JPH06286194A - Thermal transfer recorder - Google Patents

Abstract

PURPOSE:To delete necessary data amount without deteriorating image quality by multiplying by conversion factor the reference data and calculating desired data. CONSTITUTION:Before recording, a system controller 401 reads reference conducting data for realizing reference density characteristics under reference recording conditions and a conversion factor for realizing the reference density characteristics under selected recording conditions from a conducting data storage unit 501. Then, the controller 401 multiplies by the factor reference conducting time data to calculate conducting time data at all gradations under selected recording conditions, generates heat from a heat generator of a thermal head 7 in response to the calculated conducting time data, and halftone records.

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 printing an image having gradation, and in particular, can obtain a print of a constant halftone expression regardless of the difference in recording speed, the difference in color material and the like. The present invention relates to a thermal transfer recording apparatus suitable for.

[0002]

2. Description of the Related Art In a thermal transfer recording apparatus for carrying out halftone recording using a thermal head, control is carried out to reproduce predetermined halftone recording by controlling the energization time and recording density to the thermal head which are in a non-linear relationship. It is necessary to control the recording density depending on the head temperature to reproduce a predetermined halftone recording regardless of the temperature. In addition, when it is desired to change the density characteristic set in the apparatus, it is necessary to change the energization time to the thermal head.

As for the control, for example, Japanese Patent Laid-Open No. 1-133758 is disclosed. According to the present invention, the recording pulse width to the thermal head is generated so as to obtain the reference density characteristic according to the temperature of the thermal head detected before recording, and recording is performed. Further, as a means for changing the density characteristic, there is known a means for using a look-up table (hereinafter referred to as LUT) to perform conversion so that the gradation characteristic of the image data becomes the density characteristic to be changed. .

[0004]

Of the above-mentioned conventional techniques,
The control technique is that a substantially constant density characteristic can be stably obtained irrespective of the temperature of the thermal head. As shown in FIG. 2, in addition to the reference density characteristic, density characteristics A and B should be realized. When changing the recording conditions, such as when the recording density is changed or the same density characteristics are used regardless of the recording speed and the color material used, data on the energization time to the thermal head is required for each. There was a problem that was increased. Further, the technology relating to the density characteristic change is that the density characteristic can be changed without changing the energization time to the thermal head. However, when the LUT is used, the number of gradations is compressed depending on the density characteristic to be changed. If the number of tones is small or there are few tones, there will be more tones than necessary and faithful halftone reproduction will not be possible,
There was a problem that the image quality deteriorates.

The object of the present invention is to solve the above problems,
It is an object of the present invention to provide a thermal transfer recording apparatus capable of performing stable halftone recording without increasing necessary data even if recording conditions are changed, and always performing good recording without image quality deterioration.

[0006]

In order to achieve the above object, the present invention changes the reference energization time data in advance under the reference recording conditions and the recording conditions such as density characteristics, recording speed, recording density and the like. The changed energization time data is set, the ratio between the reference energization time data and the changed energization time data is obtained as a conversion coefficient, and the reference energization time data and the conversion coefficient for changing the recording condition are stored in the ROM. It is recorded in storage means such as. When a recording condition other than the reference is selected at the time of recording, the reference energization time data and the conversion coefficient for the selected recording condition are read from the storage means, and the reference energization time data is multiplied by the selected conversion coefficient. Then, energization time data for all gradations under the desired recording conditions are calculated, and recording is performed using the energization time data.

[0007]

The required amount of data can be reduced because the energization time data to the thermal head is constructed and stored only by the data under the standard recording conditions and the conversion coefficient when the recording conditions are changed. Further, since the energization time data after the change is obtained for all the gradations, it is possible to obtain a good recording result without the deterioration of the image quality without the number of gradations being compressed or the gradations being excessively large.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a thermal transfer recording apparatus according to the present invention, in which 1 is an image source and 2 is an image source.
Is an image memory, 3 is a halftone control unit, 401 is a system controller, 501 is an energization data storage unit, 6 is an analog / digital conversion unit (hereinafter referred to as A / D unit), 7 is a thermal head, 8 is a thermistor, Reference numeral 9 is an ink paper, 10 is a recording paper, 11 is a drum, and 12 is a density characteristic switching unit.

FIG. 2 is a density characteristic diagram realized by the embodiment shown in FIG. 1. In addition to the reference density characteristics, there are density characteristics A and B, where the vertical axis is density and the horizontal axis is gradation. The reference density characteristic is set for a video input image, for example, and is provided with contrast so as to have sharpness. Concentration characteristic A
Is, for example, one in which the densities are visually evenly distributed. The density characteristic B is, for example, one in which the relationship between gradation and density is linearly set. Hereinafter, an operation of selecting and recording one type from two or more types of density characteristics will be described.

Image data taken from the image source 1 before recording is written in the image memory 2. When a recording command is issued, the system controller 401 inputs the density characteristic information at the time of recording from the density characteristic switching unit 12.
Before recording the first color, the system controller 401 converts the temperature information from the thermistor 8 attached to the back surface of the thermal head 7 into digital data by the A / D unit 6 and then inputs it. According to the temperature of the thermal head 7, the system controller 401 first sets the energization data storage unit 501.
2 receives the reference energization time data to the thermal head 7 for recording the reference density characteristic shown in FIG. 2, and the density characteristic selected by the density characteristic switching unit 12 is other than the reference density characteristic, that is, in FIG. When the characteristic A or B is selected, the energization data storage unit 501 is changed to the density characteristic switching unit 1
The conversion coefficient for realizing the density characteristic selected in 2 is received. Further, the system controller 401 multiplies the reference energization time data by the conversion coefficient to calculate the conversion energization time data for realizing the selected concentration characteristic. The halftone control unit 3 reads the image data from the image memory 2, and at the same time, receives the calculated conversion energization time data from the system controller 401 and sends a strobe signal having a time width corresponding to the energization time to the thermal head 7. .
The thermal head 7 applies a current to the heating element for the time width of the input strobe signal, and the heating element generates heat accordingly.

The recording paper 10 is wound around the peripheral surface of the drum 11, and the ink paper 9 is superposed thereon and pressed by the thermal head 7. The heating element generates heat according to the energization time designated by the halftone control unit 3, and the first color ink is recorded and transferred from the ink paper 9 onto the recording paper 10 according to the amount of heat generation, and halftone recording is performed. Thereafter, recording is similarly performed for the second and subsequent colors, and the density characteristic selected by the density characteristic switching unit 12 is obtained. Next, the calculation of the reference energization time data at the temperature detected by the thermistor 8 and the calculation of the conversion energization time data for realizing the density characteristic selected by the density characteristic switching unit 12 will be described with reference to FIG.

FIG. 3 shows reference energization time data for realizing the reference density characteristic in the first embodiment of FIG. 1, in which the vertical axis represents energization time data and the horizontal axis represents gradation. Further, the reference energization time data is represented in the temperature direction at constant temperature intervals (for example, every 2 ° C.) (hereinafter referred to as a representative temperature sequence).

When a recording command is issued, the temperature of the thermal head 7 is detected by the thermistor 8 and converted into digital data by the A / D section 6 and then the system controller 401.
Entered in. In the system controller 401, representative temperature sequences Tm and Tn (Tm <T
s <Tn) is specified, each energization time data of the representative temperature series Tm, Tn is read from the energization data storage unit 501, and the reference energization time data at the detected temperature Ts is calculated. Hereinafter, the calculation of the reference energization time data at a certain gradation A will be described. When each energization time data of the representative temperature series Tm and Tn at the gradation A is DTm and DTn, and energization time data at the detected temperature Ts is DTs, DTs is expressed by the formula (1).

[0015]

## EQU1 ## DTs = a × DTn + b × DTm where a = (Ts−Tm) / (Tn−Tm) b = (Tn−Ts) / (Tn−Tm) By the above processing, the standard for all gradations is obtained. The energization time data is calculated. Next, the calculation of the conversion energization time data for realizing the density characteristic selected by the density characteristic switching unit 12 will be described.

When the reference energization time data is calculated by the equation (1), the system controller 401 reads the conversion coefficient FA from the energization data storage unit 501 according to the density characteristic information selected by the density characteristic switching unit 12, The conversion energization time data DTTs for realizing the density characteristic selected by the formula (2) is calculated.

[0017]

## EQU00002 ## DTTs = DTs.times.FA Note that the conversion coefficient FA is preset so as to realize the change data preset to realize the selected density characteristic and the reference density characteristic at a certain specific temperature. Ratio with the reference data, that is,

[0018]

[Equation 3] FA = changed data / reference data Further, the conversion coefficient is set for each color forming the ink paper 9.

Based on the conversion energization time data DTTs calculated by the above processing, the halftone control section 3 sends a strobe signal to the thermal head 7 for recording.

As described above, the energization data storage unit 501 only needs to store the reference energization time data and the conversion coefficient, and the data capacity can be reduced. In addition, since energization time data is set for all gradations, there is no deterioration in image quality.

FIG. 4 is a block diagram showing a second embodiment of the thermal transfer recording apparatus according to the present invention, in which 402 is a system controller, 502 is an energization data storage unit, 13 is a recording speed switching unit, and 141 is a drum motor. It is a control unit. Here, the recording speed is indicated by the recording time per line. In addition, the same members as those in the embodiment shown in FIG. 1 are designated by the same reference numerals.

FIG. 5 is a strobe signal diagram in the embodiment shown in FIG. FIG. 5A shows the reference recording speed, and FIG.
5B is a strobe signal when the recording speed is slower than the reference recording speed, that is, when the recording time per line is long, and FIG. 5C is when the recording time is faster than the reference recording speed, that is, when the recording time per line is shorter. Is shown. Also, H level is not energized,
The L level is energized. Here, when the speed is set to be lower than the reference recording speed, for example, it is set to obtain high density. When the recording speed is set higher than the reference recording speed, it is set, for example, for trial ejection. Generally, when recording with the same energization time data, if the recording speed is slowed, that is, the recording time per line is lengthened, the non-energization time to the thermal head 7 (the energization time is subtracted from the recording time per line) (Hereinafter referred to as a cooling time) becomes longer, the thermal head 7 is cooled more than necessary and the temperature is lowered, and the density is lowered over all gradations. Conversely, if the recording speed is increased, that is, the recording time per line is shortened, the cooling time is shortened, the thermal head 7 is not sufficiently cooled and the temperature rises, and the density increases over all gradations. Furthermore, in the high-concentration region, the surface becomes rough and the gloss is lost. The operation of recording by selecting one from two or more kinds of recording speeds will be described below.

Image data fetched from the image source 1 before recording is written in the image memory 2. When the recording command is issued, the system controller 402 inputs the recording speed information from the recording speed switching unit 13. Before recording the first color, the system controller 402 outputs the temperature information from the thermistor 8 attached to the back surface of the thermal head 7 to A
It is input after being converted into digital data in the / D section 6.
In accordance with the temperature of the thermal head 7, the system controller 402 first receives from the energization data storage unit 502 the reference energization time data to the thermal head 7 for recording the reference density characteristic at the reference recording speed, and then the recording speed switching unit. If the recording speed selected in 13 is other than the reference recording speed, the recording speed switching unit 13
The conversion coefficient for realizing the reference density characteristic at the recording speed selected in is received. Further system controller 40
In 2, the reference energization time data is multiplied by the conversion coefficient to calculate the conversion energization time data for realizing the reference density characteristic at the selected recording speed. System controller 402
Outputs a rotation speed control signal of the drum 11 to the drum motor control unit 141 in accordance with the recording speed information from the recording speed switching unit 13. The drum motor control unit 141 rotates and controls the drum 11 based on the rotation speed control signal so that the recording speed is selected by the recording speed switching unit 13. The halftone control unit 3 reads the image data from the image memory 2 and, at the same time, receives the calculated conversion energization time data from the system controller 402 and outputs a strobe signal having a time width corresponding to the conversion energization time to the thermal head 7. send. The thermal head 7 applies a current to the heating element for the time width of the input strobe signal, and the heating element generates heat in response to this, and recording is performed. Next, the calculation of the conversion energization time data for realizing the reference density characteristic at the recording speed selected by the recording speed switching unit 13 will be described.

The reference energization time data DTs for realizing the reference density characteristic at the reference recording speed is obtained by the equation (1) as described in the first embodiment shown in FIG. Next, the calculation of the conversion energization time data for realizing the reference density characteristic at the recording speed selected by the recording speed switching unit 13 will be described.

When the reference energization time data is calculated by the equation (1), the system controller 402 reads the conversion coefficient FB from the energization data storage unit 502 according to the recording speed information selected by the recording speed switching unit 13, The conversion energization time data DTTs for realizing the reference density characteristic at the recording speed selected by the formula (4) is calculated.

[0026]

## EQU00004 ## DTTs = DTs.times.FB Incidentally, the conversion coefficient FB is the change data preset to realize the reference density characteristic at the selected recording speed at a certain specific temperature, and the reference density characteristic at the reference recording speed. The ratio with the reference data set in advance to realize

[0027]

## EQU5 ## FB = changed data / reference data For example, as shown in FIG. 5B, when the recording speed is slower than the reference recording speed, the energization time data must be longer than the reference energization time data, so the conversion coefficient FB becomes 1 or more. On the contrary, as shown in FIG. 5C, when the recording speed is higher than the reference recording speed, the energization time data must be shorter than the reference energization time data.
B becomes 1 or less.

The halftone control section 3 sends a strobe signal to the thermal head 7 according to the conversion energization time data DTTs calculated for all the gradations by the above processing, and recording is performed.

As described above, the energization data storage unit 502 only needs to store the reference energization time data and the conversion coefficient, the data capacity can be reduced, and the image quality is deteriorated even when the recording speed is changed. It is possible to obtain the same concentration characteristic without the need.

FIG. 6 is a block diagram showing a third embodiment of the thermal transfer recording apparatus according to the present invention, in which 403 is a system controller, 503 is an energization data storage unit, 15 is a recording density switching unit, and 142 is a drum motor. It is a control unit. Here, the recording density is represented by the number of lines per unit length, and is set higher than the density of the heating element of the thermal head 7 in order to record the video signal with high precision,
In order to record digital data, for example, the density is set to be the same as the density of the heating element of the thermal head 7.
In addition, the same members as those in the embodiment shown in FIG. 1 are designated by the same reference numerals. The operation of recording by selecting one type from two or more types of recording densities will be described below.

Image data fetched from the image source 1 before recording is written in the image memory 2. When a recording command is issued, the system controller 403 inputs recording density information from the recording density switching unit 15. Before recording the first color, the system controller 403 outputs the temperature information from the thermistor 8 attached to the back surface of the thermal head 7 to A
It is input after being converted into digital data in the / D section 6.
According to the temperature of the thermal head 7, the system controller 403 first receives the reference energization time data for the thermal head 7 for recording the reference density characteristic at the reference recording density from the energization data storage unit 503, and then the recording density switching unit. When the recording density selected in 15 is other than the reference recording density, the energization data storage unit 503 to the recording density switching unit 15
The conversion coefficient for realizing the reference density characteristic at the recording density selected in is received. Further system controller 40
In 3, the reference energization time data is multiplied by the conversion coefficient to calculate the conversion energization time data for realizing the reference density characteristic at the selected recording density. System controller 403
According to the recording density information from the recording density switching unit 15,
A rotation amount control signal for the drum 11 is output to the drum motor control unit 142. The drum motor control unit 142 controls the rotation amount of the drum 11 based on the rotation amount control signal so that the recording density becomes the recording density selected by the recording density switching unit 15. The halftone control unit 3 reads the image data from the image memory 2 and, at the same time, receives the calculated energization time data from the system controller 403 and sends the thermal head 7 a strobe signal having a time width corresponding to the converted energization time. . The thermal head 7 applies a current to the heating element for the time width of the input strobe signal, and the heating element generates heat in response to this, and recording is performed. Next, the calculation of the conversion energization time data for realizing the reference density characteristic with the recording density selected by the recording density switching unit 15 will be described.

The reference energization time data DTs for realizing the reference density characteristic at the reference recording density is obtained by the equation (1) as described in the first embodiment shown in FIG. Next, the calculation of the conversion energization time data for realizing the reference density characteristic with the recording density selected by the recording density switching unit 15 will be described.

When the reference energization time data is calculated by the equation (1), the system controller 403 reads the conversion coefficient FC from the energization data storage unit 503 according to the recording density information selected by the recording speed switching unit 15. The conversion energization time data DTTs for realizing the reference density characteristic at the recording density selected by the formula (6) is calculated.

[0034]

[Equation 6] DTTs = DTs × FC Note that the conversion coefficient FC is the change data preset to realize the reference density characteristic at the selected recording density and the reference density characteristic at the reference recording density at a specific temperature. The ratio with the reference data set in advance to realize

[0035]

## EQU7 ## FC = changed data / reference data For example, when recording is performed more densely than the reference recording density, the density becomes high, and therefore the energization time data needs to be shorter than the reference energization time data, so the conversion coefficient FC becomes 1 or less. On the contrary, when the recording is made coarser than the reference recording density, the density becomes low, so the energization time data needs to be longer than the reference energization time data.
The conversion factor FC becomes 1 or more.

The halftone control section 3 sends a strobe signal to the thermal head 7 based on the converted energization time data DTTs calculated for all the gradations by the above processing, and recording is performed.

As described above, the energization data storage unit 503 only needs to store the reference energization time data and the conversion coefficient, the data capacity can be reduced, and the image quality is deteriorated even if the recording density is changed. It is possible to obtain the same concentration characteristic without the need.

FIG. 7 is a block diagram showing a fourth embodiment of the thermal transfer recording apparatus according to the present invention, in which 404 is a system controller, 504 is an energization data storage section, and 16 is a media discriminating section. In addition, the same members as those in the embodiment shown in FIG. 1 are designated by the same reference numerals.

FIG. 8 is a density characteristic diagram of the medium used in the embodiment shown in FIG. 7. In addition to the reference medium, there are media A and B, the vertical axis is the density, and the horizontal axis is the energization time. As shown in FIG. 8, even if recording is performed for the same energization time, the density characteristics are different due to the difference in media. The medium set here is, for example, one that produces a high density or one that has good color reproduction. An operation of selecting one type from two or more types of media and recording will be described below.

Image data fetched from the image source 1 before recording is written in the image memory 2. When a recording command is issued, the system controller 404 inputs from the medium discriminating unit 16 information on the type of medium used for recording. Before recording the first color, the system controller 404
Is input after the temperature information from the thermistor 8 attached to the back surface of the thermal head 7 is converted into digital data by the A / D unit 6. In accordance with the temperature of the thermal head 7, the system controller 404 first receives from the energization data storage unit 504 the reference energization time data for the thermal head 7 for recording the reference density characteristics when the reference medium is used, and then the media discrimination unit. When the medium selected in 16 is other than the reference medium, the energization data storage unit 5
From 04, the conversion coefficient for realizing the reference density characteristic in the medium selected by the medium discrimination unit 16 is received. Further, the system controller 404 multiplies the reference energization time data by the conversion coefficient to calculate the conversion energization time data for realizing the reference density characteristic in the selected medium. The halftone control unit 3 reads the image data from the image memory 2 and, at the same time, receives the calculated energization time data from the system controller 404 and sends a strobe signal having a time width corresponding to the converted energization time to the thermal head 7. . The thermal head 7 applies a current to the heating element for the time width of the input strobe signal, and the heating element generates heat accordingly. Next, the calculation of the conversion energization time data for realizing the reference density characteristic with the medium selected by the medium determination unit 16 will be described.

The reference energization time data DTs for realizing the reference density characteristic in the reference medium is obtained by the equation (1) as described in the first embodiment shown in FIG. Next, the calculation of the conversion energization time data for realizing the reference density characteristic with the medium selected by the medium discrimination unit 16 will be described.

When the reference energization time data is calculated by the equation (1), the system controller 404 reads the conversion coefficient FD from the energization data storage section 504 according to the media information selected by the media discriminating section 16, The conversion energization time data DTTs for realizing the reference density characteristic in the medium selected by the formula 8) is calculated.

[0043]

## EQU00008 ## DTTs = DTs.times.FD Note that the conversion coefficient FD realizes the reference density characteristic in the reference medium and the change data preset to realize the reference density characteristic in the selected medium at a certain specific temperature. The ratio with the reference data set in advance, that is,

[0044]

FD = change data / reference data

The halftone control section 3 sends a strobe signal to the thermal head 7 according to the converted energization time data DTTs calculated for all the gradations by the above processing, and recording is performed.

As described above, the energization data storage unit 504 only needs to store the reference energization time data and the conversion coefficient, the data capacity can be reduced, and the image quality is not deteriorated even when the medium is changed. The same concentration characteristic can be obtained. Further, although the case where the same density characteristic is realized has been described in the present embodiment, different density characteristics can also be realized by setting the conversion coefficient that realizes the density characteristic that makes use of the characteristics of the selected medium. Further, a plurality of recording conditions can be changed by combining a plurality of conversion coefficients of the respective embodiments shown in FIGS. 1, 4 and 6.

FIG. 9 is a block diagram showing a fifth embodiment of the thermal transfer recording apparatus according to the present invention, in which 405 is a system controller, 505 is an energization data storage unit, and 20 is a data reading unit. In addition, the same members as those in the embodiment shown in FIG. 1 are designated by the same reference numerals. Hereinafter, the recording operation based on the data read from the data reading unit 20 will be described.

Image data fetched from the image source 1 before recording is written in the image memory 2. When a recording command is issued, before recording the first color, the system controller 405 converts the temperature information from the thermistor 8 mounted on the back surface of the thermal head 7 into digital data by the A / D unit 6 and then inputs it. According to the temperature of the thermal head 7, the system controller 405 first receives from the energization data storage unit 505 the reference energization time data to the thermal head 7 for recording the reference density characteristic under the reference recording condition, and then the data reading unit 20. The conversion coefficient data for realizing the density characteristic set from the outside is received from. Further, the system controller 405 multiplies the reference energization time data by the conversion coefficient data to calculate the converted energization time data. The halftone control unit 3 reads the image data from the image memory 2 and at the same time receives the calculated conversion energization time data from the system controller 405 and sends a strobe signal having a time width corresponding to the energization time to the thermal head 7. . The thermal head 7 applies a current to the heating element for the time width of the input strobe signal, and the heating element generates heat in response to this, and recording is performed with the density characteristic set from the outside. Next, the calculation of the conversion energization time data will be described.

The reference energization time data DTs for realizing the reference density characteristic under the reference recording condition is obtained by the equation (1) as described in the first embodiment shown in FIG. Next, the calculation of the conversion energization time data for realizing the density characteristic set by the data read from the data reading unit 20 will be described.

When the reference energization time data is calculated by the formula (1), the system controller 405 reads the conversion coefficient FE from the data reading section 20, and the arbitrary density characteristic set from the outside by the formula (10) is calculated. The conversion energization time data DTTs for realizing is calculated.

[0051]

[Formula 10] DTTs = DTs × FE Note that the conversion coefficient FE realizes the reference density characteristic with the change data preset so as to realize the density characteristic arbitrarily set at a certain specific temperature and the reference recording condition. The ratio with the preset reference data, that is,

[0052]

[Equation 11] FE = modified data / reference data

The halftone control section 3 sends a strobe signal to the thermal head 7 based on the conversion energization time data DTTs calculated for all the gradations by the above processing, and recording is performed with an arbitrary density characteristic set from the outside.

[0054]

As described above, according to the present invention,
It has the following effects.

It is necessary to have only the conversion coefficient for calculating the reference energization time data under the reference recording conditions and the energization time data for realizing the same density characteristics even when the recording conditions are changed. It is possible to reduce the amount of unnecessary data. Further, even when the recording condition is changed, the energization time data is calculated and recorded for all the gradations, so that the image quality is not deteriorated. Further, since the conversion coefficients with different recording conditions are combined and calculated, a desired density characteristic can be obtained even if a plurality of recording conditions are combined.

Further, since the conversion coefficient is read from the outside of the apparatus, any density characteristic other than the density characteristic set inside the apparatus can be realized without degrading the image quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment according to the present invention.

FIG. 2 is a density characteristic diagram.

FIG. 3 is a data diagram of energization time.

FIG. 4 is a block diagram showing a second embodiment according to the present invention.

FIG. 5 is a strobe signal diagram.

FIG. 6 is a block diagram showing a third embodiment according to the present invention.

FIG. 7 is a block diagram showing a fourth embodiment according to the present invention.

FIG. 8 is a density characteristic diagram.

FIG. 9 is a block diagram showing a fifth embodiment according to the present invention.

[Explanation of symbols]

3 ... Halftone control unit, 401 ... System controller, 5
01 ... energization data storage unit, 7 ... thermal head, 9 ... ink paper, 10 ... recording paper, 12 ... density characteristic switching unit, 13 ...
Recording speed switching unit 141 ... Drum motor control unit 15 ...
Recording density switching unit, 16 ... Media discriminating unit, 20 ... Data reading unit.

Claims (7)

[Claims] 1. A thermal head having a plurality of heating elements is brought into contact with an ink sheet having a coloring material layered on a recording sheet in a frame-sequential manner, and the heating elements of the thermal head are caused to generate heat by energization. In a thermal transfer recording apparatus that changes the amount of heat applied from the heating element to the ink paper and transfers a color material to the recording paper to perform gradation recording, a density characteristic at the time of recording is selected from a plurality of density characteristics. A density characteristic switching unit is provided, and reference energization time data to the thermal head for realizing the reference density characteristics and energization time data for realizing density characteristics other than the reference density characteristics are obtained from the reference energization time data. And a conversion coefficient for storing in the storage means, and when the density characteristic selected by the density characteristic switching means is other than the reference density characteristic, the reference energization time data and the Read the 換係 number, a thermal transfer recording apparatus and calculates the energization time data independently for all gradations by multiplying. 2. A reference recording speed according to claim 1, further comprising recording speed switching means for selecting and switching a recording speed at the time of recording from a reference recording speed and a plurality of recording speeds other than the reference recording speed. From the reference energization time data, the reference energization time data to the thermal head for realizing the density characteristics and the energization time data for realizing the density characteristics substantially the same as the reference density characteristics at the recording speeds other than the reference recording speed are obtained. The conversion coefficient for obtaining is stored in the storage means, and when the recording speed selected by the recording speed switching means is other than the reference recording speed, the reference energization time data and the conversion coefficient are read from the storage means and multiplied. The thermal transfer recording apparatus is characterized by calculating independent energization time data for all gradations. 3. The reference recording density according to claim 1, further comprising recording density switching means for selecting and switching the recording density at the time of recording from the reference recording density and a plurality of recording densities set in addition to the reference recording density. From the reference energization time data, the reference energization time data to the thermal head for realizing the density characteristics and the energization time data for realizing the density characteristics substantially the same as the reference density characteristics at the recording density other than the reference recording density are obtained. The conversion coefficient for obtaining is stored in the storage means, and when the recording density selected by the recording density switching means is the reference recording density, the reference energization time data and the conversion coefficient are read from the storage means and multiplied. The thermal transfer recording apparatus is characterized by calculating independent energization time data for all gradations. 4. The medium according to claim 1, further comprising a medium discriminating means for selecting and switching a recording medium from among the reference medium and a plurality of mediums other than the reference medium, and realizes the reference density characteristic of the reference medium. And a conversion coefficient for obtaining the energization time data for realizing the density characteristic which is substantially the same as the reference density characteristic on a medium other than the reference medium from the reference energization time data. When the medium stored in the storage means and selected by the media determination means is other than the reference medium, the reference energization time data and the conversion coefficient are read out from the storage means and multiplied to obtain independent energization for all gradations. A thermal transfer recording apparatus characterized by calculating time data. 5. The reference energization time data to the thermal head for realizing a reference density characteristic on a reference medium, and the energization time for realizing an arbitrary density characteristic on a medium other than the reference medium according to claim 4. A conversion coefficient for obtaining data from the reference energization time data is stored in the storage means, and when the medium selected by the media determination means is other than the reference medium, the reference energization time data and the conversion coefficient from the storage means. Is read and multiplied to calculate independent energization time data for all gradations. 6. The conversion coefficient of the recording condition to be changed to the reference energization time data when changing a plurality of density characteristics, recording speed, recording density, and recording conditions of the medium according to claim 1, 2, 3 or 4. Is sequentially multiplied to calculate independent energization time data for all gradations. 7. A thermal transfer recording apparatus according to claim 1, further comprising data reading means for reading energization time data or conversion coefficient to the thermal head from the outside so that an arbitrary density characteristic can be set.