Patent Grant
9073346
The present application claims priority from Japanese Patent Application No. 2013-270880 filed on Dec. 27, 2013, the disclosure of which is incorporated herein by reference in its entirety.
The disclosure relates to a method for thermal head energizing time control at astable voltage.
There has conventionally been proposed a method for thermal head energizing time control at astable voltage. For instance, there is a related method. Specifically, the conventional method is configured to control intermittent time of chopping pulse to be applied to a heat element so as to enable a thermal head to constantly secure stable heat even though power supply voltage varies due to load, etc. Thereby, print quality is constantly secured.
The conventional method has intended to set temperature rise of a heat element in the thermal head at a constant rate whereas an error of resistance value and ambient temperature of the thermal head have not been reflected for the control manner of intermittent time of chopping pulse.
The disclosure has been made in view of the above-described problems and has an object to provide a method for thermal head energizing time control at astable voltage in such a manner that an error of resistance value and ambient temperature of a thermal head is reflected for the control.
To achieve the purpose of the disclosure, there is provided a method for thermal head energizing time control at astable voltage, wherein every printing period, the method carries out the steps of: (1) setting a first fixed value as initial value of a decreasing variable number and a second fixed value, the first fixed value corresponding to a type of printing medium subjected to print by the thermal head and the second fixed value corresponding to a measured resistance value of the thermal head; (2) starting energization of the thermal head immediately after a start of a printing period in simultaneous with detecting temperature and voltage of the thermal head; (3) determining a chopping duty ratio based on the voltage of the thermal head detected at the step (2) and the second fixed value set at the step (1); (4) starting energization of the thermal head and keeping the energization until lapse of a pulse application time which is calculated based on the chopping duty ratio determined at the step (3); (5) stopping the energization of the thermal head at the lapse of the pulse application time calculated based on the chopping duty ratio determined at the step (3) and withholding the energization until lapse of a unit time; (6) decrementing a calculation value from the decreasing variable so as to obtain a renewed decreasing variable number, the calculation value being calculated by using the temperature and the voltage of the thermal head detected at the step (2); and (7) repeating series of the steps (2) through (6) in a case where the renewed decreasing variable number is larger than a predetermined value whereas withholding the energization of the thermal head until the lapse of the printing period in a case where the renewed decreasing variable number is equal to or smaller than the predetermined value.
There is further provided a method for thermal head energizing time control at astable voltage, wherein every printing period, the method carries out the steps of: (1) setting a first fixed value as initial value of a decreasing variable number and a second fixed value, the first fixed value corresponding to a type of printing medium subjected to print by the thermal head and the second fixed value corresponding to a measured resistance value of the thermal head; (2) starting energization of the thermal head immediately after a start of a printing period in simultaneous with detecting temperature and voltage of the thermal head; (3) determining a chopping duty ratio based on the voltage of the thermal head detected at the step (2) and the second fixed value set at the step (1); (4) starting energization of the thermal head and keeping the energization until lapse of a pulse application time which is calculated based on the chopping duty ratio determined at the step (3); (5) stopping the energization of the thermal head at the lapse of the pulse application time calculated based on the chopping duty ratio determined at the step (3) and withholding the energization until lapse of a unit time; (6) decrementing a calculation value from the decreasing variable number so as to obtain a renewed decreasing variable number, the calculation value being calculated by using the temperature and the voltage of the thermal head detected at the step (2); and (7) repeating series of the steps (2) through (6) in a case where the renewed decreasing variable number is larger than a predetermined value whereas withholding the energization of the thermal head until the lapse of the printing period in a case where the renewed decreasing variable number is equal to or smaller than the predetermined value, wherein, in a case where the voltage detected at the step (2) is equal to or lower than a threshold, a value of the chopping duty ratio is set to “1” at the step (3).
There will be given a detailed description of an exemplary embodiment of a method for thermal head energizing time control at astable voltage, embodying the disclosure, by referring to the accompanying drawings.
There will be described details about schematic configuration of a tape printing apparatus 1 that carries out the “astable conduction control method” directed to the disclosure by referring to
As shown in
The keyboard 3 includes plural operation keys such as letter input keys 3A, a print key 3B, cursor keys 3C, a power key 3D, a setting key 3E, a return key 3R, etc. The letter input keys 3A are operated for inputting letters that create texts consisting of document data. The print key 3B is operated for commanding to print out printing data consisting of created texts, etc. The cursor keys 3C are operated for moving a cursor being indicated in the liquid crystal display 4 up, down, left or right. The power key 3D is operated for turning on or off the power supply from a battery cell 81 (refer to
The liquid crystal display 4 is a display device for indicating characters such as letters, etc. in plural lines, i.e., displaying printing data created by the keyboard 3.
As shown in
Inside the tape printing apparatus 1, a cassette holding frame 18 is arranged. As shown in
The tape cassette 5 includes a tape spool 32, a ribbon feeding spool 34, a used-ribbon-take-up spool 35, a base-material-sheet feeding spool 37 and a bonding roller 39 in a rotatably-supported manner, inside thereof. A surface tape 31 is wound around the tape spool 32. The surface tape 31 is made of a transparent tape such as PET (polyethylene terephthalate) film or the like. An ink ribbon 33 is wound around the ribbon feeding spool 34. On the ink ribbon 33, there is applied ink that melts or sublimes when heated so as to form an ink layer. A part of the ink ribbon 33 that has been used for printing is taken up in the used-ribbon-take-up spool 35. A double tape 36 is wound around the base-material-sheet feeding spool 37. The double tape 36 is configured so as to bond a release tape to one side and the other side of a double-sided adhesive tape wherein the double-sided adhesive tape includes adhesive agent layers at both sides thereof with width the same as width of the surface tape 31. The double tape 36 is wound around the base-material-sheet feeding spool 37 so that the release tape is put outside. The bonding roller 39 is used for bonding the double tape 36 and the surface tape 31 together.
As shown in
When the arm 20 fully swings clockwise, the platen roller 21 presses the surface tape 31 and the ink ribbon 33 against a thermal head 41 to be described later. At the same time, the conveying roller 22 presses the surface tape 31 and the double tape 36 against the bonding roller 39.
A plate 42 is arranged upright inside the cassette holding frame 18. The plate 42 includes a thermal head 41 at its side surface facing the platen roller 21. As shown in
In this connection, the direction that the heat elements 41A are aligned is the “main scanning direction D1 for the thermal head 41”. Further, a direction that the surface tape 31 and the ink ribbon 33 moves passing the thermal head 41 is the “sub scanning direction D2 for the thermal head 41”.
Reverting to
Further, as shown in
In the cassette holding frame 18, there is arranged a tape conveying motor 2 (refer to
Accordingly, when rotation of an output shaft of the tape conveying motor 2 is started with supply of power to the tape conveying motor 2, rotation of the used-ribbon-take-up spool 35, the bonding roller 39, the platen roller 21 and the conveying roller 22 is started in conjunction with the operation of the tape conveying motor 2. Thereby, the surface tape 31, the ink ribbon 33 and the double tape 36 in the tape cassette 5 are loosed out from the tape spool 32, the ribbon feeding spool 34 and the base-material-sheet feeding spool 37, respectively, and are conveyed in a downstream direction (toward the tape ejecting portion 10 and the used-ribbon-take-up spool 35).
Thereafter, the surface tape 31 and the ink ribbon 33 are bonded together and go through a path between the platen roller 21 and the thermal head 41 in a superimposed state. Accordingly, in the tape printing apparatus 1 of the embodiment, the surface tape 31 and the ink ribbon 33 are conveyed with being pressed by the platen roller 21 and the thermal head 41. At this moment, considerable number of the heat elements 41A aligned on the thermal head 41 are selectively and intermittently energized (in a manner of pulse application) by a control unit 60 (refer to
Each heat element 41A gets heated by power supply and melts or sublimes ink applied on the ink ribbon 33. Therefore, ink in the ink layer on the ink ribbon 33 is transferred onto the surface tape 31 in a unit of dots. Consequently, a printing-data-based dot image desired by a user is formed on the surface tape 31 as mirror image.
After passing through the thermal head 41, the ink ribbon 33 is taken up by the ribbon-take-up roller 46. On the other hand, the surface tape 31 is superimposed onto the double tape 36 and goes through a path between the conveying roller 22 and the bonding roller 39 in a superimposed state. At the same time, the surface tape 31 and the double tape 36 are pressed against each other by the conveying roller 22 and the boding roller 39 so as to form a laminated tape 38. Of the laminated tape 38, a printed-side surface of the surface tape 31 furnished with dot printing and the double tape 36 are firmly superimposed together. Accordingly, a user can see a normal image of the printed image from the reversed side for the printed-side surface of the surface tape 31 (i.e., the top side of the laminated tape 38).
Thereafter, the laminated tape 38 is conveyed further downstream with respect to the conveying roller 22 to reach the tape cutting mechanism including the cutter 17. The tape cutting mechanism consists of the cutter 17 and the tape cutting motor 72 (refer to
The laminated tape 38 thus cut off is ejected outside of the tape printing apparatus 1 via the tape ejecting portion 10. By peeling off the release paper from the double tape 36 and exposing the adhesive agent layer, the laminated tape 38 can be used as adhesive label that can be adhered to an arbitrary place.
Next, the control configuration of the tape printing apparatus 1 will be described referring to drawings. As shown in
The control unit 60 consists of a CPU 61, a CG-ROM 62, an EEPROM 63, a ROM 64 and a RAM 66. Furthermore, the control unit 60 is connected to the timer 67, the head driving circuit 68, the tape-cutting-motor driving circuit 69, the tape-conveying-motor driving circuit 70, the battery cell 81 and a head drive voltage detecting circuit 82. The control unit 60 is also connected to the liquid crystal display 4, a cassette sensor 7, a thermistor 73, the keyboard 3 and a connection interface 71.
The CPU 61 is a central processing unit that plays a primary role for various system controls of the tape printing apparatus 1. Accordingly, the CPU 61 controls various peripheral devices such as the liquid crystal display 4 etc. in accordance with input signals from the keyboard 3 as well as various control programs.
The CG-ROM 62 is a character generator memory wherein image data of to-be-printed letters and signs are associated with code data and stored in dot patterns. The EEPROM 63 is a non-volatile memory that allows data write for storing therein and deletion of stored data therefrom. The EEPROM 63 stores data that indicates user setting etc. of the tape printing apparatus 1.
The ROM 64 stores various control programs and various data for the tape printing apparatus 1. Accordingly, programs and data tables for “astable energization control method” to be described later are stored in the ROM 64.
The RAM 66 is a storing device for temporarily storing a processing result of the CPU 61 etc. The RAM 66 also stores printing data created with inputs by means of the keyboard 3, printing data taken therein from external apparatus 78 via the connection interface 71.
The timer 67 is a time-measuring device that measures passage of predetermined length of time for executing control of the tape printing apparatus 1. More specifically, the timer 67 is referred in programs for the “astable energization control method” to be describer later so as to detect a printing cycle, a unit time (250 μm sec.), start and termination of an energization (pulse application) period for a heat element 41A of the thermal head 41, etc. Further, the thermistor 73 is a sensor that detects temperature in vicinity of the thermal head 41 and attached on the thermal head 41. Further, the head drive voltage detecting circuit 82 is a circuit that serves to detect voltage of the thermal head as head drive detection voltage.
The head driving circuit 68 is a circuit that serves to supply a driving signal to the thermal head 41 for controlling drive state of the thermal head 41 in response to a control signal from the CPU 61 along with control programs for “astable energization control method” to be described later. In this connection, the head driving circuit 68 controls to energize and de-energize each of the heat elements 41A based on a signal (strobe (STB) signal) associated with a strobe number assigned to each heat element 41A for comprehensively controlling heating manner of the thermal head 41. The tape-cutting-motor driving circuit 69 is a circuit that serves to supply a driving signal to the tape cutting motor 72 based on the control signal from the CPU 61 for controlling operation of the tape cutting motor 72. Further, the tape-conveying motor driving circuit 70 is a control circuit that serves to supply a driving signal to a tape conveying motor 2 based on the control signal from the CPU 61 for controlling operation of the tape conveying motor 2.
Next, there will be described on the “astable energization control method” carried out by the above-described tape printing apparatus 1 directed to the present embodiment.
In the “astable energization control method”, a determination to de-energize the thermal head 41 during a printing period is made within an astable energization control time which is significantly short while pulse application voltage of the thermal head 41 is monitored. Consequently, an energizing time of the thermal head 41 bears a proportionate relationship to a value of integral of application voltage of the thermal head 41.
Especially, in the “astable energization control method” directed to the present embodiment, a determination to de-energize the thermal head 41 during a printing period is made within 250 μm sec. set as a unit time while application voltage of the thermal head 41 is monitored. As shown in
A chopping duty ratio is determined based on voltage of the thermal head 41 and a second fixed value which is determined according to a measured resistance value of the thermal head 41. As shown in
As shown in
Incidentally, a resistance value of a thermal head 41 is measured before the thermal head 41 is attached to the tape printing apparatus 1. A thermal head 41 of which a measured resistance value falls within any one of the ranks A, 13 and C is qualified for attachment to the tape printing apparatus 1. Accordingly, a measured resistance value of a thermal head 41 attached to the tape printing apparatus 1 falls within a range from more than 85% to less than 115% of a true value of the resistance value of the thermal head 41.
As shown in
In a case where a second fixed value is determined to be “1.0” based on a measured resistance value of a thermal head 41, namely, in a case where the measured resistance value thereof falls within rank B, a chopping duty ratio is set under 100% as indicated at a “duty” column in the data table of
Further, in a case where a second fixed value is determined to be “0.9” based on a measured resistance value of a thermal head 41, namely, in a case where the measured resistance value thereof falls within rank A, a chopping duty ratio is set under 100% as indicated at a “duty” column in the data table of
In this connection, each value at the “duty” column in the data table of
Further, in a case where a second fixed value is determined to be “1.1” based on a measured resistance value of a thermal head 41, namely, in a case where the measured value thereof falls within rank C, a chopping duty ratio is set to 100% when voltage at the thermal head 41 falls within a range from 7.2 V to 7.7 V so that energization (pulse application) of the thermal head 41 is fully continued during the unit time (250 μm sec.). That is, energization of the thermal head 41 is performed full time during a unit time when low voltage is used for rank C.
Meanwhile, when voltage at the thermal head 41 is higher than 7.7 V, a chopping duty ratio is set under 100% for rank C. In that case, energization (pulse application) of the thermal head 41 is started from a start of a unit time (250 μm sec.) and continued for a time of which duration is a product of the unit time (250 μm sec.) and a chopping duty ratio. After that, energization (pulse application) of the thermal head 41 is withheld until expiration of the unit time (250 μm sec.). That is, when voltage higher than 7.7 V is used, energization of the thermal head 41 is performed every unit time (250 μm sec.), wherein duration of energization within a unit time (250 μm sec.) is a product of the unit time (250 μm sec.) and a chopping duty ratio.
In this connection, each value at the “duty” column in the data table of
Incidentally, each chopping duty ratio at voltage higher than 7.7 V is calculated based on average amount of energy given to a thermal head 41 during a unit time (250 μm sec.) when voltage of the thermal head 41 falls within a range from 7.2 V to 7.7V, i.e., when a chopping duty ratio is set to 100%. That is, a chopping duty ratio set at the time of high voltage is calculated based average amount of pulse-application energy given to a thermal head 41 with a chopping duty ratio of 100% set at the time of low voltage. Average amount of pulse-application energy given to a thermal head 41 at the time of low voltage can be thus used for setting a chopping duty ratio at the time of high voltage per significantly short time such as unit time (250 μm sec.). Thereby, there can be precisely set pulse-application energy required at each high voltage level.
More specifically, according to the data table of
Accordingly, “600” is obtained as average amount of pulse-application energy given to a thermal head 41 at the time of low voltage within the range from 7.2 V to 7.7 V. Therefore, each chopping duty ratio at the time of voltage higher than 7.7 V is set to a value which makes amount of energy given to a thermal head 41 during a unit time (250 μm sec.) “600”.
Thus, based on a data table of proper rank determined according to a measured resistance value of a thermal head 41, energization (pulse application) of the thermal head 41 is controlled every unit time (250 μm sec.) by properly setting a chopping duty ratio. Energy control based on a chopping duty ratio setting is repeatedly at next unit time (250 μm sec.) on condition that a decreasing variable number C calculated at expiration of each unit time (250 μm sec.) is larger than “0” as long as the current printing period Ts does not reach the end. In a case where a decreasing variable number C calculated at expiration of each unit time (250 μm sec.) is under “0” at the current unit time (250 μm sec.), energy control based on a chopping duty ratio setting is terminated at the end of the current unit time and energization (pulse application) of the thermal head 41 is withheld thereafter until start of a next printing period Ts.
In this connection, a fixed number previously determined according to a type of a tape cassette 5 housed in the cassette holding portion 8 is assigned to the decreasing variable number C as its initial value. More specifically, as shown in the data table of
Incidentally, a value to be determined based on voltage and ambient temperature of the thermal head 41 is calculated by taking the following steps. Firstly, there is referred to one of values at “C(V)” column associated with respective voltage level of the thermal head 41 in any one of the data tables of
In “astable energization control method”, in a case of either rank A or rank B determined to be so according to a measured resistance value of the thermal head 41 on condition that voltage of the thermal head 41 during a single printing period Ts falls within a range from 7.2 V to 9.2 V, energization (pulse application) of the thermal head 41, of which chopping duty ratio lowers 100%, is continuously repeated every unit time (250 μm sec.) from the start of the printing period Ts. Thereby, temperature rise of the thermal head 41 can be suppressed even at high voltage level, which can possibly prevent unintended cut-off of the ink ribbon 33 due to high-heat melting and reduce frequency of fusion at a part of a surface tape 31 onto which heat elements 41 get contact (so-called sticking). As to the case of
Meanwhile, in a case of rank C determined to be so according to a measured resistance value of the thermal head 41 on condition that voltage of the thermal head 41 during a single printing period Ts falls within a range from 7.2 V to 7.7 V, energization (pulse application) of the thermal head 41, of which chopping duty ratio is 100%, is continuously repeated every unit time (250 μm sec.) from the start of the printing period Ts until point of time at which the decreasing variable number C turns to “0” during the printing period Ts. As to the case of
Meanwhile, in a case where voltage of the thermal head 41 during a single printing period is higher than 7.7 V, energization (pulse application) of the thermal head 41, of which chopping duty ratio lowers 100%, is continuously repeated every unit time (250 μm sec.) from the start of the printing period Ts, as shown in
When voltage of the thermal head 41 during the single printing period Ts thereafter falls within a range from 7.2 V to 7.7 V, energization (pulse application) of the thermal head 41, of which chopping duty ratio is 100%, is continuously repeated every unit time (250 μm sec.) until point of time at which the decreasing variable number C turns to “0” during the printing period Ts.
Among the data table of
Also, among the data table of
It is to be noted that the data tables of
Next, there will be described on the flow chart of the main program shown in
In the main program shown in
At S12, print-start or not is determined. A determination at S12 is made based on a print-command acceptance result at S11. In a case where print is not started (S12: NO), the process returns to S11 and the series of processes of S11 and S12 is repeated. In a case where print is started (S12: YES), the process shifts to S13.
At S13, ambient temperature of the thermal head 41 is detected by the thermistor 73 in a manner of analog to digital conversion. Temperature information is obtained at S13 for pulse application control according to environmental temperature. After that, the process shifts to S14.
At S14, the type of the tape cassette 5 housed in the cassette holding portion 8 is read by the cassette sensor 7. Cassette-type information is obtained at S14 for pulse application control according to type of the tape cassette 5. After that, the process shifts to S15.
At S15, the tape conveying motor 2 is turned on. After that, the process shifts to S16.
At S16, it is detected whether or not the surface tape 31 housed in the tape cassette 5 is fed by a length for a front margin. Thereby, a front margin is secured. In a case where the surface tape 31 housed in the tape cassette 5 is not fed by a length for a front margin (S16: NO), the process returns to S15 and the series of processes of S15 and S16 is repeated. In a case where the surface tape 31 housed in the tape cassette 5 is fed by a length for a front margin (S16: YES), the process shifts to S17.
At S17, data input is carried out with respect to one line of data corresponding to the line head 41B of the thermal head 41. That is, arrangement of bits for print image data is converted from the sub-scanning direction D2 to the main-scanning direction D1 of the thermal head 41, which is so-called longitudinal-lateral conversion. From the longitudinal-lateral converted print image data, there is taken out one line of data in the sub-scanning direction D2 of the thermal head 41. After that, the process shifts to S18.
At S18, a data process is carried out. Thereby, one line of data at S17 is converted to another-form data which enables energization control of the thermal head 41. After that, the process shifts to S19.
At S19, the data obtained at S18 is transferred to the thermal head 41 through the head driving circuit 68. At this stage, print data is transferred to a shift register of the thermal head 41 and data latch is completed. After that, the process shifts to S20.
At S20, astable energization control directed to the “astable energization control method” of the present embodiment is executed. The details of the astable energization control will be described later. After that, the process shifts to S21.
At S21, it is determined whether or not an error occurs. An error referred to here may be necessity of battery change, etc. In a case where an error occurs (S21: YES), current print is forcedly terminated and the process subsequently retunes S11 so that the series of processes of S11 through S21 is repeated. In a case of no error (S21: NO), the process shifts to S22.
At S22, it is detected whether or not the series of processes of S17 through S20 is done for all the lines of data in the sub-scanning direction D2 of the thermal head 41. In a case where the series of processes of S17 through S20 is not yet done for all the lines of data in the sub-scanning direction D2 of the thermal head 41 (S22: NO), the process returns to S17 and processes to follow S17 are repeated. Thereby, the series of processes is done through for the rest lines of data. In a case where the series of processes of S17 through S20 is done for all the lines of data in the sub-scanning direction D2 of the thermal head 41 (S22: YES), the process shifts to S23.
At S23, it is detected whether or not the surface tape 31 housed in the tape cassette 5 is fed by a length for a back margin. Thereby, a back margin is secured. In a case where the surface tape 31 housed in the tape cassette 5 is not fed by a length for a back margin (S23: NO), the process returns to S23 and the step of S23 is repeated. In a case where the surface tape 31 housed in the tape cassette 5 is fed by a length for a back margin (S23: YES), the process shifts to S24.
At S24, the tape conveying motor 2 is turned off. After that, the process shifts to S25.
At S25, control for print is completed. After that, the process returns to S11 and the series of processes to follow S11 are repeated.
Next, there will be described on the astable energization control at S20 in
Here will be described on a constant corresponding to a type of a tape cassette 5. A constant corresponding to a type of a tape cassette 5 is a fixed value which is related to essential application energy and individually set for a type of a print medium. More specifically, according to the data table shown
At S32, ambient temperature of the thermal head 41 is read in an analog value by the thermistor 73 and converted in a digital value. Temperature information obtained at this step is assigned to a variable TH prepared in the RAM 66. After that, the process shifts to S33.
At S33, energization of the thermal head 41 is started. After that, the process shifts to S34.
At S34, voltage at the thermal head 41 in a normal state is read in an analog value and converted in a digital value. The voltage read and converted in digital is assigned to a variable V. The variable V is stored in the RAM 66. After that, the process shifts to S35.
At S35, a variable CHP_Duty for a chopping duty ratio is determined. A variable CHP_Duty is determined based on a data table of a proper rank while the variable V (voltage at the thermal head 41) obtained at S34 is used as a parameter. Having been explained already at [Outline of “Astable Energization Control Method”] in detail, how to find rank to which a measured resistance value of the thermal head 41 belongs will be omitted. Specific examples of data tables are shown in
At S36, it is determined whether or not to keep pulse application of the thermal head 41 (energization of the thermal head 41). This determination is made based on duration of pulse application time for the thermal head 41 which is equal to the product of 250 μm sec. as a unit time and the above variable CHP_Duty. In a case where it is determined to keep pulse application to the thermal head 41 (energization of the thermal head 41) (S36: YES), the process returns to S36 itself for repeating S36. In a case where it is determined not to keep pulse application to the thermal head 41 (energization of the thermal head 41) (S36: NO), the process shifts to S37.
At S37, energization of the thermal head 41 is stopped. After that, the process shifts to S38.
At S38, it is detected whether or not a unit time (250 μm sec.) has passed since start of energization at S33. In a case where a unit time (250 μm sec.) has not passed since start of energization at S33 (S38: NO), the process returns to S38 itself for repeating S38. In a case where a unit time (250 μm sec.) has passed since start of energization at S33 (S38: YES), the process shifts to S39.
At S39, a current decreasing variable number C is replaced with a new decreasing variable number C by decrementing a value C(V) related to the variable V (voltage V of the thermal head 41) at S34 from the previous decreasing variable number C. In this connection, a value C(V) related to the variable V (voltage V of the thermal head 41) at S34 is read from a “C(V)” column of one of the data tables shown in
Meanwhile, a value C(V) related to the variable V (voltage of the thermal head 41) at S34 is corrected by using a corrective coefficient K (TH) which is related to a variable TH (ambient temperature of the thermal head 41) at S32. A corrective coefficient K (TH) is read from the “corrective coefficient” column in the data table shown in
As to ambient temperature and voltage of the thermal head 41 used at S39, a variable TH (ambient temperature of the thermal head 41) at S32 and a variable V (voltage of the thermal head 41) at S34 are used without correction. After that, the process shifts to S40.
At S40, it is detected whether or not the renewed decreasing variable number C renewed at S39 is under “0”. In a case where the renewed decreasing variable number C is not under “0” (S40: NO), the process returns to S32 and processes to follow S32 are repeated. In a case where the renewed decreasing variable number C is under “0” (S40: YES), the process shifts to S41.
At S41, energization of the thermal head 41 is stopped. After that, the process shifts to S42.
At S42, it is detected whether or not a printing period Ts has passed. In a case where a printing period Ts has not passed (S42: NO), the process returns to S42 and repeated for S42. In a case where a printing period has passed (S42: YES), the process returns to the main program shown in
The tape printing apparatus 1 carrying out the “astable energization control method” of the present embodiment includes: the thermal head 41 which is made up of plural heat elements 41A serving to perform print on a surface tape 31 by transmitting heat to the surface tape 31; the head driving circuit 68 which apples voltage to the thermal head 41; the head drive voltage detecting circuit 82 which detects voltage applied to the thermal head 41; the thermistor 73 which detects ambient temperature of a heat element 41A of the thermal head 41; the ROM 64 which stores constants as first fixed values corresponding to respective types of surface tapes 31 (tape cassettes 5); the timer 67 which measures passage of a unit time (250 μm sec.); and the control unit 60. Further, the ROM 64 stores a constant K(R) as a second fixed value corresponding to a measured resistance value of the thermal head 41.
The control unit 60 decrements a predetermined value (C(V)×K(TH)) from a constant which is preset according to a type of the surface tape 31 (tape cassette 5) so as to obtain a current decreasing variable number C (S39). After that, the control unit 60 calculates a chopping duty ratio according to voltage (variable V) detected by the head drive voltage detecting circuit 82 and a constant K(R) as a second fixed value corresponding to a measured resistance value of the thermal head 41 (S35) and subsequently controls an energizing time T of the thermal head 41 (S31 through S40), the energizing time T being made up of repetitions of unit time (250 μm sec.).
In the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, the following steps (1) through (7) are taken every printing period Ts: (1) a first fixed value corresponding to a type of a surface tape 31 (tape cassette 5) subjected to print by the thermal head 41 is set as initial value of the decreasing variable number C and a constant K(R) is determined as a second fixed value corresponding to a measured resistance value of the thermal head 41 (S31); (2) energization of the thermal head 41 is started immediately after the start of the printing period Ts (S33) and ambient temperature and voltage of the thermal head 41 are detected (S32, S34); (3) a variable CHP_Duty for a chopping duty ratio is determined according to the constant K(R) as the second fixed value which is determined based on the detected ambient temperature and voltage of the thermal head 41 (S35); (4) energization of the thermal head 41 is started and kept until lapse of a pulse application time which is calculated based on the thus determined variable CHP_Duty for the chopping duty ratio (S36: YES); (5) energization of the thermal head 41 is stopped at lapse of the pulse application time and thereafter withheld until lapse of the unit time (250 μm sec.), the pulse application time having been calculated based on the thus determined variable CHP_Duty for the chopping duty ratio in the unit time (S37, S38: NO); (6) a value (C(V)×K(TH)) calculated based on temperature and voltage of the thermal head 41 is decremented from the current decreasing variable number C so as to obtain a renewed variable number C (S39); and (7) in a case where the renewed decreasing variable number C is not under a predetermined value (i.e., larger than “0”) (S40: NO), the series of the above steps (2) through (6) are repeated, while in a case where the renewed decreasing variable number C is under the predetermined value (i.e., the same as or smaller than “0”), energization of the thermal head 41 is withheld until lapse of a printing period Ts (S41, S42: NO).
That is, according to the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, the series of the above steps (2) through (6) is repeated as long as the renewed decreasing variable number C is not under a predetermined value (i.e., larger than “0”) (S40: NO) while in a case where the renewed decreasing variable number C is under the predetermined value (i.e., the same as or smaller than “0”), energization of the thermal head 41 is withheld until lapse of a printing period Ts (S41, S42: NO). In this connection, at S35 in the above step (3), a variable CHP_Duty for a chopping duty ratio is determined according to the constant K(R) as the second fixed value which is determined only based on the detected ambient temperature and voltage of the thermal head 41 and subsequently, at S39 in the above step (6), a value (C(V)×K(TH)) calculated based on temperature and voltage of the thermal head 41 is decremented from the current decreasing variable number C so as to obtain a renewed decreasing variable number C. That is, regarding thermal head 41, an error of resistance value between a measured value and a true value as well as ambient temperature can be reflected the above steps (3) and (6) for the astable energization control.
According to the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, as shown in
According to the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, in a case where a constant K(R) as a second fixed value is determined to be “1.1” according to a measured resistance value of the thermal head 41 (i.e., in a case where the a measured resistance value of the thermal head 41 falls within rank C) and voltage of the thermal head 41 detected at S34 is 7.7 V or lower, a variable CHP_Duty for a chopping duty ratio to be determined at S35 is set to “100%” (i.e., “1”) as indicated at the “duty” column of the data table shown in
According to the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, in a case where voltage detected at S34 is 7.7V or lower, a variable CHP_Duty for a chopping duty ratio to be determined at S35 is set to “100%” (i.e., “1”) on condition that a constant K(R) as a second fixed value is determined to be “1.1” according to a measured resistance value of the thermal head 41 (i.e., in a case where the a measured resistance value of the thermal head 41 falls within rank C). Thereby, pulse application energy is secured sufficiently. In this connection, a rare case is such that a variable CHP_Duty for a chopping duty ratio to be determined at S35 is set to “100%” (i.e., “1”) while most cases are such that a variable CHP_Duty is set under “100%” (i.e., under “1”). Therefore, in further minute detail, a resistance value error of the thermal head 41 can be reflected in the astable energization control.
According to the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, in a case where a constant K(R) as a second fixed value is determined to be “1.1” according to a measured resistance value of the thermal head 41 (i.e., in a case where the measured resistance value of the thermal head 41 falls within rank C) and voltage of the thermal head 41 detected at S34 is higher than 7.7 V (a threshold), a variable CHP_Duty for a chopping duty ratio to be determined at S35 is appropriately set based on average amount of energy generated per unit time (250 μm sec.) at low voltage range of under 7.7 V (namely, 7.2 V to 7.7 V) as indicated at the “duty” column and the “power” column of the data table shown in
The present disclosure is not limited to the above-described embodiment, and therefore, modifications can be made thereto without departing from the spirit of the disclosure.
For instance, in the “astable energization control” shown in
Further, in the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, a predetermined range (falling within more than a true value×85% to less than a true value×105%) in which a true value of resistance value of the thermal head 41 is centered is set and further classified into equally-divided three ranges, as shown in
Further, in the “astable energization control method” carried out by the tape printing apparatus 1 directed to the present embodiment, the ROM 64 stores a measured resistance value of the thermal head 41, the rank-classification data table shown in
While presently exemplary embodiments have been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the disclosure as set forth in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-270880 | Dec 2013 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4675695 | Samuel | Jun 1987 | A |
| 5625399 | Wiklof et al. | Apr 1997 | A |
| 6325481 | Pietz et al. | Dec 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| H08-300713 | Nov 1996 | JP |
