JPH0376232B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal transfer recording device, and more particularly to a thermal transfer recording device using a repeatedly usable sheet-like or ribbon-like thermal transfer medium.

Structure of conventional examples and their problems In conventional heat-melting ink sheets or ribbons that have been used as thermal transfer media in thermal transfer recording devices, all the ink in the heated portion is transferred to the transfer paper. Therefore, thermal transfer media could only be used once, but in recent years, thermal transfer media have been developed that can be used repeatedly and are made so that only a portion of the heated ink is transferred to the receiving paper. If such a reusable thermal transfer medium is used, the running cost of a thermal transfer recording apparatus can be significantly reduced.

However, when such a reusable thermal transfer medium is used in a conventional thermal transfer recording device, there arises a disadvantage that the recording density gradually decreases as the number of times the thermal transfer medium is used increases. This is because in conventional thermal transfer recording devices, the heating temperature of the thermal transfer medium is always constant, so even if the thermal transfer medium can be used repeatedly, the amount of transfer ink will be higher the second time than the first time, and the third time more than the second time. This is because it decreases as the number of times it is used increases.

In order to prevent such changes in recording density, the number of recordings is counted for each heating resistor of the thermal head, that is, each pixel, and the amount of heat generated by each heating resistor is controlled according to the number of recordings. It is conceivable to control the heating temperature of the thermal transfer medium so that the amount of transfer ink becomes uniform. Such a method is
Although this is ideal, on the other hand, there is a problem in that the configuration of the thermal transfer recording apparatus becomes extremely complicated.

Purpose of the invention The present invention solves the above-mentioned conventional problems.
It is an object of the present invention to provide a thermal transfer recording device that can record images with uniform density using a repeatedly usable thermal transfer medium and that has a simple configuration.

Structure of the Invention The present invention provides a thermal transfer recording device using a reusable thermal transfer medium, which includes a preheating means for a thermal head, a counting means for counting the number of times the thermal transfer medium is used, and a number of times counted by this means. The above object is achieved by providing a means for controlling the preheating temperature of the preheating means and optimizing the heating temperature of the thermal transfer medium depending on the number of times of use.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic side view of a mechanical section of a thermal transfer recording apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic block diagram of the same thermal transfer recording apparatus.

In FIG. 1, 1 is a thermal head, 2 is an electric heater as a preheating means for the thermal head 1, 3 is a platen roller, 4 is a reusable thermal transfer film, and 5 is transfer paper. 6 is a winding roller for the thermal transfer film 4, and 7 is a rewinding roller for the thermal transfer film 4. 8 is a winding roller for the transfer paper 5, and 9 is a supply roller for the transfer paper 5. The thermal head 1 includes heat generating resistors arranged in one row with the same number of pixels as one line, a memory for storing image information for one line, and a memory for storing image information stored in this memory. It is equipped with a drive circuit that drives the heating resistor.

In FIG. 2, 10 is an image signal a from an external device.
11 is a terminal to which a signal c indicating the recording section of one page is inputted from an external device. 12 is a temperature detector such as a thermistor for detecting the temperature of the thermal head 1; 13 is an A/D converter; 14 is a counter; 15 is a ROM; and 16 is a switching section. Reference numeral 17 denotes a transfer paper feed control section for controlling the rotation of the take-up roller 8, and 18 a thermal transfer film feed control section for controlling the rotation of the take-up roller 6 and the take-up roller 7. A control section 19 controls the counter 14, the transferred paper feed control section 17, the thermal transfer film feed control section 18, and the thermal head 1.

Next, the recording operation will be explained. When the thermal transfer recording device is ready for recording, the external device turns on the signal c and serially sends the image signal a line by line to the terminal 1.
Transfer to 0. Information on this image signal a, that is, image information, is sequentially stored in the memory of the thermal head 1. When one line of image information is stored in the memory within the thermal head 1, the control section 19 outputs a recording pulse f. The drive circuit in the thermal head 1 energizes the heating resistor corresponding to the "1" bit (black pixel) of the image information in the memory for a time corresponding to the pulse width of the recording pulse f. The ink in the portion of the thermal transfer film 4 heated by the energized heating resistor is transferred onto the transfer paper 5, and one line of image is recorded.

When one line of recording is finished in this way,
The control unit 19 turns on signals g and h. When the signal g is turned on, the transferred paper feed control unit 17 rotates the take-up roller 8 by a predetermined amount, and causes the transferred paper 5 to travel by one line. Further, when the signal h is turned on, the thermal transfer film feed control section 18 rotates the take-up roller 6 by a predetermined amount, and causes the thermal transfer film 4 to travel by one line. During the period of controlling the movement of the thermal transfer film 4 and the transfer paper 5, the image signal a of the next line is
is transferred. When the image information for one line is stored in the memory within the thermal head 1, the recording pulse f is output from the control section 19 as described above, and the thermal head 1 records that line.

After transferring the image signal a of the last line of one page, the external device turns off the signal c. Control unit 19
If the signal c is off when the feeding of the thermal transfer film 4 and transfer paper 5 after recording one line is finished, it is determined that recording of one page is completed, and the counter 14
is incremented by 1, and the value of the output signal d of the counter 14, that is, the count value of the counter 14, is compared with a predetermined value.

When the count value of the counter 14 is less than or equal to a predetermined value, the control section 19 turns on the signal i. When the signal i is turned on, the thermal transfer film feed control section 18 rotates the rewinding roller 7 by a predetermined amount to rewind the thermal transfer film 4 by one page.

If the count value of the counter 14 exceeds a predetermined value, the control section 19 clears the counter 14 without rewinding the thermal transfer film 4.

As is clear from the above description, the thermal transfer recording apparatus of this embodiment repeatedly uses one page of the thermal transfer film 4 to record the number of pages corresponding to the predetermined value. The count value of the counter 14 is equal to the number of pages recorded using the same page of the thermal transfer film, that is, the number of times the page is used.

Now, as described above, when the heating temperature of the thermal transfer film 4 is constant, as the number of times of use increases, the amount of transfer ink decreases and the recording density decreases.
Therefore, in the thermal transfer recording apparatus of this embodiment, as the number of times of use increases, the preheating temperature of the electric heater 2 for the thermal head 1 is increased to increase the heating temperature of the thermal transfer film 4, thereby making the recording density uniform. Plan. Such preheating temperature control is performed as follows.

The output signal b of the temperature detector 12 is sent to the A/D converter 1.
3 is converted into a digital signal k, and used as an address signal together with the output signal d of the counter 14.
It is input to the ROM15. The ROM 15 outputs the stored data at the address specified by the address signal as a signal m. The current switching section 16 of the electric heater 2 turns it on and off at regular intervals, and its duty is controlled according to the value of the signal m. In this way, the preheating temperature of the electric heater 2 is controlled so that the recording density becomes uniform.

Here, the temperature of the thermal head 1 is detected by the temperature detector 12, and information on the temperature (signal k) is
The reason given to the ROM 15 is as follows.
Since the thermal head 1 has a heat storage phenomenon, even when the electric current of the electric heater 2 is turned on and off at a constant duty, there will be differences between when a large number of heat generating resistors are energized and when a small number of heat generating resistors are energized. There is a difference in the effect of preheating. In order to compensate for such a difference in preheating effect, temperature information of the thermal head 1 is provided to the ROM 15. Therefore, if the influence of the heat accumulation phenomenon in the thermal head 1 can be ignored, the configuration may be changed so that only the signal d is input to the ROM 15 or the signal d is directly input to the electric heater energizing circuit 16.

In the above embodiment, the thermal transfer film 4 is repeatedly used in units of pages, but it may be used repeatedly in units of one line or a plurality of lines. In that case, the number of times the thermal transfer film 4 is used is counted for each line or lines.

Effects of the Invention As described above, according to the present invention, there is provided a preheating means for the thermal head, a counting means for counting the number of times the thermal transfer medium is used, and a preheating temperature of the preheating means is controlled according to the number of times the thermal transfer medium is used. With the simple configuration of providing a means for recording, it is possible to realize a thermal transfer recording apparatus that can optimize the heating temperature of the thermal transfer medium depending on the circuit used and can always record images at a constant recording density.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a mechanical section of a thermal transfer recording device according to an embodiment of the present invention, and FIG. 2 is a schematic block diagram of the same device. 1... Marmal head, 2... Electric heater, 3
...Platen roller, 4...Thermal transfer film, 5
... Transfer paper, 6 ... Winding roller, 7 ... Rewinding roller, 8 ... Winding roller, 12 ... Temperature detector, 13 ... A/D converter, 14 ... Counter,
15...ROM, 16...Switching section, 17
. . . transfer paper feed control section, 18 . . . thermal transfer film feed control section, 19 . . . control section.

Claims (1)

[Claims] 1. A repeatable thermal transfer medium, a thermal head that selectively heats the thermal transfer medium according to an image signal, a preheating means for preheating the thermal head, and a counting means for counting the number of times the thermal transfer medium is used. A thermal transfer recording apparatus comprising: a storage means for storing data corresponding to the count value of the counting means; and a control means for controlling the preheating means based on the data stored in the storage means.