WO2003007466A1

WO2003007466A1 - Dc motor drive circuit and tape printer comprising the same circuit

Info

Publication number: WO2003007466A1
Application number: PCT/JP2002/007119
Authority: WO
Inventors: Hirotsugu Unotoro; Takamine Hokazono; Yasuhiro Shibata; Yoshio Sugiura; Naoki Tanjima; Naruhito Muto
Original assignee: Brother Kogyo Kabushiki Kaisha
Priority date: 2001-07-12
Filing date: 2002-07-12
Publication date: 2003-01-23

Abstract

A DC motor drive circuit for stabilizing the rotation of the DC motor just after power supply and for preventing its reverse rotation just after a stop of power supply. As the circuits for supplying a power source voltage to a DC motor (6), an unstable voltage supply circuit (103) is disposed as well as a stable voltage supply circuit (104) that shares a transistor (TR1) with this circuit. The stable voltage supply circuit (104) is used at the beginning of the start-up of the DC motor (6), and the unstable voltage supply circuit (103) is switched on when the DC motor (6) reaches a constant speed.

Description

Description DC motor drive circuit and tape printer using the same

Technical field

The present invention relates to a DC motor drive circuit and a tape printer using the same.

Background art

There is known a tape writer for running a wound long tape while unwinding it by a DC motor (hereinafter referred to as a DC motor) and performing line printing in a dot pattern on the tape. Among such tape writers, there is a tape writer in which a cutter for cutting a tape is disposed downstream of a printing position. If such a tape writer is used, the tape can be cut manually or automatically after printing, so that a printed tape cut to a desired length can be easily obtained.

In such a tape writer, in order to rotate the DC motor at a constant speed, in addition to an on / off circuit for supplying power from a power supply to the DC motor, the number of rotations of the tape writer is determined using a back electromotive force of the DC motor. In many cases, an electronic governor circuit for controlling to a value of is connected to the DC motor. While the power is being supplied to the DC motor and the tape is running at a constant speed, the print head is driven at regular intervals so that printing is performed at uniform dot intervals, and printing is performed on the tape. Is applied. On the other hand, while the tape is not running at a constant speed, that is, from when the power supply to the DC motor is turned off to when the tape reaches the constant speed after stopping the DC motor and restarting the power supply to the DC motor. In, printing is performed at the drive timing determined according to the mechanical characteristics of the device, the type of tape used, the magnitude of the power supply voltage, etc., so that printing is performed on the tape at the same dot interval as when traveling at constant speed The head is driven.

In a tape writer with a cutter as described above, the printing position by a print head such as a thermal head and the cutting position by a cutter are different due to mechanical structural reasons. I have to leave to some extent. Therefore, a margin equal to the distance between the printing position and the cutting position is inevitably formed at the beginning of one printed tape obtained at the start of a series of printing operations, and the user manually removes the tape later. It must be cut, which makes it inconvenient to use. Therefore, in order to obtain a printed tape with a small margin, the drive of the DC motor is interrupted during printing, the tape is temporarily stopped, the tape is cut off, and the DC motor is driven again to resume printing. Need to be done. Also, if the size of the image (including both text and graphics) data to be printed exceeds the memory capacity of the tape writer, drive the DC motor after printing the image data stored in memory. It is necessary to interrupt the tape and temporarily stop the tape, capture the remaining image data from an external device, and then restart the DC motor to resume printing. '

When the power supply to the DC motor is turned off by the on / off circuit to temporarily stop the tape, the rotation speed of the DC motor thereafter is always determined by the back electromotive force generated inside it regardless of the variation in the power supply voltage. The rate decreases at the same rate and eventually stops, with which the tape stops running. However, after the DC motor is stopped, the DC motor moves in the reverse direction due to the force received from the tape transport mechanism such as the elastic return force due to the release of the bending in the normal rotation direction of the platen roller that was stored when power was supplied. (The tape firmly held between the platen roller and the print head is rarely transported in the opposite direction even if the DC motor rotates in the reverse direction.) ). Therefore, when such a reverse rotation of the DC motor occurs, when the power supply to the DC motor is resumed, the DC motor is rotated forward by an amount equal to the reverse rotation amount to change the state of the transport mechanism such as the platen roller. You will have to start printing after you have put it back. However, since the amount of reverse rotation of the DC motor is not constant because it depends on the type of tape used, it is difficult to perform uniform control without using an additional member for detecting the amount of reverse rotation. is there. As a result, before and after the tape running interruption, the print The problem is that the gaps vary, printing does not go well, and print quality deteriorates.

Also, when the power supply to the DC motor is restarted via the on / off circuit to restart the tape running, the magnitude of the power supply voltage varies until the electronic governor circuit functions and the motor speed stabilizes (for example, , Which causes the battery voltage to drop due to use) appears as variations in the motor speed. In other words, when the power supply to the DC motor is resumed, the motor rotation speed varies according to the variation in the power supply voltage, and as a result, printing is performed according to the variation in the power supply voltage before and after the tape running interruption. There is also a problem that the dot spacing varies, printing is not performed well, and printing quality is degraded.

Therefore, an object of the present invention is to provide a DC motor driving circuit capable of preventing reverse rotation when the DC motor is stopped, and a tape writer of excellent print quality using the same.

Further, an object of the present invention is to provide a DC motor drive circuit capable of suppressing a variation in the number of rotations of the DC motor at startup due to a variation in the magnitude of a power supply voltage, and a print quality using the same. Is to provide an excellent tape writer.

Disclosure of the invention

In order to achieve the above object, a DC motor drive circuit according to the present invention comprises: a first power supply circuit having a switching element for turning on and off a power supply from a power supply to the DC motor; and a method for stopping the DC motor. And a shoving control means for intermittently turning on and off the switching element. As a result, the switching element can be intermittently turned on and off by the shoving control to intermittently turn on and off the power supply to the DC motor. It is possible to prevent reverse rotation of the DC motor at the time. In addition, any known switching element can be used. For example, a semiconductor element such as a bipolar transistor can be used. Can be used.

Further, the DC motor drive circuit according to the present invention shares the switching element with the first power supply circuit and stabilizes the voltage applied to the DC motor when the DC motor is started. And a second power supply circuit including a stability circuit for the second power supply. In this way, by using the second power supply circuit including the stabilizing circuit at the time of starting the DC motor, it is possible to prevent variations in the number of revolutions at the time of starting the DC motor. In addition, by switching to the first power supply circuit when the DC motor is traveling at a constant speed, heat generated by the switching element due to continuous use of the second power supply circuit can be suppressed and the switching element can be downsized. Will be possible. Further, since the first power supply circuit and the second power supply circuit share one switching element, the circuit configuration is simple and small. In addition, any known circuit can be used as the stabilizing circuit. For example, the stabilizing circuit may be one using a transistor or one using a Zener diode. Good.

Further, the DC motor drive circuit according to the present invention is characterized by further comprising an electronic governor circuit for controlling the number of rotations of the DC motor by using a back electromotive force of the DC motor. Thus, even when the power supply voltage that is not stabilized by the first power supply circuit is supplied, the rotation speed of the DC motor can be stabilized.

Further, a tape writer according to the present invention may further include a print head for performing printing in a dot pattern on a tape-shaped print medium, and at least one of the print medium and the print head relative to the other. A tape printer comprising a feed mechanism for moving the feed mechanism, comprising: a DC motor as a drive source of the feed mechanism; and the drive circuit for the DC motor described above. This makes it possible to prevent reverse rotation when the DC motor is stopped, so that even when the DC motor is once stopped and restarted, there is almost no variation in the positions of the printed dots. , Print quality Is improved.

Also, a DC motor drive circuit according to the present invention includes a power supply terminal, a switching element for turning on and off a power supply from a power supply connected to the power supply terminal to the DC motor, and an electric power from the switching element to the DC motor. A first power supply circuit having an output terminal for outputting, the power supply terminal, the switching element, and the output terminal being shared with the first power supply circuit, and stabilizing a voltage applied to the DC motor. A second power supply circuit that includes a stability circuit for causing the Thus, by using the second power supply circuit including the stabilizing circuit at the time of starting the DC motor, it is possible to prevent variations in the number of revolutions at the time of starting the DC motor. In addition, by switching to the first power supply circuit when the DC motor is traveling at a constant speed, heat generation in the switching element due to continuous use of the second power supply circuit is suppressed, and the size of the switching element is reduced. It becomes possible. Further, since the first power supply circuit and the second power supply circuit share one switching element, the circuit configuration is simple and small.

In the present invention, any known switching element can be used as the switching element. For example, a semiconductor element such as a bipolar transistor can be used. As the stabilizing circuit, any known circuit can be used. For example, a circuit using a transistor or a circuit using a Zener diode may be used.

Further, the DC motor drive circuit according to the present invention is characterized by further comprising an electronic governor circuit for controlling the number of rotations of the DC motor by using a back electromotive force of the DC motor. Therefore, even if the power supply voltage is not supplied by the first power supply circuit and the power supply voltage is supplied, the rotation speed of the DC motor can be stabilized.

Further, the DC motor drive circuit according to the present invention is characterized in that the DC motor drive circuit further includes a brake circuit for the DC motor. As a result, after the power supply is stopped, The DC motor can be stopped quickly. .

In addition, a tape writer according to the present invention includes a print head that prints a tape-shaped print medium in a dot pattern, and a method in which at least one of the print medium and the print head is moved relative to the other. A tape writer having a feed mechanism for moving the feed mechanism, the DC motor being a drive source of the feed mechanism, and a drive circuit for the DC motor described above. As a result, it is possible to prevent a variation in the number of rotations at the time of starting the DC motor due to the fluctuation of the power supply voltage. Therefore, even when the DC motor is stopped and then restarted, the printed image is printed. There is almost no variation in the position of the dots, and the print quality is improved.

Furthermore, the tape writer according to the present invention, a timer, and a head drive circuit for sending a drive signal to the print head so as to synchronize with the drive of the DC motor based on the timer are further provided. Features. As a result, by driving the print head based on a timer provided in a normal control device, a simple configuration that does not use an additional member such as an encoder that detects the rotation speed of the DC motor is achieved. The printing timing can be determined more.

The DC motor drive circuit of the present invention has a switching circuit connected between the power supply and the DC motor, and when the power supply to the DC motor is stopped, the switching circuit is opened and closed intermittently. The occurrence of reverse rotation of the motor can be prevented.

The DC motor drive circuit of the present invention includes: a first power supply relay circuit having an input terminal connected to the power supply and an output terminal connected to the DC motor; an input terminal connected to the power supply; A second power relay circuit having an output terminal connected to the motor and a stability circuit for stabilizing an output from the output terminal; the first power relay circuit and the second power relay circuit; And a control circuit for selectively electrically connecting the DC motor to the DC motor, when starting the power supply to the DC motor, stabilizing the voltage applied to the DC motor, Of the rotation of the motor can be prevented. BRIEF DESCRIPTION OF THE FIGURES The present invention will be described by a detailed description with reference to the accompanying drawings. Note that the following description does not limit the present invention but merely exemplifies the present invention. Also, the same reference numerals represent the same parts.

FIG. 1 is an external perspective view of a tape 7 ° writer according to an embodiment of the present invention. FIG. 2 is a plan view for explaining the structures of a tape drive printing mechanism and a tape storage cassette arranged inside the tape writer shown in FIG.

FIG. 3 is a side view of the tape drive printing mechanism of FIG. 2 viewed from the direction of arrow A without a tape storage cassette.

FIG. 4 is a block diagram of the tape writer shown in FIG.

FIG. 5 is a circuit diagram showing a part of the first embodiment of the driver circuit of the tape running DC motor shown in FIG. 4 together with the DC motor.

FIG. 6A is a graph showing the time change of the tape movement amount before and after the tape cutting performed during printing, and FIG. 6B is an MT1 signal corresponding to the tape movement shown in FIG. 6A. 7 is a graph depicting time changes of the MT2 signal and the drive signal of the thermal head 13;

FIG. 7 is a flowchart illustrating a control procedure before and after tape cutting performed during printing.

FIG. 8 is a circuit diagram illustrating a part of a second embodiment of the driver circuit of the tape running DC motor shown in FIG. 4 together with the DC motor.

FIG. 9A is a graph illustrating the time change of the tape movement amount before and after the tape cutting performed during printing, and FIG. 9B is an MT1 signal corresponding to the tape movement shown in FIG. 9A. 7 is a graph illustrating time changes of the MT2 signal, the Br signal, and the drive signal of the thermal head 13;

FIG. 10 is a flowchart illustrating a control procedure before and after tape cutting performed during printing.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a tape writer 1 according to one embodiment of the present invention. As shown in FIG. 1, the tape writer 1 has a keyboard 3 including a large number of keys such as character keys and control keys on an upper surface of a main body 2. Further, as shown in FIG. 2, the tape writer 1 has a cassette storage section frame 11 formed therein so that the tape storage cassette 30 can be detachably mounted. Further, the cassette housing frame 11 is provided with a tape drive printing mechanism 10 and a cutter 17 for cutting the tape. A tape outlet 5 is formed on the side of the main unit 2, and the tape that has been drawn from the tape storage cassette 30 and printed is cut by the cutter 17 and then discharged to the outside of the main unit 2 through the outlet 5. It is supposed to be. A control circuit (not shown) for controlling printing by the tape writer 1 in accordance with an input from the keyboard 3 is provided inside the main body 2.

As shown in FIG. 2, the tape storage cassette 30 includes a tape spool 32 in which a transparent surface tape 31 made of polyethylene terephthalate (PET) film or the like is wound, and an ink ribbon 33. Loaded ribbon supply spool 3 4, take-up spool 3 5 for winding used ink ribbon 3 3, release tape on one side of double-sided adhesive tape having the same width as surface tape 3 1 and having adhesive layers on both sides Bonding tape for superposing and bonding the double-sided tape 36 and the surface layer tape 31 to the base material supply spool 37 wound with the double tape 36 bonded with the release tape outside. Are provided rotatably at predetermined positions.

An arm 20 is attached to the cassette housing frame 11 so as to be swingable about a shaft 20a. As shown in FIGS. 2 and 3, a platen roller 21 and a feed roller 22 each having a flexible member such as rubber on the surface thereof are rotatably attached to the distal end of the arm 20. . At the position where the arm 20 is most clockwise rotated, the platen roller 21 is pressed into contact with the thermal head 13 disposed on the plate 12 described later via the surface tape 31 and the ink ribbon 33. Then, the feed roller 22 comes into pressure contact with the joining roller 39 via the surface tape 31 and the double tape 36.

A plate 12 stands upright from the cassette housing frame 11. On the platen roller 21 side of the plate 12, a thermal head 13 in which a plurality of heating elements are arranged in a line in a direction perpendicular to the plane of FIG. 2 is arranged. The plate 12 is fitted into the concave portion 14 of the tape storage cassette 30 when the tape storage cassette 30 is mounted at a predetermined position of the cassette storage frame 11. As shown in FIG. 3, a ribbon take-up roller 15 and a joining roller driving roller 16 stand upright from the cassette housing section frame 11. When the tape storage cassette 30 is mounted at a predetermined position of the cassette storage frame 11, the ribbon take-up roller 15 and the joining roller drive roller 16 are inserted into the take-up spool 35 and the joining roller 39, respectively. Is done. Further, a DC motor 6 for running the tape is mounted on the cassette housing frame 11. The rotational driving force extracted from the output shaft 41 of the DC motor 6 is applied to disk gears 42, 43, 44, which are arranged so as to mesh with each other along the cassette housing frame 11. 45, 46, 47, 48, and the ribbon take-up roller 15 through the disc-shaped gears 24, 25 arranged in series with the platen roller 21 and the feed roller 22, respectively. It is transmitted to the roller drive roller 16, platen roller 21 and feed roller 22.

Therefore, when power is supplied to the DC motor 6 and the output shaft 41 rotates, the take-up spool 35, the joining roller 39, the platen roller 21 and the feed roller 22 rotate accordingly. The surface tape 31, the ink ribbon 33, and the double tape 36 in the tape storage cassette 30 are conveyed downstream while being unwound by the driving force generated by the rotation. The surface tape 31 and the ink ribbon 33 pass between the platen roller 21 and the thermal head 13 after being superimposed on each other. While these are transported while being sandwiched between the platen roller 21 and the thermal head 13, they are selectively and intermittently supplied to a large number of heating elements arranged in the thermal head 13. As a result, the ink of the ink ribbon 33 is transferred to the surface tape 31 in units of dots, and a desired dot image is formed as a mirror image there. After the ink ribbon 33 that has passed through the thermal head 13 is wound up by the ribbon winding roller 15, the surface tape 31 is superimposed on the double tape 36 and fed by the feed roller 22. And between the joining roller 39. As a result, the surface layer 31 on which dot printing has been performed is firmly overlapped with the double tape 36 on the printing surface side.

The laminated tape 38 in which the surface tape 31 and the double tape 36 are overlapped with each other allows the normal image of the printed image to be viewed from the side opposite to the printing surface of the surface tape 31, and further includes the feed roller 22. After being cut by the cutter 17 arranged on the downstream side, it is discharged from the discharge port 5. The cutter 17 is a scissors type in which the rotary blade 17 b rotates with respect to the fixed blade 17 a to shear the object to be cut, and the rotary blade 17 b has a cutter motor 72 (fourth blade). (Refer to the figure.) To cut the laminated tape 38 by swinging back and forth around the fulcrum. The cut laminated tape 38 can be used as an adhesive label that can be attached to any location by peeling off the release tape.

Next, a control circuit of the tape writer 1 according to the present embodiment will be described with reference to a block diagram of FIG. The control circuit includes a CPU 61, a CG-ROM 62, a ROM 64, a RAM 66, a timer 80, a driver circuit 68 for the thermal head 13, a driver circuit 69 for the DC motor 6, and a driver circuit 70 for the cutter 17. The CPU 61 is connected to the CG—ROM 62, ROM 64, RAM 66, timer 80, and driver circuits 68 to 70, performs various calculations, manages signal input / output, and connects the keyboard 3 to the connection interface 67. Have been. The connection interface 67 is connected to an external device 78 such as a personal computer by wire or wirelessly.

The CG-R-M62 is a character generator memory that stores image data of characters and symbols to be printed in a dot pattern corresponding to code data. The ROM 64 stores various programs and data tables for operating the tape writer 1. The RAM 66 temporarily stores data input from the keyboard 3, data fetched from the external device 78 via the connection interface 67, calculation results in the CPU 61, and the like. The timer 80 notifies the CPU 61 of the elapsed time from the reference time based on the clock signal.

In the present embodiment, the ROM 64 stores the time required from the time when the power supply to the DC motor 6 is turned off to the time when the surface tape 31 stops, and the time required for the DC motor 6 after the power supply to the DC motor 6 is started. The time required for the surface tape 31 to start traveling at a constant speed is stored for each magnitude of the power supply voltage and the type of tape used (the tape width, the presence or absence of lamination, and the like are different from each other). Also, ROM

64 shows the power supply interval (T 0) to the thermal head 13 while the tape is traveling at a constant speed, and the period from when the power supply to the DC motor is turned off until the DC motor stops. And the drive timing (Tl, Τ2, Τ3, Τ4, Τ5) of the thermal head 13 between the time when the surface tape 31 starts to run at a constant speed after restarting the power supply to the DC motor, and the power supply voltage. It is stored for each size and tape type used.

The CPU 61 includes a print control unit 61a that controls printing by the thermal head 13, a tape motor control unit 61b that controls the operation of the DC motor 6, and a cutter motor.

72 includes a force motor control unit 61c.

The print control unit 61 a is connected to the driver circuit 68 and generates a control signal for the thermal head 13 in synchronization with the drive of the DC motor 6 with reference to the quick signal generated by the timer 80. . The driver circuit 68 supplies a drive signal to the thermal head 13 based on the control signal.

The tape motor control unit 61 b is connected to the driver circuit 69 and generates a control signal for the DC motor 6 according to a clock signal from the timer 80. The driver circuit 69 supplies a drive signal to the DC motor 6 based on the control signal. The cutter motor control section 61c is connected to the driver circuit 70 and generates a control signal for the cutter motor 72. The driver circuit 70 supplies a driving signal to the cutter motor 72 based on the control signal.

Next, a first embodiment of the driver circuit 69 of the DC motor 6 in the tape writer 1 of the present invention will be described with reference to FIG. FIG. 5 shows a configuration of a driver circuit 69 including the DC motor 6. As shown in FIG. 5, the driver circuit 69 includes an electronic governor circuit 101, an unstable voltage supply circuit 103, and a stable voltage supply circuit 104. Terminal A of DC motor 6 is connected to power supply voltage Vin via transistor TR1.

The electronic governor circuit 101 includes an IC for proportional current control of the DC motor 6 (IC for constant speed control: hereinafter, referred to as “IC 1”). Further, a resistor R 7 and a variable resistor VR 1 connected in series are connected to terminals A and B of the DC motor 6. IC 1 has four terminals, Vcc, Vref, Vo, and Vss.Vcc is connected to terminal A of DC motor 6, and Vref is connected between resistor R7 and variable resistor VR1 connected in series. Vo is connected to terminal B of DC motor 6, and Vss is connected to ground. The electronic governor circuit 101 performs proportional current control so that the back electromotive force of the DC motor 6 extracted at the terminals Vref and Vo is constant, and controls the voltage supplied to the DC motor 6 from the terminal Vcc. . Therefore, the DC motor 6 rotates at a constant speed after a predetermined time from the start of power supply, regardless of the magnitude of the power supply voltage Vin.

The unstable voltage supply circuit 103 includes a power supply terminal I to which a power supply having a power supply voltage Vin is connected, a transistor TR1 for turning on / off the power supply from the power supply terminal I to the DC motor 6, and outputting power to the DC motor 6. Output terminal O (point Q) and the transistor TR2.

The base of the transistor TR2 is supplied with the _MT1 signal via the resistor R6. The cMT1 signal is one of the control signals generated by the tape motor control unit 61b. The collector of transistor TR2 is connected to the transistor TR1 via resistor R2. The base and the emitter of transistor TR2 are connected to ground, respectively. The power supply voltage Vin is supplied to the emitter of the transistor TR1 from the power supply terminal I, and the collector of the transistor TR1 is connected to the terminal A of the DC motor 6. Further, the base and the emitter of the transistor TR1 are connected to each other via a resistor R1.

When the MT1 signal is turned on, the transistor TR2 is turned on, whereby a voltage is applied to the base of the transistor TR1 and the transistor TR1 is turned on. Therefore, the power supply voltage Vin is applied to the terminal A of the DC motor 6 from the output terminal O. At this time, the transistor TR1 functions as a mere switch by allowing a base current to flow through the transistor TR1 so that the transistor TR1 is turned on in the saturation region in the unstable voltage supply circuit 103. Since the collector-emitter voltage (VCE) is minimal, the heat lost from transistor TR1 is also minimal. Therefore, when the power supply voltage Vin is applied to the DC motor 6 using the unstable voltage supply circuit 103, the heat loss in the transistor TR1 is relatively small, and the power supply can be suppressed.

The stable voltage supply circuit 104 includes a power supply terminal I to which a power supply having a power supply voltage Vin is connected, a transistor TR1, an output terminal 出力 (point Q) for outputting power to the DC motor 6, a transistor TR3, and a transistor TR4, zener diode ZD1, and diode D1. The stable voltage supply circuit 104 shares the power supply terminal I, the transistor TR1, and the output terminal O with the unstable voltage supply circuit 103. Therefore, the circuit configuration is simple and small.

The MT2 signal is supplied to the base of the transistor TR4 via the resistor R5. Note that the MT2 signal is one of the control signals generated by the tape motor control unit 61b. The collector of the transistor TR4 is connected to the emitter of the transistor TR3 and the power source of the diode D1 via the resistor R4, and is also connected to the anode of the diode ZD1. The emitter is connected to ground. The base of transistor TR3 is connected to the cathode of zener diode ZD1 and to the emitter of transistor TR1 via resistor R3. The collector of transistor TR3 is connected to the base of transistor TR1. The anode of diode D1 is connected to the collector of transistor TR1.

When the MT2 signal is turned on, the transistor TR4 conducts, a voltage is applied to the base of the transistor TR3, the transistor TR3 conducts, and the transistor TR3 is connected from the power supply through the resistor R1 and the base of the transistor TR1. Current flows between the collector and emitter of the IGBT. Then, a voltage is applied to the base of the transistor TR1, and the collector current of the transistor TR1 also conducts.

In the stable voltage supply circuit 104, when the potential at the collector (point Q) of the transistor TR1 decreases, the potential at the emitter (point S) of the transistor TR3 decreases. Then, assuming that the base of the transistor TR3 is a point P, the voltage between PS (the voltage between the base and the emitter of the transistor TR3) increases, and the collector current of the transistor TR3 increases. Then, the base current of the transistor TR1 increases, and the collector current of the transistor TR1 increases with the DC gain hfe. Conversely, when the potential at point Q tries to rise above the Zener voltage of Zener diode ZD1, the current flowing through diode D1 increases, the collector current of transistor TR3 decreases, and the base current of transistor TR1 decreases. And the collector current of transistor TR1 is also reduced by the DC amplification factor fe. In other words, the potential at the point Q is given by VZ = VZ- (VZ = VZ = Zener voltage by Zener diode ZD1, VBE = voltage between base and emitter of transistor TR3, and VF = voltage of diode D1). VBE-VF). In addition, since VBE of the transistor TR3 and VF of the diode D1 have almost the same value, the potential VQ of the point Q becomes almost the same as the Zener-one voltage VZ. Therefore, when the MT1 signal is turned off and the MT2 signal is turned on, a constant voltage determined by the zener voltage is applied to the DC motor regardless of the fluctuation of the power supply voltage Vin. Applied to data 6.

Next, a specific control procedure of the tape writer 1 according to the present embodiment will be described with further reference to FIG. 6 and FIG. FIG. 6A is a graph showing a time change of the tape movement amount, and FIG. 6B is a graph showing various control signals MT 1 generated by the tape motor control unit 61 b to control the driving of the DC motor 6. 5 is a graph showing the timing chart of MT 2 in correspondence with the running state of the DC motor 6. FIG. 7 is a flowchart illustrating a control procedure of the DC motor 6 when cutting the tape during printing. Here, an example will be described in which, after printing on the surface tape 31, the surface tape 31 is immediately cut and discharged without performing printing continuously.

In order to tape print a desired image using the tape writer 1 of the present embodiment, first, a character or a symbol to be printed is operated by operating the keyboard 3 or an external device connected to the tape writer 1 is operated. Import the figure you want to print from device 7 8. The data input or captured in this way is stored in a predetermined area of the RAM 66 as print data. Then, if necessary, appropriate editing work is performed.

Thereafter, when the print key of the keyboard 3 is pressed or a print command is given from the external device 78, as shown in FIG. 7, in step S1, the tape motor control unit 6 1b 1 Turn on the signal. Then, electric power is supplied to the DC motor 6 by the unstable voltage supply circuit 103, and tape running is started. Further, at the same time, in step S2, the print data stored in the RAM 66 is expanded into dots by referring to the data of the CG-ROM 62, and based on the expanded data, the print control unit is controlled. The dot printing on the surface tape 31 by the thermal head 13 is started by the control of the driver circuit 68 by 61a. Then, when a certain time elapses, the DC motor 6 reaches a predetermined number of revolutions, and the surface tape 31 starts running at a constant speed. In the constant-speed running state (A) before time t0, a drive signal is supplied to the thermal head 13 every time TO. As a result, dot patterns are printed on the surface tape 31 at a uniform dot interval. Then, in step S3, the tape motor control unit 61b repeats whether or not it is time to suspend the power supply to the DC motor 6 in order to stop the tape running and cut the tape. to decide. Then, when it is determined that the time to interrupt the power supply to the DC motor 6 (time t0) has been reached (S3: YES), the process proceeds to step S4. In step S4, as shown in FIG. 6B, the chopping control of the MT1 signal is started from time 0.

In the present invention, the shoving control turns on and off the MT1 signal for operating the unstable power supply circuit 103 controlled by the tape motor control unit 61b at a predetermined duty ratio. For example, during a period from when the tape motor control unit 61 cuts off the power supply to the DC motor 6 to when the rotation of the DC motor 6 is completely stopped, a predetermined duty is set so that the DC motor 6 does not reverse. The MT 1 signal is supplied from the driver circuit 69 to the unstable power supply circuit 103 by selecting the ratio. During the period from when the rotation of the DC motor 6 stops to when the power supply is restarted, the MT 1 signal is transmitted from the driver circuit 69 at a predetermined duty ratio so that the DC motor 6 does not rotate forward or reverse. It is driven so as to supply to the unstable power supply circuit 103. In step S4, when the MT1 signal shoving starts (B temple t0), the DC motor 6 enters a through-down state (B), the rotation speed starts to gradually decrease, and the surface tape 31 travels. The speed also decreases gradually. Next, in step S5, the through-down printing is started, and in order to prevent the distance between the dots in the running direction of the surface tape 31 from becoming shorter than that at the time of constant speed running, as in the case of constant speed running, Instead of driving the thermal head 13 by the print control unit 6 1 a at every time TO, the time t 1 at which the thermal head 13 is first driven after the time t 0 is changed from the time B0 t0 to the time Tl (T1). T0). Then, at the time t2 when the thermal head 13 is driven by the print control unit 61a, the running distance of the surface tape 31 after the time t1 when the rotation speed of the DC motor 6 further decreases further becomes earlier. The time T2 (T2> T1) from the time tl and the drive signal of the thermal head 13 The interval between them is even longer. As described above, in the through-down printing, the drive timing of the thermal head 13 by the print control unit 61a is not fixed but changed according to the elapsed time from the time to when the MT1 signal is turned off. Thus, the dot interval in the traveling direction of the surface tape 31 can be maintained at the same interval as when traveling at a constant speed. In step S6, while performing the through-down printing, the cutter motor control unit 61c repeatedly determines whether the elapsed time from the time tO has reached the stop time of the DC motor 6 and the surface tape 31 stored in the ROM 64. to decide. Then, when it is determined that the elapsed time has reached the stop required time (TD) (time t3) (S6: YES), the rotation of the DC motor 6 is regarded as stopped, and the DC motor 6 It will be in the stop state (C) and proceed to step S7. In step S7, the cutter motor controller 61c controls the driver circuit 69 to swing the rotary blade 17b of the cutter 17 forward and backward. As a result, the margin of the unprinted laminated tape 38 is cut off.

Next, in step S8, following the cutting of the laminated tape 38, the shoving control of the MT1 signal is terminated at time t4, and the MT2 signal is turned on. Then, the power supply to the DC motor 6 is restarted by the stable voltage supply circuit 104, the tape running is restarted, and the DC motor 6 enters the through-up state (D). Further, in step S9, through-up printing is started. At this time, since power is supplied to the DC motor 6 using the stable voltage supply circuit 104, the voltage applied to the DC motor 6 becomes almost constant, and the rotation speed of the DC motor 6 due to the variation in the power supply voltage Is suppressed.

In the through-up printing started in step S9, as in the through-down printing started in step S5, the distance between the dots in the running direction of the surface tape 31 is shorter than in the constant speed running. Instead of driving the thermal head 13 every time TO as in the case of constant speed running, the printing interval TO at the time of constant speed running until the surface tape 31 reaches the constant speed is used to prevent this. Even at long intervals Drive 13 However, the first time the thermal head 13 is driven after the MT2 signal is turned on at the time t4, the time t5 (| t5-t2I = T3) is the time when the surface tape 31 from the time t2 until the surface tape 31 stops. In consideration of the movement amount of the surface tape 31, the total movement amount of the surface tape 31 from the time t2 to the time t5 is determined to be the distance of one dot in the constant speed traveling state of the surface tape 31. Then, the next time t6 when the thermal head 13 is driven is determined to be a time T4 (T4> T0) from the time t5, and the next time t7 when the thermal head 13 is driven is It is assumed that time T5 (T4>T5> T0) has elapsed from time t6. In this manner, even during the through-up printing, the drive timing of the thermal head 13 by the print control unit 61a is not made constant, but is adjusted according to the time elapsed from the time t4 when the MT2 signal is turned on. In this case, the dot interval in the running direction of the surface tape 31 can be maintained at the same interval as during the constant speed running.

In step S10, while performing the through-up printing, it is determined whether or not the elapsed time from the time t4 has reached the constant-speed traveling start time (TU) of the DC motor 6 and the surface tape 31 stored in the ROM 64. The tape motor control unit 61 b repeatedly determines. At time t7, when it is determined that the elapsed time has reached the above-mentioned constant speed traveling start required time (TU) (S10: YES), the through state (D) of the DC motor 6 ends. Proceed to step S11. In step S11, the DC motor 6 returns to the constant speed running state (A) again, and the MT1 signal is turned on and the MT2 signal is turned off based on the control of the tape motor control unit 6lb. . Thus, in step S12, normal printing is started. In normal printing, the DC motor 6 is driven at a constant speed by the tape motor control unit 61b, and the surface tape 31 runs at a constant speed. 13 is driven. In normal printing, since the unstable voltage supply circuit 103 is used, heat generation in the transistor TR1 is suppressed as compared with the case where the stable voltage supply circuit 104 is continuously used. Even if the power supply voltage fluctuates, the electronic governor circuit The fluctuation is suppressed by 101, and the rotation speed of the DC motor 6 becomes stable. Next, in step S13, the print control unit 61a repeatedly determines whether or not printing of the print data stored in the RAM 66 has been completed while performing normal printing. If it is determined that the printing of the print data has been completed (S13: YES), the process proceeds to step S14 after a predetermined time. In step S14, the MT1 signal is turned off based on the control of the tape motor controller 61b. Next, proceeding to step S15, the power motor controller 61c controls the driver circuit 70 to reciprocally swing the rotary blade 17b of the cutter 17. Thus, the printed laminated tape 38 is separated from the tape in the tape storage cassette 30 and discharged from the discharge port 5.

As described above, according to the tape writer 1 of the present embodiment, the transistor TR 1 is intermittently turned on and off by performing the shoving control of the MT 1 signal from the time t 0 to the time t 4. It is possible to prevent the DC motor 6 from rotating reversely after stopping. Therefore, the positions of the printed dots do not vary when printing is resumed, and the print quality is improved. In the present embodiment, the shoving control is started from time t o, but the shoving control may be started from the time when the DC motor stops (time t 3).

Further, since the DC motor drive circuit of the present embodiment has the electronic governor circuit 101, the DC motor 6 is supplied with an unstable power supply voltage by the unstable voltage supply circuit 103. Even with this, the rotation speed of the DC motor 6 can be stabilized.

Next, a second embodiment of the driver circuit 69 of the DC motor 6 of the tape writer 1 of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The driver circuit 69 includes an electronic governor circuit 101, an unstable voltage supply circuit 103, a stable voltage supply circuit 104, and a brake circuit 105. The power supply voltage Vin is supplied to terminal A of DC motor 2 via transistor TR1, and terminal B is connected to the cathode of diode D2. Have been.

The brake circuit 105 has a transistor TR5. The brake signal Br is supplied to the base of the transistor TR5 via the resistor R8. The collector of the transistor TR5 is connected to the terminal A of the DC motor 6, and the emitter of the transistor TR5 is connected to the ground. When the brake signal Br is turned on immediately after the power supply to the DC motor 6 is turned off, the transistor TR5 is turned on. The brake signal Br is one of the control signals generated by the tape motor control unit 61b. Then, due to the back electromotive force generated inside the DC motor 6, a current flows through the path of the transistor TR5, the ground, and the diode D2 in order from the DC motor 6 power. This current is a current in a direction opposite to the current flowing through the DC motor 6 due to the power supply voltage Vin and the terminal Vcc of I C1, and attempts to suppress the rotation of the DC motor 6. Therefore, by turning on the brake signal Br, the DC motor 6 can be stopped quickly, that is, at a short stopping distance.

Next, a specific control procedure of the tape writer 1 according to the present embodiment will be described with reference to FIG. 9 and FIG. FIG. 9A is a graph illustrating a time change of the tape moving amount, and FIG. 9B is a graph illustrating various control signals MT generated by the tape motor control unit 61b to control the driving of the DC motor 6. 6 is a graph showing timing charts of 1, MT 2, and Br in correspondence with the running state of the DC motor 6. FIG. 10 is a flowchart illustrating a control procedure of the DC motor 6 when cutting the tape during printing. Here, an example will be described in which, after printing is performed on the surface tape 31, the tape is immediately cut and discharged without performing printing continuously.

To print a desired image on a tape using the tape writer 1 of the present embodiment, first, the user operates the keyboard 3 to input characters or symbols to be printed, or external devices 7 connected to the tape writer 1. Import the figure you want to print from 8. The data input or captured in this way is stored in a predetermined area of the RAM 66 as print data. Then, if necessary, appropriate editing work is performed. Thereafter, when the print key of the keyboard 3 is pressed or a print command is given from the external device 78, as shown in FIG. 10, in step S101, the tape motor control unit 61b sends the MT1 signal. turn on. Then, power is supplied to the DC motor 6 via the unstable voltage supply circuit 103, and the tape starts to run. At the same time, in step S102, the print data stored in the RAM 66 is expanded into dots by referring to the data in the CG-ROM 62, and the print control is performed based on the expanded data. The dot printing on the surface tape 31 by the thermal head 13 is started by the control of the driver circuit 68 by the unit 61a. Then, after a certain period of time, the DC motor 6 reaches a predetermined number of revolutions, and the surface tape 31 starts running at a constant speed. In the constant-speed running state (A) before time t 0, a drive signal is supplied to the thermal head 13 every time TO. As a result, dot patterns are printed on the surface tape 31 at a uniform dot interval.

Then, in step S103, the tape motor control unit 61b repeatedly determines whether or not it is time to temporarily suspend the power supply to the DC motor 6 in order to stop the tape running and cut the tape. I do. Then, at time t0, the DC motor

When it is determined that the time at which the power supply to 6 has to be interrupted has been reached (S 10.3: YES), the flow proceeds to step SI04. In step S104, as shown in FIG. 10B, at time t0, the MT1 signal is turned off and the Br signal is turned on.

As a result of the MT1 signal being turned off and the Br signal being turned on in step S104, the DC motor 6 enters a through-down state (B), and the brake circuit 105 operates to increase the rotation speed of the DC motor 6 rapidly. And the running speed of the surface tape 31 rapidly decreases. In the through-down state (B), through-down printing is started (step S105). In through-down printing, to prevent the distance between the dots in the running direction of the surface tape 31 from becoming shorter than when running at a constant speed, the thermal head 13 is inserted at every time T0 as in the case of running at a constant speed. Instead of being driven by the print control unit 61a, the time 1 when the thermal head 13 is first driven after the time t0 is the time t It is assumed that the time Tl (T1> T0) has elapsed from 0. Then, at time t2 when the thermal head 13 is driven by the print control unit 61 a next, the rotation speed of the DC motor 6 further decreases, and the time t2 from time t1 to time t2 Since the traveling distance of the surface tape 31 is shorter than before, the time interval after the time T2 (T2> T1) from the time tl and the time interval are further lengthened. In this way, during through-down printing, the drive timing of the thermal head 13 by the print control unit 6 1a is not fixed, but is changed according to the elapsed time from the time t0 when the MT1 signal is turned off. By doing so, the dot interval can be maintained at the same interval as when traveling at constant speed.

In step S106, while performing the through-down printing, it is determined whether or not the elapsed time from the time t0 has reached the stop time TD of the DC motor 6 and the surface tape 31 stored in the ROM 64 by the cutter motor. The control unit 61c repeatedly determines. If it is determined that the elapsed time has reached the stop required time TD (time t 3) (S 6: YES), the DC motor 6 stops and enters the stop state (C), and the step S Proceed to 107. In step S107, the cutter motor control unit 61c controls the driver circuit 70 to reciprocally swing the rotary blade 17b of the cutter 17. As a result, the margin of the unprinted laminated tape 38 is cut off.

Next, in step S108, following the cutting of the laminated tape 38, the Br signal is turned off and the MT2 signal is turned on at Toki Ijt4. It goes up (D). Then, the power supply from the stable voltage supply circuit 104 to the DC motor 6 is restarted, and the tape running is restarted. Further, at the same time, in step S109, through-up printing is started. At this time, since power is supplied to the DC motor 6 using the stable voltage supply circuit 104, variation in the rotation speed of the DC motor 6 due to variations in the power supply voltage is suppressed.

In the through-up printing started in step S109, the distance between the dots in the running direction of the surface tape 31 is smaller than in the constant-speed running, as in the through-down printing started in step S105. When running at a constant speed, Instead of driving the thermal head 13 every time TO, the thermal head 13 is driven at a longer interval than the printing interval TO at constant speed running until the surface tape 31 reaches the constant speed. . However, the time t5 (| t5-t2 I = T3) when the thermal head 13 is first driven after the MT2 signal is turned on at the time t4 is the time when the surface tape 31 is stopped from the time 1: 2 until the surface tape 31 stops. In consideration of the movement amount of the surface tape 31 as well, the total movement amount of the surface tape 31 from time t2 to time t5 is determined to be the distance of one dot in the constant speed running state of the surface tape 31. Then, the time t6 at which the thermal head 13 is driven next is set to be after a lapse of time T4 (T4> T0) from the time t5, and the time t6 at which the thermal head 13 is driven next is t 7 is after the elapse of time T5 (T4>T5> T0) from time t6. In this manner, even during the through-up printing, the drive timing of the thermal head 13 by the print control unit 61a is not fixed, but the time elapsed from the time t4 when the MT2 signal is turned on. By changing the distance according to the distance, the dot interval in the running direction of the surface tape 31 can be maintained at the same interval as during the constant speed running.

In step S110, while performing the through-up printing, it is determined whether or not the elapsed time from time t4 has reached the time required to start the constant speed traveling of the DC motor 6 and the surface tape 31 stored in the ROM 64. The motor control unit 61b repeatedly determines. If it is determined at time t7 that the elapsed time has reached the required time for starting the constant speed traveling (S10: YES), the through-up state (D) of the DC motor 6 ends, and step S111 is performed. Proceed to. In step S111, the DC motor 6 is again in the constant speed traveling state (A), the MT1 signal is turned on, and the MT2 signal is turned off. Thus, in step S112, normal printing is started. In normal printing, the DC motor 6 is driven at a constant speed by the tape motor control unit 61b, and the surface tape 31 runs at a constant speed. Head 13 is driven. In normal printing, the unstable voltage supply circuit 103 is used. Heat generation in the star TR 1 is suppressed. Further, even if the power supply voltage fluctuates, the fluctuation is suppressed by the electronic governor circuit 101, and the rotation speed of the DC motor 6 becomes stable.

Next, in step S113, the print control unit 61a repeatedly determines whether printing of the print data stored in the RAM 66 has been completed while performing normal printing. When it is determined that the printing of the print data has been completed (S13: YES), the process proceeds to step S114 after a predetermined time. In step S114, the MT1 signal is turned off and the Br signal is turned on. Next, proceeding to step SI15, the cutter motor control section 61c controls the driver circuit 6'9 to reciprocally swing the rotary blade 17b of the cutter 17. As a result, the printed laminated tape 38 is separated from the tape in the tape storage cassette 30 and discharged from the discharge port 5.

Thus, in the tape writer 1 of the present invention, in order to drive the DC motor 6, the unstable power supply circuit 103 and the stable voltage supply circuit 104 are selectively used by the control signal. For example, when the drive of the DC motor 6 is resumed after cutting the tape during printing, the MT2 signal is turned on and the MT1 signal is turned off, and power is supplied to the DC motor 6 via the stable voltage supply circuit 104. Since the voltage applied to the DC motor & becomes constant by supplying the power, variation in the rotation speed of the DC motor 6 at the time of startup can be prevented.

When the stable voltage supply circuit 104 is used, the heat loss increases due to the relatively large collector-emitter voltage of the transistor TR1, but when the DC motor 6 runs at a constant speed, the unstable voltage supply circuit 103 By switching to, the stable voltage supply circuit 104 is only used temporarily when the DC motor 6 is started. Therefore, since heat generation in the transistor TR1 is suppressed, it is not necessary to use a large transistor TR1 or attach a heat sink to the transistor TR1. Therefore, the energy efficiency is not reduced, and the entire apparatus can be downsized. Furthermore, the unstable voltage supply circuit 103 and the stable voltage supply circuit 104 Since one transistor TR1 is shared, the circuit configuration can be simplified and small.

Further, since the DC motor drive circuit of the present invention includes the electronic governor circuit 101, even if the power supply voltage Vin supplied from the power supply by the unstable voltage supply circuit 103 fluctuates, The operation of the electronic governor circuit 101 can keep the rotation speed of the DC motor 6 almost constant. The driving circuit of the DC motor 6 in the present embodiment, in order to have a braking circuit i 0 _5, can be stopped after the stop of the power supply, the DC motor 6 in quickly.

In the tape writer 1 of the present invention, in order to prevent the reverse rotation of the DC motor 6 after the power supply to the DC motor 6 is stopped, (1) a large force is required to rotate the DC motor 6 in the reverse direction. Such a worm gear is used for one of the opposing pairs of the tape drive printing mechanism 10. (2) One of the rotating members of the tape drive printing mechanism 10 controls the rotation of the DC motor 6 in the reverse rotation direction. It is also possible to take measures such as installing a one-way clutch to be prohibited, or (3) using a motor with a large rotor inertia. However, in the tape writer of the present invention, it is preferable to use a DC motor 6 having a small rotor inertia. This is because the stop time after the power supply to the DC motor 6 is stopped and the time from when the power supply is started to when the power supply reaches the constant speed are relatively short, so that a control error hardly occurs.

As described above, since the tape writer of the present invention has the DC motor drive circuit having the above-mentioned advantages, fluctuations in the rotation speed at the time of starting the DC motor due to fluctuations in the power supply voltage are reduced. Suppressed, the position of the printed dots along the running direction of the tape hardly fluctuates, and high quality printing can be performed on the tape. In addition, since the drive timing of the thermal head 13 is set to be synchronized with the drive of the DC motor 6 based on the timer 80 provided in a normal control device, the rotation of the DC motor 6 is controlled. It is possible to adopt a simple configuration that does not use an additional member such as an encoder for detecting the number. As described above, a preferred embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various design changes can be made within the scope of the claims. It is. For example, in the above-described embodiment, a thermal head is used as a print head, but a print head other than the thermal head may be used. Further, in the above-described embodiment, the case where the tape is cut during the interruption of the printing has been described. However, according to the present invention, the printing is interrupted because the print data size is large, and the remaining print data is The present invention is also applicable to a case where data is stored in a memory. Further, in the above-described embodiment, the tape is transported by the DC motor while the print head is fixed. On the contrary, the tape may be fixed and the print head is moved by the DC motor. . Also, the tape to be used does not necessarily have to be laminated on another tape such as a double tape to form a laminated tape, and the surface tape may be simply printed and ejected as it is. . In the above-described embodiment, the MT2 signal is turned on only when the tape is cut during printing and the driving of the DC motor is restarted. However, in other cases (for example, at the start of printing), the MT2 signal is turned on. The signal may be turned on to compensate for variations in the magnitude of the power supply voltage. Further, the DC motor drive circuit of the present invention can be applied to a device other than a tape writer.

Industrial applicability

It is useful for a drive circuit of a DC motor and an appropriate tape printing apparatus provided with the DC motor and the drive circuit.

Claims

The scope of the claims

1. a first power supply circuit (103) having a switching element (TR1) for turning on and off a power supply from a power supply to a DC motor (6);

A driving circuit for a DC motor, comprising: shoving control means (61) for intermittently turning on and off the switching element when stopping the DC motor.

2. A drive circuit for a DC motor according to claim 1,

The first power supply circuit (103) and the switching element (TR1) are shared, and the voltage applied to the DC motor when starting the DC motor (6) is stabilized. A drive circuit for a DC motor, further comprising a second power supply circuit (10 4) including a conversion circuit.

3. The drive circuit for a DC motor according to claim 1 or 2, wherein an electronic device for controlling a rotation speed of the DC motor using a back electromotive force of the DC motor (6). A drive circuit for a DC motor, further comprising a governor circuit (101).

4. A print head (13) for printing a dot pattern on a tape-shaped print medium (31), and at least one of the print medium and the print head is moved relative to the other. And a feed mechanism (6, 1, 5, 16)

A DC motor (6) that is a driving source of the feed mechanism;

A tape writer, comprising: the DC motor drive circuit (61, 69) according to any one of claims 1 to 3.

5. A power supply terminal (I), a switching element (TR1) for turning on and off the power supply from the power supply connected to the power supply terminal to the DC motor (6), and an electric power from the switching element to the DC motor. Having an output terminal (o) for outputting 1 power supply circuit (103),

The power supply terminal (I), the switching element (TR1), and the output terminal (O) are shared with the first power supply circuit, and a stabilizing device for stabilizing a voltage applied to the DC motor. A driving circuit for a DC motor, comprising: a second power supply circuit (10 4) including a shading circuit.

6. A drive circuit for a DC motor according to claim 5, wherein

An electronic governor circuit (101) for controlling the number of rotations of the DC motor using a back electromotive force of the DC motor (6). .

7. The DC motor drive circuit according to claim 5 or 6, further comprising a brake circuit (105) for the DC motor (6). .

8. A print head (13) that prints in a dot pattern on a tape-shaped print medium (31), and one of the print medium and the print head is relative to the other. A tape writer provided with a feed mechanism (6, 15, 16) for moving, a DC motor (6) as a drive source of the feed mechanism,

A tape writer comprising: the DC motor drive circuit (61, 69) according to any one of claims 5 to 7.

9. The tape writer according to claim 8, wherein

A timer (80),

And a head drive circuit (61) for transmitting a drive signal to the print head in synchronization with the drive of the DC motor based on the timer.

10. A DC motor drive circuit that rotates the DC motor (6) by supplying power from the power supply,

A switching circuit (TR 1) connected between the power supply and the DC motor; A control circuit (61, 103) for controlling on / off of the switching element, wherein the control circuit intermittently opens and closes the switching element when stopping the DC motor. Drive circuit for DC motor.

1 1. A drive circuit for a DC motor according to claim 10,

A stabilizing circuit for stabilizing a voltage applied to the DC motor (6);

The drive circuit for a DC motor, wherein the stabilization circuit is operated when the DC motor is started.

12. A drive circuit for a DC motor according to claim 10, wherein

A driving circuit for a DC motor, further comprising an electronic governor circuit (101).

13. A print head (1 3) for printing on tape-shaped print media,

The print medium and the print head, comprising: a DC motor (6); and a DC motor drive circuit (61) according to any one of claims 10 to 12. A feed mechanism (6, 15, 16) for moving one of the relative to the other,

A tape printer comprising:

14. A DC motor drive circuit that rotates the DC motor (6) by supplying power from the power supply,

A first power supply relay circuit (103) having an input terminal (I) connected to the power supply, and an output terminal (O) connected to the DC motor;

A second power supply relay circuit having an input terminal (I) connected to the power supply, an output terminal (0) connected to the DC motor, and a stabilizing circuit for stabilizing an output from the output terminal; (104) and

A control circuit (61) for selectively electrically connecting the first power supply relay circuit and the second power supply relay circuit to the DC motor; A drive circuit for a DC motor, comprising:

15. A drive circuit for a DC motor according to claim 14,

A drive circuit for a DC motor, further comprising an electronic governor circuit (101).

16. A drive circuit for a DC motor according to claim 14,

A DC motor drive circuit characterized by further comprising a DC motor brake circuit (105).

1 7. A print head (1 3) for printing on a tape-shaped print medium,

A DC motor (6); and a DC motor drive circuit (61) according to any one of claims 14 to 16; Feed mechanism (6, 15, 16) for moving one of the heads relative to the other,

A tape printer comprising: