JPS5997951A - Reel bed driving device - Google Patents

Abstract

PURPOSE:To transfer stably a tape without any irregular rotation by operatively turning on and off an electromagnetic clutch mechanism section to smoothly change over the motional mode of the tape purely electrically and eliminate torque variation in each motional mode for producing stable torque. CONSTITUTION:When a tape is quickly fed or unwound, an electromagnet (of electromagnetic clutch mechanism) 18 is excited to lift a stopper 16 so that the projection 16a is inserted into a slot 3a in an idler 3. Under such condition is rotatably driven a motor, and the turning force of the idler 3 driven rotatably through a pulley 2 is transmitted to the stopper 16, an idler 9 and a reel bed to make a slip mechanism including f frictional material 11 inoperative, drive rotatably the reel bed with high speed torque and high speed and carry out quick feed and unwinding of the tape. Next, when the tape has the record reproduced while being fed with a certain speed, the electromagnet 18 is demagnetized and the reel bed is rotated through the idler 3, frictional plate 11 and the idler 9 by the rotational drive of a motor to take up the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive mechanism for a reel stand in a tape recorder, video tape recorder, etc.

As a reel stand drive mechanism for conventional tape recorders, video tape recorders, etc., (1) constant speed rotation of capstan etc.
The reel stand is driven to rotate by the rotational force of the part, and a torque limiter is used, which is made by interposing felt or the like in order to absorb the difference in rotational speed between the constant speed rotating part and the reel stand. 2) Using a special reel motor with a mechanical torque limiter using felt or a rotation speed dependent limiter using eddy current, (3) Using a dedicated reel morph without using a torque limiter. ,
'There are some that drive the reel stand while controlling the voltage of the reel motor.

However, according to the above method (1), since a small amount of transmission torque (in both two stages) is required depending on the tape running mode, it is necessary to turn on and off the limiter or switch the limiter torque, and the fluidor transmission mechanism , the lever mechanism, etc. becomes complicated, and there are many problems such as restrictions on mechanism arrangement, reliability of operation, and difficulty in adjusting switching timing.Furthermore, according to item (2) above, the mechanism In the case of a conventional limiter, there is a problem similar to (1) above, and in the case of a limiter that relies on eddy currents, although the mechanism is simpler, there is a limit to the amount of transmitted torque. .Also, the above (3)
According to the above, although the mechanism H and IH are only used, the problem is that the torque of the motor fluctuates instantaneously, which tends to cause uneven rotation (wow and flutter).

It is an object of the present invention to eliminate the need for a complicated mechanism and to arbitrarily switch the torque IJ transmitter using only a drowsiness signal, and to obtain stable transmitted torque in any tape running mode and to prevent uneven rotation. It is an object of the present invention to provide a reel stand driving device which is made less likely to occur.

The present invention will be explained below with reference to illustrated embodiments.

IX 1 b K 16, a rubber ring 4 fitted on the peripheral surface Vc of an idler 3 is brought into pressure contact with the motor pulley 2 of the reversible reel motor 1 (the idler 6 is also shown in FIG. 2). As shown in FIG. In addition, as the idler lever 5 is biased downward in FIG. The shaft 6 also has an idler 3 and an idler lever 5.
An idler 9 is rotatably fitted loosely between the two. A rubber ring 10 is integrally fitted on the peripheral surface of the idler 9. A friction material 11 such as felt is interposed between the idler 5 and the idler 9, and a friction material 12 such as felt is also interposed between the idler 9 and the idler lever 5. The coiled repulsion spring 13 forces the idler 3 downward in FIG.
Appropriate frictional force is generated between the idler 9 and the idler 9, and between the idler 9 and the idler lever 5. Therefore, when the idler 3 is rotationally driven in the clockwise direction in FIG. 1 by the motor IK via the motor pulley 2, the idler 9 is rotationally driven in the clockwise direction due to the frictional force between the idler 6 and the idler 9. 9 and the idler lever 5, the idler lever 5 is moved to the right in FIG. is rotated counterclockwise in FIG. On the contrary, when the idler 6 is rotationally driven in the counterclockwise direction in FIG. 1, the idler lever 5 is moved to the left in the same figure ( The reel stand 15 is pressed against the reel stand 15 and rotated clockwise.

The details of the mechanism in which the idler lever 5 is moved by frictional force are disclosed in Utility Application No. 11238/1985, which was previously published by the present applicant.
It is described in the specification and page 0 of No. 0.

As shown in FIG. 3, there are six arc-shaped slots 6a on the back side of the idler (lower side in Figure 2).
are formed on the same circumference (・ru. Also, on the back side of the other idler 9, a recessed portion 9a is formed as shown in FIG. Six holes 9b are formed at equal intervals on the same circumference.A ring-shaped stopper 16 as shown in FIG. Six protrusions i6a are formed on the upper surface of the stopper 16, which is loosely fitted.
These protrusions i6a are loosely fitted into three holes 9b of the idler 9.

A ring-shaped permanent magnet 17 magnetized in the thickness direction is integrally fitted and fixed to the lower surface side of the stop flange 16.

An electromagnet 18 is fitted and fixed on the upper surface of the idler lever 5 at a position facing the permanent magnet 17.

When the electromagnet 18 is energized, a repulsive force is generated between the electromagnet 18 and the permanent magnet 17. As a result, the stopper 16 moves upward as shown in FIG.
It is designed to go inside. An attraction plate 19 made of a magnetic material is fixed to the lower surface of the idler lever 5, and by creating a weak attraction between the permanent magnet 17 and the attraction plate 19, the electromagnet 18 is in a demagnetized state. At this time, the magnet 17 and the stopper 16 integrated therewith can reliably maintain the initial position.

Next, the operation of the above embodiment will be explained. First, the tape is recorded and played back (hereinafter referred to as "PLAYI") while being transported at a constant speed.
・When carrying out step 1), the reel motor 1 is driven to rotate with the electromagnet 18 demagnetized. When the electromagnet 18 is in the demagnetized state, the magnet 17 and the stopper 16 are lowered and the protrusion 16a of the stopper 16 is pulled out from the slot 3a of the idler 3, as shown in the left half of FIG. It has come out. Therefore, when the motor pulley 2 is rotationally driven in this state, the rotational force of the pulley 2 is applied to the idler 3 integrated with the rubber ring 4, the friction plate 11, and the rubber ring 1 of the idler 9.
It is transmitted to the reel stand 14 or the reel stand 15 via ゜2,
The tape is wound onto a tape reel (not shown).

While the tape is transported at a constant speed, the reel stand 14
Alternatively, the rotational speed of the reel stand 15 is driven by the tape winding thickness, but the difference in the rotational speed during this time is absorbed by the slip mechanism including the friction plate 11, and due to the intervention of the slipping mechanism. The reel stand 14 or the reel stand 15 is rotationally driven by an appropriate torque.

Next, when fast forwarding the tape (hereinafter referred to as "FFJ") or early spring reversing (hereinafter referred to as "REw,l"), the motor is driven one rotation with the electromagnet 18 energized.When the electromagnet 18 is energized, As shown in the right half of Figure 2.
As shown, the stopper 16 rises and its protrusion 16a enters the slot 3a of the idler 3. Therefore, when the motor 1 is rotationally driven in this state, the idler 3 is rotationally driven via the motor pulley 2Z, and the rotational force of the idler 3 is transmitted to the protrusion 16a of the stopper 16 by the wall surface of one end of the slot 6a. and the stopper 16 is rotationally driven.
The rotational force of the stopper 16 is transmitted to the idler 9 by the wall surface of one end of the hole 9b of the idler 9, and the rotational force of the idler 9 is transmitted to the reel stand 14 or the reel stand 15. Therefore, the slip mechanism including the grinding material 11 does not operate effectively, and the situation is substantially the same as if the idler 3 and the idler 9 were directly connected, and the reel stand 14 or 15 is driven to rotate at high torque and high speed. FF or REV operation will be performed.

In addition, when the electromagnet is demagnetized from the FF and REV states, the PLAY
If an attempt is made to do so, it is conceivable that the stopper 16 may not descend smoothly due to the mutual pressure contact between the protrusion 16a of the stopper 16 and the wall surface of one end of the slot 3a of the O-idler 3. Therefore, when changing from FF and REV to PLAY,
The motor 1 is temporarily reversed and the reel stand [idler 9] on the opposite side is applied, and the impact is used to excite the electromagnet 18 in the opposite direction, and an attractive force is applied between the magnet 17 and the electromagnet 18. The stopper 16 is forcibly pulled away from the fidget 3. In this case, a brake is applied to the reel stand to prevent it from rotating due to impact. The brake mechanism of the reel stand is based on the above-mentioned application 1123-1983.
Electromagnetic blur as described in the specification and drawings of No. 8'0.

- Can be used as a substitute.

The electromagnet 18, the reel motor 1, and the above-described
The control system for the electromagnetic brake is shown in Figure 6.

In FIG.
Each mode signal of LAY, FF, REV, and 5TOP is input to the control circuit 22, and the control circuit 22 stores the mode signal in the mode storage section 23, and also stores the mode signal from the operation means 21 and the mode storage section 23b. The reel stand electromagnetic brake drive circuit 24,
The idler electromagnetic clutch drive circuit 25 and the reel motor drive circuit 26 are controlled respectively. The wake-up magnet launch drive circuit 25 for the idler is connected to the electromagnet 1 described above.
The reel motor drive circuit 26 performs the high-speed rotation, low-speed rotation, and stopping operations of the reel motor 1 described above. Each of these drive circuits is controlled by the control circuit 22 at the timing shown in FIG. 7th
In the figure, the limiter is a torque limiter consisting of a slip mechanism including a friction material 11.
This means that the slip mechanism is effectively operating, and limiter-0FF means that the limiter is ignored and the idler 3 and idler 9 are directly connected. Now, for example, from FF to PLAY
When switching to the reel motor (see Figure 7), immediately after the reel motor VC& On the other hand, an electromagnetic brake is applied to the take-up reel stand and the supply reel stand, but in this case, since the inertia of the supply reel stand is large, the brake is applied at a high voltage to generate a large braking force on the supply reel stand. .

Further, a reverse voltage k is applied to the electromagnetic clutch to ensure that the clutch is disengaged and the slip mechanism can operate effectively. After the temporary operation is completed in this way (・Ma,
Turn off the electromagnetic clutch and the brakes of both reel stands, supply a relatively low voltage to the reel motor, rotate the motor at a relatively low speed, transport the tape at a constant speed, and perform the PLAY operation. .When switching from REW to PLAY, when switching from FF or FIEW to 5TOP, the same control is applied.Also, when switching from PLAY to FF or RE
When switching to W, first apply high voltage to the electromagnetic clutch to ensure clutch operation, then apply low voltage to maintain clutch operation, and temporarily apply brakes to both reel stands. . On the other hand, the reel motor (after being stopped once) is applied a high torque in a predetermined direction and is driven to rotate at high speed, thereby performing FF and REV operations.

According to the present invention, since the torque limiter can be switched arbitrarily by using only an electric signal, a complicated mechanism is not required, space can be saved, and operation reliability can be improved. . Furthermore, the mode setting can be completely switched electrically, and the mechanism can be simplified from this point of view. Being able to switch modes purely electrically means that the timing of each part's operation can be set freely and accurately, ensuring reliable operation. In the mode, there is no fluctuation in l·lux and stable torque is obtained, so stable tape transport 7 can be carried out without uneven rotation.

In the illustrated embodiment, the electromagnetic clutch mechanism is of a movable magnet type, but it is also possible to fix the magneto b and make it a movable coil type.

In addition, when the electromagnetic clutch is not energized, the suction piece 19c of the stopper 16, the chassis 7, or the idler lever 5
It is not necessarily necessary to provide this when the magnetic material is used. Further, in the illustrated embodiment, the reel stand driving device including the first rotating body, the second rotating body, the electromagnetic clutch, etc. is located on an axis different from the axis of the reel stand, and However, the reel stand driving device may be installed coaxially with the reel stand.

[Brief explanation of the drawing]

Fig. 1 is an external plan view showing an embodiment of the present invention, Fig. 2 is a vertical sectional view of the main part of the same embodiment, and Fig. 3 is a first part of the above embodiment.
FIG. 4 is a back view of the second rotating body in the above embodiment, FIG. 5 is a plan view of the stopper in the above embodiment, and FIG. 6 is used for non-inventive purposes. FIG. 7 is a block diagram showing an example of the control system, and a timing chart showing the operation of the same control system. DESCRIPTION OF SYMBOLS 1... Reel motor, 2... Mau reel (driving rotating body), 6... Idler (first rotating body), 5...
Idler lever, 6... Idler shaft, 9... Idler (i 2 (7) rotating body), 11... Friction material constituting the slip mechanism, 14.15... Reel stand, 16...
... Stone/:, 17... Permanent magnet, 18... Electromagnet constituting the electromagnetic clutch mechanism. Φ mouth ■4 shaku■V mouth

Claims (1)

[Claims] 1 A driving rotary body rotationally driven by a motor, a reel stand for winding the tape, and a rotational force yx of the driving rotary body
a first rotating body rotatably driven by the driving rotating body, and a first rotating body that is coaxially to the first rotating body. a second rotating body provided for transmitting rotational force to the reel stand; a slip mechanism for transmitting the rotational motion of the first rotating body to the second rotating body with a predetermined torque; A reel stand drive device comprising an electromagnetic clutch mechanism housed in one of the rotating bodies to integrally rotate the second rotating body and the second rotating body.