JPH04347648A - Thermal inkjet image forming apparatus - Google Patents

Abstract

PURPOSE:To make the apparatus simple and compact, prevent contamination of a recording medium and transfer the recording medium correctly. CONSTITUTION:A thermal head 2 is extended longer than the width of a porous film 1 downstream in the transferring direction of a recording medium 5. A heat generating part 10 is formed also in the extending part. Therefore, an ink 7 adhering to the recording medium 5 and not yet dried is immediately dried by the heat generating part 10.

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 image forming apparatus.

0002

2. Description of the Related Art In a conventional thermal ink jet image forming apparatus, as shown in FIG. The recording medium 5, which is conveyed in the predetermined direction shown by the arrow by the driving roller pair 4, is placed on the surface of the perforated film 1, facing the thermal head 2 with a required gap, and is placed in the micropores of the perforated film 1. The filled liquid ink 6 is ejected toward the recording medium 5 by vapor bubbles generated by heat given by selective driving of the thermal head 2 to form an image on the recording medium 5. In order to dry the undried ink 7 that has adhered to and permeated the rollers 5 , a heater 8 is disposed downstream of the drive roller pair 6 and is provided to dry the ink 9 .

0003

[Problems to be Solved by the Invention] In this conventional thermal ink jet image forming apparatus, a heater is separately provided in order to dry the liquid ink adhered to the recording medium. In order to convey the recording medium with dried ink on it, a pair of drive rolls, one of which is a star wheel, must be used, and the undried ink transferred to this star wheel will stain the white background of the recording medium, and There was a problem in that the star wheel did not have a conveying force, making it impossible to accurately convey the recording medium.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermal ink jet image forming apparatus that can be simplified and miniaturized, can prevent a recording medium from becoming dirty, and can accurately transport the recording medium.

[0005]

[Means for Solving the Problems] In the thermal ink jet image forming apparatus of the present invention, a thermal head is brought into contact with the back side of a perforated film having a required width and has a large number of micropores, while the thermal ink jet image forming apparatus is conveyed to the front side in a predetermined direction. In a thermal inkjet image forming apparatus, recording media are arranged facing each other with a predetermined gap, and liquid ink filled in the micropores is ejected toward the recording medium by vapor bubbles generated by heat applied from a thermal head. , the thermal head extends downstream of the recording medium beyond the width of the perforated film, and this extended portion also has a heat generating portion.

[0006]

[Operation] In the above means, the undried ink deposited on the recording medium is immediately dried by the heat generating section of the extending section of the thermal head.

[0007]

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

FIG. 1 is a side view of essential parts of a thermal ink jet image forming apparatus according to an embodiment of the present invention. In the following description, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

In the thermal ink jet image forming apparatus of this embodiment, a recording medium 5 is conveyed in the direction of arrow A in the figure by a pair of drive rolls 4 made up of ordinary rubber rollers, and a thermal head 2 is positioned downstream of the recording medium 5 in the conveying direction. It is different from the one shown in FIG. 2 in that it extends further than the width of the perforated film 1 toward the film 1, and this extended portion also has a heat generating portion 10.

In the thermal ink jet image forming apparatus having the above structure, the perforated film 1 is rotated in the direction of arrow B in the drawing by a driving means (not shown), and liquid ink 6 is filled into the micropores by an ink filling means (not shown). .

The liquid ink 6 filled in the micropores is ejected from the micropores toward the recording medium 5 by vapor bubbles generated by the selective driving of the thermal head 2, and is deposited on the recording medium 5, and is deposited on the recording medium 5 as required. form an image.

Undried ink 7 immediately after being ejected from the micropores
is immediately heated and dried by the heat generating part 10 of the extension part of the thermal head 2, and becomes dry ink 9 and is applied to the recording medium 5.
sticks to.

[0013]

Effects of the Invention As explained above, the present invention requires a thermal head to be brought into contact with the back surface of a perforated film having a required width and a large number of micropores, and a recording medium that is conveyed in a predetermined direction on the front surface. In a thermal inkjet image forming apparatus, the thermal inkjet image forming apparatus is arranged such that the liquid ink filled in the micropores is disposed facing each other with a gap therebetween and is ejected toward the recording medium by vapor bubbles generated by heat applied from the thermal head. It extends further than the width of the perforated film toward the downstream side of the recording medium, and this extension part also has a heat generating part, so that the undried ink adhering to the recording medium is immediately removed from the thermal head. Since drying is carried out by the heat generating part of the dryer, there is no need for a separate heater as in the conventional case, and the apparatus can be made simple and compact. In addition, ordinary rubber rollers or the like can be used as the means for conveying the recording medium, eliminating the need for a conventional star wheel, which has the effect of preventing stains on the recording medium and enabling reliable conveyance of the recording medium.

[Brief explanation of the drawing]

FIG. 1 is a side view of essential parts of a thermal inkjet image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of main parts of a conventional thermal inkjet image forming apparatus.

[Explanation of symbols]

1 Perforated film 2 Thermal head 4 Drive roller pair 5 Recording medium 6. Liquid ink 7 Undried ink 9 Dry ink 10 Heat generating part

Claims (1)

[Claims] Claim 1: A thermal head is brought into contact with the back surface of a perforated film having a desired width and has a large number of micropores, while a recording medium to be conveyed in a predetermined direction is disposed on the surface of the perforated film with a predetermined gap therebetween, and The liquid ink filled in the micropores
In a thermal inkjet image forming apparatus in which vapor bubbles generated by heat applied from a thermal head are ejected toward a recording medium, the thermal head extends downstream in the conveyance direction of the recording medium beyond the width of the perforated film. A thermal inkjet image forming apparatus characterized in that the extended portion also has a heat generating portion.