JPS5897152A - magnetic tape device - Google Patents

Abstract

PURPOSE:To simplify the construction and to attain light weight and low cost, by using a motor rotatable both forward and reverse and driving either of a pair of reel stands selectively depending on the direction of rotation of a capstan. CONSTITUTION:When a capstan shaft 10 is driven with a motor 18 clockwise, a magnetic tape 14 is carried toward a winding reel stand 34, a drive gear 22 is driven counterclockwise, a rotary arm 26 is driven to the winding reel stand 34, the torque is delivered to the winding reel stand 34 and the tape 14 is wound up. In inverting the motor 18 and turning the capstan shaft 10 counterclockwise, the drive gear 22 is turned clockwise, the arm 26 is driven to a supply reel stand 36, a torque is given to the stand 36 and the magnetic tape 14 is wound on a supply reel hub 40.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape device such as a video tape recorder, and particularly provides a single-motor drive type magnetic tape device that has a simple structure, is easy to assemble, and is suitable for making the device thinner. It is.

In recent years, in order to simplify the mechanism of a magnetic tape device, as a drive mechanism for a reel stand, a drive wheel is arranged approximately equidistantly from a pair of reel stands, and the drive wheel is arranged at approximately the same distance from a pair of reel stands, and the drive wheel is rotated according to the rotational direction of the drive wheel. and a transmission mechanism including an idler in rolling contact between the drive wheel and one of the pair of reel stands to selectively transmit the rotation of the drive wheel to either of the pair of reel stands; It has a reel motor that is separate from the motor that drives the capstan that synchronously drives the drive wheel. So-called two-motor mechanisms are becoming mainstream. This method selectively drives the reel base according to the rotational direction of the reel motor to control the tape feeding direction, so it is particularly practical for feather-touch magnetic tape devices. Since two motors, called reel motors, are required, there is a drawback that the cost is high. The present invention provides a magnetic tape device that has the same functions as conventional magnetic tape devices using a single motor, has a simple structure, is easy to assemble, and can be realized at low weight and low cost.

The present invention will be explained below using an example of a video tape recorder (hereinafter abbreviated as VTR).

FIG. 1 is a plan view of essential parts showing the tape running state of the VTR. In the figure, a magnetic tape 14 held between a capstan shaft 1Q and a pinch roller 12 is fed at a constant speed in the direction of the arrow by the clockwise rotation of the capstan shaft 10. As is well known, the magnetic tape 14 is
Travel is guided by being wrapped around the outer periphery of a chive guide drum 16 containing a rotating magnetic head for recording or reproducing video signals. The capstan shaft 10 is rotationally driven by a capstan motor 18 which can rotate in forward and reverse directions and which also uses the capstan shaft 1o as a rotating shaft. The capstan shaft 10 of the capstan motor 18 is provided with an output gear 2o that rotates together with the capstan shaft 1o.

The rotation of the output gear 20 is transmitted via an idler gear 21.24 to a drive gear 22 located approximately equidistant from the supply reel stand 40 and the take-up reel stand 38. A large gear 28a and a small gear 28b, which rotate as one body, are rotatably held at the tip of a rotating arm 26 which is rotatably supported coaxially with the drive gear 22.
8a meshes with the drive gear 22. The rotating arm 26 is rotated in the same direction as the rotational direction of the drive gear 22 by friction means using a felt 25 as is well known,
The small gear 28b rotationally drives the take-up reel stand drive unit 3o or the supply side reel stand drive unit 32.

As can be seen from FIG. 3, the take-up reel stand drive unit 3o is coaxially connected to a lower gear 30a that meshes with a gear portion formed on the outer periphery of the supply reel stand 36. The upper gear 30b rotates and meshes with the small gear 28b, and the upper gear 30b is rotated by a friction transmission means using a felt 30C, which is a well-known means. This is so that it is transmitted to a.

Since the supply side reel stand drive unit 32 has almost the same configuration, the explanation here will be omitted.

The rotation directions of the capstan shaft 10 and the driving gear 22 are opposite to each other. For example, when the capstan shaft 1o rotates clockwise in FIG. 1 and sends out the magnetic tape 14 toward the take-up reel stand 34, The driving gear 22 rotates counterclockwise, and the rotating arm 22 rotates as shown in FIG.
6 in the direction of the take-up side reel stand 34, and the small gear 28b is moved to the upper gear 30 of the take-up side reel stand drive unit.
b, the take-up reel stand 34 is rotated clockwise, and the magnetic tape 14 is wound onto the take-up reel hub 38.

Furthermore, in a mode in which the capstan shaft 1o rotates counterclockwise to feed the magnetic tape 14 toward the supply reel stand 36, for example, in reverse playback, the capstan motor 18 is activated as shown in FIG. When the capstan shaft 1o is reversed and rotated counterclockwise, the drive gear 22
rotates clockwise, the rotating arm 26 is rotationally displaced in the direction of the supply reel stand 36, and the small gear 28b is meshed with the small gear 32b of the supply reel stand drive unit, and the above-mentioned supply side reel stand 36 is rotated. The magnetic tape 14, which is rotated counterclockwise and fed in the direction of arrow B, is wound onto the supply side IJ-ru hub 4o.

The conditions for winding the magnetic tape 14 sent out by the capstan shaft 1o onto the take-up reel hub 38 or the supply reel hub 4o with a constant torque are as follows: the diameter of the capstan shaft 10 is 69, the number of revolutions is n, If the diameter of the side reel hub 38 or the supply side reel hub 4o is taken and the rotational speed when driven by the capstan motor 18 is N, then the reduction ratio is set so that π・D, N)π・den. The difference in the rotational speed between the capstan shaft 1o and the driven reel stand is absorbed by the sliding of the friction means of the take-up reel stand drive unit l-30 or the supply side reel stand drive unit 32. Therefore, the magnetic tape 14 is wound onto the driven reel stand with constant torque without slack.

As described above, according to the magnetic tape device of the present invention, operations that conventionally required multiple motors, such as VTR reverse playback, which has become highly requested in recent years, can now be performed using only one motor. It can be done.

Further, the rotation transmission mechanism from the capstan shaft 1o to the drive gear 22 and the rotation transmission mechanism from the drive gear 22 to the supply reel stand 36 or the take-up reel stand 34 are connected to the drive gear 22.
Place it on the opposite side.

By configuring them so that they do not overlap each other, the thickness of the device can be reduced.

Furthermore, if all the rotation transmission mechanisms for driving both reel stands from the capstan shaft 10 are placed on the side of the board where the cassette is mounted, not only will assembly be easier to automate, but the bottom side of the board Effects such as being able to arrange electrical parts and the like close to each other can be obtained, and the overall thickness of the device can also be easily reduced.

In the above explanation, only the constant speed feed mode of the magnetic tape was explained, but for example, by separating the pinch roller from the capstan shaft, the fast feed mode of the magnetic tape can also be applied. Needless to say, it is also possible to transfer in the opposite direction.

[Brief explanation of drawings]

FIG. 1 is a plan view of a main part showing a magnetic tape forward feeding state in an embodiment of the present invention, FIG. 2 is a main part plan view showing a magnetic tape backward feeding state in an embodiment of the invention, and FIG. FIG. 2 is a sectional view taken along the line I-1 in FIG. 1; 1o... Capstan shaft, 12... Pinch roller, 18... Capstan motor, 2
2... Drive gear, 28a... Large gear,
28b... Pinion gear, 30... Take-up side reel stand drive unit, 32... Supply side reel stand drive unit, 34... Take-up side reel stand, 36
...... Supply side reel stand, 38... Take-up side reel hub, 4o... Supply side reel hub.

Claims (1)

[Claims] A motor that can rotate in either forward or reverse directions, a capstan shaft that is rotationally driven by the motor and can feed the magnetic tape at a constant speed using a pinch roller, and a capstan shaft that rotates synchronously with the capstan shaft. , and a drive wheel disposed at approximately the same distance from the pair of reel stands, and the capstan shaft of the pair of reel stands controls the rotation of the drive wheel according to the rotation direction of the drive wheel. A selective rotation transmission means capable of selectively transmitting rotation to a reel stand on the sending side is provided, and selectively rotates one of the pair of reel stands depending on the rotation direction of the capstan. A magnetic tape device characterized by being configured as follows.