JPS6239495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a take-up reel stand device of a magnetic recording/reproducing device, and includes a magnetic recording/reproducing mode (hereinafter referred to as recording/reproducing mode) and a fast forward mode (hereinafter referred to as F/F mode).
The present invention provides an extremely useful reel stand device in which a take-up reel stand is driven by one reel motor when the take-up reel stand is driven by a single reel motor.

FIG. 1 shows an outline of a conventional reel stand drive system. In the figure, a supply reel stand 10, a take-up reel stand 12, and a reel motor 14 are arranged at predetermined positions, and the reel motor 14 rotates in contact with a drive wheel 16 fixed to the shaft of the reel motor 14. By selectively bringing the idler 18 into contact with the supply reel stand 10 or the take-up reel stand 12 and changing the direction of rotation of the reel motor 14, rewinding, recording/playback, F/F
etc. mode is being switched. However, recording and playback
In the F/F mode, the rotational direction of the take-up reel stand 12 is constant as shown in the direction of arrow A;
The number of revolutions of the take-up reel stand 12 differs considerably during recording/playback, F/F. Particularly in the recording/reproducing mode where the rotational speed is low, the rotational speed of the reel motor 14 is extremely low and the reel motor 14 is used in an inefficient manner, so that it is not possible to reduce the current consumption. Also, magnetic tape 1
In order to keep the winding tension of 1 constant, it was necessary to control the voltage supplied to the reel motor 14.

In order to improve these points, the present invention provides a reel stand device that has low current consumption and is capable of keeping the winding tension constant without controlling the voltage of the reel motor. The present invention will be explained below based on the embodiment shown in FIG. In the figure, a sun gear 24 and a brake drum 26 are integrally fixed to a main shaft 22 rotatably supported by a main chassis 20. As shown in FIG. The main shaft 22 has a reel disk 30 that comes into contact with the idler 18 to transmit driving force to a reel table 28 (described later) and that engages with a take-up reel (not shown) of a tape cassette (not shown). A reel table 28 having a gear on its inner circumference is rotatably held for transmitting driving force to the take-up reel (not shown). The reel disk 30 has at least one (three in this embodiment) planetary shafts 32 at predetermined positions.
is fixed upright, and the planetary shaft 32 rotatably holds a planetary gear 34 having at least one type (two types in this embodiment) of the number of teeth. The aforementioned sun gear 24 and a brake ring 40 having a gear on its inner periphery are engaged with and held by the large gear 36 of the planetary gear 34 . Further, the small gear 38 of the planetary gear 34 meshes with the internal gear of the reel table 28 described above.

Here, the number of teeth of the sun gear 24 having teeth on the outer periphery is smaller than the number of teeth of the brake ring 40 which has teeth on the inner periphery and has a larger diameter than the sun gear. The reduction ratio due to the meshing with the large gear 36 and the internal gear of the brake ring 40 is smaller than the reduction ratio due to the meshing with the inner peripheral gear of the large gear 36 and the brake ring 40.

In such a configuration, a limiter brake 4 is provided on the outer periphery of the brake ring 40 in the recording/playback mode.
2 and restricting the rotation of the brake ring 40, the rotation of the reel disk 30 is transmitted to the reel table 28 via the planetary gear 34. In this case, the F/F brake 44 is spaced apart from the brake drum 26,
The sun gear 24 is in a freely rotatable state. Therefore, the planetary gear 34 is the large gear 36
is meshed with the internal gear of the brake ring 40, rotates while revolving around its own axis, and uses its rotational force to rotate the reel table 28.

On the other hand, in the F/F mode, the limiter brake 42 is released and the F/F is applied to the brake drum 26.
The brake 44 is pressed against the brake drum 26.
By stopping the rotation of the sun gear 24, the rotation of the reel disk 30 is transmitted to the reel table 28 via the planetary gear 34. In this case, the limiter brake 42 is released from the brake ring 40, and the brake ring 40 is in a freely rotatable state. Therefore, the planetary gear 34 has its large gear 36 meshed with the sun gear 24, rotates on its axis and revolves, and rotates the reel table 28 by its revolving force.

In this embodiment, in the recording/playback mode, the limiter brake 42 is pressed against the outer periphery of the brake ring 40, and in the F/F mode, the limiter brake 42 is released, and the brake drum 26 is By applying pressure to the outer periphery of the F/F brake 44 and stopping the rotation of the brake ring 40 or the brake drum 26, even if the rotation speed of the reel disk 30 is constant, the rotation speed of the reel table 28 can be changed. It is possible to switch. Therefore, the number of teeth on the sun gear 24, the number of teeth on the large gear 36 of the planetary gear 34, and the brake ring 40.
If the reduction ratio determined by the number of teeth of the internal gear of Not only can it be used at the most efficient rotational speed as a motor, but it is also decelerated in recording/playback mode, so sufficient winding torque can be obtained. In addition, in order to keep the winding tension of the magnetic tape (not shown) constant, if the pressing force of the limiter brake 42 is set to an appropriate pressure, the reel table 28 will be able to avoid unnecessary load torque. If the magnetic tape is applied, slipping occurs between the brake ring 40 and the limiter brake 42, causing a limiter effect, and no abnormal tension is applied to the magnetic tape.

As described above, according to the present invention, the recording/playback mode,
In each F/F mode, the position where the idler contacts does not change at all, just by switching between the limiter brake and the F/F brake.
Not only can the rotation speed of the reel table be changed to cope with the recording/playback mode and F/F mode, but in the recording/playback mode, the reel motor rotation speed can be set high and can be used in an efficient state, resulting in low consumption. This greatly contributes to the generation of electric current. In addition, the winding tension of the magnetic tape can be controlled by setting the pressure contact force of the limiter brake.
This contributes to improving the performance of magnetic recording and reproducing devices. Furthermore, in each of the recording/playback mode and F/F mode, the rotation speed is uniquely set by the meshing ratio between the planetary gear, the sun gear, and the internal gear of the brake ring.Especially in the recording/playback mode, the brake slip rate is set uniquely. Since it can be set to a small value, reliability against brake wear can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a conventional reel drive system, and FIG. 2 is a side sectional view of an embodiment of the present invention. 22... Main shaft, 24... Sun gear,
26... Brake drum, 28... Reel table, 30... Reel disk, 32... Planetary shaft, 34... Planetary gear, 40... Brake ring, 42... Limiter brake, 44... F.F.
brake.

Claims (1)

[Claims] 1. A rotatable first rotating member provided to transmit driving force from the motor to the take-up reel stand and rotatably equipped with at least one planetary gear;
a brake ring having a rotation center coaxially with the rotation axis of the first rotating member and having an internal gear that meshes with the at least one planetary gear;
The rotation center is coaxial with the rotation axis of the rotating member,
a sun gear that meshes with the planetary gear at a gear ratio different from that of the at least one planetary gear and the braking gear and is fixed to the rotating shaft; and a sun gear that is coaxial with the rotating shaft of the first rotating member. a rotatable second rotating member having a rotation center at the top and meshing with the at least one planetary gear provided on the first rotating member to transmit power to the take-up reel stand; and rotation of the brake ring. a first brake means slidably associated with the sun gear so as to regulate the rotation of the sun gear; and a second brake that is movable into and out of contact with a brake drum that is rotatable integrally with the sun gear and is provided to stop the rotation of the sun gear. and means;
In the recording/playback mode, the first brake means is operated to restrict the rotation of the brake ring, while in the fast forward mode, the second brake means is operated to stop the rotation of the sun gear; A reel stand device characterized in that the rotation of the take-up reel stand in the fast-forward mode is configured to be in the same direction as the rotation of the take-up reel stand in the recording/playback mode, but at a higher speed.