JP2000062231A - Thermal head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict emission of heat, lower a consumption power and set small a spaced distance between a heat-generating resistor and a driver IC by directly forming the heat-generating resistor and an electrode to one face of a substrate and forming the driver IC to the other face of the same substrate. SOLUTION: A current for letting a heat-generation resistor 51 generate heat impresses a voltage impressed to a driver IC 56 to the heat-generating resistance body via an electrode of the driver IC 56 by a connecting pattern 55, a through hole 54 and a common electrode 52. When the driver IC 56 selects an individual electrode 53 and turns on a switch 58 corresponding to the individual electrode 53, the current runs to the selected individual electrode 53 via the heat-generating resistance body from the side of the common electrode. The current flows to the heat-generating resistor connected to the individual electrode 53, whereby the heat-generating resistor 51 generates heat. Since the driver IC 56 is set at the opposite side of the heat-generating resistor 51, printing is possible without particularly setting a spaced distance even when a card or the like of a hard material is used as a recording paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head used in a fusion type thermal transfer printing apparatus for performing thermal transfer printing using an ink ribbon coated with a meltable ink.

[0002]

2. Description of the Related Art A thermal transfer printing apparatus using a thermal head is currently widely used because of its simple recording mechanism, high image quality and easy maintenance, and low noise during printing. Widely used in various devices. FIG. 2 is a diagram showing a general configuration of a thermal transfer printing apparatus,
The ink ribbon 3 is brought into close contact with the recording paper 2 and is fed between the thermal head 4 and the platen roller 1, so that the platen roller 1
Is pressed to the thermal head 4 side to bring the ink ribbon 3, the recording paper 2 and the thermal head 4 into close contact with each other.

At this time, a current is passed through the thermal head 4 to heat the heating resistor as described later, and the ink of the ink ribbon 3 is transferred to the recording paper 2 for printing. FIG. 3A is a basic configuration diagram showing details of the conventional thermal head 4. In the figure, reference numeral 40 denotes a radiator plate made of a material having a high thermal conductivity such as aluminum, and a ceramic substrate 41 and a circuit board 42 for forming a connection pattern are formed on the radiator plate 40. A plurality of heating resistors 43 are formed in a line on the ceramic substrate 41, and a common electrode 44 and an individual electrode 45 are formed at both ends thereof. Then, a protective layer 46 is formed so as to cover the heating resistor 43, the common electrode 44, and the individual electrode 45.

An individual electrode 45 is provided on the circuit board 42.
Pattern 48 for connecting the driver IC 47 with the driver IC 47
And the common electrode 44 and the driver IC 47 are formed.
A connection pattern (not shown) for connecting the terminals is also prepared.

Then, the individual electrode 45 and the connection pattern 48
Are electrically connected by a connection line 49. Therefore,
Individual heating electrodes 43 and individual electrodes 45 and connecting wires 49,
The connection pattern 48 and the driver IC 47 are connected, and the common electrode 44 connected to the heating resistor 43 and the connection pattern (not shown) are similarly connected to the common side of the driver IC. With this configuration, if a current is selectively passed from the driver IC 47 to the heating resistor 43, only the selected heating resistor 43 generates heat, and the ink of the ink ribbon 3 can be transferred to the recording paper 2 for printing. .

[0006]

However, when the heating resistor 43 generates heat, more heat is dissipated than the ceramic substrate 41 and the heat dissipation plate 40 as shown in the usage state of FIG. The amount of heat applied to the ink is low and the efficiency is very poor. This is because conventional recording paper uses a recording paper with a smooth surface or uses an ink material with a high transfer temperature.Therefore, there is a lot of heat dissipation on the recording material side, so it was necessary to increase power consumption. Since it also increased at the same time, it was necessary to radiate heat to the side opposite to the recording side.
Therefore, the power consumption doubles and the heating resistor, connecting wire,
There has been a problem that the connection pattern, driver IC, etc. are large and thick.

The applicant of the present application has proposed a surface porous recording medium having irregularities on the surface and a multi-gradation printing apparatus using the same in JP-A-6-286181 and JP-A-7-125468. However, it was found that the energy consumption on the side of the recording material is remarkably reduced by using this surface porous recording medium and the fusible ink having a low transfer temperature as the recording material. It is considered that this is because the transfer temperature was low and the heat dissipation was reduced due to the porous structure.

FIG. 4 is a sectional view schematically showing the structure of this surface porous recording medium. As shown in the figure, the surface porous recording medium comprises a surface porous plastic sheet 2b having a thickness of 10 and several μm in which a large number of holes having a diameter of 1 to 25 μm are formed on a base material 2a of plain paper or synthetic paper. It is a laminate.

As an example of such a surface porous recording medium, Nisshinbo XEW-145 is used, the ink ribbon is Fujicopian PV-C20 (melting point 85 ° C.), and the conventional thermal head shown in FIG. 3 is used. Color Printer (Vict
or manufactured by SP-2200) and measured the energy consumption when performing saturation recording (recording the highest density), 18 mJ / m
It was confirmed that m ² was required.

However, since the SP-2200 uses the conventional thermal head as shown in FIG. 3, a large amount of heat is dissipated on the thermal head side, and further improvement is required. Further, since the driver IC is convex on the substrate, a sufficient separation distance is set so that the ink ribbon and the recording paper, which are in close contact with each other at the heating resistor portion, do not come into contact with the driver IC and are not torn or wrinkled. There was a problem that it had to be.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the invention according to claim 1 discloses that "a surface porous recording medium having a porous layer laminated on a substrate has a melting point thereof. The melting area of the ink is controlled by adhering an ink ribbon coated with a heat-meltable ink having a temperature of 60 ° C. to 110 ° C., pressing the thermal head, and controlling the amount of electricity to the thermal head A thermal head used in a fusion-type thermal transfer printing apparatus capable of obtaining a multi-gradation image on a thermal recording medium, the thermal head comprising a plurality of sets of heating resistors and electrodes for supplying current to the heating resistors. The thermal head is characterized in that it is formed directly on one surface and a drive circuit element is formed on the other surface for controlling the current flowing through the heating resistors individually. "

The invention according to claim 2 provides "the thermal head according to claim 1, wherein the heating resistor and the drive circuit element are connected by providing through holes in the substrate." And

The invention according to claim 3 is the thermal head according to claim 1 or 2, wherein the substrate on which the heating resistor and the drive circuit element are formed is a glass epoxy substrate. Is provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration and an operation example of a thermal head according to an embodiment of the present invention. FIG. 1A is a basic configuration diagram of a thermal head. Here, the heating resistor 51, the common electrode 52, and the individual electrode 53 are directly formed on the glass epoxy substrate 50. Further, through holes 54 for the common electrode 52 and the individual electrodes 53 are formed on both end sides of the glass epoxy substrate 50, a connection pattern 55 is formed on the back surface side of the glass epoxy substrate 50, and a driver IC 56 is provided. Has been. Reference numeral 57 is a protective layer provided on the surface of the glass epoxy substrate 50 so as to cover the heating resistor 51, the common electrode 52, and the individual electrode 53.

As shown in the current path diagram of FIG. 1B, the current for heating the heating resistor 51 is first connected to the voltage applied to the driver IC 56 via the 56 electrode of the driver IC. It is added to the heating resistor 51 by the pattern 55, the through hole 54, and the common electrode 52. Next, when the driver IC 56 selects the individual electrode 53 and turns on the switch 58 corresponding to the individual electrode 53 through which the current flows, a current flows from the common electrode side to the selected individual electrode 53 via the heating resistor. Flow, this selected individual electrode 5
An electric current flows through the heating resistor 51 connected to 3 to generate heat.

As shown in the use state of FIG. 1C, since the ceramic and the heat radiation plate with a large heat radiation amount are not used and only the glass epoxy substrate 50 is used, the heat radiation from the heating resistor to the substrate side is small, Therefore, power consumption can be reduced. Saturation recording (maximum density recording) with the thermal head according to the present embodiment under the same conditions as in the case of the conventional thermal head shown in FIG.
As a result of measuring the energy consumption, 6 mJ /
It was confirmed that mm ² and about ⅓ are sufficient.

Further, the driver IC 56 is connected to the heating resistor 51.
Since it is formed on the opposite side, it is not necessary to set the separation distance in particular, and printing can be performed even if the recording paper is made of a hard material such as a card. By making the separation distance as short as possible, the thermal head can be downsized.

The substrate used is one that allows through holes. Here, the glass epoxy substrate was used, but in addition, for example, in the organic laminate, paper phenol, paper epoxy, glass polyester, glass Teflon, and the like,
Inorganic materials include glass and mica laminates, which have low thermal conductivity. However, glass epoxy is practical because it has high precision and high versatility.

In the embodiment of the present invention described here, the strength required for the thermal head is obtained only by the glass epoxy substrate 50, and the reinforcing structure is not particularly adopted, but the present invention is not limited to this. It is needless to say that the reinforcing plate is not limited to this, and a reinforcing plate made of a material having low heat conduction may be attached to the back surface of the substrate 50 to reinforce it.

[0020]

As described above, according to the present invention, the heat generating resistor and the electrode are directly formed on one surface of the substrate, and the driver IC is formed on the other surface of the same substrate, so that heat dissipation is suppressed. Therefore, it is possible to configure a low-cost printer with low power consumption. Further, since the distance between the heating resistor and the driver IC can be set to be small, the thermal head can be downsized even when recording on a hard recording medium such as a card.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a thermal head according to an embodiment of the present invention, a current path explanatory diagram, and a usage state diagram.

FIG. 2 is a diagram showing an outline of a thermal transfer printing apparatus.

FIG. 3 is a diagram showing a basic configuration of a conventional thermal head and a usage state.

FIG. 4 is a sectional view schematically showing the structure of a surface porous recording medium (recording paper).

[Explanation of symbols]

1 Platen roller 2 Recording paper 3 Ink ribbon 4 thermal head 50 glass epoxy substrate 51 Heating resistor 52 common electrode 53 individual electrodes 54 through hole 55 Connection pattern 56 Driver IC 57 Protective layer

Claims (3)

[Claims] 1. An ink ribbon coated with a heat-meltable ink having a melting point of 60 ° C. to 110 ° C. is brought into close contact with a surface porous recording medium having a porous layer laminated on a substrate, and a thermal head is pressed to perform thermal treatment. A thermal head for use in a fusion type thermal transfer printing apparatus, wherein a melted area of ink is controlled by controlling an amount of electricity applied to the head to obtain a multi-gradation image on the surface porous recording medium. The thermal head is a drive circuit element for directly forming a heating resistor and an electrode for supplying a current to the heating resistor on one surface of a plurality of sets of substrates and controlling a current flowing to each of the heating resistors on the other surface. The thermal head is characterized by being formed. 2. The thermal head according to claim 1, wherein the heating resistor and the driving circuit element are connected by providing through holes in the substrate. 3. The thermal head according to claim 1, wherein the substrate on which the heating resistor and the drive circuit element are formed is a glass epoxy substrate.