JP2005074827A6 - Inkjet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To periodically and efficiently remove bubbles stored in a bubble storage chamber mounted on a carriage together with a recording head.
Ink is supplied from an ink tank for storing ink to a buffer tank provided on an upper side of a recording head mounted on a carriage via a tube. One end of the suction paths 47a to 47d formed on the upper surface side of the ceiling wall 45 of the buffer tank 36 communicates with a cylindrical suction port 46 projecting downward from the ceiling wall 45, and the other ends of the suction paths 47a to 47d. Is connected to the opening / closing valve means 41 provided on one side of the buffer tank 36, and the valve body 55 in the opening / closing valve means 41 is opened by the valve operating means (release rod 62) provided at the standby position of the carriage 17, The air (bubbles) accumulated in the bubble storage chamber 40 below the ceiling wall 45 is exhausted.
[Selection] Figure 9

Description

  The present invention relates to an ink jet printer, and more particularly, to an ink jet printer capable of storing bubbles generated in an ink flow path to maintain good recording quality and efficiently removing the stored bubbles. Concerning structure.

  2. Description of the Related Art Conventionally, a tube supply type ink jet printer that supplies ink to a recording head mounted on a moving carriage from an ink tank fixed in the ink jet printer main body through a flexible tube is disclosed in Patent Document 1 and the like. Known.

In the configuration of Patent Document 1, a bubble storage chamber (referred to as a manifold in the publication) is provided at the top of the recording head, an ink tank and a circulation pump are provided on the fixed position side, and the circulation pump is driven to remove ink from the ink tank. The first ink flow path, the bubble storage chamber, the second ink flow path, and the ink tank are circulated in this order, and the bubbles in the circulation path are returned to the ink tank and removed. In addition, at the maintenance position, the ink is sucked from the nozzle (ink ejection side) side of the recording head by the suction purge means.
JP 2000-103084 A (refer to FIG. 1 etc.)

  However, according to the configuration of Patent Document 1, the ink tank is open to the atmosphere, and air (bubbles) is easily mixed in the ink when the ink is circulated. In addition, a tube for returning from the circulation pump to the ink tank is required for circulation, and there is a problem that the apparatus becomes large and complicated.

  The present invention has been made in view of the above-described conventional problems, and provides a compact inkjet printer that can efficiently remove bubbles stored in a bubble storage chamber mounted on a carriage together with a recording head. It is the purpose.

  In order to achieve the above object, the invention according to claim 1 is a carriage equipped with a recording head for recording on a recording medium by ejecting ink from a nozzle, and an ink tank for storing ink supplied to the recording head. And an ink flow path for supplying ink from the ink tank to the recording head, on the carriage, between the ink flow path and the recording head, in the ink flow path. A buffer tank having a bubble storage chamber for storing the generated bubbles upward is disposed, a bubble discharge passage communicating with the bubble storage chamber is provided in a ceiling wall of the buffer tank, and the bubble discharge passage is provided in the carriage. Is provided with on-off valve means for opening and closing.

  According to a second aspect of the present invention, in the ink jet printer according to the first aspect, a valve operating means is provided at a position outside the carriage to open the on-off valve means when the carriage is at a predetermined movement position. It is a thing.

  According to a third aspect of the invention, in the ink jet printer according to the first or second aspect, the bubble discharge passage communicates with the bubble storage chamber below an inner surface of a ceiling wall of the buffer tank. .

  According to a fourth aspect of the present invention, in the ink jet printer according to any one of the first to third aspects, the bubble discharge passage is formed in a groove formed in the upper surface of the ceiling wall of the buffer tank and an upper surface of the ceiling wall. It is composed of a synthetic resin film adhered and fixed.

  According to a fifth aspect of the present invention, in the ink jet printer according to any one of the first to fourth aspects, the recording head has a nozzle row for each of a plurality of colors of ink, and the bubble storage chamber has a plurality of bubble storage chambers. Provided for each color ink, the length of the bubble discharge passage for each color ink formed on the top surface of the ceiling wall of the buffer tank is set to be substantially the same.

  A sixth aspect of the present invention is the ink jet printer according to any one of the first to fifth aspects, wherein the recording head has a nozzle row for each of a plurality of colors of ink, and the bubble storage chamber and the bubble discharge passage. Are provided for each of a plurality of color inks, and each end of the plurality of bubble discharge passages on the side opposite to the bubble storage chamber is positioned side by side on one side of the carriage.

  A seventh aspect of the present invention is the ink jet printer according to any one of the first to sixth aspects, wherein the on-off valve means is a passage connected to an end of the bubble discharge passage opposite to the bubble storage chamber. There is a hole, and the end of the passage hole opposite to the bubble discharge passage and the nozzle are parallel to each other.

  The invention according to claim 8 is the ink jet printer according to claim 7, wherein the on-off valve means has a valve body that can move up and down along one side of the buffer tank, and is connected to the valve body. The lower end of the valve rod is exposed at the opening end of the passage hole.

  As described in detail above, according to the first aspect of the present invention, the carriage mounted with the recording head for recording on the recording medium by ejecting ink from the nozzle, and the ink supplied to the recording head are provided. In an ink jet printer comprising an ink tank for storing and an ink flow path for supplying ink from the ink tank to the recording head, the ink flow is provided on the carriage between the ink flow path and the recording head. A buffer tank having a bubble storage chamber for storing bubbles generated in the passage upward is disposed, a bubble discharge passage communicating with the bubble storage chamber is provided in a ceiling wall of the buffer tank, and the carriage has the On-off valve means for opening and closing the bubble discharge passage is provided.

  In the present invention, bubbles (air) accumulated in the bubble storage chamber above the buffer tank can be directly discharged to the atmosphere via the bubble discharge passage and the opening / closing valve means provided in the ceiling wall of the buffer tank. Therefore, bubbles (air) accumulated in the bubble storage chamber at the upper part of the buffer tank do not flow into the lower recording head, and there is no problem that bubbles are clogged in the ink flow path in the recording head. In addition, since there is no need to discharge a large amount of ink stored in the buffer tank when the bubbles (air) are removed from the buffer tank, a negative pressure is applied from the nozzle side of the recording head as in the past. As compared with the case where the ink is sucked and the air bubbles mixed in the ink are removed, wasteful waste of the ink can be prevented, the running cost can be reduced, and it is economical. In addition, the time required for removing the bubbles can be shortened, and the remarkable effect that the bubbles can be efficiently removed is achieved.

  According to a second aspect of the present invention, in the ink jet printer according to the first aspect, a valve operating means is provided at a position outside the carriage to open the on-off valve means when the carriage is at a predetermined movement position. It is a thing.

  As described above, since the valve operating means is provided at a position where the carriage is in a predetermined moving position, such as a standby position of the moving carriage, it is operated so as to open the on-off valve means only at the predetermined position to efficiently store the bubbles. Air bubbles (air) in the room can be discharged to the atmosphere via the bubble discharge passage.

  According to a third aspect of the invention, in the ink jet printer according to the first or second aspect, the bubble discharge passage communicates with the bubble storage chamber below an inner surface of a ceiling wall of the buffer tank. .

  Accordingly, an air reservoir of an appropriate volume that cannot be discharged from the bubble discharge passage is formed in the upper part of each bubble storage chamber, and the pressure fluctuation of the ink in each bubble storage chamber accompanying the movement of the carriage to the left and right is caused in the air reservoir. There is an effect that it can be absorbed.

  According to a fourth aspect of the present invention, in the ink jet printer according to any one of the first to third aspects, the bubble discharge passage is formed in a groove formed in the upper surface of the ceiling wall of the buffer tank and an upper surface of the ceiling wall. It is composed of a synthetic resin film adhered and fixed.

  By comprising in this way, there exists an effect that the bubble discharge passage with a small cross-sectional area can be formed easily.

  According to a fifth aspect of the present invention, in the ink jet printer according to any one of the first to fourth aspects, the recording head has a nozzle row for each of a plurality of colors of ink, and the bubble storage chamber has a plurality of bubble storage chambers. Provided for each color ink, the length of the bubble discharge passage for each color ink formed on the top surface of the ceiling wall of the buffer tank is set to be substantially the same.

  With this configuration, when the bubbles (air) are discharged from the bubble storage chambers, the air flow path resistance of the bubble discharge passage for each color ink can be made substantially equal, and the exhaust action from the plurality of bubble storage chambers can be reduced. It can be terminated at the same time.

  A sixth aspect of the present invention is the ink jet printer according to any one of the first to fifth aspects, wherein the recording head has a nozzle row for each of a plurality of colors of ink, and the bubble storage chamber and the bubble discharge passage. Is provided for each of a plurality of color inks, and each end of the plurality of bubble discharge passages opposite to the bubble storage chamber is arranged side by side on one side of the carriage. .

  If comprised in this way, it can be said that opening-and-closing valve means are arranged in one side of a carriage, and each opening-and-closing valve means and each edge part on the opposite side to a bubble storage chamber among the bubble discharge passages can be easily connected. There is an effect.

  A seventh aspect of the present invention is the ink jet printer according to any one of the first to sixth aspects, wherein the on-off valve means is a passage connected to an end of the bubble discharge passage opposite to the bubble storage chamber. The end of the passage hole opposite to the bubble discharge passage and the nozzle are configured so that the opening directions thereof are parallel to each other.

  With this configuration, the direction in which ink is sucked from the nozzle when the nozzle clogging is recovered is the same as the direction in which ink leaks from the bubble storage chamber together with air through the bubble discharge passage, the opening / closing valve means and the passage hole. Thus, the air discharge operation and the ink suction operation can be performed from the same direction because the gravity direction is obtained.

  The invention according to claim 8 is the ink jet printer according to claim 7, wherein the on-off valve means has a valve body that can move up and down along one side of the buffer tank, and is connected to the valve body. Since the lower end of the valve rod is exposed at the opening end of the passage hole, the internal valve element is opened with respect to the passage hole simply by pushing the lower end of the valve rod from the opening end side of the passage hole. The valve can be easily moved and the valve opening / closing operation is easy.

  Next, an embodiment embodying the present invention will be described. In the present embodiment, the present invention is applied to a multi-function device (MFC) 1 having a printer function, a copy function, a scanner function, and a facsimile function. As shown in FIG. A paper feeding device 3 is provided on the rear end side, and an original reading device 4 for a copy function and a facsimile function is provided on the upper front side of the paper feeding device 3. An ink jet printer 5 (to be described later) for realizing a printer function is provided on the entire lower side of the document reading device 4, and a recording medium such as paper P that is recorded (printed) and discharged is provided on the front side thereof. A paper discharge tray 6 for receiving is provided.

  Although not shown, the document reading device 4 is configured to be swingable up and down by a horizontal axis at the rear end portion. When the cover body 4a is opened upward, a glass plate for placing a document is provided. An image scanner device for reading a document is provided on the lower side.

  When the entire document reader 4 is opened to the upper side, an ink cartridge 7 as an ink tank (for individual colors, ie, cartridges for black, cyan, magenta, and yellow) is used for an ink jet printer 5 for full color recording. Can be exchanged with reference numerals 7a to 7d (see FIG. 2).

  Next, a schematic configuration of the inkjet printer 5 will be described with reference to FIGS. The inkjet printer 5 includes a printing mechanism unit 9 that is included in a main body frame 14 and ejects ink onto a sheet P that is a recording medium, and a maintenance unit 11 that performs maintenance processing of the recording head unit 10 in the printing mechanism unit 9. And an ink supply unit 12 for supplying ink from the ink cartridges 7a to 7d to the recording head unit 10, an air supply unit 13 for supplying pressurized (positive pressure) air to the ink cartridges 7a to 7d, and the like. Has been.

  As shown in FIGS. 2, 3, and 5, the printing mechanism unit 9 and the maintenance unit 11 are accommodated in a box-shaped main body frame 14 whose upper part is opened in a substantially elliptical shape. A carriage 17 is slidably mounted on a left and right rear guide shaft 15 provided in parallel in the main body frame 14 and a front guide shaft 16, and the recording head unit 10 is integrally attached to the carriage 17. It has been.

  A carriage drive motor 18 disposed on the right rear side of the main body frame 14 and a timing belt 19 which is an endless belt are configured to reciprocate the carriage 17 in the left-right direction along the front and rear guide shafts 16 and 15. (See FIG. 2). On the other hand, the main conveyance below the rear guide shaft 15 via a paper feed motor 20 disposed on the left rear side of the main body frame 14 and a transmission mechanism 21 such as a belt and a gear disposed on the left side of the main body frame 14. A roller 22 and a conveyance roller (not shown) positioned below the front guide shaft 16 convey the paper P horizontally on the lower surface side of the recording head unit 10, and the recorded paper P is for discharge. It is conveyed and discharged in the direction of the tray 6.

  An ink receiving portion 8 is provided on one end side (the left end portion in FIGS. 2 and 3 in the embodiment) outside the width of the conveyed paper P, and a maintenance unit 11 is provided on the other end side. Has been placed. Thus, the recording head unit 10 periodically ejects ink to prevent nozzle clogging at the flushing position where the ink receiving portion 8 is provided, and receives ink at the ink receiving portion 8 during the recording operation. . At the head standby position on the other end side, the maintenance unit 11 is arranged to clean the nozzle surface 29, and a recovery process for selectively sucking ink for each color and bubbles in the buffer tank 36 described later. A removal process for removing (air) is performed.

  Next, the configuration of the ink supply unit 12 will be described. As shown in FIGS. 2, 4, and 5, the nozzle surface 29 on the lower surface of the recording head unit 10 is located below the conveyance path of the paper P and on the front upper surface of the lower partition plate 2 a of the main body case 2. In the lower position, there is provided a cartridge mounting portion 23 into which the ink cartridge 7 for each individual color can be inserted and mounted from the front. In FIG. 2, in order from the left side, the black (BK) ink cartridge 7a, A cyan (C) cartridge 7b, a magenta (M) cartridge 7c, and a yellow (Y) cartridge 7d are arranged horizontally and in parallel.

  In each ink cartridge 7, a flexible film material 24a (which corresponds to a deformable wall surface) is affixed to substantially the entire area, and the lower ink storage chamber 24b and the upper ink storage chamber 24b are attached by the film material 24a. It is partitioned into an air chamber 24c.

  An air hole (not shown) communicating with the air chamber 24c and the atmosphere is formed in the rear side wall surface of each ink cartridge 7, while the ink storage chamber 24b is separated from the outside by a silicone or the like. A seal member 25 is attached.

  On the rear side of the cartridge mounting portion 23, an ink needle 26 is horizontally provided so as to face the insertion direction (rear side wall surface) of each color ink cartridge 7. The base end portion of the ink needle 26 corresponding to each color ink is connected to the recording head unit 10 via the corresponding flexible ink supply tubes 27a to 27d. In this case, the middle portions of the black and cyan ink supply tubes 27a and 27b and the middle portions of the magenta and yellow ink supply tubes 27c and 27d are stacked one above the other.

  The air supply unit 13 includes four pressure-bonding pads 31 protruding forward in parallel with the ink needles 26, a diaphragm-type air pump 28 driven by a drive motor 30, and air connecting them. Each pressure pad 31 is configured to be brought into close contact with the air hole on the rear surface of each ink cartridge 7 inserted into and fixed to the cartridge mounting portion 23 by a biasing force of a biasing spring. Then, by driving the air pump 28, pressurized (positive pressure) air can be supplied to the air chambers 24c of the ink cartridges 7a to 7d, and a positive pressure can be applied to the ink in each ink storage chamber 24b.

  Here, as shown in FIG. 5, the nozzle surface 29 in which the nozzles 33 in the recording head unit 10 are opened is disposed at a position higher than the ink needle 26 by the water head H. A negative pressure (back pressure) corresponding to the water head H acts on the nozzle 33 of the unit 10. Will be. At the time of initial introduction of ink, as is well known, a suction cap member, which will be described later, is brought into close contact with the nozzle and sucked by the suction pump to be introduced from the ink cartridges 7a to 7d into the recording head 34. At this time, the air pump 28 is turned on. It may be driven to apply a positive pressure to the ink cartridges 7a to 7d.

  Next, the configuration of the recording head unit 10 and the on-off valve means 41 mounted on the carriage 17 will be described with reference to FIGS. 3 and 6 to 11. In the present embodiment, for full color recording, the recording head unit 10 is bonded to the recording head 34 having a row of nozzles 33 for each color and the upper surface of the recording head 34 as shown in FIGS. And a buffer tank 36 having a bubble storage chamber 40 and the like, a case 37 having an opening / closing valve means 41 adjacent to the side surface of the buffer tank 36, and the like.

  On the lower surface of the recording head 34, from the left side in FIG. 3, a row of black (BK) nozzles 33a, a row of cyan (C) nozzles 33b, a row of magenta (M) nozzles 33c, and yellow The row of nozzles 33d for use is formed long in a direction orthogonal to the moving direction of the carriage 17. Each nozzle 33 is exposed downward so as to face the upper surface of the paper P. The recording head 34 distributes the ink supplied from the buffer tank 36 to the pressure chambers for each nozzle, and ejects ink from the nozzles by an actuator 35 such as a piezoelectric element corresponding to the pressure chamber. is there.

  The buffer tank 36 in which the bubble storage chamber 40 (individually indicated by reference numerals 40a, 40b, 40c, and 40d, see FIG. 10 and the like) is partitioned for each color ink has a substantially rectangular shape in plan view with a synthetic resin material. An ink inflow port 39 (4 in the embodiment) is formed on one side surface of the buffer tank 36 and connected to a joint member 38 (details are omitted) to which the tips of the ink supply tubes 27a to 27d of the respective colors are connected. ) Project sideways. Each ink supplied from each ink cartridge 7 is stored in each bubble storage chamber 40, and after the bubbles in the ink are separated, the downward flow-out portion 43 from the ink flow chamber 42 on the bottom side of the buffer tank 36 is passed through. And supplied to the recording head 34. The filter 44 for partitioning most of the lower surface side of the bubble storage chamber 40 and the ink flow chamber 42 in a substantially horizontal shape is formed of a mesh made of stainless steel metal wires knitted in a mesh shape. With respect to the slow ink flow during the recording operation, the ink flow from the bubble storage chamber 40 to the ink flow chamber 42 is allowed, while the bubbles and dust contained in the ink are filtered by the ink flow. The flow to the recording head 34 side through 44 is prevented. The filter 44 has an opening 44 a having a flow resistance sufficiently smaller than the mesh of the filter 44 at an end portion far from the ink inlet 39, and is open for high-speed ink during a recovery purge processing operation described later. A sufficient flow of ink to the ink flow chamber 42 is ensured through 44a.

  As shown in FIGS. 6 (a), 6 (b), and 7, a cylindrical suction port 46 for sucking ink together with air (air) faces downward on the ceiling wall 45 of each bubble storage chamber 40. And a suction passage 47 (individual ones are indicated by reference numerals 47a to 47d) as bubble discharge passages, one end of which communicates with each of the suction ports 46 and the other end of which communicates with an inlet portion of a case 37 which will be described later. Are formed on the upper surface side of the ceiling wall 45.

  As in the prior art, when the ink is sucked from the nozzle side and the air (bubbles) accumulated in the bubble storage chamber 40 is sucked during the recovery purge operation, the recording head 34 is thin unless the suction force is increased. There is a problem that air bubbles are clogged in the ink flow path, and a large amount of air bubbles (air) on the upper side of the ink cannot be sucked out after the amount corresponding to almost all of the ink in the buffer tank 36 is discharged. There is a problem that the ink is wasted and the running cost of the ink jet printer becomes high.

  According to the configuration of the present embodiment, the air accumulated in the bubble storage chamber 40 above the buffer tank 36 is extracted from the upper portion of the buffer tank 36, particularly the location of the ceiling wall 45, so that the recording head 34 has the bubbles at the lower position. Therefore, the defect that bubbles are clogged in the ink flow path in the recording head 34 does not occur. In addition, since it is not necessary to discharge a large amount of ink stored in the buffer tank 36 in accordance with the operation of removing bubbles (air) from the buffer tank 36, the running cost can be reduced, which is economical. Play.

  In the present embodiment, the suction paths 47a to 47d are formed between a groove formed in the upper surface of the ceiling wall 45 and a film body such as a synthetic resin film 48 adhered to cover the groove. In addition, the code | symbol 45a shown in FIG. 7 is a partition which isolate | separates each said suction path 47a-47d, and the film 48 is adhere | attached on the upper surface.

  As shown in FIGS. 6B and 7, the cross-sectional area of each of the suction paths 47a to 47d is equal to or equal to the cross-sectional area of the ink inlet 39 of the buffer tank 36 or a tube (not shown) connected thereto. It is formed smaller than. Further, by setting the lengths of the suction paths 47a to 47d to be equal, the air flow path resistance when the air in the bubble storage chambers 40 is discharged through the case 37 can be made substantially equal, and a plurality of bubble storages can be obtained. There is an effect that the exhausting action in the chamber 40 can be ended almost simultaneously.

  Further, by appropriately setting a height H2 at which the cylindrical portion having the suction port 46 projects downward from the lower surface of the ceiling wall 45, an air reservoir having an appropriate volume that cannot be discharged from the suction port 46 is formed in each bubble. It is formed in the upper part of the storage chamber 40 and absorbs the pressure fluctuation of the ink in each bubble storage chamber 40 accompanying the movement of the carriage 17 to the left and right by the air reservoir.

  Because of the cross-sectional area and passage length of each of the suction paths 47a to 47d, the flow path resistance of each suction path with respect to ink is larger than that of air (bubbles). The amount of air stored in each of the bubble storage chambers 40 of the plurality (four colors) of buffer tanks 36 varies, and the air discharge operation described later is simultaneously executed for all the bubble storage chambers 40. In addition, when the ink level reaches one suction port 46, the resistance of the ink flow is large, so that the air is discharged preferentially in the other bubble storage chambers 40, and the bubble storage chambers. Even if the amount of air in 40 is different, the phenomenon that only the amount of ink discharged from the buffer tank 36 at the location where the amount of air is small (inversely, the amount of ink is large) does not increase.

  A case 37 in the on-off valve means 41 is provided adjacent to one side of the buffer tank 36 (FIG. 6A, the right side in FIGS. 7 and 10). As shown in FIG. 10, FIG. 11 (a) and FIG. 11 (b), the synthetic resin case 37 has a passage hole 51 that is long in the vertical direction and opens vertically. 50 is attached so as to be airtight. In the embodiment, four passage holes 51 are arranged side by side so as to correspond to each of the suction paths 47a to 47d. Four passage cylinders 52 communicating with the upper ends of the passage holes 51 protrude upward from the upper end of the case 37, and the passage cylinders 52 and the suction passages 47a to 47a through a cap body 53 made of soft rubber or the like. It connects with the outlet portion 54 of 47d sideways. Note that the cap body 53 is restricted from being easily removed by the eaves portion 60 projecting sideways from the upper portion of the buffer tank 36.

  Each of the passage holes 51 includes an upper half large diameter portion 51a and a lower half small diameter passage 51b. A small-diameter valve rod 56 is integrally formed at the lower end of the large-diameter valve body 55. A packing 57 such as an O-ring for sealing is disposed on the lower end surface of the valve body 55 so as to be fitted to the valve rod 56. A packing 57 and a valve body 55 are inserted into the large diameter portion 51a so as to be movable up and down, and a valve rod 56 is inserted into the small diameter passage 51b. The lower end of the valve rod 56 extends to the vicinity of the lower end opening of the small diameter passage 51b. The valve body 55 is always pressed downward by a spring means 58 such as a coil spring provided in the large diameter portion 51a. In this state, the packing 57 is pressed against the bottom surface of the large diameter portion 51a of the passage hole 51 to close the valve (see FIG. 11A). On the other hand, when the release rod 62 as the valve operating means in the bubble removing means 61 described later rises and presses the valve rod 56 upward against the urging force of the spring means 58, the packing 57 becomes the large diameter portion 51a. The valve is in an open state, that is, communicated with the atmosphere (see FIG. 11B).

  Next, the configuration of the maintenance unit 11 will be described with reference to FIGS. In the maintenance unit 11, the nozzle surface 29 of the recording head unit 10 mounted on the carriage 17 is capped while the carriage 17 is stopped at the standby position (the right end side in FIGS. 2 and 3 in the embodiment). In a state of being covered with the member 64, the ink is sucked from the nozzles, the recovery means 63 for sucking out clogged solid ink, fine dust, and bubbles in the recording head 34, and the bubble storage chambers 40. And a bubble removing means 61 for discharging and removing the air accumulated in the air through the suction path 47 as the bubble discharging path and the opening / closing valve means 41 and sucking and removing the ink leaking at that time. The recovery means 63 is disposed adjacent to the bubble removing means 61, and the bubble removing means 61 is disposed on the outermost end side in the movement direction of the carriage 17. The wiper 65 for wiping and cleaning the nozzle surface 29 is disposed on the opposite side of the lift 66 provided with the release rod 62 in the bubble removing means 61 with the cap member 64 of the recovery means 63 in plan view (FIG. 12). And FIG. 13).

  12 is a plan view of the maintenance unit 11, FIG. 13 is a perspective view, FIG. 14 is a plan view of the lifting mechanism 70, and FIG. 8 is a view of the carriage 17 and the maintenance unit 11, as shown by arrows VIII-VIII in FIG. It is a side view of a part.

  The maintenance unit 11 is provided with a mechanism portion 67 as one operation conversion means, and this mechanism portion 67 operates an elevating mechanism portion 70 for selectively raising and lowering the recovery means 63 and the bubble removing means 61. A switching valve unit 69 for selectively operating a suction pump 68 as a suction means for sucking ink and selectively connecting the suction force of the suction pump 68 to the recovery means 63 and the bubble removing means 61 The switching operation is executed.

  The mechanism portion 67 has a gear train pivotally attached to the unit base 73, and one motor 71 that can be rotated forward and reversely disposed at one end of the unit base 73 transmits power to the gear train. When the motor 71 rotates in the reverse direction (counterclockwise in FIG. 12), the driving force is rotated clockwise through the plurality of gears 72a to 72i so that negative pressure is applied to the switching valve unit 69 side. The ink can be sucked as will be described later. In this case, among the gears 72a to 72i, the gear 72e and the sun gear 72f rotate counterclockwise. Accordingly, the planetary gear 72g meshing with the gear sun gear 72f rotates clockwise while revolving counterclockwise around the axis of the sun gear 72f, meshes with the intermediate gear 72h, and through this, the tube type suction pump Power is transmitted to 68 gears 72i.

  When the motor 71 rotates forward (clockwise in FIG. 12), the driving force rotates the gear 72e and the sun gear 72f clockwise via the gears 72a to 72d. Accordingly, the planetary gear 72g that meshes with the sun gear 72f rotates counterclockwise while revolving clockwise around the axis of the sun gear 72f, meshes with the rear gear 72j, and then rotates through the gears 72k to 72o. While the moving cam body 74 is rotated counterclockwise, power is transmitted to the gear 72r through the gears 72p and 72q so as to change the angle of the switching member 110 in the switching valve unit 69.

  Next, with reference to FIGS. 10 and 12 to 20, the recovery means 63 and the bubble removing means 61, the lifting mechanism 70 for selectively raising and lowering them, and the rotating cam body 74 for driving them. While explaining.

  The recovery means 63 includes two rows of cap members 64a and 64b that come into contact with the nozzle surface 29 to cover the four rows of nozzles 33 exposed on the lower surface side of the carriage 17, and the cap members 64a and 64b are arranged on the upper surface. And a support block 75 having a substantially rectangular shape in plan view arranged in parallel with each other. The reason why the cap members 64a and 64b are separated is to avoid mixing ink colors. Each of the cap members 64a and 64b is provided with an ink suction hole (not shown), and these suction holes pass through two passages on the side surface through a passage (not shown) inside the support block 75. To the tubes 76a and 76b. In this case, the cap member 64a for black BK ink and cyan ink is connected to the port A of the switching valve unit 69 via the tube 76a. On the other hand, the cap member 64b for magenta ink and yellow ink is connected to the port B of the switching valve unit 69 via the tube 76b (see FIGS. 21, 22 and the like).

  As shown in FIGS. 10 and 15, a guide tube 77 is provided at the center of the lower surface of the support block 75 made of synthetic resin or the like, and a pair of sliding contact pins 78 as cam followers are provided on the outer surface of the guide tube 77. , 78 (only one is shown in the figure) protrudes horizontally. Further, four spring seats 79 project downward so as to surround the guide cylinder 77. On the other hand, in the guide groove 80 formed on the upper surface of the unit base 73 made of synthetic resin or the like, the guide cylinder 77 and the sliding contact pins 78 and 78 are guided in the vertical direction, and the support block 75 is raised and lowered. A pair of arc-shaped guide pieces 81 and 81 are provided so as not to rotate around a plane orthogonal to the direction to be projected (see FIGS. 14 and 15). Further, on the outer side of the guide groove 80, a protrusion 83 is provided between the spring seats 79 for positioning the lower end of the upward biasing spring 82.

  As shown in FIGS. 14 to 17, four dish-like suction portions 90 that can be in close contact with the passage holes 51 of the cylinder block 50 are formed on the upper surface of the elevating body 66 in the bubble removing means 61. Each suction portion 90 has a suction port 91 that can communicate with each small-diameter passage 51b that opens to the lower surface of the cylinder block 50, and an upwardly projecting release rod 62 that can come into contact with the valve rod 56. The port 91 communicates with a discharge cylinder 93 on the side surface via a passage 92 in the elevating body 66 (see FIG. 17A). In addition, a pair of positioning corners 94a and 94b are projected upward on the upper surface of the elevating body 66 (see FIGS. 15 to 17C), and the elevating body 66 is raised and the cylinder block is raised. When approaching 50, the pair of positioning guide grooves 95a, 95b provided in the cylinder block 50 is slidably contacted to position the elevating body 66 in two horizontal directions, and each release rod 62 is moved into each small diameter passage 51b. It is comprised so that it can fit smoothly (refer FIG. 8).

  A leg 98 that can be fitted between a pair of vertical guide pieces 97 and 97 in a translation cam body 96 (described later) projects downward from the elevating body 66. A pair of slidable contact pins 99 and 99 as cam followers project outward from the lower end of the leg 98 along the longitudinal direction of the elevating body 66 in the horizontal direction. Further, two spring seats 66a for supporting the upper end of an upward biasing spring 100 (only one is shown in FIG. 15) disposed between the lift base 66 and the unit base 73. , 66a (see FIGS. 15 to 17C).

  One operation conversion that selectively executes the operation of the cap members 64a and 64b in the recovery means moving toward and away from the nozzle surface 29 and the up-and-down movement operation of the bubble removing means for opening and closing the valve by the release rod 62. The means includes a parallel moving cam body 96 and a rotating cam body 74.

  As shown in FIGS. 10, 14, 15, 19, and 20, the translation cam body 96 includes a bifurcated horizontal guide piece 101 that is guided horizontally along the guide groove 80 in the unit base 73. , And a pair of vertical guide pieces 97, 97 etc. standing from the horizontal guide piece 101. A pin 104 protruding upward on the horizontal guide piece 101 is fitted in an endless cam groove 74a (see FIG. 18) in the rotating cam body 74, and as will be described later, the rotating cam body 74 is fixed. The direction of the translation cam body as it rotates in the direction is perpendicular to the direction in which the elevating body 66 contacts and separates from the lower surface of the cylinder block 50 (X1-X2 direction shown in FIGS. 10, 15, 19, and 20). ).

  In each of the vertical guide pieces 97, sliding contact pins 78, 78 and 99, 99 which are cam followers protruding laterally from the recovery means 63 and the bubble removing means 61, respectively, are urged by the urging springs 82, 100. A cam portion having a pair of cam surfaces 102 and 103 that are in contact with each other in the direction (upward direction) and regulate the lifting and lowering operation of the recovery means 63 and the bubble removing means 61 as the reciprocating movement of the parallel moving cam body 96 occurs. I have.

  More specifically, the pair of cam surfaces 102 and 103 are formed so that the elevating operation directions of the recovery means 63 and the bubble removing means 61 are opposite to each other. In other words, the cam surfaces 102 and 103 are connected in an inclined manner between the horizontal bottom cam surfaces 102a and 103a, the intermediate cam surfaces 102b and 103b, and the top cam surfaces 102c and 103c, respectively. The lowermost cam surfaces 102a and 103a are formed at positions approaching each other, and the uppermost cam surfaces 102c and 103c are formed at positions farthest from each other (see FIGS. 10 and 15). In the state where the recording head 34 prints on the paper, as shown in FIG. 10, the upper surfaces of the sliding contact pins 78 and 99 on the cap members 64 a and 64 b and the elevating body 66 on the intermediate cam surfaces 102 b and 103 b. Are in contact.

  In the recovery processing operation shown in FIG. 19 and in the storage state, the parallel moving cam body 96 moves in the X2 direction in the cam groove 74a of the rotating cam body 74. As a result, the sliding contact pin 78 is detached from the intermediate cam surface 102b and moved to the uppermost cam surface 102c side, the restriction on the upward movement of the sliding contact pin 78 is removed, and the support block 7 is raised by the biasing spring 82. . As a result, the upper surfaces of the cap members 64 a and 64 b are brought into close contact with the nozzle surface 29 of the recording head 34. On the other hand, the upper surface of the sliding contact pin 99 comes into contact with the lowermost cam surface 103a, and the elevating body 66 descends to the lowest position. The upper end of the release rod 62 in the elevating body 66 and the lower surface of the cylinder block 51 in the bubble removing means 61 The lifting / lowering body 66 is held at such a height as to have an appropriate gap between them.

  At the time of the bubble removal (bleeding) processing operation from all the bubble storage chambers 40a to 40d shown in FIG. 20, the parallel moving cam body 96 moves in the X1 direction in the cam groove 74a of the rotating cam body 74. As a result, the upper surface of the sliding contact pin 78 comes into contact with the lowermost cam surface 102 a and the support block 75 is held at the lowermost position where the upper surfaces of the cap members 64 a and 64 b are farthest from the nozzle surface 29 of the recording head 34. At this time, the sliding contact pin 99 is moved away from the intermediate cam surface 103b and moved to the uppermost cam surface 103c side, the restriction of the upward movement of the sliding contact pin 99 is removed, and the elevating body 66 is raised by the biasing spring 100. . As a result, each suction portion 90 of the elevating body 66 comes into close contact with the lower end opening of each small-diameter passage 51b, and the release rod 62 pushes up the valve rod 56.

  In this way, the lift 66 is raised by the other cam surface 103 with respect to the state in which the urging force of the urging spring 82 is greatest when the support block 75 is positioned at the lowest position by the one cam surface 012. The biasing force of the biasing spring 100 at that time is weak. The pair of cam surfaces 102 and 103 are formed so that the elevating operation directions of the recovery means 63 and the bubble removing means 61 are opposite to each other, so that both cam surfaces 102 and 103 are opposite to each other. , 103 are not simultaneously applied with the largest urging force, and it is not necessary to increase the strength of the cam portion more than necessary, so that the translation cam body 96 can be formed compactly.

  Next, a suction unit that sucks ink by connecting in parallel to the bubble removing unit 61 and the recovery unit 63 will be described. The suction means includes a suction pump 68 and a switching valve unit 69 as a suction switching valve. The suction means selectively executes an operation of sucking ink leaked together with the bubbles from the bubble storage chambers 40a to 40d and an operation of sucking ink from the nozzles via the recovery means 63.

  The suction pump 68 is a tube type pump that generates a negative pressure by using a volume change in the flexible tube 105. One end (discharge side) of the flexible tube 105 is connected to a waste ink storage unit that stores a waste liquid form 111 described later, and the other end (suction side) of the flexible tube 105 is switched via a connector 106 and a tube 107. It is connected to the discharge port 108 of the valve unit 69.

  As shown in FIGS. 21A, 21B, and 22, the switching valve unit 69 includes a cylindrical main body 109, a switching member 110 that is rotatably fitted in the main body 109, and a unit base. 73, and a gear 72r that rotates about a rotation shaft provided upright at 73 and rotates the switching member 110 with respect to the main body 109. The main body 109 made of synthetic resin is provided with the discharge port 108 on the upper surface, and ports A, B, W, and F are provided on the side surface of the main body at a predetermined phase angle. The port A is connected to the cap member 64a via the tube 76a, and the port B is connected to the cap member 64b via the tube 76b. The port W is connected to a discharge cylinder 93 in the bubble removing means 61 through a tube 76c. The port F is connected to a tube 76d that is open to the atmosphere. In this case, as shown in FIG. 12 and FIG. 13, the tube 76d is arranged to be sufficiently long and bent at an intermediate portion of 180 degrees or more so that ink is always stored therein. The opening end (tip opening portion) of the tube 76d is pierced upward by a thick waste liquid foam 111 in the main body case 2, and the entire multifunction device 1 is inclined and dropped, etc. Even when an impact is applied to the ink inside and the ink leaks from the opening end of the tube 76d due to the pressure of the ink at that time, it is captured by the waste liquid form 111. As shown in FIGS. 4 and 5, the waste liquid form 111 is formed on the bottom plate 2 c of the main body case 2 and the ink cartridges 7 a to 7 d arranged in parallel in the left-right direction of the main body case 2 of the ink supply unit 12. The open end of the waste ink tube 76d is located at a substantially central portion in the longitudinal direction, in other words, when the main body case is tilted in either the left or right direction, at the portion where the water head difference is minimized. Arranged to reduce the amount of ink leakage.

  The cylindrical switching member 110 is formed of an elastic body such as rubber, and top surface grooves 112a to 112d extending in four directions in the radially outward direction are formed on the circular top surface. The discharge port 108 is connected to the central portion, and the four ends thereof are connected to the outer peripheral grooves 113 a to 113 d of the switching member 110. The outer peripheral groove 113c is long downward and corresponds to the port W. The outer circumferential grooves 113a, 113b, 113d are short downward and correspond to the ports A, B, F. The outer peripheral groove 113c also corresponds to the ports A, B, and F. Furthermore, three ribs 114 are formed on the outer circumferential surface of the switching member 110 so as to surround the outer circumferential grooves 113a to 113d along the circumferential direction. By forming the rib 114, when the negative pressure is accumulated and when the switching member 110 is rotated in order to apply the negative pressure, the negative pressure is generated by a deformation that creates a gap between the switching member 110 and the main body 109. Can be prevented from leaking.

  As shown in FIGS. 10, 19 and 20, the bottom surface of the rotating cam body 74 is formed with an endless cam groove 74a into which the pin 104 of the translation cam body 96 is fitted, as described above. . FIG. 18 is a view of the rotating cam body 74 as viewed from above. A cam (not shown) for moving the wiper 65 up and down and a leaf switch 116 for detecting the rotational position (phase) of the rotating cam body 74 are provided on the outer periphery of the rotating cam body 74. It has the protruding cams 117a-117e which contact. The maintenance motor 71, the air pump 28, the carriage, the drive motor 18 and the like are controlled by a control device including a CPU and a ROM storing a program for each operation described later.

  Next, the operation of the maintenance unit will be described with reference to FIGS. In FIG. 12, when the maintenance motor 71 is rotated in the reverse direction (counterclockwise), the suction pump 68 is rotated in the clockwise direction in FIG. 12 to apply a negative pressure to the discharge port 108 at the center of the top surface of the switching valve unit 69. The ink can be sucked. At this time, the switching member 110 and the rotating cam body 74 of the switching valve unit 69 are non-rotating and stationary.

  When the maintenance motor 71 is rotated forward (clockwise), the suction pump 68 is not rotated. Instead, the switching member 110 of the switching valve unit 69 is rotated forward (clockwise) and the rotating cam body 74 is rotated. Rotates counterclockwise. In the following description, operations that can be performed in accordance with the rotation of the rotating cam body 74 will be described in order. However, it is not always necessary to perform all the operations continuously with the rotation of the rotating cam body 74, and maintenance can be performed. Only predetermined operations are selectively performed as needed.

  FIG. 23 is an explanatory diagram showing the rotation phase position of the switching member 110 and the communication and non-communication states with respect to the ports A, B, W, and F during each operation. FIG. 24 shows an air venting operation (elevating operation of the elevating body 66 which is the valve operating means) and a cap operation (elevating operation of the support block 75 of the cap members 64a and 64b in the recovery means) accompanying the rotation of the rotating cam body 74. 4 is a timing chart showing the lifting and lowering operation of the wiper 65. In FIG. 24, the high (ON) position of cam number 1 is set to ON1, the subsequent low (OFF) position is set to OFF1, and the other cam numbers are similarly marked and described.

  When there is no print command for the recording head 34 and no operation command for the maintenance unit 11, the control device moves the carriage 17 to the standby position at the right end of FIG. Before this, the leaf switch 116 descends from the ridge cam 117e (cam number 5), and the rotation cam body 74 is rotated to a position immediately after being placed on the ridge cam 117a (cam number 1) (FIG. 24, ON1), the translation cam body 96 is moved and set at the position shown in FIG. 10, and the upper surfaces of the sliding contact pins 78 and 99 are brought into contact with the intermediate cam surfaces 102b and 103b. In this state, the carriage 17 is moved to the standby position at the right end of FIG. 2, and the nozzle surface 29 of the recording head 34 and the cap members 64a and 64b are opposed to each other. As a result, an appropriate gap is maintained between the upper surfaces of the cap members 64 a and 64 b and the nozzle surface 29 of the recording head 34, and the release rod 62 and the suction portion 90 in the elevating body 66 and the cylinder block in the bubble removing means 61. A suitably narrow gap is also maintained between the lower surface of 51. In this state, the rotation position of the switching member 110 of the switching valve unit 69 is the phase of the captable position in FIG. 23, and the ports A, B, F and the discharge port 108 are in communication.

  From the above state, the cap members 64a and 64b are brought into intimate contact with the nozzle surface 29 of the recording head 34 to place the recording head 34 in a storage state. For this purpose, the rotating cam body 74 is rotated forward, and the leaf switch 116 is moved from the position (ON1) on the protruding cam 117a (cam number 1) to a position further rotated by 60 °. . In this state, the translation cam body 96 moves in the X2 direction and is set at the position shown in FIG. 19, and the sliding contact pin 78 moves away from the intermediate cam surface 102b and moves to the uppermost cam surface 102c side. The support block 75 moves up. As a result, the upper surfaces of the cap members 64 a and 64 b are in close contact with the nozzle surface 29 of the recording head 34. On the other hand, the upper surface of the sliding contact pin 99 comes into contact with the lowermost cam surface 103a, and the elevating body 66 is lowered to the lowest position (see FIG. 19).

  In this storage state, the cap members 64a and 64b communicate with the discharge port 108 via ports A and B (see the standby position in FIG. 23, ON1 state), and the tube 76d connected to the port F of the switching valve unit 69. Further, since some ink always remains in the tube 105 on the discharge side of the suction pump 68, the nozzle surface 29 can be sealed with the cap members 64a and 64b to prevent the nozzle from drying. Further, since the port F communicates with the atmospheric pressure, the cap members 64a and 64b are also in an almost atmospheric pressure state.

  The position rotated by 60 ° from (ON1) can be arranged, for example, by rotating the maintenance motor 71 made of a stepping motor from (ON1) by a predetermined number of steps (887 steps).

  When the control device issues a print operation command to the recording head 34, the maintenance motor 71 is continuously rotated in the forward direction to rotate the rotating cam body 74 to the position of ON4 in FIG. (Omitted) Again, from the state where gaps are formed between the cap members 64a and 64b and the nozzle surface 29 and between the elevating body 66 and the cylinder block 51, the carriage is moved from the standby position to the left in FIG. That is, it is moved to the printing position.

  When the control device outputs a recovery process command to the recording head 34, when the recording head 34 is not in the standby position, first, as described above, the maintenance motor 71 is rotated forward to switch the rotating cam body 74. 116 is rotated to a position immediately after being placed on the ON1, and the recording head 34 is further moved to the standby position. From this state, the maintenance motor 71 is rotated forward, and the cap members 64a and 64b are brought into close contact with the recording head 34 in the same manner as in the storage state. Further, the rotating cam body 74 is moved to a position (OFF1) where the leaf switch 116 descends from the ridge cam 117a (cam number 1). At the same time, the switching member 110 of the switching valve unit 69 is rotated to a position where none of the ports A, B, W, F communicates with the atmosphere (external) (refer to BC negative pressure storage, OFF1 in FIG. 23). In this state, by rotating the maintenance motor 71 in reverse and operating the suction pump 68 (see FIG. 25), a negative pressure is once applied to the tube 107 in order to suck ink from the nozzles of black ink and cyan ink. Save up. Next, when the maintenance motor 71 is rotated forward and the leaf switch 116 reaches the position (ON2) where the leaf switch 116 is placed on the ridge cam 117b (cam number 2), the port A and the groove 112a communicate with each other, and the above-described negative pressure is stored. As a result, ink is sucked from the nozzles of black ink and cyan ink through the cap member 64a (refer to BC suction, ON2 in FIG. 23). The air pump (positive pressure pump) 28 is operated with a slight delay from the start of the operation of the suction pump 68 to apply positive pressure to the ink in the buffer tank 36 through the ink cartridge 7.

  Next, when the rotating cam body 74 rotates to the position (OFF2) where the leaf switch 116 descends from the ridge cam 117b (cam number 2), the switching member 110 of the switching valve unit 69 is connected to any of the ports A and B. , W, F also rotate to a position that does not communicate with the atmosphere (outside) (see OFF2 in FIGS. 24 and 23). In the same manner as described above, the negative pressure storage for sucking the magenta ink and the yellow ink is performed by operating the suction pump 68 by rotating the motor 71 in the reverse direction. Next, when the maintenance motor 71 is rotated forward and the leaf switch 116 reaches the position (ON3) where the leaf switch 116 is placed on the ridge cam 117c (cam number 3) (see FIG. 24), the port B and the groove 112b communicate with each other. The negative pressure causes the ink to be sucked from the nozzles of magenta ink and yellow ink through the cap member 64b (see YM suction, ON3 in FIG. 23). At this time, the air pump 28 is operated in the same manner as described above to apply a positive pressure to the ink in the buffer tank 36.

  When the suction recovery operation is performed for only one set of the black ink and the cyan ink or the set of the magenta ink and the yellow ink, the motor 71 is reversed at the position of the cam number corresponding to the other set. By driving the suction pump 68 without rotating it, the driving of the suction pump 68 is omitted.

  After the completion of the ink suction operation, the parallel cam member 96 is moved in the X1 direction and returned toward the position of FIG. The support block 75 is lowered so as to move away from the nozzle surface 29.

  The operation of the air pump 28 described above is continued until the cap members 64 a and 64 b are separated from the nozzle surface 29. This is because the ink in the cap member is bubbled at the end of the ink suction operation, and the bubble may enter the nozzle due to back pressure acting on the ink in the nozzle 33. By the operation 28, a positive pressure is applied to the ink in the nozzle 33 to prevent bubbles from entering. The operations of the air pump 28 and the suction pump 68 do not need to be performed in parallel, and the operation of the air pump 28 is performed from immediately before the cap members 64a and 64b are separated from the nozzle surface 29 after the suction pump 68 is stopped. You may do it. The positive pressure applied to the ink in the nozzle 33 by the air pump 28 is such a magnitude that the ink does not leak from the nozzle.

  At the time when the carriage 17 starts to move due to the wiping operation by the next wiper, as shown in FIG. 10, the sliding contact pins 78 and 99 on the cap members 64a and 64b and the lifting body 66 are moved to the intermediate cam surface 102b. , 103b, the rotating cam body 74 is rotated to a position where it comes into contact.

  When the rotary cam body 74 rotates 35 degrees from the position where the leaf switch 116 descends from the ridge cam 117b (cam number 3) (OFF3), the switching member 110 of the switching valve unit 69 has any port A, B, W. , F also rotate to a position not communicating with the atmosphere (external) (wipe position in FIG. 23). On the other hand, the wiper 65 has already been lifted from the OFF1 position and protrudes into the movement locus of the nozzle surface 29. In this state, the carriage 7 is moved in the left direction in FIG. 2 to bring the nozzle surface 29 into sliding contact with the wiper 65 and wipe the ink adhering to the nozzle surface 29.

  Thereafter, the carriage 17 is moved to a position where the recording head does not face the cap member 64a, for example, a position facing the ink receiving portion 8 at the left end, and the maintenance motor 71 is continuously rotated forward to rotate. The cam body 74 is continuously rotated counterclockwise and stopped again at the ON2 position. In this state, the motor 71 is rotated reversely to operate the suction pump 68. Accordingly, so-called cap empty suction (see the cap empty suction portion in FIG. 25) can be performed, and ink remaining in the cap member 64a can be removed. Subsequently, the operation is stopped at the ON3, and the cap member 64b is similarly idled.

  Further, after the cap empty suction, the rotating cam body 74 is stopped at the OFF4 position, and the groove 113c of the switching valve unit 69 is communicated with the port F (atmospheric communication suction in FIG. 23). That is, the ink remaining in the switching valve unit 69 or the like is sucked by rotating the suction pump 68 by rotating the motor 71 in the reverse direction with the tube 76d open to the atmosphere communicating with the suction pump 68. .

  Then, the carriage 17 located at the left end position in FIG. 2 is directed to the printing operation.

  When the control device outputs a command for removing bubbles (air) from the bubble storage chambers 40a to 40d, when the carriage 17 is not in the right end standby position, the rotating cam body 74 is first placed on the ON1 as described above. The carriage 17 is rotated to the position immediately after it, and the carriage 17 is moved to the rightmost standby position. Then, the motor 71 is continuously rotated in the forward direction to continuously rotate the rotating cam body 74 to the position of ON5. Before reaching this position, the parallel moving cam body 96 is moved in the X1 direction at the position from ON4 to OFF4, and the sliding contact pin 78 is moved from the intermediate cam surface 102b to the lowermost cam surface 102a side, thereby supporting the block 7 , The sliding contact pin 99 is moved from the intermediate cam surface 103 b to the uppermost cam surface 103 c side, and the elevating body 66 is raised by the biasing spring 100. Thereby, all the release rods 62 on the lift body 66 push up all the valve rods 56, the valve bodies 55, and the packings 57 in the on-off valve means 41 to open the valves. Also, each suction portion 90 is in close contact with the lower end opening of each small-diameter passage 51b, and all the bubble storage chambers 40a to 40d are suction passages 47a to 47d, an outlet portion 54, a passage cylinder 52, a passage hole 51, a suction portion 90, It communicates with the port W of the switching valve unit 69 through the passage 92, the discharge cylinder 93, and the tube 76c (see FIGS. 20 and 9). The air pump 28 starts to operate from the position of ON4 where the elevating body 66 starts to rise, applies a positive pressure to the ink in the ink cartridges 7a to 7d, and passes through the ink needle 26 and the ink supply tubes 27a to 27d. Although the pressure in the bubble storage chambers 40a to 40d is increased, since the port W of the switching valve unit 69 is closed (OFF4 in FIG. 24), the bubbles are not discharged.

  When the port W and the groove 112c communicate with the switching member 110 of the switching valve unit 69 at the position of ON5 of the rotating cam body 74 (buffer suction in FIG. 23), each bubble is caused by the pressure of the operation of the air pump 28 described above. The ink liquid level in the storage chambers 40a to 40d is pushed up, and the air (bubbles) accumulated above the storage chambers 40a to 40d is discharged through the communicating passage. In this case, the rotational speed of the drive motor 30 is increased and the positive pressure by the air pump 28 is increased compared to the case where the air pump 28 is operated during the above-described suction operation. However, in this case as well, the positive pressure is large enough to prevent ink from leaking from the nozzles.

  Since a small amount of ink leaks along with the bubbles (air) when the bubbles are discharged, the maintenance motor 71 is rotated reversely and a plurality of times in order to suck the ink, and the suction pump 68 is intermittently turned on. (See the exhaust air suction portion in FIG. 25). As a result, a small amount of ink leaked together with bubbles (air) is sucked from the dish-shaped suction portion 90, the suction port 91, the passage 92, the discharge cylinder 93, the tube 76c, the port W, the suction around the proximal end portion of the release rod 62. It is discharged to the waste liquid form 111 through the pump 68. The reason why the ink is intermittently driven is that, unlike the empty suction of the cap, the amount of ink leaked together with the bubbles (air) is small, so that it is not necessary to continuously suck. In this case, the operation time (t4) of the air pump 28 may be changed according to the environmental temperature, and the number of intermittent operations of the suction pump 68 may be changed accordingly, or they may be set constant.

Thereafter, similarly to the recovery operation by suction described above, the rotation cam body 74 is rotated from the OFF1 position to the ON3 position, the recovery operation by suction is continued, the carriage is moved, and the wiper operation by the wiper is performed. Then, the rotating cam body 74 is rotated to the ON2 position, and the cap empty suction and the residual ink in the switching valve unit 68 are sucked. The suction recovery operation after the bubble (air) removing operation may be omitted.
Needless to say, the present invention can be applied to various types of inkjet printers.

It is a perspective view of an inkjet printer. It is a top view of a printing mechanism part. It is a top view of a main body frame. FIG. 4 is a schematic plan view of a cartridge mounting unit and an ink supply unit. FIG. 5 is a side sectional view taken along line VV in FIG. 2. (A) is a top view of the carriage which mounts a buffer tank etc., (b) is a VIb-VIb arrow directional cross-sectional view of Fig.6 (a). It is a top view which shows the suction path of a buffer tank upper surface. FIG. 13 is a side view of the carriage and the maintenance unit shown in FIG. It is a schematic cross section of the means for removing the air in the bubble storage chamber. It is a side view which shows the position of the carriage in a waiting state, a parallel movement cam body, a recovery means, and a bubble removal means. (A) is the principal part expanded sectional view of the on-off valve means of a closed state, (b) is the principal part expanded sectional view of the on-off valve means of an open state. It is a top view of a maintenance unit. It is a perspective view of a maintenance unit. It is a principal part enlarged plan view which shows the arrangement | positioning part of a translation cam body. It is a perspective view which shows the unit stand in a maintenance unit, a parallel movement cam body support block, and a raising / lowering body. (A) is a front view of a raising / lowering body, (b) is a top view, (c) is a left view. (A) is sectional drawing of a raising / lowering body, (b) is XVIIb-XVIIb arrow sectional drawing of Fig.17 (a). It is a figure which shows the shape of the cam groove and protrusion cam seen from the upper surface of the rotation cam body. It is a side view which shows the position of the carriage in a holding | maintenance state, a translation cam body, a recovery means, and a bubble removal means. It is a side view which shows the position of the carriage, the translation cam body, the recovery means, and the bubble removal means in the state in which the air is extracted from the buffer tank. (A) is a perspective view of a switching valve unit, (b) is a perspective view of a switching member. It is a schematic diagram which shows the tube connection relationship of a switching valve unit, a recovery means, and a bubble removal means. It is explanatory drawing which shows the rotational phase relationship of the switching member in each operation position in a switching valve unit. It is a time chart of each operation | movement according to the rotation angle of a rotation cam body. It is a time chart which shows operation | movement of an air pump, a suction pump, a release rod, and a cap member.

Explanation of symbols

17 Carriage 29 Nozzle surface 34 Recording head 36 Buffer tank 40a-40d Bubble storage chamber 41 Opening / closing valve means 47 Suction passage as bubble ovule passage 55 Valve body 56 Valve rod 57 Packing 61 Bubble removal means 63 Recovery means 62 Release rods 64a, 64b Cap member 66 Elevating body 74 Rotating cam body 74a Cam groove 75 Support block 78, 99 Sliding contact pin as cam follower 80 Guide groove 96 Parallel moving cam body 101 Horizontal guide piece 102, 103 Cam surface 104 Pin

Claims (8)

A carriage equipped with a recording head for ejecting ink from a nozzle to record on a recording medium, an ink tank for storing ink supplied to the recording head, and an ink flow for supplying ink from the ink tank to the recording head Ink jet printer with a road,
On the carriage, a buffer tank having a bubble storage chamber for storing bubbles generated in the ink flow path upward is disposed between the ink flow path and the recording head.
A bubble discharge passage communicating with the bubble storage chamber is provided in the ceiling wall of the buffer tank,
An ink jet printer characterized in that the carriage is provided with on-off valve means for opening and closing the bubble discharge passage.   2. The ink jet printer according to claim 1, further comprising valve operating means for opening the on-off valve means at a position outside the carriage when the carriage is at a predetermined movement position.   3. The ink jet printer according to claim 1, wherein the bubble discharge passage communicates with the bubble storage chamber below an inner surface of a ceiling wall of the buffer tank.   4. The bubble discharge passage is constituted by a groove formed in a recess on the upper surface of the ceiling wall of the buffer tank and a synthetic resin film bonded and fixed to the upper surface of the ceiling wall. The inkjet printer described in 1.   The recording head has a nozzle row for each of a plurality of colors of ink, and the bubble storage chamber is provided for each of a plurality of colors of ink, and each of the colors formed on the upper surface of the ceiling wall of the buffer tank 5. The ink jet printer according to claim 1, wherein the length of the bubble discharge passage for each ink is set to be substantially the same. The recording head has a nozzle row for each of a plurality of colors of ink, and the bubble storage chamber and the bubble discharge passage are provided for each of a plurality of colors of ink,
6. The ink jet printer according to claim 1, wherein each end of the plurality of bubble discharge passages on the side opposite to the bubble storage chamber is positioned side by side on one side of the carriage.   The on-off valve means has a passage hole connected to an end portion of the bubble discharge passage opposite to the bubble storage chamber, an end portion of the passage hole opposite to the bubble discharge passage, the nozzle, The ink jet printer according to claim 1, wherein the opening directions thereof are parallel to each other.   The on-off valve means has a valve body that can move up and down along one side of the buffer tank, and a lower end of a valve rod connected to the valve body is exposed at an opening end of the passage hole. An ink jet printer according to claim 7.