 47 is 2.3 mm. Consequently, the ink inducing element 47 can slide with a clearance L of 0.9 mm.

Therefore, a pressure contact state can be uniformly formed in a range corresponding to the effective diameter of the filter by pressing the region C constituting the recording head side of the ink path 36 against the inner region B of the filter 43 and the ink inducing element 47 excluding the hardened region.

Furthermore, the pressure contact state between the filter of the ink inlet section and the ink inducing element can be controlled so as to avoid the generation of a creeping phenomenon by slidably arranging the ink inducing element in the direction of insertion of the ink inlet section of the recording head. Therefore, the filter and the ink inducing element can be

ment are brought into pressure contact with each other in a suitable manner.

Thus, the ink path 36 from the ink cartridge to the recording head can be formed more reliably compared to other embodiments, and high print quality can be maintained without reducing the amount of supplied ink by trapping air or the like.

As shown in Figure 22D, the ink cartridge of the present embodiment further has an ink inducing element disposed at a central portion of a cross-sectional plane perpendicular to the direction of ink supply from the ink cartridge. In this case, the ink inducing element is in pressure contact with a central portion thereof.

Using the above-described construction, the ink stored in the ink absorber can be smoothly moved toward the central region when the ink inducing element concentrates the ink stored in the ink absorber.

Since the ink remaining in the ink absorber is evenly distributed, the ink can be constantly supplied to the recording head during the ink supply period depending on the ink consumption. Furthermore, the ink supply efficiency can be improved.

In this embodiment, the middle area of the ink cartridge and the middle area of the ink absorber coincide. However, the innovation is limited to this embodiment.

shape is not limited. For example, if these regions do not coincide, the ink inducing element can be brought into pressure contact with the central region of the ink absorber, thereby obtaining the same effects as in the present embodiment.

One of the methods for refilling the ink cartridge with ink comprises the steps of: sucking the air in the ink cartridge via the air communication port 48 and filling the ink cartridge with ink via the ink inlet portion where the ink inducing element is arranged by utilizing pressure equalization.

When the pressure of the internal part of the ink cartridge drops as described above, it is also possible to refill the ink cartridge with ink through the air communication port by performing a suction operation via the ink outlet portion in which the ink inducing element is arranged.
20

Another method of refilling comprises, for example, the steps of making a hole in a part of the element of the ink cartridge and injecting the ink into the ink cartridge through this hole using an injection device, for example, a syringe. In this case, the hole may be sealed via a sealant, for example, a resin.

Compared with the valve mechanism which is a comparative example of Embodiment 1, the connecting means for connecting to the refilling device is less complicated than the valve mechanism. If it is necessary to exhaust air

·

or refilling the ink through the ink outlet portion, the ink cartridge according to the invention, which is constructed so that the ink inducing element is located on the ink outlet side, can be easily refilled with ink.

The ink cartridge designed in accordance with the new design is therefore preferable both in terms of refilling the cartridge with ink and in terms of environmental problems. 10

< Embodiment 7 >

Needless to say, the ink cartridge according to the invention can be used in a full-color ink jet recording apparatus. Figs. 26 and 27 show one of the embodiments of the ink cartridge. Fig. 26 shows a recording unit 4 provided with a recording head 2 and ink cartridges Y, M, C and Bk, while Fig. 27 shows an ink cartridge from the opposite direction.

As is apparent from these figures, the ink cartridges Y, M, C and Bk each have ink inducing elements 47, so that the recording head 2 receives the ink through the ink inducing element 47.

As shown in Fig. 27, the outer side end of the ink inducing member 47 is exposed to the outside atmosphere via an opening for connecting the recording head 2. In this case, no ink leaks from the ink cartridge even if the opening faces downward.

"< Embodiment 8 >

Figure 28 is a perspective view of a printing mechanism using the above-described ink jet recording unit used with a personal computer. Figure 29 is a perspective view of the personal computer with the printing mechanism of Figure 28 built in.

In Figure 28, only the printing mechanism is shown. According to this figure, the ink jet recording unit 4, which includes the recording head 2 and the ink cartridge 3, is mounted on a carriage 1. An engaging portion is formed at one end of the carriage 1 facing the recording head 2. This engaging portion is slidably engaged with a lead screw 6. The lead screw is rotatably supported by a box member 5 formed as a frame of the housing. A guide member (not shown) is provided at the other end of the carriage 1 and is slidably engaged with a guide rail 7 formed on the box member 5. Furthermore, the carriage 1 is designed to move back and forth in the axial direction accompanied by one revolution of the lead screw 6 to keep the position thereof constant.

In synchronization with the forward and backward movement of the carriage 1 described above, the ink jet recording head 2 discharges ink droplets onto a recording medium 14 to record one line of information. The recording head 2 includes: small fluid ejection openings (i.e., orifices), fluid passages, and thermal energy application portions formed on a part of these fluid passages,

Thermal energy generation elements" at the thermal energy application portions to generate the thermal energy to be applied to the ink. The ejection of the ink droplets can therefore be carried out using the thermal energy generated by the thermal energy generation elements.

After recording one line by moving the carriage 1 described above, the recording medium 14, for example a sheet of recording paper, is conveyed over a distance corresponding to this one line, after which the recording unit starts recording the next line. The transport of the recording medium 14 is carried out by a pair of rotatable elements consisting of a transport roller 15 and a pinch roller 16 which is in pressure contact with the roller 15.

The following explanation serves for a more detailed description:

The recording medium 14 with a recording surface facing the openings of the recording head 2 is pressed against the transport roller 15 by the pinch roller and conveyed over a predetermined distance which is large enough to reach the recording position. The transport roller is driven by a sheet feed motor.

After recording, the recording medium 14 is pressed against a discharge roller 19 and moved out of the device by the rotation of the discharge roller 19.

The transport roller 15 and the discharge roller 19 are driven by a sheet feeding element 17. The transmission of the driving force is carried out via a series of reduction gears 20.
5

Denoted at 21 is a paper sensor for detecting the presence of the recording medium 14. Denoted at 22 is a photo interrupter provided as a home position sensor which detects whether or not the carriage 1 is in its home position by using a shutter plate IA for interrupting and opening the path of a light beam. The shutter plate IA is provided on the carriage 1 and moves together with it.

In the printing mechanism described above, when the recording head 2 or the ink cartridge 3 or the ink jet recording unit consisting of these parts in a casing is mounted on the carriage 1, a discharge recovery operation is performed by a suction mechanism provided at the home position of the carriage. Therefore, a channel for supplying the ink from the sponge 37 of the ink cartridge 3 to each ink path in the recording head 2 is excellently formed.

Figure 29 is a perspective view of the PC with the printing mechanism of Figure 28 installed.

As shown in Figure 10, the PC 200 has a slot with an openable cover formed at the deep end of the keyboard section. Therefore, the ink-jet recording unit or the like can be detachably arranged in the slot.

To replace the ink cartridge 3 or the like, there are two ways for detaching the ink cartridge from the PC 200 as shown in the figure. In the first way, the ink cartridge 3 is detachable as an integral part of the ink jet recording unit 4. In the other way, only the ink cartridge 3 is detachable from the PC 200.

When removing the ink jet recording unit 4 as a part, the ink jet recording head 2 is detached from the ink cartridge 3 as shown in the figure after the unit 4 is removed from the computer 200. Then, for example, the recording head is attached to a new ink cartridge in place of the old one. When only the ink cartridge 3 is removed, it is possible to replace the ink cartridge without removing the recording head 2 from the computer 200.

One of the methods for refilling the ink cartridge with ink comprises the following steps: exhausting the air in the ink cartridge through the air communication port 48 and refilling the ink cartridge with ink via the ink inlet portion where the ink inducing element is arranged by utilizing the pressure equalization. 25

When the pressure of the inside of the ink cartridge decreases, in the same manner as described above, it is possible to refill the ink cartridge with ink through the air communication port by performing suction via the ink outlet portion where the ink inducing element is arranged.

Another filling method includes, for example, the steps of making a hole in a part of the

element of the ink cartridge and injecting^ the ink into the ink cartridge through this hole by using a liquid injection device such as a syringe. In this case, the hole may be sealed by a sealant such as a resin.

Compared with the valve mechanism of the comparative example of the embodiment 1, a connecting means for connecting the refilling device is less complicated. When exhausting the air or refilling the ink through the ink outlet portion is required, the ink cartridge of the invention, which is constructed such that the ink inducing element is arranged on the ink outlet side, can be easily refilled with ink.

The ink cartridge designed in accordance with the new design is therefore preferable both in terms of refilling the ink cartridge with ink and in terms of environmental problems.

The present invention can be applied to a facsimile machine using a piezo-type ink jet recording device as a recording system, using piezoelectric elements as elements for generating ink ejection energy. The present invention is particularly suitable for an ink jet recording head having heating elements that use thermal energy as energy required for ink ejection, and a recording device using the head. This is because it enables high density of picture element and high resolution of recording.

: y

Typical designs and principles for this are described in U.S. Patent Nos. 4,723,129 and 4,740,796. This principle is particularly applicable to a so-called on-demand recording system and a continuous recording system. It is suitable for the on-demand type because at least one drive signal is applied to an electrothermal transducer disposed at a liquid (ink) holding layer or channel. The drive signal is large enough to produce a rapid temperature rise from an evaporation nucleation point. Thermal energy is thereby provided by the electrothermal transducer to produce film boiling at the heating section of the recording head, whereby a bubble can be created in the liquid (ink). Each drive signal corresponds to the formation and collapse of such a bubble. The liquid (ink) is ejected through an ejection orifice to produce at least one droplet. The drive signal is preferably in the form of a pulse because the development and collapse of the bubble can be carried out instantaneously. Therefore, the liquid (ink) is ejected with a quick response. The drive signal in the form of a pulse is preferably as described in U.S. Patent Nos ^{. 4,463,359} and 4,345,262. The rate of temperature rise of the heating surface is preferably as described in U.S. Patent No. 4,313,124.

The construction of the recording head may be as in US Pat. Nos. 45 58 33 and 44 59 600, with the neck portion being provided at a curved portion. The construction of the discharge opening, the liquid channel and the electrothermal transducer may be as in the previous

In addition, the present invention is applicable to a structure as described in Japanese Patent Application Laid-Open No. 123670/1984 in which a common slit is used as a discharge port for a plurality of electrothermal transducers. It is also applicable to a structure as described in Japanese Patent Application Laid-Open No. 138461/1984 in which an opening for absorbing pressure waves of thermal energy is formed corresponding to the discharge portion. This is because the present invention is capable of performing the recording operation with certainty and high efficiency regardless of the type of recording head.

The present invention can also be applied to a so-called full-line recording head having a length corresponding to the maximum recording width. Such a recording head can comprise a single recording head and a plurality of recording heads combined to cover the entire width.

Furthermore, the present invention can be applied to a serial type recording head in which the recording head is mounted on the main unit, a removable chip type recording head which is electrically connected to the main device and can be supplied with ink by being mounted in the main unit, or a cartridge type recording head which has an integrated ink tank.

«

^w &diams; &bull; « · ··&diams; &bull; « &bull;
·# &bull;
·«

The arrangement of recovery means and auxiliary means for preliminary operation is preferred because the effect achievable by the present innovation can be further stabilized. Such means are, for example, capping means for the recording head, cleaning means therefor, pressing or suction means, preliminary heating means by the electrothermal transducer or by a combination of the electrothermal transducer and an additional heating element, and means for preliminary ejection operation other than for recording, whereby the recording operation can be further stabilized.

As for the type and number of recording heads mounted, a single head corresponding to an ink of a single color may be provided, or a plurality of heads corresponding to a plurality of ink materials having different recording colors or resulting in different recording densities may be arranged.

Claims (55)

Protection claims 1. An ink cartridge having an ink storage portion with a porous member for storing ink and an ink supply portion for supplying ink from the ink storage portion to the outside of the ink cartridge, characterized by an ink inducing element (47) arranged between the ink storage section and the ink supply section (39) and formed as a fiber bundle, each fiber being arranged parallel to the ink supply direction. 2. Ink cartridge according to claim 1, characterized in that the ink inducing element (47) is slidably held by a holding element (41) and that the sliding distance of the ink inducing element (47) from the side of the ink storage section to the side of the ink supply section is limited by a holding element. 0 3. Ink cartridge according to claim 1 or 2, characterized in that the fiber bundle of the ink inducing element (47) has a hardened region (52) around the peripheral surface thereof in order to hold the fibers together. Telephone: 089 - 54 46 90 100446.2361@compuserve.com Dresdner Bank (Munich) Account 3939 844 (bank code 700 800 00) Tplpfav/mv (IRQ *tt9fi11 mitrmn intrnHiirtinn nhacp Deutsche Bank (Munich) Account 286 1060 (bank code 700 700 10) &igr;elerax(& i). oea - 53 26 11 (During introduction phase _{Pos(bank m} &ldquor; _{chen) Kl0} . ₆₇₀ . ₄₃ . ₈₀₄ (blz 700 ioo so) Telex: 5-24 845 twice a week.J , . .San^i Bank (Düsseldorf) Account SOO 047 (bank code 301 307 po) 4. Ink cartridge according to one of the preceding claims, characterized in that the fiber bundle is formed by permeation of a binding agent into the peripheral surface of the ink inducing element (47). 5. Ink cartridge having a porous member for storing ink supplied to a recording head through an ink inlet portion of the recording head, characterized by an ink inducing member (47) having a first end portion that can be brought into pressure contact with the ink inlet portion (45) and a second end portion that can be brought into pressure contact with the porous member (37), the ink inducing member (47) being formed as a fiber bundle, each fiber of which extends in a direction from the second end portion to the first end portion. 0 6. Ink cartridge according to claim 5, characterized in that the first end of the ink inducing element (47) has a region which can be brought into pressure contact with a region of a filter (43) in the ink inlet section (45) of the recording head (2), and that the former region is larger than the latter region. 7. Ink cartridge according to claim 5 or 6, characterized in that the ink inducing element (47) of the ink cartridge (3) is arranged such that a pressure contact portion of the ink inducing element with the ink inlet portion (45) is arranged within the peripheral surface of the ink inducing element (47). 8. Ink cartridge according to claim 7, characterized in that the pressure contact portion is spaced in the radial direction thereof more than 0.5 mm from the peripheral surface of the ink inducing element (47). 9. Ink cartridge according to one of claims 5 to ₁ , characterized in that the ink inducing member (47) can slide in a direction in which the recording head (2) is connected to the ink cartridge (3). 10. Ink cartridge according to one of claims 5 to 9, characterized in that the sliding distance of the ink inducing element (47) is in a range of 0.1 mm to 3 mm. 11. Ink cartridge according to one of claims 5 to 10, characterized in that the fiber bundle consists of polyester fibers with an average diameter in a range of 0.01 mm to 0.05. 12. Ink cartridge according to one of claims 5 to 11, characterized in that the fiber bundle of the ink inducing element (47) is formed by permeation of a binder into the peripheral surface of the ink inducing element. 13. Ink cartridge according to claim 12, characterized in that the binder is polyether polyol urethane. 14. Ink cartridge according to one of claims 5 to 13, characterized in that the ink supply section (39) of the cartridge (3), which is arranged in a casing, is sealed with a sealing element (1626) I .· ·: 5 : ⁴ VKJ which can be easily removed when the ink cartridge (3) is put into use. 15. Ink cartridge according to claim 14, characterized in that the space formed between the sealing element (1626) and the ink inducing element (47) is in communication with the space formed in the ink cartridge (3). 16. Ink cartridge according to claim 14 or 15, characterized in that the sealing element (1626) is an aluminum laminate film. 17. Ink cartridge according to one of claims 14 to 16, characterized in that the sealing element (1626) has a plurality of layers, of which at least one layer consists of polyolefin and serves as a contact layer which is brought into contact with the ink cartridge by thermal welding. 20 18. Ink cartridge according to one of claims 14 to 17, characterized in that an ink absorber (1627) is arranged between the sealing element (1626) and the ink inducing element (47). 19. Ink cartridge according to claim 18, characterized in that the ink absorber (1627) is made of a tanning material of polyvinyl alcohol. 20. Ink cartridge according to claim 18 or 19, characterized in that the ink absorber (1627) is fixed to the sealing element (1626) by thermal welding. 21. Ink cartridge according to one of claims 18 to 20, characterized in that the ink absorber (1627) consists of the same material as the contact layer of the sealing element. 22. Ink cartridge according to one of claims 1 to 4, characterized in that the capillary force of the ink inducing element (47) is greater than that of the porous element (37) and that the pressure loss of the ink inducing element (47) is 20 mm water column or less. 23. Ink cartridge according to one of claims 1 to 4 or 22, characterized in that the capillary force of the ink inducing element (47) is in a range of 85 to 400 mm water column. 24. Ink cartridge according to one of claims 1 to 4, 22 or 23, characterized in that the average size of the space between the fibers in the ink inducing element (47) is in a range of 0.01 mm to 0.05 mm. 25. Ink cartridge according to one of claims 1 to 44, 22, 23 or 24, characterized in that the length of the ink inducing element (47) in the ink feed direction is in a range of 2 mm to 6 mm. 26. Ink cartridge according to one of claims 1 to 4 or to 25, characterized in that the ink inducing element (47) has a region with a fiber density in a range of 100 to 200 fibers/mm ² . 27. Ink cartridge according to one of claims 1 to 4 or to 26, characterized in that the effective diameter of the ink inducing element (47) is in a range of 1 mm to 18 mm. 28. Ink cartridge according to one of claims 1 to 4, or 22 to 27, characterized in that the ink inducing element (47) is arranged in the central region of a cross section of the porous element (37) in the ink supply direction.
10 29. Ink cartridge according to one of claims 1 to 4 or 22 to 28, characterized in that the ink inducing element (47) is arranged in the central region of a cross section of the ink cartridge (3) in the ink supply direction. 30. Ink cartridge according to claim 5, characterized in that the ink inducing element (47) is arranged in the central region of a cross section of the porous element (37) in the ink supply direction. 31. Ink cartridge according to claim 5, characterized in that the ink inducing element (47) is arranged in the central region of a cross section of the ink cartridge (3) in the ink supply direction. 32. Ink cartridge according to claim 5, characterized in that the ink inducing element (47) is slidably held by a holding element (41) and that the sliding distance of the ink inducing element (47) from the side of the ink storage section to the side of the ink supply section is limited by a stop element. 33. Ink cartridge according to claim 1, characterized in that the ink supply section (39) has an air path for allowing air to be introduced into the ink cartridge (3) from the ink supply section (39) to escape to the outside of the ink cartridge (3) when the ink inlet section (45) of the recording head (2) is inserted into the ink supply section (39). 34. Ink cartridge according to claim 33, characterized in that the air path is formed as a groove (42) on an inner wall of the ink supply section (39). 35. Ink cartridge according to claim 33 or 34, characterized in that the air path is connected to an air connection opening (48) through the interior of the ink cartridge (3) in order to establish a connection with the outside of the ink cartridge. 36. Ink cartridge according to one of claims 33 to 35, characterized in that the capillary force of the ink inducing element (47) is higher than that of the porous element (37) and that the pressure loss of the ink guide element is 20 mm water column or less.
25 37. Ink cartridge according to one of claims 33 to 36, characterized in that the capillary force of the ink inducing element (47) is in a range of 85 to 400 mm water column. 38. Ink cartridge according to one of claims 33 to 37, characterized in that the ink inducing element (47) is designed as a fiber bundle, each fiber being arranged parallel to the ink supply direction and the average size of the space between the fibers in the ink inducing element (47) is in a range of 0.01 mm to 0.05 mm. 39. Ink cartridge, characterized by a porous element (3 7) for storing ink and an ink supply section (39) having an outlet for supplying ink to an ink jet head (2) and into which an ink inlet section (45) of the ink jet head is inserted, the ink supply section (39) having an air path for allowing air introduced into the ink cartridge (3) from the ink supply section to escape to the outside of the ink cartridge (3) when the ink inlet section (45) is inserted into the ink supply section (39). 40. Ink cartridge according to claim 39, characterized in 0 net that the air path is formed as a groove (42) on an inner wall of the ink supply section (3.9). 41. Ink cartridge according to claim 39 or 40, characterized in that the air path is connected to an air connection opening (48) via the interior of the ink cartridge (3) in order to establish a connection with the outside of the ink cartridge. 42. Ink jet recording device comprising a recording unit having a recording head with a plurality of ejection openings, an ink cartridge having a porous member for storing ink, and an ink inlet portion for supplying ink from the ink cartridge, characterized in that net that the ink cartridge (3) has an ink inducing element (47), one end of which is in pressure contact with the ink inlet section (45) and the other end in pressure contact with an ink absorber (37) and which consists of a fiber bundle, wherein a carriage (1) is provided for detachable mounting of the recording unit. 43. Ink jet recording device according to claim 42, characterized in that the capillary force of the ink ink inducing element (47) is greater than that of the porous element (37) and that the pressure loss of the ink inducing element (47) is 20 mm water column or less.
15 44. Ink jet recording device according to claim 42 or 43, characterized in that the ink supply section (39) has an air path for allowing air entering the ink cartridge (3) from the ink supply section to escape to the outside of the ink cartridge when the ink inlet section (45) of the recording head (2) is inserted into the ink supply section (39). 45. Ink jet recording device according to one of claims 42 to 44, characterized in that the capillary force of the ink inducing element (47) is greater than that of the porous element (37), that the pressure loss of the ink inducing element is 20 mm water column or less and that the ink supply element (39) has an air path for allowing air introduced into the ink cartridge from the ink supply element to escape to the outside of the ink cartridge when the ink inlet section (45) of the recording head is in &diams; * &bull;&bull;&bull;!It the ink supply element (39) is inserted. 46. Ink jet recording device with an ink jet recording unit, which has a recording head for ejecting ink and an ink cartridge for storing ink, wherein a recording process is carried out by ejecting ink onto a recording medium, characterized in that the ink cartridge (3) has an ink absorber (37) for holding ink and that an ink inducing element (47) is arranged between the ink absorber (37) and an outlet for supplying ink to the outside, wherein the capillary force of the ink inducing element (47) is greater than that of the ink absorber (37) and the pressure loss of the ink inducing element is 20 mm water column or less. 47. Ink jet recording device according to claim 46, 0 characterized in that the ink supply section (39) has an air path for allowing air introduced into the ink cartridge (3) from the ink supply section (39) to escape to the outside of the ink cartridge when the ink inlet section (45) of the recording head is inserted into the ink supply section. 48. Ink jet recording apparatus comprising a recording unit having a recording head for 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 to each other, and the recording head having an ink inducing element which is in pressure contact with the ink cartridge and which receives ink supplied to the recording head (2), characterized in that the ink cartridge (3) has an ink absorber (37) for storing the ink to be supplied to the recording head (2), an ink supply section (39) into which an ink inlet of the recording head (2) is inserted and which has an outlet formed at the front end of the ink cartridge (3) so as to form an ink path connecting the ink inlet to the ink absorber (37), an ink inducing element (47) having one end in pressure contact with the ink inlet inserted into the ink supply section and another end in pressure contact with the ink absorber (37), and an air communication path arranged between the ink inducing element (47) and a wall of the ink supply section (39) and allowing air introduced into the ink cartridge (3) from the ink supply section to escape to the outside of the ink cartridge when the Ink inlet section (45) is inserted into the ink supply section (39). 49. Ink jet recording unit comprising a recording head with a plurality of ejection openings for ejecting ink and an ink cartridge with a porous member for holding the ink supplied to the recording head, characterized in that the recording head (2) has an ink inlet for supplying ink from the ink cartridge (3) and the ink cartridge (3) an ink inducing element "30 (47) having one end in pressure contact with the ink inlet and another end in pressure contact with the ink absorber (37) and consisting of a fiber bundle in which each fiber is directed from the porous element towards the ink inlet section. 50. Ink jet recording unit according to claim 49, characterized in that the capillary force of the ink inducing element (47) is greater than that of the porous element and that the pressure loss of the ink inducing element is 20 mm water column or less. 51. Ink jet recording unit according to claim 49 or 50, characterized in that the air path which allows air to escape to the outside is formed in the ink supply section (39) and is formed when the recording head (2) and the ink cartridge (3) are connected to each other, and is arranged in a space between the ink inducing element and a wall of the ink supply section. 52. Ink jet recording unit according to one of claims 49 to 51, characterized in that the capillary force of the ink inducing element (47) is greater than that of the porous element (37) and that the pressure loss of the ink inducing element is 20 mm water column or less when the recording head (2) and the ink cartridge (3) are connected to each other, wherein the air path is arranged in a space between the ink inducing element and a wall of the ink supply section. 53. Ink jet recording unit in which an ink jet head for ejecting ink and an ink cartridge for storing ink to be supplied to the ink jet head are detachably connected to one another, characterized in that the ink cartridge (3) has an ink absorber (37) for holding stored ink and that an ink inducing element element (47) is arranged between the ink absorber and an outlet for supplying ink to the outside, wherein the capillary force of the ink inducing element (47) is greater than that of the ink absorber (37) and the pressure loss of the ink inducing element is 20 mm water column or less, and that an ink inlet of the ink jet head is in contact with the ink inducing element. 54. Ink jet recording unit according to claim 53, characterized in that an air path for letting air escape to the outside is formed in an ink supply section (39) and is arranged between the ink inducing element (47) and a wall of the ink supply section. 55. A recording unit comprising a recording head (2) for recording by ejecting ink and an ink cartridge (3) for supplying ink to the recording head, which are detachably connected to each other, wherein the recording head (2) has an ink inducing section (47) which is in contact with the ink cartridge (3) and receives the ink supply end of the ink inducing element (47) which is in contact with the ink inlet inserted into the ink supply section (39), the other end of the ink inducing element (47) being in pressure contact with the ink absorber (37), and wherein the ink cartridge (3) has an ink absorber (37) for storing ink to be supplied to the recording head (2), an ink supply section (39) into which an ink inlet of the recording head (2) is insertable and which has an outlet formed at a front end of the ink cartridge (3) for forming an ink supply path bil- which connects the ink inducing element (47) to the ink absorber (37), and has an air path for allowing air to escape to the outside, which air path is arranged between the ink inducing element (47) and a wall of the ink supply section (39) when the recording head (2) is connected to the ink cartridge (3).