JP2009083340A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal printer capable of precisely predicting disconnection of heating elements in consideration of wearing of a protective film of the heating elements caused along with sandwiched carriage of a printing medium. <P>SOLUTION: On a thermal head 12, the heating elements 121 for printing and the heating elements 122 for check are formed. The heating elements 121 are disposed within a carriage path of the printing medium 4 and used in printing. The heating elements 122 are disposed outside the carriage path of the printing medium 4 and are not used in printing. The thermal printer is provided with a wear advancing means 17 which causes the protective film of the heating elements 122 for check to wear, a printing control unit which electrifies the heating elements 122 for check so that accumulated power distribution time of the heating elements 122 for check is longer than the accumulated power distribution time of the heating elements 121 for printing, a disconnection detection unit which checks disconnection of the heating elements 122 for check, and an alarming unit which alarms a near-disconnection notification which predicts disconnection of the heating elements 121 for printing when disconnection of the heating elements 122 for check is detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal printer that performs printing by selectively generating heat from a heating element of a thermal head, and more particularly to a thermal printer having a function of predicting disconnection of a thermal head.

  The initial resistance value of each heating element formed on the thermal head is stored, the resistance value of each heating element is detected, and a warning is issued when the detected resistance value exceeds a predetermined level However, a thermal printer that detects in advance a heating element that may be disconnected has been proposed (see, for example, Patent Document 1).

However, excluding scratches caused by external causes, electrical degradation of the heating element and destruction of the heating element due to wear of the protective film of the heating element are the cause of disconnection of the heating element.
Although it is possible to detect electrical deterioration of the heating element, no consideration is given to the wear of the protective film of the heating element, and it is impossible to accurately detect a heating element that may break. Therefore, it is impossible to detect a heating element that may be disconnected in advance, and if the heating element runs out, printing cannot be issued until a replacement thermal head is prepared. For example, in a distribution process or a manufacturing process, etc. The line was stopped for a long time, and there was a problem that the work efficiency in the physical distribution process and the manufacturing process was lowered.

JP 11-291534 A

  The present invention has been made in view of such problems, and the object of the present invention is to accurately detect the disconnection of the heating element in consideration of wear of the protective film of the heating element accompanying nipping and conveyance of the print medium. Therefore, it is possible to provide a thermal printer that can prevent the line from being stopped due to disconnection of the heating element.

In order to solve the above problems, the present invention has the following configurations.
The gist of the invention described in claim 1 is that the thermal head is disposed in the transport path of the print medium, and is disposed outside the transport path of the print medium and a print heating element used for printing, A check heating element that is not used for printing, and a protective film that protects the print heating element and the check heating element are formed. Wear progressing means for wearing the protective film of the heating element for checking is approximately equal to or faster than the speed at which the wear of the protective film proceeds, and selectively energizing the heating element for printing to perform printing. And printing control means for energizing the check heating element and disconnecting the check heating element so that the accumulated energization time of the check heating element becomes longer than the accumulated energization time of the printing heating element. H A disconnection detecting means for checking, and a notification means for notifying a near disconnection notification for predicting a disconnection of the heating element for printing when the disconnection detecting means detects a disconnection of the heating element for checking. It exists in the featured thermal printer.
According to a second aspect of the present invention, there is provided the thermal printer according to the first aspect, wherein the wear progression means is replaceable.
According to a third aspect of the present invention, a plurality of the check heating elements are formed on the thermal head, and the print control means includes at least two stages of cumulative energization time of the check heating elements. 3. The thermal printer according to claim 1 or 2, wherein a difference is provided.

  The thermal printer according to the present invention is arranged in the thermal head in the conveyance path of the print medium and is used for printing, and is placed outside the conveyance path of the print medium and is not used for printing. A heating element and a protective film that protects the printing heating element and the check heating element are formed, and it is approximately the speed at which the abrasion of the protective film of the printing heating element proceeds as the printing medium is nipped and conveyed. Wear progressing means that wears the protective film of the check heating element equivalently or quickly, and the print heating element is selectively energized to perform printing, and the check heating element exceeds the accumulated energization time of the print heating element Print control means for energizing the check heating element, disconnection detection means for checking the disconnection of the check heating element, and disconnection of the check heating element by the disconnection detection means. For the check, considering the wear of the protective film of the heating element due to the nipping and conveying of the print medium by providing a notification means for notifying the near disconnection notification that predicts the disconnection of the heating element for printing. By using the heating element under stricter conditions than the printing heating element and disconnecting the checking heating element faster than the printing heating element, the disconnection of the checking heating element is detected prior to the disconnection of the printing heating element. Therefore, it is possible to accurately predict the disconnection of the heating element for printing, and it is possible to prevent the line from being stopped due to the disconnection of the heating element.

  Further, the thermal printer of the present invention is configured so that the wear progressing means can be replaced, so that the material of the wear progressing means can be changed according to the type of printing medium or ink ribbon, so that the material with a different friction coefficient can be used. It can be used for printing media and ink ribbons, and by replacing the thermal head and the wear progression means together, it is possible to notify the thermal head disconnection notice time appropriately (not too fast or too late). There is an effect.

  Furthermore, the thermal printer of the present invention forms a plurality of check heating elements on the thermal head, and changes the accumulated energization time of the check heating elements in at least two stages, thereby changing the state of the print heating element. Therefore, there is an effect that it becomes possible for the user side to select the time for replacing the thermal head according to the risk of disconnection of the thermal head.

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

  FIG. 1 is a schematic side view showing the configuration of an embodiment of a thermal printer according to the present invention, and FIG. 2 shows the arrangement of a heating element for printing and a heating element for checking provided in the thermal head shown in FIG. FIG. 3 is a diagram showing a configuration of wear progressing means for quasi-wearing the protective film of the check heating element portion shown in FIG. 2, and FIG. 4 is a diagram of the wear progressing means shown in FIG. FIG. 5 is a block diagram illustrating the configuration of the control unit illustrated in FIG. 1, and FIG. 6 is a block diagram illustrating the configuration of the print control unit illustrated in FIG. 5. is there.

  Referring to FIG. 1, the thermal printer 1 according to the present embodiment includes a platen roller 11 that is rotationally driven by a conveyance motor 10 and a plurality of heating elements that are formed on a surface facing the platen roller 11 as a printing unit. A printing medium 4 such as a label continuum in which a plurality of labels 2 are temporarily attached to a belt-like mount 3 and an ink ribbon 5 are stacked between the platen roller 11 and the thermal head 12. The ink is transferred from the ink ribbon 5 to the printing surface of the print medium 4 (label 2) by selectively heating the heating element of the thermal head 12 and printing is performed. . Instead of using the ink ribbon 5, the printing medium 4 (label 2) may be printed with heat sensitive color.

  The print medium 4 is wound around a cylindrical body 6 such as a paper tube in a roll shape, that is, is rotatably supported by a supply unit 13 as a roll paper, and the platen roller 11, the thermal head 12, Supplied during. Further, the ink ribbon 5 is bridged between a ribbon paper supply shaft 14 that is rotationally driven in conjunction with the platen roller 11 and a ribbon take-up shaft 15, and is wound around the ribbon paper supply shaft 14 in a roll shape. The ink ribbon 5 supported in the state is supplied together with the print medium 4 between the platen roller 11 and the thermal head 12, and the transferred ink ribbon 5 is taken up by the ribbon take-up shaft 15.

  A label detection sensor 16 that detects a timing mark provided on the belt-like mount 3 of the print medium 4 is provided in the conveyance path of the print medium 4 between the supply unit 13 and the printing unit. The output of the label detection sensor 16 is input to the control unit 30, and the control unit 30 recognizes the tip position of the label 2 based on the output of the label detection sensor 16 to rotate the platen roller 11. 10, the print medium 4 is conveyed in the feed direction, and the heating element of the thermal head 12 is selectively heated to print on the label 2. The timing marks provided on the belt-like mount 3 of the print medium 4 are provided at intervals of the temporarily attached label 2 and are referred to as eye marks printed on the back side of the belt-like mount 3. A rectangular black mark or the like is used. In addition, you may make it detect the strip | belt-shaped mount 3 part between the adjacent labels 2 temporarily attached to the strip | belt-shaped mount 3 instead of a timing mark. Moreover, as the conveyance motor 10, forward / reverse rotation is possible and the rotation amount can be controlled. For example, a stepping motor or the like can be used.

  Referring to FIG. 2, the thermal head 12 has a printing heating element 121 used for printing and a check heating element 122 not used for printing formed continuously on the surface facing the platen roller 11. . FIG. 2 is a view of the thermal head 12 as viewed from the platen roller 11 side. The print heating element 121 is arranged in the conveyance path of the print medium 4 and the range in which the print heating element 121 is formed is shown. This is the print area. Further, the check heating element 122 is disposed outside the transport path of the print medium 4.

  FIG. 3A shows a state in which the printing medium 4 and the ink ribbon 5 are sandwiched and overlapped by the platen roller 11 and the thermal head 12, and the check heating element 122 of the thermal head 12 is formed. As shown in FIG. 3B, the wear progressing means 17 for quasi-wearing the applied portion is formed on the peripheral surface of the platen roller 11 with a thickness substantially equal to the thickness of the printing medium 4 and the ink ribbon 5. Is provided. A protective film (not shown) that protects the print heating element 121 and the check heating element 122 is formed on the surface of the thermal head 12 where the print heating element 121 and the check heating element 122 are formed. The protective film that protects the heating element 121 for printing located in the conveyance path of the medium 4 is worn over time by sandwiching and conveying the medium 4 to be printed and the ink ribbon 5, so The protective film that protects the check heating element 122 located outside the conveyance path of the print medium 4 is worn over time by the wear progression means 17. The wear progression means 17 is set with a frictional force with the thermal head 12 so as to be worn at substantially the same speed or faster than the wear speed of the protective film positioned on the transport path of the print medium 4. ing. Further, the material constituting the wear progression means 17 is elastic so that the distance between the platen roller 11 and the thermal head 12 does not expand too much depending on the thickness of the wear progression means 17, and the heat generation of the check heating element 122. For example, a nonflammable felt can be used. Furthermore, since the speed at which wear of the protective film located in the transport path of the print medium 4 changes according to the material of the print medium 4 and the ink ribbon 5, the wear progression means 17 is configured to be replaceable, It is preferable that the frictional force with the thermal head 12 can be changed.

  In the present embodiment, the wear progression means 17 is provided on the peripheral surface of the platen roller 11. However, as shown in FIGS. 4A and 4B, the wear progression means 17 is provided separately from the platen roller 11. In this manner, when the wear progression means 17 is provided separately from the platen roller 11, the wear progression means 17 is configured so that the pressing force of the wear progression means 17 against the thermal head 12 can be changed. It is possible to change the frictional force with the thermal head 12 without exchanging.

  A host computer 40 such as a personal computer is connected to the control unit 30 via an external interface (external I / F) 18 so that various data and commands can be transmitted to and received from the host computer 40. Print data to be printed on the label 2 is transmitted from the host computer 40.

  Referring to FIG. 5, the control unit 30 operates in accordance with a ROM (read only memory) 31 that stores a predetermined control program and font data, and a control program stored in the ROM 31 and controls each unit. processing unit) 32, a random access memory (RAM) 33 for storing various data necessary for the operation of the CPU 32, and a transport signal for supplying a drive signal such as a pulse signal to the transport motor 10 to rotate the transport motor 10. Based on instructions from the control unit 34 and the CPU 32, the thermal head 12 is checked for disconnection, and the print control unit 35 that causes the thermal head 12 to perform a printing operation, and the label detection sensor 16 under the control of the CPU 32. The CPU receives the timing mark detection signal and converts it into digital data as a pitch signal. And a supplying label detector 36 to 2.

  When the CPU 32 receives print data from the host computer 40 via the external I / F 18, the CPU 32 reads out font data corresponding to the character code included in the received print data from the ROM 31 and corresponds to the print data transmitted from the host computer 40. The bitmap image data to be developed is developed in the drawing area of the RAM 33. Next, the CPU 32 notifies the print control unit 35 of the print mode, thereby instructing the print control unit 35 to print the bitmap image data developed in the drawing area of the RAM 33, and to the transport control unit 34. An instruction is given to convey the print medium 4 in the conveyance direction.

  The print control unit 35 supplies a control signal to the thermal head 12 in accordance with the bitmap image data developed in the drawing area of the RAM 33 based on an instruction from the CPU 32 and performs a printing process. Further, the transport control unit 34 supplies a predetermined drive signal to the transport motor 10 based on an instruction from the CPU 32 to drive the transport motor 10. As a result, the print data is printed on the print medium 4 (label 2) while being nipped and conveyed by the printing platen roller 11 and the thermal head 12.

  Further, the CPU 32 performs a printing process by the thermal head 12 such as a period in which the print heating element 121 formed on the thermal head 12 is in contact with the strip-like mount 3 between adjacent labels 2 or before printing is started. By notifying the print control unit 35 of the check mode during the period when the print is not performed, the print control unit 35 is instructed to check the disconnection of the print heating element 121 and the check heating element 122 formed in the thermal head 12. The print control unit 35 performs a disconnection check by sequentially energizing the check heating element 122 and notifies the CPU 32 of the check result.

  Referring to FIG. 6, the print control unit 35 is connected to the emitter, and turns on / off the NPN-type print control transistor 123 connected to one terminal of the print heating element 121. The energization control unit 351 for turning on / off the NPN type check transistor 124 connected to one terminal of the heating element 122 and the power source supplied to the other terminal of the printing heating element 121 and the checking heating element 122 are switched. The switch 352, the mode switching unit 353 that switches the switch 352 according to the mode notification (print mode or check mode) from the CPU 32, and the voltage of the other terminal of the print heating element 121 and the print heating element 121 and the check And a disconnection detector 354 that detects disconnection of the heating element 122.

  When the printing mode is notified from the CPU 32, the mode switching unit 353 switches the switch 352 so that the thermal head driving power source + Vh is supplied to the printing heating element 121, and sets the energization control unit 351 to the printing mode. The energization control unit 351 energizes the thermal head driving power source + Vh by performing ON / OFF control of the print control transistor 123 corresponding to the bitmap image data developed in the drawing area of the RAM 33, and performs printing. The heating element 121 is selectively heated to perform printing. In addition, the energization control unit 351 performs ON control of the check heating element 122 when any of the print heating elements 121 is heated by energization of the thermal head driving power supply + Vh, so that the thermal head driving power supply is turned on. It is set to energize + Vh to heat the check heating element 122 so that the accumulated energization time to the check heating element 122 is longer than the accumulated energization time to the printing heating element 121. It has become.

  Further, when the check mode is notified from the CPU 32, the mode switching unit 353 causes the disconnection detection power source Vl lower than the thermal head driving power source + Vh to pass through the voltage dividing resistor ra and the print heating element 121 and the check heating element. In addition to switching the switch 352 so as to be supplied to 122, the energization control unit 351 is set to the check mode, and the energization control unit 351 sequentially turns on the print control transistor 123 and the check transistor 124 to perform printing. The disconnection detection power source Vl is sequentially energized to the heating element 121 and the check heating element 122.

  The disconnection detection unit 354 is supplied with the disconnection detection power Vl via the voltage dividing resistor ra, the voltage at the other terminal of the printing heating element 121 and the check heating element 122, that is, the voltage dividing resistance ra and the printing. By monitoring the divided voltage between the heating element 121 and the check heating element 122, the disconnection of the print heating element 121 and the disconnection of the check heating element 122 are checked, and the check result is notified to the CPU 32.

  When any of the check heating elements 122 is disconnected, the CPU 32 urges the preparation of the replacement thermal head 12 by the notification unit 19 which is a display means such as a liquid crystal display or a sound output means such as a buzzer. Notify the user of the notification. That is, the protective film that protects the check heating element 122 is worn by the wear progression means 17 at substantially the same speed or faster than the wear progression speed of the protective film that protects the print heating element 121. Since the accumulated energization time for the check heating element 122 is set to be longer than the accumulated energization time for the print heating element 121, the check heating element 122 is used for printing. Disconnect faster than the body 121. Therefore, when the disconnection of the check heating element 122 is detected, the print heating element 121 is not disconnected, and printing can be continued. The disconnection of the check heating element 122 is caused by the disconnection of the print heating element 121. It can be used as a prediction of disconnection.

  When any of the heating elements 121 for printing is disconnected, the CPU 32 notifies the user of a disconnection notification that prompts replacement of the thermal head 12 by the notification unit 19.

  In the present embodiment, referring to FIG. 6, a plurality of check heating elements 122 are provided. However, the number of check heating elements 122 is arbitrary, and is set as appropriate according to the specifications of the thermal printer. Is done. Further, when a plurality of check heating elements 122 are provided, for example, both of the check heating element 122 and the print heating element 121 that are energized when any of the print heating elements 121 is heated. Is provided with a check heating element 122 that is always energized, including when no heat is generated, and the accumulated energization time of the plurality of check heating elements 122 is differentiated in at least two stages, so that the heating element 121 for printing is disconnected. Prediction can be performed in multiple stages.

  As described above, according to the present embodiment, the thermal head 12 is arranged in the transport path of the print medium 4 and used for printing, and the print heating element 121 used for printing and the print medium 4 outside the transport path. The heating element 122 for checking that is not used for printing and a protective film that protects the heating element 121 for printing and the heating element 122 for checking are formed. The wear progressing means 17 for wearing the protective film of the heating element 122 for check and the printing heat generating element 121 are selectively energized approximately equal to or faster than the speed at which the protective film of the body 121 progresses. A print control unit 35 that performs printing and energizes the check heating element 122 so that the accumulated energization time of the check heating element 122 is longer than the accumulated energization time of the print heating element 121; A disconnection detection unit 354 that checks for disconnection of the heating element 122 for printing, and a notification that notifies a near disconnection notification that predicts disconnection of the heating element 121 for printing when the disconnection detection unit 354 detects disconnection of the heating element 122 for printing The check heating element 122 is used under stricter conditions than the printing heating element 121 in consideration of wear of the protective film of the heating element 121 for printing due to the nipping and conveying of the printing medium 4 by providing the portion 19. The disconnection of the check heating element 122 can be detected prior to the disconnection of the print heat generating element 121 by disconnecting the check heat generating element 122 faster than the print heat generating element 121. Thus, it is possible to accurately predict the disconnection 121 and to prevent the line from being stopped due to the disconnection of the heating element 121 for printing.

  Furthermore, according to the present embodiment, by configuring the wear progressing means 17 to be replaceable, the material of the wear progressing means 17 can be changed according to the type of the printing medium 4 or the ink ribbon 5, so the friction coefficient. The print head 4 and the ink ribbon 5 of different materials can be used, and the thermal head 12 and the wear progressing means 17 are exchanged together, so that the thermal head 12 can be appropriately notified of the disconnection notice time (not too fast and slow). However, there is an effect that it can be notified.

  Further, according to the present embodiment, a plurality of check heating elements 122 are formed on the thermal head 12, and the accumulated heating time of the check heating elements 122 is differentiated in at least two stages, whereby a print heating element is formed. Since the state 121 can be recognized step by step, it is possible to select the time for replacing the thermal head 12 on the user side according to the risk of disconnection of the thermal head 12.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a number, position, shape, and the like that are suitable for implementing the present invention. In each figure, the same numerals are given to the same component.

1 is a schematic side view showing a configuration of an embodiment of a thermal printer according to the present invention. It is a figure which shows arrangement | positioning of the heat generating body for printing and the heat generating body for a check provided in the thermal head shown in FIG. It is a figure which shows the structure of the wear progress means which pseudo-wears the protective film of the heat generating body part for a check shown in FIG. It is a figure which shows the structure of other embodiment of the wear progress means shown in FIG. It is a block diagram which shows the structure of the control part shown in FIG. FIG. 3 is a block diagram illustrating a configuration of a print control unit illustrated in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 2 Label 3 Strip | belt-shaped mount 4 Printed medium 5 Ink ribbon 6 Cylindrical body 10 Conveyance motor 11 Platen roller 12 Thermal head 13 Supply part 14 Ribbon paper supply shaft 15 Ribbon take-up shaft 16 Label detection sensor 17 Wear progress means 18 External I / F
19 Informing part 30 Control part 31 ROM
32 CPU
33 RAM
34 Transport Control Unit 35 Print Control Unit 36 Label Detection Unit 40 Host Computer 121 Printing Heating Element 122 Checking Heating Element 123 Print Control Transistor 124 Checking Transistor 351 Energization Control Unit 352 Switch 353 Mode Switching Unit 354 Disconnection Detection Unit

Claims (3)

A thermal printer that performs printing while sandwiching and transporting a printing medium between a thermal head and a platen roller,
The thermal head is disposed in the conveyance path of the print medium and is used for printing, and a heating element for check that is disposed outside the conveyance path of the print medium and is not used for printing. A protective film for protecting the heating element for printing and the heating element for checking is formed,
Wear progressing means for wearing the protective film of the heating element for checking substantially equal to or faster than the speed at which wear of the protective film of the heating element for printing proceeds with nipping and conveyance of the printing medium;
The check heating element is configured to perform electrification by selectively energizing the print heating element, and to make the accumulated energization time of the check heating element longer than the accumulated energization time of the printing heating element. Printing control means for energizing the
Disconnection detecting means for checking disconnection of the heating element for checking;
A thermal printer comprising: a notifying means for notifying a near disconnection notification for predicting a disconnection of the print heating element when the disconnection detecting means detects a disconnection of the check heating element.   The thermal printer according to claim 1, wherein the wear progressing means is replaceable. The thermal head is formed with a plurality of heating elements for checking,
The thermal printer according to claim 1, wherein the print control unit makes a difference in the accumulated energization time of the check heating element in at least two stages.

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