JP4442283B2 - Thermal printer - Google Patents

Description

  The present invention relates to heat storage control of a thermal printer.

Conventionally, various recording apparatuses have been proposed for improving print drive characteristics by storing heat in a print head such as a thermal head. In particular, as a heat storage correction method considering the head voltage applied to the thermal head, for example, in Patent Document 1, heat storage correction data obtained by multiplying heat storage data indicating the heat storage state of each heat storage layer of the thermal head by a predetermined coefficient. Is used to obtain heat generation data, and based on this heat generation data, the heat generating element is controlled to be driven. Further, the coefficient used when obtaining the heat storage correction data corresponding to the aluminum plate to which the head temperature sensor for measuring the head temperature is attached is determined by an arithmetic expression including the head voltage as a parameter.
JP 2001-270144 A

  However, when an alkaline battery is used as a driving power source for the thermal head, printing is performed at a relatively low voltage and the ON time tends to be long within the energization cycle. There was a tendency for the amount of heat storage to be larger than when using other power sources, and the printing was liable to be crushed. In the conventional heat storage control, such correction of the heat storage control due to the voltage difference of the drive power supply is not considered.

  The present invention has been made in order to solve the above-described problems. Even if a power source having a relatively low power supply voltage is used, the efficiency is reduced, and further, heat storage control is effectively performed in correspondence with a printing medium, and the printing is crushed. It is an object of the present invention to provide a thermal printer that can prevent the above-described problem.

In order to achieve the above object, a thermal printer according to claim 1 of the present invention includes a thermal head having a plurality of heating elements, and pulse applying means for selectively applying a driving voltage pulse to the heating elements. A thermal printer that performs dot printing on the print medium while relatively moving the thermal head and the print medium, and an environmental temperature measurement unit that measures an environmental temperature around the thermal printer; and the printing medium detecting means for detecting a type of printing medium, and the total number of dots counting means which sequentially adding the number of dots to be printed obtains the total number of dots from the reference time, the total determined by the total dot number counting means reduction from the number of dots, are multiplied by the elapsed time from the reference time to a predetermined number of dots corresponding to the measured the environment temperature by the environmental temperature measuring means It is to be measured, an adjustment means for adjusting the total number of dots, the excess dot count being a difference between the number of dots at the time of the the number of dots after being adjusted reference by the adjustment means, and by the environmental temperature measuring means a heat storage coefficient setting means for setting a heat storage coefficient corresponding to the environmental temperature, which is a voltage measuring means for measuring a head voltage applied to the thermal head, said detected by the printing medium detecting means is said printing medium The heat storage coefficient correction means for correcting the value of the heat storage coefficient set by the heat storage coefficient setting means according to the type of the head voltage measured by the voltage measurement means and the voltage measured by the voltage measurement means Voltage fluctuation coefficient setting means for setting a voltage fluctuation coefficient corresponding to the head voltage, and at least a predetermined value set according to the thermal head Based on the application control coefficient storage means for storing the application control coefficient, the heat storage coefficient corrected by the heat storage coefficient correction means, and the voltage fluctuation coefficient stored in the voltage fluctuation coefficient storage means, the application control Pulse width setting means for correcting the application control coefficient stored in the coefficient storage means every predetermined time and setting the corrected application control coefficient to the applied pulse width of the pulse applying means; and the pulse width setting Application control means for controlling application of the drive voltage pulse by the pulse application means based on the applied pulse width set by the means .

Further, in the thermal printer according to claim 2 of the present invention, in addition to the configuration of the invention according to claim 1, the thermal storage coefficient correction means is configured such that the higher the head voltage measured by the voltage measurement means, the higher the head voltage. The heat storage coefficient is corrected to a smaller value, and the pulse width setting means reduces the rate at which the applied pulse width is decreased as the value of the heat storage coefficient is smaller .

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the invention, the thermal storage coefficient correction means is the printing medium detected by the printing medium detection means. The heat storage coefficient is corrected to a smaller value as the printing medium with higher printing energy is obtained, and the pulse width setting means reduces the rate at which the applied pulse width is reduced as the value of the heat storage coefficient is smaller. characterized in that it.

The thermal printer according to claim 4 of the present invention, in addition to the configuration of the invention according to any one of claims 1 to 3, wherein the pulse width setting means, for each of the predetermined time, the application control coefficient storage A value obtained by multiplying the application control coefficient stored in the means by the heat storage coefficient corrected by the heat storage coefficient correction means and the voltage fluctuation coefficient set by the voltage fluctuation coefficient setting means; Is characterized in that application of the drive voltage pulse is stopped when the applied pulse width set by the pulse width setting means is less than a predetermined threshold value .

  According to the thermal printer of the first aspect of the present invention, the voltage varies depending on the driving power source (battery or AC adapter) and the energization time becomes long at a low voltage. By performing the corresponding heat storage control, the print quality can be maintained appropriately.

Further, by performing heat storage control in consideration of the difference in printing energy depending on the printing medium, it is possible to realize printing control that is less likely to cause printing crushing or printing fading.

In addition, more accurate heat storage control can be performed by correcting the heat storage coefficient that corrects the applied pulse width in accordance with the accumulated temperature of the thermal head heat generating portion that rises and changes according to the cumulative number of dots, by correcting the voltage value. .

According to the thermal printer described in claim 2 of the present invention, in addition to the effect of the invention described in claim 1 , the heat storage coefficient decreases as the voltage increases, and the rate of decreasing the applied pulse width decreases. Print fading can be prevented by control.

According to a third aspect of the present invention, in addition to the effects of the first or second aspect , an applied pulse width corresponding to the accumulated temperature of the thermal head heat generating portion that rises and changes according to the cumulative number of dots. By correcting the heat storage coefficient that corrects the color according to the type of the medium to be printed, more accurate heat storage control can be performed.
In addition to the effect of the invention according to any one of claims 1 to 3, the thermal printer according to claim 4 of the present invention reduces the value obtained by multiplying the application control coefficient by the heat storage coefficient and the voltage variation coefficient to apply the applied pulse. The width is set, and the application of the drive voltage pulse can be stopped when the applied pulse width is less than a predetermined threshold.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings based on embodiments embodying the tape printer. First, a schematic configuration of the tape printer according to the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic upper external view of the tape printer 1 according to this embodiment except for a storage cover. 2A and 2B are diagrams showing a schematic configuration of the thermal head of the tape printer 1 according to the present embodiment, in which FIG. 2A is a plan view and FIG. 2B is a front view. FIG. 3 is a plan view when the cover of the tape cassette 35 mounted on the tape printer 1 is removed.

  As shown in FIG. 1, the tape printer 1 is instructed to execute a character input key 2 for creating text composed of document data, a print key 3 for instructing printing of the text, a line feed command and execution / selection of various processes. A return key 4, a keyboard 6 provided with a cursor key C for moving the cursor forward and backward, left and right on a liquid crystal display 7 (hereinafter referred to as "LCD") for displaying characters such as characters over a plurality of lines, and a later-described A cassette storage portion 8 for storing the tape cassette 35 (see FIG. 3) is covered with a storage cover (not shown). A control board (not shown) that constitutes a control circuit unit is disposed below the keyboard 6, and a thermistor 13 for detecting the environmental temperature (see FIG. 4) is attached. Further, a label discharge port 16 through which a printed tape is discharged is formed on the left side surface portion of the cassette storage portion 8, and an adapter insertion port (not shown) to which a power adapter is attached is formed on the right side surface portion of the cassette storage portion 8. ) Is provided. Since the thermistor 13 is provided at a location away from the thermal head 9, it is not affected by the heat generation drive of the thermal head 9.

  The cassette housing 8 includes a thermal head 9 (see FIG. 2) to be described later, a platen roller 10 facing the thermal head 9, a tape feeding roller 11 on the downstream side of the platen roller 10, and In addition to the tape drive roller shaft 14 facing the tape feed roller 11, an ink ribbon take-up shaft 15 for feeding an ink ribbon accommodated in the tape cassette 35 is arranged. The ink ribbon take-up shaft 15 is rotationally driven through a suitable drive mechanism from a tape feed motor 30 (see FIG. 4) constituted by a stepping motor and the like which will be described later, and an ink ribbon 43 after printing as will be described later. The ink ribbon take-up reel 44 (see FIG. 3) is inserted into the ink ribbon take-up reel 44 (see FIG. 3), and the ink ribbon take-up reel 44 is driven to rotate in synchronization with the printing speed. The tape drive roller shaft 14 is rotationally driven from the tape feed motor 30 through an appropriate transmission mechanism, and rotationally drives a tape drive roller 53 (see FIG. 3) described later.

  Further, when a tape cassette 35 (described later) is mounted in the cassette storage unit 8, the position facing the tape specifying unit 40 (see FIG. 3) of the tape cassette 35 that specifies the type of tape that is the print medium is Tape type detection sensors S1, S2, S3, S4, and S5 including push-type microswitches are provided. Each of the tape type detection sensors S1 to S5 is a known mechanical switch composed of a plunger, a micro switch, and the like, and is formed in the tape specifying unit 40 with respect to each of the tape type detection sensors S1 to S5. Whether or not there is a hole is detected, and the type of the tape stored in the tape cassette 35 is detected by the on / off signal. In the case of this embodiment, the tape type detection sensors S1 to S5 have their plungers always protruding from the bottom surface of the cassette housing portion 8, and the microswitch is in the OFF state. And when the below-mentioned through-hole of the tape specific | specification part 40 exists in the position facing each tape seed | species detection sensor S1-S5, since a plunger is not pressed down but a micro switch is in an OFF state, an OFF signal is output. On the other hand, when there is no through hole to be described later of the tape specifying unit 40 at a position facing each of the tape type detection sensors S1 to S5, the plunger is pressed and the microswitch is turned on. Is output. The cassette storage unit 8 is opened and closed by a storage cover pivotally supported to the rear of the tape printer 1, and the tape cassette 35 is exchanged in the open state.

  Here, the type of tape is specified by “tape type” and “tape width”. “Tape type” includes “receptor (non-laminate) tape” in which the surface of the printing tape is not covered with a protective film, and “laminate tape” in which the surface of the printing tape is protected with a transparent film. “Tape width” includes “6 mm”, “9 mm”, “12 mm”, “18 mm”, “24 mm”, and the like. The energy required for printing differs depending on the type of tape, and the required energy per dot is about 1.3 mJ for the “receptor tape” and about 1.1 mJ for the “laminate tape”. The difference in printing energy is that the “receptor tape” exposes the ink part on the surface, so the ink adhesion to the tape surface (rubbing resistance, fastness) is required. This is because the required energy is higher than that of the tape.

  In the case of this embodiment, as will be described later, when the “tape type” is “laminate tape” and the “tape width” is “24 mm”, the signals of the tape type detection sensors S1 to S5, that is, the sensor hole “S1” is “ON signal, ie no sensor hole”, “S2” is “ON signal, ie no sensor hole”, “S3” is “ON signal, ie no sensor hole”, “S4”. "Is an" off signal, ie, there is a sensor hole ", and" S5 "is an" on signal, ie, there is no sensor hole ". For other tape types, the relationship between the on / off signal of each tape discrimination sensor S1 to S5 and the presence or absence of a through hole formed in the tape specifying unit 40 is "no sensor hole in the case of an on signal" Since it is the same as “with sensor hole in case of OFF signal”, the description thereof is omitted.

  Next, as shown in FIG. 2, the thermal head 9 is a so-called thick film head formed in a substantially vertical rectangular flat plate shape, and a predetermined number (this embodiment) is formed on the left end edge of the front surface of the thermal head 9. In the embodiment, 128 heating elements R1 to Rn (n is a predetermined number) are arranged in a line along the side of the left edge. The other end of the flexible cable F connected to a connector (not shown) provided on the control board is electrically connected to the right end edge of the front surface of the thermal head 9 by soldering or the like. Further, the thermal head 9 has an arrangement direction of the heating elements R1 to Rn on the left end edge of the front surface of the substantially square heat sink 9A formed of a plated steel plate, a stainless steel plate or the like, and the left end edge of the heat sink 9A. It is fixed with an adhesive or the like so as to be parallel to the side of the plate. The upper right corner of the flexible cable F is fixed to the front surface of the heat sink 9A with a double-sided tape or the like. Furthermore, one end side of the flexible cable F is inserted into a horizontal substantially rectangular through-hole 9D formed in the lower end edge of the heat sink 9A, and is drawn out to the rear side. In addition, an extension portion 9B extending a predetermined width in a substantially right-angled front direction is formed at the lower edge of the heat sink 9A, and each of the four through holes 9C, 9C, 9C, 9C (only two are shown). Is drilled. The heat radiating plate 9A is arranged so that the arrangement direction of the heat generating elements R1 to Rn is substantially orthogonal to the transport direction of the label tape 36 (see FIG. 3) in the opening 52 (see FIG. 3) of the tape cassette 35. It is attached to the lower side of the cassette housing portion 8 with screws or the like through the through holes 9C, 9C, 9C, 9C.

  Next, as shown in FIG. 3, the tape cassette 35 includes a print-receiving tape 36 made of a transparent tape, an ink ribbon 43 for printing on the print-receiving tape 36, and a print-receiving tape 36 on which printing has been performed. The double-sided adhesive tape 46 to be backed is wound around a tape spool 37, a reel 42, and a tape spool 47, respectively, and can be rotated to a cassette boss 38, a reel boss 50, and a cassette boss 48 standing on the bottom surface of the cassette body 35B. Further, an ink ribbon take-up reel 44 for taking up the used ink ribbon 43 is further provided.

  Then, the unused ink ribbon 43 wound around the reel 42 and pulled out from the reel 42 is overlapped with the print-receiving tape 36 and enters the opening 52 together with the print-receiving tape 36, and the thermal head 9 and the platen roller 10. Pass between. Thereafter, the ink ribbon 43 is separated from the print-receiving tape 36, reaches the ink ribbon take-up reel 44 that is rotationally driven by the ribbon take-up shaft 15, and is taken up by the ink ribbon take-up reel 44.

  The double-sided pressure-sensitive adhesive tape 46 is wound around and stored on a tape spool 47 with the release paper facing outside, with the release paper superimposed on one side. The double-sided adhesive tape 46 pulled out from the tape spool 47 passes between the tape drive roller 53 and the tape feeding roller 11, and the adhesive surface on the side where the release paper is not superimposed is pasted on the print-receiving tape 36. Worn. In addition, spacers 46 </ b> A are inserted at both upper and lower ends of the double-sided adhesive tape 46.

  As a result, the print-receiving tape 36 wound around the tape spool 37 and drawn out from the tape spool 37 passes through the opening 52 in which the thermal head 9 of the tape cassette 35 is inserted. Thereafter, the print-receiving tape 36 to which the double-sided adhesive tape 46 is bonded is rotatably provided at one side lower part (lower left part in FIG. 3) of the tape cassette 35, and drives the tape feed motor 30 (see FIG. 4). The tape drive roller 53 that rotates in response to the tape drive roller 53 and the tape feed roller 11 disposed opposite to the tape drive roller 53 is sent to the outside of the tape cassette 35 to be labeled on the tape printer 1. It is discharged from the discharge port 16. In this case, the double-sided adhesive tape 46 is pressed against the print-receiving tape 36 by the tape drive roller 53 and the tape feeding roller 11.

  Further, when the tape cassette 35 is mounted in the cassette housing portion 8, each tape is placed in a corner portion (upper right corner portion in FIG. 3) facing the tape type detection sensors S1 to S5 on the bottom surface portion of the cassette body 35B. At a position facing the seed detection sensor S4, there is provided a tape specifying portion 40 in which each through hole 41A into which the tape seed detection sensor S4 is inserted is formed. As a result, each tape type detection sensor S4 outputs an off signal, and each tape type detection sensor S1, S2, S3, S5 outputs an on signal, and the type of print tape stored in the tape cassette 35 is determined. It is detected that the tape is a predetermined laminated tape having a tape width of 24 mm.

  Next, the electrical configuration of the tape printer 1 will be described with reference to FIG. FIG. 4 is a block diagram showing a control configuration of the tape printer. As shown in FIG. 4, the control configuration of the tape printer 1 is configured with a control circuit unit 20 formed on the control board as a core. The control circuit unit 20 includes a CPU 21 that controls each device, and an input / output interface 23, a CGROM 24, ROMs 25 and 26, and a RAM 27 connected to the CPU 21 via a data bus 22. A timer 210 is provided inside the CPU 21.

  Here, the CGROM 24 stores dot pattern data for display corresponding to the code data for each of a large number of characters.

  In addition, ROM (dot pattern data memory) 25 has print type dot pattern data for each of a large number of characters for printing characters such as alphabet letters and symbols, and the typeface (Gothic typeface, Mincho typeface, etc.) ), And for each typeface, six types (16, 24, 32, 48, 64, 96 dot sizes) of print character sizes are stored corresponding to the code data. In addition, graphic pattern data for printing a graphic image is also stored.

  Further, the ROM 26 reads out the display drive control program for controlling the LCDC 28 corresponding to the character code data such as characters and numbers inputted from the keyboard 6 and the data in the print buffer 272 to read the thermal head 9 and the tape feed motor 30. Print drive control program for driving the laser, a pulse number determination program for determining the number of pulses corresponding to the amount of energy formed for each print dot, a drive control program for each of the heating elements R1 to Rn of the thermal head 9, and other control of the tape printer 1 Various necessary programs are stored. The CPU 21 performs various calculations based on various programs stored in the ROM 26.

  Further, the RAM 27 is provided with a text memory 271, a print buffer 272, a line print dot number memory 273, a total print dot number memory 274, a parameter memory 275, a tape type memory 276, and the like. Document data input from 6 is stored. Also, the print buffer 272 stores dot patterns for printing such as a plurality of characters and symbols, the number of applied pulses that are the amount of energy for forming each dot, and the like, and the thermal head 9 is stored in the print buffer 272. Dot printing is performed according to the dot pattern data. The line printing dot number memory 273 stores a count value of the number of printing dots for one line (128 dots in this embodiment) printed by the thermal head 9. Further, the total print dot number memory 274 stores the total print dot number from the start of printing by the thermal head 9. The parameter memory 275 stores various parameter tables as will be described later. Further, the tape type memory 276 stores the type of tape detected by the tape type detection sensor.

  The input / output interface 23 includes a keyboard 6, the thermistor 13, tape detection sensors S1 to S5, and a display controller (hereinafter referred to as LCDC) 28 having a video RAM 281 for outputting display data to the LCD 7. A drive circuit 29 for driving the thermal head 9 and a drive circuit 31 for driving the tape feed motor 30 are connected to each other. Therefore, when characters or the like are input through the character keys of the keyboard 6, the text (document data) is sequentially stored in the text memory 271, and the keyboard is based on the dot pattern generation control program and the display drive control program. A dot pattern corresponding to a character or the like input via 6 is displayed on the LCD 7. The thermal head 9 is driven via a drive circuit 29 to print the dot pattern data stored in the print buffer 272. In synchronization with this, the tape feed motor 30 controls the tape feed via the drive circuit 31. Is to do. Here, the thermal head 9 prints characters or the like on the tape by selectively driving the heating elements R1 to Rn corresponding to the printing dots for one line via the drive circuit 29.

  Further, power is supplied from the power supply 32 to the control circuit unit 20, the drive circuit 29, and the drive circuit 31. The voltage of the power supply 32 is measured at a predetermined interval by the voltage measurement unit 34. In addition, the power source 32 is connected to a stabilized power source 33 that outputs an output obtained by lowering the voltage.

  Further, the power source 32 is connected to the drive circuits 29 and 31 of the thermal head 9 and the tape feed motor 30, and the power of the power source 32 is directly supplied. On the other hand, the stabilized power source 33 is connected to the control circuit unit 20 and supplies the power from the power source 32 at a constant voltage to the control circuit unit 20 including the LCD 7. The power source may be a battery power source or a DC power source composed of an AC adapter that inputs a commercial power source, rectifies the alternating current, and steps down and outputs a direct current.

  The voltage measurement unit 34 is connected to the CPU 21 of the control circuit unit 20, measures the voltage of the power supply 32, and outputs the measurement result to the CPU 21.

  Here, various parameter tables stored in the parameter memory 275 will be described with reference to FIGS. FIG. 5 is a schematic diagram showing a data configuration of the dot number parameter table 61. FIG. 6 is a schematic diagram illustrating a data configuration of the heat storage coefficient table 62. FIG. 7 is a schematic diagram showing a data configuration of the voltage variation coefficient table 63. FIG. 8 is a schematic diagram showing a data configuration of the correction coefficient table 64 for correcting the heat storage coefficient d.

  As shown in FIG. 5, the dot number parameter table 61 includes an environmental temperature 611 indicating a temperature measured via the thermistor 13, a total amount 612 corresponding to the environmental temperature 611, and an outflow amount 613. This total amount 612 is the maximum total number of printable dots that can be continuously printed, which is determined by the environmental temperature or the like. As described later, the print dots of the heating elements R1 to Rn of the thermal head 9 that rise by continuous printing are crushed. It represents the heat storage temperature that guarantees that it will not occur. The outflow amount 613 is the number of dots to be subtracted from the total number of printed dots every predetermined time (about 1 second in this embodiment) as will be described later. The outflow amount 613 includes (1) material, shape and size of the thermal head 9, (2) material, shape and size of the heat sink 9A, and (3) adhesion between the thermal head 9 and the heat sink 9A. The material and thickness of the agent, (4) the joining method of the heat sink 9A and the mechanical frame of the tape printer 1, (5) the material, shape and size of this mechanical frame, and (6) printing determined by the environmental temperature, etc. This is the number of dots, and represents the amount of natural heat released through the heat sink 9A of the thermal head 9 and the like.

  In the environmental temperature 611 of the dot number parameter table 61, three types of environmental temperature ranges of “30 ° C. or higher”, “20 ° C. or higher and lower than 30 ° C.”, and “less than 20 ° C.” are registered in advance. The total amount 612 for each environmental temperature 611 includes “250,000 dots” for the environmental temperature 611 “30 ° C. or higher”, “300000 dots” for the environmental temperature 611 “20 ° C. or higher and lower than 30 ° C.” For the environmental temperature 611 “less than 20 ° C.”, “460000 dots” is registered in advance as the total amount 612. The outflow 613 for each environmental temperature 611 includes “1800 dots” for “30 ° C. or higher” of the environmental temperature 611, “2000 dots” for “20 ° C. or higher and lower than 30 ° C.” of the environmental temperature 611, For the environmental temperature 611 “less than 20 ° C.”, “2600 dots” is registered in advance as the outflow amount 613. The total amount 612 and the outflow amount 613 corresponding to each environmental temperature 611 are parameters that can be changed to arbitrary numerical values in accordance with a change in the natural heat dissipation amount of the thermal head 9 due to a change in the shape of the heat sink 9A.

  Next, as shown in FIG. 6, the heat storage coefficient table 62 uses the total amount obtained by the dot number parameter table 61 of FIG. 5 as a reference value, and the number of excess dots in the current total number of dots that exceeds the reference value. 621 and the value of the heat storage coefficient d determined corresponding to the environmental temperature 622 measured through the thermistor 13 are stored in advance. Here, the value of “total amount” determined by the dot number parameter table 61 is used as the reference value for obtaining the excess dot number 621. The environmental temperature 622 is divided into five levels of “40 to 32 ° C.”, “31 to 28 ° C.”, “27 to 22 ° C.”, “21 to 17 ° C.”, and “16 to 10 ° C.”. A heat storage coefficient d is determined corresponding to the excess dot number 621. This heat storage coefficient d is used when re-evaluating the energy applied to the heat generating element in the heat storage control process described later, and determines a value to be subtracted to correct the applied energy corresponding to the accumulated temperature of the thermal head 9. Used for. If the number of excess dots 621 is the same, the value of the heat storage coefficient d increases as the environmental temperature 622 increases, and the value of the heat storage coefficient d increases as the number of excess dots increases if the environmental temperature 622 is the same. Therefore, in a state where the environmental temperature 622 is high and the number of excess dots 621 is large and the heat storage is advanced, the value of the heat storage coefficient d is large, so that the energization time is shortened and the heat storage print is not crushed. The heat storage coefficient d is subject to correction for both the temperature rise process (non-steady time) and saturation (steady time).

  Next, as shown in FIG. 7, the voltage variation coefficient table 63 includes a voltage variation coefficient that is a constant used to change the pulse width applied according to the voltage when setting the energy applied to each heating element. The voltage center value 631, a voltage range (hexadecimal data value) 632 corresponding to the voltage center value 631, and a voltage variation coefficient C (V) 633 corresponding to the voltage range 632. In FIG. 7, the value of the voltage variation coefficient C (V) is also described in hexadecimal data. The higher the voltage value, the shorter the energization time required for heat generation. Therefore, the higher the voltage value, the higher the value of the voltage variation coefficient C (V). As will be described later, since the heating element is controlled to be turned off when the value of C (V) is subtracted from the fixed value and becomes 0, the value of C (V) increases as the voltage increases. For example, the applied energy is adjusted so as to shorten the drive pulse application time.

  Next, as shown in FIG. 8, the correction coefficient table 64 is a table for determining a coefficient d1 for correcting the heat storage information in accordance with the voltage value and the type of the tape mounted. The correction coefficient table 64 includes a voltage center value 641, a voltage range (hexadecimal data value) 642 corresponding to the voltage center value 641, and a correction coefficient d1643 expressed as a percentage. Since the energization time becomes shorter as the voltage becomes higher, the correction coefficient becomes smaller than 100%, and furthermore, the difference in the required printing energy depending on the tape type is reflected in the heat storage situation. This increases the value of the correction coefficient d1 at the same voltage value, and acts to shorten the energization time.

  Next, the tape printing operation of the tape printer 1 configured as described above will be described with reference to the flowchart of FIG. FIG. 9 is a flowchart showing a flow of heat storage control processing of the tape printer 1.

  First, when the power is turned on and the processing of the tape printer 1 is started, the ambient temperature is acquired from the thermistor 13 (S1). Next, printing is started in accordance with an instruction from the user (S3). Note that the timer 210 starts counting when printing is started (S5). Next, based on the signal from the tape type detection sensor, the type of tape included in the tape cassette 35 mounted on the tape printer 1 is detected and stored in the tape type memory 276 (S7).

  Next, the temperature coefficient t, the total amount initial value (reference dot number), and the outflow amount are determined based on the environmental temperature acquired in S1 (S9). The temperature coefficient t is calculated by an equation such as t = a / temperature AD value + b (a and b are fixed values) with respect to the AD conversion value of the environmental temperature. Used when determining the applied energy. As the total amount value and the outflow amount, a value corresponding to the environmental temperature is substituted according to the dot number parameter table 61 stored in the parameter memory 275. The total amount and the outflow amount are stored in the total print dot number memory 274 of the RAM 27.

  Next, data for one line for executing printing is input, and the corresponding dot number for one line is stored in the one-line print dot number memory 273 of the RAM 27 (S11). Then, the total number of dots D is calculated by adding the number of dots for one line stored in the one-line print dot number memory 273 to the total amount determined in S11 (S13). Next, the total number of dots D calculated in S13 is subtracted by multiplying the outflow amount determined in S9 by the elapsed time from the start of printing to adjust the number of dots (S15). By the processing in S13 and S15, the number of dots D is obtained by adding the number of dots for one line to be printed from the total amount determined in S9 and multiplying the outflow amount determined in S9 by the elapsed time from the start of printing. Is subtracted (total number of dots ← total amount + number of printed dots−outflow amount × elapsed time). In this way, the temperature accumulation state of the thermal head 9 can be expressed by the number of dots by sequentially adding the number of printed dots, converting the heat dissipation amount to the number of dots, and subtracting from the number of printed dots. it can.

  Next, the heat storage coefficient d is set based on the excess dot number that is the difference between the dot number D adjusted in S15 and the reference dot number (total amount initial value set in S9) and the environmental temperature acquired in S1 (S17). ). The heat storage coefficient d is determined according to the heat storage coefficient table 62 stored in the parameter memory 275. In the first processing, since the difference between the current dot number D and the reference dot number is 50000 or less, the heat storage coefficient d is 1 regardless of the environmental temperature.

  Next, the voltage applied to the thermal head 9 is acquired from the voltage measuring unit 34 (S19). Then, the correction coefficient d1 is set based on the acquired voltage value and the tape type acquired in S7 (S21). For example, if the tape type is a receptor tape and the voltage value is 6.0, the correction coefficient d1 is 100%.

  Next, the voltage variation coefficient C (V) is set based on the voltage acquired in S19 (S23). The voltage variation coefficient C (V) is determined according to the voltage variation coefficient table 63 stored in the parameter memory 275, and is used when setting the applied energy (pulse width) described later.

  Next, the pulse width (energization time) applied to each heating element is set by substituting a predetermined value for the application control coefficient C (S25). Here, the value assigned to the application control coefficient C is a predetermined fixed value. From this fixed value, a value corresponding to the environmental temperature, voltage, and heat storage status is subtracted at predetermined time intervals according to the calculation formula described later, and energy is applied to the heating element until the value of C becomes 0 (energization is performed). ). Here, for example, 55400 is substituted for C.

  Next, it is determined whether or not the application control coefficient C is less than 0 (S27). If C is 0 or more (S27: NO), a drive pulse is applied to turn on the heating element (S29). Then, it is determined whether 250 microseconds have elapsed (S31). Until 250 microseconds have elapsed (S31: NO), the application of the drive pulse is continued (S29).

When 250 microseconds have elapsed (S31: YES), the value of the application control coefficient C is recalculated in order to determine whether or not the drive pulse application should be continued to determine the amount of energy to be applied in the future (S33). ). This re-evaluation of the applied energy is performed by a calculation formula of C ← C−C (V) × t × d. The voltage variation coefficient C (V) increases as the voltage value increases, the temperature coefficient t increases as the environmental temperature increases, and the value of the heat storage coefficient d increases as the number of excess dots and the environmental temperature increase. Therefore, the value derived by multiplying all these factors becomes large when the environmental temperature is high and the thermal storage of the thermal head 9 is progressing due to continuation of printing. If the value of the multiplication result is subtracted from the value of C to obtain a new value of C, the value of C becomes smaller when heat storage is progressing. That is, since the value of C approaches 0 sooner, the energization time of each heating element is shortened, and the occurrence of printing crushing can be avoided. Then, when the voltage is low, the correction factor d1 for is close to 100%, but crushed printing thermal storage control is larger stake and is avoided, if the voltage is high becomes the correction coefficient d1 is less than 100% Therefore, excessive heat storage control is applied and printing is not faint. Further, in the case of a receptor tape having a high printing energy, the correction coefficient d1 gradually decreases even when the voltage is increased. Therefore, in the case of a print-receiving tape in which heat storage is likely to proceed, the heat storage control is increased to shorten the pulse width. Is possible.

  Thereafter, the process returns to S27 and it is determined again whether or not the value of C calculated by S33 is less than 0. When C becomes less than 0 (S27: YES), the heating element is turned off for a predetermined time (S35), and the head is cooled. Then, it is determined whether or not to continue printing (S37). If it is to be continued (S37: YES), the process returns to S11 to input the next one line of data. When not continuing (S37: NO), a process is complete | finished.

  As described above, according to the tape printer 1 of the present embodiment, the heat storage coefficient d is corrected using the correction coefficient d1 determined by the type of tape currently mounted and the voltage applied to the thermal head 9, so Even when printing on tapes with different printing energies, heat storage information can be properly grasped, and even when printing in an environment with a long energization time such as under low voltage, the heat storage status can be accurately grasped to avoid crushing the printing. .

In the above embodiment, the CPU 21 that acquires the environmental temperature in S1 of the flowchart of FIG. 9 functions as the environmental temperature measuring means of the present invention, and the CPU 21 that detects the tape type in S7 is the print medium detecting means of the present invention. The CPU 21 that adds the number of printed dots in S13 functions as the total dot number counting means of the present invention, the CPU 21 that subtracts the outflow amount in S15 functions as the adjusting means of the present invention, and the heat storage coefficient d is calculated in S17. The CPU 21 to acquire functions as the heat storage coefficient setting means of the present invention, the CPU 21 that acquires the head voltage in S19 functions as the voltage measurement means of the present invention, and the CPU 21 that corrects the heat storage coefficient d in S21 corrects the heat storage coefficient of the present invention. The CPU 21 that functions as a means and sets the voltage fluctuation coefficient C (V) in S23 is the voltage fluctuation coefficient setting means of the present invention. The CPU 21 that functions and subtracts the voltage variation coefficient C (V) from the application control coefficient C in S33 functions as the pulse width setting means of the present invention, and the CPU 21 that executes the processing related to pulse application (S25 to S35) applies the application of the present invention. It functions as a control means.

  In addition, this invention is not limited to the said embodiment, A various change is possible. For example, the tape printer 1 has a keyboard 6 and prints text input from the keyboard 6 on a tape. The tape printer 1 is connected to an external device such as a personal computer, and print data is transferred to the external device. May be received and printed.

  The ambient temperature is not limited to that measured by the thermistor 13 installed in the tape printer 1, and the temperature around the tape printer 1 may be measured and transmitted to the tape printer 1.

It is a general | schematic upper external view except the storage cover of the tape printer 1 which concerns on this embodiment. It is a figure which shows schematic structure of the thermal head of the tape printer 1 which concerns on this embodiment, (A) is a top view, (B) is a front view. It is a top view at the time of removing the cover of the tape cassette 35 with which the tape printer 1 is mounted | worn. It is a block diagram which shows the control structure of a tape printer. 6 is a schematic diagram showing a data configuration of a dot number parameter table 61. FIG. It is a schematic diagram which shows the data structure of the thermal storage coefficient table 62. 6 is a schematic diagram showing a data configuration of a voltage variation coefficient table 63. FIG. It is a schematic diagram which shows the data structure of the correction coefficient table 64 for correct | amending the thermal storage coefficient d. 3 is a flowchart showing a flow of heat storage control processing of the tape printer 1.

DESCRIPTION OF SYMBOLS 1 Tape printer 9 Thermal head 32 Power supply 33 Stabilization power supply 34 Voltage measurement part 35 Tape cassette 36 Label tape 40 Tape specific part 41A, 41B, 41C Each through-hole 64 Correction coefficient table 65 Tape kind constant table 66 Dot number correction value table 67 Dot Number Correction Constant Table 273 Line Print Dot Number Memory 274 Total Print Dot Number Memory 275 Parameter Memory 276 Tape Type Memory S1, S2, S3, S4, S5 Tape Type Detection Sensor

Claims (4)

A thermal head having a plurality of heating elements; and a pulse applying means for selectively applying a driving voltage pulse to the heating elements, while the thermal head and the printing medium are relatively moved, In thermal printers that perform dot printing on
Environmental temperature measuring means for measuring the environmental temperature around the thermal printer;
A printing medium detection means for detecting a type of the printing medium;
A total dot number counting means for obtaining the total number of dots by sequentially adding the number of dots printed from the reference time;
By subtracting, from the total number of dots obtained by the total number of dots counting means, a predetermined number of dots corresponding to the environmental temperature measured by the environmental temperature measuring means multiplied by the elapsed time from the reference time. Adjusting means for adjusting the total number of dots ;
Heat storage coefficient setting a heat storage coefficient corresponding to the environmental temperature the excess dot count being a difference, and measured by the environmental temperature measuring means with the number of dots when the number of dots and the reference after being adjusted by said adjusting means Setting means;
Voltage measuring means for measuring a head voltage applied to the thermal head;
Heat storage for correcting the value of the heat storage coefficient set by the heat storage coefficient setting means according to the type of the print medium detected by the print medium detection means and the head voltage measured by the voltage measurement means Coefficient correction means;
Voltage fluctuation coefficient setting means for setting a voltage fluctuation coefficient corresponding to the head voltage measured by the voltage measurement means;
Application control coefficient storage means for storing at least a predetermined application control coefficient set in accordance with the thermal head;
Based on the heat storage coefficient corrected by the heat storage coefficient correction means and the voltage fluctuation coefficient stored in the voltage fluctuation coefficient storage means, the application control coefficient stored in the application control coefficient storage means is determined. A pulse width setting means that corrects every predetermined time and sets the application control coefficient after the correction to the applied pulse width of the pulse applying means;
A thermal printer comprising: application control means for controlling application of the drive voltage pulse by the pulse application means based on the applied pulse width set by the pulse width setting means . The heat storage coefficient correction means corrects the heat storage coefficient to a smaller value as the head voltage measured by the voltage measurement means is higher,
2. The thermal printer according to claim 1, wherein the pulse width setting unit reduces the rate at which the applied pulse width is reduced as the value of the heat storage coefficient is smaller . The heat storage coefficient correction means corrects the heat storage coefficient to a smaller value as the print medium detected by the print medium detection means is a print medium having higher printing energy,
3. The thermal printer according to claim 1, wherein the pulse width setting unit reduces the rate at which the applied pulse width is reduced as the value of the heat storage coefficient is smaller . The pulse width setting means uses the heat storage coefficient corrected by the heat storage coefficient correction means and the voltage variation coefficient setting means from the application control coefficient stored in the application control coefficient storage means at each predetermined time. Subtract the value multiplied by the set voltage fluctuation coefficient,
The said application control means stops the application of the said drive voltage pulse, when the said applied pulse width set by the said pulse width setting means is less than a predetermined threshold value , Any one of Claim 1 thru | or 3 characterized by the above-mentioned. the thermal printer of crab according.

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