JPS6341161A - Thermal printer - Google Patents

Abstract

PURPOSE:To extensively uniformize the quantity of ink to be transferred even when only a part is high in heat generating frequency and to prevent the generation of density variation or blur in printing, in a line thermal printing head part transferring heat-meltable ink to printing paper, by mounting a plurality of temp. detectors measuring the heat accumulated over the entire region of the long heat generating resistor row of said printing head part. CONSTITUTION:When it is assumed that a certain predetermined printing request is received, required operational processing is applied to each measured value detected by each of the temp. detector 3 mounted to a line thermal printing head part 7 in an operation part 6 through an A/D converter 4 and a heat generating time at each part of a row composed of split heat generating resistors 1 is determined so that the quantity of heat applied to an ink ribbon becomes uniform at every printing line. A required current is supplied to each part according the heat generating time thus determined to perform the printing of a certain predetermined one line. Further, since the accumulation quantity of heat around each heat generating resistor at every line is measured, ink density becomes uniform in a whole printing line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal printer device, and particularly to a thermal printer device in which a plurality of temperature detectors are attached to a line-type thermal print head.

[Conventional technology]

FIG. S is a schematic diagram of a line type thermal print head section in a conventional thermal printer device, and FIG. 6 is an explanatory diagram showing a method of temperature detection in the line type thermal print head section. In the figure, (C is a heating resistor, C is) V
! The heat dissipation member (J) is a temperature detector, and these constitute the line type thermal print head section (71). The A/D converter (7) converts analog signals into digital signals in order to capture the VC, and is connected to the line-type square print head.If the 1% thermal printer device receives the print request signal, , the temperature sensor (JI VC attached to the line type thermal print head section) measures the surroundings of the heating resistor (C).
/D converter (tII Vc), it is converted into a computable digital signal and sent to the computation section (5).
At the measured temperature (therefore, the time required to generate heat from the heating resistor (c) is determined, a certain predetermined heating command signal is sent to the line type thermal print head (71). The heating resistor C generates heat from the command signal, the above-mentioned print request signal, and K, melts the ink on the ink ribbon, and transfers it to the printing paper, thereby performing the desired printing.

[Problem that the invention seeks to solve]

In conventional thermal printer devices, only seven temperature detectors are attached to the line-type thermal print head, so, for example, only one part of a long row of heating resistors generates heat with high frequency. Even if the amount of heat accumulated around a specific heating resistor is uneven, the amount of ink to be transferred is not as high as the amount of heat generated because a uniform heating command is output to all of the heating resistor rows. There was a problem that the printing was not uniform throughout the resistor array, resulting in shading or blurring of the printing.

This invention was made to solve the above-mentioned problems, and even if only a certain part of the heating resistor array generates heat frequently, the amount of ink to be transferred can be made uniform over the entire surface. To provide a thermal printer device capable of printing without causing shading or blurring in printing.

Means for Solving Problem c] The thermal printer device according to the present invention has a line-shaped print head section which includes a temperature detector that measures the heat distributed and accumulated over the entire area of a long row of heating resistors. By attaching multiple temperature detectors and measuring the temperature of the corresponding part of the heating resistor array corresponding to the mounting location of these temperature detectors, the temperature distribution in the entire area is detected, and depending on the result, the temperature distribution of the heating resistor array is detected. This makes it possible to partially change the amount of heat generated.

[For production]

In the thermal printer device of the present invention, the amount of heat generated by the corresponding heating resistor is corrected based on the ambient temperature measured by a plurality of temperature detectors arranged around the heating resistor, thereby causing shading or blurring of the print. This prevents partial destruction of the heating resistor due to uneven heating frequency.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to ψ. FIG. 1 is a schematic diagram of a line-type thermal print head section of a thermal printer device according to an embodiment of the present invention, FIG. 1 is a block diagram of a line-type thermal print head section in the above embodiment, and FIG. FIG. q is an exemplary diagram for explaining the measurement operation by the temperature detector in the line type thermal print head section, and FIG. q is a flow chart diagram for explaining the print processing operation of the thermal printer device of the above embodiment. In FIG. 1, it is similar to a conventional thermal printer device.

However, regarding the temperature detector (3), a plurality of them are arranged around the heating resistor (column /1). Each of them is equipped with a temperature detector (Jl) consisting of a thermistor, and a heat generation command input line is provided corresponding to each of them.In Fig. 3, a plurality of temperature detectors (3) are connected to one microcomputer through the Ic A/D converter (4 & I), respectively.
)It is connected to the. The arithmetic unit (bl) is configured to set respective heat generation times in response to these inputs, and to change the heat generation time for each of the 14 divided rows of heating resistors.

Now, suppose that a certain predetermined printing request is received, and for each measurement value detected by the temperature sensor (Jl) installed in the line type thermal print head section (71),
Necessary calculation processing is performed in the calculation unit (61) through the D converter (61), and each of the 14 rows of heating resistors is divided into 1 parts so that the amount of heat applied to the ink ribbon is uniform for each printing line. The heat generation time in each part is determined. In addition, according to the heat generation time determined by K, each part is energized as required to print one predetermined line. This series of processing This makes it possible to make the amount of heat given to the ink ribbon uniform.In other words, even if only a part of the heating resistor (H row) generates heat frequently, the heat generation of the heating resistor (H row) The ink density on a given line becomes uniform.

Furthermore, since the amount of heat stored around the heating resistor is measured for each line of continuous printing, the ink density is uniform throughout the entire printing line.

In the above embodiment, nine temperature detectors each consisting of a thermistor are provided for the line type thermal print head.
Although the case has been described in which heating command inputs are individually prepared for each, the number thereof can be arbitrarily set depending on the length of the heating resistor row. In addition, although an example is shown in which a thermistor is used as a temperature detector, the present invention is not limited to this, and any desired device can be used as long as it can detect temperature, such as a thermocouple. Can be done. Furthermore, although the method of temperature detection processing is shown using seven microcomputers, it is not limited to this, for example, it may be configured with appropriate hardware logic for each temperature detector. You can.

Further, in the above embodiment, a thermal printer device using an ink ribbon was described, but it goes without saying that it can also be applied to other printing devices using thermal paper, such as a facsimile IJ. do not have.

〔Effect of the invention〕

As explained above, (1) the thermal printer device of the present invention is equipped with a plurality of temperature detectors in the line type thermal print head section, and heat generation command inputs are given correspondingly, so that the print density can be adjusted. It is possible to achieve uniformity, improve printing quality, prevent destruction of the heating resistor due to excessive heat generation, and improve the reliability of the printer device.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a line type thermal print head section of a thermal printer device according to an embodiment of the present invention, FIG. 2 is a block diagram of a line type thermal print head section in the above embodiment, and FIG. An illustrative diagram for explaining the temperature measurement operation in the line type thermal print head section, FIG. FIG. 6 is a schematic diagram of a line type thermal print head section in the apparatus, and is an explanatory diagram showing a method of temperature detection in the above-mentioned conventional line type thermal print head section. In the figure, (/l...heating resistor, (21*@heat dissipation member, (,?
)-・Temperature detector, (da)-・A/D converter, (6)・
-Arithmetic section, (ri)...Line type thermal print head section. In each figure, the same reference numerals indicate the same or corresponding parts. The 1st map, 2nd map, the 3rd ward, the 4th map, the 5th map, the 6th map of the city

Claims (3)

[Claims] (1) A line-type thermal print head that transfers heat-soluble ink to printing paper is equipped with a plurality of temperature detectors that measure the heat accumulated over the entire area of a long row of heat-generating resistors. Thermal printer equipment. (2) The line type thermal print head uses heat generation command signals from the number of installed temperature detectors or more.
2. The thermal printer device according to claim 1, further comprising a divided heating resistor and a drive circuit that can generate heat for a predetermined period of time. (3) The thermal printer device according to claim 1, wherein each of the temperature detectors is connected to an arithmetic unit that can set the heat generation command signal for a predetermined time based on the detected temperature value.