JPS6137686B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a video recording medium configured to run a magnetic tape in the opposite direction by a required distance by rotating a capstan in a direction opposite to that in the recording mode in connection with a pause operation in the recording mode. It relates to magnetic tape devices such as tape recorders.

In general, in magnetic recording/playback devices such as video tape recorders, when recording is restarted after temporarily stopping signal recording, the playback screen becomes distorted at the seam between the recording before the stop and the re-recording. Sometimes the screen is extremely unpleasant.

In order to solve such problems, after temporarily stopping signal recording, the magnetic tape is run in the opposite direction, and when recording again, the already recorded signal is played back, and this playback signal is A method has been considered in which the phases of the signal and the reference signal of the signal to be recorded are compared so that the phase relationship becomes a predetermined phase relationship, and then the signal is recorded.

Conventionally, in order to run the magnetic tape in the reverse direction, a method has been adopted in which the capstan is reversed in conjunction with a temporary stop operation in the recording mode. In this method, the idler that drives the reel stand during recording/reproduction is separated by a plunger solenoid mechanism or the like when the recording mode is paused. This is because if the idler is crimped even when recording is paused, in the conventional system where the idler is driven by the same drive source as the capstan, when the capstan is reversed (when recording is paused) ) This is because the idler is pressed against the reel stand, causing the reel stand to be reversed, resulting in more magnetic tape being fed out than necessary, causing extremely serious damage to the tape.

The present invention prevents unnecessary reverse rotation of the take-up reel stand when the recording mode is temporarily stopped without using a plunger solenoid mechanism, eliminates the above-mentioned inconvenience, and eliminates the need for a plunger solenoid mechanism. This provides a magnetic tape device that is low cost and lightweight.

Hereinafter, the present invention will be explained based on illustrated embodiments. In FIG. 1, a capstan 2 is rotated by a capstan motor 6 via a capstan belt 4. As shown in FIG.

Reference numeral 8 designates a take-up reel stand, which is rotatably supported on an idler shaft 14 implanted in an idler lever 12 which is urged to move in the direction of arrow A in the figure by a tension spring 10 constituting an idler urging means. and is rotated via an idler 18 that is in rolling contact with a rotating body 16 that rotates integrally with the capstan 2 and the take-up reel stand 8. The rotation of the take-up reel stand 8 is transmitted to the tape counter 22 via the belt 20.

As shown in detail in FIG. 2, the idler 18 is comprised of an idler disk 28 having a rubber tire 24 on its outer periphery that is in rolling contact with the rotating body 16 and the take-up reel stand 8. Reference numeral 30 denotes a rotating member having an arm portion 30a attached to the tip thereof with a brake shoe 36 that can move toward and away from the outer periphery of the take-up reel stand 8. , and is pressed onto the upper surface of the idler disk 28 via a friction member such as a felt 34 by a conical coil spring 32. That is, the rotation of the idler disk 28 is transmitted to the rotating member 30 via a friction clutch which constitutes a braking force applying means, and these constitute an idler means.

When recording is temporarily stopped, the capstan 2 is moved to the first position via the belt 4 by the capstan motor 6.
Rotated counterclockwise in the figure. Therefore, the rotating body 16 also rotates counterclockwise together with the capstan 2, and the idler 18 rotates clockwise. This clockwise rotation of the idler 18 is transmitted to the rotating member 30 via a friction clutch, and a brake shoe 36 such as a felt attached to the tip of the arm 30a of the rotating member 30 is used to move the take-up reel stand. By coming into contact with 8, a load torque corresponding to the friction clutch torque can be applied to the take-up reel stand 8. At this time, the reverse rotation of the take-up reel stand 8 (counterclockwise rotation in ), that is, the load torque of belt 2
Load torque such as the driving load torque of the tape counter 22 via the drive load torque of the tape counter 22 through the drive, the shaft loss of the take-up reel stand 8, the load torque of the cassette reel hub and the tape roll (not shown), and the drive load torque of the take-up reel by the rotating member 30. The torque of the friction clutch, and therefore the spring force of the conical coil spring 32, is set so that the reverse rotation transmission torque to the take-up reel stand 8 is smaller than or equal to the sum of the braking torque to the stand 8. .

Therefore, when recording is temporarily stopped, the take-up reel stand 8 does not actively try to rotate in the reverse direction, but rotates in the reverse direction by the amount of tension caused by the magnetic tape (not shown) running in the reverse direction. Therefore, the magnetic tape does not slacken between the take-up reel stand 8 and the capstan 2, and the brake shoe 36 attached to the rotating member 30 comes into contact with the take-up reel stand 8 to provide an appropriate braking force. Appropriate back tension can be given to the magnetic tape running in the opposite direction, and as a result,
It also has the effect of stabilizing the running of the magnetic tape when running in reverse.

As described in detail above, according to the present invention, when the capstan is reversed, braking force is applied to the idler so that the reverse rotation transmission torque to the take-up reel stand is smaller than or equal to the reverse rotation load torque of the take-up reel stand. By providing a braking force applying means, it is possible to prevent excess tape from being fed out from the take-up reel stand when recording is temporarily stopped, with an extremely simple structure.
This method has excellent effects in that it prevents screen distortion during continuous shooting, and it is also less expensive and lighter than the conventional plunger method.

[Brief explanation of the drawing]

Fig. 1 is a plan view of essential parts of an embodiment of the present invention, Fig.
The figure is a sectional side view of the main part of the same embodiment. 2... Capstan, 8... Take-up reel stand, 1
0...Tension spring, 12...Idler lever,
14...Idler shaft, 16...Rotating body, 18...
... Idler, 30 ... Rotating member, 32 ... Conical coil spring, 34 ... Felt, 36 ... Brake shoe.

Claims (1)

[Scope of Claims] 1. A capstan for transferring a magnetic tape at a constant speed, a rotating body that rotates integrally with the capstan, a take-up reel stand for winding the magnetic tape, and a rotational force of the rotating body. Idler means including an idler for transmitting power to the take-up reel stand, and idler urging means for intervening the idler between the rotary body and the take-up reel stand and urging the idler to move in a direction to bring it into contact with them. and a magnetic tape device configured to rotate the capstan in a direction opposite to that in the recording mode in connection with a temporary stop operation in the recording mode, thereby causing the magnetic tape to travel a required amount in the opposite direction, The idler means is a braking force applying means that applies a braking force to the idler so that the reverse rotation transmission torque to the take-up reel stand is smaller than or equal to the reverse rotation load torque of the take-up reel stand when the capstan is reversed. A magnetic tape device configured including 2. In the description of claim 1, the braking force applying means is disposed on a shaft that rotatably supports the idler so as to be rotatable separately from the idler, and a part of the braking force applying means is provided on a shaft that rotatably supports the idler. a rotating member that can approach and separate from the take-up reel stand via a brake shoe; a friction member interposed between the idler and the rotating member; A magnetic tape device including an elastic member that applies a pressing force in a direction toward an idler.