JPS5853724Y2 - Braking device for magnetic recording and reproducing equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a braking device for a magnetic recording and reproducing device, and in particular,
The present invention relates to a braking device for a magnetic recording and reproducing device, which has a dedicated drive motor and a braking device for each of a supply reel and a take-up reel, and also has tape tension detection means.

In a magnetic recording/reproducing device, the use of dedicated drive motors for rotating the supply and take-up reels makes it extremely easy to wind the tape at high speed, and it also makes it easier to operate the operating device. Although it has the feature of being able to be constructed purely electrically, various problems occur due to problems caused by the followability of the drive system of the magnetic recording/reproducing device and the operability of the operating device.

These problems include, for example, when the fast rewind button or the like on the fast rewind operating device is pressed from the tape fast rewind drive state to bring the tape into the fast rewind state, the drive motor of the take-up reel is turned off. Even if it is stopped and its torque is zero, the opposite supply reel drive motor operates and provides a very large reverse torque, creating a large tension.

Furthermore, if you perform a stop operation during fast forwarding (including fast winding and fast rewinding), the tape will run at a fast speed, so
The mechanical braking effect becomes unstable.

For example, if the braking force on the supply side is too strong compared to the braking force on the winding side of the tape, the tape may be stretched or cut. If the braking force is too weak compared to the braking force on the take-out side, the tape will loosen and be wound around the supply-side reel, resulting in the tape being bent or cut.

These drawbacks occur because the diameter of the tape wound on the reel changes from moment to moment while the tape is running, resulting in an unbalanced moment of inertia between the two reel systems. .

In order to solve this problem by using a detection arm for tape tension control, for example, when operating the tape so that it runs in the opposite direction, the torque of the reel motor on the supply side is electrically controlled by the output of the detection arm. However, if the take-up reel motor has a large torque, the tape tension will be a large tension commensurate with that torque.

Furthermore, when a stop operation is performed during tape running, the tape tension control circuit is shut off, making it impossible to stabilize the tape tension.

The present invention aims to provide a braking device for a magnetic recording/reproducing device which eliminates the above-mentioned drawbacks, and which allows the tape to be relaxed without applying harmful tension to the tape from its high-speed transport state. The tape can be run in the opposite direction or stopped.The feature is that when the tape is running in the reverse direction, it cuts off the drive signal of the reel motor on the winding side and stops the supply. The reel drive motor on the side is controlled by a tape tension detection mechanism, and when the stop of the tape is detected by the running direction detection means or the speed detection means, the control of the motor is reversed, and the tape is run in the reverse direction with a constant tension state. This was done in such a way as to make it possible.

Hereinafter, details of an example of the present invention will be explained with reference to FIGS. 1 to 3.

FIG. 1 is a plan view of an example of the braking device of the present invention. and a band brake 1b applied to the band brake 1b.
One end is fixed to the fixed end 1C, and the other end is fixed to the midpoint 1e of the lever 1d.

One end 1f of this lever 1d is rotatable, and the other end 1g is pivotally connected to a plunger 1h for releasing the supply brake device.

The supply reel 1' is driven by a supply reel motor 3.

The braking device 2 of the take-up reel 7 is constructed in the same manner as the braking device 1 of the above-mentioned supply reel 1', so similar parts are indicated by the reference numeral 2 and corresponding suffixes a to h. Although detailed explanation thereof will be omitted, the take-up reel τ is driven by the take-up reel motor 4.

The tape 17 is transferred from the supply reel 1' to the take-up reel 2'.
Then, roller 15a of supply side tension arm 15 → detection roller 7 → head group 8 → shifter 9 → pinch roller 11
The tape is wound between the capstan 10 and the guide roller 12 → the roller 16a of the tension arm 16 on the take-up side, and the tension arm 15 on the supply side and the tension arm 16 on the take-up side each have tape tension. Detector 5
6 are provided, and tape tension detection circuits 5a and 6a are provided respectively in connection therewith.

These detectors 5 and 6 are composed of, for example, differential transformers.

Furthermore, as shown in the perspective view of FIG. 2, a tape speed detection rotary plate 24 is fixed to the rotation shaft 7' of the detection roller 7 so as to rotate together with the rotation shaft 7'.

A large number of tape speed detection holes 26 are bored at predetermined intervals along the circumferential direction of the rotating plate 240, and a light emitting element 18 and a light receiving element 21 are arranged opposite to each other with the tape speed detection holes 26 in between. will be arranged.

Further, the rotating plate 25 for detecting the tape running direction is connected to the rotating shaft 7'.
are fixed for rotation together.

An arch-shaped tape running direction detection groove 2T having a substantially semicircular shape is provided along the circumference of the rotary plate 25.

Two sets of light emitting elements 19, 20 and light receiving elements 22, 23,
They are arranged facing each other with the detection groove 27 in between.

Note that these two sets of light emitting and light receiving elements 19, 20 and 22
．． 23 are arranged 90 degrees apart from each other with respect to the rotation axis 7'.

The output of the light receiving element 21 is sent to the tape speed detection circuit 28, and the output of the light receiving elements 22 and 23 is sent to the tape running direction detection circuit 2.
9a and 29b, respectively.

The above-mentioned detection circuits 5a, 6a, 2B, 29a and 29b
The outputs of the two are respectively supplied to circuits constructed as shown in the system diagram of FIG.

That is, the outputs of the tape tension detection circuits 5a and 6a are applied to switching circuits 32 and 33, respectively, via amplification circuits 30 and 31.

These switching circuits 32 and 33 are controlled by control signals from a control circuit 36, which will be described later, and pass the outputs of the amplifying circuits 30 and 31 through driving amplifying circuits 34 and 35 to the supply reel motor 3 and the take-up reel motor 4. supply to each.

Tape speed detection circuit 2B and tape running direction detection circuit 2
The outputs from 9 a and 29 b are given to a control circuit 36 .

This control circuit 36 is further provided with a group of operation buttons 37 for the magnetic recording/reproducing device, so that the control circuit 36 can
Control signals are output in response to the button group 37, the tape speed detection circuit 28, and the tape running direction detection circuits 29a and 29b.

As mentioned above, the output of this control circuit 36 is given as a control signal to the switching circuits 32 and 33, respectively, and
Plungers Ih and 2h for braking devices of supply and take-up reels 1' and 2', pinch roller 11 and shifter 9
Control signals are also given to plungers 38, 39 (not shown), etc. for moving the and.

The operation of the present invention configured as described above will be explained.

The supply and take-up reel motors 3 and 4, when energized, generate torques such as to rotate the reels 1' and 2', respectively, in the directions shown by arrows C and D in FIG.

Now, if the device is driven to the early spring removal or early spring return state and the tape 17 is running in the direction of arrow A or B in FIG.
W is pressed, supply and take-up plunger 1
h and 2h are controlled by signals from the control circuit 36, so that the band brakes 1 b and 2 b are separated from the drums 1 a and 2 a, respectively, and the supply side and winding side braking devices 1 and 2 are released, respectively.

At this time, the movement of the tension arm 15 or 16 is detected by the tape tension detector 5 or 6, and the differential transformer converts the amount of change in the tension of the tape 17 into voltage, which is then applied to the supply or take-up reel motor 3 or 4. control the torque of

In this case, for early spring retrieval, the tape tension detector 6 on the winding side is in a malfunctioning state, and the reel motor 4 on the winding side generates a large torque force to wind the tape 17. .

In this state, the tape 17 moves at high speed in the direction of arrow A (first
(see figure), the detection roller 7 is rotated by the tape 17, and simultaneously rotates the tape speed detection rotary plate 24 and the tape running direction detection plate 25.

Therefore, since the through hole 26 is provided in the rotary plate 24 as described above, a signal with a frequency proportional to the tape speed is generated in the light receiving element 21, and this signal is supplied to the tape speed detection circuit 28. Detection circuit 2B generates a voltage proportional to tape speed.

On the other hand, the tape running direction detection circuits 29a and 29b detect which of the light receiving elements 22 and 23 receives light first, and detects the running direction of the tape 17.

Now, if the button REW of the operation button group 37 is pressed from the fast forward F and FWD states as described above, the supply and winding plungers 1h and 2h are activated by the control signal from the control circuit 360.
When opened, the shoes of the brake bands 1b and 2b come into contact with the drums 1a and 2a, respectively.

At the same time, a control signal from the control circuit 36 is applied to the switching circuit 33 so that the take-up reel motor 4 is stopped, and the driving torque of the take-up reel motor 4 in the direction of the arrow is eliminated.

At this time, the reel motor 3 on the supply side is controlled by the output of the detection circuit 5a of the tension detector 5 that detects the movement of the tension arm 15 so that the tape tension is constant.

In this state, the speed of the tape 17 gradually decreases, and due to the torque force in the rotation direction C of the supply side rolling motor 3,
The running direction of the tape 17 finally begins to reverse.

Therefore, the tape speed detection circuit 28 described above detects the speed of the tape 17.
The tape running direction detection circuit 29a detects that the speed of the tape has become approximately zero.

29b detects that the running direction of the tape 17 has been reversed and releases the braking devices 1 and 2 of both reels.

As a result, the tape 17 travels in the B direction, and the torque relationship between the two reel motors 3 and 4 continues as before.

In other words, the reel motor 4 on the take-up side (changes to the supply side by reversing) has no driving torque, and the reel motor 3 on the supply side (changes to the take-up side by reversing) is reeled by the output of the detection circuit 5a of the tension detector 5. Control the torque.

Therefore, the early spring return operation can be started with a constant tension without generating a large tension as described above.

However, in general, controlling the tension of the reel motor on the tape supply side is stable in terms of fast-forward tape speed and tape tension, so the tape speed detector detects when a predetermined tape speed has been reached. The torque relationship between the two reel motors 3 and 4 is switched through the control circuit 36 based on the output of the detection circuit 2B detected by the element 21.

For this reason, torque control, which until now has been applied to the supply reel motor 3 for tape tension control, is now applied to the take-up reel motor 4, so the torque of the supply reel motor 3 is large. torque (full torque),
Further, the torque of the take-up reel motor 4, which has been large until now, becomes smaller than the torque of the supply reel motor 3.

Therefore, by the detection circuit 6a of the tape tension detector 6,
The tension of the take-up reel motor 4 is controlled so that the tension of the tape 17 is constant.

Since the present invention is constructed and operated as described above, the tape can be stopped and reversed extremely quickly from its high-speed running state with a constant tape tension, and is suitable for use in broadcasting stations or studios. It has great practical effects when used as a braking device for magnetic recording and reproducing devices.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing the magnetic recording/reproducing apparatus of the present invention, FIG. 2 is an enlarged perspective view of the detection roller portion of the present invention, and FIG. 3 is a system diagram of the present invention. In the figure, 1 and 2 are supply and take-up side braking devices, 3,
4 is a supply and take-up side reel motor, 5.6 is a supply and take-up side tape tension detector, 5a and 6a are supply and take-up side tape tension detection circuits, 7 is a detection roller, 2
8 is a tape speed detection circuit, 29a and 29b are tape running direction detection circuits, 32.33 is a switching circuit, and 36 is a control circuit.

Claims (1)

[Scope of utility model registration request] Dedicated reel drive motors associated with the supply reel and take-up reel, respective braking devices, tape tension detection means provided in the running path, and tape running direction detection means provided in connection with tape running. and tape speed detection means, when the tape is running, the braking device is released, the tape tension detection means controls the reel drive motor to maintain a constant tape tension, and When an operation is performed that causes the reel to run in the opposite direction to the above-mentioned running state, both reel braking devices are operated, the drive signal for the reel drive motor on the take-up side is cut off, and the reel on the supply side is also cut off. The drive motor is controlled by the output of the tape tension detection means to maintain a constant tape tension, decelerate the tape running speed in that state, and detect the running direction when the tape running speed has almost stopped. or the tape speed detection means detects, releases the braking devices of the reels, runs the tape in the opposite direction, and outputs from the tape speed detection means that a predetermined tape speed has been reached. A braking device for a magnetic recording/reproducing device, wherein the reel drive motor controlled by the tape tension detection means is switched to the other reel drive motor other than the reel drive motor.