JP2008194921A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce contamination by ink of a recording medium. <P>SOLUTION: Recesses 45a which communicate with discharge holes 51c-54c are formed between the adjacent discharge holes 51c-54c on the lower end surface of a discharge case 45. When a recording head 30 moves from a position where recovery processing is carried out to a region where recording to the recording medium is carried out, a nozzle opening surface of the recording head 30 and the lower end surface of the discharge case are sequentially wiped by a wiper member 131. At this time, the ink sticking to the lower end surface of the discharge case 45 without being wiped by the wiper member 131 flows by the capillary action into the recesses 45a which communicate with the discharge holes 51c-54c. Swelling of the ink at the lower end surface is prevented accordingly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus.

  Conventionally, as an ink jet recording apparatus, a box-shaped head holder that holds a recording head, an ink tank having an ink storage chamber, and a discharge housing that internally discharges air separated from ink in the ink storage chamber Are known (for example, see Patent Document 1). The ink storage chamber is connected to the ink inlet port of the recording head via an ink outlet path for leading ink. Further, the discharge housing has a discharge hole that opens the discharge passage to the outside at the lower end surface, and a valve body that opens and closes the discharge passage by an operating member provided outside the head holder. A lower end surface of the discharge housing is disposed in the vicinity of the direction.

In such a case, after performing a recovery operation such as by sucking ink from the nozzles of the recording head, the nozzle opening surface of the recording head is wiped off by the wiper member, and the ink adhered to the nozzle opening surface by the recovery operation Is to be removed. In addition, since the ink discharged together with the air adheres to the lower end surface of the discharge housing, the wiper member wipes the nozzle opening surface of the recording head continuously.
Japanese Patent Laying-Open No. 2005-271552 (FIG. 6)

  By the way, in such an ink jet recording apparatus, the discharge hole opened in the lower end surface of the discharge casing is formed to have a size sufficient to open and close the valve body, and when wiped with the wiper member, the wiper member Since a part of the ink falls into the discharge hole, the wiper member may be staggered and a stable wiping operation may not be performed.

  When the discharge housing is manufactured as a separate part from the head holder, a gap or a step is formed between the head holder and the lower end of the discharge housing. Therefore, when the wiper member wipes ink from the nozzle opening surface of the recording head to the lower end surface of the discharge housing, the wiper member fluctuates and a stable wiping operation cannot be performed.

  In this way, if the wiping operation cannot be performed stably, the ink is thinly stretched after the wiping operation, but the ink cannot be removed by wiping but eventually becomes an ink droplet due to surface tension, and the ink droplet is recorded. There is a risk of smearing the surface of the recording paper in contact with the paper.

  In particular, if the water repellency of the lower end surface of the discharge housing is high, the height of the ink droplets is high, and the occurrence rate of the recording paper is increased.

  The present invention provides an ink jet recording apparatus that reduces contamination of ink on a recording medium (recording paper) by taking measures to prevent the remaining ink from rising as described above on the lower end surface of the discharge housing. The purpose is to do.

  According to a first aspect of the present invention, a box-shaped head holder for holding a recording head has an ink tank having an ink storage chamber and a discharge passage for discharging ink in the ink storage chamber or air separated from the ink. A discharge housing, and the ink storage chamber is connected to an ink inlet port of the recording head via an ink lead-out path that guides ink from the ink storage chamber. The discharge passage has a discharge hole that opens to the outside, and has a valve body that opens and closes the discharge passage by an operating member provided outside the head holder, and a lower end surface of the discharge housing near the side of the recording head An ink jet recording apparatus in which the recording head and the lower end surface of the discharge casing are wiped by a wiper member provided outside the head holder Oite, the lower end surface of the exhaust casing, characterized in that measures are applied to prevent the swelling of the ink adhering to the lower end surface. Here, the measure for preventing the swell of ink adhering to the lower end surface is a measure for preventing the ink adhering to the lower end surface from becoming ink droplets due to surface tension and rising to the recording medium side. And measures to move the ink adhering to the lower end surface from the lower end surface to other parts.

  In this way, after the wiping operation by the wiper member, the ink remaining on the lower end surface of the casing of the discharge valve means that is not removed by the wiping operation is prevented from rising toward the recording medium. It is reduced that the ink remaining on the lower end surface comes into contact with the recording medium (for example, recording paper) and the recording medium is soiled by the ink.

  According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the head holder includes a bottom wall portion and a side wall portion that rises around the bottom wall portion, and the ink tank includes the ink tank Fixed to a head holder or a recording head fixed to the head holder, the discharge casing is provided to protrude from the ink tank laterally from the ink tank, and the discharge casing of the head holder It can be set as the structure extended along one side wall part parallel to an opening / closing operation direction.

  In this way, the discharge housing extends along one side wall of the head holder parallel to the opening / closing operation direction of the operating member, so that the operation force for opening / closing the valve element can be reduced.

  According to a third aspect of the present invention, in the ink jet recording apparatus according to the first or second aspect, the head holder is provided so as to be movable along a recording medium, and the recording head is exposed below the head holder. The end of the discharge casing opposite to the end connected to the ink tank is located near the side of the recording head, and the recording head is connected to the recording medium. A recovery mechanism that receives the ink discharged from the nozzles of the recording head opposite to the recording head and the operation member are arranged adjacent to each other outside the opposing position, and the operation member of the recovery mechanism It can be set as the structure by which the said wiper member is arrange | positioned adjacent to the opposite side.

  In this case, the end of the discharge housing opposite to the end connected to the ink tank is located in the vicinity of the side of the recording head. The recovery mechanism that receives the ink discharged from the nozzles of the recording head, the operation member, and the wiper member can be disposed adjacent to each other, and the size can be reduced.

  According to a fourth aspect of the present invention, in the ink jet recording apparatus according to the third aspect, the recording head surrounds the operation member outside the position facing the recording medium and is discharged from the discharge hole of the discharge casing. It is desirable that a cap for receiving the discharged ink or the discharged ink together with the air is disposed.

  If it does in this way, the ink discharged with the discharge of the ink or the air discharged from the discharge hole of the discharge case can be received by the cap surrounding the operation member.

  According to a fifth aspect of the invention, in the ink jet recording apparatus according to the first to fourth aspects, the countermeasure may be a concave portion or a groove portion communicating with the discharge hole.

  In this way, the ink adhering to the lower end surface of the discharge casing flows into and accumulates in the concave portion or groove portion communicating with the discharge hole, thereby preventing the ink from rising. Further, since the discharge hole has a sufficient space, it is advantageous in collecting the ink that has flowed in.

  The ink jet recording apparatus according to any one of claims 1 to 4, wherein the countermeasure is to apply a hydrophilic treatment to the lower end surface to reduce an ink contact angle with the lower end surface. can do.

  In this way, since the hydrophilic treatment is applied to the lower end surface of the discharge housing, the contact angle of the ink with respect to the lower end surface is reduced, and the ink swell is prevented.

  According to a seventh aspect of the invention, in the ink jet recording apparatus of the sixth aspect, the hydrophilic treatment can be a treatment for increasing the surface roughness.

  In this way, the hydrophilic treatment is a treatment for increasing the surface roughness, and can be easily performed.

  As described in claim 8, in the ink jet recording apparatus according to claim 7, the hydrophilic treatment can be a plasma treatment, an ozone treatment, a corona treatment, or an ittro treatment.

  In this way, since the hydrophilic treatment is a plasma treatment, an ozone treatment, a corona treatment or an intro treatment, the hydrophilic treatment can be easily performed.

  The ink jet recording apparatus according to any one of claims 1 to 4, wherein the countermeasure is provided on a side surface portion of the discharge casing on the wiping end side of the wiper member. It can be a plurality of ribs parallel to the direction.

  In this way, the ink adhering to the lower end surface of the discharge casing flows into and accumulates in the gaps between the ribs, so that the ink is prevented from rising.

  According to a tenth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to ninth aspects, the ink tank is provided with a plurality of the ink storage chambers, and ink is stored in each of the ink storage chambers. Each ink is supplied from an ink supply source stored by type through an ink supply tube for each type, ink is supplied from each ink storage chamber to the recording head, and the plurality of ink storage chambers and the recording head are recorded. The ink can be ejected while scanning the medium, and the discharge casing can be provided for each ink storage chamber.

  In this case, the invention according to claims 1 to 9 is realized in a type in which ink is supplied from the ink tank to the ink storage chamber and the recording head via the ink supply tube.

  With the configuration as described above, the present invention prevents the ink remaining on the lower end surface of the discharge casing from being swollen toward the recording medium after being wiped by the wiper member and not being removed by the wiping operation. Therefore, it is possible to reduce the ink remaining attached to the lower end surface from coming into contact with the recording medium and the recording medium being soiled by the ink.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory view showing the main structure of an ink jet recording apparatus according to the present invention in a plan view.

  As shown in FIG. 1, the ink jet recording apparatus 1 has two guide shafts 6 and 7 provided in parallel in the front and rear, and a head holder 9 that also serves as a carriage is provided on the guide shafts 6 and 7. Installed. The head holder 9 holds a recording head 30 that performs recording by discharging ink onto a recording medium (not shown). An ink tank 40 having a plurality of ink storage chambers 12, 13, 14, 15 (see FIG. 4A) is mounted on the head holder 9, and ink is supplied from each ink storage chamber 12 to 15 to the recording head. The The head holder 9 is connected to an endless belt 11 that is rotationally driven, and is provided so as to be movable along the recording medium on the guide shafts 6 and 7 by the rotational driving of the belt 11. Ink is ejected while scanning. Each ink storage chamber 12-15 has a flexible ink supply tube for each type of ink from an ink supply source (for example, a plurality of ink cartridges) provided outside the head holder 9 and containing the type of ink. Is supplied through.

  As shown in FIG. 4, the head holder 9 is formed in a box shape having a bottom wall portion 9c and a side wall portion 9d rising around the bottom wall portion 9c, and has an upper surface opened. The recording head 30 is exposed and fixed downward on the lower surface of the bottom wall portion 9c. The recording head 30 includes a cavity unit 32 having a plurality of nozzles 35, 36, 37, and 38 arranged on the lower surface in the scanning direction X of the recording head 30, and a piezoelectric device that selectively applies ejection pressure to the ink in the nozzle. The actuator 31 is stacked. A base end portion of a flexible flat cable (not shown) for applying a driving voltage to the piezoelectric actuator 31 is fixed on the upper surface of the piezoelectric actuator 31.

  A square frame-shaped reinforcing frame 33 is bonded and fixed to the upper side of the cavity unit 32. That is, the recording head 30 is fixed by an adhesive (not shown) injected between the bottom surface 9c of the head holder 9 with the square frame-shaped reinforcing frame 33 interposed on the top surface thereof. In order to eliminate the step on the lower surface side between the recording head 30 and the reinforcing frame 33 and protect the recording head 30, a protective cover 34 positioned around the recording head 30 is attached to the lower side of the reinforcing frame 33. Yes.

  As shown in FIGS. 4 and 5, the ink tank 40 is accommodated on the bottom wall portion 9 c in the head holder 9 and fixed to the head holder 9. The ink tank 40 can be fixed to the recording head 30 fixed to the head holder 9 instead of the head holder 9.

  The ink tank 40 is formed by joining an upper tank portion 40A and a lower tank portion 40B. Yellow ink and magenta ink storage chambers 12 and 13 are formed in the upper tank portion 40A, and cyan ink is formed in the lower tank portion 40B. Ink storage chambers 14 and 15 for black ink are formed in a stacked manner vertically. Each of the ink storage chambers 12 to 15 is defined by covering one surface with a flexible film 81 so as to alleviate the pressure fluctuation of the ink.

  In addition, on one side of the ink tank 40, a number of ink outlet paths 91 to 94 corresponding to the number of the ink storage chambers 12 to 15 are arranged in the scanning direction X of the recording head 30. The ink outlet paths 91 to 94 are substantially the same length and extend in the vertical direction of the tank, and the ink storage chambers 12 to 15 are connected to the side surfaces thereof. The lower ends of the ink outlet paths 91 to 94 are connected to ink inlet portions (not shown) of the recording head 30, whereby ink is supplied from the ink storage chambers 12 to 15 to the nozzles 35 to 38 for each column. Is done. At this time, the upper space of the ink lead-out paths 91 to 94 functions as an accumulating unit in which air contained in the ink is separated and temporarily accumulated. The accumulated air is discharged outside through discharge passages 95 to 98 described later.

  The discharge passages 95 to 98 are formed as concave grooves for the respective ink outlet paths 91 to 94 on the upper surface of the upper tank portion 40A, and one ends thereof are connected to the upper spaces of the ink outlet paths 91 to 94, respectively. The downstream ends of the discharge passages 95 to 98 are respectively connected to the upper ends of the discharge passages 51 to 54 in the discharge valve means 47 provided for each discharge passage. Each of the discharge passages 51 to 54 extends in the vertical direction, and discharge holes 51c to 54c, which are the lower end openings thereof, are opened in parallel with the nozzle rows in substantially the same plane as the nozzle opening surface of the recording head 30. Each of the discharge passages 95 to 98 is defined by covering the open upper surface thereof with an extension portion of the flexible film 81 that covers the uppermost ink storage chamber 12.

  Each discharge valve means 47 includes a discharge housing 45 having discharge passages 51 to 54 therein, and a valve body 102 housed in the discharge housing 45. Each housing 45 is formed in a shape that is continuous with each other in a direction orthogonal to the scanning direction X of the recording head 30. The upper tank portion 40A has a connecting portion 74A provided so as to protrude laterally beyond the side wall portion 9d of the head holder 9, and each housing 45 is connected in a suspended state below the connecting portion 74A. It extends downward along the portion 9d. That is, as shown in FIG. 4A, each housing 45 is provided so as to protrude from the side surface of the ink tank 40 to the side beyond the side wall portion 9d. Each of the discharge passages 95 to 98 is formed extending from the position corresponding to the upper ends of the ink outlet passages 91 to 94 onto the connecting portion 74A, and passes through the connecting portion 74A to correspond to the corresponding discharge passages 51 to 54 in the housing 45. Connected to. The side wall portion 9d is parallel to the opening / closing operation direction of the protruding shaft portion 121 as an operation member for opening / closing the discharge valve means 47, which will be described later.

  The lower end surface of each housing 45 opposite to the upper end portion on the side connected to the ink tank 40 is almost in the vicinity of the side of the recording head 30 and the lower surface where the nozzles 35 to 38 of the recording head open. Located on the same plane. At the lower end surface, discharge holes 51c to 54c are opened, and as shown in FIG. 2, a cross-shaped recess 45a (or groove) is provided between the adjacent discharge holes 51c to 54c so as to open downward. ing. Each recess 45a communicates with the discharge holes 51c to 54c located on both sides thereof. For the discharge hole 51c located at one end, a cross-shaped recess 45b communicating with the discharge hole 51c is provided on the side opposite to the discharge hole 52c adjacent thereto. For the discharge hole 54c located at the other end, a linear recess 45c communicating with the discharge hole 54c is provided on the side opposite to the discharge hole 53c adjacent thereto.

  The recesses 45a to 45c are formed to have a width that allows the ink to be held inside by capillary action, and a part of the ink adhering to the lower end surface of each housing 45 is in the recesses 42a to 45a or the discharge holes 51c. ˜54c is accommodated and held, and the amount of ink remaining on the lower end surface is reduced. As a result, swell of ink adhering to the lower end surface is prevented.

  The discharge valve means 47 is normally in a state in which the opening of the discharge passages 51 to 54 in each housing 45 to the outside is blocked. The discharge valve means 47 is driven and controlled to open appropriately, so that the ink in the upper part of the ink outlet paths 91 to 94 or the air accumulated in the upper space is discharged to the discharge paths 95 to 98 and the respective casings 45. It can be discharged to the outside through the inner discharge passages 51-54.

  Since the internal structure of each discharge valve means 47 is the same in all the discharge passages 51 to 54, only yellow ink will be described below with reference to FIGS. 4 (a) and 4 (b).

  The discharge passage 52 in the housing 45 is long in the vertical direction and opens up and down. The upper end communicates with the discharge passage 92, while the lower end opens to the outside as a discharge hole 52c, and the valve body 102 is slidable. It functions as a valve chamber. The discharge passage 52 has an upper large-diameter hole 52a and a small-diameter hole 52b located on the lower side. Further, a discharge hole 52c that communicates with the lower side of the small-diameter hole portion 52b and functions as an open portion to the outside is provided coaxially therewith.

  The valve body 102 includes a large-diameter valve portion 102a, a small-diameter valve rod 102b integrally connected to the lower end thereof, and a ring-shaped sealing material 102c fitted to the valve rod 102b at a position in contact with the valve portion 102a. Is provided. A large-diameter valve portion 102a is inserted into the large-diameter hole portion 52a of the discharge passage 52, and a valve rod 102b is inserted into the small-diameter hole portion 52b leaving a gap that allows ink or air to flow therethrough. Since the valve rod 102b is pushed up by the protruding shaft portion 121 provided in the maintenance unit 120 when the valve is opened as will be described later, the lower end of the valve rod 102b is positioned in the vicinity of the discharge hole 52c (when the valve is closed). Yes.

  In addition, the valve body 102 is formed between the large-diameter portion 52a and the small-diameter portion 52b by the coil spring 103 provided between the engagement convex portion 40Aa on the lower surface of the connecting portion 74A and the sealing member 102c. It is urged in a direction to contact the stepped valve seat surface. During normal times when the pushing-up force by the protruding shaft portion 121 described later does not act on the valve body 102, the discharge valve means 47 is in a valve closed state in which communication to the outside of the discharge passage 52 is blocked.

  The maintenance unit 120 that performs the recovery process of the recording head 30 and the air removal process in the ink tank 40 will be described below. The maintenance unit 120 includes a first cap member 122 (recovery mechanism unit) that covers the opening surfaces of the nozzles 35 to 38 of the recording head 30 so as to be openable and closable, and lower end surfaces (that is, the discharge holes 51c to 54c) of the discharge housings 45. And a second cap member 123 that covers the door in an openable and closable manner. In addition, a plate-like wiper member 131 made of an elastic material is disposed adjacent to the side of the first cap member 122 opposite to the second cap member 123 as is well known. The maintenance unit 120 is provided in the main body of the ink jet recording apparatus outside the head holder 9 at a position outside the position where the recording medium and the recording head 30 face each other.

  The first cap member 122 receives the ink discharged from the nozzles of the recording head 30 so as to face the recording head 30. The second cap member 123 surrounds the protruding shaft portion 121 as an operation member for opening and closing the discharge valve means 47, and is discharged together with the discharge of ink or air discharged from the discharge holes 51c to 54c of the housing 45. Receive ink. The wiper member 131 wipes the nozzle opening surface of the recording head 30 and the lower end surface of the discharge housing 45.

  Both cap members 122 and 123 are supported by a vertically moving mechanism 124 similar to a known maintenance unit so as to be vertically movable. When the recording head 30 moves to a standby position that does not face the recording medium, the cap members 122 and 123 are respectively located at the raised positions where the recording head 30 comes into close contact with the nozzle opening surface of the recording head 30 and the lower end surface of the housing 45 of the discharge valve means 47. It moves and moves to a lowered position so as to be separated from those surfaces at other positions. The first cap member 122 and the second cap member 123 are alternatively connected to the suction pump 125 by the switching valve 126.

  Similarly, the wiper member 131 is also supported by a vertically moving mechanism (not shown) so as to be vertically movable. When the recording head 30 is moved to a position facing the first and second caps 122 and 123, the recording head 30 is moved to a rising position where the nozzle opening surface of the recording head 30 and the lower end surface of the discharge housing 45 are wiped off. When the head 30 returns to the position facing the recording medium after the recovery process, the nozzle opening surface and the lower end surface of the discharge casing 45 are wiped in order, and the head 30 moves to the lowered position so as to be separated from them.

  The second cap member 123 has a protruding shaft portion 121 protruding from the cap member 123 at a position facing each of the discharge holes 51c to 54c. When the second cap member 123 comes into close contact with the lower end surface of the housing 45, the protruding shaft portion 121 pushes up the valve body 102 against the urging force of the coil spring 103, and the valve portion 102a together with the sealing material 102c is a valve seat. Open the valve away from the surface.

  According to the above apparatus, the discharge valve means 47 is in the valve closed state as described above during normal recording, and the ink storage units 12 to 15 transfer the nozzle rows of the recording head 30 for each ink color. Ink is supplied and ejected from each nozzle array onto the recording medium. On the other hand, when the recording head 30 is moved to the standby position, the second cap member 123 is brought into close contact with the lower end surface of the discharge housing 45, whereby the valve rod 102b is pushed upward by the protruding shaft 121 (operation member). The valve is opened. In this state, the second cap member 123 and the suction pump 125 are connected by the switching valve 126, and the suction pump 125 is driven to accumulate in the upper ink in the ink outlet paths 91 to 94 or in the upper space thereof. Collected air is sucked and discharged to the outside. Thereafter, the switching valve 126 is switched to connect the first cap member 122 and the suction pump 125, and the suction pump 125 is driven to suck and discharge the ink in the nozzles 35 to 38 of the recording head 30.

  Thereafter, the recording head 30 is moved from a position facing the first and second caps 122 and 123 to an area for recording on the recording medium. During the movement, the nozzle opening surface of the recording head 30 and the lower end surface of the discharge housing 45 that are wet with ink are sequentially wiped by the wiper member 131.

  At this time, ink is carried from the nozzle opening surface of the recording head 30, and there is a gap or a step between the head holder 9 and the discharge housing 45, and the lower end surface of the discharge housing 45 is discharged. The holes 51c to 54c have such a size that the protruding shaft 121 is inserted. For this reason, the thin plate-shaped wiper member 131 fluctuates due to these gaps, steps or holes, and the ink cannot be completely wiped off, and as shown in FIGS. Ink S may remain attached to the end face. However, the ink S flows into the recesses 45a to 45c communicating with the discharge hole 52c by capillary action, and finally, as shown in FIGS. 6A and 6B, the recesses 45a to 45c and the discharge hole 52c. Will be held in. As a result, the ink S remaining on the lower end surface of the casing 45 of the discharge valve means 47 is significantly reduced, and the ink S is prevented from rising. Therefore, it is reduced that the raised ink comes into contact with the recording medium and the recording medium is soiled by the ink.

  Further, since the discharge hole 52c has a space, it is advantageous in collecting the ink that has flowed in. The ink accumulated in the discharge hole 52c is sucked and discharged during the next maintenance.

  In addition to the embodiment described above, the present invention can also be configured as follows.

  (i) In the above embodiment, the recesses 45b and 45c are provided on the opposite side of the discharge holes 51c and 54c located adjacent to the discharge holes 52c and 53c adjacent thereto, but the adjacent discharge holes 52c , 53c can be omitted if there is not much space on the opposite side. Moreover, although the recessed parts 45a-45c are made into the cross shape or linear shape, the shape of a recessed part is not limited to them, If various shapes can be employ | adopted if it can be made to communicate with a discharge hole. Needless to say.

  (ii) Further, as shown in FIG. 7, a plurality of ribs 45b parallel to the opening / closing operation direction are provided on the side surface portion of the casing 45 ′ on the wiping end side of the wiper member 131, and the interval between the ribs 45b is provided. Is set to a size that can hold the ink by capillary action, so that the ink adhering to the lower end surface of the housing 45 ′ can be prevented from rising. In this case, ink is not wiped off by the wiper member 131, and the ink S may remain attached to the lower end surface of the housing 45 as shown in FIGS. 8 (a) and 8 (b). Due to the capillary action, it flows into the gaps between the ribs 45b and the upper side of the ribs 45b, and finally accumulates in the recesses 45a to 45c and the discharge holes 52c as shown in FIGS. 9 (a) and 9 (b). . Thereby, the ink S remaining on the lower end surface of the casing 45 of the discharge valve means 47 is greatly reduced, and the ink S is prevented from rising.

  (iii) Instead of the recess or groove communicating with the discharge hole, the bottom end surface of the housing is subjected to a hydrophilic treatment that reduces the contact angle of the ink with respect to the bottom surface, thereby increasing the amount of ink adhering to the bottom end surface. It is also possible to prevent this.

  As the hydrophilic treatment, for example, a treatment for roughening the surface roughness may be performed on the lower end surface of the casing. Specifically, it is possible to employ an itro process in which the surface is coated with ultra-thin silicon oxide of nanometer order by plasma treatment, ozone treatment, corona treatment or combustion chemical vapor deposition (CCVD).

(iv) In the above embodiment, the air accumulated in the upper spaces of the ink outlet paths 91 to 94 is exclusively discharged by the second cap member 123 and the suction pump 125 (in this case, a small amount of ink is also discharged). It is also possible to discharge the ink that has been thickened at the top of the ink supply tube or the ink tank that supplies ink from the ink supply source to the ink tank.
(v) In the above embodiment, air is discharged and ink is sucked from the nozzles 35 to 38 continuously. However, the first and second caps 122 and 123 are moved up and down by separate vertical movement mechanisms. Thus, only ink suction from the nozzles or only ink or air discharge through the discharge housing can be performed independently.

  (vi) Instead of the suction operation of the suction pump 125 as described above, the ink supplied from the ink supply source, that is, the ink cartridge side, applies positive pressure to the ink to pressurize the ink storage chambers 12 to 15 and increase the viscosity from the nozzles. In addition, the ink or air can be discharged through the discharge housing. Alternatively, the suction operation and the positive pressure application to the ink can be used in combination.

FIG. 2 is an explanatory diagram illustrating the main configuration of the ink jet recording apparatus according to the present invention in a plan view. It is a bottom view of a head holder on which an ink tank is mounted. It is the same top view. (A) is sectional drawing in the AA of FIG. 2, (b) is an enlarged view of the B section of FIG. 4 (a). (A) and (b) are operation | movement explanatory drawings, respectively. (A) and (b) are operation | movement explanatory drawings, respectively. It is a figure similar to FIG. 3 about other embodiment. (A) (b) is operation | movement explanatory drawing about other embodiment. (A) (b) is operation | movement explanatory drawing about other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 9 Head holder 9c Bottom wall part 9d Side wall part 12-15 Ink storage chamber 30 Recording head 40 Ink tank 45, 45 'Housing | casing 45a, 45b, 45c Recessed part 45d Rib 47 Discharge valve means 51-54 Discharge passage 51c to 54c Ejection hole 91 to 94 Ink outlet path 95 to 98 Ejection path 120 Maintenance unit 121 Projection shaft (operation member)
122 1st cap member (recovery mechanism part)
123 Second cap member 131 Wiper member

Claims (10)

A box-shaped head holder that holds the recording head is mounted with an ink tank having an ink storage chamber, and a discharge housing that internally has a discharge passage for discharging ink in the ink storage chamber or air separated from the ink. ,
The ink storage chamber is connected to an ink inlet port of the recording head via an ink lead-out path that guides ink from the ink storage chamber, and the discharge casing opens the discharge passage to the outside at a lower end surface. And a valve body that opens and closes the discharge passage by an operating member provided outside the head holder, and a lower end surface of the discharge housing is disposed near a side of the recording head,
In an ink jet recording apparatus in which a lower end surface of the recording head and the discharge casing is wiped by a wiper member provided outside the head holder.
2. An ink jet recording apparatus according to claim 1, wherein a measure for preventing swell of ink adhering to the lower end surface is provided on the lower end surface of the discharge casing. The head holder has a bottom wall portion and a side wall portion raised around the bottom wall portion,
The ink tank is fixed to the head holder or a recording head fixed to the head holder,
The discharge casing is provided to protrude from the ink tank to the side from the ink tank,
The ink jet recording apparatus according to claim 1, wherein the discharge housing extends along one side wall portion of the head holder parallel to the opening / closing operation direction. The head holder is provided so as to be movable along the recording medium, and the recording head is fixed to the head holder so as to be exposed downward, and is an end of the discharge housing on the side connected to the ink tank. The end opposite to the portion is located near the side of the recording head,
Outside the position where the recording head faces the recording medium, the recovery mechanism that faces the recording head and receives the ink discharged from the nozzles of the recording head, and the operation member are arranged adjacent to each other,
3. The ink jet recording apparatus according to claim 1, wherein the wiper member is disposed adjacent to the recovery mechanism portion on a side opposite to the operation member. 4.   Outside the position where the recording head faces the recording medium, a cap is disposed that surrounds the operation member and receives the ink discharged from the discharge hole of the discharge housing or the ink discharged together with the air. The ink jet recording apparatus according to claim 3, wherein the ink jet recording apparatus is provided.   The ink jet recording apparatus according to claim 1, wherein the countermeasure is a concave portion or a groove portion communicating with the discharge hole.   5. The ink jet recording apparatus according to claim 1, wherein the countermeasure is to apply a hydrophilic treatment to the lower end surface to reduce an ink contact angle with the lower end surface.   The ink jet recording apparatus according to claim 6, wherein the hydrophilic treatment is a treatment for roughening a surface roughness.   The ink jet recording apparatus according to claim 7, wherein the hydrophilic treatment is a plasma treatment, an ozone treatment, a corona treatment, or an itro treatment.   The said countermeasure is the some rib provided in the side part by the side of the wiping end of the said wiper member of the said discharge | emission housing | casing in parallel with the said opening-and-closing operation direction. Inkjet recording apparatus. The ink tank is provided with a plurality of the ink storage chambers, and each of the ink storage chambers is supplied with an ink from an ink supply source that stores the ink by type through an ink supply tube.
Ink is supplied to the recording head from each of the ink storage chambers, and ink is ejected while scanning the plurality of ink storage chambers and the recording head with respect to a recording medium,
The ink jet recording apparatus according to claim 1, wherein the discharge housing is provided for each of the ink storage chambers.

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