JP2004009521A - Method for controlling energization of thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a good image by surely preventing the abrasion of ink transferred onto a recording medium and the collapse of dots by melting and attributing gloss to the whole surface of the ink. <P>SOLUTION: When the ink is transferred onto the recording medium 3, an electric current is applied to each heating element on the basis of a pulse signal of a constant width for an energizing time necessary for recording each gradation dot by a constant energizing period. When the surface of the ink is coated with an overcoat material, the electric current is applied to each heating element on the basis of the pulse signal of the constant width for an energizing time necessary for recording the highest gradation dot by the constant energizing period. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an energization control method for a thermal printer, and more particularly to an energization control method for a thermal printer that coats the surface of ink transferred onto a recording medium with an overcoat material.
[0002]
[Prior art]
Generally, a plurality of heating elements arranged and arranged on a thermal head are selectively heated based on input recording data to transfer ink of an ink ribbon and print desired images such as characters and graphics on a recording medium. 2. Description of the Related Art Thermal printers for performing recording are widely used as output devices for computers and the like because of high printing quality, low noise, low cost, and ease of maintenance.
[0003]
In the thermal printer, the size of one dot is changed by printing one dot smaller when printing with lower gradation than before and by printing one dot larger when printing with higher gradation. There is known a thermal printer that performs multi-tone printing by expressing one pixel. Since such a thermal printer performs printing based on the correct dot size based on the print information, it is necessary to reduce the heat applied to one heating element from reaching other adjacent heating elements. There is.
[0004]
FIG. 3 is a graph showing the relationship between the pulse width, the energizing time and the energizing cycle and the temperature of the heating element in the energizing control method of the conventional thermal printer. As shown in FIG. The heating elements are continuously energized based on a pulse signal of a constant width for an energizing time necessary for recording a predetermined gradation at a constant energizing cycle.
[0005]
In this thermal printer, each heating element can be heated rapidly by energizing the heating elements continuously, so that the heat applied to these heating elements is Of each heating element.
[0006]
Further, in the conventional thermal printer, the ink transferred onto the recording medium is prevented from being distorted by being rubbed on the recording medium, and the glossiness is imparted to the ink. Therefore, a thermal printer that coats the surface of the ink with an overcoat material is known.
[0007]
In this thermal printer, each heating element is first pressed into contact with a recording medium onto which ink has been transferred via an overcoat ribbon. Then, using the same energization control method as when transferring the ink of the ink ribbon, a pulse signal of a constant width is applied to a predetermined heating element for a predetermined energization time necessary for recording the highest gradation with a constant energization cycle. Then, the respective heating elements are caused to generate heat by continuously energizing them. Thus, the overcoat material applied to the surface of the overcoat ribbon is transferred to the surface of the ink.
[0008]
At this time, energization for each heating element only for the energization time necessary to record the highest gradation is performed by covering the entire surface of the ink transferred onto the recording medium with the overcoat material 32 as shown in FIG. Accordingly, the dot shape is surely prevented from being broken by rubbing the ink, and glossiness is given to the entire ink.
[0009]
[Problems to be solved by the invention]
However, according to the energization control method, each heating element is rapidly heated. Therefore, when the energization time necessary for recording the highest gradation is applied to each heating element as described above, each heating element is heated. The heating of the peripheral parts of the elements causes their central parts to be excessively heated. For this reason, as shown in FIG. 5, the dots of the ink 31 transferred onto the recording medium are melted by the excessive heat applied to the respective heating elements pressed into contact with each other through the overcoat material 32, and as shown in FIG. As described above, there is a possibility that the shape of the dots may be lost, and in such a case, the thermal printer has a problem that it is not possible to obtain good image recording.
[0010]
On the other hand, in order to solve the above-mentioned problem, it is conceivable to continuously energize each heating element based on a pulse signal having a constant width for an energizing time that does not excessively heat the central portion thereof. However, in such a case, since the peripheral portion of each heating element is not sufficiently heated, a gap is formed between adjacent overcoat materials 32 as shown in FIG. The gloss of the applied ink is reduced. Further, since the entire surface of the ink 31 may not be covered with the overcoat material 32, a portion of the ink 31 that is not covered with the overcoat material 32 is rubbed, and as a result, the shape of the dot is broken.
[0011]
The present invention has been made in view of these points, and reliably prevents the deformation of the dot shape due to the rubbing and melting of the ink transferred onto the recording medium, and imparts gloss to the entire surface of the ink. Accordingly, it is an object of the present invention to provide a method for controlling the energization of a thermal printer capable of obtaining a good image.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a method for controlling the energization of a thermal printer according to the present invention energizes a plurality of heating elements arranged in a line on a thermal head to transfer ink of an ink ribbon onto a recording medium, and A method for controlling the energization of a thermal printer in which an overcoat material of an overcoat ribbon is coated on the surface of the ink, wherein when transferring the ink onto the recording medium, a dot of each gradation is applied to each heating element. When continuous energization is performed based on the energization time required for recording and a pulse signal having a constant width to cover the surface of the ink with the overcoat material, a predetermined energization time and a constant An intermittent energization is performed based on a pulse signal having a width.
[0013]
According to the energization control method according to the present invention, when the overcoat material is coated on the surface of each ink, intermittent energization is performed on each heating element according to a pulse signal having a certain width, so that each heating element is Since the temperature can be gradually increased, it is possible to prevent the central portion of each heating element from being excessively heated. Furthermore, after the temperature of each heating element rises to a certain temperature, the temperature of each heating element can be maintained within a predetermined range, so that the heat applied to the center of each heating element is reduced The heat generation element can be heated to a temperature at which the overcoat material is melted as a whole. On the other hand, when transferring ink onto a recording medium, the temperature of each heating element can be rapidly increased by continuously energizing each heating element according to a pulse signal having a constant width. Similarly, it is possible to reduce the influence of the heat of each heating element on each adjacent heating element, and it is possible to perform recording with an accurate dot size based on the recording information.
[0014]
According to another aspect of the present invention, there is provided a thermal printer energization control method, wherein the predetermined energization time when the overcoat material is coated is an energization time necessary to record a dot of the highest gradation. Features.
[0015]
According to the other energization control method according to the present invention, the heating elements are intermittently energized for the energization time of the highest gradation, so that the energization is performed for a longer time than the energization time of the low gradation. For this reason, the heat applied to the central part of each heating element can be more reliably applied to the peripheral part of each heating element, so that the temperature of the overcoat material is sufficient to melt the entire heating element. Can be heated.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a power supply control method for a thermal printer according to the present invention will be described with reference to FIGS.
[0017]
FIG. 1 is a conceptual diagram showing a thermal printer used in a method for controlling the energization of a thermal printer according to the present embodiment. As shown in FIG. 1, a carriage 2 is provided in the thermal printer 1.
[0018]
A thermal head 4 is attached to the carriage 2 at a position facing the recording medium 3, and the thermal head 4 has a plurality of heat sources selectively generating heat based on the input recording information 6. The elements 5 are arranged so as to face the recording medium 3.
[0019]
In the vicinity of the thermal head 4, a temperature measuring device 7 such as a thermistor for measuring the temperature of each of the heating elements 5 and the environmental temperature is provided.
[0020]
Further, in the thermal printer 1, a plurality of ink ribbon cassettes 9, in this embodiment, cyan (C), magenta (M), and yellow (Y) ink ribbons 10a, 10b, and 10c are housed therein. One ink ribbon cassette 9a, 9b, 9c is provided. Further, the thermal printer is provided with an overcoat ribbon cassette 12 in which an overcoat ribbon 11 in which an overcoat material is applied on the surface of the substrate is housed. The ink ribbon cassettes 9a, 9b, 0c provided in the thermal printer 1 are not limited to the ink ribbon cassettes. For example, a black (K) ink ribbon cassette may be provided. May be provided with only a single ink ribbon cassette.
[0021]
The ink ribbon cassettes 9a, 9b, 9c and the overcoat ribbon cassette 12 are attached to an automatic cassette attaching / detaching mechanism (not shown) formed on the carriage 2 by the ink ribbons 10a, 10b, 10c and the overcoat ribbon 11. The heating elements 5 and the recording medium 3 are alternately mounted so as to be located between the heating elements 5 and the recording medium 3.
[0022]
Further, the carriage 2, the thermal head 4, and the temperature measuring device 7 are connected to a CPU 15 of a control unit 14 for controlling the operation of each unit of the thermal printer 1 provided in the thermal printer 1.
[0023]
Further, the control means 14 is provided with a memory 16 formed by a RAM or the like having an appropriate capacity. The memory 16 has a size of one dot by varying the energizing time for each heating element 5. In order to perform multi-gradation printing by changing the length, an energization time table 19 including different energization times for each gradation is set. Further, the memory 16 stores a correction table 20 and the like constituted by a correction value for correcting the power-on time based on the heat accumulated in the thermal head 4 and the environmental temperature.
[0024]
In the memory 16, a first energizing program 17 for transferring the ink of the ink ribbons 10a, 10b, 10c onto the recording medium 3, and the overcoat material of the overcoat ribbon 11 are transferred onto the recording medium 3. A second energizing program 18 for covering the surface of the ink thus applied is stored.
[0025]
The first energization program 17 is provided for each desired heating element 5 by a pulse signal having a constant width for a predetermined energization time necessary for recording a dot of a desired gradation at a constant energization cycle as in the related art. It is set to be continuously energized.
[0026]
On the other hand, as shown in FIG. 2, the second energization program 18 performs the same energization cycle as that of the first energization program 17 for a predetermined energization time necessary to record a dot of the highest gradation. All the heating elements 5 are set to be intermittently energized by a pulse signal having the same constant width as that of the first energization program 17. As a result, the temperature of each of the heating elements 5 gradually increases to a certain temperature. Further, after reaching a certain temperature, the temperature of each of the heat generating elements 5 is maintained within a predetermined range including the certain temperature until the power supply to each of the heat generating elements 5 is terminated after a lapse of an energizing time. I have.
[0027]
The CPU 15 inputs the recording information 6 from the outside and the information from the temperature measuring device 7 and the like, extracts the energizing information from each energizing table 19 and the correction table 20 of the memory 16 and based on these information. According to the first energizing program 17 or the second energizing program 18, a pulse signal for energizing each heating element 5 to the thermal head 4 is output.
[0028]
Next, an energization control method for the thermal printer 1 according to the present embodiment will be described.
[0029]
First, an energization control method when the ink of the ink ribbons 10a, 10b, and 10c is transferred onto the recording medium 3 will be described.
[0030]
First, when the recording information 6 is input to the thermal printer 1, the CPU 15 takes out the first energizing program 17 from the memory 16 and, from the energizing table 19, the energizing time of the gradation for performing recording based on the recording information 6. Take out. Further, the cyan ink ribbon cassette 9a is attached to the cassette automatic attachment / detachment mechanism of the carriage 2. Next, the CPU 15 fetches a correction value from the correction table 20 based on the environmental temperature and the like measured by the temperature measuring device 7, and based on the power-on time fetched from the power-on table 19 and the correction value, applies the correction value to each heating element 5. Calculate the energization time. Subsequently, in accordance with the first energization program 17, a desired energization time is continuously energized to each desired heating element 5 by a pulse signal of a constant width for the calculated energization time at a constant energization cycle. Increase temperature rapidly. As a result, ink having a desired dot size is melted and transferred onto the recording medium 3. Further, after the lapse of the energization time, the energization of each of the heating elements 5 is terminated, the temperature of each of the heating elements 5 is rapidly lowered, and after a certain energization cycle, each of the heating elements 5 is heated again. Then, after printing for one page is completed using the cyan ink ribbon cassette 9a, printing is sequentially performed using the magenta and yellow ink ribbon cassettes 9b and 9c.
[0031]
Next, an energization control method in the case where the surface of the ink transferred onto the recording medium 3 is coated with the overcoat material of the overcoat ribbon 11 will be described.
[0032]
First, when the recording information 6 is input to the thermal printer 1, the CPU 15 extracts the second energization program 18 from the memory 16 and the energization time of the highest gradation from the energization table 19. Further, the overcoat ribbon cassette 12 is mounted on the cassette automatic attachment / detachment mechanism of the carriage 2. Subsequently, based on the second energization program 18, all the heating elements 5 are intermittently energized by a pulse signal having a constant width for a constant energizing period for the energizing time of the highest gradation by a pulse signal having a constant width. After the temperature of each heating element 5 is gradually increased to a certain temperature, the temperature of each heating element 5 is maintained within a predetermined range including the certain temperature. Then, the overcoat material of the overcoat ribbon 11 is melted by the temperature of each of the thermal elements 5, and the surface of the ink is coated with the overcoat material. Further, after the elapse of the energization time, the energization to each of the heating elements 5 is terminated, and the temperature of each of the heating elements 5 is rapidly decreased. Then, the overcoat material is coated on the entire surface of each of the cyan, magenta, and yellow inks, which are sequentially laminated and constitute one page of recording, using the overcoat ribbon cassette 12.
[0033]
According to the present embodiment, when the overcoat material is coated on the surface of each ink, the temperature of each heating element 5 is gradually increased by intermittently energizing each heating element 5 according to a pulse signal having a constant width. , It is possible to prevent the central portion of each heating element 5 from being excessively heated. Furthermore, after the temperature of each heating element 5 rises to a certain temperature, the temperature of each heating element 5 can be maintained within a predetermined range, so that the heat applied to the center of each heating element 5 is reduced. The heat can be applied to the peripheral portions thereof, so that the entire heating elements 5 can be heated to a temperature at which the overcoat material melts.
[0034]
In addition, since the intermittent current is supplied to each heating element 5 only during the energization time of the highest gradation, the energization is performed for a longer time than the energization time of the low gradation. For this reason, the heat applied to the central portion of each heating element 5 can be more reliably applied to the peripheral portion of each heating element 5, so that the overcoat material completely melts the entire heating element 5. It can be heated to a moderate temperature.
[0035]
Further, when the ink is transferred onto the recording medium 3, the temperature of each heating element 5 can be rapidly increased by continuously energizing each heating element 5 according to a pulse signal having a constant width. As in the conventional case, it is possible to reduce the heat of each heating element 5 from reaching each adjacent heating element 5, and to perform recording with an accurate dot size based on the recording information 6.
[0036]
Therefore, when coating the overcoat material, it is possible to prevent the temperature of each heating element 5 from being excessively heated, so that each heating element 5 that is excessively heated is pressed into contact with the overcoat material via the overcoat material. By doing so, it is possible to prevent the ink from re-melting and the dot shape from being collapsed. In addition, since the entire heating element 5 can be heated to a temperature at which the overcoat material is melted, the entire surface of the recording medium is covered with the overcoat material, so that the shape of the dot due to the abrasion of the ink is reduced. Can be prevented and gloss can be imparted to the entire surface of the ink. As a result, good images can be recorded.
[0037]
Further, by intermittently energizing each heating element 5 for the energization time of the highest gradation, the entire heating element 5 can be reliably heated to a temperature at which the overcoat material is melted. The entire surface of the ink on the recording medium 3 can be reliably coated with the overcoat material. As a result, it is possible to more reliably prevent the dot shape from being distorted due to the rubbing of the ink, and to impart gloss to the entire surface of the ink.
[0038]
Further, since recording can be performed with an accurate dot size based on the recording information, a good image can be recorded.
[0039]
Note that the present invention is not limited to the above embodiment, and can be variously modified as needed.
[0040]
For example, in the present embodiment, the thermal printer 1 that performs recording by moving each heating element 5 of the thermal head 4 by the carriage 2 has been described. However, the present invention is not limited to this, and may be used for a line printer or the like. .
[0041]
In the thermal printer 1 according to the present embodiment, the ink ribbons 10a, 10b, and 10c are stored in separate ink ribbon cassettes 9a, 9b, and 9c. The recording is performed sequentially, but is not limited to this. For example, one ink ribbon to which a plurality of inks and an overcoat material are sequentially applied may be used to sequentially record each ink and then cover the overcoat material.
[0042]
【The invention's effect】
As described above, according to the thermal printer of the present invention, when coating the overcoat material, it is possible to prevent the temperature of each heating element from being excessively heated. It is possible to prevent the ink from being melted again and the shape of the dots from being destroyed by the pressure contact of the heating elements via the overcoat material. In addition, since the entire heating element can be heated to a temperature at which the overcoat material is melted, the entire surface of the recording medium is covered with the overcoat material, so that the shape of the dot due to abrasion of the ink is reduced. Disintegration can be prevented and gloss can be imparted to the entire surface of the ink. As a result, good images can be recorded. In addition, since recording can be performed with an accurate dot size based on recording information, a good image can be recorded.
[0043]
Further, according to another thermal printer according to the present invention, by intermittently energizing each heating element only for the energizing time of the highest gradation, it is possible to ensure that the overcoat material completely melts the entire heating element. Since the ink can be heated to the temperature, the entire surface of the ink on the recording medium can be more reliably covered with the overcoat material. As a result, it is possible to more reliably prevent the dot shape from being distorted due to the rubbing of the ink, and to impart gloss to the entire surface of the ink.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a position embodiment of a thermal printer used in a method for controlling energization of a thermal printer according to the present invention. FIG. 2 shows a method for controlling energization when an overcoat material is coated on a thermal printer according to the present invention. FIG. 3 is a graph showing a relationship between a pulse width, an energizing time, an energizing cycle, and a temperature of a heating element. FIG. 3 shows a relationship between a pulse width, an energizing time, an energizing cycle, and a temperature of a heating element in an energizing control method of a conventional thermal printer. Graph FIG. 4 is a conceptual diagram showing the state of an overcoat material when the surface of the ink is covered. FIG. 5 is a conceptual diagram showing dots transferred onto a recording medium by the ink. FIG. 6 is an overcoat on the surface of the ink. FIG. 7 is a conceptual diagram showing dots when the material is covered. FIG. 7 is a conceptual diagram showing another state of the overcoat material when the surface of the ink is covered. Description]
1 Thermal Printer 2 Carriage 3 Recording Medium 4 Thermal Head 5 Heating Elements 9a, 9b, 9c Ink Ribbon Cassettes 10a, 10b, 10c Ink Ribbon 11 Overcoat Ribbon 12 Overcoat Ribbon Cassette 17 First Current Program 18 Second Current Program 19 Current Table

Claims (2)

A plurality of heating elements arranged in a thermal head are energized to transfer the ink of the ink ribbon onto the recording medium, the heating elements are energized, and the ink transferred on the recording medium is energized. An energization control method for a thermal printer that coats an overcoat material of an overcoat ribbon on a surface,
When transferring the ink, a continuous current is applied to each of the heating elements based on an energizing time and a pulse signal having a constant width necessary for recording dots of each gradation, and the overcoat material is applied to the surface of the ink. A method of controlling the power supply of a thermal printer, wherein intermittent power is supplied to each of the heating elements based on a predetermined power supply time and a pulse signal having a constant width. 2. The method according to claim 1, wherein the predetermined energizing time when the overcoat material is coated is an energizing time necessary for recording a dot of the highest gradation.

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