KR0141239B1 - Thermal transfer printing apparatus and method - Google Patents

Abstract

The present invention discloses a thermal transfer printer apparatus and method thereof.

The present invention provides a line memory for storing image data on a line-by-line basis, a temperature detector for detecting the temperature of the TPH, a data converter for converting output data values of the line memory according to the currently printed color information and the temperature of the TPH, and a data converter. The output is compared with the preset gray scale data, the intermediate controller for generating a strobe pulse controlling the energization time for each gray scale, the temperature information detected by the temperature detector and the color information currently printed, and the recognized information is read. A power supply for outputting to the converting means and generating a voltage corresponding to the front control signal output from the scissor micom, the front control signal output from the sciscon micom so as to vary the supply voltage of the TPH according to the detected temperature The image can be printed in high quality including the supply unit.

Description

Thermal transfer printer device and method

1 is a principle diagram of a sublimation thermal transfer method.

2 is a diagram for explaining the energy vs. concentration characteristics of a sublimable dye.

3 is a view for explaining the internal structure of the thermal transfer head (TPH).

4 is a view for explaining the temperature increase rate of TPH.

5 is a view for explaining the rate of change of concentration according to the ambient temperature of TPH.

6 is a block diagram of a conventional PWM thermal transfer printer apparatus.

7 is a view for explaining the change in the strobe pulse width according to the temperature change.

8 is a block diagram of a conventional PCM thermal transfer printer apparatus.

9 is a view for explaining the conversion of data according to the temperature change in the PCM ROM shown in FIG.

10 is a block diagram according to an embodiment of a thermal transfer printer apparatus according to the present invention.

FIG. 11 is an internal block diagram of the power supply shown in FIG.

FIG. 12 is a flowchart illustrating a power supply control of the TPH according to a temperature change performed in the ciscon micom shown in FIG. 10.

FIG. 13 is a view for explaining a temperature detection time point due to a temperature rise curve with time in the temperature detector shown in FIG. 11.

* Explanation of symbols for main parts of the drawings

210: line memory 220: Syscon Microcom

230: PCM ROM 240: intermediate conversion unit

250: thermal transfer head 260: temperature detection unit

270: power supply

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer apparatus and a method thereof, and more particularly, to a thermal transfer printer apparatus and a method for minimizing concentration variations by controlling the front applied to the TPH according to the temperature of the thermal transfer head (TPH).

Recent developments in dye technology and thermal recording devices have led to the development of color hard copier products. Among them, full color printers or videos of various computer graphics images using sublimation thermal transfer methods. Color video printers, which print pictures from signals, have been released and sold.

The sublimation thermal transfer method produces a ribbon that uses a sublimation dye, a receiving paper (also called recording paper) that adsorbs the sublimed dye well, and a sublimation dye so that the sublimable dye fixed on the ribbon can be adsorbed on the receiving paper. Consists of TPH, TPH, Ribbon and Receptacle for transporting, and controls the strength and weakness of TPH to generate the same color as original picture (graphic image or video image). It is common to be constructed.

Figure 1 shows the principle of the sublimation type thermal transfer method.When the receiving paper is attached to the drum and comes to the initial position, the TPH moves and the ribbon and the receiving paper stick to the drum. The conveyance mechanism transfers the drum and the ribbon receiving paper clamping the receiving paper at regular intervals in accordance with the image signal to form a color image.

Sublimable dyes generally used are composed of three primary colors of yellow, magenta and cyan, and such sublimation type color transfer printers or color video printers adopt surface sequential methods. Therefore, first extracting the signal corresponding to yellow from the signal of the graphic image and converting the signal to control the heat generation of the TPH, transfer the yellow ink of the ribbon to the receiving paper, and then the above process for magenta, and then cyan By repeating the above procedure, a full color recording is made on the surface of the receptacle.

FIG. 2 shows the properties of sublimable dyes, where the X axis represents the energization time (a function of energy) and the Y axis represents the concentration with energy. The sublimable dye which is widely used at present has no linearity in the change of energy vs. concentration, and when the same energy is applied, the density of yellow, magenta, and cyan is not the same. It is necessary to have compensation means to analyze the characteristics of and compensate for them.

3 shows the internal structure of the thermal transfer head. TPH (1) is composed of a heating element array (1c) consisting of a resistor and a control integrated circuit (IC), the control IC is a data that determines the ON / OFF of each power generator It consists of a shift register (1a), a latch register (1b) that temporarily stores this data, and a strobe pulse generation circuit (not shown) that determines the heat generation time, each of which is controlled by a system controller. Will be determined.

Therefore, when the TPH (1) consisting of n heating elements starts to generate heat, the temperature of the TPH (1) rises, and as a result, the print density varies between the initial concentration of the recording and the density as the recording proceeds, resulting in a concentration difference. It can also cause.

FIG. 4 is a curve showing the temperature rising rate of TPH according to one printing operation time, and FIG. 5 shows the rate of change of concentration depending on the temperature of TPH when unified energy is applied.

Therefore, in the thermal transfer printer apparatus, gamma correction, density correction, and resistance correction must be performed in order to consider the characteristics of these TPH and dyes and to obtain an even picture quality.

6 is a block diagram of a PWM (Pulse Width Midulation) type thermal transfer printer that is widely used to localize the rate of change of concentration with temperature during correction.

Referring to FIG. 6, in the line memory 10, image data flowing from a signal input source is stored in line units, and is read out from the memory controller 20 according to the read control signal, and the data of the intermediate controller 30 is stored. The first input terminal of the comparator 32 is input. Here, the signal input source may be an analog signal input source such as a personal computer or a graphic computer.

The data comparator 32 compares the gradation data (for example, 0-255 gradation level) generated from the gradation counter 31 with the read data of the line memory 10.

In the data divider 33, the output of the data comparator 32 is divided into the shift register 61 and outputted. For example, if one line is composed of 512 data, the data is divided into 1 to 256th pixel data and 257 to 512th pixel data.

On the other hand, the thermistor 71 detects the present temperature of the TPH 60 and outputs it to the A / D converter 72. The thermistor 71 outputs to the A / D converter 72. The A / D converter 72 converts the detected temperature of the TPH 60 into a digital form and outputs it to the ciscon micom 40. The ciscon micom 40 displays the currently printed color and the detected current temperature. It recognizes and outputs a control signal corresponding to the grayscale ROM 50.

The gradation ROM 50 stores the compensation data according to the temperature divided into 64 steps for each of three colors (yellow, magenta, cyan), and compensates the time head compensated according to the color and temperature karma output from the ciscon micom 40. The pulse width counter 34 is controlled to have.

The pulse width counter 34 counts in response to the compensation data of the gradation ROM 50 for each gradation according to the output of the gradation ROM 50, and the decoder 35 performs the counting period, that is, the strobe pulse (the conduction pulse). The heating element array 63 is heated during the active period.

When the duration of the strobe pulse is shown in Fig. 7 as the concentration 1.0 (D), the temperature of the TPH 60 is about 15 msec when the temperature is 30, and when it is 40, it is about 13 msec. Respond to change.

In the latch register 62, one line of output data stored in the shift register 61 is temporarily stored, and heat is generated in the heating element array 63 in the form of a current signal to perform printing.

If the temperature of TPH is different even though the data of the same image are the same, as shown in FIG. 7, the pulse width applied to the strobe stage applied to the TPH is reduced by the increase of the concentration of the agricultural field according to the temperature rise, and the difference in concentration is applied. In this method, the pulse width applied to the TPH heating element is not uniform, which can cause breakage due to thermal shock applied to the heating element.

8 is a block diagram of a PCM (pulse count modulation) type thermal transfer printer which is widely used for the purpose of equalizing image quality due to temperature rise during correction.

The line memory 100 stores image data flowing from a signal input source in units of lines.

The ciscon micom 120 recognizes the temperature detected by the thermistor 151 and the color currently being printed, and outputs it to the PCM ROM 110.

In the PCM ROM 110, as shown in FIG. 9, the data comparator 132 converts the value of data read from the current 100 into the line memory according to the temperature and the color detina output from the ciscon micom 120. Output to the first input terminal of.

The data comparator 132 compares the gradation data (0-255 gradation level) generated from the gradation counter 131 with the read data of the line memory 100.

The strobe pulses are generated under the control of the microcomputer 120 of the sheath cone and output to the heating element array 143.

The shift register 141 shifts and stores the grayscale compared data from the data comparator 132, temporarily stores one line of data in the latch register 142, and outputs the output of the latch register 142 from the heating element array 143. It generates heat by converting it into a current signal type.

8 shows a method of reducing the data applied to the TPH data line by the difference in concentration according to the temperature rise. This method also reduces the data according to the temperature rise. In this case, the data was significantly reduced compared to the original data, resulting in deterioration of image quality.

Therefore, the amount of heat energy generated in each of the TPH, such as the heat generated by the TPH, may vary depending on the power applied to the TPH and the strobe pulse. FIG. 6 shows that the size of the image data is not changed in the PWM thermal transfer printer device. According to the TPH and the energy versus concentration characteristics of the ribbon, a uniform image is obtained. In the PCM type thermal transfer printer shown in FIG. 8, the size of image data input without changing the strobe pulse width is shown. The method is used to change the TPH according to the temperature of the TPH and the color of the ribbon using the PCM ROM. However, these two methods apply the irregular strobe pulse to the TPH as described above or the original image data due to the severe change of the data according to the temperature. There was a problem that causes the deterioration of the door quality not to have.

Accordingly, an object of the present invention is to control the voltage applied to the TPH according to the temperature of the thermal transfer head (TPH) while employing a mixture of PWM and PCM method to solve the problems occurring in the thermal transfer printer device of the PWM or PCM method The present invention provides a method and method for declaring a thermal transfer printer to obtain an even degree of error.

In order to achieve the above object, the thermal transfer printer apparatus according to the present invention is a thermal transfer print for expressing the energization factor by thermal transfer after comparing the three-color image data of three primary colors from a signal input source with a gray level preset in line units. An apparatus comprising: conduction extraction means for detecting a temperature of the thermal transfer head; Power supply control means for varying a supply voltage of the thermal transfer head according to the temperature detected by the temperature detection means; and converting the value of the image data according to the color information currently printed and the detected temperature of the thermal transfer head; It is characterized by including the print control means to control the thermal transfer head to generate heat during each gray level energizing time.

In the thermal transfer printing method according to the present invention, in the thermal transfer printing method of conducting an energization factor with a thermal transfer head after comparing a three-color image data of three primary colors from a signal input source with a preset gradation value in units of lines: Temperature detection process for detecting the temperature of the thermal transfer head at the printing start point of the color: Front control process for controlling the supply voltage of the thermal transfer head in accordance with the temperature detected in the temperature detection process: and color information and the current printing And a print control process for converting the value of the image data according to the temperature of the thermal transfer head to control the thermal transfer head to generate heat during the energization time for each gradation.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the thermal transfer printer device and method according to the present invention.

10 is a thermal transfer printer apparatus according to the present invention, the line memory 210, TPH 250, the system microcomputer 220 for controlling the overall operation of the system, and the temperature detection unit for detecting the temperature of the TPH 250 Comparing the output of the PCM ROM 230 and the output of the PCM ROM 230 with preset gray scale data, and generating a strobe pulse for controlling the energization time of the TPH 250 for each gray scale. And a power supply unit 270 for controlling the TPH supply voltage according to the temperature of the TPH 250 detected at the start of the color to be printed.

The operation of FIG. 10 will be described with reference to FIGS. 11 to 13.

First, when image data to be recorded is sequentially sent from a built-in frame memory (not shown) to a computer or a printer, the image data is stored in line units in line memory 210 under the control of the scissor microcomputer 220. .

When the storage of one line of image data is completed in the line memory 210, the sheath cone microcomputer 220 operates the armature counter 241, and the temperature of the TPH 250 is attached to the TPH substrate. The A / D converter 262 converts the digital signal into a digital signal form so as to be detected by the scissor micom 220.

Here, the A / D converter 262 may be embedded in the ciscon micom 220.

The ciscon micom 220 recognizes the temperature by internal calculation and provides the temperature data and the color information of the ink ribbon to be recorded to the PCM ROM 230.

PCM ROM 230 according to the data read out from the line memory 210 and the color and temperature information recognized by the ciscon micom 220 sequentially by the read address and the read control signal output from the ciscon micom 220. The data of the lookup table (hereinafter referred to as "LUT") stored in the search function is output to the data comparator 242.

The data comparator 242 compares the LUT data output from the PCM ROM 230 with the n-bit gradation value input from the gradation counter 241, determines the size as 0 or 1, and then shifts the TPH 250. The data is matched 1: 1 in each of the m heating element arrays 252 in series with the register 251.

A process of generating a strobe pulse signal for each gray level of the TPH 250 by the strobe pulse generator 243 operating under the control of the ciscon micom 220, and radiating it from the heating element of the TPH 250 to sublimate the dye of the ribbon. Is repeated for each gradation.

Meanwhile, the amount of heat generated by the TPH 250 (heating energy) is proportional to the power consumed by the TPH 250, and can be expressed by the following equation.

E = V2 / R * t

E is the generated energy, V is the TPH applied voltage (hereinafter referred to as VH), R is the average resistance of the heating element, and t is the strobe pulse width applied to TPH.

A block diagram of a power supply 270 capable of controlling the voltage VH applied to the TPH is shown in FIG. 11, the thermistor 261 at the beginning of the color that is locally printed by the scissor micom 220. In order to recognize the temperature of the TPH 250 detected by the controller and output a voltage control signal to control the concentration variation rate according to the temperature to the supply voltage of the TPH 250, the D / A converter 271 converts the voltage control signal into an analog signal. Convert.

The current controller 272 converts the signal into a current signal type corresponding to the analog signal output from the D / A converter 271.

That is, when the detected TPH temperature is higher than the reference temperature compared to the preset reference temperature for each color information, the depressing voltage of the TPH is lowered, and when the currently detected TPH temperature is lower than the reference temperature. The supply voltage of TPH is controlled high.

The voltage oscillator 273 generates a voltage according to the current signal output from the current controller 272 and outputs the voltage to the voltage supply terminal of the TPH 250.

FIG. 12 is a flowchart for variably controlling the TPH supply voltage according to the temperature detected by the temperature detector performed in the ciscon micom shown in FIG.

First, when printing starts, the scissor micom 220 detects the initial temperature T1 of the TPH from the thermistor attached to the TPH 250 (step S101), and applies the applied voltage VH1 to the TPH 250. At the same time, the data control or strobe pulse width according to the PCM or PWM method is performed according to the gradation, the temperature, and the color of the ribbon to complete the printing operation for the yellow color (step S102), and the mechanical operation is magenta printing. When the operation is possible, the scissor micom 220 detects the temperature T2 of the TPH (step S103), and supplies a voltage control signal to the power supply unit 270 so that the voltage applied to the TPH becomes VH2.

At this time, VH2 is calculated by the following method.

As shown in FIG. 13, the image data or strobe pulse width was applied at T1 even when the temperature of TPH became T2 with the image data or strobe pulse width when VH1 was applied and the ignition concentration was maximized at T1. VH2 is determined to be equal to the maximum flash concentration at T1. (Step S104).

When the magenta printing operation is completed, the controller detects the temperature T5 of TPH when all mechanical movements are completed at the cyan printing operation position (step S105). When printing is completed for yellow magenta and cyan, one printing is completed (S107). step).

As described above, the present invention reduces the size of the image data according to the temperature increase in the PCM method if the change in the concentration according to the TPH temperature rise minimizes the difference between the original image and the data, or the temperature rise in the PWM method. As a result, the strobe pulse width is continuously reduced to improve the problem of reducing the density range, and the size of the original image data is faithfully reproduced on the recording paper, thereby obtaining a high quality image.

Claims (7)

A thermal transfer printer device for performing energization factor expression by means of a power transfer head (TPH) after comparing gray levels of three primary colors with pre-set gray level values from a signal input source, and storing the image data in line units. Line memory; Temperature detecting means for detecting a temperature of the TPH; Data conversion means for converting the output data value of the line memory according to the currently printed color information and the TPH locus; A halftone control means for comparing the grayscale data with a preset output date of the data conversion means and generating a strobe pulse for controlling the energization time for each grayscale; Recognizing the temperature report detected by the temperature detection means and the current print color information 67 outputs the recognized information to the data conversion means, and outputs a voltage control signal so that the supply voltage of the strong TPH varies according to the detected temperature. The system control means: and a thermal transfer printer apparatus, characterized in that it comprises a power supply means for generating the voltage ramp corresponding to the voltage control signal output from the system control means to supply the TPH. The thermal transfer printer apparatus according to claim 1, wherein the temperature detecting means detects a temperature of the TPH at a starting point of the color to be printed. The system control means according to claim 1, wherein the system control means is adapted to maintain the same concentration as the print concentration in the image data when the initial supply voltage is applied even when the temperature of the TPH is changed so that the maximum print concentration at the initial printing point is memorized. Thermal transfer printer device characterized in that for controlling the power supply means. The system control means according to claim 1, wherein the system control means maintains the same concentration of the ignition in the strobe pulse width when the initial supply voltage is applied even when the temperature of the TPH is changed to maximize the ignition concentration at the time of initial printing. Thermal transfer printer device characterized in that for controlling the power supply means. In the thermal transfer printing method in which three primary colors of image data are pre-set in line units from a signal input source and an electric power factor expression is performed by a thermal transfer head after a conventional tone comparison, the thermal transfer head at the starting point of printing of each color. Conduction extraction process for detecting temperature; A voltage counting step of controlling a supply voltage of the thermal transfer head according to the temperature detected in the temperature checking process; And a print control process of converting the value of the image data according to the currently printed color information and the detected temperature of the thermal transfer head to control the thermal transfer head to generate heat during the energization time for each gradation. Thermal transfer print method. 6. The voltage control process according to claim 5, wherein the voltage control process maintains the same concentration as the printing concentration in the image data when the initial supply voltage is applied even when the temperature of the thermal transfer head is changed and the printing concentration is maximized at the initial printing time. And a supply voltage is supplied to said transfer head. 6. The method of claim 5, wherein the voltage control process is performed by applying an initial supply voltage even when the temperature of the thermal transfer head changes, such that the concentration is equal to the flash concentration at the strobe pulse width when the maximum concentration is at the initial printing time. The thermal transfer printing method characterized in that the supply voltage is supplied to the thermal transfer head to maintain.