JP2006231528A - Liquid storage body and liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid storage body and a liquid jet apparatus, which enable the detection of the remaining quantity of liquid at a predetermined time in the liquid storage body capable of being attached to/detached from the liquid jet apparatus. <P>SOLUTION: An ink cartridge 1 is equipped with a buffer chamber 42 which is provided midway through a section between a liquid storage chamber and an ink delivery port 6, and a remaining-quantity detector. The inkjet cartridge 1 is mounted on an inkjet printer with a control part composed of a remaining-quantity-of-ink computing part etc., so that the remaining quantity of the ink in the ink cartridge 1 can be detected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a liquid container that contains a liquid and a liquid ejecting apparatus that includes the liquid container and ejects liquid in the liquid container from a recording head.

As an example of the liquid container and the liquid ejecting apparatus, an ink jet printer connected to a personal computer or the like and an ink cartridge for containing ink supplied to the ink jet printer can be given.

An ink jet printer is an image forming apparatus that forms an image by ejecting ink from a recording head and landing ink droplets on recording paper. When color printing is executed, for example, three colors of yellow, cyan, and magenta are ejected onto a recording sheet or the like to form various colors on the recording sheet. Each ink is accommodated in an ink cartridge for each color. When the ink in the ink cartridge runs out (out of ink), a method of replenishing ink by replacing with a new ink cartridge is common.

Some ink jet printers have a function of detecting whether the ink in the currently installed ink cartridge has become a predetermined value or less, that is, the so-called near end of ink, in order to prevent ink shortage during printing. is there. If the user can be notified that the remaining amount of ink has reached a predetermined value before the ink in the ink cartridge becomes empty (hereinafter referred to as ink end), the user prepares a new ink cartridge in advance. The ink cartridge can be replaced and printing can be continued without panicking even when the ink runs out.

As an apparatus for measuring the constant remaining amount of ink in this manner, for example, a plurality of sensors having different lengths are provided in the ink in the buffer chamber provided on the printer main body side between the ink cartridge and the recording head. By inserting and monitoring the current continuity or insulation between the sensors, the device detects the ink level in the buffer chamber and detects whether there is enough ink remaining or near-empty ink. Known (Patent Document 1)
reference).
JP 2000-326523 A

However, the apparatus disclosed in Patent Document 1 can detect the near end or the ink end, but cannot detect the remaining ink amount in the middle from the ink full to the near end or from the ink full to the ink end. In other words, it is impossible to detect how much ink is left from ink full to near-end, and if you want to know how much ink is near-end, you must take another measure or method. Don't be.
When performing near-end detection, it is necessary to change the volume of the buffer chamber and the pressurizing means of the buffer chamber according to the specifications.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a liquid container and a liquid ejection device that can appropriately detect the remaining amount of ink in the liquid container that is removable from the liquid ejection device. To do.

The object of the present invention is achieved by the following configurations.
(1) In a liquid container that pressurizes a liquid storage chamber for storing a liquid and supplies the liquid from a liquid supply port to a liquid ejecting apparatus.
The liquid storage chamber is connected to the liquid storage chamber and is disposed in a region that is cut off from the pressure applied to the liquid storage chamber. A buffer chamber that contracts when the pressurization of the liquid storage chamber is stopped;
A liquid detection mechanism for detecting a liquid remaining amount related value related to the remaining amount of liquid in the liquid container;
A liquid container characterized by comprising:
(2) The liquid detection mechanism has a pair of electrodes arranged to face each other with the buffer chamber interposed therebetween,
The liquid container according to (2), wherein the liquid remaining amount related value is a capacitance between the electrodes.
(3) The buffer chamber is formed by a fixed wall and a movable member movable with respect to the fixed wall,
The liquid container according to (1) or (2), wherein the electrode is disposed so as to be perpendicular to a movable direction of the movable member of the buffer chamber.
(4) The buffer chamber is formed by a fixed wall and a movable member movable with respect to the fixed wall,
The liquid container according to (1) or (2), wherein the electrode is disposed so as to be parallel to a movable direction of the movable member of the buffer chamber.
(5) The liquid container according to (3) or (4), wherein the movable member provided in the buffer chamber is a pressurizing member that pressurizes the liquid flowing from the liquid housing chamber.
(6) The liquid container according to any one of (1) to (5), wherein the buffer chamber is provided in a flow path connecting the liquid storage chamber and the liquid supply port. .
(7) Any one of (1) to (6), wherein the buffer chamber is configured by sealing an opening of a concave portion provided in a member forming the buffer chamber with a film.
The liquid container according to Item.
(8) One end of the movable member contacts and separates from a fixed terminal provided in the buffer chamber according to a change in the volume of the buffer chamber. Liquid container.
(9) The liquid container according to any one of (1) to (9);
A buffer internal volume calculation unit for calculating the volume of the buffer chamber from the liquid remaining amount related value;
A flow rate calculation unit that calculates a flow rate of the liquid flowing out of the liquid container according to the change amount of the volume calculated by the buffer internal volume calculation unit;
A liquid ejecting apparatus comprising: a remaining amount calculating unit that calculates a remaining amount of liquid in the liquid container based on a flow rate of the liquid flowing out of the liquid container.
(10) The flow rate calculation unit calculates a flow rate of the liquid flowing out from the buffer chamber based on a volume change amount of the buffer chamber during a predetermined time when the liquid storage chamber is pressurized ( 9) The liquid ejection apparatus according to 9).
(11) The volume calculation unit calculates a flow rate of the liquid flowing out of the buffer chamber by measuring a time required for the buffer chamber to change in a predetermined volume in a pressurized state in the liquid storage chamber. The liquid ejection device according to (9), characterized in that
(12) Any one of (9) to (11), which is an inkjet printer
The liquid ejection device according to Item.

According to the liquid container of the present invention, the liquid detection mechanism for detecting the liquid remaining amount related value related to the remaining amount of liquid in the liquid container is provided. Since this liquid remaining amount related value is a value that continuously changes in relation to the remaining amount of liquid in the buffer chamber, the rate of change of the remaining amount of liquid in the buffer chamber can be obtained by using the liquid detection mechanism. If the rate of change of the remaining amount of liquid is obtained, the amount of liquid flowing out from the liquid container can be obtained, and the remaining amount of ink in the liquid container is continuously determined by counting the amount of liquid flowing out from the liquid container. Can grasp. Therefore, according to the liquid container of the present invention, it is possible to always accurately grasp the amount of liquid remaining at the present time and notify the user thereof, not just two points such as near end and liquid shortage. Therefore, the user can predict the replacement timing of the liquid container accurately to some extent according to the amount of the liquid. If a large amount of liquid in the liquid container is expected to be used, the user can replace the liquid container in advance. A liquid container can be prepared.

Further, according to the liquid container of the present invention, the liquid detection mechanism is composed of a pair of electrodes disposed so as to sandwich the buffer chamber, and the capacitance between these electrodes is calculated as a liquid remaining amount related value. You may detect as. With such a configuration, since the liquid detection mechanism can be configured with only two electrodes, accurate remaining amount detection can be performed without substantially increasing the size of the liquid container.
In addition, by obtaining the capacitance, the amount of liquid in the buffer chamber can be easily obtained, and the flow rate of the liquid can be calculated. Therefore, accurate remaining amount detection can be performed only by a simple specification change. It becomes possible.

According to the liquid container of the present invention, the buffer chamber is formed by the fixed wall and a movable member movable with respect to the fixed wall, and the electrode is perpendicular to the movable direction of the movable member of the buffer chamber. You may arrange | position and may arrange | position so that it may become parallel to the movable direction of the movable member of a buffer chamber.

According to the liquid container of the present invention, the movable member provided in the buffer chamber may also serve as a pressurizing member that pressurizes the liquid flowing from the liquid storage chamber. When the pressurizing member configured to pressurize the liquid is configured in the buffer chamber, the liquid in the buffer chamber is discharged to the outside when the pressurization to the liquid chamber is completed, and then the pressurization to the liquid chamber is performed. At the time when is started, the change in the amount of liquid in the buffer chamber can be measured to repeatedly determine the remaining ink amount.

According to the liquid container of the present invention, it is preferable that the buffer chamber is provided in a flow path connecting the liquid storage chamber and the liquid supply port.

According to the liquid container of the present invention, the buffer chamber may be configured by sealing the opening of the concave portion provided in the member forming the buffer chamber with a film.

Further, according to the liquid container of the present invention, one end of the movable member may be configured to come in contact with and separate from a fixed terminal provided in the buffer chamber according to a change in the volume of the buffer chamber. By configuring one end of this movable terminal to abut the fixed terminal so that current etc. flows,
In addition to the ink detection mechanism, it is possible to grasp the timing when the predetermined state such as near-end or liquid breakage is reached more reliably.

According to the liquid ejecting apparatus provided with the liquid container of the present invention, the volume of the buffer chamber is calculated from the value related to the remaining amount of liquid, and the volume of the buffer is calculated according to the amount of change in the volume calculated by the buffer volume calculation unit. It is configured to calculate the flow rate of flowing liquid and calculate the remaining amount of liquid in the liquid container based on the flow rate of liquid flowing out of the liquid container. can do. Therefore, according to the liquid ejecting apparatus of the present invention, not only two points such as near end and liquid shortage, but always accurately grasp the amount of liquid remaining at the present time,
The user can be notified. Therefore, the user can predict the replacement timing of the liquid container accurately to some extent according to the amount of the liquid. If a large amount of liquid in the liquid container is expected to be used, the user can replace the liquid container in advance. A liquid container can be prepared.

According to the liquid ejecting apparatus of the present invention, the flow rate of the liquid flowing out from the buffer chamber may be calculated based on the volume change amount of the buffer chamber during a predetermined time when the liquid storage chamber is pressurized. In addition, the flow rate of the liquid flowing out from the buffer chamber may be calculated by measuring the time required for the buffer chamber to change in a predetermined volume in the pressurized state in the liquid storage chamber.

An example of the liquid ejecting apparatus of the present invention is an ink jet printer, and the above configuration can be applied to detection of the remaining amount of an ink cartridge mounted on the ink jet printer.

Hereinafter, an ink jet printer and an ink cartridge will be described in detail as an embodiment of a liquid container and a liquid ejection device of the present invention with reference to the drawings.

1 and 2 are views showing the appearance of the ink cartridge according to the present embodiment, FIGS. 3 and 4 are exploded perspective views of the ink cartridge, and FIG. 5 is a cross-sectional view of the ink cartridge.

As shown in FIGS. 1 and 2, the ink cartridge 1 has a container main body 2, and the container main body 2 includes a first case member 2A, a second case member 2B, and a third case member 2C. . As can be seen from FIGS. 3 and 4, a plurality of heat caulking ribs 3 are formed at the peripheral edge of the second case member 2B, and these heat caulking ribs 3 are formed on the first case member 2A and the third case member 2C. It inserts in the formed several through-holes 4 and 5, and is crimped by heat. Thereby, the first case member 2A is sandwiched between the second case member 2B and the third case member 2C,
These three case members 2A, 2B, 2C are integrated.

As shown in FIG. 1C, the container body 2 is provided with an ink delivery port 6 for delivering the ink inside the container body 2 to the outside. As can be seen from FIGS. 3 and 4, the ink outlet 6 is formed in the first case member 2 </ b> A.

A pressure supply port 7 for introducing compressed air into the container body 2 is formed on the same surface as the surface on which the ink delivery port 6 is formed. The pressure supply port 7 is formed in the second case member 2B.

Further, an ink injection port 8 for filling ink when the ink cartridge 1 is manufactured is formed on the same surface as the surface on which the ink delivery port 6 is formed. The ink injection port 8 has a first
It is formed in the case member.

Further, as shown in FIG. 4, an erroneous mounting prevention block 9 is provided at one corner of the container body 2 including the same surface as the surface on which the ink delivery port 6, the pressure supply port 7, and the ink injection port 8 are formed. ing. This erroneous mounting prevention block 9 is used to correctly mount the ink cartridge 1 of a predetermined ink type at a predetermined position when the ink cartridge 1 is mounted on an ink jet printer. Other than the above, a shape that prevents mounting is provided.

As shown in FIGS. 3 and 4, a bottom film 10 is provided between the third case member 2C and the first case member 2A. The bottom film 10 seals the opening on the bottom surface side of the through hole 11 for the liquid storage chamber formed in the first case member 2A.

Between the first case member 2A and the second case member 2B, a flexible liquid storage chamber film 13A, a flexible buffer chamber film 13B, and a flexible pressurization chamber film are provided. 1
4 is provided. The liquid storage chamber film 13A and the buffer chamber film 13B are integrally formed of a single film. The liquid storage chamber film 13A and the buffer chamber film 13B liquid-tightly seal the openings on the upper surface side of the liquid storage chamber through-hole 11 and the buffer chamber recess 12 formed in the first case member 2A. Yes.

Here, the recessed part 12 for buffer chambers is formed in the cross-sectional substantially square shape. Thereby, the reaction force at the time of deformation | transformation of the film 13B for buffer chambers becomes small, and it becomes possible to deform | transform the film 13B for buffer chambers with a small pressure. In addition, as other preferable cross-sectional shape of the recessed part 12 for buffer chambers, circular or a regular polygon is mentioned.

A seal rubber 28 is attached to the ink delivery port 6 formed in the first case member 2 </ b> A, and a valve element 29 is inserted inside the ink delivery port 6.

6 and 7 are enlarged perspective views of the first case member 2A. As shown in FIG. 6, the first case member 2A has a fixing hole 27 for fixing the erroneous mounting prevention block 9. As shown in FIG. Opened. Further, as shown in FIG. 7, a filter 30 is provided in the middle of the flow path connecting the recess 12 for the buffer chamber and the ink delivery port 6.

In addition, the ink injection port 8 formed in the first case member 2 </ b> A communicates with the liquid accommodation chamber through-hole 11 through the ink injection channel 32. The liquid storage chamber through-hole 11 and the buffer chamber recess 12 communicate with each other through a narrow communication path 35A. Furthermore, the filter mounting portion 31 into which the filter 30 is fitted and the buffer chamber recess 12 communicate with each other through a narrow communication path 35B.

In FIG. 6, reference numerals 33A and 33B denote film welded portions. The film welded portion 33A has a liquid storage chamber film 13A, and the film welded portion 33B has a buffer chamber film 13.
Each B is joined in a liquid-tight manner.

In FIG. 7, reference numerals 36 </ b> A and 36 </ b> B denote film welds, and the film welds 3
The bottom film 10 is liquid-tightly joined to 6A and 36B. Reference numeral 34 denotes a seal portion. In the seal portion 34, after the ink is filled in the container body 2, the ink injection channel 3 is filled.
2 is sealed.

In the present embodiment, a tank unit is configured by the first case member 2A, the liquid storage chamber film 13A, the buffer chamber film 13B, and the like. Specifically, with these,
A liquid storage chamber 40, a pressurization chamber 41, and a buffer chamber 42 are formed. The liquid storage chamber 40, the pressurization chamber 41, and the buffer chamber 42 will be described later.

Next, an ink end and a near end detection member (hereinafter referred to as a detection member 16) composed of a spring seat member 17 and a compression spring 19 mounted inside the ink cartridge 1 will be described with reference to FIGS. .

The detection member 16 has an output signal that changes according to a change in the pressure of the ink in the container body 2 that changes depending on whether or not the pressure of the compressed air is actually applied.

The detection member 16 includes a spring seat member 17 having an outer shape that can be movably inserted into a recess for the buffer chamber formed in the first case member 2 </ b> A, and the detection member 16 is formed in the through hole 17 a of the spring seat member 17. The guide protrusion 18 formed on the second case member 2B is inserted. Then, the spring seat member 17 is prevented from coming off from the guide projection 18 by applying heat caulking to the tip of the guide projection 18. Since the spring seat member 17 is attached to the guide protrusion 18 by heat caulking in this way, the assembly is easy, and for example, forming a complicated structure required when forming a hooking claw, for example. A mold is not required.

A compression spring 19 is provided between the spring seat member 17 and the second case member 2B, and the spring seat member 17 is urged away from the second case member 2B by the spring force of the compression spring 19. Yes.

The spring seat member 17 and the compression spring 19 constitute a part of the detection member 16 and at the same time constitute a pressurizing member for pressurizing ink in a buffer chamber 42 (FIG. 14) described later. In this way, by pressing the spring seat member 17 with the compression spring 19, the pressure member can be configured with a simple structure.

Further, the detection member 16 includes a contact switch 20 that opens and closes by pressure applied from compressed air to the ink in the container body 2. The contact switch 20 includes a movable terminal 20A that is displaced by pressure applied to the ink in the container body 2 from compressed air, and a fixed terminal 20B that is disposed to face the movable side terminal 20A.

An IC substrate 21 is disposed adjacent to the contact switch 20 on the inner wall surface of the second case member 2B, and the IC substrate 21 is fixed by heat caulking with a fixing rib 22. The movable terminal 20A and the fixed terminal 20B are made of a flexible member, and are pressed against the contact 23 of the IC substrate 21 by the biasing force.

In addition, the IC substrate 21 includes an antenna member 24, and information is transmitted in a non-contact manner between the ink jet printer and the IC substrate by the antenna member 24.

The pressure supply port 7 formed in the second case member 2 </ b> B communicates with the pressurizing chamber recess 15 through the air flow path 25.

Further, in FIG. 8, reference numeral 26 indicates a film welded portion, and the film 14 for a pressurizing chamber is secretly bonded to the film welded portion 26.

The second case member 2B, the detection member 16, the pressurizing chamber film 14 and the like constitute a pressurizing unit.

In this way, the first case member 2A side is configured as a tank unit and the second case member 2B side is configured as a pressure unit, thereby reducing the number of parts and reducing the manufacturing process. Recycling can be possible.

Next, each chamber formed in the ink cartridge 1 of the present embodiment will be described with reference to FIG.
FIGS. 11A, 11 </ b> B, and 11 </ b> C are schematic cross-sectional views of the ink cartridge 1.
As shown in FIG. 11, inside the container main body 2 of the ink cartridge 1, as described above, a liquid storage chamber 40 for storing ink and a pressurization chamber 41 formed above the liquid collection chamber 40, A buffer chamber 42 provided in the middle of the flow path connecting the liquid storage chamber 40 and the ink delivery port 6
And are formed. Hereinafter, the relationship between the various structures in the ink cartridge 1 described above and the ink flow path will be summarized.

The liquid storage chamber 40 is an ink storage unit that stores ink inside the ink cartridge 1. The liquid storage chamber 40 is partitioned from the pressurization chamber 41 by the liquid storage chamber film 13 </ b> A and the pressurization chamber film 14. The pressure applied to the pressurizing chamber 41 can be transmitted to the liquid containing chamber 40 through the liquid containing chamber film 13 </ b> A and the pressurizing chamber film 14.

In the pressurizing chamber 41, compressed air supplied from the printer main body side via the pressure supply port 7 is introduced. The compressed air introduced into the pressurizing chamber 41 pressurizes the ink in the liquid storing chamber 40 via the liquid storing chamber film 13 </ b> A and the pressurizing chamber film 14. The pressurized ink inside the liquid storage chamber 40 is supplied to the buffer chamber 42 via the communication path 35A.

The buffer chamber 42 is provided between the liquid storage chamber 40 and the ink delivery port 6, and the ink delivered from the liquid storage chamber 40 is delivered to the ink delivery port 6 through the buffer chamber 42. The detection member 16 described above is disposed in the buffer chamber 42. When the detection member 16 is not pressurized, the compression spring 19 of the detection member 16 is extended as shown in FIG. The buffer chamber 19 is almost free of ink.

Here, when compressed air is supplied to the pressurizing chamber 41 and the liquid storage chamber 40 is pressurized, ink is supplied to the buffer chamber 42. When ink is supplied to the buffer chamber 42, the buffer chamber 42
The inner volume expands and the compression spring 19 contracts, resulting in a state as shown in FIG.
On the other hand, when the supply of compressed air to the pressurizing chamber 41 is stopped, the supply of ink to the buffer chamber 42 is stopped when the pressurization of the liquid storage chamber 40 is stopped. In this state, the compression spring 19 pushes back the ink in the buffer chamber 42, so that the state shown in FIG.

The buffer chamber 42 is in a state where ink is present in the liquid storage chamber 40 and is not pressurized (FIG. 11).
The volume change rate calculated based on the required time from (a)) to when the liquid storage chamber 40 is pressurized to the state shown in FIG. 11B, that is, the flow rate from the liquid storage chamber 40 to the buffer chamber 42 is: When the pressure applied by the compressed air is constant, it is a function of the remaining amount of ink in the liquid storage chamber 40. When the amount of liquid stored in the liquid storage chamber 40 decreases, the flow rate decreases, and the buffer chamber 42 is shown in FIG. (
The time required from the state a) to the state shown in FIG. 11B becomes longer. This is considered to be due to the fact that the pressure in the liquid storage chamber 40 is substantially reduced because the film such as the film 13A for the liquid storage chamber and the film 14 for the pressurization chamber becomes a bending resistance as the liquid decreases. It is done.

Next, an ink remaining amount detection mechanism constituted by two electrodes provided in the ink cartridge 1 will be described.

In the ink cartridge 1 of the present embodiment, as shown in FIG. 5, the first electrode 50A is embedded at a position corresponding to the buffer chamber 42 on the ink cartridge width direction side of the third case member 2C, and the second case 2C. A second electrode 50B is embedded at a position corresponding to the buffer chamber 42 on the ink cartridge width direction side of the case member 2B. These first electrodes 50
A and the second electrode 50 </ b> B are disposed to face each other with the buffer chamber 42 interposed therebetween. In addition,
The first electrode 50A and the second electrode 50B do not have to be embedded, and the buffer chamber 42
It suffices if they are arranged to face each other.

The two electrodes 50A and 50B are configured as one electrode pair, that is, a capacitor. In the present embodiment, a closed circuit including these electrodes 50A and 50B is configured, and the capacitance is measured by passing a current. Here, the measured capacitance is a function of the amount of ink and the amount of air present in the buffer chamber 42. For this function, a capacitance corresponding to the amount of ink in the buffer chamber 42 can be obtained in advance using a computer or experimentally.

In the present embodiment, the electrostatic capacity at the time when the ink in the buffer chamber 42 increases is measured for each predetermined sampling period, and a change in the electrostatic capacity is detected or until the predetermined electrostatic capacity is reached. By detecting the required time, the flow rate of ink flowing into the buffer chamber 42 and the remaining ink amount in the buffer chamber 42 can be obtained.
That is, the electrodes 50A and 50B constitute an ink detection mechanism 50 that detects the ink flow rate and the ink remaining amount in the buffer chamber 42.
Next, the remaining ink detection control in the ink cartridge 1 using the ink detection mechanism 50 and the operation control of the detection member 16 will be described with reference to FIGS.

12 and 13 are block diagrams showing a control circuit of the ink jet printer according to the present embodiment. In this block diagram, for the sake of simplification, only main portions necessary for detecting the remaining amount of ink are described in blocks.

As shown in FIG. 12, the inkjet printer 100 of the present embodiment is connected to a host computer 60 so as to be communicable, and executes various operations such as printing and reading in accordance with various commands from the host computer 60. The ink jet printer 100 mainly includes a control unit 70, an ink cartridge control circuit 61, an ink remaining amount display mechanism 64, a pressure pump drive mechanism 65, a recording head drive mechanism 66, a pump drive mechanism 67, a ROM, and the like.
68 and a communication interface 69.

The control unit 70 is a control center of the ink jet printer, and includes a CPU, a RAM, various controllers, various registers, and the like. The control unit 70 reads the firmware written in the ROM 68 and operates according to this firmware, whereby the ink cartridge control circuit 61, the ink remaining amount display mechanism 64, and the pressure pump drive mechanism 65 are operated.
And the operation of the recording head drive mechanism 66, the pump drive mechanism 67, the ROM 68, the communication interface 69, and the like.
In the present embodiment, the control unit 70 calculates the flow rate of ink supplied from the liquid storage chamber 40 to the buffer chamber 42 and the ink amount in the buffer chamber 42, and calculates the remaining amount of ink in the ink cartridge 1, the ink end, and It is configured to detect near end.

Hereinafter, while explaining other control blocks of the ink jet printer, it will be explained how the control unit 70 calculates the remaining amount of ink at a predetermined time or how the ink end and near end are detected. .

The ink cartridge control circuit 61 is connected to a predetermined terminal of the ink cartridge 1,
This is a circuit for supplying a predetermined current to the ink cartridge 1 and acquiring predetermined information from the ink cartridge 1. The electrodes 50A and 50B are connected to the ink cartridge control circuit 6
1 is connected to form a closed circuit, and a predetermined current value or voltage value is acquired by this closed circuit. Further, it is detected whether or not the movable terminal 20A and the fixed terminal 20B are in contact with each other by being connected to the ink cartridge control circuit 61.

The ink remaining amount display unit 64 controls the control unit 70 based on detection of the flow rate of ink supplied from the liquid storage chamber 40 to be described later to the buffer chamber 42, and values detected by ink end and near end detection.
It is a display part which can be visually recognized by the user provided in the exterior of the ink-jet printer which displays the information obtained via this.

The pressure pump drive mechanism 65 is a mechanism that sends compressed air into the pressure chamber 41 in the ink cartridge 1 via the pressure supply port 7.

The recording head drive mechanism 66 includes a piezoelectric element for ejecting ink in the recording head, a voltage application circuit to the piezoelectric element, and the like. The recording head driving mechanism 66 applies a voltage to the piezoelectric element in accordance with an instruction from the control unit 70. Ink droplets are ejected from a plurality of nozzles provided. This
Characters and images are formed on a predetermined sheet.

The various drive mechanisms 67 include a paper transport mechanism provided in the inkjet printer 100, a carriage drive mechanism that reciprocates a carriage provided with a recording head, and the like, and realizes paper transport, carriage movement, and the like.

The ROM 68 is a firmware storage unit for operating the inkjet printer 100, and is read according to an instruction from the control unit 70. The ROM 68 stores various setting values used for the operation. This set value is preferably rewritable. For this purpose, for example, the ROM 68 is preferably a rewritable medium such as a flash ROM.

Next, various controls performed in the control unit 70 will be described focusing on detection of the remaining amount of ink.
FIG. 13 is a block diagram illustrating a calculation unit implemented in various control units 70 necessary for calculating the remaining amount of ink in the ink cartridge 1. Specifically, the control unit 70 includes a capacitance calculation unit 71, a buffer chamber volume calculation unit 72, a buffer chamber volume change calculation unit 73, and an ink remaining amount calculation unit 75.

The electrostatic capacity calculation unit 71 includes an ink cartridge control circuit 61 via the electrodes 50A and 50B.
The capacitance between the electrodes 50A and 50B is calculated based on the current value or voltage value obtained from the above.
This capacitance is calculated according to the sampling cycle of the ink cartridge control circuit 61.

The buffer chamber volume calculation unit 72 substitutes the capacitance obtained by the capacitance calculation unit 71 into a predetermined function or refers to a predetermined table to determine the ink amount in the buffer chamber 42. The buffer chamber volume calculation unit 72 calculates the ink amount for each capacitance value calculated by the capacitance calculation unit 71. Therefore, the ink amount is calculated in time series according to the sampling period.

The buffer chamber volume change amount calculation unit 73 obtains the ink amount change rate, that is, the flow rate of ink flowing into the buffer chamber 42 based on a plurality of ink amounts at predetermined times obtained according to the sampling period.

Here, the relationship between the flow rate of ink flowing into the buffer chamber 42 and the flow rate of ink that can be supplied from the ink cartridge 1 to the recording head will be described. The flow resistance between the liquid storage chamber 40 and the buffer chamber 42 is Rb, the flow resistance between the liquid storage chamber 40 and the recording head is Rh, the flow rate of ink supplied to the buffer chamber 42 is Qb, and the recording head Assuming that the flow rate of the ink supplied to Qh is Qh and the effective pressure obtained by subtracting the spring pressure of the detection member 16 in the buffer chamber 42 from the pressure applied by the compressed air is ΔP, the following relationship is established.

Rb · Qb = Rh · Qh = ΔP (1)

Solving for Qh,

Qh = (Rb / Rh) · Qb (2)

If Rb and Rh are obtained in advance by actual measurement values or calculation, the flow rate Qh of ink that can be supplied to the recording head can be obtained by detecting Qb. Since Qb is the same as the ink flow rate obtained by the buffer chamber volume change calculating unit 73, the flow rate Qh of ink that can be supplied to the print head can be obtained by substituting this into equation (2). When the flow rate of ink that can be supplied to the recording head is less than the maximum discharge flow rate of the recording head during printing, it is determined that a normal ink end has occurred due to poor printing due to insufficient ink supply from the ink cartridge to the recording head.

The ink remaining amount calculation unit 75 is configured by the buffer chamber 4 calculated by the buffer chamber volume change calculation unit 73.
2, the remaining amount of ink remaining in the ink cartridge 1 corresponding to the value is obtained from the remaining amount of ink flowing into the ink cartridge 2. Then, the remaining ink amount calculation unit 75 determines whether the remaining ink amount is halved, the near end, the ink end, or the like when the remaining ink amount in the ink cartridge 1 falls below a predetermined threshold value. Judge appropriately. In addition, as shown in FIG. 1C, if the ink is exhausted in the liquid storage chamber 40 and the amount of ink in the buffer chamber 42 is reduced due to consumption of the ink, the buffer corresponding to the detected capacitance. The amount of ink in the chamber 42 may be the remaining amount of ink remaining in the ink cartridge 1.

The value of the ink remaining amount calculated by the ink remaining amount calculating unit 75 is stored in the ROM 68 when the power of the ink jet printer 100 is turned off, so that it is possible to grasp how much ink is remaining at the next activation. At the same time, by adding the ink amount decreased in the operation after the next activation to the stored ink remaining amount, the ink remaining amount is constantly continuously monitored after the ink cartridge is mounted.

In the present embodiment, the remaining amount of ink can be obtained continuously by obtaining the capacitance as described above.

In the present embodiment, the urging force of the compression spring 19 varies depending on the urging amount. Therefore, the pressure P2 applied to the ink in the buffer chamber 42 by the urging force of the compression spring 19 is the amount of ink in the buffer chamber 42. It changes between P2-MAX and P2-MIN according to the above. Therefore, in this embodiment, the air pressure supplied from the pressure supply port 7 and the biasing force of the compression spring 19 are set so that P1>P2-MAX> P2-MIN. Thus, the compression spring 19
By making the maximum pressure P2-MAX due to the pressure smaller than P1, the detection member 16 can be reliably operated.

Further, in this embodiment, when the pressure loss due to the pressure at the time of deformation of the liquid storage chamber film 13A and the pressure chamber film 14 is P4, and the air pressure supplied from the pressure supply port 7 is P1 ′, P1 ′ The air pressure supplied from the pressure supply port 7 and the biasing force of the compression spring 19 are set so that -P4 = P1> P2. Accordingly, even when a reaction force is generated when the liquid storage chamber film 13A and the pressurization chamber film 14 are deformed, the detection member 16 can be reliably operated.

In the present embodiment, the pair of electrodes 50A and 50B are arranged so as to be perpendicular to the moving direction of the spring seat member 17 in the buffer chamber 42, but as a modification of the present embodiment as shown in FIG. Even if the pair of electrodes 50 are arranged so as to be perpendicular to the moving direction of the spring seat member 17 in the buffer chamber 42, the electrodes 50A and 50B can be arranged so as to sandwich the buffer chamber 42. The remaining amount of ink in the cartridge 1 can be detected.

  Next, the detection operation of the detection member 16 including the contact type switch 20 will be described.

FIG. 11A and FIG. 15A show a state in which the liquid storage chamber 40 is sufficiently filled with ink and compressed air is not introduced into the pressurizing chamber 41. In this state, since air pressure is not applied to the ink in the liquid storage chamber 40, the liquid storage chamber 40 is at atmospheric pressure.

Therefore, the spring seat member 17 is pressed against the bottom of the inner wall of the container body 2 by the urging force of the compression spring 19, and in this state, as can be seen from FIG.
The zero movable terminal 20A and the fixed terminal 20B are in contact with each other. That is, in this state, the contact switch 20 is in an on state (conducting state).

FIG. 11B and FIG. 15B show the compressed air from the pressure supply port 7 by the pressure pump drive mechanism 65 in the ink cartridge 1 in which the liquid storage chamber 40 is sufficiently filled with ink. 41 shows a state of being introduced inside 41.

The pressurizing chamber film 14 is moved by the pressure of the compressed air introduced into the pressurizing chamber 41 into the liquid storage chamber 4.
The liquid containing chamber film 13 is deformed by being pushed to the 0 side and deformed by the pressurizing chamber film 14.
A is deformed by being pushed toward the liquid storage chamber 40. As a result, the ink in the liquid storage chamber 40 is pressurized, and the pressurized ink flows into the buffer chamber 42 via the communication path 35A.

Then, the buffer chamber film 13B is formed by the pressure of the ink flowing into the buffer chamber 42.
Is deformed upward, and the spring seat member 17 is pushed up against the urging force of the pressure spring 19. Then, as can be seen from FIG. 15B, the movable terminal 20 </ b> A of the contact switch 20 is pushed up by the pushed-up spring seat member 17. As a result, the movable terminal 20A and the fixed terminal 20B are separated from each other to be in a non-contact state, and the contact type switch 20 is turned off (non-conductive state).

That is, in the detection member 16 of the ink cartridge 1 of the present embodiment, the ink in the liquid storage chamber 40 is pressurized by the compressed air, and the pressure of the pressurized ink in the liquid storage chamber 40 is within the buffer chamber 42. Transmitted to ink. At this time, when the pressure P of the ink in the buffer chamber 40 is higher than a predetermined value, that is, the pressure P2 applied to the ink in the buffer chamber 42 by the urging force of the compression spring 19, the spring seat member 17 is moved to the upper limit position. Until the contact switch 20 is turned off.

In the present embodiment, the spring seat member 17 that is displaced against the urging force of the compression spring 19 due to the increase in the volume of the buffer chamber 42 has reached the limit point (upper limit position) of the displaceable range. The movable terminal 20A is sometimes displaced by contact with the movable terminal 20A.

As the ink is consumed in the inkjet printer 100, the liquid storage chamber 4
The amount of ink in 0 decreases, and the volume in the liquid storage chamber 40 gradually decreases. At this time, if the remaining amount of ink in the liquid storage chamber 40 is equal to or greater than a predetermined value, the pressure of the compressed air applied to the ink in the liquid storage chamber 40 is transmitted to the ink in the buffer chamber 42 via the ink. Accordingly, in this state, the state in which the spring seat member 17 is pushed up to the upper limit position against the urging force of the compression spring 19 is maintained, and the contact switch 20 is maintained in the OFF state.

When the ink in the liquid storage chamber 40 is further consumed and almost no ink is present in the liquid storage chamber 40 as shown in FIG. 11C, the pressure of the compressed air is transmitted to the ink in the buffer chamber 42. Disappear. Then, as the ink in the buffer chamber 42 is consumed, the spring seat member 1
7 descends, and the pushed-up state of the movable terminal 20A by the spring seat member 17 is released as shown in FIG. 15 (c). As a result, the movable terminal 20A comes into contact with the fixed terminal 20B, and the contact type switch 20 is switched from the off state to the on state.

That is, when the pressure of the compressed air is not transmitted to the ink in the container body 2 and the ink pressure in the container body 2 is less than a predetermined value, the contact switch 20 is turned on.

In the present embodiment, the movable terminal 20A is pushed up by the raised spring seat member 17, and the contact switch 20 is switched from the on state (conducting state) to the off state (non-conducting state). As an example, the arrangement of the movable terminal 20A and the fixed terminal 20B is turned upside down, and the movable terminal 20A and the fixed terminal 20B are brought into a non-contact state in a non-pressurized state so that the spring seat is raised when pressure is applied. The movable terminal 20A may be pushed up by the member 17 so as to contact the fixed terminal 20B.

FIG. 16 is a table showing how the output signal of the detection member 16 changes depending on the presence / absence of ink and the operation / stop of the pressure pump. Note that “with ink” in FIG. 16 indicates a case where the remaining amount of ink in the liquid storage chamber 40 is equal to or greater than a predetermined value, and “no ink” indicates that the liquid storage chamber 40
The case where the remaining ink amount is less than a predetermined value is shown.

As can be seen from FIG. 16, when the pressure pump is operating in the presence of ink, the detection member 16 is turned off. On the other hand, even when the pressurizing pump is in operation, the detection member 16 is turned on when there is no ink. When the pressurizing pump is stopped, the detection member 16 is turned on regardless of the presence or absence of ink in the liquid storage chamber 40.

On / off information obtained by these detection members 16 is transmitted to the control unit 70 via the antenna member 24 installed on the IC board, and a user provided outside the inkjet printer 100 by the ink remaining amount display mechanism 64. Is displayed on the visible display portion.

As described above, according to the ink cartridge 1 of the present embodiment, the electrostatic capacity between the electrodes 50A and 50B is detected by mounting the ink cartridge 1 on the ink jet printer 100, and based on this electrostatic capacity. The remaining amount of ink in the ink cartridge 1 can be detected. Therefore, it is possible to accurately grasp not only the near end and the ink end, but also how much ink remains in the ink cartridge at all times.

In addition, according to the ink cartridge of the present embodiment, the near end and the ink end are detected by a method other than the electrodes 50A and 50B (method using the movable terminal 20A and the fixed terminal 20B). Thus, even if the value of the ink remaining amount cannot be obtained, at least the near end and the ink end can be directly detected. Therefore, the user can be surely notified of the replacement timing of the ink cartridge and prompted to prepare the ink cartridge in advance.

In the above description, the electrode 50 is used as a method for detecting the remaining amount of ink in the ink cartridge 1.
A method using A and 50B and a method using the movable terminal 20A and the fixed terminal 20B have been described.
These may be used to detect the remaining amount of ink by using both at the same time as in this embodiment, but may be configured to employ only one of them.

In the present embodiment, the flow rate of the ink flowing out from the buffer chamber 42 is calculated based on the volume change amount of the buffer chamber 42 during a predetermined time when the liquid storage chamber 40 is pressurized. The flow rate of the ink flowing out from the buffer chamber may be calculated by measuring the time required for the buffer chamber 42 in the pressurized state in the liquid storage chamber 40 to change in a predetermined volume.

In the above description, the capacitance is obtained by the electrodes 50A and 50B, and the ink remaining amount is obtained from the capacitance. However, the present invention is not limited to this, and the amount of ink in the buffer chamber 42 is time-series. If there is another method required for the method, it may be used.

For example, a mechanical switch structure that detects the position of the spring seat member 17 of the detection member 16 of the buffer chamber 42 may be used. In this case, the time from when the ink is pressurized by the pressure pump to when the contact switch 20 is switched to the ON / OFF state is measured, and the change rate of the ink amount and the remaining ink amount are obtained. Also good.

Further, for example, a plurality of contact points are provided along the moving direction of the spring seat member 17, and the position of the contact point and the contact point where the terminal provided on the spring seat member 17 contacts is detected.
, The ink amount in the buffer chamber 42 may be obtained, and the ink remaining amount may be obtained from the rate of change of the ink amount.

1A and 1B are views showing the appearance of an ink cartridge as an embodiment of a liquid container according to the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a side view, FIG. 1C is a front view, and FIG. FIG. (A) is a bottom view of the ink cartridge shown in FIG. 1, and (b) is a side view. FIG. 2 is an exploded perspective view of the ink cartridge illustrated in FIG. 1. FIG. 4 is an exploded perspective view of the ink cartridge shown in FIG. (A) is the sectional view on the AA line of the ink cartridge shown to Fig.1 (a), (b) is the BB sectional view of the ink cartridge shown in FIG. FIG. 2 is a perspective view showing a tank unit of the ink cartridge shown in FIG. 1. FIG. 7 is a perspective view illustrating a tank unit of the ink cartridge illustrated in FIG. 1, and is a diagram in which FIG. 6 is turned upside down. FIG. 2 is a perspective view showing a pressure unit of the ink cartridge shown in FIG. 1. FIG. 2 is a plan view showing a pressure unit of the ink cartridge shown in FIG. 1. FIG. 2 is an exploded perspective view showing a pressure unit of the ink cartridge shown in FIG. 1. FIG. 2 is a diagram schematically illustrating a detection operation of a detection member of the ink cartridge illustrated in FIG. 1. It is a block diagram which shows the control circuit of the inkjet printer as one Embodiment of the liquid ejection apparatus by this invention. It is a figure which shows the control part of the inkjet printer as one Embodiment of the liquid ejection apparatus by this invention. It is a figure which shows the modification of electrode arrangement | positioning. FIG. 2 is a diagram illustrating a change in an output signal of a detection member in the ink cartridge illustrated in FIG. 1. It is the table | surface which showed how the output signal of a detection member changes with the presence or absence of an ink, and the action | operation / stop of a pressurization pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ink cartridge, 2 ... Container main body, 2A ... 1st case member, 2B ...
2nd case member, 2C ... 3rd case member, 6 ... ink delivery port, 7 ... pressure supply port, 8 ... ink injection port, 9 ... erroneous mounting prevention block, 10 ..Bottom film, 1
3A ... Liquid storage chamber films 13A, 13B ... Buffer chamber films, 14 ...
・ Pressure chamber film, 16 ... detection member, 17 ... spring seat member, 19 ... compression spring, 20 ... contact type switch, 20A ... movable terminal, 20B ... fixed terminal , 21 ...
IC substrate 24 ... antenna 40 ... liquid storage chamber 41 ... pressurizing chamber 42
Buffer chamber, 50A, 50B ... Electrode, 70 ... Control unit, 71 ... Capacitance calculation unit, 72 ... Buffer chamber volume calculation unit, 73 ... Buffer chamber volume change calculation unit 75
... Ink remaining amount calculation unit

Claims (12)

In the liquid container that pressurizes the liquid storage chamber that stores the liquid and supplies the liquid from the liquid supply port to the liquid ejecting apparatus,
The liquid storage chamber is connected to the liquid storage chamber, and is disposed in a region that is cut off from the pressure applied to the liquid storage chamber. The volume of the liquid storage chamber is increased by inflow of liquid from the liquid storage chamber due to pressurization of the liquid storage chamber. A buffer chamber that contracts when the pressurization of the liquid storage chamber is stopped;
A liquid detection mechanism for detecting a liquid remaining amount related value related to the remaining amount of liquid in the liquid container;
A liquid container characterized by comprising: The liquid detection mechanism has a pair of electrodes disposed so as to sandwich the buffer chamber,
The liquid container according to claim 2, wherein the liquid remaining amount related value is a capacitance between the electrodes. The buffer chamber is formed by a fixed wall and a movable member movable with respect to the fixed wall,
The liquid container according to claim 1, wherein the electrode is disposed so as to be perpendicular to a movable direction of the movable member of the buffer chamber. The buffer chamber is formed by a fixed wall and a movable member movable with respect to the fixed wall,
The liquid container according to claim 1, wherein the electrode is disposed so as to be parallel to a movable direction of the movable member of the buffer chamber. 5. The liquid container according to claim 3, wherein the movable member provided in the buffer chamber is a pressurizing member that pressurizes the liquid flowing in from the liquid housing chamber. The liquid container according to claim 1, wherein the buffer chamber is provided in a flow path connecting the liquid storage chamber and the liquid supply port. The liquid storage according to claim 1, wherein the buffer chamber is configured by sealing an opening of a recess provided in a member forming the buffer chamber with a film. body. 8. The liquid container according to claim 1, wherein one end of the movable member is in contact with or separated from a fixed terminal provided in the buffer chamber according to a change in volume of the buffer chamber. The liquid container according to any one of claims 1 to 9,
A buffer internal volume calculation unit for calculating the volume of the buffer chamber from the liquid remaining amount related value;
A flow rate calculation unit that calculates a flow rate of the liquid flowing out of the liquid container according to the change amount of the volume calculated by the buffer internal volume calculation unit;
A liquid ejecting apparatus comprising: a remaining amount calculating unit that calculates a remaining amount of liquid in the liquid container based on a flow rate of the liquid flowing out of the liquid container. The flow rate calculation unit calculates a flow rate of the liquid flowing out from the buffer chamber based on a volume change amount of the buffer chamber during a predetermined time when the liquid storage chamber is pressurized. The liquid ejection apparatus as described. The volume calculation unit calculates a flow rate of the liquid flowing out of the buffer chamber by measuring a time required for the buffer chamber to change in a predetermined volume in a pressurized state in the liquid storage chamber. The liquid ejection apparatus according to claim 9. It is an inkjet printer, The liquid ejection apparatus of any one of Claims 9-11 characterized by the above-mentioned.

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