JPH04341871A - thermal printer - Google Patents

Abstract

PURPOSE:To apply an optimum voltage to a thermal head to obtain a good printing on various kinds of heat-sensitive paper or transfer paper and ink ribbons even at a low temperature or a high temperature. CONSTITUTION:A thermal printer is provided with a temperature sensor, a ROM storing a constant file in which electric power constants are set correspondingly to the types of paper and the types of ribbons, and a keyboard. The type of paper and the type of a ribbon are specified from the keyboard. An electric power is calculated on the basis of temperature data from the temperature sensor and an electric power constant corresponding to the types of paper and ribbon specified from the keyboard. Based on this electric power, a voltage to be applied to a thermal head is calculated and set.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label printer that prints on various types of paper using a thermal head.

0002

2. Description of the Related Art Generally, when printing on paper using a thermal head, it is known that the optimum voltage to be applied to the thermal head changes depending on the temperature of the thermal head.

Conventionally, in a label printer that prints on a label using a thermal head, for example, in order to control the voltage applied to the thermal head, voltage is applied according to the temperature of the thermal head, as shown in FIGS. 5 and 6. A file containing voltage settings was stored in memory. During printing, the temperature of the thermal head is detected by a temperature sensor. Based on the temperature data obtained, the corresponding voltage data is retrieved from a file stored in memory, and voltage is applied to the thermal head based on the retrieved voltage data. Was. What is shown in FIG. 5 is a file for thermal paper, and what is shown in FIG. 6 is a file for transfer paper printed using an ink ribbon.

[0004] The head resistance rank is determined by the resistance value at both ends of the heating element of the corresponding thermal head, and here, 16 ranks are set. The numerical values in the figure are voltage values [V].

[0005] By the way, in label printers, various types of paper may be used for labels, and such files are set for specific thermal paper or transfer paper. For papers other than paper, each voltage data in the file is corrected by adding or subtracting a certain value depending on the paper. In other words, as shown in FIG. 7(a), for example, assuming that the temperature of the thermal head set in the file - the applied voltage value is represented by the solid line x, the optimum temperature for the thermal paper or transfer paper actually used is - If the applied voltage value is indicated by the dashed line y, then
For the solid line x, a certain value (
Voltage value) was subtracted, and the two-dot broken line w of the temperature-applied voltage value shown in FIG. 7(b) was corrected and used.

[0006]

[Problem to be Solved by the Invention] Conventionally, when voltage data set for a specified thermal paper or transfer paper is used, when paper other than the specified thermal paper or transfer paper is used, thermal There is a problem in that when the temperature of the head is low (less than 20° C.), the voltage applied is too high, and when the temperature of the head is high (higher than 20° C.), the voltage applied is too low. Therefore, when using paper other than the prescribed thermal paper or transfer paper, there is a risk that good printing may not be possible when the temperature of the thermal head is low or high.

[0007] Therefore, the present invention provides a label printer that can apply an optimal voltage to a thermal head for various types of thermal paper, transfer paper, and ink ribbon, and can perform good printing at both low and high temperatures. The purpose is to

[0008]

[Means for solving the problem] The invention corresponding to claim 1 is:
In a thermal printer that prints on transfer paper using thermal paper or an ink ribbon by controlling the voltage applied to the thermal head, there is a temperature detection means for detecting the temperature of the thermal head, the types of thermal paper, various types of transfer paper, and various types of thermal paper. Constant storage means stores constants for determining the optimum power for printing corresponding to at least one of the types of combinations with the ink ribbon, and the constants stored in the constant storage means correspond to each other. The optimum power for printing is calculated based on the specification means for specifying one of the types, the temperature detected by the temperature detection means, and the constant stored in the constant storage means corresponding to the type specified by the specification means. and a voltage calculation means that calculates an optimum voltage value to be applied to the thermal head based on the optimum power calculated by the power calculation means. The voltage is applied to the head.

[0009] The invention corresponding to claim 2 provides that the constant storage means comprises:
For each temperature range in which the usable temperature range of the thermal head is divided into multiple stages, the optimum power for printing is determined in accordance with at least one of the types of thermal paper and the combinations of various transfer papers and various ink ribbons. The power calculation means stores constants for the constant storage means, and the power calculation means corresponds to one type specified from the types to which the constant stored in the constant storage means corresponds, and furthermore, the temperature detected by the temperature detection means corresponds to the constant. The optimum power for printing is calculated based on the constant stored in the constant storage means corresponding to the temperature range and the temperature detected by the temperature detection means.

0010

[Operation] In the present invention having such a structure, the constant storage means stores the optimum power for printing corresponding to at least one of the types of thermal paper or the combinations of various transfer papers and various ink ribbons. Constants are memorized. The designation means designates one type from among the types to which the constants stored in the constant storage means correspond.

The electric power calculating means calculates the optimum electric power for printing based on the constant stored in the constant storage means corresponding to the type specified by the specifying means and the temperature detected by the temperature detecting means. Based on the power calculated by the power calculation means, the voltage calculation means calculates the optimum voltage value to be applied to the thermal head. The optimum applied voltage value calculated by the voltage calculating means is applied to the thermal head.

Further, the constant storage means stores information for each temperature range in which the usable temperature range of the thermal head is divided into a plurality of stages.
Constants for determining the optimum power for printing are stored corresponding to at least one of the types of thermal paper and the combinations of various transfer papers and various ink ribbons. The designation means designates one type from among the types to which the constants stored in the constant storage means correspond.

[0013] Corresponding to the type specified by the specifying means, and furthermore, the temperature detected by the temperature detecting means is matched with the constant stored in the constant storage means corresponding to the corresponding temperature range and the temperature detected by the temperature detecting means. Based on this, the power calculation means calculates the optimum power for printing. Based on the power calculated by the power calculation means, the voltage calculation means calculates the optimum voltage value to be applied to the thermal head. The optimum applied voltage value calculated by the voltage calculating means is applied to the thermal head.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a CPU (central processing unit) constituting the main body of the control section. A ROM (read only memory) 2 in which program data for processing performed by the CPU 1 is stored and a RAM (random access memory) 3 in which various memory areas used when the CPU 1 performs processing are formed. , are connected to the CPU 1 via a system bus 4.

The ROM 2 includes a resistance value file 2a which stores resistance values (R) corresponding to the head ranks shown in FIG. 2, and a constant storage means which stores the optimum power constant for printing shown in FIG. A constant file 2b is stored. In the resistance value file 2a, 16 ranks are set corresponding to the resistance values of the heating elements of the thermal head 7. The constant file 2b also includes code numbers corresponding to the types of thermal paper and the types of combinations of various transfer papers and various ink ribbons. and various constants are set. These various constants are for each printing speed and three temperature ranges (0 to 20
℃, 22~40℃, 42~70℃...Temperature data is output from the temperature sensor 11 in 2℃ units)
The numbers "x" attached to the constants Cxy and Dxy indicate the printing speed, and "
y" indicates the temperature range (0~20℃...1, 22~
40°C...2, 42-70°C...3).

Further, a keyboard input circuit 6 for inputting and controlling an output signal from the keyboard 5 as a specifying means;
A head controller 8 that controls the thermal head 7, a motor controller 10 that controls the stepping motor 9 for conveying paper and ribbon, and an I/O (I/O) that inputs digitalized temperature data signals from a temperature sensor 11 as a temperature detection means. An input/output interface section 12 is also connected to the CPU 1 via the system bus 4. FIG. 4 shows a flowchart of the head voltage setting process performed by the CPU 1. First, whether or not to change the table is determined by key input on the keyboard 5, and if the table is not changed, this head voltage setting process is ended.

If the table is changed, the resistance value (R) is selected based on the rank file 2a shown in FIG.

Next, based on the power constant file 2b shown in FIG. 3, the type specified by the key input value on the keyboard 5 is selected from at least one of the types of thermal paper and the types of combinations of various transfer papers and various ribbons. In addition, two constants (Cxy, Dxy) are selected depending on the temperature range to which the temperature data output from the temperature sensor 11 corresponds. However, since the printing speed has already been set in another process, "x" has been determined here.

[0020] Whether or not the selection of these various constants is correct is determined by key input on the keyboard 5. If it is not correct,
Again, two constants are selected depending on the type specified by the numerical value entered by the keys on the keyboard 5. Also, if the selection of this constant is correct, the selected constant (Cxy, D
xy) and the temperature data (t) from the temperature sensor 11, the power value required for printing is calculated using the following formula. (Power calculation means) W=Cxy−Dxy·t Based on the power value calculated by the above formula, the voltage value applied to the thermal head 7 is calculated by the following formula. (voltage calculation means)

[0021]

[Math 1] The calculated voltage value data is stored in the RAM 3.

In this embodiment having such a configuration, first, the head rank of the resistance value file 2a shown in FIG. The resistance value of the head 7 is selected, and the selected resistance value data is stored in the RAM 3.
is memorized. Next, as the type of thermal paper or the type of combination of various transfer papers and various ink ribbons, No. 1 of the constant file 2b shown in FIG. is input using the keyboard 5, the type of thermal paper or the type of thermal paper input using the keyboard 5 or the type of transfer paper and each ink ribbon in the corresponding temperature range is determined from the constant file 2b based on the temperature data from the temperature sensor. A power constant corresponding to the type of combination is selected, the optimum power for printing is calculated based on the selected power constant, and the calculated power value and R
The voltage value applied to the thermal head 7 is calculated based on the resistance value data of the thermal head 7 stored in AM3. The calculated voltage value data is stored in RAM3,
A voltage is applied to the thermal head 7 based on the voltage value data stored in the RAM 3.

As described above, according to this embodiment, the applied voltage is calculated according to the temperature of the thermal head in accordance with the type of thermal paper and the type of combination of various transfer papers and various ink ribbons. An optimal voltage is applied to the thermal head, and good printing can be performed both at low temperatures and at high temperatures.

Furthermore, since the usable temperature range of the thermal head is divided into three temperature zones and constants corresponding to each are determined, fine adjustments can be made to suit each temperature zone and a more optimal applied voltage can be calculated. be able to.

Furthermore, since the applied voltage is calculated from each constant and data in this way, the storage capacity is smaller than the conventional method of storing applied voltage data in memory corresponding to each temperature of the thermal head. , which saves storage capacity.

[0026]

[Effects of the Invention] As detailed above, according to the present invention,
It is possible to provide a label printer that can apply an optimal voltage to a thermal head for various types of thermal paper or transfer paper and ink ribbon, and can perform good printing at both low and high temperatures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of a resistance value file in the same embodiment.

FIG. 3 is a diagram showing the configuration of a constant file in the same embodiment.

FIG. 4 is a diagram showing the flow of head voltage setting processing in the same embodiment.

FIG. 5 is a diagram showing the structure of a file for conventional thermal paper.

FIG. 6 is a diagram showing the structure of a file for conventional transfer paper.

FIG. 7 is a diagram showing the characteristics of applied voltage and temperature of a thermal head in a conventional example.

[Explanation of symbols]

1...CPU, 2...ROM, 2b...constant file, 3...R
AM, 5...Keyboard, 11...Temperature sensor.

Claims (2)

[Claims] 1. A thermal printer that prints on transfer paper using thermal paper or an ink ribbon by controlling a voltage applied to a thermal head, comprising: temperature detection means for detecting the temperature of the thermal head; and a type of thermal paper. and constant storage means storing constants for determining the optimum electric power for printing corresponding to at least one of the types of combinations of various transfer papers and various ink ribbons; a designation means for designating one type from among the types to which the constant corresponds; and a constant stored in the constant storage means corresponding to the temperature detected by the temperature detection means and the type designated by the designation means. and a voltage calculation means that calculates the optimum voltage value to be applied to the thermal head based on the optimum power calculated by the power calculation means. A thermal printer characterized in that an optimum applied voltage value calculated by means is applied to the thermal head. 2. The constant storage means stores information for at least one of the types of thermal paper and the types of combinations of various transfer papers and various ink ribbons for each temperature zone in which the usable temperature range of the thermal head is divided into multiple stages. Correspondingly, a constant for determining the optimum power for printing is stored, and the power calculating means corresponds to one type specified by the specifying means from among the types to which the constant stored in the constant storage means corresponds, Further, the optimum power for printing is calculated based on a constant stored in the constant storage means corresponding to the temperature range to which the temperature detected by the temperature detection means and the temperature detected by the temperature detection means. The thermal printer according to claim 1.