JPS60237661A - Driving mechanism for reel turntable of magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To control the back tension of a tape when the tape is fed forward at a high speed and rewound by controlling brake force applied to a payoff reel turntable according to the back tension of the tape corresponding to the wind diameter of the tape wound around the payoff reel. CONSTITUTION:When the driving mechanism is put in operation in fast-forward mode with an operation button, levers 17 and 18 are operated as shown by arrows (a) and (r'), and consequently sub-brakes 8 and 9 are released from rotation constraint to abut on brake abutting parts 2-2 and 3-2 with springs 10 and 11. Then, when a driving gear 6 begins to be rotated by a motor by a motor as shown by an arrow (b), an idler gear 7 engaging the driving gear 6 rotates as shown by an arrow (c) and revolves around a fulcrum 21 of revolution as shown by an arrow (d) to engage the gear part 3-1 of a take-up side reel turntable 3. The rotation of the driving gear is transmitted to a reel 5, and the tape 14 is taken up around the reel from the reel 4 through tape guides 12 and 13 through the rotation of the reel 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a tape drive mechanism of a magnetic recording/reproducing device using magnetic tape, and particularly relates to a tape drive mechanism for a magnetic recording/reproducing device using magnetic tape, and particularly to a tape drive mechanism for a magnetic recording/reproducing device using magnetic tape. Bavkutenshi, suitable for running on.

Regarding the 0 mechanism with a button.

[Background of the invention]

Magnetic recording/reproducing device & (hereinafter referred to as VTfl) using magnetic tape
An example of a fast-forward and one-rewind mechanism for tape running at high speed (referred to as ``1'') will be explained with reference to FIG.

In the figure, 2 1 is a substrate, 2.3 is rotatably held on a shaft provided on the substrate 1, a reel stand on the feeding side and the take-up side, and 4.5 is placed on the same axis of the reel stand. It's San,
The reels on the reeling side and the winding side are shown. The reel stand is provided with gear parts 2-1, 3-1 and play contact parts 2-2 and 5-2 for transmitting rotation. Reference numeral 6 indicates a drive gear, which is connected via a gear or a belt, or to the surface motor shaft. 7 is an idler gear which meshes with the drive gear 6T/C and is rotatable.
-1.3-1 meshes with the drive gear 60 rotations on reel 4
or communicate to 5. Reference numerals 8 and 9 indicate sub-brakes, and a part of the sub-brakes is connected to the playback abutment 92-2°3-2 provided on the reel stand 4.5 by means of springs 10 and 11.
Pressed by Reference numerals 12 and 13 are kites that guide the running of the tape 14. 17.18 is a lever for operating the sub-brake 8.9, which is operated by a cam or solenoid, and controls the suppression of the sub-brake 8.9 to the reel stand brake contact @2-2, 3-2. do.

Next, the tape fast forwarding 91 rewinding operation will be explained. When the fast forward mode is set using the operation button (illustration omitted), levers 17 and 18 are activated by a cam or solenoid, etc.
When the sub-brake 8.9 is operated in the 1 direction, the rotation restriction of the sub-brake 8.9 is released, and the sub-brake 8.9 is released by the spring 10.
11 makes contact with the brake contact portion 2-2.3-2.

After that, the drive gear 6 is moved by the arrow (arrow) by the motor (not shown).
At the same time as the rotation starts in the direction of the opening 1, the idler gear 7 meshed with the drive gear 6 also starts rotating in the direction of the arrow l/-1. The idler gear 7 is operated by a cam or solenoid, etc.
It revolves around the drive gear in the direction indicated by the arrow, meshes with the gear portion 3-1 of the reel stand 3, and the rotation of the drive gear is transmitted to the roll 5. Reels 4 and 51C winding rt, r: The tape 14 is rotated by the rotation of the reel 5 with a ditape guide of 12°1.
3, and is wound from reel 4 to reel 5.

Generally, when running a tape at high speed, a weak tension is applied to the tape feeding side to prevent the tape from slamming during the tape run. This prevents damage such as tape edge folding. In the illustrated example, the sub play-v-8 is moved by the spring 10 to the reel stand play thousand contact flI2-2.
Press it with the sword P, and set the radius Ro of the reel stand contact part 2-2.
The torque TK obtained from K is intended to apply tension to the tape, and their relationship is shown as follows.

Here, if the number of friction bodies between the sub-brake 8 and the reel contact portion is μ, then T=PX/jXRo (1).

If the radius at which the tape is fed out is B, reel 4
The tape tension F caused by the rotation of is F-kuni/11...
......It is expressed as (2).

Generally, the ratio of the tape winding diameter between the beginning and end of the tape is 2 to 2.5 times. Is the tape cheap? Because it is necessary to add the tape tension IF'l to the value of the FIT foot (2
) The tension of the spring 10 must be set so that a suitable tape tension can be obtained when the tape winding diameter (R1) is large at the beginning of tape winding where the tape tension is small as shown by the equation.

Therefore, at the end of the tape winding (when the tape winding diameter (81) is small), a tension that is 2 to 2.5 times the optimum tape tension is applied to the tape.

In addition, the winding diameter (8t) on the winding 9 side of the tape is -
Looking at the maintenance, the tape winding diameter at the beginning of tape winding becomes the reel hub diameter (Ro), and the winding diameter indicates the forging. At this time, the tape tension applied to 5 unwinding is the minimum value as mentioned above, and the torque (Tt) required for winding is Tt-F.
- Minimum from Rt. As the tape is unwound and wound onto the reel, the tape tension applied at the beginning of the roll increases gradually, and at the end of the roll it is 2 to 2.5 times that at the beginning of the roll. is as described above. The tape winding diameter for winding the tape into the tape is also 2 to 25 times larger, and the torque (Tt) for winding the tape needs to be as thick as the square of the tape.

In order to ensure a large winding torque at a high rotation speed of 2 at the end of winding in this high-speed fast-forward operation, a large motor is required, which has been an impediment to reducing the size and weight of VTRs.

Here, the fast-forwarding operation will be explained in the line fi-1rc, but the same thing can be said to happen twice during rewinding.

As a conventional example of a tsukuda, there is one in which the rotating shafts of the take-up 9 and feed-out reel stands are directly connected to a motor shaft, and two motors VCC F feed and rewind operations are performed.

According to this method, the number of revolutions of the reel stand on the winding V side and the heddle elongation is detected, and the reel base rotation speed is detected on the reel V side,
By controlling the drive current for reverse rotation to the rs motor, it is possible to keep the tension at the edge of the tape almost constant regardless of the diameter of the tape, but since there are two motors, The drive circuit requires a single rotation speed detection device, etc., and
It is not suitable for

[Purpose of the invention]

The object of the present invention is to eliminate the drawbacks of the above-mentioned prior art, and to
An object of the present invention is to provide a device for controlling the tape tension during rewinding.

[Summary of the invention]

In order to achieve this object, the present invention provides the idler gear's revolution support shaft on the rotating arm, and sets the idler's revolution center and the drive gear's rotation center on the same position. The drive gear and the idler gear transmit power through their tooth tips, and when the torque required for winding increases as the winding diameter increases, the idler gear
Since the driving gear and the idler gear engage with each other in a 9-inch circle, the rotary arm provided with the revolution support shaft of the idler gear rotates.

By moving this rotating arm, the force of the sub-brake pressure spring provided on the reel on the unwinding side is reduced, the tension of the tape on the unwinding side is kept constant, and the increase in tape winding torque due to the tape winding diameter on the unwinding side is suppressed. .

[Embodiments of the invention]

Hereinafter, one embodiment of the T-invention will be described with reference to FIG. 2.3.4. The same reference numerals as those shown in FIG. 1 and rifJ products are given the same reference numerals, and some explanations will be omitted.

The idler gear 7 is provided on a support arm 22 with the rotation axis of the drive gear 6 as the center of rotation, and is provided to be able to rotate and revolve around the n-shaped fork shaft 21 as a revolving support axis.

The revolution fork 21 is pressed and held by the control arm 25.26 having the rotation fork 23.24.
The strike bar 272 and the control arm 25.2 provided in the middle of the
The hook 6 is positioned by a spring 28 which is passed lr.

A spring 1° is applied to the sub-brake f-8 and the control arm 25, and it is installed to add tape tension during fast forward operation.
A hook 11 is installed so as to apply tape tension during rewinding operation by n%.

17.113 prevents rotational energization of sub brake 8.9
The blocking piece of the second lever is shown.

Next, the operation of this embodiment with the above configuration will be explained. When the fast forward mode is operated using the operating button, the levers 17, 18 are moved in one direction by the cam or solenoid to the position ζn shown in FIG. 2. As a result, the rotation restriction of the sub-brake 8.9 is releasedζ
19, Spring 10.11 and F-Fray contact part 2-2.3
-2 comes into contact. Thereafter, when the drive gear 6 starts to rotate in the direction of the arrow (to) by the motor (not shown), the idler gear 7 meshed with the drive gear 6 rotates in the direction of the arrow (to) and circles around the revolution point 21 as shown in the arrow. direction and meshes with the gear t153-1 of the reel stand 3 on the first winding side.

The rotation of the drive gear is transmitted 17' to the reel 5. reel 5
The tape 14 is moved from the reel 4 to the tape guide 1 by the rotation of
2.13, the reel 5Vc is wound up.

The gear relationship in fast forward mode is shown in Figures 3 and 4.
This will be explained to ζ et al. At the beginning of tape winding, the pressing force applied to the spring 10 by the Lv feed-out side reel stand 2 [710] is set so as to obtain the optimum tape tension at the beginning of winding. In addition, the control arm 25 is activated by the spring 28, and the buckle 27
Is it energized by 's? In addition, the revolution point 21 of the idler 7 is also used at the medium heat position of both reels. The revolution fulcrum 21 of the idler gear 7 is offset from the rotation axis of the drive gear 6.
71. Therefore, the drive gear 6 and the idler gear 7 do not mesh with each other in a circular manner, but mesh with each other at the tips of their teeth, thereby transmitting power.

As the fast-forwarding operation of the tape progresses and the tape winding diameter on the feeding side becomes small ζ, and the tape tension increases, the torque required for one winding increases, and the idler gear 7 shifts to the drive gear 6.
and starts biting into the gear part 3-1 of the reel stand (in the four directions of arrows).

Up until now, the idler 7 has revolved at the point 2 due to the spring blade of the spring 28.
1 is held by the left and right control arms 25 and 26, and the position of the ncP fire is not restricted.Then, the biting blade of the idler 7 rotates the control arm 25 against the spring 2BK to the direction of the arrow 10,000. let The length of the sub-brake 8 and control arm 25rif is shortened when installing the two springs 10.
, the pressure on the reel stand 2 by the spring 10 is reduced, the load torque applied to the reel stand 2 is reduced, and the tension is suppressed by the increase in the tension applied to the tape as it is fed out. Depending on the magnitude of the winding torque due to the tape winding diameter intensifier on the tape winding side, the pressure applied to the reel stand on the unwinding side is reduced by 71 [+], and the tension applied to the tape is applied from the beginning of winding to the end of winding. It can be kept on its feet.

In the explanation of this operation, it is assumed that the levers 17 and 18 are operated in the (E) and (E) directions by operating the fast forward mode. This is because it has an automatic neck resting mechanism using springs and felt, and is configured to perform fast forwarding and one rewinding depending on the rotational direction of the drive gear.

In this way, the mechanism is simplified by making the fast forward mode and the rewind mode have the same mechanical state except for the rotation of the drive gear.

〔Effect of the invention〕

According to the present invention, it is possible to control the play flat blade applied to the reel stand by the tape buckle tension corresponding to the winding diameter of the tape wound on the feed-out reel, thereby increasing the tape buckle tension. can be suppressed, and an increase in winding torque can be reduced.

In particular, in V'FRIC, it is very effective when the tape is running in fast forwarding or rewinding when it comes into contact with the tension bin, kite bin, eraser, kite roller, cylinder/dar, etc.

The maximum torque required for the motor is reduced, making it possible to use a motor with a small rated torque, which is effective in making the VTR smaller and lighter. In addition, the increase in back tension of the tape 71
Since zero is suppressed, it is very advantageous for problems such as tape scratches.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a conventional fast forwarding 1 rewinding mechanism, Fig. 2 is a plan view showing an embodiment of the fast forwarding 1 rewinding mechanism according to the present invention, and Fig. 3 is a summary of the operation. FIG. 4 is a sectional view of the main part. 1... Board, 2.6... Reel stand, 4.5... Reel, 6... Drive gear, 7... Idler gear, 8.
9...Sub brake, 10.11...Spring,
21...Fully point, 25.26...Control lever. Le II! I Ign,! 2 [! 1 cake 3 illustrations

Claims (1)

[Claims] It meshes with the drive gear and rotates around the drive gear. A reel drive mechanism that drives the reel stand has a fulcrum at a position equidistant from both reel stands. A revolution fulcrum of the idler gear is provided on the lever on the drive gear side with respect to the center of rotation of the idler gear, and the revolution fulcrum has a rotation fork point on a base plate and is connected to each other by a spring. Sat
In addition to being held by the second and third rotating levers, springs are provided between the 20th rotating lever and the sub-brake on the feeding side, and between the third rotating lever and the sub-brake on the winding side. Features: Reel stand drive mechanism of magnetic recording and reproducing device.