JPH0664277A - Thermal transfer recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the generation of missing dots due to the paper powder or dust on paper, the penetration of ink due to the perforation of an ink holding strip and the generation of the wavy pattern of printing. CONSTITUTION:A thermal transfer recording apparatus is equipped with the ink replenishing member 18 provided in an ink tank 17 storing hot-melt ink solid at room temp. and increased in flowability by heating and having a heater 11 and forming the ink film of the hot-melt ink 12 on one surface of an annular ink holding strip 1 and the ink smoothing member 15 provided in the ink storage tank 17 and smoothing the ink film. Further, a thermal transfer recording part 8 locally heating and melting the ink film by a thermal head 3 to transfer the same to recording paper 2 and the ink scraping member 16 positioned on this side of the ink replenishing member 18 with respect to the running direction of the ink holding strip 1 provided in the ink storage tank 17 to scrape off the residual ink film on the ink holding strip are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording apparatus,
In particular, the present invention relates to a thermal transfer recording device capable of printing on a recording medium such as plain paper using a reproducible ink film.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a conventional thermal transfer recording apparatus. Referring to FIG. 4, in this conventional thermal transfer recording apparatus, the ink holding band 1 is formed by joining both ends of a band-shaped heat-resistant film made of polyimide or polyaramid to form a ring, and a wax and a resin on the outer surface thereof. Hot-melt ink 1 mixed with carbon black
2 is applied. A part of the outer side surface of the ink holding band 1 is in contact with the platen roller 5 by sandwiching the recording paper 2 by the spring force of the head pressure spring 6 via the thermal head 3 of the thermal transfer recording unit 8. The guide rollers 4a, 4b and 4c guide the traveling of the ink holding band 1. The ink holding band 1 moves in the direction of arrow A by driving the platen roller 5 and the capstan roller 7 during printing by the thermal head 3. The reinking mechanism 100 includes a heater 11, a base 13, an ink smoothing member 15, an ink storage tank 17, and an ink replenishing member 18. Ink storage tank 1
Reference numeral 7 is made of a metal such as aluminum having good thermal conductivity, and contains the heat-meltable ink 12 therein. The heater 11 installed on the bottom surface of the ink storage tank 17 and maintaining a constant temperature slightly higher than the melting point of the heat-meltable ink 12 melts the heat-meltable ink 12 in the ink storage tank 17 into a liquid state. Ink replenishing member 18
On the surface of a stainless steel or aluminum roller is roughened by processing such as sandblasting, shallow knurled grooves are formed, or cell grooves are formed by etching after plating with chrome etc. . The ink smoothing member 15 is provided in the vicinity of the ink replenishing member 18, and is an aluminum round bar having a smooth surface or a tightly wound stainless steel wire wound around the surface thereof. Aluminum fixed to the bottom surface of the ink storage tank 17 or the like. It is fixed on a base 13 made of a material having good heat conductivity.

Next, the operation of this conventional example will be described. First, a drive signal is applied to the thermal head 3 from a control circuit (not shown), a part of the ink holding band 1 is heated based on the drive signal, and the hot-melt ink 12 is transferred onto the recording paper 2. At this time, the platen roller 5 rotates in the printing direction, that is, the arrow A direction, and the ink holding band 1 is sequentially moved by the capstan roller 7 and is conveyed to the reinking mechanism 100. This reinking mechanism 100
Then, the heat-meltable ink 12 that is melted in a liquid state in the ink storage tank 17 and is filled in the concave portion formed on the surface of the ink replenishing member 18 is rotated by the ink replenishing member 1 by the ink replenishing member 18. Supplied on the surface. The ink film on the surface of the ink holding band 1 supplied by the ink replenishing member 18 has uneven thickness because the surface of the ink replenishing member 18 is grainy. Further, due to a phenomenon called tack due to viscoelasticity of the heat-meltable ink 12, the surface of the ink film becomes rough, and the recording quality such as blurring of characters due to uneven density or transfer failure is impaired. Therefore, a smooth ink film is formed by rubbing the surface of the ink film with the ink smoothing member 15 provided near the ink replenishing member 18 and supplied with heat from the ink storage tank 17. The heat-meltable ink 12 scraped off here flows down from the ink smoothing member 15 and is collected in the ink storage tank 17. In the above-mentioned conventional example, as shown in FIG. 5, the residual ink film 21 on the surface of the ink holding band 1 is mixed with the hot-melt ink 12 attached to the surface of the ink replenishing member 18 to be in a molten state to form a new ink film. is doing.

In this conventional thermal transfer recording apparatus, as shown in FIG. 5, when a defective portion of the residual ink film 21 on the surface of the ink holding band 1 is replenished with a new heat-melting ink 12, the ink is formed. The bubbles 30 are mixed in the molten ink by the air in the defective portion being entrained together. The bubbles 30 remain on the surface of the ink film 23 even after the entire ink film 23 is smoothed by the ink smoothing member 15.
When this portion is transferred to the recording paper 2 by the thermal head 3, there is no ink and white spots appear.

Further, as shown in FIG. 4, the recording paper 2 and the ink holding band 1 are in close contact with each other when printed by the thermal head 3. At this time, if paper dust or dust adheres to the surface of the recording paper 2, it may be transferred to the surface of the ink holding band 1. This paper dust or dust is the ink replenishment member 18
When an ink film is formed in the state where the ink film is mixed with the heat-meltable ink 12 above, paper powder or dust adheres to the surface of the ink film. When this portion is transferred to the recording paper 2 by the thermal head 3, white spots are produced as described above. When a hard foreign substance such as metal powder adhering to the surface of the recording paper 2 is mixed in the ink film, the ink holding band 1 is thin when printed by the thermal head 3, and therefore there is a hole due to the foreign substance. There is a risk that the hot-melt ink 12 will leak from the holes.

Further, as shown in FIG. 6, the thermal head 3 and the ink replenishing member 18 are required to have a certain distance due to the structure. Therefore, if lateral tension in the ink retaining band 1 is not uniform during this time, 20 wavy lines on the ink retaining band 1 itself
Occurs. Ink holding band 1 in which 20 of these waves are generated
When the hot-melt ink 12 is applied on the surface, an ink film is formed along the wavy shape 20, so that the ink film thickness becomes uneven. When this portion is printed by the thermal head 3, a difference in density appears, resulting in a wavy pattern in the printing.

[0006]

A thermal transfer recording apparatus of the present invention stores a heat-meltable ink whose fluidity increases when heated in a solid state at room temperature and is provided in an ink storage tank having a heating means to hold an annular ink. An ink replenishing means for forming an ink film of the heat-meltable ink on one surface of the band, an ink smoothing means provided in the ink storage tank for making the ink film smoother, and the ink film by a thermal head. Thermal transfer recording means for locally heating and melting and transferring to a recording medium; and a residual portion on the ink holding zone which is provided in the ink storage tank before the ink replenishing means with respect to the running direction of the ink retaining zone. And an ink scraping unit for scraping the ink film.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. Referring to FIG. 1, in the thermal transfer recording apparatus of this embodiment, the ink holding band 1 is formed by joining both ends of a band-shaped heat-resistant film made of polyimide or polyaramid to form a ring, and a wax and a resin on the outer surface thereof. The hot-melt ink 12 mixed with carbon black is applied. A part of the outer side surface of the ink holding band 1 is in contact with the platen roller 5 by sandwiching the recording paper 2 by the spring force of the head pressure spring 6 via the thermal head 3 of the thermal transfer recording unit 8.
The guide rollers 4a, 4b and 4c guide the traveling of the ink holding band 1. The ink holding band 1 moves in the direction of arrow A by driving the platen roller 5 and the capstan roller 7 during printing by the thermal head 3. The reinking mechanism 10 includes a heater 11, bases 13 and 14, an ink smoothing member 15, an ink scraping member 16, an ink storage tank 17, and an ink replenishing member 18. The ink storage tank 17 is made of a metal such as aluminum having good thermal conductivity, and contains the heat-meltable ink 12 therein. Ink storage tank 17
The heater 11 installed on the bottom surface of the heater 11 and maintaining a constant temperature slightly higher than the melting point of the hot-melt ink 12 melts the hot-melt ink 12 in the ink storage tank 17 into a liquid state. The ink replenishment member 18 is formed by roughening the surface of a stainless steel or aluminum roller by a process such as sandblasting, forming a shallow knurled groove, or plating the surface of a chromium plate and then etching the cell groove. Is forming. The ink smoothing member 15 is provided in the vicinity of the ink replenishing member 18, and is an aluminum round bar having a smooth surface, or a thin wire of stainless steel closely wound around the surface, such as aluminum fixed to the bottom surface of the ink storage tank 17. It is fixed on a base 13 made of a material having good heat conductivity. The ink scraping member 16 is made of an aluminum round bar having a smooth surface, and the base 14 having good thermal conductivity such as aluminum is provided in front of the ink replenishing member 18.
Fixed on top of.

Next, the operation of this embodiment will be described. First, a drive signal is applied to the thermal head 3 from a control circuit (not shown), a part of the ink holding band 1 is heated based on the drive signal, and the hot-melt ink 12 is transferred onto the recording paper 2. At this time, the platen roller 5 rotates in the printing direction, that is, the direction of arrow A, and the ink holding band 1 is sequentially moved by the capstan roller 7 and is conveyed to the reinking mechanism 10. In the reinking mechanism 10, first, the untransferred ink film on the outer surface of the ink holding band 1 is scraped off by the ink scraping member 16. Next, the ink replenishing member 1 melted in a liquid state in the ink storage tank 17
The ink replenishing member 1 in which the heat-meltable ink 12 filled in the recess formed on the surface of the roller 8 rotates together with the ink holding band 1.
The ink is supplied to the surface of the ink holding band 1 by means of 8. The ink film on the surface of the ink holding band 1 supplied by the ink replenishing member 18 has uneven thickness because the surface of the ink replenishing member 18 is grainy. Further, due to a phenomenon called tack due to viscoelasticity of the heat-meltable ink 12, the surface of the ink film becomes rough, and the recording quality such as blurring of characters due to uneven density or transfer failure is impaired. Therefore, a smooth ink film is formed by rubbing the surface of the ink film with the ink smoothing member 15 provided near the ink replenishing member 18 and supplied with heat from the ink storage tank 17. The heat-meltable ink 12 scraped off here flows down from the ink smoothing member 15 and is collected in the ink storage tank 17. Next, a more detailed description will be given with reference to FIG. Ink film 21 that is not transferred by the thermal head 3 remaining on the surface of the ink holding band 1
The ink scraping member 16 is scraped off. The ink replenishment member 18 applies the ink 12a on the surface of the ink holding band 1 from which the ink film 21 has been scraped off, and a new ink film 22 is formed.
To form. The ink film 22 has a non-uniform film thickness due to the surface roughness of the ink replenishing member 18 and the ink pulling caused by the tack phenomenon like the ink 12c. The ink film 22 is melted again by coming into contact with the ink smoothing member 15, and a uniform ink film 23 is formed in a portion between the ink holding band 1 and the ink smoothing member 15. The excess ink 12b is scraped off by the ink smoothing member 15 and collected in the ink storage tank 7.

Since all of the residual ink film 21 on the surface of the swollen ink holding band 1 is removed by the ink scraping member 16, when a new hot melt ink 12 is replenished to the defective portion of the ink. Bubbles like ink film 23
It is not mixed in. Further, even if the paper powder or dust adhering to the surface of the recording paper 2 moves to the ink holding band 1 side, this paper powder or dust is scraped off by the ink scraping member 16 together with the ink film, so that it is newly added. Ink film 23 formed
No paper dust or dust adheres to the surface. Recording paper 2
Even if a hard foreign matter such as metal powder adheres to the surface, it is removed by the ink scraping member 16 in the same manner as described above. It is possible to prevent the hot-melt ink 12 from leaking out. Further, since the ink scraping member 36 is located between the thermal head 3 and the ink replenishing member 18, it is possible to prevent the corrugation of the ink holding band 1 from occurring during this time. Therefore, it is possible to prevent a uniform ink film from being formed on the ink holding band 1 and to prevent a wavy pattern from being generated in printing.

In this embodiment, the ink scraping member 16 is a round bar and is fixed on the base 14. However, as shown in FIG. 3, the ink scraping member 16 is made of a material having a smooth tip and good thermal conductivity. It may be 16 '.

[0011]

As described above, according to the present invention,
It is provided in an ink storage tank having a heating means for storing a hot-melt ink whose fluidity increases when heated at room temperature as a solid, and is located in front of the ink replenishing means with respect to the running direction of the annular ink holding zone Equipped with an ink scraping device that scrapes off the residual ink film, it prevents white spots from occurring due to paper powder and dust on the paper, permeation of ink due to perforations in the ink retaining band, and the occurrence of wavy print patterns. To do.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a detailed view of the reinking mechanism of FIG.

FIG. 3 is a detailed view of another embodiment of the reinking mechanism of FIG.

FIG. 4 is a configuration diagram of a conventional example.

FIG. 5 is a detailed view of the reinking mechanism of FIG.

FIG. 6 is a diagram showing the ripples of an ink holding band generated in a conventional example.

[Explanation of symbols]

 1 Ink Retaining Band 2 Recording Paper 3 Thermal Head 4a, 4b, 4c Guide Roller 5 Platen Roller 6 Head Pressure Spring 7 Capstan Roller 8 Thermal Transfer Recording Section 10 Reinking Mechanism 11 Heater 12 Thermal Melting Ink 13, 14 Base 15 Ink Smoothing Member 16, 16 'Ink scraping member 17 Ink storage tank 18 Ink replenishing member

Claims (1)

[Claims] 1. A heat-meltable ink whose fluidity increases when heated in a solid state at room temperature to store the heat-meltable ink in an ink storage tank having a heating means and having a heating means. Ink replenishing means for forming an ink film,
Ink smoothing means provided in the ink storage tank for smoothing the ink film, thermal transfer recording means for locally heating and melting the ink film by a thermal head and transferring it to a recording medium, and in the ink storage tank A thermal transfer recording apparatus, which is provided in front of the ink replenishing means with respect to the traveling direction of the ink holding zone, and scrapes off the ink film remaining on the ink holding zone.