JP3609950B2 - Thermal printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal printer that performs print output on multicolor thermal paper composed of a plurality of color layers.
[0002]
[Prior art]
As the multicolor thermal paper, for example, there is a two-color thermal paper. As the two-color thermal paper, there are a decoloring type and a color adding type. This color-added thermal paper is constructed by overlapping a red color layer and a black color layer on a mount. As shown in FIG. 10, the erasable thermal paper is configured such that a black color developing layer 102, a color erasing layer 103, and a red color developing layer 104 are superimposed on a mount 101. A coating layer 105 is formed on the surface for long-term storage, yellowing prevention and the like. The coating layer 105 is also formed for a decoloring type.
[0003]
The color development characteristics of such two-color thermal paper are shown in FIG. In the figure, the vertical axis represents the degree of color development, and the horizontal axis represents the amount of heat energy given to the thermal paper. Graph y1 shows the characteristics of the coloring layer that develops red color, and graph y2 shows the characteristics of the coloring layer that develops black color. Because of these characteristics, when printing output on such two-color thermal paper with a thermal printer, a low thermal energy amount EA is given to the thermal paper by energizing the thermal line head with a small current. Printing is performed under control such that red color is developed and the thermal line head is energized with a large current to give high thermal energy amount EB to the thermal paper to develop black color.
[0004]
When print output is performed in this way, if there is a print output portion (dot) in the print data, the heating element that outputs it is energized to generate heat up to an appropriate temperature at which the amount of heat energy EA or EB can be output. In some cases, the temperature does not rise easily even when the heating element of the thermal line head is suddenly turned on.
[0005]
For example, when using thermal paper that develops color with an appropriate amount of thermal energy E0, if only the energization pulse for printing is applied to the heating element without preheating, the thermal energy that one heating element of the thermal line head gives to the thermal paper. As shown in FIG. 12 (c), the relationship between the amount and the time is that even when the energization pulse for printing is applied to the heat generating element, the heat energy amount that the heat generating element gives to the thermal paper steeply reaches the appropriate heat energy amount E0. However, it can be seen that the amount of heat energy gradually increases. This also shortens the colored portion.
[0006]
For this reason, in order to make it easy for the thermal line head to reach an appropriate temperature, as shown in FIG. 13 (a), the color of the multicolor thermal paper is not developed even in the portion (dots) where print output is not performed in the print data. In FIG. 2B, preheating control for energizing the heater element by applying a preheating energization pulse to the heating element is performed.
[0007]
By performing such preheating control, the heating element generates heat to a certain temperature even with dots that do not perform printing output as shown in FIG. 3C. The amount of heat energy given to the paper can be reached to the appropriate amount of heat energy E0 earlier.
[0008]
[Problems to be solved by the invention]
By the way, for the purpose of extending the life of the thermal line head and preventing the deterioration of the printing quality due to the deterioration of the head, the present applicant divides the number of printing into a plurality of times and prints with a low amount of thermal energy. A thermal printer that develops a color that requires a high amount of energy has been proposed and filed (Japanese Patent Application Nos. 9-229666, 10-19917, and 10-86727).
[0009]
However, in such a thermal printer, if the above-described preheating control is performed, for example, when printing on a two-color thermal paper as shown in FIG. 10, a color that is appropriately colored with a high thermal energy amount EB is printed. However, preheating control is performed not only in the first print output process but also in the second and subsequent print output processes. In this way, preheating is repeatedly performed for dots that are not printed. As a result, the total amount of thermal energy given to the thermal paper for the dots that are not printed out may enter the color development region of a color that appropriately develops with a low thermal energy amount EA. In such a case, it is conceivable that the color (red) that develops color with a low thermal energy amount EA partially develops even though the dot is not printed.
[0010]
Therefore, the present invention performs print output generated when preheating control is performed by a printer that develops a color that requires a high energy amount by dividing the number of times of printing into a plurality of times and printing with a low amount of heat energy. It is intended to provide a thermal printer that can prevent the development of dots.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, the amount of thermal energy is applied to a multicolor thermal paper composed of a plurality of color-developing layers having different colors depending on the amount of applied thermal energy by energizing a thermal head in accordance with print dot data. The lowest thermal energy in a thermal printer that performs print output and performs preheat control that energizes the thermal head to the extent that each color of the multicolor thermal paper does not develop even for dots that are not printed out of the print dot data. When developing a color-developing layer that produces color, the pre-heating control is carried out with a normal energization amount, and the print output process is performed once with the lowest amount of heat energy, compared to the color-developing layer that produces color with the lowest amount of heat energy. When coloring a colored layer that develops color with a high amount of heat energy, print output processing with a heat energy amount lower than the high heat energy is performed multiple times. Sleep to perform, in its plurality of print processing one of performs preheating control in the normal energization amount, other print processing in a normal power supply amount is smaller than (smaller) amount of current, performs preheating control A thermal printer that performs preheating control in which a preheating energization pulse is applied by shifting a phase in a range of dots in which printing output is not performed among preheating energization pulses and print dot data .
[0013]
In the present invention, since the total amount of heat energy given to the dots that do not perform print output of the thermal paper by preheating control can be suppressed to the extent that the color that develops color with the lowest amount of heat energy does not develop, It is possible to prevent dots that are not printed out from being colored.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram showing the configuration of the main part of the present embodiment. 1 is a CPU (central processing unit) that constitutes a control unit body, and 2 is a ROM that stores program data and the like for the CPU 1 to control each unit. (Read-only memory) 3 is a RAM (random access memory) provided with a memory area used for data processing, 4 is an I / O (input / output) port, 5 is an I / F ( Interface). The CPU 1, the ROM 2, the RAM 3, the I / O port 4, and the I / F 5 are electrically connected by a bus line 6 such as an address bus, a data bus, and a control bus.
[0015]
The I / O port 4 includes a motor driver 8 that drives a paper feed motor 7 that drives a conveyance roller or the like that conveys continuous thermal paper in the forward or backward direction, and a plurality of heating elements that apply heat to the thermal paper. A head driver 10 for turning on and off the heating elements of the thermal line head 9 arranged in a line shape, a motor driver 12 for driving a cutter motor 11 for driving a cutter 21 described later, and other operations for performing various operations. Panels (not shown) are connected to each other.
[0016]
As shown in FIG. 5, the cutter 21 is disposed in the vicinity of the thermal line head 9, and is used to separate the thermal paper printed by the thermal line head 9. Further, a host device 15 composed of a personal computer or the like is connected to the I / F 5 via a communication line.
[0017]
In the thermal printer according to the present embodiment, a thermal paper 22 as shown in FIG. 5 is used. The thermal paper 22 has a color developing layer (for example, black) that develops color with a high amount of heat energy as shown in FIG. 10 on a continuous mount 22a, a color erasing layer that erases the color of the upper color developing layer, and a low amount of heat energy. A plurality of heat-sensitive portions 22b each having a color-developing layer (for example, red) and a coating layer for long-term storage and yellowing prevention are provided at regular intervals. The characteristics of these coloring layers are the same as those shown in FIG. That is, for the color-developing layer that develops color with the low amount of heat energy, the appropriate amount of heat energy that produces the best color is EA (for simplicity, this is referred to as the low amount of heat energy EA) For a color-developing layer that develops color with a high amount of heat energy, the appropriate amount of heat energy that produces the best color is EB (this is referred to as a high amount of heat energy EB for the sake of simplicity).
[0018]
In the thermal part 22b of the thermal paper 22, the high thermal energy amount EB is about twice the low thermal energy amount EA.
In order to develop a coloring layer that develops color with a high thermal energy amount EB, not only the high thermal energy amount EB is given to the thermal part 22b for a short time, but also the total amount of thermal energy given to the thermal paper 22 is the color of the color. It is only necessary to reach a high thermal energy amount EB for developing the color.
Therefore, it can be seen that the color-developing layer that develops color with a high amount of heat energy EB can be developed by printing twice with a low amount of heat energy EA.
[0019]
When printing on the thermal paper 22 by the thermal printer according to the present embodiment, the print data received from the host computer 15 is dot-developed for each color in the RAM 3. The CPU 1 performs a printing process as shown in FIG. 2 based on the dot-developed print data according to the principle described above. That is, the CPU 1 first drives the paper feed motor 7 in the forward direction in ST11 and transports the thermal paper 22 toward the thermal line head 9 to the predetermined print standby position in the forward direction. As a result, the thermal paper 22 changes from the state shown in FIG. 5A to the state shown in FIG.
[0020]
In ST12, the paper feed motor 7 is driven in the forward direction to transport the thermal paper 22 toward the thermal line head 9 by one line in the advancing direction, and in ST13, the color to cause the thermal line head 9 to develop color. Regardless of the print data, the heating element is energized and controlled based on all print data, thereby printing on one heat sensitive part 22b.
[0021]
The energization control at this time is performed by a process as shown in FIG. 3 for each heating element. That is, based on the print data of each color dot-developed in the RAM 3 in ST31, it is determined whether the print data to be processed is a dot to be printed out regardless of which color it is.
[0022]
If it is determined in ST31 that the print data to be processed is a dot to be printed, a print energizing pulse giving a low thermal energy amount EA is given to the heating element in ST32, and the process is exited.
[0023]
If it is determined in ST31 that the print data to be processed is a dot that will not be printed, the preheating is performed by applying a preheating energization pulse as shown in FIG. 7A to the heating element in ST33. Go through this process. Thus, when printing output is performed with a low amount of heat energy EA, preheating is always performed for dots that are not printed.
[0024]
When the print output for one line is completed, the process proceeds to ST14 shown in FIG. That is, in ST14, it is determined whether or not to perform print output with a color that requires a high amount of heat energy EB. Here, it may be determined whether or not printing of a color that requires a low amount of heat energy EA has been completed.
[0025]
If it is determined in ST14 that print output is not performed with a color that requires a high amount of heat energy EB, the process returns to ST12. By repeating such processing, all print data “AB” as shown in FIG. 6A is printed on one heat sensitive part 22b with a low thermal energy amount EA. As a result, as shown in FIG. 5C, red is developed for all the print data “AB”.
[0026]
If it is determined in ST14 that print output is performed in a color that requires a high amount of heat energy EB, the paper feed motor 7 is driven in the reverse direction by the amount corresponding to the thermal part 22b printed in ST15 to make the thermal paper 22. Is transported in the return direction. As a result, the thermal paper 22 changes from the state shown in FIG. 5C to the state shown in FIG.
[0027]
Next, in ST16, the paper feed motor 7 is again driven in the forward direction, and the thermal paper 22 is conveyed toward the thermal line head 9 in a forward direction to a predetermined print standby position. Subsequently, in ST17, the paper feed motor 7 is driven in the forward direction to transport the thermal paper 22 toward the thermal line head 9 by one line in the advance direction, and in ST18, energization control is performed for the heating element that performs print output. As a result, print data of a color that requires a high amount of heat energy EB is printed out to one heat sensitive part 22b.
[0028]
The energization control at this time is performed by a process as shown in FIG. 4 for each heating element. That is, based on the print data of a color that requires a high amount of heat energy among the print data that has been developed in the RAM 3 in ST41, it is determined whether or not the print data to be processed is a dot to be printed.
[0029]
If it is determined in ST41 that the print data to be processed is a dot to be printed, a print energizing pulse giving a low thermal energy amount EA is given to the heating element in ST42, and the process is exited.
[0030]
If it is determined in ST41 that the print data to be processed is a dot that will not be printed, the process exits without applying a preheating energization pulse to the heating element as shown in FIG. 7B. Thus, when printing output is performed with a high amount of heat energy EB, preheating is not performed for dots that are not printed.
[0031]
When the print output for one line is completed, the process proceeds to ST19 shown in FIG. That is, in ST19, it is determined whether or not printing is finished. At this time, if it is determined that the printing is not yet finished, the process returns to ST17. Such processing is repeated to print print data “B” that requires a high amount of heat energy EB as shown in FIG. As a result, as shown in FIGS. 5E and 6C, the print data “B” is colored black.
[0032]
If it is determined in ST19 that printing has been completed, if it is determined that printing has been completed, the cutter motor 11 is driven in ST20 to cut the thermal paper 22 at a predetermined position, and printing as shown in FIG. The completed thermal part 22b is separated from the thermal paper 22, and the printing process is terminated.
[0033]
In this embodiment, in the first print output process (ST12 to ST14), the dots that are not printed are always preheated as shown in FIG. Regardless of, all the print data are printed with the thermal energy amount EA. In the second print output process (ST17 to ST19), dots that are not printed out are not preheated as shown in FIG. 7B, and the color that requires a high amount of heat energy is used. Only the print data is repeatedly printed with the thermal energy EA.
[0034]
As a result, a dot that has been printed once is colored red, and a dot that has been printed twice is colored black.
In addition, since the total amount of heat energy given to the dots that are not printed out is only the amount of heat energy given by preheating in the first print output process, the dots are colored with a low amount of heat energy EA. Color development (red) can be prevented. In this embodiment, the case where the preheating control is performed in the first print output process and the preheat control is not performed in the second print output process has been described. However, the present invention is not necessarily limited thereto. The preheating control may be performed in the second print output process without performing the preheat control in the first print output process.
[0035]
In the above embodiment, the case where two-color thermal paper is used as the thermal paper has been described. However, the present invention is not necessarily limited to this, and thermal paper composed of three or more color layers may be used. Good. In this case, when the coloring layer that develops color with the lowest amount of heat energy is developed, the print output process with the lowest amount of heat energy is performed once while preheating control is performed, and the coloring is performed with a higher amount of heat energy than that of the coloring layer. When the coloring layer to be colored is to be colored, the print output processing with the heat energy amount lower than the high heat energy amount is repeated a plurality of times, and preheating control is performed in the first print output processing, and the second and subsequent times. In this print output process, preheating control should not be performed. Thereby, the same effect as this embodiment can be produced.
[0036]
Further, in this case, preheating control is performed once out of a plurality of print output processes (this one print output process is not limited to the first print output process, and may be any number of print output processes). ), And other print output processing may not be performed preheating control.
[0037]
Next, a second embodiment of the present invention will be described with reference to FIGS. The block diagram in the present embodiment is the same as that shown in FIG.
[0038]
This embodiment is different from the first embodiment in that dots that are not printed in the second print output are preheated in the second print output instead of preheating. This is that the amount of heat energy given to the thermal paper 22 by the first preheating is made lower than the amount of thermal energy given to the thermal paper 22 by the first print output.
[0039]
Specifically, the CPU 1 in the present embodiment performs the printing process shown in FIG. 2, but the process in ST18 is different from that in the first embodiment. In the present embodiment, the process shown in FIG. 8 is performed in ST18. That is, based on the print data of a color that requires a high amount of heat energy developed in dots in the RAM 3 in ST51, it is determined whether or not the print data to be processed is a dot to be printed.
[0040]
If it is determined in ST51 that the print data to be processed is a dot to be printed, a print energizing pulse giving a low thermal energy amount EA is given to the heating element in ST52, and the process is exited.
[0041]
If it is determined in ST51 that the print data to be processed is a dot not to be printed, the pulse width t1 of the preheating energization pulse given in the first print output process in ST53 (FIG. 9A). The preheating is performed by applying a preheating energization pulse having a narrower pulse width t2 (shown in FIG. 9B) to the heating element, and the process is exited.
[0042]
Note that the pulse width of the preheating energization pulse given in ST53 is such that the total amount of heat energy given to the thermal paper 22 in the first and second print output processes does not develop a color that requires a low amount of heat energy. Set it.
[0043]
In the present embodiment having such a configuration, in the first print output process (ST12 to ST14), as shown in FIG. The pre-heating is performed with a pulse width of the energization pulse), and all the print data is printed with the thermal energy amount EA regardless of the color to be developed. Further, in the second print output process (ST17 to ST19), pre-heating is performed as shown in FIG. 9B with a current supply amount smaller (smaller) than the normal current supply amount for the dots for which print output is not performed. Only print data for a color that requires a high amount of heat energy EB is repeatedly printed with the amount of heat energy EA.
[0044]
As a result, a dot that has been printed once is colored red, and a dot that has been printed twice is colored black.
Further, the total amount of heat energy given to the dots that do not perform print output requires a heat energy amount EA that is low in the total amount of heat energy given to the thermal paper 22 in the first and second print output processes. The color is not developed. As a result, it is possible to prevent dots that are not printed out from being colored with a color (red) that develops with a low amount of heat energy EA.
[0045]
Further, in this embodiment, since the pre-heating is performed even a little in the second print output process, the thermal energy given to the thermal paper is compared with the first embodiment in which the pre-heat is not performed in the second print output process. The amount can be reached more quickly to the proper amount of thermal energy.
[0046]
In this embodiment, the preheating energization pulse given in ST53 in FIG. 8 has the same phase as the preheating energization pulse given in ST33 in FIG. In the case of applying a pulse, the preheating energization pulse given in ST53 is further phased within the range of dots in which print output is not performed with respect to the preheating energization pulse given in ST33 of FIG. 3 in the first print output processing. The preheating energization pulse with the energization timing shifted may be applied by deviating.
Thereby, the total amount of thermal energy given to the thermal paper 22 can be made uniform within the range of dots where print output is not performed. That is, since the peak of the amount of heat energy given within the dot range can be reduced, the effect is greater.
[0047]
In the present embodiment, preheating control is performed with a normal energizing amount in the first print output process, and preheating control is performed with an energizing amount smaller than the normal energizing amount in the second print output process. However, the present invention is not necessarily limited to this, and preheating control is performed with an energization amount smaller than the normal energization amount in the first print output process, and preheating is performed with the normal energization amount in the second print output process. Control may be performed.
[0048]
In this embodiment, the case where two-color thermal paper is used as the thermal paper has been described. However, the present invention is not necessarily limited to this, and thermal paper composed of three or more color layers may be used. Good.
[0049]
In this case, when the coloring layer that develops color with the lowest amount of heat energy is developed, the print output process with the lowest amount of heat energy is performed once while preheating control is performed, and the coloring is performed with a higher amount of heat energy than that of the coloring layer. When the coloring layer to be colored is to be colored, the print output processing with the heat energy amount lower than the high heat energy amount is repeated a plurality of times, and preheating control is performed in the first print output processing, and the second and subsequent times. In the print output process, the preheating control is performed with the energization amount applied to the heating element of the thermal line head 9 by preheating being smaller than the energization amount (normal energization amount) in the first print output process. Good.
[0050]
However, each energization amount given to the heating element of the thermal line head 9 by preheating in the second and subsequent print output processes is the total amount of thermal energy given to the dots that are not printed in the print output process of all times. It is set so as not to develop a color that requires the lowest amount of heat energy. Thereby, the same effect as this embodiment can be produced.
[0051]
Further, when using thermal paper composed of three or more color layers, preheating control is performed at a normal energizing amount once in a plurality of print output processes (this one print output process is the first print output process). The number of print output processes is not limited to the output process, and other print output processes may be performed with preheating control with an energization amount smaller than the normal energization amount. In this case, the phase of the preheating energization pulse in each print output process may be shifted.
[0052]
In the first and second embodiments, the case where the thermal paper is transported line by line and printed is described. However, the present invention is not limited to this and is not limited to this. However, the present invention may be applied to a case where print output is performed while being conveyed.
[0053]
【The invention's effect】
As described above in detail, according to the present invention, when preheating control is performed with a printer that develops a color that requires a high energy amount by dividing the number of times of printing into a plurality of times and printing with a low amount of heat energy. It is possible to provide a thermal printer capable of preventing the color development of dots that do not generate print output.
[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 print processing performed by a CPU in the embodiment.
FIG. 3 is a flowchart showing “print output processing for all print dot data unrelated to color” shown in FIG. 2;
4 is a flowchart showing “print output processing for print dot data of a color requiring a high amount of heat energy” shown in FIG. 2;
FIG. 5 is a diagram illustrating an operation in the embodiment.
6A and 6B are diagrams for explaining the operation of the embodiment, in which FIG. 6A is print data output in the first print process, FIG. 6B is print data output in the second print process, and FIG. This is the final printing result.
7A and 7B are diagrams for explaining the relationship between print data and energization pulses in the embodiment, in which FIG. 7A shows the first print output process, and FIG. 7B shows the second print output. The case where a process is performed is shown.
FIG. 8 is a flowchart showing a “print output process for print dot data of a color that requires a high amount of heat energy” in the second embodiment of the present invention.
FIG. 9 is a diagram for explaining the relationship between print data and energization pulses in the same embodiment. FIG. 9A shows the first print output process, and FIG. 9B shows the second print output. The case where a process is performed is shown.
FIG. 10 is a diagram illustrating a configuration of thermal paper.
11 is a graph showing characteristics of the thermal paper shown in FIG.
FIG. 12 is a diagram for explaining the relationship among print data, energization pulse, and thermal energy when print output is performed without applying a preheating energization pulse in a conventional thermal printer.
FIG. 13 is a diagram for explaining the relationship among print data, energization pulse, and heat energy when a preheat energization pulse is applied and print output is performed in a conventional thermal printer.
[Explanation of symbols]
1 ... CPU
9 ... Thermal line head 22 ... Thermal paper 22a ... Mount 22b ... Thermal part

Claims (1)

A print output is performed by giving a thermal energy amount to a multi-color thermal paper composed of a plurality of color-developing layers having different colors depending on the amount of heat energy to be applied by energizing a thermal head according to print dot data, In a thermal printer that performs preheating control for energizing the thermal head to such an extent that each color of the multicolor thermal paper does not develop color even for dots that are not printed out of the print dot data,
When the coloring layer that develops color with the lowest amount of heat energy is colored, the print output process with the lowest amount of heat energy is performed once while performing the preheating control with a normal energizing amount,
When coloring a coloring layer that develops color with a higher amount of heat energy than the coloring layer that develops with the lowest amount of heat energy, print output processing with a heat energy amount lower than the higher heat energy is performed multiple times. The preheating control is performed with a normal energizing amount once in the plurality of printing processes, and the preheating energizing pulse and the printing dots for performing the preheating control with the energizing amount smaller than the normal energizing amount for the other printing processes. A thermal printer that performs preheating control in which the preheating energization pulse is applied by shifting the phase in a range of dots in which data is not printed out .

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