JP2003312000A - Liquid jet recorder and method of supplying recording liquid therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a serial type small portable inkjet recorder wherein supplying of ink from a main ink tank outside of a carriage to a sub-ink tank on the carriage is performed in a simple structure. <P>SOLUTION: A porous body 104 is compressed to be inserted into a sub-ink tank case 103. Residual ink detection pins 107, 108 for detecting an amount of residual ink in the sub-ink tank 101 are inserted into the sub-ink tank 101 at the bottom thereof, and then the amount of ink held by the porous body 104 is detected. An ink supply section 109 of a space to which the ink is supplied from the main ink tank 301 is provided to a portion aside the porous body 104. An ink supply hole 110 and an ink supply hole valve 111 that closes the ink supply hole 111 when the ink is not supplied are provided to the ink supply section 109. The ink supply section 109 communicates to the atmosphere through an air communicating hole 106 provided to the top of the sub-ink tank case 103. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid discharge recording apparatus, and more particularly to an ink supply means for intermittently supplying ink from a main ink tank provided outside a carriage to a sub ink tank provided on a carriage. The present invention relates to a serial type inkjet recording device provided.

[0002]

2. Description of the Related Art As a recording apparatus used at home or office, there are a printer connected to a personal computer, a printer section of a word processor, a facsimile, a copying machine and the like. The recording methods used in these recording apparatuses are mainly an electrophotographic method and an inkjet recording method.

An ink jet recording system for obtaining a recorded matter by appropriately adhering ink as minute droplets to a recording medium is much cheaper and smaller than an electrophotographic recording device, From recording office documents on paper,
Since a wide variety of recorded materials such as recording photographic images on special paper can be easily obtained, they have been widely used in recent years. In addition, a portable ink jet recording device has been proposed by taking advantage of the advantage of miniaturization.

In such an ink jet recording type recording apparatus, there are some kinds of configurations of the ink jet recording head portion and the ink tank portion.

One is an ink jet unit in which the ink jet recording head and the ink tank are integrally formed into a replaceable cartridge form.
The ink jet unit is detachably attached to a carriage provided movably in the recording apparatus, and when the ink stored in the ink tank runs out, the user replaces it with a new ink jet unit. This method is characterized in that the system is simple because the recording head and the ink tank are integrated, and a new recording head is replaced every time it is replaced. However, since the relatively expensive inkjet recording head is replaced according to the frequency of the ink tank, the running cost is inevitably increased.

As another configuration, there is a configuration in which the ink jet recording head and the ink tank are separately configured, the ink jet recording head is fixed to the carriage, and the user replaces only the ink tank. The ink tank may be directly connected to the inkjet recording head and provided on the carriage, or may be provided outside the carriage by being connected to the inkjet recording head by a flexible tube for supplying ink. This method has a feature that the running cost is low because the consumable item to be replaced is only the ink tank. However, since the apparatus main body is expensive to manufacture a long-life recording head, and if the recording head is worn out before the apparatus life, it is necessary to replace the head for repair.

As another configuration, there is a configuration in which the ink jet recording head section and the ink tank are separately constructed and then each can be replaced. Also in this case, the ink tank may be directly connected to the head and provided on the carriage, or may be provided outside the carriage via a tube. In this method, the running cost is about the middle of those two examples, and even if the print head is worn out before the life of the device, it can be easily replaced, but it requires a mechanism for attaching and detaching the print head and the ink tank separately. The operation tends to be complicated.

The ink tank has a function of supplying a necessary ink to the ink jet recording head and also generating an appropriate negative pressure to the head, that is, a pressure for pulling back the ink. A meniscus is formed at the ejection port of the ink jet recording head due to the surface tension of the ink and an appropriate negative pressure. Therefore, if the negative pressure applied to the ejection port is too small, ink may leak from the nozzle or ejection may not be performed properly. On the other hand, if the negative pressure is too large, it becomes difficult for ink to be ejected, and the recording becomes faint or cannot be ejected at all.

The mechanism for generating this appropriate negative pressure has been devised in various ways according to the configurations of the ink jet recording head and the ink tank.

One is that a porous body (mainly a sponge) provided in the ink tank absorbs ink, and the capillary force of the porous body acts as a negative pressure on the recording head. The sponge is used for the integrated type of the recording head and the ink tank, or the type which is separate but is integrated on the carriage.

Even if the recording head and the ink tank are integrated, the ink is put in a watertight and airtight soft bag,
There is also one in which a leaf spring that tries to spread the bag outward is attached to the bag to generate a negative pressure.

On the other hand, when an ink tank is provided outside the carriage via a tube, a difference in height between the recording head and the ink tank, that is, a head difference is often used.

As a device for constructing a portable printer in which ink is supplied from an ink tank outside the carriage via a tube, Japanese Patent Laid-Open No. 2000-103079 discloses a main ink tank provided outside the carriage in a spring bag. The one that has been proposed. This is because when negative pressure is generated due to the head difference, the pressure changes depending on the orientation of the recording device.

Further, in order to prevent the inertial force of the ink in the tube from acting on the head due to the reciprocating movement of the carriage, Japanese Patent Laid-Open No. 10-086402 discloses that a valve is provided in a sub ink tank on the carriage. It has been proposed to intermittently supply ink from the main ink tank to the sub ink tank.

Further, in Japanese Unexamined Patent Publication No. 10-244686, a main ink tank for replenishment is connected to a sub ink tank on a carriage to form a closed flow path system from a head to a main ink tank, and after ink replenishment, The negative pressure in the sub ink tank is adjusted by changing the vertical position of the main ink tank. A structure has been proposed in which an appropriate negative pressure can be applied to the head by separating the replenishment tank while maintaining the negative pressure.

Further, as a device for reducing the frequency of replacement of the ink tank provided on the carriage with a structure in which the recording head and the ink tank can be replaced separately, Japanese Patent Laid-Open No. 09-1
In Japanese Patent Laid-Open No. 69119, there is proposed a method in which an ink supply tube is pressed against a sponge portion of an ink tank and suction ink is sucked from the supply tube by a negative pressure of the ink tank sponge. Since the negative pressure of the sponge of the ink tank is used, it is not necessary to detect fullness, and ink replenishment can be performed with a simple configuration without considering the remaining ink amount.

As disclosed in Japanese Unexamined Patent Publication No. 09-240020, the ink tank on the carriage is replenished at the home position for each reciprocation of the carriage movement in the direction intersecting the recording material conveyance direction. It is disclosed that the liquid level of the tank is detected and the control is performed so that the replenishment operation is performed but the replenishment is not performed when the ink is in a predetermined amount.

[0018]

A small and portable ink jet recording apparatus has been proposed which has a recording head and an ink tank provided on a carriage and can be replaced separately. However, since the carriage is also made to have a minimum size in order to reduce the size of the apparatus, the frequency of replacing the ink tank is inevitably higher than that of the stationary recording apparatus. When it was attempted to construct an ink jet recording apparatus that is small in size, portable, and requires less ink tank replacement, it has been found that the above-described conventional apparatus has the following problems.

In the construction in which a small sub ink tank is provided on the carriage and a large main ink tank is provided outside the carriage and connected by a tube to supply ink from the main ink tank to the sub ink tank, the carriage can be made small. Although this is an effective technique for reducing the size of the apparatus, since the ink inside the tube causes an inertial force due to the reciprocating movement of the carriage to change the negative pressure acting on the head, a means for alleviating this is required.

Further, since the carriage reciprocates over a considerable distance, the tube connecting the main ink tank and the sub ink tank needs to bend flexibly, and if a soft resin one is used, the gas permeability will inevitably increase. Therefore, air bubbles will accumulate in the tube after being left for a long period of time, and a means for excluding this is required. Therefore, generally, a method of sucking the ink in the tube at a predetermined interval and removing all the bubbles is used, but in this method, although a large-capacity ink tank is provided outside the carriage to reduce the replacement frequency, a large amount of ink is removed. I will throw it in vain.

Further, it is assumed that the posture of the recording device is in any orientation when it is transported in a small portable recording device, and at that time, the head difference between the main tank and the recording head greatly changes, so that the recording head discharges. Another means is required to prevent the ink from leaking from the outlet.

The ink supply tube connected to the porous body of the ink tank on the carriage to suck up the ink from the supply tube by the capillary force of the porous body of the main tank is very effective for absorbing the ink. take time. Even though it is good for a structure that automatically replenishes at night when the recording device is not used, it has been found that it is not suitable for a structure that requires the ink tank on the carriage to be as small as possible in order to make the carriage extremely small. .

When the carriage moves in the direction crossing the recording material conveyance direction, the ink tank on the carriage is replenished at the home position, and when the liquid level of the ink tank is detected and there is a predetermined amount of ink, A device that controls the replenishment operation but does not replenish it has a problem that throughput is reduced because the replenishment operation is unnecessarily performed even when ink is not actually replenished.

Further, since the liquid surface is required to detect the ink amount in the ink tank, means for generating a negative pressure for the recording head is required separately from the liquid-only storage chamber, and the carriage is constructed small. Will be increased.

By connecting the main ink tank for replenishment to the sub ink tank on the carriage having the negative pressure generating means using the spring bag and changing the vertical position of the main ink tank, the negative pressure in the sub ink tank is changed. The configuration in which the replenishment tank is disconnected while adjusting the negative pressure and maintaining the negative pressure must always maintain a closed system, so be careful when connecting and disconnecting the flow path, and a complicated configuration is required. Becomes

The present invention has been made in view of the problems of the above-described conventional technique, and ink can be replenished from the main ink tank outside the carriage to the sub ink tank on the carriage with a simple structure. An object of the present invention is to provide an ink replenishment method suitable for a serial-type small portable recording apparatus to be performed and an ink jet recording apparatus using the ink replenishment method.

[0027]

A method of absorbing a recording liquid (for example, ink) in a liquid absorber made of a porous body in a sub tank and generating a negative pressure by a capillary force is a pressure caused by a posture difference of a recording device. There are many advantages in constructing a particularly small recording device, such as a small fluctuation, a space for storing the recording liquid need not be a closed system, and the influence of bubbles generated in the recording liquid is small. However, since it takes time to absorb the recording liquid only by the capillary force of the porous body, it is not suitable for a configuration in which the recording liquid is replenished during the recording operation. Therefore,
In order to solve this problem, the present inventor has the following configuration.

1. When adding a recording liquid to a liquid absorber that already holds a certain amount of recording liquid, the added recording liquid is
A space is provided adjacent to the recording liquid already held by the liquid absorbent so that the liquid absorbent can be absorbed by the liquid absorbent in a continuous state with the recording liquid already held, and the recording liquid is provided in the space. Then, the recording liquid was replenished by causing the liquid absorber to absorb by the capillary force of the liquid absorber.

2. A means for detecting the amount of the recording liquid held by the liquid absorber is provided, and the timing for replenishing the recording liquid is determined based on the value.

3. The recording liquid amount (recording liquid consumption amount) ejected from the ink jet recording head unit is integrated by counting the number of ejection dots and the suction operation, and the timing for replenishing the recording liquid is also determined based on that value.

4. To prevent the recording liquid from being consumed by the next replenishment of the recording liquid and running out of the recording liquid held in the sub tank, and to prevent the recording liquid in the sub tank from overflowing due to replenishment of the recording liquid. It was decided to replenish the recording liquid little by little with the recording liquid holding amount (recording liquid remaining amount) with a margin on both the disappearing side and the overflowing side.

That is, according to the present invention for achieving the above object, recording is performed by using a sub-tank in which a recording liquid is held in a liquid absorber made of a porous body in the tank, and the recording liquid supplied from the sub-tank. A liquid discharge recording apparatus comprising: an ink jet recording head unit for performing recording; a main tank that stores a recording liquid to be supplied to the sub tank; and a replenishing unit that replenishes the recording liquid in the main tank to the sub tank. So that the replenishment portion forming the space for replenishing the recording fluid is absorbed by the liquid absorber in a state where the recording fluid replenished to the replenishment portion is continuous with the recording liquid already held by the liquid absorber. Is provided in contact with a portion of the liquid absorber that holds the liquid.

In this configuration, since the recording liquid is replenished by contacting the portion of the liquid absorber which already holds the recording liquid, the recording liquid held in the liquid absorber before the replenishment is replenished and a new liquid is replenished. The recording liquid absorbed by the absorber is integrated.

In the above liquid ejection recording apparatus, the recording liquid replenished in the replenishing section is absorbed by the liquid absorber by the capillary force of the liquid absorber. Since the liquid absorbing body itself is replenished by the capillary force as described above, there is no need for a pressurizing means or a sucking means for forcibly absorbing the recording liquid in the liquid absorbing body, and there is no need to seal the replenishing path. Therefore, the supply system can be simply constructed.

Further, since the recording liquid is replenished into the sub tank by the capillary force of the porous member, the recording liquid is replenished by connecting a part of the replenishing means from the main tank only when replenishing the sub tank. In both the pit-in system and the so-called tube supply system in which the supply tube from the main tank is always connected to the sub-tank to appropriately replenish the recording liquid, there is no leakage or shortage of the recording liquid, and the inkjet recording head unit It is possible to configure an ink supply system capable of properly maintaining the negative pressure with respect to.

Further, in the above liquid discharge recording apparatus, it is preferable that the space for replenishing the recording liquid communicates with the atmosphere through an atmosphere communication port provided in the sub tank. With such a configuration, when the replenished recording liquid is absorbed by the liquid absorber, the atmospheric pressure of the space in which the recording liquid is replenished does not decrease. Furthermore, since the replenishment path is not a closed system and is temporarily opened to the atmosphere during replenishment, bubbles can be removed here.

In the above liquid discharge recording apparatus, an opening for supplying liquid to the space and an opening / closing member for closing the opening are provided in the space for supplying the recording liquid. It is preferable that the member opens the opening only when the recording liquid is replenished. With this configuration, when the recording liquid is not replenished, the opening of the replenishing portion space for replenishing the recording liquid is closed, so that the recording liquid does not leak from the opening for replenishing the recording liquid.

In the above liquid ejection recording apparatus, the opening / closing member is normally biased by the spring property of the spring member or the opening / closing member itself so that the opening is closed, and a part of the replenishing means. It is preferable to open by pressing. With this configuration, it is not necessary to provide a driving means only for opening and closing the opening / closing member of the opening of the replenishing portion when replenishing the recording liquid.

The above liquid discharge recording apparatus is a serial printer which performs recording by moving the recording head section in a direction intersecting with the conveyance direction of the recording medium, and the sub-tank is moved by mounting the recording head section. Is provided on the carriage, the main tank is provided outside the carriage, and the replenishing means is not connected to the replenishing portion of the sub tank when the carriage is present on the recording medium, or the sub tank The one that is always connected to the supply section of can be applied. In the former configuration,
It is possible to configure a main tank that is larger than the sub-tank while making the carriage compact. With the latter configuration, the recording liquid can be replenished to the sub tank even during the recording operation.

That is, in the former so-called pit-in type structure, although it takes time to connect / disconnect the replenishing means at the time of replenishing the recording liquid, and it may be possible to replenish only at the replenishing position, the sub tank on the carriage is connected to the main tank. Since a supply tube such as a supply tube is not connected, the reaction force of the tube is not affected even if an ultra-compact carriage is constructed, and the space for the tube is unnecessary, and the drive source such as a motor can be downsized. It is suitable for constructing a small recording device. On the other hand, the constant connection type of the supply tube which is the replenishing means is just the opposite of the pit-in type. In other words, since the reaction force of the tube is applied to the carriage, a stronger drive source such as a motor is required, and a space around the tube is required. Since it is possible to constantly replenish the recording liquid regardless of the position of the carriage without requiring the time for separation, it is suitable for the configuration of a recording apparatus that requires throughput even if it is small.

Further, the above liquid discharge recording apparatus has a detecting means for detecting the amount of recording liquid held in the sub-tank, and the recording liquid holding amount obtained from the detecting means
It is preferable to control the replenishment amount of the recording liquid. With this configuration, the replenishment amount at the time of replenishing the recording liquid is controlled by the recording liquid holding amount of the sub tank, so that the recording liquid holding amount of the sub tank can be controlled. Further, since the amount of the recording liquid held in the sub tank is detected, it is possible to detect and control the error such as the recording liquid consumption amount and the recording liquid replenishment amount as the recording liquid holding amount in the sub tank. In other words, even if there are bubbles in the supply tube that is the replenishing means and the amount of the recording liquid supplied to the replenishing section is small, it can be corrected at the next replenishment.

In the above liquid discharge recording apparatus, it is preferable that the detection value of the recording liquid holding amount by the detecting means is a value after a predetermined time after replenishment of the recording liquid. With this configuration, it is possible to detect the state where the replenished recording liquid is slowly absorbed by the capillary force of the liquid absorber.

In the above liquid discharge recording apparatus, when the recording liquid holding amount is smaller than a preset predetermined value c, it is preferable that the recording liquid is replenished to the sub tank by the replenishing means. With this configuration, since the recording liquid is replenished when the recording liquid holding amount is smaller than the predetermined value, the recording liquid holding amount in the sub tank can be controlled.

Further, the above-mentioned liquid discharge recording apparatus has means for estimating the recording liquid consumption amount coming out from the recording head portion from the operation of the recording device, and a predetermined amount from the recording liquid consumption amount obtained from the estimation. It is preferable to replenish the recording liquid when the value exceeds b. With this configuration, since the recording liquid is replenished when the recording liquid consumption amount exceeds the predetermined amount, the recording liquid replenishment timing can be accurately estimated.

In the case of this configuration, if the state in which the recording liquid is ejected from the recording head unit is the liquid ejection recording apparatus only ejecting the recording liquid droplets, the recording liquid amount ejected from the recording head unit is The estimating means is to count the number of recording droplets ejected from the recording head section. With this configuration,
Since the number of recording droplets ejected from the recording head unit is counted in estimating the consumption of the recording liquid, the consumption of the recording liquid can be estimated with a fineness of 1 dot unit.

The state in which the recording liquid is ejected from the recording head section is replaced with a liquid discharge recording apparatus which only discharges recording liquid droplets.
When the recording liquid is discharged from the recording head and the recovery device is a suction operation of the liquid discharge recording apparatus, the means for estimating the amount of the recording liquid flowing out from the recording head unit is the recording head. Counting the number of recording liquid droplets ejected from each unit, and counting the number of suction operations of the recovery device with respect to the recording head unit. With this configuration, the number of ejections of the recording liquid droplets from the recording head unit and the number of suction operations of the recovery device for the recording head unit are counted to estimate the recording liquid consumption amount. The supply timing can be accurately estimated.

Further, in the above-mentioned liquid discharge recording apparatus, when the recording liquid holding amount is larger than a predetermined value a (a> c) set in advance, the recording liquid is discharged regardless of the estimated recording liquid consumption amount. It is preferable not to replenish. With this configuration, it is possible to correct the control of the recording liquid holding amount when the actual recording liquid supply amount is larger than the estimated value of the recording liquid consumption amount.

Further, in the above liquid ejection recording apparatus, it is preferable to manage the history of recording liquid replenishment and correct the deviation between the estimated value of the recording liquid consumption and the recording liquid replenishment amount. With this configuration, it is possible to prevent the recording liquid holding amount in the sub-tank from being always large or small due to the difference between the estimated recording liquid consumption amount and the actually supplied recording liquid amount.

In this case, the correction is to change the value of the predetermined value b or to change the recording liquid replenishment amount to the sub tank. In the former configuration, the recording liquid replenishment amount can be corrected because the recording liquid replenishment interval can be corrected by correcting the determination value of whether or not to replenish the recording liquid based on the estimated value of the recording liquid consumption amount. . In the latter configuration, it is possible to finely control the recording liquid holding amount.

In the liquid discharge recording apparatus as described above, it is preferable to perform recording even before the recording liquid replenished in the replenishing section is completely absorbed by the liquid absorber. With this configuration, it is possible to shorten the time required to complete the apparent replenishment of the recording liquid.

Further, according to the present invention, there is provided a sub-tank in which a recording liquid is held in a liquid absorber made of a porous material in the tank, and an ink jet type recording head section for recording using the recording liquid supplied from the sub-tank. A recording liquid replenishing method for a liquid ejection recording apparatus, comprising: a main tank that stores a recording liquid to be supplied to the sub-tank; and a replenishing means that replenishes the recording liquid from the main tank to the sub-tank. A space for storing the recording liquid is provided in contact with the portion holding the recording liquid, and the recording liquid is stored in the space for storing the recording liquid so as to touch the recording liquid already held in the liquid absorber by the replenishing means. The recording medium is replenished and absorbed by the liquid absorbing body by the capillary force of the liquid absorbing body.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is an external perspective view showing a first embodiment of a liquid discharge recording apparatus of the present invention.
The liquid discharge recording apparatus of the form shown in FIG. 1 is an inkjet recording apparatus 1000 that records characters and figures by appropriately depositing ink droplets on a recording material 200 such as paper or an OHP sheet.

Two guide shafts 3 and 4 are arranged substantially parallel to each other in a casing of the ink jet recording apparatus 1000, and the carriage 2 is supported by the two guide shafts 3 and 4 so as to be capable of reciprocating. . The carriage 2 reciprocates so as to traverse over the recording material 200 by a driving unit (not shown). An ink jet unit 100 is integrally formed with the carriage 2.

The ink jet unit 100 has black B on the surface (the carriage lower surface in FIG. 1) facing the recording material.
nozzles 102Bk for appropriately depositing ink droplets of colors k, cyan C, magenta M, and yellow Y on the recording material.
102C, 102M, 102Y are provided. A sub ink tank 101Bk for supplying ink to the nozzles,
101C, 101M and 101Y are nozzles 102B for each color
It is provided corresponding to k, 102C, 102M, and 102Y.

A maintenance station 300 for the ink jet unit 100 is provided outside the recording material 200. The maintenance station 300 includes nozzles 102Bk, 102C, 102M,
An ink replenishment mechanism that replenishes ink to the sub ink tanks 101Bk, 101C, 101M, and 101Y, which are features of the present invention, from a general inkjet recording device such as a cap 330 and a wiper blade (not shown) that prevent 102Y from drying. 310 is provided.

The ink replenishing mechanism 310 uses black Bk,
Main ink tanks 301Bk and 301B for storing replenishment inks of cyan C, magenta M, and yellow Y
C, 301M, 301Y, a pump device (not shown) for sending the ink of the main ink tank of each color to the sub ink tank of each color, and the ink supply valves 302Bk, 30 for each color
3C, 303M, 303Y, an ink supply pipe 304B for carrying ink from the pump device to each of the ink supply valves
k, 304C, 304M, 304Y, and an ink supply valve support portion 305 that supports all the ink supply valves.
The ink replenishing valve support portion 305 includes a driving unit (not shown) that drives the ink supply valve supporting unit 305 so as to reciprocate substantially parallel to the bottom surface of the recording apparatus. This drive means uses a linear drive type solenoid type actuator, or a general drive mechanism such as a linear movement or an arc movement using a stepping motor and a rack and pinion mechanism.

FIG. 2 is a side sectional view of the carriage 2 on which the ink jet unit 100 shown in FIG. 1 is mounted and the ink supply mechanism 310.

The present embodiment is an ink jet recording apparatus using four color inks, which includes a main ink tank 301Bk,
From 301C, 301M and 301Y, nozzles 102Bk, 102C, 102M and 102 corresponding to each of these
Up to Y, four sets having the same sectional shape are provided.
Therefore, FIG. 2 shows one of the cross-sections, and the numbers assigned to the respective parts omit the subscripts for distinguishing the ink colors.

In the construction of the sub ink tank 101, a porous body 104 made of urethane sponge, polypropylene fiber or the like is compressed and inserted into the sub ink tank case 103 as an ink absorber for holding ink. The reason why the porous body is compressed is to reduce the voids in the porous body to increase the capillary force. Further, the upper portion of the ink outlet tube 105 that guides the ink from the porous body 104 to the nozzle 102 is provided so as to push the porous body 104 a little, and this portion has a higher capillary force than other portions, so that the ink is led out. The ink is configured to collect near the tube 105.

An atmosphere communication port 106 is provided in the upper portion of the sub ink tank case 103. This is for absorbing the pressure difference between the inside and the outside of the sub ink tank, and responds to the pressure increase due to the change of the atmospheric pressure of the outside and the decrease of the ink held in the porous body 104. However, in order to suppress the evaporation of ink as much as possible, the diameter of the atmosphere communication port 106 is made as small as possible and as long as possible.

Ink remaining detection pins 107 and 108 are inserted from the bottom of the sub ink tank case 103 in order to detect the amount of ink retained in the sub ink tank 101.
This electrode is connected to an electric circuit in the recording device by a conductor (not shown), and the amount of ink held by the porous body 104 is detected by a voltage change between the two electrodes. The ink held by the porous body is shown by hatching with broken lines. Regarding the remaining ink amount detecting technique, Japanese Patent Laid-Open No.
It is disclosed in Japanese Patent Publication No. 5-064898.

On the side of the porous body 104 (on the right side in the drawing), there is provided a gap where the sub ink tank case 103 does not contact. This is the ink replenishing section 109 for replenishing the ink from the main ink tank 301. The ink supply unit 109 has an ink supply port 110 and an ink supply port valve 111 that closes the ink supply port 110 when ink is not supplied.
And are provided. The ink supply port valve 111 is made of a soft elastic material such as rubber or thermoplastic elastomer. In order to prevent the pressure of the ink replenishing unit 109 from rising when the ink supplied to the ink replenishing unit 109 is absorbed by the porous body, the ink replenishing unit 109 connects the atmosphere communicating port 106 with the sub ink tank communicating port (not shown). Through the atmospheric pressure.

The portion that supplies ink to the ink supply section 109 is the ink supply valve 303 supported by the ink supply valve support section 305. Ink replenishment is performed by moving the ink replenishment valve 303 toward the ink replenishment port 110 (leftward in FIG. 2) by a driving unit (not shown) and pushing the ink replenishment port valve 111 open.

Next, the ink supply mechanism 310 shown on the right side of FIG. 2 will be described. Ink supply mechanism 3
Reference numeral 10 denotes a mechanism for appropriately replenishing the ink stored in the main ink tank 301 to the ink replenishing unit 109, and includes an ink replenishment valve 303, a main ink tank 301 that stores ink, and ink in the main ink tank 301. Pressurizing pump (replenishing pump) 306 for pressurizing the ink to the ink replenishing valve 303, and a rectilinear push-pull solenoid type actuator 307 for driving the pressurizing pump 306.
An ink supply pipe 304 for supplying ink from the pressurizing pump 306 to the ink supply valve 303, an ink supply valve support portion 305 for supporting the ink supply valve 303, and a drive (not shown) for driving the ink supply valve support portion 305. And means.

The main ink tank 301 contains a plastic ink case 313 in which ink is hermetically enclosed in a resin main case 312.

The ink bag 313 is provided with an ink supply lid 311 made of rubber or thermoplastic elastomer, and the main ink tank 301 is connected to the ink supply mechanism 3.
When set to 10, the pipe-shaped ink needle 309 pierces the ink supply lid 311 to connect the ink in the main ink tank 301 to the ink system (ink supply valve 303, ink supply pipe 304, etc.) of the ink supply mechanism 310.

A pump valve 308, which is a one-way valve, is provided integrally with the pressure pump 306 made of hemispherical rubber on the inlet side of the pressure pump 306 (the connection side of the main ink tank 301). There is. The ink supply valve 303 is also a one-way valve. FIG. 3 shows an external perspective view of the ink supply valve 303. The ink supply valve 303 has a shape in which the tip of a rubber pipe is crushed, and has a slit portion 303 at the tip.
a functions as a valve. When the liquid inside the ink supply valve 303 is pressurized, the pressure causes the slit portion 303a at the tip end to be opened and the liquid inside comes out. On the other hand, when the liquid inside the ink supply valve 303 is depressurized, the slit portion 303a at the tip is brought into closer contact with the liquid, so that the external fluid does not enter.

In this embodiment, the ink supply valve 303
Since the position is higher than the ink supply lid 311 of the ink bag 313, the ink does not leak from the tip of the ink supply valve 303 even without the slit portion 303a, but when the inkjet recording device is a portable type, Since the orientation of the device when carried is arbitrary, the pump valve 308 and the ink supply valve 303 need a force to stop the head pressure of the ink in the main ink tank 301 in any direction.

The ink supply valve 303 also has a function of preventing ink evaporation in the ink supply pipe 304 when ink is not being supplied.

In this embodiment, the ink supply pipe 304
Is a tube made of a soft resin such as vinyl chloride or polyethylene, but since the amount of movement of the ink supply valve support portion 305 is small, it was movably connected by a hinge sealed with a hard resin such as polyacetal or a metal pipe. It may be configured.

The ink replenishing operation of the recording apparatus having the above structure will be described below. The supply operation will be described with reference to FIG.

When the carriage 2 is at a predetermined position in the maintenance station (see reference numeral 300 in FIG. 1), the ink replenishing valve support portion 305 is driven by a driving means (not shown).
Is moved toward the carriage 2, the ink supply valve 3
The leading end 03 enters from the ink supply port 110 and pushes the inside ink supply port valve 111 open. Here, since the sub ink tank of the present invention holds the ink by utilizing the capillary force of the porous body, the ink supply port 110 and the ink supply valve 30
The connection of 3 is not required to be hermetic, and may be a loose connection.

Next, the pressure plunger 314 of the actuator 307, which is required in the four color ink sets of four sets, is used.
4 is driven in the direction of arrow A in FIG. 4 and the hemispherical rubber bag of the pressurizing pump 306 is pushed to supply a fixed amount of ink from the ink supply valve 303 to the ink supply unit 109. Since one-way valves are provided on the upstream side and the downstream side of the pressure pump 306, when the pressure plunger 314 is returned, ink is replenished from the main ink tank 301 into the rubber bag of the pressure pump 306.

The ink supplied to the ink supply section 109 is slowly absorbed by the porous body 104 due to the capillary force of the porous body 104.

Here, the wall 10 in the sub ink tank 101
The reason that 1a extends toward the bottom of the tank is to allow the ink to be supplied to be sucked from the lower portion of the porous body 104. As shown in FIG. 5, the ink supply port 110 is connected to the sub ink tank 10.
When the ink is replenished from above by being provided on the ceiling surface (upper surface) of No. 1, although the replenished ink soaks into the porous body 104, it is originally held by the porous body 104, and the ink outlet pipe 1
The ink concentrated in the lower part of the porous body 104 where 05 exists will not be connected (arrow B in FIG. 5).

As shown in FIG. 6, the ink replenishing section 109 is formed such that the bottom 109a of the ink replenishing section 109 is formed obliquely from above the tank to below the tank (arrow C in FIG. 6).
The shape shown in () makes it more smoothly absorbed. In addition, as shown in FIG. 7, even if the structure is such that it projects from the side wall near the bottom of the sub ink tank case 103, the porous body 1
04 A similar effect can be achieved in terms of the function of absorbing replenishment ink from below. Further, if the portion indicated by arrow E in FIG. 7 is made transparent, the ink supply state (ink absorption state of the porous body) can be detected by detecting this portion with an optical sensor. Further, the constitution of the ink supply port valve 111 is not a rubber plate shape as shown in FIG. 6, but a valve member and a spring member for biasing the plate member shown in FIG. 7 with a torsion coil spring are separately provided. It may be configured.

The configuration and operation of each section of this embodiment have been described above. Next, the ink supply method of the present embodiment using these will be described with reference to the flowchart of FIG.

Replenishment of ink is performed using two parameters, that is, the ink remaining amount (ink holding amount) of the sub ink tank 101 and the calculated ink consumption amount data. The amount of ink remaining in the sub ink tank 101 is
It is detected by the voltage of the two electrodes inserted in. The ink remaining amount obtained from this output value is set to "I". The ink consumption amount is obtained by counting and integrating the number of ejected ink droplets and the number of suction operations for nozzle recovery. The calculated ink consumption is “D”.

When the ink supply control sequence is started, first, in step S500, the ink consumption amount D by dot count (abbreviated as dot count D in the drawing) is initialized to D = 0. The operation of integrating the ink consumption amount D by the dot count is performed according to the recording ejection operation and the nozzle suction operation, separately from this flowchart. Next, in step S510, it is determined whether the remaining ink amount I at that time is less than or equal to a preset threshold value a. In the case of "YES", the value of the ink consumption amount D by the dot count is compared with the threshold value b in the next step S520. The threshold value b is the ink supply amount for one time. In the case of "NO", there is sufficient ink in the sub ink tank 101, so step S510
Return to before.

When the ink consumption amount D by dot count is equal to or larger than the threshold value b in step S520, it is determined that the ink has been consumed to some extent, and the process proceeds to step S540 to replenish the ink. Sub ink tank 101 after ink supply
In consideration of the ink absorption time by the porous body 104, a predetermined time t is waited in step S550, and the process returns to step S500.

When the ink consumption amount D is less than the predetermined value b in step S520, the process proceeds to the next step S530, and the remaining ink amount I is determined. Here, when the ink remaining amount I is less than the predetermined value c, it is determined that the ink remaining amount in the sub ink tank 101 is too small, and the process proceeds to step S540 of ink replenishment even if the ink consumption amount by the dot count is small. If the remaining ink amount I is not smaller than the threshold value c, it is determined that the ink amount in the sub ink tank 101 is still sufficient, and the process directly returns to step S510.

Here, the threshold value a for the determination based on the remaining ink amount I,
c satisfies the relationship of a> c.

The amount b of ink replenished at one time is at most half or less of the maximum amount of ink held in the sub ink tank.

The amount of ink ejected from one nozzle of the nozzle, the amount of ink sucked once by the nozzle recovery operation, and the amount of ink replenished by the ink replenishment mechanism do not match exactly because there are some errors and variations. Further, in the present invention, since the recording operation is performed after the ink is replenished without waiting for the replenished ink to be absorbed by the porous body, the amount of ink contained in the porous body changes depending on, for example, the print duty. Therefore, as a buffering means for allowing these deviations to some extent, the amount of ink in the sub ink tank 101 is maintained in the middle without being empty or full.

(Second Embodiment) Next, as a second embodiment of the present invention, the difference between the estimated value of the ink consumption amount and the ink replenishment amount is determined by using the judgment value of the remaining ink amount (ink holding amount). The correction method will be described with reference to the flowchart of FIG.

When the ink supply sequence is started, the correction coefficient value N1 is first initialized in step S600, and N1 = 1. Next, in step S602, the correction coefficient value N2 is initialized to N2 = 1. Next, in step S604, the ink consumption amount D is initialized by dot count, and D = 0 is set. Similar to the sequence of FIG.
The operation of integrating the ink consumption amount by the dot count itself is performed according to the recording ejection operation and the nozzle suction operation, separately from this flowchart.

Next, in step S606, it is determined whether the remaining ink amount I is less than or equal to a preset threshold value a. "YES"
In the case of, in the next step S610, the value of the ink consumption amount D obtained from the dot count is compared with a predetermined threshold value.
In the case of “NO”, the correction coefficient N2 is set to N2 = 1.25 in step S608, and the process returns to the step before step S606.

The threshold value in step S610 is the preset value b multiplied by the correction coefficients N1 and N2. When the ink consumption amount D is equal to or larger than the value of “b × N1 × N2”, it is determined that the ink has been consumed to some extent, the process proceeds to step S618, and ink supply is performed. "B × N1 ×
The value of “N2” is the ink supply amount for one time. When the ink consumption amount D has not reached the value of “b × N1 × N2”, it is determined that the ink consumption amount is not enough to replenish the ink, and the process proceeds to step S612.

In step S612, it is determined whether the ink remaining amount I of the sub ink tank is less than a preset threshold value c. If "YES", the next step S61
Go to 6. In the case of "NO", it is determined that the ink remaining amount is still sufficient and it is not enough to replenish the ink, and step S60 is performed.
Return to before 6.

In step S616, the remaining ink amount is determined again. It is determined whether the ink remaining amount I of the sub ink tank is less than a preset threshold value d. This threshold value d is set as the amount of ink remaining in the sub ink tank which is almost empty. In the case of "YES", it is determined that there is some abnormality in the ink supply system, error processing is performed in step S622, and the process ends.
Some abnormality is, for example, a state in which the replenishment operation itself is performed due to a failure of the pressurizing pump, but the ink is not actually replenished. In the case of "NO", the process proceeds to step S614, the correction coefficient N2 is set to 0.8, and ink is replenished in the next step S618. The case of "NO" means that the ink remaining amount is not critically low, but the ink consumption amount D is small, but the ink supply amount is reduced to a necessary amount.

After the ink replenishment at step S618, the value of the correction coefficient N2 is moved to N1 at step S620 to be used as the history for the next ink replenishment determination. After replenishing the ink, a predetermined time t is waited in step S624 in consideration of the ink absorption time by the porous body of the sub ink tank, and the correction coefficient N2
Before the initialization step S602 of FIG.

The value set in the correction coefficient is 1.
25 and 0.8. This is set to return to "1" if it appears the same number of times as 1.25 x 0.8 = 1. Any other value may be used as long as it is a combination to be multiplied by “1”, but this value is appropriately set according to the maximum ink holding amount of the sub ink tank and the ink supply amount.

The amount of ink discharged from the recording head, that is, the volume of an ink droplet of one dot, the amount of ink suctioned by the nozzle recovery operation, and the amount of ink replenished by the pressure pump vary from machine to machine, and even on the same machine due to environmental conditions. is there.
Even if the determination threshold value b based on the ink consumption amount D is set equal to the ink replenishment amount as in the first embodiment, there are cases in which the ink is replenished in a large amount or in a small amount. Since there is a difference between the actual ink consumption amount and the ink replenishment amount due to these variations, if the ink is replenished using only the integration of the ink consumption amount D by the dot count, the ink amount in the sub ink tank increases or decreases. Therefore, a means for detecting the amount of ink in the sub ink tank is provided to deal with the case where the amount of remaining ink is too large or too small. When the remaining ink amount is too large, the ink is not supplied regardless of the ink consumption amount D. Ink consumption D if the ink level is too low
Regardless of the ink supply. Further, in the case of the flowchart of FIG. 9, when the ink remaining amount exceeds the upper limit set value a before ink replenishment, the actual ink replenishment amount is too large with respect to the estimated ink consumption amount (estimated value). Therefore, the threshold value based on the ink consumption amount D of whether or not to replenish is set to be large (step S608). In addition, the history is set so that it will be retained after the next time. On the contrary, if the ink remaining amount may fall below the lower limit set value c, it is determined that the actual ink supply amount is too small, and the threshold value for the next ink consumption amount D is set to be small, that is, to be supplied a little earlier. (Step S614).

By correcting the ink replenishment amount according to the history of the ink remaining amount determination in this way, it is possible to correct the difference between the ink consumption amount and the ink replenishment amount, which is unique to the recording apparatus.

(Third Embodiment) Next, as a third embodiment of the present invention, a method for correcting the difference between the estimated ink consumption amount and the ink supply amount by increasing or decreasing the ink supply amount will be described with reference to FIG. This will be described with reference to the flowchart of. The same steps as those in the flowchart of FIG. 9 which describes the second embodiment are designated by the same reference numerals, and description thereof will be omitted. The flowchart of the present embodiment is different in that the correction coefficient N2 is processed as a correction coefficient for the ink supply amount.

When the ink remaining amount I is larger than the set value a in step S606, the process proceeds to step S625, and the correction coefficient N2 is set to 1.2. In step S616, the remaining ink amount I
Is greater than the set value d, the correction coefficient N is determined in step S627.
2 = 0.8. In step S618 of ink supply, the supply amount is changed according to the value of the correction coefficient N2 to supply the ink. The actuator 30 shown in FIGS. 2 and 4.
In 7, the amount of replenishment is changed by controlling the amount of displacement of the pressure plunger.

According to the above-described first to third embodiments, ink supply is performed while the recording operation is not being performed in the recording apparatus. The sub-ink tank holds ink by a porous body provided inside the sub-ink tank, and also generates a negative pressure necessary for the inkjet recording head section. Therefore, since the sub ink tank is not required to have airtightness for holding a negative pressure, joining / separation from the ink replenishing means becomes simple. Further, since the ink is supplied to the porous body by the capillary force of the porous body itself, a suction means for supplying the ink is not required. Furthermore, since the ink is taken up from the lower side of the porous body, which is the area where the ink is held in the porous body, air bubbles are generated between the ink remaining in the porous body and the newly supplied ink. There is no entry.

Furthermore, since the recording operation can be started without waiting for the supplied ink to be absorbed by the porous body, it does not take a long time to absorb the ink by using the capillary force of the porous body. Further, since the control is performed so as to maintain about half of the ink amount that can be held in the porous body, the difference between the supplied ink amount and the used amount can be absorbed by the increase or decrease of the ink holding amount.

Although the ink jet unit 100 and the sub ink tank 101 are fixed to the carriage 2 and are not replaced by the user, the ink jet unit and the sub ink tank 101 have a shorter life than that of the recording apparatus. The sub ink tank may be replaceable. Further, this exchangeable configuration and the ink supply method of the present invention can exist in the same manner.

At this time, the sub ink tank to be replaced may be integrated with the ink replenishing portion 109 which is a portion for receiving ink from the main ink tank outside the carriage, but the ink replenishing portion 109 is fixed to the carriage 2 as a split type. The cost can be reduced by replacing only the accommodating portion for accommodating the porous body holding the ink.

(Fourth Embodiment) FIG. 11 shows a fourth embodiment of the present invention.
3 is a cross-sectional view showing the recording apparatus of the embodiment of FIG. The present embodiment is applied to a so-called tube supply system in which a main ink tank provided outside the carriage and a sub ink tank on the carriage are always joined by a tube. In FIG. 11, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, only the portion where the ink supply valve support portion 305 is always connected to the sub ink tank 101 is different from the first to third embodiments.
Therefore, as shown in FIG. 11, the ink supply tube 304 must be long and made of a soft material to follow the reciprocating movement of the carriage 2.

With this structure, there is an effect that ink can be supplied even during the recording operation. Further, even if bubbles are mixed in the tube, the bubbles can be separated by the ink replenishment unit 109, and it is possible to cope with the fact that the amount of ink replenishment becomes smaller than a predetermined amount due to the bubbles. Further, since the ink is pressurized by the pressure pump 306 and supplied to the sub ink tank 101, the sub ink tank 101 and the main ink tank 30
The tube may be thinner than a tube used in a general tube continuous supply system in which 1 is connected by a tube to form a closed channel space. In the case of a continuous tube supply system, ink flows in the tube in accordance with the ink consumption due to recording, and therefore the ink conduit resistance is the nozzle 102 of the inkjet unit.
This is because it works as a negative pressure against.

Next, the ink supply method of this embodiment will be described with reference to the flowchart of FIG. The same steps as those in the flowchart of FIG. 9 which describes the second embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the ink replenishing method of this embodiment, the processing when the remaining ink amount I is less than a predetermined value is different.
That is, in consideration of the case where the amount of ink supply is small due to the inclusion of bubbles in the tube, an error is not immediately taken, and ink supply is repeated and the state is observed. The error processing is performed only when the ink remaining amount does not recover to the predetermined value even if the ink is replenished multiple times.

As shown in FIG. 12, in step S601 after the sequence is started, in addition to the correction coefficient N1, the counter variable N
3 is introduced, and initialization processing of N3 = 0 is performed. Step S
If the remaining ink amount I in 616 is less than the threshold value d, the recording process is stopped in step S615 so that the ink is not consumed any more. Next, in step S619, the counter variable N3 = N3 + 1 is set and the counter is advanced.

In step S621, it is determined whether the counter variable N3 is less than the preset threshold value e. "YES"
In the case of, the ink supply in step S618 is performed. Then, after performing steps S620 and S624, step S
Return to before 602. After that, the remaining ink amount I is a predetermined value d
Since ink supply is being performed in a state of less than step S6
06 is “YES”, and the recording process is stopped, so step S610 is “NO”. Then step S
If the ink remaining amount I is still less than the threshold value d at 616, steps S615 and S619 are performed again. This process is repeated until the counter variable N3 reaches e times. If the remaining ink amount I still does not exceed the threshold value d, error processing is performed in step S622 and the sequence ends.

If the remaining ink amount I becomes equal to or greater than the threshold value d before the counter variable N3 reaches e times, "N" is determined in step S616.
"O" and restart the recording process in step S613,
In step S617, the counter variable N3 is initialized to N3 = 0. After that, it is similar to the flowchart of FIG.

Even when the ink remaining amount is extremely small, the ink is replenished immediately without performing error processing to observe the situation, whereby the ink in the ink replenishing tube 304 contains bubbles and is replenished. Can be coped with when the amount of ink is extremely small, or when the ink in the ink supply pipe 304 is empty and the ink supply pipe 304 is not replenished at all until the ink is replenished with ink. .

The description so far is for the sub ink tank 101.
However, if the life of the sub ink tank 101 is shorter than the life of the recording apparatus, the user may replace the sub ink tank 101. In the case of the tube type, if the sub ink tank 101 to the main ink tank 301 are integrally replaced, the sub ink tank portion will not be replaced. In this case, a tube pump that pushes the tube from the outside is used as the ink supply pump.

Further, when the life of the ink jet recording head section is shorter than that of the recording apparatus, the ink jet unit 100 needs to be constructed so that the user can replace it. In the case of the tube type, the nozzle of the inkjet unit 100 is connected to the main ink tank 30.
If it is configured to replace up to 1 as a unit, the inkjet unit part (inkjet recording head part)
Never forget to replace. Also in this case, a tube pump that pushes the tube from the outside is used as the ink supply pump.

According to this embodiment, the sub ink tank 1
The ink replenishment system for 01 is always connected to the sub ink tank, so (1) ink can be replenished even during recording operation, (2) connection of the ink replenishing means with the sub ink tank
There is an advantage that throughput can be improved because time for separation is not required. Of course, since the joint between the sub ink tank and the ink supply system communicates with the atmosphere, the inertial force of the ink in the ink supply pipe 304 does not cause pressure fluctuations on the nozzles 102 of the inkjet unit 100.

[0114]

As described above, according to the present invention,
Since the liquid discharge recording apparatus has a structure in which the porous body in the sub-tank on the carriage generates negative pressure with respect to the ink jet recording head unit, the recording liquid in the sub-tank can be held regardless of the posture of the recording apparatus. Since the outer shell of the sub-tank is not required to be airtight, there is an effect that the replenishing unit for replenishing the recording liquid can be easily configured. Further, since the recording liquid is absorbed by coming into contact with the liquid holding portion of the liquid absorber bottom, the recording liquid originally held by the liquid absorber and the newly replenished recording liquid are integrated. And is held by the liquid absorber.

Further, since the space of the replenishing section for replenishing the recording liquid communicates with the atmosphere communication port of the sub tank, the replenished recording liquid is smoothly absorbed by the liquid absorber.
Since the replenishment section is open to the atmosphere, air bubbles from the replenishing means can be removed here.

Further, when the recording liquid is not replenished, the opening of the replenishing portion space to which the recording liquid is replenished is closed by the opening / closing member, so that the recording liquid does not leak from there, so that it is portable. An inkjet recording device can be configured.

Further, since the opening / closing member that closes the opening of the replenishing portion space is configured to be opened by the replenishing means, the driving means only for opening / closing the opening of the replenishing portion when replenishing the recording liquid is provided. The carriage can be made compact without the need.

Further, since the replenishing means from the main tank is connected to the sub tank only when the sub tank is replenished, a large-capacity main tank can be adopted while the carriage is compact, so that the tank can be replaced. The frequency can be reduced.

Further, since the replenishing means from the main tank is always connected to the sub tank, the recording liquid can be replenished to the sub tank even during the recording operation, so that the throughput of the recording apparatus is improved. Further, in the always connected constitution of the replenishing means, the replenishing portion to which the recording liquid is replenished is in communication with the atmosphere, so that the replenished recording liquid is liquid even if bubbles are mixed in the recording liquid from the replenishing means. Since the bubbles are removed when being absorbed by the absorber, another bubble removing means is not required and the structure is simple.

Also, the recording liquid holding amount (remaining amount) in the sub tank
Is detected and the replenishment amount at the time of replenishing the recording liquid is controlled by this recording liquid holding amount (remaining amount), so that the sub tank will not become empty or overflow.

Further, since the detection value of the recording liquid holding amount is to be the value after a fixed time after the recording liquid is replenished, a time-consuming method of absorbing the replenishing liquid only by the capillary force of the liquid absorber is effective. Can be used for.

When the recording liquid holding amount is smaller than the predetermined value, the recording liquid is replenished so that the sub tank does not overflow with the replenished recording liquid.

Further, by replenishing the recording liquid when the recording liquid consumption exceeds a predetermined amount, the timing of replenishing the recording liquid can be accurately estimated. Therefore, the recording liquid can be replenished only by the recording liquid holding amount in the sub tank. It can be controlled more finely than the control method.

Further, by estimating the recording liquid consumption amount by counting the number of droplets ejected from the ink jet recording head portion, the recording liquid consumption amount can be estimated with a fineness of one dot unit.

Further, by estimating the recording liquid consumption amount by counting the number of droplets ejected from the ink jet recording head section and counting the number of suctions of the nozzle recovery operation,
The recording liquid consumption can be estimated with the fineness of 1 dot unit. It is possible to accurately estimate the replenishment timing of the recording liquid.

When the recording liquid holding amount is larger than the predetermined value a, the actual recording liquid replenishment amount is larger than the estimated recording liquid consumption amount by not replenishing the recording liquid regardless of the recording liquid consumption amount. Therefore, there is no problem that the recording liquid holding amount of the liquid absorber increases and overflows.

The estimated value of the recording liquid consumption amount and the actually supplied recording amount are corrected by correcting the deviation between the actual recording liquid supply amount and the estimated value of the recording liquid consumption amount by managing the recording liquid supply history. It is possible to prevent the recording liquid holding amount in the sub-tank from being always large or small due to the difference in liquid amount.

Further, the correction is performed by changing the judgment value of whether or not the recording liquid is replenished according to the estimated value of the recording liquid consumption, so that the interval of the recording liquid replenishment can be corrected, and as a result, the recording liquid is replenished The amount can be corrected.

Further, since the correction is to change the replenishment amount, more appropriate control can be performed.

Further, by performing the recording even before the replenished recording liquid is absorbed by the porous body in the sub tank, the throughput of the recording apparatus is improved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of a liquid ejection recording apparatus of the present invention.

FIG. 2 is a schematic cross-sectional view showing the configuration of the ink supply system according to the first embodiment of the present invention.

FIG. 3 is a schematic perspective view showing an ink supply valve according to the first embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view showing a replenishing operation of the ink supply system according to the first embodiment of the present invention.

FIG. 5 is a comparative explanatory diagram illustrating effects of the ink supply unit according to the first embodiment of the invention.

FIG. 6 is a schematic cross-sectional view showing another sub ink tank configuration according to the first embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing another sub ink tank configuration according to the first embodiment of the present invention.

FIG. 8 is a flowchart illustrating an ink supply sequence according to the first embodiment of this invention.

FIG. 9 is a flowchart illustrating an ink supply sequence according to the second embodiment of the present invention.

FIG. 10 is a flowchart illustrating an ink supply sequence according to a third embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view showing the configuration of an ink supply system according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart illustrating an ink supply sequence according to a fourth embodiment of the present invention.

[Explanation of symbols] 100 inkjet unit (inkjet recording head part) 101,101Bk, 101C, 101M, 101Y Sub ink tank 101a Wall 102,102Bk, 102C, 102M, 102Y Nozzle 103,103Bk, 103C, 103M, 103Y Sub ink tank case 104 Perforated Particle 105 Ink outlet pipe 106 Atmosphere communication port 107,108 Ink residual detection pin 110 Ink supply port 111 Ink supply port valve 112 Sub tank communication port 300 Maintenance station 301,301Bk, 301C, 301M, 301Y Main ink tank 302 Pump device 303,303Bk, 303C, 303M, 303Y Ink supply valve 304, 304Bk, 304C, 304M, 304Y Ink supply pipe 305 Ink supply valve support 306 Pressurizing pump 307 Actuator 308 Pump valve 309 Ink needle 310 Ink supply mechanism 311 Ink supply lid 312 Main case 313 Ink bag 314 Pressurized plunger 330 cap

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 EA16 EA23 EA26 EB21 EB51                       EB56 EB59 EC11 EC15 EC17                       EC26 EC36 EC39 EC64 FA02                       FA10 HA37 KA01 KB04 KB09                       KB19 KB37 KC11 KC13 KC14                       KC15 KC16 KC17

Claims (19)

[Claims] 1. A sub-tank in which a recording liquid is held in a liquid absorber made of a porous material in the tank, an ink jet type recording head section for recording using the recording liquid supplied from the sub-tank, and the sub-tank. In a liquid ejection recording apparatus including a main tank for storing the recording liquid to be supplied to the sub-tank and a replenishing device for replenishing the recording liquid in the main tank to the sub-tank, a space for replenishing the recording liquid by the replenishing device is formed. A portion in which the replenishment portion holds the liquid of the liquid absorber so that the recording liquid replenished in the replenishment portion is absorbed by the liquid absorber in a state of being continuous with the recording liquid already held in the liquid absorber. A liquid discharge recording apparatus, wherein the liquid discharge recording apparatus is provided in contact with. 2. The liquid ejection recording apparatus according to claim 1, wherein the recording liquid replenished to the replenishing portion is absorbed by the liquid absorber by the capillary force of the liquid absorber. 3. The liquid ejection recording apparatus according to claim 1, wherein the space to which the recording liquid is replenished communicates with the atmosphere through an atmosphere communication port provided in the sub tank. 4. A space for replenishing the recording liquid is provided with an opening for replenishing the space and an opening / closing member for closing the opening, and the opening / closing member is provided when replenishing the recording liquid. The liquid ejection recording apparatus according to claim 1, wherein only the opening is opened. 5. The opening / closing member is normally urged by a spring member or the elasticity of the opening / closing member itself so that the opening is in a closed state, and is opened by pushing a part of the replenishing means. Item 4. The liquid discharge recording apparatus according to item 4. 6. A liquid discharge recording apparatus is a serial printer that performs recording by moving the recording head section in a direction intersecting a conveyance direction of a recording medium, and the sub-tank is moved by mounting the recording head section. 6. The carriage is provided on the carriage, the main tank is provided outside the carriage, and when the carriage is present on the recording medium, the replenishing means is not connected to the replenishing section of the sub-tank. The liquid discharge recording apparatus according to any one of 1. 7. A liquid discharge recording apparatus is a serial printer that performs recording by moving the recording head section in a direction intersecting a conveyance direction of a recording medium, and the sub-tank is moved by mounting the recording head section. 4. The liquid discharge according to claim 1, wherein the main tank is provided outside the carriage, and the replenishing means is always connected to the replenishing portion of the sub-tank. Recording device. 8. The method according to claim 1, further comprising a detection unit that detects the amount of recording liquid held in the sub-tank, and replenishment of the recording liquid is controlled by the amount of recording liquid held by the detection unit. 2. The liquid ejection recording apparatus according to any one of items. 9. The liquid ejection recording apparatus according to claim 8, wherein the detected value of the recording liquid holding amount by the detecting means is a value after a predetermined time after replenishing the recording liquid. 10. The liquid ejection recording apparatus according to claim 8, wherein when the recording liquid holding amount is smaller than a predetermined value c set in advance, the recording liquid is replenished to the sub-tank by the replenishing means. . 11. A recording liquid consumption amount ejected from the recording head unit is estimated from an operation of a recording apparatus, and when the recording liquid consumption amount obtained from the estimation exceeds a predetermined amount b, the recording liquid consumption is increased. Any one of claims 1 to 10 for replenishment
The liquid discharge recording apparatus according to item. 12. A liquid ejection recording apparatus in which the recording liquid is ejected from the recording head unit only by ejecting recording liquid droplets, and the means for estimating the amount of the recording liquid ejected from the recording head unit is used. The liquid ejection recording apparatus according to claim 11, wherein the number of ejections of recording liquid droplets from the recording head unit is counted. 13. A liquid ejection recording apparatus in which the recording liquid is ejected from the recording head unit by a recording liquid ejection and a suction operation by a recovery device, and the recording liquid amount ejected from the recording head unit. 12. The liquid ejection according to claim 11, wherein the means for estimating is the number of ejections of recording liquid droplets from the recording head unit and the number of suction operations of the recovery device with respect to the recording head unit. Recording device. 14. The recording liquid is not replenished regardless of the estimated value of the recording liquid consumption amount when the recording liquid holding amount is larger than a preset value a (a> c). 14. The liquid ejection recording apparatus according to any one of 1 to 13. 15. The liquid ejection recording apparatus according to claim 14, wherein the history of recording liquid replenishment is managed to correct the deviation between the estimated value of the recording liquid consumption and the recording liquid replenishment amount. 16. The liquid ejection recording apparatus according to claim 15, wherein the correction is to change the value of the predetermined value b. 17. The liquid ejection recording apparatus according to claim 15, wherein the correction is to change a recording liquid supply amount to the sub tank. 18. The liquid ejection recording apparatus according to claim 1, wherein recording is performed even before the recording liquid replenished in the replenishing section is completely absorbed by the liquid absorber. 19. A sub-tank in which a recording liquid is held in a liquid absorber made of a porous material in the tank, an ink jet type recording head section for recording using the recording liquid supplied from the sub-tank, and the sub-tank. A recording liquid replenishing method for a liquid ejection recording apparatus, comprising: a main tank for accommodating the recording liquid to be supplied to the sub tank; and a replenishing means for replenishing the recording liquid in the main tank to the sub tank. A space for storing the recording liquid is provided in contact with the portion holding the recording liquid, and the recording liquid is replenished in the space for storing the recording liquid so as to touch the recording liquid already held in the liquid absorber by the replenishing means, A recording liquid replenishing method for a liquid ejection recording apparatus, characterized in that the replenished recording liquid is absorbed and held by the liquid absorbing body by a capillary force of the liquid absorbing body.