JP3044895B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus having a function of drawing a magnetic tape from a cassette and loading the magnetic tape on a rotating drum.

[0002]

2. Description of the Related Art A conventional magnetic recording / reproducing apparatus will be described below with reference to the drawings.

FIG. 3 is a block diagram showing a configuration of a conventional magnetic recording / reproducing apparatus. In the figure, reels during loading
The loading control signal c for controlling the torque of the motor 1 is set to a constant voltage by the voltage dividing resistors 10 and 11. Similarly, the torque of the reel motor 1 during unloading is controlled.
The unloading control signal d to be controlled is a resistive voltage divider 12,1
3, the constant voltage is set. The reel control signal e is a signal for controlling the torque of the reel motor 1 in a mode other than the loading or unloading mode. The loading control signal c, the unloading control signal d, and the reel control signal e are connected to the switch 3 and are switched by a first mode command a and a second mode command b. The loading control signal c is turned on in the loading mode, the unloading control signal d is turned on in the unloading mode, and the reel control signal e is turned on in other modes. The output signal of the switch 3 controls the torque of the reel motor 1 via the driver 2. The loading control signal h is used during loading and unloading.
The torque of the loading motor 5 at the time is determined. The voltage is set to a constant voltage by the voltage dividing resistors 14 and 15 and applied to the driver 6. In addition, the first mode command a, the second mode command a
Is input to the driver 6 to control the rotation direction and on / off of the loading motor 5.

[0004]

In such a conventional magnetic recording / reproducing apparatus, in a loading or unloading mode, when a magnetic tape is pulled out from a cassette by a mechanical system in order to continuously apply a constant torque to a reel motor, or in the cassette, There is a problem that the tape tension changes greatly due to a change in the tape speed when the magnetic tape is stored in the tape, causing tape damage.

An object of the present invention is to solve the above-mentioned problem and to provide a magnetic recording / reproducing apparatus in which a change in tape tension is reduced in a loading or unloading mode.

[0006]

In order to achieve the above object, according to the present invention, there is provided a frequency generating means for generating a frequency proportional to the rotation speed of a loading motor, and a loading position for detecting a loading position from an output signal of the frequency generating means. There is provided torque switching means for switching the torque of the reel motor in accordance with the output signals of the detecting means and the loading position detecting means.

[0007]

With the above arrangement, in the loading or unloading mode, the torque of the reel motor is changed in accordance with the position of the mechanical system so that the fluctuation of the tape tension is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention. The loading control signal c is in the loading mode, and the unloading control signal d is in the unloading mode.
Is a signal for controlling the torque of the reel motor 1 in other modes. They are connected to switch 3,
The mode is switched by a first mode command a and a second mode command b, and the reel motor 1 is controlled via the driver 2. A frequency proportional to the rotation speed of the loading motor 5 is generated by the frequency generator 7 and is applied to the waveform shaping circuit 8. The waveform shaping output f is applied to a speed control circuit 9 and compared with a reference value. The error signal is used to drive the loading motor 5 via a driver 6 so that the rotation speed of the loading motor 5 is controlled to be constant. I do. The waveform shaping output f is also applied to the torque switching circuit 4. Place
And the amount of rotation of the mechanical loading motor
Since the relationship between the pull-out amount is generally not linear,
When the motor 5 is rotated at a constant speed,
The tape pull-out speed varies depending on the loading position.
You. Because reels and reel motors have inertia,
The tension that fluctuates on the tape due to fluctuations in the pull-out speed
Is added. This change in tape tension is applied to the reel motor.
This is counteracted by controlling the resulting torque. For example,
Tape loading speed increases at certain loading positions
Tape tension due to the inertia of the reel or reel motor.
To increase. Reduce the torque of the reel motor by this increase
By doing so, fluctuations in tape tension can be canceled.
it can.

FIG. 2 is a timing chart showing the operation of the magnetic recording / reproducing apparatus of the present invention. The first mode command a is H level only when the loading motor 5 is turned on.
This is the signal shown in FIG. The second mode command b determines the rotation direction of the loading motor 5, and is a signal shown in FIG. 2B that is at the L level in the loading direction and at the H level in the unloading direction. The waveform shaping output f is a pulse signal like C proportional to the rotation speed of the loading motor 5. Detecting the loading position of the torque switching circuit 4 is mechanism based Te <br/> by the counting the number of pulses of the waveform shaping the output f after the start of the loading, the Rodin
A loading control signal c having a pattern as shown in FIG. 2D set in advance so that the fluctuation of the tape tension at the time of loading is reduced depending on the loading position is output. Similarly, after the start of unloading , an unloading control signal having a pattern as shown in FIG. 2E set in advance so as to reduce the fluctuation of the tape tension during unloading depending on the loading position is output. Loading shown in FIGS. 2D and 2E
The patterns that represent position versus torque are
Tape unloading speed and unloading speed
Cancels the change in tape tension due to the change in delivery speed
What is necessary is just to set it to such a pattern.

As described above, according to the magnetic recording / reproducing apparatus of the present invention, the fluctuation of the tape tension can be reduced by switching the torque of the reel motor in the loading or unloading mode in accordance with the position of the mechanical system.

[0012]

As apparent from the above embodiments, according to the present invention, in the loading or unloading mode, the tape speed when the magnetic tape is pulled out from the cassette by the mechanical system or when the magnetic tape is stored in the cassette is reduced. Even if there is a fluctuation, the torque of the reel motor is switched according to the position of the mechanical system, so that it is possible to provide a magnetic recording / reproducing apparatus in which the fluctuation of the tape tension is small.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to one embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the magnetic recording / reproducing apparatus according to one embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

 4 Torque switching circuit 7 Frequency generator 9 Speed control circuit

Claims (1)

(57) [Claims] 1. A loading motor and a loading motor
Speed control that controls the motor speed to be constant
Control circuit, frequency generating means for generating a frequency proportional to the number of rotations of the loading motor, and detecting the loading position by counting the number of pulses of the output signal of the frequency generating means after starting loading or unloading. , This loading position, the tape
Cancels fluctuations in tape tension due to fluctuations in drawing speed
Magnetic recording and reproducing apparatus having a torque switching means for switching the torque of the reel motors according to the pattern of the loading position tight torque set in advance so.