WO2005092626A1

WO2005092626A1 - Inkjet cartridge refilling assembly and method

Info

Publication number: WO2005092626A1
Application number: PCT/SG2004/000288
Authority: WO
Inventors: Wooi Siang Ong; Kok Suan James Tan; Khia Huat Vincent Lim
Original assignee: Sooners Innovation Pte Ltd
Priority date: 2004-03-25
Filing date: 2004-09-09
Publication date: 2005-10-06
Also published as: TW200535012A

Abstract

An inkjet cartridge refilling assembly [fig 1] comprising an ink container [10] adapted to be brought into fluid communication with an ink reservoir [21] of the ink cartridge [20] to supply ink to the reservoir, a vacuum can [30] adapted to be brought into fluid communication with the ink reservoir to draw out air contained in the ink reservoir for facilitating supply of ink to the reservoir, a device [1140] adapted to form part of a fluid communication path between the ink container and the ink reservoir, the device having an ink supply passageway [1145] and an overflow passageway [1142].

Description

INKJET CARTRIDGE REFILLING ASSEMBLY AND METHOD

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to ink cartridge refilling assembly, to a device for use in refilling ink cartridges, to a method of refilling ink cartridges, and to a method for priming ink cartridges.

Background

An inkjet cartridge is a refillable and disposable component in an inkjet printer. It typically includes an ink reservoir and printhead which shoots droplets of ink onto paper via thermal generation of bubbles in the ink, or mechanical piezoelectric force to eject droplets of ink onto paper. Generally ink cartridge includes an ink reservoir, which is separated from the printhead, but some ink cartridges have a print head directly attached to the ink reservoir. Once the ink in the ink cartridge is used up, the cartridge is usually disposed, not withstanding that the print head is attached and is normally still workable and effective.

To overcome the drawback, there have been methods developed to refill these cartridges. The conventional methods of refilling ink range from the application of a syringe to inject the ink directly into the ink reservoir to more sophisticated systems utilising high powered pumps and vacuums to prime the cartridge after refilling. The latter system is expensive and bulky and only recyclers and remanufacturers can afford this system refilling substantial amounts of numbers to make them economically justifiable. The problem in the remanufacturing and recycling industry has been getting enough supplies of empty cartridges. In addition to this, this is uncertainty in the quality of the remanufactured cartridge, as the customer has no guarantee as to how many times the cartridge has been refilled. Hence, as a result of this, failure rate in the remanufactured cartridges has been rather high at 10% higher.

US Patent No. 5,515,663 issued to Allgeier, Sr., et al on 14 May 1996 discloses a method of refilling ink in an empty printer cartridge which comprises the steps of introducing ink into the printer cartridge and introducing air into the printer cartridge using a syringe. A plunger is used within the syringe to introduce the air into inflatable bladders contained in the printer cartridge.

US Patent No. 5,232,447 discloses a non-reusable syringe to inject ink into the reservoir. The plunger of the syringe is pressed to dispense appropriate amount of ink.

Drawbacks of such systems and methods include that the use of a syringe may not provide consistent vacuum energy as it depends on how fast and how well the user pulls the plunger to generate the vacuum energy.

In at least preferred embodiments, the present invention seeks to provide an efficient and inexpensive inkjet system which has a superior refilling capability carried out by the consumers without worrying the quality of the cartridge.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention there is provided a inkjet cartridge refilling assembly comprising an ink container adapted to be brought into fluid communication with an ink reservoir of the cartridge to supply ink to the reservoir; and a vacuum can adapted to be brought into fluid communication with the ink reservoir to draw out air contained in the ink reservoir for facilitating supply of ink to the reservoir.

The assembly may further comprise a first seal element for sealing a connection between the ink reservoir and the ink container.

The assembly may further comprise a second seal element for sealing a connection between the ink reservoir and the vacuum can.

The ink container may be pressurised for facilitating the supply of ink to the ink reservoir. The ink container may comprise an ink bag disposed inside a wall structure of the ink container.

The assembly may further comprise an adapter element for connecting the ink container and the vacuum can to one opening of the ink cartridge in fluid communication with the ink reservoir.

The ink reservoir may comprise a collapsible ink reservoir bag, and the vacuum can is adapted to draw air from the container bag for facilitating the supply of ink from the ink container to the ink reservoir bag.

The assembly may further comprise a pressure indicator element adapted to be brought into fluid communication with the ink reservoir, for monitoring a pressure in the ink reservoir.

The assembly may further comprise a volumetric displacement element adapted to be brought into fluid communication with the ink reservoir, for monitoring displacement of air in the ink reservoir during the supply of the ink. The ink container may comprise a sub-assembly comprising a syringe element containing the ink and adapted to be brought into fluid communication with the ink reservoir; and an aerosol can adapted to be brought into fluid communication with a plunger of the syringe element for facilitating the supply of ink to the ink reservoir.

The assembly may further comprise a device adapted to form part of a fluid communication path between the ink container and the ink reservoir, the device comprising an ink supply passageway for supply of the ink to the ink reservoir, and an overflow passageway for directing on overflow of ink from the ink reservoir into an overflow cavity of the device.

The device may further comprise vent openings in fluid communication with the overflow cavity for venting displaced air from the ink reservoir. In accordance with a second aspect of the present invention there is provided a device for use in refilling of ink cartridges, the device being adapted to form part of a fluid communication path between an ink container and an ink reservoir of the ink cartridge, the device comprising an ink supply passageway for supply of the ink to the ink reservoir, and an overflow passageway for directing on overflow of ink from the ink reservoir into an overflow cavity of the device.

In accordance with a third aspect of the present invention there is provided a method of refilling an ink cartridge, the method comprising utilising a vacuum can to draw air from an ink reservoir of the ink cartridge.

In accordance with a fourth aspect of the present invention there is provided a method of priming an ink cartridge, the method comprising utilising a vacuum can to draw air from a print head of the ink cartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic prospective exploded view of the inkjet system in accordance with an embodiment of the present invention.

FIG. 2 schematically shows a sectional view of the inkjet system of an example embodiment.

FIG. 3 schematically shows the ink container with ink-filled bag and the vacuum can in accordance with an example embodiment.

FIG. 4A and 4B schematically show an inkjet system of another embodiment.

FIG. 5 schematically shows the inkjet system, wherein a pressure vacuum indicator is mounted on the ink cartridge, in accordance with an embodiment of the present invention.

FIG. 6 is a perspective view of the pressure vacuum indicator in accordance with an example embodiment. FIG. 7 schematically shows a volumetric displacement indicator of an example embodiment.

FIG. 8 schematically shows another example embodiment of an inkjet system.

FIG. 9 is a schematic cross sectional view of an ink cartridge illustrating depriming of the ink cartridge.

FIG. 10 is a schematic drawing illustrating a priming method and system in an example embodiment of the present invention.

FIG. 11 is a schematic drawing illustrating an ink cartridge refilling assembly in accordance with another embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings for purposes of illustrating the preferred embodiment of the present invention and not for purposes of limiting the invention. FIG. 1 schematically shows a perspective exploded view of an inkjet system 100 of an embodiment of the present invention. The inkjet system 100 comprises an ink cartridge 20 including an ink reservoir 21 and a print head 22; an ink container 10 in communication with the ink reservoir 21 of the ink cartridge 100, and containing a pressurized ink-filled bag 14, as shown in FIG. 2, so as to deliver ink to the reservoir 21 via a delivery needle 11 connecting the ink container 10 to the reservoir 21; and a vacuum can 30 having a pressure valve 31 sealed with a vacuum seal 32 at one end thereof being connected to the ink reservoir 21 to draw out air and ink from the ink reservoir 21. As shown in FIG. 1, the top surface of the ink cartridge 20 is provided with an opening 12 so that the delivery needle 11 can be inserted via the opening 12 to the ink reservoir 21. The ink contained in the ink-filled bag 14, as shown in FIG. 3, is pressurized and ink can be forced downward to the ink cartridge 20.

The print head 22 is positioned beneath the ink cartridge 20 and the vacuum can 30 is connected to the ink cartridge 20 via the valve 31 installed at one end of the vacuum can 30. The vacuum seal 32 is provided between the valve 31 and the print head 22 so that the vacuum can 30 withdraws out air within the ink reservoir 21.

FIG. 3 schematically shows the ink container 10 and the vacuum can 30 of the example embodiment invention. As shown in the FIG. 3, the ink container 10 encloses an ink-filled bag 14 surrounded by compressed air 16 within the container 16. On the other hand, the vacuum can 30 contains a partial vacuum. Both the ink container 10 and the vacuum can 30 have a pressure valve 31 , positioned at one end of the ink container 10 and the vacuum can 30, respectively.

In manufacturing the ink container 10, ink is placed in an air-tight bag as an ink-filled bag 14 and then inserted the ink-filled bag 14 into the ink container 10 which is then pressurized on the outside of the ink-filled bag 14 within the ink container 10. The pressurizing of the ink-filled bag 14 facilitates that no air comes into contact with the ink inside the bag 14 as this is critical to the performance of the ink cartridge as excessive air bubbles trapped in the ink cartridge will cause the cartridge to deprime and the ink shall be stopped from flowing to the printhead 22.

Ink contained in the ink container 10 is injected into the ink reservoir 21 under pressure, and during the ink injecting process from the ink container 10, the vacuum can 30 draws air from the reservoir 21 creating a vacuum in place of the usual air pressure and the ink reservoir 21 becomes vacuum. It will be appreciated by a person skilled in the art that the partial vacuum may also be applied before the actual filling takes place. The synergistic effect of the ink container 10 and the vacuum can 30 causes a high absorption of ink into the cartridge reservoir 21.

It will be appreciated that for an ink cartridge to work well, in operation ink has to flow continuously to the print head from the ink reservoir. During the printing process, as ink droplets are ejected from the print head, a partial vacuum is created in the print head. As a result, this partial vacuum siphons ink from the ink reservoir into the print head to replace the ejected ink. When the cartridge is new, this continuous cycle works well. But when either the cartridge is refilled with fresh ink or when for some reason, air is introduced into the print head passageways, the cartridge is unable to print properly. As illustrated in FIG. 9, the reason is that the presence of air bubbles e.g. 90 in the ink flow passageways e.g. 92 will render the ink suction ineffective, and no or reduced amounts of ink will flow to the print head 94. After all the ink in the print head 94 is exhausted, the print head 94 will stop printing. When this happens, the print head 94 said to be deprimed. When the print head 94 is primed to restore its operation, both air e.g. 90 and ink is drawn from the ink passageways e.g. 92. As the air-ink mixture is drawn out, only ink is drawn from the ink reservoir 96 to replace this mixture in the passageways e.g. 92 thus getting rid of the trapped air bubbles e.g. 90.

Priming of the print head 94 may be done with a vacuum pump or a syringe plunger by pulling down on the plunger to create a partial vacuum within the syringe to draw the ink out of the print head 94. In an example embodiment of the present invention stored vacuum energy in a container (compare can 30 in FIG. 2) such as an aerosol can is utilized to draw ink during the priming process. While an aerosol can is typically used to store compressed air and liquid, the inventors have found that the aerosol can is suitable to hold stored vacuum energy just as well.

With reference to FIG. 10, first the print head 100 of ink cartridge 102 is mated with a priming seal 104 connected to the priming container 106. Then the valve 108 of the priming can 106 is depressed causing the print head 100 to be exposed to the partial vacuum in the can 106. In this embodiment, the vacuum is stored and then applied at a later point of use in this particular application of priming the ink cartridge

102. This is the first such application where an aerosol can is used to store vacuum energy to the knowledge of the inventors that the priming effects of this static vacuum application in the example embodiment is superior in results to the used of syringe which may not provide consistent vacuum energy as it depends on how fast and how well the user pulls the plunger to generate this vacuum energy. It has also been found that this technique can be superior to the vacuum energy generated by a vacuum pump as the high vacuum capacity of such pumps can cause air to be drawn into the ink form the foam due to excessive vacuum energy.

As shown in FIG. 4A and 4B, there is shown another example embodiment of an inkjet system of the present invention. In this embodiment, an ink container 10 and a vacuum can 30 are placed in adjacent to each other and connected together to an airtight seal (not shown) to be fitted to an adapter element in the form of a conduit element 23 connected to the print head 22. In operation, the valve 31 of the vacuum can 30 is opened to ensure the passages of the conduit element 23 (and the print head 22 and ink cartridge 20) are has minimum air trapped. The valve 31 of the vacuum can 30 is then closed after a short period, such as one second. The valve 31 of the ink container 10 is opened to force ink into the ink cartridge 20 through the conduit element 23. The airtight seal 32 around the print head 22 maintains the ink pressure to ensure the ink flow is strong enough to go through the conduit element 23 into the collapsible ink bag 21 within the ink cartridge 20. Once the collapsible ink bag 21 is filled, the valve 31 of the ink container 10 is closed and the valve 31 of the vacuum can 30 is opened again to balance the back pressure inside the ink cartridge 20.

In accordance with an alternative embodiment of the present invention, a pressure vacuum indicator 40 is positioned to the ink cartridge 20 as shown in FIG. 5. When the pressure vacuum indicator 40 shows a vacuum level inside the ink cartridge 20 reached to an appropriate vacuum level, the ink container 10 is activated and simultaneously, the valve 31 of the vacuum can 30 is closed.

FIG. 6 is a schematic view showing the pressure vacuum indictor 40 in accordance with the present invention. The pressure vacuum indicator 40 comprises a housing 42 enclosing a chamber 43 with one closed end, an air-tight plunger 44 which is free to slide along the cavity of the chamber 43, and a needle 45 extended from the chamber 43 for inserting into the ink cartridge 20. An enclosed air 46 within the top portion (i.e. the closed end) of the chamber 43 is calibrated to provide the appropriate volume required in atmospheric pressure to act as a reference reservoir. An airtight sealing (not shown) such as a pressure seal 36 as shown in FIG. 3 may be placed at the entrance of the needle 45 inserting into the ink cartridge 20 for preventing air leakage.

Returning to FIG. 5, when the ink container 10 is mounted to the ink cartridge 20 and the pressure vacuum indicator 40 shows that the vacuum inside the ink cartridge 20 has reached the right vacuum level, the ink container 10 is activated and simultaneously, the valve 31 of the vacuum can 30 is closed. At this instance, the valve 31 of the ink container 10 is opened and the vacuum in the ink cartridge 20 turns into positive pressure very rapidly. The positive pressure will be registered on the pressure vacuum indicator 40 indicating that the valve 31 of the ink container 10 should be closed. The valve 31 of the vacuum can 30 is opened again for a short period to prime the ink cartridge 2O. The sudden injection of ink may cause foam in the ink cartridge 20. The vacuum provides a pulling force and the air in the foam is drawn out and this will create a partial vacuum in the foam. When the valve 31 of the ink cartridge 20 is opened, ink rushes in to fill the vacuum space in the foam. As mentioned earlier, the delivery needle 11 of the ink container 10 deliver the ink into the foam, and when the ink spreads out through the foam, the ink neutralize the vacuum in the ink cartridge towards a positive pressure.

When the air is being drawn out of the ink cartridge 20 by the vacuum can 30 in the course of ink-filling process, air is also being drawn out from the bottom side of the plunger 44 in the pressure vacuum indicator 40. When the pressure on the bottom side drops, the plunger moves downwards. When the valve 31 of the ink cartridge 20 is opened, the pressure in the ink cartridge 20 tends to become a positive pressure. The will cause the pressure at the bottom of the plunger 44 to be at higher the top side of the plunger 44, causing the plunger 44 to move up the chamber 43. In either case, the plunger 44 stops moving once the pressure equalizes on both sides and the position of the plunger 44 is used to indicate the pressure within the ink cartridge 20.

In operating the inkjet system, the ink container 10 is first connected to the ink reservoir 21 of the ink cartridge 20 and the delivery needle 11 is inserted into the reservoir 21. The vacuum can 30 is connected to the ink reservoir 21 and the air within the reservoir 21 is withdrawn. When the vacuum can 30 is removed, ink contained in the ink-filled bag 14 is drawn to the ink cartridge 20.

FIG. 7 shows schematically a volumetric displacement device 90 which can be used to substitute the pressure vacuum device 40 shown in FIG. 5. As shown in FIG. 7, the volumetric displacement indicator 90 consist of a piston plunger 92 inserted into an airtight tube 94 forming an airtight expansion chamber and is positioned on the ink cartridge (not shown). A tube 96 extended from one end of the device body 94 opposite to the plunger 92 for inserting into the ink cartridge. The mounting of the volumetric displacement indicator 90 is similar to that of the pressure vacuum indicator 40. In operation, when ink flows into the ink cartridge 20, air is displaced into the airtight volumetric displacement device 90 mounted to the ink cartridge 20. When the desired amount of air is displaced, the valve of the ink container 10 is closed, and the valve 31 of the vacuum can 30 is opened to draw ink from the ink cartridge to prime the ink cartridge 20 and get rid of the air in the path between the ink reservoir 21 and the print head 22. Air from the ink cartridge 20 flows into the device body 94 via the tube 96 and the pressure built up in the syringe pushes the syringe plunger 92 up until the air pressure inside the syringe body 94 is just about equal to the atmospheric pressure. Accordingly, the exact amount of air displaced can be metered by the syringe displacement. When the plunger 92 is restricted from moving up further, the ink will also be prevented from flowing into the volumetric displacement device.

Referring to FIG. 8, there is shown another example embodiment of the inkjet system of the present invention. The inkjet system comprises a compressed air can 34 connected to a syringe 60 containing ink. The syringe 60 is connected to a needle (being shown in dotted line in FIG. 8) in communication with the ink reservoir of the ink cartridge 20. In operation, when the valve 35 at the pressurized air can 34 is opened, the compressed air is discharged into the chamber above the plunger 51, which pushes the inks in the syringe 60 into the reservoir 21 of the ink cartridge 20. When ink flows into the ink reservoir 21, air is displaced from the cartridge reservoir into the volumetric displacement indicator 90 positioned onto the ink cartridge 20. When more air is displaced into the chamber of the syringe 60, the air becomes compressed and pushes the plunger 92 to move upward. After the plunger 92 has reached the limit, the compressed air will reach a pressure in equilibrium with the pressure in the pressure can 34. This stops the flow of ink into the cartridge 20, and accordingly, the ink-refilling process of the ink cartridge 20 is completed. As illustrated in FIG. 8, a vacuum can 30 containing a partial vacuum may be used to prime and balance the pressure within the cartridge 20 after the ink-refilling process before removing the refilling assembly.

Another embodiment of an inkjet refill kit will now be described with reference to FIG. 11. Generally, our problem for the user is not knowing when the cartridge is filled with ink so as to stop filling it. Our approach is to just inject a presumed right amount of ink into a given cartridge. This method can work when the cartridge is empty or dry. However, very often, users refill these cartridges when they are half filled with ink or in some case more. This is the case especially when refilling color cartridges with 3 colors in one cartridge. The cartridge will need refilling when one of its colors runs out. Since it is highly probable that only one color will run out first given the average printing do not use up all 3 colors equally, one or more of the ink reservoirs will have an unknown amount of ink in it.

As required by the kit instruction, the user will typically have to inject a predetermined amount of ink by the refill kit manufacturer. This volume is typically an average volume which assumes that the cartridge is Vz empty which on average would prevent the user from overfilling the cartridge but as a result would always cause the user to underfill the cartridge. On occasion however, the ink will overflow out of the cart4ridge when the user hits a reservoir that is more than >_> filled. As a result, a mess is created leaving the user frustrated and discouraged over the experience.

As illustrated in FIG. 11, an inkfill device in the form of a capsule 1140 in an example embodiment channels both air and ink from the reservoir 1121 into a transparent overflow containment cup area 1144. The capsule 1140 is plugged into the inkfill port 1122 of the ink cartridge 1120 to form an airtight seal between tube 1142 and the port 1122. A pressurized can 1110 containing an ink bag 114 is connected to the inkfill capsule 1140 via an actuator valve 18. Ink is released into the cartridge 1120 through the inkfill capsule 1140 by pressing downward on the actuator 1118.

As ink is injected, the ink travels through a needle assembly 1145 into the cartridge reservoir 1121 and, air is displaced from the reservoir 1121 and is allowed to escape via the vent tube 1142 into the capsule 1140. From there, the air flows thru the sealed cup vent holes 1147 on the capsule 1140.

As the ink level in the reservoir 1120 rises above the vent tube entrance 1141, ink will start to flow up the tube 1142 instead of air. Once the user sees the ink flowing into the capsule 1140, he/she stops the filling process. The overflowed ink stays in capsule 1140 and may be discarded with the capsule 1140. The capsule 1140 may be discarded after single use, or after multiple use once the reservoir 1120 has reached a certain level. This simple design of ink entrapment leaves the user with a mess free, ink free refilling experience in the example embodiment.

It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments, without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respect to be illustrative and not restrictive.

Claims

1. An inkjet cartridge refilling assembly comprising an ink container adapted to be brought into fluid communication with an ink reservoir of the cartridge to supply ink to the reservoir; and a vacuum can adapted to be brought into fluid communication with the ink reservoir to draw out air contained in the ink reservoir for facilitating supply of ink to the reservoir.

2. The assembly claimed in claim 1, further comprising a first seal element for sealing a connection between the ink reservoir and the ink container.

3. The assembly claimed in claims 1 or 2, further comprising a second seal element for sealing a connection between the ink reservoir and the vacuum can.

4. The assembly claimed in any one of claims 1 to 3, wherein the ink container is pressurised for facilitating the supply of ink to the ink reservoir.

5. The assembly claimed in any one of claims 1 to 4, wherein the ink container comprises an ink bag disposed inside a wall structure of the ink container.

6. The assembly claimed in any one of claims 1 to 5, further comprising an adapter element for connecting the ink container and the vacuum can to one opening of the ink cartridge in fluid communication with the ink reservoir.

7. The assembly claimed in any one of claims 1 to 6, wherein the ink reservoir comprises a collapsible ink reservoir bag, and the vacuum can is adapted to draw air from the container bag for facilitating the supply of ink from the ink container to the ink reservoir bag.

8. The assembly claimed in any one of claims 1 to 7, further comprising a pressure indicator element adapted to be brought into fluid communication with the ink reservoir, for monitoring a pressure in the ink reservoir.

9. The assembly claimed in any one of claims 1 to 8, further comprising a volumetric displacement element adapted to be brought into fluid communication with the ink reservoir, for monitoring displacement of air in the ink reservoir during the supply of the ink.

10. The assembly claimed in any one of claims 1 to 9, wherein the ink container comprises a sub-assembly comprising a syringe element containing the ink and adapted to be brought into fluid communication with the ink reservoir; and an aerosol can adapted to be brought into fluid communication with a plunger of the syringe element for facilitating the supply of ink to the ink reservoir.

11. The assembly claimed in any one of claims 1 to 10, further comprising a device adapted to form part of a fluid communication path between the ink container and the ink reservoir, the device comprising an ink supply passageway for supply of the ink to the ink reservoir, and an overflow passageway for directing on overflow of ink from the ink reservoir into an overflow cavity of the device.

12. The assembly as claimed in claim 11, wherein the device further comprises vent openings in fluid communication with the overflow cavity for venting displaced air from the ink reservoir.

13. A device for use in refilling of ink cartridges, the device being adapted to form part of a fluid communication path between an ink container and an ink reservoir of the ink cartridge, the device comprising: an ink supply passageway for supply of the ink to the ink reservoir, and an overflow passageway for directing on overflow of ink from the ink reservoir into an overflow cavity of the device.

14. A method of refilling an ink cartridge, the method comprising utilising a vacuum can to draw air from an ink reservoir of the ink cartridge.

15. A method of priming an ink cartridge, the method comprising utilising a vacuum can to draw air from a print head of the ink cartridge.