JPS6072757A - Thermal recorder - Google Patents

Abstract

PURPOSE:To uniformize the image density in the entire screen by counting the number of lines from the starting point of printing to control the energized pulse width according to the line counts. CONSTITUTION:Each time a LATCH signal is inputted, storage energy data read out from an RAMA22 is shifted sequentially. Consequently, the storage energy data of the (i)th heat generating resistor on a thermal head is outputted from a latch 24 and those of the (i+1)th and (i+1)th heat generating resistors are outputted from latches 23 and 25 respectively to be supplied to an arithmetic unit 3, which computes the pulse width of current fed to the (i)th heat generating resistor and the amount of energy stored in the (i)th heat generating resistor upto the subsequent energization cycle after the current is fed to the heat generating resistor. Based on the heat storage value, the width of the current printing pulse signal will be lessened if the number of previous printing pulse signals is too much.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thermal recording device capable of recording with stable recording density.

[Technical background of the invention and its problems]

Thermal transfer recording devices have advantages such as recording on plain paper, low noise during recording, simple mechanism, and easy maintenance.

However, on the other hand, there is a problem in that as the recording speed is increased, the recorded image deteriorates due to the heat storage effect of the heating resistor. In other words, if you shorten the time interval between energization cycles in order to increase speed, when the heating resistor that was energized in the previous energization cycle is energized again, the heat generated in the previous energization cycle will be sufficient. New energization is performed before the heat is dissipated, and the temperature of the heating resistor continues to rise. Therefore, when the energization cycle is repeated at such short time intervals, the current temperature of each heating resistor varies depending on the past history of energization. If the heating resistors in such a state are energized at the same time, each resistor will have a different temperature, so the area where the ink will be softened on the ink film will be different, and the area of the ink transferred to the recording paper L will also be different. Otherwise, the image density of the recorded image will be non-uniform.

This becomes a more serious problem when forming color images. Furthermore, when characters are recorded, the ink is transferred to areas where there is no actual image data, such as in small gaps, where it should not be transferred, leading to phenomena such as the characters becoming blurred.

In order to solve this problem, for example,
No. 48631 (a method of shortening the energization time when mark data arrives successively as image signal data for each heating resistor so that the two are added together) than when mark data arrives following space data. has been proposed.In other words, the energization time of the next energization cycle is switched in two stages depending on whether or not there was energization in the previous energization cycle.If this method is implemented, the above-mentioned drawbacks will be alleviated to some extent. However, especially during high-volume high-speed recording, even if the pulse width is shortened by performing the side steps as described above, the heat generated by the previous energization remains until the current energization. Therefore, even if the image density is normal at the start of printing, as more lines are printed, the image density gradually becomes darker than the normal value.

Furthermore, in the case of text, etc., there was a phenomenon in which small gaps gradually collapsed, resulting in uneven image density across the screen.

[Purpose of the invention]

This invention improves the drawbacks of the conventional device mentioned above.
An object of the present invention is to provide a thermal recording device capable of outputting an image with stable recording density from the time when printing starts to the time when printing ends even during high-speed recording.

[Summary of the invention]

The gist of this invention is to count the number of lines from the start of printing, and to control the energizing pulse width based on this line value. In other words, by using pulses that are removed from the basic printing pulse by a width corresponding to the number of lines,
In this method, the printing pulse is applied to the heating resistor, and the width of the printing pulse is made shorter as the number of lines increases.

〔Effect of the invention〕

According to this invention, since the pulse width of the printing pulse signal to the heating resistor is changed depending on the number of lines from the printing start point, it is possible to improve the change in recorded image density between the start of printing and the end of printing. It is possible to make the image density uniform. This effect is particularly noticeable during high-speed recording.

[Embodiments of the invention]

Hereinafter, as an embodiment of the present invention, a resolution of 12 dots/U
A thermal transfer recording device using an L line head will be described with reference to the drawings.

FIG. 1 schematically shows an embodiment of the invention.

First, the input image data 1 is led to the input buffer 2, where it is subjected to appropriate processing and then becomes the input signal 4 to the pulse width accumulated energy data calculation section 3. The pulse width thermal control data calculation section 3 calculates the amount of energy to be energized to each heating element and the printing time of the next line after energization from the output data 4 from the input buffer 2 and the output data 6 from the stored energy data storage section 5. The data for pulse width control required to determine the pulse width is calculated by calculation, and the results are stored as pulse width data 7 and thermal control data 8, respectively, in the pulse width storage section 9. The stored energy data is outputted to the storage unit 5 and stored in each storage unit.

The stored energy data storage section 5 temporarily stores image input data 1 for the past several lines (including the line that is currently being printed) supplied to each heating resistor. Thermal control data 6 output from is supplied as an input signal to the calculation section 3, and is used when calculating the pulse width and thermal control data of the next line. In addition, the thermal control data stored in the stored energy data storage section 5 is updated to new data for each heating resistor each time new thermal control data 8 is calculated in the calculation section 3, so that it is always at the current point in time. Image input data up to this point is retained.

The pulse width storage section 9 is a storage device that temporarily stores the pulse width data 7 calculated by the calculation section 3 for one line.

By a read signal to the thermal head 17 (a group of heating resistors and their driving circuits provided on a substrate),
The pulse width data stored in the memory section 9 is read out, and the 0 head, which is supplied as input data 16 to the thermal head, generates heat in response to this and prints.

The pulse width detection section 10 is a section that detects pulse widths smaller than a certain pulse width from among the pulse width data 7 output from the pulse width calculation section 3. If, while calculating the pulse width of one line of data, a certain number or more of data with a set pulse width or less are output from the calculation unit 3 (- means that the pulse width is output from the pulse width detection unit 10 A signal to enable the counter is output to the number counter 12. Conversely, if there is no more than a certain number of data with a pulse width less than or equal to the set pulse width between one line,
A countdown signal is output to the line number counter 12.

The line number counter 12 counts the synchronization signal for each line, increases the number of lines in response to the count-up signal output from the pulse width detector, and decreases the number of lines in response to the count-down signal. It is structured as follows.

The print pulse generation section 14 is a part that generates print pulses 15 to be supplied to the thermal head 17. The printing pulses generated here are at least two or more printing pulses with different (sometimes the same) lengths, and the pulse width storage unit 1
6, a certain combination of pulses is selected from these printing pulses, and the amount of energy applied to each heating resistor of the thermal head is controlled.

Furthermore, the length of each pulse generated by the print pulse generator 14 varies depending on the number of lines output by the line number counter 12, as will be described later. Further, each of the above components is controlled by a timing controller 18. The above is the general configuration of this embodiment, and next, the functions of each part will be explained in detail.

In this embodiment, the energization pulse width for each heating resistor and the data for heat control after energization are calculated from the input image data and the current heat control data. In this embodiment, the bit configurations and calculation methods of input image data and thermal control data are as shown in FIG. 2. Although various methods can be considered as the thermal control data, in this embodiment, for simplicity, past input image data of several lines added to each heating resistor is used. Specifically, if the heating resistor that we are currently paying attention to is the t-th heating resistor on the thermal head, then the resistors lined up on the left side are sequentially L-1°t-. The 2nd, . . .th resistor is designated as the 2nd, . i+2. ... as the second resistor.

(In this example, the thermal head is A4 size.

Since a 12 dot/van line head is used,
The number of resistors is 2592 in total. ) Also, assume that the data that is currently being printed is the n-th line, and the past lines are sequentially printed (n-1, n-2, n-2, etc.).
...and... In other words, the n that is currently being printed
Image input data DT to the heating resistor of the line:
From DQ... and the past image input data D n"" t to the resistor around the resistor,..., the pulse width to be energized and the i±3 order. When printing a line, necessary thermal control data is calculated and stored in the pulse width storage section 9 and the thermal control data storage section 5, respectively.

In this embodiment, as shown in FIG. 2, the input image data D of the i-th resistor is used as the data for calculating the printing pulse to be supplied to the t-th heating resistor of the n-th line which is currently being printed. , and as past data, i
, data of the past four lines of the i±1th heating resistor are used for calculation. Here, Dll is data of "o" or "1", and the thermal control data has a 4-pit configuration.

Furthermore, the pulse width data is also set to 4 pits.

FIG. 3 shows an example of the configuration of the input buffer 2 and the stored energy storage section 5 shown in FIG. 1. In this embodiment, the image data is stored in the image memory 2θ, and is converted into an 8-bit parallel image input signal 1 by the MR multiplied signal generated by the timing controller 18.
It is read from the memory and loaded into the shift register 21 using the τj times signal. Shift register 2 is parallel.
It performs serial conversion, and outputs the loaded 8-bit data bit by bit to the arithmetic unit 3 at the next stage. 8 by 5RCLK from timing controller 18
When all bit data is output from the shift register 21, the timing controller 18 stops 5RCI and K, generates the MR multiplication signal again, reads the next data from the image memory, and thereafter reads one line of image data. Repeat the above operation until it is completed. In this embodiment, the input image data used for the pulse width etc. is 1 bit image input to the i-th resistor as shown in FIG. If you want to use it, after the shift register 21,
The configuration may be such that one shift register for serial-to-parallel conversion is installed and its output is supplied to the arithmetic unit.

Also, RAMA in FIG. 3, 22. Latch 23~25°Write address counter 26. Read address counter 2
7. The selector 28 constitutes the stored energy data storage section 5 shown in FIG. Here, RAMA2. ? stores the energy stored in each heating resistor. RAMA,
? The address supplied to the address counter 26.2 has a one-to-one correspondence with each heating resistor on the thermal head, and in this embodiment, the address supplied to the address counter 26.2 corresponds to each heat generating resistor on the thermal head. ．． The configuration is such that 27 to 2592 addresses are supplied. Furthermore, the stored energy data 8 calculated by the calculation unit 3 is composed of 4 pits, as shown in FIG. 2, and includes j5, RAMA, ? The address specified by the write address counter 26 is omitted by the W1 signal supplied to the D■N terminal of No. 2 and output from the timing controller 18. Also, R
From the Dout terminal of AMA22, lead 7)'L/
The 4-bit stored energy data written to the address designated by the counter 27 is always output when the WR multiplied signal is not output to the WR terminal of the RAMA.

Latches 23 to 25 are composed of 4-bit latches, and LATCH output from the timing controller.
Depending on the signal, the 4-bit signal that enters the input side of the latch is transmitted to the output side, and is held as it is until the next LATCH number is input. In addition, three stages of latches are connected successively to form a shift register that sequentially transfers 4-bit data to the upper latch each time the LATCH (i) is input. That is, first, the read address counter 27 The accumulated energy data of the first heating resistor designated as 1 is output from the Dout terminal of the RAMA 22, is taken into the latch 23 by the first LATC (signal), and is output to the output side of the latch 23.This LATC
Due to the H signal, the value of the read address counter 27 increases by one, and the stored energy data stored in the second heating resistor is output to the Dout terminal, and the next LAT is output.
The signal is taken into the latch 23 by the CH signal. At the same time, the stored energy data of the first resistor is taken into the latch 24.

In this way, each time the LATCH signal is input, the stored energy data read out from the RAM 22 is sequentially shifted, and as shown in Figure 2, the second heating resistor on the thermal head of interest is The stored energy data of i-1, i+1 is output from the latch 24.
The stored energy data of the th heating resistor is stored in the latch 23. The configuration is such that the signal is output from the latch 25 and supplied to the arithmetic unit 3.

In the calculation unit 3, the pulse width En of the current supplied to the second heating resistor and after this current is injected into the heating resistor,
The amount of energy Qn accumulated in this i-th heating resistor until the next energization cycle is calculated. Image human data Dt, n,... and accumulated energy amount data of each heating resistor t+1 up to now Q' t Qn-' +...
・This is the part that calculates based on 20 cities. In this embodiment, as shown in FIG. 2, the image input data is 1 bit of data supplied to the heating resistor of interest, and the stored energy amount data is 1 bit of data supplied to the heating resistor of interest. Input image data 12 of the past 4 lines to the resistors on both sides
The configuration is such that pulse width data and stored energy data are calculated from the bits.

For example, stored energy data is calculated based on the print pulse signal supplied to the heating resistor.The heat generated in the heating resistor cannot be treated like a digital signal, and its movement is exactly analog. Which ↓
It is difficult to assess how well they are transmitted and distributed. Therefore, the inventor evaluated the movement of heat using, for example, a heat conduction equation, and controlled the energy given to the ink.

That is, the heat storage (temperature) of the heating resistor to which the printing pulse signal is to be supplied is evaluated based on the printing pulse signal supplied to the heating resistor, and the printing pulse signal is controlled based on this amount of heat storage (thermal storage energy data). do. Simply put, if the number of past printing pulse signals is large, the current printing pulse signal width is narrowed.

In this way, what is detected in the calculation section is the energy (pulse width) of the printing pulse signal necessary for printing this time and the supply of this printing pulse signal, which is generated by the heating resistor when the next printing pulse signal is supplied. It is the amount of heat remaining. In this embodiment, this calculation section is constructed from a ROM. That is, the above-mentioned image data 1 is used as the ROM address data.
input bits and 12 bits of stored energy data.

Furthermore, 4-bit energizing energy 7 and 4-bit stored energy 8 are obtained as outputs of the ROM.

FIG. 4 shows the pulse width data storage section 9 and thermal radar 17 shown in FIG. In this example, the resolution is 1
2 dots/battle, A4 width thermal head is used, so the total number of heating resistors on the thermal head is 25.
There are 92 pieces.

Furthermore, in order to shorten the data transfer time to the thermal head, this embodiment uses a thermal head that has nine input ports that can input serial data. That is, the input data ports are 81N l. ~8TN
9 of 9 ('), and one boat (-) uses a head designed to input data for 288 heating resistors.

As shown in FIG. 4, the pulse width data 7 calculated by the calculation unit 3 is stored in
) or through back 72 (41) to buffer 29 (43), R1', MBll (44) to RAMBJ9 (
46) Or RAMB,? J (45) ~ RAMB29 (4
7). Here, buffer 11. Buffer 21, RAMBII.

The reason why RAMB21 etc. are all 9 in one set is because they correspond to 9 input ports. For example, if there is one input port, these buffers, RAM
may be composed of one piece. Also, is the buffer buffer 1 and buffer 2 or RAM 1? The reason why it is separated into two systems, AMJ and RAM2, is to accommodate higher speeds. For example, RA, MB11 to RAMB1
While writing data to 9, RAMB, ? J～R
Since data is being read from the AMB 29, the configuration is such that write and read operations can be performed in parallel.

When a signal arrives at the WR terminal, RAMB inputs the input terminal to the address indicated by the address counters 48 and 49.
In other cases, the data written in the address indicated by the address counter is output. Also, the address counters are RA, MB.
Address counter 4g for I, RAMB, ? address counter 49 and 2 for all RAs, respectively.
MBJ, RAMB,? The same address data is supplied to both.

The number of address data is equal to the number of heating resistors per boat, and in the case of 9 ports, 288 address data are supplied to the RAMB.

First of all, the RAMBzWR signal is output, so the RA
MB2 is completely disconnected from the energized data line 2. First, when the first energization energy of the heating resistor is calculated, the timing controller 18 generates a signal of RAMB11WR. Therefore, at this time, the gate of buffer 1 (40) is opened and the energization energy data enters the data line of RAMB11.

Then, the energization energy data is written to the address indicated by the RAMBJ address counter 48. Here, the RAMBJIWR-RAMB79WR signal is a signal divided into RAMH write WR multiplication signals 288 in FIG. 3, and the first 288 11 signals are RAMBIIWR signals.
This becomes a signal for writing data to RAMB11. This becomes a signal for writing data into the next 288 pieces. Similarly, the last 288 WR times signal RAMBz 9WR
This becomes a signal for writing data to RAMB19.

Furthermore, the gates of the buffers of each RAMH are opened only when the WR multiplied signal arrives at each RAMB, and the energization energy data is written into the RAMB.

Now, when the first energization energy data for the heating resistor is written into RAMBJJ, the timing controller 18 outputs a WRI signal and increments the address of the RAMB1 address counter by one. This WRJ signal is a signal that is output to any one of RAMB J J to BJ9 every time the WR multiplied signal is output. Next, apply energy to the second heating resistor in the same manner as RAMBIJ.
will be written to. Repeat the same thing, RAMBJJ
The energy applied to the first 288 resistors is written in .

The address counter 48 has a period of 288, and has a period of 288.
The energy applied to the 88th heating resistor is RAMBJ
7, the address counter 48 outputs the same address as the address at which the first resistor energization energy data was written. Next, the energization energy data for the 289th heating resistor is written to RAMB72 in order to output the signal of RAM13J2WR from the timing controller 18, and
The AMBJJ data line is disconnected from the energized energy data line.

, RAMBJJ, RAMB27 also has the second
After 288 pieces of energization energy data for the 89th to 577th heating resistors are written, they are disconnected from the energization energy data line. Repeating the same process, the last 288 pieces, that is, 25 pieces from the 2304th piece.
The energization energy data for the 92nd heating resistor is RA
, MB19, the arithmetic processing for one line ends.

RAMBJJ (44) to RAMB19 (46),
While one line of energization energy data is being written, RAMBJJ (45) to RAMB 29 (47)
From , data on the amount of energy applied to each heating resistor written in advance is sent to multiplexer 1 (50).
Through the multiplexer 9 (51), the thermal head 2 is read out, the resistor is energized, and an image is recorded.

At this time, RAMB? The group is in a lead position,
RAMB on the data line? The energization energy that was written at the address indicated by the address counter 49 (2) is output.The multiplexer selects the 4-bit energization energy data output from RAMB1 and the 4-bit energization energy data output from RAMB2. One bit of data from the unused RAMB is supplied to each port.In order to control the signal selection, the timing controller sends a multiplexer control signal 51.
is outputting. In the current case, RkMB21 to B29 are in the read state, so the multiplexer sends the RAM
B.? One bit of the four bits of data outputted from is output. Data that has been output to the SIN terminal of the thermal head is taken into a register within the head by a CLK signal generated from the timing controller. At the same time, the CLK2 signal is generated from the timing controller to increment the value of the RAMB' address counter by one. Then the second data is 8IN
The data that is output from the terminal (= is output and taken into the shift register in the head by the next CLK signal, and the data that first entered the shift register is shifted by one. This operation is performed by 288
By repeating the process, all data in RAMBJJ (4F) is read into the thermal head. R
The data read from AMBJ is output from the timing controller after 288 read operations are completed.
The LATCH signal causes it to be latched into the thermal head.

Note that RAMB27 (45) to RAMB x y (4
Since the data is read out simultaneously from F), all one line of data stored in RAMBz is taken into the shift register in the thermal head in 288 reads. The data taken into the head as described above is printed on recording paper by the thermal head control signal 52 generated by the timing controller.

FIG. 5 schematically shows the relationship between the 4-bit energization energy data 7 output from the arithmetic unit and the printing actually performed. In this embodiment, since the voltage applied to each heating resistor on the thermal head is constant, the current that can be injected into each heating resistor is constant. Therefore, in order to change the energization energy to each heating resistor, the energization time is changed for each resistor. In other words, the 4-bit energization energy data output from the calculation unit 3 is The data is the energization time to the heating resistor.However, due to the structure of the thermal head, the energization time cannot be changed for each foot resistor.In other words, the data taken into the head from the SIN terminal is " No current is applied to the heating resistors with a value of 0゛', only the heating resistors with data "1" are energized, and the energization time of the heating resistors that are energized is the same time width. .

Therefore, by increasing the energization time of a certain heating resistor, and
If you try to shorten the energization time to other resistors,
Enter 1" data several times for the resistor you want to lengthen the energization time, and enter 0" data for the resistor you want to shorten.
This can be achieved by turning the current on and off several times.

In this embodiment, as shown in FIG.
Four energization times of N-4 are set, and these four energization times and the energization energy data output from the calculation section correspond one-to-one. That is, for example, in the energization energy data, the most significant bit (M
SB) Ei”1 corresponds to the energization time MEN-1, and E1
n2 is MEN-2, Ei”3 KaMEN-3, Ei”4
Each corresponds to MEN-4. The energizing time of each resistor is configured such that the energizing time corresponding to the bit whose data is "1" is selected from among the 4 bits of energizing energy data. As an example, if the energization energy data is Eln1=EIn3=E1n4-1. Considering a case like Eln2-0, as shown in Figure 5(b), TI y
The energization time of TI IT4 is selected, and the resistor is energized for times T, +T, +T.

In this embodiment, the time during which electricity is applied to each heat generating resistor is changed using such a method.

Further, in this embodiment, TI, T2. T8. Since the time width of T4 can be set freely, each time width is the same as shown in Figure 6 below, that is, T, =T, =T,
=T, up to 4 levels of energization time can be selected, and if the ratios of these pulse widths are all set to be different, 16 levels of pulse width can be selected as the energization time width. It has become. Further, by increasing the number of pits in the energization energy data or changing the order of energization pulses of different lengths, it becomes possible to more precisely control the energization time.

Therefore, we return to the explanation of FIG. 4 again. It is now assumed that the data read from RAMB2 into the thermal head through 288 reads is one bit, for example, the most significant bit, of the four bits of energization energy data.

Then, the printing pulse generation unit 53 outputs the energizing pulse MEN-1 (,54) with a time width of T, and the RAMB
Only the portion where the most significant bit of the output data from 2 contains data of ".1" is printed. Timing controller 18 then generates multiplexer control signal 52 to read the second bit of RAM 13' to the thermal head. Then, a read signal is input to the head again, the second data of RAMBJ is selected, and 288
In one read, all one line is read. At this time, the print pulse generator outputs a print pulse MEN-2 having a time width of T2. The following process, ie, data RAMB? By repeating reading and printing four times, one line of printing is completed.

Next, after one line of printing is completed, the timing controller outputs the RA and MB2WR signals, and the R
The energization energy data output from the calculation section is written into AMB2.

The energization energy data is read from the RA and MBI to the head, and the next line is printed. Thereafter, the above process is repeated until printing of one screen is completed.

By adopting such a circuit configuration, it is possible to obtain a clear recorded image without any blemishes or omissions. but,
With this configuration, sufficient control is possible at a certain printing speed, but sufficient control is not possible when a high-speed, high-resolution thermal head is used. That is, when printing is performed at high speed, the next energization is performed before the heat generated in the heating resistor during the previous energization has been sufficiently dissipated, and the temperature of the resistor continues to rise. In order to prevent this, pulse width control is performed as described above, but as shown in Fig. The length is a discrete value. In addition, the minimum pulse width that can be created here has a finite length because it needs to be at least long enough to print, so as the printing speed increases, the previous printing cycle inevitably changes. A situation arises in which the current energization must be performed before the accumulated heat is completely dissipated. Therefore, at the beginning of writing, it is possible to obtain an image with normal image density without any blurring or omissions.
As many lines are recorded, the temperature of the resistor begins to rise due to the slight heat accumulation described above, and eventually the dots that should be whitened out begin to collapse, resulting in images with considerably different densities at the beginning and end of recording. turn into.

In order to solve these drawbacks, it is necessary to control the pulse width more precisely. Therefore, in the present invention, the pulse width is controlled more finely by using a circuit as shown in FIG. FIG. 6(a) shows the configuration of the print pulse generator. In this embodiment, the pulse width data 7 is 4-bit data that is output from the pulse width calculation unit 3, but as described above, this pulse width data is sent to the heating resistor to be printed and the surrounding heating resistors. is determined by historical data patterns. That is, to briefly describe the outline of heat control, control is performed in which the pulse width is shortened when past data indicates a large amount of heat accumulation, and the pulse width is lengthened when there is little heat accumulation.

The gradual change in output image density as described above is not so much of a problem when data with little heat storage is received, but it becomes noticeable when data with a large amount of heat storage is received. Therefore, it is necessary to detect a pattern in which a large amount of heat is accumulated and to control the pulse width more precisely in that case, and the circuit shown in FIG. 6 performs such control.

First, by inputting the pulse width data 2 outputted from the pulse width calculation section 3 to the pulse width detection circuit 60, it is possible to determine whether or not there is data less than a certain pulse width in one line of data. Make a judgment. In this embodiment, since the pulse width is controlled to be shortened in the case of a pattern with a large amount of heat accumulation, by supplying data for each line to the pulse width detection circuit 60, it is possible to detect the existence of a pattern with a large amount of heat accumulation. This is to determine whether or not there is a person present. If there is a pattern with a large amount of heat storage in one line of data, the pulse width detection circuit 60 outputs a count-up signal to the line number counter 61, and the pattern with a large amount of heat storage is 1. If a certain number of lines does not exist in the line, a countdown signal is output to the line number counter 61.
1 is supplied with a signal synchronized with one line, and the output of the counter is configured to count down or count up according to the [J P /down signal.

Further, this counter is in a countdown state in the initial state, and the output of the counter is O. Further 1
The configuration is such that when the output of the counter is 0 and a countdown signal is being output, the counter output always remains O even if a line synchronization signal is input.

So, returning to the explanation of FIG. 6 again, if there are many lines of data including a pattern with a large amount of heat storage, the line number counter 61 counts up the line synchronization signal.
The output is supplied to the deletion pulse width calculation section 62. The deletion pulse width calculation section 62 calculates the length of the pulse width to be deleted from the output of the line number counter 61 and outputs it to the next stage counter 63 that counts the pulse width to be deleted. ) is counted by the number output from the deletion pulse width calculation section 62 and the output is sent to the deletion pulse generation section 64.
b) shows the printing pulse in this case. Now, a case will be described in which, for example, the pulse width of MEN-1 shown in FIG. 5 is controlled. The print pulse generator 53 outputs MEN with a time width of T1.
-1 (FIG. 6(b)-(1)) is supplied. At this time, the deletion pulse width generator generates
), a deletion pulse with a pulse width T, / determined by the value output from the deletion pulse width calculating section 62 is output.

Passing these signals through the A N'D circuit (=Therefore, as shown in Figure 6(b)-(3), the length T, -T, which is the pulse width of T, minus the pulse width of T,') , 'print pulse MEN-1' is output. By doing this (2), the pulse width of the print pulse signal is controlled in units of %10-' seconds, and in fact, the print pulse signal width is continuously variable. Therefore, the printing pulse signal can be controlled more precisely, and beautiful recording can be achieved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments in any way.

5 Acid part, 17゛...Thermal head.

For example, the present invention is applicable not only to line printers but also to serial printers. In this case, the conveyance direction of the recording paper in the sub-scanning direction, that is, the number of lines (also, the determination of the number of lines may vary depending on the recording format, and in the claims, the timing at which the print pulse signal should be supplied) ), the number of times the thermal head is energized in the main scanning direction may be used as the standard. Naturally, in this case as well, control may be performed based on the number of lines. Although the control of the energization width is configured to decrease from a constant width in the embodiment, it is possible for those skilled in the art to make any modification by selecting the reference energization width, and such modification does not defeat the purpose of the present invention. It's not something to change.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of the present invention, Figure 2 is a configuration diagram of data used for thermal control, Figures 3 and 4 are actual circuit diagrams, and Figures 5 and 6 are pulse width control. FIG. 12...Line number counter, 14...Pulse width raw 6 Proxy accountant Noriyuki Chika 01 or 1 person) - RiC
l knee 6J O○○○ conversion ○○○○○′Q 0000, mi

Claims (6)

[Claims] (1) A heat generating resistor and a recording medium provided along a first direction on a substrate are connected to a second direction substantially perpendicular to the first direction.
In a thermal recording device, the thermal recording device has a conveyance means for relatively moving in the direction of , and forms a recorded image on the recording medium by supplying a printing pulse signal to the heat generating resistor while being conveyed by the conveyance means 1. , a thermal recording device comprising: a detection means for detecting the number of times the print pulse signal should be supplied; and a control means for controlling the pulse width of the print pulse signal based on the number of times the print pulse signal is to be supplied. . (2) A heating resistor is disposed in the width direction of the recording medium, and the conveying means is a means for intermittently conveying the recording medium to the heating resistor in a direction substantially perpendicular to the width direction, 2. The thermal recording apparatus according to claim 1, wherein the detecting means comprises means for detecting the number of times the recording medium is intermittently conveyed by the conveying means. (3) The thermal recording device according to claim 2, wherein the detecting means is a means for counting a line meter in recording (second position). (4) The heating resistor is moved in the same direction as the recording medium conveyance direction, and the heating resistor is conveyed in the main scanning direction perpendicular to the recording medium conveyance direction, so that the heating resistor and the recording medium Recording is performed while moving the recording medium intermittently and relatively in a sub-scanning direction parallel to the conveyance direction, and the detection means comprises means for counting the number of times the recording medium is intermittently conveyed in the scanning direction. A thermal recording device according to claim 1. (5) The detection means includes a calculation unit that calculates the accumulated energy in each heating resistor based on the supply of the printing pulse signal, and a comparison unit that compares the accumulated energy obtained by the calculation unit with a first threshold value; means for counting the number of times the comparison unit detects that the stored energy is equal to or greater than a predetermined value;
Claim 1, characterized in that the counting means xp is configured to count up when the number of times obtained by this means is larger than a second threshold, and to count down when it is smaller than the second threshold. Thermal recording device. (6) The control means includes means for generating a deletion signal having a polarity opposite to that of the print pulse signal and having a pulse width corresponding to the number of times the detection means receives a negative signal, and the deletion signal obtained by this means. 2. The thermal recording apparatus according to claim 1, further comprising means for calculating a logical sum with a printing pulse signal.