JP2007015401A - Ink cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink cartridge which can supply ink with less mixing of air in the ink cartridge where a differential pressure regulating valve is arranged between an ink supplying port and an ink storing region. <P>SOLUTION: The ink supplying port 2 is sealed by a seal 16 in a manufacturing process. The air in the cartridge is removed by acting a negative pressure to an ink chamber above a membrane valve seat 3. A pressure of the ink chamber side is lowered more than that of an ink feeding chamber 5. Therefore, a valve element supporting member 11 moves to the ink chamber side as shown in (C) in the figure, forming a gap between the membrane valve seat 3 and a valve element 8. The air in the whole cartridge can be removed regardless of the presence of the membrane valve seat 3 and the valve element 8, enabling the ink to be filled in the whole cartridge including the ink feeding chamber 5. The ink cartridge in which the ink with less mixing of the air can be filled, preventing the air from mixing into the ink feeding chamber 5 can be provided accordingly. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink cartridge suitable for being mounted on a carriage on which an inkjet recording head is mounted.

  The ink jet printer is equipped with 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. The ink droplets are ejected onto the recording paper in accordance with the print data while reciprocating the carriage.

  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.

  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.

In order to solve such a problem, for example, as shown in Patent Document 1 and Patent Document 2, an ink reservoir and a cavity are separated by a wall having a through hole in the lower part of the ink tank, and an umbrella check is placed in the through hole. Ink for an ink jet recording head, which is configured to be movably provided so that when the ink pressure of the recording head decreases, the valve is opened to discharge the ink stored in the tank into the cavity and supply it to the recording head. A cartridge has been proposed. It is disclosed that the ink cartridge is a printhead integrated type and that the cavity downstream of the valve, ie the cavity between the valve and the printhead, must be filled with ink during the printing operation. .
US Pat. No. 4,677,447 JP-A-62-2231759

  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, but in general, the umbrella check valve is used for the ink to the recording head. In order to precisely adjust the supply, the offset amount is too large, and there is a big problem that the ink supply amount fluctuates and the print quality is deteriorated.

  On the other hand, when the umbrella check valve is closed, the ink reservoir and the recording head are completely cut off. Therefore, when the ink in the cavity expands by 2 to 5% by volume due to a change in the environmental temperature, the pressure of the cavity Rises and breaks the seal at the connection port with the recording head, and ink leaks, or when it is attached to the recording head, this pressure acts on the recording head as it is, There is a problem in that the negative pressure cannot be maintained and ink leaks from the recording head.

  Further, the umbrella check valve has a weak valve closing force at a pressure difference of about several tens of mmAq to be maintained in order to stably supply ink to the recording head. There is a problem that the valve is opened and stable printing is impossible.

  Furthermore, in the ink cartridge using the differential pressure valve that is arranged between the ink supply chamber and the ink storage region and opens and closes the flow path from the ink storage region to the ink supply chamber due to the pressure difference, as described above. If air is mixed into the ink supply chamber between the ink supply port and the differential pressure valve, stable printing becomes impossible. Accordingly, the present invention has a differential pressure valve disposed between an ink supply port into which an ink supply needle for supplying ink to the recording head is inserted and an ink storage region communicating with the ink supply port, An object of the present invention is to provide an ink cartridge having a seal member at the mouth and capable of supplying ink with less air mixing.

  The present invention provides an ink supply port into which an ink supply needle for supplying ink to a recording head is inserted, an ink storage region communicating with the ink supply port, and an ink supply between the ink supply port and the ink storage region A differential pressure valve that forms a chamber, is disposed between the ink supply chamber and the ink storage region, opens and closes a flow path from the ink storage region to the ink supply chamber by a pressure difference, and seals the ink supply port An ink cartridge having a sealing member that is filled with ink including the ink supply chamber.

  The ink cartridge of the present invention enables stable printing because the entire cartridge including the ink supply chamber is filled with ink.

  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. Therefore, the ink chamber 4 and the ink supply chamber 5 can communicate with each other only by the membrane valve seat 3, and there is no flow path that allows the ink chamber 4 and the ink supply chamber 5 to communicate with each other.

  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.

  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.

  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.

  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 located 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.

  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. .

  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.

  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 via the recess 30, the groove 31, and the communication hole 32.

  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.

  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.

  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.

  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.

  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.

  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.

  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 toward the ink chamber 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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  By the way, when air enters the recording head, the pressure for ejecting the ink droplets is absorbed by the 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.

  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.

  In this embodiment, when 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 to supply ink to the recording head. Is done.

  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.

  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.

  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.

  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.

  When the ink supply needle 70 is inserted into the fitting hole 62, the valve body 60 extends to the upper limit position and is separated from 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.

  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.

It is sectional drawing which shows one Example of this invention. FIGS. (A) and (B) are views showing the operation of the membrane valve seat and the valve body when mounted on the recording head, respectively, and FIG. (C) shows the case where the ink cartridge is filled with ink. It is a figure which shows the state of a valve body. It is a diagram which shows the relationship between the discharge amount of the ink of the ink cartridge of this invention, and a water head value. It is a figure which expands and shows the other Example of this invention the ink supply chamber vicinity. It is sectional drawing which shows the other Example of this invention. FIGS. 1A and 1B are views showing the operation of the membrane valve seat and the valve body, respectively, mounted on the recording head, and FIG. 1C shows the valve when the ink cartridge is filled with ink. It is a figure which shows the state of a body. It is a figure which expands and shows the other Example of this invention the ink supply chamber vicinity. It is a figure which expands and shows the other Example of this invention the ink supply chamber vicinity. It is a figure which expands and shows the other Example of this invention the ink supply chamber vicinity. It is a figure which expands and shows the other Example of this invention the ink supply chamber vicinity. It is a figure which shows the Example of an ink supply port. FIGS. 1A and 1B are diagrams showing another embodiment of the ink supply port, respectively, in a state where the ink supply port is not attached to the recording head and a state where it is attached to the recording head.

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 25 Soft porous body film

Claims (1)

  An ink supply port into which an ink supply needle for supplying ink to the recording head is inserted, an ink storage region communicating with the ink supply port, and an ink supply chamber is formed between the ink supply port and the ink storage region. A differential pressure valve that is disposed between the ink supply chamber and the ink storage region, opens and closes a flow path from the ink storage region to the ink supply chamber by a pressure difference, and a seal member that seals the ink supply port. An ink cartridge comprising an ink cartridge filled with ink including the ink supply chamber.

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