JP2009214456A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal printer which automatically performs an open circuit check without requiring the indication by a user, and also, guarantees a highly accurate printing result while drastically shortening a period of time required for the open circuit check. <P>SOLUTION: Whether printing data is one requiring the open circuit check or not is judged. Then, when the printing data has been judged to be one requiring the open circuit check, heating elements to be turned on at the time of printing are specified conforming to the printing data. Whether heating elements having the open circuit are included in the specified heating elements or not is judged. Then, when the inclusion of the heating elements having the open circuit is judged, the result is output. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal printer that includes a thermal head having a plurality of heating elements and prints print data such as characters and barcodes on a print medium.

  In a thermal printer that performs printing using a thermal head in which a plurality of heating elements are arranged in a line, it is necessary to check for disconnection of the thermal head in order to guarantee the printing result. Conventionally, this disconnection check is performed when there is a request from a host computer connected to the thermal printer under the initiative of the user. At this time, a disconnection check is performed on all the heating elements before or after printing, and it takes several seconds to complete the disconnection check process. Therefore, when a thermal printer is used at a high operating rate, it may interfere with operation.

  As described above, for example, a thermal printer described in Patent Document 1 is known as a technique for shortening the time required for checking the disconnection of the heating element. The thermal printer described in Patent Document 1 tries to ensure smooth label issuance by checking the thermal head for disconnection when a paper jam or opening of the main body cover is recognized without a request from the host computer. It is.

As a technique related to the disconnection check, for example, a thermal printer head check device and a head check method described in Patent Document 2 are known. The head check method described in Patent Document 2 counts the number of disconnected heating elements and outputs an error signal when a certain value is exceeded.
JP-A-11-268386 JP 2002-337378 A

  The contents printed using the thermal printer vary depending on the user, and the magnitude of the influence of the disconnection of the heating element on the print result varies depending on the intended use of the print result. For example, even if there is a disconnection of several dots when printing a character, the character can often be visually recognized. However, when printing a barcode or two-dimensional code on a receipt or label, If printing is performed in a disconnected state, the scanner may recognize a code not intended by the user. Such misrecognition of a barcode or the like has a probability of leading to a major failure such as affecting the sales process of the product. In view of this, when the disconnection check is performed using the head check method described in Patent Document 2, it is dangerous to apply the same allowable disconnection dot number regardless of the intended use of the print result in all printing.

  Furthermore, as described above, it takes a few seconds to check the disconnection of the heating element every time all labels and receipts are printed. However, in a system that uses a thermal printer at a high operating rate, this is only a few seconds. However, there is a possibility of hindering its operation.

  However, it is troublesome and troublesome to individually construct a system that considers the timing of performing a disconnection check in accordance with the usage of the print result in order to cope with the problem relating to the disconnection of these heating elements.

  The present invention has been made based on the above circumstances, and its purpose is to automatically perform a disconnection check without requiring a user's instruction, and to greatly shorten the time required for the disconnection check. Is to provide a thermal printer that guarantees high-precision printing results.

  The present invention is a thermal printer that includes a thermal head having a plurality of heating elements, and that performs printing on a print medium by energizing the heating elements based on print data, and that is energized during printing based on the print data. A heating element specifying means for specifying a heating element; and a disconnection determining means for determining whether or not a disconnected heating element is included in the heating element that is energized during printing specified by the heating element specifying means; The disconnection determining means comprises an output means for outputting the result when it is determined that the disconnected heating element is included in the heating element energized at the time of printing. Yes.

  According to the present invention in which such a measure is taken, a thermal printer that automatically performs a disconnection check without requiring a user instruction, and guarantees a highly accurate printing result while greatly reducing the time required for the disconnection check. Can be provided.

The best mode for carrying out the present invention will be described below with reference to the drawings.
The present embodiment is an example of a case where the present invention is applied to a thermal printer 1 such as a barcode printer mainly used for printing print data including a barcode at a merchandise store.

  FIG. 1 is a block diagram showing a main configuration of the thermal printer 1. The thermal printer 1 includes a CPU (Central Processing Unit) 2 as a control subject. Then, a ROM (Read Only Memory) 3 that stores fixed data such as various control programs in the CPU 2, a RAM (Random Access Memory) 4 that forms a memory area for various operations according to the processing scene, wired or wireless connection Communication interface (I / F) 5 that controls communication with an external device such as a host computer (PC) 20, a display controller 6 that controls display of various processing contents on the display device 10, numeric keys, etc. The input controller 7 that processes an input signal from an input device 11 having operation keys necessary for operating the printer 1, the drive controller 8 that drives and controls the conveyance motor 12 that conveys the print medium, and the thermal head 13 are controlled. The head controller 9 is connected by a bus line 14 such as an address bus or a data bus. It is configuration control circuit of.

  In the operating state of the thermal printer 1, a check target file 31 is formed in the RAM 4 by specifying and storing the heating element 40 to be subject to a disconnection check by a method described later in the description of FIG. 3.

  The head controller 9 includes a print data buffer 30 for developing print data received via the communication interface 5 into a dot image. Further, when the head controller 9 receives an instruction to execute the disconnection check for the heating element 40 from the CPU 2, the head controller 9 executes a disconnection check for the predetermined heating element 40 based on the check target file 31. This disconnection check can be performed, for example, by connecting a voltage detection circuit to the thermal head 13 and taking into account the output of the voltage detection circuit when each heating element 40 is energized.

  FIG. 2 is a schematic diagram showing the relationship between the barcode 42 printed by the thermal printer 1 and the thermal head 13. A plurality of heating elements 40 are arranged in a line at a position where the thermal head 13 contacts a platen roller (not shown). Further, a print medium 41 and a thermal transfer ribbon (not shown) are conveyed between the thermal head 13 and the platen roller in a direction substantially orthogonal to the arrangement direction of the heating elements 40. During printing, a specific heating element 40 is energized based on the dot image developed in the print data buffer 30 under the control of the head controller 9, and the heat transfer ribbon ink is applied to the printing medium 41 by the heat generated at that time. An image is formed by thermal transfer.

  Usually, the bar code 42 is printed so that the longitudinal direction of each bar coincides with the transport direction of the print medium 41 so as not to cause tailing in the print result. That is, each bar constituting the barcode 42 is printed in a direction substantially orthogonal to the arrangement direction of the heating elements 40.

  FIG. 3 is a schematic diagram showing the relationship between each heating element 40 and the check target file 31. In the check target file 31, one memory area is assigned to each heating element 40. In this memory area, “0”, which means that the disconnection check is not performed in the initial state, is stored. When the barcode print data is received via the communication interface 5, when the CPU 2 develops the dot pattern in the print data buffer 30, the heating element 40 used for printing the barcode is identified, and the identified heating element In the memory area corresponding to 40, “1” indicating execution of disconnection check is stored. For example, in the configuration of the barcode 42 developed in the print data buffer 30, the bar 42a has a memory area for the heating elements 40a, 40b and 40c used for printing, and the bar 42b has the heating elements 40d, 40e and 40e used for printing. “1” is stored in the memory areas for 40f and 40g.

Next, the effect | action by the above structures is demonstrated.
FIG. 4 is a flowchart of processing executed by the CPU 2 when the thermal printer 1 is operating. Such processing is executed based on a control program stored in the ROM 3. First, the CPU 2 waits for reception of data transmitted from the host computer 20 as ST1.

At this time, main data transmitted from the host computer 20 includes print data, a mode selection command, a bar code designation command, and a print command.
As a result of the disconnection check, the mode selection command sends an error status to the host computer 20 to perform printing when it is determined that a disconnected element is included in the heating element 40 that is energized during printing. This is a command for instructing to switch between a print cancel mode that does not exist and a print execution mode in which a warning status is transmitted to the host computer 20 to execute printing.

  The bar code designation command is a command for indicating that the print data received at the same time includes a bar code and specifying the heating element 40 used for printing the print data.

  The print command is a command for developing the received print data as a dot image in the print data buffer 30 and performing printing based on the developed dot image.

  When it is determined that print data or various commands have been received from the host computer 20 (Yes in ST1), the CPU 2 determines whether the data received as ST2 is the mode selection command. When it is determined that the received data is the mode selection command (Yes in ST2), the type of the print stop mode or the print execution mode designated by the mode selection command received as ST3 is provided in the RAM 4 or separately. Store in non-volatile memory. Thereafter, the process returns to ST1 and waits for reception of other print data or commands. That is, in the processes of ST1 to ST3, when the disconnected heating element 40 is included in the heating element 40 that is energized at the time of printing, a selection for accepting selection of whether or not to stop printing based on the print data is selected. The reception means is configured.

  On the other hand, when determining that the data received in the process of ST2 is not the mode selection command (No in ST2), the CPU 2 determines whether or not the data received as ST4 is print data. When it is determined that the received data is print data (Yes in ST4), the print data received as ST5 is expanded in the print data buffer 30 as a dot image. Thereafter, in ST6, it is determined whether or not a barcode designation command is received together with the print data (data determination means). When it is determined that the barcode designation command has been received together with the print data (Yes in ST6), based on the dot image developed in the print data buffer 30 in ST5 as ST7, the heating element 40 energized during printing, that is, The heating element 40 that is the subject of the disconnection check is specified, and “1” is stored in the memory area of the check target file 31 corresponding to the specified heating element 40 (heating element specifying means). When it is determined that the barcode designation command is not received together with the print data after the process of ST7 or the process of ST6 (No in ST6), the process returns to the process of ST1 to receive another print data or command. wait. Then, when the print data is subsequently received, the received print data is expanded in the print data buffer 30. When accompanied by a barcode designation command, the heating element 40 used for printing is specified and the check target file 31 is set. It will be updated.

  On the other hand, when determining that the data received in the process of ST4 is not print data (No in ST4), the CPU 2 determines whether or not the data received as ST8 is the print command. When it is determined that the received data is the above print command (Yes in ST8), whether or not the heating element 40 subject to disconnection check is stored in the check target file 31 as ST9, that is, “1” is stored. It is determined whether or not there is a memory area. When it is determined that the heating element 40 subject to the disconnection check is not stored (No in ST9), the printing process is executed as ST10. In this printing process, the conveyance motor 12 is driven under the control of the drive controller 8 to convey the printing medium 41, and the head controller 9 sends the heating elements 40 to the heating elements 40 based on the dot image developed in the printing data buffer 30. This is done by controlling the energization.

  On the other hand, when it is determined in ST9 that the heating element 40 subject to the disconnection check is stored (Yes in ST9), the CPU 2 generates heat in which “1” is stored in the memory area of the check target file 31 as ST11. A disconnection check is performed on the element 40. Then, based on the result of the disconnection check, it is determined whether or not any of the heating elements 40 that have been subjected to the disconnection check in ST12 is disconnected (disconnection determination means). At this time, when it is determined that there is no disconnected heating element 40 (No in ST12), the printing process in ST10 is executed.

  On the other hand, when it is determined that there is a disconnected heating element 40 (Yes in ST12), the CPU 2 determines the type of the print stop mode or the print execution mode stored in the RAM 4 or a separately provided nonvolatile memory as ST13. To do. At this time, when it is determined that the print execution mode is set (“warning / print execution” in ST13), a warning that there is a heating element 40 that is disconnected to the host computer 20 via the communication interface 5 as ST14. The status is transmitted and the printing process of ST10 is executed.

  On the other hand, when it is determined in the process of ST13 that the print cancel mode is set (“error / print cancel” of ST13), the heating element 40 that is disconnected to the host computer 20 via the communication interface 5 is detected as ST15. Therefore, an error status indicating that printing has been canceled is sent. That is, an output means is configured to output to the host computer 20 that the heater element 40 includes a broken wire in the processing of ST14 or ST15. Further, the output means may be configured so as to give a warning that the heating element 40 is disconnected in the display device 11 together with the output to the host computer 20 or instead of the output to the host computer 20.

  When it is determined that the data received in the process of ST8 is not a print command (No in ST8), the data received from the host computer 20 is not any of the mode selection command, print data, or print command. In ST16, processing corresponding to the command is executed.

  Further, after the printing process of ST10, the error status transmission process of ST15, or the process of ST16, the CPU 2 develops various data stored in the RAM 4 including the check target file 31 and the print data buffer 30 as ST17. The dot image is cleared, and the process returns to ST1 to wait for reception of the next data.

  As described above, when the received print data includes a bar code, the thermal printer 1 automatically performs a disconnection check on only the heating elements 40 used for printing each bar constituting the bar code, and thereby, characters, images, etc. A disconnection check is not performed for the heating element 40 used only for printing other print data. Therefore, the disconnection check can be completed in a shorter time compared to the case where the disconnection check is performed on all the heating elements 40. At this time, even if the heating element 40 that has not been checked for disconnection is disconnected, the barcode printing result is not affected as long as it is not a portion of each bar constituting the barcode. Never come.

  In addition, since the disconnection check is automatically performed when necessary without any instruction from the user, the time required for the disconnection check is greatly reduced without having to build a separate system according to the intended use of the print results for the execution of the disconnection check. However, a highly accurate printing result can be guaranteed.

  In addition, since it is possible to select whether to execute printing or to cancel when a disconnection of the heat generating element 40 is detected by the mode selection command, a more suitable setting according to the usage status of the user of the thermal printer 1 can be made. realizable.

  In addition, this invention is not limited to the said embodiment as it is, In an implementation stage, in the range which does not deviate from the summary, each component can be deform | transformed and embodied suitably.

  For example, in the above-described embodiment, the case where the disconnection check is performed on the heating element 40 used when printing a barcode has been described. However, the present invention is not limited to this, and a two-dimensional code or OCR (Optical Character Reader) is used. The present invention can also be applied to print data for which a high-precision print result is desired, such as characters printed on the premise of being read by a reading device. In such a case, a predetermined command indicating that a disconnection check is required is sent from the host computer 20 together with the print data, and instead of determining whether or not a bar code designation command has been received in the process of ST6, The presence or absence may be determined.

  Further, when determining whether or not there is a disconnection in the heating element in the process of ST12, if there is even one disconnection, the process does not proceed to the process of ST13, but if the disconnection is equal to or less than a predetermined number. The process may proceed to ST10 to execute the printing process, and if it is the predetermined number or more, the process may proceed to ST13. As a result, it is possible to realize a setting corresponding to the printing accuracy desired by the user in more detail.

  In addition, the print data and various commands are received from the host computer 20 and printing is performed. However, the print data and various commands may be generated in response to the input from the input device 11, or the print data and the barcode may be generated. A storage unit that stores the designation command in association with it may be provided, and predetermined print data may be printed therefrom.

  Of course, the thermal printer according to the present invention can be applied to a receipt printer built in a POS (Point Of Sales) terminal or the like.

  In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from the overall components shown in the embodiment.

1 is a block diagram showing a main configuration of a thermal printer according to an embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a state when a barcode is printed on a print medium in the embodiment. The schematic diagram which shows the relationship between the heat generating element in the same embodiment, and a check object file. The flowchart of the process which CPU performs in the same embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Thermal printer, 2 ... CPU, 3 ... ROM, 4 ... RAM, 5 ... Communication interface, 6 ... Display controller, 7 ... Input controller, 8 ... Drive controller, 9 ... Head controller, 13 ... Thermal head, 20 ... Host Computer, 30 ... print data buffer, 31 ... file to be checked, 40 ... heating element

Claims (5)

In a thermal printer that includes a thermal head having a plurality of heating elements and performs printing on a print medium by energizing the heating elements based on print data.
Heating element specifying means for specifying the heating element to be energized during printing based on the print data;
A disconnection determining means for determining whether or not a disconnected heat generating element is included in the heat generating element that is energized during printing specified by the heat generating element specifying means;
When the disconnection determining means determines that the disconnected heating element is included in the heating element energized at the time of printing, an output means for outputting that effect;
A thermal printer comprising: Further comprising data determining means for determining whether the print data is print data that requires a disconnection inspection;
2. The heating element specifying unit, when the data determining unit determines that the print data requires a disconnection inspection, specifies a heating element to be energized during printing based on the print data. Thermal printer as described in   The thermal printer according to claim 2, wherein when the print data includes a barcode, the data determination unit determines that the print data is print data that requires a disconnection inspection.   4. The printing based on the print data is stopped when the disconnection determining means determines that a disconnected heat generating element is included in the heat generating element energized during the printing. The thermal printer of any one of these. Selection accepting means for accepting a selection as to whether or not to stop printing based on the print data when the disconnection judging means judges that a heat generating element that is disconnected is included in the heat generating elements energized during the printing. Further comprising
When the selection accepting unit accepts the selection of canceling printing, and when the disconnection determining unit determines that the disconnected heating element is included in the heating element energized at the time of printing, 4. The thermal printer according to claim 1, wherein printing based on the print data is stopped.

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