JPS5932055Y2 - 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 pressing the fast rewind button or the like on the fast rewind operation device from the tape fast rewind drive state to bring the tape into the rewind state, the take up reel drive motor stops. state, and even if its torque is zero, the opposite supply reel drive motor operates,
The drawback is that a very large reverse torque is applied, resulting in a large tension.

Furthermore, if the stop operation is performed during fast forwarding (including fast winding and fast rewinding), the mechanical braking effect becomes unstable because the tape travels at a high speed.

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 side, the tape will loosen and be wound around the supply reel, causing the tape to bend or break.

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 correspondingly large.

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

In order to eliminate such drawbacks, the present applicant first controlled the supply reel drive motor with a tape tension detection means during fast-forwarding of the tape, and cut off the take-up drive motor to maintain a constant tape expansion force or this state. When the operation is performed so that the reel runs in the opposite direction, the braking devices for both the supply and take-up reels are activated, the reel drive motor on the take-up side is shut off, and the reel drive motor on the supply side is operated to reduce tape tension. We have proposed a tape control device which is controlled by the output of the detection means, and when the tape is operated from the rewinding state to the fast forwarding state, the drive motor is controlled and cut off in the reverse manner as described above.

However, in such a control device, if the tape is operated in the reverse direction (fast rewinding) while it is running (for example, being wound), and then it is set to an electrical operation mode so that the tape is stopped immediately after the above operation is performed. The tape transitions from early winding state to early rewinding state to stop state, but the tape is actually in the winding state due to the inertia of the drive system, etc., but the electrical system operates as if a stop command had been applied from the early rewinding state. do.

Therefore, the reel drive motor on the supply side is opened and the drive torque becomes zero, and the reel drive motor on the take-up side is controlled by the output of the tape tension detector.As a result, the tape does not come to a stop, but rather is stripped prematurely. will occur.

The present invention aims to provide a braking device for a magnetic recording/reproducing device that eliminates the above-mentioned disadvantages, and does not apply harmful tension to the tape during high-speed tape transport and prevent the tape from loosening due to the above-mentioned erroneous operation. It is designed to eliminate harmful effects.

The details of an example of the present invention will be explained below 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.

Since the braking device 2 of the take-up reel 2' is configured in the same manner as the braking device 1 of the above-mentioned supply reel 1',
Similar parts are shown with reference numeral 2 and corresponding suffixes a to h, and detailed explanation thereof will be omitted, but the take-up reel 2' 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
and the capstan 10 → the guide roller 12 → the tension arm 160 on the winding side The tape is wound through the roller 16a, and the tension arm 15 on the supply side and the tension arm 16 on the winding side are each equipped with a 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 configured, for example, by 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 T' 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 facing each other with the tape speed detection holes 26 in between. and are 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 27 having a substantially semicircular shape is provided along the circumference of the rotary plate 250.

Two sets of light emitting elements 19, 20 and light receiving elements 22, 23,
They are arranged facing each other across the detection groove 2T.

Note that these two sets of light emitting and light receiving elements 19, 20 and 22,
23 are arranged at positions 900 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, 28, 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 via amplification circuits 30 and 31, respectively.

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

Tape speed detection circuit 28 and tape running direction detection circuit 2
Outputs from 9a and 29b 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.
Control signals are output in response to the button group 37, the tape speed detection circuit 28, and the tape running direction detection circuit 29at29b.

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 1h, 2h for braking devices of the supply and take-up reels 1' and 2' and plungers 38, 39 for moving the pinch roller 11 and shifter 9 (not shown)
etc., respectively, as control signals.

The logic circuit of the above-mentioned control circuit will be explained with reference to FIG. 4. In FIG.
The output terminals 36b and 36b' are used to apply a full voltage to the terminals 36b and 36b' to apply full voltage to the reels 3 and 4, respectively. Tension servo is performed by outputs from the output terminals 36b and 36b'.

In response to the operation signal from the operating device 3γ, an early spring stripping signal is sent to the input terminal 36c, an early spring return signal is sent to the input terminal 36d, a stop signal is sent to the input terminal 36e, and a tape speed detection circuit 28 is sent to the input terminal 36f. The tape running direction detection circuit 29a outputs the output to the input terminals 36g and 36h.

The outputs of 29b are respectively input, and the NAND circuits 36i to 36
n, inverter circuit 36o, 36p, OR circuit 36qt
36r constitutes a logic circuit as shown in the figure.

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. 1, the operation button (F-FWD) of the operation button group 37 or (REW) is pressed, the supply and take-up plungers 1h and 2h are controlled by a signal from the control circuit 36, and the band brakes Ib and 2b are connected to the drum 1a.

2a, supply side and take-up side braking devices 1,
2 have been canceled respectively.

At this time, the tape tension detector 5 or 5 detects the movement of the tension arm 15 or 16, and its differential transformer converts the amount of change in the tension of the tape 17 into voltage, which is then used to drive 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 inactive, and the reel motor 4 on the winding side generates a 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 28 generates a voltage proportional to tape speed.

On the other hand, the tape running direction detection circuit 29a>29b detects which of the light receiving elements 22 and 230 receives light first, and detects the running direction of the tape 170.

Now, from the early spring cutting (F-FWD) state as mentioned above,
As soon as the early spring return (REW) operation is performed, operation button group 37
If the stop button (S TOP ) is pressed and the above-mentioned running direction detector is released, the tape 17 will run in the A direction (・
Since it is determined that the stop operation has been performed while the tape is still running in the B direction, that is, in the rewinding state, the reel motor 3 on the supply side is opened and the drive torque is lost, causing the tape to rewind. Since the motor 4 on the side is controlled by the tape tension detection circuit 6a, even if the tape is stopped, the tape will be removed even earlier.

Therefore, in the present invention, the tape running direction detection circuit 29 a
, 29b detect the tape running direction, and further detect the stopped state of the motor by the output of the tape speed detection circuit, so that the reel motor 30 on the supply side is de-energized.

Therefore, it is possible to prevent the tape speed and running direction detector from malfunctioning due to erroneous operation that sometimes occurs.

That is, even if the tape is operated in a fast-forwarding state in the reverse direction and stopped, the supply and winding plunger 1h is controlled by the control signal from the control circuit 360.

2h are opened, respectively, and the shoes of the brake bands 1b, 2b come into contact with the drums 1a, 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 reel motor 30 on the supply side,
The running direction of the tape 170 eventually begins to reverse.

Therefore, the tape speed detection circuit 28 described above detects the tape 1T.
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 1γ has been reversed, and de-energizes the reel motor 30 on the supply side to bring the reel to a stopped state.

To explain the operation of the above-mentioned control circuit, when the fast winding operation button (F-FWD) is pressed from the tape stop state in FIG.
A positive signal is input to the input terminal 36d, and the fast rewind signal is not input to the input terminal 36d, but is a zero signal shown by W in FIG. This output enters the input terminal 36h (・
If so, a NAND circuit 36i is established and an OR circuit 36r
The drive motor 4 on the winding side is tension servoed by the signal taken out to the winding side output terminal 36b' through the winding side, and starts rotating in the direction D in FIG.

After turning a little, the A direction output from the tape running direction detection circuit 29a as indicated by X in FIG. An output signal for tension servoing the winding reel 2 is applied to the terminal 36b, and the inverter 36o inverts the negative signal to positive and applies a voltage to the winding side terminal 36a' for fast winding of the winding side. ' is considered to be a fast winding state.

In this state, the output of the tape speed detector as indicated by Y in Fig. 5A is taken out.If the STOP button is pressed at time t2 in the fast winding state, the STOP signal is memorized and the output is output as indicated by Z in Fig. 5A. A stop signal z1 as shown in FIG. 1 is output, and the driving/driving is stopped, thereby clearing the stop memory.

The output of the tape speed detection circuit 28 obtains a section Y1 in which the tape rotates due to inertia, and comes to a stopped state.

Furthermore, this is related to fast winding from the stop state, and to explain the case where the fast winding state is changed from the fast winding state to the fast rewinding state at time t3 at the beginning of FIG. 5, since the tape is in the fast winding state, A signal as shown in v2 is input to the input terminal 36.
Although it is added to c, the fast rewind RE of the operating device 37
W) When the button is pressed, the memory for fast winding is immediately cleared, resulting in the waveform shown by v2 at the beginning of Figure 5, and the rewinding waveform immediately rises as shown by the waveform W1 at the beginning of Figure 5, at this point t3. Now, the tape running direction detection circuit outputs a rotation signal in the right direction due to inertia, so NAND circuit 3
61 and an OR circuit 36q are established, and the supply side drive motor 3 from which a signal is derived to the output terminal 36b is tension servoed.

Next, roller 7 stops and the running direction of the tape is reversed.
At this time, the output of the tape speed detection circuit 28 is temporarily stopped, and the tape speed signal becomes zero Y3.
Since the rotation is in the opposite direction, an output signal is taken out.

Of course, the stop signal at this time is zero as shown at z2 at the beginning of FIG.

In this state, the NAND circuit 36k and the OR circuit 36R shown in FIG. 4 are established to tension servo the drive motor 4 on the winding side from the output terminal 36b', and at the same time, the output is supplied from the inverter circuit 36p to the output terminal 36a. The side drive motor 3 is brought to full voltage and unwound.

Furthermore, a case where the stop operation is performed immediately after the fast rewind operation is started from the above-mentioned fast rewind state will be explained with reference to FIG.

From the state of t3 to the time of t4, electrically, the fast winding input terminal 36c has zero input, and the waveform is as shown in v4 in FIG. 5, and the fast winding input is in the "on" state.
As shown at W4 in Figure C, the stop button (STOP) of the operating device 37 is pressed.
), the memory for fast rewinding is cleared immediately, and the output from the tape running direction detection circuits 29a, 29b maintains the fast rewinding state due to inertia.
The tape rotates and an output is taken out from the tape running direction detector 29a.

That is, it is the state shown by X4 in FIG. 5, and the stop button (STO
The stop signal memorized by the suppression of P) outputs a stop signal Z5 as shown in FIG. 5, and is cleared by the signal when the output of the tape speed detection circuit 28 becomes zero.

The tape speed detection circuit 28 outputs a signal until the tape stops as indicated by Y4 in FIG. 5C.

Therefore, a NAND circuit 36m is established by the stop signal 36e, the A running direction signal 36g, and the speed detection signal 36h.
Since the NAND circuit 36n does not hold because the B running direction is negative, the OR circuit 36q→output terminal 36b holds,
Only the supply reel drive motor 3 is tension-saved.
That is, the tape is stopped.

If the fast rewinding state is changed to the fast winding state and the stop is applied immediately, a NAND circuit 36n#'' is established and the winding side drive motor is tension servoed.

Since the present invention is constructed and operates as described above, the fast winding (rewinding) state is similar to the fast rewinding (fast forwarding) state, and even if the device is stopped immediately, it will not be rapidly reeled in on one reel, and the high speed The tape can be stopped extremely quickly from a running state with a constant tape tension, and can be used as a braking device for a magnetic recording/reproducing device for broadcasting stations or studios, and has a great practical effect.

[Brief explanation of the drawing]

Fig. 1 is a linear plan view showing the magnetic recording/reproducing device of the present invention, Fig. 2 is an enlarged perspective view of the detection roller section of the invention, Fig. 3 is a system diagram of the invention, and Fig. 4 is a control circuit diagram. The circuit diagram, FIG. 5, is a waveform explaining the operation of FIG. 4. In the figure, 1 and 2 are supply and take-up side braking devices, 3.4
Reference numerals 5 and 6 indicate supply and take-up side reel motors, supply and take-up side tape tension detectors, and 5a. 6a is a supply and take-up side tape tension detection circuit, 7 is a detection roller, 28 is a tape speed detection circuit, 29a, 29
b is a tape running direction detection circuit, 32.degree. 33 is a switching circuit, and 36 is a control circuit.

Claims (1)

[Scope of utility model registration request] A dedicated reel drive motor associated with each of the supply reel and take-up reel, a braking device for controlling the driving force of both reel drive motors, a tape tension detection means provided in the running path, and a tape running path. In a magnetic recording and reproducing apparatus equipped with a tape running direction detecting means and a tape speed detecting means provided in connection with the above, when the tape is running, the braking device is released and the reel drive motor is activated by the tape tension detecting means. When a stop operation is performed as soon as the tape is controlled to a constant tape tension and the tape runs in the opposite direction to the above-mentioned running direction from that state, both reel braking devices are operated and the tape running direction detection means The tape running direction is detected and the drive signal of the reel drive motor in the winding state is cut off, and the reel drive motor in the supply state is controlled by the output of the tape tension detection means to maintain a constant tape tension. Alternatively, in this state, the running speed of the tape is decelerated, and when the tape running speed detecting means or the running direction detecting means detects that the running speed of the tape has substantially stopped, the reel is driven on the supplying state side. A braking device for a magnetic recording/reproducing device that interrupts a motor drive signal.