JPH04347652A - Thermal inkjet ink printer - Google Patents

Abstract

PURPOSE:To reliably fill minute holes in a porous film with ink by making the liquid ink contained in a porous cylindrical body ooze out to the outer peripheral surface of the cylindrical body with utilizing the capillarity. CONSTITUTION:A porous film 2 having many minute holes 1 is wound around porous cylindrical bodies 3, 4 formed of a ceramic sintered body or a porous material such as a sponge or the like and containing a liquid ink supplied from an upper opening. At the same time, a thermal head 5 is held in touch with the rear face of the porous film 2. As one porous cylindrical body is rotated in the direction indicated by arrow A, the liquid ink oozing out to the outer peripheral surface of the cylindrical body because of the capillarity is supplied into the minute holes 1 of the porous film 2 in close contact with the cylindrical body, which is further turned to vapor bubbles by the heat of the thermal head 5 and, discharged to a recording paper. Thus, printing is executed. Since the liquid ink is allowed to ooze to the outer peripheral surface of the porous cylindrical body by utilizing the capillarity, the ink can be positively supplied into the fine holes of the porous film.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal ink jet printer, and more particularly to a thermal ink jet printer with improved ink filling means.

0002

2. Description of the Related Art In a conventional thermal inkjet printer, as shown in FIG. At the same time, the thermal head 2 is placed on the back side of the perforated film 22.
5 and an inking roller 28, which is an ink filling means immersed in liquid ink 27 in an ink reservoir 26, is in contact with the printing subsystem, and the liquid ink 27 is filled into the micropores 21 of the perforated film 22. The inking roller 28 is rotated by the friction force generated by the movement of the perforated film 22 by the drive roller 23, and the inking roller 28 is placed opposite the thermal head 25 with a required gap on the surface of the perforated film 22. When printing on recording paper (not shown), the liquid ink 27 filled in the micropores 21 is directed toward the recording paper by vapor bubbles generated by heat applied from the thermal head 25, as shown in FIG. This is done by ejecting the droplets 29.

0003

[Problems to be Solved by the Invention] In this conventional thermal inkjet printer, liquid ink is filled into the micropores of the perforated film by rotating an inking roller due to the frictional force generated by the movement of the perforated film. Therefore, if the frictional force changes, the rotation of the inking roller becomes irregular, and there is a problem in that sufficient ink is not filled.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermal inkjet printer that can ensure the filling of liquid ink into micropores.

[0005]

[Means for Solving the Problems] In the first thermal inkjet printer of the present invention, a thermal head is brought into contact with the back side of a perforated film having a large number of micropores, while a recording paper is placed on the front side with a required gap. A thermal inkjet printer in which liquid ink filled in micropores by contact with the ink filling means of the perforated film arranged opposite to each other is ejected toward the recording paper by vapor bubbles generated by heat applied from the thermal head. In,
The ink filling means is a perforated cylindrical body made of a porous material and containing liquid ink.

A second thermal inkjet printer is the same as the first thermal inkjet printer in which a perforated film is wrapped around the outer periphery of the bottomed cylindrical body.

[0007]

[Operation] In the first means, the liquid ink oozes out to the outer peripheral surface by capillary action.

[0008] In the second means, the liquid ink that has seeped out onto the outer circumferential surface by capillary action is further filled in advance into the micropores of the perforated film by capillary action.

[0009] As the porous material, a porous ceramic sintered body, a sponge, etc. are used.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of the main parts of a thermal ink jet printer according to a first embodiment of the present invention.

[0012] This thermal inkjet printer has the following features:
Both ends of a perforated film 2 having a large number of micropores 1 are fixed to the outer periphery of a pair of bottomed cylindrical bodies 3 and 4 (see FIG. 2) serving as ink filling means, and one end (see FIG. A print subsystem is provided, which is wound around the outer periphery of the bottomed cylindrical body 3 (on the left) over a required length, and in which a thermal head 5 is brought into contact with the back surface of the perforated film 2.

Each of the bottomed cylindrical bodies 3 and 4 is made of a porous material such as a porous ceramic sintered body or a sponge.
Liquid ink (not shown) supplied from the upper opening is accommodated therein. And each bottomed cylindrical body 3,
4 is provided rotatably in any direction around a vertical axis by a rotation drive device (not shown) connected to the outside of each bottom portion.

In the thermal inkjet printer configured as described above, when the other bottomed cylinder 4 rotates in the direction of arrow A in the figure, the perforated film 2 also moves in the direction of arrow B and wraps around the other bottomed cylinder 4. At the same time, one of the bottomed cylindrical bodies 3 also rotates in the direction of arrow A. At that time, the perforated film 2 that had been wrapped around one of the bottomed cylindrical bodies 3
The liquid ink that has come into close contact with the film and seeped out onto the outer circumferential surface due to capillary action is further filled in advance into the micropores 1 of the perforated film 2 due to capillary action.

Similarly, the perforated film 2 wound around the other bottomed cylindrical body 4 is also filled with ink by moving in the direction opposite to the arrows A, B, and C shown in the figure.

The filled liquid ink is ejected as ink droplets toward recording paper (not shown) by vapor bubbles generated by heat applied from the thermal head 5, thereby printing on the recording paper. However, bidirectional printing is also possible due to the rotational movement of the bottomed cylinders 3 and 4 in both directions.

FIG. 3 is a perspective view of the main parts of a thermal ink jet printer according to a second embodiment of the present invention.

[0018] This thermal inkjet printer has the following features:
A loop-shaped perforated film 7 having a large number of micropores 6 is
A print subsystem is supported in a loop by a rotatable bottomed cylinder 8 serving as ink filling means, a drive roller 9, and a plurality of guide rollers 10, and a thermal head 11 is in contact with the back surface of a perforated film 7. It is equipped with

The bottomed cylindrical body 8 is made of a porous material such as a porous ceramic sintered body or a sponge, similar to the aforementioned bottomed cylindrical bodies 3 and 4, and has an upper opening inside. Liquid ink (not shown) supplied from the unit is stored therein.

In the thermal ink jet printer having the above structure, the bottomed cylindrical body 8 is moved by the frictional force generated by the movement of the perforated film 7 by the drive of the drive roller 9.
rotates, liquid ink seeps out from the outer peripheral surface of the bottomed cylindrical body 8 due to capillary action and fills the micropores 6 of the perforated film 7, and this filled liquid ink is heated by the thermal action of the thermal head 11. It is ejected and printed on recording paper.

[0021]

As explained above, in the present invention, the means for filling ink into the micropores of a perforated film is a bottomed cylindrical body made of a porous material containing liquid ink. As the ink seeps out to the outer surface,
This has the effect of ensuring that the micropores are filled with liquid ink.

Furthermore, since the perforated film is wrapped around the outer circumference of the bottomed cylindrical body, the liquid ink that has seeped out onto the outer peripheral surface due to capillary action is further filled in the micropores of the perforated film by capillary action. This has the effect of making it possible to more reliably fill the liquid ink into the micropores.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of a thermal inkjet printer according to a first embodiment of the present invention.

FIG. 2 is a simplified perspective view of the ink filling means of the thermal inkjet printer of FIG. 1;

FIG. 3 is a perspective view of main parts of a thermal inkjet printer according to a second embodiment of the present invention.

FIG. 4 is a perspective view of main parts of a conventional thermal inkjet printer.

FIG. 5 is a perspective view showing the concept of ink ejection.

[Explanation of symbols]

1,6 Micropore 2,7 Perforated film 3, 4, 8 Bottomed cylindrical body 5,11 Thermal head

Claims (2)

[Claims] Claims: 1. A thermal head is brought into contact with the back surface of a perforated film having a large number of micropores, and a recording paper is placed on the front surface facing each other with a required gap between the perforated film and the ink filling means. In a thermal inkjet printer in which liquid ink filled in micropores by contact is ejected toward recording paper by vapor bubbles generated by heat applied from a thermal head, the ink filling means is a porous structure containing liquid ink. A thermal inkjet printer characterized by a bottomed cylindrical body made of wood. 2. The thermal ink jet printer according to claim 1, wherein a perforated film is wound around the outer periphery of the bottomed cylindrical body.