JPH0548184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a recording method for a serial type thermal transfer printer.

<Prior art> In a serial type thermal transfer printer, a transfer film whose surface is coated with ink is interposed between a thermal printing head and an image-receiving paper, and the thermal printing head slides across the image-receiving paper while transferring the transfer film. By heating the transfer film from the back side, the ink is transferred to the image receiving paper that is in close contact with the surface of the transfer film, and the desired pattern is printed on the image receiving paper.This type of printer is a thermal printer. Unlike printers, there is no need to use specific paper such as thermal paper, and there are no particular restrictions on the receiving paper that should be used, and plain paper can be used, so users can use a variety of plain paper. The current situation is that

<Problems to be Solved by the Invention> By the way, in this type of thermal transfer printer, if the image receiving paper used by the user has low smoothness and the surface of the paper is rough, the ink-applied surface of the transfer film and the surface of the image receiving paper may The adhesion was poor, and the ink was not completely transferred to the surface of the image-receiving paper, resulting in poor dot reproducibility, resulting in unclear print patterns, and a significant deterioration in print quality.

In addition, if the temperature of the environment in which this type of printer is used is low, heating the thermal print head alone will not raise the temperature of the printed area on the image receiving paper to the required temperature, and therefore the ink transferred to the image receiving paper will not rise to the required temperature. The fixing properties deteriorated, and there was a fear that the dot reproducibility would be lowered due to this as well.

On the other hand, in order to make the printing pattern clearer, it is possible to increase the power applied to the heating element of the thermal print head to increase the amount of heat generated by the heating element. If it becomes large, there will be a problem that the life of the heating element with respect to the applied power, so-called pulse life, will be shortened.

The present invention is easy to implement in a serial type thermal transfer printer, and provides clear printing with excellent dot reproducibility even when the receiving paper has low smoothness and even when the temperature of the usage environment is low. The object of the present invention is to make it possible to obtain a pattern and also to extend the pulse life of a heating element.

<Means for Solving the Problems> The present invention has been made in view of the above-mentioned problems, and is capable of solving problems when the smoothness of the image receiving paper surface is low or the environmental temperature is low in a serial type thermal transfer printer. It is characterized in that substantially the same pattern is printed over and over again by sliding the thermal printing head over the same location on the image receiving paper multiple times via a transfer film of the same color.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is an overall configuration diagram of a serial type thermal transfer printer used for carrying out the present invention, in which reference numeral 1 denotes a serial type thermal printing head, 2 a transfer film,
3 is image receiving paper. The thermal printing head 1 has heating elements 5 arranged in a row on a substrate 4, and is slid in a direction A across the image receiving paper 3 by a sliding means 6. Required parts generate heat. 8 is a sliding drive unit that energizes the sliding means 6; 9
1 is a platen, 10 is a motor for rotating the platen 9, 11 is a paper feed drive unit that drives the motor 10, and 12 is a control circuit that controls the printing operation of the thermal printing head 1 and the paper feeding operation by the platen 9. .

In the above configuration, the thermal printing head 1 slides in the direction A across the image receiving paper 3 while printing the transfer film 2.
By heating the transfer film 2 from the back side,
The ink is transferred to the image-receiving paper 3 that is in close contact with the surface of the image-receiving paper 3, and a desired pattern is printed on the image-receiving paper 3. In the present invention, the thermal printing head 1 prints the same part of the image-receiving paper 3 in two places. times or more times,
The printing operation is performed by sliding in the direction A across the image receiving paper 3, and almost the same printing pattern is repeatedly printed by multiple printing operations to form the required printing pattern for one line.

That is, as shown in the explanatory diagram of FIG. 2A, the thermal printing head 1 first slides one stroke to print one line. As a result, the first print pattern Pa is formed at the required location on the image receiving paper 3. This first print pattern Pa usually has low clarity. After the first printing operation, the image-receiving paper 3 is placed in a state where the paper is not fed and the transfer film 2 of the same color as in the previous printing is interposed between the thermal printing head 1 and the image-receiving paper 3. The thermal printing head 1 performs the same printing operation with the same color on the same location.
As a result of the printing operation in the second step, the printing pattern of the same color is printed overlappingly on the first printing pattern Pa as shown in Fig. 2B, and the final clear printing is achieved by so-called overprinting. A pattern Pb is formed.

The first printing pattern Pa and the printing pattern formed in the second process may be the same, but the printing pattern formed in the second process may compensate for the unclear parts of the first printing pattern Pa. , may partially overlap each other.

The printing operation of the thermal printing head 1 on the same location on the image receiving paper 3 may be performed three or more times.
The printing operation for the same location shall be performed at least twice. In this case, the second and subsequent printing operations are performed during the reciprocation of each stroke, but the second or even-numbered printing operations are performed during the backward motion using the backward motion of the first stroke or each subsequent stroke. good.

Furthermore, normally, overlapping printing is always performed two or more times as described above, but printing conditions such as whether or not to perform overlapping printing and how many times overlapping printing is to be performed can be changed automatically or by user operation. You can also do this. When automatically switching printing conditions, a means for detecting the smoothness of the image receiving paper 3 or a means for detecting the smoothness of the image receiving paper 3
Means for detecting the reflectance of the printed portion is provided, and printing conditions are switched in accordance with a detection signal from the detecting means.

<Effects of the Invention> As described above, according to the present invention, almost the same printing pattern in the same color is repeatedly printed multiple times at the required locations on the image receiving paper, so that it is possible to print on the image receiving paper with low smoothness and rough paper surface. Even when the temperature of the usage environment is low, a clear print pattern with good dot reproducibility can be obtained by overlapping printing, and the print quality can be maintained at a high level.

Furthermore, compared to the conventional method of forming a print pattern with the required density in a single printing operation, less power is applied to the heating element of the thermal print head during each printing operation, reducing the burden on the heating element. The pulse life of the thermal printing head can be extended.

Furthermore, the present invention slides the thermal printing head over the same location on the image receiving paper multiple times, and does not add a new mechanical structure to existing serial type thermal transfer printers. This can be easily carried out using this type of printer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a serial type thermal transfer printer used to carry out the present invention, and FIGS. 2A and 2B are explanatory diagrams showing the state of printing by the method of the present invention. 1... Thermal printing head, 2... Transfer film, 3... Receiving paper, Pa... First printing pattern, Pb... Final printing pattern.

Claims (1)

[Claims] 1. A recording method for a serial thermal transfer printer in which a transfer film is interposed between a thermal printing head and an image-receiving paper, and the thermal printing head slides in a direction across the image-receiving paper to print, and the smoothness of the image-receiving paper surface is A serial type characterized in that when the temperature is low or the environmental temperature is low, the thermal printing head slides over the same spot on the image receiving paper multiple times through a transfer film of the same color, thereby repeatedly printing almost the same pattern. Recording method of type thermal transfer printer.