JP2011251473A - Maintenance device and liquid ejection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance device capable of suppressing the leakage of a liquid from a nozzle and closing a nozzle opening, and to provide a liquid ejection apparatus.SOLUTION: The maintenance device includes a cap 45 with a bottom in a box shape which can form a closed space between a tip opening edge 49a and a nozzle forming face 19a having, thereon, the nozzle opening 34 for ejecting ink by allowing the tip opening edge 49a to abut on the nozzle forming face 19a so as to cover the nozzle opening 34, and a cam mechanism 46 which relatively moves the cap 45 to the nozzle forming face 19a. The cap 45 contains a closing member 52 which can close the nozzle opening 34 by abutting on the nozzle forming face 19a. The cap is configured so that the cap is deformed so as to reduce a volume of the closed space when the closing member 52 is brought into close proximity to the nozzle forming face 19a under a condition that the tip opening edge is in contact with the nozzle forming face 19a. The cam mechanism 46 brings the closing member 52 into close proximity to the nozzle forming face 19a to allow it to abut on the nozzle forming face after the tip opening edge 49a of the cap 45 abuts on the nozzle forming face 19a.

Description

  The present invention relates to a maintenance device and a liquid ejecting apparatus including the maintenance device.

  Conventionally, ink jet printers are widely known as liquid ejecting apparatuses that eject liquid onto a target. This printer performs printing (image formation) on a recording medium as a target by ejecting ink (liquid) supplied to the recording head (liquid ejecting head) from nozzles formed on the recording head. .

  In such a printer, there is a problem in that the ink is evaporated from the nozzles, the viscosity of the ink is increased, and the printing quality is deteriorated. Therefore, in such a printer, recently, as described in Patent Document 1, for example, a pressing member (blocking portion) is brought into contact with the nozzle forming surface on which the nozzle is formed, and the nozzle opening is closed with the pressing member. Thus, there is known one that suppresses ink evaporation.

  That is, in the printer of Patent Document 1, a pressing member formed so as to be in close contact with the nozzle forming surface in a cap having an inverted trapezoidal cross section made of an elastic material has a height lower than the peripheral wall portion of the cap. It is provided to be. Then, the tip edge of the circumferential wall portion that is widened in the cap is brought into contact with the nozzle forming surface, and the cap is deformed so that the circumferential wall portion is further spread outward, so that the pressing member in the cap is brought into contact with the nozzle forming surface. I was in contact.

JP-A-5-77433

  By the way, when the pressing member comes into contact with the nozzle forming surface with the meniscus positioned in the vicinity of the nozzle opening, the meniscus and the pressing member may come into contact with each other, destroying the meniscus and causing ink to leak from the nozzle.

  That is, as in the printer of Patent Document 1, when the pressing member is brought into contact with the nozzle forming surface, the cap is deformed from the state in which the peripheral wall portion is in contact with the nozzle forming surface. When the pressing member is brought into contact with the nozzle forming surface, the pressure in the cap does not increase because the internal volume of the cap does not decrease. Therefore, the pressing member closes the nozzle opening in a state where the meniscus is positioned in the vicinity of the nozzle opening, and there is a possibility that the meniscus is destroyed and ink is leaked.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a maintenance device and a liquid ejecting apparatus capable of closing the nozzle opening by suppressing the leakage of the liquid from the nozzle. .

  In order to achieve the above object, the maintenance device according to the present invention is configured such that a tip opening edge abuts a nozzle forming surface on which a nozzle opening for ejecting liquid is formed so as to surround the nozzle opening and the nozzle forming surface. A cap having a bottomed box shape capable of forming a closed space, and a moving means for moving the cap relative to the nozzle forming surface, the cap being in contact with the nozzle forming surface inside the cap When the closed portion approaches the nozzle forming surface with the closed portion capable of closing the nozzle opening, and the tip opening edge is in contact with the nozzle forming surface, the volume of the closed space decreases. The moving means is arranged so that the closing portion approaches and contacts the nozzle forming surface after the opening edge of the cap contacts the nozzle forming surface. Relatively moving the cap relative to the nozzle formation surface.

  According to this configuration, when the capping portion moves relative to the nozzle formation surface after the tip opening edge of the cap abuts against the nozzle formation surface, the cap forms a closed space formed between the nozzle formation surface and the cap formation surface. It is deformed so that its volume decreases. Then, the pressure in the closed space increases, and the liquid meniscus positioned near the nozzle opening rises so as to be pushed from the nozzle opening side. Therefore, the meniscus is separated from the nozzle opening when the closing portion approaching the nozzle forming surface comes into contact with the nozzle forming surface as the cap is deformed. Therefore, it is possible to suppress the contact between the blocking portion and the meniscus and to block the nozzle opening by suppressing the leakage of the liquid from the nozzle.

  In the maintenance device of the present invention, the cap includes a bottom wall portion provided with the closing portion, and a peripheral wall portion formed so as to surround the closing portion, and at least the bottom wall portion and the peripheral wall portion. One of them is configured to be deformed so that the volume of the closed space decreases.

  According to this configuration, when the moving means moves the cap relative to the nozzle formation surface so that the opening edge of the tip of the cap contacts the nozzle formation surface and the closing portion approaches the nozzle formation surface, the cap is At least one of the bottom wall portion and the peripheral wall portion is deformed. That is, by deforming at least one of the bottom wall portion and the peripheral wall portion, the volume of the closed space can be reduced, and the pressure in the closed space can be increased. Therefore, the degree of freedom in designing the cap is improved.

In the maintenance device of the present invention, at least one of the bottom wall portion and the peripheral wall portion has elasticity.
According to this configuration, when the cap is separated from the nozzle forming surface, the elastically deformed wall portion returns to its original shape. Therefore, it is not necessary to provide means for returning the deformed wall portion to the original shape, and the maintenance device can be simplified.

  The liquid ejecting apparatus according to the aspect of the invention includes the liquid ejecting head having the nozzle forming surface, the liquid supply channel that supplies the liquid from the upstream side that is the liquid supply source side to the downstream side that is the liquid ejecting head side, and the configuration described above. Maintenance equipment.

According to this configuration, it is possible to achieve the same operational effects as the invention according to the maintenance device.
The liquid ejecting apparatus of the present invention further includes a one-way valve that allows passage of liquid from the upstream side to the downstream side and restricts passage of the liquid from the downstream side to the upstream side in the liquid supply flow path.

  According to this configuration, the applied pressure in the closed space can be maintained. That is, since the passage of the liquid from the downstream side to the upstream side is suppressed by the one-way valve, the air layer formed between the raised meniscus and the closed portion is in a pressurized state. The amount of liquid evaporated to the air layer is related to the amount of saturated vapor in the air layer, and the amount of liquid evaporated to the air layer decreases as the pressure increases. Accordingly, the simple configuration of the one-way valve can suppress the evaporation of the liquid to the air layer and suppress the thickening of the liquid.

  The liquid ejecting apparatus according to the aspect of the invention further includes an electromagnetic valve capable of restricting passage of liquid in the liquid supply flow path, and a control unit that controls the electromagnetic valve and the moving unit. The solenoid valve is closed while the moving means is driven.

  Generally, the liquid supplied from the upstream side is filled up to the vicinity of the nozzle opening by capillary force. In this respect, according to this configuration, it is possible to change the movement amount of the meniscus of the liquid located near the nozzle opening by controlling the electromagnetic valve, and to maintain the position of the raised meniscus. That is, for example, when the electromagnetic valve is closed during the movement of the cap, the meniscus can be maintained at a position closer to the nozzle opening than in the case where the electromagnetic valve is closed after the movement of the cap is completed. Therefore, the pressure of the air layer between the meniscus and the closing member can be increased. Furthermore, since the movement of the liquid from the upstream side to the downstream side is also restricted, the meniscus can be prevented from descending. Therefore, when the closed portion is brought into contact with the nozzle forming surface, the contact between the liquid and the closed portion can be further suppressed.

FIG. 2 is a schematic diagram of a printer according to the first embodiment. The schematic diagram of the maintenance apparatus located in a standby position. The schematic diagram of the cap located in a cleaning position. The schematic diagram of the cap located in a contact position. The schematic diagram of the cap in 2nd Embodiment. The schematic diagram of the cap located in a contact position. The schematic diagram of the cap in 3rd Embodiment. The schematic diagram of the cap located in a contact position.

(First embodiment)
Hereinafter, a first embodiment in which the liquid ejecting apparatus of the invention is embodied in an ink jet printer will be described with reference to FIGS. In the following description, the terms “front-rear direction” and “left-right direction” refer to the direction indicated by the arrow in FIG. In addition, the term “vertical direction” refers to the vertical direction in the direction of gravity, which is the direction orthogonal to the paper surface in FIG. 1 and the direction indicated by the arrows in FIG.

  As shown in FIG. 1, a printer 11 as a fluid ejecting apparatus includes a frame 12 that has a rectangular shape in plan view. A platen 13 is provided in the frame 12 so as to extend in the left-right direction, and a sheet P as a target is fed onto the platen 13 by a paper feed mechanism (not shown). A guide shaft 14 is installed above the platen 13 in the frame 12 along the longitudinal direction (left-right direction) of the platen 13.

  A carriage 15 is supported on the guide shaft 14 so as to be capable of reciprocating in the axial direction (left-right direction) of the guide shaft 14. Further, the carriage 15 is drivingly connected to a carriage motor 18 provided on the back surface of the frame 12 via an endless timing belt 17 stretched between a pair of pulleys 16 provided on the rear surface of the frame 12. ing. The carriage 15 is reciprocated along the guide shaft 14 by driving a carriage motor 18.

  A recording head 19 as a liquid ejecting head is mounted on the surface of the carriage 15 that faces the platen 13. A valve unit 20 that temporarily stores ink as a liquid on the carriage 15 and adjusts the pressure of the ink to supply it to the recording head 19 corresponds to the color (type) of ink used in the printer 11. A plurality (four in this embodiment) are provided.

  A maintenance unit 21 as a maintenance device for cleaning the recording head 19 and the like is disposed in the home position area of the carriage 15 near the right end in the frame 12 in FIG.

  Further, a cartridge holder 23 is provided at the right end of the frame 12 on the right side of the home position area in FIG. A plurality (four in this embodiment) of ink cartridges 24 that store inks of different colors are detachably mounted on the cartridge holder 23.

  In a state where each ink cartridge 24 is mounted in the cartridge holder 23, each ink cartridge 24 and each valve unit 20 are connected to each other via an ink supply tube 25. The ink in each ink cartridge 24 is supplied to the recording head 19 via each ink supply tube 25 and each valve unit 20 by consumption of ink from the recording head 19 due to printing or the like. Accordingly, the ink supply tube 25 and the valve unit 20 function as a liquid supply flow path for supplying ink from the upstream side on the ink cartridge 24 side to the downstream side on the recording head 19 side.

  Further, a pressure pump 26 for supplying pressurized air to each ink cartridge 24 is placed above the cartridge holder 23. The pressure pumps 26 are connected to the upstream ends of the same number (four in this embodiment) of air supply tubes 27 as the ink cartridges 24 that can be attached to the cartridge holder 23, and downstream of each air supply tube 27. The end is connected to the cartridge holder 23. Therefore, in a state where each ink cartridge 24 is mounted in the cartridge holder 23, each ink cartridge 24 and the pressure pump 26 are connected to each other via the air supply tube 27.

  In FIG. 2, the recording head 19 located at the home position is illustrated together with one valve unit 20 and a maintenance unit 21 provided above the recording head 19.

  In the recording head 19, nozzle openings 34 of a large number of nozzles 30 (only one is shown in FIG. 2) are formed on a nozzle forming surface 19 a that is the lower surface of the recording head 19 to form nozzle rows (not shown) along the front-rear direction. Thus, it is regularly formed at a predetermined interval in the front-rear direction. A plurality of nozzle rows (four rows in this embodiment) are formed according to the type of ink, and are formed at predetermined intervals in the left-right direction. Printing is performed by ejecting ink onto the paper P fed from the nozzles 30 onto the platen 13 as the carriage 15 moves. However, since the configuration of each nozzle 30 is the same, one nozzle 30 is shown in FIG. In the following, description will be given by taking one nozzle 30 shown in FIG. 2 as an example.

  The recording head 19 includes a reservoir (not shown) that communicates with each nozzle 30 constituting one nozzle row, and a cavity 31 that connects the reservoir and each nozzle 30. The nozzle 30 is connected to the cavity 31 and has a tapered portion 32 that gradually decreases in cross-sectional area from the upstream side toward the downstream side, and a connecting portion 33 that connects between the tapered portion 32 and the nozzle opening 34. It is composed of When the nozzle 30 is filled with ink from the upstream side, a meniscus M is formed in the nozzle 30 and in the vicinity of the nozzle opening 34 opened in the nozzle forming surface 19a. The meniscus M is a curved surface that is formed by a capillary phenomenon so that the central portion of the ink rises so as to form a concave shape when viewed from the nozzle opening 34.

  Further, since the configuration of each valve unit 20 is the same, one valve unit 20 is shown in FIG. In the following description, one valve unit 20 shown in FIG. 2 will be described as an example.

  The valve unit 20 is provided with a one-way valve 36 that allows the passage of ink from the upstream side to the downstream side in accordance with the pressure reduction on the downstream side, and an electromagnetic valve 37 that can allow or block the passage of ink. .

  The one-way valve 36 is provided on the upstream side of the electromagnetic valve 37, and includes a storage chamber 38 that primarily stores ink pressurized and supplied from the ink cartridge 24, and a pressure chamber 39 that is positioned downstream of the storage chamber 38. have. The storage chamber 38 and the pressure chamber 39 are separated by a partition wall 40, and a valve hole 40 a is formed through the partition wall 40. The valve hole 40 a is provided with a valve body 42 that is urged in the valve closing direction by a spring 41 and abuts against the partition wall 40 from the storage chamber 38 side, and the valve body 42 resists the urging force of the spring 41. Thus, the storage chamber 38 and the pressure chamber 39 are communicated with each other by moving in the valve opening direction.

  That is, when ink is ejected from the nozzle 30 and consumed, the pressure chamber 39 is depressurized, and the film 43 is bent and deformed toward the pressure chamber 39 based on the pressure difference between the pressure chamber 39 and the atmosphere. When this bending force becomes larger than the urging force of the spring 41, the valve body 42 moves to the valve opening position away from the partition wall 40, and the pressurized ink in the storage chamber 38 flows into the pressure chamber 39 side. . When ink flows into the pressure chamber 39 and the chamber pressure increases, the urging force of the spring 41 overcomes and the valve body 42 moves to the valve closing position where it abuts against the partition wall 40 again.

  As described above, the one-way valve 36 is opened by pressure reduction on the downstream side of the valve body 42, whereas when the upstream side is pressurized, the valve body 42 receives a force in the closing direction, so that the valve body 42 is opened. Keep valve closed without valve. Similarly, when the downstream side is pressurized, the film 43 bends and deforms in the direction of increasing the volume of the pressure chamber 39, so that the valve body 42 is closed without receiving a force in the valve opening direction from the film 43. Maintain valve status. Furthermore, since the upstream ink is pressurized by the pressurizing pump 26, the upstream side of the valve body 42 is not depressurized. That is, the one-way valve 36 is a valve that opens only when the downstream side is depressurized.

  A part of the pressure chamber 39 is constituted by a film 43 made of a flexible material (for example, synthetic resin or rubber). For example, a cantilever metal piece (for example, comb teeth) that can be displaced together with the film 43 is used. A piece of metal piece) is arranged at the contact point of the valve body 42.

  Further, the maintenance unit 21 has a bottomed square box shape that can come into contact with the nozzle forming surface 19a, a cam mechanism 46 that moves the cap 45 up and down, and discharges ink from the cap 45. And a discharge mechanism 47 to be used.

  The cap 45 has a wall portion 51 including a square annular peripheral wall portion 49 and a bottom wall portion 50 that closes the lower side of the peripheral wall portion 49. Further, the bottom wall portion 50 is provided with a closing member 52 as a closing portion facing the nozzle forming surface 19a and having a height lower than that of the peripheral wall portion 49 in the vertical direction. That is, the closing member 52 is positioned in the closing space 53 (see FIG. 3) surrounded by the nozzle forming surface 19a and the wall portion 51 when the cap 45 contacts the nozzle forming surface 19a. Is provided.

  Further, the cap 45 surrounds all the nozzle openings 34 opened in the nozzle forming surface 19a when the tip opening edge 49a of the cap 45 which is the upper end (tip) of the peripheral wall portion 49 abuts the nozzle forming surface 19a. Is formed. Further, the closing member 52 is formed so as to be able to close all the nozzle openings 34 when coming into contact with the nozzle forming surface 19a. However, since only one nozzle 30 is illustrated in FIG. 2, a cap 45 corresponding to this one nozzle 30 is illustrated. In the following description, the cap 45 shown in FIG. 2 is taken as an example.

  Both the peripheral wall portion 49 and the bottom wall portion 50 of the cap 45 are formed of an elastic material (for example, rubber). The peripheral wall portion 49 has a bellows shape having a rectangular annular lower wall portion 49b continuous with the bottom wall portion 50 and a rectangular annular upper wall portion 49c continuous with the lower wall portion 49b. That is, the left and right walls of the lower wall portion 49b and the left and right walls of the upper wall portion 49c are connected by valley folds 54a, and the front and rear walls of the lower wall portion 49b and the front and rear walls of the upper wall portion 49c. Are connected by a mountain fold 54b. And the bellows-shaped peripheral wall part 49 is always urged | biased by the elastic force so that it may become a shape shown in FIG.2 and FIG.3.

  The cap 45 is supported from below by the cam mechanism 46. That is, the cam mechanism 46 includes a cam shaft 56, a cam member 57 that can rotate integrally with the cam shaft 56 and abuts against the bottom wall portion 50 to support the cap 45, and a cam motor 58 that rotates the cam shaft 56. And. Therefore, when the cam motor 58 is driven and the cam member 57 rotates, the cap 45 reciprocates in the vertical direction and moves relative to the nozzle forming surface 19a.

  Specifically, when the cam member 57 rotates in a state where the cap 45 is positioned at the standby position shown in FIG. 2, the cap 45 is lifted, and the cleaning position where the tip opening edge 49a contacts the nozzle forming surface 19a. (See FIG. 3). That is, the movement of the cap 45 is restricted by the tip opening edge 49a coming into contact with the nozzle forming surface 19a. When the cam member 57 further rotates, the cap 45 whose movement is restricted in this way is deformed so that the bellows shape is folded in the contraction direction in which the internal volume decreases, and the closing member 52 comes into contact with the nozzle forming surface 19a. The bottom wall 50 moves to the contact position (see FIG. 4).

  The cap 45 positioned at the contact position is contracted by the peripheral wall portion 49 being folded in a bellows shape, but when the cam member 57 is further rotated from this state, the peripheral wall portion 49 is now in an internal volume. The bottom wall portion 50 moves to the cleaning position while maintaining the state where the tip opening edge 49a and the nozzle forming surface 19a are in contact with each other (see FIG. 3). When the cam member 57 further rotates, the cap 45 descends, the tip opening edge 49a and the nozzle forming surface 19a are separated from each other, and move to the standby position (see FIG. 2).

  The discharge mechanism 47 includes a discharge tube 60 connected to the bottom wall 50 of the cap 45 so that an upstream end communicates with the inside of the cap 45, and a downstream end of the discharge tube 60 connected to be able to discharge ink. And a waste ink tank 61 having a rectangular parallelepiped shape. A tube pump 62 for sucking the inside of the cap 45 from the cap 45 side toward the waste ink tank 61 side is provided at an intermediate portion of the discharge tube 60 between the cap 45 and the waste ink tank 61. . The waste ink tank 61 contains a waste ink absorber 63 that absorbs and holds the ink discharged into the waste ink tank 61.

  Further, as shown in FIG. 2, the printer 11 is provided with a control unit 65 as a control unit that performs overall control of the operating state of the printer 11. Then, the control unit 65 drives and controls the carriage motor 18, the electromagnetic valve 37, the cam motor 58, and the tube pump 62 to perform maintenance processing.

  Next, the operation of the printer 11 configured as described above will be described below. Note that when the printer 11 performs printing, the cap 45 is positioned at the standby position as shown in FIG. 2 and the electromagnetic valve 37 is opened.

  For example, when a cleaning process execution command is received from the operation unit (not shown) from the user, or when it is determined that a predetermined time has passed since the previous cleaning process, the control unit 65 executes the cleaning process. That is, first, the control unit 65 controls the drive of the carriage motor 18 to move the carriage 15 to the home position. Thereafter, the controller 65 drives the cam motor 58 to rotate the cam member 57, and moves the cap 45 to the cleaning position as shown in FIG.

  Further, the control unit 65 drives the tube pump 62 to suck air in the cap 45. Then, since the inside of the closed space of the cap 45 is depressurized, the ink is discharged from the nozzle 30 and the discharged ink is discharged to the waste ink tank 61 through the discharge tube 60, and the recording head 19 is cleaned. . Thereafter, the controller 65 drives the cam motor 58 to rotate the cam member 57, thereby moving the cap 45 to the standby position (see FIG. 2).

  When the printer 11 is turned off, the controller 65 controls the carriage motor 18 to move the carriage 15 to the home position. Thereafter, the control unit 65 drives the cam motor 58 to rotate the cam member 57, moves the cap 45 to the contact position as shown in FIG. 4, closes the electromagnetic valve 37, and moves toward the nozzle 30 side. Limit the movement of ink.

  That is, the cap 45 is lifted by being pressed by the cam member 57 toward the nozzle forming surface 19a, and when the cap 45 moves to the cleaning position (see FIG. 3), the tip opening edge 49a contacts the nozzle forming surface 19a. Further, when the cam member 57 rotates, the bottom wall portion 50 is pressed and approaches the nozzle forming surface 19a, so that the circumferential wall portion 49 closes the valley fold portion 54a between the lower wall portion 49b and the upper wall portion 49c. Since the mountain fold portion 54b is deformed and contracted toward the inside of the space 53 and toward the outside of the closed space 53, the volume of the closed space 53 decreases. Then, the pressure in the closed space 53 in which the volume decreases increases, and this pressure acts on the pressure chamber 39 of the one-way valve 36 via the nozzle 30, and the film 43 is bent and deformed to the atmospheric pressure side, and the pressure chamber 39. Increase the volume of. Therefore, the meniscus M located in the vicinity of the nozzle opening 34 moves to the cavity 31 side so as to be pushed from the nozzle opening 34 side as shown in FIG. At this time, the pressure in the closed space 53 is preferably a pressure at which the meniscus M can be separated from the nozzle opening 34 (for example, 3 kPa or more).

  Therefore, when the bottom wall 50 moves from the cleaning position (see FIG. 3) to the contact position (see FIG. 4) and the closing member 52 comes into contact with the nozzle forming surface 19a and closes the nozzle opening 34, it rises. An air layer 66 of pressurized air is formed between the meniscus M and the closing member 52.

According to the first embodiment, the following effects can be obtained.
(1) When the cam member 57 further rotates from the state in which the cam member 57 rotates and the tip opening edge 49a of the cap 45 contacts the nozzle forming surface 19a, the closing member 52 in the cap 45 approaches the nozzle forming surface 19a. To do. At this time, the cap 45 is deformed so that the volume of the closed space 53 formed between the nozzle 45 and the nozzle forming surface 19a is reduced. Then, the pressure in the closed space 53 increases, and the ink meniscus M located in the vicinity of the nozzle opening 34 rises so as to be pushed from the nozzle opening 34 side. Therefore, the meniscus M is separated from the nozzle opening 34 when the closing member 52 approaching the nozzle forming surface 19a comes into contact with the nozzle forming surface 19a as the cap 45 is deformed. Therefore, the contact between the closing member 52 and the meniscus M can be suppressed, the leakage of ink from the nozzle 30 can be suppressed, and the nozzle opening 34 can be closed.

  (2) After the cam mechanism 46 presses the bottom wall portion 50 to bring the cap 45 into contact with the nozzle forming surface 19a, when the cam member 57 of the cam mechanism 46 is further rotated, the cap 45 becomes a bellows-shaped peripheral wall portion. 49 deform | transforms so that the bellows shape may be folded in the contraction direction which makes the obstruction | occlusion member 52 provided in the bottom wall part 50 approach the nozzle formation surface 19a. Then, the volume of the closed space 53 is reduced and the pressure in the closed space 53 is increased. Therefore, the ink opening from the nozzle 30 can be suppressed and the nozzle opening 34 can be closed with a simple configuration. Accordingly, the degree of freedom in designing the cap 45 is improved.

  (3) When the cap 45 is separated from the nozzle forming surface 19a, the peripheral wall portion 49 elastically deformed so as to fold the bellows shape returns so as to elastically return to the original shape. Therefore, the maintenance unit 21 can be simplified without providing a means for returning the peripheral wall portion 49 of the wall portion 51 to the original shape.

  (4) The applied pressure of the closed space 53 can be maintained. That is, since the one-way valve 36 suppresses the passage of ink from the downstream side to the upstream side, the air layer 66 formed between the raised meniscus M and the closing member 52 is in a pressurized state. The amount of ink evaporated to the air layer 66 is related to the amount of saturated vapor in the air layer 66, and the amount of ink evaporated to the air layer 66 decreases as the pressure increases. Accordingly, the simple configuration of the one-way valve 36 can suppress ink evaporation to the air layer 66 and suppress ink thickening.

  (5) Generally, the ink supplied from the upstream side is filled up to the vicinity of the nozzle opening 34 by the capillary force. In this regard, by controlling the electromagnetic valve 37, the amount of movement of the ink meniscus M located near the nozzle opening 34 can be changed, and the position of the raised meniscus M can be maintained. That is, for example, when the solenoid valve 37 is closed during the movement of the cap 45, the meniscus M is maintained at a position closer to the nozzle opening 34 than when the solenoid valve 37 is closed after the movement of the cap 45 is completed. Can be made. Therefore, the pressure of the air layer 66 between the meniscus M and the closing member 52 can be increased. Further, since the ink movement from the upstream side to the downstream side is also restricted, the meniscus M can be prevented from descending. Therefore, when the closing member 52 is brought into contact with the nozzle forming surface 19a, the contact between the ink and the closing member 52 can be further suppressed.

  (6) The nozzles 30 formed in the recording head 19 are communicated with each other via a reservoir (not shown). Therefore, for example, when the meniscus M is raised by reducing the pressure from the upstream side, it is difficult to pull up the meniscus M at each nozzle 30 uniformly. Furthermore, when the pressure is reduced from the upstream side, the air layer 66 formed between the meniscus M and the closing member 52 is in a reduced pressure state. Therefore, there is a problem that the amount of saturated vapor in the air layer 66 increases and the ink is easily evaporated and thickened as compared with a state where the pressure in the air layer 66 is increased. In that respect, the same pressure can be applied to each nozzle 30 by reducing the volume of the closed space 53 of the cap 45 surrounding the nozzle opening 34 and increasing the pressure in the closed space 53. Therefore, the variation of the meniscus M in each nozzle 30 can be suppressed and the pressure of the air layer 66 can be increased.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment only in that the shape of the peripheral wall portion of the cap is changed, and the other configurations are the same. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the square annular peripheral wall portion 71 of the cap 70 has a shape when the peripheral wall portion 49 of the cap 45 in the first embodiment is cut by a plane passing through the valley fold portion 54 a and the mountain fold portion 54 b, That is, it is formed in a shape corresponding to the lower wall portion 49b of the peripheral wall portion 49 in the first embodiment.

  The bottom wall portion 72 is provided with a closing member 74 as a closing portion so as to be lower than the peripheral wall portion 71 in the vertical direction and to face the nozzle forming surface 19a. That is, the closing member 74 is enclosed by the wall portion 75 including the peripheral wall portion 71 and the bottom wall portion 72 and the nozzle forming surface 19a when the cap 70 contacts the nozzle forming surface 19a. It is designed to be located inside.

The cap 70 is supported by the cam member 57, reciprocates in the vertical direction as the cam member 57 rotates, and moves relative to the nozzle forming surface 19a.
The cap 70 is formed so as to surround all the nozzle openings 34 opened on the nozzle forming surface 19a when the tip opening edge 71a contacts the nozzle forming surface 19a. Further, the closing member 74 is formed so as to be able to close all the nozzle openings 34 when coming into contact with the nozzle forming surface 19a.

  However, since only one nozzle 30 is illustrated in FIGS. 5 and 6, a cap 70 corresponding to this one nozzle 30 is illustrated. In the following, the operation when the power of the printer 11 is turned off will be described using the one nozzle 30 and the cap 70 shown in FIGS. 5 and 6 as an example. The recording head 19 is located at the home position, and the cap 70 is located at a standby position (not shown) in which the nozzle formation surface 19a and the tip opening edge 71a are separated from each other.

  First, the control unit 65 drives the cam motor 58 to rotate the cam member 57. Then, as shown in FIG. 5, the cap 70 moves to the cleaning position where the tip opening edge 71a contacts the nozzle forming surface 19a.

  Then, when the cam member 57 further rotates, the cap 70 whose movement is restricted by the tip opening edge 71 a coming into contact with the nozzle forming surface 19 a has the left and right edges of the square annular tip opening edge 71 a directed toward the inside of the closed space 76. At the same time, the front and rear edges are elastically deformed and contracted so as to go to the outside of the closed space 76. Therefore, the bottom wall 72 moves to a contact position where the closing member 74 contacts the nozzle forming surface 19a (see FIG. 6). Note that the cap 70 is deformed in a state where the opening area of the tip opening edge 71a is suppressed from expanding. Therefore, the volume of the closed space 76 is reduced by the amount of the height of the cap 70, the pressure in the closed space 76 is increased, and the meniscus M is raised.

  Therefore, as shown in FIG. 6, when the bottom wall 72 moves to the contact position and the closing member 74 contacts the nozzle forming surface 19a and closes the nozzle opening 34, the raised meniscus M and the closing member 74, an air layer 66 of pressurized air is formed.

According to the said 2nd Embodiment, in addition to the effect of (1)-(6) in 1st Embodiment, the following effects can be acquired further.
(7) By reducing the peripheral wall portion 71 in the height direction (vertical direction), the cap 70 can be downsized in the height direction.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. Note that the third embodiment differs from the first embodiment only in that the configuration of the cap is changed, and the other configurations are the same. The detailed overlapping explanation is omitted.

  As shown in FIG. 7, the rectangular annular peripheral wall portion 81 of the cap 80 has a bottom wall portion 82 such that a cross-sectional area when cut along a plane parallel to the bottom wall portion 82 is equal to the area of the bottom wall portion 82. It is formed perpendicular to. Further, the bottom wall portion 82 is provided with a closing member 84 as a closing portion so as to be lower than the peripheral wall portion 81 in the vertical direction and to face the nozzle forming surface 19a. That is, the closing member 84 is enclosed by the wall portion 85 including the peripheral wall portion 81 and the bottom wall portion 82 and the nozzle forming surface 19a when the cap 80 contacts the nozzle forming surface 19a. It is designed to be located inside.

The cap 80 is supported by the cam member 57, reciprocates in the vertical direction as the cam member 57 rotates, and moves relative to the nozzle forming surface 19a.
The cap 80 is formed so as to surround all the nozzle openings 34 opened on the nozzle forming surface 19a when the tip opening edge 81a abuts on the nozzle forming surface 19a. Further, the closing member 84 is formed so as to be able to close all the nozzle openings 34 when coming into contact with the nozzle forming surface 19a. However, since only one nozzle 30 is illustrated in FIGS. 7 and 8, a cap 80 corresponding to this one nozzle 30 is illustrated. In the following, the operation when the power of the printer 11 is turned off will be described using the one nozzle 30 and the cap 80 shown in FIGS. 7 and 8 as an example. The recording head 19 is located at the home position, and the cap 80 is located at a standby position (not shown) in which the nozzle forming surface 19a and the tip opening edge 81a are separated from each other.

  First, the control unit 65 drives the cam motor 58 to rotate the cam member 57. Then, as shown in FIG. 7, the cap 80 moves to a cleaning position where the tip opening edge 81a contacts the nozzle forming surface 19a.

  When the cam member 57 further rotates, the cap 80 whose movement is restricted by the tip opening edge 81a coming into contact with the nozzle forming surface 19a is elastically deformed so that the bottom wall portion 82 approaches the nozzle forming surface 19a. Therefore, the volume of the closed space 86 decreases, the pressure in the closed space 86 increases, and the meniscus M rises.

  Therefore, as shown in FIG. 8, when the bottom wall portion 82 is elastically deformed to the contact position and the closing member 84 is in contact with the nozzle forming surface 19a and closes the nozzle opening 34, the raised meniscus M and the closed portion are blocked. An air layer 66 of pressurized air is formed between the members 84.

According to the said 3rd Embodiment, in addition to the effect of (1)-(7) in 1st Embodiment and 2nd Embodiment, the following effects can be acquired further.
(8) Since the peripheral wall portion 81 that is in contact with the nozzle forming surface 19a receives a force in a direction in which the tip opening edge 81a is pressed against the nozzle forming surface 19a, air is prevented from leaking from the pressurized closed space 86, Greater pressure can be maintained.

In addition, you may change the said embodiment as follows.
In each of the above embodiments, the one-way valve 36 and the electromagnetic valve 37 may not be provided. Further, only one of the valves may be provided.

  -In the said 1st, 2nd embodiment, you may make it form the bottom wall parts 50 and 72 with a rigid member. In the third embodiment, the peripheral wall portion 81 may be formed of a rigid member. Further, when the peripheral wall portions 49, 71, 81 and the bottom wall portions 50, 72, 82 are both formed of a rigid material, for example, the peripheral wall portions 49, 71, 81 are formed by slidably connecting the annular peripheral wall portions in the vertical direction. By using the telescopic shape, the volume of the closed space can be reduced.

  In each of the above embodiments, the caps 45, 70, and 80 are formed of a flexible material, and a configuration (such as a spring) for returning the deformed caps 45, 70, and 80 to the original shape may be separately provided. Good.

  In each of the above embodiments, the closing members 52, 74, 84 may be integrally formed with the caps 45, 70, 80. Further, as in the third embodiment, when the bottom wall portion 50 is deformed, or by forming a recess in the portion where the peripheral wall portions 49, 71, 81 abut on the nozzle forming surface 19a, the bottom wall portion 50, The nozzle openings 34 may be closed by bringing the nozzles 72 and 82 into contact with the nozzle forming surface 19a. In this case, the bottom wall portions 50, 72, and 82 function as blocking portions. For example, the nozzle opening 34 may be closed by the peripheral wall portion 49 folded inward. In this case, the peripheral wall portion 49 functions as a blocking portion.

  In the first embodiment, the peripheral wall portion 49 includes a plurality of valleys by alternately connecting the lower wall portion 49b and the upper wall portion 49c via the valley fold portion 54a and the mountain fold portion 54b. You may form in the shape of a bellows which has the folding part 54a and the mountain fold part 54b. Each of the valley fold portion 54a and the mountain fold portion 54b may be formed in a spiral shape.

In each of the above embodiments, a plurality of caps 45, 70, and 80 may be provided so as to correspond to each nozzle row.
In each of the above embodiments, a pinion and a rack may be used as the moving means for moving the caps 45, 70, 80. Further, the recording head 19 and the caps 45, 70, 80 may be moved relative to each other by moving the recording head 19.

  In each of the above embodiments, the maintenance unit 21 mounted on the printer 11 is embodied, but the present invention can also be applied to a maintenance device that closes the nozzle openings 34 used in other devices.

  In the above embodiment, the liquid ejecting apparatus is embodied in the ink jet printer 11, but a liquid ejecting apparatus that ejects or discharges liquid other than ink may be employed. The present invention can be used for various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And a liquid as one state of a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, a color filter, or the like in a dispersed or dissolved state. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid as a sample used as a precision pipette, a textile printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate or a liquid ejecting apparatus that ejects an etching solution such as an acid or an alkali to etch the substrate may be employed. The present invention can be applied to any one of these liquid ejecting apparatuses.

  DESCRIPTION OF SYMBOLS 11 ... Printer (liquid ejecting apparatus), 19 ... Recording head (liquid ejecting head), 19a ... Nozzle formation surface, 20 ... Valve unit (liquid supply flow path), 21 ... Maintenance unit (maintenance apparatus), 24 ... Ink cartridge ( (Liquid supply source), 25 ... ink supply tube (liquid supply flow path), 34 ... nozzle opening, 36 ... one-way valve, 37 ... solenoid valve, 45, 70, 80 ... cap, 46 ... cam mechanism (moving means), 49, 71, 81 ... peripheral wall portion, 49a, 71a, 81a ... tip opening edge, 50, 72, 82 ... bottom wall portion, 52, 74, 84 ... closing member (blocking portion), 53, 76, 86 ... closing space 65, a control unit (control means).

Claims (6)

A bottomed box-like cap capable of forming a closed space with the nozzle forming surface by abutting a tip opening edge so as to surround the nozzle opening on a nozzle forming surface on which a nozzle opening for ejecting liquid is formed;
Moving means for moving the cap relative to the nozzle forming surface;
The cap has a closing portion that can contact the nozzle forming surface to close the nozzle opening, and the closing portion is in contact with the nozzle forming surface while the tip opening edge is in contact with the nozzle forming surface. When approaching the formation surface, it is configured to deform so that the volume of the closed space decreases,
The moving means moves the cap relative to the nozzle forming surface so that the closed portion approaches and contacts the nozzle forming surface after the tip opening edge of the cap contacts the nozzle forming surface. A maintenance device that is moved. The cap has a bottom wall portion provided with the closed portion and a peripheral wall portion formed so as to surround the closed portion, and at least one of the bottom wall portion and the peripheral wall portion has a volume of the closed space. The maintenance device according to claim 1, wherein the maintenance device is configured to be deformed so as to decrease. The maintenance device according to claim 2, wherein at least one of the bottom wall portion and the peripheral wall portion has elasticity. A liquid jet head having the nozzle forming surface;
A liquid supply channel for supplying liquid from an upstream side which is a liquid supply source side to a downstream side which is the liquid jet head side;
A liquid ejecting apparatus comprising: the maintenance apparatus according to claim 1. 5. The liquid supply channel according to claim 4, further comprising a one-way valve that allows liquid to pass from the upstream side to the downstream side and restricts passage of the liquid from the downstream side to the upstream side. The liquid ejecting apparatus described. An electromagnetic valve capable of restricting the passage of liquid in the liquid supply channel;
Control means for controlling the solenoid valve and the moving means, and
The liquid ejecting apparatus according to claim 4, wherein the control unit closes the electromagnetic valve in a state where the moving unit is driven.

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