JP2702808B2 - Ink supply device and ink receiving unit - Google Patents

Description

The present invention relates to an ink supply device for an ink jet recording head, and an ink supply unit and an ink cartridge in the ink supply device.

2. Description of the Related Art As an output device of an electronic device such as a word processor and a personal computer, a printer provided with an ink jet recording head is known.

FIG. 5 is a cross-sectional view showing an ink supply device and an ink jet recording head in this type of conventional printer.

In FIG. 1, reference numeral 10 denotes an ink cartridge which is a part of the ink supply device, 11 denotes an ink receiving unit which is also a part of the ink supply device, and 12 denotes an ink jet recording head. The ink receiving unit 11 has an ink tank inside
The ink jet recording head 12 is in communication with the ink tank 13. The ink tank 13 also has an ink supply port 14 into which the ink cartridge 10 is inserted. The ink jet recording head 12 has piezoelectric elements 16 and 17 that apply pressure to the ink sent through the passage 15. In the ink tank 13, sensors 18 and 19 for detecting the liquid level of the ink are provided.

FIG. 6 is a sectional view showing the conventional ink cartridge shown in FIG. 5 in an enlarged manner in the vertical direction.

As shown in FIG. 1, sealing sheets 10a and 10b for sealing are provided on the upper surface and the lower surface of the ink cartridge 10, respectively, and the ink 10c is stored inside thereof. When using this ink cartridge 10,
The cutter 20 having the protrusions 20a is pressed from the upper surface side of the ink cartridge 10 to break the sealing sheet 10a, and the lower surface side of the ink cartridge 10 is inserted into the ink supply port 14 of the ink receiving unit 11. Since the ink supply port 14 is provided with the break pin 21, the sealing sheet 10 b
Is pressed against this and is broken. Thereby, the ink 10c in the ink cartridge 10 flows into the ink tank 13 of the ink receiving unit 11 and is stored.

In such an ink supply device, an ink cartridge
If the sealing sheets 10a and 10b are torn once, the injection of the ink 10c cannot be stopped halfway, and all the ink in the ink cartridge 10 will flow out. There is a risk that it will. For this reason, the present applicant has already proposed a technique of preventing a dripping from an ink cartridge by providing a porous member in an ink chamber of an ink cartridge and impregnating the ink with the porous member (Japanese Patent Application No. 2-89664, (Filed on April 4, 1990).

[Problems to be Solved by the Invention] The conventional ink supply device shown in FIG. 5 and the ink supply device proposed by the present applicant have the following disadvantages. That is, when the ink in the ink tank becomes empty, air enters the nozzles of the ink jet recording head, so that even if ink is refilled with the ink cartridge, ink cannot be ejected from the nozzle once filled with air. , Printing becomes impossible. This causes an operation of removing air bubbles from the nozzle each time.

In order to avoid such inconveniences, there is a method of constantly monitoring the ink level in the ink tank so that the ink tank is not completely emptied. However, for this purpose, a two-electrode sensor for detecting the liquid level of the ink is separately required, and in particular, the liquid level of the ink which is hard to dry and harden for this type of ink jet recording head is detected. This requires a rather expensive sensor.

Accordingly, an object of the present invention is to provide an ink supply device and an ink receiving unit that can prevent air bubbles from entering an ink jet recording head without using an expensive sensor.

[Means for Solving the Problems] An ink supply device for achieving the above object is an ink supply device for supplying ink to an ink supply passage leading to a nozzle of an ink jet recording head. And an ink path containing a porous member having the other end detachably connected to one end of the ink supply path, and an opposite side of the ink supply path communicating with the nozzle. The fiber bundle member is provided so as to be narrowed from the ink path side toward the ink supply path on the nozzle side.

Further, the ink receiving unit for achieving the above-described object includes:
In an ink receiving section, one end of which is connected to an ink supply path side for supplying ink to an ink supply path communicating with a nozzle of the ink jet recording head, one end is connected to the nozzle of the ink jet recording head, and the other end is ink. An ink supply path connected to an ink path containing a porous member for supplying ink, and a fiber bundle member provided on a connection portion side of the ink supply path to receive ink from the porous member And a filter member provided on the ink receiving portion side where the fiber bundle member is provided, for allowing ink to pass therethrough and preventing air bubbles from passing therethrough, wherein the fiber bundle member is located between the ink path side and the ink supply path on the nozzle side. It is characterized by being provided to be narrowed down.

[Operation] When the amount of ink impregnated in the porous member in the ink cartridge is large, the ink passes through the fiber bundle member and is sent to the recording head side. When the amount of ink in the ink cartridge decreases, the air in the ink cartridge becomes air bubbles and reaches the fiber bundle member or the filter member.
In particular, air bubbles that have reached the filter member adhere to the filter surface or the fiber bundle member surface without being crushed by the surface tension. As the amount of ink decreases, the amount of bubbles increases, and eventually adheres to the entire surface such as the filter surface and automatically shuts off the ink supply path to the recording head. At this time, the used ink cartridge is detached to replace the ink cartridge, and a new ink cartridge impregnated with the porous member is attached to the ink cartridge. Etc. dry and air accumulates in the filter. Thereafter, when a new ink cartridge is installed, the air in the filter hardly enters the ink supply path due to the fiber bundle member provided at one end of the ink supply path. Even if it enters, it is held inside the fiber bundle member and does not reach the nozzle side. In addition, since the fiber bundle member is narrowed down toward the nozzle side, the air that has entered is prevented from being further sent to the ink supply path. This facilitates replacement of the ink cartridge.

Further, even if ink supply to some fiber bundle members becomes difficult due to the incorporation of air, the flow resistance of the fiber bundle members is low, so that ink flows from other fiber bundle portions, and ink is not ejected from nozzles. Ink can be supplied without any problem.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples.

FIG. 1 is a sectional view showing an ink cartridge, an ink receiving section, and an ink jet recording head before use in one embodiment of the present invention.

As shown in FIG.
a housing 31 made of, for example, resin, which is a container having only one a, and an ink chamber 32 for storing ink inside the housing 31 and an ink for guiding ink in the ink chamber 32 to the outside. A path 33 is formed. One end of the ink path 33 communicates with the ink chamber 32 above the ink chamber 32, a part of the side surface is covered with the partition wall 34, and the other end is opened downward.

The inside of the ink chamber 32 and the ink path 33 is filled with a porous member 35 impregnated with ink. Porous member 35
Is a member in which the capillary path is complicated and complicated, and is formed of a member easily impregnated with a liquid, such as a sponge or felt made of polyester or another material.

A plurality of ribs (projections) 36 are provided outside the porous member 35, that is, between the inner wall of the ink chamber 32 and the partition wall 34 and the housing 31 of the ink path 33. The plurality of ribs 36 form an air introduction passage 37 between the housing 31 and the porous member 35 for introducing air from outside to the ink chamber 32. Near the opening of the ink path 33, the porous member 35 forms a flat end face 35a, and this end face 35a
It is formed inside from the 33 opening surface. This porous member
A filter member 38 of a multi-porous body is attached to the end face 35a of the 35 in close contact. A packing 39 is provided around the filter member 38, and the packing is used to prevent air and ink from passing therethrough.
It is fixed to the partition 34 via 39.

The multi-porous body constituting the filter member 38 is a net-like member through which ink can pass, and is formed by weaving a fiber such as a resin such as polyester, stainless steel, or glass into a cloth. The diameter of the mesh of the multi-porous body only needs to be large enough to allow ink to pass therethrough and not allow air bubbles to pass therethrough. This depends on the suction force of the nozzle of the ink jet recording head and the surface tension of the ink. It may be in the range of 〜25 μm. However, this range is when the suction force of the nozzle of the inkjet recording head 12 is about 260 mm water head pressure and the surface tension of the ink is about 37 dyn / cm.

On the opening side of the ink path 33 from the filter member 38, a packing 40 is provided. The packing 40 is a member for preventing external air from directly entering the ink path 33 when the ink cartridge 30 is mounted on the ink receiving unit 42, and is made of, for example, an elastic body such as rubber. ing.
The opening of the ink path 33 of the ink cartridge 30 before use is sealed by a sealing sheet 41 made of, for example, aluminum foil. The sealing sheet 41 is configured to be easily broken at the time of use. As the sealing sheet 41, other than aluminum foil, other metal or resin that can be easily opened at the time of mounting is used.

The housing 31 may be formed by partially forming a resin by injection molding, inserting a porous member 35 or the like into the resin, and then joining the members. Further, the housing 31 may be formed of a metal, and in that case, a part partially processed by a press may be joined and formed. The ink to be impregnated into the porous member 35 is a mixture of a dye, an organic solvent, and about 30% water, and has a viscosity higher than that of a commonly used ink. Therefore, unless the porous member 35 is intentionally pressed, the ink stays in the porous member 35 due to surface tension and does not drop naturally from the surface of the porous member 35. As a result, unnecessary outflow of ink can be avoided. Ink cartridge 30
To inject the ink into the ink cartridge 30, the pressure in the ink cartridge 30 may be reduced by a device such as a vacuum pump.

Next, the ink receiving section 42 to which the ink cartridge 30 is mounted and the ink jet recording head 43 will be described. The ink receiving unit 42 and the inkjet recording head 43 are integrally formed as shown in FIG. 3, and the ink receiving unit 42 does not have an ink tank as in the related art.

The ink receiving section 42 is provided with an ink supply path 44 for guiding ink without an ink cartridge to the ink jet recording head, and one end thereof communicates with the nozzle 45 and the pressure chamber 46 of the ink jet recording head 43. A piezoelectric element 47 is formed on a part of the inner wall of the pressure chamber 46, and pressurized ink is ejected from the nozzle 45 to perform recording.

The other end of the ink supply path 44 is provided with an ink reservoir 48 having an open end, and the inside of the ink reservoir 48 is filled with a fiber bundle member 49. The fiber bundle member is configured by bundling a plurality of linear members such as plastic fibers, glass fibers, and metal wires. By bundling a plurality of linear members in this way, a capillary path is formed between the linear members. In this embodiment, a plurality of polyethylene plastic fibers (20 to 30 μm in diameter)
m) as a core, a plurality of polypropylene plastic fibers (20 to 30 μm in diameter) are put on the outside of the bundle, and the whole is formed, for example, in a columnar shape. The fiber bundle member 49 is narrowed down by a tapered portion below the ink reservoir 48. For this reason, the upper portion of the fiber bundle member 49 is cylindrical and has a substantially uniform density, whereas the lower portion has a higher density than the upper portion. As a result, capillary action occurs effectively.

End face 49 of fiber bundle member 49 on the opening end side of reservoir 48
a is formed flat so that the ink reservoir 48 is in close contact with the filter member 38 when the ink cartridge 30 is mounted, that is, when the ink reservoir 48 is inserted into the opening of the ink path 33 of the ink cartridge 30. Project above the open end of the. In the present embodiment, the end face of the fiber bundle member 49
49a is projected 2-3mm, and when configured in this way,
The fiber bundle member 49 is deformed by hitting the bottom surface 48a of the ink reservoir 48 to increase the squeezing effect, so that the capillary phenomenon is likely to occur. In the figure, the fiber bundle member 49 is omitted from the bottom of the ink reservoir 48, but actually, the ink reservoir 48 is not shown.
48 is filled with a fiber bundle member 49, and the fiber bundle member 49 and the tip of the ink supply path 44 are in contact with each other.

 Next, the operation of this embodiment will be described.

First, attachment of the ink cartridge 30 to the ink receiving unit 42 will be described. Advances in the arrow D ₁ direction in a state where the ink cartridge 30 of the unused broke the sealing sheet 41, is mounted on the ink reservoir 48 portion. That is, the ink cartridge 30 is mounted so that the ink reservoir 48 of the ink receiving unit 42 is inserted into the opening of the ink path 33 of the ink cartridge 30. Thereby, the porous member 35 in the ink path 33 and the end face 49 of the fiber bundle member 49 in the ink reservoir 48
and a are in close contact with each other via a filter member 38 made of a multiporous body. In this case, since the packing 40 is provided, the ink reservoir 48 of the ink receiving section 42 is hermetically inserted and mounted in the ink path 33 of the ink cartridge 30. Therefore, the outside air does not directly enter the ink path 33, but is guided into the ink chamber 32 through the air introduction path 37.

As a result, the ink contained in the porous member 35 in the ink chamber 32 due to the capillary phenomenon is discharged through the porous member 35 in the ink path 33, the filter member 38, and the fiber bundle member 49 in the ink reservoir 48. It is supplied to the passage 44. This ink is further supplied to the pressure chamber 46 of the ink jet recording head 43.
Is supplied to the recording medium and is urged by the recording signal to be ejected from the nozzle 45 to print on a sheet or the like.

When the amount of ink contained in the porous member 35 of the ink cartridge 30 decreases, air guided from the outside of the ink cartridge 30 through the air introduction passage 37 into the ink chamber 32 is bubbled inside the porous member 35. And reaches the multi-porous filter member 38. The air bubbles that have reached the filter member 38 are not broken by the surface tension due to the fine mesh of the multi-porous body, and adhere to the filter surface and cover a part of the surface without passing through the filter member 38. At this time, the ink can be passed through the filter member 38 through the gap between the bubbles attached to the filter member 38, so that the ink is supplied. As the amount of ink decreases, the amount of bubbles increases, and when the ink impregnated in the porous member 35 becomes empty, it eventually adheres to the entire surface of the filter. When the air bubbles adhere to the entire surface of the filter member 38, the ink path to the recording head to the ink jet recording head 43 is automatically shut off. That is, the supply of the ink to the inkjet recording head 43 is automatically stopped. Since the recording cannot be performed by stopping the supply of the ink, the operator can know that the ink is insufficient and replace the ink cartridge 30.

According to the present embodiment, since no bubbles are mixed in the ink receiving unit 42 and the ink jet recording head 43,
When printing with the inkjet recording head 43, inconvenience such as missing dots does not occur. Further, although the supply of ink is stopped, the state in which the fiber bundle member 49 in the ink reservoir 48 is filled with ink is maintained, so that even if the ink cartridge 30 is detached for replacement,
No air enters inside. Therefore, it is not necessary to perform the bubble removing operation, and it is not necessary to detect the ink liquid level by using an expensive sensor as in the related art, so that the manufacturing cost can be reduced and the reliability can be improved accordingly.

FIG. 2 is a sectional view showing an ink cartridge, an ink receiving section, and an ink jet recording head according to another embodiment of the present invention.

The difference between this embodiment and the embodiment of FIG. 1 is that in this embodiment, the filter member 138 is not provided on the ink cartridge 130 side, but is provided on the ink receiving section 142 side. .

As shown in the figure, an ink cartridge 130 has a housing 131 similar to the housing 31 in the embodiment of FIG.
An ink chamber 132 for storing ink and an ink path 133 for guiding the ink in the ink chamber 132 to the outside are formed inside the housing 131.

The only difference between the ink cartridge 130 of this embodiment and the ink cartridge 30 of the embodiment shown in FIG. 1 is that no filter member is provided in the ink path 133, and the other configurations are exactly the same. In the vicinity of the opening of the ink path 133, the porous member 135 has an end face 135 having a flat tip end face.
The end face 135a has a shape in which the center protrudes from the periphery thereof so that when the ink reservoir 148 is inserted into the opening of the ink path 133, the end face 135a comes into close contact with the filter member 138 on the ink reservoir 148 side. Has become. And this end face
135a is exposed with nothing attached. A packing 140 is provided in the ink path 133 on the opening side from the end surface 135a of the porous member 135 in the same manner as in the embodiment of FIG.

The ink receiving section 142 to which the ink cartridge 130 is mounted and the ink jet recording head 143 will be described.

An ink supply path 144 is provided in the ink receiving section 142, and one end thereof communicates with the inside of the inkjet recording head 143. An ink reservoir 148 having an open end is provided at the other end of the ink supply path 144, and the inside of the ink reservoir 148 is filled with a fiber bundle member 149.

The difference between the ink receiving unit 142 in the present embodiment and the ink receiving unit 42 in the embodiment of FIG.
148 is only provided with a filter member 138,
Other configurations are exactly the same. The end surface 149a of the fiber bundle member 149 on the opening end side of the ink reservoir 148 is formed flat, and a filter member 138 of a multi-porous body similar to the embodiment of FIG. Installed.

 Next, the operation of this embodiment will be described.

The ink cartridge 130 is mounted so that the ink reservoir 148 of the ink receiving unit 142 is inserted into the opening of the ink path 133 of the ink cartridge 130. As a result, the end face 135a of the porous member 135 in the ink path 133 and the ink reservoir
The fiber bundle member 149 in the 148 is in close contact with the fiber bundle member 149 via the filter member 138 made of a multiporous body. As a result, the ink contained in the porous member 135 in the ink chamber 132 is supplied to the ink through the porous member 135 in the ink path 133, the filter member 138 in the ink reservoir 148, and the fiber bundle member 149 due to the capillary action. Route 144. This ink is further supplied to the ink jet recording head 143 to perform printing on paper or the like.

When the amount of ink contained in the porous member 135 of the ink cartridge 130 decreases, the bubbles reach the multi-porous filter member 138. The air bubbles that reach the filter member 138 are not broken by the surface tension due to the fine mesh of the multi-porous body, adhere to the filter surface, and cover a part of the surface without passing through the filter member 138. At this time, the ink can be passed through the filter member 38 through the gap between the bubbles attached to the filter member 138, so that the ink is supplied. As the amount of ink decreases, the amount of bubbles increases, and when the ink impregnated in the porous member 135 becomes empty, it eventually adheres to the entire surface of the filter.
When the air bubbles adhere to the entire surface of the filter member 138, the ink path of the recording head to the inkjet recording head 143 is automatically shut off. That is, the supply of the ink to the inkjet recording head 143 is automatically stopped. Since the recording cannot be performed by stopping the ink supply,
The operator can know the ink shortage and replace the ink cartridge 30.

According to the present embodiment, no bubbles are mixed into the ink receiving unit 142 and the inkjet recording head 143, so that there is no inconvenience such as missing dots when printing by the inkjet recording head 143. Although the supply of ink is stopped, the state in which the fiber bundle member 148 in the ink reservoir 148 is filled with ink is maintained, so that even if the ink cartridge 130 is detached for replacement, Does not enter the air. Therefore, it is not necessary to perform the bubble removing operation, and it is not necessary to detect the ink liquid level by using an expensive sensor as in the related art, so that the manufacturing cost can be reduced and the reliability can be improved accordingly.
Further, in this embodiment, since the opening of the ink reservoir 148 is covered with the filter member 138, it is possible to prevent dust from entering the inside of the ink receiving unit 142 and the inside of the inkjet recording head 143. That is, the filter member 138
The diameter of the mesh of the multi-porous body is in the range of 1 to 25 μm, and the orifice diameter of the nozzle of
Since it is μm, it is possible to prevent dust from being clogged which may cause nozzle clogging. Moreover, according to the present embodiment, since the filter member 138 is not provided on the ink cartridge 130 side, the ink cartridge 130, which is a consumable item, is more inexpensive.

FIG. 3 is a sectional view showing an ink receiving section and an ink jet recording head according to still another embodiment of the present invention.

In the figure, reference numeral 242 denotes an ink receiving unit, 243 denotes an ink jet recording head, and 248 denotes an ink reservoir of the ink receiving unit 242. As can be seen from the drawing, in this embodiment, the packing 40 is not provided in the ink cartridge, and the packing 2 is provided on the outer periphery of the upper portion of the ink reservoir 248.
Forty are provided. Other configurations and operations of this embodiment are exactly the same as those of the embodiment of FIG.

FIG. 4 is a sectional view showing an ink receiving section and an ink jet recording head according to still another embodiment of the present invention.

In the figure, reference numeral 342 denotes an ink receiving unit, 343 denotes an ink jet recording head, 348 denotes an ink reservoir of the ink receiving unit 342, and 338 denotes a filter member. As is clear from the drawing, in this embodiment, the packing 140 is not provided in the ink cartridge, and the ink reservoir 348 is not provided.
A packing 340 is provided on the outer periphery of the upper part of. Other configurations and operations of this embodiment are exactly the same as those of the embodiment of FIG.

According to the embodiment shown in FIGS. 3 and 4, compared to the embodiment shown in FIGS. 1 and 2, there is no need to provide a packing on the ink cartridge side, so that this is a consumable product. The ink cartridge becomes cheaper.

[Effect of the Invention] According to the ink supply apparatus of the present invention, ink can be supplied without bubbles being mixed when ink is supplied from the ink supply side to the recording head side. Further, since the fiber bundle member is provided so as to be narrowed toward the recording head side, even if air bubbles are mixed in the fiber bundle member, further mixing is prevented, and the supply of air bubbles to the head side is ensured. Blocked, stable ink ejection can be performed. Therefore, there is no concern that air bubbles and the like may be mixed, and the replacement work of the ink cartridge and the like becomes easy.

Further, according to the ink receiving section of the present invention, it is possible to effectively prevent air bubbles from entering the ink supply path. Further, if a filter member for preventing the passage of air bubbles is provided on the receiving portion side, consumables on the ink cartridge side can be reduced, and the ink cartridge can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ink cartridge, an ink receiving section, and an ink jet recording head according to an embodiment of the present invention. FIG. 2 is a sectional view of an ink cartridge, an ink receiving section, and an ink jet recording head according to another embodiment of the present invention. FIGS. 3 and 4 are cross-sectional views of an ink receiving section and an ink jet recording head according to still another embodiment of the present invention. FIG. 5 is a cross-sectional view of a conventional ink jet recording head and ink receiving section. The figure is a sectional view of the conventional ink cartridge used in FIG. 30, 130 ... ink cartridge, 31, 131 ... housing, 32, 132 ... ink chamber, 33, 133 ... ink path, 34 ...
... partition walls, 35, 135 ... porous members, 36 ... ribs, 37 ...
Air introduction passage, 38, 138, 338 ... Filter member, 39, 40,
140, 240, 340: packing, 41: sealing sheet, 42, 142, 242, 342: ink receiving unit, 43, 143, 24
3, 343 ink jet recording head, 44, 144 ink supply path, 48, 148, 248, 348 ink reservoir 4,
9, 149: Fiber bundle member.

Claims (2)

(57) [Claims] 1. An ink supply device for supplying ink to an ink supply passage communicating with a nozzle of an ink jet recording head, wherein one end communicates with an ink chamber containing a porous member for impregnating the ink, and the other end communicates with the ink chamber. An ink path incorporating a porous member detachably connected to one end of the ink supply path,
A fiber bundle member provided at one end opposite to the ink supply path communicating with the nozzle.The fiber bundle member is provided so as to be narrowed down from the ink path side toward the ink supply path on the nozzle side. An ink supply device, characterized in that: 2. An ink receiving section having one end connected to an ink supply path side for supplying ink to an ink supply path leading to a nozzle of an ink jet recording head, one end of which communicates with the nozzle of the ink jet recording head. An ink supply path connected to an ink path having a built-in porous member for supplying ink at the other end, and an ink supply path provided on the side of the ink supply path for receiving ink from the porous member; A fiber bundle member, and a filter member provided on the ink receiving unit side where the fiber bundle member is provided, for allowing ink to pass therethrough and preventing air bubbles from passing therethrough, wherein the fiber bundle member is closer to the nozzle than the ink path side. An ink receiving section provided so as to be narrowed down toward the ink supply path of the ink supply section.