JPH05147246A - Thermal printing apparatus - Google Patents

Abstract

PURPOSE:To attempt to improve operating characteristics and to decrease cost of expandable supplies by using a toner being practiced in use in an electrophotographic system as a printing medium instead of using an ink ribbon in a printing apparatus using a thermal head. CONSTITUTION:A toner layer 10 is formed on a developing sleeve 9 and when a print paper 18 passes through the developing sleeve 9, a uniform toner layer is transferred on the print paper 18 by applying an electric voltage having reverse polarity to the toner and the toner on the print paper is welded on the print paper 18 with a heat generated in a heat-sensitive head 20 to form a print and unnecessary toner which has not been used for printing is removed from the print paper 18 by means of a recovery roller 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive printing apparatus using a heat-sensitive head, and is characterized by printing using toner used in electrophotography instead of the conventional ink ribbon. ..

[0002]

2. Description of the Related Art In a conventional thermal printer, an ink ribbon coated with ink is arranged on a thermal head, the ink on the ink ribbon is melted by heat generated by the thermal head, and the melted ink is transferred to paper. As a result, a predetermined print can be written on the paper.

[0003]

However, in this method, the ink ribbon scanned by the thermal head is often useless because it cannot be reproduced even if it is printed or not. That is, since the entire ink ribbon is replaced by only using a part of the ink ribbon surface, the cost per sheet is high and the operability is poor because the ink ribbon must be replaced frequently.

[0004]

SUMMARY OF THE INVENTION The thermal printing apparatus of the present invention which solves the above problems uses a toner having a small particle size, which is used in electrophotographic development, instead of an ink ribbon to print. The feature is that a uniform toner layer is formed on the paper, the toner is directly fused to the printing paper in a predetermined printing shape by the heat of the thermal head, and unnecessary toner not used for printing is removed from the printing paper. ..

[0005]

According to this structure, it is possible to print with toner without using an ink ribbon. Therefore, it is sufficient to replenish only the used toner, which improves the operability and eliminates the waste of waste and the price of consumables. It can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.

In FIG. 1, a frame 1 also serving as a paper guide
Holds the paper transport rollers 2 and 3. The printing paper 1P is separated one by one by the paper feed roller 4 and the paper separating pad 5 and enters the inside of the apparatus. Move in the direction of arrow D.

The developing unit 8 is provided with a developing sleeve 9 for conveying toner, a toner 10, a doctor blade 11 for uniformizing a toner layer, and a lid 12 for opening and closing when replenishing toner. .. Also,
The developing unit 8 has a collecting roller 13 for collecting toner that is no longer needed after printing, a scraper 14 for cleaning the toner on the collecting roller 13,
A conveyor belt 15 for conveying the collected toner toward the developing sleeve 9 and a scraper 16 for cleaning the toner on the conveyor belt 15 are provided.

The rotations of the developing sleeve 9, the collecting roller 13, and the conveying belt 15 are indicated by arrows A, B, and respectively.
It is the direction of C. That is, the toner on the collecting roller 13 is separated from the collecting roller 13 by the scraper 14, the separated toner is conveyed to the developing sleeve 9 side by the conveying belt 15, and the conveying belt 1 is conveyed by the scraper 16.
The toner is separated from No. 5 and accumulated in the toner reservoir 8a and used again.

One end of the upper paper guide 17 is swingably fixed to the frame 1 by a shaft 19, and a thermal head 20 for printing is fixed to the other end of the upper paper guide 17, and a spring 21 is used when printing is not performed. Is pushed upward in the drawing so as not to contact the printing paper 18.

The surface of the developing sleeve 9 is a conductor, the surface of which is electrically grounded, and when the first paper detection sensor 22 detects that the printing paper 18 has come to the lower part of the developing sleeve 9. , A voltage having a polarity opposite to that of the toner charge is applied to the corona wire 23 provided so as to face the developing sleeve 9 via the printing paper 18, and the toner 10 on the developing sleeve 9 is evenly transferred to the printing paper 18. Let Further, the toner on the developing sleeve 9 which has been printed and has disappeared is replenished by the toner reservoir 8a by rotating in the direction of arrow A, and a uniform toner layer is formed again on the developing sleeve 9.

A printing paper 18 to which this toner is evenly attached.
Is further moved and is detected by the second paper detection sensor 24, the plunger 25 is driven to pull the upper paper guide 17 downward against the urging force of the spring 21. The heat sensitive head 20 is pressed against and the print signal is applied to the heat sensitive head 20 in this state, and the heat generated in the heat sensitive head 20 is used to fuse the toner 10 on the print paper 18 to print on the print paper 18. Is.

The surface of the collecting roller 13 is a conductor, and the surface of the collecting roller 13 is electrically grounded so that the printing paper 18
When the toner reaches the position of the collecting roller 13, a voltage having the same polarity as that of the toner 10 is applied to the corona wire 26 arranged so as to face the collecting roller 13 via the printing paper 18, thereby printing on the printing paper 18. The toner not used for the transfer is transferred to the collecting roller 13, and the printed print paper 18 is discharged by the paper transport roller 3 and the drive roller 7.

[0014]

As described above, in the thermal printing apparatus of the present invention, the developing toner for electrophotography is used instead of the conventional ink ribbon, so that printing can be performed by only replenishing the toner consumed by printing. Therefore, it is possible to realize a long life and a low price of consumables.

[Brief description of drawings]

FIG. 1 is a sectional view of a thermal printer according to an embodiment of the present invention.

[Explanation of Codes] 1 Frame 2, 3 Paper Conveying Roller 8 Developing Unit 9 Developing Sleeve 10 Toner 13 Collecting Roller 15 Conveying Belt 18 Printing Paper 20 Thermal Head 22 Paper Detection Sensor 23 Corona Wire 24 Paper Detection Sensor 26 Corona Wire

Claims (2)

[Claims] 1. A heat sensitive head is brought into contact with a print paper on which toner is evenly attached, and the heat generated from the heat sensitive head causes the toner on the print paper to be fused to the print paper, and the toner on the unnecessary print paper which is not printed. A thermal printing device characterized in that a predetermined printing operation is performed by removing the. 2. A thermal printer according to claim 1, wherein unnecessary toner not to be printed is collected and the collected toner is attached again to the printing paper.