JPH05314711A - Magnetic tape cassette - Google Patents

Abstract

PURPOSE:To provide a magnetic tape cassette capable of surely preventing the generation of irregularity and surface level difference of the tape by controlling the height of tape even at the time of fast forwarding and unwinding of the tape, is the same way as at the time of carrying and transporting when external forces such as a shock, etc., are easily to be exerted. CONSTITUTION:The subject cassette is provided with plural kinds of energizing means 5 arranged in opposite to an upper edge of the magnetic tape T wound around a reel hub 3 to energize the upper edge pressing downward and a releasing means 5a to release the energizing force pressing downward of at least one energizing means among these energizing means. When the cassette is unloaded in a recording/reproducing device, a strong pressing force is exerted on the upper edge of the wound magnetic tape by the energizing means, and on the other hand, the strong pressing force is released with the operation of the releasing means by a releasing member provided the device side when the cassette is loaded the recording/reproducing device. By this procedure, the constitution is made in such a manner that a weak energizing force in the degree not obstructing the rotation of reel hub is exerted on the upper edge of a magnetic tape winding body (Tc).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette having a reel hub, and particularly to urging a tape winding body (reel hub) with a weak pressing force when it is mounted on the main body of the device and with a strong pressing force when it is not mounted. The present invention relates to a magnetic tape cassette provided with a means for doing so.

[0002]

2. Description of the Related Art A magnetic tape cassette (hereinafter also simply referred to as "tape cassette" or "cassette") used in a magnetic recording / reproducing apparatus accommodates a reel hub around which a magnetic tape is wound. As this reel hub, it faces the upper and lower edges of the wound magnetic tape,
Of the reel hub with the upper and lower flanges having the lower flange, the reel hub with the lower flange having only the lower flange, and the flangeless reel hub without the upper and lower flanges,
There are 3 types.

[0003]

In any tape cassette containing a reel hub of any of the above types, the tape cassette is mounted in a recording / reproducing device for fast-forwarding or rewinding, or when the cassette is not mounted (transportation, transportation, When an external force is applied to the tape during transportation, uneven winding (unevenness) occurs on the magnetic tape wound around the reel hub, and a step is easily formed.
In addition, in tape cassettes that use a flangeless reel hub or a reel hub with a lower flange, countless fine protrusions are used to reduce the dynamic friction that occurs between the upper and lower edges of the magnetic tape and the inner wall of the cassette housing during reel rotation. Some sliding sheets have a formed surface with high surface smoothness and try to reduce such uneven spots as much as possible, but to prevent such uneven spots and to correct the uneven spots. Was not possible. Therefore, when a tape cassette having such a winding spot is mounted on a recording / reproducing apparatus and is run, the tape tension fluctuates, which causes deterioration of image quality and sound quality.

[0004]

A magnetic tape cassette according to the present invention is arranged so as to face the upper edge of a magnetic tape wound around a reel hub, and urges a plurality of types to urge the upper edge downward. Means and at least one of these biasing means
And a releasing means for releasing the downward biasing force of the two biasing means, and when the cassette is not attached to the recording / reproducing apparatus,
A strong pressing force is applied to the upper end edge of the wound magnetic tape by an urging device, while the releasing member provided on the device operates the releasing device to attach a strong pressing force to the recording / reproducing device. The above problem is solved by, for example, canceling the above and applying a weak biasing force to the upper end edge of the magnetic tape that does not hinder the rotation of the reel hub, so that winding irregularity does not occur in the tape at any time and any time. I did it.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the magnetic tape cassette of the present invention will be described with reference to FIG. FIG. 1 is a top view of a magnetic tape cassette 10 of the present invention. In this figure, 1 is a cassette housing, 1d is a front cover, 16 is a cassette mouse (opening), 3 and 4 are supply reel hubs and take-up reel hubs for winding tapes, 5 is a pressing member, and 8 is a spring (spring). Members), 14 are sliding sheets, 15a to 15d are positioning holes, and T is a magnetic tape wound around both reel hubs 3 and 4. The portion of the magnetic tape wound around the reel hub 3 or 4 will be referred to as "tape winding body Tc".

When the tape cassette 10 having such a structure is pushed in from the cassette insertion port of the recording / reproducing apparatus, the cassette transfer mechanism automatically operates to carry it to the mounting position, and the front cover 1d is rotated upward by the rotating mechanism. , Positioning holes 15a ~
Mount correctly with 15d etc. A magnetic tape T is stretched inside the front lid 1d, and the magnetic tape T is pulled out of the cassette 10 by two tape pulling arms that relatively enter into the opening 16 when the cassette is mounted. The recording and reproducing of the video signal and the like are performed by the rotary head which is wound diagonally over a predetermined angle range and is provided at a predetermined position on the side surface of the rotary drum.

FIG. 2 is an enlarged plan view showing a reel hub 3 (4) which is an essential part of the cassette 10 of the present invention, and FIGS. 3 (A) and 3 (B).
2 is a cross-sectional view of the reel hub 3 taken along line XX in FIG. 2, which is shown together with the cassette housing 1 (upper half 1a and lower half 1b). Note that FIG. 3B shows a state in which the recording / reproducing apparatus is mounted, and FIG. 3A shows a state immediately before being mounted in the recording / reproducing apparatus. Will be called "when not installed"}
In these figures, 1c is a boss integrally formed in a predetermined portion of the upper half 1a in a substantially fan shape, and 5 is a pressing member (first attachment) for pressing the upper end edge of the tape winding body Tc. Urging member), 7 is a reel disk for rotation drive provided on the recording / reproducing apparatus side, 8 is a ridge member (biasing means; hereinafter also simply referred to as "ridge"), 14a is an upper sliding sheet,
14c is a ridge (second biasing member) radially formed around the reel hub 3 on a part of the upper sliding sheet 14a.
In the illustrated example, three ridges 14c are formed, but if they are formed evenly from the innermost circumference to the outermost circumference of the tape winding body Tc, the number and size of the ridges 14c are large. It is not limited to this.

As is apparent from FIGS. 3 (A) and 3 (B), the reel hub 3 of the cassette 10 of the first embodiment has an engaging hole (opening the lower surface for engaging the reel disk 7 of the recording / reproducing apparatus). A reel hole) 3a is formed. The protrusion 14c of the sliding sheet 14a urges the upper end edge of the tape winding body Tc downward with a relatively weak elastic force. Further, the pressing member 5 placed on the reel hub 3 urges the upper end edge of the tape winding body Tc downward with a required elastic force by the spring 8 fixed to the upper half 1a. The pressing member 5 includes
Hole 5b formed in a fan shape at a position deviated from the central portion
Is provided, and the rotation is stopped by fitting the boss 1c into the hole 5b.

The state shown in FIG. 3 (A) (including when not attached)
In this case, since the protrusion 14c and the pressing member 5 strongly press and urge the tape winding body Tc downward by the urging force of the ridge 8, the slack of the tape T is suppressed and the tape winding is performed. Since the upper edge of the body Tc does not shift and does not cause a step, winding unevenness does not occur and the body can be carried with confidence.

Next, as shown in FIG.
As shown in (B), as the protrusion (pivot portion) 7a formed at the tip of the rotation shaft of the reel disk 7 pushes up the convex portion 5a provided at the substantially center of the pressing member 5, The pressing member 5 moves upward against the pressing force of the spring 8. As a result, the pressing member 5 deviates from the upper edge (and the reel hub 3) of the tape winding body Tc, and the lower sliding sheet 14b and the upper sliding portion are in contact with the upper edge of the tape winding body Tc. Only the protruding portion 14c of the seat 14a is provided.

By the way, since the pressing biasing force of the protrusion 14c is considerably weak as described above, the rotational force of the reel disk 7 is hardly disturbed and the reel hub 3 (and the tape winding body Tc) rotates sufficiently smoothly. .. Moreover, this ridge 14
Since c is in contact with the upper edge of the magnetic tape T even when the magnetic tape T is fast-forwarded or rewound, the tape height can be properly regulated, and uneven winding can be reliably prevented. Although the supply reel hub 3 has been described above, the same applies to the take-up reel hub 4, and detailed description thereof will be omitted.

Next, a second embodiment of the tape cassette of the present invention will be described with reference to FIGS. 4 (A) and 4 (B). Figure 4 (A),
3B is an enlarged partial cross-sectional view showing a state when the cassette 11 is not mounted and a state where the cassette 11 is mounted, and FIG.
The same components as those of the first embodiment cassette 10 shown in (A) and (B) are designated by the same reference numerals, and detailed description thereof will be omitted.
The main difference between this cassette 11 and the cassette 10 is that a reel hub 3 having a lower flange 3c is used and a magnetic tape T is wound around it. Therefore, the lower sliding sheet 14b is unnecessary. Further, when mounted on the apparatus, not only the pressing member 5 is separated from the tape winding body Tc by pushing up the convex portion 5a but also separated from the lower half 1b of the lower flange 3c. The load is very small. This is shown in Figure 4.
As shown in (A) and (B), the reel disk 7 is provided with a reel base 7b on the periphery thereof, and when the cassette 11 is mounted, the reel hub bottom surface 3b of the reel hub 3 is a circumferential portion of the reel base 7b. This is because the upper surface 7c lifts a little as shown in FIG. 4 (B).

As described above, also in the tape cassette accommodating the reel hub with the lower flange, as shown in FIGS. 4A and 4B, when the tape winding body Tc is not attached, as in the first embodiment. The upper edge of the pressing member 5 and the upper sliding sheet
Since the ridge 14c of 14a strongly presses downward,
The slack of the magnetic tape T is suppressed and winding unevenness does not occur. Further, since the pressing by the pressing member 5 is released at the time of mounting, the upper end edge of the tape winding body Tc is urged by the weak pressing force of only the protruding portion 14c, and the winding spot is generated without hindering the rotation of the reel. Is to prevent.

Next, a third embodiment of the tape cassette of the present invention will be described with reference to FIGS. 5, 6 (A) and 6 (B). FIG. 5 is an enlarged plan view of a reel hub 3 with an upper and lower movable type upper flange 6, which is a main part of the third embodiment cassette 12.
(A) and (B) are enlarged partial sectional views of the reel hub 3 taken along the line YY in FIG. 5, showing the upper half 1a and the lower half 1b of the cassette.
It shows with. 6B shows a state in which the recording / reproducing apparatus is mounted, and FIG. 6A shows a state immediately before mounting in the recording / reproducing apparatus (when not mounted).
Also in the above, the same components as those of the first and second embodiment cassettes 10 and 11 shown in FIGS.
Detailed description thereof will be omitted.

The main feature of the tape cassette 12 is that the reel hub 3 is provided with a vertically movable upper flange (hereinafter simply referred to as "upper flange") 6, and between the upper flange 6 and the tape winding body Tc. The sliding sheet 14a having a plurality of ridges 14c is sandwiched. Further, a projection (pivot portion) 6a is integrally formed at the center of the upper side of the upper flange 6, and the projection (pivot portion) 6a is formed by the tip portion 9a of the plate-shaped spring 9 attached to the upper half 1a.
Is urged downward.

When the tape cassette 12 is not attached, the state shown in FIG.
As shown in (A), the upper flange 6 is urged downward by the pressing force of the spring 9, and the protrusion 14c of the sliding sheet 14a moves the tape winding body Tc through the upper flange 6. Since the magnetic tape T is strongly pressed downward, slack of the magnetic tape T is surely suppressed, and uneven winding and steps are prevented.

Further, when the recording / reproducing apparatus is mounted, the configuration shown in FIG.
As shown in (B), the upper flange 6 is attached to the reel disc 7
Since it is pushed up against the pressing force of the spring 9 by the upper surface of the sliding sheet 14 attached to the lower surface of the upper flange 6,
a also rises, and the urging force of the protrusion 14c against the tape winding body Tc is weakened sufficiently, so that the tape winding body T
c can rotate smoothly together with the reel hub 3, and prevents uneven winding of the magnetic tape T and occurrence of steps.

Finally, a fourth embodiment of the tape cassette of the present invention will be described with reference to the enlarged sectional views of the main part of FIGS. 7 (A) and 7 (B). 7 (A) and 7 (B) show states when the recording / reproducing apparatus is not mounted and when it is mounted, respectively. This tape cassette 13 is the first embodiment cassette 10 shown in FIGS.
The main feature is that a reel lock mechanism that prevents rotation of the reel hub 3 when not mounted is provided. The reel lock mechanism is integrally formed with the reel gear portion 3d formed on the bottom surface of the annular groove portion 3c provided around the reel hub 3 and a plurality of pressing members 5 facing the annular groove portion 3c at substantially equal intervals. The reel gear portion 3d includes a gear portion 5c that can be engaged (engaged) with the reel gear portion 3d, and a spring 8 that biases the pressing member 5 toward the reel hub 3 side.

When the tape cassette 13 is attached to the recording / reproducing apparatus, as shown in FIG.
As the projection 7a at the tip of the rotating shaft pushes up the convex portion 5a on the pressing member 5 side, the pressing member 5 moves upward against the pressing biasing force of the spring 8. As a result, the meshing of both gear parts 5c and 3d is released to release the reel lock, and as described in the first embodiment, the pressing member 5 is separated from the upper end edge of the tape winding body Tc (and the reel hub 3). However, only the protrusion 14c of the upper sliding sheet 14a is in contact with the upper edge of the tape winding body Tc, and the reel disk 7
The occurrence of uneven winding and unevenness is reliably prevented without hindering the rotational force due to.

In the above description of each of the first to fourth embodiments, the reel on the recording / reproducing apparatus side is used as a mechanism for pushing up the pressing member 5 that directly or indirectly presses the upper edge of the tape winding body Tc. I used a disc, but not limited to this,
For example, a pin or the like is provided on the device side in addition to the reel disc,
The pin may be configured to push up the pressing member 5 at the time of mounting. In addition, in the first to third embodiments, the pressing member 5 that is pressed downward by the ribs 8 (, 9) on the reel hub 3 and the protrusion 14c on the upper sliding sheet 14a are provided. The present invention is not limited to this. For example, a pressing member biased downward by a separate spring member may be provided on the inner wall of the upper half 1a so as to face the upper end edge of the tape winding body Tc, or the inner surface of the upper half 1a or An elastic body instead of the protrusion 14c may be directly provided on the lower surface of the upper flange 6.

In particular, as seen in the first and second embodiments, a plurality of independent pressing members are used as the pressing members, for example, a plurality of pressing members for urging the upper end edge of the tape winding body Tc downward. Biasing means {corresponding to the pressing member 5 and the protruding portion 14c of the sliding sheet 14a in the first and second embodiments} are provided, and each biasing means is provided to the upper edge of the tape winding body Tc when not mounted. By applying a strong pressing force and releasing at least one of the plurality of biasing means at the time of mounting to the device, a weak biasing force that does not hinder the rotation of the reel hub 3 as compared to when not mounted, The tape winding body Tc may be provided on the upper edge of the winding body Tc.

Further, although the tape cassette in which the supply reel hub and the take-up reel hub are housed in the cassette housing has been described, the present invention is not limited to this, for example, a so-called single reel in which only the supply reel wound with a magnetic tape is housed. The same applies to the type of tape cassette.

[0023]

As described above, according to the magnetic tape cassette of the present invention, when mounted on the recording / reproducing apparatus, the upper end edge of the magnetic tape (winding body) is weak enough not to hinder the rotation of the reel hub. Since a biasing force is applied, uneven winding and unevenness can be prevented even during fast-forwarding and rewinding of the tape, and when not attached, a strong pressing force is applied to the tape winding body for transportation and transportation. Even if an external force such as a shock is applied, it has an excellent feature that it is possible to reliably prevent uneven winding and unevenness.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a magnetic tape cassette of the present invention.

FIG. 2 is an enlarged plan view of a reel hub and its vicinity, which is a main part of the first embodiment of the present invention cassette.

FIG. 3 is an enlarged partial sectional view of the first embodiment of the cassette of the present invention.

FIG. 4 is an enlarged partial sectional view of a second embodiment of the cassette of the present invention.

FIG. 5 is an enlarged plan view of an upper flange of a reel hub which constitutes a third embodiment of the cassette of the present invention.

FIG. 6 is an enlarged partial sectional view of a third embodiment of the cassette of the present invention.

FIG. 7 is an enlarged partial sectional view of a fourth embodiment of the cassette of the present invention.

[Explanation of symbols]

 1 cassette housing 1c boss 3,4 reel hub 5 pressing member 5a convex part 5b rotation stop hole 6 upper flange 6a, 7a protrusion (pivot part) 7 reel disk 8,9 spring 10-13 magnetic tape cassette 14a, 14b sliding sheet 14c Ridge T Magnetic tape.

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[Procedure amendment]

[Submission date] May 19, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Figure 3]

[Fig. 2]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

Claims (2)

[Claims] 1. A magnetic tape cassette containing a reel hub for winding a tape between an upper half and a lower half of a cassette housing. The magnetic tape cassette is arranged so as to face an upper edge of a magnetic tape wound around the reel hub. A plurality of types of biasing means for biasing the upper end edge downward, and a releasing means for canceling the downward biasing force of at least one of the biasing means. When not attached to the recording / reproducing apparatus, a strong pressing force is applied to the upper edge of the wound magnetic tape by the urging means. The member is configured to operate the releasing means to release a strong pressing force, and to apply a weak biasing force to the upper end edge of the magnetic tape that does not hinder the rotation of the reel hub. Te Tape cassette. 2. A magnetic tape cassette containing a reel hub for winding a tape between an upper half and a lower half, wherein an elastic body that abuts on an upper edge of a magnetic tape wound on the reel hub is provided. A vertically movable upper flange and a spring member that is attached to the upper half and urges the upper flange downward are provided.When the cassette is not attached to the recording / reproducing apparatus main body, the spring member is pushed. A strong pressing force is applied to the upper edge of the tape by the pressure through the upper flange, and at the time of mounting to the recording / reproducing apparatus, the upper flange is applied to the pressing member by the releasing member provided on the apparatus side. The magnetic tape cover is configured so that a weak biasing force that does not hinder the rotation of the reel hub is applied to the upper edge of the magnetic tape by pushing up against it. Tsu door.