Abstract:
A liquid storage container which is mounted on a carriage of a liquid ejecting apparatus ejecting a liquid while reciprocating the carriage on which an ejecting head is provided and supplies the liquid to the ejecting head includes a liquid storage chamber configured to store the liquid therein, a stirring member has a stirring surface and provided in the liquid storage chamber in a state capable of being swung by the reciprocation of the carriage, a support member that supports the stirring member, and a first buffer member is provided between the support member and the stirring member.

Description:
Priority is claimed under 35 U.S.C. §119 to Japanese Application No. 2011-017645 filed on Jan. 31, 2011 which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid storage container which is applied to a liquid ejecting apparatus ejecting a liquid such as ink and stores the liquid therein. 
     2. Related Art 
     A printing apparatus which prints an image by ejecting ink onto a printing medium is widely used. In the printing apparatus, the image is printed by ejecting the ink from an ejecting head while reciprocating a carriage on which the ejecting head is provided on the printing medium. Moreover, the ejected ink is stored in an exclusive storage container referred to as an ink cartridge and mounted on the carriage. 
     When components (pigments or the like) having a greater specific gravity than a solvent are included in the ink which is stored in the ink cartridge, the components settle by gravity as time passes and variation in concentration of the ink is generated. Therefore, a stirring mechanism of ink is provided in an ink storage chamber of the ink cartridge. For example, the stirring mechanism includes a plate-shaped stirring member which is provided in the ink storage chamber, a supporting member which supports the stirring member in the ink storage chamber, and the like. A notch is provided at one end of the stirring member, and the stirring member is swingably supported by engaging the notch to the supporting member. If the ink cartridge including the ink stirring mechanism is mounted on the carriage, the stirring member is swung by reciprocation of the carriage, and the ink can be stirred by the movement of the stirring member (JP-A-2007-69351). 
     However, when the above-described stirring mechanism of JP-A-2007-69351 is adopted, there is a problem in that noise generated due to stirring of the ink may be very large. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a technology capable of controlling noise generated due to an operation of a stirring member which is provided in an ink cartridge. 
     According to an aspect of the invention, there is provided a liquid storage container which is mounted on a carriage of a liquid ejecting apparatus ejecting a liquid while reciprocating the carriage on which an ejecting head is provided and supplies the liquid to the ejecting head including a liquid storage chamber that stores the liquid therein, a stirring member that is provided in the liquid storage chamber, and a support structure that supports the stirring member in a state where the stirring member can swing, wherein the stirring member is a member which is provided in the liquid storage chamber in a state capable of being swung by the reciprocation of the carriage, and in which a stirring surface, which stirs the liquid in the liquid storage chamber by the swinging at the liquid storage chamber, is formed on at least a portion of the stirring member, and a first buffer member is provided between the supporting structure and the stirring member. 
     According to the liquid storage container of the aspect of the invention, the stirring member swings in the liquid storage chamber by the reciprocation of the carriage if the liquid storage container is mounted on the carriage. In addition, according to the liquid storage container of the aspect of the invention, the first buffer member is provided between the supporting structure which supports the stirring member in the state where the stirring member can swing and the stirring member. 
     Since the liquid in the liquid storage chamber is stirred by the stirring surface if the stirring member swings, a concentration of the liquid in the liquid storage chamber can be uniformly held. In addition, due to the fact that the first buffer member is provided between the supporting structure which supports the stirring member in the state where the stirring member can swing and the stirring member, collision noise, which is generated between the support structure and the stirring member by a vibration of the stirring member with respect to the support structure generated due to the fact that the stirring member collides with the wall surface of the liquid storage chamber, can be decreased. Thereby, the noise according to the operation of the stirring member provided in the liquid storage container is suppressed. 
     In the liquid storage container of the aspect of the invention, first, a hole or a notch may be provided on at least a portion of the stirring member, and the stirring member may be swingably supported in the liquid storage chamber due to the fact that the hole or the notch is engaged to a protrusion which is provided in the liquid storage chamber and is the support structure. In addition, the buffer member may be provided between the hole or the notch of the stirring member and the protrusion which is engaged to the hole or the notch and is the support structure. Moreover, the buffer member may be mounted on the hole or the notch, or on the protrusion, and may be separately mounted on the hole, the notch, or the protrusion. 
     Thereby, since the impact when the hole or notch of the stirring member abuts the protrusion can be absorbed, it is possible to effectively suppress the noise during the stirring of the liquid. In addition, since a liquid stirring mechanism can be assembled by only engaging the hole or the notch of the stirring member to the protrusion, it is possible to stir the liquid in the liquid storage chamber, and the assembly operation of the liquid storage container is not complicated. 
     In addition, in the liquid storage container of the aspect of the invention, a second buffer member may be provided on either of the stirring surface of the stirring member or a surface which faces the stirring surface at an inner surface of the liquid storage chamber. 
     Thereby, an abutting sound, which is generated when the stirring member moves in the direction of stirring the liquid and abuts the liquid storage container, can be also suppressed. As a result, it is possible to further effectively suppress the noise when the liquid is stirred. 
     Moreover, in the liquid storage container of the aspect of the invention, the first buffer member may be provided on an inner edge portion of the hole of the stirring member. Thereby, the noise according to the operation of the stirring member which is provided in the liquid storage container is suppressed. 
     In addition, in the liquid storage container of the aspect of the invention, the first buffer member may be provided at the protrusion. Thereby, the noise according to the operation of the stirring member which is provided in the liquid storage container is suppressed. 
     In addition, in the liquid storage container of the aspect of the invention, the first buffer member may be provided at the inner edge portion of the hole of the stirring member. Thereby, the noise according to the operation of the stirring member which is provided in the liquid storage container is suppressed. 
     According to another aspect of the invention, there is provided a liquid storage container which is mounted on a carriage of a liquid ejecting apparatus ejecting a liquid while reciprocating the carriage on which an ejecting head is provided and supplies the liquid to the ejecting head including a liquid storage chamber that stores the liquid therein, a stirring member that is provided in the liquid storage chamber, and a support structure that supports the stirring member in a state where the stirring member can swing, wherein the stirring member is a member which is provided in the liquid storage chamber in a state capable of being swung by the reciprocation of the carriage, and in which a stirring surface, which stirs the liquid in the liquid storage chamber by the swing at the liquid storage chamber, is formed on at least a portion of the stirring member, and the support structure is formed of rubber. 
     According to the liquid storage container of the aspects of the invention, the noise according to the operation of the stirring member which is provided in the liquid storage container is suppressed, it is not necessary to provide the buffer member as the separated member, and therefore, the number of parts can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view exemplifying a state where an ink cartridge is mounted on a carriage of an ink jet printer. 
         FIGS. 2A and 2B  are perspective views showing an appearance configuration of the ink cartridge. 
         FIG. 3  is a plan view showing an inner structure of the ink cartridge by peeling a sealing film which is stuck to a rear side of the ink cartridge. 
         FIG. 4  is a plan view showing the inner structure of the ink cartridge by peeling a display label which is stuck to a front side of the ink cartridge. 
         FIG. 5  is an explanatory view showing a stirring mechanism of ink which is provided in an ink chamber. 
         FIGS. 6A to 6C  are explanatory views showing a reason why noise during stirring of the ink is effectively suppressed by providing a buffer member to a hole of a stirring plate. 
         FIGS. 7A and 7B  are explanatory views showing an inner structure of an ink chamber of a first modification. 
         FIGS. 8A and 8B  are explanatory views showing an inner structure of an ink chamber of a second modification. 
         FIG. 9  is an explanatory view showing an inner structure of an ink chamber of a third modification. 
         FIG. 10  is an explanatory view showing an inner structure of an ink chamber of a fourth modification. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, in order to explain the contents of the above-described invention, embodiments will be explained according to the following order. 
     A. Configuration of Ink Cartridge 
     B. Reason why Collision Noise due to Stirring of Ink is Suppressed 
     C. Modification 
     C-1. First Modification 
     C-2. Second Modification 
     C-3. Third Modification 
     C-4. Fourth Modification 
     A. Configuration of Ink Cartridge 
       FIG. 1  is an explanatory view exemplifying a state where an ink cartridge  100  is mounted on a carriage  10  of an ink jet printer  1 . As shown in  FIG. 1 , the carriage  10  which reciprocates on a printing medium  2  is provided on the ink jet printer, and the ink cartridge  100  is mounted on the carriage  10 . An ejecting head  20  which ejects the ink is provided in a lower surface side (side facing the printing medium  2 ) of the carriage  10  for each ink cartridge  100 , and the ink stored in the ink cartridge  100  is supplied to the ejecting head  20  and ejected from the ejecting head  20  toward the printing medium  2 . Moreover, the ink jet printer  1  prints an image by using cyan ink (C ink), magenta ink (M ink), yellow ink (Y ink), and black ink (K ink). According to this, four ink cartridges  100  of the ink cartridge  100  which stores the C ink, the ink cartridge  100  which stores the M ink, the ink cartridge  100  which stores the Y ink, and the ink cartridge  100  which stores the K ink are mounted on the carriage  10 . 
       FIGS. 2A and 2B  are perspective views showing an appearance configuration of the ink cartridge  100  which mounted on the carriage  10 . As shown in  FIGS. 2A and 2B , the ink cartridge  100  is an approximately rectangular shape, and a cartridge main body  102  is formed of a hard resin material. Moreover, as shown in  FIG. 2A , in each ink cartridge  100 , a display label  120  is stuck so as to be bent from the front side surface to the upper surface. 
     In addition, as shown in  FIG. 2B , a sealing film  130  is stuck to the rear side surface of the ink cartridge  100 , and the sealing film  130  is covered from the outside of the ink cartridge  100  by a cover (not shown). As described below, the rear side surface of the ink cartridge  100  is opened, and the ink can be stored in the ink cartridge  100  for the first time by sticking the sealing film  130  on the opening and sealing the ink. Moreover, an ink supply port  104  for supplying the ink toward the ejecting head  20  of the carriage  10  is provided on the bottom surface of the ink cartridge  100 . 
       FIG. 3  is a plan view showing the inner structure of the ink cartridge  100  by peeling the sealing film  130  which is stuck to the rear side surface of the ink cartridge  100 . As shown in  FIG. 3 , if the sealing film  130  which is stuck to the rear side of the ink cartridge  100  is peeled, a largely opened concave portion  105  appears. In addition, the concave portion  105  is largely divided into four regions of regions  105   a  to  105   d  by a plurality of ribs  102   r  which is vertically and horizontally provided. Moreover, the ink chamber which stores the ink is formed between the concave portion  105  and the sealing film  130  by sticking the sealing film  130  onto the rear side of the ink cartridge  100  and sealing the concave portion  105 . 
     Here, with reference to  FIG. 3 , four regions (accordingly, configuration of ink chamber) configuring the concave portion  105  is simply explained. As shown by an oblique line in  FIG. 3 , the region  105   a  which becomes a first ink chamber is provided at the right side of  FIG. 3 , and the region  105   b  which becomes a second ink chamber is provided at the upper left of  FIG. 3 . The region  105   c  shown by a finely oblique line is provided at the lower left in  FIG. 3  with respect to the region  105   b  which becomes the second ink chamber. The region  105   c  includes a sensor (not shown) and becomes a sensor chamber. In addition, the region  105   d  which becomes a buffer chamber is obliquely provided to the upper right of the region  105   c  which becomes the sensor chamber. Moreover, the region  105   d  which becomes the buffer chamber communicates with a pressure regulation chamber  107  by a small round communicating hole  105   h . A membrane valve, a spring (all not shown), and the like are housed in the pressure regulation chamber  107 , and the pressure regulation chamber includes a function which regulates pressure of the ink supplied to the carriage  10 . 
     Moreover, the first ink chamber (region  105   a  in  FIG. 3 ) and the second ink chamber (region  105   b  in  FIG. 3 ) are connected to each other by a connecting passage  106   b , the second ink chamber (region  105   b ) and the sensor chamber ( 105   c  in  FIG. 3 ) are connected to each other by a maze-like passage, and the sensor chamber (region  105   c ) and the buffer chamber ( 105   d  in  FIG. 3 ) are connected to each other by a connecting passage  106   c . Accordingly, when the ink is ejected from the ejecting head  20 , after the ink flows from the communicating hole  105   h  into the pressure regulation chamber  107  via the second ink chamber, the sensor chamber, and the buffer chamber from the first ink chamber, the ink is supplied from the ink supply port  104  to the ejecting head  20 . 
     Moreover, in the ink cartridge  100  of the present embodiment, a stirring plate  109  made of stainless-steel for stirring the ink is provided at the inner portions of the region  105   a  which becomes the first ink chamber and the region  105   b  which becomes the second ink chamber respectively. An ink stirring mechanism including the stirring plate  109  will be described in detail hereinafter. 
     In addition, as shown in  FIG. 3 , a region  108   d  which becomes an air chamber is provided at the lower left in  FIG. 3  with respect to the region  105   a  which becomes the first ink chamber. A communicating hole  108   h  is provided at the region  108   d , and as described hereinafter, the communicating hole is connected to a hole open to the atmosphere via an air passage which is provided at the front side of the ink cartridge  100 . In addition, the region  108   d  which becomes an air chamber is connected to the region  105   a , which becomes the above-described first ink chamber, by a connecting passage  106   a . When the ink flows backward to the hole open to the atmosphere from the first ink chamber (region  105   a ) due to the fact that the air in the ink cartridge  100  is expanded by an ambient temperature change, a posture of the ink cartridge  100  is changed, or the like, the air chamber (region  108   d  in  FIG. 3 ) traps the ink in the inner portion and prevents the ink from being leaked to the outside. 
       FIG. 4  is a plan view showing the inner structure of the ink cartridge  100  by peeling the display label  120  which is stuck to the front side of the ink cartridge  100 . As shown in  FIG. 4 , an elongated groove  108  appears if peeling the display label  120  attached to the front side of the ink cartridge  100 . In  FIG. 4 , the groove  108  is indicated by an oblique line. The groove  108  includes a communicating hole  108   p  which communicates with a hole open to the atmosphere  108   o  opened to the bottom surface of the cartridge main body  102 , as the starting end; an upstream side elongated groove  108   a  which meanders while changing direction several times; a downstream side elongated groove  108   c  which has the communicating hole  108   h  shown in  FIG. 3  as the termination; and an approximately rectangular intermediate groove  108   b  which is provided between the upstream side groove  108   a  and the downstream side groove  108   c  and formed in a shallow concave shape, or the like. In addition, an upstream side air passage is formed by the upper side groove  108   a  and the display label  120  if sticking the display label  120  onto the front side of the ink cartridge  100 , an air reservoir is formed by the intermediate groove  108   b  and the display label  120 , and a downstream side air passage is formed by the downstream side groove  108   c  and the display label  120 . Moreover, the surface configuration of the pressure regulation chamber  107  is shown in the vicinity (right side in  FIG. 4 ) of the groove  108 . 
       FIG. 5  is an explanatory view showing a stirring mechanism of ink which is provided in the ink cartridge  100  of the embodiment.  FIG. 5  shows a state when viewing a cross-section, which is taken along a line V-V with respect to the region  105   b  which becomes the second ink chamber shown in  FIG. 3 , in the arrow of the line. Moreover, as described above, in the ink cartridge  100  of the embodiment, the ink stirring mechanism is also provided at the region  105   a  which becomes the first ink chamber (refer to  FIG. 3 ). However, the configurations of the stirring mechanisms are the same as each other, and the ink stirring mechanism in the second ink chamber will be explained as the example below. Moreover, in the below explanation, the second ink chamber is simply referred to as an ink chamber. 
     As shown in  FIG. 5 , a hole is provided at one end side of a stirring plate  109  which is provided in the ink chamber  110 , and a rubber buffer member  109   c  is mounted on the inner edge portion of the hole. In addition, the stirring plate  109  is supported into the ink chamber  110  in a state of having a gutter by engaging the hole of the stirring plate  109  on which the buffer member  109   c  is mounted to a protrusion  112  which is provided at the inner wall of the ink chamber  110 . 
     When the ink cartridge  100  including the ink stirring mechanism of the embodiment is mounted on the carriage  10 , the ink cartridge  100  is reciprocated in a side surface direction (direction indicated by an arrow in  FIG. 5 ) according to the reciprocation of the carriage  10 . At this time, the stirring plate  109  in the ink cartridge  100  is swung with the movement of the ink cartridge  100 . As described above, since the stirring plate  109  is formed of a material (stainless-steel in the embodiment) having a sufficiently greater specific gravity than the ink, the stirring plate  109  is swung in the left and right direction in the drawing while pushing the ink in the ink chamber  110  with a position which engages the hole of the stirring plate  109  and the protrusion  112  as the supporting point. As a result, since the stirring plate can stir so as to mix in the components of the ink which have settled below (that is, in the gravity direction in the state where the ink cartridge  100  is mounted on the carriage  10 ) in the drawing in the ink chamber  110 , it is possible to uniformly maintain a concentration of the ink in the ink chamber  110 . 
     Moreover, since a gutter (predetermined gap) is provided between the hole of the stirring plate  109  and the protrusion  112  which engages the hole, the fixation of the stirring plate  109  to the protrusion  112 , which is generated by thickening of the ink entering the gap between the hole of the stirring plate  109  and the protrusion  112 , is not generated. 
     Certainly, in the configuration, there is a concern that the stirring plate  109  which is swung in the ink cartridge  100  may collide with the inner wall of the ink cartridge  100  and noise may be generated. However, in the ink cartridge  100  of the embodiment, as described above, the buffer member  109   c  is provided at the inner edge portion of the hole which engages the stirring plate  109  to the protrusion  112  of the ink chamber  110  (refer to  FIG. 5 ). Thereby, it is possible to suppress the noise which is generated by stirring of the ink. That is, it is expected that the vicinity of the tip of the stirring plate  109  will collide with the inner wall of the ink cartridge  100  when the stirring plate  109  is swung. However, actually, providing the buffer member  109   c  in the inner edge portion of the hole which engages the stirring plate  109  is more effective in the suppression of noise than providing the buffer member in the vicinity of the tip of the stirring plate  109 . This point will be explained below. 
     B. Reason why Noise Due to Stirring of Ink is Suppressed 
       FIGS. 6A to 6C  are explanatory views showing a reason why noise during stirring of the ink is effectively suppressed by providing a buffer member  109   c  to a hole which engages the stirring plate  109  to a protrusion  112 . For the explanation,  FIGS. 6A to 6C  show the movement of the stirring plate  109  which generates noise during stirring the ink. 
     First, as shown in  FIGS. 6A and 6B , when the stirring plate  109  moves in the direction which stirs the ink, there is a concern that the tip of the stirring plate  109  may collide with the inner wall of the ink chamber  110  and collision noise may be generated. However, actually, the noise generated in this manner is not so great. On the other hand, the tip of the stirring plate  109  collides with the inner wall of the ink chamber  110 , and the stirring plate vibrates with respect to the protrusion  112  which is a support structure with the stirring plate  109 . Therefore, due to the fact that the inner edge portion of the hole of the stirring plate  109  and the protrusion  112  collide with each other at the time of the vibration, collision noise is generated. Thus, the collision noise is the major example of noise which is generated when the ink is stirred.  FIG. 6C  shows the state where the stirring plate  109  vibrates with respect to the protrusion  112  which is the support structure due to the fact that the tip of the stirring plate  109  collides with the inner wall of the ink chamber  110 . 
     As described above, it is considered that the major cause of the noise generated during the stirring of the ink is the collision noise generated when the hole of the stirring plate  109  and the protrusion  112  collide with each other at the time of the stirring due to the fact that the stirring plate  109  vibrates when the stirring plate  109  collides the ink chamber  110 . Therefore, since the impact at the time of the collision of the stirring plate  109  and the protrusion  112  can be suppressed by providing the buffer member  109   c  in the inner edge portion of the hole of the stirring plate  109 , it is possible to decrease the major noise (collision noise of stirring plate  109  and protrusion portion  112 ). As a result, it is possible to effectively suppress the noise generated during the stirring of the ink. 
     C. Modification 
     In the above-described embodiment, some modifications are considered. Hereinafter, the modifications will be simply described. Moreover, in the modifications described below, the same components as the above-described embodiment are denoted by the same reference numerals as the embodiment, and detailed explanation will be omitted. 
     C-1. First Modification 
     In the above-described embodiment, the case where the buffer member  109   c  is provided at the inner edge portion of the hole which engages the stirring plate  109  to the protrusion  112  of the ink chamber  110  is explained. Here, the buffer member  109   c  may be provided at the protrusion  112  side instead of providing the buffer member  109   c  in the stirring plate  109 . 
       FIGS. 7A and 7B  are explanatory views showing the inner structure of the ink chamber  110  of the ink cartridge  100  of a first modification. In the protrusion  112  in the ink chamber  110  shown in  FIG. 7A , the portion, in which the hole of the stirring plate  109  is engaged to the protrusion  112 , is covered by the rubber buffer member  109   c . Thus, similarly to the ink stirring mechanism shown in  FIG. 5 , since the impact when the stirring plate  109  and the protrusion  112  collide with each other can be suppressed, it is possible to effectively suppress the noise during the stirring of the ink. Moreover, as shown in  FIG. 7B , if the protrusion  112  itself is formed of a rubber material, the same effects as those of the above-described case can be obtained, and the operation which separately mounts the buffer member  109   c  to the stirring plate  109  (or protrusion  112 ) may not be performed. Therefore, the manufacture of the ink cartridge  100  can be simply performed. 
     C-2. Second Modification 
     In the embodiment and the first modification described above, the case where the buffer member  109   c  is provided only between the hole which engages the stirring plate  109  to the protrusion  112  and the protrusion  112  is explained. Here, if the buffer member  109   c  is added to the following positions, it is possible to further suppress the noise which is generated during the stirring of the ink. 
       FIGS. 8A and 8B  are explanatory views showing the inner structure of the ink chamber  110  of the ink cartridge  100  of a second modification. In the stirring plate  109  shown in  FIG. 8A , the buffer member  109   c  is provided at the position (lower end of stirring plate  109 ) at which the stirring plate  109  and the inner wall of the ink chamber  110  collide with each other when the stirring plate  109  swings through the inertial force. Moreover, in  FIG. 8B , the buffer member  109   c  is provided at the position at which the stirring plate  109  collides with the inner wall side of the ink chamber  110 . 
     As described above, a small collision noise is generated even though the stirring plate  109  and the inner wall of the ink chamber  110  collide with each other (refer to  FIGS. 8A and 8B ). Accordingly, if the buffer member  109   c  is provided at the position at which the inner wall of the ink chamber  110  and the stirring plate  109  collide with each other, it is possible to further suppress the noise during the stirring of the ink. 
     C-3. Third Modification 
     In the second modification described above, the case where the buffer members  109   c  are separately provided at the inner edge portion of the hole of the stirring plate  109  and the portion at which the inner wall of the ink chamber  110  and the stirring plate  109  collide with each other is explained. However, the buffer members  109   c  may be integrally formed. 
       FIG. 9  is an explanatory view showing the inner structure of the ink chamber  110  of the ink cartridge  100  of a third modification. In the stirring plate  109  of the third modification shown in  FIG. 9 , the buffer member  109   c  which is provided at the inner edge portion of the hole of the stirring plate  109  is connected to the buffer member  109   c , which is provided at the portion at which the inner wall of the ink chamber  110  and the stirring plate  109  collide with each other, by a rubber and the buffer members are integrally formed. If the buffer members  109   c  are formed in this way, since the entire buffer member  109   c  can be mounted on the stirring plate  109  in the mounting operation once when the buffer member  109   c  is mounted on the stirring plate  109 , it is possible to simply manufacture the ink cartridge  100 . 
     C-4. Fourth Modification 
     In the embodiment and the modifications described above, the case where the stirring plate  109  is engaged to the protrusion  112  in the ink chamber  110  is explained. However, the stirring plate  109  may be accommodated in the ink chamber  110  in a state of being capable of swinging by the reciprocation of the carriage  10 . For example, as shown in  FIG. 10 , the stirring plate  109  may be only put in the ink chamber  110 . Even though when the stirring plate is provided in this way, the stirring plate can stir in the ink chamber  110  due to the fact that the stirring plate  109  swings according to the reciprocation of the carriage  10 . Moreover, as shown in  FIG. 10 , if the buffer member  109   c  is provided at the upper end side and the lower end side of the stirring plate  109  respectively, as described above, since the collision noise can be suppressed when the stirring plate  109  vertically swings (refer to  FIG. 6C ) and collides with the upper surface or the lower surface of the ink chamber  110 , it is possible to effectively suppress the noise during the stirring of the ink. 
     As described above, various embodiments are described. However, the invention is not limited to all the above-described embodiments and can be performed in various aspects within the scope which does not depart from the gist. For example, in the embodiment and the modifications described above, the case where the rubber material is used for the buffer member is described. However, any other materials may be used if the material can absorb an impact.