JPH0560189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic tape cassettes such as compact cassettes.

In a magnetic tape cassette (hereinafter simply referred to as a cassette) such as a compact cassette, a tape pad that is biased in the direction of the magnetic tape is arranged inside the magnetic tape in the part that contacts the magnetic head, and the tape pad is biased in the direction of the magnetic tape. When the magnetic head of the device is inserted into the cassette, the magnetic tape is elastically pressed against the magnetic head by the action of the tape pad. In reel-to-reel type tape recorders, etc., the tape path is set so that the magnetic tape comes into pressure contact with the magnetic head to achieve close contact between the tape and the head. Since such a tape path setting is impossible for a cassette that cannot be pulled out at any time, the tape and the head are brought into pressure contact by the tape pad as described above.

The above-mentioned tape pad is generally made of felt, is fixed to the center of a leaf spring arranged inside the magnetic tape and approximately parallel to the tape, and is pressed against the back side of the magnetic tape biased by the leaf spring. However, conventional cassettes using this type of tape pad tend to cause uneven wear of the magnetic head of the recording/reproducing device.

That is, in the case of a conventional cassette, the leaf spring is formed by punching out an elastic plate material such as phosphor bronze into a shape in which an elongated strip extends left and right from the center of a rectangular pad support, that is, in a cross shape. However, due to distortion during punching, etc., the center pad support part was not formed completely flat, and the upper part of the band-shaped part In some cases, the upper part and the lower part were bent slightly in different directions. Naturally, the pad pressure of the tape pad fixed to such a leaf spring becomes non-uniform in the vertical direction of the magnetic head. In addition to the shape of the leaf spring, such pad pressure irregularities can also occur due to, for example, dimensional errors on the cassette half side that supports the leaf spring, or even incorrect insertion posture of the magnetic head of the recording/reproducing device. As is well known, most recording/playback devices that use cassettes record and play back tapes in both directions.
Therefore, the magnetic core of the magnetic head is arranged offset to either the upper or lower side with respect to the magnetic tape, but the portion of the magnetic head outside the magnetic core is relatively more likely to wear than the core portion. Therefore, if the above-mentioned pad pressure irregularity is particularly such that a large pad pressure is applied to a portion outside the core, this portion outside the core will wear out at an accelerated rate.

Incidentally, usually a plurality of tracks are formed on a magnetic tape, but even in such a case, the above-mentioned tape pad is formed so as to press the magnetic tape over its entire width without being divided into tracks. It is common to That is, if the tape pads are divided into tracks as described above, the edges of each tape pad will come into contact with the magnetic tape, which may cause creases or scratches on the tape as the tape runs.

The present invention has been made in view of the above circumstances, and aims to eliminate the extreme pad pressure irregularity as described above,
The object of the present invention is to provide a cassette that does not cause uneven wear of the magnetic head.

In the cassette of the present invention, as described above, one leaf spring that presses the magnetic tape against the magnetic head is connected to an upper support portion that supports the upper half of the tape pad and a pair of leaf springs that extend from the upper support portion in the left-right direction. an upper half consisting of an upper arm; a lower support part supporting the lower half of the tape pad; and a pair of lower parts extending in the left-right direction from the lower support part and having both sides connected to both ends of the upper arm. The upper arm and the lower arm are branched directly from the supporting portions of the left and right ends of the leaf spring to the cassette main body essentially without intervening the gathering portion,
Accordingly, the upper half and the lower half are formed to be elastically deformable independently of each other in the direction of pressing the tape pad against the magnetic head.

When a leaf spring is divided into an upper half and a lower half as shown above, the leaf spring half to which a large force is applied will deflect more independently of the other half, and this half of the leaf spring will be supported. Reduce the pad pressure of the tape pad in the area where the tape pad is located and average the pad pressure. As a result, extremely large pad pressure is not applied to a portion of the magnetic head, and uneven wear of the magnetic head as described above can be prevented.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the tape pad and leaf spring of a cassette according to one embodiment of the invention. Leaf spring 1
includes a rectangular upper support part 2 and a pair of upper arms 3 extending left and right downward from the upper end of this upper support part 2.
It has an upper half 4 consisting of upper arms 3a and 3b, and a lower half 7 formed symmetrically with the upper half 4 and consisting of a lower support part 5 and lower arms 6a and 6b. The lower arms 6a, 6b are connected at their respective ends. These upper arms 3a, 3
The further outer ends of the connecting portions of b and lower arms 6a and 6b are bent at right angles, and the supporting portions 8
a, 8b. The leaf spring 1 is made of phosphor bronze, nickel silver, etc., like a conventional cassette leaf spring.
It is formed from an elastic plate material such as stainless steel.

The upper support part 2 and the lower support part 5 are separated from each other with a slit 9 between them, and one tape pad 10 is attached to the upper support part 2 and the lower support part 5. That is, the upper support part 2 supports the upper half of the tape pad 10, and the lower support part 5 supports the lower half of the tape pad 10. This tape pad 10 is made of felt or the like, similar to the tape pad of a conventional cassette.

The leaf spring 1 to which the tape pad 10 as described above is fixed is held in the cassette half by combining the supporting parts 8a and 8b with both ends of the shield plate.

FIG. 2 shows that the cassette of this embodiment having the above-mentioned leaf spring 1 and tape pad 10 is installed and used in a recording/reproducing apparatus in which the magnetic head 11 cannot be inserted perpendicularly to the magnetic tape 12 of the cassette. It indicates the condition. The magnetic head 11 is inserted into the cassette with the upper side tilted forward, and comes into contact with the magnetic tape 12 pressed from the back side by the tape pad 10 biased by the leaf spring 1. At this time, the upper support part 2 supporting the upper half of the tape pad 10 corresponds to the attitude of the magnetic head 11 as shown in the figure by bending the upper arms 3a and 3b more than the lower arms 6a and 6b. Then, it exits to the inside of the cassette (to the left in the figure) from the lower support part 5. Therefore, the pressure with which the tape pad 10 presses the magnetic tape 12 against the magnetic head 11, that is, the pad pressure, would normally be greater toward the top of the tape pad 10, but due to the withdrawal of the upper support portion 2, the pad pressure is reduced from the center to the top. Equalized. Therefore, large pad pressure is not applied to the relatively easily worn portion above the magnetic core 11a of the magnetic head 11, and uneven wear of the magnetic head 11 is prevented.

The mechanism for compensating for pad pressure irregularities due to incorrect insertion posture of the magnetic head 11 has been explained above, but the leaf spring 1 of the cassette of this embodiment is formed with the upper support part 2 or the lower support part 5 itself being distorted. Alternatively, pad pressure irregularities caused by the plate spring 1 being disposed obliquely due to manufacturing errors in the plate spring support portion such as the shield plate can of course be compensated for in the same manner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a part of a cassette according to an embodiment of the present invention, and FIG. 2 is a side sectional view showing the embodiment of FIG. 1 in use. 1... Leaf spring, 2... Upper support part, 3a, 3b... Upper arm, 4... Upper half of leaf spring, 5... Lower support part, 6a, 6b... Lower arm, 7... Lower half of leaf spring, 8a , 8b...Supporting portion of leaf spring, 10...Tape pad, 12...Magnetic tape.

Claims (1)

[Scope of Claims] 1. A plate spring arranged approximately parallel to the tape inside the magnetic tape stretched over the cassette opening, and a plate spring fixed to the plate spring to press the magnetic tape against the magnetic head. In a magnetic tape cassette having one tape pad, the leaf spring includes an upper support part that supports the upper half of the tape pad, and a pair of upper arms extending in the left-right direction from the upper support part. a lower support part that supports the lower half of the tape pad; and a lower support part that extends from the lower support part in the left-right direction and has both ends connected to both ends of the upper arm.
The upper arm and the lower arm are branched directly from the supporting portions of the left and right ends of the leaf spring to the cassette body essentially without intervening the gathering portion; A magnetic tape cassette, wherein the upper half and the lower half are elastically deformable independently of each other in a direction that presses the tape pad against a magnetic head.