JPS6222256A - Tape tension generation device - Google Patents

Abstract

PURPOSE:To make the tape running stable by providing a winding running guide means running a tape after passing a press contact means pressing a fixed member implanted while facing a tape running path between a supply level base and a head device at recording/reproduction via the tape by winding the tape with a prescribed angle. CONSTITUTION:The tape 9 drivne by a capstan 14 and a pinch roller 15 at recording/reproduction and coming out of a supply reel base (not shown) has a very small tension T0 by a load in a tape cassette even when the load torque of the supply reel base is zero. After the brake force is applied to the tape 9 by the press contact force, the tape is wound on a fixed guide roller 10 and the friction due to the winding is applied to form a tension T1 and then the tape is wound on a guide drum 3. The tape 9 is wound by the guide roller 10 at a winding angle theta.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tape tension generator for tape application equipment such as video tape recorders and audio tape recorders.

2. Description of the Related Art In recent years, tape tension generators have been implemented in various forms in tape application equipment.

An example of the conventional tape tension generating device mentioned above will be described below with reference to the drawings.

FIG. 3 is a top view schematically showing a rotary head type tape recorder having a conventional pack tension generating device. In FIG. 3, 1 and 2 are rotating heads, 3 is a guide drum, 4 is a supply side tape winding layer, 6 is a winding side tape winding layer,
6 is a braked net on the supply reel stand, and 7 is a brake shoe that generates back tension in the supply tape 9. A brake arm 8 presses the brake shoe 7 against the brake net 6 with a constant elastic force. 9 is a magnetic tape, 10 is a tape guide'
The roller 11 is a tape guide inclined pin that moves together with the tape guide roller 10, and is attached to the guide drum 3.
Configure the tape loading guide at the entrance to the

Similarly, 12 is a tape guide roller, and 13 is a tape guide inclined bin, which constitute a tape loading guide on the exit side. 14 is a capstan, 15 is a pinch roller, and the magnetic tape 9 is sandwiched between the capstan 14.
Performs constant speed feed.

The operation of the tape tension generating device for the rotary head type tape recorder constructed as described above will be explained below.

First, a cassette (not shown) is attached to a predetermined performance position.
The tape 9 is drawn out of the cassette by the tape loading guide means and is wound around the guide drum 3 over a predetermined winding angle.

From this state, by pressing the pinch roller 15 against the capstan 14, the magnetic tape is fed at a constant speed. The rotating disks 1 and 2 perform recording or reproduction on the magnetic tape 9 by helical scanning while rotating at a constant high speed in the direction of the arrow. Further, the tape sent out by the capstan 14 and the pinch roller 15 is wound up by a take-up reel stand (not shown), and is wound onto the winding layer section 5 on the winding side. On the other hand, on the supply side, the supply side tape winding layer portion 4 is also unwound and supplied in accordance with the tape winding. The supplied magnetic tape 9 requires an appropriate post-stretching tape tension, and a constant load torque is applied by a brake shoe 7 that presses against the brake target 6 provided on the supply reel stand.

Problems to be Solved by the Invention However, in the above configuration, since the tape tension is based on a constant load torque, the tape tension changes in inverse proportion to the winding radius of the tape on the supply side, and this change greatly affects the tape running. In addition, in order to reduce this change, a so-called tension system is used that detects the tape tension on the supply side and changes the pressure on the brake target depending on the magnitude of the tension. Some devices are equipped with a John regulator, but the structure is complicated and there are problems in downsizing the device or increasing costs.

In view of the above-mentioned problems, the present invention provides a tape tension generating device that has an extremely simple configuration and can provide a nearly constant tape tension.

Means for Solving the Problems In order to solve the above-mentioned problems, the tape tension generating device of the present invention includes a fixed tension generator installed in the tape running path between the supply reel stand and the head device during recording or playback. The present invention includes a member, a pressure contact means that presses against the fixed member via a tape, and a winding traveling guide means that causes the tape to be wound and run at a predetermined angle after passing through the pressure contact means.

With the above-described configuration, the present invention applies almost no load torque to the supply reel stand, clamps the tape in the middle of running between the fixing member and the pressure welding means, applies a braking force due to friction, and then Wrapping a predetermined amount around a fixed tape guide pole takes advantage of the increase in braking force on the tape due to friction, which is not affected by changes in the tape winding diameter on the supply reel stand like in the past. A more or less consistent tape tension is obtained.

Furthermore, since the increase in tension caused by wrapping is utilized, the tape pressing force in the pressing means can be extremely reduced.

Embodiment Hereinafter, a tape tension generator according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic top view showing the configuration of an embodiment of the present invention. In the figure, 16 is a protrusion projecting from the lower end of a guide roller 10 constituting tape loading guide means, and 17 is a stopper that can be used as needed. In order to stop the rotation of the guide roller 10, it is displaced from the position shown by the dotted line to the position shown in the figure. Reference numeral 18 denotes a fixing member which is planted on the chassis so as to extend over the tape running path. 19 is the member 1 that fixes the tape 9.
8 is a brake pad that is sandwiched and press-contacted to generate a braking force on the tape 9; 20 is a pad arm; 21 is a spring that generates a press-contact force; and 22 is a pivot shaft of the pad arm 20. Since the other constituent members are the same as those of the conventional example, their explanation will be omitted.The operation of the tape tension generating device constructed as above will be described below with reference to FIG. A supply reel stand (not shown) driven by a capstan 14 and a pinch roller 15 during recording or reproduction
Even if the load torque of the tape supply reel stand that comes out of the tape cassette is zero, the tension T is extremely small due to the tape load generated within the tape cassette. will be supplied with. After this tape 9 is given a braking force by the pressing force between the fixing member 18 and the brake pad 19, it is wound around the fixed guide roller 10, and the frictional force due to the winding is applied to the tape 9, which becomes T1 and is placed on the guide drum 3. wrapped around. θ
is the winding angle at 10 parts of the guide roller.

Now, T at the outer circumference of the tape winding. :2qr, fixing member and tape, and tape and brake pad.

The coefficient of friction between the tape and the fixed guide roller is set to 0.
3. Set the winding angle at the guide roller part to 90°, and set T1
If you want to obtain = 1 oqr, find the pressure required for the brake pad and the tension Tin when wrapped at an angle θ.
' General formula for Tout % Formula % However, μ is due to the coefficient of friction, and keeping in mind that the tape 9 is pressed by both the fixing member 18 and the brake pad 19, 10= (2+ (0,3+ 0.3 ) Pl)e”x
157 to P, : l near, 1 qr.

On the other hand, the required pressure of the brake shoe according to the conventional example is determined by assuming that the diameter of the braked shoe is approximately 56% of the maximum tape winding diameter: 10 = P2X O, 3X
From O,56+2, P2=48 gr.

Also, if T0 = 1qr at the inner circumference of the tape winding, then the value of T1 according to the present invention is TI - (1+
o, 6X 7-1) eO, 3X1.57 to T1=
It becomes 8.8 gr.

On the other hand, when using the conventional example, the ratio of the outer diameter of the tape to the inner diameter of the tape is 2.4, and T, = (10-2) X 2.4 + 1T'I=
It becomes 20.2 gr.

That is, in the case of the present invention, the brake pad pressure is 48gr compared to the conventional example? , 1gr, which is about 16% of the pressure required, and the tape tension value is 10g in the conventional example.
While it increases by 2.02 times from r to 20.2qr, it only needs to decrease by 12% from 10 (Jr to B and Bqr).

FIG. 2 is a schematic top view showing the configuration of a tape tension generating device according to a second embodiment of the present invention, in which the fixing member in FIG. 1 is also used as a guide roller, that is, a guide to which a brake pad 19 is fixed. The tape is in pressure contact with the roller 10, and the tape is wound around the outer periphery of the guide roller 1° and runs. By doing so, the configuration can be extremely simplified.

Note that during tape feeding operations other than recording or reproducing, the brake pad 19 must be released from pressure and the guide roller 1o
It is possible to release the rotation restriction and allow free rotation, reducing the load when fast forwarding or rewinding the tape.

Effects of the Invention As described above, the present invention provides a rotating member installed in a tape running path between a supply reel stand and a head device, and a pressure contact means that presses the fixing member through the tape during recording or reproduction. By providing a winding guide means for winding and running the tape after passing through the pressure contact means at a predetermined angle, optimum tape tension can be obtained with extremely low brake pad pressure, and therefore the life of the pad can be significantly extended. At the same time, stable tape tension with little change from the beginning to the end of winding can be obtained, so that stable tape running and head touch can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic top view showing the configuration of a tape tension generating device according to a first embodiment of the present invention, and FIG.
FIG. 3 is a schematic top view showing the configuration of a tape tension generating device in the embodiment, and FIG. 3 is a schematic top view showing the configuration of a conventional tape tension generating device. 1.2... Rotating head, 3... Guide drum, 7... Braking shoe, 8... Braking arm, 9... Table, 10, 12...Guide roller, 11.13...Tape guide inclined bin, 18
...-fixing member, 19 ...brake pad. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (4)

[Claims] (1) During recording or playback, a fixing member installed in the tape running path between the supply reel stand and the head device, a pressure contact means that presses against the fixation member via the tape, and a tape after passing through the pressure contact means. 1. A tape tension generator comprising a winding guide means for winding and running the tape at a predetermined angle. (2) The tape tension generating device according to claim 1, wherein the fixing member and the winding guide means are made of the same material. (3) The tape tension generating device according to claim 1, wherein the fixing member is rotatable as required. (4) The tape tension generating device according to claim 1, wherein a part of the tape loading guide means is a fixed member.