Patent Application
20090237469
The present application claims the priority based on Japanese Patent Application No. 2008-73324 filed on Mar. 21, 2008, the disclosure of which is hereby incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a liquid delivery system for delivering liquid to a liquid jetting device, and to a method of manufacturing the same.
2. Description of the Related Art
Ink-jet printers are an example of one known class of liquid jetting device. In an ink-jet printer, ink is delivered from one or more ink cartridges. In one known conventional technology, a large-capacity ink tank is provided outside of the ink-jet printer and is connected by a tube to an ink cartridge in the printer, thereby increasing the ink storage capacity.
However, depending on the type of ink cartridge, simply connecting a tube to the ink cartridge may result in loss of ink cartridge functionality, with a possibility that ink will not be delivered appropriately to the print head of the printer. This problem is not limited to ink-jet printers, but is a problem that is common generally to liquid jetting devices or liquid-consuming devices installable of liquid receptacles.
An object of the present invention is to provide technology for appropriate delivery of liquid to a liquid jetting device that accommodates installation of a liquid receptacle.
According to an aspect of the present invention, there is provided a method of manufacturing a liquid delivery system that delivers liquid to a liquid jetting device. The method includes the steps of: (a) providing a liquid receptacle that is installable on the liquid jetting device; (b) providing a liquid supply device for supplying the liquid receptacle with the liquid; and (c) connecting the liquid receptacle and the liquid supply device with a liquid flow passage member. The liquid receptacle may have a liquid storage chamber that stores liquid; a liquid delivery port that delivers the liquid to the liquid jetting device; an intermediate flow passage leading from the liquid storage chamber to the liquid delivery port; and a sensor, disposed in the intermediate flow passage, for sensing whether the liquid is present or not. The step (c) includes connecting the liquid flow passage member to the intermediate flow passage at a connection location downstream of the sensor. Typically, within the entire liquid flow passage, the flow passage resistance will be high at the location of the sensor which has been disposed in the intermediate flow passage. Consequently, if the liquid flow passage member is connected to the upstream side of the sensor, it is possible that replenishing liquid supplied from the liquid supply device to the liquid flow passage member will not be delivered sufficiently to the liquid jetting device, due to the high flow passage resistance at the sensor location. According to the above configuration on the other hand, because the liquid flow passage member is connected to the intermediate flow passage at a connection location downstream of the sensor, it is possible for replenishing liquid supplied from the liquid supply device via the liquid flow passage member to be delivered appropriately to the liquid jetting device.
The intermediate flow passage may have a buffer chamber located downstream of the sensor, and the liquid flow passage member may be connected to the buffer chamber. According to this configuration, the liquid flow passage member is connected to the buffer chamber of relatively large ink storage capacity, thus making connection relatively easy.
The intermediate flow passage may include: a differential pressure valve housing chamber, disposed downstream of the sensor, for housing a differential pressure valve that opens and closes responsive to a differential pressure arising through consumption of the liquid; and a vertical flow passage, disposed downstream of the differential pressure valve housing chamber, for leading the liquid to the liquid delivery port in the vertical direction. In this case, the liquid flow passage member may be connected to the vertical flow passage. According to this configuration, since the liquid flow passage member is connected to the vertical flow passage, even if air bubbles are introduced via the liquid flow passage member, the air bubbles will rise directly into the differential pressure valve chamber and become trapped there. Consequently, the likelihood of air bubbles being discharged into the liquid jetting device from the liquid delivery port situated below the vertical flow passage will be reduced.
The intermediate flow passage may include a liquid communication hole which is disposed downstream of the sensor and which is formed in a wall inside the liquid receptacle, and the liquid flow passage member may be connected to the liquid communication hole With this configuration, the liquid communication hole that has been formed in the wall of the liquid receptacle is utilized to connect the liquid flow passage member, thereby affording a simple connection procedure.
The liquid receptacle may further include an air flow passage that connects the liquid storage chamber to an outside air, and the step (c) may further include closing off the air flow passage at a location upstream of the connection location of the liquid flow passage member to the intermediate flow passage. With this configuration, air (air bubbles) will be prevented from flowing into the sensor via the air flow passage, and malfunction of the sensor will be prevented accordingly.
There are various possible modes of working the present invention, including but not limited to a liquid delivery system and a method of manufacturing the same; a liquid receptacle for use in a liquid delivery system and a method of manufacturing the same; and a liquid jetting device or a liquid consuming device, for example.
The embodiments of the present invention will be described in the order indicated below.
A. Overall Configuration of Ink Delivery System
B. Basic Configuration of Ink Cartridge
C. Configuration of Ink Cartridge for Use in Ink Delivery System and Method of Manufacturing the Same
D. Modified Examples
Herein the system composed of the ink cartridges 1, the large-capacity ink tank 900, and the ink supply tubes 910 will be referred to as the “ink delivery system.” In some instances, the entire system inclusive of the ink-jet printer will be referred to as the “ink delivery system.”
Following is a description first of the design of the ink cartridges that are utilized in the embodiments of the ink delivery system herein; followed by a description of the detailed configuration of the ink delivery system and of a method for manufacturing it. While the following description relates for the most part to the use of an on-carriage type printer, the specifics thereof are applicable analogously to an ink-jet printer of off-carriage type.
The ink cartridge 1 stores liquid ink inside. As depicted in
As depicted in
On the bottom face 1b there is disposed a liquid delivery port 50 having a delivery hole for delivering ink to the ink-jet printer. Also, an air vent hole 100 for introducing air into the ink cartridge 1 opens onto the bottom face 1b (
The air vent hole 100 has a depth and diameter such that a projection 230 (
As depicted in
A circuit board 34 is disposed to the lower side of the locking lever 11 on the left face id (
An outer surface film 60 is adhered to the top face 1a and the back face if of the ink cartridge 1.
The internal configuration and configuration of parts of the ink cartridge 1 will be described with reference to
Ribs 10a of various shapes have been formed on the front face side of the cartridge body 10 (
A differential pressure valve housing chamber 40a and a vapor-liquid separation chamber 70a are formed to the back face side of the cartridge body 10 (
A plurality of grooves 10b are also formed to the back face side of the cartridge body 10 (
Next, the arrangement in the vicinity of the circuit board 34 mentioned earlier will be described. A sensor housing chamber 30a is formed to the lower face side of the right face of the cartridge body 10 (
While not illustrated in detail, the liquid level sensor 31 includes a cavity that defines part of the intermediate flow passage (to be discussed later); an oscillating plate that defines part of the wall of the cavity; and a piezoelectric element arranged on the oscillating plate. The terminals of the piezoelectric element are connected electrically to some of the electric terminals of the circuit board 34; and with the ink cartridge 1 installed in the ink-jet printer, the terminals of the piezoelectric element will be electrically connected to the ink-jet printer via electric terminals of the circuit board 34. By applying electrical energy to the piezoelectric element, the ink-jet printer can induce oscillation of the oscillating plate through the agency of the piezoelectric element. The presence of any air bubbles in the cavity will be ascertained through subsequent detection, through the agency of the piezoelectric element, of a characteristic (frequency etc.) of residual vibration of the oscillating plate. Specifically, when due to consumption of the ink stored in the cartridge body 10, the state inside the cavity changes from an ink-filled state to an air-filled state, there will be a change in the characteristics of residual vibration of the oscillating plate. By detecting this change in characteristics of residual vibration via the liquid level sensor 31, the ink-jet printer detects whether ink is present in the cavity.
The circuit board 34 is provided with a rewritable nonvolatile memory such as EEPROM (Electronically Erasable and Programmable Read Only Memory), which is used to store parameters such as the amount of ink consumed by the ink-jet printer.
On the bottom face side of the cartridge body 10 there are disposed the liquid delivery port 50 and the air vent hole 100 mentioned previously, as well as a depressurization hole 110, a sensor flow passage forming chamber 30b, and a labyrinthine passage forming chamber 95a (
The openings of the liquid delivery port 50, the air vent hole 100, the depressurization hole 110, the labyrinthine passage forming chamber 95a, and the sensor flow passage forming chamber 30b will be respectively sealed off by sealing films 54, 90, 98, 95, 35 upon completion of manufacture of the ink cartridge 1. Of these, the sealing film 90 is intended to be peeled off by the user prior to installing the ink cartridge 1 in the carriage 200 as described earlier. By so doing, the air vent hole 100 will communicate with the outside, allowing air to be introduced into interior of the ink cartridge 1. The sealing film 54 is designed to be ruptured by an ink delivery needle 240 provided on the carriage 200 when the ink cartridge 1 is installed in the carriage 200 of the ink-jet printer.
In the interior of the liquid delivery port 50 are housed, in order from the lower face side, a seal member 51, a spring seat 52, and a blocking spring 53. When the ink delivery needle 240 has been inserted into the liquid delivery port 50, the seal member 51 will function to seal the gap between the inside wall of the liquid delivery port 50 and the outside wall of the ink delivery needle 240. The spring seat 52 is adapted to contact the inside wall of the seal member 51 and block off the liquid delivery port 50 when the ink cartridge 1 is not installed in the carriage 200. The blocking spring 53 is adapted to urge the spring seat 52 in the direction of contact with the inside wall of the seal member 51. When the ink delivery needle 240 is inserted into the liquid delivery port 50, the upper end of the ink delivery needle 240 will push up the spring seat 52 and create a gap between the spring seat 52 and the seal member 51 so that ink is delivered to the ink delivery needle 240 through this gap.
Next, before proceeding to a more detailed description of the internal structure of the ink cartridge 1, for purposes of aiding understanding, the pathway leading from the air vent hole 100 to the liquid delivery port 50 will be described in conceptual terms with reference to
The pathway leading from the air vent hole 100 to the liquid delivery port 50 will be broadly divided into ink storage chambers for holding ink, an air flow passage situated on the upstream side of the ink storage chambers, and an intermediate flow passage situated on the downstream side of the ink storage chambers.
The ink storage chambers include, in order from the upstream side, a first ink holding chamber 370, a holding chamber connector passage 380, and a second ink holding chamber 390. The upstream end of the holding chamber connector passage 380 communicates with the first ink holding chamber 370, while the downstream end of the holding chamber connector passage 380 communicates with the second ink holding chamber 390.
The air flow passage includes, in order from the upstream side, a serpentine passage 310, a vapor-liquid separation chamber 70a that houses the vapor-liquid separation membrane 71 discussed earlier, and connecting paths 320 to 360 that connect the vapor-liquid separation chamber 70a with the ink storage chamber. The serpentine passage 310 communicates at its upstream end with the air vent hole 100, and at its downstream end with the vapor-liquid separation chamber 70a. The serpentine passage 310 is elongated and extends in a sinuous configuration so as to maximize the distance from the air vent hole 100 to the first ink holding chamber 370. Through this arrangement, evaporation of moisture from the ink inside the ink storage chambers will be kept to a minimum. The vapor-liquid separation membrane 71 is constructed of material that permits vapor to pass, but does not allow liquid to pass. By situating the vapor-liquid separation membrane 71 between the upstream end and the downstream end of the vapor-liquid separation chamber 70a, ink backflowing from the ink storage chambers will be prevented from advancing upstream beyond the vapor-liquid separation chamber 70a. The specific configuration of the connecting paths 320 to 360 will be discussed later.
The intermediate flow passage includes, in order from the upstream side, a labyrinthine flow passage 400, a first flow passage 410, the aforementioned sensor section 30, a second flow passage 420, a buffer chamber 430, the aforementioned differential pressure valve housing chamber 40a housing the differential pressure valve 40, and third flow passages 450, 460. The labyrinthine flow passage 400 has a three-dimensional labyrinthine configuration and includes the space defined by the aforementioned labyrinthine passage forming chamber 95a. Through the labyrinthine flow passage 400, air bubbles entrained in the ink will be trapped so as to prevent air bubbles from being entrained in the ink downstream from the labyrinthine flow passage 400. The labyrinthine flow passage 400 is also termed an “air bubble trap flow passage.” The first flow passage 410 communicates at its upstream end with the labyrinthine flow passage 400, and communicates at its downstream end with the sensor flow passage forming chamber 30b of the sensor section 30. The second flow passage 420 communicates at its upstream end with the sensor flow passage forming chamber 30b of the sensor section 30, and at its downstream end with the buffer chamber 430. The buffer chamber 430 communicates directly with the differential pressure valve housing chamber 40a with no intervening flow passage. Thus, the space from the buffer chamber 430 to the liquid delivery port 50 is minimized, and the likelihood of ink accumulating and settling out in that space will be reduced. In the differential pressure valve housing chamber 40a, through the action of the differential pressure valve 40, the pressure of the ink to the downstream side of the differential pressure valve housing chamber 40a will be maintained to be lower than the ink pressure on the upstream side, so that the ink in the downstream side assumes negative pressure. The third flow passages 450, 460 (see
At the time of manufacture of the ink cartridge 1, the cartridge will be filled up to the first ink holding chamber 370, as indicated by the liquid level depicted conceptually by the broken line ML1 in
The specific configuration of each element on the pathway from the air vent hole 100 to the liquid delivery port 50 within the ink cartridge 1 will be described with reference to
In the ink storage chambers, the first ink holding chamber 370 and the second ink holding chamber 390 are formed on the front face side of the cartridge body 10. In
In the air flow passage, the serpentine passage 310 and the vapor-liquid separation chamber 70a are formed on the back face side of the cartridge body 10, at the respective locations shown in
Turning now to a more detailed description of the connecting paths 320 to 360 of the air flow passage depicted in
In the intermediate flow passage, the labyrinthine flow passage 400 and the first flow passage 410 are formed on the front face side of the cartridge body 10 at the respective locations shown in
A space 501 shown in
The discussion now turns to a method of manufacturing an ink delivery system (
The tube 910 connection operation is carried out by a procedure such as the following, for example. First, the ink cartridge and the tube 910 are prepared. The ink cartridge depicted in
It should be noted that the location of the buffer chamber 430, at the downstream side of the ink flow passages with high flow passage resistance (i.e. the labyrinthine flow passage 400 and the sensor section 30), has the advantage that the ink supplied from the large-capacity ink tank 900 need not pass through these ink flow passages 400, 30. If the tube 910 is connected upstream from the ink flow passages 400, 30 of high flow passage resistance, the flow passage resistance from the large-capacity ink tank 900 to the tube 910 will be compounded by the flow passage resistance of these ink flow passages 400, 30, with the possibility that sufficient ink may not be delivered to the print head. That is, as taught in the present embodiment, by connecting the tube 910 to the buffer chamber 430 on the downstream side of the sensor section 30, it will be possible for ink to be delivered to the print head at appropriate pressure. In this regard, it is possible for the tube 910 to be connected to any flow passage that is situated on the downstream side from the sensor section 30.
It should be also noted that the buffer chamber 430 is present to the upstream side of the differential pressure valve housing chamber 40a that houses the differential pressure valve 40. Consequently, it will be possible for ink supplied through the tube 910 to be delivered to the print head at stable pressure conditions, by utilizing the function of the differential pressure valve 40.
It should be further noted that in Embodiment 1, the communication hole 311 between the second ink holding chamber 390 and the labyrinthine flow passage 400 is closed off. As a result, air will be prevented from flowing into the sensor section 30 from the air vent hole 100. By so doing, it will be possible to avoid situations where inflowing air causes the sensor section 30 to mistakenly sense that no ink is present. It is possible for this closing off of the ink flow passage to be made at any location to the upstream side of the tube 910 connection site.
According to Embodiment 1, because the ink supply tube 910 is connected to the downstream side of the sensor section 30, the ink supplied from the tube 910 will be delivered to the print head of the printer without passing through the sensor section 30 which represents an ink flow passage with high flow passage resistance. It is accordingly possible to achieve stable ink delivery.
In Embodiment 2, as in Embodiment 1, it is preferable to prevent air from flowing into the sensor section 30 from the air vent hole 100. This is the reason for closing off the communication hole 432 which is situated upstream from the tube 910 connection location. It is possible for closing off of the ink flow passage to be done at any site upstream from the tube 910 connection location.
In Embodiment 2, because the tube 910 is connected to the downstream side of the differential pressure valve housing chamber 40a, the function of the differential pressure valve 40 is not utilized. Accordingly, in Embodiment 2, in order that ink may be supplied at appropriate pressure to the print head from the cartridge it is preferable to keep the pressure of the ink delivered from the large-capacity ink tank 900 within an appropriate pressure range. It is acceptable for example to furnish the large-capacity ink tank 900 with a pressure maintenance or regulating mechanism. As one exemplary pressure maintenance mechanism, it is possible to employ a mechanism whereby the ink tank 900 is moved up or down to maintain the liquid level therein within an fixed height range from the nozzle faces of the print head, irrespective of the ink level inside the large-capacity ink tank 900. In this case, the head differential from the nozzle face of the print head to the liquid level of the ink tank will preferably be within a range of about +100 mm and −500 mm. If this head differential is too great, the meniscus cannot be maintained at the nozzle face of the print head, and it is possible that ink will leak out inadvertently. On the other hand, if the head differential is too small, it is possible that a sufficient amount of ink cannot be delivered to the print head from the ink tank. In the case of an off-cartridge type ink-jet printer, however, since in most instances a differential pressure valve is provided to the print head, in such cases it will not be necessary to regulate the head differential between the large-capacity ink tank 900 and the print head.
In this way, in Embodiment 2, because the ink supply tube 910 has been connected downstream from the sensor section 30 in a manner comparable to Embodiment 1, ink supplied from the tube 910 will be delivered to the print head of the printer, making it possible to achieve stable ink delivery. Moreover, in Embodiment 2, in a manner analogous to the modified examples of Embodiment 1, it is possible for the tube 910 to be introduced from either the left or right wall face of the cartridge.
Although the tube 910 is connected to the vertical flow passage 460 in Embodiment 2, it is possible to obtain similar advantages by connecting the tube 910 to the other vertical flow passage 450 situated thereabove (see
In Embodiment 3, as in Embodiment 1, it is preferable to prevent air from flowing into the sensor section 30 from the air vent hole 100. This is the reason for closing off the communication hole 311 which is situated upstream from the tube 910 connection location. It is possible for closing off of the ink flow passage to be done at any site upstream from the tube 910 connection location.
In this way, in Embodiment 3 as well, because the ink supply tube 910 has been connected downstream from the sensor section 30 in a manner comparable to Embodiment 1, ink supplied from the tube 910 will be delivered to the print head of the printer without passing through the sensor section 30 which represents an ink flow passage with high flow passage resistance, making it possible to achieve stable ink delivery. Also, as in Embodiment 1, in Embodiment 3 the function of the differential pressure valve 40 is utilized when delivering ink from the large-capacity ink tank 900 to the print head side. Furthermore, in Embodiment 3, since the distal end of the tube 910 need simply be fastened into the communication hole 432 that has been provided beforehand to the cartridge, there is the advantage of a simple tube connection operation. Also, the tube 910 may be connected to another communication hole in the cartridge, instead of the communication hole 432. In this case as well, it will be preferable to connect the tube 910 to a communication hole that is situated on the downstream side of the sensor section 30. Moreover, in Embodiment 3, in a manner analogous to the modified examples of Embodiment 1, it is possible for the tube 910 to be introduced from either the left or right wall face of the cartridge.
The present invention is not limited to the embodiments shown hereinabove, and may be reduced to practice in various other modes without departing from the spirit thereof, as in the possible modifications described below.
While the preceding embodiments describe various flow passages, holding chambers, and communication holes provided to the ink cartridges, some of these arrangements may be dispensed with.
While in the preceding embodiments, a large-capacity ink tank 900 is employed as the ink supply device, an ink supply device of some other configuration may be used. For example, it is possible to employ an ink supply device having a pump provided between the large-capacity ink tank 900 and the ink cartridge 1.
While the preceding embodiments have described an ink delivery system adapted for an ink-jet printer, the present invention is adaptable generally to liquid delivery systems that deliver a liquid to a liquid jetting device or a liquid consuming device; with appropriate modifications, it is possible for the invention to be employed in liquid consuming devices of various kinds equipped with a liquid jetting head adapted to eject small amounts of a liquid in drop form. Herein, a drop refers to the state of the liquid ejected from the liquid jetting device, and includes those with tails of granular, teardrop, or filiform shape. Herein, a liquid refers to any material that can be jetted from a liquid jetting device. For example, substances of any state when in the liquid phase would be acceptable including those of a high- or low-viscosity liquid state, of a fluid state such as a sol, gel water, or other inorganic solvent, organic solvent, solution, liquid resin, liquid metal (molten metal), or substances having the liquid state as one of their states; as well as materials containing particles of functional materials consisting of solids such as pigments or metal particles dissolved, dispersed, or mixed into a medium. Typical examples of liquids are the inks described in the preceding embodiments, and liquid crystals. Here, the term “ink” is used to include typical water based inks and oil based inks, as well as shellac, hot melt inks, and various other kinds of liquid compositions. Specific examples of liquid consuming devices are liquid jetting devices adapted to jet liquids containing materials such as electrode materials or coloring matter in dispersed or dissolved form, and employed in manufacturing liquid crystal displays, EL (electroluminescence) displays, plane emission displays, or color filters; liquid jetting devices adapted to jet liquids containing bioorganic substances used in biochip manufacture; liquid jetting devices adapted to jet liquids as specimens for use as precision pipettes; textile printing devices; or microdispensers. The system may further be employed as a delivery system in liquid jetting devices used for pinpoint application of lubricants to precision instruments such as clocks or cameras; in liquid jetting devices adapted to jet an ultraviolet curing resin or other transparent resin solution onto a substrate for the purpose of forming a micro semi-spherical lens (optical lens) for use in optical communication elements etc.; or in liquid jetting devices adapted to jet an acid or alkali etchant solution for etching circuit boards etc. The present invention is adaptable as a delivery system to any of the above types of liquid jetting devices. The liquid delivery systems that deliver liquid other than ink will employ a liquid flow passage member made of material suitable for the particular liquid, in place of the ink supply tube.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-073324 | Mar 2008 | JP | national |
