JPH04184746A - Tape tension controller - Google Patents

Abstract

PURPOSE:To apply a back tension to a tape and to obtain a stable tape feeding by rotating a guide lever in a direction for increasing a tape back tension when an operation mode is shifted from a reproduction mode to a reverse rotation mode. CONSTITUTION:When a reproduction mode is shifted to a reverse rotation mode, a cam lever 36 is rotated in cooperation with the rotation of a mode cam, a pin 35 stood on a sector gear 34 is pressed by the cam 36a of the lever 36 to rotate the gear 34 in a direction of an arrow A. As a result, a guide lever 31 is rotated in a direction of an arrow B to apply a back tension to a tape 18 through a movable post 30. A pinch roller holds the tape 18 during the switching operation to be brought into press-contact with a capstan shaft, and a winding side reel base is softly braked. Thus, the back tension can be simultaneously applied to the tape, and the tape feeding direction can be smoothly and stably switched.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a tape tension control device provided in a magnetic recording/reproducing device, and in particular, when changing from a playback mode to a reverse mode, The present invention relates to a tape tension control device that increases tension.

(Prior Art) Magnetic recording and reproducing devices such as video tape recorders are equipped with a tape tension adjustment device in order to keep the tension of the tape pulled out from the cassette and attached to the drum on which the magnetic head is mounted within an appropriate range. It is provided. Conventionally, this adjustment device has been a combination of a movable post that biases the tape and a band brake that changes the rotational braking force of the tape reel in conjunction with the movable post.

However, this device is normally used only during playback and recording, and is not used when changing from playback to reverse mode. On the other hand, in order to realize stable tape running during this mode transition, it is necessary to apply pack tension of a certain value or more. However, the conventional apparatus does not take the second point into consideration, and there is a problem in that stable tape running cannot be obtained.

(Problems to be Solved by the Invention) As described above, the conventional tape tension adjustment device has the problem that pack tension is not applied to the tape when the mode changes from playback to reverse mode, making it impossible to obtain stable tape running. Ta.

The present invention has been made in view of these points, and provides a tape that can realize stable tape running by applying pack tension to the tape when changing from the playback mode to the reverse mode in a magnetic recording/playback device. The purpose of the present invention is to provide a tension control device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the purpose of refilling, the present invention provides a tape loading means for pulling out a tape from a cassette and attaching it to a drum on which a video head is mounted; a driving means for switching and driving the tape between a forward direction and a reverse direction for recording and reproduction, and a post that is interposed in a tape running path from the drum to the cassette and guides the pulled-out tape when the tape runs in the forward direction. a rotatable guide lever, an operation mode setting means for setting an operation mode, and the operation mode setting means sets the guide lever to a tape back tension when the operation mode shifts from the playback mode to the reverse mode. and a means for rotating in an increasing direction.

(Function) According to the above configuration, the post provided on the guide lever applies tension to the tape by rotating the guide lever in synchronization with the mode transition from the playback mode to the reverse mode by the guide lever rotation means. can give. As a result, pack tension is applied to the tape,
The running direction of the tape can be switched smoothly and stably.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing the main parts of this embodiment, and FIG. 2 is a configuration diagram showing a tape running system of a video tape recorder to which this embodiment is applied.

In FIG. 2, a main base 1 is provided with a supply reel stand 2, a take-up reel stand 3, a drum 4 on which a magnetic head (not shown) is mounted, a motor 5, and the like. A capstan shaft 6 and a pulley 7 are coaxially fixed to the output shaft of the motor 5, and a pinch roller 8 is provided opposite to the outer periphery of the capstan shaft 6 so as to be able to come into contact with and separate from the pinch roller 8.

Further, a pulley 9 is rotatably provided on the main base 1 between the two reel stands 2 and 3, and a belt 10 is stretched between the pulleys 7 and 9. A clutch device (not shown) is provided coaxially with the pulley 9, and the rotation of the pulley 9 is transmitted to the idler gears 11, 12 via the clutch device. Furthermore, the idler gears 11, 12 are adapted to selectively mesh with reel stand gears 2a and 3a provided on the supply side reel stand 2 and the take-up side reel stand 3, respectively.

On the other hand, a pair of sliders 13.14 are movably provided on both sides of the drum 4 guided by guide grooves (not shown), and each slider 13.14 has a vertical post 13.
a, 14a and inclined posts 13b, 14b are erected. By moving the slider 13.14, the tape 18 is pulled out from the reel 16.17 in the cassette 15 loaded on the reel stand 2.3 through each post and attached to the drum 4. At this time, a movable post 19 provided on a tension lever (not shown)
The tape tension in the recording and playback modes is adjusted by the brakes (not shown) provided on the reel stands 2 and 3. Further, on the take-up reel stand 3 side, the tape 18 on the downstream side of the slider 14 is pulled out by a movable post 20 provided at the tip of a guide lever, which will be described later.
It is held between the capstan shaft 6 and the pinch roller 8.

In the figure, reference numerals 21, 22, 23, and 24 are fixed posts that guide the running of the tape 18, and 25 and 26 are full-width erasing heads and audio control heads, respectively.

FIG. 1 shows the structure of a guide lever 31, which is a feature of this embodiment. One end of the guide lever 31 is rotatably supported by a support shaft 32 erected on the main base 1, and a movable post 20 is provided at the other end of the guide lever 31. Also, on the outer periphery of the end of the guide lever 31 on the support shaft 32 side,
An outer gear 31 a is formed concentrically with respect to the support shaft 32 . Also, main base 1 has support 1 [! A sector gear 34 is rotatably attached via an i33, and a gear 34a is attached to one end of the sector gear 34 around a support shaft 33.
is formed. The outer gear 31a of the guide lever 31 and this gear 34a mesh with each other. A bin 35 is provided upright at the other end of the sector gear 34, and is in contact with a cam portion 36a formed on a cam lever 36 that is rotated by a mode cam (not shown).

Next, the operation of this embodiment will be explained. FIG. 2 shows the state in the reverse mode, in which the output of the motors is transmitted to the pulley 9 via the pulley 7 and belt 10, and the idler gear 11
is transmitted to the reel stand 2 via.

In the playback mode, the idler gear 12 and the reel stand gear 3a of the reel stand 3 mesh with each other, and the outputs of the motors are similarly transmitted to the reel stand 3.

When shifting from the playback mode to the reverse mode, the cam lever 36 rotates in conjunction with the rotation of the mode cam, and the cam portion 36a of the cam lever 36 pushes the pin 35 provided upright on the sector gear 34, causing the sector gear 34 to move in the direction of arrow A. Rotate it. As a result, the guide lever 31 rotates in the direction of arrow B, applying pack tension to the tape 18 via the movable post 30. The value of this back tension can be arbitrarily set depending on the shape of the cam portion 36a. During this switching operation, the pinch roller 8 is pressed against the capstan shaft while holding the tape 18, and a soft brake is applied to the take-up reel stand 3.

According to this embodiment, the guide lever 3
1 to apply back tension to the tape 18, the tape running direction can be switched smoothly and stably.

By changing the shape of the cam portion 36a formed on the cam lever 36, the movement of the guide lever 31 can be controlled in a complicated manner, for example, the tape drawing operation during tape loading can be controlled.

Although the above embodiment describes a tape tension control mechanism provided in a video tape recorder, the present invention can also be applied to other magnetic recording and reproducing devices.

[Effects of the Invention j As explained above, according to the present invention, it is possible to simultaneously apply pack tension to the tape when switching the mode from the playback mode to the reverse mode in the magnetic recording and playback device, and to Switching can be performed smoothly and stably.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the configuration of essential parts of an embodiment of the present invention;
FIG. 2 is a block diagram showing a tape running system of a video tape recorder to which this embodiment is applied. 3... Take-up side reel stand 4... Drum 6... Capstan shaft 15... Cassette 18... Tape 20... Movable post 31... Guide lever 34... Sector gear (rotation) (Moving means) Agent Patent attorney Norihiro Chika Yudo Hiroshi UjiFigure 1

Claims (1)

[Claims] a tape loading means for pulling out a tape from a cassette and attaching it to a drum on which a video head is mounted; a driving means for switching and driving the tape between a forward direction for recording and reproduction and a reverse direction; a rotatably provided guide lever having a post that is interposed in a tape running path from the tape to the cassette and guides the pulled out tape; an operation mode setting means for setting an operation mode; and an operation mode setting means for setting an operation mode. 1. A tape tension control device comprising: means for rotating the guide lever in a direction in which tape back tension increases when the operation mode is shifted from a reproduction mode to a reverse mode.