JPS62299351A - Printing apparatus - Google Patents

Abstract

PURPOSE:To enhance transfer efficiency and to perform high quality printing, by constituting a heat energy applying means of a heat generating element having such a characteristic that a heat generating temp. distribution of said element corresponding to one picture element has a plurality of heat peaks. CONSTITUTION:A printing apparatus is constituted of a thermal head 11, an ink medium 12, paper 13 to receive transfer, an electromagnet 14, the support layer 15 of an ink medium and a magnetic ink layer 16, and the magnetic ink of the ink medium 12 and the paper 13 to receive transfer are arranged in a non-contact state. A heat generating element 21 corresponding to one picture element of a thermal head has such a structure that a resistor is divided into two. Since the heat generating temp. distribution of the heat generating element has a plurality of heat peaks, the temp. distribution of an ink surface due to the heat conduction from the heat generating element becomes flat in the surface direction.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a non-impact printing device, and more particularly, the present invention relates to a non-impact printing device, and more specifically, it relates to a non-impact printing device that prints thermoplastic magnetic ink by the action of heat and magnetism. The present invention relates to a printing device that obtains two images of characters by transferring them to a transfer medium.

[Conventional technology]

As a compact, low-cost, non-impact printing method, many methods using magnetic ink have been proposed.For example, the method described in Japanese Patent Application Laid-Open No. 52-96541 uses magnetic ink as the ink of the melt thermal transfer method, and heat supply. The ink corresponding to the thermal image is transferred by applying a magnetic attraction force to the ink by a magnetic means provided separately from the thermal image. That is, as shown in FIG.
2 - Transfer paper 35 - Magnet 36 are installed in this order, and the thermoplastic magnetic ink 34 as the ink medium is brought into contact with the transfer paper when heat is applied from the base film 33 surface by a thermal head (directly below the head), and is melted. After adhering the ink to the transfer target, the ink medium is peeled off from the transfer paper,
This is for ink transfer. Furthermore, the magnetic attraction force is used to reduce the probability of molten ink contacting the transfer paper, and to increase the transfer rate to the paper when the ink medium is peeled off, resulting in poor surface smoothness. , was devised so that 9 images of characters can be printed with high quality even on rough paper.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, when the ink medium is peeled off, the ink in the recording area to be transferred is in contact with the base film and the ink in the non-recording area, so it melts and adheres to the transfer paper. This force acts to peel off the ink in the recording area along with the base film from the transfer paper, causing transfer defects. In general thermal transfer recording in Figure 3Cb), FA (ink-to-transfer paper adhesion force) and FB (ink cohesive force), which act as accelerating forces to transfer the ink in the recording section to the transfer paper, and the transfer FB,
FA))] If the relationship between rO and FD always holds true, transcription is completed.

In the figure, 41 is the base film, 42 is the recording part ink,
43 is non-recording ink, and 44 is transfer paper.

In addition, in the above-mentioned conventional technology, when the ink melts, the ink in the recording section is attracted toward the transfer paper by magnetic attraction, so the probability of contact with the transfer paper increases. However, increasing IPA had the effect of increasing the transfer efficiency to some extent. However, when removing the ink medium, the base film still
NPC and FD exist because the ink and the transfer paper are bonded. Therefore, especially when transferring to paper with very poor surface smoothness, yA<yc or FA<FD
The following cases occur, resulting in a problem of poor transfer.

In addition, when printing using the conventional method, if the surface of the transfer medium is rough, there will be areas where the recording dots do not come into contact with the transfer medium and the magnetic ink layer, so that the recording dots will be of a normal shape. was not obtained. In particular, when the transfer medium is paper such as rough paper with very poor surface smoothness (Beck smoothness of 1 to 2 seconds), even if magnetic attraction is used as in the prior art described above, the fibers on the surface will The magnetic ink adhered only to the vicinity of the convex portion, such as the tip, and recording dots with a normal shape could not be obtained.

Further, the same phenomenon is particularly noticeable when the density of recording dots increases, and recording dots with a small area cannot have a normal shape.

Furthermore, in the conventional method, since the plastic magnetic ink 54 and the transfer paper 35 are in contact as shown in FIG. It had escaped to the transfer paper 35.

Therefore, during transfer, a large amount of spacing is caused by the plastic magnetic ink 3
There was a problem in that 4 was lost as heat loss without being thermally melted. (This phenomenon is hereinafter referred to as heat loss)
Furthermore, in the conventional method, as shown in Fig. 3 <a>, the magnetic ink 3
Since the plastic magnetic ink 4 and the transfer paper 35 are in contact with each other, friction, heat conduction, etc. occur between the plastic magnetic ink 34 and the transfer paper 35. For this reason, there is a problem in that the plastic magnetic ink 34 is recorded on the non-recording portion of the transfer paper by a method other than the normal recording means using the thermal head (hereinafter referred to as character smearing).

In addition, in the conventional method, the heating element corresponding to one pixel of the thermal head is composed of a continuous rectangular or elliptical surface, so the temperature distribution in the plane direction of the ink surface has a peak at the center. However, there was a problem in that the ink in the central part was preferentially transferred, and the ink in the peripheral part was likely to cause transfer failure, which in turn deteriorated the image quality. In the figure, 71 indicates a heating element, and 72 indicates an electrode.

Therefore, the present invention aims to solve these problems.
The purpose is to provide a device that can satisfy at least one of the following four items.

1. Ink transfer defects can be eliminated.

Z Normally shaped dots can be recorded on transfer paper with very poor surface smoothness or on film that does not have very high affinity with ink.

Five-character stains can be prevented.

4. To reduce heat loss in printing energy Even if the density of recording dots is increased, dots with a normal shape can be printed.

[Means for solving problems]

The printing device of the present invention has means for applying thermal energy to a recorded portion of thermoplastic magnetic ink and means for generating magnetic attraction force to the ink, and the printing device has a means for applying thermal energy to a recorded portion of the thermoplastic magnetic ink, and a means for generating a magnetic attraction force to the ink. In a printing device that transfers images onto a transfer medium using magnetic attraction, the means for applying thermal energy is a heating element, and the heating temperature distribution of the element corresponding to one pixel has a plurality of thermal peaks. It is characterized by

[Effect]

According to the above configuration of the present invention, the thermoplastic magnetic ink and the transfer medium are not in contact with each other in the non-recording portion of the ink. Therefore, ink transfer is performed by melting the ink in at least the transfer portion by thermal energy, and deforming or flying the ink recording portion due to the magnetic attraction force when the ink is activated by heat. That is, the imprinting on the receiving medium is completed almost simultaneously with the application of thermal energy to the ink, and the process of peeling off the ink medium of the prior art is unnecessary. That is, in FIG. 3Cb), when the ink medium was peeled off, the IF that was preventing the transfer
(:!, Transfer is complete because FD is not present.

In addition, the ink recording area deforms or flies regardless of the shape of the transfer medium, and the ink transfer is performed without contact between the ink medium and the transfer medium, so the surface smoothness is not as smooth as that of rough paper. The transfer efficiency is high, and recording dots with a normal shape can be produced even on a medium with poor transfer characteristics or recording dots with a high density and a particularly small area.

Furthermore, since the ink medium and the transfer medium are not in contact with each other, the non-ink recording area and the transfer medium do not come into contact with each other, so that smearing of characters does not occur. Furthermore, since the ink medium and the transfer medium are not in contact with each other, there is no heat loss due to heat conduction from the ink medium to the transfer medium.

Furthermore, since the heating element according to the present invention has a heat generation temperature distribution having a plurality of heat peaks, the temperature distribution on the ink surface due to heat conduction from the heating element becomes flat in the surface direction,
Transfer defects can be eliminated.

〔Example〕

Embodiment 1 A block diagram of a printing apparatus in this embodiment is shown in FIG. In the figure, 11 is a thermal head, 12 is an ink medium, 15 is a transfer paper, 14 is an electromagnet, 15 is a support layer for the ink medium, 1
6 is a magnetic ink layer.

As shown in the figure, in the present invention, the magnetic ink of the ink medium and the transfer paper are placed in a non-contact manner.

Hole 2 (I-α) shows a plan view of the thermal head used in this example. As shown in the figure, the thermal element corresponding to one pixel has a structure in which a resistor is divided into two. In the figure, 21 indicates a heating element, and 22 indicates an electrode. Also A, B, C
represent the thermal element width, thermal element spacing, and pixel pitch, respectively. Further, the direction of the arrow in the figure is the scanning direction of the head.

In this example, C is 141 μtlL, A and B are 5
A 5 μm thermal head was used.

The ink medium used was a PET (polyethylene terephthalate) film with a thickness of 4 μm coated with a magnetic ink having the composition shown below by a hot melt method so that the ink thickness was 8 μm.

〔composition〕

1゜Magnetite) Fine particles 45wt%2 Carnauba wax 15wt%5 Paraffin wax
S 0wt%4, EV A
4 wt%5, dispersant 1vrt
% & dye 5wt
% transfer conditions are magnetomotive force of electromagnet N = 2000. Thermal energy from the thermal head E” [lL7 mJ
/dot. The transfer paper used had a Peck smoothness of 2 seconds.

The transfer evaluation results are shown in Table 1. In the table, the transfer efficiency is expressed as a percentage of the amount of ink transferred to the transfer paper with respect to the ink corresponding to the thermal element area of the thermal head (thermal element area x ink thickness).

Example λ A printing device similar to Example 1, with a thermal head in the second
The one shown in Figure-b) was used. The element is A=B=231
1 m, O=1'41/Jy3. The ink medium and transfer conditions were the same as in Example 1.

. The transfer evaluation results are shown in Table 1.

Example 5 A printing apparatus similar to that of Example 1 was used, and the thermal head shown in FIG. 2-α) was used. The element is A=40/J
m, B = 30/j m, O: 141
It was set as pm. The ink medium used was the same as in Example 1, and the transfer conditions were N = 1500. I! :=165
InJ/dot.

Comparative example FIG. 3 shows a printing device in this comparative example.

A conventional rectangular thermal head was used. The inter-element pitch was 141μ. The ink medium is Example 1
The thermal energy from the thermal head was set to E=(L 7 mJ/dot).

Table 1. Ink Transfer Planning Results of Examples and Comparative Examples [Effects of the Invention] As described above, according to the present invention, there is provided a means for applying thermal energy to a recording portion of thermoplastic magnetic ink, and a means for applying magnetic attraction force to the ink. In the printing device, the recording portion of the ink is transferred to the transfer medium by magnetic attraction force by controlling the application of thermal energy, the means for applying the thermal energy generates a plurality of heat waves in the heat distribution. Since the heating element has a peak, the temperature distribution in the surface direction of the ink surface during heat application can be set to 7 lats, so that the transfer efficiency can be improved. That is, it is possible to eliminate ink transfer defects. Furthermore, it is possible to perform transfer with excellent reproducibility of dot shapes even on mats that require smoothness, and high-quality printing is possible. Furthermore, by making the ink and the transfer medium non-contact, it is effective to prevent characters from becoming smeared and to reduce printing energy.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIGS. 2(α) and 2(A) are plan views of a thermal head according to an embodiment of the present invention. FIG. 3(α) is a diagram showing a conventional printing device. FIG. 3(b) is a diagram showing the conventional transfer principle. Figure 1

Claims (1)

[Claims] It has a means for applying thermal energy to a recorded portion of thermoplastic magnetic ink and a means for generating a magnetic attraction force to the ink, and by controlling the application of thermal energy, the recorded portion of the ink is transferred to a transfer medium by the magnetic attraction force. What is claimed is: 1. A printing device for transferring image data, wherein means for applying thermal energy is a heating element, and the heating temperature distribution of the element corresponding to one pixel has a plurality of thermal peaks.