JP4018521B2 - Ink tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink tank provided with a gas-liquid separation member, and more particularly to an ink tank that defines the state of attachment of the gas-liquid separation member to the ink tank.
[0002]
[Prior art]
Only a negative pressure introduction part for introducing a negative pressure inside the sub tank, an ink intake part for taking ink into the inside by the negative pressure introduced from the negative pressure introduction part, and a gas fixed to the negative pressure introduction part A gas-liquid separation member (hereinafter referred to as a porous membrane) that passes through the sub tank moves to the ink supply position when the ink in the sub tank decreases below a predetermined amount, and supplies ink from the main tank to the sub tank via the ink intake section. However, an ink supply method has been proposed in which the supply is stopped when the ink reaches the porous film.
[0003]
Based on the same concept, there is also proposed a device in which a porous film is fixed to a recording apparatus side that is joined to a negative pressure introducing portion instead of a sub tank.
[0004]
In addition, in a liquid tank equipped with a container body for storing liquid, an opening for taking out liquid, and an air communication part, the air communication part is provided with a porous film, and air is supplied from the air communication part according to the pressure fluctuation in the liquid accompanying a temperature change. There has also been proposed a liquid tank configured so that liquid does not leak to the outside while being configured to be able to enter and exit.
[0005]
In such a configuration, the porous membrane has a ventilation surface formed in various shapes such as a circle, a rectangle, and an ellipse, and a predetermined width of the outer edge thereof is fixed by heat welding or an adhesive.
[0006]
[Problems to be solved by the invention]
However, in the above configuration, every time ink is supplied to the sub tank, the ink reaches the porous film surface, and the period from when the supply of the ink is stopped until the driving of the pump that is the negative pressure generating mechanism is stopped The surface is maintained in a state where pressure by suction is applied while ink is in contact, that is, in a state where the surface is pressurized with ink. 20 and 21, reference numeral 1001 denotes a sub tank, 1002 denotes an absorber that holds ink, 1003 denotes a porous member, and 1004 denotes an outer peripheral portion of the porous member 1003.
[0007]
FIG. 22 is an exploded perspective view of the periphery of the porous member 1003, and the upper direction in the figure is the sub tank internal side. Reference numeral 1001 a denotes a member constituting the upper surface of the sub tank 1001. Reference numeral 1006 denotes a convex portion for fixing the porous member 1003, and reference numeral 1006a denotes a joint surface when the outer peripheral portion 1004 (see FIGS. 20 and 21) of the porous member 1003 is welded or bonded. In the porous member 1003, the inside of the joint surface 1006a is a breathable region.
[0008]
The arrows in FIG. 20 indicate the air flow when the air inside the sub tank 1001 starts to be sucked by a pump (not shown). When ink is supplied from the main tank (not shown) into the sub tank 1001 and reaches the porous member 1003, the state shown in FIG. The pressure at this time is 30 kPa (about 0.3 kg / cm ² ), The force from the liquid contact surface side to the pump side is applied to the porous member 1003. Since the porous member 1003 has only the outer edge portion 1004 fixed by heat welding or an adhesive, the air permeable region gradually bends to the pump side while repeating the ink supply, and cannot be restored as it is as shown in FIG. .
[0009]
As the porous member 1003 bends, even if the ink in the sub-tank is consumed, a part of the ink 1005 that has reached the porous member 1003 remains attached to the ventable region, and the area that can be vented gradually decreases. In the worst case, the porous member 1003 cracks and ink leaks to the pump side.
[0010]
An object of the present invention is to prevent deflection of the gas-liquid separation member to the pump side.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, an ink tank of the present invention is introduced from a negative pressure introducing portion for introducing a negative pressure into a stored ink tank for storing ink supplied to an inkjet head, and the negative pressure introducing portion. An ink intake portion for taking ink into the stored ink tank by a negative pressure, and a gas-liquid separation member that is arranged in an air passage extending from the stored ink tank to the negative pressure introduction portion and allows only gas to pass therethrough. In the prepared ink tank,
A fixing portion for attaching the gas-liquid separation member on the negative pressure introducing portion side with respect to the gas-liquid separation member; and a peripheral portion of the fixing portion, the gas-liquid separation member, and a ventilation region of the gas-liquid separation member It is characterized in that a part of is fixed by welding.
[0012]
The fixing portion includes a lattice portion in which a wall is configured in a lattice shape in a region corresponding to the ventilation region of the gas-liquid separation member, and a lattice of the lattice portion is welded to a part of the gas-liquid separation member. This is a preferred configuration.
[0013]
In addition, it is a more preferable configuration that the plurality of openings partitioned by the lattice of the fixed portion are gathered together in the air passage leading to the negative pressure introducing portion.
[0014]
The fixing portion includes a lattice portion having a wall formed in a lattice shape in a region corresponding to the ventilation region of the gas-liquid separation member, and the lattice of the lattice portion intersects with a part of the gas-liquid separation member. It is a preferable configuration to be a vertex portion.
[0015]
In addition, it is a more preferable configuration that a lattice area other than the apex portion where the lattice of the fixed portion intersects is provided with a gap region that allows ventilation between the lattice and the gas-liquid separation member.
[0016]
The fixing portion is provided with a circular opening in a region corresponding to the ventilation region of the gas-liquid separation member, and it is preferable that a portion other than the opening is welded to a part of the gas-liquid separation member. is there.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0018]
(Embodiment 1)
1 and 2 are cross-sectional views illustrating a schematic structure of an ink jet printer according to an embodiment of the present invention. The image forming apparatus according to the present embodiment is a serial scan method in which a liquid discharge head moves in the main scanning direction. This is an application example. In FIG. 1, the printer main body is composed of a medium feeding unit 1 for feeding a printing medium S, a printing unit 2 for performing a printing operation, an ink replenishing unit 3 for replenishing ink as a liquid according to the present invention, and the like. Yes. 4 is a cover provided on the outside of the printer main body, and 5 is an installation table on which a plurality of print media S are stacked. The print medium S is inserted into the insertion port 4a provided in the cover 4 and discharged from the discharge port 4b. On the inner side of the side plate 6 provided in the cover 4, a mounting base 8, a feeding roller 9 and a guide member 11 are provided. The mounting base 8 constitutes means for mounting the print medium S, and is urged by the spring 7 toward the upper feed roller 9. The feeding roller 9 constitutes a medium feeding unit, and abuts on the uppermost position of the plurality of print media S on the mounting table 8. The guide member 11 guides the single print medium S separated by the separating means 10 toward the print unit 2. Reference numeral 12 denotes a photosensor for detecting the print medium S passing through the downstream side of the guide member 11. Reference numeral 13 denotes a pair of conveyance rollers that convey the fed print medium S at a constant speed, and reference numeral 14 denotes a pair of carry-out rollers that carry out the print medium S after printing an image. A carriage 19 is guided by guide members 15 and 16 so as to be movable in the main scanning direction (width direction of the print medium S) indicated by arrows 28 and 35 in FIG. The carriage 19 moves in the main scanning direction by the driving force transmitted from the carriage motor 70 via the belt 18 that is stretched between the pair of pulleys 17. Reference numeral 20 denotes a storage liquid tank, that is, a storage ink tank, which is mounted on the carriage 19 in a replaceable manner. Reference numeral 20a denotes an ink jet head (hereinafter referred to as a print head) as a liquid discharge head according to the present invention, which discharges ink supplied from a stored ink tank 20 based on image information.
[0019]
In the case of this embodiment, the storage ink tank 20 and the print head 20a constitute a head cartridge that is integrally coupled. The ink tank 20 and the print head 20 a may be configured separately and may be detachably coupled to each other, or may be individually mountable on the carriage 19. Reference numeral 24 denotes an electric wiring board disposed on the inner side of the cover 4, which is provided with a plurality of operation buttons 23 that penetrate the cover 4 and protrude from the surface thereof. Reference numeral 25 denotes a control means, on which a microcomputer, a memory, and the like are mounted on a control electrical wiring board disposed inside the cover 4. The control means 25 controls the printer while communicating with the host computer.
[0020]
In FIG. 6, cap members 101 and 54 that are urged to the left by springs 107 and 108 are slidably fitted to the outer periphery of the hollow pipe 21 a and the conduit 55 provided on the printer main body side. . In the pipe 21 a and the conduit 55, communication holes 21 f and 55 a that are opened and closed by the cap members 101 and 54 are formed. The distal ends of the pipe 21a and the conduit 55 are closed, and the base end side is connected to the replenishment ink tank 22 of FIG. 109 and 110 are cap members provided on the printer main body side so as to be movable up and down. The recovery processing cap member 110 is connected to a waste liquid container (not shown) via a recovery processing suction pump 111. Reference numeral 112 denotes a platen for guiding a print medium to an image print position by the print head 20a.
[0021]
FIG. 6 shows a state in which the print head 20a has moved to its home position and a state in which the printer main body is turned off. In this state, the cap members 109 and 110 are raised, and the ejection port surface 44a of the print head 20a is capped by the recovery processing cap member 110. In this case, the supply cap member 101 closes the ink intake port 20b while closing the communication hole 21f of the pipe 21a. At the same time, since the supply cap member 101 is in a position where the air communication port 104 is not closed, in this state, the supply cap member 101 is moved between the inside and the outside of the storage ink tank 20 according to the pressure fluctuation in the storage ink tank 20 due to the change in the ambient temperature. It is possible to introduce and exhaust air. The cap member 54 closes the common suction port 53 while closing the communication hole 55 a of the conduit 55. With respect to the print head 20a at the home position, the ink discharge state can be kept good by a head discharge recovery process (hereinafter simply referred to as a recovery process) for discharging ink that does not contribute to image printing. As the recovery process, a negative pressure generated by the recovery process suction pump 111 is introduced into the recovery process cap member 110, and a process of forcibly sucking and discharging ink from the ejection port 44 of the print head 20a, This includes a process of ejecting ink from the outlet toward the recovery processing cap member 110.
[0022]
A state in which ink is supplied to the storage ink tank 20 is shown in FIG. When ink replenishment is performed, the print head 20a is further moved from the home position in FIG. As described above, when the print head 20a moves to the ink supply position, the cap members 109 and 110 are lifted, and the discharge port surface 44a of the print head 20a is covered with the supply cap member 109. The replenishing cap member 109 seals the discharge port 44 of the print head 20a. In this case, the supply cap member 101 opens the communication hole 21f by relative movement with the pipe 21a while the ink intake port 20b is closed. The communication hole 21 f opens in the reservoir ink tank 20, thereby forming an ink supply path between the reservoir ink tank 20 and the replenishment ink tank 22. Since the supply cap member 101 closes the atmosphere communication port 104, ink does not flow from the stored ink tank 20 to the atmosphere communication port 104.
[0023]
The cap member 54 opens the communication hole 55 a by relative movement with the conduit 55. The communication hole 55 a forms a suction path between the common suction port 53 and the replenishment suction pump 31.
[0024]
A porous member 48 (details will be described later) manufactured by stretching PTFE as a gas-liquid separation member that allows only gas to pass through is incorporated into this suction path.
[0025]
At the time of ink replenishment, the air in the stored ink tank 20 is sucked through the porous member 48 by the replenishing suction pump 31, and the air is discharged into a waste liquid container (not shown). As a result, the inside of the storage ink tank 20 becomes negative pressure, and the ink in the replenishment ink tank 22 is sucked into the storage ink tank 20 by this negative pressure. The ink that has flowed into the stored ink tank 20 penetrates into the ink holding body 41, and the ink level rises as the penetration proceeds. Since the rising speed of the ink level depends on the suction force of the replenishment suction pump 31, it is set to an appropriate speed according to the operation amount. When the ink level reaches the porous member 48, the porous member 48 does not pass the ink, that is, the liquid molecules, so that the ink supply automatically stops.
[0026]
After the ink suction operation is completed, the printer returns to the state shown in FIG. 6 or 5 by moving the print head 20a to the home position or the print operation position.
[0027]
FIG. 3 shows an exploded state of the head cartridge in the present embodiment. FIG. 3 is an exploded perspective view of FIG.
[0028]
In other words, the print head 20a is composed of a plurality of independent head portions for each ink color, and each head portion includes a common ink chamber 43 communicating with the ink supply port 42 of the corresponding ink tank 20, and each ink portion. A plurality of discharge ports 44 for discharging droplets are provided. In an ink passage portion that communicates the common ink chamber 43 and the discharge port 44, a discharge energy generation unit (not shown) that generates energy for discharging ink from the discharge port 44 is provided.
[0029]
In the case of this embodiment, ventilation between each reservoir ink tank 20 and the common suction port 53 and the atmosphere communication port 104 is achieved by the groove on the upper surface of the main body of the stored ink tank 20 and the cover member 100 coupled to the upper surface of the main body. Paths 49 to 51 and 52 are formed. Although the air communication port 104 in this embodiment has a relatively small diameter, the cross-sectional area of the air passage 52 itself is changed in order to prevent the air communication port 104 from being blocked by ink adhering to the periphery of the ink intake port 20b. Instead, only the opening end may have a large diameter. Each reservoir ink tank 20 is provided with a porous member 48.
[0030]
The porous member 48 provided in each of the ink tanks 20 functions as a gas-liquid separation unit of the present invention that does not pass ink and allows only gas such as air or water vapor to pass through. The porous member 48 has a thin film shape made of, for example, PTFE (tetrafluoroethylene resin) or a resin porous material similar thereto. In the present embodiment, the air discharge path in the ink tank 20 is connected to the common suction port 53 from the common air passages 50 and 51 through the porous members 48 and the air passages 49 as shown in FIG. As will be described later, the air in the ink tank 20 is sucked out by the replenishing suction pump 31 through the conduit 55 from the cap member 54 that is in close contact with the surface where the common suction port 53 opens. That is, the above-described air passages 49 to 51 and the common suction port 53 correspond to the negative pressure introducing portion of the present invention.
[0031]
The material of the porous member 48 is fluorine such as PTFE, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, etc. The resin is particularly preferable because it is excellent in air permeability and chemical resistance. For example, a membrane in which a sheet made of PTFE is made porous by a uniaxial stretching method or a biaxial stretching method is particularly suitable.
[0032]
The porous member 48 only needs to have a gas-liquid separation function, and various materials can be used according to the type of ink and usage pattern. In addition to the above-mentioned PTFE and a gas permeable film made of a resin porous material similar thereto, porcelain, ceramic ware, ceramic, or the like, or a similar porous material can also be used.
[0033]
The porous member 48 may be subjected to a liquid repellent treatment according to the properties of the ink. As the liquid repellent treatment agent, various fluorine-containing polymers having a perfluoroalkyl group can be used. A polymer having a fluorine-containing chain forms a low surface free energy film on the surface of the fiber and exhibits a liquid repellent effect. The liquid repellent treatment can be achieved by impregnating the porous member 48 with a liquid repellent treating agent or applying it by spraying. The application amount of the liquid repellent treatment agent is preferably adjusted so that sufficient liquid repellency is obtained and the air permeability of the porous member 48 is not hindered.
[0034]
As shown in FIGS. 3 and 4, a common suction port 53 and an ink intake port 20 b are formed on the side surface of the stored ink tank 20. Air between the ink tanks 20Y, 20M, 20C, and 20B, the common suction port 53, and the atmosphere communication port 104 is formed by the groove on the upper surface of the main body of the storage ink tank 20 and the cover member 100 coupled to the upper surface of the main body. The discharge route is formed. The atmosphere communication port 104 is sealed by the sealing means 122 when ink is supplied, but the atmosphere communication ports 104 for four colors are gathered in one place and can be sealed in four places with one sealing member 122. The air communication port 104 is independent at four locations to avoid color mixing in the flow path when the pressure in the stored ink tank 20 fluctuates and ink flows out.
[0035]
In the above-described embodiment, the porous member is attached to the storage ink tank 20, but on the recording apparatus main body side, at a position facing the common suction port 53 of the storage ink tank 20 in the ink supply state of FIG. 7. Even when a porous member is provided, the method of the present invention can be employed.
[0036]
In FIG. 8, reference numeral 501 denotes a stored ink tank capable of containing ink, 502 denotes a recording head capable of ejecting ink in the stored ink tank 501 from the nozzle portion 502A, and these are main-scanned along the guide shafts 503A and 503B. It is moved in the direction (in the directions of arrows A1, A2). The storage ink tank 501 and the recording head 502 can be detachably mounted on a carriage (not shown) guided by the guide shafts 503A and 503B. The storage ink tank 501 is formed with an ink intake port 501A, a suction port 501B, an air communication port 501C, and an ink supply port (not shown) communicating with the recording head 502. Accommodates an ink absorber 504 for absorbing and holding ink.
[0037]
In this example, the storage ink tank 501 is formed with ink storage portions 501C, 501M, 501Y, and 501Bk for storing cyan, magenta, yellow, and black ink, as shown in FIG. An ink intake port 501A, a suction port 501B, an air communication port 501C, and an ink supply port are formed in the ink container. In consideration of the usage frequency of the black ink, the storage portion 501Bk is formed larger than the other storage portions. The nozzle portion 502A of the recording head 502 is provided for each ink color. The storage ink tank 501 and the recording head 502 may be combined to form an ink jet cartridge, and the storage ink tank 501 and the recording head 502 have a structure divided for each ink color. May be.
[0038]
Reference numeral 521 denotes a hollow projecting member provided on the apparatus main body side, and a seal member 523 urged to the left by a spring 522 is slidably fitted to the outer peripheral portion thereof. The protruding member 521 is formed with a through-hole 521A that is opened and closed by a seal member 523. The distal end of the protruding member 521 is closed, and the proximal end is connected to a main tank (not shown).
[0039]
Reference numeral 531 denotes an arm member, which is pivotally supported by the support member 533 on the apparatus main body side so as to be rotatable in the vertical direction, and is urged downward by a spring 534. An opening 532A capable of communicating with the suction port 501B and a seal portion 532B capable of closing the suction port 501B and the atmosphere communication hole 501C are formed in the seal member 532 attached to the distal end side of the arm member 531. The opening 532 </ b> A is connected to the suction pump 513 through the suction pipe 512. In the case of this example, the openings 532A for the ink storage portions 501C, 501M, 501Y, and 501B are gathered by the suction pipe 512 as shown in FIG. 9 and then connected to the common suction pump 513. Further, a porous member 505 that allows gas to pass through without passing ink is attached to the opening 532A. The porous member 505 is made of the same material as the porous member 48 described in the above embodiment, and the surface is subjected to the same liquid repellent treatment. On the other hand, a blade 536 capable of wiping the lower surface of the seal member 532 including the porous member 505 is provided on the storage ink tank 501 side. 535 is a stopper member that regulates the upward movement position of the arm member 531.
[0040]
Reference numerals 524 and 525 denote first and second cap members provided on the apparatus main body side so as to be movable up and down. The second cap member 525 is connected to a waste liquid tank (not shown) through a suction pump 526. Reference numeral 527 denotes a platen for guiding a recording medium to an image recording position by the recording head 502. The recording medium is transported in the sub-scanning direction intersecting the main scanning direction (arrow A1, A2 direction) by a transport mechanism (not shown). Images are sequentially formed on the recording medium by repeating the main scanning of the recording head 502 while ejecting ink and the conveying operation of the recording medium in the sub-scanning direction.
[0041]
During the recording operation, the recording head 502 records an image by ejecting ink while moving in the directions of arrows A1 and A2 at a position to the left of the home position in FIG.
[0042]
When the recording head 502 moves to the home position, as shown in FIG. 10, the first and second cap members 524 and 525 are raised, and the nozzle portion 502A of the recording head 502 is capped by the second cap member 525. The At this time, the seal member 523 closes the ink intake port 501A while closing the through hole 521A of the protruding member 513, and the seal member 532 closes the suction port 501B. In this way, the intake port 501A and the suction port 501B are closed, thereby preventing the viscosity of the ink in the stored ink tank 501 from increasing. The porous member 505 is located on the right side in FIG. 10 away from the suction port 501, and contact with the ink in the stored ink tank 501 is prevented. As a result, the performance deterioration of the porous member 505 is prevented by avoiding long-term contact between the porous member 505 and the ink. With respect to the recording head 502 at the home position, the ink ejection state can be kept good by the recovery process for discharging ink that does not contribute to image recording. As the recovery process, the negative pressure generated by the suction pump 526 is introduced into the second cap member 525, and the ink is forcibly sucked and discharged from the ink discharge port of the nozzle part 502A, and the nozzle part 502A. A process of discharging ink from the ink discharge port toward the inside of the second cap member 525 is included.
[0043]
During the ink supply operation, as shown in FIG. 11, the recording head 502 further moves from the home position to the ink supply position in the direction of arrow A1. When the recording head 502 moves to the ink supply position, as shown in FIG. 11, the first and second cap members 524 and 525 are raised, and the first cap member 524 caps the nozzle portion 502 of the recording head 502. Is done. The cap member 524 seals the ink discharge port of the nozzle portion 502A. At this time, the seal member 523 opens the through hole 521A by relative movement with the protruding member 521 while the ink intake port 501A is closed. The through hole 521A opens in the stored ink tank 501 to form an ink supply system between the stored ink tank 501 and the main tank. Further, the seal member 532 closes the air communication port 501C and connects the opening 532A to the suction port 501B to form an air suction system between the suction port 501B and the suction pump 513. The porous member 505 is interposed in the suction system.
[0044]
When supplying ink, the suction pump 513 sucks the air in the stored ink tank 501 through the porous member 505 and discharges the air into a waste liquid container (not shown). As a result, the stored ink tank 501 has a negative pressure, and the ink in the main tank is sucked into the stored ink tank 501 by the negative pressure. The ink that has flowed into the stored ink tank 501 penetrates the ink absorber 504, and the ink level rises as the penetration proceeds. Since the rising speed of the ink level depends on the suction force of the suction pump 513, it is set to an appropriate speed according to the operation amount. When the ink level reaches the porous member 505, ink supply is automatically stopped because the porous member 505 does not allow liquid such as ink to pass through. Further, ink supply to the ink storage portions 501C, 501M, 501Y, and 501B is started at the same time, and ink supply is automatically performed by the porous member 505 in order from the ink filling state first. It will be stopped.
[0045]
After the completion of such ink replenishment operation, the recording apparatus returns to the state shown in FIG. 10 or FIG. 8 by moving the recording head 502 to the home position or the recording operation position.
[0046]
The blade 536 is in contact with the lower surface of the seal member 532 in accordance with the movement of the stored ink tank 501, thereby rotating the arm member 531 up and down as shown by a two-dot chain line in FIG. The lower surface of the seal member 532 including the 505 is wiped. By such wiping, foreign matters such as thickened ink adhering to the porous member 505, the opening 532A, and the seal portion 532B are removed, and they are kept in a good state.
[0047]
In the above configuration, a configuration for preventing the ventilation surface from being bent toward the pump side even when a force from the liquid contact surface side to the pump side is applied to the porous member will be described below.
[0048]
FIG. 12 is an exploded perspective view around the porous member 48.
[0049]
In the configuration in which the porous member is fixed to the stored ink tank, 301 corresponds to a top plate in which the upper surface is integrated with the cover member 100 of the stored ink tank 20 in FIG. On the inside.
[0050]
In the configuration in which the porous member is fixed to the recording apparatus main body side, 301 corresponds to the seal member 532 in FIG. 8, and the upper direction in the figure is the direction facing the suction port 501B of the stored ink tank 501.
[0051]
Since the effect is exactly the same when the porous member 48 is fixed to either the stored ink tank side or the recording apparatus main body side, a configuration in which the porous member 48 is fixed to the stored ink tank will be described below as an example.
[0052]
In the upper surface plate 301, an opening 301a partitioned by a lattice portion is formed in the central portion, and the porous member 48 is fixed to the outer peripheral portion 301b by heat welding.
[0053]
FIG. 13 is a cross-sectional view taken along the line aa in FIG. 12 and shows a state in which the porous member 48 is fixed. The openings 301a are gathered together inside the upper surface plate 301 and reach the common suction port 53 of FIG.
[0054]
Thermal welding is performed by heating from the porous member 48 side (stored ink tank 20 inside) by a welding head (not shown) to melt the outer peripheral portion 301b. Since the heat welding head (not shown) is hollow except for the outer peripheral portion 301b, the region where the porous member 48 can be vented (the portion facing the opening 301a) is not exposed to high temperature even during welding. Prevents the liquid repellency from deteriorating.
[0055]
The lattice portion 301c at the center of the upper surface plate 301 has the same height as the outer peripheral portion 301b, and the back surface of the central portion of the porous member 48 is in contact with the surface of the lattice portion.
[0056]
Due to this configuration, the porous member 48 is pressurized with ink from the time the ink supply is stopped until the drive of the replenishing suction pump 31 (FIG. 2), which is a negative pressure generating mechanism, is stopped. However, it can be held down by the lattice part on the back. Since each of the ventable regions facing the large number of openings 301a has a small area, the applied force is small and the deflection of the portion is extremely small. Therefore, it is possible to prevent the ink from remaining on the surface and reducing the area that can be vented, or the porous member 48 from cracking and causing ink to leak to the pump side.
[0057]
FIG. 14 is a view of the top plate 301 as viewed from the porous member 48 side. The porous member 48 is not limited to the outer peripheral portion 301a and may be heat-welded as necessary. For example, the central vertical and horizontal portions may be fixed in addition to the outer peripheral portion 301a as indicated by the hatched portion in the figure. In this case, the welding head can be fixed without deteriorating the liquid repellency of the ventilation portion if only the hatched portion is in contact with the porous member 48.
[0058]
Further, the shape of the opening may be other than a rectangle as long as a necessary ventilation area can be secured.
[0059]
FIG. 15 shows an example in which the opening is formed in a circular shape, and is a view of the top plate 301 as seen from the porous member 48 side as in FIG. is there. As in the above example, the outer peripheral portion 301b may be welded, and portions other than the inner ventable region may be welded. In any case, the welding head may be configured so as not to contact the air permeable region of the porous member 48.
[0060]
The present invention is not limited to the configuration of the embodiment described above. For example, a container main body that stores ink supplied to an inkjet head, an opening for taking out the liquid, and the container main body communicate with the atmosphere. It is good also as an ink tank provided with the atmosphere communication opening which attaches a gas-liquid separation member by the composition indicated by the present invention to the place where communication with the atmosphere is made. For example, it can be employed in a main tank not shown in the above embodiment. The structure of the main tank at this time may be the same as that of the above-described embodiment and the stored ink tank 20, or may be a tank configured to hold ink without using the absorber 41.
[0061]
In addition, the present invention is not limited to the field of the ink jet recording apparatus described above, and does not like the ingress of moisture, for example, a communication portion that communicates the inside and outside of an electric / electronic device, for example, the inside of a switch, button, etc. It is possible to apply the configuration disclosed in the present invention when attaching the gas-liquid separation member to a place where it is preferable to attach the gas-liquid separation member such as an operation part having a possibility of intrusion. The fear of failure can be suppressed.
[0071]
(Embodiment 2)
FIG. 16 is an exploded perspective view showing an example in which the shape of the lattice portion of the top plate is formed to be uneven so that the contact surface with the porous member 48 is reduced. Similar to the above embodiment, reference numeral 302 denotes a top plate in which the upper surface is integrated with the cover member 100 of the stored ink tank 20 in FIG. 3, and the upper direction in the figure is the inner side of the stored ink tank 20.
[0072]
As in the first embodiment, the effect is exactly the same when the porous member 48 is fixed to either the storage ink tank side or the recording apparatus main body side, and hence the porous member 48 is fixed to the storage ink tank. The configuration will be described as an example. The lattice portion is formed to be uneven, and the apex 302c of the convex portion is formed at the same height as the outer peripheral portion 302b.
[0073]
FIG. 17 is a cross-sectional view taken along the line aa in FIG. 16 and shows a state in which the porous member 48 is fixed. As in the first embodiment, the porous member 48 is fixed to the outer peripheral portion 302b by heat welding, and the inside of the porous member 48 is not supported except for the vertex 302c, and is a ventable region. The air that has passed through the porous member 48 passes through a portion that is lower than the vertex 302c and reaches the common suction port 53 of FIG.
[0074]
FIG. 18 is a view of the top plate 302 as viewed from the porous member 48 side.
[0075]
As in the above embodiment, the porous member 48 may be welded only on the outer peripheral portion 302b, or may be welded by selecting all or some of the vertices 302c shown in the hatched portion in FIG. With this configuration, the porous member 48 is greatly increased by the top surface 302c on the back surface even when the ink is pressurized until the drive of the pump, which is the negative pressure generating mechanism, is stopped after the supply of the ink is stopped. Suppresses bending. The porous member 48 is a breathable region except for the portions facing the outer peripheral portion 302b and the apex 302c, and since the respective areas are small, the applied force is small and the deflection of the portion is extremely small. Therefore, it is possible to prevent the ink from remaining on the surface and reducing the area that can be vented, or the porous member 48 from cracking and causing ink to leak to the pump side.
[0076]
FIG. 19 is an exploded perspective view of the top plate. The upper side is the upper surface of the stored ink tank 20, and the lower side is the cover member 100 of the stored ink tank 20. Grooves are formed on the upper surface, and uneven ribs are formed on the cover member 100. These are integrated by a method such as ultrasonic welding, heat welding, adhesion, or the like, and the states shown in FIGS. 16 and 17 are obtained.
[0077]
(Embodiment 3)
Further, without being limited to the configuration of the embodiment described above, for example, a container main body that stores ink supplied to the ink jet head, an opening for taking out the liquid, and an air that communicates the container main body with the air The ink tank may include a communication port, and the gas-liquid separation member may be attached to a location where communication with the atmosphere is made by the configuration disclosed in the present invention.
[0078]
A system in which the storage ink tank and the replenishment ink tank are connected by a tube will be described.
[0079]
As shown in FIG. 23, there is a system in which an ink jet recording head 2002 and a stored ink tank 2010 are arranged on a carriage 2001 and the stored ink tank 2010 ink is supplied from a replenishing ink tank 2003 via a tube 2004. In order to generate the negative pressure, the replenishment ink tank 2003 is disposed on a plane −H that is several centimeters lower than the gravity height (water head = head) surface of the inkjet recording head 2002. Reference numeral 2007 denotes a recording paper, and reference numeral 2008 denotes a cap that prevents the nozzles of the ink jet recording head 2002 from drying when the power is turned off or in a standby state.
[0080]
Reference numeral 2009 denotes a gas permeable member fixed to the replenishment ink tank. As the ink in the replenishment ink tank decreases through the gas permeable member 2009, air is introduced from the outside and ink leakage to the outside is prevented.
[0081]
The gas permeable member can also be employed in a system (on-carriage system) in which the ink tank stored on the carriage is replaced without having a replenishment ink tank. A gas permeable member may be fixed at an arbitrary position of the stored ink tank (not shown).
[0082]
【The invention's effect】
With the configuration as described above, even if pressure is applied in a state where ink is supplied to the storage ink tank and the ink reaches the porous member, it is possible to prevent the breathable region from being bent.
[0083]
As a result, a part of the ink that has reached the porous member remains attached, and the area that can be ventilated gradually decreases, or the porous member cracks and the ink leaks to the pump side. Disappears.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment in which an image forming apparatus of the present invention is applied to a serial type ink jet printer.
2 is a cross-sectional view taken along the line II-II in FIG.
3 is an exploded perspective view of the head cartridge in the embodiment shown in FIG. 1. FIG.
4 is a perspective view of the head cartridge in the embodiment shown in FIG. 1. FIG.
FIG. 5 is a diagram illustrating a state during printing by the inkjet printer.
FIG. 6 is a diagram illustrating a state where the power of the inkjet printer is off or in standby.
FIG. 7 shows a state during ink supply.
FIG. 8 is a diagram illustrating a state during printing by the inkjet printer.
FIG. 9 is a diagram illustrating a side surface of a carriage portion.
FIG. 10 is a diagram illustrating a state in which the inkjet printer is powered off or in standby.
FIG. 11 shows a state during ink supply.
12 is an exploded perspective view around a porous member 48. FIG.
13 is a cross-sectional view taken along the line aa in FIG.
14 is a view of the upper surface plate 301 as viewed from the porous member 48 side. FIG.
FIG. 15 is a diagram in which an opening is formed in a circular shape.
16 is a diagram for explaining the second embodiment, and is an exploded perspective view of the periphery of a porous member 48. FIG.
17 is a cross-sectional view taken along the line aa in FIG. 16;
18 is a view of the upper surface plate 302 as viewed from the porous member 48 side. FIG.
19 is an exploded perspective view of the upper surface plate 302. FIG.
FIG. 20 is a diagram illustrating a periphery of a porous member in a diagram illustrating a conventional example.
FIG. 21 is a diagram illustrating a state in which ink reaches a porous member in a diagram illustrating a conventional example.
FIG. 22 is an exploded perspective view of the periphery of a porous member 48 showing a conventional example.
FIG. 23 is a diagram showing a system for supplying stored ink tank ink from a replenishment ink tank through a tube.
[Explanation of symbols]
1 Medium feeding section
2 Print section
3 Ink supply section
4 Cover
4a insertion slot
4b outlet
5 installation stand
6 Side plate
7 Spring
8 Mounting base
9 Feeding roller
10 Separation means
11 Guide members
12 Photosensor
13 Transport roller
14 Unloading roller
15, 16 Guide member
17 pulley
18 belt
19 Carriage
20 Storage ink tank
20a Inkjet head (print head)
20b Ink intake
20B-1 side
21 (21Y, 21M, 21C, 21B) Ink supply means
21a Piping
22 (22Y, 22M, 22C, 22B) Supply ink tank
23 Operation buttons
24 Electric wiring board
25 Control means
28 Main scan direction
31 Suction pump for replenishment
35 Main scan direction
41 Ink holder
42 Ink supply port
43 Common ink chamber
44 Discharge port
44a Discharge port surface
48 Porous material
49-52 Airway
53 Common suction port
54 Cap members
55 conduit
55a Communication hole
70 Carriage motor
100 Cover member
101 Supply cap member
104 Air communication port
301 Top plate
301a opening
301b Outer periphery
301c lattice part
302 Top plate
302b Outer periphery
302c lattice part

Claims (6)

A negative pressure introduction part for introducing a negative pressure into a stored ink tank that stores ink supplied to the inkjet head, and a negative pressure introduced from the negative pressure introduction part for taking ink into the stored ink tank In an ink tank comprising: an ink intake portion; and a gas-liquid separation member that is disposed in a ventilation path extending from the storage ink tank to the negative pressure introduction portion and allows only gas to pass therethrough,
A fixing portion for attaching the gas-liquid separation member on the negative pressure introducing portion side with respect to the gas-liquid separation member; and a peripheral portion of the fixing portion, the gas-liquid separation member, and a ventilation region of the gas-liquid separation member A part of the ink tank is fixed by welding.   The fixing portion includes a lattice portion having walls configured in a lattice shape in a region corresponding to the ventilation region of the gas-liquid separation member, and a portion of the gas-liquid separation member is welded to the lattice portion The ink tank according to claim 1, wherein the ink tank is a lattice.   3. The ink tank according to claim 2, wherein a plurality of openings partitioned by the lattice of the fixing portion are gathered together in a ventilation path reaching the negative pressure introduction portion.   The fixing portion includes a lattice portion having walls configured in a lattice shape in a region corresponding to the ventilation region of the gas-liquid separation member, and a portion of the gas-liquid separation member is welded to the lattice portion The ink tank according to claim 1, wherein the ink tank is an apex portion where the lattices intersect.   The ink tank according to claim 4, wherein a lattice area other than the apex portion where the lattice of the fixed portion intersects is provided with a gap region that allows ventilation between the lattice and the gas-liquid separation member.   The fixing portion is provided with a circular opening in a region corresponding to the ventilation region of the gas-liquid separation member, and a portion other than the opening is welded to a part of the gas-liquid separation member. The ink tank according to claim 1.

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