JPH0761012A - Melt type heat transfer print system - Google Patents

Abstract

PURPOSE:To provide a melt type heat transfer print system, with which high resolution and high image quality multiple tone image can be obtained with hot-melt ink. CONSTITUTION:Ink ribbon 1, which is produced by produced by applying hot- melt ink prepared by mixing paint having the particle diameter (phi) and hot-melt binder on thin film 1b by the thickness T corresponding to the spread of 2.5g/m<2> or less, and porous surfaced recording medium 2, which is produced by forming porous surfaced layer 2a having a large number of pores with the pore diameter (k) on base material 2b are conveyed between a thermal head 18 and a platen roller 3. At this time, the relation among the pore diameter (k) of the porous surfaced layer 2a, the particle diameter (phi) of the paint and the coating thickness T are set to satisfy an inequality: phi<=k<=4T. Further, the melt area of the ink 1a is controlled by controlling pulse fed to the thermal head 18 from gradation to gradation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusing type thermal transfer printing system for performing multi-gradation expression using a hot-melting ink.

[0002]

2. Description of the Related Art In the case of performing multi-gradation expression using a heat-melting ink, generally, a multi-gradation image is obtained by a dither method using a plurality of pixels (matrix) or a heating resistor is small. A multi-tone image is obtained by the heat concentration method using a special thermal head (see, for example, Imaging Industry Publishing Co., Imaging Part 1, p103 to p108).

[0003]

In the conventional fusion type thermal transfer printing system, when a plurality of pixels are used, the resolution is deteriorated and the image quality is remarkably deteriorated, and the cost is high when a special thermal head is used. There is a problem. Therefore, the present invention has been made in view of such problems, and a fusion type capable of obtaining a multi-gradation image of high resolution and high image quality by using a thermal head used in an ordinary thermal transfer printing apparatus. An object is to provide a thermal transfer printing system.

[0004]

In order to solve the above-mentioned problems of the prior art, the present invention provides a heat-meltable ink prepared by mixing a paint having a particle diameter φ and a heat-meltable binder on a thin film. An ink ribbon coated to a thickness T with a coating amount of 0.5 g / m ² or less, a surface porous recording medium having a surface porous layer having a large number of pores with a pore diameter k formed on a substrate,
A thermal head in which a plurality of heating resistors having a temperature gradient having the highest temperature in the central portion and a lower temperature in the peripheral portion at the time of heating are formed in a line, and the heating resistor by controlling the amount of electricity to the thermal head A gradation control circuit for controlling the melted area of the ink by the body, the ink of the ink ribbon is brought into close contact with the surface porous layer of the surface porous recording medium, and the thermal head is connected to the ink ribbon. While pressing from the thin film side,
A fusion-type thermal transfer printing system for obtaining a multi-gradation image on the surface porous recording medium by controlling the melting area of the ink by the gradation control circuit, wherein the surface porosity of the surface porous recording medium is -Type thermal transfer characterized in that the relationship between the hole diameter k of the pores of the conductive layer, the particle diameter φ of the coating material on the ink ribbon, and the ink coating thickness T on the ink ribbon is φ ≦ k ≦ 4T. A printing system is provided.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fusion type thermal transfer printing system of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an enlarged view of a main part of the fusion type thermal transfer printing system of the present invention, and FIG.
3 is a diagram showing the relationship between the temperature and viscosity of the ink of the ink ribbon used in the fusion type thermal transfer printing system of the present invention, FIG.
FIG. 4 is a diagram showing an ink ribbon used in the fusion type thermal transfer printing system of the present invention, FIG. 4 is a diagram showing the relationship between the ink ribbon heating time and the ink density when the ink application amount is changed, and FIG. 5 is the surface porosity. FIG. 6 is a sectional view for explaining the recording medium, and FIG. 6 is a pore diameter k of pores of the surface porous layer in the surface porous recording medium and a particle diameter φ of the paint in the ink ribbon.
And FIG. 7 are views for explaining the relationship between the ink coating thickness T of the ink ribbon, FIG. 7 is a side view showing the configuration of an example of a main part of the fusion type thermal transfer printing system of the present invention equipped with a pressing means, and FIG. FIG. 9 is a diagram showing the relationship between the pressing force applied by the pressing means and the permeation rate into the surface porous recording medium. FIG. 9 is a block diagram showing the configuration of an example of a gradation control circuit used in the fusion type thermal transfer printing system of the present invention. FIG. 11 is a diagram for explaining the operation of the gradation control circuit shown in FIG.

In the present invention, by examining from various angles such as a thermal head, an ink ribbon, a recording paper, a heating control method, etc., an extremely high resolution image can be obtained by using a thermal head used in a general thermal transfer printing apparatus. It is an object of the present invention to provide a fusion type thermal transfer printing system capable of obtaining a high quality multi-tone image. In the fusion type thermal transfer printing system of the present invention, as shown in FIG. 1, a surface porous recording medium 2 and an ink ribbon 1 which will be described in detail later are superposed and conveyed between a platen roller 3 and a thermal head 18. , The thermal head 18 is pressed against the platen roller 3 and the heating resistor of the thermal head 18 is heated to transfer the ink 1a of the ink ribbon 1 to the surface porous recording medium 2
Transfer to.

The heating resistor of the thermal head 18 is often formed in a rectangular shape, as is well known.
The temperature distribution of the heat generating resistor has the highest temperature gradient in the central portion of the heat generating resistor and becomes lower toward the periphery, and the portion above the melting temperature of the ink melts. The melting area of the ink can be controlled by utilizing this temperature gradient. In addition, the ink 1a of the ink ribbon 1
As shown in FIG. 2, if the ink whose viscosity becomes lower as the temperature becomes higher at a temperature higher than the melting point is used, the ink viscosity in the central portion becomes low due to the temperature distribution of the heating resistor, and the viscosity becomes high in the peripheral portion. The amount of ink permeated into the porous recording medium 2 correspondingly increases in the central portion and decreases in the peripheral portion. Therefore, when the current flowing through the heating resistor is changed according to the gradation of expression, the permeation amount and the permeation area of the ink are controlled at the same time, which facilitates multi-gradation expression.

By the way, the surface temperature of the recording medium fluctuates depending on the thickness of the ink ribbon, and the thinner the temperature is, the closer the temperature gradient becomes to the temperature distribution of the heating resistor and the steeper the temperature gradient. Therefore, the thickness of the ink ribbon should be thin. Since the practical thinness limit of the ink ribbon film is about 3.5 μm, a thin film having a thickness of 3.5 μm is generally used for the ink ribbon. The thickness of the ink ribbon is determined by the film and the ink applied on the film. Therefore, the surface temperature distribution of the recording paper can be made closer to the temperature distribution of the heating resistor as the amount of ink applied is smaller.

3A and 3B are views showing an ink ribbon 1 used in the fusion type thermal transfer printing system of the present invention. FIG. 3A is a perspective view thereof, and FIG. 3B is a sectional view thereof. As shown in FIG. 3A, the ink ribbon 1 has a plurality of colors (for example,
Ink 1a (formed by mixing a paint and a heat-melting binder), which is a set of yellow (Y), magenta (M), cyan (C), and black (K), is continuous in the longitudinal direction. Further, as shown in FIG. 3B, the heat-meltable ink 1a is applied on the thin film 1b having a thickness of 3.5 μm having a back coat 1c (0.05 μm), for example. It is a thing. Further, FIG. 4 shows the relationship between the heating time of the ink ribbon applied with the ink having a thickness of 3.5 μm and the density (OD) of the ink on the recording paper, the ink application amount of 2.0 g / m ² , 2. 5 g / m ² ,
The figure shows the case of 3.0 g / m ² . With a conventional ink ribbon, for example, 3.0 g on a 3.5 μm film
Although the amount of ink applied was / m ² or more, it was found from FIG. 4 that multi-gradation expression could be achieved by setting the amount of ink applied to the film to 2.5 g / m ² or less.
The thickness of the film is 3.5 μm here,
It was also confirmed that there was no problem if the thickness was 4.5 μm or less.

Next, the recording medium used for printing was a surface porous recording medium, and the transfer characteristics of the ink were examined. As shown in FIG. 5, the surface porous recording medium 2 (surface porous plastic sheet) used in the present invention has a thickness of, for example, about 10 μm.
The surface porous layer 2a is formed on the substrate 2b. Then, when the heat-meltable ink 1a is transferred to the surface porous recording medium 2, the ink 1a will have pores of the surface porous layer 2a when the surface roughness (pore diameter) of the surface porous layer 2a is a predetermined condition. It was confirmed that it was most suitable for multi-tone expression by being transferred and absorbed in the part of. The surface porous recording medium (surface porous plastic sheet) is put to practical use and sold by Nisshinbo Industries, Inc. under the name Peachcoat.

Here, the pore diameter of the surface porous layer 2a in the surface porous recording medium 2 will be examined. The pore diameter of the pores of the surface porous layer 2a is k, the particle diameter of the paint of the ink 1a on the ink ribbon 1 is φ, and the coating thickness of the ink 1a on the ink ribbon 1 is T. As shown in FIG. 6A, assuming that the hole diameter k is equal to the ink coating thickness T and the pores of the surface porous layer 2a are regularly arranged at the same intervals, the ink 1a is melted and the surface porous layer 2a is formed. In the state where all the pores have penetrated by the capillary phenomenon, ink columns having a depth of 2T are formed in each pore. If the amount of ink applied is 2.0 g / m ² (= about 2.0 μm), about 4 μm
It becomes the ink pillar of. At this time, the ink 1a that has permeated the pores
Respectively contact the thin film 1b within the range of the hole diameter k = T, and since there are inner walls of pores on both sides of the ink 1a contacting the thin film 1b, the adhesive force of the ink 1a to the thin film 1b: ink The adhesion of the pores of 1a to the inner wall is 1: 4. Therefore, the ink 1a is peeled off from the thin film 1b and transferred to the pores of the surface porous layer 2a.

As shown in FIG. 6B, even when the hole diameter k is four times the ink application thickness T and the pores of the surface porous layer 2a are regularly arranged at the same intervals, the ink 1a is In the state of being melted and completely permeating into the pores of the surface porous layer 2a by the capillary phenomenon, an ink column having a depth of 2T is formed in each pore. If the amount of ink applied is 2.0 g / m ² (= about 2.0 μm), the ink column will be about 4 μm. However, at this time, the ink 1a that has penetrated into the pores contacts the thin film 1b within the range of the pore diameter k = 4T, and since the ink 1a contacting the thin film 1b has inner walls of the pores on both sides. , Thin film 1b of ink 1a
Adhesion force to the inner wall of the ink 1a is 1: 1. However, since the cooling after the ink is melted starts from the surface porous recording medium 2 side away from the heat source, if the ink ribbon 1 and the surface porous recording medium 2 are separated from each other immediately after the thermal head 18 finishes heating, the adhesive force is increased. Is stronger on the pore side, the ink 1a is peeled from the thin film 1b and transferred to the pores of the surface porous layer 2a.

Ink 1 in the ink ribbon 1
Considering that even the melted ink 1a does not penetrate into the pores having the pore diameter k smaller than the particle diameter φ of the paint of a, and considering the above-mentioned examination, the surface porous layer 2a in the surface porous recording medium 2 is considered. The diameter k of the pores, the particle diameter φ of the paint on the ink ribbon 1, and the ink 1 on the ink ribbon 1
If the relation of a with the coating thickness T is set to φ ≦ k ≦ 4T, it is possible to satisfactorily perform ink penetration according to the heating amount without waste.

Using the surface porous recording medium 2 in such a state, the ink 1a of the ink ribbon 1 is brought into close contact with the surface porous layer 2a of the surface porous recording medium 2 and the thermal head 1
8 is pressed against the platen roller 18 from the side of the film 1b of the ink ribbon 1, and the amount of electricity to the thermal head 18 is controlled to utilize the temperature gradient of the heating resistor described above, whereby the ink generated by the heating resistor is If the melting area of the ink 1a is controlled, the ink 1a is easily and instantly transferred and absorbed from the ink ribbon 1 to the surface of the recording medium and the inside thereof in accordance with the heating amount of the thermal head 18 at the time of the melting, so that high resolution and high image quality can be obtained. It was found by experiments that a gradation image can be obtained.

If the pressing force of the thermal head 18 against the platen roller 3 is small, the ink 1a may not be sufficiently transferred and absorbed in the pores of the surface porous recording medium 2 and may remain on the surface thereof. FIG. 7 is an improvement of the problem in such a case. In FIG. 7, 1 is an ink ribbon, 2 is a surface porous recording medium, 3 is a platen roller, 4 is a plunger which is a pressing means, and 18 is a thermal head. The shaft is pulled up in the direction of the arrow by applying a voltage to the plunger 4, and the thermal head 18 is pressed against the platen roller 3 via the ink ribbon 1 and the surface porous recording medium 2. As described above, when the ink is transferred to the surface porous recording medium, by applying a predetermined pressure by the pressing means, the ink permeates into the pores of the surface porous recording medium, resulting in a multi-stage image with extremely high resolution and high image quality. It was found by experiment that a tonal image can be obtained.

FIG. 8 shows the relationship between the pressing force (kg) by the pressing means and the permeation rate (%) into the surface porous recording medium. In addition, here, the film thickness of the ink ribbon is 3.5 μm, the ink application amount is 2.0 g / m ² , the hole diameter of the surface porous recording medium is 1 to 10 μm, and the print length of the thermal head is 260 mm (26 cm). It is a result of an experiment in which the heating resistor interval of the thermal head is 84.5 μm (12 dots / mm) and the heating resistor shape is a partial glaze. For example, a thermal head used in a facsimile has a heating resistor spacing of about 8 dots / mm, and in order to obtain a visually sufficient high resolution and high quality multi-gradation image, the heating resistor spacing is An interval of 8 dots / mm or less is required. Conventionally, the pressing force of the thermal head having the above print length is usually 4 to 6 kg. According to the experiment, the transfer of the ink is unstable at 8 kg or less, and the transfer is often only on the surface.
It was confirmed that the ink penetrated satisfactorily without fail at 0 kg or more. From 9 kg / 26 cm = 0.346 ... 0.35 k per unit length of the print length of the thermal head
It is considered that good results are exhibited at g / cm or more.

Next, the structure and operation of an example of a gradation control circuit used in the fusion type thermal transfer printing system of the present invention for controlling the melted area of the ink by controlling the amount of electricity supplied to the thermal head will be described. To do. In FIG. 9, the interface circuit 11 receives input data Id obtained by processing image data obtained by an image input device such as a television camera with a personal computer or the like. The input data Id is obtained by adding control data required by the printing device to the image data and represents the number of gradations corresponding to the image to be printed. Of the input data Id input to the interface circuit 11, the image data is the buffer memory 1
2 and the control data is input to the print control circuit 13. The print control circuit 13 generates various control signals according to the operation of the printing apparatus. Here, the printing device refers to a printing unit including the thermal head 18 and an ink ribbon.

The print control circuit 13 supplies a start signal to the address counter 14 in accordance with the operation of the printing apparatus, and determines the operating state of the printing apparatus, that is, the color of the ink on the ink ribbon, which heating pattern is used for printing, and the like. Corresponding selection signal TC
Is supplied to the linearity conversion table 17. The address counter 14 generates the address AD by the start signal,
It is supplied to the buffer memory 12. According to the address AD of the buffer memory 12, the thermal head 1 is read from the input image data as shown in FIGS.
The data Di (D1 to Dn) for one line of 8 is sequentially output to the parallel / serial conversion circuit 15. Note that FIG.
FIG.

Now, the data Di for one line of the thermal head 18 output from the buffer memory 12 will be described. As described above, consider a case where the gradation number m is expressed using the thermal head 18 having the heating resistors (R1 to Rn) formed in a line shape. When expressing the gradation number m, the heating amount (heating pulse) is given to each of the heating resistors R1 to Rn in m steps.
Therefore, as for the data Di for one line output from the buffer memory 12, as shown in FIG. 11, the data D1 to Dn corresponding to the heating resistors R1 to Rn are the first data Di.
The gradation is sequentially output from the mth gradation. Then, the data Di of these lines (L1, L
2, ...) are sequentially output. In general, 256 is often used as the expression gradation number m, and 0 to 255 is also used in this embodiment.
There are 256 gradations.

The address counter 14 outputs a pulse to the gradation counter 16 every time one line of data Di of the thermal head 18 is read from the buffer memory 12. The gradation counter 16 generates a gradation signal ST based on the input pulse, as shown in FIGS. 10 and 11, and supplies it to the parallel / serial conversion circuit 15 and the linearity conversion table 17. As can be seen from FIG. 10, the gradation signal ST is 1 for the first gradation data Di, 2 for the second gradation data Di, and m for the mth gradation data Di. It is a signal that represents a number.

Then, the parallel / serial conversion circuit 15 receives the respective data of the data Di (D1 to Dn) and the gradation signal S.
Comparing with T, as shown in FIG. 10 and FIG.
If Dn is greater than or equal to the gradation signal ST (Di ≧ S
T) 1, if the data Di is smaller than the gradation signal ST (D)
A comparison signal Ci of i <ST) 0 is generated and input to the shift register 19 in the thermal head 18. A clock CK as shown in FIG. 10 is input to the shift register 19 from the address counter 14, and the shift register 1
The comparison signal Ci input to 9 is shifted by this clock CK, and the comparison signal Ci for one line is arranged in the shift register 19. In FIGS. 10 and 11,
For each gradation number, D1 = m, D2 = 3, D3 = 2
This is an example when D4 = 1, ..., Dn-1 = m-2, Dn = m-3. In the fourth gradation, since the gradation sequence of D1 to Dn is compared with "4", the comparison signal Ci in the fourth gradation is Ci.
Becomes "1000 ... 11" as shown in FIG.

Further, as shown in FIGS. 10 and 11, the address counter 14 stores in the latch circuit 20 and the linearity conversion table 17 each time one line of data Di of the thermal head 18 is read from the buffer memory 12. The load pulse LD is output. The comparison signal Ci for one line arranged in the shift register 19 is the load pulse L
It is stored in the latch circuit 20 by D. Latch circuit 20
The comparison signal Ci output by the above is input to the gate circuit 21.

By the way, the gate circuit 21 heats the heating resistors R1 to Rn by the comparison signal Ci (ON).
Generates a signal indicating whether or not to heat (off). That is,
When the comparison signal Ci is 1, it is on, and when it is 0, it is off. The heating resistor R1 from the first gradation to the m-th gradation shown in FIG.
~ Rn corresponding to the comparison signal Ci determines the heating state of each heating resistor R1 ~ Rn. In FIG. 11, heating resistors R1, R2, R3, R4, Rn- are shown.
Heating period tR1, tR2, tR3 for each of R1 and Rn
tR4, tRn-1, and tRn are shown. Since the heating resistors R1 to Rn start to be heated at the time when the data Di of the next gradation is output, the heating by the first gradation starts from the second gradation. For example, the heating resistor R1
Since the comparison signal Ci is “1111 ... 11”, the heating resistor R1 is heated (ON) at the first to fourth gradations, the m−1th gradation and the mth gradation, and the heating resistor R2. Since the comparison signal Ci is “1110 ... 00”, the heating resistor R2
Is heating (ON) from the 1st gradation to the 3rd gradation, m-1th
It is not heated (OFF) in the gradation and the m-th gradation.

On the other hand, the linearity conversion table 17 has a selection signal TC, an address AD, a gradation signal ST, and a load pulse L.
D is input and the heating time setting signal S as shown in FIG.
Output B. The ON period of the heating time setting signal SB is set to a period corresponding to each gradation. Therefore, the heating period t of each of the heating resistors R1 to Rn described above is
R1 to tRn are gated by turning on / off the heating time setting signal SB in each gradation, and the heating resistors R1 to R1
Rn is actually heated while the heating time setting signal SB is on in the heating period determined by the comparison signal Ci. For example, the heating period of the heating resistor R1 is as shown in FIG.
Is set as indicated by the broken line. As described above, the heating period of each of the heating resistors R1 to Rn is finely set by the heating time setting signal SB in each of the first gradation to the m-th gradation.

The gate circuit 21 receives the comparison signal Ci input from the latch circuit 20 and the heating time setting signal S input from the linearity conversion table 17 as described above.
An ON pulse is generated in the heating period of each heating resistor determined by B and this pulse is generated by the driver circuit 2
Supply to 2. Therefore, the shift register 19, the latch circuit 20, and the gate circuit 21 operate as pulse output means for outputting a pulse for heating the heating resistor of the thermal head 18. Based on this pulse, the driver circuit 22 applies a current to the heating resistors R1 to Rn to heat the ink ribbon and transfer the applied ink to a recording medium to print an image. As a result, the amount of heat applied to the ink ribbon can be set finely, and multi-gradation expression can be realized using the heat-meltable ink.

[0026]

As described above in detail, in the fusion-type thermal transfer printing system of the present invention, 2.5 g of a heat-meltable ink obtained by mixing a paint having a particle diameter φ and a heat-meltable binder on a thin film. / M ² or less and a thickness T applied to the ink ribbon, a surface porous recording medium in which a surface porous layer having a large number of pores having a pore diameter k is formed on a substrate, The thermal head in which a plurality of heating resistors having a temperature gradient with the highest temperature and the lower temperature in the peripheral portion have a temperature gradient is formed, and by controlling the energization amount to the thermal head, the melting area of the ink by the heating resistors is controlled. Since it is equipped with a gradation control circuit for controlling, it is possible to use a thermal head used in a normal thermal transfer printing device without using a special thermal head, and to obtain extremely high resolution and high image quality multi-gradation. An image can be obtained, and the relationship between the pore diameter k of the pores of the surface porous layer in the surface porous recording medium, the particle diameter φ of the paint on the ink ribbon and the ink coating thickness T on the ink ribbon can be expressed as φ ≤k≤4T
Therefore, there is a feature that ink permeation according to the heating amount can be favorably performed without waste.

Further, if a pressing means for pressing the thermal head at a rate of 0.35 kg / cm or more per unit length of printing length is provided, the ink sufficiently penetrates into the pores of the surface porous layer of the surface porous recording medium. It is possible to obtain a more stable multi-gradation image with extremely high resolution and high image quality.

[Brief description of drawings]

FIG. 1 is an enlarged view of a main part of the present invention.

FIG. 2 is a diagram showing the relationship between the temperature and viscosity of the ink of the ink ribbon used in the present invention.

FIG. 3 is a diagram showing an ink ribbon used in the present invention.

FIG. 4 is a diagram showing the relationship between the ink ribbon heating time and the ink density when the ink application amount is changed.

FIG. 5 is a cross-sectional view for explaining a surface porous recording medium.

FIG. 6 is a diagram for explaining the relationship between the pore diameter k of the pores of the surface porous layer in the surface porous recording medium, the particle diameter φ of the paint on the ink ribbon, and the ink coating thickness T on the ink ribbon. .

FIG. 7 is a side view showing a configuration of an example of a main part of the present invention including a pressing unit.

FIG. 8 is a diagram showing a relationship between a pressing force by a pressing unit and a penetration rate into a surface porous recording medium.

FIG. 9 is a block diagram showing a configuration of an example of a gradation control circuit used in the present invention.

FIG. 10 is a diagram for explaining the operation of the gradation control circuit shown in FIG.

FIG. 11 is a diagram for explaining the operation of the gradation control circuit shown in FIG.

[Explanation of symbols]

 1 Ink Ribbon 1a Ink 1b Thin Film 2 Surface Porous Recording Medium 2a Surface Porous Layer 2b Base Material 3 Platen Roller 4 Plunger (Pressing Means) 18 Thermal Head

Claims (2)

[Claims] 1. A heat-meltable ink obtained by mixing a paint having a particle diameter φ and a heat-meltable binder on a thin film is 2.5 g /
An ink ribbon applied to a thickness T with a coating amount of m ² or less, a surface porous recording medium in which a surface porous layer having a large number of pores with a pore diameter k is formed on a substrate, and a center when heated. A thermal head in which a plurality of heating resistors having a temperature gradient that is the highest in a part and a temperature that is lower in a peripheral part are formed in a line, and by the heating resistor by controlling an energization amount to the thermal head, A gradation control circuit for controlling a melted area of the ink, the ink of the ink ribbon is brought into close contact with the surface porous layer of the surface porous recording medium, and the thermal head is attached to the thin film side of the ink ribbon. A fusion-type thermal transfer print sheet for obtaining a multi-gradation image on the surface porous recording medium by further pressing and controlling the melting area of the ink by the gradation control circuit. The relationship between the pore diameter k of the pores of the surface porous layer in the surface porous recording medium, the particle diameter φ of the coating material in the ink ribbon, and the ink coating thickness T of the ink ribbon, A fusion type thermal transfer printing system characterized in that φ ≦ k ≦ 4T. 2. The fusion type thermal transfer printing system according to claim 1, wherein the thermal head is pressed with a pressing force of 0.35 kg / cm or more per unit length of printing length.