JP2542911B2 - Tape drive reel drive control device - Google Patents

Description

The present invention relates to a reel drive that detects the number of rotations of a winding-side reel motor and a supply-side reel motor, and drives and controls each reel motor based on this number of rotations. Regarding the control device.

[Conventional technology]

FIG. 10 shows a reel drive control device of a rotary head type tape player used in a conventional DAT (digital audio tape recorder) or the like.

In the figure, reference numeral 1 is a supply-side reel stand on which a supply-side tape reel R1 is installed, and reference numeral 2 is a take-up-side reel stand on which a take-up tape reel R2 is installed. Reference numeral 3 is a rotary head drum. The magnetic tape T wound on both tape reels R1 and R2 is pulled out by the tape loading mechanism and wound on the rotary head drum 3. Codes 4a and 4b
Is a low dig post for pulling out the magnetic tape T. When recording or reproducing, the magnetic tape T
However, it is sandwiched by the capstan 5 rotating at a constant speed and the pinch roller 6 pressed against the capstan 5, and the capstan 5 is caused to travel toward the take-up reel stand 2 in accordance with the number of rotations of the capstan 5.

The supply-side reel base 1 is driven by the supply-side reel motor M1, and the winding-side reel base 2 is driven by the winding-side reel motor M2. As shown in FIG. 11, the reel motor M1 on the supply side includes a stator coil 7 and a rotor magnet 8.
It is composed of a brushless motor consisting of
Similarly, the winding side reel motor M2 is also configured by a brushless motor.

A rotation speed detection pattern 9a is formed at the base end of the supply-side reel stand 1, and the optical detector 10a faces the rotation speed detection pattern 9a. Similarly, a rotation detection pattern 9b is also formed at the base end of the take-up reel stand 2, and the optical detector 10b faces this. The rotation speed detection patterns 9a and 9b are formed by alternately forming a reflection portion and a non-reflection portion along the rotation direction, and the optical detector 10a or 10b.
The number of rotations of the reel bases 1 and 2 can be detected by detecting the reflected light. Various controls are performed by detecting the number of rotations of the reel bases 1 and 2. For example, during high speed search operation, both reel bases 1 and 2 are operated.
The number of rotations is counted by the rotation number counting circuit 11, and the difference is calculated by the reel motor drive control circuit 12. Further, the reel motor drive control circuit 12 calculates the traveling speed of the magnetic tape T at that time, and the rotation control of both reel motors M1 and M2 is performed according to the calculated value, so that the tape traveling speed is always constant. Controlled by the situation.

[Problems to be Solved by the Invention]

Thus, conventionally, as a mechanism for detecting the number of rotations of the reel bases 1 and 2, that is, the reel motors M1 and M2, the number of rotations detection pattern is provided on the bases of the reel bases 1 and 2.
9a and 9b are formed, and optical detectors 10a and 10b facing each pattern are provided. Therefore, the mechanism for detecting the reel rotation speed is complicated and the number of parts is also increased.

The present invention is to solve the above problems, and to provide a reel drive control device of a tape player that can detect the number of rotations by utilizing the function of a motor without using a special detection device. Has an aim.

[Means for Solving the Problems] A reel drive control device according to the present invention includes a winding-side reel motor that drives a winding-side tape reel, a supply-side reel motor that drives a supply-side tape reel, and a space between both tape reels. In the tape player provided with a magnetic head that comes into contact with the magnetic tape, the winding-side reel motor is provided with a magnetic detection element for detecting the magnetic pole of the rotor magnet, and the supply-side reel motor is rotated by the rotor magnet. Is provided with a detection unit for detecting electric power generated in the stator coil, and when the tape is traveling at high speed, the number of rotations of the winding-side reel motor detected by the magnetic detection element and the supply-side reel motor detected by the detection unit. The drive of the motor is controlled based on the rotation speed of the tape, and when the tape is running at low speed, the winding side reel detected by the magnetic sensing element is detected. The motor is drive-controlled based on the rotation speed of the motor.

Further, in the above, when the tape is running at a high speed, a difference between the rotation speed of the winding reel motor detected by the magnetic detection element and the rotation speed of the supply reel motor detected by the detection unit is calculated. Both motors are drive-controlled so that the tape runs at a constant speed based on the difference.

[Work]

Further, in the reel drive control device of the tape player according to the present invention, a rotation detection device that uses a magnetic detection element is used for the winding-side reel motor, and a rotation detection device that uses electromotive force of the coil is used for the supply-side reel motor. ing. The rotation detection device using the magnetic detection element can detect the number of rotations not only at high speed but also at low speed.
Further, in the rotation detecting device using the electromotive force of the coil, the detection accuracy can be exhibited in the case of high speed rotation. Therefore, in the reel drive control device of this tape player, in the case of high-speed search or the like, the rotation speed detection value of the supply-side reel motor and the rotation speed detection value of the winding-side reel motor are used to
It is possible to detect the difference in the number of rotations of the two reels at that time, and it is possible to control the number of rotations of the motor such that the tape running speed is always constant according to the difference. Further, when the tape is running at a low speed such as during recording / reproduction, the reel rotation speed can be known from the rotation speed detection value of the winding-side reel motor using the magnetic detection element.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings of FIGS.

1 to 7 show the tape winding side of a tape player, and show a motor rotation detecting device using a magnetic detection element.

FIG. 1 is a sectional view showing the structure of the brushless motor M, FIG. 2 is a plan view showing a stator portion thereof, and FIG. 3 is a plan view showing a surface of a rotor magnet facing the stator.

In this brushless motor M, a flexible substrate 22 is attached to a stator yoke 21, and a plurality of stator coils 23 are installed thereon. The rotor yoke is attached to the rotary shaft 24.
25 is fixed, and the rotor magnet 26 is fixed to this rotor yoke. This brushless motor M is
It is an 8-pole 6-coil motor, and six stator coils 23 are provided as shown in FIG. 2. The rotor magnet 26 has N-poles and S-poles alternating in the direction of rotation as shown in FIG. It has 8 poles. Of the six stator coils 23, the ones indicated by A1 and A2 are the A phase, and current is supplied to both of them simultaneously. What is shown by B1 and B2 is the B phase,
What is indicated by C1 and C2 is the C phase. Further, as shown in FIG. 2, three magnetic detecting elements (Hall elements) 27 are provided on the stator side.
Is provided. One of the three Hall elements 27 corresponds to each of the A-phase, B-phase, and C-phase stator coils, and each of the three Hall elements 27 is connected to each stator coil according to the change of the magnetic pole detected by each Hall element 27. The supply of the current is switched.

FIG. 4 shows a motor drive circuit 31 for driving the motor shown in FIGS. 1 to 3 and a rotation speed detection device which is a feature of the present invention. In the motor drive circuit 31,
Depending on the magnetic pole detection signals from the three Hall elements 27, the A phase,
The currents to the B-phase and C-phase stator coils 23 are switched. In FIG. 4, a coil in which both A1 and A2 coils are connected in series is schematically shown as one A-phase coil. The same applies to the B-phase and C-phase coils. Although there are various circuit configurations of the motor drive circuit 31, FIG. 5 shows an example of a drive circuit of a three-phase drive system using three Hall elements 27. Blocks surrounded by dotted lines in FIG. 5 are, for example, C-phase stator coils 23.
The current supply to (C1 and C2) is shown. In the case of a three-phase motor, two other similar block configurations corresponding to the A phase and the B phase are provided. In one block, when one Hall element 27 detects a change in the magnetic pole of a rotor magnet passing therethrough, the transistors Tr1 and Tr2 are activated by the detection signal, and the switching operation causes the C phase (C1 And C2) stator coil
Current is supplied to 23. Similarly, for the B-phase and C-phase stator coils, the supply of current is switched according to the magnetic detection signals from the Hall elements. The switching of the current supply to the coils of each phase is performed in order.

FIG. 7 conceptually shows the principle that the rotor magnet 26 is rotationally driven according to the supply of current to the stator coil 23 of each phase. For convenience of explanation, each magnetic pole of the rotor magnet 26 and the stator coil 23 are illustrated as horizontally extending. The traveling direction (rotational direction) of the rotor magnet 26 is the leftward direction in the drawing. First, in the stage (I),
Current is supplied to the A-phase stator coils A1 and A2,
Due to the relationship with the magnetic poles of the rotor magnets 26 that face each other (according to Fleming's left-hand rule), a driving force in the left direction in the drawing acts on the rotor magnets. When the rotor magnet 26 advances to the stage (II), current is supplied to the C-phase stator coils C1 and C2 by the switching operation of the motor drive circuit 31 shown in FIG. ), The current is supplied to the B-phase stator coils B1 and B2. Then, at the stage (IV), the current is again supplied to the A-phase stator coil. However, in the steps (IV) and (I), the magnetic poles of the magnets facing the A-phase stator coils are opposite to each other, so that the current supply directions to the coils A1 and A2 are opposite. By such a switching operation by the motor drive circuit 31, the rotor magnet 26 is continuously driven to rotate.

Further, in the rotation speed detection circuit 32 of the present invention shown in FIG.
The rotation speed is measured based on the magnetic pole detection signal from the Hall element 27. The rotation speed detection circuit 32 includes, for example, a waveform shaping circuit 33 and a counting circuit 34. These circuits can be provided in the same IC as the motor drive circuit 31, or the rotation speed detection circuit 32 can be provided. The same function as 32 can be performed by the CPU of the microcomputer. As described above, the three Hall elements 27 output magnetic pole detection signals in response to passage of the magnetic poles of the rotor magnet 26. With one Hall element 27, eight magnetic pole detection signals are obtained per one rotation of the rotor magnet 26 having an eight-pole structure. Therefore, a total of 24 detection signals can be obtained from the three Hall elements 27 per one rotation of the rotor magnet 26. In FIG. 4, assuming that the three Hall elements 27 are (a), (b) and (c), respectively,
The magnetic pole detection signal detected by 27 is shaped by the waveform shaping circuit 33, and the waveforms of (a), (b), and (c) with a fixed time are obtained as shown in FIG. This (a)
By adding the waveforms (b) and (c) in the counting circuit 34, a pulse signal having a constant time pitch as shown in (d) can be obtained. As described above, 24 pulses shown in (d) are obtained per one rotation of the rotor magnet 26. For example, by counting the number of pulses indicated by (d) in the counting circuit 34 within a fixed time, it becomes possible to know the number of revolutions of the plasticless motor M. This count value can be used in various ways. For example, by displaying this count value on a display device, the number of rotations of the motor can be immediately known. Also, this count value can be used as various control data. For example, according to this data, the motor M
The rotation speed at that time can be known, and if the switching of the motor drive current is controlled based on this, it becomes possible to control the rotation speed to be constant.

FIG. 8 shows a motor on the tape supply side of the tape player, which does not use the Hall element described above.
It is used as a detection signal of the magnetic pole of the rotor magnet based on the electromotive force generated in the stator coil.
FIG. 8 shows the connection state of each of the A-phase, B-phase, and C-phase stator coils 23. Further, this figure shows the magnetic poles of the stator coil 23 and the rotor magnet 26 in a horizontally expanded state, as in FIG.

In FIG. 8, for example, a current I is applied between the common terminal D ₀ and the C-phase (C1 and C2 are connected in series) coil terminal C _0.
When a clockwise current in the figure is supplied to the stator coils C1 and C2 at a certain point in time, a driving force in the arrow direction is exerted on the rotor magnet 26 by this current and the magnetic poles of the rotor magnet 26. . In the A-phase or B-phase coil in which the motor drive current I does not flow at this time, an electromotive force is generated according to the movement of the magnetic poles of the rotor magnet (in this case, Fleming's right-hand rule), and the A-phase coil or B A current i due to an electromotive force is obtained in the phase coil. FIG. 8 shows a case where a current i due to an electromotive force is flowing through the B-phase coil terminal C ₀ . This current i is taken out in a timely manner, and when, for example, a current of a certain level or more or an electromotive force of more than a certain voltage is generated, the waveform is shaped to generate a signal from the Hall element as shown in FIG. Similar magnetic sensing signals are obtained. The same operation as that of the Hall element can be achieved by performing the switching operation of supplying the current to the coils of each phase according to the magnetic detection signal. In the present invention, the rotation speed is detected by utilizing the signal generated by the electromotive force of this coil. Since this electromotive force is a signal corresponding to the number of times the magnetic poles of the rotating rotor magnet have changed, this signal is detected and counted by the counting circuit 34 equivalent to that shown in FIG. Rotor magnet 26
It becomes possible to know the rotation speed of.

Next, FIG. 9 shows a reel drive control device in a rotary head type tape player using a motor rotation detection device.

In FIG. 9, reference numeral 1 is a supply-side reel stand, on which a supply-side tape reel R1 is installed. Reference numeral 2 is a winding-side reel stand, on which a winding-side tape reel R2 is installed. The magnetic tape T wound around each tape reel R1 and R2 is pulled out by the loading posts 4a and 4b of the tape loading mechanism and wound around the rotary head drum 3. Further, reference numeral 5 is a capstan,
A pinch roller 6 presses the magnetic tape T against the capstan.

The supply-side reel base 1 is driven by the supply-side reel motor Ma, and the winding-side reel base 2 is driven by the winding-side reel motor Mb. The winding side reel motor Mb is shown in FIGS.
The rotation detection device shown in the figure is used. That is, the winding-side reel motor Mb is adapted to obtain the magnetic pole detection signal S2 of the rotor magnet 26 detected by the hall element 27. In the supply reel motor Ma, the rotation detecting device shown in FIG. 8 is used. That is, in the supply-side reel motor Ma, the magnetic pole detection signal S1 of the rotor magnet 26 is obtained by the electromotive force generated in the stator coil of the phase in which the motor drive current is not flowing at a certain point. The rotation speed detection circuit 41 to which both of the detection signals S1 and S2 are input is obtained from a plurality of Hall elements provided in the winding side reel motor Mb, like the rotation speed detection circuit 32 shown in FIG. The detection signal S2 is waveform-shaped to obtain a pulse signal as shown in FIG. 6 (d). At the same time, the rotation speed detection circuit 41 forms a pulse signal corresponding to the rotation speed of the supply reel base 1 based on the magnetic pole detection signal S1 obtained from the electromotive force generated in the coil by the supply reel motor Ma. In the reel motor control circuit 42, the magnetic pole detection signal S1 from each of the motors Ma and Mb is
And the motor speed calculated by S2 are compared,
The difference between the rotational speeds of the reel motors Ma and Mb at that time is calculated. Further, the reel motor drive control circuit 42 calculates a motor rotation speed for keeping the tape running speed constant in accordance with the difference between the rotation speeds of the two motors, and based on the result, the motor drive circuit as shown in FIG. Is controlled,
The motor drive signals Sa and Sb are given to the respective motors Ma and Mb.

In the above rotation detecting device, the winding side reel motor Mb
In this case, since the rotation speed is measured based on the signal from the Hall element, the detection operation is possible regardless of whether the rotation speed is high or low. On the other hand, in the supply reel motor Ma, since the magnetic pole detection signal S1 is obtained by the electromotive force of the coil, it is difficult to obtain a signal from the electromotive force unless the rotation speed of the motor is high to some extent. Therefore, the actual control operation is performed as follows by utilizing the characteristics of the rotation detection devices of both motors.

In the high-speed search operation, the rotation speed of the supply-side reel motor Ma becomes faster. Therefore, it is possible to accurately extract the magnetic pole detection signal S1 due to the electromotive force. That is, in the search operation during fast forward tape (FF), the reel motor on the take-up side
Although Mb is driven and the supply reel motor Ma is not driven, it is possible to obtain the magnetic pole detection signal S1 by the electromotive force generated in the stator coil of the supply reel motor Ma.
Further, in the search operation in the tape rewinding (REW), the supply-side reel motor Ma is driven at a high speed, so that it is possible to obtain the magnetic pole detection signal S1 by the electromotive force of the stator coil that does not flow the drive current. Rewind (RE
In the search operation in (W), the reel motor Mb on the take-up side is not driven, but only the detection operation by the hall element can be performed. In this way, in both the fast-forward and rewind search operations, the rotational speeds of the two motors and the difference between the rotational speeds of the two motors are detected from the magnetic pole detection signals S1 and S2 extracted from the motors Ma and Mb. The drive control of the motors Ma and Mb is performed to keep the traveling speed of the vehicle constant.

Next, in the recording or reproducing operation, the winding side reel motor Mb
Causes the tape to be wound at a low speed. At this time, it is difficult for the supply reel motor Ma to extract the electromotive force from the coil, and it is difficult to obtain the magnetic pole detection signal S1. However, since the magnetic pole detection signal S2 from the Hall element is obtained in the take-up reel motor Mb, the drive control of the take-up reel motor Mb, the drive control of the capstan 5, or the rotation is performed using this signal S2. Various kinds of control such as reading timing control can be performed together with the rotation speed information of the head drum 3.

In the illustrated embodiment, the brushless motor on the horizontally opposed side is described as shown in FIG. 1. However, a shaft in which a stator coil is arranged in a cylindrical shape and a cylindrical rotor magnet is provided outside thereof Even in the case of the opposed type brushless motor, the same operation can be performed.

Further, in the tape player, not only the control for keeping the tape running speed constant but also various controls are possible by knowing the number of rotations of each reel stand. Further, the tape player is not limited to the rotary head type, and even a fixed head type tape player can similarly control the tape running.

〔The invention's effect〕

The reel drive control device of the tape player according to the present invention enables reel drive control in both the high-speed search operation and the recording / reproducing operation without providing a special detection device. In particular, since the magnetic sensing element is used only for the take-up reel motor and it is not necessary to provide the magnetic sensing element for the supply reel motor, the drive unit of the tape player can be realized with the minimum component configuration. .

[Brief description of drawings]

1 to 7 are provided on the tape winding side and show a motor rotation detecting device using a magnetic detecting element. FIG. 1 is a cross-sectional view showing the structure of a brushless motor, FIG. 2 is a plan view of the stator side, FIG. 3 is a plan view showing a stator facing surface of a rotor magnet, and FIG. 4 is based on a signal from a magnetic sensing element. FIG. 5 is a circuit configuration diagram showing a motor drive circuit and a rotation speed detection circuit, FIG. 5 is a circuit diagram showing an example of the motor drive circuit, FIG. 6 is a diagram showing a magnetic pole detection signal obtained from a magnetic detection element, and FIG. It is explanatory drawing which shows typically the switching operation of the electric current with respect to each stator coil of a brushless motor. FIG. 8 is a schematic diagram showing a wire connection state of a stator coil of a motor used in a rotation detecting device which is provided on the tape supply side and uses a coil electromotive force to obtain a magnetic pole detection signal, and FIG. FIG. 10 is a plan view showing a reel drive control device of a rotary head type tape player, FIG. 10 is a plan view showing a reel drive control device of a conventional rotary head type tape player, and FIG. 11 is a structure of a conventional rotation speed detection mechanism. It is a perspective view shown. 1 ... Supply side reel stand, 2 ... Take up side reel stand, 3 ...
Rotary head drum, 5 capstans, 6 ... pinch rollers, R1 ... supply tape reel, R2 ... take-up tape reel, M ... brushless motor, Ma ... supply reel motor, Mb ... take-up Side reel motor, 23 …… stator coil, 26 …… rotor magnet, 32 …… rotation speed detection circuit,
41 ... Revolution detection circuit, 42 ... Reel motor drive control circuit.

Claims (2)

(57) [Claims] 1. A winding-side reel motor for driving a winding-side tape reel, a supply-side reel motor for driving a supply-side tape reel, and a magnetic head for contacting a magnetic tape between both tape reels. In the tape player, the winding-side reel motor is provided with a magnetic detection element for detecting a magnetic pole of a rotor magnet, and the supply-side reel motor is provided with a detection unit for detecting electric power generated in a stator coil due to rotation of the rotor magnet. When the tape is running at high speed, the motor is drive-controlled based on the rotation speed of the winding-side reel motor detected by the magnetic detection element and the rotation speed of the supply-side reel motor detected by the detection unit. When the tape is running at a low speed, the motor is drive-controlled based on the rotation speed of the winding-side reel motor detected by the magnetic detection element. - up reel drive control apparatus for a tape player according to claim. 2. When the tape is running at a high speed, the difference between the rotation speed of the winding reel motor detected by the magnetic detection element and the rotation speed of the supply reel motor detected by the detection unit is calculated. 2. The reel drive control device for a tape player according to claim 1, wherein the running speed of the tape is controlled based on the difference.