JPH0457270B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a thermal transfer printing device that prints on recording paper using a transfer paper using lens heat-melting ink or heat sublimation ink.

[Prior art and its problems]

The principle of a thermal transfer type printing device is as shown in FIG. 4. A recording paper 1 and a transfer paper 2 are fed between a pressure roller 3 and a thermal head 4 so as to overlap each other, and as shown in FIG. 5, which will be described later. When the transfer paper 2 is heated by passing a current through each of the heating paper resistors R ₁ , R ₂ , R _{3 .} . . Ro of the thermal head 4, the ink 2a applied to the transfer paper 2 melts or sublimates. The ink 2a is attached to the recording paper 1 to form a printed matter. Note that the transfer paper that is no longer needed is wound up by a take-up roller 6 via a guide roller 5. As shown in FIG. 5, this thermal head printing involves converting an analog video signal obtained from a TV signal generator 10 such as a TV camera or VTR into a digital signal using an A/D converter 11.
This digital signal is sent to a data storage device 12 such as a semiconductor memory, addresses are determined and stored for the required number of pixels, a start pulse is added to the address counter 14, and a reference clock is sent to the address counter 14. The first address is sent from the counter 14 to the data storage device 12, and the data stored at that address is sent back from the data storage device 12. The data sent back from the data storage device 12 is inverted by the inverter circuit 13 (for example, if the data from the data storage device 12 is 1011
If this is inverted (0100), this inverted data is sent to the grayscale data comparison circuit 15. At this time, UP/DN switching circuit 1
The count of the data counter 16 whose output is turned up by 9 is set to 0, and this count 0 is compared with the inverted data by the gray data comparison circuit 15, and the inverted data is output from the data counter 16. If the inverted data is smaller than the data from the data counter 16, a signal of 1 is sent to the shift register circuit 17, and if the inverted data is greater than or equal to the data from the data counter 16, a signal of 0 is sent. Then, the address counter 14 counts the total number n of heating resistors R ₁ , R ₂ , ..., _Ro of the thermal head 4.
When counting is completed, one data transfer pulse is sent to the latch circuit 18. Also, at the same time as sending the first data transfer pulse, the heating pulse is gated G ₁ ,
G ₂ , ..., send to G _o . Thereafter, in the same manner, each time the address counter 14 finishes counting n, the count of the data counter 16 is increased by one, and if the count number corresponding to the maximum color density is m, the count of n of the address counter 14 is increased. Do this m times. When the count of the data counter 16 reaches m, the UP/DN switching circuit 19 converts the count m of the data counter 16 and the inverted data sent back from the data storage device 12 via the inverter circuit 13. are compared by the gray data comparison circuit 15, and the inverted data is sent to the data counter 1.
If it is smaller than the count m of 6, a signal of 1 is sent to the shift register circuit 17, and if the inverted data is greater than or equal to the count from the data counter 16, a signal of 0 is sent. However, the centers of the printed dots obtained as described above lie on a straight line in the line direction, regardless of the size of the dots, and for this reason, the printing is not beautiful. In other words, when trying to print, for example, the letter S using the conventional printing device as described above, as can be seen from the partially enlarged view shown in Fig. 6, the diagonal portions are not continuous and do not appear beautiful. .

[Means to solve problems]

The present invention has been made in view of the above-mentioned problems, and is a thermal transfer printing device that prints by applying a current to each of a plurality of heating resistors of a thermal head to adhere ink from a transfer paper to a recording paper. In this case, when the heating resistor is energized according to the input data for printing and the kth printing is performed on the l line, the input data for the kth printing on the l-1 line is changed to the kth printing on the l+1 line. If the input data is larger than the input data for printing, the power supply to the heating resistor is changed so that the start of the power supply is the same as the first start of printing on the lth line, and then for a predetermined time corresponding to the specified density. If the input data for the k-th printing on the l-1 line is smaller than the input data for the k-th printing on the l+1 line, the energization of the heating resistor is stopped until the end of the energization. The present invention provides a thermal transfer printing device equipped with an energization timing control means for controlling the energization timing so that the energization ends at the same time as the end of the energization in the l-th line, and for a predetermined time corresponding to a prescribed density at the end of the energization.

【Example】

FIG. 1 is a block diagram of an embodiment of a thermal transfer printing device according to the present invention, FIG. 2 is an explanatory diagram illustrating the timing of energizing the heating resistor, and FIG. 3 is a thermal transfer printing device according to the present invention. FIG. 2 is a partially enlarged schematic explanatory diagram of a case where, for example, S is printed by a printer. As shown in Figure 1, TV such as TV camera or VTR
The analog video signal obtained by the signal generator 10 is converted into a digital signal by the A/D converter 11, and this digital signal is sent to a data storage device 12 such as a semiconductor memory, and addresses are determined for the required number of pixels. Then, when a start pulse is added to the address counter 14 and a reference clock is sent to the address counter 14, the first address is sent from the address counter 14 to the data storage device 12, and the data corresponding to the address is stored.
That is, for example, data on the lth line to be printed is sent back from the data storage device 12 to the grayscale data comparison circuit 15, and data before and after the lth line, that is, data on the l-1th line and l+1
The data on the line is before and after line data comparison circuit 3
It is configured to be sent back to 0. Then, the front and rear line data comparison circuits 30
The k-th data on the line and the k-th data on the l+1 line are sent, and a comparison is made between the k-th data on the l-1 line and the k-th data on the l+1 line, and the k-th data ≧ on the l+1 line. l+1
If it is the k-th data on the line, 1 is output from the front and rear line data comparison circuit 30 to the output inverting circuit 31 composed of an exclusive OR gate, etc., and conversely, if the k-th data < l on the l-1 line,
If it is the k-th data on the +1 line, the output from the front and back line data comparison circuit 30 is output from the inversion circuit 31.
The configuration is such that 0 is output. Depending on the output 1 or 0 of the front and rear line data comparison circuit 30, the output inversion circuit 31 passes or inverts the signal φ from the data counter 16 and sends it to the gray data comparison circuit 15. Then, the l-th line data sent back from the data storage device 12 and the output from the output inversion circuit 31 are compared in the gray data comparison circuit 15, and the data from the data storage device 12 is compared with the output from the output inversion circuit 31.
If the data is equal to or larger than the data from , a 1 signal is sent to the shift register circuit 17, and if it is smaller, a 0 signal is sent to the shift register circuit 17. Also, the address counter 14 is connected to the thermal head 4.
When the total number n of the heating resistors R ₁ , R ₂ , R ₃ , . . . , _Ro has been counted, one data transfer pulse is sent to the latch circuit 18 . Furthermore, when the first data transfer pulse is sent, a heating pulse is simultaneously applied to the gates G ₁ , , G ₂ , G ₃ ,...
..., it is now being sent to G _o . Thereafter, in the same manner, the data counter is incremented by one each time the address counter 14 finishes counting n. Furthermore, if the maximum color density is m, the address counter 14 is counted m times, and the output inverting circuit 31 is incremented m times. Output and data storage 1
The gray data comparison circuit 15 compares the data of each address sent back from 2 at each time, and if the data of the address is larger than or equal to the output of the output inverting circuit 31, it sends a signal of 1 to the shift register circuit 17, It sends a 0 signal. Then, when the address counter 14 has finished counting the total number n of the heating resistors R ₁ , R ₂ , R ₃ , . . . _Ro of the thermal head 4, one data transfer pulse is sent to the latch circuit 18, and At the same time, heating pulses are sent to gates G ₁ , G ₂ , ..., _Go . With the above configuration, if you want to print the kth data on the l line,
As shown in FIG. 2, if the k-th data in the l-1 line is greater than or equal to the k-th data in the l+1 line, the energization start time is from the initial stage in the l-th line, and the predetermined concentration is The heating resistor is energized for a period corresponding to , and conversely the kth data on the l-1 line is
If it is smaller than the k-th data in the line, the energization start time is not from the beginning but from the middle, and the predetermined concentration is adjusted so that the energization end time is the same as the end of energization in the l-th line. The heating resistor is energized for the corresponding period. Therefore, when the energization is controlled in this way and the k-th printing is performed on the l line, if the k-th data on the l-1 line ≧ the k-th data on the l+1 line, then the l-th printing is performed on the l line. Printing is performed on the printing side of the l-1 line, and conversely, if the kth data on the l-1 line < the kth data on the l+1 line, the printing on the lth line is on the printing side of the l+1 line. It will be printed. For example, if we consider a compensation dot formed by small dots, as shown in Fig. 3, which is a partially enlarged schematic explanatory diagram when S is printed, the position of this compensation dot is the same as that of a large dot. The dots are in contact with each other, and the gap between them is extremely small. Therefore, the lines formed by the collection of these dots are extremely smooth and beautiful, so the resulting printed matter is extremely natural and beautiful. .

【effect】

A thermal transfer printing device according to the present invention is a thermal transfer printing device that prints by applying a current to each of a plurality of heating resistors of a thermal head to cause ink on a transfer paper to adhere to a recording paper. When the k-th printing is performed on the l line by energizing the heating resistor according to the data, l
-The input data for the kth print on the 1st line is l+
If the input data for one line is larger than the k-th printing input data, the heating resistor is energized so that the start of energization is the same as the first printing start for the l-th line, and then the specified The input data for the k-th print on the l-1 line is set to the k-th print data on the l+1 line, so that the predetermined time corresponds to the density.
If it is smaller than the input data for printing,
When energizing the heating resistor, the end of energization is l.
Since the energization timing control means is provided so that the energization ends at the same time as the end of the energization at the line, and the end of the energization takes a predetermined time corresponding to the specified concentration, the center of the small dot and the center of the large dot are The dots are now printed close together, and the lines expressed by the collection of these dots are smooth and not jerky, improving print quality and producing beautiful prints. become,
In addition, the printing time required to obtain such high-quality printed matter is the same as that of conventional printing, and it has the advantage of being able to be obtained quickly.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of one embodiment of a thermal transfer printing device according to the present invention, Fig. 2 is an explanatory diagram illustrating when to flow current to the heat generating resistor in this thermal transfer printing device, and Fig. 3 is a block diagram of an embodiment of the thermal transfer printing device according to the present invention. FIG. 4 is an explanatory diagram showing the principle of a thermal transfer printing device; FIG. 5 is a block diagram of a conventional thermal transfer printing device; FIG. 6 is a partially enlarged schematic explanatory diagram when, for example, S is printed by this thermal transfer printing device. 4... Thermal head, 10... TV signal generator, 12... Data storage device, 14... Address counter, 15... Grayscale data comparison circuit, 16
... Data counter, 17 ... Shift register circuit, 18 ... Latch circuit, 30 ... Front and rear line data comparison circuit, 31 ... Output inversion circuit.

Claims (1)

[Claims] 1. In a thermal transfer printing device that prints by applying a current to each of a plurality of heat generating resistors of a thermal head to cause ink from a transfer paper to adhere to a recording paper, the heat generating resistors are adjusted according to input data for printing. When the k-th printing is performed on the l line by energizing, if the input data for the k-th printing on the l-1 line is larger than the input data for the k-th printing on the l+1 line, the heating resistor energizing the body so that the start of energization is the same as the start of the first printing on the lth line, and for a predetermined time corresponding to the specified density;
The input data for the kth print on the l-1 line is l
If the input data for the +1 line is smaller than the k-th printing input data, the energization of the heating resistor is specified so that the end of the energization is the same as the end of the energization in the l-th line, and the end of the energization is defined as the end of the energization. 1. A thermal transfer printing device characterized by comprising a energization timing control means for controlling the energization timing to a predetermined time corresponding to the concentration of the energization.