JP3659351B2 - ink cartridge - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an ink cartridge suitable for being mounted on a carriage on which an ink jet recording head is mounted.
[0002]
[Prior art]
An ink jet printer includes an ink jet recording head that applies pressure to a pressure generating chamber that communicates with a common ink chamber and a nozzle opening to eject ink droplets from the nozzle opening, and an ink cartridge that supplies ink to the recording head. It is configured to eject ink droplets onto a recording sheet in accordance with print data while reciprocating the carriage.
[0003]
By the way, since the nozzle opening of the recording head is located at a position lower than the ink liquid level of the ink cartridge, water head pressure acts on the nozzle opening. A measure is taken to prevent the ink from oozing out from the nozzle opening by configuring the pressure of the ink cartridge to be slightly lower than the nozzle opening due to the surface tension by the body.
[0004]
However, as the ink consumption progresses and the amount of ink absorbed by the porous body decreases, the surface tension of the porous body increases and the supply of ink to the recording head tends to stagnate. There is a problem that it cannot be consumed completely.
Further, since the ink that can be accommodated in the cartridge is reduced by the substantial volume of the porous body, there is a problem that the ink cartridge is increased in size.
[0005]
In order to solve such a problem, for example, as shown in US Pat. No. 4,677,447 (Japanese Patent Laid-Open No. 62-231759), an ink reservoir and a cavity are formed by a wall having a through hole in the lower part of the ink tank. An umbrella check valve is movably provided in this through-hole, and when the ink pressure of the recording head drops, the valve is opened to discharge the ink in the tank reservoir to the cavity and supply it to the recording head. An ink cartridge for an ink jet recording head configured as described above has been proposed.
[0006]
[Problems to be solved by the invention]
According to this, since it is not necessary to store the porous body in the cartridge, it becomes possible to increase the substantial ink storage capacity of the tank. However, since the ink is not held in the porous body, the cartridge is When tilted, there is a problem that ink leaks from the air communication hole.
The present invention has been made in view of such problems, and an object of the present invention is to provide an ink cartridge capable of preventing ink leakage from the air communication hole.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, an ink supply port is formed on the bottom surface, a container that forms an ink chamber communicating with the ink supply port, and an air communication hole that communicates the ink chamber with the atmosphere. a lid member for sealing the upper surface of the container wherein the conjunction is provided in the ink chamber side of the lid member, and a flexible membrane for opening and closing the atmosphere communication hole, said ink chamber around said air communication hole A convex part formed on the side, and a capillary that communicates the ink chamber and the air communication hole in a state where the flexible film is not in contact with the convex part, and the flexible film comprises: Ink in a case where the ink chamber is normally separated from the atmosphere communication hole and communicated with the atmosphere communication hole via the capillary, and is tilted to the extent that the ink comes into contact with the flexible film due to a change in the posture of the container. before under the pressure of The protrusion abuts is configured to seal the air communication hole.
[0008]
[Action]
When the container is tilted and the ink in the ink chamber moves to the atmosphere communication hole side, the flexible film receives the pressure of the ink and seals the through hole to prevent leakage of the ink from the atmosphere communication hole.
[0009]
【Example】
Therefore, the details of the present invention will be described below based on the illustrated embodiment.
FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a container constituting an ink cartridge main body, and an ink supply port 2 into which an ink supply needle of a recording head is inserted into a bottom surface 1a. The space in the container is divided into an ink chamber 4 and an ink supply chamber 5 by a membrane valve seat 3 described later.
[0010]
Reference numeral 3 denotes the above-described membrane valve seat, which is configured by forming a through-hole 6 in the center in an elastic film such as a rubber film or a polymer elastomer film having durability against ink, and is formed in the lower part of the container 1. The stepped portion 7 is stretched.
[0011]
A valve body 8 is inserted into a through hole 10 provided in the valve assembly 9 so as to be movable up and down, has a thickness that can secure a gap enough to allow ink to flow down, and is long. Is configured to be slightly longer than the thickness of the valve assembly 9, and the lower part of the valve assembly 9 is elastically attached to the membrane valve seat 3 by a valve body support member 11 to be described later so that the lower portion normally seals the through hole 6 of the membrane valve seat 3. It is touched. The valve assembly 9 is formed with an ink flow path 15 for guiding ink.
[0012]
Reference numeral 11 denotes the above-mentioned valve body support member, which is stretched on the surface of the valve assembly 9, and always makes the valve body 8 elastically contact the membrane valve seat 3, while the valve body 8 is lowered from a certain position. In this configuration, the through-hole 12 is formed in an elastic membrane made of the same material as that of the membrane valve seat 3, and the top portion of the valve body 8 is held by the through-hole.
[0013]
The upper surface of the container 1 is sealed by a lid member 13 having an air communication hole 14. On the ink chamber side of the lid member 13, a concave portion 30 surrounding the communication hole 14, a communication port 32 positioned at a certain distance from the concave portion 30, and a narrow groove 31 constituting a capillary for connecting them are formed. ing. On the upper surfaces of the recesses 30 and the grooves 31, a flexible film 33 is stretched so that the lid member 13 is slackened so as to be separated from the through hole when the lid member 13 is positioned above.
[0014]
The membrane valve seat 3, the valve body support body 11, and the valve body 8 are preferably assembled integrally with the valve assembly 9, and are inserted into the stepped portion 7 of the container 1 and incorporated into the container 1. .
[0015]
In this embodiment, when the container 1 is tilted and the ink in the ink chamber 4 comes into contact with the lid member 13, the flexible film 33 receives the pressure of the ink and comes into contact with the convex portion 14 a around the through hole 14. The through hole 14 is sealed, and leakage of ink from the atmospheric communication hole 14 is prevented.
[0016]
When the ink supply port 2 is inserted into the ink supply needle of the recording head on which the carriage is mounted, the ink supply chamber 5 and the recording head are connected. In this state, since the flexible film 33 of the lid member 13 hangs down due to gravity and the through hole 14 is opened, the ink chamber 4 communicates with the atmosphere through the recess 30, the groove 31, and the communication hole 32.
[0017]
In this state, when printing is performed and ink droplets are ejected from the recording head, the ink in the ink supply chamber 5 flows from the ink supply port 2 into the recording head, and the pressure in the ink supply chamber 5 gradually decreases. Corresponding to the pressure drop in the ink supply chamber 5, the membrane valve seat 3 receives the pressure from the ink chamber 4 and drops while expanding into a spherical shape having a radius R due to its elasticity. At this time, since the valve body 8 follows the membrane valve seat 3 (FIG. 2A), the pressure from the ink chamber 4 to the ink supply chamber 5 is prevented while preventing the pressure in the ink supply chamber 5 from excessively decreasing. Ink flow is prevented and the pressure in the ink supply chamber 5 is prevented from excessively rising. As a result, the pressure of the recording head is maintained in a constant negative pressure state with respect to the ink chamber 4.
[0018]
Further, when the consumption of ink in the recording head further advances and the membrane valve seat 3 is further lowered, the valve body 8 is prevented from being lowered below a certain position by the valve body support member 11. It is very far from 3 (Fig. 2 (b)). As a result, the ink in the ink chamber 4 flows into the ink supply chamber 5 from the through hole 6 through a narrow gap formed between the valve body 8 and the membrane valve seat 3.
[0019]
When the pressure in the ink supply chamber 5 rises slightly due to the inflow of ink, the membrane valve seat 3 moves toward the valve body 8 due to its elasticity and elastically contacts the valve body 8, and the through hole 6 is blocked by the lower surface of the valve body 8. Can be removed. As a result, the flow of ink from the ink chamber 4 to the ink supply chamber 5 stops. As a result, the pressure of the ink supply port 2 is kept constant regardless of the amount of ink in the ink chamber 3.
[0020]
Thereafter, every time the pressure in the ink supply chamber 6 slightly decreases, the membrane valve seat 3 expands slightly downward to form a gap with the valve body 8, and the ink in the ink chamber 3 is discharged from the gap to the ink supply chamber 5. Let it flow into. Since the membrane valve seat 3 formed of an elastic membrane contacts and separates from the valve body 8 as the ink is consumed in this way, when the elasticity of the membrane valve seat 3 is set to an appropriate size, the pressure at the start of ink supply In addition, the pressure difference when the ink supply is stopped, that is, the offset can be made extremely small, and all the ink in the ink chamber 4 can be discharged to the recording head.
[0021]
On the other hand, when the environmental temperature rises while printing is interrupted, the pressure of the ink supply chamber 5 rises, but the ink chamber in which the membrane valve seat 3 is opened to the atmosphere in response to this pressure. Move to the 4th side. As a result, the pressure in the ink supply chamber 5 is prevented from increasing, and an optimum negative pressure is maintained with the recording head regardless of the temperature rise, so that ink leakage from the recording head due to the pressure increase is prevented. Will be prevented.
[0022]
FIG. 3 shows a membrane valve seat 3 made of a rubber film having a thickness of 0.04 mm and an effective diameter, that is, an elastically deformable region having a diameter of 20 mm. 2 (a)) shows the change in the water head value of the ink cartridge of the present invention in which the lower limit position of the valve body 8 is set so that the radius R of the spherical surface is 26 mm. A large amount of ink of 5 grams per minute is shown. Even when the ink is supplied, the increase in the water head value is small, and it can be seen that the ink can be supplied smoothly without applying an excessive negative pressure to the recording head even when a large amount of ink is consumed by the recording head.
[0023]
On the other hand, in the manufacturing process, when the ink supply port 2 is sealed with the seal 16 and a negative pressure is applied to the ink chamber 4 to eliminate air in the cartridge, the pressure in the ink chamber 4 is higher than that in the ink supply chamber 5. 2, the valve body 8 moves to the ink chamber side against the elastic force of the valve body support member 11 and moves between the membrane valve seat 3 and the valve body 8 as shown in FIG. Since the space is formed, the air in the entire cartridge can be eliminated regardless of the presence of the membrane valve seat 3 and the valve body 8, and the entire cartridge including the ink supply chamber 5 can be filled with ink. It becomes.
[0024]
FIG. 4 shows another embodiment of the valve body 8. In this embodiment, when the lower surface of the valve body 8 contacts the membrane valve seat 3, a flat plate that contacts the upper surface of the valve assembly 9. A shaped positioning piece 35 is provided.
[0025]
According to this embodiment, in a state where the valve body 8 is in contact with the membrane valve seat 3, the positioning piece 35 contacts the upper surface of the valve assembly 9, and the valve body 3 is supported by the valve assembly 9. Since the vertical posture is maintained as much as possible, the through-hole 6 of the membrane valve seat 3 can be reliably sealed against vibration caused by movement of the carriage or the like.
[0026]
FIG. 5 shows another embodiment of the present invention. In FIG. 5, reference numeral 20 denotes a valve body, which is constantly pressed downward by a spring 21 in a valve body housing chamber 9a formed in the valve assembly 9. The lower limit position is defined by the positioning piece 36 formed on the valve body 20 coming into contact with the convex portion 9b below the valve body housing chamber 9a. In the figure, reference numerals 22 and 23 denote through holes for connecting the ink chamber 4 and the ink supply chamber 5, respectively.
[0027]
In this embodiment, in response to the pressure drop in the ink supply chamber 5, the membrane valve seat 3 receives the pressure from the ink chamber 4 and drops while expanding into a spherical shape having a radius R due to its elasticity. At this time, the valve body 20 follows the membrane valve seat 3 due to the elasticity of the spring 21, and the positioning piece 36 abuts against the convex portion 9b so that the valve body 20 is held in a vertical posture (FIG. 6 (a)). ) Ink flow from the ink chamber 4 to the ink supply chamber 5 is prevented while preventing the pressure in the ink supply chamber 5 from excessively decreasing. Accordingly, the membrane valve seat 3 contacts the valve body 20 regardless of the swinging caused by the movement of the carriage, so that the ink pressure of the recording head is maintained in a constant negative pressure state with respect to the ink chamber 4.
[0028]
When the consumption of ink at the recording head proceeds and the membrane valve seat 3 is further lowered, the valve body 20 is prevented from being lowered below a certain position by the projection 9b of the valve body housing chamber 9a. It is very far away from the valve seat 3 (FIG. 6 (b)). As a result, the ink in the ink chamber 4 flows into the ink supply chamber 5 from the through hole 6 through a narrow gap formed between the valve body 8 and the membrane valve seat 3.
[0029]
When the pressure in the ink supply chamber 5 rises slightly due to the inflow of ink, the membrane valve seat 3 moves toward the valve body 20 due to its own elasticity and elastically contacts the valve body 20, and the through hole 6 is blocked by the lower surface of the valve body 8. Can be removed. As a result, the flow of ink from the ink chamber 4 to the ink supply chamber 5 stops. As a result, the pressure of the ink supply port 2 is kept constant regardless of the amount of ink in the ink chamber 3.
[0030]
On the other hand, in the manufacturing process, when the ink supply port 2 is sealed with the seal 16 and a negative pressure is applied to the ink chamber 4 to eliminate air in the cartridge, the pressure in the ink chamber 4 is higher than that in the ink supply chamber 5. 6 (C), the valve body 8 moves to the ink chamber side against the spring 21 and forms a gap between the membrane valve seat 3 and the valve body 20, as shown in FIG. Regardless of the presence of the membrane valve seat 3 and the valve body 20, the air in the entire cartridge can be eliminated, and the entire cartridge including the ink supply chamber can be filled with ink.
[0031]
In the above-described embodiment, an elastic member for bringing the valve body 20 into contact with the membrane valve seat 3 is incorporated into the valve assembly 9. However, as shown in FIG. It may be formed in a mold so that the cap portion 37a functions as a positioning piece and a stopper, and the apex is pressed against the membrane valve seat 3 side by a spring 38.
[0032]
According to this embodiment, since the valve body 37 and the spring 38 can be attached from the outside of the valve assembly 9, the assembling work can be simplified.
[0033]
In the above-described embodiment, a spring is provided above the valve body. However, as shown in FIG. 8, the container 40 is separated from the ink chamber 42 and the ink supply chamber by the partition plate 41 having the through holes 41a. 43, the membrane valve seat 44 in the ink supply chamber 43, a spherical surface 46a that seals the through hole 45 of the membrane valve seat 44 on the lower surface, and the through hole 45 of the membrane valve seat 44 that extends vertically from the spherical surface 46a. It is apparent that the same effect can be obtained even if the valve body 46 including the support portion 46b penetrating the housing is accommodated and the support portion 46b is supported via the spring 47 that always presses downward. In the figure, reference numeral 48 indicates a positioning guide hole that fits the lower end of the support portion 46b to bring the valve body 46 into a vertical posture, and 49 indicates an ink supply port.
[0034]
According to this embodiment, since the lower portion of the valve body 46 is pulled downward by the spring 47, the posture is stabilized regardless of the buoyancy caused by the ink. Can be supplied stably.
[0035]
FIG. 9 shows another embodiment of the present invention. In the figure, reference numeral 50 denotes a liquid level stabilizing film, which is a flexible porous film that can follow the movement of the membrane valve seat 3. A through-hole 51 is formed in a region facing the valve body 8 and is fitted to the valve body 8. The periphery is fixed to the assembly 9, and the central part is the valve body 8. It is fixed.
[0036]
In this embodiment, when the pressure of the ink supply chamber 5 decreases due to consumption of ink, the membrane valve seat 3 moves away from the valve body 8 and the ink in the ink chamber 4 passes through the liquid level stabilizing film 50 to supply ink. Flow into chamber 5.
[0037]
When the ink consumption further progresses and the liquid level in the ink chamber 4 decreases to the vicinity of the assembly 9, the ink oscillates vigorously in the vicinity of the valve body 8 due to the movement of the carriage. After the pressure fluctuation is suppressed as much as possible, it passes through the through hole 6 of the membrane valve seat 3, and the ink pressure of the recording head is kept constant regardless of the decrease in the ink amount in the ink chamber 4.
[0038]
In the above-described embodiment, the valve body is elastically contacted with the membrane valve seat 3 by using elastic means. However, if the elastic force of the membrane valve seat 3 itself is positively used, the valve body is removed from the membrane valve. An elastic member that elastically contacts the seat 3 can be dispensed with.
FIG. 10 shows an embodiment in which an elastic member for elastically pressing the valve body against the membrane valve seat is not required. In the figure, reference numeral 24 denotes a membrane valve seat, and a through hole 25 is provided in a region facing a valve body 28 described later. And the periphery is fixed by a valve assembly 27. Reference numeral 28 denotes a valve body, which is fixed so as not to move so as to have a posture perpendicular to the valve assembly 27. Reference numeral 29 in the drawing denotes a through hole that connects the ink chamber 4 and the ink supply chamber 5.
[0039]
In this embodiment, when the differential pressure between the ink chamber 4 and the ink supply chamber 5 is equal to or smaller than a predetermined value, the membrane valve seat 24 elastically contacts the valve body 28 with the through hole 25 by its own elasticity. To the ink supply chamber 5 is stopped.
[0040]
On the other hand, when the pressure in the ink supply chamber 5 is lowered, the membrane valve seat 24 is lowered while expanding into a spherical shape, so that the through hole 25 is separated from the valve body 28 and the ink flows from the ink chamber 4 into the ink supply chamber 5. When the ink supply advances and the pressure in the ink supply chamber 5 rises, the membrane valve seat 24 overcomes the differential pressure and elastically contacts the valve body 28 to stop the ink outflow.
[0041]
By the way, when air enters the recording head, the pressure for ejecting ink droplets is absorbed by the air bubbles generated in the flow path of the recording head due to the air and causes printing defects. It is necessary to prevent the recording head from sucking air at the end of ink.
[0042]
FIG. 11 shows an embodiment of an ink cartridge that prevents air from entering the recording head at the end of the ink of the recording head. The ink cartridge is shown above the connection region between the ink supply port 52 and the ink supply chamber 53. A conical valve seat 54 is formed to expand, and a spherical floating valve 55 that floats due to buoyancy is accommodated therein, and a valve pressing plate 56 such as a net that allows ink to pass through is provided on the upper part to provide a shielding valve. It is composed. Reference numeral 57 in the figure denotes a membrane valve seat that contacts the valve body 58 and controls the inflow of ink from the ink chamber.
[0043]
In this embodiment, in a state where the ink cartridge is mounted on the recording head, the floating valve 55 is stuck to the valve pressing plate 56 by buoyancy, and the ink supply port 52 is opened and ink to the recording head is opened. Is supplied.
[0044]
On the other hand, when the ink consumption of the cartridge progresses and the ink level drops to the vicinity of the ink supply port 52, the floating valve 55 loses buoyancy due to the ink and comes into contact with the valve seat 54 (indicated by the dotted line in the figure). To do. Therefore, even if printing progresses further, since the ink supply port 52 is sealed, the intrusion of air into the recording head is prevented, and the occurrence of a printing failure can be prevented.
[0045]
Further, normally, when the ink cartridge is mounted on the recording head, it is not inserted or removed until the ink in the ink chamber is exhausted, but it may still be pulled out of the recording head by an erroneous operation. Thus, once the mounted cartridge is removed from the recording head, the ink supply port 2 is opened to the atmosphere, and air enters the ink supply chamber and the ink chamber, which adversely affects the recording operation.
[0046]
FIG. 12 shows an embodiment for preventing the above-described inconvenience due to the attachment and detachment of the ink cartridge. In FIG. 12, reference numeral 60 denotes an extendable valve body provided in the ink supply port 61. An ink supply needle fitting hole 62 into which the ink supply needle 70 is fitted is provided. Further, a through hole 64 is formed to connect the ink supply chamber 63 and the ink supply needle fitting hole 62 when moved to the upper limit position.
[0047]
In this embodiment, normally, as shown in FIG. 12A, the valve body 60 elastically contacts the bottom 63a of the ink supply chamber 63 to reliably prevent the ink from flowing out from the ink supply chamber 63 as shown in FIG.
[0048]
When the ink supply needle 70 is inserted into the fitting hole 62, the valve body 60 extends to the upper limit position to leave the bottom surface 63a of the ink supply chamber 63, and the communication hole 64 is exposed to the ink supply chamber 63 (same as above). Figure (b)). As a result, the ink supply chamber 63 and the ink flow path 70a of the ink supply needle 70 are connected via the communication holes 64 and 70b, the ink in the ink supply chamber 63 flows into the ink supply needle 70, and the ink is supplied to the recording head. Will be.
[0049]
When the ink cartridge mounted on the recording head is removed, the valve body 60 moves downward to shut off the ink supply chamber 63 and the ink supply port 61 (FIG. 6A), so that the ink from the ink supply chamber 63 is removed. Outflow and air intrusion into the ink supply chamber 63 is prevented.
[0050]
【The invention's effect】
As described above, according to the present invention, even if an ink cartridge does not have an ink holding member such as a porous body, if the container is tilted and the ink in the ink chamber moves to the atmosphere communication hole side, the ink cartridge is flexible. The atmosphere communication hole can be sealed with a conductive film to prevent ink leakage from the atmosphere communication hole.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIGS. 2A and 2B are views showing the operation of the membrane valve seat and the valve body when mounted on the recording head, respectively, and FIG. It is sectional drawing which shows the state of the valve body in the case of filling.
FIG. 3 is a graph showing the relationship between the ink discharge amount and the water head value of the ink cartridge of the present invention.
FIG. 4 is an enlarged cross-sectional view showing the vicinity of an ink supply chamber according to another embodiment of the present invention.
FIG. 5 is a cross-sectional view showing another embodiment of the present invention.
FIGS. 6A and 6B are diagrams showing the operation of the membrane valve seat and the valve body when mounted on the recording head, respectively, and FIG. 6C is a diagram illustrating the ink cartridge filled with ink. It is sectional drawing which shows the state of the valve body in the case of doing.
FIG. 7 is an enlarged cross-sectional view showing the vicinity of an ink supply chamber according to another embodiment of the present invention.
FIG. 8 is an enlarged sectional view showing the vicinity of an ink supply chamber according to another embodiment of the present invention.
FIG. 9 is an enlarged sectional view showing the vicinity of an ink supply chamber according to another embodiment of the present invention.
FIG. 10 is an enlarged cross-sectional view showing the vicinity of an ink supply chamber according to another embodiment of the present invention.
FIG. 11 is a cross-sectional view showing an embodiment of an ink supply port.
FIGS. 12A and 12B are cross-sectional views showing another embodiment of the ink supply port, respectively, in a state where the ink supply port is not mounted and a state where the ink supply port is mounted.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Container 2 Ink supply port 3 Membrane valve seat 4 Ink chamber 5 Ink supply chamber 6 Through-hole 7 Step part 8 Valve body 9 Valve assembly 14 Atmospheric communication hole 25 Soft porous body film 30 Recessed part 31 Groove 33 Flexible film

Claims (1)

A container having an ink supply port formed on the bottom surface and forming an ink chamber communicating with the ink supply port;
A lid member for sealing the upper surface of the container provided with air communication hole for communicating the ink chamber with the atmosphere,
A flexible film that is provided on the ink chamber side of the lid member and opens and closes the atmosphere communication hole ;
A convex portion formed on the ink chamber side around the atmosphere communication hole;
A capillary for communicating the ink chamber and the air communication hole in a state where the flexible film is not in contact with the convex portion;
With
The flexible film is normally separated from the atmosphere communication hole , communicates the ink chamber with the atmosphere communication hole via the capillary, and ink contacts the flexible film due to a change in posture of the container. ink cartridge, wherein the benzalkonium that abolish sealing the air communication hole in contact with the convex portion receives the pressure of the ink in the case of inclined extent.

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