JPS5855261A - Heat transfer printer - Google Patents

Abstract

PURPOSE:To enable ink on a transfer tape to be transferred in a best state on a recording paper, by a method wherein melt point information physically prepared on a heat transfer tape or a case thereof is read to control a heating amount of a thermal head. CONSTITUTION:A physical means for indicating melt point information is formed on a case of heat transfer tape or at the start part of the tape. For example, a projection 10 is formed on the case. Temperature information, which the projection 10 has, is detected through turning ON and OFF of a microswitch 11 in a detector 2, and a detecting signal consisting of an electric signal is outputted to a CPU1. By means of the signal, a voltage applied to a thermal head 4 is controlled into a most suitable condition.

Description

[Detailed Description of the Invention] This patent relates to a thermal transfer printer, and in particular to a thermal transfer printer that can control the amount of heat generated by the thermal head and maintain uniform printing quality even when using various transfer tapes. It is.

When printing characters, symbols, etc. using a thermal transfer printer using a thermal head, in general, heat-melting ink is applied on one side between the recording medium (paper) and the heating element (the thermal head), and a transfer tape is used to perform the transfer. A thermal transfer printer has been proposed in which a specific ink portion on a tape is thermally transferred onto printing paper using a thermal head. In such printers, the amount of ink transferred to the paper depends on the melting point of the ink used.

If the same amount of heat is applied to the thermal head, ink with a high melting point will transfer only a small amount to paper, and ink with a low melting point will transfer a large amount to paper.

If you always use transfer tape with the same color ink, it is best to determine the melting point of the ink in advance according to the heat capacity of the multi-color head. It is difficult to match the melting points due to differences in the pigments of the inks.In this case, if the same thermal head is used to transfer the same amount of heat, the amount of ink transferred to the paper will be different due to the difference in the melting point of the ink, resulting in a difference in color. Due to the difference, there is a drawback that the print density varies.

An object of the present invention is to provide a thermal transfer printer that processes melting point information of ink on a transfer tape to eliminate the above-mentioned nine defects, thereby making it possible to vary the amount of heat applied to a thermal head. In a typical implementation of the present invention having such an objective, a detector detects the melting point of the ink of the transfer tape used for printing, and the voltage applied to the thermal head is varied to generate the required amount of heat according to that information. Adjust this to ensure the best possible transfer of the ink from the transfer tape to the paper.

Hereinafter, details of one embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

Here, l is a central processing unit (CPU) that detects the melting point of the interstices of the transfer tape unit 3 using a detector, and prints by varying the voltage supplied to the thermal head using a voltage control signal in accordance with the information. 2 is a detector that detects the melting point of the ink on the tape using the signal from the transfer tape unit;
Output to PUI. 3 is a transfer tape enit, which outputs the melting point of the inserted ink to a detector. 4 is a thermal head that applies heat to the transfer tape to melt the ink on the tape and print on paper. A voltage control unit 5 controls the voltage of the power supply supplied to the thermal head. A variable voltage power supply 6 supplies power controlled by the voltage control unit 5 to the thermal head. FIG. 2 is a first diagram showing signal states in each part of FIG. 1. When printing on a practical thermal transfer printer, CP
U1 inputs the melting point information of the ink of the transfer tape stored in the transfer tape unit 3 using the detector 2; According to the information, the CPU controls the voltage control section 5 using a voltage control signal, and sets the variable voltage power supply 6 to the optimum voltage value for the melting point of the ink on the transfer tape. After that, by outputting the dot information to be printed on the thermal head 4 and at the same time outputting a heat signal, the voltage is set to the optimum voltage for the melting point of the ink, and the nine voltages are output from the variable voltage power supply 6 and placed on the thermal head 4. A specific dot generates heat, melts the ink on the transfer tape, and transfers it onto the paper.

Since the heating element of the thermal head 4 is a resistive element, the amount of heat generated is proportional to the voltage and time applied to the heating element. When time is constant, when the voltage is high, the power consumption of the resistance element per constant time increases, and therefore the amount of heat generated increases.

Conversely, as the voltage decreases, the power consumption decreases, so the amount of heat generated decreases. The CPU detects the melting point of the ink on the transfer tape, and when the melting point is low, the voltage control section 5 sets the output voltage V of the variable voltage power supply 6 to a low value, such as v in FIG. 2. The amount of heat generated is proportional to VX (heat time). When the melting point is high, the voltage control unit 5 sets the output voltage V of the variable voltage power supply 6 to a high value (for example, Vs in Figure 2).
Set to . This is clear from the fact that the total power consumption of the resistive elements of the thermal head is proportional to VX (heating time). In this way, the calorific value of the thermal head 4 is increased for ink that is hard to melt with a high melting point, and the calorific value of the thermal head 4 is decreased for ink that is easy to melt and has a low melting point. The amount of ink transferred to paper is the same as that of transfer tape. - Next, detection of melting point information of the transfer tape will be explained.

In the above-mentioned Example fII, since the melting point of the transfer tape is known in advance, the transfer tape can be transferred! A physical means for transmitting melting point information is formed on the case of the tape or at the start of the tape. As shown in FIG. 3, the physical means may be nine protrusions 10 formed on the case. Turn on the micro switch 11 in the detector 2 to obtain the temperature information of the protrusion, 0F
Ft is converted into an electrical signal representing temperature information and outputted to the CPU 1 as a detection signal. As shown in FIG. 3B, in place of the microswitch 11, a phototransistor 12 equipped with a light source and a light receiving part is provided on the detector 2, and a reflective mirror 13 is provided on the transfer tape unit 3, thereby increasing the melting point of the transfer tape. It is also possible to detect. In addition, the CPU
1 does not need to be an arithmetic device, but may be any electric circuit that can obtain a predetermined output signal.

Since the present invention is configured and operates as described above,
The thermal head can generate nine degrees of heat corresponding to the melting point of the transfer tape. Therefore, according to the present invention, even when using transfer tapes having various melting points, it is possible to always perform the best printing.

[Brief explanation of the drawing]

Figure w4I is a block diagram showing an embodiment of the configuration of a thermal transfer printer according to the present invention, Figure 2 is a tie-ink chart diagram showing signal states in each part of Figure 1, and Figure 3 is a diagram showing melting point information and its detection. FIG. 2 is a detailed view of the transfer tape enit and the detector. Here, 1- central processing unit (CPU), 2... detector, 3-... transfer tape unit, 4- thermal head,
5-voltage control section, 6-variable voltage power supply. Agent: Yasushi Otsuka, patent attorney. Figure 2 Cause 3 (A) 1 Figure 3 CB)

Claims (1)

[Scope of Claims] 1. A thermal transfer printer characterized by processing melting point information of ink on a thermal transfer tape to control the amount of heat generated by a thermal head. 2. The thermal transfer printer according to item 1, wherein melting point information that is physically prepared on the transfer tape or its case is read as temperature information by a reader 9 as an image.