JPS5959456A - Ink cartridge and ink-supplying device - Google Patents

Abstract

PURPOSE:To enable to securely perform a changing-over action for pressure feeding of an ink at the time of purging, by a method wherein a stiff casing incorporating an ink-containing bag made of a flexible material is provided with an ink-supplying means and a gas-instrducing hole, in an ink jet recorder. CONSTITUTION:When purging is required due to clogging of a nozzle in a recording head or the like, a solenoid for a connecting means 54 is turned ON to depress a movable shaft 55, which is pressed against a stiff cartridge casing 23 through a pressing member 57, and when an air pump 56 is operated, an ink is fed under pressure into the recording head 40 through a filter 37 to purge the nozzle 41. When the connecting means 54 is turned OFF after completing purging, the gas-introducing hole 24 is opened to the atmosphere side, thereby enabling to jet an ink droplet by a hydrostatic ink. Accordingly, a cartridge can be fitted and detached easily, change-over between normal supplying of the ink and pressure feeding thereof at the time of purging is securely accomplished, and constructin is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink cartridge for an inkjet recording device that replenishes recording ink using a cartridge method, and in particular, it is capable of removing air bubbles in the ink flow path from the ink cartridge to the recording head. This relates to an ink cartridge made in Japan.

An inkjet recording device records characters, figures, etc. on recording paper by ejecting small droplets of ink from a narrow nozzle.In this case, in order to draw high-quality characters, figures, etc. It is necessary to regularly and intermittently eject fine ink droplets of equal diameter.In order to make the ejection flight of such ink droplets smooth and to stably draw characters, figures, etc. on the recording paper, it is necessary to The properties of the ink itself need to be sufficiently uniform and stable, but at the same time, it is also necessary to prevent air bubbles from entering the ink flow path from the ink tank to the recording head.

Furthermore, dryness of the ink within the nozzle, dust, paper powder, etc., may cause solid matter to form within the ink, often resulting in clogging. For this reason, ink may not be ejected or ejected unstablely, and ejection accuracy such as ejection efficiency, stability of ink droplet formation, and responsiveness may deteriorate, so it is necessary to remove these impurities as described above.

As described above, in an inkjet recording apparatus, it is an essential condition to completely remove air bubbles and solidified substances generated or mixed in the ink flow path.

When air bubbles or solidified substances enter the nozzles or other ink flow paths in the recording head, the following measures have conventionally been taken.

(1) A method in which the movable or flexible part of the ink cartridge is pressed to increase the ink pressure and solidified air bubbles, etc. are discharged together with the ink from the nozzle at the end of the ink flow section.

(2) A pressurized chamber is provided in the middle of the ink supply system that fluidly connects the ink tank and the recording head, and the ink is sent to the nozzle side by increasing the ink feed rate and ink pressure using an electric pump, etc., to prevent bubbles and solidification from the nozzle. A method of discharging objects (Japanese Patent Laid-Open Publication No. 55-53570, etc.) (3) A method of placing a cap close to the nozzle surface and sucking out ink from the nozzle with a suction pump to remove air bubbles, solidified matter, etc. (Patent No. 56-113464) However, each of the above-mentioned methods for removing (purging) air bubbles and solidified substances has the following drawbacks, which poses practical problems.

(1) Mechanical pressing means lacks pressure accuracy and stability,
In particular, it is difficult to apply constant pressure regardless of the remaining amount of ink.

The pump pressurizing means (2) requires an expensive liquid pump, which poses a cost problem.

(3) The suction means from the nozzle surface is complicated and expensive, and requires high precision due to the relative relationship between the suction speed and the ink supply speed.

As described above, all conventional purging means are still inadequate in terms of structure, cost, and stability.

On the other hand, in an inkjet recording device, a sealed ink cartridge is usually used as the ink tank of the ink supply device that supplies ink to the recording head in order to keep the ink in a stable state without exposing it to the outside air. . In this ink cartridge, ink is filled in a highly airtight bag or container to prevent air from entering.

This ink cartridge is removably attached to the cartridge receiver, and new ink can be replenished by replacing the ink cartridge.

As a conventional example of a replaceable ink cartridge, Japanese Utility Model Publication No. 52-38215 is known. 1st
The figure shows its cross-sectional view. In the figure, the ink supply device consists of an ink cartridge 1 containing replenishing ink and an ink cartridge receiver part 7, and this ink cartridge 1 includes an ink cartridge base 3 in the form of a cylinder with an air hole 2 bored at one end, and The ink storage bag 4 is comprised of an ink storage bag 4 housed inside a cylinder 3, and a gap 5 made of an elastic member that makes the ink storage bag 4 liquid-tight and is fitted to the other end of the base 3 in a sealed state. 6 is refill ink.

Furthermore, the ink cartridge receiver part 7 has a base 8 with a receiver formed in the concave part, and this receiver has an extremely narrow ink flow path protruding from a protrusion in the approximate center of the base 8 via a needle support plate 9. It consists of a needle 10 for inserting the cartridge, and an ink flow path 11 that passes through the base 8 and is connected to a liquid pump (not shown) so as to communicate with the ink flow path.

However, in this conventional example, the air hole 2 is constantly connected only to the outside air, and in order to increase the ink pressure with this configuration, a pressurizing liquid pump, an ink tank, and a liquid inverter are installed between the ink cartridge and the recording head. This must be done by driving stop valves, pressure regulators, etc. This posed a practical problem as it required the use of the above-mentioned members whose structure and movement were complicated and expensive.

The present invention has been made to solve the above-mentioned problems and to improve the conventional embodiments.

In other words, the invention is to maintain a predetermined ink pressure in the recording head to uniformly supply the ink during recording, and to remove air bubbles and solidified particles in the ink flow path during non-recording, during recording. This provides a replaceable ink cartridge that feeds pressurized ink into the cartridge.

An ink cartridge for an inkjet recording device according to the present invention is composed of an ink storage bag made of a flexible material filled with recording ink, and a rigid casing that houses the ink storage bag. It is characterized by having holes for introducing gas.

Further, the ink supply device according to the present invention is configured such that an exhaust port of the gas pressure feeding means can communicate with the gas introduction hole of the ink cartridge, and pressurized gas from the gas pressure feeding device is passed from the exhaust port to the introduction hole. By introducing the ink cartridge and filling it into the housing, the ink is sent from the ink storage bag toward the recording head, thereby causing air bubbles and solidified matter in the recording head to be ejected together with the ink, and when recording is resumed. , stopping pressurized feeding by the gas pressure feeding means,
The present invention is characterized in that the gas inside the housing of the ink cartridge is discharged from the introduction hole to restore the gas pressure inside the housing.

The ink cartridge and ink supply device of the inkjet recording device according to the present invention have a simpler structure than conventional methods and operate reliably, providing two types of highly accurate and stable ink supply, namely, ink supply during recording and ink supply during recording. It is now possible to smoothly switch between air bubbles and ink supply during solid matter removal (purge).

The effects of the ink cartridge and ink supply device of the ink jet recording apparatus according to the present invention are as follows.

(a) Ink can always be pumped at a constant pressure regardless of the amount of ink left in the ink storage bag.

(1) It is easy to switch between ink supply using hydrostatic pressure during recording and pressurized supply for purging during non-recording.

(C) The ink inside the ink cartridge can be evenly pressurized.

(d) Since no excessive force is applied to any part of the ink storage bag, the ink storage bag will not be destroyed.
・.

(e) The structure is simple and the operation is reliable.

(f) Cost can be reduced.

(g) Switching between steady-pressure ink supply during recording and high-pressure ink supply during purging is easy and reliable.

The present invention will be specifically described below with reference to the drawings.

FIG. 2 is a sectional view showing the structure of an ink cartridge according to the present invention. In the figure, an ink cartridge 20 includes an ink storage bag 22 made of a flexible material filled with ink 21 for replenishment, and a gas introduction hole 24 in a part of the airtight rigid material structure that houses the ink storage bag 22. a cartridge housing 23, and a base portion 25 made of an elastic or rigid material that is airtightly connected to the opening of the ink storage bag 22 and fixed to one opening of the cartridge housing 23.
and an elastic member 26 that is filled inside the mouthpiece 25 and prevents the replenishment ink from flowing out and gas from flowing in from the outside.

Incidentally, among the above-mentioned structural members, the ink storage bag 22 and the mouthpiece 2 are
5, or it is also possible to integrally mold the base portion 25 and the elastic member 26 from the same material.

In this way, the refill ink 21 in the ink cartridge 20 is maintained in a sealed state that can completely prevent leakage to the outside and entry of external gases.

Next, FIG. 3 is a cross-sectional view of the receiver that allows the ink cartridge 20 to be attached and detached. In the figure, the receiving part 30 includes a receiving member 31 that fits into the cap part 25 so as to removably hold the ink cartridge 20, and
an elastic cap member 32 filled approximately in the center of 1;
A hollow needle 33 is a communication means for supplying the ink 21 in the ink cartridge 20 to a recording head (not shown) of an inkjet recording apparatus, and an outer body that holds the hollow needle 33 and guides the receiving member 31. It is composed of a cylinder 34 and a coil spring 35 that biases the receiving member 31. In this way, the hollow needle 33 is held in the outer cylinder 34, one end of which is elastically capped by the elastic keying member 32, and the other end connected to the ink supply tube 36.

For example, the materials of each member constituting the ink cartridge according to the present invention are as follows.

The ink storage bag 22 is made of a flexible material, such as a plastic sheet such as polyethylene or vinylidene chloride, a metal foil such as aluminum, or a laminate of these materials, and can be used for a long time without changing due to the refill ink 21 or aging. It must be able to maintain an airtight condition over a period of time.

The material of the cartridge housing 23 is a hard plastic that does not deform even under pressure as described below, such as acrylic resin, impact styrene resin, polypropylene resin, etc., and is preferably transparent or translucent so that the inside can be observed.

The material of the elastic member 26 is, for example, natural rubber or synthetic rubber, and by repeatedly penetrating the hollow needle 33, it can prevent friction from being broken and constantly surround the outer periphery of the hollow needle 33 in a compressed state, so that the replenishing ink can be filled. Materials are required that will not leak or allow air bubbles to escape from the outside air. still,
The hollow needle 33 of the receiver part 30 is made of stainless steel or the like.

FIG. 4 is a sectional view showing the connection state between the ink cartridge 20 and the receiving part 30 according to the present invention.9 The convex part of the mouthpiece part 25 forming one end of the ink cartridge 20 and the convex part of the mouth part 25 fixedly installed in the inkjet recording apparatus are shown in FIG. The four parts of the receiving member 31 forming one end of the part 30 are fitted to the received part 30, and when the ink cartridge 20 is pushed toward the left in the figure, the receiving member 3
1 is a hollow needle pushed inward and fixed /I/3
3 protrudes from the elastic cap member 32, further penetrates the elastic member 26 on the side of the ink cartridge 20, and connects to the refill ink 21 in the ink storage bag 22. passes through the hollow needle 33 and communicates with the recording head (not shown) via an ink supply pipe 36.

Inkjet recording is performed in this state. That is, since the gas introduction hole 24 is opened in a part of the cartridge housing 23, the gas pressure inside the cartridge housing 23 is equal to the external pressure, so that the refill ink 21 inside the ink storage bag 22 The hydraulic pressure also matches the outside pressure. Therefore, the hydraulic pressure of the ink in the recording head, which communicates with the inside of the ink storage bag 22 through the hollow needle 33 and the ink supply pipe 36, is as follows.
A constant value is maintained by the liquid pressure of the ink in the ink storage bag 22 and the hydrostatic pressure caused by the difference between the water level in the ink storage bag 22 and the water level at the nozzle position of the recording head.

Next, FIG. 5 is a sectional view showing an outline of an ink jet recording apparatus including an ink cartridge and an ink supply device according to the present invention. In the figure, the ink flow path in the recording head 40 includes a plurality of nozzles 41 that eject ink droplets, the same number of pressure chambers 42 communicating with the nozzles, and each pressure chamber 42.
It is composed of a common ink chamber 43 for distributing ink to the common ink chamber 43, and an inlet means 44 for introducing ink from the ink cartridge 20 into the common ink chamber 43. The supply system that supplies recording ink to the recording head 40 includes an ink cartridge 20 and a receiver section 3 that includes a hollow needle 33.
0, an ink supply pipe 36, and a filter 37.

In the ink supply system configured as described above, by connecting the ink cartridge 20 to the receiving part 30, the ink in the ink storage bag 22 is fluidly connected to the mouth part 25 and the receiving part 30, and the ink cartridge 20 is connected to the receiving part 30. It is supplied into the recording head from the inlet means 44 of the recording head 40 through the supply pipe 36 and through the filter 37 . The ink supplied into the recording head first enters the common ink chamber 43,
Inwardly from a plurality of nozzles 41 corresponding to pixels in the vertical direction of a dot matrix character to be recorded one more time, the nozzles 41 are filled with ink from the ink cartridge. The positional relationship between the ink cartridge 23 and the recording head 40 is such that the recording head is filled with ink when not recording, and the ink does not leak from the nozzles 41 of the recording head 40, and the ink is normally ejected from the nozzles 41 during recording. , so that the consumed ink is supplied normally,
The hydrostatic pressure within the recording head 40 and the nozzle 4 are determined by taking into account the surface tension of the ink at the tip. Note that in a system in which the ink supply system is provided with an ink supply valve, it is not necessary to take such an arrangement in consideration of hydrostatic pressure.

On the other hand, a part of the wall of the pressure chamber 42 is a flexible wall, and a piezoelectric transducer 52 electrically connected to an electronic pulse generator 51 is adhered to the outer wall surface of the wall. The piezoelectric transducer 52 is an electric device that deforms when receiving an electrical signal from the pulse generator 51 and changes the fluid pressure in the pressure chamber 42.
For the rear plate conversion element, for example, a piezoelectric crystal, a polymer piezoelectric film, or the like is used.

In the inkjet recording device having the above configuration,
The piezoelectric transducer 52 is suddenly deflected inward by the electric signal from the electronic pulse generator 51, and the resulting rapid decrease in the volume of the pressure chamber 42 causes the ink inside to be ejected from the nozzle 41 as ink droplets. A dot image is recorded by causing the dot to fly and reach a recording paper that is relatively moving in the opposite direction.

Next, the ink cartridge pressurizing device according to the present invention will be explained based on FIG. 5. The cartridge housing 23 that houses the ink storage bag 22 has a sealed structure except for the gas introduction hole 24, and the inside of the cartridge housing normally communicates with outside air through the gas introduction hole 24 as shown in the figure. . Further, when the cartridge 20 is properly installed in the receiver 30 of the main body of the recording apparatus, a connecting means 54 is fixedly installed outside the gas introduction hole 24, and furthermore, this connecting means 54
One end of the hollow movable shaft 55 is connected to a pressurizing air pump 56. At the other end of the movable shaft 55, a pressure contacting member (for example, an O-ring) 57 having a rigidity is attached.

The connecting means 54 is, for example, an electromagnetic solenoid, and when a current is connected to a built-in coil, a movable shaft 55 made of iron moves up and down.

The movable shaft 55 is hollow and has a pressurizing air pump 56.
An air flow path is formed through which compressed air sent through the tube 58 flows and reaches the other end.

When the purge is required during non-recording, the solenoid of the connecting means 54 is turned on by an automatic or manual switch, the movable shaft 55 is pushed down, and the movable shaft 55 is pressed against the cartridge housing 23 via the pressure contact member 57. Close. As a result, the air pump 56 passes through the tube 58, the movable shaft 55, the pressure contact member 57, and the gas introduction hole 24 to the car) ridge housing 2.
The air-tight air channels leading to No. 3 are connected. In this state, the air pump 56 automatically operates, and the air pump 56 automatically operates.
The six airflows pass through the air flow path and are press-fitted into the cartridge housing 23, the pressure of the air inside the cartridge housing 23 increases, and the built-in ink storage bag 22 is compressed, so that the inside of the cartridge housing 23 is compressed. The ink is pressurized. As a result, the ink in the ink storage bag 22 is forced to pass through the mouthpiece 25 and the receiver 30 connected thereto, through the ink supply pipe 36 and the filter 37, and is introduced into the recording head 400 through the mouth means 44. , overflows from the nozzle 41 to the outside. At this time, air bubbles and solidified substances within the nozzle 41 and the recording head are discharged from the nozzle 41 together with overflowing ink, and the nozzle and other parts are cleaned and no longer clogged.

Next, when the purge operation is completed and printing is started again, the power to the connecting means 54 is turned off, the solenoid coil current is cut off, and the movable shaft 55 returns to its original state. Movable shaft 5 having pressure contact member 57
The distal end portion of the cartridge housing 23 is detached from the outer wall of the cartridge housing 23. At the same time, the power to the pressurizing air pump 56 is also cut off, and the pumping operation is also stopped.

Thus, the pressurized air within the cartridge housing 23 flows out to the outside air through the gas introduction hole 24, and the air within the cartridge housing 23 is maintained at atmospheric pressure, allowing the hydrostatic ink to eject ink droplets.

Next, FIG. 6 shows another embodiment of the ink cartridge and ink supply device according to the present invention. This is a part of the cartridge housing 61 of the ink cartridge 60 with the mouthpiece 25.
An air hole 63 is formed on the inner surface of the tapered hollow protrusion 62 at a position parallel to the above. A connecting member 64 having a shape that can be fitted and connected to the hollow protrusion 62 is provided inside the cartridge loading chamber on the recording apparatus main body side. Connecting member 6
The other end of 4 is connected to a tube 65, and further connected to a manual blower 66. The air hole 67 is open in the open state.In this open state, the manual blower 66 has the pipe 65, the connecting member 64, and the hollow protrusion 63.
The flow paths leading to the cartridge housing 61 through the casing 61 are all at atmospheric pressure. Inkjet recording is performed in this state.

When purging is required, the air hole 67 of the manual blower 66 is closed and compressed using the finger 68 or the operating part, and this volume reduction causes pressurized air to be blown, increasing the air pressure inside the cartridge housing 61, and ink. The ink in the storage bag 22 is pressurized, and the nozzle 4 of the recording
1 to eject air bubbles and solid matter along with the ink.

The pressure returns to atmospheric pressure, and the air pressure and ink pressure inside the cartridge housing also return to atmospheric pressure, making it possible to print.

The ink cartridge and ink supply device of this system have a simple structure and are effective when a relatively small pressing force is required.

The structure of the ink cartridge is also extremely effective when filling ink into the ink cartridge. For example, first, pressurized gas is introduced into the cartridge housing 23 through the gas introduction hole to increase the gas pressure inside the housing, or
Alternatively, the receiver section 30 is connected to a vacuum pump to expel the air in the ink storage bag to create a vacuum state, and then the receiver section 30 is connected to an ink tank containing replenishment ink.
When a vacuum pump is connected to the gas introduction hole 24 of the cartridge housing 23 and the pressure inside the cartridge housing is reduced, the replenishment ink in the ink tank can be introduced into the ink storage bag 22.

The ink shed recording device of the present invention having the above configuration is characterized in that an ink supply means and a gas introduction hole are provided in the cartridge housing that stores the ink storage bag containing the recording ink. Normally, the cartridge is allowed to communicate with atmospheric pressure, but when it is necessary to remove air bubbles and solidified substances within the recording head during non-recording, pressurized gas is introduced through the introduction hole to increase the pressure inside the cartridge housing and encapsulate it. An ink cartridge and an ink supply device that eject ink under pressure. The thread membrane operation of the car 1-IJ is easy, and the switching operation between steady ink supply and pressurized supply during purging is also reliable. Furthermore, the structure is simple, so it is a practically effective device.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional ink cartridge and a receiving part, Fig. 2 is a cross-sectional view showing the structure of an ink cartridge of the present invention, and Fig. 3 is a cross-sectional view of a receiving part for connecting an ink cartridge according to the present invention. 4 is a cross-sectional view showing the connection state between the ink cartridge and the receiving portion according to the unexploded QI, FIG. 5 is a cross-sectional view schematically showing an embodiment of the inkjet recording apparatus according to the present invention, and FIG. FIG. 3 is a sectional view showing another embodiment of the ink pressurizing means for an inkjet recording apparatus according to the invention. 20.60... Ink cartridge 21... Refill ink 22... Ink storage bag 2
3.61... Cartridge housing 24.63... Gas introduction hole 25... Mouth part 26... Elastic part 30.
...Receiving part 31...Receiving part Tochi 33...Hollow needle 54.64...Connection means 56...Air pump 66...Hand flh 7” Lower agent Yoshimi Kuwabara

Claims (2)

[Claims] (1) Consists of an ink storage bag made of a flexible material filled with recording ink and a rigid housing that houses the ink storage bag, with holes provided in the housing for introducing and discharging pressurized gas. An ink cartridge featuring: (2) An ink cartridge consisting of an ink storage bag made of a flexible material filled with recording ink, and a rigid casing that houses the ink storage bag and has holes for introducing and discharging pressurized gas, and the casing a gas pumping means that can be brought into and out of contact with the body and has a gas outlet communicating with the hole, and the gas pumping means is brought close to the ink cartridge to supply pressurized gas into the housing through the hole. By sending
The gas in the housing is discharged from the hole by sending ink from the ink storage bag toward a recording head and ejecting it from a nozzle of the recording head, and separating the gas pressure feeding means from the ink cartridge. An ink supply device characterized by: