JP2004050537A - Inkjet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet printer capable of ejecting an ink dot of a fixed size stably over a long term without requiring any cleaning. <P>SOLUTION: Ink is circulated through an ink circulation path 10 and an ink tank 8 is provided with a stirrer 11 in order to sustain a constant dispersion mixing ratio of ink components. The ink tank 8 is also provided with a temperature regulator 12 and a temperature regulator 13 is provided in the vicinity of an ink chamber 7 in order to sustain the temperature of ink 3 at a constant level. An ink dot 14 of a fixed size can be ejected stably over a long term by sustaining constant surface tension and viscosity of ink 3 at an ejection opening 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet printer, and more particularly to an improvement in a function of preventing clogging of an ink ejection port.
[0002]
[Prior art]
In a conventional ink jet printer, when printing is performed for a long time, the ink discharge ports are clogged. Therefore, it is necessary to intermittently clean the ink discharge ports during printing. Since this cleaning is automatically performed, there is no particular inconvenience when the inkjet printer is used in a home or office.
[0003]
[Problems to be solved by the invention]
However, when an inkjet printer is to be installed in a part of an industrial production line to perform printing work, the occasional step of cleaning the ink discharge port to prevent ink clogging significantly reduces productivity. It is a big evil.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet printer capable of stably ejecting ink dots of a fixed size without clogging of ink ejection ports for a long period of time without cleaning.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention relates to an ink jet printer including an ejection unit that ejects ink dots to a target, and an ink tank that supplies ink to the ejection unit. The ink tank has ink stirring means and first temperature adjusting means for keeping the temperature of the ink constant, and the ink chamber of the discharging means keeps the temperature of the ink constant. The gist of the present invention is that a second temperature adjusting means is provided.
[0006]
In the present invention, the ejection means may be provided below the object, so that the ink dots are ejected against gravity.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a basic schematic configuration of an embodiment of the ink jet printer of the present invention. In FIG. 1, reference numeral 1 denotes an LCD glass substrate as a printing target, on which a black matrix 2 is printed, and a color filter is formed by applying ink 3 between the black matrices 2. The inkjet printer 15 of the present invention is applied to a production line of such formed color filters.
[0008]
The ink jet printer 15 is for discharging ink dots 14 for applying the ink 3 between the black matrixes 2 of the glass substrate 1 for LCD, and 4 is disposed opposite to the discharge port 5 and 5 is disposed opposite to the discharge port 4. A hammer 6 is a driving source for vibrating the hammer 5 and is formed of a piezo element or an electromagnetic solenoid element, and 7 is an ink chamber for filling the ink 3 between the discharge port 4 and the hammer 5. This constitutes an ink dot discharging unit.
Reference numeral 8 denotes an ink tank for supplying the ink 3 to the ink chamber 7.
9 is a pump, 10 is a tube, and the tube 10 constitutes an ink circulation path connecting the ink chamber 7 and the ink tank 8.
[0009]
The ink jet printer of the present invention has the above-described configuration, and the ink source 14 is ejected from the ejection port 4 by vibrating the hammer 5 by the driving source 6, and the ink 3 is applied between the black matrix 2 of the glass substrate 1. I do.
[0010]
In the ink jet printer of the present invention, first, the pump 3 is driven to circulate the ink 3 from the ink tank 8 to the ink chamber 7 through the ink circulation path. Further, an agitator 11 for the ink 3 formed by an ultrasonic vibrator or a propeller attached to the ink tank 8 is attached to the ink tank 8 in order to keep the temperature of the ink 3 in the ink tank 8 constant. And a temperature controller 13 mounted near the ink chamber 7 to maintain the temperature of the ink 3 in the ink chamber 7 constant.
[0011]
The temperature controller 12 includes, for example, a temperature detector for the ink 3 and a controller that feeds back the detection signal to supply energy to a heater or a cooler. These can be easily formed by a known technique.
[0012]
The effects of the ink circulation path 10, the stirring device 11, and the temperature controllers 12 and 13 are as follows.
As seen in the past, the cause of clogging of the ink discharge port is that the ink itself contaminates the ink discharge port, and further this ink stain causes the discharge ink to scatter at the discharge port. It has been found to occur. This ink scattering occurs because the size of the ink dot ejected from the ejection port changes, and the change in the size of the ink dot changes the surface tension and viscosity of the ink dot at the ink ejection port. It turned out to happen because.
[0013]
Therefore, in the present invention, the above devices 10 to 13 are used in order to keep the surface tension and the viscosity of the ink 3 at the ink discharge port 4 constant.
That is, the ink 3 is formed by dispersing and mixing a colorant and other various chemical components. In the present invention, the ink in the ink chamber 7 and the ink in the ink tank 8 is circulated by the ink circulation path 10 to form the ink. The temperature controllers 12 and 13 are used to prevent the aggregation and precipitation of the components, to keep the dispersion ratio of the ink components constant by the stirring device 11, and to keep the temperature of the ink 3 constant. Since the dispersion and mixing ratio of the ink components can be kept constant and the ink temperature can be kept constant in this way, the surface tension and viscosity of the ink 3 at the ink ejection port 4 can be kept constant. As a result, the ink dots 14 of a fixed size can be stably ejected for a long period of time. Therefore, it is possible to provide an inkjet printer that does not require cleaning during the printing operation. For example, by applying the inkjet printer to a production line as a means for printing an LCD color filter, productivity can be significantly improved.
[0014]
FIG. 2 shows another embodiment of the ink jet printer according to the present invention, in which an ink discharge means is provided below the glass substrate 1 for LCD, and the discharge ports are formed so as to discharge ink dots from below toward the glass substrate 1. The other configuration is the same as that of the embodiment of FIG.
[0015]
When the ink dots are ejected downward, the degree of change of the ink dots is increased by the influence of gravity, but when the ink dots are ejected downward as in the embodiment of FIG. 2, the change in the size of the ink dots is reduced, It is possible to more stably eject dots of a fixed size.
[0016]
【The invention's effect】
As described above, according to the present invention, it is possible to stably eject ink dots of a fixed size for a long period of time, so there is no need to interrupt printing during the printing operation and perform cleaning, and the present invention is applicable to a production line. As a result, productivity is greatly improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of one embodiment of the present invention.
FIG. 2 is a schematic view of another embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 1 LCD glass substrate 3 Ink 4 Ink ejection port 5 Hammer 7 Ink chamber 8 Ink tank 9 Bump 10 Tube (ink circulation path)
11 stirrer 12 temperature controller 13 temperature controller 14 ink dots

Claims (2)

Discharging means for discharging the ink dots to the object;
An ink tank that supplies ink to the ejection unit,
In an inkjet printer equipped with
Providing an ink circulation path that connects the ejection means and the ink tank,
The ink tank has ink stirring means and first temperature adjusting means for maintaining the temperature of the ink constant, and the ink chamber of the discharging means has a second temperature adjusting means for maintaining the temperature of the ink constant. An ink jet printer comprising: 2. An ink jet printer according to claim 1, wherein said ejection means is provided below the object so that said ink dots are ejected against gravity.

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