JP2564380B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a mechanism for optimizing tape tension during forward rotation and reverse rotation in a magnetic recording / reproducing apparatus such as a VTR.

[Conventional technology]

BACKGROUND ART Conventionally, there is a tension servo mechanism as a well-known technique for obtaining a tape back tension by applying an appropriate load brake to a reel-side reel stand during tape running to obtain tape running stability. However, there is a reverse play function in the VTR function, but this is to play the tape while running the tape in reverse and winding it on the reel side of the payout side. At this time, in order to stabilize the reproduced image, the above-mentioned back tension applying mechanism is operated to release the load brake to the reel base on the feeding side to prevent the tape tension from being lowered by these load brakes. Therefore, the mechanism position is usually different for normal rotation and reverse rotation because the tension applying mechanism is operated.

JP-A-58-153255 is known as an apparatus of this type.

[Problems to be Solved by the Invention]

In the above-mentioned conventional example, the mechanism mode at the time of forward rotation and reverse rotation is set to the forward rotation (recording / reproduction) position and the reverse rotation (reverse rotation reproduction or a small amount of tape reverse return necessary for continuous shooting) position by a drive source such as a motor. It is necessary to switch to
These mode transitions are accompanied by some movement time and start / stop operations of the drive motor. However, in recent years, as a recording method for camera-integrated VTRs, it has become possible to see camera-integrated VTRs that have so-called interval recording functions such as short-time recording, pause, and short-time recording. This makes it possible to observe changes in development over a long period of time while compressing the time axis, and is equivalent to the time-lapse photography seen in recorded movies and the like.

However, in order to perform the same operation with a VTR, after recording for a specified time, it is paused, and the tape is slightly reversed back so that the recording pattern on the tape can be accurately aligned with the next recorded portion and the already recorded portion. There is a need to. This is an operation commonly called continuous shooting. Therefore, during one continuous shooting, the mechanism drive motor (hereinafter referred to as the loading motor) starts and stops the mechanism from the "forward" position to the "reverse" position and from the reverse position to the forward position again. Will be done once. However, in the interval recording, there is known a method of recording from a few frames of a normal screen for about 1 second, pausing for a long time of about 1 minute, and recording again for a short time.

Therefore, if interval recording of several frames is performed on all commercially available 120-minute tapes, the number of consecutive shots exceeds 50,000 and there is a possibility that the durability of the loading motor will be problematic.

In addition, there is a conventional example that runs in reverse without changing the position of the mechanism, but in this case the tape tension is lowered because the tape is wound against the back tension torque given to the reel reel base during forward rotation, Problems such as difficulty in obtaining a stable reproduction signal are likely to occur during special reproduction such as reverse reproduction. That is, there is a merit that it can be reversed without changing the mechanism position, but problems often occur during special playback.

[Means for solving the problem]

In order to achieve the above purpose, the reverse running position is set to 2
It is possible to switch the mechanism to the appropriate reverse running state according to each purpose. In other words, in reverse running where the life is a problem such as interval recording, reverse running is performed without moving the mechanism position, and in order to obtain stable playback video output during reverse running, the reel-side reel stand is used. By operating the back tension applying mechanism which is applied to, the load torque is reduced, the necessary and sufficient tape tension is secured, and the signal output can be stably obtained.

[Action]

A clutch member is attached to the outer circumference of a reel base incorporating a coupling mechanism that generates an appropriate load torque with a weak elastic force. When the reel base is rotating in the forward direction, the clutch member is in the escaped state, and when the reel base is rotating in the reverse direction, the clutch member rotates to the bite side, and one end of the clutch member is coupled to the coupling mechanism. Apply load brake to the reel stand. Therefore, the load brake can be applied depending on the forward / reverse rotation direction of the reel stand, and the reverse running of the tape becomes possible without moving the position of the mechanism. Also, when outputting a reproduced image, the tension applying mechanism that applies load torque to the reel-side reel base is operated by the driving force of the cam gear via an appropriate speed reduction mechanism to remove the load torque and It is possible to obtain stable tape reproduction by obtaining various tape tensions.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
The figure is a plan view of the entire VTR mechanism showing an embodiment of the present invention.
It shows the stop mode. FIG. 2 is a plan view and a side view (partial cross-sectional view) showing main parts. Shan 1
A pair of reel shafts 2a and 3a are provided on the upper side, and reel bases 2 and 3 are rotatably mounted on the reel shafts 2a and 3a, respectively. Reference numeral 4 denotes a DD capstan motor, to which a pulley 5 that rotates integrally with the capstan 5a is fixed. On the other hand, a shaft 6a that is erected on the chassis 1 is rotatably supported by a pulley gear 6 including a pulley and a gear, and a belt 46 is stretched between the pulley portion 6b and the pulley 5. The shaft 8a is a fixed shaft provided on substantially vertical bisectors of both reels, and a drive gear 7 which is gear-coupled to the pulley gear 6 is rotatably rotatably supported as shown in FIGS. 2 and 3 in detail. Has been done. The drive gear 7 is composed of gears 7a and 7b having different gears vertically and is rotated by an idler gear 10 which is also rotatably supported by a shaft 9a on an idler arm 9 which is rotatably supported by the support shaft 8a. Gears are freely connected. The arm 9, the idler gear 10 generate a friction torque required for swinging the arm 9 by means of the felt 11, the spring 12, the spring seat 13, and the stopper 14. The idler arm 9 can move up and down on the support shaft 8a as shown by an arrow, and its vertical position is determined by a drilling arm 15 that holds a boss 9b planted in the idler arm 9. Now, let us consider a case in which the drill arm 15 is located below (the direction opposite to that shown in FIG. 2) and the idler arm 9 is held below. FIG. 3 is a sectional view of the vicinity of the coupling and reel stand 3. The idler gear 10 is engaged with the coupling gear 16 and is gear-coupled with the gear portion 17 of the reel die.
Is configured to generate a predetermined torque by an existing friction coupling composed of felts 19a, 19b, springs 20, stoppers 21, and crimping plates 22.
It is rotatably supported by 16a and 16b. In FIG. 2, the Kirikaban 23, which is pivotally supported by the support shaft 23a on the chassis and is pressed and held by the torsion spring 24 and the stop washer 25, is clamped by the screw spring 24 and is biased in one direction by the spring force. (Shown by a chain line). The spring 24
The tip of the nose is pivotally supported by a bearing 47 planted in the chassis,
It penetrates through a hole of a drill arm 15 rotatably held on an axis parallel to the chassis.

The idler arm 9 moves up and down on the support shaft 8a in accordance with the rotation of the drill arm 15, and the idler gear 10 can be selectively engaged with the coupling gear 16 and the gear 18.
Therefore, when a high torque is required for fast-forwarding and rewinding, the idler arm 9 is positioned upward (state of FIG. 2), the idler gear 10 and the gear 18 are engaged, and the rotational force is immediately after the gear of the reel base. The driving force transmitted from the DD capstan motor 4 is transmitted to the reel stand 2 without the coupling.
It is transmitted to 3. The rotary vane 23 pivotally supported on the chassis is rotated clockwise by a cam arm 26, which will be described later, and when it is rotated by a predetermined amount, the spiral spring 24 held by a boss 23b planted on the rotary vane 23 is supported. Then, in FIG. 2, it is biased clockwise (shown by a solid line). Chirikae arm through the spring force of the arm
15 is constructed so as to be biased to rotate counterclockwise in the side view.

In FIG. 4, the reel base 3 is internally provided with an existing coupling mechanism having a ratchet-shaped crimping van 27, a crimping spring 28, and a felt 29 on its outer peripheral portion.
That is, by fixing the crimping van 27 from the outside, a predetermined friction torque is generated on the reel stand 3. Also, in FIG. 1, the shaft 30a on the chassis 1
An arm 30 is rotatably supported on the arm 30.
When the contact member 31 is rotatably supported on the support shaft 30b which is erected above, a torsion spring 32 is provided between the member 31 and the arm 30.
Is incorporated to urge the member 31 to rotate clockwise. One end of the member 31 is in contact with the side surface of the reel stand 3. The splicing member 31 has a semicircular shape centered on the support shaft 30a, and the arm 30 is rotated around the support shaft 30a by a contact frictional force between the member 31 and the third side surface of the reel as the reel stand 3 rotates. It can be rotated. A claw at one end of the arm 30
30c is configured to abut and engage with the ratchet on the outer peripheral portion of the crimping van 27 incorporated inside the reel stand 3 (see FIG. 9).

Next, the configuration around the drive system will be briefly described.
In FIG. 5, a loading motor 33 capable of rotating in forward and reverse directions
Is rotated in one direction, the cam gear 34 is rotated counterclockwise through a predetermined speed reduction mechanism, and a predetermined speed reduction drive mechanism operates (not shown) to operate the tape guide bodies 35a, 35 in FIG.
Drive b to pull out the tape 36 from the cassette (not shown), and as shown in FIG.
The tape is wound around the rotary head cylinder 39 while being held in contact with the 7a and 37b, and at the same time, also comes into contact with the voice control head 38 to form a predetermined tape running path as shown in the drawing.

In FIG. 5, in the cam groove 34a formed in the cam gear 34, which is rotatably supported on the chassis by a support shaft 34b,
A pin 26b planted on a cam arm 26 pivotally supported by a spindle 26a on the chassis is engaged, and the cam arm 26 is rotated according to a predetermined cam lift in accordance with the rotation of the cam gear 34. The other end of the cam arm has a link mechanism 40 that is pivotally supported by a shaft 40a on the chassis.
Engages with the existing toggle mechanism to form the pinch roller 42
At the time of crimping, as shown in FIG. 7, the pinch roller arm 41a is pressed. Although detailed description is omitted, although the pinch roller arm 41a is rotatably supported by the shaft 42a on the chassis, it has a double structure and a torsion spring is provided between the first arm 41a and the second arm 41b. 43 is incorporated and is configured to generate a predetermined pinch roller pressing force. In FIG. 2, the aforesaid Kirikaevan 23 is arranged so as to be brought into contact with and driven by an engaging portion implanted in the cam arm 26, and drives the aforesaid Kirikaevan at a predetermined cam arm 26 rotating position.
The rotary arm 15 is rotated to move the idler arm 9 up and down, and the reel base drive is selected depending on the presence or absence of the coupling so as to correspond to each mechanism position.

On the other hand, in FIG. 5, a cam shape 34c provided on the cam gear 34 is rotatably supported by a support shaft 49 on the chassis, and is rotated by a spring body 50 so as to press one end against the cam shape. There is an operation arm 52 which is urged in a dynamic manner and arranged so that the other end thereof can come into contact with the tension arm 51. In FIG. 7, the recording arm is separated from the tension arm 51 at the time of recording / reproducing, and the tension arm 51 constitutes an existing tension servo mechanism composed of a band 53 and a spring 54 as shown in FIG. are doing.

In FIG. 8, a cam gear is used during so-called reverse reproduction, in which reproduction is performed while being wound around the tape feeding reel base 2.
34 makes a predetermined rotation, and the cam shape 34c causes the operation arm 5 to move.
2 is rotationally driven to come into contact with the tension arm 51, and the tension arm 51 is rotated clockwise. Therefore, the band 53 wound around the reel stand 2 becomes loose, and the reel stand 2
Indicates that there is no load torque, and the tape can be wound by the winding torque of the coupling 45a. The stop position is shown in FIG. 5, and the recording / reproducing position is shown in FIG.

Next, the operation will be described. In FIG. 1, when the reproduction (recording) operation button (not shown) is pressed in the stop mode, the loading motor is first activated to start the brake arms 44a, 44.
b is coupling means 45c, 4 by means of releasing means (not shown)
The braking of the reel bases 2, 3 separated from 5b and thus gear-coupled is released. At the same time, the tape in the cassette is pulled out by the tape guides 35a and 35b, and the tape 36 is wound around the rotary head cylinder 39 at a predetermined angle, and at the same time, a predetermined tape path is formed (see FIG. 5). When the tape guide reaches the stoppers 37a, 37b and presses them, and when the tape loading is completed, the pinch roller 42 moves the tape to the capstan 5a.
Insert 36 and crimp. At this time, the capstan 5a rotates clockwise, so that the tape 36 is driven in the arrow direction. After the pinch roller 42 is pressed and driven, the limiter switch (not shown) of the motor 33 is switched to stop the rotation.

On the other hand, in FIG. 2, the rotational force of the pulley 5 is the belt 46.
Is transmitted to the pulley gear 6 and the drive gear 7, and the idler gear 10 is rotated. At this time, the idler arm 9 is rotated counterclockwise by the friction torque composed of the felt 11, the spring 12 and the like incorporated in the idler gear, and the idler gear is moved to the right. It engages and drives the gear 18 with a predetermined coupling torque composed of felts 19a, 19b, spring 20, etc., the reel base 3 is rotated clockwise, and the capstan 5a
Take up the tape fed at a constant speed by the pinch roller 42 without slack.

At this time, in FIG. 9 which is a plan view of the vicinity of the reel stand 3, when the reel stand rotates clockwise (indicated by an arrow),
The arm 30 is urged to rotate counterclockwise, and the claw portion of the arm separates from the crimping bun 27 and contacts the stopper 1a on the chassis. The load torque applied to the reel stand 3 is a frictional force generated when the member 31 abuts on the reel stand 3 by the screw spring 32, and can be set to a small load torque of about 10 g cm normally. In this way, reproduction or recording, which is a constant speed drive in the forward direction, is performed. Next, the constant-speed feed drive in the reverse direction, such as rewinding the tape a little in reverse for continuous shooting, will be described. The operations from the stop mode to the pinch roller pressure bonding are exactly the same, but only the rotation of the capstan motor 4 is reversed and the idler arm rotates leftward in FIG. 2 to rotate the reel stand 2 counterclockwise through the coupling. Drive in the direction and tape is capstan 5a, pinch roller 4
It is driven in the reverse direction by 2 and wound on the reel stand 2.

In FIG. 10, when the reel base 3 rotates counterclockwise (indicated by an arrow), the arm 30 is urged to rotate clockwise around the support shaft 30a, and the pawl portion 30c of the arm 30 is pressure-bonded as described above. The ratchet portion of the bun 27 is brought into contact with and engaged with the ratchet portion, and the rotation of the crimp bun 27 is restricted. Therefore, a predetermined coupling torque (30-40 g cm) is applied to the reel stand 3.

When recording, pausing, or resuming recording, press the pause button (not shown) during recording to start the capstan motor 4
Performs a reversing operation, reverses the recorded tape portion for about 1 second, and enters a pause state. Next, when the angle pause button is pressed (pause is released and recording is resumed), the capstan motor 4 is driven in the forward direction to reproduce the portion rewound in the reverse direction for about 1 second described above, and the end of the recording festival is not disturbed. The recording is continued by adjusting the taming so that the records can be connected.

At this time, since the tension arm 51 is in the recording / reproducing position, the band 53 is in a state in which the reel base 2 is tightened. Here, the winding torque is configured to have a minimum torque necessary to wind the tape against the band brake load applied to the reel stand. Therefore, since the tape tension at this time is set to the value necessary for winding the tape, the tension is not sufficient to stably generate the reproduction signal, but the reproduced image is not required at this time. There is no problem with the tape tension mentioned above.

Next, the operation from the normal reproduction mode to the reverse reproduction mode will be described. In Fig. 8, the reverse button (not shown) during playback
When is pressed, the loading motor 33 is activated and the cam gear 34 rotates a predetermined amount. The operation arm 52 is rotated by the cam shape 34c, abuts and presses the tension arm 51, and the tension arm 51 is rotated clockwise. Therefore, the band 53 wound around the reel base 2 is loosened, and the reel base 2 is in a state where there is no load torque, and the reel base 2 is wound with the tape by the winding torque generated by the coupling. Since there is no load on the band brake, it is possible to wind the tape with a large winding torque, and it is possible to set a stable tape tension value that sufficiently satisfies the video output during reverse playback.

〔The invention's effect〕

As described above, according to the present invention, the reverse running state is set to 2
By installing it in the same way, during reverse running where the life is a problem, it can be run in reverse without changing the mechanism position, and during reverse running where stability of the reproduced image is a problem, the mechanism position can be moved to obtain an appropriate tape tension. It is possible and effective in improving reliability, durability and performance stability.

[Brief description of drawings]

1 is a plan view of an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a side view, FIG. 4 is a side sectional view, FIG. 5 is a plan view, and FIG. , Fig. 7, Fig. 8 are plan views, Fig. 9, Fig.
FIG. 10 is a plan view around the reel stand. 1 ... Chassis, 2, 3 ... Reel stand, 4 ... Capstan motor, 5 ... Pulley, 6 ... Pulley gear, 7 ... Drive gear, 9 ... Idler arm, 10 ... Idler gear, 26 ... Cam arm, 30 …… arm, 31 …… contact member, 41 …… pinch roller arm, 42 …… pinch roller, 51 …… tension arm.

Claims (2)

(57) [Claims] 1. In a magnetic recording / reproducing apparatus for pulling out a magnetic tape stretched on a pair of reels, loading it in a predetermined path, and recording / reproducing, a forward / reverse rotatable tape driving capstan motor and a feeding reel. The table is provided with a tension applying means for applying an appropriate back tension to the tape at the time of recording / reproducing, and an operating means for operating the tension applying means to switch the presence / absence of the back tension. A magnetic recording / reproducing apparatus having a first reverse running state in which the tape is run in reverse, and a second reverse running state in which the tape is run in reverse without applying the back tension by operating means. 2. The magnetic recording according to claim 1, wherein the second reverse running state is set at the time of reverse playback for outputting a reproduced image, and the first reverse running state is set at another reverse running state. Playback device.