JP4916190B2 - Ink tank and printer - Google Patents

Description

The present invention relates to an ink tank and a printer using the ink tank.

  An example of a recording apparatus that uses ink stored in an ink tank is an inkjet recording apparatus that uses an inkjet recording head capable of ejecting ink. Further, such an ink jet recording apparatus is of a serial scan type in which an ink tank is mounted on a carriage together with an ink jet recording head, and an image is recorded on a recording medium as the carriage moves in the main scanning direction. There is.

  This serial scan type inkjet recording apparatus includes a carriage capable of mounting an inkjet recording head and an ink tank that supplies ink to the recording head. During recording, while moving the carriage with respect to the recording medium, ink droplets are ejected from fine ejection ports provided in the recording head, and the ink droplets are landed on the recording medium, thereby obtaining a desired image. Record.

  As an ink used for an ink jet recording head, a dye ink using a dye as a coloring material has been mainly used. However, it is difficult for the recorded matter recorded with the dye ink to have the performance required for uses such as outdoor posted printed matter that places importance on light resistance and weather resistance. Instead, pigment ink using a pigment as a coloring material Has been put to practical use. However, since the pigment is not a dissolution system but a dispersion system, the pigment ink is unavoidably caused by precipitation of pigment particles in the ink tank.

  For example, when the ink tank is left in the ink jet recording apparatus for a long period of time, the pigment particles in the ink gradually settle inside the ink tank. Therefore, a concentration gradient of pigment particles is generated in the ink tank from the bottom to the top. As a result, the ink near the bottom of the ink tank has a high pigment particle concentration and forms a dark color layer, while the ink at the top of the ink tank has a low pigment particle concentration and forms a light color layer. become.

  When the ink in the ink tank is derived from the bottom of the ink tank, when the ink derived from the ink tank is supplied to the recording head, first, ink that forms a layer having a high pigment particle concentration is supplied, and the color changes. A dark image will be recorded. In other words, there is a possibility that a difference in recording density to the extent that it can be recognized visually is produced between the recorded image in the initial use of the ink tank and the recorded image in the latter stage of use. Such a phenomenon becomes particularly remarkable in color recording in which a color image is recorded based on color shading.

  Patent Documents 1 and 2 describe a configuration in which an agitator is provided in the ink tank, and the ink in the ink tank is agitated by moving the agitator by the inertial force of the reciprocating movement of the carriage.

  That is, Patent Document 1 describes an ink tank provided with a stirring body in a swingable manner, and the center of swinging of the stirring body is set at a substantially central position in the ink tank in the carriage movement direction. Has been. The stirrer similarly swings in one direction and the other direction by the reciprocating motion of the carriage. Patent Document 2 describes an ink tank provided with an agitating body that can be swung with elastic deformation therein, and the agitating body has a shape that hangs down from a substantially central portion of the upper inner surface of the ink tank. It has become. The stirrer also swings in one direction and the other in the same manner due to the reciprocating movement of the carriage. Patent Document 2 also describes a configuration in which an agitator that can freely move on the bottom surface of the ink tank is provided. The stirrer moves freely on the bottom surface of the ink tank by the reciprocating movement of the carriage.

Japanese Patent Application Laid-Open No. 2004-216761 Japanese Patent Laying-Open No. 2005-066520

  However, the ink tanks described in Patent Documents 1 and 2 have the following problems.

  First, in the ink tank described in Patent Document 1, the stirrer similarly swings in one direction and the other direction around the substantially central portion in the ink tank. Therefore, in order to increase the agitation range of the agitator and improve the agitation performance, it is necessary to increase the width of the ink tank in the carriage movement direction. However, a plurality of ink tanks mounted on the carriage are often mounted along the moving direction of the carriage, and the width of the ink tank is limited to be relatively small, so that the swing range of the stirring member can be increased. However, the ink flow generated by the shaking of the stirring member is small. In order to sufficiently stir the ink, it is necessary to increase the number of times the carriage is reciprocated and lengthen the stirring time.

  On the other hand, in the ink tank described in Patent Document 2, the ink tank provided with a stirring body that hangs down from the substantially central portion of the upper inner surface of the ink tank has the stirring body in one direction and the other direction centering on the substantially central portion in the ink tank. Swing. In order to increase the agitation range of the agitator and improve the agitation performance, it is necessary to increase the width of the ink tank in the carriage movement direction, as in the ink tank disclosed in Patent Document 1. Therefore, there is a problem similar to that of the ink tank disclosed in Patent Document 1. In addition, when the acceleration of the carriage is set to be large in order to greatly elastically deform the stirrer, the drive motor for the carriage is increased in size and cost, and the vibration of the recording apparatus may be increased. In addition, in the ink tank described in Patent Document 2, an ink tank provided with a stirring body that can freely move on the bottom surface thereof is separated from the upper layer portion of the ink in the ink tank. On the other hand, there is a problem that the stirring performance is poor.

  Such problems of the ink tanks described in Patent Documents 1 and 2 are apparent from the viewpoint of the form of the following general ink tank and recording apparatus.

  In general, the width and length of an ink tank (also referred to as an “on-carriage type ink tank”) mounted on a carriage is set in order to improve detachability. That is, the width of the ink tank in the carriage movement direction (main scanning direction) is relatively small, and the length of the ink tank in the recording medium conveyance direction (sub-scanning direction) intersecting with the main scanning direction is relatively large. Is set. Therefore, the amount of displacement cannot be set large in the main scanning direction, which is the displacement direction of the stirrer. Therefore, the amount of displacement of the stirrer is small, and a strong ink flow cannot be generated. Therefore, the ink stirring efficiency is poor, and it takes too much time to stir the entire ink inside the ink tank. For example, if the recording device did not perform recording for a long time with the ink tank mounted on the carriage, and the pigment particles in the ink in the ink tank settled, for a long time before the start of recording, The carriage must be reciprocated. For this reason, the warm-up time until the recording operation becomes possible becomes longer. In particular, when the pigment particle size in the pigment ink is large or the specific gravity of the pigment particles is large, the sedimentation is quick, and even if the ink tank is left for a few days, the density distribution that adversely affects the recorded image is present in the ink tank. May occur. In this case, the ink stirring operation must be performed every few days, and recording cannot be started during the stirring operation.

  Further, when the ink supply port to the recording head of the ink tank is at the lower part of the ink holding part, another problem arises. In order to explain this, first, the ink settling state will be described in detail.

  FIG. 5 shows the ink density at the height position in the ink tank. If the ink does not settle at the bottom of the ink tank in the initial stage of use of the ink tank, the ink density is the same regardless of the height of the ink. However, when stored for a long time with the supply port facing downward, the concentration of the ink stored at a high position in the tank as shown by the curve L in the figure decreases. And the high density part arises in the ink accommodated in the low position in an ink tank. In particular, the density rapidly changes (increases) near the bottom surface (bottom) of the ink tank. In general, the higher the concentration of pigment particles, the higher the viscosity of the ink, so the lowermost layer has a higher specific gravity and higher viscosity than the rest, forming a layer that is physically different from the other parts. Will be.

As described above, when the specific gravity and viscosity of the ink settled in the lower layer portion of the ink tank are increased, and the ink supply port to the recording head is formed at the lower portion of the ink tank, the following two Challenges arise.
The first problem is that the settled ink in the lower layer of the ink storage chamber has a high specific gravity, so that it moves to a lower position and enters the ink supply port. The ink flow generated by the stirrer does not easily reach the inside of the ink supply port, and cannot be sufficiently stirred. Therefore, the sedimented ink that has entered the ink supply port must be discharged to the outside due to suction recovery or the like, and the ink is discarded wastefully, resulting in an increase in running cost.

  The second problem is that the sedimented ink in the lower layer of the ink containing chamber has a high viscosity, so that the flow of ink generated by the stirring body is decelerated, and it takes a lot of time to obtain a sufficient stirring state. In other words, since it takes a lot of time to stir the ink that has settled at the bottom of the ink tank and uniformize the ink density in the ink tank, there is much time until the recording operation is started after the recording device is started. Waiting time is required.

  An object of the present invention is to provide an ink tank that can efficiently stir the ink in the ink tank, and a recording apparatus that can record a high-quality image with a uniform concentration of ink.

In order to solve the above problems, the present invention has the following configuration.
A first aspect of the present invention is an ink tank that is mounted on a printer, and includes an ink storage chamber that stores ink, and a protruding member that is provided on an inner wall of the ink storage chamber and protrudes into the ink storage chamber A stirring member having an engaging portion engaged with the protruding member, an ink outlet provided in the ink storage chamber, an ink supply port provided outside the ink tank, and the ink outlet and connects with the ink supply port, the ink of the ink containing chamber and an ink outlet passage comprising a flow path in supplying to the ink tank outside the ink outlet port, the ink tank is the printer in the posture to be attached to, is arranged from above the lowermost surface of the inner wall of the ink accommodating chamber, the stirring member rotates the engaging portion as a rotation axis, and a direction in which the protruding member protrudes The engaging portion along is characterized that you move.

According to a second aspect of the present invention, there is provided a printer having an ink tank that stores a pigment ink containing a pigment component used for printing and a carriage that reciprocates by mounting a head that discharges the liquid. An ink storage chamber for storing ink, a protruding member provided on an inner wall of the ink storage chamber, protruding into the ink storage chamber, and an agitation member having an engaging portion engaged with the protruding member; An ink outlet port provided inside the ink storage chamber, an ink supply port provided outside the ink tank, and the ink outlet port and the ink supply port are connected, and the ink in the ink storage chamber is removed from the ink tank. and an ink outlet passage comprising a flow path in supplying to the ink outlet port, in the attitude of the ink tank is mounted on the carriage Arranged above the lowermost surface of the inner wall of the ink storage chamber,
As the carriage reciprocates, the stirring member rotates about the engaging portion as a rotation shaft, and the engaging portion moves along a direction in which the protruding member protrudes. .

  According to the present invention, the ink outlet for supplying ink to the recording head disposed in the ink storage chamber is positioned above the lowest position of the ink storage chamber. It is possible to reduce the supply of the high-concentration and high-viscosity ink in which the color material is precipitated to the ink supply port.

Therefore, according to the present invention, after the printer is started, the recording operation can be started quickly, and furthermore, the amount of ink to be discharged at the start of recording after being left for a long time can be suppressed to a small amount, thereby reducing the running cost. It can also be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
(Ink tank configuration)
FIG. 1 is a cross-sectional view of an ink tank 1 according to the first embodiment of the present invention, and FIG. 2 is a perspective view of the ink tank 1. 1 corresponds to a cross-sectional view taken along the line II in FIG. FIG. 3 is an exploded perspective view of the ink tank 1. FIG. 4 is a perspective view showing a state in which the stirring members 20A and 20B are assembled to the tank case (tank body) 10.

1 and 2, the ink tank 1 is a container that stores the ink 2 in an ink storage chamber R constituted by a tank case 10 and a flexible member 40. As shown in FIG. The ink jet recording apparatus is mounted in a posture directed downward. The ink supply port 60 is connected to an ink supply path of an ink jet recording head (not shown) and communicates with an ink outlet path 66 formed in the ink storage chamber R. An ink outlet 64 that communicates with the ink storage chamber R is formed at the upper end of the ink outlet 66. The ink outlet path 66 in this example is a space surrounded by the outlet flow path wall 10 </ b> C rising upward from the bottom wall portion 10 </ b> B of the tank case 10. The opening at the upper end of the lead-out path wall 10 </ b> C serves as the ink lead-out port 64. The bottom wall portion of the tank case 10 also forms the bottom portion of the ink storage chamber R.
The ink tank 1 of this example can be separated from the recording head. However, the ink tank 1 may be a recording head integrated type in which the recording head is provided so as not to be separated.

  As shown in FIG. 3, the ink tank 1 mainly includes a tank case 10, stirring members 20A and 20B, a spring member 30, a pressure plate 31, a flexible member 40, a lid member 50, a capillary member 61, and a meniscus holding member. 62 and a supply port member 63. The tank case 10, the lid member 50, and the supply port member 63 constitute a casing of the ink tank 1.

  A supply port member 63 is fixed to the lower end portion of the tank case 10. The supply port member 63 is formed with an ink supply port 60 that can be connected to the ink jet recording head. The ink supply port 60 is provided with a capillary member 61 and a meniscus holding member 62 so as to close it. The capillary member 61 is made of a material having a certain degree of flexibility so that, when a recording head is connected to the ink supply port 60, the displacement of the recording head in the vertical direction (vertical direction in FIG. 1) can be absorbed. Has been. Further, the capillary member 61 has a capillary force that serves as an ink flow path. As will be described later, the inside of the ink storage chamber R is maintained at a negative pressure so that ink does not drip from the ink supply port 60. The meniscus holding member 62 generates an ink meniscus so that bubbles are not drawn from the ink supply port 60 due to the negative pressure in the ink storage chamber R. Therefore, as the meniscus holding member 62, a member that generates a meniscus holding pressure stronger than the maximum value of the negative pressure generated in the ink storage chamber R is selected.

  Inside the tank case 10, stirring members 20A and 20B located in the ink storage chamber R are supported. The stirring members 20A and 20B of this example are configured in a plate shape from a material having a certain degree of rigidity and mass such as metal. As shown in FIG. 4B, a pair of recesses 21A and 21B recessed inward are formed on the upper portions of the stirring members 20A and 20B. As shown in FIG. 4 (a), two shaft-like support portions 15 and 16 for supporting the stirring members 20A and 20B are projected from the inner wall of the tank case 10, respectively. The support portions 15 and 16 include shaft portions 15A and 16A that protrude in a carriage movement direction (direction indicated by an arrow A) of a recording apparatus, which will be described later, and retaining portions 15B and 16B formed at the tips of the shaft portions 15A and 16A. It consists of. The support portions 15 and 16 are formed, for example, by forming bosses integrally on the inner surface of the tank case 10 made of a resin material to form shaft portions 15A and 16A. , 16B can be easily configured.

  As shown in FIG. 4B, the shaft portions 15A and 16A of the support portions 15 and 16 are loosely fitted in the left and right concave portions 21A and 21B of the stirring members 20A and 20B, respectively. That is, when the stirring members 20A and 20B are suspended downward from the shaft portions 15A and 16A, a gap g is formed between the stirring members 20A and 20B and the shaft portions 15A and 16A. Both agitating members 20A and 20B can rotate in the C1 and C2 directions around the contact positions with the shaft portions 15A and 16A within the range of the gap g, and further tanks along the shaft portions 15A and 16B. The reciprocating movement in the moving direction A is also possible. In addition, concave digging portions 14A and 14B that can accommodate the stirring members 20A and 20B are formed on the inner wall 10A of the tank case 10 at positions facing the stirring members 20A and 20B.

  Further, the spring member 30 is configured by a coil spring having a truncated cone shape, and is positioned in the digging portion 11 formed on the inner wall 10 </ b> A of the case 10. Further, the spring member 30 is disposed so that the load center and the center of gravity of the pressure plate 31 substantially coincide. The peripheral portion of the flexible member 40 is welded to the welded portion 13 of the tank case 10, and a space sealed by the flexible member 40 and the tank case 10 except for the ink supply port 60, that is, the ink storage chamber R. Is formed.

  The shape of the central portion of the flexible member 40 of this example is regulated by the pressure plate 31 that is a flat plate-like support member, and the peripheral portion of the flexible member 40 can be deformed. The flexible member 40 is previously formed with a convex central portion and has a substantially trapezoidal cross-sectional shape. As will be described later, the flexible member 40 is deformed in accordance with a change in the ink amount or pressure fluctuation in the ink storage chamber R. At that time, the peripheral portion of the flexible member 40 is deformed in a well-balanced and flexible manner, and the central portion of the flexible member 40 is maintained in a posture substantially parallel to the inner wall 10A of the tank case 10 in FIG. Move left and right. As the flexible member 40 is smoothly deformed (moved) in this way, no impact is generated due to the deformation, and no abnormal pressure fluctuation occurs in the ink storage chamber R due to the impact. .

  The spring member 30 is used as a compression spring in the ink tank. The spring member 30 presses the pressure plate 31, and the biasing force acts in the direction in which the ink storage chamber R is enlarged. In a state where ink is filled in the ink storage chamber R, the pressure plate 31 urges the flexible member 40 in the left direction in FIG. Depending on the configuration of these members. A predetermined negative pressure is generated in the ink storage chamber R. Due to the negative pressure, the ink in the recording head is applied with a negative pressure in a range that enables the ink ejection operation of the recording head in equilibrium with the holding force of the meniscus of the ink formed in the ink ejection portion. . That is, in the ink storage chamber R, a negative pressure is generated in a range that allows the ink ejection operation of the recording head. FIG. 1 shows a state in which the ink storage chamber R is almost completely filled with ink. Even in this state, the spring member 40 is in a compressed state, and an appropriate negative pressure is generated in the ink storage chamber R.

  A lid member 50 is attached to the opening of the tank case 10, and the flexible member 40 is protected by the lid member 50. The lid member 50 is provided with an air communication portion 51, and the outside of the ink storage chamber R in the tank case 10 is at atmospheric pressure. The pressure in the ink storage chamber R is negative with respect to the atmospheric pressure by a pressure corresponding to the pressing load of the spring member 30 against the pressure plate 31 and the area of the flat portion of the flexible member 40. Yes.

  As shown in FIG. 1, when the ink 2 is supplied to the recording head and consumed from the state where the ink 2 is almost completely filled in the ink storage chamber R, the pressure is resisted against the biasing force of the spring member 30. The plate 31 moves to the right in FIG. 1, and the flexible member 40 is deformed accordingly. As the spring member 30 is compressed and the load of the spring member 30 increases, the negative pressure in the ink storage chamber R slightly increases. As the ink consumption further proceeds, the volume in the ink storage chamber R eventually decreases until the pressure plate 31 comes into contact with the inner bottom surface of the tank case 10 and cannot be displaced. The spring member 30 is a coil spring having a truncated cone shape so that the strands forming the spring member 30 do not interfere with each other when the spring member 30 is compressed, and can be compressed to a width corresponding to the diameter of the strand. . Since the spring member 30 is completely accommodated in the digging portion 11 when it is completely compressed, the displacement of the pressure plate 31 is not hindered.

  When the pressure plate 31 is displaced as the ink 2 is consumed, the rocking range of the stirring members 20A and 20B decreases, but the dug portions 14A and 14B are formed in the tank case 10, so that the stirring members 20A and 20B The swing of 20B is possible. Further, the displacement of the pressure plate 31 is not hindered by the stirring members 20A and 20B. Furthermore, in this example, the outlet channel wall 10C forming the ink outlet 64 is configured to rise above the lowermost surface 10B of the ink storage chamber R, but the pressure plate 31 has a notch 32 formed therein. Therefore, there is no interference with the outlet flow channel wall 10C. Therefore, the pressure plate 31 can be displaced until it contacts the inner wall 10 </ b> A of the tank case 10. In this example, since air is not taken into the ink storage chamber R from the outside, the ink positioned below the ink outlet 64 is also pushed up by the movable member 40 and supplied to the recording head as the ink is consumed. It is possible.

(Configuration of inkjet recording apparatus)
FIG. 6 is a diagram for explaining a configuration example of an ink jet recording apparatus (printer) to which the present invention is applicable.

  The recording apparatus 150 of this example is a serial scanning ink jet recording apparatus, and a carriage 153 is guided by guide shafts 151 and 152 so as to be movable in the main scanning direction of an arrow A. The carriage 153 is reciprocated in the main scanning direction by a carriage motor (moving means) and a driving force transmission mechanism such as a belt for transmitting the driving force. An ink jet recording head (not shown) and the above-described ink tank 1 for supplying ink to the recording head can be mounted on the carriage 153. In this example, four ink tanks 1 are mounted. However, the number of ink tanks 1 may be any number as long as it is one or more.

  After the paper P as a recording medium is inserted from the insertion port 155 provided at the front end of the apparatus, the transport direction is reversed, and then the paper P is transported in the sub-scanning direction indicated by the arrow B by the feed roller 156. The recording device 150 sequentially records images on the paper P by repeating the recording operation and the conveying operation. The recording operation is an operation of ejecting ink toward the recording area of the paper P on the platen 157 while moving the recording head together with the carriage 153 in the main scanning direction. The transport operation is an operation of transporting the paper P in the sub-scanning direction (direction indicated by the arrow B) orthogonal to the main scanning direction by a distance corresponding to the width of the region recorded by one recording scan of the recording head. It is.

  (A), (b), (c), and (d) in FIG. 6 indicate moving positions when the carriage 153 reciprocates along a virtual trajectory along the main scanning direction. The position (a) is a position when the carriage 153 starts to move in the forward direction of the arrow A1. The position (b) is moving in the direction of the arrow A1, and the position (c) is a position when the moving direction of the carriage 153 is reversed after that and starts moving in the backward direction of the arrow A2. The position (d) is a position when the carriage 153 subsequently moves in the direction of the arrow A2. The ink 2 in the ink tank 1 is agitated as described later by using such a reciprocating motion of the carriage 153 in the directions of arrows A1 and A2.

  The recording head may use thermal energy generated from the electrothermal transducer as energy for ejecting ink. In that case, film boiling occurs in the ink due to the heat generated by the electrothermal converter, and the ink can be ejected from the ink ejection port by the foaming energy at that time. Further, the ink ejection method in the recording head is not limited to such a method using an electrothermal transducer, and may be a method for ejecting ink using a piezoelectric element, for example.

  A recovery system unit (recovery processing means) 158 is provided at the left end in FIG. 6 in the movement region of the carriage 153 so as to face the ink discharge port formation surface of the recording head mounted on the carriage 153. The recovery system unit 158 includes a cap capable of capping the ink discharge port of the recording head, a suction pump capable of introducing a negative pressure into the cap, and the like. Then, by introducing a negative pressure into the cap covering the ink discharge port, the ink can be sucked and discharged from the ink discharge port, and a recovery process for maintaining a good ink discharge state of the recording head can be performed. . In addition, a recovery process (also referred to as a preliminary ejection process) for maintaining a good ink ejection state of the recording head by ejecting ink that does not contribute to image recording from the ink ejection port toward the inside of the cap may be performed. it can.

(Stirring mechanism)
FIGS. 7A, 7B, 7C, and 7D are cross-sectional views for explaining the stirring operation of the ink 2 by the stirring member 20A. Each of the positions (a) of the carriage 153 in FIG. ), (B), (c), and (d) show operating states. The stirring member 20B operates in the same manner as the stirring member 20A.

  First, as shown in FIG. 7A, when the carriage 153 starts to move in the direction of the arrow A1, the stirring member 20A in the ink tank 1 is moved in the direction of the arrow C1 by an inertial force around the contact position with the support portion 15A. Begin to rotate. When the stirring member 20A starts to rotate in the direction of the arrow C1, the space S between the stirring member 20A and the inner wall 10A expands, and ink starts to flow into the expanded space S.

  Next, as shown in FIG. 7B, when the carriage 153 further moves in the direction of the arrow A1, the rotation angle of the stirring member 20A (the angle formed between the side surface of the stirring member and the vertical direction) is the recess of the stirring member 20A. It further rotates in the range of the gap g (see FIG. 1) between the shafts of 21A and the support portion 15A. As a result, the space S between the stirring member 20A and the inner wall 10A further expands, and ink near the bottom of the ink tank 1 flows into the space S as indicated by the arrow D1. FIG. 7B shows a state in which the stirring member 20A is almost at the maximum angle. In this state, the carriage 153 is still moving in the direction of the arrow A1, and the inertial force is still applied to the stirring member 20A. Is added. Due to this inertial force, the stirring member 20A starts to move in the direction indicated by the arrow C3 along the support portion 15A. Then, the carriage 15 reaches the reversing position while decelerating before the reversing position shown in FIG. 7C, and then starts reversing in the direction of the arrow A2. At this time, the space S has the maximum volume. Accordingly, the ink further flows into the space S as the stirring member 20 moves in the C3 direction.

  As the carriage 153 is accelerated from the reverse position in the direction of the arrow A2, the stirring member 20A that has been maximally swung in the direction of the arrow C1 until then starts swinging in the direction of the arrow C2. As a result, the distance between the stirring member 20A and the inner wall 10A starts to decrease, and the ink in the space S is pressed by the stirring member 20 and flows upward as indicated by the arrow D2.

  Next, as shown in FIG. 7D, when the carriage 153 continues to move in the direction of the arrow A2, the free end of the stirring member 20A approaches the inner wall 14A, and the ink in the space S is stirred as shown by the arrow D3. The member 20A is pushed out toward the gap on the support side. At this time, when the flow resistance of the ink pushed out of the space S is larger than the inertia force generated in the stirring member 20A, the swing speed of the stirring member 20A is greatly reduced. For this reason, it is preferable to adjust the acceleration force of the carriage 153, the mass of the stirring member 20A, and the like so that the inertial force of the stirring member 20A is larger than the ink flow resistance. Thereafter, when an inertial force is further applied to the stirring member 20A, the stirring member 20A moves to the arrow C4 along the support portion 15 as indicated by an arrow C4, and returns to the state shown in FIG. Thereafter, as long as the carriage 153 continues to reciprocate, the states of FIGS. 7A, 7B, 7C, and 7D are repeated.

  As described above, in this example, since frictional resistance is generated between the stirring member 20A and the support portion 15, when the carriage 153 starts moving, first, the free end of the stirring member 20A moves in advance. Subsequently, an operation in which the support side end is moved is performed. This operation creates a pumping effect and enables the ink below the ink storage chamber R to circulate upward. Further, since the free end side that moves greatly is positioned on the lower side in the vertical direction, the pigment component that has settled below the ink storage chamber R can be stirred. For this reason, it is possible to efficiently mix the pigment components contained in the ink stored in the ink storage chamber R in combination with the above-described pump effect, and uniform ink density can be achieved.

  That is, when the recording apparatus is left for a long period of time with the ink tank 1 mounted on the carriage 153, the pigment component of the ink in the ink tank 1 settles, and the ink in the ink tank 1 in the vertical direction. Concentration distributions with different concentrations occur. In this example, the ink in the ink tank 1 can be efficiently stirred by generating the upward ink flow as described above. Therefore, the ink in the ink storage chamber R can be surely made to have a uniform concentration by a short stirring operation.

  Further, in this example, as shown in FIG. 1 or FIG. 4, the ink outlet 64 is disposed at an upper position from the lowermost surface in the ink storage chamber R. As a result, the sedimentation of the pigment component contained in the ink immediately above the ink outlet 64 reaches the meniscus holding member 62 or the capillary member 61, but the pigment component of the ink located in the other part enters the ink outlet 64. Does not invade. However, when the sedimentation of the pigment component of the ink proceeds and the ink with a high density reaches the height of the ink inlet 64, the ink with the high density enters from the ink outlet 64. However, this ink is not an ink having the highest density, but an ink having a density slightly increased from the initial density as shown in FIG. For this reason, within a certain storage period, it is not necessary to discharge the ink positioned in the flow path from the ink outlet 64 to the capillary member 61 by the recovery operation before the start of the recording operation. The recording operation can be started immediately.

  In addition, at the beginning of the use of the stored ink tank, near the lowermost surface of the ink storage chamber R, ink with a high concentration in which pigment components are deposited exists. However, if the height of the ink outlet 64 is secured to some extent as in the present example, the ink density at the position of the ink outlet 64 is printed as shown in FIG. 5 when the storage period is relatively short. The initial concentration may be appropriate. In this case, it is possible to supply ink with an appropriate concentration to the recording head without performing stirring before the start of the recording operation, and then performing stirring to equalize the ink concentration in the ink storage chamber R. All inks can be used at the proper density.

As described above, according to this example, the height of the ink outlet 64 is set to a position higher than the lowermost surface of the ink storage chamber, so that the recording operation is started after the user starts the recording apparatus. The waiting time can be reduced, and the recording operation can be started promptly.
On the other hand, if the ink outlet 64 is arranged on the lowermost surface of the ink storage chamber R, the pigment component that has settled moves to the capillary member 61 of the ink supply port when left for a long period of time. There are things to do. That is, the highest density ink stays in the capillary member 61. Since the ink flow by the stirring members 20A and 20B does not easily reach the ink inside the capillary member 61, the ink inside the capillary member 61 may not be stirred. Similarly, when the ink outlet 64 is small, the ink flow by the stirring members 20 </ b> A and 20 </ b> B is abruptly attenuated inside the ink outlet 64. For this reason, it is difficult to stir up to the inside of the ink outlet 64. Therefore, in this case, it is necessary to discharge the high density ink inside the ink outlet 64 to the outside through the recording head by the recovery device of the recording apparatus. Further, when the ink outlet 64 is located on the lowermost surface of the ink storage chamber R, it is necessary to start the recording operation after reliably stirring the ink located on the lowermost surface. Therefore, the user waits for a long time after starting the recording apparatus until the recording operation is started.

  Incidentally, since the pressure plate 31 approaches the inner surface of the tank case 10 as the ink in the ink storage chamber R is consumed, the swingable range of the stirring members 20A and 20B gradually decreases. However, in this example, since the dug portions 14A and 14B are formed on the tank case 10 side, the stirring function of the stirring members 20A and 20B can be maintained to the end. Further, by forming the dug portions 14A and 14B, the width of the ink tank 1 in the left-right direction in FIG. 1 can be set small while securing the swingable range of the stirring members 20A and 20B. As a result, a plurality of ink tanks 1 can be arranged compactly in the main scanning direction indicated by the arrow A on the carriage 153.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 8 is a perspective view of an ink tank according to the second embodiment of the present invention. FIG. 9 is a perspective view showing the internal structure of the ink tank shown in FIG. It shows the state assembled.
In this example, the internal structure is substantially the same as that of the first embodiment, but the formation position of the supply port 60 is different. That is, it is different in that it is mounted on the recording head (not shown) in the direction shown by the arrow Y in FIG. As apparent from FIGS. 8 and 9, since the ink supply port 60 does not exist below the ink storage chamber R in the vertical direction (X direction in the figure), the ink is not contained in the capillary member 61 or the meniscus holding member 62. The pigment component does not settle. Therefore, according to this example, 1) discharging high density ink that has entered the ink supply port to the outside. 2) The recording operation is started by reliably stirring the ink located on the lowermost surface of the ink storage chamber. Can solve the problem.

  Incidentally, even in the ink tank 1 of this example, when the ink supply port 60 is placed downward before the recording head is mounted, the pigment component of the ink may accumulate in the ink supply port 60. Therefore, the ink tank of this example is effective for sedimentation of the pigment component in the mounting state on the recording apparatus, but immediately after the ink tank is mounted, the high viscosity and high sedimentation in the ink supply port as in the conventional case. It may be necessary to discharge a concentration of ink.

  However, in the ink tank of this example, as shown in FIG. 9, the ink outlet 64, the capillary member 61, and the meniscus holding member 62 are positioned higher than the lowermost surface in the ink storage chamber R when the recording head is mounted. Has been placed. For this reason, after the ink tank is mounted on the recording head, the pigment component accumulated in the capillary member 61 and the meniscus holding member 62 is stirred in the ink storage chamber R, and the ink storage chamber is located below the vertical direction. Move to the lower surface side of R. Therefore, even when ink is discharged from the ink supply port immediately after the ink tank is installed, the ink discharge amount can be reduced, and the running cost can be suppressed.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
FIG. 10 is a cross-sectional perspective view showing a state in which the ink tank 1 according to the third embodiment of the present invention is attached to the recording head 80, and FIG. 11 is a cross-sectional view showing a state in which the ink tank 1 is attached to the recording head.
The ink supply port 60 of the ink tank 1 of this example is formed by a through hole 60A formed at the bottom of the tank body 10 and an O-ring shaped seal rubber 67 fixed to the inner surface thereof. The ink supply port 60 is always kept closed by the joint ball 66 urged by the joint spring 65 to prevent the ink from dripping out of the ink storage chamber R. .
On the other hand, the recording head 80 to which the ink tank 1 is mounted is provided with a tubular needle (ink outlet tube) 70 corresponding to the ink supply port 60 of the ink tank 1, and this ejects ink. 73 is communicated.

  The ink tank 1 is attached to the recording head 80 by inserting the needle 70 into the insertion hole 67 of the seal rubber 67. At this time, the needle 70 of the recording head 80 pushes up the joint ball 66 against the urging force of the joint spring 65. Further, since the needle 70 is in liquid-tight contact with the inner surface of the insertion hole 67 of the seal rubber 67, ink does not leak from the seal rubber 67. An opening 71 is formed in the vicinity of the upper end portion of the needle 70, and the ink in the ink storage chamber R flows into the needle 70 from the opening 71 and passes through the head filter 72 to the ink discharge portion 73. Supplied with. When the ink tank is mounted, the opening 71 of the needle 70 is positioned above the bottom surface in the ink storage chamber R in the vertical direction. For this reason, according to this example, even when the pigment component of the ink settles on the lowermost surface in the ink storage chamber R, the high viscosity and high concentration ink flows into the opening 71 of the needle 70. Absent. Therefore, according to this example, the above-mentioned two problems can be solved as in the other embodiments described above. That is, according to this example, it is not necessary to discharge the ink that has entered the ink supply port to the outside, and the recording operation can be started without reliably stirring the ink located at the lowermost surface of the ink storage chamber. It becomes possible.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.
FIG. 12 is a cross-sectional view of the ink tank 1 according to the fourth embodiment of the present invention.
In the ink tank of this example, two ink outlet ports 64A and 64B that open toward both the left and right sides are formed by the outlet port forming walls 68A and 68B. The outlet port side wall 68A is disposed at a position facing substantially parallel to a surface (hereinafter referred to as an opening surface) surrounded by the edge of the opening of the ink supply port. The outlet port side wall 68B protrudes in a direction perpendicular to the opening surface of the ink supply port, and the outlet port side walls 68B and 68A form ink outlet ports 64A and 64B. The ink outlets 64A and 64B are located above the lowermost surface of the ink storage chamber R, as in the first and second embodiments. For this reason, it is possible to suppress the ink whose viscosity and concentration have been increased by the pigment component that has settled at the bottom of the ink storage chamber from entering the ink supply port.

  In this example, the direction of the ink outlets 64A and 64B is formed so as to be orthogonal to the direction of the ink supply port 60. Therefore, compared to the first and second embodiments, Furthermore, the following effects can be expected.

  That is, as in the first embodiment, when the ink outlet port is located above the ink supply port and the directions thereof are the same, the pigment component of the ink above the ink outlet port remains as it is. To settle. On the other hand, in this example, it is possible to suppress the pigment component contained in the ink on the ink supply port from directly sinking to the ink supply port portion by the discharge port side wall 68A that forms the respective ink discharge ports 69A and 69B. .

  Further, as in the first embodiment, when the ink outlet port 64 is located above the ink supply port 60 and has the same orientation, the ink tank 1 may fall while the ink supply port 60 faces downward. In some cases, ink dripping from the ink supply port 60 when it is shaken strongly. This is because the inertial force that acts on the ink directly due to the action of dropping or shaking moves directly to the ink supply port 60, and the resistance that occurs in the meniscus holding member 62 and the capillary member 61 cannot fully attenuate the inertial force that acts on the ink. is there. In order to cope with such a phenomenon, in this example, the ink outlet flow path from the ink outlet 64 to the ink supply port is formed to bend as shown by the arrow in FIG. It is distributed by the outlet side wall. For this reason, a large inertial force does not reach the ink supply port directly. Further, a plurality of communication ports (here, three communication ports 69A, 69B, 69C) are formed between the flow paths from the ink outlets 64A, 64B to the ink supply port 60, and the ink in the flow paths is formed. The flow resistance is increased. According to this structure, even when the ink inertia force reaches the ink outlet, the inertia force can be attenuated by the ink flow resistance generated at each communication port. Therefore, according to the above configuration, it is possible to suppress dripping of ink due to dropping or hand shaking.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described.
FIG. 13 is a cross-sectional view of the ink tank 1 according to the fifth embodiment of the present invention.
In the ink tank 1 in this example, as with the ink tank 1 in the first embodiment, the ink outlets 64A and 64B are located above the lowermost surface of the ink storage chamber R, and the ink supply port for the settled pigment ink. The intrusion to is suppressed. Also in this configuration, since the direction of the ink outlet 64 is different from the direction of the ink supply port, the configuration is more preferable as ink dripping due to dropping or shaking.

[Other Embodiments]
In the above embodiment, the case where the pigment ink is stored in the ink storage chamber of the ink tank has been described as an example, but the present invention is effective not only in the pigment ink but also in the ink tank storing the dye ink. That is, even in the case of dye ink, dye particles may settle depending on long-term storage and the like, and in such a case, the ink tank in the present invention is effective.

  As described above, each of the above-described embodiments includes a configuration that prevents high-viscosity, high-concentration ink containing a pigment component that has settled in the ink storage chamber of the ink tank from entering the ink supply port and the recording head. It has become a thing. However, in the physical distribution state, the posture of the ink tank may change variously, and there is a possibility that slightly high-viscosity and high-density ink may enter the ink supply port. Therefore, when high-viscosity and high-density ink enters the ink supply port, it is necessary to efficiently discharge the ink with a suction pump. Therefore, if there is a portion where the shape or area of the abrupt flow passage cross section changes in the flow passage from the ink outlet to the ink supply port, such that stagnation occurs during suction, the ink in that portion is discharged. In addition, it is necessary to increase the ink discharge amount. Therefore, as in this configuration, it is desirable to eliminate the stagnation part in the suction and discharge by smoothly changing the cross-sectional shape and area of the flow path from the ink outlet port to the ink supply port. The ink inside can be sucked and discharged.

It is sectional drawing of the ink tank in the 1st Embodiment of this invention. FIG. 2 is an external perspective view of the ink tank of FIG. 1. FIG. 2 is an exploded perspective view of the ink tank of FIG. 1. (A) is sectional drawing which shows the internal structure in the ink tank of FIG. 1, (b) is a side view which shows the relationship between the stirring member shown in the figure (a), and the axial part of a support part. It is a graph which shows the relationship between the ink density | concentration in the state which the pigment component of the ink settled, and the position (height) in an ink tank. It is a perspective view of the principal part for demonstrating the structural example of the inkjet recording device which can mount the ink tank of this invention. (A), (b), (c), (d) is sectional drawing for demonstrating the stirring mechanism in the ink tank of FIG. It is a perspective view of the ink tank in the 2nd Embodiment of this invention. It is a perspective view which shows the internal structure of the ink tank shown in FIG. 8, and has shown the state which attached the stirring member to the ink case. FIG. 10 is a cross-sectional perspective view illustrating a state where an ink tank is mounted on a recording head according to a third embodiment of the present invention. FIG. 10 is a cross-sectional view illustrating a state where an ink tank according to a third embodiment of the present invention is mounted on a recording head. It is sectional drawing of the ink tank in the 4th Embodiment of this invention. It is sectional drawing of the ink tank in the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink tank 2 Ink 10 Tank case 10A Inner wall 14A, 14B Excavation part 15, 16 Support part 15A, 16A Shaft part 15B, 16B Retaining part 20A, 20B Stirring member 30 Spring member 31 Pressure plate 40 Flexible member 60 Ink Supply port 61 Capillary member 62 Meniscus holding member 63 Supply port member 64 Ink outlet port 65 Joint spring 66 Joint ball 67 Seal rubber 68A, 68B Lead port side wall 69A, 69B, 69C Communication port 70 Needle 71 Opening portion 72 Head filter 73 Ink discharge portion 80 Recording Head 150 Recording Device 153 Carriage

Claims (8)

An ink tank attached to the printer,
An ink storage chamber for storing ink;
A protruding member provided on an inner wall of the ink storage chamber and protruding into the ink storage chamber;
A stirring member having an engaging portion engaged with the protruding member;
An ink outlet provided in the ink storage chamber;
An ink supply port provided outside the ink tank;
An ink outlet channel connecting the ink outlet port and the ink supply port, and serving as a channel when the ink in the ink storage chamber is supplied to the outside of the ink tank ;
With
The ink outlet is disposed above the lowermost surface of the inner wall of the ink storage chamber in a posture in which the ink tank is attached to the printer.
An ink tank wherein the agitating member is rotated the engagement portion as a rotation axis, and the engagement portion along the direction in which the protruding member protrudes is characterized that you move. The ink tank is mounted on a carriage of a reciprocating printer,
The stirring member has a free end;
The ink outlet port is in a posture in which the ink tank is mounted on the carriage.
Provided below the free end of the stirring member;
The ink tank according to claim 1, wherein the agitating member is moved as the carriage is reciprocated. The ink storage chamber has a first inner wall that intersects the reciprocating direction in a state where the ink tank is mounted on the carriage.
The ink tank according to claim 2 , wherein the stirring member is a plate-like member and is disposed to face the first inner wall. The protruding member protrudes along a direction in which the carriage reciprocates;
The ink tank according to claim 2 , wherein the engagement portion is moved after the stirring member starts rotating. The ink tank according to claim 2 , wherein the rotation shaft is provided in a horizontal direction in a state where the ink tank is mounted on the carriage. The ink storage chamber comprises a space in which the inner wall and a flexible member are combined, and the volume of the ink storage chamber decreases with consumption of the liquid stored in the space. The ink tank according to any one of 1 to 5 . The ink storage chamber, an ink tank according to any one of claims 1-6, characterized by comprising housing a pigment ink containing a pigment component. In a printer having an ink tank that stores pigment ink containing a pigment component used for printing and a carriage that reciprocates by mounting a head that discharges the liquid,
The ink tank is
An ink storage chamber for storing ink;
A protrusion member provided on the inner wall of the ink storage chamber and protruding into the ink storage chamber;
A stirring member having an engaging portion engaged with the protruding member;
An ink outlet provided in the ink storage chamber;
An ink supply port provided outside the ink tank;
An ink outlet channel connecting the ink outlet port and the ink supply port, and serving as a channel when the ink in the ink storage chamber is supplied to the outside of the ink tank ;
With
The ink outlet is disposed above the lowermost surface of the inner wall of the ink storage chamber in a posture in which the ink tank is mounted on the carriage.
As the carriage reciprocates, the stirring member rotates about the engaging portion as a rotation shaft, and the engaging portion moves along a direction in which the protruding member protrudes. Printer.

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