JPS63202474A - Thermal recording printer - Google Patents

Abstract

PURPOSE:To print a vertical one line clearly, by providing a previous record control circuit which controls applied energy, depending upon the presence of printing data of a previous line, a buffer memory circuit which transfers a present line data and a previous line data to the previous record control circuit, and a control means which switches the previous line data to white by an arrangement of a present line data. CONSTITUTION:A printing data signal inputted to a read buffer selector 21 of a printing data receive part 17 is sent to a neighbour control circuit 8 of a printing control circuit part 6 through line buffer memories 18, 19, 20 and a read buffer selector 22. Printing energy is controlled, depending upon the presence of a neighbour printing data in a heating element 2. When a printing data of neighbouring both lateral two dots is white, the printing data of a previous line is made white and a previous record control circuit 7 is so constituted as not to be operated. That is, the previous line control circuit 7 controls energy to be applied to the heating element 2 in printing of a following line on the basis of the printing data of the previous line. When a black printing data was colored in the previous line, printing energy is decreased by a remaining heat content in printing of the following line and a printing of a good density is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermal recording printer using a thermal recording method.

The conventional thermal recording method is easy to maintain, so
It is used as a printer for many types of paperbacks, including facsimile machines, and in recent years, thermal transfer methods have also been developed, making it possible to record in multiple colors or in full color.

Conventionally, in a thermal recording printer using this type of thermal recording method, printing is controlled by the following configuration.

That is, when there is print data from the previous line, only previous history control is performed that takes into account the influence of residual heat and reduces the energy applied to the heating element.

Problems to be Solved by the Invention In such a conventional configuration, the influence of the presence or absence of adjacent dots is not considered, so the data of adjacent dots
In the case of "White", the thermal energy of the heating element flows horizontally, making it impossible to obtain a sufficient temperature rise, making it impossible to print a single vertical line clearly.

The present invention solves these conventional problems, and aims to control the energy applied to the heating element depending on the presence or absence of two adjacent dots on both sides, and to provide the necessary and sufficient applied energy to the head. It is something.

Means for Solving the Problems In order to solve these problems, the present invention provides a previous history control circuit that controls the mark m energy key depending on the presence or absence of print data of the previous line, and a previous history control circuit that controls the current line and the previous line. The heat-generating printer includes a buffer memory circuit for transferring line data, and a control means for switching the previous line data to white according to the arrangement of the current line data.

Effect: With this configuration, when the two adjacent horizontal dots are white, even if the data on the previous line is black, the marking energy is not reduced by the operation of the previous history control circuit, so that a single vertical line can be printed neatly. I can do it.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the circuit configuration of a thermal recording printer according to an embodiment of the present invention. In the figure, 1 is a thermal head section, and this thermal head section 1 is arranged in a line on an insulating substrate. A heating element 2 consisting of a plurality of heating resistors arranged in a row and electrically divided into N units of each heating element, and N drivers provided for each unit of this heating element 2. The circuit 3 includes a circuit 3, N latch circuits 4 provided corresponding to each of the driver circuits 3, and N shift registers 6 provided corresponding to each of the latch circuits 4.

In this thermal head section 1, one electrode of the heating elements 2 is connected in common to a printing power source, and the other electrode is connected to an output terminal of a driver circuit 3. In addition, the input terminal of the driver circuit 3 is connected to the latch circuit 4.
The input terminal of the latch circuit 40 is connected to the output terminal of the shift register 6, and the print data signal input to each shift register 6 is output as a parallel signal to the corresponding latch circuit 4. The driver circuit 3 is driven by the print data signal sent from the latch circuit 4, and the heating element 2 corresponding to the print data signal is energized to perform thermal recording. Here, each of the driver circuits 3 is configured so that enable signals for controlling all operations of the driver circuit 3 are individually and independently generated in parallel.

Reference numeral 6 denotes a print control circuit section, and this print control circuit section 6 is composed of a previous history control circuit 7 and an adjacent control circuit 8.

The previous history control circuit 7 includes a data selector 9 that outputs the print data signal to the shift register 6, an AND gate 1o whose output terminal is connected to one input terminal of the data selector 9, and one of the AND gates 1o. It is composed of an inverter 11 connected to an input terminal.

Further, the adjacent control circuit 8 includes an OR gate 12 whose output terminal is connected to the inverter 11 of the previous history control circuit 7, and this O
A 2-bit shift register 13 connected to one input terminal of the R gate 12, an AND gate 14 whose output side is connected to the other input terminal of the OR gate 12, and this AN
It is composed of a shift register 16 that transfers signals directly to the D gate 140 input terminal and via an inverter 16.

Further, in this print control circuit section 6, a previous history control circuit 7
The other input terminal of the data selector 9 is the ND gate 1.
0 and the output terminal of the shift register 1θ of the adjacent control circuit B to which the inverter 15 is connected. Furthermore, one input terminal of the AND gate 14 is connected to the input side of the shift register 16.

Reference numeral 1A denotes a print data receiving section, which is composed of three line buffer memories 1B, 19.20, a reading buffer selector 21, and a reading buffer 1 selector 22. In this print data receiving section 17, one line of the three line buffer memories is used for reception, and the remaining two lines are used for gold printing. That is, when the reception and printing of one line is completed, the role of the memory is switched and the next line is received and printed.

Table 1 shows this situation.

(Explanation below) In the thermal recording printer having such a configuration, the print data signal input to the read buffer 1 selector 21 of the print data receiving section 17 is sent to the line buffer memories 18 and 19.
,20. It passes through the read buffer selector 22'ii and is sent to the adjacent control circuit 8 of the print control circuit section 6.

This adjacent control circuit 8 controls the print m energy depending on the presence or absence of adjacent print data on the heating element 2.
When the print data of two adjacent dots on both sides is “white”,
By setting the print data of the previous line to "white" 1,
The previous history control circuit 7 is configured so as not to operate. In the circuit shown in Figure 1, "white" is set to high level (a
), tt black" is set to low level (L). Therefore, when the print data of the two dots on both sides are "white", that is, the print data of the current line is set to "H, H" in the shift register 16.

When lined up as "L, H, H", it works to change the print data of the previous line to "white", that is, "IH", thereby making it possible to print a single vertical line clearly.

The print data controlled by this adjacent control circuit 8 is
It is sent to the previous history control circuit 7.

This previous history control circuit 7 controls the energy applied to the heating element 2 when printing the next line based on the print data of the previous line.
When printing data of , the residual heat remains in the heating element, so when printing the next line, the energy applied to the heating element 2 must be reduced by the amount of residual heat, otherwise excessive energy will be applied. , it becomes impossible to obtain prints with good density. In order to prevent this problem, the previous history control circuit 7 controls the pulse width of mm energy applied to the heating element 2 for each dot based on the print data of the previous line. Note that in a printer with a line-type head unit like the present invention, it is difficult to control the Kani pulse for each dot, so two lines of print data are transferred in order to print one line. As a result, the pulse width of mm energy to the heating element 2 is controlled depending on whether printing is performed once or twice. Table 2 shows an example of control in this previous history control circuit 7. In addition, previous history control data (
The second print data) is output according to Table 3. In the circuit shown in Figure 1, white is "i", "H" is white, and black is "?". The circuit is configured so that the output voltage becomes "tt L".

(Left below) The print data controlled by this previous history control circuit 7 is
The signal is input to the shift register 5 of the thermal head section 1.

The print data signal input to the shift register 6 is input to the driver circuit 3 through the latch circuit 4, and the driver circuit 3 controls the energization of the heating element 2 based on the print data signal and the enable signal. As a result, the heating element 2 selectively generates heat and predetermined printing is performed.

Here, in this embodiment, since the enable signal is inputted independently and in parallel to each of the driver circuits 3, there is no possibility that the printing will be misaligned even if the printing data controlled by the previous history is continuously applied. do not have. That is, when performing previous history control as described above, it is necessary to send two pieces of data as shown in FIG. 2 for one line of printing. In Fig. 2, the times of M and C vary depending on the head temperature, and are controlled so that appropriate energy is applied. However, when printing 4 human sizes in 1 minute, a head with a heating element divided into 7 is used. If used, the maximum time for C is 700 μsec.
The minimum time is 25071 Se
c.

In the head part where such prior history control data is input, if an enable signal is input independently and in parallel to each of the driver circuits 3, when using a head divided into 7 parts with the size of 8 dots/mm and 4 mm, Since the number of dots per block is 224, the data transfer time is 224 μSec, which is the minimum value of the above-mentioned time of 260 μSec.
As long as it stays within the µ-square, print data can be applied continuously, and there will be no misalignment of print.

In the thermal recording printer configured as described above, in the present invention, when the data of two adjacent inner product dots is "°1 white", that is, the print data of the current line is stored in the shift register 16 as "H, H, L, H.

When lined up with “H”, all AND gate 140 inputs are “H”
Tona! +, the output to the OR gate 12 becomes "H", so the previous line data input to the previous history control circuit 7 is "H" regardless of the previous line data input to the adjacent control circuit 8.
In other words, it becomes ゞwhite.

As a result, when writing a single vertical line, the previous history control data can be set to "black", so by applying sufficient energy to the heating element 2, it is possible to write a single vertical line without blurring. become.

Effects of the Invention As described above, according to the present invention, a single vertical line can be drawn neatly using a simple circuit configuration for controlling previous history data.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing the circuit configuration of a thermal recording printer according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram for explaining the control operation of the main parts of the circuit. 1...Thermal head section, 2...Heating element, 3...Driver circuit, 4...
Latch circuit, 5゜13.16...Shift register, 6...Print control circuit section, 7...Previous history control circuit, 8...Adjacent control circuit , 9...
...Data selector, 10.14...AND gate, 11.15...Inverter, 12...
...OR gate, 17...Print data receiving section, 18゜19, 20...Line buffer memo IJ, 218. -,,. Read buffer selector, 22... Read buffer selector. Name of agent: Patent attorney Toshio Nakao and one other name
2 figure

Claims (1)

[Claims] a previous history control circuit that controls applied energy depending on the presence or absence of print data of the previous line; a buffer memory circuit that transfers data of the current line and the previous line to the previous history control circuit;
and control means for switching the previous line data to white data according to the arrangement of the current line data.