JPH0777067B2 - Magnetic tape cassette - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette, and more particularly to a magnetic tape cassette having a structure in which a magnetic tape is pulled out to the front of the cassette for recording and reproduction.

(Prior Art) In recent years, high-density recording has been performed using a magnetic tape. A typical example of this is a magnetic tape cassette (video cassette) such as the VHS system or the β system.

This type of magnetic tape cassette usually has a structure in which a magnetic tape is pulled out from an opening in the front of the cassette for recording and reproduction. That is, it has a rotatable guard panel that opens and closes the opening, and this guard panel closes the opening when the cassette is stored (when not in use) to prevent dust from entering the cassette and protect the tape. The recording / reproducing device has a structure in which it opens to open the opening when recording / reproducing, etc., and a tape pull-out member provided in the recording / reproducing apparatus enters the back side (non-magnetic surface side) of the tape to appropriately pull out the magnetic tape. . Further, when the cassette is stored, the outer periphery of the flange of the tape winding body around which the magnetic tape is wound is formed in a tooth shape as disclosed in, for example, Japanese Utility Model Laid-Open No. 55-57184 and 58-141485. The reel brake engaged with the toothed portion prevents the tape winding body from rotating unexpectedly and prevents loosening of the magnetic tape or tape jamming. Then, the release of the reel brake is performed by an insertion member that enters the cassette through a hole on the bottom surface of the cassette. As described above, the conventional magnetic tape cassette (video tape cassette) requires a hole for the above-mentioned insertion member to enter the cassette, and thus the dustproof property is inevitably reduced by the hole.

In particular, in recent years, various researches and developments have been made in various fields in order to realize higher quality recording and reproducing than ever, and as a part of that, even in the above magnetic tape cassette (video tape cassette), A highly reliable structure that can be applied to high-density recording / reproduction is desired.

FIG. 6 shows an example of a reel brake structure of a magnetic tape cassette which has already been proposed to meet the above-mentioned requirements.

The reel brake 60 is urged by spring means 65 to form gear parts 62a, 62b formed on the lower flanges 61a, 61b of the reel.
Engaging claws 63, 64 that engage with, and holes 6 through which the insertion member 80 is inserted.
8, the engaging claws 63, 64 are disengaged from the gear parts 62a, 62b against the spring biasing force, and the operating parts 66, 67 for releasing the brake are respectively provided on the rotating body parts 69, 70. It is configured as a combined structure of two brake members formed so as to project.

However, in general, magnetic tape cassettes have subtle dimensional differences on the recording / reproducing device side (dimensions of reel rotation shafts, etc.).
In order to cope with the above, the reel has a structure in which it can be slightly moved in the cassette along the bottom surface of the cassette. For this reason, the reel brake shown in FIG.
In 60, as is clear from the figure, when the reel moves toward the hole direction and acts to push the engaging claws 63 and 64, the body portions 69 and 70 rotate to form the hole 68. A gap was created in a part between the closed operating parts 66 and 67, which became a problem in terms of dust prevention.

Such a problem was also found in a video cassette such as the conventional VHS system.

That is, the closing means (the operating portion in the above example) for closing the hole is not directly biased in the closing direction by, for example, the spring means, but indirectly by the arrangement of the brake member having the engaging claw, for example. It is provided so as to be closed by pressing the hole. For this reason, when the arrangement state of the brake member changes due to the movement of the reel or the like, the closing means is also acted, and a gap is created between the insertion member 80 and the hole into which the insertion member 80 is inserted.

(Object of the invention) The present invention has been made in view of the above-mentioned problems, and at the time of storing a cassette, it is possible to improve the performance of the cassette by always perfectly closing the holes formed in the cassette. It is intended to provide a tape cassette.

(Structure of the Invention) An object of the present invention is to build a pair of tape winding bodies around which a magnetic tape is wound, and to take out the magnetic tape from the cassette for recording / reproducing. In the reel brake for preventing rotation of the tape winding body, one end is swingably supported and the free end is biased in a direction to engage with a gear portion formed on a flange portion of the tape winding body. The engaging claws, the abutment portion for abutting the substantially middle step portion in the longitudinal direction of the engaging claws to move the engaging claws in the disengaging direction from the gear portion, and the engaging claws are inserted into the cassette through the holes in the wall surface of the case. Each of the rotating body parts includes a pair of rotating body parts that are in contact with an insertion member for releasing the brake and move the corresponding part, and the rotating body parts project in the radial direction of rotation. The rotating body parts are in contact with each other to close the hole. Biased in the direction When the operating portions are moved in the separating direction from each other, the abutting portion presses the engaging claws so as to interlock with the direction in which the engaging portions separate from the gear portion, while the movement of the engaging claws causes the operating portion to move. This is achieved by a magnetic tape cassette that is characterized in that it does not interlock.

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

In the present embodiment, a recording / reproducing apparatus in which a light emitting source is incorporated in an insertion member for releasing the brake, and a tape detection mechanism for detecting light from the light emitting source to detect a tape end (start / end) is added. A compatible magnetic tape cassette will be described. That is, in such a magnetic tape cassette, a hole separately formed in the cassette for the tape detection mechanism can be omitted, and the dustproof effect can be enhanced accordingly, and a highly reliable cassette can be obtained.

1 is a perspective view showing the back surface of the magnetic tape cassette 1 of this embodiment, FIG. 2 is a perspective view of a reel brake 13 provided in the magnetic tape cassette 1 shown in FIG. 1, and FIG. 3 is a reel. 3 is an exploded perspective view of a brake 13. FIG.

The magnetic tape cassette 1 shown in FIG. 1 has a pair of tape winding bodies (hereinafter referred to as "reels") around which a magnetic tape is wound rotatably incorporated in a cassette case composed of upper and lower half cases 2 and 3. The structure is almost the same as that of the conventional VHS type video cassette, but the major difference from the conventional one is the reel brake structure structure.

The reel brake 13 shown in FIG. 2 is provided substantially in the center of the cassette case and on the front side of the case, and is an insertion member for releasing the brake that enters the case from the hole 8 provided in the lower half case 3. It is configured so that the lower flanges 11a, 11b of the reels are disengaged from the gear portions 12a, 12b by the appropriate operation of the reel 30.

The reel brake 13 includes a first brake member 15 and a second brake member 15 that rotate around a first support shaft 14 that is provided near the hole 8 of the lower half case 3 and projects in the center between the reels.
The brake member 20 and the two second support shafts 19 that are arranged close to the first support shaft 14 and symmetrically with respect to the support shaft 14.
It has engaging claws 17a and 17b that swing around a and 19b.

Each of the two brake members 15 and 20 has a cylindrical rotating body portion 16a, 16b through which the first support shaft 14 passes, and an abutting portion 24a, which extends radially from the body portion 16a, 16b. 24b
And actuating portions 18a and 18b that project in the direction of the hole 8.

The abutting portions 24a and 24b are formed in a substantially T-shape if the tip end portion protruding from the body portions 16a and 16b has a rod-shaped portion extending toward the cassette thickness direction.

Then, as shown in FIG. 3, the first brake member 15,
Attach the second brake member 20 to the first support shaft 14 in this order,
Further, the body portion 16b of the second brake member 20 or the first portion 16b.
A torsion spring 25 is wound around the spindle 14 of. The torsion spring 25 is mounted so that both ends thereof engage with the upper sides of the rod-shaped portions forming the contact portions 24a and 24b, respectively. Therefore, the biasing force of the torsion spring 25 causes the operating portions 18a and 18b of the two brake members 15 and 20 to come into contact with each other to close the hole 8. Also, the operating portion 18
It is desirable that the contact portions 24a, 24b and the engaging claws 17a, 17b are not in contact with each other when the hole 8 is closed by a, 18b. This can ensure the engagement between the engagement claws 17a, 17b and the gear portions 12a, 12b, which will be described in detail later.

The shape of the operating portions 18a, 18b is not particularly limited, but as shown in FIGS. 2 and 3, for example, a plate-like shape along the bottom face of the cassette capable of closing the hole 8 Further, it is desirable that the whole is appropriately inclined so that a component force that moves to the left and right is easily generated by the contact of the insertion member 30 when entering the cassette, or at least the surface facing the bottom surface of the cassette is inclined.

The engaging claws 17a and 17b are respectively connected to the second support shafts 19a and 19b.
The ends of the arms 21a, 21b pivotally supported by b are formed in a shape that engages with the gear parts 12a, 12b, and are constantly urged toward the gear parts by the torsion springs 22, 23 that come into contact with the respective ends. ing. The engaging claws 17a and 17b are connected to the arm 21.
The middle part of a, 21b is 1 by the lower side of the contact parts 24a, 24b.
It is arranged so that its tip can be separated from the gear parts 12a, 12b by being pressed only from the direction (from the side near the gear part).

The tips of the arms 21a, 21b are not particularly limited as long as they have a shape that meshes with the gear portions 12a, 12b, but they can be formed in a plate shape along the cassette thickness direction as shown in the figure. The feature of the present invention resides in that the reel brake 13 is provided with the contact portion 2 that interlocks with the operation portions 18a and 18b.
4a, 24b and the engaging claws 17a, 17b have an independent double brake structure. That is, the pressing force that accompanies the movement of the actuating portions 18a, 18b due to the insertion of the insertion member 30 causes the engaging claws 17a, 1 through the contact portions 24a, 24b.
7b, the brake is released, but on the other hand, the engaging claws 17a,
17b follows the reel in a state in which the gear portions 12a and 12b are always biased by the biased movement toward the gear portion against inadvertent movement of the reel in the lateral direction of the reel during storage of the cassette, and the movement is It stays only in the engaging claws 17a, 17b, and does not act on the contact portions 24a, 24b and the operating portions 18a, 18b. On the other hand, in the recording / reproducing apparatus in which the magnetic tape cassette 1 is loaded, a rod-shaped insertion member 30 is provided at a position corresponding to the hole 8 of the magnetic tape cassette 1. This insert 30
A light-emitting source such as a light-emitting diode is incorporated into the insertion barrel to project light in the horizontal direction of the cassette along the horizontal direction, and the tip is formed in a pointed shape.

When the magnetic tape cassette 1 is loaded in the recording / reproducing apparatus, the bucket holding the magnetic tape cassette 1 moves downward, for example. As a result of this movement, the insertion member 30 enters the cassette through the hole 8 (in the direction of arrow B) as shown in FIG.
18a and 18b start to be expanded, and by further advancing, both actuating portions 18a and 18b are moved in the direction away from each other against the force of the torsion spring 25, and expanded by the diameter of the insertion member 30 (direction of arrow C). ). Therefore, in the two brake members 15 and 20, the body portions 16a and 16b rotate in the relative directions (directions of the arrow D), respectively, and the abutting portions 24a and 24b are engaged with the engaging claws 17a and 1.
By pressing the center portion of 7b, the tip of the engaging claw is the gear portion 12a,
Remove from 12b. As a result, the reel around which the magnetic tape is wound is released from the engagement with the reel brake 13 and becomes rotatable. In addition, the reel is the engaging claw 12
When moving in the direction of escape from a, 12b, the contact portion 24a, 2
If the 4b and the arms 21a, 21b have an appropriate gap and are not in contact with each other, the engaging claws 17a, 17b can follow the movement of the reel, and the reel locking can be more reliable.

The guard panel 5 is moved along with the downward movement of the bucket.
Moves in the direction of arrow A (see FIG. 1) around the support shafts 10 on both ends thereof, and the tape pull-out member enters into the cassette in the mouse portions 7a and 7b on the bottom face of the cassette, and further the reel shaft insertion hole. A reel shaft for driving the reel to rotate is inserted into the reel 4.

The insertion member 30 has a function of detecting the tape end in addition to the function of releasing the lock function of the reel brake 13 as described above. This function is that light emitted from the light source provided in the insertion member 30 in the left and right direction of the cassette passes through the tape running path, passes through the openings 6 formed on the left and right side walls of the cassette case, and enters the opening 6. It is configured so that it can be detected by the light-receiving elements provided facing each other. That is, the magnetic tapes having different light transmittances and the leader tapes at both ends of the magnetic tapes can be detected by the light receiving elements, and the tape running can be appropriately controlled by the detection signals.

Thus, unlike the conventional video tape cassette, the magnetic tape cassette 1 of the present embodiment does not require the brake structure portion of the reel and the detection structure portion of the tape end to be separately provided.
By combining the two functions into a combined structure, it is not necessary to provide two holes for inserting the brake release lever and the light emitting source as in the conventional VHS method, which is preferable from the viewpoint of dust prevention. For example, the ribs and protrusions can be minimized to simplify the structure, and the limited space can be used more efficiently than ever before. It is possible to improve the performance of the magnetic tape cassette by giving it other new functions.

Further, in the recording / reproducing apparatus corresponding to the magnetic tape cassette 1 according to the present aspect, it is not necessary to separately provide the brake releasing means and the light emitting source, and one member such as the inserting member 3 can be used.

FIG. 4 illustrates a reel brake according to another embodiment of the present invention.

The same components as those of the embodiment shown in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted.

The reel brake 43 is a first brake member that rotates around a single support shaft 41 that is projectingly provided on the lower half case 3.
It has 42 and a second brake member 44. The two brake members 42, 44 are cylindrical rotating bodies 4 through which the support shaft 41 penetrates.
Engaging claws 46a, 4 which have 5a, 45b (see FIG. 5) and project from the rotating body parts 45a, 45b toward the gear parts 12a, 12b, respectively.
6b and actuating portions 18a, 18b that project in the direction of the hole 8 are provided.

The feature of this embodiment lies in that FIG. 2 and FIG.
Unlike the reel brake 13 shown in the figure, the engaging claws 46a, 46b are mounted so as to be pivotally supported by the body portions 45a, 45b.

Referring to FIG. 5, the brake member 42 will be described in more detail. The engaging claw 46a has an arm 47 protruding from the body portion 45a.
The base portion of a is thinly formed as a hinge portion, and is provided so as to be swingable in the left-right direction of the cassette.

However, the engagement claw 46a moves only in one direction in conjunction with the movement of the actuating portion 18b by the contact support part 48a fixed to the body 45a adjacent to the engagement claw 46a (arrow D). Direction) That is, when the engaging claw 46a is disengaged from the gear portion 12a, the abutting portion 48a comes into contact with a portion of the arm 47a closer to the tip than the thin portion of the arm 47a and presses the arm in the detaching direction. It is arranged.

The second brake member 44 is similarly formed.

Returning to FIG. 4, the engagement claws 46a, 46b are mounted on the support shaft 41 and both ends thereof are engaged with the spring hooking portions 49a, 49b provided on the engagement claws 46a, 46b. Is always urged toward the gear section. Therefore, the biasing force of the torsion spring 50 causes the engagement claw 46a of the first brake member 42 to move to the gear 12a and the engagement claw 46b of the second brake member 44 to move to the gear 12b.
And the actuating portions 18a, 18b abut each other to close the hole 8.

Therefore, the body parts 45a and 45b by entering the insertion member 30
With the rotation of the engaging claw 46, the abutting portion 48 acts to prevent the bending of the engaging claw 46, and abuts and presses the arm 47 of the engaging claw 46. It can be suitably disengaged from the gear portion 12.

On the other hand, when the cassette is stored, the reel moves in the radial direction by the play allowance, presses the engaging claws 46a, 46b, and rotates the body parts 45a, 45b in the direction in which the operating parts 18a, 18b open. Even if this is done, since the engaging claws 46a, 46b are bent so that the base part swings, the body parts 45a, 45b are not rotated. Therefore, the operating portions 18a, 18b do not open the hole 8 without moving.

Even when the reel moves in the direction away from the hole 8, the engaging claws 46a, 46b are urged so as to always engage with the gear portions 12a, 12b, and the movement of the reel is prevented. Since they follow each other and can move independently of the trunk portions 45a and 45b, the actuating portions 18a and 18b do not move at all and do not act to release the hole 8.

(Effects of the Invention) As described above, according to the present invention, the reel brake includes the brake member that is operated by the insertion member for releasing the brake and the swingable engagement claw that is engaged with the gear portion of the reel. , A double action structure that is interlocked with the brake release direction due to the movement of the brake member and is not interlocked at other times, and the movement of the engaging claw that follows the unexpected movement of the reel is directly transmitted to the operating portion. Since it is configured so that it does not move due to movement (rattle) of the reel that accompanies the play allowance, the hole is always reliably closed when the cassette is stored.

Further, in particular, by adding a tape detection mechanism to the brake release insertion member, the number of holes formed in the cassette is reduced as compared with the case where the tape detection mechanism is provided alone, and the dustproof effect is increased accordingly. And a highly reliable cassette is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic tape cassette according to an embodiment of the present invention, FIG. 2 is a perspective view of a reel brake provided in the magnetic tape cassette shown in FIG. 1, and FIG. 2 is an exploded perspective view of the reel brake shown in FIG. 2, FIG. 4 is a perspective view of a reel brake according to another embodiment of the present invention, and FIG. 5 is a perspective view showing one brake member of the reel brake of FIG. ,
FIG. 6 is a perspective view showing a reel brake according to a conventional example. 1 ... Magnetic tape cassette, 2 ... Half case, 3 ... Lower half case, 4 ... Reel shaft insertion hole, 6 ... Opening, 7a, 7b ... Mouse part, 8 ... Hole, 10 ... Support Shaft, 11a, 11b …… Lower flange, 12a, 12b …… Gear part, 13 …… Reel brake, 14 …… First support shaft, 15,42 …… First brake member, 16a, 16b, 45a, 45b ...... Rotating body, 17a, 17b, 46a, 46b …… Engagement claws, 18a, 18b …… Operating part, 20,44 …… Second brake member, 22,23,25 …… Torsion spring, 30,40 …… Insertion member, 24a, 24b, 48a, 48b …… Abutting part.

Claims (2)

[Claims] 1. A magnetic tape cassette configured to incorporate a pair of tape winding bodies around which a magnetic tape is wound, and to perform recording and reproduction by pulling the magnetic tape out of the cassette. The reel brake for preventing the rotation of the reel has one end swingably supported, and the free end urged in a direction to engage a gear portion formed on the flange portion of the tape winding body, An abutting portion for abutting the substantially middle portion of the engaging claw in the longitudinal direction to move the engaging claw in the disengaging direction from the gear portion, and an insertion member for releasing the brake inserted into the cassette through a hole in the wall surface of the case. And a pair of rotating bodies that are in contact with each other to move the contacting portions and project in the radial direction of rotation.The rotating body is urged in a direction in which the operating portions contact each other and close the hole. The operating parts are separated from each other. When the contact portion is moved in the direction, the contact portion presses the engaging claw to interlock with it in a direction away from the gear part, while the movement of the engaging claw prevents the operating portion from interlocking. A magnetic tape cassette featuring. 2. The magnetic tape cassette according to claim 1, wherein the engaging claw and the abutting portion are formed in a non-contact manner so as to have a slight gap.