JP2005212350A - Liquid ejecting apparatus and inkjet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejection device capable of suppressing a rise in temperature of ink supplied to a head even when continuous printing is performed for a long time and obtaining stable printing characteristics.
A sub-tank 2 that temporarily stores liquid supplied from a liquid supply source 1 and a liquid discharge head 3 that discharges liquid supplied from the sub-tank 2 are provided, and at least from the liquid discharge head 3 to the sub-tank. 2. A liquid discharge apparatus comprising a cooling means 50 for cooling the liquid in the liquid path leading to 2 or in the liquid path for collecting the liquid discharged from the liquid discharge head 3 to the sub tank 2.
[Selection] Figure 1

Description

  The present invention relates to a liquid discharge apparatus and an ink jet recording apparatus.

In a liquid discharge apparatus such as an ink jet recording apparatus, in order to discharge a small amount of liquid, liquid is supplied from a liquid tank to a liquid discharge head, and droplets are discharged from each nozzle as necessary. However, since the diameter of the nozzle of the liquid ejection head is very small, problems such as bubbles mixed in the nozzle or nozzle clogging due to dust occurred depending on the state of the liquid, causing liquid ejection failure.
Therefore, liquid is forcibly sent from the liquid feed pump to the head at a controlled timing before liquid discharge or after liquid discharge, and liquid and bubbles inside the head are forcibly discharged from the nozzle to the outside to recover the head function. There is a need to do. In such a head function recovery operation, the liquid discharged forcibly is discarded wastefully, so that the liquid is recovered in a separately provided liquid tank and supplied to the liquid discharge head again. Is disclosed in Patent Document 1.
This conventional example is an example of an ink-jet head printer which is one of application examples of a liquid discharge apparatus. That is, the ink used for the function recovery operation of the inkjet head is collected in a different tank from the new ink cartridge, mixed with the new ink supplied from the new ink cartridge in the tank, and returned to the inkjet head again. It is an example of an ink jet printer having a circulation type ink supply system for supplying.
In order to eject ink, this ink jet head is an electrothermal transducer that causes film boiling corresponding to recorded information to form bubbles in the ink and eject the ink. At this time, a part of the thermal energy from the heater or the like for ejecting ink is discharged to the outside of the head by ejecting ink droplets, but the remaining energy is stored in the ink ejecting head and the temperature of the ejecting head rises. The ink is heated and the viscosity decreases.
As the ink viscosity decreases, more ink is ejected. That is, as the number of printed sheets increases, the temperature of the head rises and the ink is heated. As a result, there has been a problem in that the viscosity of the ink decreases, the amount of ink discharged increases, and the image density gradually increases.
In order to solve this problem, Patent Document 2 discloses an ink jet printing apparatus in which an ink supply path is provided in a print head to supply ink to the head during printing, and the head heated by printing is cooled using ink as a refrigerant. was suggested.
In order to solve the problem that the temperature of the ink jet head rises with ink ejection and the ink droplet ejection characteristics fluctuate, this conventional example in which a heat radiation function unit having a heat radiation function is integrally formed on a diaphragm driven by a piezo element Then, since the diaphragm has a heat dissipation action, there are material limitations and shape limitations, and the degree of freedom in head design is reduced.

An ink jet recording apparatus, which is one application example of the liquid ejection apparatus, will be described. Ink is supplied from the ink tank to the inkjet head, and the ink used when the head function is restored during the printing operation or after the printing operation is collected into the ink tank and reused for a long period of continuous recording. If this is done, the temperature of the recovered ink rises due to the heat generated by the inkjet head itself.
When the temperature of the collected ink rises in this way, the temperature of the ink in the ink tank rises as a result. When the ink temperature rises, the ink viscosity decreases, so that the amount of ink discharged increases, and the printing density gradually increases as the printing time increases.
In order to solve this problem, as disclosed in the above Japanese Patent Laid-Open No. 2000-255048, the ink-jet head that has generated heat by continuous printing operation using the circulating ink as a refrigerant is cooled, and the ink supply path is a cooling channel. A structure that is also used as a joint was proposed.
JP 2000-255048 A Japanese Patent Laid-Open No. 11-151811

However, the above-described conventional technique has a problem that the temperature control of the ink cannot be sufficiently performed because the cooling efficiency is low because an organic resin tube as an ink supply path is used as a cooling flow path. Further, since the cooling function is not provided in the path for collecting the ink ejected when the head function is recovered, the temperature of the ink in the tank rises when the head function is recovered, and a sufficient effect cannot be obtained.
This has been a cause of deterioration in printing characteristics during long-time continuous driving in which the temperature of ink supplied to the head gradually increases. The degree of such deterioration becomes more conspicuous in a long inkjet represented by a line type in which a large number of nozzles are densely distributed.
The present invention solves the conventional problems as described above, and can suppress an increase in the temperature of ink supplied to the head even if continuous printing is performed for a long time under the condition that the head size is large and the calorific value is increased. It is an object of the present invention to provide a liquid ejection apparatus and an ink jet recording apparatus that can obtain stable printing characteristics.

In order to achieve the above object, the invention according to claim 1 includes a sub tank that temporarily stores the liquid supplied from the liquid supply source, and a liquid discharge head that discharges the liquid supplied from the sub tank. Further, the liquid discharge apparatus having a cooling means for cooling the liquid at least in the liquid path from the liquid discharge head to the sub tank or in the liquid path for collecting the liquid discharged from the liquid discharge head to the sub tank is the main feature.
The invention according to claim 2 is characterized in that, in the liquid discharge apparatus according to claim 1, the cooling means is a liquid discharge apparatus which is a heat radiating portion which also serves as a liquid flow path.
According to a third aspect of the present invention, in the liquid ejection device according to the second aspect, the heat radiating portion is a member different from the liquid path constituent member, and the thermal conductivity is set larger than that of the liquid path forming member. Features the device.
The invention according to claim 4 is characterized in that, in the liquid discharge apparatus according to claim 3, the heat radiating portion is mainly a liquid discharge apparatus cooled by a blower.
The invention according to claim 5 is characterized in that, in the liquid discharge apparatus according to claim 4, the blower has a liquid discharge apparatus which also serves as an internal cooling means.
The invention according to claim 6 is most characterized by an ink jet recording apparatus using the liquid ejection apparatus according to claim 1.

  The present invention relates to a sub-tank that temporarily stores liquid supplied from a liquid supply source, a liquid discharge head that discharges liquid supplied from the sub-tank, and at least in a liquid path from the discharge head to the sub-tank or from the discharge head By providing cooling means for cooling the liquid in the liquid path for collecting the discharged liquid into the sub tank, the intended purpose can be achieved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Examples of the liquid discharge head include a liquid discharge apparatus that discharges liquid resist as droplets, a liquid discharge apparatus that discharges DNA samples as droplets, and liquid discharge that discharges liquid containing conductive material to form electrical wiring. Although there are apparatuses and the like, description will be made mainly with an example of an ink jet printer.

FIG. 1 is a configuration diagram showing a liquid supply system of an ink jet printer which is a liquid discharge apparatus according to Embodiment 1 of the present invention. Since the printer of the first embodiment is a color printer and uses four colors of ink of cyan, magenta, yellow, and black, actually, four ink paths shown in FIG. 1 are provided for each color. The paths are arranged in parallel independently of each other. The description will be given for one of the ink paths, but the same is true for the other color inks.
As shown in FIG. 1, an ink cartridge 1 filled with unused ink, a sub tank 2 for temporarily storing ink supplied from the ink cartridge 1, and image formation including characters on a recording medium or the like are performed. An ink jet head (liquid discharge head) 3 is provided.
Here, the inkjet head 3 is a thermal system that uses bubbles of ink film boiling as a discharge force, a piezo system that uses expansion and contraction of a piezoelectric element, an electrostatic system that sucks a diaphragm by electrostatic force and discharges ink by its repulsive force, etc. There are various driving methods, but here, an example using the thermal method will be described.
The inkjet head 3 is a full-line inkjet head capable of printing on A4 size paper. An ink feed pump 7 is provided between the ink cartridge 1 filled with unused ink and the sub tank 2, and an ink feed pump 8 is also provided between the sub tank 2 and the buffer tank 6. Here, the buffer tank 6 is for absorbing the pressure fluctuation of the ink feeding pump 8 and feeding the ink to the inkjet head 3 at a constant pressure.
In the sub-tank 2, an air opening 10 is provided for communicating the inside 2 a of the sub-tank 2 with the atmosphere. The sub tank 2 is connected to one end of the inkjet head 3 by a pipe through a cooling means 51 for cooling the ink. A buffer tank 6 is connected to the other end by piping.
An ink collection container 11 that collects ink to the sub tank 2 when ink is forcibly ejected from the nozzle by the ink ejection function recovery operation is installed at a position facing the ink jet head 3. A recovery pump 12 and a cooling means 50 for cooling the ink are provided between the recovery containers 11. In particular, since the cooling means 50 is provided between the recovery pump 12 and the sub tank 2, it is possible to cool not only the head 3 but also the ink whose heat has risen by the recovery pump 12 during the head function recovery operation. Become.

Next, the operation will be described. When the ink cartridge 1 filled with unused ink is connected to the ink supply unit, the ink is fed to the sub tank 2 by the ink feeding pump 7 (arrow A). An ink amount sensor is installed in the sub-tank 2 and ink is fed until a predetermined amount is reached.
Next, the head function recovery operation is performed. In this operation, ink is forcibly sent from the sub tank 2 to the inside of the head from one supply port of the inkjet head 3 via the buffer tank 6 by the ink feeding pump 8 (arrow C1). Since the ink forcibly sent to the inside of the head is forcibly ejected from the nozzle, dust, ink solidified matter, and bubbles inside the nozzle are discharged.
The ink forcibly ejected from the nozzle is collected by the ink collection container 11 and collected by the collection pump 12 to the sub tank (arrow C3). On the other hand, air and ink inside the head are also discharged from the other end of the inkjet head 3 and collected into the sub tank 2 (arrow C2). In this way, the ink jet printer enters a print standby state.
When printing an image, ink is supplied from the sub tank 2 to the inkjet head 3 (arrow B). When ink is consumed by printing and the ink remaining amount in the sub tank 2 decreases, unused ink is supplied from the ink cartridge 1 to the sub tank 2 by using the ink feeding pump 7. In the middle, in order to maintain the print quality at a certain level, the head function recovery operation is performed at a predetermined timing.
During the head function recovery operation (C3 flow), since the ink-jet head 3 is generating heat, the temperature of the ink recovered in the ink recovery container 11 is higher than that at the start of printing. After being cooled by the above, it is recovered into the sub tank 2. Similarly, in the other ink recovery means path (flow of C2), the ink temperature rises from the initial value until it passes through the ink cooling means 51, so that the ink is cooled by the ink cooling means 51 and the ink is transferred to the sub tank 2. Collected.
In this way, by providing the ink cooling means 50 and 51 in all the ink paths collected to the sub tank 2, an increase in the ink temperature in the sub tank due to the collected ink is suppressed.

The ink cooling means 50 used in Example 1 will be described with reference to FIGS. FIG. 5A is a top view and FIG. 5B is a side view. The ink cooling unit 500 constituting the ink cooling means 50 includes an aluminum pipe member 500b having a higher thermal conductivity than the ink pipe 501 made of an organic resin material, an aluminum base plate 500a, and a plurality of aluminum heat sinks arranged in a fin shape. The ink is cooled by bringing the piping member 500b into contact with the base plate 500a and the heat radiating plate 500c.
Here, in order to ensure reliability, the aluminum piping member 500b was coated with a material having corrosion resistance against the ink in order to ensure reliability. In order to confirm the effect of ink cooling, the temperature difference between the ink temperature collected by the head function recovery operation performed during printing and the ink temperature passed through the ink cooling unit 500 was measured with a thermistor inserted into the ink pipe.
It was confirmed that when the ink whose ink temperature was raised from the initial temperature before printing in the printing operation flows into the ink cooling unit 500, it is radiated by the base plate 500a and the heat radiating plate 500c, and the temperature of the ink is lowered by about 10 ° C. . Similarly, when the ink temperature difference was measured in the ink cooling means 51 provided in another recovery path, it was confirmed that the temperature dropped similarly by about 10 ° C.
By providing the ink cooling means 51 and 50 in the ink circulation path and the ink recovery path in this way, the temperature of the ink in the sub tank 2 rises even if the ink is recovered from the head that has generated heat in the printing operation for a long time. There was no. In other words, the ink temperature did not rise even when repeated head recovery operations were performed during continuous printing for a long period of time, and there was no problem that the print density was increased due to a decrease in ink viscosity.
On the other hand, in the case of the conventional configuration in which no ink cooling mechanism is provided for comparison, the ink viscosity decreases and the print density gradually changes with increasing temperature of the ink collected by the continuous printing operation for a long time. The following problems occurred. In this embodiment, separate cooling units are provided in the ink supply systems for the respective colors, but there is no problem even if the collected ink of each color is performed by one cooling means.

The second embodiment is an example applied to an ink jet printer head which is one of application examples of the liquid ejecting apparatus as in the first embodiment. The configuration of the ink jet recording apparatus of this embodiment is shown in FIG. 2, but the basic configuration is the same as that of the ink jet recording apparatus shown in the first embodiment. The part is omitted.
In this embodiment, the ink path (C3) collected in the ink collection container 11 shown in FIG. 2 and the ink path (C2) for feeding the ink to the inkjet head 3 and circulating and collecting the head inside when the head function is recovered are shared. A type of ink cooling means 60 is provided. In this case, since it is not necessary to provide a separate ink cooling unit for each collected ink path, the configuration is simplified and the cost can be reduced.
The ink cooling means used in Example 2 will be described. Here, since the ink cooling means shown in FIGS. 5A and 5B used in the first embodiment is used, the description is omitted, but in order to increase the cooling efficiency, the heat radiating plate 500c is replaced by the blower 401 shown in FIG. A structure for forced cooling was adopted.
Here, in order to confirm the effect of ink cooling, the temperature difference between the ink temperature collected by the head function recovery operation performed during printing and the ink temperature passed through the ink cooling unit 500 was measured with a thermistor inserted in the ink pipe. It was confirmed that when the ink whose ink temperature was raised from the initial temperature before printing in the printing operation flowed into the ink cooling unit 500, it was radiated by the base plate 500a and the heat radiating plate 500c, and the temperature of the ink dropped by 15 ° C. .
In other words, the fact that the temperature drop was larger than that in Example 1 despite the fact that the two systems of ink were collected and the heat generation amount increased was due to the effect of the cooling fan. By providing the cooling means 60 in the ink circulation path and the ink recovery path in this way, the temperature of the ink in the sub tank 2 does not rise even when the ink is recovered from the head that has generated heat in the printing operation for a long time. . In other words, the ink temperature did not rise even when repeated head recovery operations were performed during continuous printing for a long time, and there was no problem that the print density was increased due to a decrease in ink viscosity.
On the other hand, in the case of the conventional configuration in which no ink cooling mechanism is provided for comparison, the ink viscosity decreases and the print density gradually increases as the temperature of the ink collected by the continuous printing operation for a long time increases. It caused a problem such as. In this embodiment, separate cooling units are provided in the ink supply systems for the respective colors. However, there is no problem even if the collected inks for the respective colors are cooled by one cooling means.

As in the first embodiment, the third embodiment is an example applied to an ink jet printer head which is one of application examples of the liquid ejecting apparatus. The configuration of the ink jet recording apparatus of this embodiment is shown in FIG. The head of the ink jet printer of Example 3 has a head size capable of printing on A5 size recording paper. In addition, since the basic configuration is the same as that of the ink jet recording apparatus shown in the first embodiment, the same reference numerals are used for the corresponding parts, and duplicate explanations are omitted.
In this embodiment, the ink cooling unit 50 is formed in the ink path (C3) collected by the ink collection container 11 when the head function is restored. Here, the thermistor in which the ink is cooled by natural cooling by the heat radiating plate 500c shown in FIG. 5A, and the temperature difference between the ink temperature recovered by the head function recovery operation and the ink temperature passed through the ink cooling unit 500 is inserted into the ink pipe. As a result of measurement, it was confirmed that the temperature of the ink decreased by 10 ° C.
By providing the ink cooling means 50 in the ink recovery path in this way, the temperature of the ink in the sub tank 2 does not rise even when the ink is recovered from the head that has generated heat in the printing operation for a long time. That is, no increase in ink temperature was observed even when repeated head recovery operations were performed in continuous printing for a long time, and there were no problems such as an increase in print density caused by a decrease in ink viscosity.
In this embodiment, a separate cooling unit is provided for the ink supply system for each color, but there is no problem even if the collected ink for each color is performed by one cooling means. Thus, even when the ink cooling means 50 is formed only in the ink path (C3) recovered by the ink recovery container 11 when the head function is recovered, a sufficient effect was observed.

In the same manner as the first embodiment, the fourth embodiment is an example applied to an ink jet printer head which is one of application examples of the liquid ejecting apparatus. The configuration of the ink jet recording apparatus of this embodiment is shown in FIG. Since the basic configuration is the same as that of the ink jet recording apparatus shown in the first embodiment, the same reference numerals are used for the corresponding parts, and duplicate explanations are omitted.
In this embodiment, when the head function is recovered, the ink cooling means 60 is formed in the ink path (C2) for supplying the ink to the ink jet head 3 and circulating and recovering the inside of the head. Here, the thermistor in which the ink is cooled by natural cooling by the heat radiating plate 500c shown in FIG. 5A, and the temperature difference between the ink temperature recovered by the head function recovery operation and the ink temperature passed through the ink cooling unit 500 is inserted into the ink pipe. As a result of measurement, it was confirmed that the temperature of the ink decreased by 10 ° C.
By providing the ink cooling means 60 in the ink recovery path in this way, the temperature of the ink in the sub tank 2 does not rise even when the ink is recovered from the head 3 that has generated heat in the printing operation for a long time. That is, no increase in ink temperature was observed even when repeated head recovery operations were performed in continuous printing for a long time, and there were no problems such as an increase in print density caused by a decrease in ink viscosity.
In this embodiment, separate cooling means are provided in the ink supply system for each color. However, there is no problem even if the collected ink of each color is performed by one cooling means. As described above, even when the ink cooling means 60 is formed only in the ink path (C2) that circulates and collects inside the head when the head function is recovered, a sufficient effect is observed.

Since the basic configuration of the ink jet recording apparatus of the fifth embodiment is the same as that of the ink jet recording apparatus shown in the second embodiment, the same reference numerals are used for the corresponding portions, and duplicate descriptions are omitted. The ink cooling means 60 used in Example 5 will be described with reference to FIGS.
The ink cooling unit 700, which is the ink cooling means 60, is composed of an aluminum base plate 700a and an aluminum heat radiating plate 700c that have higher thermal conductivity than the piping 701 made of organic resin material. It was performed by making it heat-dissipate by making it contact with the aluminum base plate 700a in which 700c was formed. It is characteristic that the pipe 700 is arranged on the outer surface of the base plate 700a.
In order to confirm the effect of cooling, the temperature difference between the ink temperature collected in the head function recovery operation performed during printing and the ink temperature passed through the ink cooling unit 700 was measured with a thermistor inserted in a pipe. When ink whose ink temperature is higher than the initial temperature before printing in the printing operation flows into the ink cooling unit 700, it is radiated by the base plate 700a and the heat radiating plate 700c, and it has been confirmed that the ink temperature is reduced by about 10 ° C. .
In this way, by providing the ink cooling section 700 that is the ink cooling means 60 in the ink circulation path and the ink recovery path, even if the ink is recovered from the head 3 that has generated heat in the printing operation for a long time, the ink in the sub tank 2 is recovered. The temperature did not increase. In other words, the ink temperature did not rise even when repeated head recovery operations were performed during continuous printing for a long period of time, and there was no problem that the print density was increased due to a decrease in ink viscosity.
On the other hand, in the case of the conventional configuration in which no ink cooling mechanism is provided for comparison, the ink viscosity decreases and the print density gradually increases as the temperature of the ink collected by the continuous printing operation for a long time increases. It caused a problem such as. In this embodiment, separate cooling units are provided in the ink supply systems for the respective colors, but there is no problem even if the collected ink for each color is cooled by a single cooling means.

Since the basic configuration of the ink jet recording apparatus of the sixth embodiment is the same as that of the ink jet recording apparatus shown in the second embodiment, the same reference numerals are used for the corresponding parts, and duplicate explanations are omitted. The ink cooling means 60 used in Example 6 will be described with reference to FIG.
The ink cooling unit 800, which is the ink cooling means 60, has an organic resin pipe 802 connected to the sub tank 2 and the ink recovery container 11, and an organic resin pipe 803 connected to the inkjet head 3 and the sub tank 2. It is a structure which cools by contacting the metal housing | casing 801 which is a high metal plate and comprises the apparatus main body, and radiating heat | fever.
In order to confirm the effect of cooling, the temperature difference between the ink temperature in the pipe recovered by the head function recovery operation performed during printing and the ink temperature in the pipe passing through the ink cooling unit 800 is measured with a thermistor inserted in the pipe. did. It was confirmed that when the ink whose ink temperature was raised from the initial temperature before printing in the printing operation flows into the ink cooling unit 800, it is dissipated in the metal casing 801 of the apparatus, and the temperature of the ink is lowered by about 10 ° C.
In this way, by providing the ink cooling section 800 that is the ink cooling means 60 in the ink circulation path and the ink recovery path, even if the ink is recovered from the head 3 that has generated heat in the printing operation for a long time, the ink in the sub tank 2 is recovered. The temperature did not increase. In other words, even if repeated head recovery operations were performed during continuous printing for a long time, the ink temperature did not rise, and there was no problem that the print density was increased due to a decrease in ink viscosity.
On the other hand, in the case of the conventional configuration in which no ink cooling mechanism is provided for comparison, the ink viscosity decreases and the print density gradually increases as the temperature of the ink collected by the continuous printing operation for a long time increases. It caused a problem such as. In this embodiment, separate cooling units are provided in the ink supply systems for the respective colors, but there is no problem even if the collected ink for each color is cooled by a single cooling means.

Since the basic configuration of the ink jet recording apparatus of the seventh embodiment is the same as that of the ink jet recording apparatus shown in the second embodiment, the same reference numerals are used for the corresponding portions, and duplicate descriptions are omitted.
The ink cooling means 60 used in Example 7 will be described with reference to FIG. The ink cooling means 60 includes a stainless steel pipe 902 connected to the sub tank 2 and the ink recovery container 11, and a stainless steel pipe 903 connected to the inkjet head 3 and the sub tank 2, and a metal casing 901 constituting the apparatus main body 904. The inside of the apparatus main body 904 including the housing 901 is forcibly cooled by a cooling fan (blower) 905.
In order to confirm the cooling effect, the temperature of the ink recovered by the head function recovery operation performed during printing was measured with a thermistor inserted in the pipe. In the temperature measurement, the ink temperature between the region where the ink recovered from the recovery container 11 flows out and the stainless steel pipe 902 contacts the metal casing 901, the area where the stainless steel pipe 902 contacts the metal casing 901, and the sub tank 2 are measured. The temperature of the ink was measured and the temperature difference was measured. As a result, it was confirmed that the ink temperature decreased by about 15 ° C.
Thus, the cooling of the ink temperature can be combined with the cooling of the apparatus main body. That is, the temperature of the ink in the sub tank 2 did not rise even when the ink was collected from the head 3 that generated heat in the printing operation for a long time. In other words, even if repeated head recovery operations were performed during continuous printing for a long time, the ink temperature did not rise, and there was no problem that the print density was increased due to a decrease in ink viscosity.
On the other hand, in the case of the conventional configuration in which no ink cooling mechanism is provided for comparison, the ink viscosity decreases and the print density gradually increases as the temperature of the ink collected by the continuous printing operation for a long time increases. It caused a problem such as. In this embodiment, separate cooling units are provided in the ink supply systems for the respective colors, but there is no problem even if the collected ink for each color is cooled by a single cooling means.

1 is a configuration diagram illustrating a liquid supply system of an inkjet printer that is a liquid discharge apparatus according to Embodiment 1 of the present invention. FIG. It is a block diagram which shows the liquid supply system of the inkjet printer which is a liquid discharge apparatus which concerns on Example 2 of this invention. It is a block diagram which shows the liquid supply system of the inkjet printer which is a liquid discharge apparatus which concerns on Example 3 of this invention. It is a block diagram which shows the liquid supply system of the inkjet printer which is a liquid discharge apparatus which concerns on Example 4 of this invention. It is a block diagram of the ink cooling means (the 1). It is a block diagram of an ink cooling means (the 2). FIG. 6 is a configuration diagram of an ink cooling unit (No. 3). FIG. 6 is a configuration diagram of an ink cooling means (part 4). FIG. 6 is a configuration diagram of an ink cooling unit (No. 5).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Ink cartridge (liquid supply source), 2 Sub tank, 3 Inkjet head (liquid discharge head), 50, 60 Cooling means

Claims (6)

  A sub-tank that temporarily stores liquid supplied from a liquid supply source, and a liquid discharge head that discharges liquid supplied from the sub-tank, and at least in a liquid path from the liquid discharge head to the sub-tank or a liquid discharge head A liquid discharge apparatus comprising a cooling means for cooling the liquid in a liquid path for collecting the liquid discharged from the sub tank.   2. The liquid discharge apparatus according to claim 1, wherein the cooling means is a heat radiating portion that also serves as a liquid flow path.   3. The liquid discharge apparatus according to claim 2, wherein the heat dissipating part is a member different from the liquid path constituent member, and the thermal conductivity is set larger than that of the liquid path forming member.   4. The liquid discharge apparatus according to claim 3, wherein the heat radiating portion is cooled by a blower.   5. The liquid discharge apparatus according to claim 4, wherein the blower also serves as a cooling means in the apparatus main body.   An ink jet recording apparatus using the liquid discharge apparatus according to claim 1.

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