JP2832192B2 - Thermal transfer recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording apparatus for thermally transferring ink on an ink sheet to recording paper by a thermal head and displaying a density gradation.

[0002]

2. Description of the Related Art Hitherto, as a thermal transfer type recording apparatus, there are a sublimation type recording apparatus and a fusion type recording apparatus, and these are properly used depending on the application. The sublimation type recording apparatus can change the density gradation for each pixel,
When three colors of magenta and yellow are used, n ³ colors can be expressed for each pixel when recording with n gradations of each color. For example, when recording at 256 gradations for each color, about 1670
All colors can be expressed. Therefore, beautiful print recording is possible, and it is often used for image print recording. However, there are disadvantages such as a long print recording time and a high running cost.

On the other hand, a fusion-type recording apparatus is represented by binary signals (on / off) of three colors, for example, cyan, magenta and yellow, for each dot. Law and organized dithering were applied. In the density pattern method, dots are arranged in a matrix of 2 × 2, 4 × 4, etc.
A pixel is represented. In the systematic dither method, one pixel is represented by one dot. Pseudo gradation is obtained by multiplying each dot by a so-called dither matrix. Therefore, although it is inferior to the sublimation type in gradation expression, it has advantages in that the printing recording time is short and the running cost is 1/3 to 1/5 lower than that of the sublimation type.

[0004] In view of the above, the sublimation-type and fusion-type recording apparatuses have the advantages described above. When test printing or a very precise gradation is not required, the printing recording time is short and the running cost is low. A sublimation-type and fusion-type recording apparatus that uses a sublimation-type ink sheet and recording paper for final print recording that requires precise gradation using an ink sheet of a type and recording paper has been considered.

FIG. 5 shows a general structure of a thermal head for performing thermal transfer recording. That is, an insulating substrate such as alumina (not shown)
A glaze layer (not shown) made of glass is formed on the surface of the glass, and Ta ₂ N or Ta −
A heating resistor 13 made of SiO ₂ or the like is formed by vapor deposition, sputtering, or the like, is formed into a plurality of rectangular shapes by photoetching, and is arranged in a straight line. On the upper surface of these heating resistors 13, a common electrode 11 is shared by the respective heating resistors 13 from above in the figure.
Then, individual electrodes 12 are formed and connected to the respective heating resistors 13 from below. The other ends of the common electrode 11 and the individual electrode 12 are connected to respective terminals of a drive IC 14, and the drive IC outputs signals for individually and selectively driving the plurality of heating resistors 13.

The thermal head further includes a common electrode 1
1. An oxidation-resistant film layer and a wear-resistant layer (not shown) are formed on the upper surfaces of the individual electrodes 12 and the heating resistor 13. Each of the heating resistors 13 is independently formed between the common electrode 11 and the individual electrode 12 so as to expose a heating dot corresponding to one dot which is a minimum printing unit. The IC 14 generates heat by applying a voltage between the common electrode 11 and the individual electrodes 12.

In the above-described thermal transfer recording apparatus, the heating resistors 13 are arranged as a thermal head for one line in the main scanning direction, and the thermal head is pressed against recording paper via an ink sheet, and based on predetermined print information. A predetermined signal is applied to the individual electrode 12 corresponding to the desired dot to cause the heating resistor 13 connected to the individual electrode 12 to generate heat, thereby sublimating or melting the ink on the sublimation type or melting type ink sheet. The desired print record can be obtained by heat-transferring to the recording paper.

[0008]

However, in the conventional sublimation-type and fusion-type recording apparatus, the appropriate size of the heating dot of the thermal head for beautifully printing and recording is limited to the sublimation type and the fusion type. In this case, the sublimation-type and the fusion-type thermal transfer recording devices were simply combined.

That is, in the heating resistor of the thermal head used for the sublimation type thermal transfer, the dimension M in the main scanning method and the dimension S in the sub scanning direction are relatively S / M> 1 to S / M ≒ 2. When performing the fusion type thermal transfer recording using the same thermal head, the dot length in the sub-scanning direction is reduced because the ink having the same area as the size of the heating resistor is transferred from the ink sheet to the object to be transferred. However, if the line width in the main scanning direction is different from the line width in the sub-scanning direction, or pseudo-gradation expression based on the systematic dither method, etc. It decreases significantly. On the other hand, the heating resistor of the thermal head used for the fusion type thermal transfer has a dimension M in the main scanning direction and a dimension S in the sub-scanning direction that are relatively S / M ≒ 1.
When sublimation-type thermal transfer is performed using the same thermal head, a density dent is generated between printed lines, the density becomes discontinuous, and the image quality is significantly reduced.

Therefore, the dual-purpose recording apparatus is not at a technically completed level, and has not been put to practical use. SUMMARY OF THE INVENTION It is an object of the present invention to provide a sublimation-type and fusion-type recording apparatus which can also be used as a thermal head, miniaturize the apparatus, and are inexpensive and easy to use.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a sublimation-type and fusion-type thermal transfer recording apparatus having a paper feed mechanism for moving one line by N paper feed control pulses. A thermal head in which the dimension M of the heating resistor in the sub-scanning direction and the dimension S in the sub-scanning direction are S / M ≒ 1, and a signal applied to the thermal head to obtain a desired gradation. And a flag means for detecting the paper feed control pulse and activating the applied pulse generation means. In the same line, an N / 2-th and an N-th paper feed control pulse are generated. By generating the same application pulse, a sublimation type and a fusion type thermal head were used.

[0012]

In the thermal transfer recording apparatus constructed as described above, the relative relationship between the dimension M in the main scanning direction and the dimension S in the sub-scanning direction of the heating resistor of the thermal head is S / M ≒ 1. An ordinary configuration can be applied as it is as a fusion type thermal head. The sublimation type thermal head is half the size of a conventional sublimation type thermal transfer recording apparatus, but the same applied pulse is applied to the same line when the N / 2th and Nth paper feed control pulses are activated. , A print record having the same beauty as that of a conventional sublimation-type thermal transfer recording apparatus is obtained.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is an explanatory diagram showing the configuration of the thermal head as described above. The shape and size of the heating resistor corresponding to one dot, which is the minimum printing unit, is represented by l ₁ × l ₃ , and the pitch of the heating resistor is represented by l ₂ . l ₁ to l ₃
Is determined as follows.

The print recording resolution in the main scanning direction is 300d.
For pi, l ₂ = 1 inch / 300 dots ≒ 85 μ
m. Here, l ₃ is about 65 μm obtained by subtracting the width of the insulating portion 15 between the heating resistors 13 from l ₂ . The paper feed amount is determined from the resolution in the sub-scanning direction. For example, in the case of a paper feed mechanism that moves one line by two pulses, in order to obtain a resolution of 300 dpi in the sub-scanning direction, about 4 pulses per pulse are required.
The paper feed amount is 2 μm. The dimension l ₁ of the thermal head in the sub-scanning direction is determined based on the amount of paper feed in the sub-scanning direction and the quality of print recording. Now, as described above, the resolution in the sub-scanning direction is 300 dpi, one line is driven by two pulses, and the paper feed amount per pulse is 42 μm. Under this condition, l ₁ = 140 to 180 in the sublimation type thermal transfer recording apparatus.
μm provides a beautiful print record, and l ₁ = 80
A good print record was obtained at a thickness of up to 120 μm.

According to the present invention, in the thermal transfer recording apparatus of 300 dpi, the dimension l ₁ of the heating resistor 13 of the thermal head is provided.
Is set to 80 to 90 μm, so that the optimal print recording can be performed by a normal drive circuit and an applied pulse in the fusion type thermal transfer recording apparatus, and the drive circuit and the applied pulse are configured as follows in the sublimation type thermal transfer recording apparatus. By doing so, it was possible to obtain a print record of the same beauty as in the case of l ₁ = 140 to 180 μm. This makes it possible to use both the sublimation type and the fusion type thermal heads.

The driving circuit and the applied pulse when sublimation-type print recording is performed using a sublimation-type ink sheet and recording paper will be described below. FIG. 1 shows an embodiment of a drive signal generation circuit for generating an applied pulse to be supplied to a thermal head according to the present invention. FIG. 2 is a timing chart of the drive signal generation circuit. 5 is a timing chart of an applied pulse output from a generation circuit. Hereinafter, the present invention will be described by taking as an example a case where the resolution of the thermal head is 300 dpi, the paper feed resolution in the sub-scanning direction is 300 dpi, and the paper is fed in one line by two pulses.

In FIG. 1, a memory 1 is a memory for temporarily storing multivalued image data input from a user interface circuit (not shown). Multi-valued image data is represented by 8 bits when expressed by 256 gradations per color of one dot, and expressed by 4 bits when expressed by 16 gradations. In the case of a color display, the colors are generally expressed in three colors of cyan, magenta and yellow.
When expressing in six gradations, 24 bits per dot are required, and when expressing each color in 16 gradations, 12 bits per dot are required. FIG. 1 shows a case where each color is represented by 4 bits of 16 gradations.

The comparator 3 compares the output of the memory 1 with the output of the counter 4, and sets the signal a to "0" when the comparison results match. The counter 4 is loaded with a preset initial value 1H (indicated by 1 in hexadecimal; the same applies hereinafter) according to the output signal b of the flag 5, and after the load is released, the falling edge of the signal c output from the counter 7 This is an asynchronous load counter that counts at (1). The output value of the counter 4 is connected to the comparator 3 and the table ROM 6. The flag 5 is cleared by the enable signal e, and performs a toggle operation by the line clock d and the signal h.

Here, the signal h is a signal obtained by gating the coincidence signal a output from the comparator 3 and the signal c output from the counter 7. The table ROM 6 is a ROM that uses the count value output from the counter 4 as an address signal and outputs data corresponding to the address to the counter 7.
It is. The counter 7 is a synchronous counter that loads the data output from the table ROM 6 as an initial value in synchronization with the clock f, counts the clock f after the release of the load signal, and generates an RC signal when the counting is completed. The gate 8 is a NAND gate for holding the initial state of the flag 5 so that the applied pulse g is not generated when the data read from the memory 1 is 0H.

Next, the 4-bit multi-valued image data value read from the memory 1 is 0010b (indicating 2 in binary).
The operation will be described by taking the case of (same below) as an example. FIG. 2 shows a timing chart at this time. The enable signal e is "0" in the initial state. At this time, the flag 5 is cleared and the output signal b is "0". Signal b
Is "0", the counter 4 is in the loaded state, and the output of the counter 4 is at the preset 1H. The output value 1H of the counter 4 is input to the comparator 3 and the table ROM 6. The table ROM 6 outputs the data n1 of the address 1 using the input value 1H as an address. When the enable signal e is “0”, the flag 5
Is "0", so that the counter 7
Is in the load state, and holds the output value n1 of the table ROM 6.

As shown in FIG. 2, the enable signal e is set to "0".
When the line clock d is input after changing from “1” to “1”, the output signal b of the flag 5 changes from “0” to “1” at the falling edge of the line clock d. When the signal b becomes "1", the load state of the counter 4 and the counter 7 is released, and the applied pulse g changes from "1" to "0" as shown in FIG. An energizing pulse called heat 1a is generated.

When the load state is released, the counter 7 starts counting the clock f.
Outputs C signal. The RC signal is gated with the clock f to become a signal c, which becomes the clock signal c of the counter 4.
The applied pulse g becomes "1" while the signal c is "0", indicating that the heat 1a has been completed. At the falling edge of the signal c, the counter 4 counts up, the output value becomes 2H, and the address 2 of the table ROM 6 is accessed. Since the signal c is gated with the output signal b of the flag 5 and connected to the load terminal of the counter 7, the signal c
While the counter 7 is "0", the counter 7 is loaded, and the data n2 at address 2 of the table ROM 6 is input to the counter 7.

The comparator 3 has a multi-valued image data value 001
0b is compared with the output value 2H of the counter 4 counted up, the coincidence signal a is changed from "1" to "0", and the signal h
Is set to "1" after the rise of the signal c, but the output signal b of the flag 5 does not change. The applied pulse g becomes "0" again after the rise of the signal c, and generates an energizing pulse called heat 2a. Here, the counter 7 operates in the same manner as above, and after counting n2 clocks f, outputs the RC signal again. Similarly to the above, the signal c changes to "0" by the RC signal, the signal h changes from "1" to "0", and the output signal b of the flag 5 changes from "1" to "0". Signal b
Becomes "0", the counters 4 and 7 are in the loaded state, the counter 4 is loaded with 1H, and the counter 7 is loaded with the data n1 at address 1 of the table ROM 6 again. Further, the applied pulse g becomes “1”. Thus, an energizing pulse corresponding to the multi-level image data at the line clock d of the first pulse of the paper feed has been generated.

In this state, when the second pulse line clock d is input, the flag 5 is inverted and its output signal b
Changes from “0” to “1”. Hereinafter, the same operation as above is performed, and heat 1b and heat 2b are generated as energizing pulses corresponding to the multi-valued image data. In the present invention, the energizing pulse for the first pulse line clock and the energizing pulse for the second pulse line clock are the same pulse.

After an energizing pulse for the second line clock d is generated, the multivalued image data of the next line is read from the memory 1 and the above operation is repeated. In this embodiment, the case where the multi-valued image data value is 0010b has been described. However, even when the multi-valued image data value is other than that, it can be realized by reading out the data value corresponding to each heat pulse stored in the table ROM 6. . For example,
If the multivalued image data value is 1111b, the table RO
By sequentially reading data n1 to n15 from M6, heat 1 to heat 15 are generated for the two line clocks as energizing pulses. When the multi-valued image data value is 0000b, the output value of the NAND gate 8 is "0", the flag 5 is cleared, and the applied pulse g remains "1". Therefore, the thermal head does not perform printing.

In the present embodiment, the case where the multi-valued image data is represented by 4 bits for each color has been described, but the present invention is not limited to this. In the thermal transfer recording apparatus, multi-valued image data is given to each dot of one line, and an application pulse corresponding to each multi-valued image data is supplied to the heating resistor of each dot of the thermal head.
In the present invention, the same application pulse is supplied twice during two paper feeding periods to perform one line print recording.

For reference, FIG. 4 shows a relationship between an applied pulse and a paper feed cycle which are conventionally used. here,
The case where a heating resistor having a size in the sub-scanning direction of 140 to 180 μm is used is described, and an application pulse is generated over two line clocks for paper feeding. As in the present invention, the dimension of the heating resistor in the sub-scanning direction is set to 80 to
When the thickness was 90 μm, satisfactory printing and recording results could not be obtained by applying the applied pulse as shown in FIG.

[0028]

According to the thermal transfer recording apparatus of the present invention, the relative relationship between the dimension M in the main scanning direction and the dimension S in the sub-scanning direction of the heating resistor of the thermal head is set to S / M ≒ 1, and is applied to the thermal head. And an application pulse generating means for generating a signal for obtaining a desired gradation, and detecting a paper feed control pulse,
And a flag means for activating the application pulse generation means. The same application pulse is generated for the N / 2th and Nth paper feed control pulses on the same line. It can be used for both purposes. Thereby, an inexpensive and high-performance sublimation-type and fusion-type thermal transfer recording apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an application pulse generating means of a thermal transfer recording apparatus according to the present invention.

FIG. 2 is a timing chart showing an operation of an application pulse generating means of the thermal transfer recording apparatus according to the present invention.

FIG. 3 is an explanatory view of an applied pulse generated by an applied pulse generating means of the thermal transfer recording apparatus according to the present invention.

FIG. 4 is an explanatory diagram of applied pulses of a conventional thermal transfer recording apparatus.

FIG. 5 is an explanatory diagram showing a configuration of a thermal head.

[Explanation of symbols]

 1 Memory 3 Comparator 4 Counter 5 Flag 6 Table ROM 7 Counter 11 Common electrode 12 Individual electrode 13 Heating resistor 14 Drive IC

Claims (1)

(57) [Claims] 1. A sublimation-type and fusion-type thermal transfer recording apparatus having a paper feed mechanism for moving one line by N paper feed control pulses, wherein a size of a heating element in a main scanning direction and a size in a sub-scanning direction are determined. A thermal head having a ratio of approximately 1, an application pulse generating means for applying a signal to the thermal head to generate a signal for obtaining a desired gradation, and detecting the paper feed control pulse and starting the application pulse generating means In the case of sublimation type recording , an application pulse based on the same recording data is generated for the N / 2th and Nth paper feed control pulses, and in the case of fusion type recording, For the Nth paper feed control pulse
A thermal transfer recording apparatus characterized in that a sublimation-type and a fusion-type thermal head are used by generating an application pulse .