JP2003211695A - Ink cartridge and printer therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect an ink end in an ink cartridge. <P>SOLUTION: The ink cartridge 10 is provided with an ink impregnation chamber 12 in which an ink impregnated body 17 is stored, an ink liquid chamber 13 which can store an ink liquid flowing in from the ink impregnated body 17, a pressure adjustment chamber 14 constituted to be able to adjust an atmospheric pressure by opening/closing a vent openable to the atmosphere, a first filter 18 set at a communication part between the ink impregnation chamber 12 and the ink liquid chamber 13, a second filter 24 set between the ink liquid chamber 13 and the pressure adjustment chamber 14, and a detecting mechanism 20 constituted to detect bubbles flowing into the ink liquid chamber 13 via these filters. The first filter 18 has a plurality of passing holes 18a. A first capillary force is generated when an interface between the ink liquid and a gas is formed at the passing holes. The second filter 24 has a plurality of passing holes 24a, and a second capillary force generated by an interface formed between the ink liquid and the gas at the passing holes is set to be smaller than the first capillary force. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink cartridge applied to, for example, an ink jet printer, and in particular, a state in which the ink cartridge contains a small amount of ink (hereinafter referred to as "ink end" in the present application). Technology for detecting

[0002]

2. Description of the Related Art Generally, an ink cartridge is used in an ink jet printer.
It is configured to be able to supply a fixed amount of ink to the print head.

By the way, conventionally, when detecting the ink remaining amount of the ink cartridge, the ink amount actually consumed from the print head at the time of printing, for example, the ink consumption amount corresponding to one dot of the printed image And accumulate
Regarding the amount of ink actually sucked from the print head when cleaning the nozzle clogging, for example,
The ink remaining amount is detected from such an estimated ink consumption amount by adding from the suction capacity of the ink pump and the number of times of operation.

[0004]

However, in such conventional detection of the remaining ink amount, an error occurs between the estimated ink consumption amount and the actual ink consumption amount, and therefore, the estimated ink consumption amount is increased. Since there is a certain amount of margin in the ink cartridge, when it is detected that the remaining amount of ink is very small (ink end) even though a considerable amount of ink remains in the ink cartridge, the ink is wasted. However, there has been a problem that the ink impregnated body has to have a volume capable of impregnating an ink amount larger than the actually consumed ink amount.

Therefore, in recent years, a technique for directly detecting the ink remaining amount in the ink cartridge is being developed, instead of calculating the ink amount consumed by the print head or the ink pump communicating with the ink cartridge.

In this technique, ink is allowed to collect from the ink impregnation chamber to the ink liquid chamber through a mesh-shaped filter, and the volume ratio of air in the ink impregnation body increases as the ink is consumed. In the state close to the ink end, bubbles that have passed through the pores are detected optically or electrically in the ink liquid chamber in the state close to the ink end to make the ink end.

However, in detecting the remaining ink amount, if the capillary attraction of the filter is set based on the magnitude relationship with the capillary attraction of the print head, the ink suction force of the ink pump generally becomes the capillary attraction of the print head. Since it is larger, air may pass through the filter during the suction of the ink pump even if there is ink in the ink impregnated body, and the bubbles may cause false detection of the ink end.

On the other hand, if the capillary attraction of the filter is set in relation to the suction force of the ink pump, air bubbles will not pass through the filter during printing even though there is no ink in the ink impregnated body, and the ink end It may not be detected.

The present invention has been made in order to solve the problems of the prior art as described above, and an object of the present invention is to accurately detect the ink end in the ink cartridge.

[0010]

SUMMARY OF THE INVENTION The present invention, which has been made to achieve the above object, provides an ink impregnation chamber containing a porous ink impregnation body, an ink communicating with the ink impregnation chamber, and flowing from the ink impregnation body. An ink liquid chamber that can store liquid, a communication port that communicates with the ink liquid chamber, and a ventilation port that can be opened to the atmosphere, and the pressure adjustment configured to adjust the atmospheric pressure by opening and closing the ventilation port. A first chamber that is provided between the chamber and the ink impregnation chamber and the ink liquid chamber, has a plurality of passage holes, and causes a first capillary attraction force by the interface between the ink liquid and the gas formed in the passage holes; Of the filter, is provided between the ink liquid chamber and the pressure adjusting chamber, has a plurality of passage holes, the interface between the ink liquid and the gas formed in the passage holes,
A second filter that produces a second capillary attraction that is weaker than the first capillary attraction, and detection configured to detect bubbles that have flowed into the ink chamber from the first filter or the second filter. An ink cartridge including a mechanism. According to the present invention, in the ink end state, for example, during printing, air bubbles are taken into the ink liquid chamber from the second filter of the pressure adjusting chamber that is open to the atmosphere, while during ink suctioning. By closing the pressure adjusting chamber from the atmosphere and taking in air bubbles from the first filter into the ink liquid chamber, even if the flow rate of the ink liquid varies during printing and during ink suction, At the time of the end, the air bubble can be surely detected in the ink liquid chamber, so that the ink end can be accurately detected.

In the present invention, it is also effective that the pressure adjusting chamber is provided with a valve mechanism for opening and closing the vent hole.

According to the present invention, by opening and closing the valve mechanism, the pressure adjusting chamber is opened to the atmosphere, or the pressure adjusting chamber is shut off from the atmosphere, and the pressure applied to the second filter is made different, thereby changing the pressure of the ink end. In the state, it is possible to select a flow path for taking in gas from the second filter and a flow path for taking in gas from the first filter into the ink liquid chamber.

On the other hand, the present invention is provided with any one of the above ink cartridges and a print head configured to eject ink droplets from a plurality of nozzles communicating with the ink liquid chamber of the ink cartridge. And a third capillary that is weaker than the first capillary attraction and stronger than the second capillary attraction with respect to the relationship between the respective capillary attraction generated by the interfaces of the ink liquid and the gas formed in the first and second filters and the nozzle. The printer is characterized by generating attractive force in a nozzle.

According to the present invention, the first capillary attraction and the second capillary attraction
The capillary attraction force of the print head is determined by the magnitude relationship with the capillary attraction force of the nozzle of the print head, so that when the ink liquid cannot be supplied through the first filter in the ink end state, the gas from the second filter is discharged during printing. Can be taken into the ink liquid chamber.

In the present invention, an ink pump for sucking the ink liquid from the nozzle of the print head is provided, and the ink pump is set so that the pressure when sucking the ink is stronger than the first capillary attraction force. It is also effective to be present.

According to the invention, the first capillary attraction and the second capillary attraction
The capillary attraction force of the ink is determined according to the magnitude relationship with the pressure of the ink pump, so that when the ink liquid cannot be supplied through the first filter in the ink end state, gas is sucked from the first filter during ink suction. It can be taken into the liquid chamber.

In the present invention, a drive mechanism for driving both the valve mechanism and the ink pump is provided, and the drive mechanism is such that the vent hole of the valve mechanism is closed when the ink pump is in the state of sucking the ink liquid. It is also effective to hold the valve mechanism in the open state while holding the valve mechanism in the open state when the ink liquid is not sucked.

According to the present invention, the operation of the drive cam mechanism causes the valve mechanism and the ink pump both to open the valve mechanism without sucking ink and to close the valve mechanism to suck ink. To selectively switch between the flow path through the first filter and the flow path through the second filter to take in air bubbles into the ink liquid chamber with a minimum number of parts and power. You can

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a printer provided with an ink cartridge according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an exploded perspective view of the main part of the printer of this embodiment.

FIG. 2 is a side view showing the state of the ink pump and the valve mechanism when the print head of the printer is in a printing state, and FIG. 3 is the ink pump when the ink is sucked from the print head of the printer. It is a side view which shows the state of a valve mechanism.

FIG. 4 (a) is a diagram showing a state in which the ink remaining amount is detected during printing in the ink cartridge of this embodiment, and FIG. 4 (b) is an ink remaining amount during ink suction in the same ink cartridge. It is a figure which shows the state which detects.

As shown in FIG. 1 or 2, the printer 1 of the present embodiment is for performing printing by an ink jet method, and includes an ink cartridge 10, a print head 50, a maintenance mechanism 60, a drive cam. And a mechanism 70.

The ink cartridge 10 has an ink tank 11 which is formed in a rectangular parallelepiped shape and opens upward. The inside of the ink tank 11 is the ink impregnation chamber 1
2, the ink liquid chamber 13, and the pressure adjusting chamber 14, and the opened portion is closed by the tank cover 15. The tank cover 15 is provided with a ventilation port 16 for communicating a part of the ink impregnation chamber 12 with the atmosphere.

The ink impregnation chamber 12 is formed so as to occupy most of the volume of the ink tank 11, and accommodates an ink impregnation body 17 in which, for example, polyurethane foam (porous material) is impregnated with the ink liquid. ing. The ink impregnation body 17 has a property that when ink flows out from a large number of cells contained therein, the cells are filled with bubbles.

The ink liquid chamber 13 is for storing the ink liquid flowing from the ink impregnating body 17 in the portion surrounded by the partition wall 13a formed in the central bottom portion of the ink tank 11, and the upper portion of the partition wall 13a. And ink impregnation body 17
By interposing the first filter 18 between
The ink impregnation chamber 12 is partitioned.

Here, the first filter 18 allows the ink liquid to pass from the ink impregnation chamber 12 to the ink liquid chamber 13, and further allows the bubbles to pass when the remaining ink amount is very small (ink end). The first filter is, for example, a mesh made of a felt material, and has a hole diameter of 8 μm to 25 μm.
a to 1000 pieces per inch (25.4 mm)
The one with 00 is used.

As a result, the first filter 18 gives a predetermined flow path resistance to the ink liquid supplied to the ink liquid chamber 13 at the inner wall of the passage hole 18a, and further,
With almost no ink in the ink impregnation chamber 12, a capillary attraction P1 (negative pressure: -1200) of a predetermined magnitude is applied to the interface between the ink liquid and the gas formed in the passage hole 18a.
0 Pa ≦ P1 <−4000 Pa) is generated.

The ink liquid chamber 13 is provided with a detection mechanism 20 for detecting bubbles generated in the ink liquid.
The detection mechanism 20 includes a light reflection type sensor 21 having a light emitting portion and a light receiving portion, and a prism 22. When the ink chamber 13 is filled with ink, the light emitted from the light emitting unit to the prism 22 is refracted at the surface where the prism 22 and the ink are in contact with each other, and the light is not incident on the light receiving unit.
On the other hand, when bubbles exist in the ink liquid chamber, the light emitted from the light emitting unit to the prism 22 is reflected by the surface where the prism 22 and the bubbles are in contact, and the light enters the light receiving unit.
Ink end is detected.

The pressure adjusting chamber 14 is formed at a position adjacent to the ink liquid chamber 13 in the bottom portion of the ink tank 11, and the ink liquid is passed through a communication port 14a provided in a partition wall 13a between the pressure adjusting chamber 14 and the ink liquid chamber 13. A vent 14b communicating with the chamber 13 and provided on the outer wall of the ink tank 11.
It is designed to open to the atmosphere via.

In the case of the present embodiment, the second filter 24 is attached to the partition wall 13a of the pressure adjusting chamber 14 so as to cover the communication port 14a.

The second filter 24 is for allowing bubbles to pass from the pressure adjusting chamber 14 to the ink liquid chamber 13 in the case of ink end. As such a second filter 24, the first filter 18 is used. Similar to the above, the mesh material is made of a felt material, and the through hole 24a having a hole diameter of 25 μm to 50 μm is formed at 500 per inch (25.4 mm).
The one having 1000 to 1000 is used.

As a result, the second filter 24 has the first filter 24 when the pressure adjusting chamber 14 is opened to the atmosphere with respect to the interface between the ink liquid and the gas formed on the inner wall of the passage hole 24a.
Capillary force P2 weaker than the capillary force P1 of the filter 18 of FIG.
(Negative pressure: −4000 Pa ≦ P2 <−2000 Pa) is generated.

In the second filter 24, the capillary attraction P2 and the standard atmospheric pressure P0 (1.01325 × 10 ⁵ P
From the relationship of a), the interface generated between the ink liquid and the gas exists in the passage hole 24a, and the ink liquid in the ink liquid chamber 13 does not flow out from the second filter 24.

The pressure adjusting chamber 24 is provided with a valve mechanism 30 for opening and closing the vent hole 14b of the ink tank 11. The valve mechanism 30 includes a ring-shaped packing 31 fitted in the vent 14b, and a valve member 32 is configured to be able to penetrate inside the packing 31. A head surface is formed on the filter 24 side of the valve member 32, and is urged toward the packing 31 side by a compression coil spring 33 attached between the head surface and the partition wall 13a of the pressure adjusting chamber 14. It is arranged in a closed position that closes the vent hole 14b.

On the other hand, an operating lever 34 for moving the valve member 31 to the open position against the biasing force of the compression coil spring 33 is provided outside the ink tank 11. The actuating lever 34 is swingably supported about the support shaft 34a, and its operation is described later in a drive cam mechanism 70.
It is regulated by.

The print head 50 is a flat plate made of, for example, silicon or stainless steel, and is provided at the bottom of the ink tank 11. A plurality of nozzles 51 for ejecting ink droplets are arranged and formed on the print head 50. In the case of the present embodiment, the nozzle diameter of the print head 50 is set to 20 μm to 35 μm. As a result, the print head 50 moves from −4900 Pa to the interface between the ink liquid and the gas formed on the inner wall of the nozzle 51.
Within the range of −2900 Pa, it is weaker than the capillary attraction P1 of the first filter 18 and less than the capillary attraction P2 of the second filter 24.
It is designed to generate a stronger capillary force P3.

Such a print head 50 has a nozzle 51.
Is communicated with the ink liquid chamber 13 via a supply needle 53 sealed at the bottom of the ink tank 11 by a packing 52, and the ink droplets in the nozzle 51 are pressure generating elements (not shown) provided near each nozzle. ) Is applied to apply the voltage.

In the print head 50, due to the relationship between the capillary attraction P3 and the standard atmospheric pressure P0, the interface between the ink liquid and the gas is formed in the nozzle, and the ink liquid in the ink liquid chamber 13 becomes a pressure generating element. It does not flow out of the print head 50 when no voltage is applied.

The maintenance mechanism 60 comprises a head cap 61 and an ink pump 62. The head cap 61 is for sealing the print head 50, and is configured to move in a direction toward or away from the print head 50.

The ink pump 62 is for sucking the clogged ink liquid from the nozzles 51 of the print head 50, and the piston valve 64 fixed to the piston rod 63 moves in the cylinder 65 so that the inside of the cylinder 65 is moved. The pressure P4 of the first filter 18 reaches a negative pressure stronger than the capillary attraction P1 of the first filter 18.

And, such an ink pump 62 is
The cylinder 65 is connected to the head cap 61 via the connecting pipe 66.
By communicating with the head cap 61, the ink liquid flows from the print head 50 sealed by the head cap 61 into the cylinder 65.

The drive cam mechanism 70 is for driving both the valve mechanism 30 and the ink pump 62 described above, and is constituted so that the disk-shaped cam member 71 rotates about the support shaft 74 in the arrow direction. Has been done.

As shown in FIG. 2 or 3, the cam member 71
The cam follower 34b of the operating lever 34 is provided on the outer peripheral portion of the
A circular arc cam 72 is formed so as to abut. The circular arc cam 72 has a large circular arc portion 72a having a radius required to move the operating lever 34 to the open position of the valve member 31, and a radius sufficient to move the operating lever 34 to the closed position of the valve member 31. It is formed so as to be smoothly connected to the small arc portion 72b having.

On the side surface of the cam member 71, the piston rod 63
A grooved cam 73 that engages with a cam follower 63a formed at the end of is formed. The groove cam 73 is formed in an arc shape around the operation groove portions 73a and 73c for reciprocating the piston rod 63 and the support shaft 74, and the piston rod 63 is positioned at the ink suction position (a negative pressure is generated in the cylinder 65). The non-operating groove portion 73b which is retained at a position where ink is sucked from the nozzle 51 is formed so as to be smoothly connected.

Regarding the positional relationship between the arcuate cam 72 and the groove cam 73, while the cam follower 63a of the piston rod 63 is engaged with the operation groove portions 73a and 73c, the operation lever 34 is used.
Cam follower 34b contacts the large arc portion 72a, while the cam follower 34b of the operating lever 34 contacts the small arc portion 72b while the cam follower 63a of the piston rod 63 is engaged with the non-operating groove portion 73b. Are arranged as follows.

As a result, the drive cam mechanism 70 opens the valve mechanism 30 without sucking ink to both the valve mechanism 30 and the ink pump 62 and closes the valve mechanism 30 to suck ink. Can be selected as an alternative.

In the case of this embodiment having such a configuration, when a voltage is applied to the print head 50 and ink droplets are ejected from the nozzles 51, as shown in FIG.
The ink pump 62 is in the standby state (the piston rod 63 cam follower 63a is located between the cam grooves 73a and 73c), and at this time, the valve mechanism 30 is in the open state, and the pressure adjusting chamber 14 is It is open to the atmosphere.

In this case, as shown in FIG. 4A, in the print head 50, due to the capillary attraction P3 of the nozzle 51, the ink liquid corresponding to the amount of ink consumed during printing flows, and along with this, The ink liquid of the ink impregnated body 17 flows into the ink liquid chamber 13 by a flow rate Q1 in the nozzle 51 while resisting the flow path resistance of the first filter 18.

On the other hand, the ink liquid is the first filter 1
8 through the passage holes 18a to the nozzles 51 of the print head 50. Therefore, in the second filter 24, the passage holes 2
The capillary attraction P2 acting on the interface between the ink liquid and the gas formed in 4a maintains a state of equilibrium with the standard atmospheric pressure P0, and the gas does not flow into the ink liquid 13 chamber from the passage hole 24a.

When the ink liquid flows out from the cells of the ink impregnated body 17 in accordance with printing, the cells are filled with the gas flowing from the vent holes 16 of the tank cover 15 as bubbles.

After that, when the ink liquid in the ink impregnated body 17 has almost disappeared and the ink impregnated body 17 is filled with bubbles, the bubbles block most of the passage holes 18a of the first filter 18, whereby the first filter 18 is filled. The flow passage area of the filter 18 becomes small, and the apparent flow passage resistance increases. For this reason, the ink liquid of the ink impregnated body 17 has only the capillary attraction P3 of the print head 50, and the passage hole 18 of the first filter 18 does
You cannot pass a. (Ink end condition)
Since the interface between the ink liquid and the gas is formed in the passage hole 18a, the capillary attractive force P1 generated by this interface is stronger than the capillary attractive force P3 of the print head 50.
At the pressure generated by the discharge of the ink liquid by 0,
Air bubbles do not flow into the ink liquid chamber 13 from the filter 18 of FIG.

As described above, in the ink end state, the first filter 18 is set due to the strength relationship between the capillary attraction forces P1 and P3.
Since air bubbles cannot flow into the ink liquid chamber 13 from the above, the capillary attractive force P3 resulting from the flow rate Q1 in the nozzle 51 acts on the interface existing in the passage hole 24a of the second filter 24, and while resisting this, Although the capillary attractive force P2 of the filter 24 increases, it is weaker than the capillary attractive force P3 of the print head 50 even if the capillary attractive force P2 becomes maximum. Bubbles flow into the ink liquid chamber 13.

By detecting such bubbles with the detection mechanism 20, it is possible to accurately detect the ink end even during printing.

On the other hand, in the case of cleaning the print head 50, the print head 50 is attached to the head cap 6.
In the state where the drive cam mechanism 70 is actuated and the valve mechanism 30 is closed to seal the pressure adjusting chamber 14 after being sealed by 1, the ink pump 62 causes the ink liquid to be sucked from the nozzle 61 of the print head 50.

From the standby state shown in FIG. 2, by rotating the cam member 71 around the support shaft 74 in the direction of the arrow, the cam follower 63a is guided by the operating groove cam portion 73a, and the piston rod 63 moves to the right. As a result, the space formed on the left side of the piston valve 64 in the cylinder 65 is
A negative pressure is generated because the volume increases while being sealed. Further, when the cam member 71 is further rotated, as shown in FIG. 3, the cam follower 63a reaches the contact point of the operating groove cam portion 73a and the non-operating groove cam portion 73b, and the space formed on the left side of the piston valve 64 is connected pipe 66. And the pressure P4 is applied to the nozzle 51, and the ink is sucked.

From the state shown in FIG. 3, a cam member 71 is further added.
When the cam follower 63a is rotated,
While engaged with 3b, the piston valve 64 does not move,
The state where negative pressure is applied to the nozzle 51 is maintained. afterwards,
The cam follower 63a is guided by the operating cam groove portion 73c,
The piston rod 63 moves to the standby position. At this time, a gap is formed between the piston rod 63 and the piston valve 64, and the space formed in the cylinder 65 on the left side of the piston valve 64 is reduced in volume with the atmosphere being opened. To do.

By rotating the cam member 71 a predetermined number of times and repeating the cycle described above, a predetermined amount of ink is sucked from the nozzle 51. At this time, due to the positional relationship between the circular arc cam 72 and the groove cam 73 described above, the cam follower 6
While 3a is engaged with the non-operation groove portion 73b, that is, while the ink is sucked from the nozzle 51, the valve mechanism 30 is
Holds closed.

As shown in FIG. 4B, the print head 50
In the above, the pressure P4 of the ink pump causes the ink liquid corresponding to the amount of ink to be sucked to flow, so that the ink liquid of the ink impregnated body 17 has a flow rate of Q2 in the nozzle 51 and the flow path of the first filter 18. Ink liquid 13 while resisting resistance
Flows into the chamber.

On the other hand, the ink liquid is the first filter 1
8 through the passage holes 18a of the print head 50, and because the pressure adjusting chamber 14 is sealed, it is generated by the interface between the ink liquid and the gas formed in the second filter 24. Capillary attraction P2 is due to pressure adjustment chamber 14
The gas in the passage hole 24a does not flow into the ink liquid chamber 13 while maintaining a state of equilibrium with the internal pressure.

When the pressure adjusting chamber 14 is closed, the second
The pressure required to take gas from the first filter 18 into the ink liquid chamber 13 is smaller than the pressure required to take gas from the filter 24 into the ink liquid chamber 13. Therefore, the ink impregnation body 17 is almost free of ink liquid, the ink impregnation body 17 is filled with bubbles, and the bubbles block the passage holes 18a of the first filter 18 to increase the flow path resistance. If you do
The pressure P4 of the ink pump caused by the flow rate Q2 in 1 acts on the interface existing in the passage hole 18a of the first filter 18. Therefore, although the capillary attraction P1 of the first filter 18 increases while resisting the pressure P4 of the ink pump, even if the capillary attraction P1 is maximized, it is weaker than the pressure P4 of the ink pump, and the difference is approximately at the interface. As a result, the interface is broken, and bubbles flow into the ink liquid chamber 13 through the passage hole 18a.

By detecting such bubbles with the detection mechanism 20, it is possible to accurately detect the ink end even during cleaning.

As described above, according to this embodiment,
In the ink end state, during printing, by opening the pressure adjusting chamber 14 to the atmosphere, air bubbles are taken into the ink liquid chamber 13 from the second filter 24, while
During the ink suction, the pressure adjusting chamber 14 is closed from the atmosphere so that the air bubbles are taken into the ink liquid chamber 13 from the first filter 18, so that the case of printing and the case of ink sucking are performed. Even if there is a difference in the flow rate of the ink liquid, the ink liquid chamber 13 can be reliably
Since the bubbles can be detected inside, the ink end can be detected with high accuracy.

Further, according to the present embodiment, the first capillary attraction P1 and the second capillary attraction P2 are determined by the magnitude relationship between the capillary attraction p3 of the print head 50 and the pressure P4 of the ink pump 62. Therefore, when the ink liquid cannot be supplied through the first filter 18 in the ink end state, the gas from the second filter 24 is taken into the ink liquid chamber 13 during printing, and the first liquid is supplied during the ink suction.
The gas from the filter 18 can be taken into the ink liquid chamber 13.

Further, according to the present embodiment, the valve mechanism 3
By opening and closing 0, the pressure adjusting chamber is opened to the atmosphere, or the pressure adjusting chamber is cut off from the atmosphere so that the pressure applied to the second filter 24 is made different. A flow path for taking in gas from the filter 24 and a flow path for taking in gas from the first filter 18 can be selected.

Further, according to the present embodiment, the operation of the drive cam mechanism 70 causes the valve mechanism 30 and the ink pump 62 to be opened without ink suction, and the valve mechanism 30 is opened. Since the mechanism 30 is closed and ink suction is selectively performed, air bubbles are taken into the ink liquid chamber through the first filter 18 and the second filter 24. The switching to the flow path to be performed can be performed with the minimum number of parts and power.

The present invention is not limited to the above-mentioned embodiment, and various modifications can be made.

For example, the capillary attraction P of the second filter 24
By changing the value of 2, it is possible to adjust the sensitivity of extracting bubbles from the second filter 24 at the ink end.

In the above embodiment, an optical sensor is used as the detection mechanism 20, but in the case of the present invention, as the detection mechanism, for example, electrical resistance in the ink liquid and bubbles in the ink liquid are used. It is also possible to apply a mechanism configured to detect the bubble based on the difference from the included electric resistance.

[0070]

As described above, according to the present invention, in the ink end state, for example, during printing,
By opening the pressure adjusting chamber to the atmosphere, air bubbles are taken into the ink liquid chamber from the second filter, while during suction of ink, the pressure adjusting chamber is closed from the atmosphere to remove air bubbles from the first filter. By introducing the ink into the liquid chamber, even if the flow rate of the ink liquid is different between during printing and during ink suction, air bubbles can be reliably detected in the ink liquid chamber at the end of the ink, so it is accurate. The ink end can be detected.

Further, according to the present invention, by opening and closing the valve mechanism, the pressure adjusting chamber is opened to the atmosphere, or the pressure adjusting chamber is shut off from the atmosphere, so that the pressure applied to the second filter 24 is made different. This makes it possible to select a flow path for taking in gas from the second filter and a flow path for taking in gas from the first filter in the ink end state.

Further, according to the present invention, the first capillary attraction force and the second capillary attraction force are determined by the magnitude relationship with the capillary attraction force of the print head, so that the ink liquid of the first filter is in the ink end state. When the flow path of is closed, the flow path of gas from the second filter can be secured during printing. Furthermore, according to the present invention, by determining the first capillary attraction force and the second capillary attraction force according to the magnitude relationship with the pressure of the ink pump, the ink liquid can be supplied through the first filter in the ink end state. When the ink is exhausted, the gas can be taken into the ink liquid chamber from the first filter during the ink suction.

In addition, according to the present invention, the operation of the drive cam mechanism causes the valve mechanism and the ink pump to open the valve mechanism without sucking ink, and to close the valve mechanism to close the ink. By selectively selecting the suction state, it is possible to minimize the switching between the flow path through which gas is taken into the ink liquid chamber through the gas of the first filter and the flow path through which gas of the second filter is passed. It can be done with the number of parts and power.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a main part of a printer according to an embodiment.

FIG. 2 is a cross-sectional view showing a state of an ink pump and a valve mechanism when a print head of the printer is in a printing state.

FIG. 3 is a cross-sectional view showing a state of an ink pump and a valve mechanism when sucking ink from a print head of the printer.

FIG. 4A is a diagram showing a state in which the remaining amount of ink is detected during printing in the ink cartridge of the present embodiment. (B): It is a diagram showing a state in which the remaining amount of ink is detected during ink suction in the same ink cartridge.

[Explanation of symbols]

12 ... Ink impregnation chamber 13 ... Ink liquid chamber 14 ... Pressure adjustment chamber 17 ... Ink impregnated body 18 ... First filter 20 ... Detection mechanism 24 ... Second filter 30 ... Valve mechanism 50 ... Print head 62 ... Ink pump 70 ... Drive cam mechanism (drive mechanism)

Claims (5)

[Claims] 1. An ink impregnation chamber containing a porous ink impregnation body, an ink liquid chamber which communicates with the ink impregnation chamber and can store the ink liquid flowing from the ink impregnation body, and the ink liquid chamber. A pressure adjusting chamber having a communication port that communicates with each other and a ventilation port that can be opened to the atmosphere and configured to adjust the atmospheric pressure by opening and closing the ventilation port; and the ink impregnation chamber and the ink liquid chamber. Provided between
Between the ink filter chamber and the pressure adjusting chamber, a first filter that has a plurality of through holes and generates a first capillary attraction force by the interface between the ink liquid and the gas formed in the through holes. A second filter having a plurality of passage holes, the second filter generating a second capillary attraction force weaker than the first capillary attraction force by the interface between the ink liquid and the gas formed in the passage holes; And a detection mechanism configured to detect bubbles that have flowed into the ink liquid chamber from the second filter or the second filter. 2. The ink cartridge according to claim 1, wherein the pressure adjusting chamber is provided with a valve mechanism for opening and closing the vent hole. 3. The ink cartridge according to claim 1 or 2 and the ink liquid chamber of the ink cartridge communicating with the ink liquid chamber, the interface between the ink liquid and the gas is weaker than the first capillary attraction force. And a print head configured to eject ink droplets from a plurality of nozzles that generate a third capillary attraction that is stronger than the capillary attraction. 4. An ink pump for sucking an ink liquid from a nozzle of the print head is provided, and the ink pump is set so that the pressure when sucking the ink is stronger than the first capillary attraction force. 4. The method according to claim 3, wherein
The listed printer. 5. A drive mechanism for driving both the valve mechanism and the ink pump, wherein the drive mechanism sets the valve mechanism to the vent hole when the ink pump is in a state of sucking ink liquid. 5. The valve mechanism is configured to be held in a state in which the ventilation port is opened when the ink is not sucked while the valve is held in a closed state. Printer.