JPS6140174A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To automatically print in accordance with the smoothness of an image-receiving paper even where the smoothness is low and enable clear printed patterns to be constantly obtained with excellent dot reproduction, by providing a controlling circuit for controlling changes in printing conditions and a detecting means for the smoothness of the image-receiving paper. CONSTITUTION:The smoothness of the image-receiving paper 3 is detected on the paper-supplying side of a platen 9 by a smoothness-detecting means 13, and where the detected smoothness is lower than a preset value, the printing conditions under control of the controlling circuit 12 are switched in response to a detection signal from the means 13. Namely, the circuit 12 controls a printing action of a thermal printing head 1 and a paper-feeding action of the platen 9 so as to conform to the image-receiving paper 3 havng the lower smoothness, and printed patterns are made to be clear by overlap printing or the like, whereby printing quality is maintained at a high level.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermal transfer printer using a transfer film.

<Prior art> Thermal transfer printers interpose a transfer film, whose surface is coated with ink, between a thermal print head and an image receiving paper, and heat the transfer film from the back side with the thermal print head. A thermal transfer printer prints a desired pattern on a paper by transferring ink to the paper that is in close contact with the surface of the paper. Unlike thermal printers, this thermal transfer printer prints a specific paper such as thermal paper. Since it is not necessary to use plain paper and there are no particular restrictions on the image receiving paper that should be used, and plain paper can be used, various kinds of plain paper are used by users.

<Problems to be solved and improved by the invention> By the way, if the image receiving paper used by the user in a thermal transfer printer has low smoothness and the paper surface is rough, the ink-coated 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 Yt reproducibility, resulting in unclear print patterns, and a significant deterioration in print quality.

The present invention enables a thermal transfer printer to automatically print according to the smoothness of the image receiving paper, so that a clear print pattern with excellent dot reproducibility can always be obtained. The purpose is to

Means for Solving the Problems> The present invention has been made in view of the above-mentioned problems, and is a thermal transfer printer in which a transfer film is interposed between the thermal print head and the image receiving paper. The apparatus is characterized in that it includes a control circuit for controlling the change, and means for detecting the smoothness of the image receiving paper, and that the control section switches the printing conditions according to the detected smoothness of the image receiving paper.

<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 embodying the present invention. In the figure, reference numeral 1 denotes a serial type thermal print head, 2 a transfer film, and 3 an image receiving paper. The thermal printing head 1 has heating elements 5 arranged in a row on a substrate 4.
The heating element 5 is slid in a direction A across the image receiving paper 3 by the sliding means 6, and a required portion of the heating element 5 generates heat by being energized by the heating drive section 7.

8 is a sliding drive unit that energizes the sliding means 6; 9 is a platen;
10 is a motor that rotates the platen 9; 11 is a paper feed drive unit that drives the motor 10; 12 is a control circuit that controls the printing operation of the radar 1 for thermal printing and the paper feeding operation of the platen 9; and 13 is an image receiving unit. A smoothness detecting means 13 detects the smoothness of the paper 3, and this smoothness detecting means 13 is arranged on the supply side of the image receiving paper 3. As the smoothness detection means 13,
Received.

There are various types of devices, such as those that convert the vibrations of a probe in contact with the paper 3 into electrical signals using a differential coil, and those that detect the smoothness of the paper 3 by receiving reflected light from the paper 3 with a light receiving element. things are available for adoption.

The control circuit 12 switches the printing conditions in accordance with the smoothness detection signal of the image receiving paper 3 from the smoothness detection means 13. Here, the printing conditions are conditions that are useful for adjusting the clarity of the printing pattern.The specific conditions, the configuration for changing the conditions, and the operation when changing the conditions are explained below. do.

(A) Print once on the required location on image receiving paper 3, or
If the smoothness of the image receiving paper 3 is low under conditions related to overprinting, such as whether the same printing pattern is repeatedly printed on the same location, the control operation of the control circuit 12 is switched based on a detection signal indicating the low smoothness. After the thermal printing head 1 slides one stroke and prints one line, the RAD 1 performs the same printing operation for thermal printing on the same part of the image receiving paper 3 without paper feeding, The printing pattern is made clearer by so-called overprinting.

(B) The conditions regarding overlapping are changed in the same way as above. As shown in the configuration diagram of FIG. 2, on the single substrate 4 of the thermal print head 1, a plurality of (two in the embodiment) heat generating units are placed at intervals along the sliding direction A of the thermal print head 1. body 5a, 5
b are arranged in parallel, and when the smoothness of the image receiving paper 3 is low, the heating element 5b at the rear stage prints the same pattern on the area printed by the heating element 5a at the former stage. According to such means and operations, since overprinting is performed in one stroke of the rad 1 for thermal printing, the printing speed remains the same whether or not overlapping is performed.

(C) Change the conditions regarding the temperature of the printed part.

If the smoothness of the image receiving paper 3 is low, the temperature of the heating element 5 during printing is increased by increasing the voltage applied to the heating element 5 of the thermal print head 1 or the like.

(D) Similarly, change the conditions regarding the temperature of the printed part. A heater for heating the image-receiving paper 3 is provided near the thermal printing pad 1, and when the smoothness of the image-receiving paper 3 is low, the heater heats the image-receiving paper 3 and improves the fixability of the ink on the image-receiving paper 3. make it good.

Now, the smoothness of the image receiving paper 3 is detected by the smoothness detecting means 13 on the supply side to the platen 9, and if the detected smoothness is lower than a predetermined setting value, a detection signal from the smoothness detecting means 13 is detected. , the printing conditions controlled by the control circuit 12 are switched. Through the control of this control circuit 12, the printing operation of the thermal print head 1 and the paper feeding operation of the platen 9 are made to operate in accordance with the image receiving paper 3, which has low smoothness, and the printing pattern is made clear by overprinting, etc., and the printing Quality is maintained at a high standard.

FIG. 3 is a block diagram of another embodiment, showing a line type thermal transfer printer embodying the present invention, in which the same parts as in the embodiment of FIG. 1 are given the same reference numerals. That is, 1' is a line-type thermal printing head, 2 is a transfer film, 3 is an image receiving paper, 4 is a substrate of thermal printing head 1', 5 ta, 5'b is a heating element of thermal printing head 1', and 7 is a heating element of thermal printing head 1'. Heat generating drive unit, 9 is a platen,
10 is a motor for rotating the platen 9, 11 is a paper feed drive section, 12 is a control circuit, and 13 is a smoothness detection means.

Also in this embodiment, the smoothness detection means 13 detects the smoothness of the image receiving paper 3 on the image receiving paper supply side of the platen 9, and if the detected smoothness is lower than the set value, the control circuit 12
The printing conditions controlled by switch are changed, and accordingly, the same pattern is printed by the heating element 5'b of the latter stage in the place printed by the heating element 5'a of the former stage of the thermal printing radar 1'', etc. The behavior is changed so that the sharpness of the printed pattern is maintained at a level similar to that on high-smooth receiver paper.

<Effects of the Invention> As described above, according to the present invention, the smoothness of the image receiving paper is detected by the smoothness detection means, and if the smoothness of the image receiving paper is lower than a predetermined value, the smoothness of the image receiving paper is Since the printing conditions change, such as changing the number of printing times, printing is automatically performed to match the smoothness even on receiving paper with low smoothness and rough paper surface, so dot reproducibility is always good. It is possible to obtain a clear print pattern and maintain a high level of print quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a serial type thermal transfer printer embodying the present invention, FIG. 2 is a block diagram of a thermal print head, and FIG. 3 is a block diagram of another embodiment. 1.1゛...Thermal printing head, 2...Transfer film,
3... Receiving paper, 12... Control circuit, 13... Smoothness detection means.

Claims (1)

[Claims] (1) A thermal transfer printer in which a transfer film is interposed between a thermal printing head and an image-receiving paper, comprising a control circuit for controlling changes in printing conditions and means for detecting the smoothness of the image-receiving paper; A thermal transfer printer characterized by switching printing conditions according to the detected smoothness of image receiving paper.