JP2007181932A - Printer and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently carry out disconnection checking of heating elements which constitute a printing head, without the printing number of sheets per unit time reduced. <P>SOLUTION: The label printer detects the heating elements of the printing head in charge of printing dots "square frame" where printing is performed and blank dots where printing is not performed. The label printer sets a priority in the order from the printing dot immediately near the head, the far printing dot and the blank printing dot. The label printer carries out checking of the presence or absence of disconnection of the heating element in charge of each dot during a printing processing term to a paper. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus and a printing method, and more particularly to a printing apparatus and a printing method for performing a printing process and checking for disconnection of a heating element of a print head.

  In general, in a label printer as a printing apparatus, a heating element constituting the print head may be disconnected due to friction between the paper and the print head during conveyance of the paper. If the heating element is not printed due to the disconnection of the heating element, fading will occur. In particular, if this fading occurs in the print area where the barcode is printed, the printed barcode will be When reading with a scanner, reading may be impossible.

  As described in the prior art column of Japanese Patent Laid-Open No. 2001-38943, a check resistor is provided in parallel to each heating element and connected to one end thereof. This is done by measuring the voltage at the check terminal. When a minute current is passed through the heating element, if there is no disconnection in the heating element, most of the energization current flows through the heating element, so the voltage value of the check terminal is low. On the other hand, when the heating element is disconnected, most of the energized current flows through the detection resistor, so that the voltage value of the check terminal is high. As described above, the heating element to be diagnosed is energized one by one and the voltage check is performed via the check terminal, thereby diagnosing disconnection of the heating element.

  FIG. 8 is a timing chart for explaining a printing operation and a heating element disconnection check operation in a conventional label printer. In the following description, it is assumed that a number of labels are attached to the mount so as to be peeled off at regular intervals. 1 and 2 in the description of the embodiment of the invention described later is common to the prior art, and will be described with reference to this.

  In the prior art, the process for diagnosing disconnection of the heating element is performed during a period in which the print head is not performing the printing process, for example, a period in which the heating element of the print head is located in a gap portion between the labels.

  8A shows an image data signal c and a head check signal d transmitted from the CPU 11 (FIG. 2) of the label printer 100 (FIG. 1) to the head controller 15 (FIG. 2), and FIG. 8B shows a head. The print strobe signal e and the head check strobe signal f transmitted from the control unit 15 to the print head 5 are shown.

  The head control unit 15 converts the image data signal c received from the CPU 11 into a dot (dot) data signal corresponding to each heating element of the print head 5 to generate a print strobe signal e, and sends it to the print head 5. Send. The head control unit 15 generates a head check strobe signal f from the head check signal d received from the CPU 11 and transmits the head check strobe signal f to the print head 5.

At this time, the motor control unit 14 (FIG. 2) drives the stepping motor 7 in synchronization with the period of the printing strobe signal e, and conveys the sheet (label) 1 by one period (one line).
Therefore, as shown in FIG. 8, a disconnection check (head check) period is provided after (or before) the print processing period, and the sheet conveyance is stopped during this period (in the present specification, the description is omitted). The “printing process” is a concept that includes an operation during the conveyance of a sheet consisting of only blank dots as a printing area in addition to the process of printing on printing dots).

JP 2001-38943 A

As described above, since the head check period is provided between the print processing periods, the time required for the head check becomes longer as the print head becomes larger in recent years. There is a problem that the number of sheets) decreases. Furthermore, since the paper transport speed changes intermittently, such as fast during printing processing and stopped during head check, it generates noise and vibration, and transport mechanisms such as paper and other printing media and motors. There is a problem that a large load is applied.
The present invention has been made in view of such a situation, and makes it possible to efficiently check the disconnection of the heating elements constituting the print head without reducing the number of printed sheets per unit time. Is.

  In order to solve the above problems, a printing apparatus according to a first invention includes a line thermal type print head in which a plurality of heating elements are linearly arranged, and a conveying unit that conveys a sheet toward the print head, A dot detection unit that detects, for each heating element, printing dots that are printed on the paper from the print head and blank dots that are not printed on the paper; a checking unit that checks whether the heating element is disconnected or not; and the check Storage means for storing the address of the heating element that has been checked, and based on the detection result of the dot detection means, priorities are set in the order of the print dots farthest from the print dots closest to the print head, and blank dots, It is characterized in that the presence or absence of disconnection of the heating element in charge of dots is checked while printing on the paper or transporting the paper.

  Here, the check of the heating element can be performed for the portion in charge of the printing range of the paper.

  When the printing of the paper is finished, if the check of the heating element responsible for the blank dot is not finished, the check can be performed while the paper is being conveyed.

  Also, when checking the heating element while transporting the paper, if the check does not end while transporting the paper from the print head to the nearest print dot, or when printing of the paper is finished, When the check of the heating element in charge is not completed, the paper conveyance can be stopped and the check can be performed.

  Furthermore, in the second invention, a step of detecting, for each heating element, all print dots and blank dots to be printed on one sheet from a line thermal print head in which a plurality of heating elements are arranged in a straight line. , A step of setting the priority in the order of the print dots farthest from the print head in the order of the print head and the blank dots based on the result of the dot detection, and each dot according to the priority order while printing or transporting the paper. There is provided a printing method comprising a step of checking whether or not the heating element in charge is disconnected, and a step of storing the address of the checked heating element.

  According to the printing apparatus and the printing method of the first to fifth aspects of the present invention, the heating element of the print head in charge of the printing dot that the printing apparatus performs printing and the blank dot that does not perform printing is detected, and the printing closest to the head is performed. Priorities were set in the order of the print dots far from the dots and the blank print dots, and the heating element in charge of each dot was checked for disconnection during the print processing period on the paper. The body disconnection check can be performed, and the number of sheets that can be printed per unit time can be increased.

  Further, since the intermittent operation of paper conveyance and stop is reduced, the printing device can be made quieter and the load on the paper and the mechanism portion can be reduced.

  In addition, since the heating elements in charge of dots with high priority are checked in order, and the check means stores the addresses of the heating elements that have been checked, when priority is given to the printing speed, before printing processing (or after printing processing) However, it is not necessary to check the disconnection of all the heating elements, only the printing dots are checked first, and after the printing is finished early, the heating elements responsible for the remaining blank dots may be checked. Therefore, when printing is issued one by one, the apparent processing time is shortened and the working efficiency is improved.

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

  1 to 7 are examples of embodiments for carrying out the invention. In the drawings, the same components as those described in the conventional example are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 1 shows a configuration example of an embodiment of a label printer to which the present invention is applied. As shown in FIG. 1, the label printer 100 includes a control unit 10 that controls each unit, a line thermal type print head (hereinafter simply referred to as a head as appropriate) 5 that performs printing on the paper 1, and a control unit 10. The stepping motor 7 driven by the above control and the stepping motor 7 transmitted via a timing belt (hereinafter simply referred to as a belt as appropriate) 8 are rotated by the rotational driving force of the stepping motor 7 and set on a supply shaft 2 described later. A platen roller (hereinafter simply referred to as a “platen” as appropriate) 6 that conveys the sheet 1 to the head 5, a supply shaft 2 that rotatably supports the sheet 1, and a sheet 1 The guide roller 3 that guides the head 5 at the approach angle, the light emitting part that emits predetermined light, and the light that is reflected from the paper 1 of the light emitted from the light emitting part and receives the received light It is composed of a light receiving unit that outputs an electrical signal corresponding to the intensity (the amount of light received per unit time). A pitch sensor 9 that detects an eye mark (black rectangular mark) or a gap between the labels when the paper 1 is a label affixed to the mount based on the amount of light received by the light receiving unit is provided. ing.

  FIG. 2 is a block diagram showing an example of the electrical configuration of the embodiment of FIG. As shown in the figure, a control unit 10 includes a ROM (ready memory) 12 that stores a predetermined control program, and a CPU (central processing unit) 11 that operates according to the control program stored in the ROM 12 and controls each unit. A random access memory (RAM) 13 that stores various data necessary for the CPU 11 to operate, and an EEPROM (electrically erasable and programmable read only memory) that stores various data that should be retained even when the power is turned off. ) 21, a motor control unit 14 for supplying a pulse signal to the stepping motor 7 to rotate the stepping motor 7, and characters to be printed supplied from the CPU 11, FIG. And a control signal corresponding to print data such as a bar code and the like, and are supplied to the head 5 to perform a print operation, and at the same time, a head control unit 15 for checking a disconnection of a heating element constituting the head 5, and a CPU 11 Under control, the sensor control unit 16 controls the light emitting unit of the pitch sensor 9 to emit light, receives an electrical signal output from the light receiving unit, converts it into digital data, and supplies it to the CPU 11 as pitch detection data; The external interface 17 and the interface 20 are provided. The control unit 10 includes an input unit 18 for inputting various data and commands, and a display unit 19 for displaying input data and various information input from the input unit 18 via an interface 20. It is connected. Input data input from the input unit 18 is supplied to the CPU 11 via the interface 20, and display data corresponding to various information displayed on the display unit 19 is supplied from the CPU 11 via the interface 20. ing. In addition, various data and commands can be exchanged with various devices such as a personal computer (PC) 200 connected to the outside via the external interface 17.

  3 to 6 are schematic diagrams showing a procedure for performing a disconnection check of the heating elements constituting the head 5 during the print processing period.

  3A shows the image data signal c and the head check signal d transmitted to the head controller 15 by the CPU 11 of the label printer 100, as in the prior art described with reference to FIG. FIG. 6 is an explanatory diagram (timing chart) showing a print strobe signal e and a head check strobe signal f transmitted from the head control unit 15 to the print head 5;

  One of the features of the present invention is that the CPU 11 detects the heating element of the print head responsible for the print dots and the blank dots based on the print image developed by the label printer on the internal image memory (not shown), and the head 5 The priority order is set in the order of the print dots farthest from the most recent print dot and the blank print dot, and the presence or absence of disconnection of the heating element in charge of each dot is performed during the print processing period on the paper.

  For this reason, the CPU 11 alternately transmits the image data signal c and the head check signal d to the head controller 15.

  Further, the print control strobe signal e and the head check strobe signal f generated by the head control unit receiving the image data signal c and the head check signal d are alternately transmitted to the print head 5. As a result, the head check is performed while the paper is being conveyed during the printing process.

4, 5 and 6 are explanatory diagrams of printing processing using an actual printing example.
In each figure, the rectangles to which the symbols a1 to a8 on the left side are attached indicate a set of heating elements of the print head 5 at each time point (position), and each rectangle does not become difficult to see. I draw every other one.
The right rectangle shows the mount 21, the label 22 and the print data printed on the label, and the right and left heating elements and the print data are plotted so as to coincide with each other in time.

In FIG. 4, the head length A is proportional to the number of heating elements included in the head 5, and the heating elements are arranged in a line in the longitudinal direction of the head 5 (left-right direction in the figure). In the figure, “Δ” indicates a heating element for which a disconnection check is performed, and “■” indicates a heating element used for printing. The heating element in this part needs to be checked for disconnection before printing.
In FIG. 4 to FIG. 6, for the sake of simplicity, the number of heating elements that can be checked for disconnection while conveying the paper for one cycle is shown as Δ. However, the number is not limited to this number. Absent.

  In the present invention, the disconnection check of the heating element is performed during the printing process period. Also, unlike the conventional case, priority is given to the printing speed. The number of heating elements that are checked for disconnection by one disconnection check is checked before the head 5 reaches the nearest print dot on the label. Possible number.

  For example, if the printing speed is F (millimeters / second), the length in the conveyance direction to the printing dots is L (millimeters), and the time required to check whether one heating element is disconnected is T (seconds), The number of heating elements B can be obtained from the following equation.

Formula 1

B = L ÷ F ÷ T

  The “temporary stop, disconnection check” shown in parentheses in FIGS. 4 to 6 is performed by giving priority to the disconnection check without carrying when the disconnection check is not in time for the printing speed. Represents a thing.

  Next, a head check processing procedure performed by the CPU 11 will be described in detail with reference to a flowchart of FIG.

  First, in step 1, the operator operates the input unit 18 to input the printing speed and the number of printed sheets. The print data is input in advance from the PC 200 via the external interface 17 and stored in the RAM 13, for example.

  Next, in step 2, the CPU 11 expands the print data received from the PC 200 in the image memory, and calculates a print area (print dot) and a blank area (blank dot) based on the obtained print image. Then, the heating element of the print head 5 in charge of each dot is detected, and a priority order is set in the order of the print dot far from the print dot closest to the head 5 and the blank print dot (step 3). Then, the number of heating elements B that can be checked for disconnection within the conveyance time is obtained as in the above formula 1 (step 4).

Next, in step 5, the number B of the heating elements is compared with the number (size) in the horizontal direction of the print dots closest to the head 5. If B is equal to C or B is larger, the check of the corresponding heating element is completed until the print dot is reached, so a disconnection check is performed while performing the printing process (step 6, A1 to a7 in FIG.
If C is larger in step 5, the heating element is not checked in time for printing. Therefore, the heating element is checked for disconnection without being conveyed, and printing is started after the check (step 14, FIG. 4 and a1 to a2 in FIG.

  If a disconnection is detected in the processes so far, an error is displayed through the display unit 19 and the printing process is stopped (step 15). If there is no disconnection, the address of the checked heating element is stored (step 8), and the processing from step 6 is repeated until the paper printing process is completed (step 9).

Next, when the check process for all printed dots is completed (step 9 is “Y”), it is determined whether or not the disconnection check is completed based on the address of the heating element stored in step 8 (step 10). . Each of a7 to a8 in FIGS. 4, 5, and 6 indicates a state where the disconnection check is not completed at the end of printing (step 10 is “N”).
In this case, the process proceeds to the next step 11, and whether or not the remaining blank dots are the number that can be checked for disconnection while being transported is examined by the same method as in step 5. If it is possible (step 11 is “Y”), the disconnection check is performed while performing the printing process (step 12). If not possible, the conveyance is stopped and the disconnection check is performed (step 16).

  If disconnection is detected in the disconnection check in step 12 or step 16, an error display in step 15 is displayed and the printing process is stopped. If no disconnection is detected, the printing process is terminated at the end.

  As described above, in the present embodiment, the heating element of the print head that is in charge of the printing dot that the label printer performs printing and the blank dot that does not perform printing is detected, and the printing dot far from the printing dot closest to the head, Priorities were set in the order of blank print dots, and the heating element in charge of each dot was checked for breakage during the printing process on the paper. The number of sheets that can be printed per unit time can be increased, and at the same time, the intermittent operation of paper transport and stop is reduced, so that the label printer can be made quieter and the load on the paper and the mechanism can be reduced. Can do.

  In addition, since the heating elements in charge of dots with high priority are checked in order, and the check means stores the addresses of the heating elements that have been checked, when priority is given to the printing speed, before printing processing (or after printing processing) It is not necessary to check the disconnection of all the heating elements, but only the printing dots are checked first, and after the printing is finished early, the heating elements responsible for the remaining blank dots can be checked (in FIG. 7). Step 16). In this way, when issuing labels one by one, the apparent processing time is shortened, and the work efficiency is improved.

  It should be noted that the printing apparatus and printing method of the present invention are not limited to the illustrated examples described above, and it is needless to say that various changes can be made without departing from the scope of the present invention.

  The printing apparatus and printing method of the present invention can also be used for label printers and other printers (such as fax machines) equipped with a thermal line type head.

1 is a configuration diagram of an embodiment of a label printer to which a printing apparatus of the present invention is applied. It is a block diagram which shows the structural example of the control part of FIG. It is a schematic diagram for demonstrating the process sequence of embodiment shown in FIG.1 and FIG.2. It is a schematic diagram for demonstrating the process sequence in the other case. It is a schematic diagram for demonstrating the process sequence in the other case. It is a schematic diagram for demonstrating the process sequence in the other case. 4 is a flowchart for explaining the processing procedure of the embodiment. It is explanatory drawing which shows the procedure of the conventional disconnection check process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Paper, 5 ... Print head, 7 ... Stepping motor, 9 ... Pitch sensor, 14 ... Motor control part, 15 ... Head control part, 16 ... Sensor control part, 17 ... External interface, 18 ... Input part, 19 ... Display , 20 ... interface, 21 ... mount, 22 ... label, 100 ... label printer, 11 ... CPU, d ... head check signal, d ... head check signal, e ... print strobe signal, f ... head check strobe signal

Claims (5)

  A line thermal type print head in which a plurality of heating elements are arranged in a straight line, a conveying means for conveying paper toward the print head, a print dot printed on the paper from the print head, and a blank dot not printed on the paper Dot detecting means for detecting the heating element for each heating element, checking means for checking the presence or absence of disconnection of the heating element for each heating element, and storage means for storing the address of the heating element checked by the checking means. Based on the detection result of the dot detection means, priorities are set in the order of the print dots farthest from the print dots closest to the print head and blank dots, and the presence or absence of disconnection of the heating element responsible for each dot is printed on the paper or the paper Printing apparatus characterized by checking while carrying   The printing apparatus according to claim 1, wherein the heating element is checked for a portion in charge of a printing range of paper.   2. The printing apparatus according to claim 1, wherein, when the printing of the paper is finished, if the check of the heating element responsible for the blank dot is not finished, the printing apparatus performs the check while conveying the paper.   When checking the heating element while transporting the paper, if the check does not end while transporting the paper from the print head to the nearest print dot, or when printing of one sheet of paper is finished, blank dots The printing apparatus according to claim 1, wherein when the heating element in charge of the check is not completed, the sheet conveyance is stopped and checked. A step of detecting, for each heating element, all print dots and blank dots to be printed on a sheet from a line thermal type print head in which a plurality of heating elements are arranged in a straight line, and a conveyance direction based on the result of the dot detection A step in which priority is given in the order of the print dots that are farthest from the closest to the print head and blank dots in order, and whether or not the heating element responsible for each dot is disconnected according to the priorities while printing or transporting the paper. And a step of storing the address of the checked heating element.

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