Patent Description:
There is known a printing apparatus that discharges ink stored in an ink tank from a printhead to a print medium, thereby printing an image. If the remaining ink amount in the ink tank decreases, the user replenishes ink to the ink tank. If the replenishing work is quickly performed, convenience of the user improves. <CIT>, <CIT> and <CIT> disclose ink tanks including a channel in which ink flows, and a channel used to remove air. Gas-liquid exchange is performed between an ink tank and a replenishing bottle by the two channels.

However, the structures disclosed in <CIT>, <CIT> and <CIT> have room for improvement in terms of the flow-in speed of ink from the replenishing bottle to the ink tank.

The present invention provides a technique for improving the flow-in speed of a liquid from a replenishing bottle to a liquid container.

The present invention in a first aspect provides a liquid container as specified in claims <NUM> to <NUM>.

The present invention in a second aspect provides a printing apparatus as specified in claim <NUM>.

<FIG> is a perspective view of a printing apparatus <NUM> according to an embodiment of the present invention, which is viewed from the front side. <FIG> is a perspective view showing the configuration of a part of the printing apparatus <NUM> viewed from the rear side. The printing apparatus <NUM> according to this embodiment is an inkjet printing apparatus that performs printing on a print medium by discharging ink. In the drawings, arrows X, Y, and Z indicate directions intersecting each other, and these are orthogonal to each other in this embodiment. The arrow Z indicates a vertical direction (gravity direction). The X direction is the widthwise direction of the printing apparatus <NUM> (the left- and-right direction, or the widthwise direction of a print medium). The Y direction is the depth direction of the printing apparatus <NUM> (front-and-rear direction).

Note that "printing" includes not only forming significant information such as characters and graphics but also forming images, figures, patterns, and the like on print media in a broad sense, or processing print media, regardless of whether the information formed is significant or insignificant or whether the information formed is visualized so that a human can visually perceive it. In addition, although in this embodiment, sheet-like paper is assumed as a "print medium", cloth, a plastic film, and the like may also be used.

The printing apparatus <NUM> includes a conveyance roller <NUM> extended in the X direction. The conveyance roller <NUM> conveys a sheet-like print medium <NUM> in the Y direction (sub-scanning direction). The conveyance roller <NUM> is rotated by a conveyance motor (not shown) that is a driving source for the conveyance roller. When the conveyance roller <NUM> rotates, the print medium <NUM> is conveyed on a platen <NUM>.

Ink tanks 2Bk, 2C, <NUM>, and 2Y (to be referred to as ink tanks <NUM> hereinafter generically or without distinction) are liquid containers in which liquid inks are stored. In this embodiment, the ink tank <NUM> is a stationary type container fixed in the printing apparatus <NUM>. If the remaining ink amount decreases, a user replenishes ink to the ink tank <NUM> using a replenishing bottle <NUM> (to be described later) without detaching the ink tank <NUM> from the printing apparatus <NUM>.

Inks of different types are stored in the four ink tanks <NUM>. In this embodiment, inks of different colors are stored in the ink tanks <NUM>. More specifically, black ink is stored in the ink tank 2Bk, cyan ink is stored in the ink tank 2C, magenta ink is stored in the ink tank <NUM>, and yellow ink is stored in the ink tank 2Y Note that the types of inks are not limited to four types, as in this embodiment, and one type of ink may be used, or a plurality of types other than the four types may be used. The number of ink tanks <NUM> need only be equal to or more than the number of types of inks.

The printing apparatus <NUM> includes a carriage <NUM>. The carriage <NUM> is a support member that supports a printhead 13A and a printhead 13B. The carriage <NUM> according to this embodiment can move in the X direction (main scanning direction) with the printhead 13A and the printhead 13B mounted thereon. The printhead 13A and the printhead 13B each perform printing by discharging ink to the print medium <NUM>. The printhead 13A discharges cyan ink, magenta ink, and yellow ink supplied from the ink tanks 2C, <NUM>, and 2Y via tubes <NUM>. The printhead 13B discharges black ink supplied from the ink tank 2Bk via the tube <NUM>. The tube <NUM> is provided for each ink type, and the number of tubes <NUM> is four in this embodiment.

The lower surface of each of the printheads 13A and 13B includes a discharge surface with a plurality of nozzles for discharging ink. The discharge surface is arranged to face the platen <NUM>. Each nozzle is provided with, for example, an electrothermal transducer (heater). When the electrothermal transducer is energized, it is heated to foam ink, and the ink is discharged by the foaming energy. A structure that discharges ink using a piezoelectric element in place of the electrothermal transducer may be used.

The carriage <NUM> is guided by a guide member <NUM> and reciprocally moved in the X direction by the driving force of a driving unit (not shown). The driving unit includes, for example, a driving pulley and a driven pulley which are arranged apart in the X direction, an endless belt wound around the pulleys, and a carriage motor that is a driving source for rotating the driving pulley. The carriage <NUM> is connected to the endless belt. When the endless belt is made to travel, the carriage <NUM> moves in the X direction.

In the process of the movement of the carriage <NUM>, ink is discharged from each of the printhead 13A and the printhead 13B to the print medium <NUM> on the platen <NUM>, thereby printing an image. This operation is sometimes called print scanning. A printing operation is performed by alternately repeating a print medium conveyance operation by the conveyance roller <NUM> and print scanning.

As described above, the printing apparatus <NUM> according to this embodiment is a serial type inkjet printing apparatus in which the printhead 13A and the printhead 13B are mounted on the carriage <NUM> that reciprocally moves in the X direction. However, the present invention can also be applied to another printing apparatus such as an inkjet printing apparatus including a so-called full-line printhead in which a plurality of nozzles configured to discharge ink are provided in a region corresponding to the width of a print medium.

The ink tanks 2C, <NUM>, and 2Y are containers having the same structure. The ink tank 2Bk is a container that substantially has the same structure as the ink tanks 2C, <NUM>, and 2Y and has a larger capacity than these. For this reason, the ink tank 2Bk is a container having a larger width in the X direction than the ink tanks 2C, <NUM>, and 2Y. The ink tank 2Bk is arranged at the left end in the front portion of the printing apparatus <NUM>. The ink tank 2Bk is made of a translucent material, and the user can visually recognize the remaining amount of stored ink. The ink tanks 2C to 2Y are arranged side by side in the Y direction at the right end in the front portion of the printing apparatus <NUM>. The ink tanks 2C to 2Y are also made of a translucent material. The user can visually recognize the remaining amount of stored ink.

The structure of the ink tanks <NUM> will be described using the ink tank 2C as a representative. <FIG> are exploded perspective views of the ink tank 2C. <FIG> are side views of the ink tank 2C. <FIG> shows a side portion 21d, and <FIG> shows a side portion 21c.

The ink tank 2C has an L outer shape as a whole. The ink tank 2C includes a main body <NUM>, and left and right sealing members 20a and 20b. The main body <NUM> is a container main body including a top portion 21a, a front portion 21b, and the left and right side portions 21c and 21d, and is a hollow structure made of a resin. The sealing members 20a and 20b according to this embodiment are flexible films and are fixed to the side portions 21c and 21d of the main body <NUM> by adhesion or welding. The sealing members 20a and 20b cover and seal openings and grooves of the side portions 21c and 21d of the main body <NUM>. All the main body <NUM> and the sealing members 20a and 20b are translucent members. These members may be colored transparent or colorless transparent.

A needle <NUM> projects upward from the top portion 21a of the ink tank 2C. The needle <NUM> is a tubular member formed integrally with the main body <NUM> and extending in the Z direction, and forms a channel used to inject replenishing ink from the outside into the ink tank 2C. A detachable cap <NUM> is attached to the distal end (upper end) of the needle <NUM>.

A tubular outlet portion <NUM> is formed on the rear portion of the ink tank 2C. The outlet portion <NUM> is the outlet for the ink stored in the ink tank 2C, and is a liquid outlet used to make the ink flow to the printhead 13A. The tube <NUM> is connected to the outlet portion <NUM>, and the ink stored in the ink tank 2C is supplied from the outlet portion <NUM> to the printhead 13A via the tube <NUM>.

A lower limit indicator 24b roughly indicating the lower limit of a remaining amount serving as an ink replenishing timing and an upper limit indicator 24a roughly indicating the upper limit when replenishing ink are formed on the front portion 21b. The upper limit indicator 24a and the lower limit indicator 24b are formed by the shape of the main body <NUM> (by forming a concave portion or a convex portion) or by printing a chart.

An engaging portion 23a is formed on the front portion 21b of the ink tank 2C, and an engaging portion 23b is formed on the rear portion. The engaging portions 23a and 23b engage with engaging portions (not shown) formed on the housing (not shown) of the printing apparatus <NUM>, thereby fixing and positioning the ink tank 2C.

The ink tank 2C includes, on the side of the bottom portion, a storage portion <NUM> that stores ink. The storage portion <NUM> is defined by a space opening to the side portion 21d of the main body <NUM> and the sealing member 20b. The storage portion <NUM> communicates with the needle <NUM> via channels <NUM> and <NUM>. The channels <NUM> and <NUM> are defined by grooves opening to the side portion 21c of the main body <NUM> and the sealing member 20a. The outlet portion <NUM> is formed to be higher than the liquid surface of ink when a maximum amount of ink is stored in the storage portion <NUM>.

The storage portion <NUM> and the outlet portion <NUM> communicate with the other via a channel 29a. The channel 29a is defined by a groove opening to the side portion 21c of the main body <NUM> and the sealing member 20a. Ink stored in the storage portion <NUM> is supplied to the printhead 13A via the channel 29a, the outlet portion <NUM>, and the tube <NUM>.

An air communicating port <NUM> is formed in the front portion 21b that is the front side portion of the ink tank 2C. The air communicating port <NUM> opens to the front side of the ink tank 2C in the Y direction. Since an upward opening is not formed, a foreign substance hardly closes the air communicating port <NUM>. The air communicating port <NUM> communicates with the storage portion <NUM> via buffer chambers 28a to 28e and channels 29b to 29f. Even if the ink tank 2C is placed in a posture different from that in use time, the ink in the storage portion <NUM> is prevented from leaking from the air communicating port <NUM>.

The buffer chambers 28a and 28b are defined by spaces opening to the side portion 21c of the main body <NUM> and the sealing member 20a. The buffer chambers 28c to 28e are defined by spaces opening to the side portion 21d of the main body <NUM> and the sealing member 20b. The channel 29c is defined by a groove opening to the side portion 21d of the main body <NUM> and the sealing member 20b. The channels 29d to 29f are defined by grooves opening to the side portion 21c and the sealing member 20a.

One of the two end portions of the channel 29b opens to the storage portion <NUM>, and the other opens to the buffer chamber 28b. The storage portion <NUM> and the buffer chamber 28b communicate via the channel 29b. One of the two end portions of the channel 29c opens to the buffer chamber 28a, and the other opens to the buffer chamber 28b. The buffer chamber 28a and the buffer chamber 28b communicate via the channel 29c. One of the two end portions of the channel 29d opens to the buffer chamber 28a, and the other opens to the buffer chamber 28c. The buffer chamber 28a and the buffer chamber 28c communicate via the channel 29d. One of the two end portions of the channel 29e opens to the buffer chamber 28c, and the other opens to the buffer chamber 28d. The buffer chamber 28c and the buffer chamber 28d communicate via the channel 29e. One of the two end portions of the channel 29f opens to the buffer chamber 28d, and the other opens to the buffer chamber 28e. The buffer chamber 28d and the buffer chamber 28e communicate via the channel 29f. The buffer chamber 28e communicates with the air communicating port <NUM>.

If the printing apparatus <NUM> is left stand for a long time in a posture other than that in use time, and the atmospheric pressure/temperature changes in that state, it is considered that air in the ink tank 2C expands or shrinks. A mechanism that suppresses ink leakage from the air communicating port <NUM> in this state will be described using, as an example, a state in which the maximum amount of ink is stored in the storage portion <NUM> for storing ink.

Assume a case where the printing apparatus <NUM> is in a posture with the sealing member 20a located on the lower side and the sealing member 20b located on the upper side. The ink liquid surface is located on the lower side of the channel 29b that makes the storage portion <NUM> and the buffer chamber 28b communicate. Since the interior of the ink tank 2C communicates with the exterior of the ink tank 2C, the ink never flows from the channel 29b into the buffer chamber 28b. For this reason, the ink never leaks from the air communicating port <NUM>.

Next, assume a case where the printing apparatus <NUM> is in a posture with the sealing member 20a located on the upper side and the sealing member 20b located on the lower side. The ink liquid surface is located at a position higher than the channel 29b that makes the storage portion <NUM> and the buffer chamber 28b communicate. Hence, the ink flows from the storage portion <NUM> to the buffer chamber 28b. Also, since the buffer chamber 28b communicates with the buffer chamber 28a via the channel 29c, the ink flows to the buffer chamber 28a via the channel 29b, the buffer chamber 28b, and the channel 29c. However, the end portion of the channel 29d that makes the buffer chamber 28a and the buffer chamber 28c communicate is located on the surface covered with the sealing member 20a. Hence, the ink does not flow to the next channel 29d and the buffer chamber 28c unless the buffer chamber 28a is filled with the ink. Since the buffer chambers 28c and 28d have similar configurations, the risk that the ink leaks from the air communicating port <NUM> is low.

Next, assume a case where the printing apparatus <NUM> is in a posture with its top and bottom portions being inverted. Since the ink liquid surface is located at a position higher than the channel 29b that makes the storage portion <NUM> and the buffer chamber 28b communicate, the ink flows to the buffer chamber 28b. In this posture, the end portion of the channel 29c in the buffer chamber 28b is located on the upper side of the buffer chamber 28b. For this reason, the ink does not flow to the buffer chamber 28a via the channel 29c unless the buffer chamber 28b is filled with the ink. Since the buffer chambers 28a and 28c have similar configurations, the risk that the ink leaks from the air communicating port <NUM> is low.

Next, assume a case where the printing apparatus <NUM> is in a posture with its front portion located on the lower side. In this posture, the ink tank 2C is in a posture with the air communicating port <NUM> facing downward. Since the channel 29b is located on the lower side of the ink liquid surface, the ink flows to the buffer chamber 28b via the channel 29b. In this posture, the end portion of the channel 29c in the buffer chamber 28b is located on the upper side of the buffer chamber 28b. For this reason, the ink does not flow to the buffer chamber 28a via the channel 29c unless the buffer chamber 28b is filled with the ink. In addition, even if the buffer chamber 28b is filled with the ink, an ink amount that causes the ink liquid surface in the storage portion <NUM> to be located on the lower side of the channel 29b can be stored in other buffer chambers. Hence, the risk that the ink leaks from the air communicating port <NUM> is low.

Finally, assume a case where the printing apparatus <NUM> is in a posture with its rear portion located on the lower side. The ink tank 2C is in a posture with the air communicating port <NUM> facing upward. This posture is the same as that when the printing apparatus <NUM> is in a posture with the sealing member 20a located on the upper side and the sealing member 20b located on the lower side. That is, the ink does not flow to the next buffer chamber 28c unless the buffer chamber 28a is filled with the ink. Since the buffer chambers 28c and 28d have similar configurations, the risk that the ink leaks from the air communicating port <NUM> is low.

As described above, in this embodiment, even if the printing apparatus <NUM> is left stand for a long time in a posture different from that in use time, and the atmospheric pressure/temperature changes, the risk of ink flow-out can be reduced, and ink leakage from the air communicating port <NUM> can be suppressed.

The structures of the needle <NUM> and the channels <NUM> and <NUM> will be described with reference to <FIG> in addition to <FIG>. <FIG> are perspective views showing a part of the ink tank 2C, and particularly show the boundary portion between the needle <NUM> and the channels <NUM> and <NUM>. <FIG> is a sectional view taken along a line A - A in <FIG>, and <FIG> is a sectional view taken along a line B - B in <FIG>. <FIG> is a sectional view taken along a line C - C in <FIG>.

The needle <NUM> has a cylindrical outer shape extending in the Z direction. The internal space of the needle <NUM> is divided by a partition wall <NUM>, and a channel <NUM> and a channel <NUM> are formed. The partition wall <NUM> is a plate on the X-Z plane. Both the channels <NUM> and <NUM> are channels extended in the Z direction, and their channel direction is the Z direction. The distal end (upper end) of the needle <NUM> has a mountain shape. Both the opening portions (the opening portions on the side of the replenishing bottle <NUM>) of the distal ends (upper ends) of the channels <NUM> and <NUM> open obliquely with respect to the channel direction. In other words, the end face of the formation portion of the channel <NUM> and the end face of the formation portion of the channel <NUM> in the needle <NUM> tilt at an angle within the range of <NUM>° to <NUM>° with respect to the X-Y plane. This suppresses formation of a liquid film of ink in the opening portions due to the surface tension of ink and improve the flow of ink at the time of ink replenishing.

As shown in <FIG>, the partition wall <NUM> is located at a position deviated from a center axis CT of the needle <NUM> to the front side in the Y direction. The sectional shape (the sectional shape on the X-Y plane) of each of the channels <NUM> and <NUM> is a fan shape. The channel <NUM> and the channel <NUM> have different sectional areas, and the sectional area of the channel <NUM> is larger than that of the channel <NUM>. The flow amount of ink at the time of replenishing can be larger in the channel <NUM> than in the channel <NUM>. The sectional shape of the channel <NUM> at an arbitrary position in the Z direction is the same except the tilting portion at the distal end of the needle <NUM>. The sectional shape of the channel <NUM> at an arbitrary position in the Z direction is also the same, except the tilting portion at the distal end of the needle <NUM>. At an arbitrary position in the Z direction including the distal end of the needle <NUM>, the channel <NUM> and the channel <NUM> have different sectional areas, and the sectional area is larger in the channel <NUM> than in the channel <NUM>.

The channel <NUM> and the channel <NUM> are extended in the Z direction and are adjacent to each other in the Y direction. The channel <NUM> and the channel <NUM> are partitioned by a partition wall <NUM> in the Y direction. The partition wall <NUM> is a plate on the X-Z plane, which is formed continuing to the partition wall <NUM> of the needle <NUM>.

The channel <NUM> is formed between the channel <NUM> and the storage portion <NUM> and communicates with these. The channel <NUM> includes, at the end portion on the side of the storage portion <NUM>, an opening portion 31a opening to the storage portion <NUM>. In addition, the channel <NUM> opens to an upper end face 31b.

The channel <NUM> is defined by the partition wall <NUM>, an inner wall surface 31c facing the partition wall <NUM>, the sealing member 20a, and an inner wall surface (the bottom portion of the groove) 31d facing the sealing member 20a. The channel <NUM> includes a shape portion <NUM> formed at the end portion on the side of the channel <NUM>. The partition wall <NUM> and the inner wall surface 31c are parallel. The sectional shape (the sectional shape on the X-Y plane) of the channel <NUM> orthogonal to the channel direction is a rectangular shape except the portion of the shape portion <NUM>. On the upper end face 31b, the channel <NUM> opens at a position closer to the inner wall surface 31d than the sealing member 20a.

The width of the channel <NUM> in the X direction changes depending on the position in the Z direction. The channel <NUM> has a width W1 in a region R1 on the side of the needle <NUM>, and a width W3 (< W1) in a region R3 on the side of the storage portion <NUM>. The regions R1 and R3 are each a uniform portion having the same width. In an intermediate region R2, the width in the X direction continuously changes. The region R2 is a changing portion whose width decreases along with approach to the storage portion <NUM>. A width W21 of the channel <NUM> in the Y direction is the same at an arbitrary position in the Z direction.

The shape portion <NUM> is formed at the end portion (the end portion on the side of the channel <NUM>) of the channel <NUM>. The shape portion <NUM> has a sectional shape common to a part of the sectional shape of the channel <NUM>. More specifically, in the shape portion <NUM>, a sectional shape having an arc concentric with respect to the center axis CT, which is common to a part of the arc of the fan shape that is the sectional shape of the channel <NUM>, is formed continuously from the channel <NUM>. The shape portion <NUM> is formed downward from the upper end face 31b in the Z direction within the range of a section P1.

When viewed in the X direction, the shape portion <NUM> is formed to the far side from a position apart by a distance L from the side portion 21c of the main body <NUM>. The arc portion of the sectional shape of the channel <NUM> is an arc within the range of about <NUM>°, and the arc of the sectional shape of the shape portion <NUM> is an arc within the range of about <NUM>°. Within the range of <NUM>°, the inner wall surface of the channel continues from the channel <NUM> to the channel <NUM>.

As is apparent from <FIG>, the sectional area of the channel largely changes between the channel <NUM> and the channel <NUM>, and the pressure loss of a fluid readily occurs. The pressure loss of the fluid is reduced by providing the shape portion <NUM> and partially maintaining the shape of the channel <NUM> even in the channel <NUM>. This can reduce the resistance to the ink passing through the boundary between the channel <NUM> and the channel <NUM> and improve the flow-in speed of the ink at the time of ink replenishing. In particular, the channel <NUM> and the channel <NUM> sometimes have different shapes due to constraints on molding of the main body <NUM> or ink replenishing efficiency. In this case, the shape portion <NUM> is effective in reducing the pressure loss of the fluid at the boundary portion between the channels.

In a section P2 of the section P1, the portion of the shape portion <NUM> having an arc sectional shape gradually becomes small downward in the Z direction. When the shape is gradually made to match from the shape portion <NUM> to the inner wall surface 31d, generation of the resistance to the flow of ink can be reduced.

Next, the channel <NUM> is defined by the partition wall <NUM>, an inner wall surface 32c facing the partition wall <NUM>, the sealing member 20a, and an inner wall surface (the bottom portion of the groove) 32d facing the sealing member 20a. The channel <NUM> includes a shape portion <NUM> formed at the end portion on the side of the channel <NUM>. The partition wall <NUM> and the inner wall surface 32c are parallel. The sectional shape (the sectional shape on the X-Y plane) of the channel <NUM> orthogonal to the channel direction is a rectangular shape except the portion of the shape portion <NUM>. On an upper end face 32b, the channel <NUM> opens at a position closer to the inner wall surface 32d than the sealing member 20a.

The width of the channel <NUM> in the X direction changes depending on the position in the Z direction. The channel <NUM> has a width W11 in a region R11 on the side of the needle <NUM>, and a width W13 (< W11) in a region R13 on the side of the storage portion <NUM>. The regions R11 and R13 are each a uniform portion having the same width. In an intermediate region R12, the width in the X direction continuously changes. The region R12 is a changing portion whose width decreases along with approach to the storage portion <NUM>. A width W22 of the channel <NUM> in the Y direction is the same at an arbitrary position in the Z direction.

The shape portion <NUM> is formed at the end portion (the end portion on the side of the channel <NUM>) of the channel <NUM>. The shape portion <NUM> has a sectional shape common to a part of the sectional shape of the channel <NUM>. More specifically, in the shape portion <NUM>, a sectional shape having an arc concentric with respect to the center axis CT, which is common to a part of the arc of the fan shape that is the sectional shape of the channel <NUM>, is formed continuously from the channel <NUM>. The shape portion <NUM> is formed downward from the upper end face 32b in the Z direction within the range of a section P11.

When viewed in the X direction, the shape portion <NUM> is formed to the far side from a position apart by the distance L from the side portion 21c of the main body <NUM>. The arc portion of the sectional shape of the channel <NUM> is an arc within the range of about <NUM>°, and the arc of the sectional shape of the shape portion <NUM> is an arc within the range of about <NUM>°. Within the range of <NUM>°, the inner wall surface of the channel continues from the channel <NUM> to the channel <NUM>.

In a section P12 of the section P11, the portion of the shape portion <NUM> having an arc sectional shape gradually becomes small downward in the Z direction. When the shape is gradually made to match from the shape portion <NUM> to the inner wall surface 32d, generation of the resistance to the flow of ink can be reduced.

When the channel <NUM> and the channel <NUM> are compared, W1 = W11, W3 < W13, the length of R2 in the Z direction > the length of R12 in the Z direction, and the length of R3 in the Z direction < the length of R13 in the Z direction. Note that the channel <NUM> and the channel <NUM> have the same length in the Z direction. In addition, W21 < W31.

When the entire capacity is compared between the channel <NUM> and the channel <NUM>, the entire capacity of the channel <NUM> is larger than that of the channel <NUM>. When the sectional area (on the X-Y plane) at an arbitrary position in the Z direction is compared between the channel <NUM> and the channel <NUM>, the sectional area of the channel <NUM> is larger than that of the channel <NUM>. Also, the opening area of the opening portion 31a < the opening area of an opening portion 32a. The change of the sectional area at the boundary between the channel <NUM> and the channel <NUM> is larger than the change of the sectional area at the boundary between the channel <NUM> and the channel <NUM>.

When the shape portion <NUM> and the shape portion <NUM> are compared, the length of the section P1 in the Z direction < the length of the section P11 in the Z direction. When viewed in the X direction, both the shape portions <NUM> and <NUM> are formed to the far side from the position apart by the distance L from the side portion 21c of the main body <NUM>, and the sectional area of the channel <NUM> is larger than the sectional area of the channel <NUM>. Hence, the contour length of the sectional shape of the shape portion <NUM> common to the channel <NUM> (the arc length within the range of about <NUM>° in <FIG>) is longer than the contour length of
the sectional shape of the shape portion <NUM> common to the channel <NUM> (the arc length within the range of about <NUM>° in <FIG>).

When the set of the channel <NUM> and the channel <NUM> of the needle <NUM> and the set of the channel <NUM> and the channel <NUM> of the needle <NUM> are compared, these have the following characteristics. A larger amount of ink readily flows through the channel <NUM> because its sectional area is larger than that of the channel <NUM>. On the other hand, the ink amount that the channel <NUM> can hold is small because the sectional area and the capacity of the channel <NUM> are smaller than those of the channel <NUM>. A liquid film is readily formed on the opening portion 31a of the channel <NUM> due to generation of a surface tension because the opening area is smaller than that of the opening portion 32a of the channel <NUM>.

<FIG> is a view showing a replenishing mode in which the replenishing bottle <NUM> is attached to the ink tank 2C. <FIG> are views showing the attachment procedure of the replenishing bottle <NUM> to the ink tank 2C. The replenishing bottle <NUM> is a bottle configured to replenish ink. The replenishing bottle <NUM> is provided for each ink type, and replenishes ink to the ink tank <NUM> of corresponding ink. The replenishing bottle <NUM> shown in <FIG> is a bottle for cyan ink. Replenishing bottles corresponding to other types of inks have similar structures.

The replenishing bottle <NUM> includes a storage portion <NUM> that stores ink, and a closing member <NUM> fixed to an end portion of the storage portion <NUM>. The storage portion <NUM> is a container having a cylindrical shape with one end portion open, and the closing member <NUM> is fixed to the storage portion <NUM> to close the open end portion.

An insertion hole <NUM> configured to receive the needle <NUM> is formed in the closing member <NUM>. The insertion hole <NUM> communicates with the storage portion <NUM> via a valve <NUM>. A seal member <NUM> is provided around the insertion hole <NUM>. The valve <NUM> includes an opening/closing member 55a that is movably provided, and a spring 55b configured to bias the opening/closing member 55a in a closing direction. By the bias of the spring 55b, the opening/closing member 55a is located at a closing position where the opening/closing member 55a contacts the seal member <NUM> to block the communication between the insertion hole <NUM> and the storage portion <NUM>.

An ink replenishing work using the replenishing bottle <NUM> will be described. Here, a case where cyan ink is replenished to the ink tank 2C will be described. The user prepares the replenishing bottle <NUM> that stores cyan ink. The user also detaches the cap <NUM> from the needle <NUM> of the ink tank 2C. As shown in <FIG>, the replenishing bottle <NUM> in a vertical posture with the side of the closing member <NUM> facing downward is attached to the ink tank 2C such that the needle <NUM> is inserted into the insertion hole <NUM>.

<FIG> shows a state in which the replenishing bottle <NUM> is pushed to the side of the ink tank 2C, and the needle <NUM> begins being inserted into the insertion hole <NUM>. At the stage shown in <FIG>, the needle <NUM> does not reach the opening/closing member 55a yet, and the valve <NUM> remains a closed state.

<FIG> shows a stage when the attachment of the replenishing bottle <NUM> is completed. The needle <NUM> pushes the opening/closing member 55a up against the biasing force of the spring 55b, and the opening/closing member 55a is displaced to an opening position apart from the seal member <NUM>. The valve <NUM> changes to an open state, and the storage portion <NUM> and the channel <NUM> and the channel <NUM> of the needle <NUM> communicate. The cyan ink in the storage portion <NUM> flows from the channels <NUM> and <NUM> to the ink tank 2C.

When the ink replenishing ends, the replenishing bottle <NUM> is detached from the ink tank 2C. The detachment work is done in accordance with a procedure reverse to that at the time of attachment. When the replenishing bottle <NUM> is pulled up from the state shown in <FIG>, the needle <NUM> separates from the opening/closing member 55a, and therefore, the state returns to the state shown in <FIG>. By the bias of the spring 55b, the opening/closing member 55a returns to the closing position, and the valve <NUM> returns to the closed state. Hence, the cyan ink in the storage portion <NUM> never flows out from the insertion hole <NUM>.

A behavior that ink flows from the replenishing bottle <NUM> to the storage portion <NUM> via the channels <NUM> and <NUM> of the needle <NUM> and the channels <NUM> and <NUM> in the state shown in <FIG> will be described with reference to <FIG>. <FIG>, <FIG>, <FIG>, and <FIG> correspond to sectional views taken along the line A - A in <FIG> and schematically show the flow of ink in the channels <NUM> and <NUM>. <FIG>, <FIG>, <FIG>, and <FIG> correspond to sectional views taken along the line B - B in <FIG> and schematically show the flow of ink in the channels <NUM> and <NUM>. <FIG>, <FIG>, <FIG>, and <FIG> correspond to side views of the ink tank near the channels <NUM> and <NUM>.

<FIG> show a stage when the ink begins flowing from the replenishing bottle <NUM> into the channels <NUM> and <NUM>. At the initial stage of ink flow-in, the ink substantially similarly flows into the channels <NUM> and <NUM>. After that, as shown in <FIG>, the ink reaches the opening portion 31a of the channel <NUM> and the opening portion 32a of the channel <NUM>. A liquid film is readily formed on the opening portion 31a due to a surface tension because the opening area is small. A liquid film is hardly formed on the opening portion 32a because the opening area is large. In other words, the opening portion 31a is designed to have a small opening area such that a liquid film is readily formed, and the opening portion 32a is designed to be large such that a liquid film is hardly formed.

If closing of the channel <NUM> occurs, to solve the negative pressure in the replenishing bottle <NUM>, air flows from the channel <NUM> that is not closed into the replenishing bottle <NUM>, and the ink builds up in the channel <NUM>, as shown in <FIG>. When the weight of the ink built up in the channel <NUM> becomes more than the surface tension of the liquid film on the opening portion 31a, the ink begins passing through the opening portion 31a and flowing into the storage portion <NUM>. After that, as shown in <FIG>, the ink in the replenishing bottle <NUM> continuously flows into the storage portion <NUM> via the channel <NUM>, and the air continuously flows into the replenishing bottle <NUM> via the channel <NUM>. By this gas-liquid exchange, it is possible to smoothly make the ink flow from the replenishing bottle <NUM> into the storage portion <NUM>.

In this embodiment, a liquid film by a surface tension is intentionally formed on the opening portion 31a at the initial stage, thereby implementing smooth and stable ink injection. To avoid formation of a liquid film by a surface tension at an unintended point, for example, the channels <NUM> and <NUM> are made to open obliquely at the distal end of the needle <NUM>. This makes it difficult to form a liquid film of ink. In addition, the sectional area of the channel <NUM> is made larger than that of the channel <NUM>, thereby allowing a larger amount of ink from the replenishing bottle <NUM> to flow into the ink tank <NUM> and improving the speed.

Here, in this embodiment, R1 < R11 holds concerning the length in the Z direction, and a relationship W3 < W13 holds. That is, viewed from the needle <NUM>, the channel <NUM> has a portion in which the sectional area or space is enlarged, as compared to the channel <NUM>. In this enlarged portion, flowing ink may generate a vortex and lose energy, and its flow may be impeded. When the channel <NUM> is used as the distribution path of ink, and the channel <NUM> is used as the distribution path of air, the efficiency of ink flow-in to the ink tank <NUM> can be improved.

In the above-described embodiment, a shape portion <NUM> is provided in a channel <NUM>, and a shape portion <NUM> is provided in a channel <NUM>. However, the shape portion may be provided only in one of the channel <NUM> and the channel <NUM>. In this case, the shape portion may be provided only in the channel <NUM> in which ink continuously flows.

In the above-described embodiment, an ink tank <NUM> has been exemplified as a liquid container, and a printing apparatus <NUM> including printheads 13A and 13B that discharge ink has been exemplified as an application purpose. However, the present invention can also be applied to a liquid container that stores a liquid other than ink or the application purpose of an apparatus including a discharge head that discharges a liquid other than ink.

The above-described embodiments disclose the following inventions of items.

The invention of Item <NUM> below is disclosed as an invention for providing a technique for mainly improving the flow-in speed of a liquid from a replenishing bottle to a liquid container.

Item <NUM>. A liquid container comprising:.

The invention of Item <NUM> below is disclosed as an invention for providing a technique for mainly suppressing liquid leakage from an air communicating port when a printing apparatus is installed in a posture different from use time or due to the influence of an external atmospheric pressure/temperature change.

Claim 1:
A liquid container (<NUM>) for a printing apparatus (<NUM>) comprising:
a storage portion (<NUM>) arranged to store a liquid to be supplied to a discharge head (13A,13B) that discharges the liquid;
a first channel (<NUM>) arranged to be inserted into a replenishing bottle (<NUM>), which is arranged to replenish the liquid to the storage portion (<NUM>), and to communicate with the replenishing bottle (<NUM>); and
a second channel (<NUM>) between the first channel (<NUM>) and the storage portion (<NUM>), which communicates with the first channel (<NUM>) and the storage portion (<NUM>),
wherein the second channel (<NUM>) differs in its sectional area from the first channel (<NUM>),
characterized in that
the second channel (<NUM>) includes a first shape portion (<NUM>), formed from an end portion on a side of the first channel (<NUM>) in a direction of the second channel (<NUM>) within the range of a section (P1) of the second channel (<NUM>), and having a sectional shape common to a part of a sectional shape of the first channel (<NUM>).