JP2003089216A - Ink jet recorder and method for operating ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder and a method for operating an ink jet recorder whereby ink flowing to the side of an atmosphere communication chamber can be removed in a state while an amount of discharge ink is limited as much as possible in spite of the cost-restricted configuration of the apparatus when an ink tank with the ink still remaining is to be separated from a recorder body. SOLUTION: In the case where the ink flows out to the atmosphere communication chamber when the ink tank with the residual ink is separated, a connecting member such as an empty ink tank is set fresh to a position where the ink tank is separated, and a suction operation is carried out while a recording head is capped by a suction cap, whereby the ink remaining in the atmosphere communication chamber can be sucked and removed. Moreover, the ink is prevented from being sucked by an extra amount not smaller than an amount of the ink remaining in the atmosphere communication chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus and a method for operating the ink jet recording apparatus, and more specifically, an ink jet recording apparatus having a structure in which ink is supplied from an ink tank to a recording head through an ink supply path formed by a tube or the like. The present invention relates to a device and a method of operating such an inkjet recording device.

[0002]

2. Description of the Related Art Ink jet recording apparatuses, which are a kind of various recording apparatuses such as printers, eject ink droplets from respective ejection openings (nozzles) arranged in a recording head to form dots on a recording medium. Characters and images are formed and recorded. Since the ink jet recording apparatus performs recording by the non-impact recording method as described above, it has relatively low noise, and high density and high speed recording operation is possible by adjusting the ink ejection amount and ejection method from the nozzles. Therefore, it has been widely adopted in recent years.

In a general ink jet recording apparatus, a carriage equipped with a recording head is scanned in a predetermined direction on a recording medium, and a recording operation of ejecting ink from the recording head at the time of the scanning, and a recording medium of the recording head. Recording is performed on the entire recording medium by alternately repeating a conveying operation of conveying a predetermined amount in a direction perpendicular to the scanning direction. A device that performs a recording operation while moving the carriage is called a serial type.

As a method of supplying ink to the recording head of such a serial type ink jet recording apparatus, a so-called head tank integrated system in which an ink tank containing the ink is integrated with the recording head, a tube is used for the ink tank and the recording head. Connected so-called tube supply system,
In addition, an ink tank and a recording head are separately provided, and the inkjet recording head is moved to the position of the ink tank to connect the both, if necessary, and ink is supplied from the ink tank to the inkjet recording head in the meantime,
There is a so-called pit-in system.

It is convenient for the user to replace the ink tank less frequently. For example, in the case of the head tank integrated system, the larger the capacity of the ink tank is, the heavier the weight of the ink tank becomes. If this happens, problems will occur during recording, and it is difficult to increase the capacity of the ink tank in the head tank integrated system. On the other hand, in the tube supply method and the pit-in method, since the ink tank and the recording head are separated, it is relatively easy to increase the capacity of the ink tank. In many cases, the supply method or pit-in method is adopted. However, the pit-in system is not suitable for shortening the recording time because it is necessary to stop the recording operation during the supply of ink. In that respect, the tube supply system is
With the ink supply structure described below, the ink can be supplied to the print head at any time, which is effective when a large amount of print data is continuously printed for a long time.

FIG. 1 is a diagram showing a positional relationship between a recording head and an ink tank in a tube supply type ink jet recording apparatus.

The recording head 1 and the ink tank 4 have a height H higher than the ink level of the ink tank 4 in a state where the recording head 1 and the ink tank 4 are connected by a tube 6 and the flow path is filled with ink. The nozzles of the recording head 1 are located at a high position. That is, the inside of the recording head 1 is in a state of being maintained at the negative pressure corresponding to the head difference of the height H.

The discharge nozzle 1g of the recording head is a fine hole, and there is no particular valve mechanism in the nozzle, and by maintaining a negative pressure inside the nozzle, a meniscus of ink is stretched in the nozzle,
Ink leakage from nozzles and air from the atmosphere are eliminated. The ink is ejected by pushing out the ink in the nozzle by the film boiling energy of a heater (not shown) arranged near the nozzle, and after ejection, the cycle of filling the ink in the nozzle again by the capillary force of the nozzle is repeated. It can be sucked up from the ink tank 4 at any time. In this way, ink is supplied from the ink tank to the recording head. Therefore, the recording operation can be continued without interruption in the middle until the ink in the ink tank is exhausted.

FIG. 3 is a schematic view showing an ink supply path of a general tube supply type ink jet recording apparatus.

The recording head 1 and the ink tank 4 are shown in FIG.
It is arranged with a head difference as shown in. And
One end of the supply tube 6 is confidentially connected to the liquid connector insertion port 1a of the recording head 1. Further, the other end of the supply tube 6 is connected to the ink supply unit 5. The ink supply unit 5 includes a valve 10 that shuts off a flow path to the recording head as necessary, and a supply path that connects to the ink tank 4, and a supply needle 5 a is attached to a stopper 4 b at the bottom of the ink tank 4. By being inserted, it communicates with the ink tank 4. The stopper 4 at the bottom of the ink tank 4
Since b is made of an adhesive material such as rubber, when the supply needle 5a is pulled out, the opened hole is closed to the extent that the ink inside does not leak. In this way, the ink inside the ink tank 4 reaches the recording head 1 via the ink supply unit 5 and the supply tube 6, and this section is always filled with ink.

The ink tank 4 has another plug 4c in addition to the plug 4b connected to the supply tube 6.
The atmosphere communication needle 5b inserted in the stopper 4c is connected to the atmosphere communication chamber 5f.
Through the flow path 5e. The atmosphere communication chamber 5f is provided for temporarily storing the ink pushed out by the expansion of the air in the ink tank 4, etc., and when the main body is in a standby state or a rest state, the ambient environmental temperature rises and the ink tank When the air in 4 expands, the ink flows into the atmosphere communication chamber 5f through the flow path 5e. The atmosphere communication chamber 5f communicates with the atmosphere via the atmosphere communication port 5g.

On the other hand, on the recording head 1 side, in order to remove clogging of the nozzle 1g in the head, the nozzle 1g
A recovery unit 7 forcibly sucking ink or air from the surface is provided. The recovery unit 7 includes a suction cap 7a and a suction pump 7c connected to the suction cap 7a. If necessary, the nozzle 1g of the recording head 1 is covered with the suction cap 7a, and the suction pump 7c operates to remove the nozzle 1g. Suction ink to eliminate clogging.

Ink supply using negative pressure in such an ink supply path is specifically as follows.

FIG. 4 is a view showing the state of the ink tank.

Needles are pierced at the bottom two places of the ink tank 4, and the ink flows out of the tank from the outlets at the two places. One of the two needles
The supply needle 5a communicates with the tube 6 through the flow path c. Since the tube 6 is connected to the recording head,
The ink tank is connected to the recording head. The other is connected to the atmosphere communication chamber 5f by an atmosphere communication needle 5b. The atmosphere communication chamber 5f communicates with the atmosphere through the atmosphere communication port 5g.

FIG. 4A shows a normal state. If the print head to the tube are filled with ink,
Since the inside of the ink tank 4 is airtight except for the air communication needle 5b, the inside of the tank is kept at a negative pressure, and the tip 9a of the ink flows through the channel 5
Stay in the middle of e. In this state, the pressure of the ink tip 9a is in contact with the atmosphere, so that the atmospheric pressure is 0 Pa. The flow path 5e in which the ink tip 9a is located and the flow path 5d communicating with the tube 6 are at the same height, and there is no air layer between the flow path 5d and the flow path 5e, and the flow path 5d communicates only with the ink. The internal pressure also becomes atmospheric pressure = 0 Pa. This is the tip 9a of the ink.
Is determined by the height relationship between the ink tank 4 and the flow path 5d.
It does not matter whether the amount of ink inside is large or small. When the ink is consumed, the tip 9a of the ink gradually becomes the air communication needle 5
The air moves to the side b (FIG. 4 (b)), and when it reaches just below the atmosphere communication needle 5b, the air becomes bubbles and floats by the buoyancy of the bubbles themselves.
At the same time as the bubbles float, the ink drops (FIG. 4 (c)), and the ink tip 9a returns to the original state (FIG. 4 (a)).

When the air in the ink tank expands,
When the difference between the atmospheric pressure in the ink tank and the atmospheric pressure disappears as the ink is used, the ink is transferred to the atmosphere communication chamber 5
It flows toward f.

FIG. 4 (d) shows a state where ink has accumulated in the atmosphere communication chamber 5f. In this case, the ink tip 9a and the flow path 5d
Is different in height by h1 (mm), the pressure in the flow path 5d is -h1.
It becomes x9.80665 (kPa).

As the ink in the ink tank 4 is consumed, the pressure in the ink tank 4 becomes lower than that in the atmosphere.
It gradually returns to the ink tank 6 side.

In this way, the ink flows to the recording head side and continues to be supplied to the recording head side until the liquid level of the ink in the ink tank 4 becomes lower than the tip of the supply needle 5a. When the ink level in the tank reaches this position, it is necessary to replace the ink tank 4. When replacing the ink tank, the ink tank may be replaced after the supply path is blocked by the valve 10.

Since the valve 10 is closed, the ink tank 4
Even if it is removed, the ink in the supply needle 5a and the flow path 5c does not move, and there is no concern that air will enter the flow path.

Further, by covering the recording head with the suction cap 7a with the ink tank removed and driving the suction pump, the ink remaining in the supply tube 6 and the flow path 5c can be sucked. It is possible to remove the recording head after the ink remaining in the supply path has been sucked out.

[0023]

However, in the above ink tank replacement, since the ink is used up,
It is assumed that ink is not in the atmosphere communication chamber. However, the work of removing the ink tank can be assumed not only when the ink runs out, but also in the following cases.

For example, when it is necessary to transport the ink jet recording apparatus to a remote place, ink may leak due to shock or vibration during transportation. Therefore, in order to prevent ink leakage, it is necessary to remove the recording head 1 to drain the ink inside the apparatus.

However, as described above, when the ink is flowing not only in the ink tank but also in the atmosphere communication chamber 5f, the ink in the atmosphere communication chamber 5f remains if the ink tank is simply removed. Ink may leak.

Therefore, conventionally, before the ink tank 4 is removed, the ink amount equivalent to the atmosphere communication chamber 5f is sucked in advance,
After that, the method of removing the ink tank 4 and discharging all the ink in the recording head 1 from the supply needle 5a has been used. That is, by performing the suction work, the pressure in the ink tank 4 is lowered, and the ink remaining in the atmosphere communication chamber 5f flows into the ink tank side. Therefore, if ink equivalent to the volume of the atmosphere communication chamber 5f is sucked,
The atmosphere communication chamber 5f can be surely emptied. However, with this method, even if the ink does not flow out to the atmosphere communication chamber 5f, the ink amount corresponding to the atmosphere communication chamber 5f is always discarded.

Further, a sensor for detecting the outflow of ink to the atmosphere communication chamber 5f is provided to detect whether or not the ink is flowing into the atmosphere communication chamber 5f, and if the ink is not flowing out to the atmosphere communication chamber 5f, the ink is kept as it is. A method has also been proposed in which the tank 4 is removed, and when it is flowing out, ink in the atmosphere communication chamber 5f phase or the like is sucked as described above.
However, a sensor for observing the outflow of ink and a circuit associated therewith are required, which increases the cost of the apparatus.

In view of the above-mentioned conventional problems, the present invention has a device structure that suppresses the cost, but flows into the atmosphere communication chamber side when the ink tank that still contains the ink is removed from the main body of the recording device. It is an object of the present invention to provide an inkjet recording apparatus and an operating method of the inkjet recording apparatus, which can remove the remaining ink while suppressing the amount of discharged ink as much as possible.

[0029]

An ink jet recording apparatus of the present invention comprises a recording head having an ejection nozzle for ejecting ink, a suction means for sucking the ink in the recording head from the ejection nozzle, and an ink for the recording head. An ink supply path for supplying the ink, an ink tank that stores ink inside and one of which is connected to the ink supply path and the other is connected to the atmosphere communication port and is removable, and a predetermined amount of ink provided in the atmosphere communication port. An ink storage chamber that can store the ink, and one flow path that is sealed from the atmosphere communication port to the ink supply path through the ink tank to the atmosphere can be connected and disconnected by attaching and detaching the ink tank. Inkjet recording apparatus, wherein the ink supply path and the atmosphere communication port are connected to the atmosphere in a hermetically sealed manner instead of the ink tank Characterized in that it is fitted.

In the method for operating an ink jet recording apparatus of the present invention, a recording head having an ejection nozzle for ejecting ink, a suction member for sucking the ink in the recording head from the ejection nozzle, and the ink are supplied to the recording head. And an ink tank for storing the ink therein, one of which is connected to the ink supply path and the other of which is connected to the atmosphere communication port and is detachable, and an ink which is provided in the atmosphere communication port and can store a predetermined amount of ink A method for operating an ink jet recording apparatus, comprising a storage chamber, and connecting and disconnecting a single flow path that is sealed from the atmosphere communication port to the ink supply path through the ink tank to the atmosphere by attaching and detaching the ink tank. And attaching a connecting member for removing the ink tank and connecting the ink supply passage and the atmosphere communication port in a sealed manner with respect to the atmosphere. A mounting step that, after the connection member is mounted by said mounting step, characterized in that it comprises a suction step for sucking ink from the ejection nozzle by the suction member.

According to the above construction, even if the ink flows out to the ink storage chamber that stores the ink expanded due to the temperature rise, the ink tank is removed, the connecting member is attached, and the suction operation is performed. With this, not only can the ink remaining in the ink storage chamber be removed efficiently, but
It does not suck in extra ink.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an ink jet recording apparatus of the present invention will be described below with reference to the drawings.

The positional relationship between the recording head and the ink tank in the ink jet recording apparatus of this embodiment is similar to that of the prior art and has the relationship shown in FIG.

FIG. 2 is a perspective view showing the entire ink jet recording apparatus of this embodiment.

The recording head 1 is mounted on the carriage 2 so as to face the recording medium S. During recording, the carriage 2 reciprocates in the main scanning direction indicated by arrow B, and ink droplets are ejected from each nozzle of the recording head 1 during this movement. When the carriage 2 moves to one end of the recording medium S, the conveyance roller 3 moves the recording medium S by the arrow A by a predetermined amount.
The sheet is conveyed in the sub-scanning direction indicated by. By alternately repeating the recording operation and the conveying operation in this manner, an image is formed on the entire recording medium S. In addition, although the serial type recording head is used in the present embodiment, the present invention is not limited to this and may be a full line type.

The ink supply unit 5 includes black, cyan,
An ink tank 4 is provided for each ink color such as magenta and yellow, and a supply tube 6 is connected to each ink tank 4.

The surface of the recording head 1 facing the recording medium S has a plurality of nozzle rows (not shown) in a direction substantially orthogonal to the main scanning, and is connected to the supply tube 6 in nozzle row units. That is, since the ink sent from the supply tube 6 is discharged for each nozzle row, different colors are discharged for each nozzle row.

Further, a recovery unit 7 is provided adjacent to the ink supply unit 5. The recovery unit 7 arranged outside the recording medium range in the main scanning direction and at a position facing the nozzle surface of the recording head 1 forcibly ejects ink or air from the surface of the ejection nozzle 1g of the recording head 1 as necessary. Suction, nozzle cleaning, and ink filling described later are performed.

FIG. 3 is a schematic diagram showing the ink supply path. First, the internal structure of the recording head 1 will be described. The electric board 1j is connected to the contact 2a on the carriage 2 and has a plurality of terminals for supplying power from the recording apparatus main body and signals. Some terminals have two terminals short-circuited, and the main body side determines that there is no head if the contact 2a corresponding to that terminal is open, and that there is a head if it is closed, then supplies power and exchanges signals. To start.

The ink passage path inside the recording head 1 is supplied with ink from a liquid connector insertion port 1a to which a supply tube 6 is airtightly connected, a sub tank 1b for storing a fixed amount of ink, a filter 1c for preventing foreign matters in the ink,
The ink is supplied to the ejection nozzle 1g through the liquid chamber 1f that directly supplies the ink to the nozzle portion. Further, a pressure adjusting chamber 1h is fixedly connected to the opening on the upper surface of the sub tank 1b, and
The space between a and the discharge nozzle 1g is kept airtight against the atmosphere.

The ejection nozzle 1g has a cylindrical structure having a nozzle hole diameter of about 20 μm and is usually filled with ink. Further, a heat generating heater is provided inside the cylinder, and this heat generating heater selectively generates heat according to a command from the CPU. When the heater generates heat, the dissolved air of the ink in contact with the heater expands and foams, pushes out the ink in the nozzle, ejects the ink, and after ejection, the ink is filled in the nozzle by the capillary force of the nozzle. Usually, this ink ejection cycle is repeated at a high speed of 20 KHz or higher to form a fine and high-speed image. The discharge nozzle 1 of the present embodiment
Although g uses such an ejection method, the present invention is not limited to this, and a piezo method or the like may be used.

If the negative pressure of the ink in the discharge nozzle 1g is too weak, even at about atmospheric pressure, if dirt or ink drops adhere to the nozzle tip, the ink meniscus in the discharge nozzle 1g collapses and the ink leaks. It may happen. On the other hand, if the negative pressure is too strong, the force for pulling back the ink in the ejection nozzle 1g is stronger than the ejection force, resulting in ejection failure. Therefore, the negative pressure in the discharge nozzle 1g needs to be maintained in a certain range, which is slightly lower than the atmospheric pressure. The range of this negative pressure varies depending on the nozzle type depending on the shape of the nozzle, the performance of the heater, and the like.
392.226 kPa (-40 mAq, about 0.0040 atm)
~ -1973.3kPa (-200mAq, about 0.0200atm)
The range is (specific gravity of ink ≈water).

The filter 1c is for the purpose of removing foreign matters that may clog the discharge nozzle 1g, and collects the foreign matters with a metal mesh which is smaller than the nozzle diameter and is 10 μm or less.

The area of the filter is set so that the pressure loss due to the ink is equal to or less than the allowable value. The pressure loss increases as the filter mesh becomes finer and the ink flow rate increases. On the contrary, it is inversely proportional to the area of the filter. In recent years, high-speed, multi-nozzle, small-dot printers tend to have high pressure loss, and the filter size is 10 × 20 mm.
In the case of a large degree, a sub-tank upstream of the filter and a liquid chamber space downstream are required. Since the area where the filter is soaked in the ink upstream of the filter becomes the effective area of the filter in the ink permeation, the filter is arranged horizontally on the bottom surface of the sub tank.

In the filter, when the ink stains, a fine meniscus is spread on each mesh forming the filter. This mesh has a property that ink can easily permeate but air flow becomes difficult. The finer the mesh, the higher its meniscus strength, and the more difficult it is for air to pass. In the filter of this embodiment, the pressure required for permeating air is 0.
It is about 1 atm (experimental value). Therefore, if air is present in the liquid chamber located downstream of the filter, the air cannot rise to the sub tank by the buoyancy of the air itself and stays in the liquid chamber.

When air or bubbles in the ink enters the discharge nozzle 1g, the ink is not replenished in the nozzle and discharge failure occurs. Therefore, the discharge nozzle 1g is arranged downward at the bottom of the liquid chamber that stores a certain amount of ink or more. However, the ejection nozzle 1g is arranged so as to be constantly immersed in the ink so as not to be exposed to the air.

The pressure adjusting chamber 1h is a chamber whose volume decreases as the negative pressure increases, and is composed of an elastic member such as a rubber material.

Ink is ejected at a high rate such as ejecting ink from all nozzles (hereinafter referred to as high duty).
Then, the pressure in the sub-tank 1b is subject to resistance due to the pressure loss when the ink passes through the tube, the ink supply unit, and the ink tank, and the ink supplied to the discharged ink becomes insufficient and the negative pressure rises. Will end up. The negative pressure of the discharge nozzle portion 1g is the above-mentioned limit value-1973.3 kP.
If it exceeds a (-200 mmAq, about -0.0200 atm), the ejection becomes unstable, which is inconvenient for image formation.

In a printer in which the recording head 1 is mounted on the carriage 2 for reciprocal recording in the main scanning direction, high Dut
After y recording, the carriage 2 is reversed. Therefore, since there is a rest state without discharging, the pressure adjusting chamber 1h reduces the volume during recording, alleviates the negative pressure rise in the sub tank 1b, and plays a role like a capacitor that restores when the carriage 2 reverses. It is a thing.

Next, the ink supply unit 5 and the ink tank 4 will be described.

The ink tank 4 is constructed so that it can be attached to and detached from the ink supply unit 5, and it has two rubber stoppers 4b and 4c at the bottom of a rigid case 4a.
A single unit is a closed container. Ink tank 4
The ink 9 is contained therein as a liquid. When the ink tank 4 is attached to the ink supply unit 5, a hollow supply needle 5a and an air introduction needle 5b arranged in the ink supply unit 5 are provided.
Penetrates the rubber plugs 4b and 4c, so that the flow paths in the ink tank 4 and each needle can communicate with each other.

The supply needle 5a communicates with the ink supply tube 6 and the recording head 1 through the cutoff valve 10 which can be selectively opened and closed via the flow path 5c and the flow path 5d.

The atmosphere introducing needle 5b communicates with the atmosphere via the flow path 5e, the atmosphere communicating chamber 5f and the atmosphere communicating port 5g. Supply needle 5
Both a and the air introduction needle 5b have a large inner diameter of φ1.6 in order to suppress the flow resistance of the ink.

The valve 10 is a diaphragm 1 made of a rubber material.
The opening and closing of the flow path is performed by moving up and down 0a. When the spring 10c presses the central part of the diaphragm 10a via the spring holder 10b, and the diaphragm 10a is pressed, the central part is lowered, and the lower surface of the diaphragm 10a is in a flow path blocking state in which the opening of the flow path 5d is pressed. The spring holder 10b is connected to the lever 1 by a link 7b from a recovery unit 7 described later.
When the force point of 0d is pushed, the diaphragm 10a is lifted and the flow paths 5c and 5d are brought into a communicable state.
The valve opens when the recording head is ejecting ink,
It is closed during standby and rest, and is opened and closed at the same time as the recovery unit at the time of ink filling described later.

The above-mentioned constitution is constituted for each color ink of black, cyan, magenta, yellow or the like, and the flow path and the needle,
Although the valve and the atmosphere communication chamber are integrally arranged in the ink supply unit 5, the number of levers 10d of the valve 10 is one, and by engaging the spring holder 10b of the valve 10 of each color with the action point of the lever 10d, Open and close each valve simultaneously.

When the recording head 1 consumes the ink, the negative pressure causes the ink to be sent from the ink tank to the recording head at any time. At that time, the same amount of air as the ink is introduced into the ink tank 4 from the atmosphere introducing port 5g through the atmosphere communicating needle 5b.

The atmosphere communication chamber 5f is a room for temporarily storing the ink pushed out by the expansion of the air in the ink tank. When the ambient temperature rises and the air in the ink tank 4 expands while the main body is on standby and at rest, the ink 9 in the ink tank 4 flows from the atmosphere communication needle 5b to the flow path 5e.
After that, it flows out to the atmosphere communication chamber 5f. Conversely, when the ambient temperature decreases, the air inside the ink tank 4 contracts, and the ink that has flowed out into the atmosphere communication chamber 5f returns to the ink tank 4. When recording is performed with ink in the atmosphere communication chamber 5f, the ink in the atmosphere communication chamber 5f first returns to the ink tank 4, and when the ink in the atmosphere communication chamber 5f is exhausted, the ink tank is normally used. Air is introduced into 4. The volume V of the atmosphere communication chamber 5f is set so as to satisfy the usage environment of the product. For example, 5 ℃ (278K) ~ 35 ℃
If it is a product used at (308K) and the volume of the ink tank is 100cc, V = 100 x (308-278) / 308c
It is required to be greater than or equal to c.

The behaviors of the air and the ink in the atmosphere communication passage when the basic head of the ink tank 4 and the air are introduced are as described in the prior art, and are shown in FIG.

FIG. 5 is a diagram showing a negative pressure due to a head difference applied to the discharge nozzle 1g.

The negative pressure due to the water head difference applied to the discharge nozzle 1g is a height h2 (mm) between the flow path 5d and the ink upper surface 9b in the sub tank 1b, and a height h3 (mm) between the ink upper surface 9b and the filter 1c. Assuming that the height h4 (mm) between the ink upper surface 9c in the liquid chamber 1f and the ejection nozzle 1g, the negative pressure on the ejection nozzle 1g surface is P≈- (h2-h3-h4) × 9 in a normal state. .806
It is 65 kPa. In the state where ink is accumulated in the atmosphere communication chamber 5f, P≈- (h2-h1-h3-h4) × 9.80665 kPa
Becomes The value of P is the above-mentioned recordable range {-392.2
26 kPa (-40 mmAq, about 0.0040 atm) to -197
It is set to fit within 3.3 kPa (-200 mmAq, about 0.0200 atm)}.

A rewritable non-volatile memory 4m is mounted on the ink tank 4, and is used to manage the remaining amount of ink in the ink tank 4 by writing the ink consumption of the main body or the like at any time. The memory 4m comes into contact with the contact point 5h of the main body with the tank mounted. Ink tank 4
When removed, it comes off from the contact 5h. Some terminals of the memory 4m have two terminals short-circuited, and the main body side can determine that there is no tank if the contact 2a corresponding to the terminal is open, and that there is a tank if it is closed.

Further, the ink jet recording apparatus is provided with a recovery unit 7 for removing thickened ink and bubbles remaining in the ejection nozzle 1g of the recording head. The recovery unit 7 suctions the discharge nozzle 1g and opens and closes the valve 10.
The suction cap 7a is made of a rubber material. When the suction cap 7a is raised, the suction cap 7a covers and seals the nozzle surface of the recording head 1, and when the suction cap 7a is lowered, it can be moved to a position retracted from the recording head 1.
Move up and down with b. A suction pump 7c is connected to the suction cap 7a, and suction is performed from the inside of the suction cap 7a by driving a pump motor 7d. Suction pump 7
c is a tube pump system having a plurality of rollers, is capable of continuous suction, and the suction amount can be changed according to the rotation amount of the motor. Also, the suction capacity can be reduced to 0.4 atm. The link 7e slides by the cam 7f and moves the lever 10d of the valve 10 to open and close the valve 10.

The cam 7b and the cam 7f are coaxially arranged, and when the cam control motor 7g rotates in the normal direction, the cam 7b and the cam 7f rotate in the direction of the arrow through the pendulum gear 7h, and at the positions a, b and c in the figure,
The suction cap 7a and the link 7e are controlled to come into contact with each other. At the position of the cam a, the suction cap 7a is opened and the valve 10 is also opened, as shown in the figure. On the other hand, when the cam is at the position b, the suction cap 7a is closed and the valve 10 is also closed, and when the cam is at the position c, the suction cap 7a is closed and the valve 10 is closed.
Is open.

During the printing operation, the cams 7b and 7f are set to the position a, and the suction cap 7a and the valve 10 are opened to enable ejection and ink supply. While the device is on standby, the cams 7b, 7
f is the position of b, the suction cap 7a covers the nozzle surface of the recording head 1 to prevent the ejection nozzle 1g from drying, and
The valve 10 is closed to prevent the outflow of ink due to the inclination when the apparatus is moved.

When the cam control motor 7g rotates in the reverse direction, the cover release cam 7j is rotated once through the pendulum gear 7h. When the cover release cam 7j is rotated once, the cover lock 11 for releasing the lock of the tank cover 12a described later slides back and forth once. However, in the configuration described above, there is a problem that air is accumulated in the recording head 1 when recording is performed for a long period of time.

For example, in the sub tank 1b, the air that penetrates through the material of the ink supply tube 6 or the pressure adjusting chamber 1h and the air dissolved in the ink accumulates. For air that permeates a material, its shielding performance (gas barrier property) and the cost of the material are in a substantially proportional relationship,
In mass production machines, high-performance materials cannot be used easily because of cost considerations. Therefore, a low cost, flexible and easy-to-use polyethylene tube is used for the tube, and a rubber material is used for the pressure adjusting chamber.

In the liquid chamber 1f, when the heater of the nozzle is heated and the dissolved air in the ink is foamed to eject the ink, the foamed bubbles are split and returned to the liquid chamber, and the temperature around the heater rises. As a result, fine bubbles dissolved in the ink collect to form bubbles, and air gradually accumulates. According to experiments, in this configuration, the accumulated amount of air in the sub tank 1b is less than 1 cc / month, and the accumulated amount of air in the liquid chamber 1f is about 0.5 cc / month.

When the amount of mixed air increases, the sub tank 1
The amount of ink stored in each of b and the liquid chamber 1f decreases.

Further, if the ink in the sub tank 1b is insufficient, the filter 1c is exposed to the air, the effective area of the filter is reduced, the pressure loss of the filter is increased, and the ink cannot be supplied.

Further, in the liquid chamber 1f, the ink supply port of the nozzle 1g is exposed to the air, making it impossible to supply the ink to the nozzle 1g. It becomes a fatal problem.

Therefore, in order to solve such a problem,
For example, an appropriate amount of ink is contained in the sub tank 1b and the liquid chamber 1f (1 cc + margin for the sub tank 1b, 0.5 cc + for the liquid chamber 1f).
By filling each of the margins), it is possible to normally operate for one month or more despite using an inexpensive material.

Next, the exterior 12 will be described. Exterior 1
Reference numeral 2 surrounds the entire body and protects the mechanism. A tank cover 12a that covers the ink tank 4 is provided on the top surface of the exterior 12, and when the above-described cover lock 11 slides, the lock claw 12c is disengaged and opened by the spring 12d. When the tank cover 12a is opened, the ink tank 4 can be attached and detached. When the attachment / detachment of the ink tank 4 is completed, the lock claw 12c is caught by the cover lock 11 and does not open when manually closed to prevent the ink tank 4 from being attached / detached at any time. Tank cover 1
There is a cover sensor 13 for detecting the opening / closing of the tank 2a, and the opening / closing of the tank cover 12a can be monitored by the control circuit.

A carriage cover 12 is provided above the carriage 2.
e, and when the carriage cover 12e is opened, just above the specific position where the carriage 2 passes in the main scanning direction,
There is a head replacement hole 12f. The recording head 1 can be attached and detached only when the carriage 2 is directly under the head exchange hole 12f, and prevents the recording head 1 from being attached or detached at any time. There is a cover sensor 14 for detecting the opening / closing of the carriage cover 12e, and the opening / closing of the carriage cover 12e can be monitored by the control circuit.

The operation button 12g is a button to be pressed when the operator desires a predetermined operation, and inputs a request signal to the control circuit through the switch 15, and a plurality of buttons corresponding to each operation are installed.

In such an ink supply structure, ink filling and ink tank replacement are performed as follows.

In the ink filling operation, first, the carriage 2 is moved in the main scanning direction to a position where the recording head 1 faces the suction cap, the cam control motor 7g of the recovery unit 7 is driven, and the cams 7b and 7f are moved to the position b. Rotate until. Then, the cap 7a covers and seals the nozzle surface of the recording head 1, and the valve 10 closes the ink flow path.

In this state, the pump motor 7d is driven so that the suction pump 7c sucks from the inside of the cap 7a. By suction, the ink and air remaining in the recording head 1 are sucked out through the discharge nozzle 1g, and the pressure in the recording head 1 is reduced. At a predetermined suction amount (a suction amount that reaches a predetermined pressure. A value obtained by calculation or experiment), the suction pump 7c is stopped and the cam control motor 7g is driven to drive the cam 7b and the cam 7b.
Rotate f to position c and open valve 10.

Then, the ink flows into the recording head 1 whose pressure is reduced, and the ink is sub-tank 1b and liquid chamber 1f.
Are filled in each. The amount of ink to be filled is a volume required when the pressure of each chamber that has been depressurized returns to approximately atmospheric pressure, and is determined by the volume and pressure of each chamber.

Ink filling is completed in about 1 second after opening the valve 10. When the ink filling is completed, the cam control motor 7g is driven to rotate the cams 7b and 7f to the position a, the suction cap 7a is opened, and the ink remaining in the suction cap is discharged by the suction pump 7c. Since the valve 10 is also in the open state, it becomes a recordable state. If there is no recording command, the cam control motor 7g is driven again to rotate the cams 7b and 7f to the position b, and the standby state is set.

Next, tank replacement will be described.

First, when the operator presses the operation button 12g corresponding to the tank exchange, if the recording is in progress, the recording is stopped,
During the filling operation and the writing to the memory 4m, the cam drive motor 7g is normally rotated after waiting until the operation is completed, and the cam is moved to the position of b. Then, the valve 10 is in a state of blocking the flow path.

Subsequently, the cam drive motor 7g is rotated in the reverse direction to rotate the cover release cam once to open the tank cover 12a.
When the operator attaches and detaches the ink tank 4 and closes the tank cover, it is detected that the cover sensor 13 is closed, and it is confirmed whether the memory 4m is connected to the contact 5h. If so, the replacement work is completed. .

At this time, since the valve 10 is closed when the ink tank 4 is removed, the ink in the supply needle 5a and the flow path 5c does not move, and there is no concern that air will enter the flow path. .

To remove the recording head 1, the recording head 1
When the operation button 12g corresponding to the removal of the cam is pressed, the recording is stopped during the recording, and the operation of the cam drive motor 7 is stopped after the operation is completed during the filling operation or the writing to the memory 4m.
Rotate g forward and move the cam to position b. Then, the valve 10 is in a state of blocking the flow path. Then cam drive motor 7g
When the operator removes the ink tank 4 and closes the tank cover, it detects that the cover sensor 13 is closed, and the memory 4m contacts the contact 5h. After confirming that they are connected and confirming that they are not attached, the cam drive motor 7g is rotated in the normal direction to bring the cam to the position c. Then, the valve 10 is opened and the suction cap 7a is closed. Here, the pump motor 7d is driven, and the suction pump 7c sucks ink from the discharge nozzle 1g.

By sucking for a certain period of time, all the ink in the recording head 1 can be discharged from the supply needle 5a. When the suction is completed and the carriage cover 12e is opened, the cover sensor 14 detects it, and the cam drive motor 7g is rotated in the normal direction to bring the cam to the position a. The suction cap 7a is opened, and then the carriage 2 is moved to a position right below the head exchange hole 12f so that the recording head 1 can be removed.

Because of this procedure, the recording head 1 cannot be removed from the ink tank 4, and the ink will not flow back into the tank. Further, since the ink in the ink flow path is removed, the ink does not leak from the supply needle 5a even if the recording head 1 is removed.

If the recording head 1 and the ink tank 4 are attached from the above-mentioned state, the new recording head 1 is attached to the carriage 2 as it is. When the carriage cover 12e is closed, the cover sensor 14 detects it, and the contact 2a on the carriage 2 confirms the presence or absence of the recording head 1. When it is detected that the recording head 1 is present, the carriage 2 moves to the cap position, and the cam drive motor 7g
To rotate the cam forward to bring the cam to position b. Then the valve 10,
The flow path is closed together with the suction cap 7a. Subsequently, the cam drive motor 7g is rotated in the reverse direction to turn the cover release cam 1
When the operator mounts the ink tank 4 and closes the tank cover by rotating and opening the tank cover 12a, it is detected that the cover sensor 13 is closed, and the memory 4m contacts the contact 5
It is confirmed whether or not it is connected to h, and if it is attached, the above ink filling operation is executed and the installation is completed. In this case also, the ink tank 4 is not attached without attaching the recording head 1, and air is not introduced into the atmosphere communication chamber 5f by introducing air from the supply needle 5a in the ink tank 4.

However, the above-mentioned ink tank replacement operation is performed when the ink tank is emptied and replaced with a new one, and it is premised that ink has not flowed into the atmosphere communication chamber 5f. .

However, there are cases where the ink tank in use must be removed in order to prevent the ink from spilling during transportation. In this case, with the above method,
Since the atmosphere communication chamber 5f is separated from the ink supply path, if there is ink in the atmosphere communication chamber 5f, the ink remains without being sucked.

Therefore, in the present invention, an ink removing operation (hereinafter, also referred to as a "transporting sequence") when the ink is still in the ink tank as described above will be described below.

The operator presses the operation button 12g in the same manner as when replacing the above ink tank. Then, the ink jet recording apparatus stops the recording during the recording, waits until the operation is completed during the filling operation or the writing operation in the memory 4m, and then rotates the cam drive motor 7g forward to move the cam to the position b. To the position. Then, as in the case of replacing the ink tank, the valve 10 is in the state of blocking the flow path. Subsequently, the cam drive motor 7g is rotated in the reverse direction to rotate the cover release cam once, the tank cover 12a is opened, and the operator removes the ink tank 4.

However, in this state, if the ink has flowed to the atmosphere communication chamber 5f, the ink in the atmosphere communication chamber 5f cannot be removed. Therefore,
After taking out the ink tank 4, the operator attaches an empty ink tank 40 not filled with the ink 9 at that position in place of the ink tank 4, and connects the ink path from the supply tube 6 to the atmosphere communication chamber 5f. Leave.

FIG. 6 is a view showing a state in which the empty ink tank 40 is attached. When the tank cover 12a is closed,
It is detected that the cover sensor 13 is closed. By confirming whether the memory 4m is connected to the contact 5h, it is confirmed that the empty ink tank 40 is attached.

Next, in order to remove the ink remaining in the atmosphere communication chamber 5f, the cam drive motor 7g is normally rotated to bring the cam to the position c and the valve 10 is opened. In this state, since the suction cap 7a covers the discharge nozzle and the valve 10 is open, the flow path from the ink tank 40 to the recording head 1 is open.

Then, the pump motor 7d is driven so that the suction pump 7c sucks the ink from the discharge nozzle 1g.
Due to this suction force, the pressure in the empty ink tank 40 drops sharply, and the ink remaining in the atmosphere communication chamber 5f flows into the ink tank side, and further flows through the supply needle 5a into the supply tube 6. By further suctioning for a certain period of time, the ink in the device flow path can be discharged from the atmosphere communication chamber 5f to the recording head 1. A small amount of ink remains in the empty ink tank 40 by the amount of the ink surface up to the hole at the tip of the supply needle 5a. However, if the cam drive motor 7g is rotated in the normal direction after suction and the cam is set to the position of b, the valve 10 blocks the flow path between the ink tank 40 and the recording head 1, and therefore, fluctuations in transportation occur. Ink does not flow into the recording head side. Further, if the cam drive motor 7g is rotated in the reverse direction to rotate the cover release cam once, the tank cover 12a is opened, and the operator removes the empty ink tank 40, no ink remains in the apparatus. After that, when the tank cover is closed, it is detected that the cover sensor 13 is closed, and the transportation sequence ends.

At this time, since the suction cap 7a and the valve 10 are closed, it is possible to prevent the ink from sticking inside the recording head 1 due to the moisture of the ink remaining in the supply passage.

Further, this eliminates the risk of ink spilling during transportation.

In the empty ink tank, the ink does not increase beyond the above-mentioned amount in the transportation sequence, and can be used repeatedly.

In this way, when the ink tank in use is taken out, and the empty ink tank is newly inserted to perform the suction operation, when the ink remains in the atmosphere communication chamber, the ink is removed. You can Furthermore, the amount of suction ink is about the amount of ink remaining in the atmosphere communication chamber, and no more suction is performed. Further, if no ink remains in the atmosphere communication chamber, there is no ink to be sucked even if the suction operation is performed, so that no ink is wastefully sucked.

Further, even if a sensor for detecting whether or not ink is flowing into the atmosphere communicating chamber is not provided, the extra ink is not sucked for the above reason.

In the present embodiment, the empty ink tank is used to seal the space between the supply needle and the air communication needle after taking out the ink tank in use, but the present invention is not limited to this. Any connecting member may be used as long as it has a shape that seals between the supply needle and the atmosphere communicating needle.

[0102]

As described above, by using the present invention, the ink tank is removed and the connecting member is removed even if the ink has flown into the ink storage chamber for storing the ink expanded due to the temperature rise, that is, the atmosphere communication chamber. By performing the suction operation after mounting the ink cartridge, not only the ink remaining in the atmosphere communication chamber can be efficiently removed, but also the extra ink is not sucked.

Further, the amount of discharged ink can be minimized and all the ink in the apparatus can be discharged without providing a means for detecting the outflow of ink to the atmosphere communication chamber.

Further, by providing a valve for shutting off the path between the ink supply path and the ink tank, even if the connecting member is removed after the ink has been sucked, the path is shut off by the valve so that the ink on the recording head side is cut off. Flows to the ink tank side,
It is possible to prevent the ink from flowing out from the supply needle in the removed state.

Furthermore, by using an empty ink tank as the connecting member, no special mechanism is required for mounting, and the same effect as the ink tank can be obtained without increasing the cost.

[Brief description of drawings]

FIG. 1 is a diagram showing a positional relationship between a recording head and an ink tank in a tube supply type inkjet recording apparatus.

FIG. 2 is a perspective view showing the entire inkjet recording apparatus.

FIG. 3 is a schematic diagram showing an ink supply path of an inkjet recording apparatus.

FIG. 4 is a schematic diagram illustrating the behavior of ink from an ink tank to an atmosphere communication channel.

FIG. 5 is a schematic diagram illustrating pressure due to a head difference on the nozzle in the ink supply path illustrated in FIG.

FIG. 6 is a schematic diagram showing an ink supply path when an empty ink tank is attached.

[Explanation of symbols]

1 recording head 1a Connector insertion port 1b Sub tank part 1c filter 1d opening 1e Partition 1f liquid chamber 1g discharge nozzle 1h Pressure adjustment chamber 1j Electric board 2 carriage 3 Conveyor rollers 4 ink tank 4a case 4b, 4c rubber stopper 5 Ink supply unit 5a Ink supply needle 5b Atmosphere introduction needle 5c First liquid path 5d Second liquid path 5e liquid path 5f atmosphere communication room 5g atmosphere communication port 5h detection circuit 6 supply tubes 7 Recovery Unit 7a Suction cap 7b First cam 7f Second cam 7c suction pump 7d pump motor 7e link 7g cam control motor 9 ink 9a tip 9b Ink top surface 9c Ink top surface 10 Shut-off valve 10a diaphragm 10b holder 10c Pressing spring 10d lever 40 empty ink tank S recording medium

Claims (6)

[Claims] 1. A recording head having ejection nozzles for ejecting ink, suction means for sucking ink in the recording head from the ejection nozzles, and an ink supply path for supplying ink to the recording head. An ink tank that stores ink and has one of which is connected to the ink supply path and the other of which is connected to an atmosphere communication port and which is removable, and an ink storage chamber that is provided at the atmosphere communication port and can store a predetermined amount of ink are provided. An ink jet recording apparatus capable of connecting and disconnecting one flow path sealed from the mouth to the ink supply path through the ink tank by attaching and detaching the ink tank to the ink tank. Instead, an ink jet recording apparatus is provided with a connecting member for sealingly connecting the ink supply path and the atmosphere communication port to the atmosphere. . 2. A recording head having an ejection nozzle for ejecting ink, a suction means for sucking the ink in the recording head from the ejection nozzle, an ink supply path for supplying ink to the recording head, and An ink tank that stores ink and has one of which is connected to the ink supply path and the other of which is connected to an atmosphere communication port and which is removable, and an ink storage chamber that is provided at the atmosphere communication port and can store a predetermined amount of ink are provided. An ink jet recording apparatus in which one flow path sealed from the mouth to the ink supply path through the ink tank is closed by attaching and detaching the ink tank, wherein the ink is replaced in place of the ink tank. A connection member for sealing and connecting the supply passage and the atmosphere communication port to the atmosphere is attached, and in the state where the connection member is attached, the suction means is Ri jet recording apparatus characterized by sucking ink from the ejection nozzle. 3. A valve further comprising a valve capable of blocking a path between the ink supply path and the ink tank, wherein the valve is operated after the suction means performs suction with the connection member attached. 3. The connection member can be detached by blocking a path between the ink supply path and the ink tank.
The inkjet recording device according to item 1. 4. The ink jet recording apparatus according to claim 1, wherein the connection member is an empty ink tank in which the ink tank is not filled with ink. 5. The recording head is characterized in that bubbles are generated in the ink by the thermal energy of the electrothermal converter, and the ink is ejected as droplets from the ejection nozzles in accordance with the generation of the bubbles. 5. The inkjet recording device according to any one of 1 to 4. 6. A recording head having ejection nozzles for ejecting ink, a suction member for sucking ink in the recording head from the ejection nozzles, an ink supply path for supplying ink to the recording head, and An ink tank that stores ink and has one of which is connected to the ink supply path and the other of which is connected to an atmosphere communication port and which is removable, and an ink storage chamber that is provided at the atmosphere communication port and can store a predetermined amount of ink are provided. A method of operating an inkjet recording apparatus, wherein one flow path sealed from the mouth to the ink supply path through the ink tank is closed by attaching and detaching the ink tank, wherein the ink tank is removed. A mounting step of mounting a connection member for sealingly connecting the ink supply path and the atmosphere communication port to the atmosphere, and a connection member by the mounting step. After being mounted, the operation method for an ink jet recording apparatus characterized by comprising a suction step for sucking ink from the ejection nozzle by the suction member.