KR0141244B1 - Thermal transfer printer - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer printing in a printer device, wherein a plurality of temperature sensors are used to accurately detect the temperature of each heating element of the TPH, and convert image data without complicated calculations to quickly produce a high quality image. It has the effect of printing.

Description

Thermal Transfer Printer Device

1 is a block diagram of a conventional thermal transfer printer apparatus.

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

3A and 3B are diagrams for explaining the structure of the TPH shown in FIG.

4 is a detailed block diagram of the temperature detection unit shown in FIG.

FIG. 5 is a detailed block diagram of the line temperature data generator shown in FIG.

6A and 6B are waveform diagrams of the parts shown in FIGS. 4 and 5.

7A to 7J are waveform diagrams of the parts shown in FIGS. 2 to 5 during one period of the line synchronization signal.

* Explanation of symbols for main parts of the drawings

210: frame memory 220: frame memory controller

230: line memory 240: line memory controller

250: TPH control unit 260: TPH

270: temperature detector 280: line temperature data generator

290: image data conversion unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer printer in a printer apparatus, and more particularly, to a thermal transfer printer apparatus which accurately detects a temperature change of a thermal transfer head and compensates for a temperature change caused by thermal storage of an image.

In general, a thermal transfer type color video printer using a sublimation dye (hereinafter referred to as a CVP) is a device that prints a predetermined process on image data of an input external image signal, which is a means of performing printing. A heat generating element (hereinafter referred to as TPH) is used as a head. TPH consists of a number of heating elements, and in order to express gradation, energy should be applied to the heating element. When energy is applied to the TPH, the heating element generates heat. The desired image can be obtained. At this time, the amount of dye transferred to the recording paper is proportional to the heating temperature of the heating element. Therefore, in order to print the input image without any error in color, it is necessary to control for optimal temperature compensation according to the temperature change of the heating element of the TPH.

To this end, the conventional CVP detects the temperature of the TPH by performing a temperature compensation according to the temperature by attaching a temperature sensor to the center of the heat sink to measure the most recent temperature of the TPH.

1 is a block diagram of a conventional thermal transfer printer apparatus.

Controlling the data writing and reading of the frame memory 11 and the frame memory 11 in which information on colors, i.e., red (R), green (G), and blue (B), are stored from an external signal source A frame memory controller 12 for storing the data, a line memory 13 for storing data in lines, a line memory controller 14 for controlling the line memory 13, and data read from the line memory 13; The TPH control unit 15 for comparing the gradations, the TPH 16 that generates heat according to the data output from the TPH control unit 15, the temperature sensor 17 for measuring the temperature of the TPH 16, and the temperature sensor 17 A / D converter 18 for converting analog temperature data output from the digital data into digital temperature data, and a strobe signal for subtracting the temperature data from the control signal DATA STROBE, which is compared with the gray level, and outputting a strobe signal. It is comprised by the generation part 19.

A video input signal is input from a signal input source (not shown) such as a video camera or a television, and separated into red (R), green (G), and blue (B) signals and stored in the frame memory 11 in units of frames. . At this time, the frame memory controller 12 outputs a line synchronization signal LINE SYNC for distinguishing each line while controlling the writing and reading of data in the frame memory 11.

The line memory 13 stores the red (R), green (G), and blue (B) signals output from the frame memory 11 in line units. The line memory controller 14 controls the writing and reading of data from the line memory 13 in accordance with the line synchronization signal LINE SYNC output from the frame memory controller 12.

The TPH controller 15 compares the data read out from the line memory 13 on a line-by-line basis with a preset gradation value and a gradation value, and then controls the STORB signal DATA STORBE to control the heating time for each gradation. A clock CLOCK for transmitting each pixel data, a latch signal LATCH for printing lines, and data DATA for gradation comparison are output.

The TPH 16 generates heat in response to the control signal HEAT STROBE, which is output from the strobe generator, from the data input from the TPH controller 15.

At this time, only one temperature sensor 17 mounted at the center of the heat sink of the TPH 16 detects the heat generation temperature of the TPH 16.

The analog temperature data detected by the temperature sensor 17 is converted into digital temperature data by the A / D converter 18 and output to the strobe generator 19 for temperature compensation.

The strobe generator 19 subtracts the temperature data output from the A / D converter 18 from the strobe signal DATA STROBE output from the TPH controller 15, and outputs the data output from the TPH controller 15 ( Outputs a temperature compensated control signal (HEAT STROBE) that controls the heat generation time of DATA.

At this time, since only one temperature sensor 17 is provided at the center of the heat sink of the TPH 16, the temperature detection value by one temperature sensor 17 becomes an average temperature value for the entire heating element. There is a time difference of about several seconds until the ambient temperature of the heating element is transmitted to the temperature sensor 17, and the temperature data applied to the temperature compensation is delayed from the actual temperature, and all other temperature data in the longitudinal direction of the TPH are used. Since the temperature detection by one temperature sensor is not seen as accurate temperature data, there is a problem in that there is a limit in temperature compensation.

In addition, in order to solve this problem, in some cases, temperature compensation is performed by directly calculating heat storage phenomena of heat sinks that generate heat rather than temperature data transmitted from a temperature sensor. However, in this case, in order to calculate the ambient temperature data, which is the reference data for the heating of one of the heating elements of thousands of TPH, the matrix operation is required from the matrix image data centered on the position. To be valid data, the size of the matrix must be quite large. In practice, there is a limit to increase the size of the matrix, and there is a problem in that one line printing time takes a lot due to the matrix operation.

Accordingly, an object of the present invention is to provide a more accurate temperature compensation for accurately detecting the temperature of each heating element of the TPH using a plurality of temperature sensors in a sublimation type thermal transfer printer device, and to convert image data without complicated calculations, thereby allowing the temperature to be rapidly increased. The present invention provides a printer device that enables compensation.

In order to achieve the above object, the thermal transfer printer temperature compensating apparatus according to the present invention provides an electric power factor expression to a thermal transfer head composed of a plurality of (K) heating elements after image signals are preset in line units from a signal input. In the thermal transfer printer device to be performed,

A temperature detector for attaching a predetermined number (N) of temperature sensors to the thermal transfer head to detect the temperature from the temperature sensors to the N channel: Sampling the temperature data output from the temperature detector by clocks corresponding to K heating elements Temperature data generation unit for generating temperature data of K heating elements: and subtracted image data in line units from the temperature reference point generated by the temperature data generation unit and the heat transfer head of the thermal transfer head (the temperature compensated data). ) Is characterized in that it comprises an image data modulator for outputting the heat generating data of the thermal transfer head.

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

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

Controls the writing and reading of data in the frame memory 210 and the frame memory 210 in which information on colors, i.e., red (R), green (G), and blue (B), are stored from an external signal source. A TPH controller for comparing the grayscale between the frame memory controller 220 for storing the image, the line memory 230 for storing image data in lines, and the data read from the line memory 230, and outputting a control signal for printing ( 250, the TPH 260 generated by the image data and the control signal output from the TPH controller 250, the temperature detector 270 for detecting the temperature of the TPH 260, and the temperature detector 270 The line temperature data generator 280 for generating temperature data corresponding to all heating elements from the output temperature data, the temperature data output from the line temperature data generator 280 and the image data output from the frame memory 210 are displayed. Input temperature compensated image It consists of the itaconic to the image data converting section 290 outputs to the line memory 230.

3A and 3B are views showing the structure of the TPH 260, and FIG. 3A shows a plurality of K heating elements, and FIG. 3B shows a temperature sensor mounted directly behind the heating element substrate.

FIG. 4 is a detailed block diagram of the temperature detector 270 shown in FIG. 2, and includes a plurality of temperature sensors T1 to TN and multi-channel A / converting analog temperature data output from the temperature sensor to digital temperature data. A D conversion unit 272 and an A / D controller 273 for outputting a clock required for A / D conversion.

FIG. 5 is a detailed block diagram of the line temperature data generator 280 shown in FIG. 2 and includes a D / A converter 281 for converting digital temperature data output from the temperature detector 270 into analog temperature data. A low pass filter (LPF) 282 for detecting low frequency components of the output signal of the D / A converter 281 and A for sampling the output signal of the LPF 282 by the number of heating elements and converting the digital signal into digital temperature data. RAM 284 for storing temperature data as many as the number of heating elements that are output signals of the A / D converter 283, the RAM controller 285 for controlling the RAM 284, and the like. It consists of.

2 will be described with reference to FIGS. 4 to 7J.

According to the present invention, the image data output from the frame memory 210 is transferred to the image data conversion unit 290 without transferring the image data from the frame memory 210 to the line memory 230 as in the conventional thermal transfer printer. send.

As shown in FIG. 4 in the temperature detector 270, the number of the temperature sensors is a separate heating element of the TPH 260 at regular intervals in the longitudinal direction of the TPH 260 with N number proportional to the M integer multiplier of 2. Attach to the back of the board and measure the temperature before heat transfer to the heat sink.

Here, the number of temperature sensors corresponding to a multiplier of 2 is used to implement hardware selection of an A / D conversion channel using a plurality of channels. For example, if there are 32 temperature sensors, the number of bits on the bus to select 32 channels is 5, which is sequentially increased in the range of 00000B to 11111B, and circulates repeatedly per line printing.

The operation of the temperature detector 270 and the line temperature data generator 280 occurs in a section where the line synchronous signal LINE SYNC (Fig. 7A) is HIGH.

The multi-channel A / D converter 272 is configured by the A / D CLOCK1 (Fig. 7B) output from the A / D controller 273 and the M-bit channel selector signal (Fig. 7C) for selecting a channel. As shown in FIG. 6A, the temperature detected by the temperature sensor is input for each channel to output SIGNAL0 converted to a digital signal. 6B is an analog signal having sampled data corresponding to the number of temperature sensors in the TPH 260.

SIGNSL0 flowing into the line temperature data generator 280 shown in FIG. 5 is generated by the D / A converter 281 by the A / D CLOCK1 (FIG. 7B) output from the A / D controller 273. FIG. The analog signal SIGNAL1 shown in Fig. 7D is converted. SIGNAL1 (Fig. 7D) detects the low pass component in LPF 282 and becomes a smooth analog signal of SIGNAL2 shown in Fig. 7E. The A / D converter 283 uses the A / D CLOCK2 (FIG. 7F) output from the A / D controller 273 to convert SIGNAL2 (FIG. 7E) by the number of heating elements K to digital temperature data (FIG. 7G). Outputs

It is possible to leak temperature data along all TPH 260 length directions from the limited temperature sensor such that the temperature along the TPH 260 length direction when the TPH 260 is generating heat to print any image. This is because the distribution takes the form of a continuous temperature distribution due to natural thermal diffusion.

The digital temperature data output from the A / D converter 283 is stored in the RAM 284 having a first in first out (FIFO) type in which data first input by the A / D CLOCK2 is first output. The RAM controller 285 stores temperature data output from the A / D converter 283 by one pixel by the line synchronous signal LINE SYNC and A / D CLOCK2. Control to output data.

The operation of the low phase data conversion unit operates in the low section of the line synchronization signal LINE SYNC.

The image data converter 290 converts data by simultaneously transmitting the line temperature data generated by the line temperature data generator 280 from the image data read out line by line from the frame memory 210. The data conversion is performed by converting the line temperature data (Fig. 7J) generated by the line temperature data generation unit 280 from the image data (Fig. 7I) read out line by line from the frame memory 210 to the frame data output from the frame memory controller. The temperature data subtracted by the synchronization signal and compensated for temperature is output to the line memory 230. That is, since the line temperature data having a high temperature has a large value, it is subtracted by the corresponding temperature data from the data driving the TPH 260 and transmitted to the line memory 230.

In order to print one line, the temperature compensated line temperature data according to the temperature data detected by the temperature detector 270 in the section where the line sync signal is high is converted to the image data compensated by the temperature in the section where the line sync signal is low. Transmitted to the line memory 230, the temperature is detected again at the same time the printer operation occurs in the next cycle.

As described above, the thermal transfer printer apparatus according to the present invention accurately detects the temperature of each heating element of the TPH by using a plurality of temperature sensors, and converts image data without complicated calculations so that a high quality image can be printed quickly. It has an effect.

Claims (5)

A thermoelectric printer apparatus for performing energization factor expression on a thermal transfer head composed of a plurality of (K) heating elements after comparing image signals in a line unit from a signal input source to preset gray level data, and attached to the thermal electronic heads. Including a temperature sensor of the number (N), a multi-channel A / D converter for converting the analog temperature data output from the temperature sensor to digital temperature data, and a controller for providing a control signal required for the A / D converter, Temperature detection unit for detecting the temperature for the N-channel: Temperature data generation unit for generating temperature data sampled by the clock corresponding to the K heating elements in the temperature detection unit: and temperature data generated in the temperature data generation unit and The temperature compensated data generated by subtracting line-level image data from the heat generation reference point of the thermal electronic head is stored in the line memory. A thermal transfer printer device characterized by including an image data conversion unit for outputting. The thermal transfer printer apparatus according to claim 1, wherein the number of temperature sensors is an integer multiplier of two. The D / A converter of claim 1, wherein the temperature data compensator converts a plurality of digital signals output from the temperature detector to an analog signal by the first clock signal. A low pass filter for detecting low frequency components of an analog signal output: An A / D converter for sampling a signal output from the low pass filter by a second clock signal determined by the number of heating elements: The A / D converter RAM for storing and outputting the data output in the order of input: Thermal transfer printer device characterized in that configured to the RAM controller for controlling the RAM to output data in line units. The thermal transfer printer apparatus according to claim 3, wherein the RAM has a size corresponding to the number of heating elements. In the thermal transfer printer apparatus which introduces an image signal from a signal input source and expresses an energization factor to the thermal transfer head which consists of heating elements, The thermal transfer head which consists of several K heating elements with a predetermined number (N) of temperature sensors. (TPH): Frame memory for storing image data from a signal input source in units of frames: Temperature detector for detecting the temperature of the TPH from the temperature sensors to N channels: Temperature data output from the temperature detector is used for K heating elements. A temperature data generation unit for generating temperature data: An image data conversion unit for subtracting the temperature data generated by the temperature data generation unit and the image data in line units output from the frame memory and outputting the subtracted data to the line memory: And comparing the image data output from the line memory with a preset gray scale value and outputting the same to the thermal transfer head. The thermal transfer printer apparatus, characterized in that it comprises a control unit for TPH.