JPH05120761A - Tape reverse tension mechanism of magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a tape reverse tension mechanism of a magnetic recording and reproducing apparatus. According to the present invention, a reel table has a structure including a reel disk and a reel gear that are frictionally coupled to each other, and a fixed gear that is constantly meshed with the reel gear and a fixed gear that are always meshed with each other. It is configured to include a floating gear that is connected to or separate from the reel gear depending on the rotation direction, and a connecting lever that connects the fixed gear and the idle gear. The present invention has a simple structure and can provide a back tension to the magnetic tape, which enables the size and the number of parts of the device to be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a tape recorder, a video player, etc., and in particular, a tape can be reproduced in a clockwise direction such as reproduction and fast-forward, reverse reproduction, and rewinding. The present invention relates to a tape reverse tension mechanism in which a constant tension is applied to a tape when traveling in a counterclockwise direction.

[0002]

2. Description of the Related Art Generally, in a magnetic recording / reproducing apparatus such as a tape recorder or a video player, when a tape cassette containing a magnetic tape is mounted on a supply reel table and a take-up reel table, the tape is loaded and the head drum is loaded. Is closely attached to the outer peripheral surface of. The idler gear selectively engages the supply reel table or the take-up reel table according to the operation mode. That is, in the play and fast-forward modes, the idler gear is engaged with the take-up reel table to drive the tape clockwise, and in the review and rewind modes, the idler gear is engaged with the supply reel table and runs counterclockwise to the tape. Let

However, when the tape is run in the selected direction by the rotation of the selected reel table, the tape is unwound by the rotational inertia force of the unselected reel table. Therefore, in the play and review modes, the tape is loosened on the outer peripheral surface of the head drum, which causes noise. Further, in the fast forward / rewind mode, the tape unwinds transiently from the unselected reel table, so that the tape is entangled or noise is generated in the apparatus. Therefore, when the tape is run in the play, review, fast-forward, and rewind modes, it is necessary to apply weak reverse tension to the tape. That is, it is required to install a weak brake that can weakly resist the tape running on the unselected reel table.

FIG. 1 is disclosed in US Pat. No. 4,899,951 and shows a braking system including a weak brake for applying reverse tension to the magnetic tape. The cam gear 1 has an irregularly formed slot 2, and the roll follower 4 is slidably inserted into the irregularly formed slot. The roll follower 4 is connected to one arm of the Y-shaped brake releasing member 3. The brake releasing member 3 is rotatably fixed to the pivot 3a and is pulled in the non-releasing direction by the spring 3b.
As a result, the roll follower 4 is caught and maintained in the slot 2 of the cam gear 1. The brake release parts 3s and 3t are
The brake release member 3 is fixed to the other arm. The brake release parts 3s and 3t are provided on the supply reel 7s and the take-up reel 7 respectively.
t reel brakes 5s and 5t, respectively.

Further, the brake release section 3s has a weak brake 6
And the pivot 5a coaxially with the reel brake 5s.
Fixed to. The reel brakes 5s and 5t of the supply reel 7s and the take-up reel 7t can rotate around the bipots 5a and 5a ', and are pressed against the rotation of the reels 7s and 7t under the influence of the springs 5b and 5b'. It Similarly, the weak brake 6 is pressed against the rotation of the supply reel 7s under the influence of the spring 5b.

In operation, FIG. 1 illustrates the fast forward or fast forward mode. Cam gear 1
When is rotated clockwise, the brake release member 3 is rotated counterclockwise. Then, the reel brakes 5s, 5
t is released, so only the weak brake 6 provides a weak braking force to the supply reel 7s. As a result, the weak brake 6
Reverse tension is applied to the tape in the fast-forward mode with the braking force of
It prevents the tape from unraveling.

However, the brake system including the weak brake device having such a structure requires many components in order to selectively operate the weak brake 6 depending on the mode. That is, a cam gear in which slots are irregularly formed, and another drive source for driving the cam gear,
The brake release member is connected to the cam gear and operates the weak brake by rotation of the cam gear.

Therefore, the structure of the device becomes complicated, the installation space of the device occupies a lot, and the manufacturing and assembling work is very difficult.
This causes a problem that the operation is poor and the accuracy is lowered.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tape reverse tension mechanism for a magnetic recording device which solves the above problems. That is, it is to provide a tape reverse tension mechanism having a simple structure, a narrow installation space for the device, and a weak brake having a reliable braking force.

Another object of the present invention is to provide a tape reverse tension mechanism in which the weak brake is activated by rotation of the reel table without a separate drive source.

[0011]

In order to achieve the above object, a tape reverse tension mechanism according to the present invention operates a reel disk of a supply reel table and a take-up reel table on which a supply reel and a take-up reel are mounted, respectively. The reel disk and the reel gear, which are coupled so as to frictionally rotate each other, apply a predetermined tension so as to prevent the tape from loosening due to inertia by being stopped while being rotated during mode conversion. In a tape reverse tension mechanism of a magnetic recording / reproducing apparatus having a structure having a structure, a fixed gear that is always meshed with the reel gear and is rotated at least on one side of the supply reel table and the take-up reel table, and the fixed gear are constantly meshed. , Depending on the direction of rotation, it may be connected to the reel gear or may be detachable. And the gears that, characterized by comprising, including connecting lever for connecting said fixed gear and idler gear.

[0012]

According to the tape reverse tension mechanism of the magnetic recording / reproducing apparatus according to the present invention, the fixed gear which is constantly meshed with the reel gear and the fixed gear which is constantly meshed with the fixed gear can be meshed with or released from the reel gear depending on the rotation direction of the reel gear. By using such a floating gear, the structure is simple, and it is possible to reliably apply reverse tension to the magnetic tape with a weak braking force, and it is possible to reduce the size and the number of parts of the reverse tension device.

[0013]

2 to 4 show a tape reverse tension mechanism according to the present invention. Here, in order to selectively transmit power to the reel tables 30 and 40 according to a mode selected between the supply reel table 30 and the take-up reel table 40 on which the supply reel and the take-up reel of the tape cassette are mounted, respectively. The idler gear 20 is installed.
The idler gear 20 always meshes with the drive gear 10 driven by the power source, and is movable in the rotation direction of the drive gear 10. The reel tables 30 and 40 are reel discs 3 on which reels of a tape cassette are mounted.
1, 41 and a reel gear 32 having a keyed outer surface,
It consists of 42.

The reel gears 32 and 42 have respective shafts 38,
The reel discs 31 and 41 are press-fitted and installed in the 48.
Is coaxially mounted on the reel gears 32 and 42 and rotatably installed on the shaft. And according to FIG. 4, the reel gear 4
A wear felt F is provided between the reel disk 41 and the reel disk 41, and similarly between the reel gear 32 and the reel disk 31 shown in FIG. Then, the idler gear 20 is engaged with the reel gears 32 and 42 of the reel tables 30 and 40 by a selected mold. Then, the weak brakes, ie, the fixed gear and the idle gear, which provide the weak braking force, which is a characteristic element of the present invention, are installed as follows.

A fixed gear 44 is fixedly installed on the deck 50 so as to always mesh with the reel gear 42. Similarly,
A fixed gear 34 is fixedly installed on a deck (not shown) so as to always mesh with the reel gear 32 of FIG. Then, the idle gears 35 and 45, which always mesh with the fixed gears 34 and 44, are connected by the connecting levers 36 and 46. The floating gears 35 and 45 can move according to the rotation direction of the fixed gears 34 and 44. Therefore, the idle gears 35 and 45 can be connected to or separated from the reel gears 32 and 42. Then, in a desirable configuration, the connecting levers 36, 4
6, and 36a and 46a are formed, and stoppers 37 and 47 are formed on the deck at a predetermined distance from the protrusion.

In operation, as shown in FIG. 2, in the play and fast-forward modes, the idler gear 20 rotated by the drive gear 10 is the reel gear 42 of the winding table 40.
Engage in. At the same time, the reel gear 42 is rotated clockwise and the fixed gear 44 is rotated counterclockwise. Then, the floating gear 45 is rotated clockwise and separated from the reel gear 42. At this time, since the protruding portion 46a of the connecting lever 46 is engaged with the stopper 47 in the floating gear 45, excessive disengagement can be prevented.

On the other hand, the reel gear 32 of the supply reel table 30 is frictionally rotated clockwise by the reel disk 31. At this time, since the fixed gear 34 is rotated counterclockwise, the floating gear 35 is rotated clockwise so as to mesh with the reel gear 32. Therefore, since the reel gear 32, the fixed gear 34, and the idle gear 35 are engaged with each other, the reel gear 32 is stopped. Therefore, the supply reel disc 31 is frictionally rotated with respect to the reel gear 32. As a result, in the play / fast-forward mode, the take-up reel disc 41 is rotated in an unloaded state, and the supply reel disc 31 is rotated while enduring a friction load. Accordingly, when the play or fast-forward mode is changed to the stop mode, the friction load provides reverse tension to the magnetic tape in spite of the rotational inertia force of the take-up reel disk 41, thereby preventing the tape from unraveling. ..

As shown in FIG. 3, in the review and rewind modes, the idler gear 20 meshes with the supply reel gear 32 and is rotated. Therefore, the supply reel disk 31 is rotated without a load by the above-described operation, and the take-up reel disk 41 is rotated while withstanding a frictional load. As a result, when the review or rewind mode is switched to the stop mode, the friction load applies reverse tension to the magnetic tape in spite of the rotational inertia force of the supply reel disk 31, thereby preventing the tape from unwinding.

[0019]

As described above, in the tape reverse tension mechanism according to the present invention, the fixed gears 34 and 44, which constantly mesh with the reel gears 32 and 42, and the reel gears 32 and 42, are connected by the rotation direction of the fixed gears 34 and 44. Alternatively, not only the structure is simplified by providing only the floating gears 35 and 45 which are separably installed, but also the installation space thereof is significantly narrowed, and the reel gears 32 and 42, the fixed gears 34 and 44, and the floating gears Since the gears 35 and 45 are connected to each other by gear meshing, when a mode such as play, review, fast forward and rewind is changed to a stop mode, a braking force, that is, a friction load is generated depending on the rotation direction of the reel gears 32 and 42. The reel disks 31 and 41 selected are instantly and accurately provided. Further, the fixed gear and the floating gear can be operated depending on the rotating direction of the reel gear rotated by the idler gear. Therefore, a weak brake, that is, a fixed gear and a floating gear, can be operated without a separate power source.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional braking system.

FIG. 2 is a schematic view showing a play or fast-forward position in the tape reverse tension mechanism according to the present invention.

FIG. 3 is a schematic view showing a review or rewind position in the tape reverse tension mechanism according to the present invention.

FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3 and developed.

[Explanation of symbols]

 10 drive gear 20 idler gear 30 supply reel 31,41 reel disc 32,42 reel gear 34,44 fixed gear 35,45 idle gear 36,46 coupling lever 37,47 stopper 38,48 shaft 40 take-up reel table 50 deck

Claims (2)

[Claims] 1. A tape is prevented from loosening due to inertia by stopping each reel disk of a supply reel table and a take-up reel table on which a supply reel and a take-up reel are respectively mounted while being rotated during operation mode conversion. In the tape reverse tension mechanism of the magnetic recording / reproducing apparatus, the reel table and the reel gear are connected to each other so that the respective reel tables are frictionally rotated. At least one side of the supply reel table and the take-up reel table, a fixed gear that is always engaged with the reel gear and rotated, and a fixed gear that is always engaged, and is connected to or separated from the reel gear depending on the rotation direction. It includes an idle gear and a connecting lever for connecting the fixed gear and the idle gear. Tape back tension mechanism of a magnetic recording and reproducing apparatus characterized by. 2. A protrusion is formed extending from the connecting lever, and a stopper is formed at one point in the rotation path of the protrusion to prevent excessive rotation of the idle gear due to rotation of the fixed gear. The tape reverse tension mechanism of the magnetic recording / reproducing apparatus according to claim 1, characterized in that.