JPS6317099Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic tape cassettes, and more particularly to a new compact cassette of approximately the same size as the so-called Phillips type.

In recent years, cassette tape recorders have become smaller and lighter, and the magnetic tape cassettes used in them have also become smaller, creating a strong desire for something that can handle long-term, high-quality, high-density recording and playback. I'm getting used to it.

However, conventional compact cassettes commonly used for audio and the like record and reproduce data using analog signals, and when high-density recording and reproduction is desired, this analog system naturally has its limits. Under these circumstances, by using a digital method such as pulse code modulation (PCM), which converts the input signal into pulses and performs recording and playback, it is possible to avoid being affected by the signal communication path and the quality of the recording medium. It is known that high-density recording and reproduction can be performed without any problems.

In addition, recent research and development has led to the development of a magnetic head that can perform high-density recording and playback such as multi-track even on narrow magnetic tapes used in Philips type tapes. It has become possible to record and play multi-tracks even on compact cassettes that are comparable to the cassette type.

When performing multi-track recording using the fixed head method on the compact cassette, for example, suppose 36 tracks are recorded in a round trip.
The width of one track is about 100 μm, which is extremely narrow compared to the four tracks in a conventional Philips type cassette. As a result, the effective sliding contact surface between the recording track of the magnetic head and each track is reduced, and the influence of dust that adheres to the magnetic tape and enters between the sliding surfaces on the recording and playback characteristics of the head is greater than in the past. becomes extremely large.

On the other hand, among magnetic tape cassettes that use high-density recording and reproduction, video tape cassettes that use a rotating head system are generally popular. Since this video tape cassette protects the magnetic tape and performs high-density recording and reproduction, a rotatable guard panel is provided at the opening in front of the cassette to prevent the influence of dust. In the case of this rotating head system, except for special types of cassettes, recording and playback can only be performed on magnetic tape running in one direction, and the cassette case has a so-called symmetrical front and back surface that can use side A and side B. It didn't need structure. Furthermore, in the rotating head method, two magnetic heads normally alternately slide against the magnetic tape while rotating at a fixed angle with respect to the tape running direction, so the magnetic heads have the effect of sweeping out dust. Compared to the fixed head method, the influence of dust on the recording and reproducing characteristics was less.

However, the magnetic tape cassette to which the present invention is directed uses a fixed head system, such as the Phillips type, and has a large number of recording tracks, and uses the upper and lower halves of the magnetic tape for recording and reproduction, so-called A. Both side and B side (front and back of the cassette) can be used. Since the cassette uses a fixed head system, as mentioned above, the recording and playback characteristics are more likely to be affected by dust compared to the rotating head system, and the cassette has a more reliable dust-proofing effect than the guard panel of the video tape cassette. A guard panel is required.

In view of the above-mentioned problems, it is an object of the present invention to provide a new magnetic tape cassette that has a guard panel with a reliable dust-proofing effect, is symmetrical on the front and back, and is capable of multi-track recording and playback.

The purpose of the present invention is to provide a cassette case with a built-in pair of hubs wrapped with magnetic tape.
In a magnetic tape cassette having an opening for inserting a magnetic head, a slide groove is formed behind the opening and on the upper and lower outer surfaces of the cassette case along the left-right direction of the cassette case, and the slide groove has a substantially U-shaped vertical cross section. A pair of slideable guard panels that have a sliding portion that engages with the groove and close the opening, and compression springs that are disposed on the left and right sides of the opening and bias the guard panel in the closing direction. The magnetic tape cassette is further characterized in that the upper and lower edges of the front wall of the guard panel are formed with recesses in which opening means for sliding the guard panel from side to side engages, and the entire cassette is symmetrical from front to back. achieved.

Hereinafter, the present invention will be described in detail based on embodiments illustrated in the drawings.

FIG. 1 is a perspective view showing a magnetic tape cassette according to one embodiment of the present invention.

In FIG. 1, a magnetic tape cassette 1 is a compact cassette having a size comparable to that of a conventional Phillips type. The magnetic tape cassette 1 has a rectangular opening 3 at the center of the front surface of the cassette case body 2, which is rectangular and receded toward the rear of the cassette. They are installed so that they can be slid open in each direction. The opening 3 is a portion into which a recording/reproducing head, an erasing head, a pinch roller, and a capstan of a recording/reproducing apparatus are inserted.

A magnetic tape T wound around a pair of hubs (not shown) is housed in the cassette case body 2 so as to be able to run across the opening 3 from side to side. The hub has a pair of shaft insertion holes 5 into which the drive shaft of the recording/reproducing device is inserted.
They are arranged in the same manner as before. Although not shown in the drawings, the opening 3 includes a shield plate for blocking external noise during recording and reproduction, and a plate spring having a pressure pad for ensuring sliding contact between the magnetic tape T and the magnetic head. may be provided.

The guard panel 4 has a front wall 6 and upper and lower end pieces 7.
The vertical cross section thereof has a substantially U-shape and is configured to cover the opening 3.
In the figure, the guard panel 4 on the left side when viewed from the front of the cassette is slidable to the left (direction B), and the guard panel 4 on the right side is slidable to the right (direction C).

Two slide grooves 11 are provided in the upper and lower outer surfaces of the cassette case slightly behind the opening 3 and are formed in series along the lateral direction of the cassette case. Furthermore, sliding portions 8 are formed at the tip ends of the upper and lower end pieces 7 of the guard panel 4, respectively, so as to face each other and protrude along the left-right direction of the guard panel 4. The guard panel 4 is attached so that the slide portion 8 engages with the slide groove 11.

At the center of the upper and lower edges 16 of the front wall 6 of the guard panel 4, recesses 9 are formed vertically symmetrically. The recessed portion 9 is an engaging portion through which an opening means 20 (see FIG. 3), which will be described later, slides the guard panel 4 in the left and right directions when the magnetic tape cassette 1 is loaded into a recording/reproducing apparatus. .

A spring storage groove 13 is formed in the front side wall 12 of the cassette case main body 2, and the spring storage groove 13 divides the front side wall 12 into upper and lower halves, and a compression spring 14 is provided in each of the spring storage grooves 13. There is.
In the guard panel 4, a protrusion 10 formed inside the front wall 6 is inserted into the spring storage groove 13, and when the compression spring 14 comes into contact with the protrusion 10, the right side The guard panel 4 is always biased toward the left, and the guard panel 4 on the left side is always biased toward the right.

The guard panel 4 on the right side is regulated to the closed position of the opening 3 by the end of the slide section 8 closer to the center of the cassette coming into contact with the left end of the slide groove 11 on the right side, and the guard panel 4 on the left side is regulated to the closed position of the opening 3. The closed position of the guard panel 4 is similarly regulated. Further, a notch 15 is formed in a portion of the slide portion 8 that is closer to the center of the cassette, so that each of the guard panels 4 can be reliably fitted together. By configuring the slide groove 11 and the slide portion 8 in this way, the guard panel 4 can reliably close the opening 3 even if the compression forces of the compression springs 14 disposed on the left and right sides are different. be able to.

Note that the spring storage groove 13 accommodates the compression spring 1.
The cross-sectional shape is configured to widen toward the rear of the cassette so that the cassette 4 does not protrude toward the front of the cassette.

The material of the cassette case body 2 may be a conventionally used plastic resin such as polyacetal or ABS resin, and is not particularly limited. The material of the guard panel 4 may be plastic resin such as polyacetal or metal, but it is preferable that the guard panel 4 has appropriate elasticity so that it can be easily attached to the cassette case body 2.

The magnetic tape T may be a ferromagnetic iron oxide or chromium dioxide tape, but is preferably a metal tape or a vapor-deposited tape suitable for high-density recording and reproduction.

The magnetic tape cassette 1 constructed as described above
When the cassette is loaded into a recording/reproducing apparatus, the guard panel 4 is opened by the opening means 20 provided at the cassette insertion section. Hereinafter, the opening means 20
The operation of the guard panel 4 will be explained based on FIG. 3.

In FIG. 3, the opening means 20 consists of a pair of plate-shaped arms 21 each having a fitting part 22 at its tip that engages with the recess 9 of the guard panel 4, and a tension spring 24. The arms 21 intersect in an X-shape approximately at the center thereof, and are rotatably provided with the intersection 23 as a fulcrum, and the tension spring 24 pulls the opposite ends of the fitting portion 22 together. It is attached so that it draws against the The opening means 20 is provided at the upper or lower side of the cassette insertion section of the recording/reproducing apparatus. Further, the opening means 20 is configured such that the fitting part 22 is directed toward the cassette insertion slot, and the interval l between the recesses 9 of both the guard panels 4 and the interval between the fitting parts 22 match. There is.

Therefore, at the middle stage when the magnetic tape cassette 1 is pushed into the cassette insertion section (in the direction of arrow A),
The fitting portion 22 and the recess 9 fit together. Thereafter, by further pushing in the magnetic tape cassette 1, both arms 21 are inserted into the fitting portion 22.
the guard panel 4.
are opened by sliding left and right (B direction and C direction), respectively. Note that the guard panel 4
Since the recesses 9 are vertically symmetrical as described above, the magnetic tape cassette 1 can be opened even if it is loaded in either direction (side A or side B).

In this manner, the guard panel 4 is opened left and right, and the opening 3 is opened, thereby making it possible to record and reproduce information on the magnetic tape T. Further, when the magnetic tape cassette 1 is taken out from the recording/reproducing apparatus again, the guard panel 4 is automatically closed by the force of the compression spring 14, and the opening 3 is completely closed.

Although the guard panel 4 of the embodiment described above has the concave portions 9 formed vertically symmetrically to the upper and lower edges 16 of the front wall 6, the present invention is not limited to such a configuration; for example, as shown in FIG. For example, the engagement groove 17 may be vertically carved so as to divide the front wall 6 into left and right halves. Note that the recess 9 does not necessarily have to be formed in the center of the upper and lower edges 16. That is, the magnetic tape cassette 1 is symmetrical on the front and back, and may be formed at appropriate positions on the upper and lower edges 16 so that the A side and the B side can be used.

Further, the slide portion 8 does not necessarily have to have the same length in the left-right direction as the guard panel 4. For example, it may be about half the length of the above embodiment, or it may be a plurality of protrusions formed in the shape of spots at regular intervals.

As described above, the magnetic tape cassette 1 of the present invention has the recesses 9 formed symmetrically above and below on the upper and lower edges 16 of the guard panel 4, which can be opened by sliding left and right, and by simply pushing the magnetic tape cassette 1 forward, the mating portion 22 engages with the recesses 9, allowing the guard panel 4 to be opened left and right, making this a magnetic tape cassette extremely suitable for recording and playback of multi-track data that can be used on both sides using a fixed head system.

Also, when storing the cassette, the guard panel 4
Since it completely closes the opening 3, it has a protective and dustproof effect on the magnetic tape T located in the opening 3, and prevents damage to the magnetic tape T and deterioration of recording and reproducing characteristics. I can do it.

Further, according to the present invention, the guard panel 4 can be opened and moved by a very simple structure such as the opening and moving means 20, so that the recording and reproducing apparatus does not become complicated.

Although the opening 3 in the above embodiment has a rectangular shape and is set back toward the rear of the cassette, the present invention is not necessarily limited to this embodiment. For example, it is also possible to apply the embodiment as shown in FIG. Hereinafter, another embodiment of the present invention will be described based on FIG. 5.

The cassette case main body 32 shown in FIG. 5 has an opening on the front surface mainly consisting of three rectangular holes 33, similar to the conventional compact cassette, and there are holes slightly toward the rear of the cassette of the rectangular holes 33 on both the left and right sides. A capstan hole 35 is formed that passes through the cassette case in the vertical direction. Each of the rectangular holes 33
A magnetic head, an erase head, and a pinch roller are respectively inserted into the capstan hole 35, and a capstan is inserted into the capstan hole 35.

Note that the guard panel 4 shown by the broken line that closes the opening 33, the slide groove 11, the compression spring 14 that biases the guard panel 4, and the storage structure for the compression spring 14 can be constructed in the same manner as in the embodiment described above. I can do it. Further, the cassette case main body 32 is configured such that the thickness _l1 of the front portion thereof is thicker than the thickness _l2 of the rear portion.

The magnetic tape cassette 3 configured as above
0 also has the same effect as the embodiment described above.

Although it was mentioned earlier that the present invention is applied to magnetic tape cassettes that are about the same size as conventional compact cassettes, it is not necessarily limited to this.
It can also be applied to various other magnetic tape cassettes.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention, Fig. 2 is a perspective view showing the inside of the guard panel shown in Fig. 1, Fig. 3 is a perspective view showing the operation of the guard panel, Fig. 4 5 is a perspective view showing a modified example of the guard panel, and FIG. 5 is a perspective view showing another embodiment of the present invention. 1,30...magnetic tape cassette, 2,32...
...Cassette case body, 3, 33...Opening, 4
...Guard panel, 5...Shaft insertion hole, 6...
...Front wall, 7... Upper and lower end pieces, 8... Slide part,
9... recess, 10... protrusion, 11... slide groove, 12... front side wall, 13... spring storage groove, 1
4... Compression spring, 15... Notch, 16... Upper and lower edges, 17... Engagement groove, 20... Opening means, 21...
...Arm, 22...Mating part, 23...Intersection part, 2
4...Tension spring, 35...Capstan hole.

Claims (1)

[Scope of utility model registration request] In a magnetic tape cassette that has an opening for inserting a magnetic head in the front of the cassette case in which a pair of hubs wrapped with magnetic tape are built-in, a magnetic tape cassette is provided at the rear of the opening and on the upper and lower outer surfaces of the cassette case in the left-right direction of the cassette case. a pair of slideable guard panels that close the opening and have a sliding groove formed along the opening and a sliding portion that has a substantially U-shaped vertical cross section and engages with the sliding groove; a compression spring disposed in the guard panel to bias the guard panel in the closing direction; and a recess formed in the upper and lower edges of the front wall of the guard panel, into which opening means for sliding the guard panel left and right engages. , a magnetic tape cassette characterized in that the entire cassette is symmetrical on the front and back.