JP2001328291A - Method of controlling printing for thermal transfer line printer, and thermal transfer line printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of controlling printing for a thermal transfer line printer, and the thermal transfer line printer capable of performing adequate and high quality printing. SOLUTION: This thermal transfer line printer comprises a temperature detecting means 22, a system controller 24, an energizing ROM 25, a timing control signal generating circuit 26, a selector 27, a data counter 28, a comparator 29 and a head control section 30. An energizing time period for one line is divided into a continuous energizing time period for continuous energizing and an intermittent energizing time period for intermittent energizing. This printer is controlled such that a switching timing TA for switching from a region of the continuous energizing time period to a region of the intermittent energizing time period is always constant with respect to a paper feed timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer line suitable for performing printing by transferring the ink of an ink film to paper by selectively heating a plurality of heating elements of a line thermal head based on print data. The present invention relates to a printing control method for a printer and a thermal transfer line printer.

[0002]

2. Description of the Related Art Conventionally, a line thermal head having a length capable of facing a printing area in a longitudinal direction or a lateral direction of a sheet via an ink film such as an ink ribbon or an ink sheet and a sheet is brought into contact with a platen roller. In this contact state, the platen roller is driven to rotate, and while the ink film and the paper are being conveyed, the plurality of heating elements of the line thermal head are selectively driven based on the print data to generate heat, whereby the ink in the ink film is heated. There is known a thermal transfer line printer that transfers an image onto paper and prints desired characters and images on the paper.

FIG. 3 shows an example of a conventional thermal transfer line printer. The conventional thermal transfer line printer 1 includes a temperature detecting means 2, a system clock generating circuit 3, a system control 4, a power supply ROM 5, a timing control A signal generation circuit 6, a data counter 7, a comparator 8,
And a head control unit 9. The head controller 9 includes a shift register 9a, a latch circuit 9b, and a driver 9c, and is configured to be able to control energization of each heating element 10a of the line thermal head 10.

The temperature detecting means 2 is formed of, for example, a thermistor or the like, detects a temperature near the heating element 10a of the line thermal head 10, for example, a temperature of the head substrate 10b, and uses this temperature as temperature data of environmental temperature. Output to system control 4.

The system clock generating circuit 3 forms a system clock which is an operation reference necessary for controlling the operation of the device and outputs it to at least the system control 4 and the timing control signal generating circuit 6.

The system control 4 supplies an address for selecting predetermined strobe data based on at least the temperature data inputted from the temperature detecting means 2 to the power supply R.
Output to OM5. In addition, system control 4
Is an energizing pulse for a continuous energizing period in which continuous energizing is performed by continuously applying energizing pulses required to print the smallest size dots on paper with print data including tone values input from the outside. , And the number of energizing times of the energizing pulse during the intermittent energizing period in which the energizing pulse for intermittently applying the energizing pulse for controlling the size of the dot to be formed on the paper according to the gradation value included in the print data The data TD is determined after being corrected based on the environmental temperature, and is output to the comparator 8. Furthermore, system control 4
Outputs to the timing control signal generation circuit 6 a start signal indicating a print start timing synchronized with the paper feed timing of the paper.

The power supply ROM 5 stores strobe data for each temperature, and outputs strobe data corresponding to the environmental temperature to the timing control signal generation circuit 6 based on the address input from the system control 4. That is, the energization ROM 5 stores data on the continuous energization period and the intermittent energization period according to the environmental temperature. For example, data is stored in which the continuous energizing period is lengthened when the environmental temperature is low, and is shortened when the environmental temperature is high.

The timing control signal generating circuit 6 includes a strobe signal which is a timing signal necessary for controlling the energization of the line thermal head 10 when printing at least one line, and a unit time for dividing one line energizing period into a plurality of units. And a shift clock are output to the head controller 9, and a counter reset signal and a counter clock are output to the data counter 7.

The strobe signal is configured to be formed by strobe data corresponding to the environmental temperature stored in the energizing ROM 5. For example, when the environmental temperature is low, the energizing pulse during the continuous energizing period is applied. The energizing time is lengthened by increasing the number-of-times data, and when the environmental temperature is high, the energizing time data of the energizing pulse in the continuous energizing period is reduced to shorten the energizing time.

That is, the strobe signal is detected by the temperature detecting means 2 in the vicinity of the heating element 10a of the line thermal head 10 immediately before printing, for example, the head substrate 10b.
The energization period is variably controlled depending on the temperature.

The data counter 7 is cleared (cleared to zero) by the input of the counter reset signal, and thereafter counts up at every counter clock, and outputs the count value CD to the comparator 8. The counter value CD of the data counter 7 is set to “0” during the continuous energization period, and from “0” to “N−1” (N
Counts up to the maximum number of energizing pulses for intermittent energization).

The comparator 8 compares the count value CD output from the data counter 7 with the energization count data TD output from the system control 4, and counts the count value C.
The energization data for instructing the energization only when D is greater than the energization number data TD, for example, the output “1” is output to the head controller 9.
To the shift register 9a.

The head controller 9 receives the energization data to each heating element 10a of the line thermal head 10 by the shift register 9a for each shift clock, and
The energizing data of the shift register 9a is latched for each latch signal by a, and the energizing data latched based on the strobe signal is output by the driver 9c to each heating element 10a of the line thermal head 10 for printing.

According to such a configuration, as shown in FIG. 4, one line energizing period when printing one line on a sheet is defined as a region of a continuous energizing period in which continuous energizing is performed. And an intermittent energization period in which intermittent energization is applied intermittently. Then, two data of continuous data formed by the number of energizing pulses for performing continuous energization and intermittent data formed by the number of energizing pulses for performing intermittent energization are converted into temperature data of the environmental temperature detected by the temperature detecting means 2. By correcting and outputting according to the temperature, the temperature of each heating element 10a is set to the transfer temperature in a short time, and the range of dot size forming a gradation control area is widened.

That is, as shown in FIG. 4, when the environmental temperature of the thermal head 10 is low, the energization frequency data T
By increasing the number of energizing pulses in the continuous energizing period of D, the energizing time, which is the continuous energizing period, is extended, and when the temperature of the thermal head is high, the energizing pulse in the energizing number data TD is reduced to reduce the energizing pulse in the continuous energizing period. The lubrication time has been shortened.

The number of energizing pulses of the energizing pulse number data TD in the intermittent energizing period following the continuous energizing period is controlled in accordance with the gradation value included in the print data. When the number of pulses is 1 and the gradation value is 2
In this case, by controlling the number of energizing pulses to 2, gradation printing according to the gradation value, that is, printing with different dot sizes depending on the density, is performed on the paper.

[0017]

However, in the above-described conventional thermal transfer line printer 1, as shown in FIG. 4, the energization reference position SP at which energization is started is always fixed, and the continuous energization period itself is not changed. Is controlled according to the environmental temperature, so that the length of the continuous energization period differs between when the environmental temperature is low and when the environmental temperature is high. The boundary position between the continuous power-on period and the intermittent power-on period is different due to the difference in the length of the continuous power-on period. Therefore, the transfer start position DP for forming dots on the paper is different depending on the environmental temperature. Will be. If the transfer start position DP differs depending on the environmental temperature, for example, when color printing is performed by superimposing three primary color inks of Y (yellow), M (magenta), and C (cyan), each color formed on the paper The position of the dot is displaced and the dot interval varies, resulting in color unevenness.

Therefore, a printing control method for a thermal transfer line printer and a thermal transfer line printer capable of performing proper and high-quality printing are desired.

The color unevenness due to the shift of the transfer start position DP is caused by a low paper feed speed, a low resolution and a large dot size in a video printer which performs printing by transferring thermal sublimation type ink to paper. A relatively inconspicuous thermal transfer line printer that can print by transferring hot-melt ink onto paper, has a high paper feed speed, and prints high-quality images with small dots with a resolution of about 600 dpi or more. Is remarkable.

SUMMARY OF THE INVENTION The present invention has been made in view of these points, and has as its object to provide a thermal transfer line printer printing control method and thermal transfer line printer capable of performing proper and high-quality printing.

[0021]

In order to achieve the above-mentioned object, a feature of the printing control method of the thermal transfer line printer according to the present invention is that a one-line energizing period when printing one line on paper is always fixed. The one-line energizing period is defined as a continuous energizing period in which continuous energization is performed by continuously applying an energizing pulse necessary for printing a dot of a minimum size on a sheet, and a size of a dot formed on the sheet. Is divided into an intermittent energizing period in which an intermittent energizing for applying an intermittent energizing for intermittently applying an energizing pulse for controlling according to the gradation value included in the print data, The point is that the switching timing to the area is controlled to be always constant with respect to the paper feeding timing of the paper. And by adopting such a configuration,
Since the transfer start position can always be kept constant, proper and high-quality printing can be performed.

Further, it is preferable that the number of energizing pulses in the continuous energizing period is corrected based on at least the environmental temperature, and the number of energizing pulses in the intermittent energizing period is determined based on at least the environmental temperature and the print data. By adopting such a configuration, the heating temperature of each heating element of the line thermal head can be precisely controlled, so that print quality can be improved.

Furthermore, it is preferable to use the temperature near the heating element of the line thermal head as the environmental temperature. And by adopting such a configuration,
Temperature correction during the continuous energizing period and the intermittent energizing period can be easily and reliably performed.

Further, the thermal transfer line printer according to the present invention is characterized in that a temperature detecting means for detecting an environmental temperature and a print data including a gradation value inputted from the outside are corrected at least according to the environmental temperature. In addition, the continuous data formed by the number of energizing pulses that perform continuous energization necessary to print the smallest size dot on the paper, and the size of the dot formed on the paper to the gradation value included in the print data In addition, the data is divided into two pieces of data, namely, intermittent data formed by the number of energizing pulses for performing intermittent energization necessary for printing in accordance with the data, and output, and a start signal synchronized with the paper feeding timing is output. Continuous energization period for continuous energization during one line energization period when printing one line on the heating element of the line thermal head for system control An energizing ROM that stores one type of strobe data including the maximum number of energizing pulses and the maximum number of energizing pulses in an intermittent energizing period in which intermittent energizing is performed, and at least a start signal, a system clock, and an energizing ROM that are input. Based on the obtained strobe data, at least the strobe signal, the latch signal, the shift clock, the counter reset signal, the counter clock, and the switching timing from the continuous energizing period region to the intermittent energizing period region with respect to the paper feeding timing. A timing control signal generating circuit for forming and outputting a data switching control signal for keeping the data constant at all times, continuous data, intermittent data, and a data switching control signal, and receiving continuous data or intermittent data based on the data switching control signal. Select the energization count data for When the selector outputs a continuous data, it is cleared by the input of the counter reset signal and the counter reset signal, and it counts up every counter clock synchronized with the latch signal, and when the selector outputs the intermittent data, The data counter that counts down every counter clock synchronized with the latch signal and outputs these count values, the energization count data and the count value are input, and compares the energization count data with the count value. And a comparator that outputs energization data that instructs energization only when the value is greater than the value of, and shift-clocks at least energization data to each heating element of the line thermal head to control energization data to each heating element of the line thermal head. A shift register received every time, and a shift A latch circuit for latching the energization data of the
And a head control unit including a driver that outputs energization data latched based on a strobe signal to each heating element of the line thermal head.
By adopting such a configuration, the transfer start position can always be kept constant irrespective of the level of the environmental temperature, so that appropriate and high-quality printing can be executed.

Further, it is preferable that the temperature detecting means is configured to detect a temperature near the heating element of the line thermal head. By adopting such a configuration, it is possible to easily and reliably execute the temperature correction in the continuous energizing period and the intermittent energizing period.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 is a block diagram showing a main part of an embodiment of a thermal transfer line printer to which a printing control method for a thermal transfer line printer according to the present invention is applied.

As shown in FIG. 1, the thermal transfer line printer 21 according to the present embodiment includes a temperature detecting means 22, a system clock generating circuit 23, a system control 24,
Power supply ROM 25, timing control signal generation circuit 26
, Selector 27, data counter 28, comparator 2
9 and a head control unit 30. Then, the head control unit 30 includes the shift register 30a, the latch circuit 3
0b and a driver 30c, so that the energization of each heating element 31a of the line thermal head 31 can always be kept constant irrespective of the environmental temperature as described later. ing.

The temperature detecting means 22 is, as in the prior art,
For example, it is formed of a thermistor or the like, and is configured to detect a temperature near the heating element 31a of the line thermal head 31, for example, a temperature of the head substrate 31b.

The system clock generating circuit 23 forms a system clock, which is an operation reference necessary for controlling the operation of the device, and outputs it to at least the system control 24 and the timing control signal generating circuit 26, as in the prior art. It is configured.

The system control 24 includes a CPU (not shown), a memory having a suitable capacity such as a ROM and a RAM, a start signal generating circuit, and the like. The print data input from the outside, the correction data for the continuous energizing period and the intermittent energizing period according to the environmental temperature, and the minimum size of the paper after adding at least the correction according to the environmental temperature. The continuous data formed by the number of energizing pulses in the continuous energizing period in which continuous energizing is performed by continuously applying energizing pulses necessary to print dots of dots, and the size of dots to be formed on paper are printed data. Two data are formed, namely, intermittent data formed by the number of energizing pulses in an intermittent energizing period in which intermittent energizing is performed in which intermittent energizing is performed in which an energizing pulse necessary for printing is controlled in accordance with a gradation value included. And a control program for this purpose are stored. The memory also stores various control programs such as a control program for controlling the operation and the operation order of each unit such as a control of paper feed, a control program for performing an initialization operation of the apparatus when the power is turned on, and printing. Data other than the data on the power-on period required for execution is also stored. Further, the system control 24 is configured to form a start signal for instructing a print start timing synchronized with the paper feed timing of the paper and output the start signal to the timing control signal generation circuit 26.

In the power supply ROM 25, unlike the conventional one,
1 for the heating element 31a of the line thermal head 31
One type of strobe consisting of the maximum number of energizing pulses in a continuous energizing period in which continuous energizing is performed in one line energizing period when printing one line, and the maximum number of energizing pulses in an intermittent energizing period in which intermittent energizing is performed Data is stored, and the strobe data is configured to be output to the timing control signal generation circuit 26.

The timing control signal generating circuit 26
Start signal, system clock, and said energizing ROM
25 based on the input of the strobe data stored in
A strobe signal, which is a timing signal necessary for controlling the energization of the line thermal head 31 when printing at least one line, a latch signal generated for each unit time obtained by dividing the energizing period into a plurality of lines, a shift clock, and a counter reset The switching timing TA from the area of the continuous energizing period to the area of the intermittent energizing period necessary to keep the transfer start position DP constant regardless of the level of the signal, the counter clock, and the environmental temperature is set as the paper feed timing. On the other hand, a data switching control signal for instructing a timing of switching data from continuous data to intermittent data for keeping the data constant at all times is formed and output. This data switching control signal is supplied to the selector 2 in synchronization with the latch signal one time before the switching timing TA from the area of the continuous energizing period to the transfer start position DP to the area of the intermittent energizing period.
7 is output.

The selector 27 is configured to select and output the energization count data TD of continuous data or intermittent data based on a data switching control signal.

The data counter 28 is cleared by the input of a counter reset signal, and when the selector 27 is outputting continuous data, it counts up every counter clock synchronized with the latch signal. Is output, the countdown is performed for each counter clock synchronized with the latch signal, and the count value CD is output.
Detailed operation of the data counter 28 will be described later.

The comparator 29 compares the energization count data TD with the count value CD, unlike the prior art, and supplies energization data for instructing energization only when the count value CD is greater than the energization count data TD, for example, an output. It is configured to output “1” to the shift register 30a of the head control unit 30.

The head control unit 30 is, as in the prior art,
The energization data is received by the shift register 30a for each shift clock, the energization data of the shift register 30a is latched for each latch signal by the latch circuit 30b, and the energization data latched by the driver 30c based on the strobe signal is transferred to the line thermal head 31. Each heating element 3
1a.

Next, the operation of this embodiment having the above-described configuration will be specifically described with reference to FIGS. 1 and 2 together with a print control method.

FIG. 2 is a timing chart for explaining the operation of the main part of the embodiment of the thermal transfer line printer to which the printing control method of the thermal transfer line printer according to the present invention is applied.

As shown in FIGS. 1 and 2, in the present embodiment, when the printing operation is performed, first, the temperature detecting means 22 first operates the heating element 31 of the line thermal head 31.
A temperature near a is detected, and this temperature is output to the system control 24 as temperature data of the environmental temperature.

The system controller 24 converts the print data including at least the tone value input from the outside into a dot having a minimum size on a sheet after correcting at least a correction corresponding to the environmental temperature. Performs intermittent energization necessary for printing by controlling continuous data formed by the number of energization pulses for performing necessary continuous energization and controlling the size of dots to be formed on paper in accordance with the gradation value included in the print data. The data is divided into two data, that is, intermittent data formed by the number of energizing pulses, and output to the selector 27.

At this time, the system control 24 corrects the number of energizing pulses in the continuous energizing period in the region of the continuous energizing period based on at least the environmental temperature, and determines the number of energizing pulses in the intermittent energizing period in the intermittent energizing period. Determined based on temperature and print data.

The correction and calculation of the number of energizing pulses will be further described.

The operation of calculating the number of energizing pulses for performing continuous energizing as continuous data by the system control 24 is performed by acquiring a continuous energizing time as a continuous energizing period according to the environmental temperature from a data table stored in a memory. Start. Next, in order to perform correction in accordance with the power supply history in units of several lines, a correction calculation corresponding to the power supply history is executed. Next, from the start of printing, in order to perform correction according to the accumulated energization time of each heating element 31a for each predetermined area, a correction calculation corresponding to the accumulated energization history of the predetermined area is executed.
Next, in order to perform a correction according to a device-specific variation such as a variation in the resistance value of each heating element 31a, a correction calculation corresponding to the device-specific variation is executed. Then, the number of energization pulses for performing continuous energization is obtained from the energization time after performing each correction.

The operation of calculating the number of energization pulses for performing intermittent energization as intermittent data by the system controller 24 is performed by using the data stored in the memory as the intermittent energization time as the intermittent energization period according to the gradation value and the environmental temperature. Start by retrieving from a table. Next, from the start of printing, in order to perform correction according to the accumulated energization time of each heating element 31a for each predetermined area, a correction calculation corresponding to the accumulated energization history of the predetermined area is executed. Next, in order to perform a correction according to a device-specific variation such as a variation in the resistance value of each heating element 31a, a correction calculation corresponding to the device-specific variation is executed. Then, the number of energization pulses for intermittent energization is obtained from the energization time after each correction.

In this embodiment, as shown in detail in FIG. 2, the ON / OFF cycle for performing the intermittent energization is fixed, but the ON / OFF duty is reduced with time. May be.

The operation of calculating the number of energizing pulses for performing the intermittent energizing is as follows: the intermittent energizing time corresponding to the gradation value and the environmental temperature is obtained from a data table stored in the memory, and the intermittent energizing time is obtained from the obtained energizing time. May be obtained to obtain the number of energizing pulses for performing the above.

Further, the system control 24
Outputs to the timing control signal generation circuit 26 a start signal instructing a print start timing synchronized with the paper feed timing of the paper.

Next, the timing control signal generation circuit 26
Is a strobe signal based on at least an input start signal, a system clock, and strobe data,
A latch signal and a shift clock are output to the head control unit 30, and a counter reset signal and a counter clock are output to the data counter. further,
The timing control signal generation circuit 26 outputs a data switching control signal to the selector 27.

Next, based on the data switching control signal input from the timing control signal generation circuit 26, the selector 27 converts one of the energization count data TD of the continuous data and the intermittent data input from the system control 24 into one. Select and output to the comparator 29.

Next, when the data counter 28 is cleared by the input of the counter reset signal and the selector 27 is selected to output continuous data,
The countdown is performed until the count value CD changes from “M−1” to “0” (M is the maximum number of energizing pulses for continuous energization). When the selector 27 is selected to output intermittent data, the count value CD changes from "0" to "N-1" (N is the maximum number of energizing pulses for intermittent energizing). Count up.

That is, the data counter 28 differs from the conventional one in that when the counter reset signal is output in synchronization with the start signal, the maximum number of continuous energizing pulses M
Is loaded as the count value CD by subtracting 1 from the value "M-1". While the selector 27 is outputting continuous data, the count value CD is decreased by "1" in synchronization with the latch signal so that the count value CD becomes "0".
Count down until. Further, when the count value CD of the data counter 28 becomes “0”, more specifically, the latch signal immediately before the switching timing TA from the area of the continuous energization period to the transfer start position DP to the area of the intermittent energization period At the time of output, the data switching control signal is output, and the data output from the selector 27 switches from continuous data to intermittent data. Next, at the output timing of the latch signal next to the output timing of the data switching control signal, the switching timing TA from the actual continuous energizing period region to the intermittent energizing period region is reached, and the count value CD is set to "1". Thereafter, the count value CD is incremented by “1”, and the count value CD is a value obtained by subtracting 1 from the maximum pulse number N of the intermittent energizing pulse “N−
Count up until it becomes "1". As a result, FIG.
As described in detail above, the transfer start position DP, which is the boundary position between the continuous energizing period and the intermittent energizing period, can always be kept constant with respect to the paper feed timing of the paper regardless of the level of the environmental temperature.

Next, the comparator 29 outputs the energization frequency data T
D is compared with the count value CD, and only when the count value CD is greater than the number of times of energization data TD, energization data for instructing energization, for example, output “1”, is output to the shift register 30 a of the head control unit 30. Then, as in the conventional case, the head control unit 30 receives the energization data by the shift register 30a for each shift clock, and
0b, the energization data of the shift register 30a is latched for each latch signal, and the energization data latched by the driver 30c based on the strobe signal is individually output to each heating element 31a of the line thermal head 31. .

As described above, according to the thermal transfer line printer 21 of the present embodiment, the one-line energizing period when printing one line on a sheet is always constant, and the one-line energizing period is set to the minimum for the sheet. The continuous energization period required for continuous energization by continuously applying energization pulses necessary to print dots of a size, and the size of the dots to be formed on the paper to the gradation value included in the print data And an intermittent energization period in which intermittent energization for applying an intermittent energization pulse for intermittent application is performed, and the continuous energization period in the continuous energization period region is determined at least based on the environmental temperature. The intermittent energizing period in the intermittent energizing period is determined based on the environmental temperature and the print data, and the intermittent energizing period is changed from the continuous energizing period to the intermittent energizing period. Since the switching timing TA can be controlled so as to be always constant with respect to the paper feeding timing of the sheet, the temperature of each heating element 31a is set to the transfer temperature in a short time, and the size of the dot as the gradation control area is reduced. The formation range can be widened, and the switching timing TA from the continuous energizing period region to the intermittent energizing period region, that is, the transfer start position DP is always constant with respect to the paper feed timing of the paper regardless of the level of the environmental temperature. Can be

Therefore, according to the thermal transfer line printer 21 of the present embodiment, the transfer start position DP can always be kept constant with respect to the paper feed timing.
When performing color printing, it is possible to reliably prevent the inconvenience that the positions of the dots for each color to be formed on the paper are shifted and the dot intervals are varied, thereby causing color unevenness, thereby facilitating proper and high quality printing. And it can be executed reliably.

Further, according to the thermal transfer line printer 21 of this embodiment, the number of energizing pulses in the continuous energizing period is corrected based on at least the environmental temperature, and the number of energizing pulses in the intermittent energizing period is at least the environmental temperature and the print data. Therefore, the heating temperature of each heating element 31a of the line thermal head 31 can be precisely controlled, and the printing quality can be improved.

Further, according to the thermal transfer line printer 21 of the present embodiment, the temperature detecting means 22 is configured to detect the temperature of the head substrate 31b as the temperature near the heating element 31a of the line thermal head 31. In addition, temperature correction in the continuous energizing period and the intermittent energizing period can be easily and reliably performed. You.

The present invention is not limited to the above embodiment, but can be variously modified as needed.

[0059]

As described above, according to the thermal transfer line printer printing control method and thermal transfer line printer of the present invention, the transfer start position can always be kept constant regardless of the level of the environmental temperature. In addition, an extremely excellent effect such as high-quality printing can be achieved.

The number of energizing pulses in the continuous energizing period is corrected based on at least the environmental temperature, and the number of energizing pulses in the intermittent energizing period is determined based on at least the environmental temperature and the print data. Since the heating temperature of the heating element can be precisely controlled, an extremely excellent effect such as an improvement in print quality can be achieved.

Further, by using the temperature in the vicinity of the heating element of the line thermal head as the environmental temperature, it is possible to perform the temperature correction for the continuous energizing period and the intermittent energizing period more easily and reliably. It works.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of an embodiment of a thermal transfer line printer to which a print control method for a thermal transfer line printer according to the present invention is applied.

FIG. 2 is a timing chart for explaining the operation of the main part of the thermal transfer line printer of FIG. 1;

FIG. 3 is a block diagram illustrating a main part of an embodiment of a thermal transfer line printer according to a conventional print control method of the thermal transfer line printer.

FIG. 4 is a timing chart for explaining the operation of the main part of the thermal transfer line printer of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 Thermal transfer line printer 22 Temperature detection means 23 System clock generation circuit 24 System control 25 Power supply ROM 26 Timing control signal generation circuit 27 Selector 28 Data counter 29 Comparator 30 Head control unit 31a Shift register 31b Latch circuit 31c Driver 31 Line thermal head 31a Heating element 31b Head substrate CD count value TD energization count data DP Transfer start position TA Switching timing (from continuous energizing period to intermittent energizing period) M Maximum pulse number N (intermittent energizing pulse for continuous energizing) Maximum number of energizing pulses to energize

Claims (5)

[Claims] 1. A print control method for a thermal transfer line printer that performs printing on a sheet by individually controlling energization times of a plurality of heating elements of a line thermal head based on print data. The one-line energization period during printing is always constant, and the one-line energization period is continuously energized by continuously applying an energization pulse necessary to print the minimum size dot on the paper. A continuous power supply period is divided into a continuous power supply period and an intermittent power supply period in which an intermittent power supply is applied intermittently to apply a power supply pulse for controlling the size of a dot to be formed on the paper according to a gradation value included in the print data. The switching timing from the area of the continuous energizing period to the area of the intermittent energizing period is controlled to be always constant with respect to the paper feeding timing. Printing control method of a thermal transfer line printer according to. 2. The method according to claim 1, wherein the number of energizing pulses in the continuous energizing period is corrected based on at least an environmental temperature, and the number of energizing pulses in the intermittent energizing period is determined based on at least the environmental temperature and print data. A print control method for the thermal transfer line printer according to claim 1. 3. The printing control method for a thermal transfer line printer according to claim 2, wherein a temperature near a heating element of the line thermal head is used as the environmental temperature. 4. A thermal transfer line printer that performs printing on paper by individually controlling the energization time for a plurality of heating elements of a line thermal head based on print information based on print data, and detects an environmental temperature. Temperature detection means, and performs continuous energization necessary for printing the smallest size dot on the paper after correcting print data including a tone value input from the outside at least according to the environmental temperature. It is formed by continuous data formed by the number of energizing pulses and energizing pulses that perform intermittent energization necessary for printing by controlling the size of the dots to be formed on the paper according to the gradation value included in the print data. System output that divides the data into two data, ie, intermittent data, and outputs a start signal synchronized with the paper feed timing. When printing one line on the heating element of the line thermal head, the maximum number of energizing pulses in the continuous energizing period in which continuous energizing is performed in one line energizing period, and the number of energizing pulses in the intermittent energizing period in which intermittent energizing is performed. An energizing ROM in which one type of strobe data having the maximum number of pulses is stored; and at least a strobe signal, a latch signal, and a shift clock based on at least a start signal, a system clock, and strobe data stored in the energizing ROM. , A counter reset signal, a counter clock, and a data switching control signal for keeping the switching timing from the continuous energizing period region to the intermittent energizing period region constant with respect to the paper feed timing, and outputting the same. Between the timing control signal generation circuit and the continuous data A selector that receives data and a data switching control signal, selects and outputs continuous data or intermittent data energization count data based on the data switching control signal, and a selector that is cleared by input of a counter reset signal and outputs continuous data. When the selector outputs the intermittent data, the counter counts up every counter clock synchronized with the latch signal.
The data counter that outputs these count values, the energization count data and the count value are input, the energization count data and the count value are compared, and energization is instructed only when the count value is greater than the energization count data value. A comparator that outputs data; a shift register that receives at least a shift clock for energizing data to each heating element of the line thermal head for controlling energizing data to each heating element of the line thermal head; and a latch signal. A latch circuit for latching the energization data of the shift register every time, and a head control unit including a driver for outputting the energization data latched based on the strobe signal to each heating element of the line thermal head. And thermal transfer line printer. 5. The thermal transfer line printer according to claim 4, wherein said temperature detecting means is configured to detect a temperature near a heating element of said line thermal head.