JP2000190548A - Thermal printer and printing method of thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent bleeding and trailing resulting from preheating control by judging whether a coloring heat energy amount for processing dots not to be printed out is high or low when printing out to a multicolor heat-sensitive paper and refraining preheating for the dots in the case of only a high energy amount of a predetermined condition. SOLUTION: A CPU 1 drives a paper feed motor 7 in a forward direction to transfer a heat-sensitive paper by one line towards a thermal line head 9. Printing data is printed out to one heat-sensitive part by supplying electricity to heating elements of the head 9. Based on printing data of each color developed in dots to a RAM 3, whether printing data to be processed hence is dots to be printed out high or low is judged. A power feed pulse for printing based on each color is applied to the heating elements when the data is judged as dots to be printed out. When the data is judged as dots not to be subjected to a printing process, whether or not processed printing data is dots of a color to be printed with a high heat energy amount is judged. If the previously processed data is dots of a high energy, a preheating process is not carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer and a printing method for a thermal printer for performing printing on a multicolor thermal paper comprising a plurality of color layers.

[0002]

2. Description of the Related Art For example, there is a two-color heat-sensitive paper as a multi-color heat-sensitive paper. The two-color heat-sensitive paper further includes a decoloring type and an additive color type. This color-added thermosensitive paper is composed of a mount and a red-colored layer and a black-colored layer superposed on each other. As shown in FIG. 9, the decolorizable type thermal paper is formed on a mount 101 with a black coloring layer 102,
The red coloring layer 104 is configured to overlap. Further, a coating layer 105 for long-term storage and prevention of yellowing is provided on the surface.
Is formed. This coating layer 105 is also formed for the decoloring type.

FIG. 10 shows the coloring characteristics of such a two-color thermal paper.
Shown in In the figure, the vertical axis indicates the degree of color development, and the horizontal axis indicates the amount of thermal energy applied to the thermal paper. The graph y1 shows the characteristics of the coloring layer that emits red, and the graph y2 shows the characteristics of the coloring layer that emits black. Because of these characteristics, when printing is performed on such two-color thermal paper with a thermal printer, a small amount of current is applied to the thermal line head to give the thermal paper a low thermal energy EA. Printing output is performed under such a control that a red color is generated and a large amount of current is supplied to the thermal line head to apply a high thermal energy EB to the thermal paper to generate a black color.

When printing is performed in this manner, if there is a portion (dot) of the printing data for which printing is to be performed, a heating element for outputting the portion is energized to supply the thermal energy EA or EB.
Is generated to an appropriate temperature at which the output of the thermal line head can be output. However, even if the heating element of the thermal line head is energized suddenly from a cold state, the temperature may not easily rise.

For example, when using a thermal paper which develops a color with an appropriate amount of thermal energy E0, if only a printing energizing pulse is applied to the heating element without preheating, one heating element of the thermal line head is applied to the thermal paper. As shown in FIG. 11 (c), the relationship between the amount of heat energy applied and the time is such that even when an energizing pulse for printing is applied to the heat generating element, the heat energy applied to the thermal paper by the heat generating element sharply changes to the appropriate amount of heat energy. E
It can be seen that the heat energy amount does not reach 0 but gradually increases. In this case, the portion that develops color is also shortened.

Therefore, in order to make it easier for the thermal line head to rise to an appropriate temperature, a portion (dot) of the print data which is not subjected to print output as shown in FIG.
FIG. 12 shows that each color of the multi-color thermal paper does not develop color.
A preheating control was performed in which a preheating energizing pulse as shown in (b) was applied to the heating element to energize it.

By performing such preheating control, as shown in FIG. 12 (c), the heating element generates heat to a certain temperature even for dots for which printing is not performed. If this is the case, the amount of heat energy given to the thermal paper can reach the appropriate amount of heat energy E0 more quickly.

[0008]

However, in such a thermal printer that performs such preheating control, a multicolor thermal paper comprising a plurality of coloring layers having different colors depending on the amount of applied heat energy, for example, as shown in FIG. When printing on two-color thermal paper, printing is performed immediately after the thermal line head is energized in order to print dots of a color (black) that develops with a high thermal energy EB as shown in FIG. A preheating energizing pulse is also given when there are no more dots.

For this reason, the heating element to which the energizing pulse for printing is applied is preheated before it is completely cooled by natural cooling, and depending on the degree of preheating, the printing output immediately after the dot printed in black on the thermal paper is reduced. As shown in FIG. 13 (b), the total amount of heat energy applied to a dot that is not performed may fall into a color-developing region of a color that appropriately develops with a low heat energy EA. In such a case, the color (red) which develops with a low thermal energy EA at the dot immediately after the dot printed and output in black is partially developed, and the dot in the portion of the thermal paper which is printed out in black is printed. There is a problem that the contour on the downstream side in the transport direction becomes red.

The phenomenon in which the outline of the printed portion is colored in another color is called "bleeding". In particular, the "bleeding" of the downstream portion of the printed portion in the transport direction is called "bleeding".
Are called "tails".

Accordingly, the present invention is to provide a thermal printer and a printing method of a thermal printer which can prevent "bleeding", especially "tailing" generated due to such preheating control. is there.

[0012]

According to the first aspect of the present invention, a thermal head is supplied to a multi-color thermal paper comprising a plurality of coloring layers having different colors depending on the amount of applied heat energy in accordance with print dot data. In this way, a printout is performed by giving an amount of thermal energy, and preheating control for energizing the thermal head is performed to such an extent that each color of the multicolor thermal paper does not develop even for the dots for which the printout is not performed among the print dot data. In a thermal printer, when performing print output on multi-color thermal paper, when processing dots that do not perform print output, the previously processed print dot data is determined by the lowest amount of thermal energy among the coloring layers of the multi-color thermal paper. It is determined whether or not the dot is a color of a color that develops with a higher amount of thermal energy than the color to be developed, and the previously processed print dot data is used as the high thermal energy. Only when it is determined that the dots of colors developed by formic amount for the dot is a thermal printer which is characterized by being configured so as not to perform preheating control.

According to a second aspect of the present invention, the amount of heat energy is supplied to a multicolor thermal paper comprising a plurality of coloring layers having different colors depending on the amount of heat energy applied thereto, by energizing a thermal head in accordance with print dot data. In the printing method of a thermal printer, a preheating control is performed in which the thermal head is energized to the extent that each color of the multi-color thermal paper does not develop even for the dots for which the printing is not performed among the printing dot data. When printing on multicolor thermal paper, the thermal head is energized to print out a color that develops with a higher amount of heat energy than a color that develops with the lowest amount of thermal energy among the coloring layers of the multicolor thermal paper. If there is a print dot data for a dot for which no print output is performed after that, do not perform preheating control for that dot. A printing method for a thermal printer, characterized in that it has.

In the present invention having such a configuration, since the preheating control does not hinder the natural cooling of the thermal head which is energized to output a high heat energy amount, the color developed by the high heat energy amount is prevented. Even if the print dot data of the dots for which no print output is performed immediately after the print dot data of, the thermal paper can be prevented from being colored by the dots for which the print output is not performed, that is, the occurrence of "tailing" can be prevented.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a main part configuration of the present embodiment. Reference numeral 1 denotes a CPU (central processing unit) constituting a control unit main body, and 2 denotes an R which stores program data and the like for the CPU 1 to control each unit.
OM (Read Only Memory), 3 RAM (Random Access Memory) provided with a memory area used for data processing, 4 I / O (input / output) port, 5 I / F (Interface). The above CPU
1 and the ROM 2, RAM 3, I / O port 4, and I / F 5 are electrically connected by a bus line 6 such as an address bus, a data bus, and a control bus.

The I / O port 4 has a motor driver 8 for driving a paper feed motor 7 for driving a transport roller or the like for transporting continuous thermal paper in a forward or backward direction, and a plurality of heat-generating papers for applying heat to the thermal paper. A head driver 10 for turning on and off the heating elements of a thermal line head 9 having heating elements arranged in a line, a motor driver 12 for driving a cutter motor 11 for driving a cutter 21, and other various operations. An operation panel (not shown) and the like are connected.

The cutter 21 is disposed near the thermal line head 9 as shown in FIG. 4, and is for separating the thermal paper printed by the thermal line head 9. A host device 15 composed of a personal computer or the like is connected to the I / F 5 via a communication line.

The thermal printer according to the present embodiment uses a thermal paper 22 as shown in FIG. The heat-sensitive paper 22 has a coloring layer (for example, black) that forms a color with a high heat energy amount on the continuous backing paper 22a as shown in FIG.
A plurality of heat-sensitive portions 22b formed by laminating a color-erasable layer for erasing the color of an upper color-developing layer, a color-developing layer (for example, red) that produces a color with a low heat energy amount, and a coating layer for long-term storage or prevention of yellowing are provided at regular intervals. Provided. The characteristics of these coloring layers are the same as those shown in FIG. That is, for the color-forming layer that forms a color with the low heat energy, the appropriate heat energy at which the color is best formed is EA.
(For the sake of simplicity, this is referred to as a low thermal energy EA), and for a color-forming layer that develops a color with a high thermal energy, the appropriate thermal energy at which color development is best performed is EB (see This is called a high thermal energy EB for simplicity).

In order for the coloring layer of the heat-sensitive portion 22b of the heat-sensitive paper 22 to develop a good color, the entire heat energy applied to the heat-sensitive paper 22 only needs to be an appropriate heat energy.

When printing on the thermal paper 22 with the thermal printer according to the present embodiment, the print data received from the host computer 15 is developed into dots in the RAM 3 for each color. The CPU 1 performs a printing process as shown in FIG. 2 based on the dot-expanded print data (print dot data). That is, CP
U1 first drives the paper feed motor 7 in the forward direction in ST (step) 1 to transfer the thermal paper 22 to the thermal line head 9;
To a predetermined print standby position.
Thus, the thermal paper 22 changes from the state shown in FIG. 4A to the state shown in FIG.

In ST2, the paper feed motor 7 is driven in the forward direction to convey the thermal paper 22 by one line toward the thermal line head 9 in the advancing direction. In ST3, the heating elements of the thermal line head 9 are removed. By controlling the energization, the print data is printed out to one heat sensitive part 22b.

The energization control at this time is performed for each heating element by a process as shown in FIG. That is, ST
Based on the print data of each color which has been dot-developed into the RAM 3 at 11, the print data to be processed is a dot for printing output (a color (black) for EB printing with a high heat energy amount).
It is determined whether or not the dot is a color (red dot) to be printed with a low thermal energy amount EA.

If it is determined in ST11 that the print data to be processed is a dot for print output, the process proceeds to ST11.
At 12, an energizing pulse for printing based on each color is given to the heating element. For example, when printing in red, a heating pulse for outputting a low heat energy EA is given to the heating element, and when printing in black, a printing pulse for outputting a high heat energy EB is generated. It is applied to the element and the process exits.

If it is determined in ST11 that the print data to be processed is a dot for which print output is not to be performed, the previously processed print data (thermal paper 2) is determined in ST13.
It is determined whether the second dot (the dot located upstream in the transport direction) is a dot of a color (black) to be printed with a high thermal energy EB.

If it is determined in ST13 that the previously processed print data is a black dot, the process exits from this process.
Therefore, preheating is not performed on the dot to be processed this time. If it is determined in ST13 that the print data processed last time is not a black dot, a preheating energizing pulse is applied to the heating element to exit this processing. Therefore, if the print data processed last time is a dot for which printing is not performed or a dot of a color (red) to be printed with a low thermal energy EA, the dot processed this time is preheated.

When printing of one line is completed, the process proceeds to ST4 shown in FIG. That is, ST4
It is determined whether or not printing is completed. At this time, if it is determined that the printing has not been completed, the process returns to ST1. By repeating such processing, characters such as "A" and "B" are printed out as shown in FIGS. 4 (c) and 4 (d).

If it is determined in ST4 that the printing has been completed, and if it is determined that printing has been completed, the cutter motor 11 is driven in ST5 to cut the thermal paper 22 at a predetermined position.
The printed heat-sensitive portion 22b shown in FIG.
2 and the printing process is terminated. FIG. 5 shows print data, energizing pulses, and timings for one heating element of the thermal line head 9 in the above processing.

In the embodiment of the present invention having such a configuration, as shown in FIG. 5A, a dot which is not printed out or a dot of a color (red) which develops with a low heat energy EA is placed next to the dot. When dots for which printing is not performed continue, dots for which printing is not performed are preheated. However, as shown in FIG. 5B, printing is performed next to a dot of a color to be printed with a high thermal energy EB. When the dots that are not output continue, the dots that are not printed are not preheated.

As a result, as shown in FIG. 5C, after printing a dot of a color to be printed with a high heat energy amount EB,
Since the process of lowering the temperature of the heating element is not hindered by the preheating, the temperature of the heating element is sufficiently reduced by natural cooling, and the color developed by the low heat energy EA does not develop. Therefore, "bleeding" due to preheating control can be prevented. In particular, it is possible to prevent "tailing" occurring in the contour of the portion printed and output with a high thermal energy EB on the downstream side in the transport direction.

Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the block diagram in this embodiment is the same as that shown in FIG.
A detailed description thereof will be omitted.

This embodiment is different from the first embodiment in that the thermal paper 22 is printed once while being conveyed once in the feed direction, whereas the thermal paper 22 is fed for each color. This is the point where the sheet is conveyed again in the direction and printed out for each color. In the case of this embodiment, when printing is performed with a low thermal energy EA, dots that are not printed are preheated, and when printing is performed with a high thermal energy EB, the first embodiment is performed. The point is that the same preheating control is performed.

Specifically, when printing on the thermal paper 22 with the thermal printer according to the present embodiment, the CPU 1
Performs a printing process as shown in FIG.
That is, the CPU 1 first starts the paper feed motor 7 in ST21.
Is driven in the forward direction to transport the thermal paper 22 toward the thermal line head 9 to a predetermined print standby position in the advance direction. As a result, the thermal paper 22 changes from the state shown in FIG. 8A to the state shown in FIG.

Then, in ST22, the paper feed motor 7 is driven in the forward direction to move the thermal paper 22 to the thermal line head 9.
The print data to be output in a color requiring a low heat energy amount EA is transmitted to one heat-sensitive portion 22b by controlling the energization of the heating element for performing the print output in ST23 by transporting one line in the forward direction toward. Print out.

The energization control at this time is performed for each heating element by a process as shown in FIG. That is, ST
At 41, it is determined whether or not the print data to be processed is a dot to be printed out based on the print data of each color which has been dot-developed in the RAM 3 at 41.

If it is determined in ST41 that the print data to be processed is a dot for print output, the process proceeds to ST41.
At 42, a print energizing pulse based on each color is given to the heating element, and the process exits. In this case, a print energizing pulse is output to the heating element so as to always output a low thermal energy EA.

If it is determined in ST41 that the print data to be processed is a dot for which printing is not to be performed, a preheating energizing pulse is applied to the heating element in ST43 to perform preheating, and the process exits. As described above, when printing is performed with a low thermal energy amount EA, dots that are not to be printed are always preheated.

When the print output for one line is completed, the process proceeds to ST24 shown in FIG. That is, ST
At 24, it is determined whether or not printing is to be performed in a color requiring a high thermal energy EB. Here, it may be determined whether or not printing of a color requiring a low heat energy amount EA has been completed.

If it is determined in ST24 that printing is not performed in a color requiring a high thermal energy EB, the process proceeds to ST2.
It returns to the process of 2. By repeating such processing, FIG.
The print data "A" to be printed out with a small amount of heat energy EA as shown in FIG.

Further, in ST24, the high heat energy EB
If it is determined that printout is to be performed in a color that requires
Paper feed motor 7 for at least the heat-sensitive portion 22b printed at 25
Is driven in the reverse direction to transport the thermal paper 22 in the return direction. As a result, the thermal paper 22 changes from the state shown in FIG. 8C to the state shown in FIG.

Next, in ST26, the paper feed motor 7 is driven in the forward direction again, and the thermal paper 22 is conveyed toward the thermal line head 9 to a predetermined print standby position in the advancing direction. Subsequently, in ST27, the paper feed motor 7 is driven in the forward direction to convey the thermal paper 22 by one line in the advancing direction toward the thermal line head 9, and in ST28, the energization control of the heating element for performing print output is performed. As a result, print data to be output in a color requiring a high thermal energy amount EB is printed out to one heat-sensitive portion 22b. The energization control at this time is
The processing is performed for each heating element in the same manner as in the first embodiment shown in FIG. However, FIG.
In the process of ST12, the heat energy EB is always high.
Is supplied to the heat generating element so as to output.

When the printing of one line is completed, the process proceeds to ST29 shown in FIG. That is, ST
At 29, it is determined whether or not printing is completed. At this time, if it is determined that printing has not been completed, the process returns to ST27.
By repeating such processing, print data "B" to be printed out with a high thermal energy EB as shown in FIG. 8E is printed.

If it is determined in ST29 that printing has been completed, if it is determined that printing has been completed, the cutter motor 11 is driven in ST30 to cut the thermal paper 22 at a predetermined position.
The printed heat-sensitive portion 22b as shown in FIG. 8E is separated from the heat-sensitive paper 22 to end the printing process.

In this embodiment, when printing is performed with the low heat energy amount EA for the first time and printing is performed with the high heat energy amount EB for the second time, and each color of the thermal paper is colored, In the print output with the low heat energy EA, all the dots that do not perform the print output are preheated, and in the print output with the high heat energy EB, the dots that do not perform the print output after the dot that performs the print output are provided. Only when the dots are continuous, the dots are not preheated.

In this manner, "bleeding" due to preheating control can be prevented as in the above embodiment. In particular, "tailing" occurs in the contour of the portion printed out with a high thermal energy EB on the downstream side in the transport direction.
Can be prevented.

In the embodiment of the present invention, a case has been described in which the present invention is applied to the case where the thermal paper is conveyed line by line and printout is performed. However, the present invention is not limited to this. The present invention may be applied to a case in which print output is performed while being conveyed to a printer.

Further, in the present embodiment, the case where the two-color thermal paper is used as the thermal paper has been described. However, the present invention is not necessarily limited to this, and the thermal paper having three or more color developing layers is used. May be. In this case, after the thermal head is energized in order to print out a color that develops with a higher amount of heat energy than a color that develops with the lowest amount of thermal energy, immediately after that, the print data of a portion that does not perform printout continues. However, if preheating is not performed on that portion, it is possible to prevent "tailing" due to the color developed by the lowest heat energy.

[0047]

As described in detail above, according to the present invention, "bleeding", especially "tailing", which occurs due to preheating control.
It is possible to provide a thermal printer and a printing method of the thermal printer, which can prevent the occurrence of the problem.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a printing process performed by a CPU according to the embodiment.

FIG. 3 is a flowchart showing print output processing performed by a CPU according to the embodiment;

FIG. 4 is a view for explaining the operation in the embodiment.

5A and 5B are diagrams for explaining the relationship among print data, energizing pulses, and the amount of heat energy given to thermal paper in the embodiment. FIG. 5A shows the case where printing is performed with a low amount of heat energy. FIG. 7B shows a case where printing is performed with a high amount of heat energy, and FIG. 7C shows an amount of heat energy given to the thermal paper.

FIG. 6 is a flowchart illustrating a printing process performed by a CPU according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a print output process of a color requiring a low heat energy amount performed by the CPU according to the embodiment;

FIG. 8 is a view for explaining the operation in the embodiment.

FIG. 9 is a diagram illustrating a configuration of thermal paper.

FIG. 10 is a view showing characteristics of the thermal paper shown in FIG. 9;

FIG. 11 is a diagram illustrating the relationship among print data, energizing pulses, and heat energy when printing is performed without applying a preheating energizing pulse in a conventional thermal printer.

FIG. 12 shows print data when a print output is performed by applying a preheating energizing pulse in a conventional thermal printer;
The figure explaining the relationship between an energization pulse and the amount of thermal energy.

FIG. 13 shows print data, energizing pulses, and print data when printing is performed on two-color thermal paper in a conventional thermal printer.
The figure explaining the relationship with the amount of heat energy.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CPU 9 ... Thermal line head 22 ... Thermal paper 22a ... Mount 22b ... Thermal part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Isao Yawata 6-78 Minamimachi, Mishima-shi, Shizuoka Prefecture Inside the Tec Mishima Plant (72) Inventor Makoto Okada 6-78 Minamimachi, Mishima-shi, Shizuoka Tec Corporation F term in Mishima Plant (reference) 2C065 AB01 DC19 2C066 AA04 AD01 DA02 DA08 2H026 AA07 AA14 AA28

Claims (2)

[Claims] 1. A multicolor heat-sensitive paper comprising a plurality of color-forming layers of different colors depending on the amount of heat energy to be applied is supplied with a heat energy according to print dot data to give a heat energy amount to perform printing output. A thermal printer that performs preheating control to energize the thermal head to such an extent that each color of the multicolor thermal paper does not develop a color even for dots that do not perform print output among the print dot data. When performing printing on dots that do not perform printing, the previously processed printing dot data has higher heat than the color generated by the lowest heat energy amount among the coloring layers of the multicolor thermal paper. It is determined whether or not the dot is a color that develops according to the energy amount, and the previously processed print dot data is determined based on the high thermal energy amount. Only when it is determined that the color of the dot color thermal printer for the dot, characterized by being configured so as not to perform preheating control. 2. A multicolor heat-sensitive paper comprising a plurality of color-forming layers of different colors depending on the amount of heat energy applied to the thermal head in accordance with print dot data to give the amount of heat energy and print out. A printing method of a thermal printer for performing preheating control for energizing the thermal head to such an extent that each color of the multi-color thermal paper does not generate a color even for dots for which printing is not performed among the printing dot data. When printing on the color thermal paper, the thermal head was energized in order to print out a color developed by a higher thermal energy than a color developed by the lowest thermal energy in the color developing layer of the multicolor thermal paper. Sometimes, even if there is print dot data for a dot for which print output is not to be performed, preheating control is not performed for that dot. The method of printing a thermal printer, characterized in that the.