JP5033581B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus having an ink jet head including ink discharge ports.

  The ink jet recording apparatus mainly includes an ink image forming unit including an ink head device, and a paper transport unit that transports paper to the ink image forming unit. The ink head device has a plurality of ink jet heads, and each ink jet head is formed with an ink discharge port.

  In such an ink jet recording apparatus, the paper is transported to the ink image forming unit by the paper transporting unit, and ink is ejected from the ink ejection port to the paper according to the image information to form an ink image. Is done. The sheet on which the ink image is formed is conveyed to the discharge unit by the sheet conveying unit.

  Here, when the ink image forming operation is completed and the standby state continues for a long time, the ink in the ink discharge port is dried and the ink flow path connected to the ink discharge port is clogged, or dust adheres around the ink discharge port. Sometimes. In such a case, dot missing or the like occurs during ink image formation, and the image quality deteriorates.

  Therefore, a protective cap is provided to prevent the ink from drying in the inkjet head or to prevent dust and the like from adhering to the tip of the inkjet head. The protective cap is formed of, for example, an elastic body that is open at a portion facing the ink discharge surface, surrounds the periphery of the ink discharge port, and presses the peripheral portion of the cap against the surface on which the ink discharge port is formed. By doing so, drying of ink, adhesion of dust, and the like are prevented.

  In addition, as another protection mechanism for the inkjet head, an ink drying prevention device is also proposed in which the cap is made of an expandable member and the expanded cap is brought into contact with the surface of the ink discharge port to seal the ink discharge port. (Patent Document 1).

In the apparatus of Patent Document 1, when the ink image forming operation is completed and the apparatus enters a standby state, the expansion member as a cap moves to the tip of the inkjet head. Then, the expansion member expands and is pressed against the tip surface of the inkjet head. As described above, the expansion member is pressed against the front end surface of the ink jet head in which the ink discharge port is formed, so that the inside of the ink discharge port is sealed, and the ink in the ink flow path is prevented from being dried and deteriorated. Dust is prevented from adhering to the exit portion.
JP 2002-29283A

  In the apparatus described in Patent Document 1, the expansion member is brought into contact with the front end surface of the ink jet head in a state where no image is formed, and the expansion member is separated from the front end surface of the ink jet head during ink image formation.

  In this apparatus, when the expansion member is separated from the front end surface of the ink jet head, the ink meniscus (liquid bridge) formed in the ink discharge port may be collapsed by the movement of the expansion member. In this case, since the meniscus is collapsed, there is a possibility that ink is not ejected during image formation. When ink is not ejected, it is necessary to recover the meniscus by ejecting ink or the like by applying pressure regardless of image formation.

  Further, since the expansion member is pressed against the surface on which the ink discharge port is formed, the ink adheres to the expansion member. When the ink adhering to the expansion member dries and increases in viscosity, the viscosity increases. The surface of the ink discharge port is contaminated by pressing the formed ink again on the surface of the ink discharge port. In this case, the ink droplets cannot be accurately ejected from the ink ejection port, and the image quality may be deteriorated.

  An object of the present invention is to prevent ink from becoming defective during image formation, to suppress contamination of the surface of the ink jet head where the ink discharge port is formed, and to cover the portion where the ink discharge port is formed with a cap. It is to realize high sealing performance when sealing.

An inkjet recording apparatus according to the present invention includes an inkjet head support, an inkjet head, a cap, a cap moving mechanism, and an expansion mechanism. The ink jet head has an ink discharge port on a nozzle face surface that protrudes from the surface of the ink jet head support. The cap can be opposed to the nozzle face surface and has an inflatable portion that can be inflated at least partially. The inflated inflated portion is in close contact with the surface around the ink jet head except for the nozzle face surface. This is for sealing the ink discharge port. The cap moving mechanism relatively moves the cap between a protection position facing the inkjet head and a standby position retracted from the protection position. The expansion mechanism is a mechanism for expanding the expansion portion of the cap.

  In this apparatus, the ink jet head is formed so as to protrude from the surface of the ink jet head support portion, and this ink jet head has a nozzle face surface in which an ink discharge port is formed at the tip. That is, the nozzle face surface and the surface of the inkjet head support portion are not flush with each other, and a step is formed. And the expansion part of a cap closely_contact | adheres to the surrounding surface of the inkjet head except a nozzle face surface in an expanded state, and, thereby, the ink discharge port of an inkjet head is sealed.

  Here, the expansion part provided in at least a part of the cap expands and adheres closely to the surface around the inkjet head, so that the space near the ink discharge port can be well sealed, and the ink is dried and dust is attached. Can be prevented. Further, the nozzle face surface at the tip of the ink jet head is formed so as to protrude from the other surface, and the expanding portion contacts and seals a surface other than the nozzle face surface. That is, the expanding portion does not contact the nozzle face surface even in the expanded state. For this reason, it is possible to prevent the meniscus of the ink discharge port from collapsing due to expansion and contraction or movement of the expansion portion, and it is possible to prevent ink contamination due to the collapse of the meniscus.

An ink jet recording apparatus according to the present invention, in the apparatus, the expansion portion of the cap is in contact with the side surface of the inkjet head support and / or the ink jet head around the nozzle face surface in the expanded state.

  In this case, similarly to the above, the expansion part of the cap is in close contact with the surface around the ink jet head, and the space near the ink discharge port can be well sealed. Further, since the expanding portion does not contact the nozzle face surface, it is possible to prevent the meniscus of the ink discharge port from collapsing due to expansion / contraction or movement of the expanding portion.

Ink jet recording apparatus according to the present invention, in the apparatus, the expansion portion of the cap is formed a fluid storable bag shape inside, the expansion mechanism of the expansion portion by injecting a fluid into the interior of the inflatable portion Inflate.

  In this apparatus, fluid is injected into the inside of the expansion portion of the cap, whereby the expansion portion expands and adheres closely to the surface around the inkjet head. In this case, the degree of expansion can be easily adjusted by controlling the injection amount of a fluid such as air, and the pressing force for sealing can be easily adjusted.

An ink jet recording apparatus according to the present invention, in the device, the cap moving mechanism, only by moving in a horizontal plane of the cap is moved between the cap and the protective position and the standby position.

  Here, the cap is moved between the protection position and the standby position by the cap moving mechanism. And in a protection position, a cap opposes an inkjet head and protects an inkjet head. When the ink image is formed, the cap is moved to the standby position.

  During this movement, the cap is moved only in the horizontal plane. Specifically, since the height of the inflatable portion of the cap can be lowered when the cap is not inflated, the height of the cap does not interfere with the nozzle face surface when the inflatable portion is not inflated. Can be arranged. Thereby, the cap which has an expansion | swelling part can be set to a protection position by the movement only in a horizontal surface, without moving to a height direction. For this reason, the structure of a moving mechanism can be simplified.

An ink jet recording apparatus according to the present invention, in the device, when moved by the moving mechanism, in contact with the nozzle face surface moves together with the cap further has a cleaning member for cleaning the nozzle face surface.

  In this case, the nozzle face can be cleaned as the cap moves.

An ink jet recording apparatus according to the present invention, in the device, the cap has a cap body. The cap body has an opening in a portion facing the ink jet head and is formed in a box shape having a side wall portion formed so as to face the peripheral portion of the ink jet head in the ink jet head support portion. And the expansion | swelling part is mounted | worn with the upper part of the side wall part of a cap main body.

  Here, the entire cap is not formed by the inflating portion, but the cap is formed by the cap body and the inflating portion. Therefore, the strength of the cap can be increased by forming the cap body from a resin or the like.

An ink jet recording apparatus according to the present invention, in the apparatus, the side wall portion, a fluid passage for injecting a fluid is provided inside the inflatable portion from the expansion mechanism.

  Here, since the fluid passage for injecting the fluid into the inflating part is provided in the side wall part of the cap body, the fluid can be easily supplied to the inflating part.

An ink jet recording apparatus according to the present invention, in the device, the cap body, the discharge passage for discharging the ink droplets discharged from the ink discharge ports of the ink jet head to the outside.

  Here, in the ink jet recording apparatus, it is necessary to perform discharge recovery processing of the ink jet head. At this time, since the cap is provided with the discharge flow path, the waste ink in the discharge recovery process can be discharged to the outside with the cap set at the protection position.

An ink jet recording apparatus according to the present invention, in the apparatus, the expansion portion is intended to contact the ink jet head supporting portion in an inflated state, detects that the inflatable portion comes into contact with the portion where the expansion portion of the ink jet head supporting portion is in contact Further possible contact detection sensors are provided.

  Here, the contact detection sensor can reliably detect that the expanding portion is in contact with the inkjet head support portion. By controlling the degree of expansion of the expansion part based on the detection result of the contact detection sensor, reliable sealing can be realized.

  According to the present invention, it is possible to suppress contamination of the surface of the ink jet head where the ink discharge port is formed, and to achieve high sealing performance when the portion where the ink discharge port is formed is sealed with the cap.

[overall structure]
FIG. 1 shows an ink jet printer 1 as an ink jet recording apparatus in which an embodiment of the present invention is adopted. The ink jet printer 1 is an apparatus capable of forming an image based on image information transmitted from an external computer, and includes an ink head device 2, a protection mechanism 11 for protecting an ink head mechanism 10 to be described later, and paper A storage unit 3, a paper transport unit 4, and a discharge unit 5 are provided. The ink used in the ink jet printer 1 is obtained by coating the surface of a pigment with a resin.

[Ink head device]
FIG. 2 is a plan view of the ink head device 2 as viewed from above, and FIG. 3 is an enlarged view of the main part of the device including the ink head device 2 of FIG. FIG. 4 is a front sectional view of the inkjet head 15 described later. The ink head device 2 forms an image on a sheet based on image information, and has an ink head mechanism 10 as shown in FIGS.

<Ink head mechanism>
The ink head mechanism 10 includes an inkjet head support member 13, a head body 14, and a plurality of inkjet heads 15.

  The inkjet head support member 13 is a member for supporting a plurality of inkjet heads 15 and is a plate-like member provided with a plurality of holes 13a (see FIGS. 6 and 7) in which the inkjet heads 15 can be arranged. .

  The head body 14 is a member that can accommodate the inkjet head support member 13 and the plurality of inkjet heads 15 therein, and is a metal member. Further, the head main body 14 is formed in a substantially rectangular parallelepiped shape, and an ink tube and wiring connection portions (not shown) are provided on the upper surface in FIG. Further, the head main body 14 has a large opening on the lower surface so that the inkjet head 15 and the inkjet head support member 13 are exposed, and supports the inkjet head support member 13 on the inner side.

  The ink jet head 15 is a part for ejecting ink toward the paper, and mainly includes an upper head 151 and a lower head 152 as shown in FIG. The inkjet head 15 is a member disposed in a hole 13 a provided in the inkjet head support member 13, and supports the inkjet head so that about one third of the entire length protrudes downward from the inkjet head support member 13. It is fixed to the member 13 (see FIGS. 1 and 3). For this reason, as shown in FIG. 6, a step is formed between the lower end surface (nozzle face surface 152 a) of the inkjet head 15 and the inkjet head support member 13. FIG. 6 is an enlarged view of one inkjet head 15 supported by the inkjet head support member 13 and a part of the protection mechanism 11 corresponding to the inkjet head 15. The upper head 151 has two ink supply ports 151a formed at the top, and is provided inside the first ink reservoir 151b communicating with the two ink supply ports 151a and the bottom side of the first ink reservoir 151b. A filter 151c, a second ink reservoir 151d communicating with the first ink reservoir 151b via the filter 151c, and an ink distribution port 151e extending downward from the bottom of the second ink reservoir 151d. The lower head 152 has a plurality of (for example, 4000) ink discharge ports 152b (see FIG. 6) formed on the lower surface (nozzle face surface 152a), and includes a supply passage 152c, a pressure chamber 152e, a piezoelectric element 152f, and And individual electrodes (not shown). A plurality of supply passages 152c are provided along the longitudinal direction of the inkjet head 15, and ink is supplied to the pressurizing chamber 152e. One pressurizing chamber 152e is provided for each ink discharge port 152b. The piezoelectric element 152f and an individual electrode (not shown) are provided above the pressurizing chamber 152e. The pressurizing chamber 152e and the supply channel 152c are connected by a supply hole 152h.

  Each voltage element 152f is individually driven by applying a driving pulse to an individual electrode (not shown) from a head driving unit (not shown). The pressure chamber 152e is compressed by driving the voltage element 152f, and pressure is applied to the ink in the pressure chamber 152e. Then, the ink is ejected from the ink ejection port 152b as ink droplets onto the paper, and an image is formed on the paper by the ejected ink.

[Protection mechanism]
The protection mechanism 11 protects, in particular, the nozzle face surface 152a in which the ink discharge port 152b is formed, among the inkjet heads 15 of the ink head mechanism 10, and can move only within a horizontal plane below the ink head mechanism 10. It is configured. The moving direction of the protection mechanism 11 is indicated by arrows AB in FIG.

  The protection mechanism 11 includes a support plate 16, a plurality of caps 18 having an inflating portion 17 and disposed on the support plate 16, a wiping blade 19, and the support plate 16, as shown in FIGS. A moving mechanism 20 for moving the cap 18 and a fluid supply device 21 as an expansion mechanism for expanding the expansion portion 17 are provided. FIG. 5 is a perspective view showing the support plate 16 and the moving mechanism 20. FIGS. 6 and 7 show, as described above, one inkjet head 15 fixed to the inkjet head support member 13 and the inkjet head 15. The cap 18 corresponding to the inkjet head 15 is shown enlarged. Here, only the tip of the inkjet head 15 is shown in a simplified manner.

  As is clear from FIG. 2, the support plate 16 is a plate member formed slightly larger than the head body 14 in plan view. More specifically, as shown in FIG. 5, the support plate 16 includes a main body portion 16 a on which a plurality of caps 18 are arranged, and a pair of walls extending in the vertical direction from a pair of opposing side portions of the main body portion 16 a. It has a portion 16b (only one is shown in FIG. 5) and a pair of flange portions 16c extending laterally outward from the pair of wall portions 16b. The main body portion 16 a is disposed in parallel with the inkjet head support member 13. The pair of flange portions 16 c are connected to the moving mechanism 20. The relationship between the two will be described later.

  The plurality of caps 18 are disposed at positions corresponding to the plurality of inkjet heads 15 as shown in FIG. As shown in FIG. 6 and the like, each cap 18 has a box-shaped cap body 25 having an open upper portion facing the inkjet head 15. The cap body 25 includes a bottom portion 25a and a side wall portion 25b extending upward from the bottom portion 25a. The side wall portion 25 b is provided so as to face a portion around the inkjet head 15 in the inkjet head support member 13. That is, the side wall portion 25b does not overlap with the inkjet head 15 in the vertical direction, but is provided so as to surround the inkjet head 15 when the cap 18 is located at a protection position described later.

  A fluid passage 25c is formed in the bottom portion 25a and the side wall portion 25b of the cap body 25, and the fluid passage 25c formed in the side wall portion 25b opens at the upper end portion of the side wall portion 25b. A connecting portion 26 such as a tube for connecting the fluid passage 25 c formed in the bottom portion 25 a and the fluid supply device 21 is provided on the lower surface of the bottom portion 25 a.

  Further, a discharge channel 27 for discharging the ink discharged into the cap body 25 to the outside is formed at the bottom 25a of the cap body 25. A tube connection port for connecting to a waste ink tank (not shown) is provided at the end of the discharge flow path 27 and a tube 29 is connected thereto.

  The inflatable portion 17 provided in the cap 18 is a bag-like member made of an inflatable elastic material, and is attached to the upper portion of the side wall portion 25 b of the cap body 25. The fluid supplied from the fluid supply device 21 can be injected into the expansion portion 17 via the fluid passage 25c. Then, in a state where the fluid is not injected into the interior and is not expanded, as shown in FIG. 6, the fluid is retracted by its own elastic restoring force, and is positioned at a position lower than the nozzle face 152 a at the height position. . On the other hand, in a state in which the fluid is injected into the inside of the inflating portion 17 and inflated, a part of the inflating portion 17 is part of the ink jet head support member 13 around the ink jet head 15 and the side surface 15a of the ink jet head 15 as shown in FIG. Can be touched. Here, the fluid supplied from the fluid supply device 21 is, for example, a liquid such as oil or a gas such as air. The expanding portion 17 is made of a rubber such as fluorine rubber that is resistant to fluid or ink (silicone rubber can be used when the fluid is air or water).

  As shown in FIGS. 6, 7, etc., in the inkjet head support member 13, the expansion portion 17 is located at a position facing the expansion portion 17, that is, a position where the expansion portion 17 expands and contacts. A contact detection sensor 28 is provided for detecting contact with the touch panel 13.

  The moving mechanism 20 moves the support plate 16 provided with the cap 18 only in a horizontal plane, as indicated by arrows A-B in FIG. 2, so that each cap 18 corresponds to the corresponding inkjet head 15. And a support position where the support plate 16 does not face the inkjet head support member 13 (position shown in FIG. 2).

  As shown in FIG. 5, the moving mechanism 20 includes a drive motor 30, a pair of guide rails 31 arranged along the moving direction of the support plate 16, a first pulley 32a, a second pulley 32b, A third pulley 32c, a fourth pulley 32d, a fifth pulley 32e, a pair of moving belts 33, and a transmission belt 34 are provided.

  The drive motor 30 is fixed to a frame on the back side (rear side) of the apparatus, and a gear is attached to the tip of the motor shaft. This gear meshes with a gear for driving the first pulley 32a. The pair of guide rails 31 are members for guiding the movement of the support plate 16 (specifically, the flange portion 16c). The first pulley 32a is disposed in the right back corner of FIG. The second pulley 32b is disposed in the left back corner of FIG. The third pulley 32c is disposed at the left front corner of FIG. The fourth pulley 32d is disposed at the right front corner of FIG. The fifth pulley 32e is disposed at the right back in FIG. 4 and is disposed side by side with the first pulley 32a. The pair of moving belts 33 are provided so as to circulate along the respective guide rails 31 and are respectively stretched around the first pulley 32a, the fourth pulley 32d, the second pulley 32b, and the third pulley 32c. Yes. The transmission belt 34 communicates the fifth pulley 32e in the vicinity of the drive motor 30 and the second pulley 32b provided at the rear end portion of the one guide rail 31 so as to transmit power to the one moving belt 33. It is provided as follows.

  A plurality of locking pieces 35 are fixed to the pair of moving belts 33, and the locking pieces 35 are locked to notches formed in the flange portion 16 c of the support plate 16. . Therefore, the support plate 16 can be moved in the front-rear direction by circulating the moving belts 33 in the opposite directions.

  Here, the front side of FIG. 5 is the front side of the page of FIG. 1, and the rear side is the back side of the page of FIG. Further, the standby position of the support plate 16 (cap 18) is a position in a state where an image forming operation with ink is being performed, and the protection position is the next position where there is no image forming command for a certain period after the image forming operation is completed. This is a position when the image forming command is waiting, and is a position when the cap 18 provided on the support plate 16 is located immediately below the corresponding inkjet head 15.

  The wiping blade 19 is a member for cleaning the nozzle face 152a, and is attached to the front end portion of the support plate 16. More specifically, the support plate 16 is arranged side by side so as to correspond to the position of each inkjet head 15 at the front end portion. The wiping blade 19 is an elastically deformable member and extends toward the nozzle face surface 152a, that is, upward.

[Paper compartment]
The paper storage unit 3 is a part that can store paper, and is disposed at the bottom of the inkjet printer 1 as shown in FIG. In addition, the paper storage unit 3 includes a paper feed cassette 41 that stores paper, and a paper supply roller 42 for supplying paper to the paper transport unit 4 above the front end on the paper transport direction side. ing.

[Paper transport section]
The paper transport unit 4 includes a paper feed transport unit 50 that transports the paper in the paper storage unit 3 to the ink head mechanism 10, and a belt transport unit 51 that is disposed directly below the ink head mechanism 10 so as to face the ink head mechanism 10. And a paper discharge conveyance unit 52 for discharging the paper on which the ink image is formed to the discharge unit 5.

  Each of the paper feed conveyance unit 50 and the paper discharge conveyance unit 52 includes a conveyance guide 55 that guides conveyance of a sheet, and a plurality of roller pairs 56 for conveying the sheet.

  The belt conveyance unit 51 includes a pair of circulation rollers 57, a belt 58 stretched over the pair of circulation rollers 57, and a suction device 59. The pair of circulation rollers 57 extends in a direction orthogonal to the paper surface of FIG. And one circulation roller is connected with the drive mechanism containing the motor etc. which are not shown in figure. A plurality of holes are formed in the belt 58, and the sheet is sucked by the belt 58 by the suction device 59 through the plurality of holes.

  Also, below the belt conveyance unit 51, a conveyance unit moving mechanism 60 for moving the belt conveyance unit 51 to the image forming operation position and the standby position is provided. The transport unit moving mechanism 60 has a pair of support members 61. Each of the pair of support members 61 is a curved ball-shaped member partially protruding outward from a substantially circular portion, and four small rollers 62 are provided on the outer peripheral surface. The small roller 62 is in contact with a frame (not shown) constituting the belt conveyance unit 51. Further, each of the pair of support members 61 is attached to the frame of the apparatus so that the center of the substantially circular portion is rotatable, and is rotatable in the direction of the arrow in FIG. Here, the state of FIG. 1 is an image forming operation position, and the pair of support members 61 rotate inward from this state, whereby the belt conveyance unit 51 is lowered, and the inkjet head 15 and the belt The support plate 16 on which the cap 18 is disposed can be inserted between the transport unit 51. FIG. 3 shows a state in which the support plate 16 and the cap 18 are inserted between the inkjet head 15 and the belt conveyance unit 51.

[Discharge part]
The discharge unit 5 is a part for discharging the paper on which the ink image is formed, and is disposed on the upper part of the inkjet printer 1.

[Operation]
First, an ink image forming operation will be described. During the ink image forming operation, the protection mechanism 11, that is, the support plate 16 including the cap 18 is moved to a standby position that does not face the ink head mechanism 10 as shown in FIG. Further, the belt conveyance unit 51 is raised by the conveyance unit moving mechanism 60 and moved to the image forming operation position shown in FIG.

  In this state, for example, when an image forming operation is instructed from a computer connected to the outside, an ink image is formed on a sheet based on image information transmitted from the computer. That is, first, a sheet is fed from the sheet storage unit 3, and the sheet is conveyed to the ink head device 2 by the sheet feeding / conveying unit 50. In the ink head device 2, ink is ejected from the inkjet head 15 onto the paper while the paper is conveyed by the belt conveyance unit 51, and an image is formed on the paper. The paper on which the ink image is formed is transported by the paper discharge transport unit 52 and discharged to the discharge unit 5. In this way, the printing operation is completed.

  Next, the protection operation of the inkjet head 15 will be described.

  If the next image formation command is not issued until the predetermined time has elapsed after the image forming operation is completed, or if a power switch (not shown) is turned off, the power is turned on until the next image forming operation is performed. Wait until it is turned on. In this standby state, the belt conveyance unit 51 moves to the lower standby position, and the support plate 16 and the cap 18 move to the protection position.

  Specifically, when the pair of support members 61 of the transport unit moving mechanism 60 are turned inward, the belt transport unit 51 (specifically, the frame) supported by the support member 61 is lowered. . A space is formed below the inkjet head 15 due to the lowering of the belt conveyance unit 51. Next, the drive motor 30 of the moving mechanism 20 circulates the belts 33 and 34 via the gears and the pulleys 32a, 32b, 32c, 32d, and 32e. Since the moving belt 33 is provided with a locking piece 35 for locking to the flange portion 16c of the support plate 16, the support belt 16 and the cap 18 are moved in the direction B in FIG. To the space below the inkjet head 15 described above. That is, the cap 18 moves to a position (protective position) immediately below the corresponding inkjet head 15.

  When the support plate 16 and the cap 18 are moved to the protection position, the nozzle face 152a is cleaned by the wiping blade 19 attached to the support plate 16.

  In the state as described above, the fluid is supplied from the fluid supply device 21 to the fluid passage 25 c via the communication unit 26. The fluid supplied to the fluid passage 25c is injected into the inside of the inflating part 17, and thereby the inflating part 17 is inflated. When the expansion part 17 expands, as shown in FIG. 7, a part of the expansion part 17 contacts the inkjet head support member 13 and also contacts the side surface 15 a of the inkjet head 15. At this time, when the contact detection sensor 28 detects the contact between the expanding portion 17 and the inkjet head support member 13, the supply of fluid by the fluid supply device 21 is stopped.

  In this way, the expanding portion 17, the ink jet head support member 13, and the side surface 15a of the ink jet head 15 are reliably in contact with each other, and the space in the vicinity including the ink discharge port 152b is sealed. Thereafter, a predetermined amount of ink is ejected from the ink ejection port 152b as necessary, and an ink ejection function recovery operation is executed. That is, by ejecting ink in the inkjet head 15, the ink in the vicinity of the ink ejection port 152b is replaced, and the ink ejection function is restored. The ink discharged from the inkjet head 15 is discharged to the outside of the cap 18 through the discharge channel 27.

  In the next image forming operation, the fluid that has been injected into the expansion portion 17 is discharged by the fluid supply device 21. As a result, the inflating portion 17 is degenerated by its own elastic force, and is in a state as shown in FIG. Thereafter, the support plate 16 including the cap 18 is moved to the standby position by the moving mechanism 20.

[Feature]
Here, when the expansion part 17 is expanded, the expansion part 17 and the inkjet head support member 13 are in contact with each other, and the nozzle face 152a is sealed. For this reason, it is possible to prevent the ink inside the ink discharge port 152b from being dried and to prevent dust and the like from adhering to the nozzle face 152a. In particular, here, when the inkjet head 15 is protected, the expansion portion 17 does not come into contact with the nozzle face surface 152a, so that the meniscus in the ink discharge port 152b is not easily collapsed and air or the like is pushed into the ink discharge port 152b. Can be prevented. For this reason, it is possible to prevent the nozzle face surface 152a from being contaminated, and to prevent the image quality from being deteriorated.

  Moreover, since the seal | sticker is implement | achieved by expanding the expansion part 17, a pressing force can be controlled by controlling the expansion degree of the expansion part 17, and it becomes easy to control sealing (sealing) performance.

  Further, in the state in which the expansion portion 17 is retracted, it is located at a position lower than the nozzle face surface 152a in the height direction. Therefore, by moving the cap 18 only in the horizontal plane, the standby position and the protection position are The mechanism for moving up and down for sealing and releasing the seal becomes unnecessary, and the mechanism is simplified.

4). Other Embodiments (a) The fluid injected into the inflating portion 17 is generally considered to be air, but other gases and liquids can be used.

  (B) In the above embodiment, the cap 18 is moved only in the horizontal direction by the moving mechanism 20, but the present invention is not limited to this, and after moving the cap in the horizontal direction, the cap 18 is moved closer to the inkjet head 15. It may be moved in the vertical direction.

  (C) In the above embodiment, the contact detection sensor 28 is disposed on the inkjet head support member 13. However, the present invention is not limited to this, and the fluid supply amount to the inflating portion 17 is controlled without disposing the contact detection sensor. By doing so, the degree of expansion (pressing force) of the expansion part 17 may be controlled.

  (D) In the above embodiment, the expansion portion 17 of the cap 18 is in contact with the inkjet head support member 13 and also in contact with the side surface 15a of the inkjet head 15. However, the present invention is not limited to such a configuration. For example, as shown in FIG. 7, the expansion portion 17 ′ of the cap 18 ′ may be configured to contact only the inkjet head support member 13, or may be configured to contact only the side surface 15 a of the inkjet head 15 as illustrated in FIG. 8. You may comprise.

1 is an overall schematic diagram of an inkjet printer. The top view of an ink head apparatus. The front view of an ink head apparatus. FIG. 3 is a front sectional view of the ink jet head. The perspective view which shows the moving mechanism of a cap. The cross-sectional schematic of a nozzle and a cap. The cross-sectional schematic of a nozzle and a cap. The cross-sectional schematic which shows the cap of other embodiment. Furthermore, the cross-sectional schematic which shows the cap of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Ink head apparatus 3 Paper storage part 4 Paper conveyance part 5 Discharge part 10 Ink head mechanism 11 Protection mechanism 13 Inkjet head support member 15 Inkjet head 15a Side surface 16 Support plate 17 Expansion part 18 Cap 19 Wiping blade 20 Movement mechanism 21 Fluid supply device (expansion mechanism)
25 Cap body 25b Side wall 25c Fluid passage 27 Discharge passage 28 Contact detection sensor 152a Nozzle face surface 152b Ink discharge port

Claims (8)

An inkjet head support;
An ink jet head having an ink discharge port on a nozzle face formed to protrude from the surface of the ink jet head support;
The inkjet face is capable of facing the nozzle face surface and has an expandable portion that can expand at least partially, and the expanded portion in an expanded state is in close contact with a surface around the inkjet head excluding the nozzle face surface. A cap for sealing the ink discharge port of the head;
A cap moving mechanism for relatively moving the cap between a protection position facing the inkjet head and a standby position retracted from the protection position;
An expansion mechanism for expanding the expansion portion of the cap ,
The cap moving mechanism moves the cap only in a horizontal plane, moves the cap between the protection position and the standby position,
The vertical distance between the cap and the inkjet head does not change,
Inkjet recording device.   2. The inkjet recording apparatus according to claim 1, wherein the expansion portion of the cap contacts the inkjet head support portion and / or the side surface of the inkjet head around the nozzle face surface in an expanded state. The inflatable portion of the cap is formed in a bag shape that can contain a fluid therein,
The expansion mechanism inflates the expansion part by injecting a fluid into the expansion part;
The ink jet recording apparatus according to claim 1. Wherein when the cap by the moving mechanism is moved, and moves together with the cap in contact with the nozzle face surface, said further has a cleaning member for cleaning the nozzle face surface, one of claims 1 to 3 the ink-jet recording apparatus according to either. The cap is
A box-shaped cap body having an opening in a portion facing the ink-jet head and having a side wall portion formed so as to face the peripheral portion of the ink-jet head in the ink-jet head support portion;
The inflatable part is attached to the upper part of the side wall part of the cap body,
The ink-jet recording apparatus according to any one of claims 1 to 4. The ink jet recording apparatus according to claim 5 , wherein a fluid passage for injecting a fluid from the expansion mechanism into the expansion portion is provided in the side wall portion. The cap body is provided with a discharge flow path for discharging ink droplets discharged from the ink discharge port of the inkjet head to the outside.
An ink jet recording apparatus according to claim 5 or 6. The inflatable part is in contact with the inkjet head support part in an inflated state,
A contact detection sensor capable of detecting that the inflating part is in contact with a portion of the ink jet head support part in contact with the inflating part;
The ink-jet recording apparatus according to any one of claims 1 to 7.

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