KR0134344B1 - The counting apparatus for the numbers of simultaneous heating dots - Google Patents

Abstract

The present invention relates to an apparatus for calculating the number of simultaneous heating dots for each gray level of a sublimation thermal transfer printer. In particular, in a thermal transfer printer using a thermal recording head, one-line system is counted by counting binary data indicating whether heat is generated for each gray level applied from a gray level comparator. The invention allows one to easily obtain the number of simultaneous heating dots in each group. Therefore, in order to compensate for the common drop for each gray level, the hardware configuration is simple and economically large compared to the gray level simultaneous heating dot calculation method printer.

Description

Simultaneous heating dot counting device for each gradation of printer

FIG. 1 is a convex diagram showing a simultaneous heating dot count calculating device for each gray level of a conventional sublimation thermal transfer printer. FIG.

FIG. 2 is a block diagram showing a simultaneous heating dot count calculating device for each gray level of a sublimation type thermal transfer printer according to an exemplary embodiment of the present invention.

3 is a block diagram showing a simultaneous heating dot calculation apparatus for each gray level of a sublimation thermal transfer printer according to another exemplary embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

21, 31: frame memory 22, 32: clock generator.

23, 33: Address generator 24, 34: Line memory.

25, 35: Gradation counter 26, 36: Gradation comparison.

27, 37: counter part 28, 39: strobe generation part.

29, 40: TPH (Thermal Print Head) 38: Adder

The present invention relates to a sublimation type thermal transfer printer, and in particular, by generating the number of simultaneous heating dots for each gray level, controlling the strobe time, and simultaneously generating the gray level of the printer capable of compensating for image quality degradation due to voltage drop inside the thermal recording head. It relates to a dot counting device.

Technologies that provide color printing include inkjet, thermal transfer, dye dissipation, and laser. Thermal transfer color printing, which provides high quality output at an affordable price, can be applied to paper or forge film from special ink sheets. Use heat to transfer it. That is, in color thermal printing, the color transfer ribbon in which the colored waxes on the film are connected one by one, and the heat generating element capable of emitting 100 to thousands of heats in the heat recording head in the form of dots in the form of dots in the form of dots. Melt and stick to a smooth, flat paper. In this method, the color transfer ribbon is divided into four colors of yellow, cyan, magenta, and black, so that three to four printers are required to complete one sheet.

Thermal transfer has the advantage of providing fast print speeds, good color output, and excellent addressability. However, due to the parasitic resistance component present in the thermal print head (hereinafter referred to as TPH), a voltage drop occurs to change the applied energy of the TPH. Therefore, there is a disadvantage in that deterioration in image quality occurs. Therefore, this problem is solved by calculating the number of simultaneous heating dots per gray level and adjusting the heating time using the same. This prior art is shown in FIG.

1 is a block diagram showing a simultaneous heating dot calculation apparatus for each gray level of a sublimation type thermal transfer printer according to the related art. The apparatus of FIG. 1 includes a frame memory 11 for storing one screen of image data to be printed, and a line memory 14 connected to the output terminal of the frame memory 11 by a parallel data transmission line of a predetermined bit. And a TPH 20 for embedding a shift register and a heating element and subliming ink, and a gradation comparator 16 positioned between the above-described line memory 14 and the TPH 20. The address generator 13 connected to apply the read / write address to the line memory 14 and the clock generator 12 applying the clock signal CLK to operate the address generator 13 are provided to the address generator 13. Connected. A gradation counter 15 is connected to an input terminal of the gradation comparator 16 by a parallel data transmission line of a predetermined bit. On the other hand, the means 100 for calculating the number of simultaneous heating dots per gradation is configured as follows. The output terminal of the frame memory 11 and the gradation counter 15 is further connected to a switch SW for switching between the contacts corresponding to the two output terminals by a predetermined control signal CTL. The output unit of the switch SW is connected to a storage unit 18 that stores the number of simultaneous heating dots per gray level. A control unit 17 is provided to supply the control signal CTL to the above-described switch unit SW and to control the storage state of the storage unit 18. A strobe generator 19 is configured between the storage 18 and the TPH 20 to generate a strobe signal STB having a variable pulse width under the control of a signal applied from the storage 18.

In FIG. 1, data transmitted from the frame memory 11, which stores one screen of image data to be printed, is input to the line memory 14 via a parallel data bus of a predetermined bit. The clock generator 12 applies a clock signal CLK to the address generator 13 that outputs the address data. Accordingly, data of a predetermined bit size transmitted to the line memory 14 is stored in the line memory 14 according to the address value generated by the address generator 13 in accordance with the clock signal CLK. When the data storage for one line of the line memory 14 is completed, the line memory 14 is adapted to the address value generated by the address generator 13 in accordance with the clock signal CLK applied from the clock generator 12. The stored predetermined printing data is output. The printing data output from the line memory 14 is input to the gradation comparator 16 through a predetermined bit transmission line. The gradation comparator 16 compares the input of predetermined printing data with a comparison reference gradation level of a predetermined bit applied from the gradation counter 15. That is, when reading data from the line memory 14 and actually printing in the TPH 20, printing is performed for each gray level. For example, if the size of the image data is 8 bits, the gradation level of 0 to 255 can be represented. The TPH 20 prints 255 times for each pixel (dot) from 1 to 255 gradations. The gradation counter 15 also increases from 1 to 255, and compares with the output data of the line memory 14. The gray scale comparator 16 outputs binary data 1 when the printing data is greater than or equal to the comparative reference gradation level, and outputs binary data 0 when the printing data is less than the comparative reference gradation level. The binary data output from the gradation comparator 16 is transmitted to a shift register embedded in the TPH 20. Here, the comparison reference gradation level is used for comparison with all image data applied from the line memory 14. Therefore, the predetermined tone value of the tone data for one line stored in the line memory 14 is converted into binary data of 1 or 0 and stored in the shift register of the TPH 20. The binary data stored in the TPH 20 generates the heating elements corresponding to the flip-flop of the shift register storing the binary data 1 by the strobe signal STB for enabling each heating element by the strobe time.

On the other hand, the simultaneous heating dot count calculation unit 100 for each gray level has a higher voltage drop in the TPH 20 as the number of simultaneous heating dots increases, resulting in a decrease in energy. It is a means to compensate for the disadvantage. That is, when one line of data is transferred from the frame memory 11 to the line memory 14, one line of data is also applied to the first contact a of the switch unit SW. At this time, in response to the control signal CTL applied from the control unit 17, the control unit 17 is connected to the first contact point a to output data for one line to the address terminal ADDR of the storage unit 18. The storage unit 18 assigns a corresponding address to the data applied from the switch unit SW. Each address addresses the designated address by incrementing the data by one by the controller 17 each time a corresponding address is designated. In other words, when image data is composed of 8 bits and the number of data for one line is composed of 1000, the data of any one line is 100 gray scale data, 50 gray scale data, 50 gray scale data, 235 gray scale. Suppose you have 850 data. Then, in the storage unit 18, data of 850 is stored at 100, 5 at 50, 235 at address 1, and 0 at the remaining address. Here, the number stored at each address of the storage unit 18 indicates how many data have been input for each gray level among the data for one line. Next, the number of simultaneous heating dots for each gray level is calculated. First, the controller 17 sequentially receives data stored from address 1 to address 255, adds all of them, and writes them back to address 1 of the storage 18. Next, data stored from address 2 to address 255 of the storage unit 18 are sequentially applied to the controller 17 again, and all of them are added and recorded at address 2. In this way, the number of simultaneous heating dots is calculated for each gray level. At 255, previously stored data is left as is. The reason for calculating in this way is that printing is performed for each gradation. Therefore, if one gradation printing is performed, the comparison reference gradation level applied from the gradation counter 15 is 1, and the gradation comparator 16 has one line of data. All data of more than 1 gradation (that is, 1 to 255 gradations) are outputted by outputting the binary signal 1 of the high state to the TPH 20, and when the 2 gradation printing, the comparative reference gradation level becomes 2, All data of two or more gray levels (i.e., 2 to 255 gray levels) generate a binary signal in a high state to generate heat. In the case of 254 gradation printing, the gradation comparator 16 receives the gradation level 254 applied from the gradation counter 15 to the second input terminal IN2 and receives data for one line from the first input terminal IN1 to compare each other. The binary signal in the high state is outputted only when data of 254 or more gray levels, i.e., 254 or 255 gray levels is applied, to generate heat. When printing 255 gradations, the gradation level becomes 255 and only the data corresponding to the 255 gradations are generated, and one-line printing is completed. When the data calculated through the above-described calculation process reads data from the line memory 14 and prints for each gray level, the comparison reference gray level level output from the gray level counter 15 is the second contact point b of the switch unit SW. The switch unit SW is connected to the second contact point b and is supplied to the address terminal ADDR of the storage unit 18 under the control of the control signal CTL applied from the control unit 17. . The storage unit 18 outputs the data stored at the address corresponding to the received current comparison reference gradation level. That is, in response to the current comparison reference gradation level applied from the storage unit 18 through the switch unit SW, the number of simultaneous heating dots of the corresponding gradation is transmitted to the strobe generator 19. The strobe generator 19 controls the heating time of the heating elements inside the TPH 20 by varying the pulse width according to the number of simultaneous heating dots for each gradation, and transmitting the variable strobe signal STB to the TPH 20. do. That is, the energy applied to the TPH 20 varies according to the magnitude of the strobe signal STB. For example, the longer the strobe pulse width, the more energy is applied, so the greater the number of simultaneous heating dots per gray level, the longer the strobe pulse width to compensate for the energy drop due to the common drop.

However, the compensation method as described above requires a separate complicated device for calculating the number of simultaneous heating dots for each gray level, which is expensive and has a complicated calculation method.

Accordingly, it is an object of the present invention to provide an apparatus which can calculate the number of simultaneous heating dots per gray level simply by using a counter instead of using a complicated calculation to solve the above-mentioned problems. The object of the present invention as described above is in a device for calculating the number of simultaneous heating dots for each gray level of a printer having a gray scale expression function, which compares grayscale data with a predetermined reference gray level and generates a binary signal. When the first signal is applied from the gradation comparator, the count operation is performed in response to a negative clock and a predetermined clock signal, and when the second signal is applied, the counting operation is performed by maintaining the previous value as it is. And a strobe generator for generating a strobe signal having a variable magnitude in response to a count value applied from the counter.

An object of the present invention is also a frame memory for storing image data for one screen, and an apparatus for calculating the number of simultaneous heating dots for each gradation of a printer having a gradation expression function, the line being applied from the frame memory. A plurality of memories for parallel processing of data, a line memory for sequentially storing and simultaneously outputting a predetermined unit in a memory in response to a predetermined control signal, and a plurality of gradation comparators, and each gradation comparator A gradation comparison unit for generating a binary signal by comparing gradation data applied from a corresponding memory of the line memory with the same comparison reference gradation level, and a plurality of counters, each counter being provided with the same clock signal When the first signal of the binary signal applied from the corresponding tone comparator of the tone comparison unit is applied, A counter unit for performing an operation and maintaining a previous value when a second signal is applied, an adder for calculating the number of simultaneous heating dots per gray level by adding count values applied from counters of the counter unit; It is achieved by the strobe generating section for varying the magnitude of the strobe signal in response to the count value applied from the adder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram showing a simultaneous heat generating dot calculation apparatus for each gray level of a sublimation thermal transfer printer according to an exemplary embodiment of the present invention. The apparatus of FIG. 2 is connected to a frame memory 21 storing image data of one screen to be printed, and a parallel data transmission line of a predetermined bit to an output terminal of the frame memory 21, and a clock signal from the clock generator 22. And a line memory 24 connected to the address generator 23 that receives the CLK to generate the address value of the line memory 24. To the output end of the line memory 24, a gradation comparator 26 for comparing the gradation data applied from the line memory 24 with a predetermined comparison reference gradation level is applied to each input end. The output terminal of the gradation comparator 26 is connected with a TPH 29 that embeds a shift register and a heat generating element and sublimates ink, and is also connected to the enable terminal ENB of the counter 27. The strobe generator 28 is connected between the output terminal of the counter 27 and the TPH 29.

In FIG. 2, data of one line unit is received from the frame memory 21, stored in the line memory 24, the stored data is read out, and the TPH (compared with the reference reference gradation level through the gradation comparison unit 26). Since printing binary data for generating the heating element of step 29) and performing printing for each gray level are the same as in the related art, a detailed description of the operation is omitted.

The address generator 23 generates a number of data for one line so that data for one line can be stored in the line memory 14. Then, the stored data can be repeatedly read in sequence 255 times (for example, when the input image data is 8 bits). The clock generator 22 also generates a clock signal CLK by the number of data for each gray level printing. The counter 27 for calculating the number of dots that are simultaneously generated for each gradation is the number of simultaneous heating dots for each gradation using a signal applied from the gradation comparator 26 and a clock signal CLK applied from the clock generator 22. Calculate That is, when the high signal is applied to the enable terminal ENB of the counter 27, the counter is counted by one, and when the low signal is applied, the previous value is kept without counting. The counting operation is operated in synchronization with the clock signal CLK applied from the clock generator 22. The counting operation is performed by the number of data for one line for each gradation and maintains the initial state. In this process, the number of simultaneous heating dots is calculated for each gradation and transmitted to the strobe generator 28. The strobe generator 28 receives the number of simultaneous heating dots for each gray level to vary the strobe pulse width to compensate for image quality degradation due to the common drop.

3 is a block diagram showing a simultaneous heating dot calculation device for each gradation of a sublimation thermal transfer printer according to another preferred embodiment of the present invention, and in order to shorten the time taken for comparing the gradation data and transmitting the result thereof. It is configured to allow parallel processing. The apparatus of FIG. 3 has a frame 31 for storing one screen of image data. An output terminal of the frame memory 31 is connected to a line memory 34 having a plurality of memories for storing one line of data in predetermined units. The address generator 33 and the clock generator 32 which control the read and write states of the respective memories of the line memory 34 are provided. Comprising a plurality of gradation comparators connected to the corresponding memory of the line memory 34, a level comparison section 36 for generating a signal of the previous type by comparing the data of one line by each unit at the same time. A plurality of counters CTN1, CTN2... CNTn applied to the respective enable terminals ENB corresponding to the binary signals applied from the level comparators, and the clock signal applied from the clock generator 32 And a counter 37 for performing a counting operation in synchronization with CLK. The adder 38 which adds all the count values output from the counters CNT1, CNT2, ... CNTn of the counter 37 to obtain the number of simultaneous heating dots per gray level is connected. The strobe signal generator 39 is connected to the output terminal of the adder 38.

In FIG. 3, if a plurality of data blocks of the TPH 40 are configured, data processing must be performed for each block simultaneously. Thus, one line of data transmitted from the frame memory 31 is configured to transfer data of each block unit according to the address generated by the address generator 33 in accordance with the clock generated by the clock generator 32. Store sequentially in each memory. Each gradation comparator of the gradation comparator 36 receives gradation data simultaneously transmitted from each memory corresponding to the first input terminal IN1 and receives a comparison reference gradation level applied from the gradation counter 35 as a second input terminal ( IN2) and compare with each other. When the gradation data is greater than the reference reference gradation level, a binary signal of a high state and a low state is applied to each corresponding data block of the TPH 40 and supplied to the counter unit 37 at the same time. The counters CNT1, CNT2, ... CNTn of the counter 37 receive a binary signal from the corresponding grayscale comparator of the grayscale comparator 36 and generate a clock generated by the clock generator 32. The high signal is counted among the binary signals in synchronization with the signal CLK. The adder 38 adds a counting value in units of blocks applied from the counters CNT1, CNT2, ... CNTn of the counter unit 37 to obtain the number of simultaneous heating dots for each gray level. The strobe generator 39 is controlled by the number of simultaneous heating dots for each gray level applied from the adder 38 to vary the pulse width of the strobe signal and apply it to the TPH 40.

As described above, the present invention relates to an apparatus for calculating simultaneous heating dots for each gray level of a sublimation thermal transfer printer. A counter is provided at the rear end of the gray level comparison unit to count the binary data output from the gray level comparison unit, and a line for each gray level. By calculating the number of simultaneous heating dots, the hardware implementation for common drop compensation can be simplified and economically effective.

Claims (6)

A device for calculating the number of simultaneous heating dots for each gray level of a printer having a gray scale expression function, the gray level comparison unit generating a binary signal by comparing the gray level data with a predetermined reference level of gray level: Responding to a predetermined clock signal And a counter unit for counting the number of simultaneous heating dots for each gray level by maintaining a previous value when a first signal is applied from a binary signal applied from the gray level comparator. And a strobe generator for generating a strobe signal having a variable size in response to a count value applied from the same. The apparatus of claim 1, wherein the strobe signal controls a heat generation time of the printer. The apparatus of claim 2, wherein the pulse width of the strobe signal corresponds to the number of simultaneous heating dots for each gray level. The apparatus of claim 1, wherein the clock signal is generated equal to the number of data of one line for each gray level. A frame memory for storing image data for one screen, and an apparatus for calculating the number of simultaneous heating dots for each gray level of a printer having a gray scale expression function, for parallel processing of data for one line applied from the frame memory. A line memory having a plurality of memories, and sequentially stored in the memory in a predetermined unit in response to a predetermined control signal, and output at the same time: a plurality of gradation comparators, each gradation comparator is a corresponding memory of the line memory A gradation comparison unit for generating a binary signal by comparing the gradation data applied from the gradation level with the same comparison reference gradation level, each counter having a plurality of counters, each counter being supplied with the same clock signal from a corresponding gradation comparison unit of the gradation comparison unit Each count operation is performed when a first signal of the applied binary signals is applied, Counter unit for maintaining the previous value when the second signal is applied: Adder for calculating the number of simultaneous heating dots for each gradation by adding the count value applied from each counter of the counter unit: And applied from the adder A gradation generating dot count calculation device for each gray level of a printer including a strobe generator for varying and outputting a magnitude of a strobe signal in response to a count value. The gradation comparator of claim 5, wherein each gradation comparator of the gradation comparator generates a first signal when the input gradation data is greater than the comparison reference gradation level, and generates a second signal when the gradation data is smaller. Exothermic dot product calculating device.