JPH0226763A - Thermal recorder - Google Patents

Abstract

PURPOSE:To record a picture image in the same size regardless of the kind of an ink sheet by detecting the kind of the ink sheet mounted and controlling recording in response to the sheet. CONSTITUTION:When the mark 16a of an ink sheet 132 is detected by a phototransistor 136, a thermal head 130 and the ink sheet 132 are set at mutually recording-able positions. Consequently, the winding of the ink sheet 132 and the revolution and driving of a platen 120 are stopped, and a mark 16b is detected by a photosensor 136-2. As a result, the kind of the ink sheet 132 is discriminated, and the kind of the ink sheet is stored in the RAM of a CPU 42. A picture data from a buffer memory 43 is input as an address, and a four bit data is output when a melting ink sheet is mounted and a six bit data is output when a sublimating ink sheet is set up in accordance with a control signal 47 from the CPU 42. Accordingly, recording having excellent gradation can be conducted even at the time of either ink sheet.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a thermal recording device that records on recording paper by thermal transfer using an ink sheet coated with either sublimable ink or meltable ink. be.

[Prior Art] Color printers that print out displayed color images such as color computer graphics and color videos have been actively developed in recent years. Among these color printers, thermal transfer color printers using thermal heads use ink sheets coated with yellow (Y), magenta (M), cyan (C), and even black (Bk) coloring materials. There is a printer that uses a head to transfer images onto recording paper, producing a multi-color, multi-gradation color image.

Typical ink sheets for color recording are
There are sublimable ink sheets coated with sublimable ink and fusible ink sheets coated with meltable ink. In general, sublimation ink sheets are suitable for gradation recording, but require expensive and special recording paper with an ink-receiving layer, whereas fusible ink sheets can be used for recording on inexpensive plain paper, but gradation recording It has the characteristic that it is not suitable for

[Problems to be Solved by the Invention] Conventionally, thermal transfer recording using sublimable ink sheets and meltable ink sheets has been realized by separate thermal transfer printers. Therefore, in consideration of the type of data to be printed, printing cost, etc., when it is desired to change the ink sheet to be used, it is necessary to prepare at least two printers.

This has placed a heavy financial burden on users. Therefore, it has been expected that a thermal transfer printer will be developed that can record by replacing these two types of ink sheets.

In order to realize such a thermal transfer printer, since the reproducibility of gradation varies depending on the ink sheet as mentioned above, for example, when performing gradation recording using a meltable ink sheet with low gradation reproducibility, it is necessary to use sublimation. Even if the thermal head is activated in the same way as with the thermal ink sheet, there is a problem in that recording will be performed at different gradations due to the difference in the characteristics of the thermal head.

The present invention has been made in view of the above-mentioned conventional example, and by changing the recording data conversion method corresponding to meltable ink sheets and sublimable ink sheets, it is possible to achieve good REIN properties with either ink sheet. The purpose of the present invention is to provide a thermal recording device capable of performing recording.

[Means for Solving the Problems] In order to achieve the above object, the thermal recording device of the present invention has the following configuration. That is, the thermal recording device records by a thermal transfer method through an ink sheet, and includes a discriminating means for determining whether the attached ink sheet is a meltable ink sheet or a sublimable ink sheet, and when the meltable ink sheet is attached, a first gradation determining means that divides input one pixel data into a plurality of dots corresponding to each heating element of the thermal head and determines the gradation level of each dot in accordance with the gradation level of the input pixel; and sublimable ink. a second gradation determining means that allocates the plurality of dots to one input pixel data and determines the gradation of the plurality of dots in accordance with the gradation of the one pixel data when the sheet is mounted; and recording means for driving and recording each heating element of the thermal head according to the gradation of each dot determined by the second gradation determining means.

According to another claim, the plurality of dots is composed of an n×n dot matrix, and in the case of a sublimable ink sheet, each dot of the dot matrix is set to the gradation level of one input pixel data.

[Function] According to the above configuration, when it is determined that a fusible ink sheet is attached, one input pixel data is divided into multiple dots, and the gradation level of each dot is adjusted according to the gradation level of the input pixel. decide. Each recording element of the thermal head corresponding to each dot is driven to generate heat in accordance with the determined gradation level. On the other hand, when a sublimation ink sheet is attached, multiple dots are assigned to one input pixel data, the gradation level of the multiple dots is determined according to the gradation level of the pixel data, and the 1 pixel data is assigned multiple dots. It operates to record in accordance with the .

Furthermore, when recording on a fusible ink sheet, each dot of the dot matrix has a gradation level of 1/n2 compared to the case of a sublimable ink sheet.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of Color Printer (Figures 1 and 2)] Figures 1A and 1B are block diagrams showing the circuit configuration of a thermal transfer color printer according to an embodiment of the present invention.
Figure A shows an input image processing unit, and Figure 1B shows a printer unit including the mechanism shown in Figure 1C.

In the image processing section 30 , the color image input from the telephone line input terminal 31 is input to the color demodulator 34 . This color image is demodulated by a demodulator 34 into an NTS C signal or a color difference signal, and when the switch 32 is connected to the (b) side, it is decomposed into R, G, and B signals by a decoder 35.

In addition to the telephone line input terminal 31, the image processing section 30 has a video input terminal 36, and the video signal input to the video input terminal 36 can also be input to the decoder 35 by switching the switch 32 to the (a) side. ing. The color image signal decomposed into RGB signals by this decoder 35 is
For example, the D converter 37 converts each RGB signal into multi-value data of 6 bits (64 gradations) per pixel, and
It is stored in the GB memory 38.

40 represents RGB signal data, C (cyan) and M (
This is a color conversion circuit that converts the signal into magenta) and Y (yellow) signals. The color image data signal converted into YMC signal data by this color conversion circuit 40 is sent to a printer section 41 shown in FIG. 1B. Note that each circuit block and switch 32 described above are controlled by a CPU 42 shown in FIG. 1B. Note that the CPU 42 has a ROM that stores processing procedures and the like that will be described later in the flowchart of FIG. 11, and a RAM that is used as a work area for control.

In the printer section 41, the image data output from the image processing section 30 is processed into one of the images to be recorded as shown in FIG.
After being stored in the buffer memory 43 once, it is output to the pixel data conversion table 45 whose details are shown in FIG. 2B in synchronization with the recording speed based on the control of the CPU 42. be done. Here, pixel data conversion corresponding to the type of ink sheet installed is executed and output to the head drive pulse control circuit 44. The configuration of the head drive pulse control circuit 44 is the second A.
It is shown in detail in the figure, and the details will be explained in detail later. 46 is a display unit, and the CPU 42 determines the type of ink sheet 132 as will be described later, and displays the determination result, the presence or absence of recording paper, various error displays, etc. on the display unit 46.

Next, the configuration of the printer section 41 will be explained.
The mechanical section of the printer unit 41 shown in Fig. B is shown in detail in the side sectional view of Fig. 1C, and will be described below with reference to Fig. 1C. Note that common parts in FIG. 1B and FIG. 1C are indicated by the same symbols.

In FIG. 1C, 101 is a plain paper cassette, and 201 is a cassette for storing sublimation ink recording paper. 1st C
As shown in the figure, the printer has two cassettes 101 and 2.
It is important to install 01 at the same time. The cassette 101 stores plain paper used for thermal transfer using a fusible ink sheet, and the cassette 201 stores, for example, sublimation thermal transfer recording paper having an ink receiving layer from an ink sheet coated with sublimation ink. It looks like this.

If two types of recording paper are of the same size, they may be mistakenly stored in different cassettes. Therefore, in the printer of this example, marks as shown in FIG. 4 are attached to the back sides of the ordinary recording paper 301 and the sublimation type thermal transfer recording paper 302, respectively. The plain paper 301 is
Alternatively, the sublimation type thermal transfer recording paper 302 is detected.

Therefore, the sublimation type thermal transfer recording paper 302 is placed in the cassette 101.
However, the plain paper 301 may be incorrectly stored in the cassette 201, or
Sometimes it is stored upside down. Or even if plain paper without markings is stored, the photosensor 102 or 20
No. 2 does not detect recording paper, and displays an appropriate message on the display section 46 indicating that there is no paper.

Each of the recording sheets stored in the cassettes 101 and 201 is transferred to the corresponding pickup roller 103 and 2031.
The paper is fed to the printer main body by separation rollers 104, 105, 204, 205, etc. The drives 9jJ#i of the rollers are motors 106 and 206, and by selectively driving these, plain paper 301 or sublimation thermal transfer recording paper 302 is fed into the printer body.

Reference numerals 107 and 108 and 207 and 208 are paper guides, respectively, and the plain paper or sublimation type thermal transfer recording paper fed by the paper feeding mechanism is sent to the platen 120 by these paper guides. Reference numerals 121 and 122 indicate pinch rollers, which are connected to the platen 120 by springs (not shown).
The recording paper is conveyed while sandwiching the recording paper between the platen 120 and the platen 120 . The motor 123 is a stepping motor, and drives the platen 120 via a deceleration mechanism (not shown). 124 is a paper guide, and 125 is a paper discharge tray for discharging the recorded recording paper.

126 is a paper guide lever;
is biased by a spring and plunger (not shown),
When the plunger is on, the suction force of the plunger causes the 1C
When the plunger is off, it is oriented to the state shown by the solid line in the figure, and to the state shown by the broken line due to the biasing force of the spring.

FIG. 6 shows the positional relationship between the platen 120, the paper guide lever 126, and the width direction of the recording paper. The length of the platen 120 in the longitudinal direction is formed to be slightly narrower than the width of the recording paper, and is long enough to be contacted by the head over the entire recording range indicated by diagonal lines. Further, paper guide levers 126 are disposed on both sides of the platen 1200 so as to be within the width of the recording paper, and guide the conveyance of the recording paper.

Therefore, when the paper guide lever 126 is in the position shown by the solid line as shown in FIG. and 122, and is again sent to the recording position by the head 130. In addition, the paper guide lever 126
When is in the position indicated by the broken line, the recording paper is guided by the 12b (upper) side of the paper guide lever 126,
The paper leaves the platen 120 and is ejected to the paper ejection tray 125.

Next, a mechanism for bringing the head 130 into contact with the platen 120 will be described. Reference numeral 131 is a motor for moving the head up/down, and the driving force of the motor 131 moves the head 13.
0 is pressed against the platen 120 via the ink sheet 132 and the recording paper (down state) or separated from the platen 120 (up state). That is, motor 1
The rotation obtained from the worm gear 133 attached to the shaft 31 is transmitted to the gears 19 and 20 shown in FIG. 3 via a speed reduction mechanism (not shown). The head 130 and a rotary plate are integrally attached to the head drive shaft 134 of the gear 20, and both ends of the I return coil spring 23 are fixed to the rotary plate 22 and the gear 21, respectively.

Therefore, when the motor 131 is driven to rotate the gear 20 in the counterclockwise direction shown by the arrow in FIG.
34, and further the head 130 is driven in the direction of arrow A shown in FIG.
20. Furthermore, the motor 131 is driven to shift gear 2.
0 in the counterclockwise direction, the tear spring 23 is charged and the head 130 is pressed against the platen 120 by its charging force. At this time, gear 20
By detecting the rotational phase of the head 130 with a detection mechanism (not shown), the charge amount of the spring 23 can be detected, and the pressing force of the head 130 against the platen 120 can be controlled in at least two stages. Here, the two-stage pressing means force, and the pressing means force when plain paper is used, and the optimum pressing means force when sublimation type thermal transfer recording paper is used. Furthermore, if the motor 131 is driven in the opposite direction (clockwise) to the above direction, the gear 20 is driven in the opposite direction to the arrow in FIG. It is rotated in the opposite direction and driven to the position shown by the broken line, and is separated from the platen 120.

In addition, the head pressing mechanism shown in FIG.
The pressing against the platen 120 by the gear 19.
20, the rotary plate 22, and the 1-return recoil spring 23 are disposed on both of two base plates (not shown) that support the platen 120. Furthermore, since the worm gear 133 is attached to the shaft of the motor 131, even if the power to the motor 131 is cut off after the spring 23 is charged and the head 130 is pressed against the platen 120, the shaft of the motor 131 is is rotated in the opposite direction and head 1
30 is never released from being pressed against the platen 120.

[Explanation of the ink sheet and its drive system (Figure 5)] Next,
The structure of the ink sheet 132 and its drive system will be explained. As shown in FIG. 5, the ink sheet 132 includes
In this order, four parts are formed, each consisting of a transparent part provided with a mark 16a for sheet position detection, and a part coated with three dyes, yellow Y, magenta M, and cyan C, for color recording. formed continuously. The transparent part molecule is a part for synchronizing the colors to be printed, and when this part molecule is detected, it can be detected that the yellow 7 part comes next.

In addition, in the sublimation ink sheet, sublimation dye is applied to the Y, M, and C portions, and at this time, the cassette 2
Color recording is performed using sublimation type thermal transfer paper No. 01, and the Y, M, and C portions of the fusible ink sheet are coated with fusible ink, and at this time, the cassette 101
Color recording is performed using plain paper stored in the . 16b is a mark added only to the sublimable ink sheet and not to the meltable ink sheet. Therefore, the sublimable ink sheet is provided with a positioning mark 16a and an identification mark 16b, and the meltable ink sheet is provided with only a positioning mark 16a.

Note that the position of the mark representing the type of ink sheet is not limited to this. For example, in the case of a single-color ink sheet, a mark indicating the type of ink sheet is placed at the end of the ink sheet that is not used for recording in the length direction of the ink sheet. A line indicating the type of ink sheet is placed along the line, for example, on the right side of Figure 5 for a sublimation ink sheet, and on the left side for a fusible ink sheet, and the printer detects the position of this line using a photo sensor. etc., and read the f! on the ink sheet. The neck may also be determined.

In FIG. 1C, the stepping motor 139 is the driving source for the feeding mechanism of the ink sheet 132, and the motor 139
The rotation of the ink sheet 132 is transmitted to the drive @140.
is wound up in the direction of arrow B. Further, since an appropriate friction is applied to the rotating shaft 141 of the roll-shaped ink sheet 132, the ink sheet is
When the ink sheet 32 is wound up, the shaft 141 applies a load to the winding shaft 140, so that the ink sheet 132 does not slacken. Further, even when the platen 120 is rotated with the head 130 pressed against the platen 120, the head 130 is fixed so that the ink sheet 132 does not sag due to the frictional force between the recording paper and the ink sheet 132 or the electrostatic force.
The force with which it is pressed against the platen 120 can be adjusted.

[Mark detection on ink sheet (Fig. 1C, Fig. 5)] In Fig. 1C, 135 and 136 are a photodiode and a phototransistor, respectively, and two sets of transmission type photosensors (135-1, 136-1 and 135-2
, 136-2). These are the marks 16 marked on the ink sheet 132 as described above.
a or 16b, those for detecting mark 16a (135-1 and 136-1) and those for detecting mark 16b (135-2 and 133-2)
are arranged in two sets in the width direction of the recording paper.

Now, when the mark 16a is detected by one set of photosensors while the thermal head 130 is down, it means that the ink sheet 132 has been set to the initial position for starting recording. At this time, if the mark 16b is detected by the other set of photosensors, it can be determined that the installed ink sheet 132 is a sublimable ink sheet, and if the mark 16b is not detected, it is a meltable ink sheet. It can be determined that there is.

Further, as shown in FIG. 5, on the downstream side of the mark 16b on the ink sheet 132, there is a length L°° from the position of the photosensors 135, 136 in the printer body to the recording position 13a (FIG. 1C) by the head 130. There is only a transparent part. Therefore, when the mark 16a is detected by the photosensors 135 and 136, the leading portion of the ink sheet Y is facing the head 130, and this indicates that the initial position of the ink sheet for starting recording has been set. become.

Further, the reduction ratio in the reduction system of the stepping motors 123 and 139 is such that when the stepping motors 123 and 139 are driven in the same way, the ink sheet is faster at feeding the recording paper and the ink sheet at the recording position 13a of the head 130. However, since the winding shaft 140 is provided with a slip mechanism (not shown), the ink sheet is wound in an amount similar to the amount of recording paper fed by the head and platen.
The slip mechanism is configured to absorb the difference.

[Description of Head Drive Pulse Control Circuit (FIGS. 2, 8 to 10)] The head drive pulse control circuit 44 has a configuration as shown in FIG. 2A.

FIG. 8 is a diagram showing the configuration of the thermal head 130.

230 is a heating resistor element, which in this example has a capacity of 12 pels (
They are provided for one line in the width direction of the recording paper with an element spacing of 12 heating elements/mm). 233 is a latch circuit that latches one line of recording data, and 234 is a shift register. The serial data 444 input to the shift register 234 is changed to type 1 by the clock pulse CLK.
The data is then shifted in, latched into a latch circuit 233 by a latch signal 235, and converted into parallel data. In this way, the recording data corresponding to each heating resistor element 230 is held in the latch circuit 233. Then, the timing and time of voltage application are determined by the strobe signal 5TB445, and the output transistor 231 of the element with data is turned on. In this way, the corresponding heating resistor element 230! , : Electrified and driven to generate heat.

In FIG. 2A, 450 is a predetermined frequency clock CL.
The oscillator 451 outputs the clock signal CLK,
For example, it is a frequency dividing circuit that outputs a latch signal 235 every time the number of heating elements in one line of the thermal head 130 is counted. 440 corresponds to each pixel of input pixel data,
Gradation data 44 to each register stage of the shift register 234
This is a gradation conversion decoder that transfers 4 in synchronization with the CLK signal. When processing a color image, a gradation conversion decoder 440 performs gradation conversion for each of Y, M, and C colors.

The gradation counter 441 is a gradation counter that counts up every time the latch signal 235 is input, and based on the instruction signal 61 of the CPU 42, for example, in the case of a sublimable ink sheet, the count of mode 4 (6 bits) is In this case, the 9-gradation conversion decoder 440, which performs mod16 (4-bit) counting, compares the counted value from the gradation counter 441 with each input pixel data, and determines whether the pixel data is larger or When equal, gradation data 444
When the pixel data becomes smaller, "0" is output.

The strobe signal generation circuit 442 outputs the strobe signal 5TB445 with a slight delay from the latch signal, thereby driving the heating element to perform recording. 443 is a gradation ROM table that stores the adjustment data for the pulse width of the STB signal for the sublimable ink sheet, and 447 is the gradation ROM for the fusible ink sheet, which contains adjustment data for the 5TEI signal pulse width for the fusible ink sheet. is stored. These ROMs contain a temperature correction signal 4 from the head temperature detector.
46 is input, and based on this temperature correction signal 446, correction data is stored so that the optimum gradation characteristics can be obtained for each color. A switch 448 is switched by the CPU 42 in accordance with the type of ink sheet 132 installed, and outputs gradation correction data corresponding to the type of ink sheet 132 to the strobe generation circuit 442.

[Explanation of Pixel Data Conversion (Figures 2B to 2F)] Figure 2B shows pixel data conversion in which each pixel of image data read from the buffer memory 43 is converted in accordance with the type of ink sheet installed. FIG. 2 is a block diagram showing the configuration of a table.

In the figure, 51 is the color of the read image data (MMC
), a switch 52 is a conversion memory containing conversion data to be described later, and a buffer memory 43
Input the image data as an address and send it to the CPU 42.
According to the control signal 47, 4-bit data is output when a fusible ink sheet is attached, and 6-bit data is output when a sublimable ink sheet is attached. Of the control signals 47, 53 is an instruction signal for instructing the type of ink sheet 132, and 54 is a 2×2 matrix x, y address signal output when the ink sheet is a fusible ink sheet.

Next, the data structure of this conversion memory 52 will be explained.

FIG. 2C is a diagram showing the relationship between the energy applied to the thermal head 130 and the recording density, corresponding to the type of ink sheet. 58 shows the relationship between applied energy and recording density when a sublimable ink sheet is used, and 59 shows the relationship between applied energy and recording density when a meltable ink sheet is used. In this way, in the case of a sublimable ink sheet, a recording density that is approximately proportional to the applied energy can be obtained, but in the case of a fusible ink sheet, the value sharply increases near △E, and the sublimation Multi-gradation recording, such as with ink sheets, is becoming difficult.

So, for example, if the gradation level of the image data that was just input is set to 64
In the case of gradation (6 bits), in the case of a sublimable ink sheet, it is output as 645jJi (6 bits), but in the case of a fusible ink sheet, the input 1 pixel data is converted into 2×
By dividing the dot into 4 dots of 2 and expressing each dot with 16 gradations (4 x 16 =) 64 gradations, the gradation level does not appear to decrease even in the case of a meltable ink sheet. . Note that in the case of a fusible ink sheet, one input pixel is recorded as four dots, so in order to make the size of the recorded image data the same, even in the case of a sublimation ink sheet, one input pixel data is recorded as four dots. is expressed by 2×2 dots. However, the gradation level of each dot recorded at this time is equal to the gradation level of the input pixel data.

FIG. 2D shows an example of a pixel conversion matrix used in this embodiment, and as shown in the figure, the x and y axes are defined and addresses are set.

FIG. 2E is a flowchart showing the process of creating the table data for the fusible ink sheet in the conversion memory 52. This data creation process is shown to explain the data structure of the conversion memory 52, and is used in the color printer of this embodiment. It is not necessary to execute the process in a similar manner, and it is sufficient if data having such characteristics is stored in the memory 52. Note that since each address stores the same data as the address (image data) as conversion data for the sublimation ink sheet, the data read from the buffer memory 43 is output as is to the head drive pulse control circuit 44. Ru.

In FIG. 2E, in step 5100, pixel data D
Set to “01” and set y at steps 5tot and 1゜2, respectively.
-0, set x=O. d in step S3. (D/4
), and set d to the remainder of (D/4). In step 5104, out of the matrix of FIG. 2D,
Compare the pixel indicated by (x, y) with the value of dl, and
, is larger, the process proceeds to step 5105, and (d0+1) is written in that pixel portion; otherwise, the process proceeds to step 5106, and do is written in that pixel portion. In this way, data is first written to the position corresponding to (0, 0) in the matrix, and then (1°o), (o, i, (t, t)
) are written to each pixel position in this order. In this way 4
When the pixel data is written, the process advances to step 5111, where the pixel data D is incremented by 1 and the above-described process is repeated until the pixel data D reaches the maximum gradation level (64) or higher.

FIG. 2F shows the conversion data created in accordance with the gradation level of the input pixel data based on the matrix shown in FIG. 2D. Here, the gradation level of the input pixel is shown in parentheses at the bottom of each matrix.

Therefore, for example, when the gradation level of the input pixel is "10",
Each dot is converted into data indicated by 60 and output as 4 bits. Here, the gradation of each dot is recorded in gradation under the control of the head drive pulse control section 44, as in the case of the sublimation ink sheet.

FIG. 2G is a diagram showing the relationship between the input pixel data (pi to Pn) and the recording density in the case of a meltable ink sheet and the recording density in the case of a sublimable ink sheet.

In FIG. 2G, (a) shows an input pixel data string, and P
1 to Pn correspond to each pixel. (b) shows the dot data recorded after the input pixel data is converted for use on the fusible ink sheet, and the shaded area 62 is the pixel P1.
is converted and recorded. Dot k. -3 is pixel P1
indicates the converted dot data, which corresponds to the matrix part shown in Figure 2F, where each dot is 12Pel.
This corresponds to one heating element of the thermal head 130. (C) shows a printing dot row in the case of a sublimation ink sheet, where one input pixel data is recorded in two rows of two pixels each in the horizontal direction, for a total of four dots (6 Pal). . By doing this, if the input image data size is the same, the recording size by the meltable ink sheet and the recording size by the sublimable ink sheet will be the same.

Next, a method of driving the thermal head 130 to generate heat according to the embodiment will be described.

FIG. 9 is a diagram showing the relationship between the head current supply time and the recording density by the thermal head 130. In order to obtain the density of Po, (Bl + B2 + B3 + B4 + Bs)
The heating resistor element 230 is energized for a period of time. As is clear from FIG. 9, the time the head 130 is energized is not proportional to its recording density; for example, to obtain a recording density of Pl, the head 130 requires an energization time of approximately (Bl+82). be.

FIG. 10 is a diagram showing head drive and control pulses during color image recording in a color printer having the current application time and recording density characteristics as shown in FIG. 9.

Here, the thermal head 130 is a line head, and
0 indicates the data recording timing for one line.

Now, assuming that the image data per pixel input to the gradation conversion decoder 440 in FIG. 2A is composed of, for example, 6 bits, 64 types of data are handled per pixel.

Therefore, in this case, N of N gradations is "64". First, the gradation data 444 corresponding to the first STB signal of one line of data is transferred to the shift register 234 and latched by the latch circuit 233 by the latch signal 235. Next, the STB signal B1 is output, and the heating element that outputs data "1" by the pulse width of B is driven.

During this heat generation drive, the next data is transferred to the shift register 234.
When the STB signal falls, the latch signal 23
5, it is latched by the latch circuit 233. In this way, the STB signal is then output at 82. Such operations are executed 64 times (STB signals 81 to B64) to record one line.

That is, the gradation conversion decoder 440 inputs image data,
When the value of the m-th pixel data of the line to be recorded in the image is "20", the value of the gradation counter 441 is placed in the m-th stage of the shift register 234 corresponding to the position of the pixel data. While referring to it, output data 71 a total of 64 times such that the first 20 pieces of data are 1° and the latter 44 (64-20) pieces are 0. case). However, at this time, data is of course set in the other stages of the shift register 234 according to the gradation level of the corresponding pixel, and in the case of a fusible ink sheet, data is output a total of 16 times.

At this time, the pulse width of each strobe signal STB is changed in accordance with the number of outputs of the STB signal, as shown in FIG. 10, for the reason shown in FIG. 9. The strobe signal generation circuit 442 executes such pulse width adjustment of the STB signal. As described above, this strobe signal generation circuit 442 receives the gradation data corresponding to the type of ink sheet 132 from the corresponding ROM table, and the width and period of the STB signal 445 correspond to the type of ink sheet 132. etc. are being adjusted.

[Operation Description of Color Printer (FIG. 11)] First, the sequence of color printing will be explained with reference to the flowchart shown in FIG. 11. The control program shown in this flowchart is stored in the ROM of the CPU 42.

First, in step S1, the image signal input terminal shown in FIG. 1A is selected, that is, the telephone line input terminal 31 or the video input terminal 3.
Enter from 6 automatically or manually.
The color image data input in step S2 is
It is stored in the GB memory 38. Next, in step S3, the thermal head 130 is brought into contact with the platen 120. At this time, the mold drive motor 131 causes the t-return coil spring 23 to
By appropriately charging the pressure of the head 130 and the platen 120, the pressure is optimal for thermal transfer printing.

Next, in step S4, rotation of the platen 120 and winding of the ink sheet 132 are started, and the initial position of the ink sheet 132 shown in FIG. 5 is performed. Here, the phototransistor 136 that detects the signal from the photodiode 135 is 135-1, 136-1 for detecting the mark 16a shown in FIG. 5, and 135-2, 136- for detecting the mark 16b. The ink sheet 132 is made up of two sets of 2, and the ink sheets 132 are rolled six times in the direction of the arrow shown in FIG. 5 until the ink sheet 136-1 outputs a detection signal in step S5.

In step S5, the mark 16a is the phototransistor 13.
6, it means that the thermal head 130 and the ink sheet 132 are set at positions where they can print with each other. In this way, in step S6, the ink sheet 1
The winding of the mark 16 and the rotation of the platen 120 are stopped, and the photo sensor 136-2 detects the mark 16 in step S7.
By detecting b, the type of ink sheet 132 is determined. That is, when the mark 16b is detected by the reflective photosensor 136-2, the ink sheet 13
2 is a sublimable ink sheet, the process proceeds from step S7 to step S8, and the photosensor 136-2 marks 1.
If 6b is not detected, the process proceeds to step S12 as a meltable ink sheet. The type of ink sheet detected here is stored in the RAM of the CPt 142 and used for control described later.

In step S8, the switch 448 is switched to the (a) side, and the display unit 46 indicates that it is a sublimation ink sheet.
In step S9, it is determined whether recording paper for sublimable ink sheets is stored in the cassette 201. If the recording paper for sublimable ink sheets is stored in the cassette 201, the process advances to step S9 and the thermal head 130 is Move it up and away from the platen, and then move the motor 206 in step Sll.
The pickup roller 203 and separation roller 204.
205 is driven to feed recording paper from the cassette 201 to the platen 120 side.

On the other hand, when using a fusible ink sheet, the switch 448 is switched to the (b) side in step S12, and the display unit 448 is switched to the (b) side.
6 indicates that it is a meltable ink sheet, and in step S13 it is checked whether plain paper is stored in the cassette 101. If plain paper is stored, the process advances to step S14, the thermal head 130 is raised, and the process advances to step S15, where the pickup roller 103 and separation roller 1041
05 is driven by the motor 106, and the plain paper is transferred to the platen 1.
Feed paper to the 20 side. Note that step S9 and step S
If the corresponding recording paper does not exist in Step 13, step S1
Proceed to step 6 and perform error processing such as paper out display. Note that during the paper feeding operation and initial positioning of the recording paper (steps S17 and 522) shown below, the ink sheet does not reach the platen 12.
In order to prevent the ink sheet 132 from being fed due to zero rotation, the head 130 is moved slightly away from the platen 120 before paper feeding to prevent the ink sheet 132 from being fed together with the recording paper.

Next, in step S17, the platen 12 (not shown)
The rotational position of the platen 120 is detected by the rotational phase angle detector 0, and if it is determined in step S18 that the position of the recording paper is at a recordable position, the thermal head 130 is lowered in step S19 and the platen 120 is rotated.
The recording process shown in the flowchart of FIG. 12C is performed in step Sho, and the image data for one color (
Y data) is recorded for one page. At this time, head 1
The pressing force 30 is controlled to a predetermined pressing force optimal for each ink sheet according to the type of the ink sheet 132. When the image data for one color has been recorded for one page, the process advances to step S21, and the paper guide lever 126 is moved to the position shown by the solid line in FIG. 1C.

Next, in steps S22 and S23, the recording paper is conveyed to the recording position again by rotation of the platen 120. That is, based on the rotational position of the platen 120, the platen 120 is rotated until the recording paper and the ink sheet 132 are placed at the recordable position. Next, in step S24, color recording of the next color is performed. Note that during the recording operation in step S20 and step 324, as described above, the strobe signal generation circuit 442 outputs the STB signal 445 corresponding to the attached ink sheet 132.

Further, in this recording operation, from the time when the recording paper reaches a position where recording is possible, the ink sheet 132 is also driven at the same moving speed as the recording paper to perform recording. Thus the steps,
If it is determined in S25 that recording has been completed for each of the three YMC color data, the process proceeds to step 326.

In step 526, the paper ejection lever 126 is turned off and the first
Then, in step S27, the platen 120 rotates to eject the recorded recording paper onto the tray 125, and in step 328, the platen 120 stops rotating. Next, in the process of step S29, if recording is to be continued, the process returns to step S3 and the above-described operation is performed.

FIG. 12C is a flowchart showing the recording process of the embodiment shown in steps S20 and 24 of FIG. 12B.

In step S30, the type of ink sheet installed is determined based on the information stored in the RAM of the CPtJ42, and if it is a fusible ink sheet, a 4-bit count is instructed by the instruction signal 61 in step S31, and the instruction signal 5
In step 3, the read data of the conversion memory 52 is changed to data for the fusible ink sheet. On the other hand, if it is a sublimable ink sheet, the process proceeds to step S32, and instruction signals 53 and 61 for the sublimable ink sheet are output. One pixel data is read from the buffer memory 43 in step S33, the (x, y) address signal 54 is set to (0°0) in step S34, and the address signal 54 is set to (1, O) in step S35. Then, in step 536, it is checked whether reading of data for one line is completed, and steps S33 to S36 described above are executed until reading of data for one line is completed.

When recording for one line is completed in this way, step S37
Proceed to , determine the type of ink sheet installed,
In steps 338 and 39, the recording paper feeding speed corresponding to the type of ink sheet is set, and in step S40, the recording paper is conveyed for one line at a speed corresponding to the type of ink sheet. This is because the recording time is shorter with a meltable ink sheet than with a sublimable ink sheet, and furthermore, the gradation level of one dot is 1/4th that of a sublimable ink sheet.
Therefore, the recording time of the fusible ink sheet can be significantly reduced compared to the case of the sublimation ink sheet, and in the case of the fusible ink sheet, the paper feeding speed can be increased.

In step S41, data on the same line as in step S33 is read out, and in steps S42 to S44, the second line of the dot matrix is recorded. When one line of pixel data is thus recorded in two lines, the process advances to step 345, and the recording paper is conveyed in the same manner as in step S40. In this way, if the recording of image data for one page is not completed in step S46, the next read address of the buffer memory 43 is set in step S47, and the process returns to step 333, and the process described above is continued until the recording process for one page is completed. processing is executed.

As explained above, according to this embodiment, it is possible to detect the type of ink sheet installed and perform recording control corresponding to that sheet, so even if a fusible ink sheet is installed, It has the effect of recording the key.

Further, there is an effect that images of the same size can be recorded by any ink sheet.

[Effects of the Invention] As explained above, according to the present invention, recording with good gradation is possible even when using a meltable ink sheet as in the case of a sublimation ink sheet, and reproduction is possible with any ink sheet. This has the effect of making the images the same size.

[Brief explanation of the drawing]

1A and 1B are block diagrams showing the configurations of the image processing section and the printer section of the color printer of the embodiment. FIG. 1C is a side sectional view of the mechanical section of the printer section of the color printer of the embodiment. FIG. 2A 2B is a block diagram showing a schematic configuration of a head drive pulse control circuit, FIG. 2B is a configuration diagram of a pixel data conversion table, and FIG. 2C is a diagram showing recording density with respect to applied energy for each of the meltable ink sheet and the sublimable ink sheet. , Fig. 2D is a diagram showing an example of a pixel conversion matrix, Fig. 2E is a flowchart showing the conversion data creation process of the conversion memory, Fig. 2F is a diagram showing an example of the conversion data matrix, and Fig. 2G is a diagram showing input pixels and the use of each sheet. 3 is a perspective view showing the pressing mechanism of the thermal head shown in FIG. 1C; FIG. 4 is a top view for explaining the marking on the recording paper in the embodiment; The figure is a top view for explaining the ink sheet in the embodiment, FIG. 6 is a top view showing the arrangement of the paper guide/idle lever, platen, and recording paper shown in FIG. 1C, and FIG. 7 is the same as in FIG. 1. 8 is a block diagram showing details of the thermal head in the embodiment; FIG. 9 is a diagram showing the relationship between head energization time and image density in the embodiment; 10. The figure is a waveform diagram of signal pulses for driving the thermal head in the printer unit of the embodiment, and FIG. 11 is a flowchart showing the recording processing procedure in the color printer of the embodiment. In the figure, 16a, 16b... Mark, 30... Image processing unit, 34... Color demodulator, 35... RGB decoder, 38... RGB memory, 40... Color conversion circuit, 41 ...Printer section, 42...CPU, 43...
- Buffer American sled, 44... Head drive pulse control circuit, 45... Pixel data conversion table, 46... Display section, 52... Changing fishing memory, 53.61... Instruction signal, 101.2011 - Cassette, 120I...Platen, 126...Paper guide lever 130...Thermal head, 132...Ink sheet, 1315-Photodiode, 136...Phototransistor, 230...
...Heating resistance element, 231...Output transistor, 2
32...AND circuit, 233...Latch circuit, 23
4...Shift register, 301...Plain paper, 302
. . . Sublimation recuperative transfer recording paper, 440 . . . Gradation conversion decoder, 441 . . . Gradation counter, 442 . 444...gradation data, 445...
- Strobe signal STB, 447... Gradation ROM for fusible ink sheet, 448... Switch, 450...
- Oscillator, 451... is a frequency dividing circuit. ΔE - High 1) Ink grt work full Y- Fig. 2C Fig. 2D Fig. 3 Wearing nine ducks sublimation! #! ! , transcription guide Figure 4 Figure 5 Figure 8 Figure 7 Ntl group diagram Figure 9 Figure O

Claims (2)

[Claims] (1) A thermal recording device that records by a thermal transfer method via an ink sheet, which includes a means for determining whether the installed ink sheet is a melting ink sheet or a sublimation ink sheet, and when installing the meltable ink sheet. , a first gradation determining means that divides input one pixel data into a plurality of dots corresponding to each heating element of the thermal head and determines the gradation degree of each dot in accordance with the gradation degree of the input pixel; When installing the ink sheet, allocate the plurality of dots to one input pixel data,
a second gradation determining means for determining the gradation of the plurality of dots in accordance with the gradation of the pixel data; and a gradation of each dot determined by the first and second gradation determining means. A thermal recording device comprising a recording means for recording by driving each heat generating element of the thermal head. (2) The plurality of dots are composed of an n×n dot matrix, and in the case of a sublimable ink sheet, each dot of the dot matrix is set to the gradation level of one input pixel data, and is recorded on the fusible ink sheet. 2. The thermal recording apparatus according to claim 1, wherein each dot of said dot matrix has a gradation level of 1/n^2 compared to that of a sublimable ink sheet.