JP5550711B2 - Ink tank - Google Patents

Description

  The present invention relates to an ink tank used in an ink jet recording apparatus or the like.

  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. Furthermore, such an ink jet recording apparatus includes a serial scan type device 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. is there.

  This serial scan type inkjet recording apparatus includes a carriage on which an inkjet recording head and an ink tank that supplies ink to the recording head can be mounted. 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, the concentration gradient of the pigment particles is generated in the ink tank as it goes from the bottom to the top. As a result, the ink at the bottom of the ink tank has a high pigment particle concentration and forms an excessively dark layer, while the ink at the top of the ink tank has a low pigment particle concentration and an excessively thin layer. Will form.

  Consider a case where the ink tank is stored in a constant posture (the bottom portion is directed downward in the vertical direction) for a long period in the configuration in which the ink is derived from the bottom portion of the ink tank. When ink is derived from such an ink tank, when the ink derived from the ink tank is supplied to the recording head, the ink that forms a layer having a high pigment particle concentration is supplied first, and an image with an excessively dark color is formed. Will be recorded. That is, there is a possibility that a difference in recording density to the extent that it is visually observed may occur between the recorded image in the early stage of use of the ink tank and the recorded image in the later stage of use. Such a phenomenon becomes particularly remarkable in color recording in which a color image is recorded based on color shading.

  As a method for solving such a problem, Patent Documents 1 and 2 disclose that an ink tank is provided with a stirring member (stirring body), and the stirrer is moved by the inertial force of the reciprocating movement of the carriage. A configuration for stirring the ink is described.

  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. ing. The stirrer similarly swings in one direction and the other direction by the reciprocating movement of the carriage. Patent Document 2 describes an ink tank provided with an agitating body that can swing 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 direction by 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 freely moves on the bottom surface of the ink tank by the reciprocating motion of the carriage.

  Further, in Patent Document 3, a stirring member is provided in the ink storage chamber of the ink tank to stir the ink in the ink storage chamber, and an ink outlet port is provided above the bottom of the ink storage chamber that is the lowest in use. The configuration is described. By disposing the ink outlet port above the lowermost part, the sedimentary ink in the lowermost layer having a high specific gravity is prevented from entering the ink supply port into the recording head. The stirring member is configured such that one end side thereof is rotatably supported by a support portion provided in the ink storage chamber, and the rotation fulcrum is linearly movable along the support portion.

  FIG. 14 shows an ink density gradient in the height direction in the ink tank. When no precipitation of the pigment occurs, the ink density is uniform and exhibits the same density regardless of the height. However, by storing for a certain period of time, as shown by curve B in the figure, a portion with a low concentration occurs at a high position in the tank, and as the height decreases, the concentration gradually approaches the initial concentration. Is almost the same as the initial concentration. And a part with a high density | concentration arises in the part with a low position in a tank. In particular, the concentration rapidly changes (increases) near the bottom (bottom). 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.

  Therefore, in the ink tank described in Patent Document 3, the ink outlet port in the ink storage chamber is provided above the lowermost part, thereby preventing the precipitated pigment deposited in the lowermost part from moving into the ink supply port.

Japanese Patent Application Laid-Open No. 2004-216761 Japanese Patent Laying-Open No. 2005-066520 JP 2007-230189 A

  However, providing the ink outlet port at a position higher than the bottom surface of the ink tank means that the portion forming the ink outlet port protrudes from the bottom surface in the ink storage chamber. For this reason, in an ink tank in which the volume of the ink storage chamber is changed so as to mitigate the increase in negative pressure associated with the lead-out (consumption) of ink without taking in the atmosphere, the volume change is performed when the remaining amount of ink decreases. The ink outlet may be covered with a flexible member for generating the ink. Therefore, there is a possibility that the amount of ink that can be derived or supplied may not be stable for each ink tank.

  Therefore, the present invention can stabilize the amount of ink to be derived or supplied in an ink tank in which the volume of the ink storage chamber is changed so as to alleviate the increase in negative pressure associated with the extraction (consumption) of ink without taking in the atmosphere. The purpose is to.

For this purpose, the ink tank of the present invention is an ink tank having an ink storage chamber, and an opening surface that is located inside the ink storage chamber and has a plurality of ink outlets for discharging ink in the ink storage chamber; A flexible member that constitutes at least a part of the storage chamber and deforms as the ink is led out to reduce the volume of the ink storage chamber; and is provided on the opening surface in the vicinity of the plurality of ink outlets A suffocation suppressing member that prevents the ink outlet from being blocked by deformation of the flexible member, and the suffocation suppressing member is a stepped portion that is convex with respect to the opening surface, It is characterized by a comb-tooth shape in which each tooth extends from the inner wall toward each ink outlet .

  According to the present invention, it is possible to reduce the possibility that the ink outlet is blocked by the flexible member in the ink tank that allows the ink to be discharged by the volume change caused by the displacement or deformation of the flexible member without taking in the atmosphere. . Therefore, it is possible to discharge ink in the ink storage chamber without waste, and high ink use efficiency can be obtained.

1 is a perspective view showing an ink tank according to a first embodiment of the present invention. It is the II-II sectional view taken on the line of FIG. FIG. 2 is an exploded perspective view of the ink tank of FIG. 1. (A) And (b) is a perspective view of the tank case which makes the principal part of the ink tank which concerns on 1st Embodiment, respectively, and the perspective view which expands and shows a part. FIG. 4 is a cross-sectional view for explaining a state in which ink in an ink storage chamber is used in the ink tank according to the first embodiment. FIG. 6 is a schematic enlarged view of the vicinity of an ink outlet 64 for explaining a state in which ink in an ink storage chamber is almost used up in the ink tank according to the first embodiment. It is a perspective view which shows the internal structure of the ink tank which concerns on the modification of 1st Embodiment. It is explanatory drawing for demonstrating the design reference | standard for selecting the position (height) of an ink outlet. 1 is a perspective view for explaining a configuration example of an ink jet recording apparatus to which the present invention is applicable. (A)-(d) is typical sectional drawing for demonstrating the stirring mechanism in the ink tank which concerns on 1st Embodiment. (A) And (b) is a typical perspective view which shows the internal structure of the ink tank which concerns on the 2nd Embodiment of this invention, respectively, and its one part enlarged view. FIG. 6 is a schematic cross-sectional view for explaining a state in which ink in an ink storage chamber is almost used in an ink tank according to a second embodiment. (A) and (b) are a schematic perspective view showing the vicinity of the ink outlet of the ink tank according to the comparative example of the second embodiment, and a state in which almost all the ink in the ink tank is used up. It is a typical sectional view for explaining. It is a graph which shows the relationship between the ink density | concentration of an ink sedimentation state, and the position in a tank.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

(Ink tank configuration)
1 is a perspective view of an ink tank 1 according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II, and FIG. 3 is an exploded perspective view. FIG. 4A is a perspective view of a tank case forming the main part of the ink tank according to the embodiment, and FIG. 4B is a perspective view showing an enlarged part thereof.

  The ink tank 1 is a container that stores the ink 2 in the ink storage chamber R constituted by the tank case 10 and the flexible member 40, and the ink outlet 64 disposed in the ink storage chamber R is an ink supply port. Communicate to 60. Then, as shown in FIGS. 1 and 2, the ink supply port 60 is attached to the ink jet recording apparatus in a posture in which the ink supply port 60 is directed downward in the vertical direction. The ink supply port 60 is connected to an ink supply path of an inkjet recording head described later. The ink tank 1 of this example is configured to be separable from the recording head. However, the ink tank 1 may be configured as an integral type having a recording head.

  As shown in FIGS. 2 and 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, and a capillary force generating member. 61, a meniscus holding member 62 and a supply port forming member 63. In particular, the tank case 10, the lid member 50, and the supply port forming member 63 constitute a casing of the ink tank 1.

  The supply port forming member 63 is formed with an ink supply port 60 that can be connected to the ink jet recording head. On the other hand, the tank case 10 is formed with an ink outlet 64 for extracting ink in the ink storage chamber R and a flow path forming portion 10B (described later) that defines a flow path from there to the ink supply port 60. . As shown in FIG. 3, a capillary force generating member 61 and a meniscus holding member 62 are disposed at the ink supply port 60. The capillary force generating member 61 is a material having a certain degree of flexibility so that, when a recording head is connected to the ink supply port 60, the vertical displacement (vertical direction in FIG. 2) of the recording head can be absorbed. Generates capillary force. As will be described later, the ink storage chamber R is maintained at a negative pressure so that the ink does not leak from the ink supply port 60 to the outside. The meniscus holding member 62 forms 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 force 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 attached so as to be swingable in the directions of arrows C1 and C2. The stirring members 20A and 20B in this example are mainly plate members made of metal, and are provided on the inner wall of the tank case 10 in the respective recesses 21A and 21B, as shown in FIGS. 3 and 4A. It is supported by the support portions 15A and 15B.

  The support portions 15A and 15B include a shaft portion and a retaining portion that are provided so as to be parallel to the carriage movement direction of the recording apparatus described later. The shaft portions are inserted into the recesses 21A and 21B provided at the upper ends of the stirring members 20A and 20B, thereby supporting the stirring members 20A and 20B so as to be swingable. Yes. For example, the support portion may be a member formed in a rivet shape by expanding the tip portion of a boss protruding from the tank case 10 made of a resin material by thermal processing. That is, a portion protruding from the tank case 10 can be a shaft portion, and a portion widened by thermal processing can be a retaining portion.

  Furthermore, concave digging portions 14A and 14B corresponding to the shapes and dimensions of the stirring members 20A and 20B are formed in the inner wall 10A of the tank case 10, and the stirring members 20A and 20B can enter. is there.

  The spring member 30 which is a conical coil spring is positioned in the digging portion 11 formed on the inner wall 10 </ b> A of the tank 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 central part shape of the flexible member 40 of this example is regulated by the pressure plate 31 which is a flat plate-like support member, and the peripheral part of the flexible member 40 can be deformed. The flexible member 40 has a central portion formed in advance in a convex shape, and its cross-sectional shape is substantially trapezoidal. 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 described above, the flexible member 40 is smoothly deformed (moved), so that an abnormal pressure fluctuation does not occur in the ink storage chamber R due to the impact.

  The spring member 30 in the form of a compression spring urges the flexible member 40 in the left direction in FIG. 3 (right direction in FIG. 2) via the pressure plate 31. A predetermined negative pressure is generated in the ink storage chamber R by the biasing force acting in the direction of expanding the ink storage chamber R. Due to the negative pressure, the ink in the recording head is balanced with the holding force of the meniscus of the ink formed in the ink discharge portion, and a negative pressure in a range where the ink discharge operation of the recording head is possible is applied. 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. In this state, the spring member 30 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 a negative pressure with respect to the atmospheric pressure due to the pressure load of the spring member 30 against the pressure plate 31 and the pressure added to the plane area of the flexible member 40.

  When the ink 2 is supplied to the recording head and consumed from the state in which the ink storage chamber R is almost completely filled as shown in FIG. 2, the pressure plate resists the biasing force of the spring member 30. 31 moves to the left in FIG. 2, 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 conical coil spring in which the strands do not interfere so that the thickness at the maximum compression is equal to the wire diameter. Since the spring member 30 is completely accommodated in the digging portion 11 at the time of maximum compression, the spring member 30 does not hinder the displacement of the pressure plate 31.

  When the pressure plate 31 is displaced as the ink 2 is consumed, the rocking range of the stirring members 20A and 20B is reduced by being restricted by the pressure plate 31, but the dug portions 14A and 14B are formed in the tank case 10. Therefore, the stirring members 20A and 20B can be swung. Further, the displacement of the pressure plate 31 is not hindered by the stirring members 20A and 20B. Furthermore, although the ink outlet 64 is located above the lowermost surface of the ink storage chamber R, the pressure plate 31 has a notch 32 having a shape corresponding to the ink outlet 64, so that the pressure The plate 31 can be displaced until it contacts the inner wall 10 </ b> A of the tank case 10. In the case of this example, since air is not taken into the ink storage chamber R from the outside, it is possible to supply ink positioned below the ink outlet 64 to the recording head.

  As shown in FIG. 4A, the ink outlet 64 in the ink storage chamber R is installed at a position higher than the lowermost surface (bottom surface) of the ink storage chamber.

  The present inventors have verified how high the sedimentation layer deposited at the lowest part in the direction of gravity is when the ink tank is stored in a constant posture (the state shown in FIG. 2) for a long period of time. And when it confirmed with the ink containing the pigment particle with the density | concentration of 4% which is most prone to sedimentation, it turned out that it is about 3% of the height of an ink storage chamber. Therefore, in this embodiment, the ink tank 1 is configured such that the ink outlet 64 is positioned at a position higher than the bottom of the ink storage chamber by 3% or more of the height of the ink storage chamber.

  When such an ink tank 1 is mounted on the recording apparatus and left in a usable state (a state in which the ink supply port 60 faces downward), the precipitated pigment layer is deposited at the bottom of the ink storage chamber. As described above, when the ink outlet port is provided at the lowermost part, the deposited precipitated pigment layer enters the ink outlet port while drawing the precipitated pigment layer around the ink outlet port. A large amount of the precipitated pigment that has moved further downstream from the ink outlet port is deposited on the portion of the capillary force generating member 61. In such an accumulation state, stirring cannot be performed by the operation of the stirring members 20A and 20B provided in the ink storage chamber, and the recording head flows into the recording head during recording, disturbs the recording quality, and the ejection port is clogged. May cause a discharge failure.

  On the other hand, in the present embodiment, the ink outlet 64 is basically disposed at a position higher than the height of the sedimented pigment to be deposited, so that the sedimented pigment deposited in the standing state enters the ink outlet 64. Is prevented. That is, it is possible to prevent the sedimentation pigment from accumulating in the non-stirable region in the ink tank in the long-term leaving with being attached to the recording apparatus, in particular, in the standing state with the supply port 60 facing downward.

  Further, in the present embodiment, as shown in FIG. 4B, the flow path forming portion 10B of the tank case 10 is provided with two ink outlets 64, each of which is a raised portion having a triangular cross section. The highest portion, that is, the ridge line portion formed by joining two inclined surfaces is provided. That is, in a posture in which the ink supply port 60 faces downward, the flow path forming portion 10B in the vicinity of the ink outlet port 64 has a raised portion having a shape with an inclined surface that descends in the direction of gravity with the ink outlet port 64 as a top. Yes. As a result, most of the precipitated pigment in the vicinity of the ink outlet 64 slides down the inclined surface, moves away from the ink outlet 64, and moves to the bottom surface portion of the ink storage chamber R away from the ink outlet 64. Accordingly, when the ink moves due to the ink derivation, it is difficult to be dragged into the ink outlet 64.

  In addition to such effects, the configuration of the present embodiment can also obtain the following effects.

  FIG. 5 is a sectional view of the ink tank 1 and shows a state in which the ink 2 in the ink storage chamber R is used. FIG. 6 is a schematic enlarged view of the vicinity of the ink outlet 64 (B portion in FIG. 5).

  In FIG. 5, the ink 2 in the ink storage chamber R is discharged to the outside through the ink outlet 64, the flexible member 40 is deformed, and the volume of the ink storage chamber R changes. When the remaining amount of ink decreases, as shown in FIG. 6, the flexible member 40 is in a state of covering the ink outlet 64 due to deformation accompanying the volume change of the ink storage chamber R. When the raised portion of the flow path forming portion 10B where the ink outlet 64 is present is a horizontal plane, the ink outlet 64 is blocked by the flexible member 40 as described above, and there is a possibility that the ink cannot be led out. . Then, the amount of ink that can be derived or supplied is not stable, and non-ejection or the like may occur during recording, which may cause recording failure.

  On the other hand, in the present embodiment, the ink outlet 64 is on the ridge line portion where the inclined surface K1 and the inclined surface K2 of the raised portion are joined, and on the ridge line portion where the inclined surface K3 and the inclined surface K4 of the raised portion are joined. Are provided respectively. For this reason, as shown in FIG. 6, the ink outlet 64 is formed so as to extend from the ridgeline where the inclined surface joins to a low position along the inclined surface, and does not form a plane that faces the flexible member 40. Become. That is, even when the flexible member 40 contacts the ridge line portion, a predetermined gap is formed between the ink outlet 64 and there is no possibility that the ink outlet 64 is blocked. It becomes possible.

  FIG. 7 shows a modification of the present embodiment. In this example, the ink outlet 64 or the raised portion where the flow path is formed has a semicircular cross section, and the ink outlet 64 is the top of the semicircular raised portion farthest from the bottom surface of the ink storage chamber R. Is formed. Also according to this modification, the same effects as described above can be obtained. As described above, if the expected effect of the present invention can be expected, the shape of the raised portion provided with the ink outlet 64 can be determined as appropriate.

  Further, the number of the ink outlets 64 or the protruding portions forming the ink outlets 64 is not limited to the number shown in the figure, and the required number is arranged based on the required ink flow rate and the pressure loss in the flow path. That's fine.

  Although it has been described that the ink outlet 64 is preferably disposed at a position higher than the bottom surface of the ink storage chamber R, if it is configured to be higher than necessary, a problem in ink stirring performance occurs.

  FIG. 8 is a schematic perspective view showing the internal structure of the ink tank for explaining this. In FIG. 8, the ink outlet 64 is formed at a position higher than the bottom surface of the ink storage chamber R. Here, if the left and right stirring members 220A and 220B have the same length and a sufficient length, but the raised portion forming the ink outlet 64 or the flow path is high, it interferes with one stirring member 220A. . For this reason, if the length of the stirring member 220A is shorter than that of the stirring member 220B, the stirring effect is deteriorated, and the left and right stirring balance is lost, and it is considered that the stirring in the vicinity of the ink outlet is not sufficiently performed.

  Therefore, the ink tank of this embodiment may be designed by optimizing the height of the ink outlet from the initial pigment concentration and the settling rate. Thereby, it becomes possible to obtain a configuration in which the precipitated pigment is not deposited in the non-stirred region without deteriorating the stirring performance.

(Configuration of inkjet recording apparatus)
FIG. 9 is a diagram for explaining a configuration example of an ink jet recording apparatus to which the present invention can be applied.

  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 driving force transmission mechanism such as a carriage motor and 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 can be set to an arbitrary number of 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 in the direction A together with the carriage 153. The transport operation is an operation for transporting the paper P in the sub-scanning direction, for example, by a distance corresponding to the width of the region recorded by one recording scan of the recording head.

  (A), (b), (c), and (d) in FIG. 9 indicate movement positions when the carriage 153 reciprocates along the virtual locus along the direction A. 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 continuously moves in the direction of the arrow A2 thereafter. By using such a reciprocating motion of the carriage 153 in the directions of arrows A1 and A2, the ink 2 in the ink tank 1 is agitated as will be described later.

  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.

  At the left end in FIG. 9 in the movement area of the carriage 153, a recovery system unit 158 is provided that faces 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.

(Ink stirring mechanism)
FIGS. 10A, 10B, 10C, and 10D 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 the operating states. The stirring member 20B operates in the same manner as the stirring member 20A.

  First, as shown in FIG. 10A, when the carriage 153 starts to move in the direction of the arrow A1, the stirring member 20A in the ink tank starts to rotate in the direction of the arrow C1 by the inertial force around the support portion 15A. . 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 begins to flow into the expanded space S.

  Next, as shown in FIG. 10B, the rotation angle of the stirring member 20A, in which the carriage 153 further moves in the direction of the arrow A1, is within the range of the gap between the recess 21A of the stirring member 20A and the shaft of the support portion 15A. Ink flows into the generated space S as shown by the arrow D1. In this state, the stirring member 20A has the maximum angle, but since the carriage 153 is still moving in the direction of the arrow A1, further inertial force is applied, and the end of the stirring member 20A on the support portion side as indicated by the arrow C3. Even begin to move.

  Next, as shown in FIG. 10C, when the carriage 153 reverses and starts to move in the direction of the arrow A2, the space S has the maximum volume. Thereafter, by the deceleration of the carriage 153 and the acceleration in the direction of the arrow A2, the stirring member 20A that has been maximally swung in the direction of the arrow C1 so far starts swinging in the opposite direction of the arrow C2. As a result, the distance between the stirring member 20A and the inner wall 10A begins to decrease, and ink flows further upward as indicated by the arrow D2.

  Next, as shown in FIG. 10D, 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 portion 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. Therefore, 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, an inertial force is further applied to the stirring member 20A, and the support side end portion starts to move as indicated by an arrow C4.

  With such an ink flow, the ink stirring efficiency in the entire ink storage chamber R can be increased. Since a frictional resistance is generated between the stirring member 20A and the support portion 15A, an operation in which the free end of the stirring member 20A moves in advance and then the support portion side end moves is possible. The operation creates a pump effect and allows the ink in the lower part of the ink storage chamber to circulate upward. Furthermore, by configuring the free end side that moves greatly to the lower side in the vertical direction, it becomes easier to stir the pigment component that has settled below the ink storage chamber, and in combination with the pump effect described above, the ink in the entire ink storage chamber Can be mixed.

  Thereafter, the agitating member 20A returns from the state of FIG. 10D to the state of FIG. 10A, and thereafter, as long as the reciprocating operation of the carriage 153 continues, FIGS. 10A, 10B, 10C, 10C Repeat d).

  By the way, when the recording apparatus is left for a long period 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. The ink in the ink tank 1 can be efficiently stirred by causing an upward ink flow as described above. Therefore, the ink in the ink storage chamber R can be reliably stirred to a uniform concentration in a short time.

  Further, in this example, as described above, the ink outlet 64 is disposed above the lowermost surface of the ink storage chamber R. As a result, the sedimentation of the ink immediately above the ink outlet 64 reaches the meniscus holding member 62 or the capillary force generating member 61, but the other portion of the precipitated ink does not enter the ink outlet 64. That is, in this embodiment, the ink outlet 64 is provided at a position higher than the height at which the ink layer having a high ink density shown in FIG. 14 exists. For this reason, the precipitated ink at a position higher than the height and immediately above the ink outlet 64 enters from the ink outlet 64, but the other portions of the precipitated ink do not enter. In particular, the ink outlet 64 is not formed on a horizontal plane as described above, but is formed on the ridge portion where the inclined surfaces are joined, which makes it more effective to prevent the precipitation ink from entering.

  Further, the intruding ink is not a portion having the highest density but an ink having a density slightly increased from the initial density. Thereby, in a certain storage period, it is not necessary to discharge the ink from the ink outlet 64 to the capillary member 61 by the recovery operation before executing the recording operation. For example, if the operation (reciprocating movement of the carriage) as shown in FIGS. 10A to 10D is performed several times before the recording operation and agitation is performed, 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 this example, the ink concentration at the position of the ink outlet 64 is as shown in FIG. 14 when the storage period is relatively short. In some cases, the concentration gradient is an initial concentration suitable for recording. 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.

  Furthermore, 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)
FIGS. 11A and 11B are a schematic perspective view and a partially enlarged view showing the internal configuration of the ink tank according to the second embodiment of the present invention, respectively. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, three ink outlets 164 are provided and formed in one plane, but the formation surface is not a horizontal plane, but a surface inclined in the direction of gravity in the mounting posture to the recording apparatus. It is. In the case where the tank case 10 is a resin molded part, this inclination angle may be an inclination angle formed with a general draft that is required depending on the mold configuration. In addition, convex steps 18 extend from the ink storage chamber inner wall 10 </ b> A toward both sides of the ink outlet arrangement range and positions between the ink outlets.

  According to the present embodiment, by providing a plurality of (three in the illustrated example) ink outlets 164 on one plane, the flow path when the ink consumption is advanced and the flexible member 40 is displaced to the maximum extent. It becomes possible to reduce the unusable capacity formed between the formation part 10B. That is, in the first embodiment, since the plurality of ink outlets 164 or the flow paths are formed in the different raised portions in the flow path forming portion 10, the volume of the space between the raised portions becomes an unusable capacity. obtain. On the other hand, in this example, such unusable capacity can be reduced, and the amount of ink remaining in the ink storage chamber R can be reduced.

  In this example, the flat portion where the ink outlet 164 opens is inclined in the direction of gravity in the recording apparatus mounting posture. Accordingly, most of the precipitated pigment deposited on this plane moves from the flat surface where the ink outlet 164 is formed to the bottom surface of the ink storage chamber R along the inclined surface, and the ink outlet 164 or in the flow path. The amount flowing into the can be reduced.

  Furthermore, in this example, a step 18 that is more convex than the ink outlet 164 is provided on the plane (inclined surface) where the ink outlet 164 opens. In the configuration as shown in FIG. 13A in which the step 18 is not provided, the plane formed by the ink outlet 164 and the plane formed by the flexible member 40 at the end of use of the ink tank are in a parallel state. As shown in (b), the ink outlet 164 is blocked by the flexible member 40. That is, there is a possibility that the amount of ink that can be used in the ink storage chamber R is not stable and the use efficiency is sometimes lowered. Further, such blockage prevents ink from being led out at all, which may lead to a non-ejection state during the recording operation.

  On the other hand, in this example, the convex step 18 present at a position higher than the ink outlet 164 causes the flexible member 40 to be displaced as much as possible on the ink outlet 164 as shown in FIG. Even in the positioned state, a certain gap is formed between the ink outlet 164. That is, the ink outlet 164 is not blocked.

  As described above, also in the ink tank of the present embodiment, it is possible to prevent the occurrence of inconvenience that an image with uneven density due to the precipitated pigment is formed or non-ejection occurs, and the ink tank is stable to the end. Ink can be supplied.

  The number of ink outlets 164 is not limited to the number shown in the figure, and the required number may be arranged based on the required ink flow rate and pressure loss in the flow path.

  The step 18 is effective when the ink outlet port can be closed by the relationship between the plane formed by the ink outlet port 164 and the plane formed by the flexible member 40 at the end of use of the ink tank. It suffices if the height is different from the surface on which 164 is formed. Furthermore, as a configuration for obtaining the same function and effect, a concave groove penetrating the ink outlet 164 from the inner wall 10A, for example, along the plane is indicated by a one-dot chain line in FIG. You may form as follows. It is also possible to use a combination of such a groove and a convex step.

DESCRIPTION OF SYMBOLS 1 Ink tank 2 Ink 10 Tank case 10A Inner wall 10B Flow path formation part 18 Level | step difference 20A, 20B, 220A, 220B Stirring member 64, 164 Ink outlet

Claims (6)

An ink tank having an ink storage chamber,
An opening surface that is located inside the ink storage chamber and has a plurality of ink outlets for discharging ink in the ink storage chamber ;
A flexible member that constitutes at least a portion of the ink storage chamber and causes a reduction in the volume of the ink storage chamber by being deformed as the ink is led out;
A suffocation suppressing member that is provided on the opening surface in the vicinity of the plurality of ink outlets and prevents the ink outlets from being blocked by deformation of the flexible member;
Have
Said choking suppression member is a stepped portion that is convex with respect to they said opening surface, toward the inner wall of the ink storage chamber between each said ink outlet port each tooth is a comb tooth shape that extends Characteristic ink tank.   The ink tank according to claim 1, wherein the plurality of ink outlets are open upward in a use posture of the ink tank. 3. The ink tank according to claim 1, wherein, in the use posture of the ink tank, the opening surface is disposed above a portion located at the lowest position of the ink storage chamber.   4. The ink tank according to claim 1, wherein a normal line of the opening surface is inclined with respect to a direction of gravity in the use posture of the ink tank. 5. The ink tank according to claim 1, further comprising a stirring member that stirs the ink in the ink storage chamber. The ink tank according to claim 1, wherein ink containing a pigment component is stored in the ink storage chamber.

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