JPS6260665A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To provide thermal transfer printing which can be applied to even common paper by attracting thermomelting ink containing magnetic material to printing paper with a magnetic force generated by a magnetic force generating means. CONSTITUTION:An electromagnet 17 is internally installed in a platen 12 as a magnetic force generating means. This electromagnet 17 is so constituted as to generate a magnetic force of prearranged strength at position opposed to a thermal head 11 on a platen 12. Thermomelting ink 14a containing magnetic powder is applied evenly on one side of a base film 14b, thus forming an ink sheet 14. The magnetic powder is of extremely fine grain, so that trouble may occur due to the entrainment of magnetic powder during the formation of ink sheet 14 and thermal transfer. In addition, printing paper 13 fed into a thermotransfer printer 10 in an overlapped form together with an ink sheet 14 is of a common type.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal transfer printing device, and particularly to a thermal transfer printing device that can print even on printing paper having poor surface smoothness.

2. Description of the Related Art With the recent spread of personal computers and the like, the demand for printers has been increasing. Various printing methods have been proposed for printers, one of which is known as a thermal transfer printing device shown in FIG. The thermal transfer printing device 1, which is not shown in the figure, generally includes a thermal head 2. An ink sheet 4 coated with a thin layer of heat-melting ink 3. It consists of a platen 5, etc., and with the thermal head 2 pressed against the platen 5 with an appropriate pressure, the printing paper 6 and the ink sheet 4 are overlapped and passed between the thermal head 2 and the platen 5,
The thermofusible ink 3 is activated by the heat generated by the thermal head 2, and the activated thermofusible ink 3 is transferred to the printing paper 6 via the above-mentioned pressing force, thereby performing printing. .

Problems to be Solved by the Invention Generally, in a thermal transfer printing device 1 having a thermal head 2, high-quality paper or lightly coated paper is used as printing paper.

This is because high-quality paper and lightly coated paper have good surface smoothness and good solid ink transfer efficiency. Here, FIG. 8 shows an enlarged view of a state in which plain paper, which has a surface smoothness inferior to that of the above-mentioned high-quality paper and lightly coated paper, is passed between the thermal head 2 and the platen 5 of the thermal transfer device @1. As shown in the figure, the plain paper 7 has irregularities on its surface. Thermal head 2
is pressed against the platen 5 with a predetermined pressure, the unevenness of the plain paper 7 causes unevenness on the ink sheet 4, and the ink sheet 4 and the space between the thermal head 2 and the ink sheet 4 and between the ink sheet 4 and the plain paper 7. Gaps 8 and 9 are created between them. Due to this gap 8, the heat-melting ink 3 is actually melted in the heated portion of one thermal head 2 (indicated by the arrow L1 in the figure) when the ink sheet 4 is attached to the thermal head 2.
(indicated by arrow L2 in the figure). Furthermore, if the melted portion of the heat-melting ink 3 is located at a position where a gap 9 exists between the ink sheet 4 and the plain paper 7, the heat-melting ink 3 will not adhere to the plain paper 7. When the plain paper 7 is used in the thermal transfer printing device 1 as described above, the heat-melting ink 3 is not attached to the plain paper 7 in correspondence with the thermal head 2, and therefore the surface such as the inexpensive plain paper 7 is There is a problem in that printing paper that does not have good smoothness cannot be used in the thermal transfer printing device 1.

Therefore, in the present invention, a magnetic material is mixed into the hot melt ink, and a magnetic force generating means is provided on the platen and the platen and the thermal head, and the magnetic force generated by the magnetic force generating means is used to print the hot melt ink mixed with the magnetic material. It is an object of the present invention to provide a thermal transfer printing device that solves the above-mentioned problems by drawing it to paper.

Means for Solving the Problems In order to solve the above problems, in the first invention, a transfer paper coated with heat-melting ink and a printing paper are superimposed and sent between the thermal head and the platen, and the thermal In a thermal transfer printing device that performs printing by heating a head to melt hot melt ink and attaching it to printing paper, a magnetic material is mixed in the hot melt ink applied to the transfer paper, and a platen is mixed with a magnetic material. A magnetic force generating means was installed.

When the heat-melting ink is attached, the magnetic force generating means generates a magnetic force to draw the heat-melting ink toward the platen to which the printing paper is attached.

In addition, in the second invention, a transfer paper coated with heat-fusible ink and printing paper are superimposed and sent between the thermal head and the platen, and the thermal head is heated to melt the heat-fusible ink and print the paper. In a thermal transfer printing device that prints by adhering it to paper, a magnetic material is mixed into the heat-melting ink applied to the transfer paper, and the thermal head is provided with a first magnetic force generating means, and a second magnetic force generating means is provided on the platen. A magnetic force generating means was provided. First, when the hot-fusible ink is melted, a first magnetic force generating means generates a magnetic force, and the hot-fusible ink is first drawn toward the thermal head, and then when the hot-fusible ink is attached, a second magnetic force generating means generates a magnetic force. It is configured to generate magnetic force to draw the heat-melting ink toward the platen to which the printing paper is attached.

Embodiment FIG. 1 shows the main structure of a first embodiment of a thermal transfer printing apparatus according to the present invention. The thermal transfer printing device 10 shown in the figure has a thermal head 11. It is composed of a platen 12. Printing paper 13 (plain paper is used as described later) is fed between thermal head 11 and platen 12 in the direction shown by arrow A in the figure while being overlapped with ink sheet 14 .

Then, printing is performed by melting the heat-melting ink 14a (shown as a satin finish in the figure) applied to the ink sheet 14 by the heated thermal head 11 and adhering it to the printing paper 13.

The thermal heater 11 is an electric-thermal converter that converts an electric signal into a thermal signal, and a plurality of heating elements 16 corresponding to a predetermined number of dots are formed in rows on a ceramic substrate 15 using thin film or thick film technology, and will be described later. It has a structure in which electric circuits are installed in one piece.

The plurality of heating elements 16 are individually driven to generate heat according to electric signals supplied to the thermal head 11, so that printing corresponding to dots can be performed. The platen 12 has rubber disposed around its outer periphery, and is rotated in the direction of arrow B in the figure by a rotating mechanism (not shown) to send out the overlapping printing paper 13 and ink sheet 14 in the six directions of arrows in the figure. This platen 12 is provided with eleven stones 17 serving as magnetic force generating means. The electromagnet 17 is configured to generate a magnetic force of a predetermined strength (described later) at a position on the platen 12 facing the thermal head 11.

The ink sheet 14 has a structure in which a heat-melting ink 14a is applied onto a base film 14b. A material is selected for the base film 14b that has good thermal conductivity and can maintain a predetermined mechanical strength even if the thickness is reduced. The heat-melting ink 14a is formulated with carnauba wax, ester wax, oil, pigments, dyes, etc. to have appropriate physical properties (melting point, melt viscosity, etc.), and magnetic powder, which is a feature of the present invention. (e.g. iron oxide.

ferrite, etc.) are also mixed in. The heat-melting ink 14a mixed with this magnetic powder is uniformly applied to one side of the base film 14b to form an ink sheet 14. Note that since the magnetic powder has an extremely fine particle size, there will be no inconvenience caused by the mixing of the magnetic powder during the formation of the ink sheet 14 and during thermal transfer, which will be described later. Further, the printing paper 13 superimposed on the ink sheet 14 and fed into the thermal transfer printing device 10 is plain paper as described above (hereinafter referred to as plain paper 13). Plain paper 13 has relatively large irregularities on its surface, and is inferior in surface smoothness compared to high-quality paper and light coated paper. However, it is cheaper and more profitable than high-quality paper or light cord paper.

Plain paper 13 and ink sheet i.
FIG. 2 shows an enlarged view of the state in which the ink is sandwiched between the paper 1 and the platen 12, and the manner in which the heat-melting ink 14a is attached to the plain paper 13 will be described below.

As shown in the figure, the plain paper 13 has irregularities on both sides. Since the thermal head 11 is pressurized toward the platen 12, the ink sheet 14 also has some unevenness due to the unevenness of the plain paper 13. Therefore, due to the unevenness of the ink sheet 113 and the ink sheet 14, a gap 19 is created between them. In this state, an electric signal is applied to the thermal head 11 and the heating element 16 generates heat. Assume now that the heating elements 16a and 16b are heated. Heating element 16a.

The heat from the ink 16b is conducted through the base film 14b, heats the heat-melting ink 14a, and melts it.

At this time of melting, the electromagnet 17 installed inside the platen 12 is not energized and no magnetic force is generated.

Subsequently, the ink is heated for a predetermined period of time, and when the heat-melting ink 14a is completely melted by the heating elements 16a and 16b (hereinafter referred to as adhesion), a voltage is applied to the electromagnet 17 to generate magnetic force. . In the contact area between the heat-melting ink 14a and the plain paper 13 (the area indicated by arrow C in the figure),
Thermofusible ink 1 that melts without applying any particular magnetic force
4a adheres to the plain paper 13. However, in the area where the void 19 is formed, the plain paper 13 and the heat-melting ink 1
4a are spaced apart from each other, the heat-melting ink 14a will not adhere to the plain paper 13 unless some measure is taken. In the present invention, magnetic powder is mixed into the heat-melting ink 14a. Therefore, when a voltage is applied to the electromagnet 17 installed inside the platen 12, the magnetic powder mixed in the heat-fusible ink 14a is drawn toward the platen 12 due to the generated magnetic force, and accordingly, the heat-fusible ink 14a is also attracted to the platen 12. I am drawn towards it. As a result, a gap 19 is created, and the plain paper 13
Even if the hot-melt ink 14a is separated from the hot-melt ink 14a, the hot-melt ink 14a mixed with magnetic powder is attracted to the platen 12 by the magnetic force of the electromagnet 17, and adheres to the plain paper 73 in the process. The strength of the magnetic force generated by the electromagnet 17 is selected to be strong enough to attract the thermofusible ink 14a toward the platen 12 across the gap 19. That is, thermal transfer printing can be performed even on printing paper with poor surface smoothness, such as plain paper 13, and inexpensive printing paper can be used.

FIG. 3 shows a second embodiment of the thermal transfer printing apparatus according to the present invention. Note that the same configurations as those shown in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted. The thermal transfer printing device @2o shown in the figure is characterized in that in addition to the platen 12, the thermal head 21 is also provided with an electromagnet 22 as a magnetic force generating means. The thermal head 21 has a structure in which a plurality of heating elements 16 corresponding to a predetermined number of dots are arranged in a row on a magnetic substrate 23, and a coil 24 is wound around the magnetic substrate 23 to form an electromagnet 22. There is. A first electromagnet 22 formed on this thermal head 21 and a platen 12
A second electromagnet 17 installed in the electric circuit 2 described later
5 (shown in FIG. 5), a voltage is applied to generate magnetic force.

In the thermal transfer printing apparatus 20 having the above configuration, the manner in which the heat-melting ink 14a is attached to the plain paper 13 will be described below. The electromagnet 22 formed in the thermal head 21 is configured such that a voltage is applied when an electric signal is applied to the heating element 16, in other words, when the heat-fusible ink 14a is melted. Here, referring again to FIG. 2, as mentioned above, both sides of the plain paper 13 are uneven, and each heating element 16 is pressurized by the platen 12, so the ink sheet 14 is normal. It is distorted in response to the unevenness of the paper 13. As a result, in addition to the gap 19 created between the plain paper 13 and the ink sheet 14, each heating element 16 and the ink sheet 1
A gap 26 is also formed between the holes 4 and 4. The heat of the heating element 16 is thermally conducted through the base film 14b, reaches the heat-melting ink 14b, and melts it. Therefore, in order to reliably melt the heat-melting ink 14a corresponding to one dot (this corresponds to the heating range of one heating element), it is desirable that each heating element 16 be in complete contact with the base film 14b. . This makes it possible to achieve high-resolution printing that matches the heating element 16.

As described above, magnetic powder is mixed in the heat-melting ink 14a, and when it is melted, a voltage is applied to the electromagnet 22 formed on the thermal head 21 to generate magnetic force. Therefore, the magnetic powder mixed in the heat-melting ink 14a is drawn toward the thermal head 21, and the ink sheet 14 is also drawn toward the thermal head 21 accordingly. Since the ink sheet 14 is a flexible sheet with a small thickness, and the electromagnet 22 is configured to generate a relatively strong magnetic force, the ink sheet 14 attracted to the thermal head 21 is As shown in FIG. 4, it comes into close contact with each heating element 16. Further, voltage application to the electromagnet 22 is continued until the hot-melt ink 14a is reliably melted. Therefore, when the heating element 16a generates heat during melting, the heating element 16a
Since it is in close contact with the base film 14b, heat is efficiently transmitted to the heat-melting ink 14a, and the heat-melting ink 14a in the portion corresponding to the heating element 16a is uniformly melted without spots.

When the heat-melting ink 14a is completely melted, the heating element 1
The supply of the electric signal to 6a and the voltage application to the electromagnet 22 are stopped, and then the voltage is applied to the second electromagnet 17 installed inside the platen 12.

The plain paper 13 has irregularities, so that gaps 9 are formed between the plain paper 13 and the ink sheet 14. However, as explained in the first embodiment, by drawing the heat-melting ink 14a mixed with magnetic powder to the platen 12 by the electromagnet 17, the heat-melting ink 14a can be applied to the plain paper 13 without being affected by the existence of the gap 19. It can be attached. As described above, when the hot-melt ink 14a is melted, J3
to generate magnetic force in the first electromagnet 22 and ink sheet 1.
4 to the thermal head 21, the heat-melting ink 14a can be melted evenly and uniformly in correspondence with the heating element 16, and then the second electromagnet 77 is applied during adhesion.
By generating a magnetic force, the hot-melt ink 14a can be attached to the plain paper 13 regardless of the existence of the gap 19.

Therefore, it is possible to perform high resolution printing on plain paper 13 whose surface smoothness is not good.

Next, FIG. 5 shows an example of an electric circuit that drives the first and second electromagnets 22, 17 and heating element 16 of the thermal transfer printing device 20, and FIG. 6 shows a timing chart of signals supplied to each terminal. It is shown and explained below. The electric circuit 25 shown in the figure is roughly a shift register 26 integrated into the thermal head 21. Latch circuit 27. Gate circuit 28
．． 892229292 heating element 1 functioning as a switch
6 and first and second electromagnets 22, 17, etc. In this electric circuit 25, data for driving each heating element 6 is first sent to the data terminal 30 of the shift register 26 (the timing chart for supplying the data is shown in the sixth figure).
(shown in Figure (A)). Next, a load pulse is supplied to the latch circuit 27 from the terminal 31. A timing chart for supplying the load pulse is shown in FIG. 6(B))1. After temporarily storing the data in the latch circuit 27, the terminal 3
A strobe pulse is applied to the transistor 29 (a timing chart for applying the strobe pulse is shown in FIG. 6(C)) to open the gate circuit 28 in accordance with the data.
is activated to supply current to the heating element 16 and heat it. At this time, power in phase with the strobe pulse is applied to the terminal 33 of the first electromagnet 22 via the buffer 34 to generate magnetic force. Therefore, while the heating element 16 is generating heat, in other words, when it is melting, the first electromagnet 22 generates magnetic force and draws the ink sheet 14 toward the thermal head 21.

At the moment when the strobe pulse is reversed from high level to low level, the inverter 3 is connected to the terminal 35 of the second electromagnet 17.
6 (a timing chart in which this power is applied is shown in Figure 6(D)).
is applied. As a result, when the heat-melting ink 14a is attached to the plain paper 13, the heat-melting ink 14a is attached to the plain paper 13.
4a is drawn towards the platen 12 and attached to the plain paper 13. Note that the thermal transfer printing device 10 shown in the first embodiment
In the electric circuit 25 shown in the figure, lir! 1
It is obvious that a circuit configuration that excludes the stone 22 and the buffer 34 is sufficient.

Effects of the Invention As described above, according to the thermal transfer printing apparatus of the present invention, a magnetic material is mixed in the heat-melting ink applied to the transfer paper, and a magnetic force generating means is provided on the platen, so that the heat-melting ink is mixed with a magnetic material. When attached, a magnetic force is generated by a magnetic force generating means to draw the heat-melting ink toward the platen to which the printing paper is attached, so that the printing paper has unevenness on both sides and has poor surface smoothness. Even when printing paper is used and there is a gap between the transfer paper and the printing paper,
Since the magnetic material is attracted by the magnetic force generating means, the thermofusible ink is also attracted towards the platen, so the thermofusible ink is adhered to the printing paper without being affected by the presence of air gaps. Thermal transfer printing can be performed on printing paper with poor surface smoothness, and the thermal head is provided with a first magnetic force generating means, and the platen is provided with a second magnetic force generating means. A magnetic force is generated by the first magnetic force generating means to first draw the hot melt ink towards the thermal head, and then a magnetic force is generated by the second magnetic force generating means at the time of adhesion so that the hot melt ink is attached to the printing paper. By arranging the paper so that it is pulled toward the platen that is in contact with it, the transfer paper is drawn in close contact with the thermal head during melting, so the heat from the heating element is efficiently transferred to the heat-melting ink through the base film. The heat-melting ink is uniformly melted without spots in response to the heating element, and when it is attached, it is drawn toward the platen by the second magnetic force generating means without being affected by the existence of the i-1 gap. Its advantages include the ability to perform high-resolution, clear printing on printing paper with poor surface smoothness.

[Brief explanation of the drawing]

FIG. 1 is a main part configuration diagram for explaining the first embodiment of the thermal transfer printing device according to the present invention, and FIG. 2 shows the overlapped plain paper and ink sheet in the thermal transfer printing device shown in FIG. 1. A diagram showing a state where the thermal head is sandwiched between a thermal head and a platen, FIG. 3 is a configuration diagram of main parts for explaining the second embodiment of the thermal transfer printing device according to the present invention, and FIG. 4 is a diagram showing the thermal transfer printer shown in FIG. 3. A diagram showing a state in which an ink sheet is drawn toward a thermal head in a printing device, FIG. 5 is a diagram showing an example of an electric circuit that electrically drives the thermal transfer printing device shown in FIG. 3, and FIG. A timing chart of the electric circuit shown in the figure, FIG. 7 is a main part configuration diagram for explaining an example of a conventional thermal transfer printing device, and FIG. 8 shows a state in which plain paper is fed into the thermal transfer printing device shown in FIG. 7. FIG. 10.20 Thermal transfer printing device, 11.21 Thermal head, 12 Platen, 13 Printing paper (plain paper), 14 Ink sheet, 16.16a. 16b...Heating element, 17.22...Electromagnet, 18.
...Base film, 19.26...Void. Patent Applicant: Victor Japan Co., Ltd. Figure 1 Figure 3 Plate Figure 6 (D) -ichiyufF? lJ! Figure 7

Claims (2)

[Claims] (1) Transfer paper coated with heat-melting ink and printing paper are overlapped and fed between the thermal head and platen, and the thermal head is heated to melt the heat-melt ink and adhere to the printing paper. In a thermal transfer printing device that performs printing by applying heat-melting ink, a magnetic material is mixed in the heat-melting ink applied to the transfer paper, and a magnetic force generating means is provided on the platen to generate magnetic force when the heat-melting ink is attached. 1. A thermal transfer printing apparatus, characterized in that a magnetic force is generated by a magnetic force generating means to draw the heat-melting ink toward the platen to which the printing paper is attached. (2) Transfer paper coated with heat-melting ink and printing paper are overlapped and sent between the thermal head and the platen, and the thermal head is heated to melt the heat-meltable ink and adhere to the printing paper. In a thermal transfer printing device that performs printing by printing, a magnetic material is mixed in the heat-melting ink applied to the transfer paper, the thermal head is provided with a first magnetic force generating means, and the platen is provided with a second magnetic force generating means. The first magnetic force generating means generates a magnetic force when the thermofusible ink is melted, first attracts the thermofusible ink toward the thermal head, and then draws the thermofusible ink toward the thermal head. A thermal transfer printing device characterized in that the second magnetic force generating means generates a magnetic force at the time of adhesion to draw the heat-melting ink toward the platen to which the printing paper is attached.