JPH0127146Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape tension generator in a cassette type recording/reproducing apparatus such as a cassette type tape recorder.

Generally, in tape recorders, various losses occur during the electromagnetic conversion process between the tape and the magnetic head, but in order to reduce this loss, it is necessary to make the contact between the tape and the head close, and for this purpose, general As a method, a certain tension is applied to the tape.

Conventionally, the means for generating tape tension has been to apply a certain amount of friction to the supply reel side, or
Alternatively, a certain tape tension is generated between the capstans using a dual capstan method or the like.

However, the means to obtain a constant tape tension by applying friction torque to the supply reel side is generally complicated and expensive, and the dual capstan method has the disadvantage that a large erasing head cannot be used. It was hot.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tape tension generator that can overcome the above-mentioned conventional drawbacks and provide the necessary tape tension.

Embodiments of the present invention will be described below based on the drawings. The illustrated example shows an example implemented in a cassette-type tape recorder. In the figure, only the main parts of cassette A are shown.
4 is the large window of the cassette half, and 4 is the capstan hole on the erase head side (supply reel side). 5 is a chassis of the tape recorder, 6 is a tension roller shaft rotatably supported by a bearing 7 attached to the chassis 5, and a tension roller 8 made of an elastic material such as rubber is integrated with the tension roller shaft. is installed. This tension roller 8 is designed to be inserted into the capstan hole 4 when the cassette A is inserted into a tape recorder, and the outer peripheral shape of the tension roller 8 corresponds to the width of the tape 2 as shown in the figure. It has a contact surface 8a corresponding to. Reference numeral 9 denotes a head board to which a recording head (not shown), a playback head, etc. are attached, and is provided to move back and forth in the a-b direction.In a conventional tape recorder, the erasing head 10 is also fixed to this. In the present invention, an erase head base 11 dedicated to the erase head is attached to the head substrate 9. The erasing head base 11 is rotatable around a mounting shaft 12, and is wound around the mounting shaft 12, with one end attached to a spring stopper 14 provided on the head board 10, and the other end attached to the erasing head base. The first
In the figure, rotational force is applied in a counterclockwise direction and is regulated by a stopper 16. The erasing head 10 is attached to the erasing head base 11, and when the head board 9 moves from direction b to direction a, it is pressed against the tension roller 8 by the elastic force of the erasing head base 11, and is arranged so as to clamp the tape 2. has been done.

Next, the case where this apparatus is placed in a tape constant speed running state (recording or reproducing) will be explained with reference to FIG. From the state shown in FIG. 1, the head board 9, which moves together with the recording and playback heads (not shown), moves forward in the direction a, resulting in the state shown in FIG. 3. The erasing head base 11 and therefore the erasing head 10 also move forward, and the erasing head 10 enters the large window 3 of the cassette half 1 and applies the tape 2 to the tension roller 8 inserted into the capstan hole 4. It is held in between and touched. In this case, the erasing head base 11 rotates against the elastic force of the spring 13, so that the erasing head 10 is pressed against the tension roller 8 by the elastic force. Further, in this state, the tape 2 is running at a constant speed in the direction of arrow c by a tape drive device (not shown) (for example, a capstan and a pinch roller).

As described above, since the outer peripheral shape of the tension roller 8 has a contact surface 8a corresponding to the width of the tape 2, the frictional resistance acting on the tape 2 can be determined by the following equation. The friction coefficient between the tape 2 and the erasing head 10 is μ _E The friction coefficient between the tension roller shaft 6 and the bearing 7 is μ _B The pressing force of the erasing head 10 against the tension roller 8 is P _R
Assuming that the thrust resistance added to the tension roller shaft 6 is R _S , the total frictional resistance R _T is R _T =P _R (μ _E + μ _B ) + R _S. This becomes the back tension for tape 2, and it is possible to obtain the necessary tension for the tape, increasing the degree of adhesion between the recording and playback head and the tape, and reducing various losses that occur between the tape and the recording and playback head. .

Adjustment of the tape tension can be easily done by varying the strength of the spring 13. In addition, since the tape runs wrapped around a tension roller, it absorbs tape vibrations that occur between the supply reel and the erase head, and it is also possible to cut out modulation noise caused by tape vibrations. As a result, the sound quality can be improved.

According to the tape tension generator of the present invention in a cassette type recording/reproducing device, the necessary tape tension can be obtained with a simple configuration, and the tape tension can be adjusted by varying the elastic force of the erasing head base. Can be adjusted.
In addition, even if you use a large-window erasing head, you can obtain the tape tension equivalent to current dual capstans, and the only part where the tape slips is on the surface of the erasing head. Vibration is reduced and sound quality can be improved.

Furthermore, in the conventional method in which the erasing head is pressed onto a pad (felt), level fluctuations and dropouts occur due to unevenness in the felt and tape vibration caused by contact between the tape and the corner of the felt on the exit side of the tape. However, since the present invention uses rollers made of elastic material, there is no such fear.
Adhesion to the tape is improved and various losses occurring between the tape and the recording/reproducing head can be reduced. In addition, the tension roller absorbs vibrations of the tape, thus acting as a filter.

[Brief explanation of the drawing]

The drawings show an embodiment of the tape tension generator in the cassette type recording/reproducing apparatus according to the present invention, FIG. 1 is a plan view, FIG. 2 is a partially sectional side view,
FIG. 3 is a plan view showing the operating state. A: Cassette, 1: Cassette half, 2: Tape, 3: Large window, 4: Capstan hole, 5: Chassis, 6: Tension roller shaft, 7: Bearing,
8: Tension roller, 8a: Contact surface, 9: Head board, 10: Erasing head, 11: Erasing head base, 12: Mounting shaft, 13: Spring, 1
4, 15: Spring stopper, 16: Stopper for erase head base.

Claims (1)

[Scope of utility model registration request] A shaft is rotatably supported on the chassis so that it is inserted into the capstan hole on the erasing head side when a cassette is inserted, and a rubber-made shaft is attached to the shaft and has a contact surface that corresponds to the width of the tape. a tension roller consisting of an elastic body; an erasing head base having one end pivotally supported on a head substrate and an erasing head attached to the other end; and the erasing head being brought into pressure contact with the tension roller. 1. A tape tension generator for a cassette type recording/reproducing apparatus, comprising a spring means for biasing an erasing head base.