JP3363760B2 - Ink supply device and printing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply device for supplying a large amount of ink and a printing device having the same.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus for recording with ink has been widely used as a printer or a copying machine of a personal computer. This ink jet recording apparatus is inexpensive and is capable of full-color recording, and therefore its demand is ever increasing. Recently, A1
Ink jet recording apparatuses are used even for plotters for recording photographic images on large-sized sheets such as printing plates and A0 plates. It is also used in textile printing systems that print on cloth.

Further, application of ink jet recording to medical multi-tone image recording such as X-ray film and CT scan image has been studied. In such a medical image recording apparatus, a plurality of kinds of inks having different densities are combined, and the inks are recorded twice or three times so that gradations far greater than the number of kinds of inks can be expressed. It will be possible.

However, since a large amount of ink is used in the above-mentioned plotter, textile processing system, and medical image recording apparatus, if the ink tank is mounted on the carriage together with the recording head, the ink tank must be replaced frequently. It is inconvenient.

Therefore, an ink supply device as shown in FIG. 3 is generally used in an ink jet recording apparatus which consumes a large amount of ink in this way.

In FIG. 4, 101 is a print head, and the recording head 101 is mounted on a carriage 102 movable with respect to the apparatus main body. A main tank 103 is fixed to the main body of the apparatus. When the ink becomes low, the main tank 103 is replenished with ink. The recording head 101 and the main tank 103 are connected by an ink flow path 104 formed of a tube, a joint, and the like. The carriage 102 reciprocates during printing, but at least a part of the ink flow path 104
By using a flexible tube (eg, silicon tube, polyethylene tube, etc.), the carriage 10
The movement of 2 is not hindered. Main tank 103
An atmosphere communication hole 105 that communicates the inside of the main tank 103 with the atmosphere is provided therein. Therefore, the air chamber side of the main tank 103 can always be maintained at the atmospheric pressure, and when ink is ejected from the recording head 101, the main tank 1
Ink is supplied from 03 through the ink flow path 104.

The pressure inside the recording head must be maintained at a negative pressure so that ink does not leak from the ejection port 106. The pressure in the recording head is the main tank 103
Is determined by the ink level H1 of H.sub.2, and H1 is preferably provided at a position about 20 to 100 mm lower than the height H0 of the ejection port 106 of the recording head 1.

When this method is used, ink supply can be realized with a very simple structure, but since the flexible tube used for the ink flow path 104 is made of rubber or resin, some gas is used. Has transparency. On the other hand, since the inside of the tube has a negative pressure like the inside of the recording head, air gradually enters from the atmosphere into the tube through the tube wall to generate bubbles. When the air bubbles flow into the recording head 101, normal ink droplets cannot be ejected and printing failure occurs. Further, if H1 is brought close to H0 in order to reduce the generation of bubbles as much as possible, the ink easily leaks from the recording head due to a change in temperature, shock, vibration, or the like.

Therefore, an ink supply system as shown in FIG. 4 has been proposed so that even if a bubble is generated, the bubble does not enter the recording head.

In FIG. 5, 201 is a print head, and 202 is a sub tank for storing ink to be supplied to the recording head 201. The recording head 201 and the sub tank 202 are a carriage 20 that is movable with respect to the apparatus main body.
It is installed in 3. A main tank 204 is fixed to the main body of the apparatus. When the ink is low, the main tank 204 is replenished with ink. Sub tank 20
The main tank 204 and the main tank 204 are connected to each other by two ink flow paths 205 and 206 formed of tubes and joints. The first ink flow path 205 is the main tank 204.
Of the ink is sent to the sub tank 202, and the second ink flow path 206, on the contrary, returns the ink contained in the sub tank 202 to the main tank 204. Second ink flow path 206
A so-called piston type pump 207 is provided midway. Sub tank 20 by pump 207
The ink in 2 is transferred to the main tank 204. The main tank 204 is provided with an atmosphere communication hole 208 that communicates the inside of the main tank 204 with the atmosphere. The sub tank 202 has a closed structure, and the inside thereof is not in contact with the atmosphere.

Therefore, when the pump 207 is driven,
The ink in the sub tank 202 is the second ink flow path 206.
The ink in the main tank 204 is sucked into the sub tank 202 through the first ink flow path 205 while being sent to the main tank 204. In this way, the ink is circulated between the sub tank 202 and the main tank 204.

The pressure in the sub-tank 202 must be kept in a negative pressure state so that ink does not leak from the recording head 201. The pressure in the sub tank 202 is determined by the ink level H1 in the main tank 204,
Is 20 to 1 higher than the chip surface height H0 of the recording head 201.
It is preferably provided at a position as low as about 00 mm.

A liquid level sensor 209 is provided inside the main tank 204. When the liquid level sensor 209 detects that the ink level in the main tank 204 is below this sensor position, a display LED (not shown) or the like prompts the user to replenish the ink.

According to such a structure, bubbles are generated in the first ink flow path 205 as in the conventional example, but the bubbles once enter the sub-tank 202 and then the second ink flow path. It passes through 206 and is discharged into the main tank 204. Therefore, the bubbles generated on the way do not enter the inside of the recording head, and printing defects do not occur.

[0015]

In the plotter, the printing processing system, and the medical image recording apparatus described above, the types of ink tend to increase in order to realize more complex gradation expression and color expression. . For example, in a photographic color plotter, it has been proposed to use six or more colors of ink, such as addition of normal cyan, magenta, yellow, and black, as well as light cyan and magenta with low ink density. Even with medical image recorders, it's just like an X-ray image.
In order to produce an image that requires gradation expression of 000 gradations or more, at least 6 shades of black ink are required. For example, when six types of ink are used, six ink supply systems are required, and if a cylinder type pump or a gear pump is used, one pump for each color, six pumps in total is required.

However, it is obviously disadvantageous in terms of cost and space to provide one pump for each color. In such a case, the liquid is sent by squeezing the tube with a plurality of rollers. It has been proposed to use so-called tube pumps.

FIG. 3 shows a schematic view of the tube pump 50.

In FIG. 3, six rollers 51 are arranged concentrically on the roller holder 52. Roller holder 5
2 is rotatably supported about a rotary shaft 53,
1 is also rotatably supported around a roller rotation shaft 54 fixed to the roller holder 52. Pressing member 5
5, the roller 51 side is biased by the compression spring 56,
A tube 57 arranged along the outer periphery of the roller holder 52 is crushed on a part of the outer peripheral portion of the roller holder 52. When the roller holder 52 is rotated in the direction of the arrow D1 by a motor (not shown), the roller 51 revolves around the rotation shaft 53 of the roller holder 52, so that the tube 57 is made up of a plurality of rollers 5.
The ink in the tube 57 is squeezed by 1 and the pressing member 55 and flows in the arrow direction.

In the case of a tube pump, for example, when 6 types of ink are used, 6 tubes are arranged side by side and squeezed by the roller 51 which revolves as described above, so that 6 types of ink can be collectively driven by one drive source. Then you can send it. Even if the number of types of ink in the tube pump increases, the cost and space do not increase so much.
It is a suitable pump for an ink supply system that uses various types of ink. As a tube to be used, it does not require a large force to be crushed by a roller, has an appropriate restoring force, does not deform even if crushed for a long time, and does not deteriorate or denature due to ink. Is the most suitable.

However, since the tube 57 of the tube pump 50 does not move in the lengthwise direction, the same portion of the tube is squeezed, so if it is used for a long period of time, it will inevitably be contained in the scrap powder and the tube material inside the tube. Also, oil and fat components will be deposited, and if such impurities are mixed in the ink, the ejection ports of the recording head will be clogged, and this will easily cause printing defects.

A first object of the present invention is to prevent impurities from being mixed in the ink even though the ink is moved by using the tube pump.

A second object of the present invention is to smoothly circulate ink by a simple mechanism.

A third object of the present invention is to enable switching between the circulation of the ink and the replenishment of the ink from the replaceable replenishment ink tank by using a simple mechanism.

[0024]

In order to achieve the above object, an ink supply device of the present invention comprises a first ink tank for storing ink to be supplied to a print head, and the first ink tank.
A second ink tank for supplying ink to the second ink tank, a third ink tank for receiving the ink overflowed in the first ink tank, and a pump for sucking an air chamber portion in the third ink tank. A first valve provided in a path from the third ink tank to the second ink tank, and by driving the pump with the first valve closed, The ink in the first ink tank is introduced into the third ink tank, and the ink in the second ink tank is supplied into the first ink tank.

If the first valve is a check valve that allows only the flow of ink from the third ink tank to the second ink tank, the third ink tank and the second ink tank
Since the opening and closing of the first valve can be easily controlled by providing a height difference in the ink level with the ink tank, the ink can be circulated smoothly by a simple mechanism.

Further, it further includes a second valve for switching between communication with the atmosphere in the air chamber portion of the third ink tank and switching of the cutoff, and by opening the first valve and the second valve, the second valve is opened. The ink in the third ink tank can be smoothly moved to the second ink tank.

Further, it further includes a first ink level detecting means for detecting an ink level in the third ink tank and a second ink level detecting means for detecting an ink level in the second ink tank, Since the first ink level detecting means is located higher than the second ink level detecting means, the timing of moving the ink in the third ink tank to the second ink tank is detected in both tanks. It can be judged based on the result.

For example, by opening the first valve and the second valve when the maximum ink level in the third ink tank is detected by the first ink level detecting means, both tanks are opened. The ink can be replenished from the third ink tank into the second ink tank as the replenishment tank of the first ink tank until the inside level becomes the same. The same applies to the case where the first valve and the second valve are opened when the second ink level detecting means detects the minimum ink level in the second ink tank.

A replaceable replenishment ink tank for replenishing ink to the third ink tank may be further connected.

In this case, if the third ink tank has a negative pressure, the ink can be easily replenished.

Furthermore, the printing apparatus of the present invention is characterized in that printing is performed using a print head that receives ink supplied from the ink supply apparatus.

Here, the print head may include a thermal energy generator that applies thermal energy to the ink as energy used for ejecting the ink.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing the appearance of a textile printing processing system including an ink supply device of the present invention. Reference numeral 199 indicates an ink jet printer main body, and the ink jet printer 199 is roughly configured by an ink supply unit 100, a printer unit 200, and a cloth conveying unit 300.

The actual printing operation in the above configuration will be described step by step with reference to FIG.

The cloth 301 as a recording medium is set on the cloth supply roller 302 in a roll state. This cloth 30
1 passes under the printer unit 200 while being guided by various guide rollers 303 and 304, reaches a cloth take-up roller 307 after being also given an appropriate tension by the guide rollers 305 and 306. These rollers 3
02 to 307 configure the cloth transporting unit 300. The printer frame 201 is located above the cloth transport unit 300.
The printer frame 201 includes two guide rails 20.
2, 203 are supported and fixed in parallel with each other along the arrow A direction. Carriage 204 has two guide rails 2
It is supported by 02 and 203 so as to be movable in the direction of arrow A. On the carriage 204, 16 print heads (typically shown as 205a and 205b) are cloth 30
It is attached at a position facing 1. Carriage 2
When 04 is moved in the direction of arrow A by a drive motor (not shown), for example, print heads 205a, 205b
An ink ejection command is issued as necessary to perform printing. At the end of the movement of the carriage 204, one line of printing is performed at a predetermined position on the cloth 301 according to the ejected ink. After printing one line on the cloth 301,
The cloth 301 is conveyed by a predetermined amount in the direction of arrow B (sub scanning direction) in FIG. 2 by a cloth feed belt (not shown). Next, for example, when the carriage 204 moves in the direction A while the print heads 205a and 205b perform ejection as needed, the second line is printed on the cloth 301. By repeating such a series of operations, desired continuous printing is performed on the cloth 301.

Incidentally, for example, the print head 205a,
An ink tube group 206 is connected to 205b and the like, and each time ink is repeatedly ejected, ink used is replenished from the ink supply unit 100 to the print heads 205a, 205b and the like via the ink tube group 206.

FIG. 2 is a schematic sectional view showing the structure of an ink supply unit 100 as an ink supply device in the textile printing system shown in FIG.

The ink supply unit 100 includes a recording head 205.
a (or 205b), a first ink tank 2 for containing the ink to be supplied, a second ink tank 4 for supplying the ink to the first ink tank 2, and an ink for the second ink tank 4. And a third ink tank 5 for supplying the ink and storing the ink for the overflow in the first ink tank 2.

The first ink tank 2 is mounted on a carriage 204 which is movable together with the recording head 205a (or 205b) with respect to the main body of the apparatus constituting the system. Further, the second ink tank 4 and the third ink tank 5 are fixed to the apparatus main body which constitutes the system.

The first ink tank 2 and the second ink tank 4 are connected by the first ink flow path 6,
One end of the first ink flow path 6 is connected to the lower portion of the first ink tank 2, and the other end is connected to the lower side portion of the second ink tank 4. On the lower side of the second ink tank 4,
A liquid level sensor 24 as an ink level detecting means for detecting the ink level (liquid level) in the second ink tank 4 is arranged above the connection position of the first ink flow path 6.
An atmosphere communication hole 26 is provided above the second ink tank 4.

The bottom of the second ink tank 4 and the bottom of the third ink tank 5 are connected by the second ink flow path 8. A first valve 9 is provided in the middle of the second ink flow path 8.

An atmosphere communication passage 11 is provided above the third ink tank 5, and a second valve 10 for switching between communication with the atmosphere and shutoff is attached to the middle of the atmosphere communication passage 11. . One end of a third ink flow path 7 for containing the overflowed ink in the first ink tank 2 is connected to a side portion of the third ink tank 5, and the middle of the ink flow path 7 is connected. A third valve 22 is attached to the. Further, one end of an air chamber suction passage 12 for sucking air in the air chamber portion inside is connected to the upper portion of the third ink tank 3, and the other end is connected to the waste ink tank 13. The tube pump 50 shown in FIG. 3 is arranged in the middle of the air chamber suction passage 12,
By rotating the pump 50 in the direction of the arrow D1, the air in the air chamber portion of the third ink tank 3 can be sucked. In addition, the air chamber suction passage 12 has the waste ink tank 1
In the unlikely event that it is led to No. 3, the third ink tank 5
Even if the ink inside is discharged through the air chamber suction passage 12, the ink is prevented from leaking out of the apparatus.

Here, in this embodiment, both the atmosphere communication passage 11 and the air chamber suction passage 12 are made of a flexible material, and for example, a silicon tube is used. The first valve 9 and the second valve 10 are opened and closed by crushing the atmosphere communication passage 11 with a cam member (not shown). Second valve 1
By opening and closing 0, it is possible to switch between communication and interruption of the air chamber portion of the third ink tank 5 with the atmosphere.

Further, the upper portion of the third ink tank 5 and the upper portion of the replenishment tank 16 are connected by a fourth ink flow passage 14, and in the middle of the flow passage 14, a backflow prevention function as a fourth valve. A valve 21 is attached. The ink supply port 1 of the supply tank 16 is provided at one end of the fourth ink flow path 14.
A first needle member 15 that is inserted through 7 is attached. The first needle member 15 is a tubular member having a hole at its tip. The atmosphere communication port 20 of the supply tank 16 is opened to the atmosphere by an atmosphere communication passage 28. It should be noted that one end of the atmosphere communication passage 28 has a second tubular shape having a hole at its tip.
The needle member 18 is attached and the member 18 is inserted into the atmosphere communication port 20.

Further, on the inner wall portion of the third ink tank 5, a liquid level sensor 25 as an ink level detecting means is provided at a position higher than the liquid level sensor 24 of the second ink tank 4.
Is attached. The liquid level sensor 25 detects the maximum ink level in the third ink tank 5, and the liquid level sensor 24 detects the minimum ink level in the second ink tank 4.

With such a configuration, the print head 20
The pressure of the first ink tank 2 close to 5a (205b) is determined by the ink level H1 of the second ink tank 4, and the level of the discharge port level H0 of the print head and the level H1 of the second ink tank 4 is high or low. The difference H is 20 to 100
It is desirable to be in the range of mm. Height difference H is 20m
When it is less than m, the difference is too small and the ejection performance becomes unstable due to the influence of the fluctuation of the level H1 of the second ink tank 4, and the ink may leak from the ejection port. Further, when the height difference H exceeds 100 mm, the negative pressure in the head is too large, and ejection failure may occur.

The operation of the ink supply device of the present invention will be described with reference to FIGS. 6, 7, 8 and 9.

When the power is turned on (S1), the valves 9, 10, 2
2 is closed (S2, S3, S4). Tube pump 50
Starts driving (S5), and suctions and depressurizes the air chamber of the ink tank 5. The air chamber of the ink tank 5 is decompressed,
The ink in the supply tank 16 passes through the ink flow path 14 and is injected into the ink tank 5. When the ink level detecting means (sensor) 23 in the ink tank 5 detects the ink level (S6), the valve 10 is opened (S7), and the inside of the ink tank 5 is returned to atmospheric pressure. After opening the valve 10, the tube pump 50 is stopped. In S8, the tube pump 50 has the valve 1
Since 0 is open, it is not always necessary to stop, but it is desirable to stop to reduce power consumption.

Then, when the valve 9 is opened (S9), the ink is transferred from the ink tank 5 to the ink tank 4 and the ink is leveled. Here, the leveling means that the ink surfaces of both of the connected ink tanks 4 and 5 become equal, and the ink does not move to either tank. Whether the ink in the ink tanks 4 and 5 is completely leveled depends on the shape of the ink tanks 4 and 5, the diameter of the ink passage 8 and the diameter of the valve 9, but the leveling time is estimated. A signal indicating completion of leveling is sent to a supply system control unit (not shown) depending on the waiting time from the time when the valve 9 is opened (S10).

The supply system control unit closes the valves 9 and 10 (S11, S12) when receiving the signal, and the tube pump 5
0 is driven (S13), and the air chamber portion of the ink tank 5 is sucked and sucked by the same operation as the ink filling in the ink tank 5 described above.
The pressure is reduced and the ink in the supply tank 16 is sucked up to fill the ink tank 5 with the ink. When the ink level sensor 23 detects ink (S14), the valves 10, 9 are opened in this order (S15, S16), and the tube pump 50 is stopped (S).
17) After waiting for a certain period of time (S18), the ink is leveled.

By repeating the above series of operations a plurality of times, the ink surface of the ink tank 5 can be brought close to the vicinity of the ink level sensor 23. The number of times of this series of operations may be appropriately determined. In the present embodiment, it is set to twice.

Next, the filling of the ink in the ink tank 2 will be described with reference to FIGS. 8 and 9. First, after the ink in the ink tanks 4 and 5 is leveled, the valves 9 and 10 are closed (S21). , S22), and further opens the valve 22 (S2
3). When the tube pump 50 is driven (S24), the air chamber portion of the ink tank 5 is sucked and the pressure inside the ink tank 5 decreases, so that the pressure inside the ink tank 2 also decreases. At this time, since the ejection port of the recording head 1 is blocked by a capping unit (not shown), air does not enter from the ejection port. As a result, the ink flows from the ink tank 4 to the ink tank 2 through the ink flow path 6.
Is supplied to. When the ink is collected in the ink tank 2 and reaches the connection port with the ink flow path 7, the ink is guided from the ink tank 2 to the ink tank 5 through the ink flow path 7. In this way, the ink in the ink tank 4 moves to the ink tank 5 via the ink tank 2 and all the tanks can be filled with the ink.

At this time, the fourth valve 21 is opened by an elastic member so that the ink in the replenishment tank 16 does not flow into the third ink tank 5 through the fourth ink flow path 14 by opening the fourth valve 21. It is urged in the closing direction by 27.

However, the tube pump 5 remains as it is.
When 0 is continuously driven, the ink in the ink tank 4 continues to decrease, and conversely, the ink in the ink tank 5 increases and overflows. Therefore, the above operation ends when the ink level sensor 24 detects the absence of ink (S25) or the sensor 23 detects the presence of ink (S26).

After this, the valve 10 is opened (S27), and the ink tank 5 is returned to atmospheric pressure. Further tube pump 50
Is stopped (S28), the valve 9 is opened (S29),
When the ink is leveled after waiting for a certain period of time (S30), image printing becomes possible (S31).

The ink circulation operation of S21 to S30 is performed to remove bubbles in the ink supply system when the apparatus is powered on or when printing is not performed for a long time while the power is on.

Thereafter, an image is printed according to a print instruction signal from a computer (not shown) (S32), and when the image recording is completed (S33), the ink level sensor 24 does not detect the absence of ink, and the printable state is obtained. If ink is detected (S34), the ink tanks 4, 5
The ink replenishing operation to the printer is started.

In this operation, when the valves 9, 10, 22 are closed (S35, S36, S37) and the tube pump 50 is driven (S38), the air chamber of the ink tank 5 is sucked and depressurized, and the ink in the replenishment tank 16 is discharged. Is sucked up and ink is filled in the ink tank 5. When the ink level sensor 23 detects ink (S39), the valves 10, 9 are opened in this order (S40, S41), and the tube pump 50 is stopped (S4).
2) Wait for a certain period of time (S43) to level the ink.

After this, if recording is continued, S is continued.
Return to the printable state of 31. If the recording is to be ended (S44), the power of the apparatus is turned off (S45), and a series of ink replenishing operation is ended.

When the apparatus is restarted to perform image recording, since the ink tanks are already filled with ink, the ink circulation operation from S11 is started in order to remove bubbles in the ink supply system. Bubbles are prevented from entering the ink nozzles and stable printing is possible.

When the ink level sensor 23 does not detect ink even after a certain period of time in these series of operations,
This is because the ink in the replenishment tank 16 is exhausted, and it is displayed that the replenishment tank is filled with ink or that the replenishment tank filled with ink is replaced.

In the present embodiment, the printing is started after the ink circulation operation of S21 to S30, but the negative pressure in the ink tank 2 does not change much if the amount of liquid sent by the tube pump is reduced in S24. Therefore, it is also possible to set a sequence in which printing is performed during ink circulation. For example, the amount of liquid sent by a tube pump is 2 ml /
If the pressure is set to about 10 minutes, the negative pressure in the ink tank 2 is 10 to 20.
mmH ₂ O is increased (that is, it is equivalent to the liquid level of the ink tank 4 being lowered by 10 to 20 mm from the actual level), and there is almost no effect on ink ejection.

(Embodiment 2) In the previous embodiment, the first valve is a general on-off valve, but the ink flow is limited to the direction from the third ink tank 5 to the second ink tank 4. It may be a so-called check valve that allows the flow. An embodiment in which a check valve is used as the first valve will be described with reference to FIG.

In the present embodiment, basically, only the check valve 301 is provided instead of the first valve 9 of the first embodiment. The check valve 301 is provided at the base of the second ink flow path 8 to the second ink tank 4, and is composed of a conical taper portion 302 and a sphere 303. Sphere 303
Has a higher specific gravity than ink, but is preferably as light as possible. For example, a plastic sphere such as polyacetal or polypropylene is used. It is preferable that the taper portion has some flexibility such as hard rubber so that the check valve can be closed without a gap.

When a leveling command is issued from the control unit of the control system,
The second valve 10 opens. Then, the air chamber of the ink tank 5 communicates with the atmosphere, the pressure of the ink head difference between the ink tank 4 and the ink tank 5 pushes the ball 303 upward, the check valve 301 opens, and the ink flows through the flow path 8. It flows from the ink tank 5 into the ink tank. When the ink levels in the ink tanks 4 and 5 become almost equal, the sphere 301 comes into contact with the tapered portion 302 again and the flow of ink stops.

When the check valve 301 is provided instead of the first valve 9 as described above, the mechanism and sequence can be simplified.

On the contrary, the same purpose can be achieved by using an ordinary on-off valve such as a valve for crushing a tube by a cam or a solenoid valve instead of the check valve for the fourth valve 21.

Further, in the above-described embodiment, the ink is replenished by sucking the ink from the replenishment tank 16 to the third ink tank 5, but the ink replenishment method is not limited to this. For example, the user may directly pour the ink from the bottle or the like into the second ink tank, or the ink may be liquid-fed from the replenishment tank to the second or third ink tank by using another pump. .

(Others) The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, particularly in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the electrical connection to the main body of the apparatus or the ink from the main body of the apparatus by being mounted on the main body of the apparatus. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add the ejection recovery means of the recording head, the preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single-color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function are provided. It may be a form or the like.

[0079]

As described above, according to the present invention,
Even if the tube pump is used to move the ink, the ink is not allowed to pass through the tube related to the tube pump, so that impurities generated in the tube when the tube pump is used are mixed with the ink used for ejection. This can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a textile printing processing system including an ink supply device of the present invention.

FIG. 2 is a schematic cross-sectional view showing an embodiment of an ink supply device of the invention.

FIG. 3 is a partial cross-sectional view showing a pump that constitutes a part of the ink supply device of the present invention.

FIG. 4 is a schematic cross-sectional view showing an example of a conventional ink supply device.

FIG. 5 is a schematic cross-sectional view showing another example of a conventional ink supply device.

FIG. 6 is a flowchart for explaining the operation of the ink supply device according to the first embodiment of the invention.

FIG. 7 is a flowchart following the flowchart shown in FIG.

FIG. 8 is a flowchart following the flowchart shown in FIG. 7.

9 is a flowchart following the flowchart shown in FIG.

FIG. 10 is a schematic cross-sectional view showing the main parts of a second embodiment of the ink supply device of the invention.

[Explanation of symbols]

1 print head 2 First ink tank 3 carriage 4 Second ink tank 5 Third ink tank 6 First channel 7 Third ink channel 8 Second ink flow path 9 First valve 10 Second valve 11 atmosphere passage 12 Air chamber suction path 13 Waste ink tank 14 Fourth ink flow path 15 First needle member 16 Supply tank 17 Ink supply port 18 Second needle member 19 atmosphere communication hole 20 atmosphere communication port 21 Fourth Valve 22 Third valve 23 Ink level detecting means 24 Ink level detecting means 26 Air communication port 27 Elastic member 28 atmosphere passage 50 tube pump 51 Laura 52 Roller holder 53 rotation axis 54 roller drive shaft 55 Pressing member 56 compression spring 57 tubes 100 ink supply path

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-194560 (JP, A) JP-A-10-6521 (JP, A) JP-A-56-162661 (JP, A) JP-A-8- 238772 (JP, A) Actual Kaihei 8-27145 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/175

Claims (10)

(57) [Claims] 1. A first ink tank for storing ink to be supplied to a print head, a second ink tank for supplying ink to the first ink tank, and an ink overflowing in the first ink tank. And a pump for sucking the air chamber portion in the third ink tank, and a first valve provided in a path from the third ink tank to the second ink tank. By driving the pump with the first valve closed, the ink in the first ink tank is guided into the third ink tank, and the second ink tank is provided. An ink supply device for supplying the ink contained therein to the inside of the first ink tank. 2. The ink supply device according to claim 1, wherein the first valve is a check valve for allowing only the flow of ink from the third ink tank to the second ink tank. . 3. The opening of the first valve is based on a level difference between an ink level in the third ink tank and an ink level in the second ink tank. Item 2. The ink supply device according to item 2. 4. A second valve for switching between opening and closing of communication with the atmosphere in the air chamber portion of the third ink tank is further included, and by opening the first valve and the second valve, the second valve is opened. The ink supply device according to claim 1, wherein the ink in the third ink tank is moved to the second ink tank. 5. Further comprising first ink level detecting means for detecting an ink level in the third ink tank and second ink level detecting means for detecting an ink level in the second ink tank, The ink supply device according to claim 4, wherein the first ink level detecting means is located at a position higher than that of the second ink level detecting means. 6. The first valve and the second valve are opened when the maximum ink level in the third ink tank is detected by the first ink level detecting means. Item 5. The ink supply device according to item 5. 7. The first valve and the second valve are opened when the second ink level detecting means detects the minimum ink level in the second ink tank. Item 5. The ink supply device according to item 5. 8. The ink supply device according to claim 1, further comprising a replaceable replenishment ink tank for replenishing the third ink tank. 9. A printing apparatus, which prints using a print head supplied with ink from the ink supply apparatus according to any one of claims 1 to 8. 10. The printing apparatus according to claim 9, wherein the print head includes a thermal energy generator that applies thermal energy to the ink as energy used to eject the ink.