JPS59196293A - Heat sensitive transfer recording method and apparatus therefor - Google Patents

Abstract

PURPOSE:To attain to enhance heat conductivity and recording faithfulness, in applying that in such a state that a transfer sheet supporting an ink layer is contacted with recording paper, by interposing a liquid substance between the base film of the transfer sheet and a thermal head. CONSTITUTION:A transfer sheet 3 prepared by coating the single surface of a base film with an ink layer is supplied from an unwinding roll 4 and, thereafter, the base film of said sheet 3 is coated with the silicone oil 11 in a tank 12 by a coating roll 13 before said sheet 3 reaches between thermal head 8 and recording paper 1. By this method, the space between the head 8 and the base film is filled with the oil not only to smooth the running of the head but also to uniformly transfer the heat of the head 8 to the ink layer. As the liquid substance, one having flowability at 100 deg.C or less such as animal or vegetable oil or synthetic oil is used other than the silicon oil. In addition, an oil supply method may be performed by supplying the oil from an emitting port by connecting an oil tank and the head by a pipe.

Description

[Detailed Description of the Invention] Industrial Application Field The contact surface of the ilm is improved to improve the heat transfer performance of the heat pulse of the head to the base film, thereby improving recording fidelity and recording density, and further improving heat resistance. The present invention relates to a thermal transfer recording method and apparatus that allows the use of inferior base films.

Conventional structure and problems The transfer body used for thermal transfer recording has an ink layer supported on a base film.The so-called wax method uses an ink layer made of a heat-melting material, and the other uses sublimation in the ink layer. There is a so-called sublimation dye method that includes a dye.

In the case of the wax method, the thermal energy required for the ink layer is not large, but if you want to increase the recording speed, if you apply a large amount of thermal energy to the thermal head (hereinafter referred to as the head), the base film will be damaged. A phenomenon called "stick" occurs, which causes the head to become stuck.
Unable to obtain stable records.

However, the sublimable dye method still requires more thermal energy than the wax method to sublimate or evaporate the dye, and for example, when polyethylene terephthalate is used as the base film, the required recording speed is When thermal energy is applied to the head to obtain , a phenomenon similar to that described above occurs.

Conventionally, in order to eliminate this phenomenon, methods have been proposed in which the transfer body is made of a metal or the like having excellent thermal conductivity, but this method is still insufficient.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a recording method and apparatus which eliminates the above-mentioned conventional drawbacks, allows the use of a base film with poor heat resistance, and further improves recording characteristics.

Structure of the Invention The present invention is a recording method in which a liquid substance is interposed in the contact portion between a head and a base film, and also a recording apparatus having a device for supplying the liquid substance to the head or the base film.

According to this configuration, the liquid substance fills the minute voids that occur at the contact area between the head and the base film, which are caused by the surface roughness of the head and the base film, and which impede heat conduction. Therefore, uniform transmission of heat pulses from the head and smooth heat conduction occur. 1. Due to the presence of the liquid substance, the base film moving on the head is made to travel smoothly, and there is no imbalance on the base film.
- Since there is no heat concentration or heat accumulation, the stick phenomenon does not occur even when using a base film with poor thermal properties, and the recording fidelity and recording density of the heat pulses of the multiple heat generating elements of the head are increased. Obtainable.

Description of examples Examples of the present invention will be described below.

FIG. 1 shows an example of the structure of a thermal transfer recording apparatus according to the present invention.

1 is a recording paper, 2 is a platen roll, and the recording paper 1 is fed in the direction of the arrow in the figure. A transfer sheet 3 is a base film coated with an ink layer on one side, and is supplied from an unwinding roll 4 and wound onto a winding roll 7 via a guide roll 6.6.

The transfer sheet 3 is fed at the same speed as the recording paper 1 with its ink layer on the recording paper 1 side. 08 is a thermal head that presses the transfer sheet 3 against the recording paper 1 and presses the transfer sheet 3 against the recording paper 1 in response to an electric signal. A heat pulse is applied to the recording paper 1, whereby the ink on the sheet 3 is transferred to the recording paper 1, and a recording is obtained on the recording paper. In this way, for example, by repeatedly transferring three types of ink, cyan, magenta, and yellow, a full-color image can be obtained.

1o is the base film of the transfer sheet and the thermal head 8
This is a device that supplies silicone oil to the contact area.

This example consists of a tank 12 containing silicone oil 11 and a coating roll 13, and the roll 13 applies the silicone oil to the base film of the transfer sheet.

In the example shown in FIG. 2, a tank 14 containing silicone oil 11 is connected to the thermal head 8 by a pipe 15.

The oil flowing down from the tank 14 is discharged from a discharge port 16 opened at the tip of the head.

The silicone oil supplied to the base film of the transfer sheet 3 by the roll 13 comes into contact with the head, filling the gap between the head and the base film with oil, lowering the coefficient of friction between the base film and the head, and allowing smooth running. Further, oil supplied from the discharge port 16 of the head has a similar effect.

In the above example, silicone oil was used as the liquid substance interposed in the contact portion between the head and the base film, but the liquid substance to be interposed is not limited to the above example. The liquid substance in the present invention is a substance or liquid that exhibits fluidity at 100° C. or lower. Substances or liquids that exhibit fluidity at temperatures below 100° C. exhibit good properties because they become fluid or are promoted to fluidize by the heat of the head. Particularly good properties are exhibited when the liquid substance is, for example, various animal or vegetable oils, synthetic oils, mineral oils, or waxes. Good properties are also exhibited when the liquid substance contains lubricants, surfactants, etc.

A specific example will be explained below.

Example 1 A polyethylene terephthalate film with a thickness of 5 μm is used as the base film. An ink prepared by mixing 2 parts by weight of a dye represented by the following molecular structure A, 4 parts by weight of polycarbonate, and 100 parts by weight of methylene chloride in the following margins was applied to the upper surface using a wire bar, and then dried with hot air at 6oC. Two of these transfer sheets were produced and wound separately around the unwinding roll 4 shown in FIG. One of the transfer sheets undergoes thermal transfer recording without applying silicone oil to the back side as in conventional methods, and the remaining one
The sheet was coated with silicone oil via the roll 13 in FIG. Activated clay coated paper was used as the recording paper, and recording was carried out under the following thermal head recording conditions.

Main and sub-scan linear density: 4 dots/brain recording power
: 0.7W/Heating time of dot head: 2-8ms As a result, the transfer sheet without silicone oil caused a stick phenomenon at 3 m5 eC, but the transfer sheet coated with silicone oil showed a stick phenomenon at 8 m5 eC.
No sticking phenomenon was observed up to ec, and the shape of each dot was faithfully recorded on the recording paper.

In the above examples, polyethylene terephthalate was used as the base film, but the present invention is not limited to the type of base film. For example, polyester polymers such as polyethylene terephthalate and polycarbonate, amide polymers such as nylon, acetyl cellulose,
Cellulose polymers such as cellophane, polyvinylidene fluoride, fluorine polymers such as Teflon, and polyoxymethylene.

Applicable to all low heat resistant and high heat resistant films and sheets such as polyether polymers such as polyacetal, olefin polymers such as polypropylene and methylpentene polymers, and imide polymers such as polyimide and polyetherimide. It is. Further, the ink layer can be applied to either a wax method or a sublimable dye method.

Effects of the Invention As described above, according to the present invention, a low heat resistant film such as a polyester film can be used for high thermal energy recording, which could not be used conventionally. It is possible to take advantage of the thin film properties up to 100%, and since the dot reproducibility is faithful, the recording density and the clarity of the recorded image are dramatically improved.

[Brief explanation of drawings]

FIGS. 1 and 2 each show an example of the structure of a thermal transfer recording apparatus according to an embodiment of the present invention. 1... Recording paper, 2... Platen roll,
3... Transfer sheet, 4... To unwinding rotor 7... Winding roll, 8... Thermal head, 12.14...・Oil tank, 13・
... Application roll, 15 ... Pipe, 16
...Discharge port.

Claims (5)

[Claims] (1) A transfer sheet carrying an ink layer on one side of a base film is brought into contact with the recording paper, and
A method of obtaining records by transferring the ink to recording paper by applying heat using a thermal head in contact with the other surface of the base film, the method comprising interposing a liquid substance between the base film and the thermal head. A thermal transfer recording method characterized by recording. (2) The thermal transfer recording method according to claim 1, wherein the liquid substance is oil. (3) A device for supplying recording paper, a device for supplying a transfer sheet carrying an ink layer on one side of a base film with the ink layer facing the recording paper, and a device in contact with the other side of the base film. A thermal transfer recording device comprising: a thermal head that applies heat to a transfer sheet; and a device that supplies a liquid substance to a contact portion with the base material. (4) The thermal transfer recording device according to claim 3, wherein the device for supplying the liquid substance is a device for applying the liquid substance to a base film. (5) The thermal transfer recording device according to claim 3, wherein the device for supplying the liquid substance is a device for supplying the liquid substance to a contact portion of the thermal head with the base film.