JPH0997487A - Tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the transfer of the difference in level between a hub and a clamping member to a tape by providing a tape cassette with a structure to wind a leader tape on the hub of a reel and to adhere a part of a tape with an adhesive tape. SOLUTION: The leader tape 6 is formed to have a length greatly extended from the length of the conventional leader tape. The leader tape 6 is wound 6 and 7 times around the outer peripheral surface of the hub 4A to be in the state of allowing a specific length to remain. A part of the leader tape 6 wound around the hub 4A is adhered in this state with the adhesive tape 20 in the position approximately corresponding to the clamping member 8. As an example, the tape made of polyethylene terephthalate (PET) having a thickness approximately equal to the thickness of the leader tape 6 is used as a base and both surfaces thereof are coated with a tacky adhesive to form adhesive surface. The transfer of the difference in level between the hub 4A and the clamping member 8 to the tape is prevented by the tape cassette in which the leader tape 6 is wound 6 to 7 times on the hub 4A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette used for recording and reproducing, and more particularly to a structure of a portion for fixing an end portion of a tape to a reel hub.

[0002]

2. Description of the Related Art First, a conventional example will be described with reference to FIGS.

As shown in FIG. 1, inside a cassette housing 1 of a tape cassette, a pair of reels 4 and 4 are inserted into left and right reel drive shaft insertion holes 3 and 3 formed in a lower shell 2.
Is rotatably housed, and a magnetic tape 5 having a surface coated with a magnetic material as a recording medium is wound around the reels 4 and 4. In addition, the cassette housing 1 is a lower shell 2,
Although the upper shell which covers the lower shell 2 is combined, the upper shell is not shown in the drawings of this example.

The reel 4 comprises a central hub 4A around which the magnetic tape 5 is wound, a lower flange 4B integrally formed with the hub 4A, and an upper flange 4C fixed to the hub 4A by welding or the like. Become.

A leader tape 6 not coated with a magnetic material is connected to both ends of the magnetic tape 5 by a splicing tape 7, and the end of the leader tape 6 is a hub 4A of the reel 4. Is fastened to.

The end portion of the leader tape 6 is fixed to the hub 4A of the reel 4 by the clamp member 8. That is, as shown in FIG. 3, the hub 4A of the reel 4 is provided with a fitting recess 9 into which the clamp member 8 fits, and the leader tape is provided between the fitting recess 9 and the clamp member 8. The leader tape 6 is fixed to the hub 4 </ b> A of the reel 4 by fitting the clamp member 8 into the fitting concave portion 9 with the end portion of 6 being sandwiched.

[0007]

DISCLOSURE OF THE INVENTION In this part,
Although the outer peripheral surface of the hub 4A and the outer peripheral surface of the clamp member 8 are designed so as to form the same circumferential surface, in reality, due to dimensional error due to resin shrinkage after molding, the hub as shown in FIG. A slight difference (about 20 to 30 μm) between the outer peripheral surface of 4A and the outer peripheral surface of the clamp member 8 causes a step a.

Therefore, when the magnetic tape 5 is wound around the outer peripheral surface of the hub 4A, the step a is transferred to the magnetic tape 5, that is, the magnetic tape 5 is deformed at the portion corresponding to the step a, and this is changed. The transfer mark 10 called "sleeping" remains. When the transfer mark 10 is present on the magnetic tape 5 as described above, a dropout is likely to occur in the recording / reproducing signal at that portion, which adversely affects the sound quality and the image quality.

The present invention has been made in view of the above points,
An object of the present invention is to provide a tape cassette having a structure capable of effectively suppressing transfer to a magnetic tape due to a step between a hub and a clamp member.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a cassette housing in which a reel for winding a magnetic tape is rotatably accommodated, and a leader is provided at an end of the magnetic tape. In a tape cassette having a structure in which a tape is connected and an end of the leader tape is fixed to a hub of a reel by a clamp member, the leader tape is wound around the reel hub a plurality of times and the leader tape is wound around the hub. A part of is bonded by an adhesive tape at a position substantially corresponding to the clamp member.

In the tape cassette of the present invention thus constructed, even if there is a step between the hub and the clamp member, the influence of the step is mitigated by the leader tape wound around the hub a plurality of times. As a result, the magnetic tape hardly has a transfer mark due to a step. Moreover, in the present invention, since the adhesive tape for adhering the leader tape is at a position substantially corresponding to the clamp member, the influence of the step is further alleviated.
The transfer of the step shape to the magnetic tape is more reliably prevented.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The basic component structure of the tape cassette according to the present invention is the same as that of the conventional example shown in FIGS.

That is, as shown in FIG. 1, inside the cassette housing 1 of the tape cassette, a pair of reels 4 corresponding to the left and right reel drive shaft insertion holes 3 and 3 formed in the lower shell 2. 4 is rotatably stored, and this reel 4,
A magnetic tape 5 as a recording medium is wound around 4.

The reel 4 is composed of a central hub 4A around which the magnetic tape 5 is wound, a lower flange 4B integrally formed with the hub 4A, and an upper flange 4C fixed to the hub 4A by welding or caulking. Become.

A leader tape 6 not coated with a magnetic material is connected to the end of the magnetic tape 5 by a splicing tape 7, and the end of the leader tape 6 is fixed to the hub 4A of the reel 4. There is.

The end portion of the leader tape 6 is fixed to the hub 4A of the reel 4 by the clamp member 8. That is, the hub 4A of the reel 4 is provided with a fitting concave portion 9 into which the clamp member 8 is fitted, and the end of the leader tape 6 is clamped between the fitting concave portion 9 and the clamp member 8. The leader tape 6 is fixed to the hub 4A of the reel 4 by fitting the member 8 into the fitting recess 9.

In general, the hub 4A and the clamp member 8 of the reel 4 are made of POM (polyoxymethylene), and the leader tape 6 is made of PET (polyethylene terephthalate) having a thickness of about 10 μm.

In the tape cassette having such a structure, when the fitting portion of the clamp member 8 to the hub 4A is enlarged, as shown in FIG. 4, the outer peripheral surface of the hub 4A and the outer peripheral surface of the clamp member 8 are separated. Although there is a step a of about 20 to 30 μm between them, the tape cassette according to the present invention employs a structure as shown in FIG. 5 in order to prevent transfer to the magnetic tape 5 due to this step a.

That is, in the present example, first, the leader tape 6 has a length greatly extended as compared with the conventional one. Then, the leader tape 6 is attached to the outer peripheral surface of the hub 4A by 6 to 7
A part of the leader tape 6 wound around the hub 4A is adhered by an adhesive tape 20 at a position substantially corresponding to the clamp member 8 while being wound and leaving a predetermined length.

FIG. 6 is an enlarged view of an adhesive portion of the leader tape 6 by the adhesive tape 20. The adhesive tape 20 used here is a so-called double-sided adhesive tape in which a PET tape having a thickness similar to that of the leader tape 6 is used as a base, and an adhesive surface is formed by applying an adhesive on both sides thereof.

FIG. 7 shows another example of the adhesive tape 20. The adhesive tape 20 shown here is a so-called single-sided adhesive tape having an adhesive surface only on one side, and is used by bending it.

The leader tape 6 can be surely adhered to any of the adhesive tapes 20 shown in FIGS. 6 and 7, but the double-sided adhesive tape shown in FIG. 6 has an advantage that the adhering work is simple. On the other hand, the single-sided adhesive tape of FIG. 7 has the advantages that it is cheaper than the double-sided adhesive tape and that the adhesive strength against the tensile force of the leader tape is high.

In the above structure, the length (distance) L from the bonding position of the leader tape 6 by the adhesive tape 20 to the connecting portion between the magnetic tape 5 and the leader tape 6 is about 6
5 mm. This satisfies the effective length of the leader tape defined in the standard of the tape cassette of this example.

In the tape cassette of this embodiment constructed as described above, since the leader tape 6 is wound around the hub 4A 6 to 7 times, even if there is a step between the hub 4A and the clamp member 8, The influence of this step is mitigated by the leader tape 6 and hardly reaches the magnetic tape 5.

That is, when the leader tape 6 having a thickness of 10 μm is wound 6 to 7 times, it becomes a layer having a thickness of 60 to 70 μm in total, and PET, which is the material of the leader tape 6, is a relatively flexible material. Since the step shape between the hub 4A and the clamp member 8 is absorbed in the winding layer of the leader tape 6, the magnetic tape 5 wound on the leader tape 6 may not have a transfer mark due to the step. Almost never.

Further, in this example, the leader tape 6
Since the adhesive tape 20 that adheres to the magnetic tape 5 is at a position substantially corresponding to the clamp member 8, the transfer of the stepped shape to the magnetic tape 5 is more reliably prevented.

That is, generally, the step between the hub 4A and the clamp member 8 is formed such that the outer peripheral surface of the clamp member 8 is retracted from the outer peripheral surface of the hub 4A, and therefore the clamp member 8 is formed.
By arranging the adhesive tape 20 at a position substantially corresponding to, the thickness of the adhesive tape 20 acts so as to make up the step between the hub 4A and the clamp member 8. Therefore, the influence of the step between the hub 4A and the clamp member 8 on the magnetic tape 5 can be alleviated more effectively, so that the step shape is almost completely prevented from being transferred to the magnetic tape 5. it can.

The inventors of the present invention actually manufactured a tape cassette of this structure as a prototype and conducted a tape winding test. As a result, it was confirmed that the magnetic tape 5 had almost no transfer marks of steps.

[0029]

As described above, according to the present invention, the reel around which the magnetic tape is wound is rotatably housed inside the cassette housing, and the leader tape is connected to the end of the magnetic tape. In a tape cassette having a structure in which the end portion of the tape is fixed to the hub of the reel by a clamp member, the leader tape is wound a plurality of times around the hub of the reel, and a part of the leader tape wound around the hub is substantially attached to the clamp member. Even if there is a step between the hub and the clamp member, it is possible to effectively prevent the step from being transferred to the magnetic tape by having a structure in which the tape is adhered at the corresponding position. By preventing the transfer of the step to the magnetic tape in this way, the dropout of the recording / reproducing signal due to the transfer is eliminated, and the sound quality and the image quality are improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a main part of a tape cassette.

FIG. 2 is a perspective view of a reel showing a conventional example.

FIG. 3 is a plan view of the same.

FIG. 4 is an enlarged view of a fitting portion of the clamp member with respect to the hub.

FIG. 5 is a plan view of a reel showing an example.

FIG. 6 is an enlarged view of an adhesive portion of a leader tape with an adhesive tape.

FIG. 7 is an enlarged view of another example of the same.

[Explanation of symbols]

 1 cassette housing 4 reel 4A hub 5 magnetic tape 6 leader tape 8 clamp member 20 adhesive tape a step

Claims (3)

[Claims] 1. A reel for winding a magnetic tape is rotatably housed inside a cassette housing, a leader tape is connected to an end of the magnetic tape, and an end of the leader tape is attached to the reel. In a tape cassette having a structure in which a hub is fixed by a clamp member, the leader tape is wound around the hub of the reel a plurality of times, and a part of the leader tape wound around the hub is placed at a position substantially corresponding to the clamp member. A tape cassette, characterized in that it has a structure adhered by an adhesive tape. 2. The tape cassette according to claim 1, wherein the adhesive tape is a double-sided adhesive tape having both surfaces as adhesive surfaces. 3. The tape cassette according to claim 1, wherein the adhesive tape is used by bending a single-sided adhesive tape having one surface thereof as an adhesive surface.