KR0132892B1 - Video printer - Google Patents

Abstract

Disclosed is a video printing apparatus. The apparatus comprises a signal generator and a preheat controller. The signal generator generates a line preheat synchronizing signal which has a predetermined time after a line synchronizing signal is generated. The preheat controller preheats all heaters of a thermal transfer head(TPH) while the line preheat synchronizing signal is generated from the signal generator. The non-linear characteristic at a low density period of the TPH is compensated to be linear. Thereby,the print quality can be improved.

Description

Video printer device

1 is a block diagram of a conventional video printer apparatus.

2A to 2D are operational waveform diagrams of the video printer apparatus shown in FIG.

3A to 3C are diagrams for explaining the relationship between the exothermic time of TPH and OPTICAL DENSEITY.

4 is a block diagram of a video printer apparatus according to an embodiment of the present invention.

5A to 5E are operational waveform diagrams of the video printer apparatus shown in FIG.

* Explanation of symbols for main parts of the drawings

110: line memory 120: first signal generator

130: grad counter 140: grad comparator

150: data generator 160: selection unit

170: second signal generator 180: T. P. H

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preheating apparatus in a video printer apparatus. In particular, the present invention relates to a video printer apparatus which generates heat by preheating a predetermined time for printing before printing.

Generally, a sublimation type thermal transfer printer that prints using a thermal print head (hereinafter referred to as TPH) is a device that performs printing. The dye is applied by energy generated by TPH by applying energy to TPH. Sublimation of the dye on the film is performed to obtain a desired image or picture by the amount of dye transferred onto the recording paper.

As shown in FIG. 1, the video printer apparatus divides the 1 KHz clock output from the first clock generator 21 that generates the 1 KHz clock as the system clock into the divider 22 in FIG. The signal as shown is output to the enable terminal EN of the second clock generator 23 generating the 1 MHz clock and the enable terminal EN of the gradation counter 30. The second clock generator 23 generates a 1 MHz clock as the output of the divider 22 is input to generate the gradation counter 30, the clock generator 61, the latch signal generator 62, and the strobe signal generator 63. Output to the clock terminal CLK.

Here, as shown in FIG. 2A, the output signal of the frequency divider 22 has a total line printing time of 25 mSEC, and the line sync signal corresponds to a low level period during the first 1 mSEC of the total line period, and the rest of the period. Is the printing expiration date that can be expressed in real terms during 24msec.

On the other hand, the line memory 10 reads and writes line-by-line from the frame memory which processes the video signal flowing from the signal input source and stores it as the frame.

In the gradation comparator 40, the gradation data output from the gradation counter 30 and the data read out from the line memory 10 are compared.

The data generator 50 generates the output of the gray scale comparator 40 as a pulse width modulation (PWM) signal.

On the other hand, the clock generator 61 of the signal generator 60 generates a data clock as shown in FIG. 2B as a shift control signal for storing data in a shift register (not shown) of the TPH 70. Generates a latch signal as shown in FIG. 2C for shifting the output from the shift register of the TPH 70 to a latch register (not shown) in the latch signal generator 62, and the strobe signal generator 63. FIG. ) Generates a heat generating strobe signal as shown in FIG. 2D which controls the heat generating element constituted by the resistance of the corresponding TPH 70 to substantially generate heat by data stored in the latch register.

That is, the TPH (70) in the line memory 10 for the remaining 24mSEC except for the sync section 1mSEC corresponding to the line sync signal in order to express the data corresponding to one line composed of 8 bits is stored in the line memory 10. TPH generates heat according to the data for one line corresponding to the number of heating elements in

In addition, when the TPH 70 expresses one-byte data composed of 8 bits, it is possible to express 256 levels. The data having 256 levels stored in the line memory 10 are generated by the heat generating strobe signal of the TPH 70. Is generated 256 times as shown in FIG. 2D. At this time, the heating element of the TPH generates or does not generate heat according to the value of 1 or 0 of the data register in the TPH.

When the output of the gradation counter 30 is counted from 0 to 255 in 256 steps, the output value of the gradation counter 30 and the data read from the line memory 10 are compared with the gradation comparator 40 to compare the gradation with the line memory 10. When the data is large, the output of the gradation comparator 40 becomes high (1) and is transmitted to the data generator 50. At the same time, the clock is generated by shifting the shift register inside the TPH 70 by the data clock generated from the clock signal generator 70. When the number of heating elements (64 in this case) is transferred in the divided block of the TPH, the TPH (70) is completed. The data from the shift register in < RTI ID = 0.0 > 1) is transferred once < / RTI > The heat is generated during the active time (80 uSEC) of the heat generating strobe signal.

With the signal generation and data transmission as described above, 256 periodic data clocks of 256 times shown in FIG. 2B and one data latch shown in FIG. 2C during 24mSEC, which is an effective printing period as shown in FIG. 2A. By the signal and one heat generating strobe signal shown in FIG. 2D, data having 256 kinds of branches in the line memory 10 is represented as heat generation 256 of the thermal transfer head.

In such a sublimation thermal transfer video printer, the OPTICAL DENSITY of the color thermally transferred from the color ink ribbon to the photo paper by the amount of heat generated from the TPH is expressed as a non-linear characteristic as shown in FIG. 3A. When printed with the characteristics as shown in FIG. 3a, the low-concentration expression is distorted, thereby causing a problem in that gray scale expression is not properly represented.

Therefore, in order to have a linear relationship between the calorific value generated from TPH and the factor concentration as shown in FIG. 3b, as shown in FIG. 3c, the heat generation time of the thermal transfer head corresponding to the equal interval of the factor concentration is A. Should increase almost rapidly to the point.

Accordingly, an object of the present invention is to preheat the line by inserting a separate line preheating sink signal in a section following the line sink in the low concentration part of the print expression, which is distorted by the nonlinear characteristics of the printing concentration and the heating time in the sublimation thermal transfer printer. The present invention provides a video printer apparatus in which the heat generating elements of all the heat transfer heads generate heat for a predetermined time period.

In order to achieve the above object, a video printer apparatus according to the present invention includes a print control circuit which inputs a video signal from a signal input source, stores it line by line, and compares the gray level with a preset gray level value. In the video printer apparatus which drives the heat transfer head (TPH) which consists of a heat generating body, and expresses electricity supply factor,

Signal generating means for generating a line preheating sink signal having a predetermined period after the line sink signal is generated; In the line preheating sink signal period generated by the signal generating means, the preheating control means for preheating the preheating element of the TPH is characterized in that the linear compensation of the non-linear heating characteristics between the low concentration tools of the TPH.

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

4 is a configuration diagram according to an embodiment of a preheating apparatus of a video printer according to the present invention.

4 shows a line memory 110 which inputs a composite video signal from a signal input source and processes the signal, and stores the frame memory in line units from a frame memory for a frame, and a signal generator for generating a line sink and a line preheating sink. 120, a gradation counter 130 for outputting preset gradation data, a gradation comparator 140 comparing gradation data previously stored from the gradation counter 130 with data read out from the line memory 110, and gradation The data generator 150 stores the output signal of the comparator 140 by the divided blocks of the TPH 180, and selects the power supply in the line preheating sink section and selects the output of the data generator 140 in the other printing section. The selector 160 configured as a multiplexer and a second signal generator 170 for generating a drive signal for driving the TPH 180 are included.

In this case, the first signal generator 120 divides the first clock generator 121 that generates the 1 KHz clock, which is the system clock, and the 1 KHz clock output from the first clock generator 121, and generates a first line sync signal. Counter 122 having a detector 123, a second detector 124 for generating a line preheating sink signal, and a second clock generator for generating a 1 MHz clock by introducing the output of the first detector 123 as an enable signal. And an AND gate G1 that logically multiplies the line sync signal output from the first detector 123 and the second detector 124 with the line preheat sink signal.

In the second signal generator 170, a clock signal generator 171 for generating a data clock as a shift control signal for storing data in a shift register (not shown) of the TPH 180, and a shift register of the TPH 180. A latch signal generator 172 for generating a data latch signal for moving from the latch register (not shown) to the latch register (not shown), which stirs the heating element of the corresponding TPH 180 to substantially generate heat by data stored in the data register. A strobe signal generator 173 for generating a heat generating strobe signal is provided.

Next, the operation of FIG. 4 will be described with reference to FIG.

According to FIG. 4, although the video printer apparatus according to the present invention is not shown in the figure, video signal processing means in which a digital signal is stored in units of frames after the video signal flowing from a signal input source performs A / D conversion. And video display means for displaying a signal processed signal, but detailed descriptions of the video signal processing means and the video display means will be omitted here.

The line memory 110 stores data read from the frame memory of the video signal processing means in line units.

On the other hand, the first clock generator 121 generates a 1 KHz clock and outputs it to the enable terminal EN of the counter 122. The counter 122 counts the 1 KHz clock from 1 to 25, and the first detector 123 that detects the result of counting the counter 122 detects 1 and generates a low level line sync signal for a 1 m SEC period as shown in FIG. 5a. The second detector 124 outputs the enable terminal EN of the clock generator 125 and the first input terminal of the AND gate G1 and detects the result 2 of counting of the counter 122, as shown in FIG. A line preheating sync signal generated during 1 mSE C following the line sink signal is output to the second input terminal of the AND gate G1.

The second clock generator 125 inputs the output of the first detector 123 as an enable signal to generate a 1 MHz clock signal from the rising edge of the line sync signal shown in FIG. 5A, thereby clocking the gray scale counter 130. The terminal CLK is output to the clock terminal CLK of the clock signal generator 171, the latch signal generator 172, and the strobe signal generator 173.

In addition, the output of the first detector 123 is input to the enable terminal EN of the clock signal generator 171, the latch signal generator 172, and the strobe signal generator 173, and the output of the second detector 124 is output. It is input to the selection terminal SEL of the multiplexer 160.

Meanwhile, as shown in FIG. 5B, the heat generated by the TPH 180 is sufficiently increased through preheating before heat generation according to data of the line memory 110 which is performed for 23mSEC time after the line preheating sink signal is generated. A steep slope can be achieved up to the point A shown in 3c.

In detail, the data bus of the TPH 180 during the one-line preheating period is used by the multiplexer 160 as the selection signal so that all data from the data generator 150 can be transferred to the supply power supply (Vcc). Input the power supply input to the second input terminal B during the low level 1mSEC shown in FIG. 5b so that all data of the TPH 180 is stored as 1 so that the strobe signal generator 173 When one heating strobe signal shown in FIG. 5e is generated, all the heating elements of the TPH 180 are simultaneously heated.

In the line preheating sink section shown in FIG. 5B, 64 data clock signals are generated as shown in FIG. 5C, and the power supply Vcc is directly received by the multiplexer 160 as data of the No. 64 TPH 180. Once received, the latch signal generator 172 recognizes the output of the clock signal generator 171 input to the enable terminal EN1, and immediately afterwards generates one data latch signal as shown in FIG. In the strobe signal generator 173, which is transferred to the data register at once and then inputs a latch signal as an enable signal, a heat generating strobe signal as shown in FIG. 5e is generated to generate a TPH for the rest of the line preheating sink. All the heat generating elements of 180 generate heat, and line preheating is performed.

On the other hand, during the effective printing period of 23mSEC shown in FIG. 5B, the gray level counter 130 is operated by inputting the output of the AND gate G1 to the enable signal, and counts in 256 steps from the preset 0 to 255 levels. The counted gradation counter at that time is output to the first input terminal of the gradation comparator 140.

In the gray scale comparator 140, the output value of the gray scale comparator 140 becomes 1 when the data of the line memory 110 is large compared with the output of the gray scale counter 130 and the data read from the line memory 110, and thus the data generator 140 At the same time, the signal is shifted to the shift register inside the TPH 180 by the clock signal as shown in FIG. 5C generated by the clock generator 171 and stored.

When the number of heat generating elements (64 in this case) in the divided block of the TPH 180 is transferred, the shift register in the TPH 180 is in accordance with the latch signal generated by the latch signal generator 172 as shown in FIG. 5D. To the register in the TPH 180 is transferred once.

The heat generating strobe signal is generated by the strobe signal generator 173 so that the heat generating element of the TPH 180 generates heat for the active time of the strobe signal.

Here, the strobe signal generator 173 receives the output of the gradation counter 130 as an address signal, and stores data corresponding to the low level width of the strobe signal indicating the heating time for each gradation.

The strobe signal generator 173 stores data corresponding to the width of the strobe signal representing the heat generation time from when the latch signal is generated to the end of the line preheating sink period when 64 clocks are generated during the line preheating period.

As described above, the video printer apparatus according to the present invention generates a predetermined heat for a predetermined period of time for each heating unit of the TPH along the TPH headline, thereby preheating the non-linear characteristics of the printing concentration and the heating time. Thereby, a high quality image can be obtained by compensating for the low density concentration factor expression.

Claims (6)

It is equipped with a print control circuit which inputs the video signal from the signal input source and stores it on a line basis and compares it with a preset gradation value, and drives the thermal transfer head (TPH) composed of heating elements according to the output of the print control circuit. A video printer apparatus for performing expression, comprising: signal generating means for generating a line preheating sync signal having a predetermined period after a line sink signal is generated; And a preheat control means for preheating the TPH preheating element in the line preheating sink signal period generated by the signal generating means, to linearly compensate for the non-linear heating characteristics of the low concentration section of the TPH. The apparatus of claim 1, wherein the signal generator comprises: a first clock generator for generating a system clock; A counter for dividing the system clock output from the first clock generator 121 to generate a line sync signal and a line preheat sink signal; And a second clock generator which is enabled when the line sync signal output from the counter is generated to generate a system clock. 2. The apparatus of claim 1, wherein the preheating control means comprises: selection means for selecting a supply power in a line preheating sink section and an output of the print control circuit in the other printing section; And the line preheating sink section includes drive signal generating means for outputting a drive signal for generating heat to the heat transfer head. 4. The driving signal generating means according to claim 3, wherein the driving signal generating means stores the data clock as a shift control signal for storing all data as one for inputting the power supply to the shift register in the thermal transfer head during the line preheating sink period by the selecting means. Generating a clock signal generator; A latch signal generator for generating a data latch signal for moving from said shift register to a latch register (not shown); And a strobe signal generator for generating a heat generating strobe signal so that a corresponding heat generating element of said heat transfer head can generate heat substantially by data stored in a data register. The strobe signal generator of claim 4, wherein the strobe signal generator comprises a ROM in which data corresponding to a width of a strobe signal representing a heat generation time from a latch signal generation to a time point when a predetermined line preheating sink period ends during the line preheating period is stored. A video printer apparatus, characterized in that. The video printer apparatus of claim 5, wherein the ROM has a strobe signal corresponding to a heat generation time for each gray level.