JP3104269B2 - Hot melt inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt ink jet printer having two ink tanks.

[0002]

2. Description of the Related Art Conventionally, a hot-melt type ink-jet printer of this type has a large-capacity ink tank installed in a main body of the apparatus, a small-capacity ink tank provided in a movable print head, and these ink tanks. , And the solid ink is heated by the heaters to completely melt the solid ink. Then, the completely melted ink is pressurized in the large-capacity ink tank, and is sent to the small-capacity ink tank of the print head via a flexible tube connecting the respective ink tanks.

[0003]

However, in the above-mentioned system in which the ink is fed under pressure, if the solid ink is not completely melted, the ink in the semi-molten state has a high viscosity, so that even if the ink is pressed, the ink is not melted. Could not be sent to a small capacity ink tank. Therefore, the ink in the large-capacity ink tank is heated by the heater at a temperature sufficiently higher than the melting point of the ink, and is completely melted. Further, in order to keep the ink in a molten state also in the flexible tube, it is necessary to further provide a heater in the flexible tube. When the ink is melted and held at a high temperature for a long time, a component having a large specific gravity among various components of the ink precipitates on the bottom of the ink tank or the flexible tube, and the print quality is deteriorated due to a change in the ink component. There is a problem that deterioration is caused, and there is a problem that energy consumption for heating the heater is large and the device is broken down by generated heat.

[0004] In order to prevent this, it is conceivable to heat the ink only when necessary so as not to keep the ink in a molten state for a long time. However, there is a problem in that the print processing speed becomes longer and the print processing speed becomes slower.

[0005] The present invention has been made to solve the above-mentioned problems, and by reducing the heating temperature,
In addition to preventing print quality deterioration due to changes in ink components,
It is an object of the present invention to provide a hot-melt ink jet printer that can reduce energy consumption, reduce device failure due to heat, and does not slow down printing processing speed.

[0006]

In order to achieve this object, a hot-melt ink jet printer according to the present invention is provided.
A first ink tank installed in the apparatus main body, a first heater provided in the first ink tank, for heating the ink at a temperature that keeps the ink in a flexible solid state, and a printing direction. A print head that reciprocates, a second ink tank provided in the print head, and a flexible heater by the first heater.
When the solidified ink is required, the first ink
A screw supplying to the second ink tank from ink, provided in said second ink tank, the first i
Flexible solid state ink supplied from the ink tank ,
A second heater for melting the liquid at a higher temperature than the first heater .

[0007]

The first ink tank according to the present invention having the above-described structure stores ink which has been made into a flexible solid state by the first heater. Screw is inside the first ink tank
A flexible solid state ink is supplied into the second ink tank when needed. Further, the second ink tank has a liquid at a temperature higher than a temperature at which the flexible solid state ink supplied by the screw is kept in the flexible solid state by the second heater.
Jo in melted houses. The print head is supplied with the liquid ink melted in the second ink tank, and performs printing by ejecting the liquid ink.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a first ink tank 3 for replenishing solid ink is fixed to the main body 1 of the hot melt type ink jet printer of the present invention. As shown in FIG. 1, the upper wall 4 of the first ink tank 3 is detachable, and solid ink is supplied by removing the upper wall 4. In addition, a first heater 5 is provided below the first ink tank 3.
The solid ink is heated at a temperature (about 80 ° C.) for keeping the ink 7 in a soft state and keeping the ink 7 in the soft state as it is. Also, on the lower side of the first ink tank 3,
There is provided a cylindrical ink guide 11 having a tapered end for guiding the ink 7 in the first ink tank 3 to the second ink tank 9. A supply port 13 for supplying the ink 7 to the second ink tank 9 is opened at the tip of the ink guide 11. A screw 15 having a spiral shape is provided in the ink guide 11.
Is rotatably provided, and is driven by a well-known drive source (not shown).

As shown in FIG. 2, the main body 1 is provided with a rotatable platen 17 for holding and feeding the recording paper 16, and two platens 17 in parallel with the platen 17. Guide rails 18 are arranged. A carriage 19 that is guided by the two guide rails 18 and reciprocates along the longitudinal direction (the direction of the arrow) of the platen 17 is provided. The carriage 19 has the second ink tank 9 and the carriage 19. An ink ejecting head 20 for ejecting ink is mounted. A receiving port 21 is provided above the side surface of the second ink tank 9, and a supply port 1 of the first ink tank 3 is provided below the receiving port 21.
An ink receiver 23 is provided for receiving the ink 7 supplied from the ink tank 3 and guiding the ink 7 to the inside of the second ink tank 9. The supply of the ink 7 from the first ink tank 3 to the second ink tank 9 is performed at the left end position of the printing range, that is, the ink guide 11 of the first ink tank 3 as shown in FIG. This is performed at a position where the ink receiver 23 of the ink tank 9 matches.

In the lower part of the second ink tank 9, FIG.
As shown in (2), a second heater 25 is provided, and the second heater 25 heats the ink 7 supplied to the second ink tank 9 higher than the temperature in the first ink tank 3. The liquid ink 27 is melted at a temperature (about 100 to 120 ° C.), and the liquid ink 27 is kept as it is. Further, a thermistor 31 is provided at a predetermined position in the second ink tank 9 in order to detect the height of the liquid surface of the liquid ink 27. The detection of the liquid level by the thermistor 31 is performed by using the thermistor 3.
Utilizing the fact that the electrical resistance value differs depending on whether 1 is in the liquid or in the air, it is determined whether it is in the liquid or in the air. When it is determined that the thermistor 31 is in the air,
Since the ink in the second ink tank 9 is insufficient,
Printing is interrupted, and the carriage is moved to the ink supply position to supply the ink. The supply of the ink is performed by rotating the screw 15, and the thermistor 3 is supplied.
The liquid level of the ink in the second ink tank 9 is kept substantially at a predetermined position until the predetermined time elapses after it is determined that 1 is in the liquid, and then the rotation of the screw 15 is stopped and the process is terminated. I do. Then, the printing operation is restarted after the supply of the ink is completed. A supply port 29 for supplying the molten liquid ink 27 in the second ink tank 9 to the ink jet head 20 is provided on a lower side of the second ink tank 9.
The liquid ink 27 is supplied to the ink jet head 20 by a known method of supplying liquid ink.

Next, the ink supply operation of the hot-melt type ink jet printer thus configured will be described.

First, the upper wall 4 of the first ink tank 3 is removed to supply solid ink. Then, the solid ink supplied to the first ink tank 3 is heated by the first heater 5 to keep the ink in a flexible state.
Then, the liquid ink 27 in the second ink tank 9 is
The presence of the liquid ink at a predetermined position in the second ink tank 9 is detected by a circuit using the thermistor 31, and when the liquid ink 27 is not detected, the printing is temporarily stopped and the ink guide of the first ink tank 3 is stopped. The carriage 19 is moved to a position where 11 and the ink receiver 23 of the second ink tank 9 coincide with each other, and the screw 15 is rotated there to supply ink. The amount of ink to be supplied is such that the supply of ink is continued until a predetermined time elapses after the thermistor 31 determines that the thermistor 31 is in the liquid, and the liquid level of the ink 27 in the second ink tank 9 is substantially at a predetermined position Quantity. At this time, the ink 7 pushed out of the first tank tank 3 by the screw 15 is supplied directly into the second ink tank 9 or guided to the ink receiver 23. In this manner, the ink 7 supplied to the second ink tank 9 has already been heated by the first heater 5, so that the second heater 25 It reaches the melting temperature determined by the heating temperature. The molten liquid ink 27 in the second ink tank 9 is supplied from the supply port 29 to the head 20 by a known method of supplying liquid ink, and is wound from the head 20 to the platen 17 according to print information. The recording paper 16 is ejected.

The present invention is not limited to the embodiment described in detail above, and various changes can be made without departing from the gist of the present invention.

For example, in this embodiment, only one type of ink is shown. However, when several types of ink are used, the first ink tank 3 and the Second ink tank 9 and first heater 5
And a second heater 25 and a screw 15. The ink guide 1 of the first ink tank 3 is provided for each color.
The ink 7 is supplied from the first ink tank 3 to the second ink tank 9 at a position where 1 and the ink receiver 23 of the second ink tank 9 match.

[0016]

As described above, according to the hot melt ink jet printer of the present invention, the ink in the first ink tank is supplied to the first heater.
Stored in a more flexible solid state, with screws
Into the second ink tank when needed in a flexible solid state
The supplied, second heater is supplied, flexible solid state
Of the second ink into a liquid state, and the print head
Since the printing is performed by ejecting the liquid ink in the tank,
The heating temperature of the first heater can be reduced. So
Therefore, it is possible to prevent the deterioration of the printing quality due to the change of the ink component, reduce the energy consumption, reduce the trouble of the apparatus due to the heat, and have the effect that the processing speed of the printing is not reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an ink supply unit of a hot melt inkjet printer according to the present invention.

FIG. 2 is a schematic diagram of the entire hot-melt ink jet printer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 3 First ink tank 5 First heater 9 Second ink tank 15 Screw 20 Ink jet head 25 Second heater

Claims (1)

(57) [Claims] 1. A hot-melt ink-jet printer which performs printing using an ink which is solid at normal temperature and melts when heated, comprising: a first ink tank installed in an apparatus main body; and a first ink tank provided in the first ink tank. A first heater that heats the ink at a temperature that keeps the ink in a soft solid state, a print head that reciprocates in a printing direction, a second ink tank provided in the print head, and the first heating. a screw supplying to the second ink tank from the first ink tank when necessary the ink which is in soft solid state by the vessel, is provided in the second ink tank, the first ink
The ink of soft solid state supplied from the tank, the
A hot-melt ink jet printer, comprising: a second heater for melting the liquid at a higher temperature than the first heater .