JPS5982647A - Device for controlling revolution of feeding reel in magnetic picture recording and reproducing device - Google Patents

Abstract

PURPOSE:To apply always proper tension to a magnetic tape to prevent the tape from damage and to stabilize the intial travelling of the tape by rotating a feeding reel reversely while braking a winding reel strongly to wind the magnetic tape around the feeding reel. CONSTITUTION:After completing unloading operation, an unloading operation completion detecting circuit 24 outputs an operation completion detecting signal. Receiving the signal, a loading motor controlling circuit 22 stops a loading motor M1 and an operation timing controlling circuit 26 outputs a strong brake signal to a winding reel brake controlling circuit 25, so that the circuit 25 brakes the winding reel strongly. Until the 1st prescribed time passes after the generation of the unloading operation completion detecting signal, the feeding reel 2 turns reversely and the winding reel 3 is strongly braked, so that the magnetic tape 4 is wound strictly while applying proper tension to the feeding reel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a supply reel rotation control device for a magnetic recording/reproducing device such as a VTR, and more particularly to a supply reel rotation control device during unloading or loading a video cassette tape.

<Prior art> In a magnetic recording/playback device such as a VTR (video tape recorder), when you press any button to stop, eject a cassette, or fast forward or rewind during recording mode, the tape is wound in an S'l shape on a magnetic rotating drum. The attached magnetic tape is removed from the magnetic rotating drum and unloaded. During this unloading operation, the loading guide roller, which had guided the magnetic tape to a position around the magnetic rotating drum, is returned to the video cassette tape from the guiding position around the magnetic rotating drum. At the same time, in order to eliminate the loosening of the magnetic tape due to the return of the loading guide roller, the supply reel rotates in the opposite direction to wind the magnetic tape. However, if the reverse rotation torque of the supply reel is too strong even though the return speed of the loading guide roller is slow, a large tension is applied to the magnetic tape, which may damage the magnetic tape. In the opposite case, only a small amount of tension is applied to the magnetic tape, but because the tension on the magnetic tape is insufficient, when it is loaded again, the magnetic tape will not follow the guide in a good manner, and the magnetic tape will be damaged. There are cases. Furthermore, even if the magnetic tape is able to follow the guide in good condition, the initial running of the magnetic tape becomes unstable, and the reproduced image is likely to be disturbed and cause wow and flutter.

Purpose of the present invention: It is an object of the present invention to always apply an appropriate tension to the magnetic tape to eliminate damage to the magnetic tape, and to stabilize the initial running of the magnetic tape to eliminate disturbances and wow and flutter in reproduced images. do.

For this purpose, the present invention winds the magnetic tape around the supply reel tightly when unloading or loading the video cassette tape.

<Embodiment> FIG. 1 is a block diagram of a main part of a VTR to which an embodiment of the present invention is applied. In FIG. 1, symbol (1) is a video cassette tape, (2) is a supply reel, (3) is a take-up reel, (4) is a magnetic tape, (5) is a tension arm, (
6) is a pole base, (7) (7) is a pole base (
loading guide roller attached to (6), (8)
) is a magnetic rotating drum. In Figure 1, the magnetic tape (4) is moved by the loading guide rollers (7) (7), while in the magnetic unloading mode the loading guide rollers (7) (7) and the tension arm (5) return to the imaginary line position. Then, the supply reel (2) is marked with an arrow (
The magnetic tape (4) rotates in the opposite direction to (a) and comes to the imaginary line position.

FIG. 2 is a block circuit diagram of this embodiment.

In FIG. 2, the symbol θη is a circuit for setting the loading mode in FIG. 1 to the unloading mode.

This unloading setting circuit Q) outputs first to fourth unloading setting signals.

The first unloading setting signal is input to the loading motor control circuit (a). The loading motor control circuit (a) controls the rotation and direction of rotation of the loading motor (Ml), and reversely rotates the loading motor (M,) at a predetermined speed based on the first unloading setting signal. When the loading motor (Ml) rotates in the reverse direction, the loading guide roller (7) in Fig. 1
(7) is returned toward the imaginary line position via the pole base (6). The fourth unloading setting signal is input to the reel motor control circuit (c).

The reel motor control circuit (c) controls the rotation and direction of rotation of the reel motor (M2), and reversely rotates the reel motor (M2) at a predetermined speed based on the fourth unloading setting signal. This will cause the supply reel (2)
is rotated in the direction opposite to the arrow (G) in FIG.

The second unloading setting signal is input to the unloading operation completion detection circuit. The unloading operation completion detection circuit (c) is set to the unloading operation completion detection operation mode by this input. The third unloading setting signal is input to the take-up reel brake control circuit (c).

The take-up reel brake control circuit (c) applies a moderate brake to the take-up reel in response to this input. (C) Take-up reel brake control circuit (C) Take-up reel motor control circuit (
This is a circuit that controls the operation timing of (b).

This operation timing control circuit (c) sends out a strong brake signal to the take-up reel brake control circuit (c) in response to the unloading operation completion detection signal from the unloading operation completion detection circuit (c), and after sending out the strong brake signal, the magnetic After a first predetermined time (for example, 0.8 seconds) necessary for tightening the tape (4) has elapsed, a motor stop signal is sent to the reel motor control circuit (c). Operation timing control circuit (E)
Also, the take-up reel brake control circuit (c) is activated after a second predetermined time (for example, 01 seconds) necessary for the reel motor (M2) to completely stop after the output of the motor stop signal.
Sends a brake release signal to The loading motor control circuit (A) stops the loading motor (Ml) at the same time when the unloading operation completion detection signal is input.

The operation of the apparatus having such a configuration will be explained with reference to the program flowchart shown in FIG.

This flowchart shows the unloading processing routine when the circuit shown in FIG. 2 is constructed by a microcomputer.

First, the first to fourth unloading setting signals are outputted from the unloading setting circuit c2) to enter the unloading mode. Loading motor control circuit (a)
The loading motor (Ml) is reversely rotated by the first unloading setting signal. As a result, the loading guide rollers (7) (7) are returned to the imaginary line position in FIG. The take-up reel brake control circuit (c) applies a moderate brake to the take-up reel in response to the third unloading setting signal.

The reel motor control circuit (c) reversely rotates the reel motor (M2) in response to the fourth unloading setting signal.

This causes the supply reel (2) to rotate in the opposite direction to the arrow (2) in FIG. Loading guide roller (
7) By returning (7), the magnetic rotating drum (8)
The magnetic tape (4) being unwound from the magnetic tape (4) is wound onto the supply reel (2) by the reverse rotation of the supply reel (2). In this way, the loading guide roller (7)
(7), magnetic tape (4), etc. reach the virtual line position and the unloading operation is completed [first step (n,
)), an unloading operation completion detection signal is output from the unloading operation completion detection signal (c). This signal causes the loading motor control circuit (A) to stop the loading motor (M) [second step (n2)].
], the operation timing control circuit (26) outputs a strong brake signal to the take-up reel brake control circuit (c), so that the take-up reel brake control circuit (c) operates the take-up reel (c).
3) Apply strong brakes [3rd step (n3)
l). In this way, the supply reel (2) rotates in reverse until the first predetermined time (for example, 0.8 seconds) elapses after the next unloading operation completion detection signal is generated, and the take-up reel (3)
) has a strong brake, so the magnetic tape (4
) is wound onto the supply reel (2) such that appropriate tension is maintained. When the first predetermined time has elapsed (fourth step (n4)), a motor stop signal is sent from the operation timing control circuit (c) to the reel motor control circuit (a), so that the reel motor control circuit (c) Stop the reel motor (M2) [5th step (n5))
. Furthermore, when a second predetermined period of time (for example, 0.1 seconds) has elapsed after this stop [sixth step (ne)], the operation timing control circuit (c) switches the take-up reel brake control circuit (
When the brake release signal is applied to c), the take-up reel brake control circuit (c) releases the brake of the take-up reel (3) [seventh step (n7)). In this way, after the unloading operation is completed, the supply reel (2)
Since the magnetic tape (4) is wound tightly, the magnetic tape (4) will have an appropriate tension after unloading is completed.

Figure 4 is a configuration diagram of the main parts of the VTR, which is the same as Figure 1.
While Figure 1 shows the loading state, Figure 4 shows the video cassette tape after it has been loaded and before loading. FIG.

FIG. 5 is a block circuit diagram of another embodiment of the present invention in the case of FIG. 4, and parts corresponding to those in FIG. 2 are given the same reference numerals. In FIG. 5, (51) is a circuit that controls a slider (not shown) for loading the video cassette tape (1) into a VTR. This slider control circuit (51) rotates a cassette motor (M3) in order to lower the slider and load the video cassette tape (1) into the position shown in FIG. This slider control circuit (51) sends a slider down completion signal to the operation timing control circuit (a) when the slider is down.

(5) is a control circuit for applying a brake to the supply reel 2) in response to the supply reel brake signal from the operation timing control circuit (c).

Next, the operation of the apparatus having the above configuration will be explained with reference to the program flowchart shown in FIG. FIG. 6 shows a processing routine when the circuit shown in FIG. 5 is constructed by a microcomputer.

First, when the video cassette tape (1) is inserted into the VTR and placed on the slider, the slider control circuit (51)
is activated and the cassette motor (M3) rotates.

As a result, the slider moves down and the video cassette tape (1) is loaded in the position shown in Figure 4.
1 step (nl, )]. When a third predetermined time (for example, 0.02 seconds) has elapsed after this loading, [twelfth step (n
12)], the operation timing control circuit (c) stops the cassette motor (M3) [13th step (n13)
).

At this point, a medium brake signal for applying a medium brake is input from the operation timing control circuit (e) to both brake control circuits (52) (c).

Therefore, both reels (2) and (3) are applied with a moderate brake. Next, after the cassette motor (M3) is stopped, after a fourth predetermined time (for example, 0.2 seconds) necessary for the cassette motor (M3) to actually stop completely has elapsed.
(Fourteenth step (n+4)) A motor reverse rotation signal for reversely rotating the reel motor (M2) is input from the operation timing control circuit (c) to the reel motor control circuit (c). The reel motor control circuit (c) reversely rotates the reel motor (MO) based on this input [15th step (n+,)l). However, at this point the supply reel (
2) has a medium brake applied as described above, so the supply reel (2) does not rotate in reverse. Next, after the 5th predetermined time (for example, 002 seconds) necessary to match the reel drive mechanism switching timing after the motor reverse rotation signal is input (16th step (n+6)), the operation timing control circuit (a) A brake release signal is input to the supply reel brake control circuit (5).

As a result, the brake of the supply reel (2) is released [seventeenth step (n17)]. Subsequently, a strong brake signal is manually applied from the operation timing control circuit (a) to the take-up reel brake control circuit (c). As a result, a strong brake is applied to the take-up reel (3) [18th step (no+), l. Therefore, only at this point is the supply reel (2) reversely rotated and the take-up reel (3) subjected to strong braking. In this way, the magnetic tape (4) is wound around the supply reel (2) such that an appropriate tension is maintained between the reels (2) and (3). Such unloading mode [19th
From step (nt9)), the sixth predetermined time (for example, 08 seconds) necessary for the magnetic tape (4) to be sufficiently tightened.
After the lapse of time [20th step (n2o)], a motor stop signal is input from the operation timing control circuit (c) to the reel motor control circuit (a). As a result, the reel motor (M2) stops [21st step (nz+): l
]. At the same time, the operation timing control circuit (c) sends a brake release signal to the take-up reel brake control circuit (c).

This releases the brake on the take-up reel (3).
22nd step (nz2)). In this way, after the magnetic tape (4) is sufficiently wound around the supply reel (2), after the seventh predetermined time (for example, 02 seconds) has elapsed [the 23rd
In step (nz:+)), a motor forward rotation signal is sent from the operation timing control circuit (c) to the reel motor control circuit (c). This causes the take-up reel (3) to move with the arrow (
C) direction [24th step (n24)].

<Effects> As described above, according to the present invention, when an unloading operation is completed or a video cassette tape is loaded, a strong brake is applied to the take-up reel to rotate the supply reel in the reverse direction, thereby tightly winding the magnetic tape around the supply reel. Therefore, it is possible to always apply an appropriate tension to the magnetic tape, and damage to the magnetic tape due to excessive or insufficient tension on the magnetic tape can be eliminated. Furthermore, since the initial running of the magnetic tape is stabilized, it is possible to eliminate disturbances and wow/flutter in reproduced images during the initial running.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a configuration diagram of the main parts of a VTR used to explain this embodiment, FIG. 2 is a block circuit diagram, and FIG. 3 is an explanation of operation. 4 to 6 show other embodiments, FIG. 4 is a configuration diagram of the main parts of the VTR used to explain this embodiment, FIG. 5 is a block circuit diagram, and FIG. 6 is an operation diagram. It is an explanatory flowchart. (1)...Video cassette tape, (2)...Supply reel, (3)...Take-up reel, (4)...Magnetic tape, (7)...Loading guide roller, (8)...・
・Magnetic rotating drum, el)...Unloading setting circuit, (A)...Loading motor control circuit, (A)
... Reel motor control circuit, (C) ... Unloading operation completion detection circuit, (C) ... Take-up reel brake control circuit, (C) ... Operation timing control circuit,
(51)...Slider down control circuit, (52)...
・Supply reel brake control circuit, (Ml)...Loading motor, (M2)...Reel motor, (M3)
...Cassette motor applicant Sharp Co., Ltd. agent Patent attorney Oka 1) Kazuhide Figure 2-305- Figure 3

Claims (1)

[Claims] 1) It includes at least a take-up reel brake control circuit and a reel motor control circuit, and when at least one of the unloading operation is completed or the video cassette tape is loaded, a strong brake signal is given to the take-up reel brake control circuit, and the reel motor is The control circuit has a circuit that gives a motor reverse rotation signal to reversely rotate the supply reel, and both of the signals apply a strong brake to the take-up reel, while the supply reel is reversely rotated to tighten the magnetic tape on the supply reel. A supply reel rotation control device for a magnetic recording/playback device, characterized by: