JPH10241323A - Tape reel for tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the envelope characteristic and electromagnetic transduction characteristic of a tape by reducing the ruggedness on the surface of a 2nd cylinder part and suppressing transfer traces to the tape due to the surface ruggedness in the manner of integrally molding a lever flange to a hub provided with a 1st cylinder part capable of inserting to a rotary shaft and the 2nd cylinder part wound with the magnetic tape. SOLUTION: A clamp part 23 is made to a part of the outer surface 12b of the 2nd cylinder part 12, and the outer surface 24a of a hinge part 24 is made to the continuous surface having no ruggedness connected to the outer surface 12b and the outer surface 23a of clamp part 23. Consequently, the slight ruggedness is generated only at the joint part between a tip part 23c of the clamp part 23 and an end surface part 12c of the 2nd cylinder part 12, and the ruggedness around the 2nd cylinder part 12 wound round with a leader tape and the magnetic tape is almost eliminated. Then, plural projected pieces 31 are provided for positioning so that a cover is closed for the clamp part 23 by the projected pieces 31 even though the upper flange part 16 is fitted to the hub 13 at any positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape reel for a tape cassette having flanges at upper and lower ends of a hub around which a magnetic tape is wound, and more particularly to a structure of a clamp portion for fixing a leader tape to the hub. .

[0002]

2. Description of the Related Art Digital video cassettes (DVC), V
A tape reel used for a tape cassette such as an HS video tape cassette or an 8 mm VTR tape cassette is provided with a hub 101 on which a magnetic tape is wound and a lower end portion of the hub 101 as shown in FIGS. A lower flange portion 102 and an upper flange portion 103 attached to and fixed to an upper end portion of the hub 101.

The upper flange 103 has a circular hole 10 in the center.
The upper flange portion 103 is fixed to the hub 101 by rotating the upper flange portion 103 by fitting the circular hole 104 into an engaging portion 105 formed at the upper end of the hub 101. On the other hand, the lower flange portion 102 is
The magnetic tape is formed integrally with the hub 101, and the upper flange portion 103 adjusts the winding state of the magnetic tape wound around the hub 101.

The hub 101 has a transparent leader tape (not shown) connected to a magnetic tape.
Is attached. The clamp portion 106 is formed as a flat rectangular member that fits into a cutout portion 107 formed as a straight groove along the axial direction of the hub 101 and forms a part of the peripheral surface of the hub 101. ing. The clamp portion 106 fits the notch 107 to fix the leader tape pushed into the notch 107.

[0005]

However, in the tape reel having the above-mentioned structure, both side edges of the clamp 106 and the joints 108a and 108b of the notch 107 are provided.
As shown in FIG. 13, transfer marks 110 a and 110 b are generated on the magnetic tape 109 due to the unevenness. The transfer marks 110a and 110b adversely affect the recorded information recorded on the magnetic tape 109 and cause wow and flutter, thereby deteriorating the envelope characteristics and electromagnetic conversion characteristics of the magnetic tape.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tape reel for a tape cassette which can improve the envelope characteristics and electromagnetic conversion characteristics of a magnetic tape by softening a transfer mark on the magnetic tape by a clamp unit for fixing the leader tape to a hub. Is to provide.

[0007]

According to the first aspect of the present invention,
A magnetic tape is wound around a first cylindrical portion having an engaging hole into which a rotating shaft provided in a magnetic recording and / or reproducing device is inserted and engaged, and a predetermined gap is provided around an outer periphery of the first cylindrical portion. A hub having a second cylindrical portion to be mounted, a lower flange portion integrally formed at a lower end portion of the hub, and an engaging portion formed at an upper end portion of the hub, which are fixed by being fitted and rotated. A tape reel for a tape cassette, comprising: an upper flange portion having a hole in the center thereof, wherein the second cylindrical portion has an opening through which a leader tape connected to the magnetic tape is inserted into the gap. A clamp portion is formed in the axial direction of the cylindrical portion, and a clamp portion that closes the opening and becomes a part of the peripheral surface of the cylindrical portion is integrally formed with the cylindrical portion via a hinge portion, and is turned. It is free to move. By projecting piece occluding the opening by the clamp portion are input to provide a tape reel for a tape cassette, characterized in that provided at least three, in which to achieve the above object.

According to a second aspect of the present invention, in the tape reel of the first aspect, the outer surface of the hinge portion is continuous with the outer surface of the second cylindrical portion and the outer surface of the clamp portion. The above object has been achieved by providing a tape reel for a tape cassette characterized by having a continuous surface without irregularities.

According to a third aspect of the present invention, in the tape reel for a tape cassette according to the first or second aspect, the hub and the lower flange portion are made of a polyacetal resin.
The above object has been attained by providing a tape reel for a tape cassette, wherein the upper flange portion is made of a polystyrene resin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.
In this embodiment, the tape reel for a tape cassette according to the present invention is applied to a digital video cassette (DVC) which is a small cassette used for a digital video tape recorder.

FIG. 1 is a perspective view showing a state where the tape cassette is viewed from the front side, FIG. 2 is a perspective view showing a state where the tape cassette is viewed from the back side, and FIG. 3 is a state where the upper half of the tape cassette is removed. 4 is a sectional view of the tape cassette, FIG. 5 is an exploded perspective view of the tape reel, FIG. 6 is an exploded sectional view of the tape reel, FIG. 7 is a sectional view of the tape reel, and FIG. It is a top view which shows a series of process of fixing sequentially.

As shown in FIGS. 1 to 4, the digital video cassette has a pair of tape reels 4 and 4 rotatably housed in a cassette body 3 composed of an upper half 1 and a lower half 2. At the front end of the cassette body 3, a lid including a front lid 5, an upper lid 6, and a back lid 7 is rotatably attached.

As shown in FIGS. 1 to 4, the cassette body 3 is formed by combining a flat rectangular upper half 1 and a lower half 2, and a pair of magnetic tapes are wound inside the upper half 1 and the lower half 2. The tape reels 4 and 4 are rotatably stored. At the front end of the cassette body 3, there is formed an opening recess 8 through which a rotating head of a recording and / or reproducing apparatus (hereinafter, referred to as a drive) not shown faces.
The magnetic tape wound around the tape reels 4, 4 runs along the front end of the cassette main body 3 in the opening concave portion 8.

As shown in FIGS. 1 and 2, the front lid 5 is provided so as to cover the recording surface side of the magnetic tape running on the front surface of the cassette body 3, and both sides of the front lid 8 are provided. It is attached to the cassette body 3 rotatably about a support shaft 9 provided on the plate. And
The front lid 5 is formed by an elastic member such as a torsion coil spring (not shown) hung on the support shaft 9.
The cassette body 3 is constantly urged to be closed so as to cover the front end thereof.

As shown in FIGS. 1 and 2, the upper lid 6 is provided so as to cover the upper surface of the front end of the cassette body 3, and is connected to the front lid 5 so as to be connected to the front lid 5. And relatively rotate. That is, the upper lid 6 rotatably engages a connection shaft (not shown) projecting rearward on the inner surface of both side plates with the front lid 5 and protrudes forward on the inner surface of the both side plates. A guide groove 1 having a projection provided on a side surface 3a of the cassette body 3.
The front lid 5 can be relatively rotated by interlocking with the opening and closing operation of the front lid 5 by engaging with 0 and 10 so as to be slidable.

As shown in FIG. 2, the back lid 7 is provided so as to cover the back side of the magnetic tape running on the front surface of the cassette body 3, and is connected to the upper lid 6 to It is configured to rotate relative to the lid 6. When the front lid 5 and the upper lid 6 are in a closed state, the back lid 7 sandwiches the magnetic tape with a predetermined gap between the front lid 5 and the front lid 5 so that dust or the like adheres to the magnetic tape. Is made not to occur.

As shown in FIGS. 5 to 7, the tape reels 4 and 4 have a first cylindrical portion 11 having an engaging hole 18 into which a rotary shaft provided in a drive is inserted and engaged, and the first cylindrical portion 11 and the first cylindrical portion 11.
A hub 13 having a second cylindrical portion 12 around which a magnetic tape is wound with a predetermined gap around the outer periphery of the cylindrical portion 11, and a lower flange portion 1 integrally formed at a lower end portion of the hub 13
4 and an engaging portion 17 formed at the upper end of the hub 13 and fixed by rotating the fitting.
5 is formed.

As shown in FIGS. 5 and 6, the first cylindrical portion 11 is formed as a cylindrical body having an engagement hole 18 below which a drive shaft is inserted and engaged. On the inner peripheral surface of the engagement hole 18, a ridge 19 for engaging with the rotation shaft of the drive and rotating the tape reels 4, 4 reliably is provided at predetermined intervals along the axial direction. Are formed. Further, an engagement portion 17 for fixing the upper flange portion 16 is provided at an upper end portion of the first cylindrical portion 11.

The engaging portion 17 is formed as a circular projection having a diameter smaller than the diameter of the first cylindrical portion 11, and at least three projections are formed at a predetermined interval on the outer peripheral surface on the tip side.
It has two projections 20. The projecting portion 20 is formed as a projection having an arc-shaped tip so as to project outward from the outer peripheral surface of the engaging portion 17. The protrusions 20 are not formed over the entire height of the engaging portion 17 but are formed only on the outer peripheral surface on the distal end side of the engaging portion 17.

As shown in FIGS. 5 and 6, the second cylindrical portion 12 has a predetermined gap 2 around the outer periphery of the first cylindrical portion 11.
2 so as to surround the first cylindrical portion 11. An opening 21 for inserting a leader tape into the gap 22 is formed in the second cylindrical portion 12. The opening 21 is formed in a part of the second cylindrical portion 12 as a slit groove along the axial direction.

Further, the second cylindrical portion 12 is provided with a clamp portion 23 which closes the opening 21 and becomes a part of the peripheral surface of the second cylindrical portion 12. Such a clamp part 2
3 is formed integrally with the second cylindrical portion 12 through a hinge portion 24 which is a thin portion remaining by forming a straight groove in the inner surface 12a of the second cylindrical portion 12 along the axial direction. The hinge 24 is rotatable about the fulcrum.

The clamp portion 23 is provided on the second cylindrical portion 12.
Is formed as a rectangular piece having the same curvature as the curvature of the outer peripheral surface 12b of the second cylindrical portion 12 and becomes a part of the peripheral surface of the second cylindrical portion 12 when the opening 21 is closed.
Also, the outer surface 24a of the hinge portion 24 is the outer surface 12b of the second cylindrical portion 12 and the outer surface 23 of the clamp portion 23.
It has a continuous surface without irregularities continuous with a. Therefore, in a state where the opening 21 is closed by the clamp portion 23, only a slight unevenness occurs only at the edge portion of the opening 21 and the second cylinder around which the leader tape and the magnetic tape are wound. Almost no irregularities occur on the peripheral surface of the portion 12.

Further, the tip 23c of the clamp portion 23
Is a tapered surface like the end surface portion 12c of the second cylindrical portion 12. The distal end portion 23c of the clamp portion 23 and the end surface portion 12c of the second cylindrical portion 12 have their tapered surfaces fitted to each other. As described above, if the tapered surfaces are fitted to each other, the level difference between the joint portions becomes small.

As shown in FIG. 5, the lower flange portion 14 is formed in a disk shape and is formed integrally with the hub 13. On the outer periphery of the lower flange portion 14,
As shown in FIG. 3, an engaged portion 27 that engages with a lock claw 26 of a slidable reel lock member 25 is formed in the cassette body 3. The engaged portion 27 has a plurality of uneven portions formed on the entire outer periphery of the lower flange portion 14.

On the other hand, as shown in FIG. 5, the upper flange portion 16 is formed in a disk shape having substantially the same diameter as the lower flange portion 14. A hole 15 is formed at the center of the upper flange 16 for inserting and engaging an engaging portion 17 formed at the upper end of the first cylindrical portion 11. The hole 15 has a cut-out portion 28 facing at least three protrusions 20 formed in the engagement portion 17, a receiving portion 29 for supporting and fixing the protrusion 20 from below, and a contact with the protrusion 20. In addition, a positioning protrusion 30 for determining a fixing position of the upper flange portion 16 to the hub 13 is formed. In addition, on the upper surface of the receiving portion 29,
A recess for fitting the protrusion 20 is formed.

After the projections 20 of the engaging portion 17 face the notches 28, respectively, the upper flange portion 16 is brought into contact with the positioning projections 30 until the projections 20 come into contact with the positioning projections 30. By rotating in the inward direction, each projection 20 rides on the corresponding receiving portion 29 and is supported and fixed from below, thereby being fixed to the upper end of the hub 13.

As shown in FIGS. 5 to 7, when the upper flange 16 is rotated and fixed to the upper end of the hub 13 as shown in FIGS.
2, at least three protruding pieces 31 are provided to press the clamp portion 23 toward the opening 21 side and close the opening 21 with the clamp portion 23.

Each of the projections 31 has a tongue shape that hangs downward, and has a position where each projection 20 faces each cutout 28 and does not contact the clamp 23 in the state shown in FIG. 8B. The projections 20 are provided on the upper flange 16 such that the projections 20 are in contact with the clamps 23 in the state shown in FIG. Further, these protruding pieces 31 are connected to the upper flange portion 16.
When the is rotated, it slides on the inner surface 12a of the second cylindrical portion 12 and presses against the inner surface 12a.

In the tape reels 4 and 4 configured as described above, the leader tape is fixed to the hub 13 as follows. First, as shown in FIG. 8A, the base end of the leader tape 32 is inserted into the gap 22 through the opening 21. Next, as shown in FIG.
Each of the protrusions 20 formed at the upper end of the first cylindrical portion 11 faces each of the cutouts 28 formed in the upper flange portion 16, and each of the protrusions 31 is inserted into the gap 22. The part 16 is rotated.

Then, each of the projections 20 is connected to each of the receiving portions 2.
9 and comes into contact with the positioning projection 30 to receive the receiving portion 2.
Nine recesses. At the same time, as shown in FIG. 8 (c), the projection 31 inserted into the gap 22 slides against the inner surface 12a of the second cylindrical portion 12, and the clamp portion 23 as shown in FIG.
Is pressed toward the opening 21, and the opening 21 is finally closed by the clamp 23.

As a result, the tip portion 23c of the clamp portion 23
And the end surface portion 12c of the second cylindrical portion 12 are fitted, and the leader tape 32 is sandwiched and fixed between them.
Further, since each projection 20 contacts each positioning projection 30 and fits into the recess of the receiving portion 29, the upper flange 16
Is fixed to the upper end of the hub 13.

The hub 13 and the lower flange portion 14 are made of polyacetal resin such as polyoxymethylene (POM), polypropylene (PP), polyethylene (PE), and especially, A polyacetal resin is desirable, and the upper flange portion 16 is desirably a polystyrene resin, particularly an acrylonitrile styrene resin (AS), in that the upper flange portion 16 has transparency so that the tape winding state can be easily viewed from the outside.

The tape reels 4, 4 constructed as described above
According to this, the clamp portion 23 becomes a part of the outer surface 12 b of the second cylindrical portion 12, and the outer surface 24 a of the hinge portion 24 becomes the outer surface 12 b of the second cylindrical portion 12 and the outer surface 12 b of the clamp portion 23. Since it is a continuous surface having no irregularities continuous with the surface 23a, the tip portion 23c of the clamp portion 23 is
Only a slight unevenness occurs only at the joint between the cylindrical portion 12 and the end surface portion 12c, and almost no unevenness occurs on the peripheral surface of the second cylindrical portion 12 around which the leader tape 32 and the magnetic tape are wound. Therefore, the tape reels 4, 4
The leader tape 32 and the magnetic tape wound around
The occurrence of transfer marks due to the unevenness at the joints is reduced. As a result, the generation of wow and flutter is suppressed, so that the envelope characteristics can be improved, and the electromagnetic conversion characteristics of the magnetic tape can be improved.

The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the gist of the present invention. In the above-described embodiment, the projecting piece 31 is provided so that the clamp portion 23 can be closed by the projecting piece 31 regardless of the position at which the upper flange portion 16 is fitted to the hub 13.
Are provided at predetermined positions, but some alignment is required, but four or more protruding pieces 31 may be provided.

In the above embodiment, the tape reel according to the present invention is applied to a digital video cassette.
The same effect can be obtained even when applied to a tape cassette such as a VHS video tape cassette or an 8 mm VTR tape cassette.

[0036]

As is apparent from the above description, according to the tape reel for a tape cassette of the present invention, the transfer mark on the magnetic tape by the clamp portion for fixing the leader tape to the hub is reduced, and The present invention can provide a tape reel for a tape cassette in which the envelope characteristics and the electromagnetic conversion characteristics of the tape cassette can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a state in which a tape cassette according to an embodiment is viewed from a front surface side.

FIG. 2 is a perspective view showing a state in which the tape cassette of the present embodiment is viewed from the back side.

FIG. 3 is a plan view showing a state where an upper half of the tape cassette according to the embodiment is removed.

FIG. 4 is a sectional view of the tape cassette of the embodiment.

FIG. 5 is an exploded perspective view of a tape reel in the tape cassette according to the embodiment.

FIG. 6 is an exploded sectional view of a tape reel in the tape cassette according to the embodiment.

FIG. 7 is a sectional view of a tape reel in the tape cassette of the embodiment.

FIG. 8 is a plan view sequentially showing a series of steps for fixing the leader tape to the hub in the tape cassette of the present embodiment.

FIG. 9 is an exploded perspective view of a conventional tape reel.

FIG. 10 is an exploded sectional view of a conventional tape reel.

FIG. 11 is a sectional view of a conventional tape reel.

FIG. 12 is a plan view of a conventional tape reel.

FIG. 13 is a plan view of a conventional magnetic tape showing a state where transfer marks are formed on a magnetic tape wound on a tape reel.

[Explanation of symbols]

 4 Tape Reel 11 First Cylindrical Part 12 Second Cylindrical Part 13 Hub 14 Lower Flange Part 16 Upper Flange Part 21 Opening 22 Gap 23 Clamping Part 24 Hinge Part

Claims (3)

[Claims] 1. A first cylindrical portion having an engaging hole into which a rotating shaft provided in a magnetic recording and / or reproducing device is inserted and engaged, and a predetermined gap is provided around the outer periphery of the first cylindrical portion. A hub provided with a second cylindrical portion around which the magnetic tape is wound, a lower flange portion integrally formed at a lower end portion of the hub, and an engagement portion formed at an upper end portion of the hub. A tape reel for a tape cassette, comprising: an upper flange portion having a hole in the center, the tape reel being fixed by being rotated, wherein the second cylindrical portion has a leader connected to the magnetic tape in the gap. An opening through which the tape is inserted is formed in the axial direction of the cylindrical portion, and a clamp portion that closes the opening and becomes a part of the peripheral surface of the cylindrical portion is integrated with the cylindrical portion via a hinge portion. Formed on the upper flange part. Tape cassette tape reel, characterized in that projecting piece occluding the opening is provided at least three by the clamping portion is inserted into the gap. 2. The tape according to claim 1, wherein the outer surface of the hinge portion is a continuous surface having no irregularities continuous with the outer surface of the second cylindrical portion and the outer surface of the clamp portion. Tape reel for cassette. 3. The tape reel for a tape cassette according to claim 1, wherein the hub and the lower flange are made of a polyacetal resin, and the upper flange is made of a polystyrene resin.