JPH02105363A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To improve the reliability and the durability of a magnetic recording/ reproducing device by securing such a constitution where a mechanism position is not changed in a reverse drive state where the lifetime is important and then changed in a reverse drive state where the stability of a reproduced picture is important so as to secure the proper tape tension. CONSTITUTION:In the record, temporary stop and record restart modes, a temporary stop button is pushed and a capstan motor 4 is driven reversely for about one second to perform the following recording operations with no disturbance produced at the recording termination. In this case, a tension arms 51 is kept at a record/reproduction position and a band 53 becomes a least necessary take-up torque since a reel 2 is kept clamped. Thus the durability is improved. When a reproduction mode is changed to a reverse reproduction mode, a loading motor 33 is started and an operation arm 52 is turned by a cam 34c via a cam gear 34. Thus the arm 51 is pushed and the band 53 is unfastened. As a result, the satisfactory tape tension is secured with the take-up torque and the reliability and the durability are improved for a magnetic recording/ reproducing device.

Description

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

[Conventional technology]

Conventionally, there is a tension servo mechanism as a well-known technique for obtaining tape pack tension by applying an appropriate load brake to the reel stand on the feeding side during tape running to obtain tape running stability.

However, among the VTR functions, there is a reverse playback function, which performs playback while running the tape in reverse and winding it on the reel stand on the feeding side. At this time, in order to stabilize the reproduced image, the aforementioned pack tension applying mechanism is operated to remove the load brakes on the reel stand on the feeding side, thereby preventing the tape tension from decreasing due to these load brakes. Therefore, the mechanism position is usually different between forward and reverse rotations to operate the tension applying mechanism.

Japanese Patent Laid-Open No. 58-153255 is known as this type of device.

[Problem to be solved by the invention]

In the above conventional example, the mechanism mode is set to normal rotation (recording) by a drive source such as a motor during forward rotation and reverse rotation.

It is necessary to switch between the playback) position and the reverse (reverse playback, or a small amount of tape reversal required for continuous shooting) position, and these mode transitions involve some movement time and starting and stopping operations of the drive motor. become. However, in recent years, as a recording method for camera-integrated VTRs,
Recorded for a short time.

Camera-integrated VTRs with so-called interval recording functions such as time stop, short-time recording, etc. are now available. This is capable of compressing the time axis of phenomena changes over a long period of time to 112 meters, and is equivalent to time-lapse photography seen in documentary films.

However, in order to perform a similar operation on a VTR, after recording for a predetermined period of time, the tape must be stopped, and the tape must be moved slightly so that the recorded pattern on the tape can be accurately aligned with the next recording section and the previously recorded green section. need to reverse. This is what is commonly called continuous shooting. Therefore, during one continuous shooting, the mechanism drive motor (hereinafter referred to as the loading motor) rotates the mechanism in ``forward rotation, reverse rotation from position to position, starts the mechanism from reverse rotation position to normal rotation position again, and stops the mechanism twice. I will do it twice.

However, interval recording usually ranges from several frames to one.
A method is known in which data is recorded for about seconds, stopped for a long time of about one minute, and then recorded again for a short time.

Therefore, if interval recording of several frames is performed on commercially available 120-minute tapes, the number of consecutive shots may exceed several thousand times, which may cause problems in the durability of the loading motor.

Also, there is a conventional example of running in reverse without changing the position of the mechanism, but in this case, the tape tension decreases because the tape is wound against the back tension 1-lux applied to the feed reel stand during forward rotation. However, during special playback such as reverse playback, problems such as difficulty in obtaining a stable playback signal tend to occur.

In other words, although there is an advantage of being able to reverse the rotation without changing the mechanism position, problems tend to occur during special playback.

[Means to solve the problem]

In order to achieve the above object, two reverse running positions are set so that the mechanism can be switched to an appropriate reverse running state according to each purpose. In other words, in reverse running where the repeated 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 stand on the feeding side is required. By operating the pack tension applying mechanism applied to the tape, the load torque is reduced, the necessary and sufficient tape tension is secured, and signal output can be stably obtained.

[Effect]

A latch member with a weak elastic force is attached to the outer periphery of the reel stand, on which a coupling mechanism that generates an appropriate load of 1 to 100 lbs. When the reel stand is rotating in the forward direction, the clutch member is in the escape state, and when the reel stand is in the reverse direction, the clutch member rotates to the engagement side, and one end of the clutch member is coupled to the coupling mechanism, Add a load brake to the reel stand. Therefore, the load brake can be applied depending on the forward and reverse rotation directions of the reel stand, and the tape can be run in reverse without changing the position of the mechanism. In addition, when outputting a reproduced image, the tension applying mechanism that applies load torque to the reel stand on the feeding side is operated by the pulsating force of the cam gear via an appropriate deceleration mechanism, the load torque is removed, and an appropriate amount is applied. It is possible to obtain a stable playback image by obtaining the appropriate tape tension.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of the entire VTR mechanism showing one embodiment of the present invention, and shows a stop mode. FIG. 2 is a plan view and a side view (partial sectional view) showing the main parts. A pair of reel shafts 2a and 3a are provided on the chassis 1, and reel stands 2 and 3 are rotatably attached to each of them.

4 is a DD capstan motor, and a pulley 5 that rotates coaxially with a capstan 5a is fixed thereto. On the other hand, a pulley gear 6 consisting of a pulley and a gear is rotatably supported on a shaft 6a installed on the chassis 1''.
A belt 46 is stretched between the pulley 5 and the pulley 5. The shaft 8G is a fixed shaft provided approximately on the perpendicular bisector of both reels, and as shown in detail in FIGS. 2 and 3, the drive gear 7 coupled to the pulley gear 6 is rotatably supported. has been done. The drive gear 7 has different upper and lower gears 'la and 7b.
It is rotatably coupled to an idler gear 10, which is also rotatable, and which is rotatably supported by a shaft 9a on an idler arm 9, which is rotatably supported by the support shaft 8a.

The arm 9 and the idler gear 10 have a fer l-11, a spring 12° and a spring seat 13. The stopper 14 generates the friction torque necessary for swinging the arm 9. The idler gear zz 9 is movable up and down on the support shaft 8a as shown by the arrow, and its vertical position is determined by a round arm 15 that clamps a boss 9b set on the idler arm 9. Now, consider the case where the cut crab arm 15 is located downward (in the opposite direction from FIG. 2) and holds the idler arm 9 downward. Figure 3 shows coupling and reel stand 3
It is a sectional view of the vicinity. The idler gear 10 is engaged with the coupling gear 16, and the gear 18 and the gear 16 are connected to the gear part 17 of the reel die.
9b, spring 20° stopper 21. It is configured to generate a predetermined torque by an existing friction coupling made of a pressure bonding plate 22, and the supporting shaft on the chassis 1], 6
a, 1.6b is rotatably supported. In FIG. 2, a sharp crab pan 23, which is rotatably supported by a support shaft 23a on the chassis and held down by a torsion spring 24 and a stop washer 25, holds the arm of the torsion spring 24 and is biased in one direction by the spring force. (-shown by dotted chain line). The tip of the arm of the spring 24 is rotatably supported by a bearing 47 installed in the chassis, and penetrates through a hole in a round arm 15 that is 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 cut crab arm 15, and the idler gear 10 can selectively engage with the coupling gear 16 and the gear 18. Therefore, if strong torque is required during fast forwarding and rewinding, the idler arm 9 should be moved upward (as shown in Figure 2).
position, the idler gear 10 and gear 8 are engaged, and the rotational force is directly transmitted and driven to the gear 17 of the reel stand, and the rotating egg power of the DD capstan motor 4 is transferred to the reel stands 2 and 3 without going through a coupling. It is designed to be transmitted to The cut crab pan 23, which is pivotally supported on the chassis, is rotated clockwise by a cam arm 26, which will be described later, and when rotated by a predetermined amount, the torsion spring 24, which is held between bosses 23b set on the cut crab bread 23, is rotated clockwise. In FIG. 2, the clockwise bias is shown by a solid line).

The arm 15 is configured to be biased to rotate counterclockwise in a side view through the spring force of the arm.

In FIG. 4, the reel stand 3 has an internal crimp pan 27 having a radiet shape on the outer periphery. Compression streak link 28. The existing coupling mechanism with felt 29 is incorporated. That is, by fixing the crimp pan 27 from the outside, a predetermined friction torque is generated on the reel stand 3.

Further, in FIG. 1, an arm 30 is rotatably supported on a shaft 30 (l) on the chassis 1, and a contact member 31 is rotatably supported on a support shaft 30b set on the arm 30. When pivoted, a torsion spring 32 is installed between the member 31 and the arm 30, and urges the member 31 to rotate clockwise.One end of the member 31 is attached to the side surface of the reel stand 3. The attachment member 31 has a semicircular shape centered on the support shaft 30a, and as the reel stand 3 rotates, the contact friction force between the member 31 and the third side surface of the reel causes the arm 30 to be attached to the support shaft 30a. The claw portion 30c at one end of the arm 30 is configured to abut and engage with a ratchet on the outer periphery of the crimp pan 27 incorporated inside the reel stand 3. (See Figure 9).

Next, the configuration around the drive system will be briefly described. In FIG. 5, a loading motor 33 capable of forward and reverse rotation is shown.
When the cam gear 34 rotates in one direction, the cam gear 34 rotates counterclockwise via a predetermined deceleration mechanism, and a predetermined deceleration drive mechanism (not shown) operates to rotate the tape guide body 35 in FIG.
(Driving the tape 36 from the cassette (not shown) by driving the tape guide member 35a as shown in FIG.
, 35b are held in contact with the stoppers 31a and 37b, and wind the tape around the rotary head cylinder 39, and also contact the audio control head 38 at the same time, forming a predetermined tape running path as shown.

In FIG. 5, a cam arm 26 is rotatably supported on the chassis by a support shaft 34b, and in a cam groove 34α formed in the cam gear 34, a cam arm 26 is rotatably supported on a support shaft 26α on the chassis.
The pin 26b planted above engages and rotates the cam arm 26 according to a predetermined cam lift in response to the rotation of the cam gear 34. The other end of the cam arm engages with a link mechanism 40 pivotally supported by a shaft 40a on the chassis, forming an existing toggle mechanism, and when the pinch roller 42 is pressed, the pinch roller arm 41α pinches as shown in FIG. Although the roller arm 41α is rotatably supported by a shaft 42a on the chassis, it has a double structure, and a torsion spring 43 is incorporated between the first arm 41a and the second arm 41b, and a predetermined rotational speed is achieved. The pinch roller is configured to generate pressure force. In FIG. 2, the above-mentioned cut crab bread 23 is arranged so as to be driven into contact with the engaging portion implanted in the cam arm 26, and the above-mentioned cut crab bread is driven at a predetermined rotation position of the cam arm 26, and the cut crab arm 15 The idler arm 9 is rotated to move the idler arm 9 up and down, and the reel stand drive is selected with or without 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 has a spring body 50 which is rotatably supported on a support shaft 49 on the chassis and has one end pressed against the cam shape.
There is an operation arm 52 which is rotatably biased and arranged so that its other end can come into contact with the tension arm 51. In FIG. 7, the operation arm 52 is separated from the tension arm 51 during recording and reproduction, and the tension arm 51 constitutes an existing tension servo mechanism composed of a band 53 and a spring body 54, as shown in FIG. are doing.

In FIG. 8, the cam gear 3 is rotated during so-called reverse playback, in which playback is performed while winding the tape onto the reel stand 2.
4 performs a predetermined rotation, the operation arm 52 is rotationally driven by the cam shape 34c, comes into contact with the tension arm 51, and causes the tension arm 51 to rotate clockwise. Therefore, the band 53 wound around the reel stand 2 becomes loose.
The reel stand 2 is in a state where there is no load torque, and the tape can be wound with the winding torque provided by the coupling 45a. FIG. 5 shows the stop position, and FIG. 7 shows the recording/reproducing position.

Next, we will discuss the operation. In FIG. 1, when the playback (recording) operation button (not shown) is pressed from the stop mode, the loading motor starts, and the brake arm 44α,
44b is separated from the couplings 45α, 45b by respective release means (not shown), and therefore the braking of the gear-coupled reel stands 2, 3 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, at the same time forming a predetermined tape path (see FIG. 5). The tape guide body is a stopper 37a,
37b and when the tape loading is completed, the pinch roller 42 pinches and presses the tape 36 against the capstan 5a. At this time, since the capstan 5a rotates clockwise, the tape 36 is driven in the direction of the arrow. After the pinch roller 42 is pressed and driven, a limiter switch (not shown) is switched and the motor 33 stops rotating.

On the other hand, in FIG. 2, the rotational force of the pulley 5 is
is transmitted to the pulley gear 6 and drive gear 7, and rotates the idler gear 10. At this time, the felt 11 incorporated inside the idler gear. The idler arm 9 is rotated counterclockwise by the friction torque formed by the spring 12, etc., and the idler gear moves to the right, and as shown in FIG. -9b.

It is driven by a predetermined coupling torque constituted by a spring 20, etc., rotates the reel stand 3 clockwise, and winds up the tape fed at a constant speed with a capstan 5a and a 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 the arrow), the arm A30 is urged to rotate counterclockwise, and the claw portion of the arm It is separated from the crimp pan 27 and comes into contact with the collars 1 to 1a on the chassis. The load torque applied to the reel stand 3 is applied to the member 31.
is the frictional force generated when the torsion spring 32 comes into contact with the reel stand 3, and the load torque can be set to a small load torque of usually about 10 gcm. In this way, reproduction or recording, which is constant speed drive in the forward rotation direction, is performed.

Next, we will discuss constant speed feed drive in the reverse direction, such as rewinding the tape slightly in the reverse direction for continuous shooting. Stop mode From l<, the operation up to the pinch roller crimping is performed in exactly the same way, but only the rotation of the capstan motor 4 is reversed, and in Fig. 2, the idler arm rotates to the left and connects the reel stand 2 via the coupling. The tape is driven counterclockwise and capstan 5
(L, it is driven in the reverse direction by the pinch roller 42 and wound onto the reel stand 2.

In FIG. 10, when the reel stand 3 rotates counterclockwise (indicated by an arrow), the arm 30 is urged to rotate clockwise about the support shaft 30a, and the claw portion 30c of the arm 30 is Bread 27 ratchet! - Abuts and engages with the crimping pan 27 to restrict rotation of the crimp pan 27. Therefore, the reel stand 3 is given a predetermined coupling 1 heel (30 to 40 gcm).

When recording, stopping at -, and restarting recording, press the pause button (not shown) during recording, and the capstan motor 4 performs a reversal operation to reversely feed the recorded tape portion for about 1 second, and then continue recording. - Enter time stop state. Next, when the angle-hour stop button is pressed (-hour stop is canceled and recording is resumed), the capstan motor 4 opens and rotates in the forward direction, plays the part that was rewound in reverse for about 1 second, and is disturbed at the end of the record festival. Continue recording by adjusting the timing so that you can connect the next record without any problems.

At this time, since the tension arm 51 is in the recording/reproducing position, the band 53 is in a state of tightening the reel stand 2. Here, the winding torque is configured to have the minimum torque necessary to wind the tape against the pan brake load applied to the reel stand. Therefore, since the tape tension at this time is set to just enough to wind the tape, it is less than sufficient tension to generate a stable playback signal, but at this time no playback image is required. Therefore, there is no problem with the tape tension mentioned above.

Next, the operation from the normal playback mode to the reverse playback mode will be described. In FIG. 8, when a reverse rotation button (not shown) is pressed during playback, the loading motor 33 is activated and rotated by a predetermined amount by the cam gear 34. The operating arm 52 is rotated by the cam shape 34c and presses against the tension arm 51, so that the tension arm 51 is rotated clockwise. Therefore, the band 53 wound around the reel stand 2 becomes loose, and the reel stand 2 becomes in a state with no load torque, and the tape is wound up by the winding torque generated by the coupling. Therefore, the reversal running at the recording and playback positions described above is performed. Since there is no load on the band brake, it is possible to wind the tape with a larger winding torque, and it is possible to set a stable tape tension value that sufficiently satisfies the video output during reverse playback.

〔Effect of the invention〕

As explained above, the present invention provides two reverse running states, so that during reverse running where life is a problem, reverse running is performed without changing the mechanism position, and reverse running where the stability of the reproduced image is a problem. It is sometimes possible to obtain the appropriate tape tension by moving the mechanism position, which is effective in improving reliability, durability, and performance stability.

[Brief explanation of the drawing]

Fig. 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. 6. , FIGS. 7 and 8 are plan views, and FIGS. 9 and 10 are plan views of the area around the reel stand. Toshashi, 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, 4
1...Pinch roller arm, 42...Pinch roller, 51...Tension arm.

Claims (1)

[Claims] 1. Pulling out a magnetic tape stretched on a pair of reels,
A capstan motor for driving a tape that is loaded on a predetermined path and capable of forward rotation in a magnetic recording and reproducing device that performs recording and reproducing; and a tension applying means that is located on a feeding reel stand and that applies appropriate back tension to the tape during recording and reproducing; An operating means is provided for operating the tension applying means to switch between the presence and absence of back tension, and during recording and reproduction,
Magnetic recording and reproducing characterized by having a first reverse running state in which the tape runs in reverse while applying back tension, and a second reverse running state in which the tape runs in reverse without applying back tension by an operating means. Device. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the magnetic recording and reproducing apparatus is configured to be in the second reverse running state during reverse playback for outputting a reproduced image, and to be in the first reverse running state in other reverse running states.