Liquid ejection apparatus

A liquid ejection apparatus includes a recording unit which ejects liquid to record an image, a tank having a storage chamber which stores liquid for the recording unit and a communication port which allows the liquid storage chamber to communicate with atmosphere, a first housing, and a second housing which holds the recording unit and the tank and is rotatable about an axis line relative to the first housing between a close position where the recording unit comes close to the first housing and a separate position where the recording unit is separated from the first housing. An upper surface of the storage chamber has two regions divided by an imaginary plane to have same area, which is parallel with the axis line and intersects with the upper surface, and the communication port is provided in a region of the two regions, which is away from the axis line.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2011-218716, filed on Sep. 30, 2011, the entire subject matter of which is incorporated herein by reference.

TECHNICAL FIELD

Aspects of the present invention relate to a liquid ejection apparatus having a liquid ejection head which ejects liquid from an ejection port.

BACKGROUND

There has been known an inkjet printer including: an upper housing having a recording head which ejects ink on a sheet and thus records an image on the sheet, and a sub-tank which supplies ink to the recording head; and a lower housing having a sheet conveyance mechanism. In the inkjet printer, the upper housing is provided rotatably with respect to the lower housing so as to easily perform a maintenance operation.

In some cases, the sub-tank is formed with an atmosphere communication port which allows a liquid storage chamber storing the liquid and the atmosphere to communicate with each other so as to stabilize an ink meniscus formed in an ejection port. In this case, when rotating the upper housing, the sub-tank is inclined, so that the stored ink might be leaked to the outside through the atmosphere communication port. The ink leaked to the outside cannot be used to form an image, so that the ink is wasted.

SUMMARY

Accordingly, it is an aspect of the present invention to provide a liquid ejection apparatus capable of preventing liquid from being leaked to an outside even when a tank which stores liquid to be supplied to a recording head is inclined.

According to an illustrative embodiment of the present invention, there is provided a liquid ejection apparatus including a support unit, a recording unit, a tank, a first housing, and a second housing. The support unit is configured to support a recording medium. The recording unit has an ejection port for ejecting liquid to record an image on the recording medium supported on the support unit. The tank includes a liquid storage chamber configured to store liquid to be supplied to the recording unit, and an atmosphere communication port configured to allow the liquid storage chamber and atmosphere to communicate with each other. The first housing is configured to hold the support unit. The second housing is configured to hold the recording unit and the tank. The second housing is configured to be rotatable about a predetermined axis line with respect to the first housing to be moved between a close position where the recording unit comes close to the first housing and faces the support unit and a separate position where the recording unit is separated from the first housing than the close position. An upper surface of the liquid storage chamber includes two regions divided by a first imaginary plane to have same area, which is parallel with the axis line and intersects with the upper surface, and the atmosphere communication port is provided in a region of the two regions, which is away from the axis line.

According to the above configuration, the upper surface of the liquid storage chamber includes two regions divided by the first imaginary plane to have same area, which is parallel with the axis line and intersects with the upper surface, and the atmosphere communication port is located in a region of the two regions, which is away from the axis line. Therefore, even though the tank is inclined when the second housing is moved from the close position to the separate position, it is possible to suppress a liquid level of the liquid stored in the liquid storage chamber from contacting the atmosphere communication port. Thereby, it is possible to prevent the liquid stored in the tank from being leaked to the outside.

DETAILED DESCRIPTION

First, an overall configuration of an inkjet printer1(an example of a liquid ejection apparatus) is described with reference toFIGS. 1 to 3.

The printer1has an upper housing (second housing)1aand a lower housing (first housing)1b, both of which have a rectangular parallelepiped shape and the substantially same size. The upper housing1ahas an opened lower surface and the lower housing1bhas an opened upper surface. The upper housing1ahas a frame1a1and an outer cover1a2which covers an outer side of the frame1a1. The lower housing1balso has a frame1b1and an outer cover1b2which covers an outer side of the frame1b1. The upper housing1aoverlaps with the lower housing1band the opened surfaces thereof match each other, so that an interior space of the printer1is defined (refer toFIG. 2). An upper part of a top plate of the upper housing1ais provided with a sheet discharge part31. A sheet conveyance path in which a sheet P is conveyed from a feeder unit1c(which will be described later) toward the sheet discharge part31along a thick arrow shown inFIG. 2is formed in the space defined by the upper and lower housings1a,1b.

As shown inFIGS. 2 and 3, the upper housing1ais coupled to the lower housing1bvia a shaft1hwhich extends in a main scanning direction at a substantial center (in a vertical direction) of one end portion (right end portion in the drawings) of the upper housing1ain a sub-scanning direction. The upper housing1ais rotatable with respect to the lower housing1babout the shaft1h. The upper housing1ais rotated to be moved between a close position (a position shown inFIG. 2and a position shown with the solid line inFIG. 3) which is close to the lower housing1band a separate position (a position shown with the dashed-two dotted line inFIG. 3) which is separated away from the lower housing1bthan that of the close position. When the upper housing1ais located at the separate position, a part of the sheet conveyance path, which is formed by the upper housing1ain the close position and the lower housing1b, is exposed to the outside, so that a user's operation space is provided in the sheet conveyance path. When the upper housing1ais located at the separate position and the operation space is thus provided, the user can remove a jammed sheet P in the sheet conveyance path or perform a maintenance operation on a recording unit9or a support unit60. The maintenance operation of the recording unit9or the support unit60is an operation of removing foreign matters attached on an ejection surface10a, a support surface61aand a facing surface62a, for example. The shaft1his provided with a spring (not shown) which urges the upper housing1ain an opening direction (from the close position toward the separate position). In this illustrative embodiment, the upper housing1acan be opened up to an inclination angle of about 35 degrees with respect to a horizontal surface. In the meantime, in the printer1, a left surface ofFIG. 3is a front face and an opposite surface to the front surface is a rear face.

The upper housing1aaccommodates therein two heads10(a pre-coat head10which ejects pre-processing liquid and an inkjet head10which ejects black ink, in order from an upstream side of the sheet conveyance direction shown with the thick arrow inFIG. 2), a frame3which supports the two heads10and an upper roller of a pair of conveyance rollers24, a head lifting mechanism (not shown) which lifts the frame3up and down along a vertical direction, two cartridges (not shown) corresponding to the heads10and a controller1pwhich controls operations of respective units of the printer1. In this illustrative embodiment, the two heads10and frame3configure the recording unit9which records an image on the sheet P. The recording unit9is held at the upper housing1avia the head lifting mechanism.

Also, the upper housing1aaccommodates therein upper rollers of conveyance roller pairs25,26, an upper guide of guides29between the roller pairs25,26, conveyance roller pairs27,28and two sets of guides29between the conveyance roller pairs26,28along the sheet conveyance direction. That is, when the upper housing1ais rotated from the close position to the separate position, all the above accommodated parts are moved together with the upper housing1a.

The lower housing1baccommodates (holds) the support unit60, a wiper unit, two waste liquid trays65and the feeder unit1c. Further, the lower housing1balso accommodates therein a sheet sensor32, conveyance roller pairs22,23and two sets of guides29between the feeder unit1cand the pair of conveyance rollers23along the sheet conveyance direction.

Each cartridge stores the pre-processing liquid or black ink (hereinafter, collectively referred to as ‘liquid’) which is supplied to the corresponding head10via a liquid supply mechanism (not shown). The pre-processing liquid is liquid having a function of preventing the ink from bleeding or exuding back, a function of improving color expression property or quick-drying of the ink and the like. The respective cartridges are connected to the heads10via sub-tanks51a,51b. The sub-tanks51a,51bare provided to form a negative pressure in flow paths of the heads10so as to stabilize menisci formed in ejection ports of the heads10when recording an image. The liquids in the sub-tanks51a,51bare automatically supplied to the heads10.

Each head10is a line type which is long in the main scanning direction and has a substantially rectangular parallelepiped shape. The two heads10are separated from each other in the sub-scanning direction and are supported to the frame3. The respective heads10are provided on upper surfaces thereof with joints, to which other ends of tubes (not shown) having one ends connected to the sub-tanks51a,51bare attached, and on lower ejection surfaces10awith a plurality of opened ejection ports, and are formed therein with flow paths along which the liquids supplied from the sub-tanks51a,51breach the ejection ports. The frame3is provided with annular members40each of which surrounds a lower end periphery of each head10.

The head lifting mechanism lifts the frame3up and down in the vertical direction when the upper housing1ais located at the close position, thereby moving the two heads10between a recording position and a retraction position. At the recording position, the two heads10face the support unit10at an interval which is appropriate for recording. Under control of the controller1p, the head lifting mechanism is controlled such that the heads10are provided at the appropriate recording position, depending on types of the sheet P.

The feeder unit1chas a sheet feeding tray20and a sheet feeding roller21. The sheet feeding tray20is detachably mounted to the lower housing1bin the sub-scanning direction. The sheet feeding tray20is a box which is opened upward and can accommodate therein sheets P having various sizes. The sheet feeding roller21is rotated under control of the controller1pand feeds the uppermost sheet P in the sheet feeding tray20. The sheet P fed by the sheet feeding roller21is guided by the guides29, sequentially held by the conveyance roller pairs22,23and then sent to the support unit60.

The support unit60is provided to face the recording unit9in the vertical direction. The support unit60has two rotary members63which face the heads10, respectively, two platens61and two facing members (facing parts)62which are fixed on circumferential surfaces of the rotary members63and a frame11which rotatably supports the two rotary members63. The rotary member63has a shaft in the main scanning direction and is rotated about the shaft under control of the controller1p. Also, the frame11rotatably supports the lower conveyance roller24.

The platen61and the facing member62have larger sizes than the ejection surface10ain the main scanning direction and in the sub-scanning direction, and are provided to face each other in the vertical direction.

The platen61has a support surface61awhich faces the ejection surface10aand supports the sheet P and is made by material and processed to keep the sheet P. For example, a weak adhesive silicon layer is formed or a plurality of ribs is formed on the support surface61aalong the sub-scanning direction, so that the sheet P put on the support surface61ais prevented from floating. The platen61is made of resin.

As shown inFIGS. 4A and 4B, an atmosphere communication mechanism is fixed to the upper housing1a. The atmosphere communication mechanism includes the sub-tanks51a,51bhaving liquid storage chambers71, communication tubes52a,52b, a buffer tank54and communication tubes56a,56b. The sub-tanks51a,51bare provided in the vicinity of the left side surface of the upper housing1a(refer toFIG. 6). The sub-tanks51a,51bhave the liquid storage chambers71. The liquid storage chambers71have atmosphere communication ports72which allow the interior spaces thereof and the atmosphere to communicate with each other. The liquid storage chamber71of the sub-tank51astores black ink, and the liquid storage chamber71of the sub-tank51bstores the pre-processing liquid. The liquids stored in the sub-tanks51a,51bare supplied to the heads10. Specifically, the controller (an example of a storage amount control unit)1pcontrols a pump such that the liquids are introduced into the liquid storage chambers71from the cartridges until liquid levels, which are detected by liquid-level sensors (not shown) provided to the sub-tanks51a,51b, reach predetermined positions. A storage amount of the liquid storage chamber71becomes a maximum when the liquid level reaches the predetermined position. In the meantime, the controller1pmay perform control of opening and closing valves which are provided in liquid introduction paths of the liquid supply mechanism from the cartridges to the liquid storage chambers71.

As shown inFIG. 5, when dividing an upper surface of the liquid storage chamber71into two regions having the same area by an imaginary plane X which is parallel with the shaft1h(axis line), i.e., the main scanning direction and intersects with the upper surface, the atmosphere communication port72is located in one region of the two regions, which is away from the shaft1h. In other words, the upper surface of the liquid storage chamber71includes two regions divided by the imaginary plane X to have same area, and the atmosphere communication port72is located in one region of the two regions, which is away from the shaft1h. Also, when further dividing the region into two sections having the same area by an imaginary plane Y which is parallel with the sub-scanning direction and intersects with the upper surface, the atmosphere communication port72is located in one section of the two sections, which is closer to the buffer tank54(refer toFIG. 6). In other words, the region in the upper surface, which includes the atmosphere communication port, includes two sections divided by the imaginary plane Y to have same area, and the atmosphere communication port72is located in one section of the two sections, which is closer to the buffer tank54. Further, the atmosphere communication port72is provided such that the stored liquid does not reach the port even though the sub-tanks51a,51bare inclined when the upper housing1ais rotated from the close position about the shaft1hby a maximum amount in a case where a liquid storage amount in the liquid storage chamber71is a predetermined amount which is the maximum storage amount. Accordingly, the liquid which is stored in the liquid storage chamber71is not leaked from the atmosphere communication port72.

The buffer tank (liquid holding chamber)54is provided at an upper position than the sub-tanks51a,51bat the time when the upper housing1ais provided at the close position and has a pair of discharge flow paths which accommodate a sponge (absorption member)75for holding the liquid. The buffer tank54is connected with joints53,55. An upstream port (not shown) is formed at a boundary between the joint53and the buffer tank54and a downstream port (not shown) is formed between the joint55and the buffer tank54. The upstream port and downstream port are configured such that the upstream port of each discharge flow path is located at an upper position than the downstream port thereof by the joints53,55when the upper housing1ais located at the close position. At this time, the joints53,55, i.e., the upstream port and the downstream ports are located above the sponge75. Also, a part of each discharge flow path, in which the sponge75is provided, has a larger flow path sectional area than the surrounding area thereof.

The atmosphere communication ports72of the respective sub-tanks51a,51bare connected with one ends of the communication tubes52a,52b, respectively. The other ends of the communication tubes52a,52bare connected to the joint53. The joint55is connected with one ends of the communication tubes56a,56b, respectively. The communication tubes56a,56bextend in a downward direction which is a direction separating away from the atmosphere communication ports72and valves57a,57bare respectively connected to end portions thereof. In the meantime, flow path sectional areas of the communication tubes52a,52bare larger than those of the communication tubes56a,56b, as depicted inFIG. 11.

As shown inFIGS. 6 and 7, in the state where the upper housing1ais provided at the close position, the communication tubes52a,52bextend upward from the atmosphere communication ports72, are bent at a right angle and extend in a direction coming close to the shaft1hsuch that the communication tubes have components orthogonal to the shaft1has separating away from the atmosphere communication ports72. Also, the communication tubes52a,52bextend to have components parallel with the shaft1h, are bent at a right angle, extend upward and are then connected to the joint53.

That is, the communication tube52a, one discharge flow path of the buffer tank54and the communication tube56aconfigure an atmosphere communication flow path which allows the liquid storage chamber71and the atmosphere to communicate with each other via the atmosphere communication port72of the sub-tank51a. And, the communication tube52b, the other discharge flow path of the buffer tank54and the communication tube56bconfigure an atmosphere communication flow path which allows the liquid storage chamber71and the atmosphere to communicate with each other via the atmosphere communication port72of the sub-tank51b. Thereby, when the valves57a,57bare opened, the interiors of the liquid storage chambers71are made to be atmospheric pressure, so that the liquid supply to the heads10can be stabilized. In the meantime, when the printer1is under non-use state, the valves57a,57bare closed to prevent the liquids from being dried.

In the below, the liquid state stored in the sub-tanks51a,51bwhen the printer1is turned over is described.FIG. 8Ashows a state where the printer1is turned by 90° such that the left side surface becomes the bottom andFIG. 8Bshows a state where the printer1is turned by 90° such that the right side surface becomes the bottom.FIG. 9Ashows a state where the printer1is turned by 90° such that the front face becomes the bottom andFIG. 9Bshows a state where the printer1is turned by 90° such that the rear face becomes the bottom.FIG. 10shows a state where the printer1is turned over by 180°.

As shown inFIG. 8A, when the printer1is turned by 90° such that the shaft1hbecomes vertical and the left side surface becomes the bottom, the liquids which are stored in the liquid storage chambers71of the sub-tanks51a,51bare moved in the direction separating away from the atmosphere communication ports72. Accordingly, the stored liquids are not leaked from the atmosphere communication ports72.

As shown inFIG. 8B, when the printer1is turned by 90° such that the shaft1hbecomes vertical and the right side surface becomes the bottom, the liquids which are stored in the liquid storage chambers71of the sub-tanks51a,51bare moved in the direction coming close to the atmosphere communication ports72. Accordingly, the liquids flow from the atmosphere communication ports72to the communication tubes52a,52b. At this time, the liquids having flown into the communication tubes52a,52bare stopped at positions of the parts extending in the upper-lower direction of the communication tubes52a,52binFIG. 8Bat heights which are flush with the liquid levels in the liquid storage chambers71.

As shown inFIG. 9A, when the printer1is turned by 90° such that the shaft1his kept horizontal and the front face becomes the bottom, the liquids which are stored in the liquid storage chambers71of the sub-tanks51a,51bare moved in the direction coming close to the atmosphere communication ports72. Accordingly, the liquids flow from the atmosphere communication ports72to the communication tubes52a,52b. At this time, the liquids having flown into the communication tubes52a,52bare stopped at positions of the parts (the components which are orthogonal to the shaft1has separating away from the atmosphere communication ports72) extending in the upper-lower direction of the communication tubes52a,52binFIG. 9Aat heights which are flush with the liquid levels in the liquid storage chambers71.

As shown inFIG. 9B, when the printer1is turned by 90° such that the shaft1his kept horizontal and the rear face becomes the bottom, the liquids which are stored in the liquid storage chambers71of the sub-tanks51a,51bare moved in the direction separating away from the atmosphere communication ports72. Accordingly, the stored liquids are not leaked from the atmosphere communication ports72.

As shown inFIG. 10, when the printer1is turned over by 180°, the liquids which are stored in the liquid storage chambers71of the sub-tanks51a,51bare moved in the direction coming close to the atmosphere communication ports72. Accordingly, the liquids flow from the atmosphere communication ports72to the communication tubes52a,52b. At this time, the liquids having flown into the communication tubes52a,52bpass through the buffer tank54and are stopped at the positions of the parts extending in the upper-lower direction of the communication tubes56a,56binFIG. 10at heights which are flush with the liquid levels in the liquid storage chambers71.

As described above, according to the printer1of the present illustrative embodiment, the upper surface of the liquid storage chamber71includes two regions divided by the imaginary plane X to have same area, which is parallel with the shaft1hand intersects with the upper surface, and the atmosphere communication port72is located in one region of the two regions, which is away from the shaft1h. Therefore, when the upper housing1ais rotated from the close position about the shaft1hby a maximum amount, even though the sub-tanks51a,51bare inclined, it is possible to suppress the liquid levels of the liquids stored in the liquid storage chambers71from contacting the atmosphere communication ports72. In other words, the atmosphere communication ports72are located in the region of the two regions, which is away from the shaft1h, so that it is possible to store the liquids in the liquid storage chambers71as much as possible without leaking the liquids from the atmosphere communication ports72, compared to a configuration where the atmosphere communication ports72are located in the region of the two regions, which is close to the shaft1h. Also, even when the printer1is turned over such that the shaft1his kept horizontal and the rear face becomes the bottom, it is possible to suppress the liquid levels of the liquids, which are stored in the liquid storage chambers71, from contacting the atmosphere communication ports72. Thereby, it is possible to prevent the liquids, which are stored in the sub-tanks51a,51b, from being leaked to the outside.

Also, the atmosphere communication port72is provided such that the stored liquid does not reach the port even though the sub-tanks51a,51bare inclined when the upper housing1ais rotated from the close position about the shaft1hby a maximum amount in a case where a liquid storage amount in the liquid storage chamber71is a predetermined amount. Thereby, it is possible to prevent the liquid from being leaked to the outside even at a state where there is a high possibility that the liquid will be leaked from the atmosphere communication port72.

Also, the sub-tanks51a,51bare connected with the atmosphere communication flow paths which allow the liquid storage chambers71and the atmosphere to communicate to each other via the atmosphere communication ports72. Accordingly, the liquid which is leaked from the atmosphere communication ports72flow into the atmosphere communication flow paths, so that it is possible to further prevent the liquid stored in the sub-tanks51a,51bfrom being leaked to the outside.

At this time, the flow path sectional areas of the communication tubes52a,52blocated at the upstream side are larger than those of the communication tubes56a,56blocated at the downstream side. Accordingly, the parts close to the atmosphere communication ports72have the relatively large sectional areas, so that it is possible to prevent the blockade due to liquid attachment, foreign matters and the like. Also, the parts, which are distant from the atmosphere communication ports72, have the relatively small sectional areas, so that it is possible to prevent the liquid from being leaked to the outside.

Also, since the communication tubes52a,52bare bent, it is possible to effectively prevent the liquids stored in the sub-tanks51a,51bfrom being leaked to the outside.

Furthermore, at the state where the upper housing1ais provided at the close position, the communication tubes52a,52bextend in the direction coming close to the shaft1hsuch that the communication tubes have components orthogonal to the shaft1has separating away from the atmosphere communication ports72. Therefore, even though the printer1is turned over such that the shaft1his kept horizontal and the front face becomes the bottom, the liquids are stopped at those components. Thereby, it is possible to more effectively prevent the liquids stored in the sub-tanks51a,51bfrom being leaked to the outside.

Furthermore, the atmosphere communication ports72are located in one section of the two sections dividing the region, which is close to the buffer tank54. The communication tubes52a,52bhave the parts which extend from one section toward the other section such that the communication tubes have components parallel with the shaft1has separating away from the atmosphere communication ports72. Therefore, when the printer1is turned over, even though the atmosphere communication ports72are located in the relatively lower section (the printer1is turned by 90° such that the shaft1hbecomes vertical and the right side surface becomes the bottom), the liquids are stopped at the parts which are parallel with the shaft1hand extend from one section toward the other section. As a result, it is possible to more effectively prevent the liquids stored in the sub-tanks51a,51bfrom being leaked to the outside. Also, when the atmosphere communication ports72are located in the relatively upper section due to the horizontal turnover (the printer1is turned by 90° such that the shaft1hbecomes vertical and the left side surface becomes the bottom), it is possible to suppress the liquid levels of the liquids stored in the liquid storage chambers from contacting the atmosphere communication ports72.

Also, at the state where the upper housing1ais provided at the close position, the atmosphere communication flow paths have the communication tubes52a,52b, which are located at the upper positions than the sub-tanks51a,51b, and the communication tubes56a,56b, which are directed downward as separating away from the atmosphere communication ports72at the more downstream side than the communication tubes52a,52b. Therefore, even when the printer1is turned upside down, the liquids are stopped at the communication tubes52a,52b. Hence, it is possible to prevent the liquids stored in the sub-tanks51a,51bfrom being leaked to the outside.

Furthermore, when the upper housing1ais provided at the close position, the lower ends of the communication tubes56a,56bare located at the lower position than the sub-tanks51a,51b. Accordingly, when the printer1is turned upside down, it is possible to more securely prevent the liquids stored in the sub-tanks51a,51bfrom being leaked to the outside.

Also, the atmosphere communication flow paths have the buffer tank54. Thereby, the liquids leaked from the sub-tanks51a,51bare kept in the sponge75, so that it is possible to securely prevent the liquids stored in the sub-tanks51a,51bfrom being leaked to the outside.

Furthermore, when the upper housing1ais provided at the close position, the upstream port and downstream port of the buffer tank54are located at the upper position than the sponge75. Therefore, when the printer is turned over by 180°, the liquid is temporarily kept in the space of the buffer tank54close to the upstream port and downstream port. After that, when the printer is returned to the normal position, the liquid can be kept by the sponge54. At this time, the upstream port is located at the upper position than the downstream port. Hence, when the printer is turned over by 180°, since it is difficult for the liquid, which is introduced from the upstream port, to flow out from the downstream port, it is possible to suppress the liquid from being leaked to the outside.

For example, in the above illustrative embodiment, the atmosphere communication port72is provided such that the stored liquid does not reach the port when the upper housing1ais rotated from the close position about the shaft1hby a maximum amount in the case where the liquid storage amount in the liquid storage chamber71is the predetermined amount. However, the stored liquid may reach the atmosphere communication port72when the upper housing1ais rotated by the maximum amount. Also in this case, the liquid which is leaked from the atmosphere communication port72is stopped in the atmosphere communication flow path, so that it is not leaked to the outside.

Further, in the above illustrative embodiment, the sub-tanks51a,51bare connected with the atmosphere communication flow paths which allow the liquid storage chambers71and the atmosphere to communicate with each other via the atmosphere communication ports72. However, the atmosphere communication flow paths may not be provided.

Further, in the above illustrative embodiment, the flow path sectional areas of the communication tubes52a,52blocated at the upstream side are larger than those of the communication tubes56a,56blocated at the downstream side. However, the relation between the flow path sectional areas thereof may be arbitrary.

Further, in the above illustrative embodiment, the communication tubes52a,52bare bent. However, the communication tubes may not be bent.

Further, in the above illustrative embodiment, the communication tubes52a,52bextend in the direction coming close to the shaft1hsuch that communication tubes have the components orthogonal to the shaft1has separating away from the atmosphere communication ports72. However, the communication tubes may not have the components orthogonal to the shaft1h.

Further, in the above illustrative embodiment, the atmosphere communication ports72are located in the section which is close to the buffer tank54and the communication tubes52a,52bextend to have the components parallel with the shaft1has separating away from the atmosphere communication ports72. However, the atmosphere communication ports72may be located in the section which is distant from the buffer tank54and the communication tubes may not have the components parallel with the shaft1h.

Further, in the above illustrative embodiment, the communication tubes52a,52bextend upward from the atmosphere communication ports72, are bent at a right angle, extend in the direction coming close to the shaft1hsuch that the communication tubes have the components orthogonal to the shaft1has separating away from the atmosphere communication ports72and then extend to have the components parallel with the shaft1h. However, the positional relation between the components orthogonal to the shaft1hand the components parallel with the shaft1hmay be reverse.

Further, in the above illustrative embodiment, when the upper housing1ais provided at the close position, the communication tubes52a,52bare located at the upper position than the sub-tanks51a,51band the communication tubes56a,56bat the more downstream side than the communication tubes52a,52bare directed downward as separating away from the atmosphere communication ports72. However, the upstream-side communication tubes may be located at the same position as or at the lower position than the sub-tanks51a,51b. Also, the downstream-side communication tubes may have arbitrary shapes.

Further, in the above illustrative embodiment, the lower ends of the communication tubes56a,56bare located below the sub-tanks51a,51b. However, the lower ends of the communication tubes may be located at the same as or higher height than the sub-tanks51a,51b.

Further, in the above illustrative embodiment, the atmosphere communication flow path has the buffer tank54including the sponge75. However, the sponge75may not be provided in the buffer tank54or the atmosphere communication flow path may not have the buffer tank54.

Further, in the above illustrative embodiment, when the upper housing1ais provided at the close position, the upstream port and downstream port of the buffer tank54are located above than the sponge75. However, the upstream port and downstream port may be disposed at any positions with respect to the sponge75.

The present invention can be applied to any of the line type and the serial type inkjet printer. Also, the present invention can be applied to a facsimile, a copier and the like as well as the printer. Further, the present invention can be applied to a recording apparatus which performs recording by ejecting liquid, other than the ink.