JP2003136756A - Ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet printer capable of stably ejecting the ink by heating a UV ink inside a recording head for lowering the viscosity thereof. SOLUTION: The ink-jet printer has a recording head for ejecting an ink, for ejecting a UV ink to be hardened by the ultraviolet ray irradiation, from the recording head. The recording head comprises an ink inlet part for injecting the UV ink, a plurality of ejection openings for ejecting the UV ink, a supply path for guiding the UV ink from the ink inlet part to the ejection openings, and a heating means for heating the UV ink in the supply path at least in a part of the inside or the outside of the supply path.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a UV recording liquid.
The present invention relates to an inkjet printer that uses ink.

[0002]

2. Description of the Related Art Some conventional inkjet printers use a UV ink, which is cured by being irradiated with ultraviolet rays, as a recording liquid. In this way, when printing is performed using UV ink, if UV rays are radiated after printing, UV
The ink hardens, the printed image cannot be easily erased for a long period of time, and excellent weather resistance can be exhibited even when the printed matter is placed outdoors. However, UV
The ink has a characteristic that its viscosity is higher than that of a general ink at room temperature, and in order to obtain stable ejection, it was necessary to reduce the viscosity of the UV ink before ejection.

In order to solve such a problem, in an ink jet printer using UV ink, UV is provided in a supply path for supplying UV ink from an ink tank to a recording head.
A UV ink has been developed which is provided with a heating means for heating the ink to reduce its viscosity. If the UV ink passing through the supply path is reduced in viscosity as necessary for stable ejection, it is a UV ink. Also, the stable ejection can be performed similarly to general ink.

[0004]

However, in the ink jet printer in which the heating means is provided in the supply path as described above, the UV ink can be heated in the supply path but not in the recording head. That is, even if the UV ink is heated in the supply path, the UV ink may be cooled by being affected by the temperature of the print head when being supplied to the print head. In this case, although the viscosity is reduced to the extent necessary for stable ejection, the viscosity increases in the recording head, and it becomes difficult to always perform stable ejection.

It is an object of the present invention to provide an ink jet printer which enables stable ink ejection by heating the UV ink in the recording head to reduce its viscosity.

[0006]

According to another aspect of the present invention, there is provided an ink jet printer which has a recording head for ejecting ink and ejects UV ink which is cured by being irradiated with ultraviolet rays from the recording head. In the recording head, an ink inlet part for injecting UV ink, a plurality of ejection ports for ejecting the UV ink, a supply path for guiding the UV ink from the ink inlet part to the ejection port, and the supply path And a heating unit for heating the UV ink in the supply path at least at a part inside or outside the container.

According to the first aspect of the invention, since the UV ink in the supply path of the recording head is heated by the heating means, the UV ink supplied into the recording head is affected by the temperature of the recording head. Cooling can be prevented, and the viscosity of the UV ink can be reduced in the recording head as much as necessary for stable ejection. Therefore, stable ejection can be maintained and clear printing can be performed. Further, even if the UV ink inside the recording head is cooled and becomes highly viscous, it is possible to heat the UV ink again by the heating means to make the viscosity low.

According to a second aspect of the invention, in the ink jet printer according to the first aspect, the UV of the recording head is UV.
It is characterized by including a temperature detecting means for detecting the temperature of the ink and a heating control means for controlling the heating means based on the detection result of the temperature detecting means.

According to the second aspect of the present invention, the heating control means controls the heating means based on the detection result of the temperature detection means. Therefore, heating is performed in accordance with the temperature of the UV ink in the recording head. The output of the means can be changed.
That is, if the temperature of the UV ink in the recording head is equal to or higher than a predetermined temperature (for example, the temperature at which the viscosity is lowered as much as necessary for stable ejection), the output of the heating unit is weakened, and if the temperature is equal to or lower than the predetermined temperature, the output is output. It becomes possible to strengthen. Therefore, the UV ink can be efficiently heated in the recording head.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the ink jet printer described in the paragraph 1, the heating means heats each temperature of the UV ink ejected from each of the ejection ports to fall within a predetermined temperature range.

According to the third aspect of the present invention, the heating means heats the UV ink ejected from each ejection port so that each temperature is within a predetermined temperature range. Therefore, the UV ejected from each ejection port is heated. It is possible to prevent the viscosity of the ink from varying.
UV ink can be stably ejected from each ejection port.

According to a fourth aspect of the present invention, in the ink jet printer according to any one of the first to third aspects, a process of guiding the UV ink from the ink inlet portion to the ejection outlet in the supply passage of the recording head. Then, an ink storage unit for storing the UV ink is provided once, and at least one of the shape and the temperature distribution of the heating unit is determined so that the temperature of the UV ink in the ink storage unit approaches uniformly. It is characterized by being.

According to the fourth aspect of the invention, at least one of the shape of the heating means and the temperature distribution is determined so that the temperature of the UV ink in the ink containing section approaches uniformly, so that the ink containing section is made uniform. Generated by the shape of
It is possible to prevent temperature unevenness of the ink, and it is possible to perform stable ejection from each ejection port.

According to a fifth aspect of the present invention, in the ink jet printer according to any one of the first to fourth aspects, the heating means has a viscosity of the UV ink in the supply path of 10 mPa · s or more and 50 mPa · s or less. It is characterized by heating so that

According to the fifth aspect of the invention, since the UV ink in the supply path is heated by the heating means so as to have a viscosity of 10 mPa · s or more and 50 mPa · s or less, stable ejection and clear printing can be performed. It can be carried out. In general,
When the viscosity of the UV ink is less than 10 mPa · s, clear printing may not be performed due to bleeding between the state of being discharged onto the recording medium and the time of curing. Further, when the UV ink is ejected from the recording head (for example, a piezo element or the like), it is difficult to always perform stable ejection when the viscosity of the UV ink is a value larger than 50 mPa · s. However, by heating the UV ink so that the viscosity is within the above range, stable ejection and clear printing can be performed.

According to a sixth aspect of the present invention, in the ink jet printer according to any one of the first to fourth aspects, the heating means has a viscosity of the UV ink of the supply passage of 20 mPa · s or more and 40 mPa · s or less. It is characterized by heating so that

According to the sixth aspect of the invention, the UV ink in the supply path is 40 mPa · s or more by 40 by the heating means.
Since it is heated to mPa · s or less, more stable ejection can be performed and clear printing can be performed.

[0018]

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

The ink jet printer 1 exemplified in this embodiment ejects UV ink (hereinafter referred to as ink), which becomes less viscous as the temperature rises and hardens when irradiated with ultraviolet rays, to a recording medium for printing. It is something to do. As shown in FIG. 1, the main configuration of the ink jet printer 1 includes a conveyance unit (not shown) that conveys a sheet-shaped recording medium 2 forward during printing, and a recording head 3 that ejects ink onto the recording medium 2. A carriage 4 having a recording head 3 for each of a plurality of colors, an ink tank 9 for accommodating ink to be supplied to the recording head 3, and the ink tank 9
Ink supply path 1 for supplying ink from the recording head 3 to the recording head 3
1, a maintenance unit 5 for performing maintenance of the recording head 3, a guide rail 6 for guiding the carriage 4 along the horizontal direction (arrow A) during printing or maintenance, and a waiting place for the carriage 4. Home position 7 and control unit 3 that controls these parts
0 (FIG. 4).

At the time of printing, the conveying means conveys the recording medium 2 on the printing area C at the same timing as the operation of the carriage 4, and the recording medium 2 is moved downward from the printing area C (at the end of printing). It is conveyed toward the arrow B).

As shown in FIG. 2 or 3, the recording head 3 has an ink inlet portion 17 into which ink is injected, a plurality of ejection outlets 15 for ejecting ink, and the ink inlet portion 17 to the ejection outlet 15. An in-head supply path (supply path) 22 that guides ink, a head temperature sensor 19 that detects the ink temperature of the in-head supply path 21, and a surface heater that heats the ink from at least a part outside the in-head supply path 21 ( A heating unit 16 and a head heater (heating unit) 20 that heats the ink in at least a part of the inside-head supply path 21 are provided. The recording head 3 includes types of ink used in the inkjet printer 1 (Y: yellow, LY: light yellow, M: magenta, LM: light magenta, C: cyan, LC: light cyan, K: black, LK: light. Depending on the color), a plurality of them are provided.

The ink inlet portion 17 is shown in FIGS. 3 (a) and 3 (b).
As shown in FIG. 3, the recording head 3 is formed in a funnel shape that tapers inward from the side. This ink inlet 1
Reference numeral 7 is connected to the ink supply path 11, and ink is supplied from the ink tank 9 through the ink supply path 11.

The ejection ports 15 are provided on the lower surface (nozzle surface 15a) of the recording head 3 and are arranged at equal intervals along the center line of the lower surface.

The in-head supply passage 21 has an ink inlet portion 17
In the process of guiding the ink from the ink ejection port 15 to the ejection port 15, an ink storage unit 18 that temporarily stores the ink and an ink nozzle 22 that guides the ink from the ink storage unit 18 to the ejection port 15 are provided.

The ink accommodating portion 18 is formed in a trapezoidal shape in a side view, which is tapered toward the front (left in FIG. 3A). The front end of the ink inlet portion 17 is connected to the rear surface of the ink storage portion 18 so that both the ink storage portion 18 and the ink inlet portion communicate with each other. In addition, the ink storage unit 18
Includes an ink nozzle 22 that guides ink to the ejection port 15.
Are provided on the lower surface facing the nozzle surface 15a so as to correspond to each ejection port. That is, the ink nozzles 22 are arranged at equal intervals along the flow direction of the ink flowing from the ink inlet portion 17. In this way, the ink nozzles 2 are arranged along the ink flow direction.
In the case of arranging No. 2, the pressure of the ink flowing into the ink nozzle 22 located at a position distant from the ink inlet portion 17 is weakened, and there is a possibility that stable ejection cannot be performed. Therefore, in the present embodiment, the pressure of the ink flowing into each ink nozzle is prevented from varying by forming the shape of the ink storage portion 18 into a trapezoidal shape in a side view, which becomes narrower toward the front.

Head temperature sensor (temperature detecting means) 19
In order to detect the temperature of the ink that has flowed in from the ink inlet portion 17, the ink is provided in the vicinity of the ink inlet portion 17, that is, in a state of extending inward from the rear surface of the ink storage portion 18.

The surface heater 16 is formed in a U shape inside the recording head 3 so as to cover the in-head supply path 21, and the surface heater 16 heats the ink in the in-head supply path 21 to reduce the viscosity. To do.

The head heater 20 is formed in a columnar shape and is extended from the front end to the rear end of the ink containing portion 18 so that the head heater 20 is aligned with the ink nozzles 22 below the ink containing portion 18. The head heater 20 heats the ink so that each temperature of the ink ejected from each ejection port falls within a predetermined temperature range.
As described above, the head heater 20 has the ink storage portion 18
Since the ink nozzles 22 are in a state of being aligned with the ink nozzles 22 at the lower portion, the ink can be heated without variation in each temperature before flowing into each ink nozzle 22.

As shown in FIG. 1, the carriage 4 repeats the reciprocating movement along the horizontal direction (arrow A) by the guide rail 6, and the recording head 3 is moved to the printing surface of the recording medium 2 in the printing area C. Move along. A UV light source 10 that irradiates ultraviolet rays to cure the ink ejected from the recording head 3 is provided on a side portion of the carriage 4.

The ink tank 9 is, for example, an ink cartridge or the like that is exchangeably provided, and has an ink tank remaining amount sensor for detecting the remaining amount of ink in the ink tank 9. A plurality of ink tanks 9 are provided in accordance with each color of ink stored in each recording head 3.

The ink tank remaining amount sensor may be any one as long as it detects the remaining amount of ink in the ink tank 9, and for example, the liquid surface of the ink is irradiated with light and the reflected light is detected by the optical sensor. There are a type that detects the remaining amount of ink by the response speed, a type that detects the remaining amount of ink by applying electricity to the ink and its conductive state, and a type that detects the remaining amount of ink by the weight of the tank.

The ink supply path 11 connects the respective ink tanks 9 and the respective recording heads 3 to each other so that the inks can be supplied from the ink tanks 9 to the recording heads 3 for each color. The ink supply path 11 is formed of a flexible member so as to correspond to the movement of the recording head 3. The ink supply path 11 is provided with a supply path heater that heats the ink to reduce its viscosity so that the ink can be stably supplied to the recording head 3.

The maintenance unit 5 includes the recording head 3
A suction cap 13 that covers the nozzle surface having the discharge port and sucks ink from the discharge port, and a blade unit that wipes off the ink remaining on the nozzle surface of the recording head 3 after the suction cap 13 sucks the ink. 14 and a blade cleaner part (not shown) for cleaning the blade part
It has and.

The home position 7 is provided at one end of the path along which the carriage 4 reciprocates. Moisturizing caps 8 for moisturizing the nozzle surface of the recording head 3 are provided at the home position 7 in the same number as the recording head 3, and the nozzle surface of the recording head 3 is covered and sealed while the carriage 4 is on standby. ing.

As shown in FIG. 4, the control section (heating control means) 30 includes an interface 31 and a ROM (Read Only).
Memory) 32, RAM (Random Access Memory) 33,
It is composed of a CPU (Central Processing Unit) 34 and the like, and controls various devices connected to the interface 31 in accordance with control programs and control data written in the ROM 32.

The interface 31 includes an ink tank remaining amount sensor, a surface heater 16, and a head heater 2.
0, the head temperature sensor 19 and the like are electrically connected.

In the ROM 32, various data for ink supply, various control programs and control data relating to the operation of each section of the ink jet printer are written. The various data in the ink supply include the ink remaining amount in the ink tank 9 that serves as a reference for the replacement time of the ink tank 9, the ink temperature that serves as a reference for heating the surface heater 16 and the head heater 20, and the surface area. Heater 1
6 and the heating temperature data of the head heater 20.

Surface heater 16 and head heater 20
The ink temperature that is a reference for whether or not to heat the ink is supplied when the ink is supplied from the in-head supply passage 21 to the ejection port 15 without being heated by the surface heater 16 and the head heater 20, that is, the ink. Even when the ink reaches the ejection port 15 while cooling, the temperature of the ink reaching the ejection port 15 is set to be equal to or higher than the temperature at which stable ejection is possible. Surface heater 16 and head heater 2
The heating temperature data of 0 is a predetermined temperature range (ink viscosity is 10 mP
a temperature range from a · s to 50 mPa · s, preferably an ink viscosity of 20 mPa · s to 40 mPa · s
It is the heating temperature of the surface heater 16 and the head heater 20 that can be heated up to the temperature range below), and this heating temperature is set according to the ink temperature detected by the head temperature sensor 19. In other words, if the detected ink temperature is low, it is necessary to give as much heat as possible to the ink. Therefore, if the ink temperature is high, it is necessary to give too much heat to the ink. Therefore, the heating temperature is set to a low temperature.

The RAM 33 can store a plurality of data input only while power is supplied, and a storage area for storing various data such as image data to be printed and a CPU.
A work area by 34 is provided.

The CPU 34 reads out a program designated from various programs stored in the ROM 32 as R
It is developed in the work area in the AM 33, and various processes according to the program are executed according to the input signal from each sensor.

The control unit 30 controls the entire operation of the ink jet printer 1. Here, the control performed when the ink is supplied from the ink tank 9 to the recording head 3 will be described.

When the ink is supplied, the controller 30
Detects the ink temperature in the ink storage portion 18 based on the detection result of the head temperature sensor 19. Then, the control unit 30 selects the heating temperature data corresponding to the detected temperature, controls the output states of the surface heater 16 and the head heater 20 based on the selected heating temperature data, and supplies in the head. Heating is performed so that the ink in the passage 21 is within the predetermined temperature range.

As described above, according to the ink jet printer 1 of the present embodiment, the ink of the recording head 3 is heated by the surface heater 16 and the head heater 20, so that the ink supplied into the recording head 3 is discharged. Also, it is possible to prevent the recording head 3 from being cooled due to the influence of the temperature thereof, and it is possible to reduce the viscosity of the ink in the recording head 3 as much as necessary for stable ejection. Therefore, stable ejection can be maintained and clear printing can be performed. Even if the ink inside the recording head 3 is cooled and becomes highly viscous, the surface heater 16 and the head heater 20 can heat the ink again to lower the viscosity.

Further, since the control unit 30 controls the surface heater 16 and the head heater 20 based on the detection result of the head temperature sensor 19, the surface heater 16 is made to correspond to the temperature of the ink in the recording head 3. And the output of the head heater 20 can be changed. That is, if the temperature of the ink in the recording head 3 is equal to or higher than a predetermined temperature (for example, the temperature at which the viscosity is lowered as much as necessary for stable ejection), the outputs of the surface heater 16 and the head heater 20 are weakened, and the temperature is lower than the predetermined temperature. If so, the output can be increased. Therefore, the ink can be efficiently heated in the recording head 3.

Further, in the present embodiment, the ink containing portion 1
As shown in FIG. 3A, 8 is formed in a trapezoidal shape in a side view, which narrows in the ink flow direction, so that the ink volume at the rear end and the front end of the ink storage unit 18 is large. Will be different. Therefore, when the surface heater 16 covers the ink storage portion 18 as described above, the area where the rear end portion of the ink storage portion 18 and the surface heater 16 are adjacent to each other becomes large, and the front end portion of the ink storage portion 18 is The area adjacent to the surface heater 16 becomes smaller. That is,
By making the contact area with the surface heater 16 different for each location of the ink storage unit 18, the amount of heat applied to the ink is changed for each location. Therefore, even if the amount of ink varies in each place of the ink storage unit 18, the ink storage unit 1
It can be heated so that the temperature of the ink in 8 approaches uniformly.

Further, the ink supplied to the ink containing section 18 is cooled as it goes away from the ink inlet section 17, and the ink inside the ink containing section 18 may have temperature unevenness. In order to prevent this temperature unevenness, the amount of heat per unit volume applied to the ink must be increased as the distance from the ink inlet 17 increases. Therefore, in the present embodiment, in order to increase the amount of heat per unit volume as the distance from the ink inlet portion 17 increases, the head heater 2
0 is formed in a cylindrical shape corresponding to the shape of the ink storage portion 18. With such a configuration, the amount of heat per unit volume applied to the ink at the front end of the ink storage unit 18 is larger than the amount of heat per unit volume applied to the ink at the rear end of the ink storage unit 18. Therefore, it is possible to heat the ink in the ink storage portion 18 so that the temperature of the ink approaches uniformly. In this way, the surface heater 16 and the head heater 20 have their shapes determined in accordance with the shape of the ink storage portion 18 so that the temperature of the ink in the ink storage portion 18 approaches uniformly. Part 1
The temperature unevenness of the ink caused by the shape of 8 can be prevented, and stable ejection can be performed from each ejection port.

In this embodiment, the ink storage unit 1
Although the shape of the heating means (the surface heater 16 and the head heater 20) is determined according to the shape of No. 8, the temperature distribution of the heating means may be determined according to the shape of the ink containing portion. That is, by increasing the heating temperature in the portion having a large ink volume and decreasing the heating temperature in the portion having a small ink volume, the ink temperature in the ink containing portion 18 can be made to approach uniformly.

The UV ink is preferably a liquid having a viscosity at 30 ° C. of 50 to 3000 mPa · s. It is more preferably 50 to 1000 mPa · s, and even more preferably 100 to 500 mPa · s. If it is 50 mPa · s or less, clear printing may not be performed in some cases due to easy bleeding. At 3000 mPa · s or higher, the smoothness of image quality may be lost. Further, it is preferably a liquid having a viscosity at 60 ° C. of 10 to 50 mPa · s. If it is less than 10 mPa · s, a problem may occur in high-speed injection, and if it exceeds 50 mPa · s, the injection property may be deteriorated. Also,
Particularly when ejected from a recording head composed of a piezo element, a liquid having a viscosity of 10 to 50 mPa · s is preferable.

The composition of the UV ink used in this embodiment is, for example, an oligomer such as a high viscosity oligomer or a low viscosity oligomer (resin such as polyester acrylate, epoxy acrylate, urethane acrylate).
And a monomer, a photopolymerization initiator, a pigment, an antifoaming agent, various regulators, a polymerization inhibitor, and the like.
The viscosity of the UV ink, which is a mixture having the above composition, changes drastically with a temperature change in the vicinity of its glass transition point, and the viscosity drops sharply at a temperature below the glass transition point.
Therefore, it is preferable to heat the UV ink in the recording head 3 so that the heating means exceeds the glass transition point of the UV ink.

In this embodiment, the ink storage unit 1
Although the head temperature sensor 19 provided in FIG. 8 has been exemplified as the temperature detecting means, it may be provided at any place as long as the temperature of the ink in the in-head supply passage 21 can be detected. In particular, if the temperature detecting means is provided near the ejection port 15, the heating means can be controlled based on the temperature of the ink at the time of ejection, and more stable ejection can be performed.

It should be understood that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0052]

According to the first aspect of the present invention, it is possible to prevent the UV ink supplied into the recording head from being cooled due to the temperature of the recording head, and the UV ink is stably ejected inside the recording head. The viscosity can be reduced as much as necessary. Therefore, stable ejection can be maintained and clear printing can be performed. Further, even if the UV ink inside the recording head is cooled and becomes highly viscous, it is possible to heat the UV ink again by the heating means to make the viscosity low. According to the second aspect of the present invention, the output of the heating means can be changed according to the temperature of the UV ink in the recording head. That is, if the temperature of the UV ink in the recording head is equal to or higher than a predetermined temperature (for example, the temperature at which the viscosity is lowered as much as necessary for stable ejection), the output of the heating unit is weakened, and if the temperature is equal to or lower than the predetermined temperature, the output is output. It becomes possible to strengthen. Therefore, the UV ink can be efficiently heated in the recording head. According to the third aspect of the invention, it is possible to prevent the viscosity of the UV ink ejected from each ejection port from varying, and it is possible to stably eject the UV ink from each ejection port. According to the invention described in claim 4, it is possible to prevent the temperature unevenness of the UV ink caused by the shape of the ink containing portion, and it is possible to perform stable ejection from each ejection port. According to the invention described in claim 5, stable ejection and clear printing can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a recording head provided in the inkjet printer of FIG.

3A and 3B are cross-sectional views of the recording head of FIG. 2, where FIG. 3A is a cross-sectional view taken along the D plane of FIG. 2, and FIG. 3B is a cross-sectional view taken along the E plane of FIG.

FIG. 4 is a main control block diagram of a control unit included in the inkjet printer of FIG.

[Explanation of symbols]

1 inkjet printer 3 recording head 15 outlets 16-side heater (heating means) 17 Ink inlet 18 Ink storage 19 Head temperature sensor (temperature detection means) 20 Head heater (heating means) 21 In-head supply path (supply path) 30 control unit (heating control means)

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 EA26 EA28 EB09 EB30 EB50                       EC08 EC09 EC16 EC21 EC22                       EC29 EC45 EC55 EC57 EC64                       FC01 FD20 KB13 KC02                 2C057 AF73 AG71 AG80 AH20 AK01                       AL14 AL24 AM40 BA03 BA14                 2H086 BA01 BA02 BA60 BA61                 4J039 AD10 AD21 AE04 AE05 AE06                       BE01 BE16 BE27 CA01 EA06                       GA24

Claims (6)

[Claims] 1. An ink jet printer having a recording head for ejecting ink and ejecting UV ink which is cured by being irradiated with ultraviolet rays from the recording head, wherein the ink is injected with the UV ink. An inlet part, a plurality of ejection ports for ejecting the UV ink, a supply path for guiding the UV ink from the ink inlet part to the ejection port, and a UV ink for the supply path at least at a part inside or outside the supply path. An inkjet printer, comprising: a heating unit that heats the ink. 2. The ink jet printer according to claim 1, wherein a temperature detection unit that detects the temperature of the UV ink of the recording head, and a heating control unit that controls the heating unit based on the detection result of the temperature detection unit. An inkjet printer characterized by comprising: 3. The ink jet printer according to claim 1, wherein the heating means heats the UV ink ejected from the ejection ports so that each temperature is within a predetermined temperature range. And inkjet printer. 4. The ink jet printer according to any one of claims 1 to 3, wherein the UV ink is once supplied to the supply path of the recording head in the process of guiding the UV ink from the ink inlet portion to the ejection outlet. An ink storage unit for storing the ink is provided, and at least one of the shape and the temperature distribution of the heating unit is determined so that the temperature of the UV ink in the ink storage unit approaches uniformly. Inkjet printer. 5. The ink jet printer according to any one of claims 1 to 4, wherein the heating unit has a viscosity of the UV ink of the supply path of 10 or less.
An ink jet printer characterized by heating so as to be not less than mPa · s and not more than 50 mPa · s. 6. The ink jet printer according to claim 1, wherein the heating means has a viscosity of the UV ink of the supply passage of 20.
An ink jet printer characterized by heating so as to be not less than mPa · s and not more than 40 mPa · s.