JP2019171742A - Printer and printer control method - Google Patents

Abstract

To achieve elongation of a service life of a thermal head.SOLUTION: A printer comprises: a thermal head for printing on a printing medium; use degree determination means which determines a use degree of each of a plurality of heat generators which the thermal head has; and heat generator changing means which changes a heat generator for use in printing so that when any one of respective use degrees of the heat generators, which have been determined by the use degree determination means, becomes larger than a threshold which is set in a range of use degrees for enabling normal printing, an electric application frequency to the heat generator whose use degree has become larger than the threshold is decreased.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printer and a printer control method.

  In Patent Document 1, when a defective heating element that cannot be printed properly occurs on the heating element of the thermal head, printing that adjusts the printing position of the barcode on the print medium to a position where the defective heating element does not perform printing. A unit is disclosed.

JP 2013-244706 A

  According to the above technique, it is possible to continue printing even after a defective heating element is generated. However, this is an emergency measure, and it is necessary to replace the thermal head promptly based on the fact that a defective heating element is generated.

  On the other hand, thermal heads are expensive, and there is a demand for extending the life of thermal heads in order to reduce their replacement frequency.

  The present invention has been made in view of such technical problems, and an object thereof is to extend the life of a thermal head.

  According to an aspect of the present invention, a thermal head that performs printing on a print medium, a usage degree determination unit that determines the usage level of each of the plurality of heating elements included in the thermal head, and a plurality of levels determined by the usage level determination unit When any one of the usage levels of the heating elements becomes larger than a threshold value set within the range of the usage levels that can be normally printed, the usage level becomes larger than the threshold value. In addition, a printer is provided that includes heating element changing means for changing the heating element used for printing so that the frequency of electrical application to the heating element is reduced.

  According to said aspect, by reducing the electrical application frequency to a heat generating body with a high degree of use and a large deterioration, subsequent deterioration of the heat generating body is suppressed before it becomes unusable. Therefore, the life of the thermal head can be extended.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. It is a figure for demonstrating the relationship between printing information and the resistance value of a heat generating body. It is the figure which illustrated the relationship between the electrical application frequency of a heat generating body, and resistance value. It is a flowchart for demonstrating an averaging process. It is a figure for demonstrating the shift of a printing position. It is a figure for demonstrating the change of a layout.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a printer 100 according to an embodiment of the present invention. The printer 100 is a thermal coloring type printer that performs printing on a printing medium M that is thermal paper.

  As the print medium M, for example, a roll paper, a roll label in which a plurality of labels are temporarily attached continuously at a predetermined interval on a roll-like base sheet to form a roll, or a belt-like label provided with a release agent on the surface is rolled. A non-mounting label is used.

  The configuration of the printer 100 will be described. The printer 100 includes a printing mechanism 1, a medium supply unit 4, a cutter 5, a controller 7, and a position detection sensor 9.

  The printing mechanism 1 includes a head unit 11, a platen roller 12, and a platen drive motor 14, and is a mechanism that performs printing on the printing medium M and conveyance of the printing medium M.

  The head unit 11 holds the thermal head 16 in a state where the plurality of heating elements H1 to Hn (see FIG. 2) of the thermal head 16 are exposed from the lower surface. The platen roller 12 is disposed immediately below the thermal head 16 and constitutes a printing unit 15 that performs printing on the printing medium M together with the thermal head 16.

  The head unit 11 is supported by a support shaft 13 so as to be swingable in the direction of the arrow in FIG. The head unit 11 includes a head open position where the thermal head 16 indicated by a two-dot chain line in FIG. 1 is separated from the platen roller 12 and a head closed position where the thermal head 16 indicated by a solid line in FIG. Can be moved.

  The platen drive motor 14 drives the platen roller 12 via a belt, a gear or the like.

  The medium supply unit 4 holds the printing medium M supplied to the printing unit 15 in a roll shape. The printing medium M is guided to the printing unit 15 by the guide shaft 41 and is sandwiched between the thermal head 16 and the platen roller 12.

  When the heating medium H1 to Hn of the thermal head 16 is energized while the printing medium M is sandwiched between the thermal head 16 and the platen roller 12, the printing medium M is colored by the heat of the heating elements H1 to Hn. Then, printing on the printing medium M is performed.

  When the platen roller 12 is rotated forward by the platen drive motor 14, the print medium M is conveyed downstream in the conveyance direction, and the print medium M is discharged from the printer 100 through the discharge port 8. A cutter 5 is provided in the vicinity of the discharge port 8 and the continuous print medium M can be cut into a single sheet.

  The position detection sensor 9 is a reflection type photoelectric sensor, and detects a timing mark (not shown) pre-printed on the print medium M at a predetermined pitch, so that when the print is issued continuously, the print unit The relative position of the print medium M with respect to 15 is detected.

  The controller 7 includes a microprocessor, a storage device such as a ROM and a RAM, an input / output interface, and a bus for connecting them. The controller 7 receives print data from an external computer (not shown), a detection signal from the position detection sensor 9 and the like via an input / output interface. The controller 7 executes various programs stored in the storage device by the microprocessor, and controls energization to the heating elements H1 to Hn of the thermal head 16, energization to the platen drive motor 14, and the like. The controller 7 may be constituted by a plurality of microcomputers.

  The printer 100 performs printing by selectively applying heat to the heating elements H1 to Hn according to the printing information 50 (see FIG. 2) to be printed on the printing medium M to generate heat. The resistance value decreases earlier as the heating element has a higher use frequency among ˜Hn. That is, the heat generating element having higher usage frequency among the heat generating elements H1 to Hn is greatly deteriorated. When a defective heating element is generated in the heating elements H1 to Hn and printing cannot be performed normally, the thermal head 16 needs to be replaced.

  On the other hand, thermal heads are expensive, and there is a demand for extending the life of thermal heads in order to reduce their replacement frequency. Therefore, the controller 7 of the present embodiment performs an averaging process that extends the life of the thermal head 16 by averaging the usage frequency of the heating elements H1 to Hn.

  First, the printing operation of the printer 100 and the deterioration of the heating elements H1 to Hn will be described with reference to FIGS. FIG. 2 is a diagram of the thermal head 16 and the print medium M viewed from the print surface side, and shows the relationship between the print information 50 printed on the print medium M and the resistance values of the heating elements H1 to Hn. In FIG. 2, the print information 50 includes a barcode as an identification code, a destination, a product name, a frame line 51, and the like.

  As shown in FIG. 2, a plurality of heating elements H <b> 1 to Hn are arranged along the width direction of the print medium M on the lower surface of the thermal head 16.

  The platen roller 12 rotates forward and the print medium M is conveyed downstream in the conveyance direction, and electrical application is selectively applied to the heating element used for printing the print information 50 among the heating elements H1 to Hn. Thus, the print information 50 is printed on the print medium M.

  Here, in FIG. 2, the resistance value of the heating element Ha is the lowest. This is because the heating element Ha is used for printing the vertical ruled lines 51a in the frame line 51 of the printing information 50, and therefore the printing amount, that is, the number of times of electrical application, is larger than that of the other heating elements. The heating element Hb at the position where the vertical ruled line 51b is printed also has a greatly reduced resistance value, similar to the heating element Ha. As described above, the heating elements H1 to Hn have a lower resistance value as the heating element is more electrically applied.

  FIG. 3 is a diagram illustrating the relationship between the number of electrical applications of the heating element and the resistance value.

  In the example of FIG. 3, the standard resistance value of the heating element is 1000Ω, and the resistance value is reduced to 850Ω when the number of times of electrical application is 1 million times. In this case, the resistance value is reduced by 15% from the standard resistance value, and the rate of decrease in the resistance value of the heating element (hereinafter simply referred to as “decrease rate”) is 15%. The standard resistance value is a new resistance value (initial value) determined by design.

  In the example of FIG. 3, the reduction rate of 15% is the limit value of the reduction rate, that is, the upper limit of the reduction rate that can be normally printed. In other words, in the example of FIG. 3, when the resistance value of the heating element decreases and the rate of decrease exceeds 15%, there is an increased risk that the heating element is disconnected due to overcurrent and printing cannot be performed normally. Means. Note that the limit value of the reduction rate is determined in advance by experiments or the like.

  Next, the averaging process executed by the controller 7 will be described with reference to the flowchart of FIG.

  In step S1, the controller 7 determines the rate of decrease as the degree of use of each of the heating elements H1 to Hn.

  Specifically, the controller 7 applies a constant voltage to the heating elements H1 to Hn. Then, the current values flowing through the heating elements H1 to Hn are detected, and the resistance values of the heating elements H1 to Hn are calculated.

  The storage device of the controller 7 stores standard resistance values that are initial values of the resistance values of the heating elements H1 to Hn. Therefore, the rate of decrease of each of the heating elements H1 to Hn is derived based on the calculated resistance value and standard resistance value. For example, a heating element whose resistance value has decreased by 10% from the standard resistance value is determined to have a reduction rate (degree of use) of 10%. Note that “the rate of decrease is large” means “the degree of use is high”.

  In addition, as shown in FIG. 3, the relationship between the electrical application frequency of the heating element and the resistance value generally exhibits a linear function relationship. The storage device of the controller 7 stores the number of times of electrical application to each of the past heating elements H1 to Hn. Therefore, the determination of the usage of the heating elements H1 to Hn can be performed based on the number of electrical applications to each of the heating elements H1 to Hn. In this case, “a large number of electrical applications” means “high use”.

  In step S2, the controller 7 compares the reduction rates of the heating elements H1 to Hn with a predetermined threshold value, and any of the reduction rates of the heating elements H1 to Hn is greater than the predetermined threshold value. Judge whether or not.

  In the present embodiment, as shown in FIG. 3, the predetermined threshold is set to a reduction rate of 10%. The predetermined threshold value can be set within a range of a reduction rate that allows normal printing, that is, within a limit value range.

  If the controller 7 determines that any one of the reduction rates of the heating elements H1 to Hn has become larger than a predetermined threshold value, the process proceeds to step S3. If it is determined that the decrease rate of each of the heating elements H1 to Hn is equal to or less than a predetermined threshold value, the process proceeds to step S4.

  In step S3, the controller 7 selects a heating element to be used for printing from among the plurality of heating elements H1 to Hn so that the frequency of electrical application to the heating element having a decrease rate greater than a predetermined threshold value decreases. change.

  In the present embodiment, as shown in FIG. 2, the rate of decrease of the heating element Ha is the largest, and the rate of decrease is initially greater than a predetermined threshold value. When the decrease rate of the heating element Ha becomes larger than a predetermined threshold, the controller 7 sets the print position of the print information 50 to be printed on the print medium M as a whole in the width direction of the print medium M as shown in FIG. Shift to.

  In FIG. 5, the print position of the print information 50 on the print medium M is generally shifted by W to the right side (the heating element Hn side) in FIG. As a result, the heating element Ha is not used for printing. That is, the frequency of electrical application to the heating element Ha decreases, and the usage frequency of the heating elements H1 to Hn is averaged. Note that the state in which the frequency of electrical application is reduced includes a state in which electrical application is zero.

  According to this, since the frequency of electrical application to the heat generating element Ha having a large reduction rate is reduced while normal printing is possible, the subsequent deterioration of the heat generating element Ha is suppressed. Therefore, the life of the thermal head 16 can be extended.

  Note that the frequency of electrical application to the heating element Ha can also be reduced by shifting the printing position of the printing information 50 on the printing medium M to the entire left side (heating element H1 side) in FIG. However, in this case, the heating element Ha prints the horizontal ruled lines 51c and 51d in the frame line 51. Therefore, the frequency of electrical application to the heating element Ha can be further reduced by shifting the printing position to the right side in FIG.

  As described above, the controller 7 shifts the position of the print information 50 to be printed on the print medium M as a whole in the width direction of the print medium M, so that the heat generator used for printing among the plurality of heat generators H1 to Hn. change.

  Further, as shown in FIG. 6, by changing the layout of the print information 50 itself, the heating element used for printing can be changed among the plurality of heating elements H1 to Hn. In the example of FIG. 6, the position of the barcode and the position of the character information such as the destination are switched. Note that the print information 50 in FIG. 6 is an example in which the frame line 51 is not provided. The changed layout is stored in the storage device of the printer 100 in advance.

  The print position of the print information 50 may be shifted in the width direction and the layout of the print information 50 itself may be changed. How to move the print position and change the layout can be set in advance.

  For example, it is possible to set in advance how many heating elements are moved when the print position of the print information 50 is shifted. For example, when 2 dots (two heating elements) are used for printing the vertical ruled line 51a, it is necessary to shift the print position of the print information 50 by at least 2 dots. Further, once the process of step S3 is executed, the heating element used for printing can be changed periodically, for example, every predetermined number of times of printing.

  In step S4, the controller 7 executes a printing process. As a result, the print information 50 is printed on the print medium M.

  As described above, the printer 100 according to this embodiment includes the thermal head 16 that performs printing on the print medium M and the usage degree determination unit that determines the usage degrees of the plurality of heating elements H1 to Hn included in the thermal head 16 (see FIG. When any of the usage levels of the controller 7) and the determined plurality of heating elements H1 to Hn becomes larger than a threshold value set within the range of usage levels that can be normally printed, the usage level is reduced. Heating element changing means (controller 7) for changing the heating element used for printing so that the frequency of electrical application to the heating element that has become larger than the threshold value decreases.

  According to this, by reducing the frequency of electrical application to the heat generating element having a high degree of use and large deterioration, the subsequent deterioration of the heat generating element is suppressed before it becomes unusable. Therefore, the life of the thermal head 16 can be extended.

  Further, the heating element changing means (the controller 7) shifts the position of the print information 50 to be printed on the printing medium M in the width direction of the printing medium M while maintaining its layout, so that the heating element used for printing is used. To change.

  According to this, since the printing position of the printing information 50 on the printing medium M is shifted as a whole, the user does not feel uncomfortable.

  Further, the heating element changing means (controller 7) changes the heating element used for printing by changing the layout of the print information 50 itself printed on the printing medium M.

  According to this, when the print position of the print information 50 cannot be shifted as a whole, or even when the print position is shifted as a whole, the frequency of electrical application to a heating element having a high degree of use is reduced. Even if it is not possible, the heating element used for printing can be changed among the plurality of heating elements H1 to Hn so that the frequency of electrical application to the heating element having a high degree of use is reduced.

  Further, the usage degree determination means (controller 7) measures the resistance values of the plurality of heating elements H1 to Hn, and determines the usage degree based on the changes.

  According to this, the usage of each of the heating elements H1 to Hn can be accurately determined.

  Further, the usage degree determination means (controller 7) determines the usage degree based on the number of times of electrical application of each of the plurality of heating elements H1 to Hn.

  The embodiment of the present invention has been described above, but the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  For example, in the above-described embodiment, the printer 100 is described as a thermal coloring device, but the printer 100 heats the ink ribbon and transfers the ink on the ink ribbon onto a printing medium for printing. It may be.

  Further, the controller 7 may be provided with a communication function and connected to a cloud server on the Internet. In this case, the execution subject of each of the above processes whose controller 7 is the execution subject may be a cloud server.

  In the above-described embodiment, the predetermined threshold value is set to a reduction rate (usage level) of 10%. However, the threshold value can be appropriately set within the range of the usage level that allows normal printing. For example, the threshold value may be 5%. Further, the threshold value may be provided in two stages of a reduction rate of 5% and a reduction rate of 10%, or the threshold value may be provided in three or more stages. Further, the heating element used for printing may be changed a plurality of times every time one of the reduction rates of the heating elements H1 to Hn becomes larger than the threshold value. The same applies when determining the degree of use based on the number of electrical applications.

DESCRIPTION OF SYMBOLS 1 Printing mechanism 4 Medium supply part 5 Cutter 7 Controller (usage degree determination means, heating element change means)
8 Discharge port 9 Position detection sensor 11 Head unit 12 Platen roller 13 Support shaft 14 Platen drive motor 15 Printing unit 16 Thermal head 41 Guide shaft 50 Printing information 51 Frame line 51a Vertical ruled line 51b Vertical ruled line 51c Horizontal ruled line 51d Horizontal ruled line 100 Printer M Printing medium H1-Hn, Ha, Hb

Claims (6)

A thermal head for printing on a print medium;
A usage degree determining means for determining a usage degree of each of the plurality of heating elements of the thermal head;
When any of the usage levels of each of the plurality of heating elements determined by the usage level determination unit is greater than a threshold value set within the range of usage levels that can be normally printed, the usage level is determined. Heating element changing means for changing the heating element used for printing, so that the frequency of electrical application to the heating element that is greater than the threshold value decreases,
Printer with. The printer according to claim 1,
The heating element changing means changes the heating element used for printing by shifting the position of printing information to be printed on the printing medium in the width direction of the printing medium while maintaining the layout of the printing information. To
Printer. The printer according to claim 1,
The heating element changing means changes the heating element used for printing by changing the layout of the printing information itself to be printed on the printing medium.
Printer. A printer according to any one of claims 1 to 3,
The usage degree determining means measures a resistance value of each of the plurality of heating elements, and determines the usage degree based on a change thereof.
Printer. A printer according to any one of claims 1 to 3,
The usage degree determining means determines the usage degree based on the number of electrical applications of each of the plurality of heating elements.
Printer. A method for controlling a printer having a thermal head for printing on a printing medium,
Determining the degree of use of each of the plurality of heating elements of the thermal head,
When any one of the determined usage levels of the plurality of heating elements is larger than a threshold value set within the range of usage levels at which printing can be normally performed, the usage level exceeds the threshold value. The heating element used for printing is changed so that the frequency of electrical application to the heating element that has become larger is reduced.
Printer control method.

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