JP4303327B2 - Thermal head device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal head device provided with means for inspecting the state of a heating element of a thermal head and informing the possibility of disconnection.
[0002]
[Prior art]
None of the conventional thermal head devices have a function of notifying the disconnection, and each dot of the thermal head device is inspected one by one to detect the presence or absence of the disconnection (Japanese Patent Publication No. 6-104367). No. publication).
[0003]
[Problems to be solved by the invention]
For this reason, in a thermal head device that prints a label to be affixed to a packed product of a predetermined amount at a fixed time, maintenance is required to immediately replace the thermal head if the heating element used for printing is disconnected. Necessary. However, since this work must be done by a specialized worker, it becomes a very difficult problem for the department in charge of maintenance depending on the place and time.
[0004]
The present invention has been made for the purpose of solving the above-described problems, and detects a change in the resistance value of each heating element of the thermal head printing device, monitors the change state, and generates heat that may cause disconnection. An object of the present invention is to obtain a device capable of detecting in advance a disconnection of a thermal head that can issue a warning when a body is detected.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a thermal head printer according to one configuration of the present invention includes a plurality of heating elements, storage means for storing an initial resistance value of each heating element, and a resistance value of each heating element. A resistance value detecting means for performing the notification, a notifying means for issuing a warning with different contents depending on the location of the heating element, and a notifying control means for operating the notifying means when the detected change amount of the resistance value exceeds a predetermined level; The information control means comprises a comparison means for comparing the resistance value obtained by the resistance value detection means for each heating element with the initial resistance value read from the storage means. , or the heating element is in the bar code printing area, by classifying or in other areas, whether a change rate obtained by the comparison exceeds a predetermined level, determine on the basis of the area A judging means for, which was equipped with,
The notification means includes a display device, and the display device includes a case in which a risk of disconnection occurs in the barcode printing portion area and a case in other areas due to the determination by the determination means. The warning contents are displayed differently.
According to the above configuration, when the amount of change from the initial value of the detected resistance value of the heating element exceeds a predetermined level, a warning with a different content is issued depending on the location of the heating element. Therefore, it is understood that there is a possibility of disconnection, and it can be appropriately dealt with.
[0006]
A thermal head printer according to another configuration of the present invention includes a plurality of heating elements, storage means for storing initial resistance values of the heating elements, and resistance value detection for detecting the resistance values of the heating elements. Means, an energization time integration means for integrating the energization time of each heating element from the start of use of the thermal head, an informing means for issuing a warning with different contents depending on the location of the heating element, and an integrated energization of each heating element And a notification control means for operating the notification means when a change rate of the detected resistance value with respect to time exceeds a predetermined level, the notification control means for the heating elements comparing means for comparing said initial resistance value in which the resistance value obtained by the resistance value detection means and read from the storage means, or the heating element is in the bar code printing area, the other region By classifying whether there, and a cumulative energization time read from said energizing time integrating means and the resulting rate of change by the comparison, the rate of change in resistance whether exceeds a predetermined level, determined on the basis of the area Determination means, and the notification means includes a display, and the display includes a case where an abnormality has occurred in the bar code printing portion region due to the determination by the determination means, and The warning content is displayed differently when it occurs in other areas.
According to the above configuration, when the change rate (for example, the increase rate) of the detected resistance value of the heating element from the initial value exceeds the change rate corresponding to the travel distance of the printing medium, it varies depending on the location of the heating element. A content warning is issued. For this reason, disconnection of the heating element can be prevented in advance by eliminating the cause of problems such as overheating of the heating element, particularly in the barcode printing area.
[0007]
Further, the notification control means, than is configured to alert of different content depending on the location of the heating element, a warning is output in accordance with the importance of the position of the heat generating element abnormality is detected Therefore, it is possible to select a response means according to the size of the problem when a disconnection occurs.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the thermal head device according to this embodiment. In the figure, reference numeral 1 denotes a thermal head driving reference power source constituted by a constant voltage power source, which outputs a thermal head driving reference voltage VH. A power source 10 for detecting the resistance value of the heating element 6 applies a constant voltage of the disconnection detection voltage Vi, which is much lower than the reference voltage VH for driving the thermal head, to the non-inverting input terminal (+) of the operational amplifier 11. A fixed resistor RO is connected between the output terminal of the operational amplifier 11 and the inverting input terminal (-), and this inverting input terminal is connected to the a terminal of the switch 12.
[0009]
An output voltage VH of the thermal head driving reference power supply 1 is applied to the b terminal of the switch 12, and a first capacitor C1 is connected between the b terminal and the grounding point. The c terminal of the switch 12 is connected in parallel with n series of heating elements 6-1 to 6-n of the thermal head 5 and switching transistors Q-1 to Qn, and further, a second capacitor C2 is provided. Connected in parallel. An operation mode setting means 13 switches the operation mode of the thermal head 5 to “initial value writing mode”, “test mode”, and “printing mode”. The switch 12 is switched in response to a command signal from the operation mode setting means 13.
[0010]
The output voltage signal VO of the operational amplifier 11 is input to the A / D converter 14 and converted into digital data. The digital data output from the A / D converter 14 is input to the resistance value detection means 15 that detects the resistance value of the heating element 6. The output of the resistance value detection means 15, that is, the detected resistance value of the heating element 6 is sent to an initial resistance value memory (hereinafter referred to as “memory”) 17 by a switch 16 that operates in response to a command signal from the operation mode setting means 13. The information is switched to the notification control means 18 and output. The notification control means 18 has a comparator 19 and a determiner 20.
[0011]
In the initial value writing mode and the test mode, the comparator 19 is connected to the heating element 6-i in which the switching transistor Q is turned on based on the address indicating the heating element number input from the energization control means 9. The initial resistance value r0 is read from the memory 17, compared with the resistance value ri input from the switch 16, and the comparison result is output to the notification means 21. The notification means 21 includes a display 22 such as a CRT that displays a determination result of the determination device 20 and a warning, and a warning sound generator 23 that generates a warning sound such as a buzzer based on the determination result of the determination device 20. is doing.
[0012]
The energization control means 9 has a set value from the energization time setting means 24 that sets the energization time so that the print density becomes uniform in correspondence with the resistance values of the heating elements 6-1 to 6-n in the print mode. Is connected, and the energization time integrating means 25 for integrating the energization time of each heating element 6 energized by the energization control means 9 from the start of use of the thermal head 5 (for example, when it is replaced with a new one) is connected. Yes.
[0013]
Next, the operation of the initial value reading mode executed when the thermal head 5 is incorporated into the printer apparatus will be described.
The operational amplifier 11 operates so that the voltage at its inverting input terminal (-) matches the voltage Vi at the non-inverting input terminal (+). The operation mode setting means 13 to which the initial resistance value write mode command signal is input by an external operation switches the switch 12 to the a terminal side, and sets the terminal voltage Vi of the inverting input terminal (−) of the operational amplifier 11 to the thermal head. 5 and the switch 16 is switched to the d terminal side. Upon receiving the initial resistance value write mode command from the operation mode setting unit 13, the energization control unit 9 turns on the switching transistor Q-1 to energize the heating element 6-1 with the current i1.
[0014]
At this time, if the resistance value of the heating element 6-1 is r10, the energization current i1 of the heating element 6-1 is
i1 = Vi / r10 (1)
Accordingly, the output voltage V01 of the operational amplifier 11 is
V01 = i1 · R0 + Vi (2)
Therefore, the output terminal voltage V0 = Vi when the current i1 does not flow is increased by i1.R0. The A / D converter 14 converts the output voltage V01 into digital data and outputs it to the resistance value detecting means 15.
[0015]
The resistance value detecting means 15 calculates the initial resistance value r10 of the heating element 6-1 from the inputted V01 data based on the following equation (3) and writes it in the memory 17.
r10 = (V01−Vi) / i1 (3)
Thereafter, the energization control means 9 sequentially turns on the switching transistors Q2 to Qn, writes the initial resistance values r20 to rn0 of the heating elements 6-1 to 6-n in the memory 17, and ends the initial resistance value writing mode. .
[0016]
Next, the operation in the print mode will be described.
The operation mode setting means 13 to which the print mode command signal is inputted by an external operation switches the switch 12 to the b terminal side, and uses the thermal head driving voltage VH outputted from the thermal head driving reference power supply 1 as the thermal head. 5 and the energization control means 9 is set to the print mode.
[0017]
The energization time setting means 24 reads the resistance values r10 to rn0 of the heating elements 6-1 to 6-n written in the memory 17, and the optimum energization time in which the temperature of each heating element 6 at the time of energization becomes the optimum print density. t1 to tn (pulse width) are set and supplied to the energization control means 9. The energization control means 9 performs ON / OFF control of each switching transistor Q of the thermal head 5 based on the inputted print data, and energizes each heating element 6 of the thermal head 5 with the thermal head driving voltage VH. Print on paper at optimal density.
[0018]
Next, an explanation will be given of the operation in the test mode that is executed at an appropriate time such as when the power switch is turned on for printing with the printer or when the “test mode” is instructed.
The operation mode setting means 13 to which the test mode command signal is inputted switches the switch 12 to the a terminal side, applies the voltage Vi of the inverting input terminal of the operational amplifier 11 to the thermal head 5, and switches the switch 16 to the e terminal side. At the same time, the energization control means 9 is set to the test mode.
[0019]
The energization control means 9 sequentially energizes the heating elements 6-1 to 6-n by sequentially turning on the switching transistors Q-1 to Q-n as in the initial resistance value writing mode.
[0020]
The comparator 19 first reads the heating element read from the memory 17 based on the resistance value r1 of the heating element 6-1 inputted from the resistance value detecting means 15 via the switch 16 and the address inputted from the energization control means 9. The initial resistance value r10 of 6-1 is compared, and the rate of change in resistance value (r1 -r10) / r10
Is calculated and output to the determiner 20. That is, the amount of change in the resistance value r1 of the heating element 6-1 is taken as the rate of change. The determination unit 20 will be described later based on the change rate of the input resistance value and the number of the heating element 6-1 input from the address input from the energization control means 9, that is, the position on the thermal head 5. The determination is made according to the determination criteria, and the determination result is output to the notification means 21. This operation is sequentially executed for the heating elements 6-1 to 6-n. Of course, the change amount (r1-r10) may be calculated by the comparator 19, and the determination unit 20 may determine based on the change amount (r1-r10).
[0021]
Next, determination criteria set in advance in the determiner 20 will be described.
As determination criteria, the positions of the heating elements 6-1 to 6-n on the thermal head 5 are classified as follows, for example.
(1) A first area that cannot be used if one is broken, such as a bar code printing part. (2) A second area that is practically unhindered even if one is broken, such as a price printing part (3). Third area within label width but not used for printing (4) Fourth area outside label width
Further, the rate of change of the resistance value is classified as follows, for example.
(A) When the change rate exceeds + 60% (b) When the change rate changes over time, that is, when the change rate exceeds 1.3 times the average change rate In the case of (a) above The resistance value changes (for example, increases) due to wear of the heating element accompanying an increase in travel distance (printing distance), and is considered to be approaching the end of its life.
In the case of (b), if the platen and the thermal head are not uniformly pressed against each other, the thermal head surface is not in close contact with the label, or foreign matter is adhered to the thermal head surface. This is a case where it is considered that deterioration of the heating element is proceeding at an abnormal speed with respect to the integrated energization time due to overheating that occurs when the toner is not in close contact with the label.
[0023]
FIG. 2 is a diagram showing the determination contents in the determiner 20, and the determiner 20 displays when a heating element having a rate of change (a) is detected in the region (1), as shown in FIG. The number of the heating element that may cause disconnection in the region (1) is displayed on the device 22 and its position is indicated by blinking on the graphic of the thermal head. “Necessary” is displayed, and the warning sound generator 23 generates a warning sound.
[0024]
When a heating element having a rate of change (a) is detected in the area (2), the display 22 indicates the number of the heating element that may cause a break in the area (2), and the position thereof Is flashed on the figure of the thermal head, and a warning indicating that level 2 “replacement of the thermal head is necessary” is displayed. The warning sound generator 23 does not generate a warning sound.
[0025]
When the heating element having the rate of change (a) is detected in the areas (3) and (4), the display 22 indicates the number of the heating element that may cause a disconnection in the areas (3) and (4). And the position is displayed by blinking on the figure of the thermal head. The warning sound generator 23 does not generate a warning sound.
[0026]
Next, when a heating element having a rate of change (b) is detected in the area (1), the display 22 indicates the number of the heating element having an abnormality in the area (1), and the position is indicated as thermal. A warning is displayed on the figure of the head by blinking, and a warning that “immediate inspection is required” is displayed to cause the warning sound generator 23 to generate a warning sound.
[0027]
When the heating element having the rate of change (b) is detected in the area (2), the display 22 indicates the number of the heating element having an abnormality in the area (2), and the position is indicated by the thermal head. Is displayed by blinking, a warning that “inspection is required” is displayed, and a warning sound is generated by the warning sound generator 23.
[0028]
When the heating element having the rate of change (b) is detected in the areas (3) and (4), the display 22 shows the number of the heating element having an abnormality in the areas (3) and (4), and The position is displayed by blinking on the figure of the thermal head. The warning sound generator 23 does not generate a warning sound.
[0029]
When the administrator of the printer apparatus receives the warning (a) for the area (1), in the case of (a), it is possible to take measures such as switching to a printer apparatus having no other abnormality. Troubles caused by disconnection can be prevented in advance.
[0030]
Further, in the case of (a) with respect to the area (2), since it is possible to determine whether or not the printer device can be used from the position of the heating element that may cause the disconnection, even if the disconnection occurs during use, Because there is no big trouble, the thermal head can be replaced at an appropriate time.
[0031]
Furthermore, in the case of (a) in the region (3) or (4), even if a disconnection occurs during use, there is no problem, so that the use can be continued and the thermal head can be replaced at an appropriate time.
[0032]
Furthermore, in the case of (b) with respect to the area (1) or (2), there is a risk of label displacement, contact between the platen and the thermal head, etc., so the administrator should check and correct these factors. Therefore, it is possible to prevent the breakage of the resistor due to overheating or the like.
[0033]
Since the voltage V0 applied to the heating element 6 in the test mode is about 1/20 of the drive voltage VH applied in the print mode, the region (1) or (2) can be used even in the case of (b). There is no possibility that the heating element is disconnected due to overheating, and overheating that occurs in the printing mode can be prevented in advance.
[0034]
【The invention's effect】
As described above, according to the present invention, the initial resistance value of each heating element of the thermal head having a plurality of heating elements is stored in the memory, and the resistance value of each heating element is set at an appropriate time such as the start of use. Is detected and compared with each initial resistance value, and when the amount of change exceeds a predetermined level, a warning is given to warn of the possibility of disconnection. Can be prevented.
[0035]
In addition, when a heating element having a large resistance change rate with respect to the cumulative energization time of each heating element is detected, the fact is notified so that overheating occurs during use and the heating element is disconnected. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a thermal head device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a determination operation in the same embodiment.
FIG. 3 is a diagram showing a screen of a display device in the same embodiment.
[Explanation of symbols]
1 ... Reference power source for driving thermal head, 5 ... Thermal head, 6 ... Heating element,
DESCRIPTION OF SYMBOLS 9 ... Current supply control means, 10 ... Disconnection detection power supply, 11 ... Operational amplifier, 12, 16 ... Switch, 13 ... Operation mode setting means, 14 ... A / D converter, 15 ... Resistance value detection means, 17 ... Initial resistance Value memory, 18 ... notification control means, 19 ... comparator, 20 ... determining device, 21 ... notification means, 22 ... display, 23 ... warning sound generator, 24 ... energization time setting means, 25 ... energization time integration means, Q: Switching transistor.

Claims (2)

A plurality of heating elements;
Storage means for storing the initial resistance value of each heating element;
Resistance value detecting means for detecting the resistance value of each heating element;
Informing means for issuing a warning with different contents depending on the location of the heating element;
A thermal head printing apparatus comprising: a notification control unit that activates the notification unit when a detected change amount of the resistance value exceeds a predetermined level;
The notification control means compares the resistance value obtained by the resistance value detection means for each heating element with the initial resistance value read from the storage means,
Judgment whether the heating element is in the barcode printing area or the other area, and determining whether the rate of change obtained by the comparison exceeds a predetermined level based on the area Means, and
The notification means is provided with a display unit, the indicator, by the determination by the determination means, and if the risk of breakage occurs in the bar code printing area, and when occurring in other regions A thermal head printer that displays different warnings. A plurality of heating elements;
Storage means for storing the initial resistance value of each heating element;
Resistance value detecting means for detecting the resistance value of each heating element;
Energization time integration means for integrating the energization time of each heating element from the start of use of the thermal head;
Informing means for issuing a warning with different contents depending on the location of the heating element;
A thermal head printing apparatus comprising: a notification control unit that activates the notification unit when a change rate of the detected resistance value with respect to the cumulative energization time of each heating element exceeds a predetermined level,
The notification control means compares the resistance value obtained by the resistance value detection means for each heating element with the initial resistance value read from the storage means,
A resistance value is determined from the change rate obtained by the comparison and the integrated energization time read from the energization time integration means by classifying whether the heating element is in the barcode printing area or the other area. Determination means for determining whether or not the rate of change of the value exceeds a predetermined level , based on the region ,
The notification means is provided with a display unit, said display unit is a and when the abnormality is determined in the determination means is caused by the bar code printing area, and when occurring in other regions, warning Thermal head printer that displays different contents.

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