JP2001338451A - Tape tension adjusting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel tape tension adjusting mechanism capable of eliminating the necessity of a conventional tape tension adjusting mechanism, and stabilizing tape tension. SOLUTION: This tape tension adjusting mechanism 1 is provided with a tension arm 3 having a tension pole 2 in one end, and a notched part 3b in the other end, and a brake arm 4 having a rotation suppressing part 4d engaged with the notched part 3b of the tension arm 3 for one end, and a spring lever 5 for the other end, for braking a reel base 7 by being partially brought into contact with the reel base 7. In this case, the rotation suppressing part 4d of the brake arm 4 is provided with an elastic part 4f formed integrally with the brake arm 4, and pressed into contact with the reel base 7 while being elastically deformed by the movement of the tension arm 3 in correspondence to strong/weak tape tension, and thus a press-contact force to the reel base 7 is made variable to obtain specified tape tension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a tape tension adjusting mechanism in a recording / reproducing apparatus such as a video tape recorder (VTR).

[0002]

2. Description of the Related Art In general, a video tape recorder (VTR)
In order to perform good recording / reproduction, it is necessary for the recording / reproducing device to run the magnetic tape with a proper tension applied thereto, and to maintain the tension as constant as possible. Need to be done. Particularly in a VTR, etc., it is important to keep the winding of the magnetic tape around the outer peripheral surface of the head drum as stable as possible during the recording and reproduction of information. If the tape tension is not appropriate or the tape tension fluctuates greatly, In addition, the state of winding the magnetic tape around the head drum becomes unstable, and accurate recording and reproduction of information cannot be performed.

For this reason, in a conventional recording / reproducing apparatus in which a magnetic tape such as a VTR is obliquely wound around a rotary head drum and travels, a tape tension adjusting mechanism for maintaining a substantially constant tape tension is provided.

For example, in a conventional tape tension adjusting mechanism, as described in Japanese Patent Application Laid-Open No. 5-290452, a tenregeg pin 32 for hanging a magnetic tape is erected on a tenleg arm 33, and this tenleg arm 33 is
Attached so that it can rotate in the horizontal direction about the fulcrum shaft 34,
An engagement step 35 is formed near the fulcrum shaft 34. Further, while the biasing force is applied by the spring 36 in the direction in which the above-mentioned ten leg pin 32 comes into contact with the magnetic tape T, a pin 38 is erected at one end of the brake arm 37 and a rotation suppressing member 39 is attached to the other end. The brake arm 37 is pivotally mounted near a reel base by a fulcrum shaft 40 so that the pin 38 of the brake arm 37 is engaged with the engagement step 35 of the ten leg arm 33 described above.

With this configuration, when the tape tension is weakened, the tension arm 33 rotates counterclockwise about the fulcrum shaft 34, and in conjunction therewith, the brake arm 37 rotates.
Is rotated clockwise about the fulcrum shaft 40, and the rotation suppressing member 39 is pressed against the peripheral surface of the reel base 41.

When the tape tension increases, the ten leg arm 33 rotates clockwise about the fulcrum shaft 34, and in conjunction with this, the brake arm 37 rotates the fulcrum shaft 40.
, The pressure of the rotation suppressing member 39 against the peripheral surface of the reel base 41 is reduced, and the tape tension is adjusted.

Further, a vertical fixed guide 42 for changing the running direction of the magnetic tape T is provided near the tape tension adjusting mechanism 31 in the recording / reproducing apparatus. Fixed inclined guides 43 and 43 'for inclining T, roller guides 44 and 44' for winding the magnetic tape T obliquely around the head drum H and guiding the magnetic tape T back to the vertical state again;
Roller guides 45, 45 'and tilt guides 46, 4
6 'is provided and arranged on a moving base (not shown).

Then, the magnetic tape T is sent from the fixed inclined guide 43 ′ through the capstan 47 and the moving guide 48 into the cassette C on the outlet side with respect to the head drum H, and wound on the other reel 49. Has become.

In the recording / reproducing apparatus configured as described above, for the tension adjusting mechanism configured to apply a rotational load to the reel base by the brake arm, a flexible material such as felt is used as the rotation suppressing member. In general, the rotation suppressing member is substantially deformed by the pressing force against the peripheral surface of the reel base, and the frictional force is stabilized by making contact with a certain surface instead of linear contact.

[0010]

As described above, in the conventional recording / reproducing apparatus, the flexible member such as felt is used as the rotation suppressing member after being substantially deformed. The amount of deformation is not constant due to variation factors such as the application accuracy and the deformation of the felt that occurs during the attaching operation, and the position of the brake arm at the time of pressing is not fixed at a certain position. Therefore, a position adjusting mechanism for the tenlegi pin was required as in the conventional example. For this reason, there is a problem that not only the number of parts increases, but also an adjustment operation is required, so that productivity is deteriorated and cost is increased.

In order to prevent molding unevenness and deformation, a hard material such as polyimide may be used for the rotation suppressing member. However, this material has a low coefficient of friction and has a low friction coefficient with respect to the peripheral surface of the reel base. When a very small foreign substance such as dust adheres to the peripheral surface of the reel base due to the line contact, uneven rotation occurs in the rotation suppressing force, causing a tension fluctuation.

Further, the structure in which the rotation suppressing member is attached to the brake arm requires a certain amount of adhesive area to prevent peeling and the like, and the brake arm becomes large, making it difficult to reduce the size and thickness of the entire apparatus. There is a problem of becoming.

Accordingly, the present invention has been made to solve such a problem. The rotation suppressing portion is formed integrally with the brake arm by using a resin, and the rotation suppressing portion is elastically deformed so that a predetermined amount of deformation is obtained. It is an object to stabilize the tape tension by eliminating the need for a tape tension adjusting mechanism by making a configuration in which the tape tension adjusting mechanism is configured to be pressed against the peripheral surface of the reel base with a contact area.

[0014]

According to a first aspect of the present invention, there is provided a tension arm 3 having a tension pole 2 at one end and a cutout 3b at the other end. Engages with the notch 3b of the tension arm 3 and has the other end provided with a spring lever 5
, A part of which contacts the reel base 7 to apply a brake to the reel base 7.
d) of the tape tension adjusting mechanism 1 including the brake arm 4 provided with the brake arm 4, wherein the rotation suppressing portion 4 d of the brake arm 4 has an elastic portion 4 f formed integrally with the brake arm 4, and A tape tension adjusting mechanism that presses against the reel base 7 while elastically deforming by the movement of the tension arm 3 corresponding to the strength, thereby varying the pressing force on the reel base 7 to obtain a predetermined tape tension. 1 as a second invention, the rotation suppressing portion 4d of the brake arm 4 is made of a material having abrasion resistance and elasticity so that it comes into contact with the reel base 7 in a plane. The present invention provides a tape tension adjusting mechanism 1 according to the first aspect.

[0015]

The tape tension adjusting mechanism of the present invention operates as follows by having the above-described structure. If the tape tension is different from the predetermined tape tension in the running state of the magnetic tape, the braking force applied to the reel base of the rotation restraining portion of the tension arm and the brake arm engaged with the tension arm is reduced. Move in a variable direction.

That is, when the tape tension becomes stronger than a predetermined value, a detection mechanism (not shown) having an adjusting means for adjusting the tape tension to a predetermined value in advance is operated, and the tension arm 3 moves the rotation fulcrum 3a. The brake arm 4 rotates clockwise about the center and the groove 3b pushes the pin 4b of the brake arm 4 clockwise, so that the brake arm 4 rotates counterclockwise about the fulcrum 4a.
As a result, the pressing force of the rotation suppressing portion 4d against the reel base 7 is reduced, the load on the reel base 7 is reduced, the tape tension of the magnetic tape T is reduced, and a predetermined tape tension is obtained.

When the tape tension becomes weaker than a predetermined value, the tension arm 3 acts in the opposite manner to the above-described case by the detection mechanism, and the predetermined tape tension is applied to the magnetic tape T to stabilize the magnetic tape T. Tape running is obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tape tension adjusting mechanism to which the present invention is applied will be described below with reference to FIGS. FIG. 1 is a partial schematic plan view of a recording / reproducing apparatus to which a tape tension adjusting mechanism according to the present invention is applied, and FIG.
FIG. 3 is an explanatory view of an operation of a main part of the tape tension adjusting mechanism according to the present invention, and FIG. 3 is an enlarged view of a brake arm.

The tape tension adjusting mechanism 1 of the present embodiment
Is provided with a tension arm 3 having a tension pole 2 erected at a tip thereof, and one end of a brake arm 4 having elasticity described later is engaged with the tension arm 3. That is, the tension pole 2 is for hanging the magnetic tape T, has a cylindrical shape, stands upright on the tip end side of the tension arm 3, and is rotatable together with the tension arm 3 around its rotation fulcrum 3a. Is configured.

As shown in FIG. 3, the brake arm 4 has a substantially triangular planar shape, and a hollow portion 4e is formed substantially at the center of the brake arm 4, so that the bottom portion has an elastic force. An elastic portion 4f formed into a narrow (thin) shape so as to have the same is formed, and is configured as a rotation suppressing portion 4d serving as a brake portion.

The brake arm 4 has a pin 4b erected at a tip portion corresponding to a vertex of a substantially triangle, and a fulcrum 4a near the bottom side of the hollow portion 4e. A pressing portion 4c is formed at the other end of the brake arm 4.

The pin 4b erected at the tip of the brake arm 4 is located in the notch 3b of the tension arm 3 and is engaged with a part thereof.

The other end 4c of the brake arm 4 is
The spring lever 5 is configured to abut a pin 5b erected on one end of the spring lever 5, which will be described later.

The spring lever 5 has a substantially I-shaped planar shape. The pin 5b is provided upright at one end, and a hole 5c is formed at the other end. 5a is
A rotary shaft is provided substantially at the center, and a spring 18 is mounted between the hole 5c and the device. That is, the spring lever 5 is normally urged counterclockwise by the spring 18. Therefore, the rotational urging force of the spring lever 5 urges the brake arm 4 clockwise around the fulcrum 4a from the engagement relationship between the pin 5b and the other end 4c of the brake arm 4.

The rotation suppressing portion 4d of the brake arm 4 is provided in substantially the same direction as the tangential direction of the outer periphery of the reel base 7 to be engaged with one of the reels (supply reels) 6. 7 comes into contact with the outer peripheral surface of the reel 7 and the rotation of the reel 6 is suppressed.

Further, in the recording / reproducing apparatus, similarly to the above-mentioned conventional example, fixed guides 8, 9 which are located in the vicinity of the tension adjusting mechanism 1 and are arranged vertically to change the running direction of the magnetic tape T. And a tilt guide 10 is disposed immediately before the head drum H to incline the head drum H and wind the magnetic tape T therearound.

On the downstream side of the head drum H, after the magnetic tape T is guided by the tape guide 11 and the running of the magnetic tape T is returned to the vertical state again by the inclined guides 12, 13, the capstan 14, the tape guide 1
It is configured to be sent into the cassette C via the reference numerals 5 and 16 and wound up on the other reel (take-up reel) 17. In addition, 19 is a pinch roller.

Next, the operation of the tape tension adjusting mechanism 1 of the present embodiment having the above configuration will be described with reference to FIGS. The brake arm 4 is formed of a resin having abrasion resistance and elasticity, such as polyacetal. The rotation suppressing unit 4d is provided with a reel base 7
As described above, the side contacting the reel base 7 is formed into a thin-walled shape to form the elastic portion 4f, and when pressed against the reel base 7, is elastically deformed by the pressure contact force and comes into contact with the outer peripheral surface.

That is, the rotation suppressing section 4d is mounted on the reel base 7
As a result, the frictional force is stabilized, and the influence can be reduced even when dust adheres to the outer peripheral surface. In addition, since the amount of elastic deformation is also constant, the position of the tension pole 2 is accurately determined at a predetermined position as compared with the case where a felt is used as a rotation suppressing member. Therefore, it is necessary to provide a conventional position adjusting mechanism. This is advantageous in terms of productivity and cost.

When the tape cassette C is mounted on the recording / reproducing apparatus, a vertical fixed guide 9, an inclined guide 10, and a tape guide 11 on a moving base (not shown) serving as loading means are loaded into the mouse of the tape cassette C. The magnetic tape T in the tape cassette C is drawn out of the mouth part by the movement of the moving base and is wound around the head drum H.

Next, after this loading, the magnetic tape T
The case where the tape tension becomes stronger than a predetermined tape tension for some reason during the traveling will be described.

If the tape tension becomes stronger than a predetermined value during the running of the magnetic tape T, the tension arm 3 is rotated clockwise about the pivot 3a by the above-mentioned detection mechanism (not shown), and the groove 3b is formed. Presses the pin 4b of the brake arm 4 clockwise by a predetermined amount. As a result, the brake arm 4 is rotated by a predetermined amount counterclockwise about the fulcrum 4a. As a result, the rotation suppressing unit 4
The pressing force of d to the reel base 7 is reduced, and the load on the reel base 7 is reduced, so that the tape tension of the magnetic tape T is weakened, and the predetermined tape tension is obtained.

On the contrary, if the tape tension is weakened for some reason during the running of the magnetic tape T, the tension arm 3 acts in the opposite way to the above-mentioned case by the detection mechanism (not shown). Tape T
Is given a predetermined tape tension, and stable tape running is obtained.

The present invention can be modified in various ways without departing from the spirit thereof. For example, the material of the brake arm 4 is not made of resin but made of metal such as sheet metal, and the rotation suppressing portion 4 is provided.
It is possible to form the elastic body d in one piece, and it is of course possible to use a combination of resin and metal.

[0035]

As described above, according to the tape tension adjusting mechanism of the present invention, since the position adjusting mechanism of the tension pole is not required, the number of parts can be reduced, and the adjusting operation is not required. Cost can be reduced.

Further, since the rotation suppressing portion comes into contact with the outer peripheral surface of the reel base in a certain area, the frictional force is stabilized, and even if foreign matter such as dust adheres to the outer peripheral surface of the reel base, the influence is mitigated. This allows the tape tension to be constant and the tape running to be stable.

Further, since there is no need to attach the rotation suppressing member, not only the number of parts and the number of attaching operations can be reduced, but also there is no danger of peeling off, so that the area of the rotation suppressing member is minimized. As a result, the size and thickness of the tension adjusting mechanism can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial schematic plan view of a recording / reproducing apparatus to which a tape tension adjusting mechanism according to the present invention is applied.

FIG. 2 is an operation explanatory view of a main part of the tape tension adjusting mechanism according to the present invention.

FIG. 3 is an enlarged view of a brake arm.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tension adjustment mechanism 2 Tension pole 3 Tension arm 3 b Notch 4 Brake arm 4 d Rotation suppression part 4 f Elastic part 5 Spring lever 7 Reel base

Claims (2)

[Claims] 1. A tension arm having a tension pole at one end and a notch at the other end, one end engaging with the notch of the tension arm and the other end engaging with a spring lever. A brake arm provided with a rotation restraining portion that applies a brake to the reel base when a part thereof contacts the reel base. By having an elastic portion formed integrally with the arm, by pressing the reel base while being elastically deformed by the movement of the tension arm corresponding to the strength of the tape tension, the pressing force on the reel base can be varied. A tape tension adjusting mechanism for obtaining a predetermined tape tension. 2. The brake arm according to claim 1, wherein the rotation suppressing portion is made of an abrasion-resistant and elastic material, and is brought into surface contact with the reel base. The tape tension adjusting mechanism according to claim 1.