JP2001096779A - Power applying time control method of thermal printer and thermal printer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal printer apparatus capable of obtaining good printing quality even with the open face character in solid printing. SOLUTION: A history memory 14 for storing micro-printing data of several past lines inclusive of an adjacent element and macro-printing data of several hundred lines or more of the element concerned, a heat history correcting table 17 converting the micro-printing and macro-printing data read from the history memory to the power applying level of a thermal head and a head control part 18 for controlling the power applying time of the thermal head corresponding to the power applying level outputted from the heat history correcting table are provided and the heat history correcting table 17 has a plurality of micro-printing data correcting tables and these tables are selected on the basis of the macro-printing data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer energizing time control method and a thermal printer device capable of obtaining good print quality even with white characters.

[0002]

2. Description of the Related Art In a thermal printer, printing is performed by heating a thermal head, so that when printing is performed, the thermal head stores heat. Due to the heat accumulation of the thermal head, a portion where there is no print data may be printed in black, which causes a problem that print quality is deteriorated.

Conventionally, in order to solve such a problem, deterioration of print quality has been corrected by controlling energy for printing by a thermal head by referring to past print information of a corresponding dot or an adjacent dot. Was. From a macro perspective, the thermal storage state of the thermal head is monitored by a thermistor, and the energy supplied to the thermal head is controlled based on the information.

[0004] Conventionally, the printing content printed by a thermal printer has mainly been printing such as characters and bar codes, solid printing, and the like. However, in recent years, the print content printed by the thermal head is actually of many types. For example, it has been required to form minute white characters in a solid print like a nameplate label attached to a product.

[0005]

When the printing speed of the thermal printer is low or when the printing content is a small printing rate such as characters, the energy of the thermal head is controlled based on the printing information of the past several lines. I should have done it.

However, in the case where minute white characters are to be formed in solid printing by high-speed printing of 2 ms / line or more, it is difficult to control the thermal head based on printing information of the past several lines as in the related art. , The white letters were crushed. In addition, if the energy supplied to the thermal head is controlled so that the outline characters are not destroyed, there is a problem that a blur occurs at a solid printing portion at the start of printing.

[0007] Therefore, if it is attempted to control the energy supplied to the thermal head based on a large amount of past printing information, a large amount of memory is required and the hardware becomes large-scale. there were.

Further, in the method of reflecting the information of the head thermistor on the printing energy, when printing is performed at a high speed of 2 ms / line or more, the printing character is crushed in white characters before the thermistor reacts, and the thermal wrinkles of the ink ribbon are generated. And other problems occur.

[0009] The present invention has been made in view of the above points,
An object of the present invention is to provide a thermal printer energization time control method and a thermal printer device that can obtain good print quality even with white characters in solid print.

[0010]

According to a first aspect of the present invention, there is provided a method for controlling the energization time of a thermal printer, wherein an energization is applied to a line thermal head in which a plurality of heating elements are arranged, and the heat generated by the energization causes the ink of the ink ribbon to be applied to the paper. In a thermal printer that melts or sublimates the thermal head, the energizing time of the thermal head is controlled based on both the micro print information of the past several lines including the adjacent element and the macro print information of the past several hundred lines or more of the corresponding element. It is characterized by the following.

According to a second aspect of the present invention, there is provided a thermal printer.
In a thermal printer that energizes a line thermal head in which a plurality of heating elements are arranged, and the heat generated by the energization melts or sublimates the ink on the ink ribbon onto the paper, the microprint information on the past several lines including the adjacent elements A history memory for storing macro print information of the past several hundred lines or more of the element, a thermal history correction table for converting the micro print information and the macro print information read from the history memory to the power supply level of the thermal head, A head control unit that controls the energization time of the thermal head according to the energization level output from the thermal history correction table, wherein the thermal history correction table has a plurality of micro print information correction tables, and includes macro print information. A micro print information correction table is selected.

According to a third aspect of the present invention, there is provided a thermal printer.
The macro print information according to claim 2 is read out from the history memory for each corresponding dot, and the macro print information is incremented by 1 when the corresponding dot is on, and is decreased by -1 when only a predetermined line is turned off by an up / down counter. It is characterized by being updated.

According to a fourth aspect of the present invention, there is provided a thermal printer.
The operation of the up-down counter according to the third aspect is selectively changed according to the printing speed.

According to a fifth aspect of the present invention, there is provided a thermal printer.
The selection of the micro print information correction table based on the macro print information according to the second aspect is performed nonlinearly.

According to a sixth aspect of the present invention, there is provided a thermal printer.
The selection of the micro print information correction table based on the macro print information according to claim 2 changes according to the print speed.

According to a seventh aspect of the present invention, there is provided a thermal printer.
The micro print information according to the first aspect includes future print information of the dot.

The thermal printer according to claim 8 is
The micro print information according to claim 2 includes future print information of the dot.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;
An embodiment will be described. FIG. 1 is a block diagram showing a system configuration of the thermal printer. In the figure, reference numeral 11 denotes a controller which controls the thermal printer apparatus. The controller 11 is constituted by, for example, a microprocessor.

Reference numeral 12 denotes an image memory that stores print data to be printed by a thermal head described later. In this thermal head, the same number of heating elements as the number of dots are arranged in rows so that 2560 dots can be printed on one line. The image memory 12 stores print data as bitmap data.

The image data stored in the image memory 12 is read out at a predetermined timing under the control of the controller 11 and stored in the micro register 13.

The micro register 13 has a configuration as shown in FIG. That is, an M shift register for storing print information of the corresponding sub-scanning line, an R shift register for storing print information of a right line adjacent to the relevant sub-scanning line, and storing print information of a left line adjacent to the relevant sub-scanning line. An L shift register is provided.

M (0) is the print data of the dot on the main scanning line currently being printed, and when this data is "1", it means that the heating element is energized.
When this data is "0", it means that the heating element is not energized.

M (-1) stores print data of dots on the main scanning line to be printed next. M (1) is the print data of the line printed immediately before the corresponding main scanning line, M (2) is the print data of the line printed immediately before, and M (3) is the print data of one line before. The print data of the line, M (4) stores the print data of the previous printed line, and M (5) stores the print data of the previously printed line.

Further, R (-1), R (0) to R (5)
Stores print information similar to the above-described M (-1) to M (5) for a sub-scanning line adjacent to the right of the relevant sub-scanning line.

Further, L (-1) to L (5) store print information similar to the above-described M (-1) to M (5) for the sub-scanning line adjacent to the left of the relevant sub-scanning line. ing.

The information stored in R (-1) to R (5) is shifted to M (-1) to M (5) by a predetermined timing signal output from the controller 11. Further, the information stored in M (0) is shifted to L (0) by a predetermined timing signal output from the controller 11.

R (-1) to R (R)
The 6-bit micro print information of (4) is output to the history memory 14. Further, the 6-bit micro print information stored in the history memory 14 is stored in R (0) to R (5).

The history memory 14 stores 6-bit micro print information and 10-bit macro print information for 2560 dots per line. That is, 2560
It has a storage capacity of × 16 bits. This history memory 14
Are the print information of the past 5 lines.

Reference numeral 15 denotes a macro register for storing macro print information. The macro register 15 stores 10-bit macro print information M (6) to M of the corresponding sub-scanning line.
(15) an M macro register for storing 10-bit macro print information, an R macro register for storing 10-bit macro print information R (6) to R (15) of a line adjacent to the right of the relevant sub-scanning line It is composed of

The macro print information M (6) to M (15) of the macro register 15 is output to the bits 6 to 15 of the history memory 14 described above.

Bits 6 to 15 of the macro print information stored in the history memory 14 are latched by a 10-bit up / down counter 16. The up / down counter 16 stores the micro print information R from the micro register 13.
(0) to R (5) are input. Further, the printing speed information V is input from the controller 11 to the up / down counter 16.

When the input printing speed information is in the high-speed mode, the up-down counter 16 displays the current main scanning line R.
If (0) is “1”, +1 is added, and R (0) to R (0)
If (5) is all "0", that is, if all the past 6 dots including the current scanning line are "0", -1 is set.

On the other hand, when the input printing speed information is in the low speed mode, if the current main scanning line R (0) is "1", the up / down counter 16 increments by one, and R (0) to R (0).
If (3) is all "0", that is, if all the past four dots including the current scanning line are "0", -1 is set.

The macro print information updated by the up / down counter 16 is stored in the macro register M described above.
(6) to M (15) are latched.

As described above, by inputting the printing speed information V to the up / down counter 16, the cooling method of the thermal head is changed according to the printing speed.

M (-1) to M of micro register 13
(5), L (0), R (0) are thermal history correction tables 17
, The upper print information M (14) and M (15) of the micro-register 15 are input to the upper addresses 9 and 10 of the thermal history correction table 17, respectively. The thermal history correction table 17 outputs a 4-bit head energization level to the head controller 18.

The thermal history correction table 17 stores the address 11
It has a configuration of 16 bits x data. That is,
The thermal history correction table 17 includes macro information M (14),
Four micro correction tables corresponding to two bits of M (15) are stored. Specifically, the macro information M (1
4) If M (15) is "00", it is determined that the past heat storage of the corresponding dot is small, and a micro correction table having a high head energizing energy level is selected. Also, the macro information M (14) and M (15) are changed from "01" to "10".
As “→ 11” is reached, it is determined that the degree of heat storage of the dot is large, and a micro correction table accompanying the determination is selected.

Each micro-correction table outputs head energization levels 0 to 15 to the head controller 18 based on past print patterns including adjacent dots. That is, the 4-bit energization level signal is transmitted to the head controller 1
8 is output.

The head controller 18 controls to energize the heating elements constituting the line thermal head 19 for an energizing time corresponding to the input head energizing level.

Next, the operation of the first embodiment of the present invention configured as described above will be described. First, 1-bit image data read from the image memory 12 is read at a predetermined timing by the controller 1 and latched by R (−1) of the macro register 13. In synchronization with this timing, the corresponding dot M
At (0), the past 16-bit print information of the R line adjacent to the right side is read.

Of the print information, bits 0 to 5 are latched by R (0) to R (5) of the micro register 13.

In this print information, 1 of bits 6 to 15
The 0-bit macro print information is latched by a 10-bit up / down counter 16.

When the input printing speed information is in the high-speed mode, the up-down counter 16 displays the current main scanning line R.
If (0) is “1”, +1 is added, and R (0) to R (0)
If (5) is all "0", that is, if all the past 6 dots including the current scanning line are "0", -1 is set.

On the other hand, when the input printing speed information is in the low speed mode, if the current main scanning line R (0) is "1", the up / down counter 16 increments by one, and R (0) to R (0).
If (3) is all "0", that is, if all the past four dots including the current scanning line are "0", -1 is set.

The macro print information updated by the up / down counter 16 is stored in the macro register M described above.
(6) to M (15) are latched.

As described above, by inputting the printing speed information V to the up / down counter 16, the cooling method of the thermal head is changed according to the printing speed.

Further, R (-1) to
R (5) and R (6) to R (1) of the macro register 14
At the timing when the print information is latched in 5), the print information stored in R (-1) to R (15) until then is
The corresponding sub-scanning line registers M (-1) to M (15) are shifted. Further, the information contained in M (0) is shifted to the adjacent left register L (0).

The print information R (−1) to R (4) latched by the micro register 13
The print information R (6) to R (15) latched in the macro register 14 are written at predetermined addresses as data of bits 6 to 15 of the history memory 14 as data of.

M (-1) to M of micro register 13
(5), L (0), R (0) are thermal history correction tables 17
, The upper print information M (14) and M (15) of the micro-register 15 are input to the upper addresses 9 and 10 of the thermal history correction table 17, respectively. The thermal history correction table 17 outputs a 4-bit head energization level to the head controller 18.

When the macro information M (14) and M (15) are "0"
If 0 ", it is determined that the past heat accumulation of the dot is small, and a micro correction table having a high head energizing energy level is selected. Also, the macro information M (14), M
As (15) changes from “01” → “10” → “11”, it is determined that the degree of heat storage of the corresponding dot is large, and a micro correction table accompanying the determination is selected.

Each micro-correction table outputs head energization levels 0 to 15 to the head controller 18 based on a past print pattern including adjacent dots. That is, the 4-bit energization level signal is transmitted to the head controller 1
8 is output.

The head controller 18 controls to energize the heating elements constituting the line thermal head 19 for an energizing time corresponding to the input head energizing level.

The next image data is stored in the image memory 12.
, The above-described operation is repeatedly performed, and the data conversion processing for one line is completed by repeating the operation for the number of heating elements of the line thermal head 19, that is, 2560 times.

The energization level output from the thermal history correction table 17 is transferred to the line thermal head 19 by the head controller 18. The line thermal head 19 repeats the above-described operation for a predetermined line to form a print image.

As described above, since the head energizing level is determined based on both the micro print information, which is the print information of the past 5 lines, and the macro print information of the past several hundred lines, the white characters in the solid print are displayed. However, good print quality can be obtained.

Next, a second embodiment of the present invention will be described with reference to FIGS. The system configuration of the thermal printer device shown in FIG. 5 is similar to the system configuration diagram shown in FIG. Is provided.

That is, in FIG. 1, the upper two bits M (14) and M (15) of the micro register 15 are output as the upper address of the thermal history correction table 17, but in FIG. The macro print information of 10 bits of M (6) to M (15) output from the printer is converted into a 2-bit upper address of the heat history correction table 17 by switching between a print mode of a high speed mode and a print mode of a low speed mode. are doing.

Specifically, in the high-speed print mode, when the macro information is 0 to 63, the upper address of the heat history correction table 17 is set to "00" and the macro information is set to 64 to 255.
, The upper address of the heat history correction table 17 is “0”.
When the macro information is 256 to 1022, the upper address of the heat history correction table 17 is “10”, and when the macro information is 1023 or more, the upper address of the heat history correction table 17 is “11”. Is done.

In the low-speed printing mode, when the macro information is 0 to 127, the upper address of the heat history correction table 17 is set to “00”, and when the macro information is 128 to 511, the upper address of the heat history correction table 17 is set. Address is "0"
When the macro information is 512 to 1022, the upper address of the heat history correction table 17 is “10”. When the macro information is 1023 or more, the upper address of the heat history correction table 17 is “11”. Is done.

This is because in the high-speed printing mode and the low-speed printing mode, the state in which the thermal head 19 accumulates heat is not linear but nonlinear as shown in FIG.

By providing the address conversion unit 21 in this manner, the address can be changed to the upper 2 bits address of the heat history correction table 17 in accordance with the actual heat storage state of the head. That is, since the head energization level corresponding to the actual heat storage state of the head can be output to the head controller 18, good printing quality can be maintained regardless of whether the printing speed is high or low.

In the first and second embodiments, the up-down counter 16 is set to -1 if all of the past 6 dots are "0" in the high-speed mode.
In the low-speed mode, all of the past 4 dots are
If it is "0", it has been decremented by one, but all the past is "0".
Alternatively, the predetermined dot may be “0”.

In the first and second embodiments described above, the thermal history correction table 17 is stored in the ROM (read / read).
Alternatively, the table 17 may be constituted by a RAM (random access memory) so that the table 17 can be rewritten. As described above, by enabling the table 17 to be rewritten, a more accurate correction result can be obtained by rewriting the contents of the table 17 according to the printing speed, the paper used, the ink ribbon, and the like.

Further, in the second embodiment, by configuring the address conversion unit 21 with a RAM, it is possible to perform accurate heat history control according to the printing speed.

[0065]

As described above in detail, according to the present invention, a large amount of past print information is stored as macro print information, and even in the case of information on a minute area in the past several lines, the thermal head is used as micro print information. Is reflected in the energization time, so that not only the printing quality of ordinary minute characters and the like but also the printing quality of white characters and the like in solid printing can be improved. Further, good printing quality can be maintained regardless of whether the printing speed is high or low.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a thermal printer device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a microregister according to the embodiment.

FIG. 3 is a diagram showing a configuration of a macro register according to the embodiment.

FIG. 4 is a diagram showing a configuration of a history memory according to the embodiment.

FIG. 5 is a system configuration diagram of a thermal printer device according to a second embodiment of the present invention.

FIG. 6 is an exemplary view for explaining the function of an address conversion unit according to the embodiment;

FIG. 7 is a view for explaining a head heat storage state in a high-speed print mode and a low-speed print mode according to the embodiment;

[Explanation of symbols]

 11: Controller, 12: Image memory, 13: Micro register, 14: History memory, 15: Macro register, 16: Up / down counter, 17: Thermal history correction table, 18: Head controller, 19: Thermal head. 21: Thermal history correction table.

Claims (8)

[Claims] An electric power is supplied to a line thermal head in which a plurality of heating elements are arranged, and heat generated by the electric power is applied to the line thermal head.
In a thermal printer that melts or sublimes the ink of the ink ribbon onto paper, the thermal head is based on both the micro print information of the past several lines including the neighboring elements and the macro print information of the past several hundred lines or more of the corresponding element. A power supply time control method for a thermal printer, wherein the power supply time is controlled. 2. A current is supplied to a line thermal head in which a plurality of heating elements are arranged.
In a thermal printer that melts or sublimes the ink of an ink ribbon onto paper, a history memory that stores micro print information of past several lines including adjacent elements and macro print information of several hundreds or more lines of the corresponding element, and a history memory. A thermal history correction table for converting the micro print information and macro print information read from the thermal head into a power supply level of the thermal head; and controlling the power supply time of the thermal head according to the power supply level output from the heat history correction table. A thermal printer device comprising: a head control unit that performs a plurality of micro print information correction tables; and the micro print information correction table is selected based on macro print information. 3. The up / down counter which reads out the macro print information from the history memory for each corresponding dot, increases the macro print information by +1 when the corresponding dot is on, and decrements by -1 when only a predetermined line is off. 3. The thermal printer according to claim 2, wherein the thermal printer is updated by: 4. The thermal printer according to claim 3, wherein the operation of the up / down counter is selectively changed according to a printing speed. 5. The thermal printer according to claim 2, wherein the selection of the micro print information correction table based on the macro print information is performed nonlinearly. 6. The thermal printer according to claim 2, wherein the selection of the micro print information correction table based on the macro print information changes according to the print speed. 7. The method according to claim 1, wherein the micro print information includes future print information of a corresponding dot. 8. The thermal printer according to claim 2, wherein the micro print information includes future print information of the dot.