JPS6317102Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to magnetic tape cassettes, and in particular to a novel compact cassette of approximately the same size as a so-called Phillips type cassette.

Prior Art In recent years, cassette tape recorders have become smaller and lighter, and the magnetic tape cassettes used in them have also become smaller, and there is a strong desire for something that can be adapted to high-quality, high-density recording and playback over long periods of time. It's starting to look like this.

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 approximately 100 μm, which is extremely narrow compared to the four tracks in a conventional Phillips 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 is much greater than in the past. growing.

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 the magnetic tape running in one direction, and the cassette case has a so-called so-called cassette case in which side A and side B can be used. There was no need for a symmetrical structure on the front and back.
Furthermore, in the rotating head method, two magnetic heads normally rotate and alternately slide against the magnetic tape at a fixed angle with respect to the tape running direction, so the magnetic heads have the effect of sweeping out dust and are fixed. Compared to the 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 like the Phillips type and has a large number of recording tracks, and recording and reproduction uses the upper and lower halves of the magnetic tape, the so-called A-side. B side (front and back of cassette)
It can be used. If the cassette is of the fixed head type, as mentioned above, the recording and playback characteristics are more likely to be affected by dust than if it is of the rotating head type, so the cassette has a more reliable dust-proofing effect than the guard panel of the video tape cassette. A guard panel is required.

Purpose of the invention In view of the above-mentioned problems, the present invention provides a new magnetic tape cassette that has a dust-proof guard panel and its locking structure, allows the entire cassette to be used on both sides, and is capable of multi-track recording and playback. The purpose is to

Structure of the Invention An object of the present invention is to provide a magnetic tape cassette having an opening for inserting a magnetic head in the front face of a cassette case in which a pair of hubs wound with magnetic tape are built in, and a magnetic tape cassette having an opening for inserting a magnetic head at the rear of the opening and the cassette. A pair of slideable guards that have slide grooves formed along the left and right directions of the cassette case on the upper and lower outer surfaces of the case, and a slide portion that has a substantially U-shaped vertical cross section and that engages with the slide grooves, and that close the opening. a panel, a biasing means installed between both guard panels for biasing both the guard panels in the direction of closing the opening; Sometimes, the guard panel is comprised of a rotatable locking member having a substantially L-shaped horizontal cross section, with locking end pieces engaging the end faces of the guard panel near the left and right side walls of the cassette case, and furthermore, the entire cassette can be used both front and back. This is achieved by a magnetic tape cassette with special features.

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

FIG. 1 is a perspective view showing 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 cassette case main body 2 with a rectangular opening 3 at the center of the front surface recessed toward the rear of the cassette. Two slide grooves 11 formed in series along the lateral direction of the cassette case are provided on the upper and lower outer surfaces of the cassette case slightly behind the opening 3, and a pair of guard panels 4 that close the opening 3 are provided. is the slide groove 1
1 and slide the cassette in the left and right directions to open it. Moreover, the opening 3
A plate-shaped locking member 30 having a substantially L-shaped horizontal section is provided on each of the front surfaces of the left and right cassette cases, and both guard panels 4 are connected to the opening 3.
is configured to lock in the closed position.

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 enter.

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 is equipped with a shield plate for blocking external noise during recording and reproduction, and a plate with a pressure pad for ensuring sliding contact between the magnetic tape T and the magnetic head. A spring may be provided.

As shown in FIG. 2, both guard panels 4 are composed of a front wall 6 and upper and lower end pieces 7, and have a substantially U-shaped vertical cross section and are configured to cover the opening 3. ing. Furthermore, sliding portions 8 protruding along the left-right direction of the guard panel 4 are formed at the tip ends of the upper and lower end pieces 7, respectively, so as to face each other, and the sliding portions 8 are arranged in the sliding groove 11. to be slidably engaged.

A spring attachment notch 10 is formed in one of the tips of the upper and lower end pieces 7 near the center of the cassette, and within the spring attachment notch 10 is a protrusion 14 with which a tension spring 13 engages. It is provided. The tension spring 13 is mounted between the protrusions 14 of both the guard panels 4, so that
This urges both guard panels 4 to attract each other.

The guard panel 4 on the right side is caused by the tensile force of the tension spring 13 to cause the lower end of the slide portion 8 near the center of the cassette to move into the slide groove on the right side.
By coming into contact with the left end portion of the opening 3, the position is regulated so as to close the opening 3. The guard panel 4 on the left side is similarly regulated to the closed position. Further, the lower part of the slide part 8 near the center of the cassette has a slide notch 15.
is formed so that both the guard panels 4 are reliably fitted together. By configuring the slide groove 11 and the slide portion 8 in this manner, both the guard panels 4 can reliably close the opening 3 without shifting in the left-right direction of the cassette.

An end face notch 17 is formed in the end face of the front wall 6 of both the guard panels 4 located near the left and right side walls of the cassette case, and the locking end piece 31 of the locking member 30 (see FIG. 3) is formed in the end face notch 17. reference) is engaged. Therefore, both guard panels 4 are locked so that they do not open laterally when the cassette is stored.

As shown in FIG. 3, the locking member 30 is plate-shaped with a substantially L-shaped horizontal cross section.
That is, the locking member 30 has the locking end piece 31 bent toward the front of the cassette at the tip end near the center of the cassette, and the locking end piece 31 is bent toward the front of the cassette.
The left and right side walls 12 of the cassette case are located at the ends closer to 2.
A tapered portion 32 is formed with a tapered surface that recedes toward the rear of the cassette as it approaches the cassette half body 2. Further, on the back surface of the tapered portion 32, there is provided a rotation support shaft 18 (FIG. 4) provided in the cassette half body 2. A bearing portion 33 is formed into which a bearing (see ) is fitted.

FIG. 4 shows a plan view of the arrangement of the locking member 30.

The locking members 30 are inserted into the rotational shafts 18 provided at both left and right ends of the front surface of the cassette case, and are arranged to be rotatable through a certain angle.
A compression spring 35 is provided in the gap between the partition wall 19 at the rear of the lock member 30 and the lock member 30, and biases the locking end piece 31 to engage with the end face notch 17 of the guard panel 4. ing. or,
In order to prevent the locking member 30 from rotating too much due to the biasing force of the compression spring 35, the tapered portion 3
2 and the front end portions 25 of the left and right side walls 12 of the cassette case are configured to abut appropriately.

Upper and lower edges 16 of the front wall 6 of both guard panels 4
A recess 9 is vertically symmetrical and engages with an opening means 20 that slides the guard panel 4 in the left and right directions.

When the magnetic tape cassette 1 is loaded into a recording/reproducing apparatus, the guard panels 4 are unlocked by the lock release means 40 provided on the left and right sides of the cassette insertion section, and the lock release means 40 provided on the left and right sides of the cassette insertion section release the locks. It is opened to the left and right by the opening movement means 20. The unlocking operation by the lock releasing means 40 and the operation of the guard panel 4 by the opening means 20 will be explained below.

The lock release means 40 are disposed on the left and right sides of the cassette insertion section, respectively, and have an L-shape with a contact portion 41 that abuts against the tapered portion 32 of the lock member 30 when the magnetic tape cassette 1 is loaded. belongs to. Further, a lock member tension spring 43 is attached to the lock release means 40, which urges the lock release means 40 toward the insertion opening of the cassette insertion portion. direction).

On the other hand, the opening means 20 is composed of a pair of plate-shaped arms 21 having fitting portions 22 at their tips that engage with the recesses 9 of both the guard panels 4, and an arm 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 arm tension spring 24 extends from the tip on the opposite side of the fitting portion 22. They are attached so that they attract each other. 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 the guard panel 4 matches the interval between the fitting parts 22. .

Therefore, in the middle of pushing the magnetic tape cassette 1 into the cassette insertion section, the abutting section 41 of the lock release means 40 abuts against the tapered section 32 of the locking member 30 (see FIG. 4). At this time,
The abutting portion 41 is configured such that the portion of the tapered portion 32 that protrudes most forward of the cassette is connected to the rear of the cassette (arrow D).
direction). Furthermore, the magnetic tape cassette 1
When the locking member 30 is pushed in, the locking member 30 rotates (in the direction of arrow E) about the rotational support shaft 18 so that the locking end piece 31 enters inside the cassette, and the locking member 30 locks both guard panels 4. will be canceled.

The unlocking direction of the locking member 30 (arrow E
The rotation in this direction is achieved by the fact that the abutting position of the tapered part 32 and the abutting part 41 is located closer to the center of the front surface of the cassette case than the rotational support shaft 18, so that the locking member 30 is locked. This is done by applying a rotational moment in the release direction. Further, the end face notch 17 of the guard panel 4 is provided with a tapered surface (see FIG. 4) corresponding to the rotational arc of the tip of the locking end piece 31, and the tapered portion 32 is provided with the tapered surface as described above. Due to this, the locking member 3
0 lock release operation is performed smoothly.

Note that rotation of the locking member 30 in the unlocking direction is restricted by the partition wall 19.

At the same time as or immediately after the unlocking of both guard panels 4, the fitting portion 22 of the opening means 20 is opened.
and the recess 9 fit together. Thereafter, by further pushing the magnetic tape cassette 1, the arms 21 open to widen the gap between the fitting parts 22, and the guard panels 4 slide to the left and right (in the direction of arrows B and C). It will be opened. The guard panel 4 has the concave portions 9 formed vertically symmetrically and the locking members 30 also horizontally symmetrically.
(side) It can be opened no matter which direction it is loaded.

In this manner, both the guard panels 4 are 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, both the guard panels 4 are automatically closed by the force of the tension spring 13 and are locked by the locking member 30, so that the opening 3 is closed.
is completely occluded.

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. Further, the material of the lock member 30 may be the same as that of the cassette case body 2, and is not particularly limited.

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

The locking member 30 in the above embodiment is
Although the configuration is such that rotation due to the biasing force of the compression spring 35 is stopped by the back surface of the tapered portion 32 coming into contact with the front end portion 25 of the left and right side walls 12 of the cassette case, the present invention is not necessarily limited to such a configuration. It's not a thing. For example, the lock member 3
A protrusion is formed closer to the opening 3 than the locking end piece 31 of No. 0, and the protrusion comes into contact with the inner surface of the front wall 6 to stop rotation due to the biasing force of the compression spring 35. You can also change it as follows.

Furthermore, a torsion spring may be used instead of the compression spring 35. In this case, as shown in FIG. 5, a bearing notch 34 is formed which divides the bearing part 33 into upper and lower halves, and a torsion spring 36 is provided within the bearing part notch 34. A coiled portion of the torsion spring 36 is wound around the rotation support shaft 18, one end of which is engaged with a spring locking portion 37 formed inside the cassette case body 2, and the other end is engaged with the lock. Member 30
It is attached so that it presses against the back of the

In FIG. 5, the same components as the locking member 30 shown in FIG. 3 are designated by the same reference numerals.

Effect: The magnetic tape cassette 1 configured as described above
Since the guard panel 4 completely closes the opening 3 during storage, it protects the magnetic tape T located in the opening 3 and prevents dust from entering the cassette. This prevents damage to the magnetic tape T and deterioration of recording and reproducing characteristics.

Further, according to the present invention, since the guard panel 4 slides symmetrically to open the opening 3, the magnetic tape cassette 1 can be used on both sides, and multi-track recording and playback using a fixed head system is possible. suitable to do.

Further, when the magnetic tape cassette 1 is stored, both the guard panels 4 are locked by the locking member 30 so that the opening 3 is not opened, so that the opening 3 is more securely closed.

Furthermore, the lock release and opening of the guard panel 4 can be performed simply by pushing the magnetic tape cassette 1 into the cassette insertion section, and can be performed using simple structures such as the lock release means 40 and the opening means 20, so there is no need to complicate the recording/playback device.

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 an embodiment of the present invention, FIG. 2 is a perspective view showing the inside of the guard panel shown in FIG. 1, and FIG. 3 is a perspective view showing the lock member shown in FIG. 1.
FIG. 4 is a fragmentary plan view showing the arrangement of the lock member shown in FIG. 1, and FIG. 5 is a perspective view showing a modification of the lock member. 1... Magnetic tape cassette, 2... Cassette case body, 3... Opening, 4... Guard panel,
5... Shaft insertion hole, 6... Front wall, 7... Upper and lower end pieces, 8... Slide portion, 9... Recessed portion, 10...
...Spring mounting notch, 11...Slide groove, 1
2...Cassette case left and right side walls, 13...Tension spring, 14...Protrusion, 15...Slide notch,
16... Upper and lower edges, 17... End face notch, 18... Rotating shaft, 19... Partition wall, 20... Opening means, 21
... Arm, 22 ... Fitting part, 23 ... Crossing part,
24... Arm tension spring, 25... Front end,
30... Lock member, 31... Locking end piece, 32...
...Tapered portion, 33... Bearing portion, 34... Bearing portion notch, 35... Compression spring, 37... Spring locking portion, 40... Lock release means, 41... Contact portion,
43...Lock member tension spring.

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 are provided with a slide groove formed along the line, a slide portion with a substantially U-shaped vertical cross section that engages with the slide groove, and that close the opening; and a pair of slideable guard panels that are installed between the guard panels urging means disposed on the front surfaces of the cassette case on the left and right sides of the opening, when the guard panel is closed, the urging means urges both the guard panels in the direction of closing the opening; A magnetic tape cassette comprising a rotatable locking member having a substantially L-shaped horizontal cross section with a locking end piece engaged with the opposite end face, and further characterized in that the entire cassette can be used from either side.