JP2003182103A - Recorder and printing method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder which can perform recording with a specified ink viscosity constantly using a UV-curing ink under high temperature in order to enhance reliability of ink ejection. <P>SOLUTION: In the recorder comprising a head section performing recording in ink jet system, a UV-curing ink, an ink tank containing ink, a first channel for supplying ink from the ink tank to the head section, and a heating means for sustaining the head section at a specified temperature, recording is performed after discharging ink in the head section by an ink discharging means when recording is performed again after the head section is heated to a specified temperature and left as it is for a specified time or longer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer using an ultraviolet curable ink.

[0002]

2. Description of the Related Art Up to now, a water-based ink used in an ink jet printer can be fixed (printed) only on a recording medium having permeability. Further, there is a problem that it takes time for the ink on the recording medium to dry after printing, and the printing throughput is limited.

In recent years, particularly in the field of industrial use where a large amount and high speed printing are required using various recording media, there is a demand for an ink jet type recording method using an ultraviolet curable ink which instantly hardens when irradiated with ultraviolet rays. Is increasing. For example, as described in Japanese Patent Application Laid-Open No. 5-186725, there is one that uses a water-soluble dye to facilitate printing on plain paper or recycled paper. In addition, there is a UV-curable inkjet ink that uses a water-soluble monomer as an ink for printing on a recording material having no ink permeability.

[0004]

The ultraviolet curable ink has a larger gradient of viscosity change with temperature than conventional water-based ink, and in particular, the lower the temperature, the larger the amount of change in viscosity with temperature. On the other hand, in an ink jet type print head having nozzles for ejecting ink, the characteristics such as speed and size of ejected ink droplets are greatly affected by the viscosity of the ink. It is desirable to keep the viscosity. In order to mitigate the effect of the change in the viscosity of the ink as described above, there is a method of using high-temperature ink in which the amount of change in viscosity with respect to temperature is relatively small.

However, since the viscosity of the ultraviolet curable ink increases rapidly when left in a high temperature state for a long time, the ink is left in a high temperature state after recording, and thereafter,
When recording is performed again, there are problems that the ink in the print head has increased in viscosity, the ejection characteristics of the ink are changed, and the nozzles are clogged to cause ejection failure. Also, even when the power of the recording apparatus is cut off immediately after recording, the ink temperature does not drop rapidly,
The viscosity increases as it is exposed to high temperature for a while. Therefore, when the power is turned on thereafter, the same problem as described above occurs.

The present invention solves the above-mentioned problems, and an object of the present invention is to always provide a predetermined ink in an ultraviolet curable ink used at high temperature in order to improve the reliability of ink ejection. An object of the present invention is to provide a recording device capable of recording with viscosity.

[0007]

To achieve this object, according to the present invention, a head portion for recording by an ink jet method using an ultraviolet curable ink, an ink tank containing the ultraviolet curable ink, and First to supply the ultraviolet curable ink from the ink tank to the head portion
It is characterized by comprising a flow passage and a heating means for heating and maintaining the head portion at a predetermined temperature.

Further, when the ultraviolet curable ink heated to a predetermined temperature is left for a predetermined time or more and recording is performed again, the recording is performed after discharging the ultraviolet curable ink in the head portion.

A head portion for recording by an ink jet system, an ultraviolet curable ink, an ink tank for containing the ultraviolet curable ink, and a head portion for supplying the ultraviolet curable ink from the ink tank to the head portion. 1 flow path, heating means for maintaining the head portion at a predetermined temperature, a second flow path for circulating the ultraviolet curable ink from the head portion to the upstream side of the heating means, and a second flow path Is characterized in that a pump is provided.

Further, the ultraviolet curing ink heated to a predetermined temperature is circulated by a pump provided in the second flow path, and the temperature of the ultraviolet curing ink is controlled by a cooling means provided in the second flow path. The feature is that the temperature is quickly lowered to room temperature.

[0011]

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

FIG. 1 is a schematic diagram showing a first example of the present invention.

Reference numeral 1 is a head portion for ejecting ink by an ink jet system for recording, 2 is an ink tank for storing ultraviolet curable ink, and 3 is a first flow path for supplying ink from the ink tank 2 to the head portion 1. is there. The ink tank 2 is a hollow container or a flexible bag, and by keeping the liquid level of the ink in the ink tank 2 within a predetermined range, the ink tank 2 has a predetermined height relative to the ink surface. Ink is supplied to the head unit 1 installed at the height due to the head difference.

The head section 1 is provided with a heating means 4 for heating and maintaining the head section 1 up to a predetermined temperature. 5
Is an ink ejecting means, which can suck ink from the head portion 1 by sucking the nozzle surface (not shown) of the head portion 1.

FIG. 2 is a flow chart showing the recording operation of the first example of the present invention. In the recording operation, first, the ink that has been left at a high temperature in the head after the power was turned off last time is discharged by the ink discharging means 5. Next, the heating means 4
Head unit 1 up to a predetermined temperature at which the ejection of ink drops is good
And heating and maintaining the ink. After that, record,
To continue recording, repeat as it is.

When the recording data is interrupted, the standby state is entered. When recording is restarted, the heated ink is left in the head portion 1 at a high temperature and the viscosity increases, and when recording is performed with the ink in that state, the ejection characteristics such as the speed and size of the ink droplet are increased. May change or the nozzle may be clogged to cause ejection failure.

Therefore, the elapsed time T from the end of the previous recording
Is compared with the time t1 during which the viscosity increases to an extent unsuitable for recording, and if T <t1, recording is performed as it is, but if T> t1, the ink left at high temperature in the head unit 1 Recording is performed after the paper is discharged by the discharging means 5. As a result, it is possible to always record with a predetermined viscosity.

FIG. 3 is a schematic diagram showing a second example of the present invention. Reference numeral 6 is a second flow path for circulating ink from the head portion 1 to the upstream side of the heating means 4 by the pump 7. Reference numeral 8 denotes a valve. If the pump 7 is operated with the valve 8 closed, the ink in the head portion 1 can be circulated. If the valve 8 is opened when the pump 7 is stopped, the ink is supplied to the head portion 1. Is supplied. As a method that does not use the valve 8, the first flow path 3
If the flow path resistance on the upstream side of the connecting portion 9 between the second flow path 6 and the second flow path 6 is set to be larger than that on the downstream side, the second flow path 6 to the first flow path 3
The ink flowing into the ink does not flow to the ink tank 2 side, and when the pump 7 is operated, the first flow path 3 and the second flow path 6
Ink can be circulated in the circulation path formed by and. Reference numeral 10 denotes a cooling means, which can quickly cool the ink when the pump 7 circulates the ink.

FIG. 4 is a flow chart showing the recording operation of the second example of the present invention, and the recording operation will be described. First, before recording, the heating unit 4 heats and maintains the head unit 1 and ink up to a predetermined temperature at which ejection of ink droplets becomes good. After that, recording is performed, and when recording is continued, the recording is repeated as it is.

When the recording data is interrupted and the process shifts to the standby 1, the elapsed time T from the end of the previous recording and the time t at which the cooling is started.
2 is compared, and if the recording is restarted when T <t2, the recording is performed as it is.

On the other hand, if T> t2 before the recording is restarted, the pump 7 and the cooling means 10 are operated to circulate the high temperature ink in the head portion 1 to cool it to the normal temperature. As a result, it is possible to prevent an increase in the viscosity of the ink and to always perform recording with a predetermined viscosity.

Further, the running cost can be further suppressed without discharging the ink. Furthermore, power supply O
When performing FF, power off after cooling ink to room temperature
By doing so, the viscosity of the ink in the head unit 1 does not increase after the power is turned off.

[0023]

According to the present invention, by ejecting the ink, which has been left at a high temperature and has an increased viscosity, by the ink ejecting means before recording, it is possible to always perform recording with a predetermined ink viscosity. It is possible to provide a high recording device.

Further, a flow path for circulating the ink and a cooling means for the ink are provided, and the high temperature ink in the head is circulated during standby to quickly lower the temperature to room temperature, thereby preventing an increase in the viscosity of the ink and always It is possible to provide a recording apparatus with high ink ejection reliability that enables recording with a predetermined ink viscosity.

[Brief description of drawings]

FIG. 1 is a diagram showing a recording apparatus that realizes a first example of the present invention.

FIG. 2 is a flowchart showing a recording operation of the first example of the present invention.

FIG. 3 is a diagram showing a recording apparatus that realizes a second example of the present invention.

FIG. 4 is a flowchart showing a recording operation of a second example of the present invention.

[Explanation of symbols]

1 is a head part, 2 is an ink tank, 3 is a first flow path, 4 is a heating means, 5 is an ink discharging means, 6 is a second flow path, 7 is a pump, 8 is a valve, 9 is a connecting part, 10 is a It is a cooling means.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoru Tobita             Hitachiko, 1060 Takeda, Hitachinaka City, Ibaraki Prefecture             Machine Co., Ltd. F-term (reference) 2C056 EA26 EB38 EC07 EC16 EC19                       EC29 EC43 EC45 FD07

Claims (4)

[Claims] 1. A head section for performing recording by an ink jet method using an ultraviolet curable ink, an ink tank containing the ultraviolet curable ink, and the ultraviolet curable ink is supplied from the ink tank to the head section. A recording apparatus comprising a first flow path and heating means for heating and maintaining the head portion at a predetermined temperature. 2. The recording apparatus according to claim 1, wherein when the ultraviolet curable ink heated to a predetermined temperature is left for a predetermined time or more and recording is performed again, the ultraviolet curable ink in the head portion is discharged. A printing method for a recording apparatus, which comprises performing recording later. 3. A head portion for performing recording by an ink jet system, an ultraviolet curable ink, an ink tank for containing the ultraviolet curable ink, and a head for supplying the ultraviolet curable ink from the ink tank to the head portion. 1 channel,
A heating unit that maintains the head unit at a predetermined temperature, a second flow path that circulates the ultraviolet curable ink from the head unit to an upstream side of the heating unit, and a pump is provided in the second flow path. A recording device characterized by the above. 4. The recording apparatus according to claim 3, wherein the ultraviolet-curable ink heated to a predetermined temperature is circulated by a pump provided in the second flow path, and the cooling means is provided in the second flow path. A method for printing on a recording apparatus, wherein the temperature of the ultraviolet curable ink is rapidly lowered to room temperature.