JPH037355A - Thermal transfer recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer recording device, and particularly to a thermal transfer recording device that enables stable color printing.

[Conventional technology]

In a thermal transfer type recording device, printing is performed by causing a heating element constituting a thermal head to generate heat, and ink corresponding to the amount of heat generated is transferred from an ink paper to a recording paper.

At this time, one printing (floor!81) is performed by controlling the energy injected into one heating element (for example, the energization time) and changing the amount of heat generated by the heating element.

The ink paper used in color printers has layers of ink in three colors, yellow, cyan, and magenta, coated periodically and repeatedly.
The ink paper is sequentially supplied between the recording paper and the heating element.

By the way, in color printers, the coloring characteristics depending on the amount of heat generated by the thermal head differ depending on the color of the ink paper. If they are different, they must be different.

FIG. 8 is a diagram showing the relationship between the energization time to the thermal head and 1 degree for each of the ink sheets. In this way, even if the current application time is the same, the density at that time will be yellow, cyan, and magenta.

Furthermore, it is known that the density characteristics of even the same ink paper vary depending on the environmental temperature. However, in this specification, the environmental temperature refers to the temperature of the head substrate on which the thermal head is mounted.

FIG. 9 is a diagram showing the relationship between the energization time to the thermal head and the color density characteristics for each environmental temperature for ink paper of the same color. From the figure, it can be seen that in order to obtain the same concentration when the environmental temperature is low, it is necessary to increase the time during which the current is applied to the thermal head.

Therefore, when printing the above-mentioned three-color ink paper side by side to obtain one color image, the energization time is determined by (1) for each ring lft temperature, (2) for each gradation, (
3) Must be set for each ink paper.

Recently, to realize such printing,
As described in Japanese Patent Application Laid-Open No. 56-130379,
An apparatus has been proposed in which nine gradations of environmental temperature and ink paper are used as parameters, and a gradation ROM is provided in which energization time data for each gradation of three colors of ink paper is registered for each environmental temperature.

In addition, instead of selecting each temperature range and each gradation, select representative temperatures and gradations, and store that data in the gradation ROM. A method of calculating and interpolating data has also been attempted, but this method also requires a considerable amount of memory.

In addition, in such a conventional technique, if the i-environment temperature is extremely low and the temperature does not reach the range registered as a parameter in the gradation ROM, preheating is performed to raise the environmental temperature.

[Problem to be solved by the invention]

The above-mentioned conventional technology has the following problems.

That is, since the above-mentioned gradation ROM requires a large capacity, there is a problem in that it becomes expensive.

Furthermore, in the apparatus configured as described above, the environmental temperature is determined (1) immediately before printing one sheet of pudding 1- or (2) immediately before printing each color using an appropriate means such as a temperature sensor. Then, the energization time data corresponding to the ll++1 constant result was read from the gradation ROM.

The relationship between the environmental temperature and time when printing is performed in this manner is shown in No. 212I.

In the method (1) above, in which the environmental temperature immediately before printing one page is determined 6111 and the energization time is selected based on the result, ideally, the environmental temperature, It is also desirable that the head substrate temperature be the same value at the start of printing for each color, as shown by the solid line in the figure.

However, in reality, the temperature of the head board rose during printing of the first color, and the printing of the first color was completed! Then, because it takes time to locate the beginning of the ink paper for the first color, the temperature of the head board will drop somewhat during that time, but when printing of the next color starts, the temperature will be the same as that of the previous color. The temperature is not the same as when it starts, and the temperature of the hent substrate gradually increases as shown by the broken line.

As a result, there was a problem in that a faithful color image could not be obtained due to the relationship between a degree and the environmental temperature explained with reference to FIG.

On the other hand, in method (2) above, which measures the environmental temperature immediately before printing each color and selects the energization time based on the result, even if the head substrate temperature is measured at the end of printing the first color, Since the heat generation temperature of each heating element differs depending on the pattern of the first color pudding 1~, temperature unevenness occurs on the head substrate.

In home thermal transfer recording devices, a line head of 61 mm/image is used as a thermal head, for example,
Most print images are 486 dots (81 inclination) in the vertical direction and 512 dots (85,3 ann) in the horizontal direction, and the image sources are TVs and VTRs.

Optical discs, CDs, computer graphics (CG)
), most of the images are still images from video movies, etc., so when using a thermal head of the size mentioned above, the temperature distribution of the head substrate is uniform at the end of printing each color, especially the first color. There are very few cases where this happens.

Therefore, depending on the location of the headboard, the al! There are areas with higher temperatures and areas with lower temperatures than the I constant results, and this temperature unevenness causes color unevenness, which again poses a problem in that a faithful color image cannot be obtained.

An object of the present invention is to solve the problems described in -L-, to provide an inexpensive thermal transfer recording device that makes it possible to obtain faithful color images.

[Means to solve the problem]

In order to solve the above problems, the present invention has taken the following measures.

(1) In a thermal transfer recording device that performs color printing in a field sequential manner based on color screen information, the temperature TO of the support on which the thermal head is mounted is i11! The temperature detecting means for determining
A preheat determining means outputs a preheat command if I'2, and outputs a print command when -1゛0≧T2 and then 'rO≦T1; and means for heating the thermal head.

(2) Using the color of the ink paper and the gradation of the image as parameters, it is possible to print when the temperature of the support is at the planned temperature.
The heating means further includes a storage means in which data indicating an appropriate thermal/ped heating time is registered in advance, and the heating means selects the optimal thermal for printing from the storage means according to the color of the ink paper and the gradation of the image. The head heating time was selected and the thermal head was heated for the selected heating time.

(Function) (1) After the above-mentioned preheating is completed, the temperature of the support is sufficiently heated, so the temperature unevenness of the support becomes smaller, and as a result, the temperature unevenness of the thermal head is also reduced and stabilized. You can now print.

(2) In the storage means configured as described above, since temperature is not a parameter, the storage capacity can be reduced.

〔Example〕

FIG. 1 is a block diagram for explaining the basic concept of a thermal transfer recording apparatus according to the present invention.

In the figure, the temperature detection means 7 detects the temperature of the hens 1 to 3, that is, the environmental temperature 1'0, based on the detection signal of the temperature sensor 6 installed on the head substrate 3, and detects this as the preheat determination means 8. Output to.

As will be described in detail later, the preheat determination means 8 compares the environmental temperature To and a preset lower limit temperature Tl.

The current application time determining means 2 compares the temperature with the upper limit temperature T2 and issues a preheat command or a print command according to the comparison result.
Output to.

The energization time determining means 2 further includes an image source 1° gradation ROM 4 in which digital image data of the print screen is stored.
and a thermal head 5 are connected.

In the thermal transfer recording apparatus having such a configuration, when printing is started, the temperature detection means 7 detects the environmental temperature 'rO using the temperature sensor 6, and outputs the value to the preheat determination means 8.

A lower limit temperature T1, which is the lowest environmental temperature that can guarantee faithful color printing, and an upper limit temperature T2, which is the highest temperature, are registered in advance in the preheat determination means 8, and the environmental temperature TO is set as the lower limit temperature. Compare with temperature T1 and upper limit temperature T2. Then, when the environmental temperature To is in a state of Ω degrees that can guarantee faithful color printing, print 1~ commands are output to the energization time determining means 2.

The gradation ROM 4 uses the color of the ink paper and the gradation of the image as parameters. Data indicating the optimum thermal head heating time for printing is stored in M8 in advance.

Upon receiving the print command, the energization time determining means 2 determines the optimum energization time for printing the pixel based on the signal indicating the ink paper output from the image source 1 and the signal indicating the gradation of the pixel to be printed. The thermal head is heated based on the selection from the control ROM4.

Further, the preheat determining means 8 does not output a print command when the substrate 3 is in a state where faithful color printing cannot be guaranteed, and the environmental temperature T is maintained.

If the temperature itself is too low or if there is a possibility that there is large temperature unevenness on the board even if the temperature itself is appropriate, a preheat command is output, and if the environmental temperature 1゛0 is too high, neither of the above commands is output. It goes into a standby state without outputting.

FIG. 10 is a flowchart showing a method of controlling the thermal transfer recording apparatus by the preheat determining means 8, and FIG.
The figure shows the temperature change of the head substrate 3 (environmental temperature) when color printing is performed in a frame sequential manner according to this control method.

When the print operation is started at time L1, step S1
In step S2, the recording paper is fed, and in step S2, initial settings such as ink head positioning and detection of the first line print position are performed.

In step S3, the temperature sensor 6 detects the environmental temperature To.
is detected, and its value is output to the preheat determining means 8. The determining means 8 compares the environmental temperature TO and the upper limit temperature T2.

In the example shown in FIG. 3, immediately after the start of the printing operation, the environmental temperature TO<the upper limit temperature T2, and the temperature is too low to guarantee faithful color printing, so the process moves to step S4.

In step S4, a preheat command is output from the preheat determining means 8, and the energization time determining means 2 heats the thermal head in accordance with the preheat command, and as a result, the temperature of the head substrate 3 gradually increases.

In step S5, the environmental temperature is monitored, and the environmental temperature To<
Preheating is continued in step S4 during the upper limit temperature T2.

At this time, the environmental temperature To exceeds the lower limit temperature T1 before the environmental humidity To reaches the rising temperature T2.

Lower limit temperature Tl<environmental temperature To<upper limit temperature T2, and looking only at the temperature, it means that the environmental temperature has reached a temperature that can guarantee faithful color printing, but this state is
Since there is a possibility that there is a large temperature unevenness in Stops output and enters standby state.

In step S7, heating by the energization time determining means 2 is stopped, so that the head substrate 3 is cooled.

In step S8, the environmental temperature TO and the upper limit temperature T1 are compared in the pre-1 determination means 8, and the environmental temperature TO
>If the lower limit is degree T1, the process moves to step S7 and cooling of the head substrate 3 is continued.

When the environmental temperature TO≦lower limit temperature T1 is reached at time 3, printing starts from the first line of the first color in step S9, and in step S10, it is determined whether printing of all lines of the first color has been completed. If it is determined that the process has not ended, the process moves to step S9 to continue printing.

When printing of all the lines of the first color is completed at time L4, the process advances to step Sll, where it is determined 11)i whether printing of gold has been completed.

If the process has not been completed, the process moves to step S2, where the initial settings such as the beginning of the second color ink and the detection of the 1st line print position are performed in the same way as in 11; J. It will be done.

At this time, during printing of the first color, the thermal head is heated according to the image data, so the temperature of the head substrate 3 gradually rises, and when printing of the first color is finished, the upper limit temperature T2 is reached. In such a case, the process will proceed from steps S3 to S8.
Move to 7.

In steps 87 to S8, the process waits until the environmental Ω degree 1゛0≦lower limit - degree T1.

At time L5, when the environment temperature TO≦lower limit temperature Tl is again established, printing starts from the first line of the second color opening in step S9, and printing of all lines of the second color is finished at 1 hour 6. Then, the process returns to step S.
Move to 2.

At this time, if the heat generation rate of the thermal head due to printing of the second color is small, the temperature at the end of printing will be the upper limit temperature T.
Lower than 2. Therefore, in step S4, the thermal head is heated by the preheat execution means, and as a result, the temperature of the head substrate 3 gradually rises.

Thereafter, in step S8, when the environmental temperature To≦lower limit temperature T1, printing starts from the first line of the third color,
Printing for one sheet is completed at time L9.

As described above, according to this embodiment, the environmental temperature 1゛0 is raised until the environmental temperature TO≧upper limit temperature 1゛2, and then printing is started after cooling to the environmental temperature 'rO≦lower limit temperature T1. Therefore, at the start of printing, the temperature of the head substrate 3 becomes uniform, making it possible to perform faithful printing.

FIG. 16 is a block diagram showing the configuration of the main parts of a thermal transfer recording apparatus which is an embodiment of the present invention.

The same reference numerals as in FIG. 1 represent the same or equivalent parts.

In the figure, when a system controller 62 that controls the entire system of the thermal transfer recording apparatus requests image data, one screen worth of image data is output from the image source 1 to the system controller 62.

In response to a request from the system controller 62, the temperature detection circuit 68 detects the environmental temperature TO based on the detection signal of the temperature sensor 6, and outputs this to the system controller 62.

The system controller 62 has the lower limit temperature of one stomach '■゛1.
and upper limit temperature T2 are registered, and as described above, the environmental temperature TO is compared with the lower limit temperature T1 and upper limit temperature T2, and a preheat command or a print command is output to the energization time control circuit 63 according to the comparison result. do.

The energization time control circuit 63 to which the print command is manually input receives energization time information corresponding to the color and gradation of the ink paper from the one-gradation ROM 4 and outputs the energization time information to the intermediate control circuit 64.

The intermediate control circuit 64 sequentially receives the energization time information output from the energization time control circuit 63 and outputs a strobe signal indicating the energization time to the thermal head 5.

FIG. 4 is a sectional view of the temperature sensor 6 of the thermal head 5 shown in FIGS. 1 and 16 and the Hen FiJ board 9 which has been dried for a month, and FIG. 5 is a two-sided view thereof.

In the figure, 6 is a temperature sensor attached to a heat sink 901, 902 is a lead wire, 90J is a mounting hole for the temperature sensor 6,
904 is an alumina ceramic substrate, 905 beam 1 to wire 902. Board 909 is a flexible board;
10 is a navel cover, 911 is a pressing rubber, and 912 is an IC that electrically constitutes a thermal head 5, which will be described later.

In Fig. 5, the parts not covered in the above explanation will be described.

913, 913b, 914tL, and 914b are mounting holes for positioning the thermal head 5, 915 is a compression spring (not shown) mounting hole, and 916 is a mounting hole for the heat sink 901.

Next, FIG. 6 shows an electronic circuit configuration diagram of the thermal head 5, and FIG. 7 shows a waveform diagram of the signals shown in FIG. 6, and the circuit configuration and its operation will be described.

Color printing using the field sequential method is yellow.

Color recording is completed by sequentially transferring three colors of ink, magenta and cyan, over one page for each color, and one page of each color is printed on the print 1.

This is done by performing line printing over the number of lines equivalent to one page.

At this time, gradation expression in one line is achieved by making the total energization time for the heating element corresponding to the high part of one gradation longer than that for the heating element corresponding to the lower part of the gradation. be exposed.

In FIG. 6, the shift register 501 includes the shift register 501 shown in FIG.
As shown in c), data for one line consisting of a total of 64 types of pulse trains, 0 gradation pulse train, 1 gradation pulse train...63 gradation pulse train, necessary to print 1 line, is sequentially generated. Cursed data is human-powered.

Each bit making up each gradation pulse train corresponds to each heating element making up the heating element.
A heat generation signal of 1'' is output.

For example, the pulse at the focus position corresponding to a heating element printed at 63 gradations is °゛1''' in all of the O gradation pulse train to 63V;
The pulse corresponding to the heating element that prints in gradation is "l\" in all of the O gradation pulse train to 30 gradation pulse train.
", L10'' in all of the 31st to 63rd gradation pulse trains.

Therefore, during printing for one line, 64 pulses are input to the heating element that prints at 63 gradations, and 30
Since 31 pulses are manually applied to the heating element that prints in gradation, the total energization time can be controlled.

Now, the OrQ pulse train is changed to I'! by the clock pulse (d). When the a-th shift register 501 is manually inputted, a data string corresponding to the O gradation pulse string is registered in the shift register 501. This data column is

When the latch pulse (a) falls, it is input to the latch, and the strobe pulse (head energization pulse) (f) is “L”.
Only during the period of level 11, head dry/<5 (13 energizes the heating element 504, and the head voltage becomes
04.

During printing of this O gradation, the next gradation, the 1st gradation pulse train, is input to the next shift register 501 at around j by the clock pulse (d), and in the same manner, when printing of the 63rd gradation is completed, This means that printing of one line of a certain color has been completed.

In the gradation control system having such a configuration, the pulse width of the strobe pulse (f) is determined by the data registered in the gradation ROM 4.

Further, when the preheat command (a) is output from the system controller 62 (Fig. 16) to the energization time control circuit 63, all the heating elements are Data for heating (C), clock pulses (d), strobe pulses (f), etc. are output to the thermal head 5 prior to printing. During the strobe pulse preheating during this period, the substrate 9 is not pressed against the ink paper. Therefore, the ink on the ink paper is not thermally transferred to the recording paper due to preheating.

For example, when a sublimation transfer recording method using a sublimable dye as an ink is adopted as a thermal transfer recording method, the sublimation temperature of the three color inks is approximately 80°C to approximately 200°C;
The total time width of the strobe pulse required to obtain the maximum 1 degree of 63 gradations with a reflection density close to 2 in Figure (f) depends on the head potential, but is usually selected to be about 20 milliseconds.

As shown in Figure 8, the current application time and the color density are not linear over the entire area, but if it is assumed that they are linear,
The current application time corresponding to the gradation is approximately 0.3 milliseconds, and at this time the temperature of the heating element 504 is approximately 180"C to 20"C as described above.
Since the temperature is 0° C., if a strobe pulse with a total time width of less than 0.3 milliseconds is generated, the head substrate temperature easily reaches the second limit temperature (approximately 40° C.).

When the head substrate temperature reaches the upper limit temperature, the head substrate 3 is pressed against the ink paper and allowed to cool naturally until the substrate temperature falls to the lower limit temperature.

According to the present invention, the energization time data for each gradation of three-color ink paper at the lower limit temperature T Since there is no need for separate data, the memory capacity is significantly reduced, which has an economical effect.

Furthermore, as a trend in future home-use thermal transfer recording devices, it is expected that a plurality of ink papers with different sensitivities will be used depending on the recording source. Even in this case, the present invention is advantageous in that it can be handled by having only energizing time data for each color and each gradation for each ink paper.

Next, one embodiment of the method for detecting the head substrate temperature, which has been mentioned more than once, will be described with reference to FIGS. 11 and 12.

In FIG. 11, resistors R1 to R5 and R6 to R11
constitutes a "ladder type D/A conversion circuit", and the resistor R
The values of 1 to R5 are twice the values of resistors R6 to R11, respectively. DAO (LSB) to DA4 (MSB) which are digital output signals from the system controller 62
When is output, the corresponding DC voltage is applied to the resistor ■ 1
Occurs at both ends of 1.

This voltage is inverted by the next stage operational amplifier A1.

It is manually applied to comparator A2 as reference voltage Vg.

On the other hand, the constant current output from the constant current circuit composed of transistors Q1 and Q2 and resistors R14 to 1<16 is resistor R1.
7, R18, and a temperature sensor 6, typically using a thermistor. Since the resistance value of the temperature sensor 6 changes depending on the temperature, the head substrate temperature is determined by the DC comparison voltage V.
It is converted and detected as p and applied to the non-inverting input terminal of comparator A2.

When a thermistor is used as the temperature sensor 6, the temperature-resistance characteristic of the thermistor exhibits nonlinearity as is well known. However, by appropriately selecting the values of the resistor R18 connected in series and the resistor R17 connected in parallel, the characteristic between temperature and comparison voltage Vp can be made linear within a certain humidity range.

To detect the head substrate temperature, that is, the comparison voltage Vp, the digital output signal DAO of the system controller 62 is used.
- Count up the 5 bits of DA4 from the state of 0 one pin at a time. Then, at some point, the output voltage of the comparator A2 is inverted from 0 to 1, so the head substrate temperature can be detected from the digital output signal at that time.

The characteristics of the temperature detection circuit 68 shown in FIG. 11 are shown in more detail in FIG. 12.

In Figure 12, the vertical axis is the digital output, that is, the first
1 shows the resolution of the reference voltage Va in FIG.

The comparison voltage Vp obtained by converting the aforementioned head substrate temperature into a DC voltage has a substantially linear relationship with the reference voltage VM. Therefore, as described above, the head substrate temperature can always be detected by the change in the output of the comparator A2.

Next, another embodiment of the thermal transfer recording apparatus according to the present invention will be described as a first embodiment.
Shown in Figure 3. The difference between FIG. 13 and FIG. 16 is that in FIG. This is because it is added to the voltage control circuit 11 that controls the output voltage of the power supply circuit 10.

A specific example of the added power supply circuit 10 and voltage control circuit 11 is shown in FIG.

In FIG. 14, the signal is output from the system controller 62. For example, a 2-bit control signal is input to the D/A conversion circuit 111 and converted to a DC voltage.The output signal converted to a DC voltage is sent to the D/A converter circuit 111 through a buffer amplifier A3.
It is supplied to the control terminal of the terminal regulator 101, and controls the output voltage V= of the voltage supply transistor Q3, that is, the head power supply voltage. Note that 102 is an input terminal for unstabilized DC voltage, R19 is a bias resistor, and C1 and Ca are smoothing capacitors.

System controller 6 shown in FIGS. 13 and 14
The head power supply voltage VA controlled by 2 will be explained with reference to FIG.

In FIG. 15, four types of power supply voltages indicated by 1 to v4 are determined based on digital signals output from the system controller 62.

As shown in the figure, (1), ~V, are used for preheating, and (4) is used as the head power supply voltage during printing. That is, when a print command is output from the user of the thermal transfer recording apparatus, the system controller 62 detects the head substrate temperature after initial setting as described above.

At this time, if the substrate temperature is very low, a large amount of time is required for preheating, so a high power supply voltage V□ is supplied to the thermal head 5.

In addition, if it is necessary to preheat a little because the head substrate temperature has not reached the set temperature T2 at the end of printing the second color, as in the state at time t6 in FIG. 3, under the control of the system controller 62, Ensure that a relatively low power supply voltage ■ is supplied.

As mentioned above, by using a higher voltage for the head power supply voltage during preheating than during printing, the preresult is -
The printing time required to obtain one color image is reduced.

In the explanation so far, all data 1 was input to the thermal head 5 under the control of the system controller 62 in order to make all the heating elements generate heat equally during preheating. Since the data of the image source 1 in FIGS. 16 and 13 already exists, the image data may be used as the data at the time of preheating.

Additionally, using a fan to reduce cooling time
It was not possible to uniformly cool the entire head board, and the cooling had to be done locally.

Temperature distribution will occur on the substrate.

As a method for solving this problem, there is a method in which the mechanism for pressing and releasing the head substrate on the drum is moved, that is, the head substrate is moved up and down at least once according to a command from the system controller 62.

In this way, the head substrate can be uniformly cooled and the cooling time can be shortened compared to when the head substrate is left to cool naturally.

Note that the temperature reached during preheating (upper limit temperature) and the temperature reached during cooling (lower limit temperature) do not need to be fixed values.
A temperature setting knob may be provided so that the user can freely select and set the temperature.

Furthermore, since printing time increases when preheating and cooling processes are added, an on/off switch for preheating and cooling may be provided.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to always keep the temperatures of the three colors the same immediately before printing and to make the temperature distribution inside the head substrate uniform, so that a certain ink paper color among the three colors can be made uniform. Uneven coloring due to dark or light printing,
There is no temperature variation, and printed images that are faithful to the original can always be obtained. Furthermore, according to the present invention, since printing starts at the same head substrate temperature for all three colors of ink paper, the data stored in the Ill tone ROM reduces the memory capacity of the tone ROM compared to the conventional method. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining the basic concept of the thermal transfer recording apparatus of the present invention, FIGS. 2 and 3 are explanatory diagrams of embodiments,
Figures 4 and 5 are structural diagrams of the head board, Figures 6 and 7 are electrical block diagrams and waveform diagrams of the head board, Figures 8 and 9 are 1-degree characteristic diagrams of ink paper, and FIG. 10 is a flowchart for explaining FIG. 1, FIGS. 11 and 12 are specific circuits and waveform diagrams of the temperature detection circuit, FIG. 13 is a block diagram of another embodiment of the present invention, and FIG. FIG. 13 is a specific circuit diagram of the voltage control circuit and power supply circuit, FIG. 15 is a waveform diagram of the output voltage of the power supply circuit, and FIG. 16 is a block diagram showing an embodiment of the thermal transfer recording device of the present invention. be. 1... Image source, 2... Energization time determining means. 4... Floor I ROM, 5... Thermal head, 6... Temperature sensor, 8... Preheat determination means, 62... System controller. Akikuni〈-Gin Saine Nakko 4 Kuni Daimide=S Ko Akira Otoguchi Akira Ward〔1 Pukunn-Sirototopwa ℃-To A1Phi===:===:::Norakunov)nt== =========Honna/σguchi Taro// 15th Otsu to Akira Kuchi 72

Claims (1)

[Scope of Claims] 1. In a thermal transfer recording device that performs color printing on recording paper using ink paper in a field-sequential manner based on color screen information, there is provided a support on which a thermal head composed of a large number of heating elements is mounted. A temperature detection means for measuring body temperature T0; and comparing the temperature T0 with a preset lower limit temperature T1 and upper limit temperature T2, and determines whether T0<T0 before starting printing of each color.
If T2, output a preheat command, and T0≧T2
A thermal transfer recording characterized by comprising: a preheat determination unit that outputs a print command when T0≦T1 after T0≦T1; and a unit that heats the thermal head in accordance with the preheat command and the print command. Device. 2. A storage means is provided in which data indicating an optimal heating time for the thermal head for printing when the temperature of the support is T1 is registered in advance, using the color of the ink paper and the gradation of the image as parameters. , the heating means selects a heating time for the thermal head most suitable for printing from the storage means according to the color of the ink paper and the gradation of both images, and heats the thermal head for the selected heating time. The thermal transfer recording device according to claim 1. 3. The thermal transfer recording apparatus according to claim 1 or 2, wherein the preheating is performed by uniformly heating all the heating elements constituting the thermal head. 4. The thermal transfer recording apparatus according to claim 1 or 2, wherein the preheating is performed by heating the heating element constituting the thermal head based on arbitrary color screen information. 5. Any one of claims 1 to 4, further comprising a voltage control means for controlling the heating voltage according to the temperature T0, and the preheating is performed based on the output voltage of the voltage control means. The thermal transfer recording device described above. 6. A claim characterized in that it comprises a swinging means for sliding the support, and the swinging means swings the support after T0≧T2 and until T0≦T1. The thermal transfer recording device according to any one of claims 1 to 5. 7. The thermal transfer recording apparatus according to claim 1, further comprising temperature setting means for setting at least one of the lower limit temperature T1 and the upper limit temperature T2 to an arbitrary value.