JPH05120835A - Tape cassette - Google Patents

Abstract

PURPOSE:To prevent a friction sheet from being inversely mounted for the front side, rear side in a tape cassette. CONSTITUTION:In upper/lower halves 2, 3, the inside wall parts 2q, 3q corresponding to the back side of cassette casing are formed asymmetrically (stepped parts 2r, 3r), and the shape of the sheet 30 is also formed asymmetrically (stepped part 33) in accordance with the asymmetrical shape of the upper/lower halves 2, 3, then the sheet 30 can be arranged in the upper/lower halves only under the state of specific directions for front/rear sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette in which a tape-shaped recording medium is wound around a reel hub and accommodated therein, and a sheet member having a sliding action is arranged in each gap between the reel hub and the upper and lower halves. It is related to the existing tape cassette.

[0002]

2. Description of the Related Art Tape cassettes used in cassette type tape players, VTRs, and other recording / reproducing devices such as audio cassettes and video cassettes containing magnetic tapes are more than those using flanged reels. So-called irregular winding of the tape, such as step winding, irregular winding, and bulk winding of the tape-shaped recording medium wound around the reel hub, is likely to occur. Therefore, conventionally, a pair of seats as a slidable body are arranged above and below a pair of left and right reel hubs that are rotatably held in a housing composed of an upper half and a lower half, and a pair of sheets parallel to the facing surfaces of the pair of seats. A pair of convex strips is provided so that the convex strips elastically sandwich the reel hub and the tape-shaped recording medium wound around the reel hub from above and below to prevent the winding disorder of the tape.

FIGS. 8 (a) and 8 (b) are a plan view and a side view of an example of such a sheet, and FIG. 9 is a cross-sectional view showing a reel hub and a seated state in a tape cassette. .. In FIG. 9, reel fitting portions 51a and 52a are provided on an upper half 51 and a lower half 52, respectively, which form a cassette housing.
A reel hub 53 is engaged with and held by a and 52a, and a magnetic tape T is wound around the reel hub 53.

A sheet 54 is arranged between the reel hub 53 and the upper half 51 and the lower half 52.
As shown in FIG. 8, each sheet 54 is provided with two parallel projecting ridges 54a. The ridges 54a project toward the reel hub 53 as shown in FIG. Will be placed. By arranging the ridges 54a so as to abut the reel hub 53 and the magnetic tape T in this way, the sheet 54 positions the tape in the tape width direction and the reel hub when the tape is running, thereby preventing the winding disorder of the tape. ing. The sheet 54 has holes 5 corresponding to the reel fitting portions 51a and 52a.
4b is formed.

[0005]

By the way, in such a tape cassette, when the sheet 54 is mounted in the reverse direction, the sheet 54 does not make any sense. That is, unless the ridge 54a is mounted so as to face the reel hub 53, the tape winding disorder prevention and loss torque generation prevention function cannot be exhibited. However, there is a problem in that when a sheet that is very thin and normally transparent is mounted, reverse mounting in the front and back directions easily occurs, and the frequency of defective products in the tape cassette is relatively high. In particular, this problem is prominent in a microminiature tape cassette, which is a component whose housing and sheet are very small.

[0006]

The present invention has been made in view of the above problems, and a pair of reel hubs in which a tape-shaped recording medium is wound in a cassette housing in which upper and lower half members are fitted and fixed. And a sheet cassette arranged in the gap between the pair of reel hubs and the upper half member, and in the gap between the pair of reel hubs and the lower half member, in the upper half member and the lower half member. The inner wall portion corresponding to the back side of the cassette housing is formed asymmetrically to the left and right, and the shape of the sheet member is changed so as to correspond to the back side inner wall portions formed asymmetrically in the upper half member and the lower half member. The sheet members are formed asymmetrically, and only in a specific front-back direction, the gap between the pair of reel hubs and the upper half member, and the pair of reel members The gap portion between the reel hub and the lower half member, and constitutes, as is respectively positionable.

[0007]

[Function] By making the plane shape of the seat asymmetrical in accordance with the upper and lower halves, the seat can be mounted only in a specific direction in the front and back directions. Therefore, the mounting direction can be regulated so that the convex shape of the sheet always faces the reel hub.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the tape cassette of the present invention will be described below with reference to FIGS. The tape cassette of this example is ultra-small (the plane size of the housing is 20 mm in the vertical direction,
The width is about 30 mm).

In FIGS. 3 to 7, reference numeral 1 denotes a tape cassette as a whole which houses a magnetic tape for recording / reproducing a PCM signal, and the housing of the tape cassette 1 has an upper half 2 and a lower half 3 opposed to each other. It is constructed by tightening screws 4 to combine them and rotatably pivoting a lid 6 for opening and closing the openings 5 formed on the front sides of the halves 2 and 3.

As shown in FIGS. 3, 4 and 5, the inside of the housing of the tape cassette 1, that is, between the upper and lower halves 2, 3.
Hub drive shaft insertion holes 2a, 2 in the upper and lower halves 2, 3
b (and 3a, 3b) is accommodated in a state in which the magnetic tape T is wound between a pair of both hubs 7, 8 arranged corresponding to
A part of the magnetic tape T is exposed in the opening 5 on the front side of the housing in a stretched state via pinch rollers 9 and 10 which are rotatably supported on both sides of the front side opening 5 and also function as guide rollers. It is done like this.

On the upper and lower surfaces of the housing of the tape cassette 1,
Erroneous erasure prevention mechanisms 12 and 13 which are located on both sides of the rear part (near the rear face part) and communicate with the upper and lower halves 2 and 3 are arranged, and for positioning on the rear part in the center front-rear direction and on both side parts in the rear lateral direction. Of the reference holes 15, 16 and 17 of
Further, a plurality of required detection holes 18 and 19 are formed in the lateral direction of the rear edge portion, and further grip portions 20 and 2 are provided on the rear portions of both side surfaces.
1 is formed.

Further, as can be seen from FIGS. 3 and 4, a rack gear 23 is provided along the lateral guide groove 22 in the lid 6 that opens and closes the opening 5 on the front side of the housing. With the tape cassette 1 stored in the cassette magazine, the cassette changer is used as an engaging means when the tape cassette is taken out from the cassette magazine. Furthermore, upper and lower halves 2, 3
Windows 2c, 3 made of transparent resin in the center of the plane of the
c is provided so that the remaining amount of the magnetic tape T can be confirmed from the outside of the housing of the tape cassette 1.

In this tape cassette 1, a magnetic tape T housed in a cassette housing is recorded by a rotary head in a helical scan system when loaded in a recording / reproducing apparatus.
It is designed to be played back. That is, FIG.
As shown in FIG. 5, the rotary head 41 is configured to rotate at a required angle with respect to the head drum 42, and the head drum 42 is rotated by rotating the lid 6 of the cassette housing 1 upward or downward. The magnetic tape T partially inserted into the open front side opening 5 and stretched across the opening 5 is slid so as to wind around the insertion side peripheral surface of the head drum 42, and is rotated. When the head 41 rotates, an inclined track that diagonally crosses the magnetic tape T is formed.

At this time, the magnetic tape T is attached to the head drum 42.
In order to ensure that the upper half 2 is removed, as shown in FIG. 5, which is a plan view with the upper half 2 removed, the insertion portion of the head drum 42 in the opening 5 of the cassette housing is A pair of tape guide members 24, 25 whose guide surfaces 24a, 25a are inclined in opposite directions are arranged inside the pinch rollers 9, 10. Therefore, by inserting the head drum 42 into the opening 5 as shown in FIG. 6, the guide surfaces 24a and 25a of the tape guide members 24 and 25 come into contact with the peripheral surface of the head drum 42, that is, the head drum. The magnetic tape T is sandwiched between the outer peripheral surface 42 and the peripheral surface of the guide 42.

On both sides of the head drum 42, both wing guides 43, 44 inserted between the pinch rollers 9, 10 and the tape guide members 24, 25 on both sides of the opening 5 of the cassette housing 1 are provided. The wing guides 43, 44 are equipped with rollers 43a,
44a is mounted and the magnetic tape T is attached to the tape guide member 2
It presses against 4,25. The two wing guides 43 and 44 are used to prevent the protrusion of the tapes located between the support pieces 26 and 27 and the pinch rollers 9 and 10 from the inside in the opening 5 of the cassette housing 1. It is inserted between the guide protrusions 28 and 29.

The internal structure of the tape cassette 1 of this embodiment is shown in FIG. 5. The hubs 7 and 8 are inner hubs 7a and 8a into which the hub drive shafts are inserted and engaged, and the inner hubs 7a and 7a, respectively.
8a, the outer hubs 7b and 8b are movable in the axial direction and are engaged in the circumferential direction. In particular, the inner hubs 7a and 8a are provided with gear-like locked portions 7 on the peripheral surfaces thereof that project from the outer hubs 7b and 8b at least toward the lower half 3 side.
a ₁ . 8a ₁ is formed.

Then, the locked portions 7a ₁ . By engaging with 8a ₁ , a brake member 11 for performing a braking operation so that the hubs 7 and 8 are incapable of rotating when the tape cassette 1 is not in use is formed in a recessed portion 3 formed on the inner surface of the lower half so as to be lowered by one step.
It is located in e.

In normal times (when not in use), the brake member 11 is in contact with the pressure contact portion 3d in the cassette housing 1 by the brake spring 11c made of, for example, a stainless wire fixed to the spring fixing portions 11b ₁ and 11b _2. 7 (a) by the urging force obtained by the contacting, that is, the locking claws 11a ₁ and 11a ₂ come into contact with the gear-shaped locked portions 7a ₁ and 8a _{1 of the} inner hubs 7a and 8a, respectively. Is in a state of
The hubs 7 and 8 are in a non-rotatable hublock state.

The spring fixing portion 11b ₁ is completely fixed by insert molding or the like with the brake spring 11c inserted in the spring fixing portion 11b ₁ .
This prevents the brake spring 11c from falling off.
On the other hand, the spring fixing portion 11b ₂ is only held by the two locking pieces protruding in a staggered manner.

When the tape cassette 1 is loaded in the recording / reproducing apparatus, as shown in FIG. 7B, the positioning pin 99 provided in the recording / reproducing apparatus is located on either the upper half 2 side or the lower half 3 side. It is inserted from the reference hole 15 for positioning. This guides the loading position of the tape cassette 1 in the recording / reproducing apparatus in the left-right direction, but at the same time, the positioning pin 99 acts as a brake release pin.

That is, the brake member 11 has a pressing operation portion 11d having cam surfaces 11d ₁ and 11d ₂ inclined in a substantially V-shaped cross section with respect to the thickness direction of the housing of the tape cassette 1.
Since the positioning pin 99 is formed, the positioning pin 99 has the cam surface 11d ₁ or 11d of the pressing operation portion 11d of the brake member 11.
_When it comes into contact with ₂ , the brake member 11 will move to the brake spring 11
7B is slid in the front direction of the tape cassette 1 guided by the guide pin 3f inserted into the guide portion 11f and the guide pin 3g inserted into the guide portion 11g against the biasing force of c. Locking claw 11a
The engagement between ₁ and 11a ₂ and the locked portions 7a ₁ and 8a ₁ is released. Therefore, the hubs 7 and 8 are made rotatable.

Further, when the tape cassette 1 is ejected from the recording / reproducing apparatus and the positioning pin 99 escapes from the reference hole 15, the brake member 11 is moved from the state shown in FIG.
After returning to the state (a), the rotation of the hubs 7 and 8 is locked. As shown in FIG. 7, in the inner hub 8a (7a), the locked portion 8a ₁ is also attached to the peripheral surface of the inner hub 8a (7a) protruding from the outer hub 8b (7b) toward the upper half 2 side where the brake member 11 is not disposed. Although (7a ₁ ) is formed, by doing so, the up-down directionality at the time of arranging the hub in the hub assembling step is eliminated, and the work is simplified.

The brake member 11 is positioned so as to shield the inner surface of the window 3c formed in the lower half 3. However, since the brake member 11 is made of transparent resin, the brake member 11 is It does not hinder the confirmation of the remaining tape amount through the window 3c. The brake member 11
Even if the brake member 11 is not transparently formed, if a hole is provided which has a size that does not cover the windows 2c and 3c regardless of the sliding position of the brake member 11, the tape remaining from the window 3c can be removed. Checking the quantity is not hindered.

Further, as can be seen from FIG. 5, a rail 3j is formed in the recess 3e in which the brake member 11 is loaded. That is, the brake member 11 is housed in the recess 3e in a state of being stacked on the rail 3j, and when sliding as described above, only sliding is performed by linear contact with the rail in the recess 3e. Therefore, excessive friction is not generated in the sliding operation, and smoothness is not impaired.

Although not shown in the drawings for the sake of explanation in each of FIGS. 3 to 7, both sides of the hubs 7 and 8, that is, the gap between the hubs 7 and 8 and the inner surface of the upper half 2, Also, a transparent friction sheet (hereinafter, simply referred to as a sheet) is interposed in the gap between the hubs 7 and 8 and the lower half 3 (brake member 11) to improve the smoothness of the rotating operation of the hubs 7 and 8 and the magnetic tape. It has the function of preventing winding disorder and the generation of loss torque.

The shapes of the seat and the seat mounting portions of the upper and lower halves 2 and 3 in this embodiment will be described below. 1A and 1B are a plan view and a side view of a seat in this embodiment, and FIGS. 2A and 2B are upper halves 2.
FIG. 3 is a plan view showing a state in which a seat is attached to the inner surface side and a state in which a seat is attached to the inner surface side of the lower half 3.

In FIGS. 1 and 2, reference numeral 30 denotes the entire sheet formed in a substantially spectacle shape corresponding to the shape of the magnetic tape storage portion shown in FIG. 5, and 31 is provided on the sheet 30 in parallel. A pair of ridges, 32 are upper and lower halves 2,
3 hub drive shaft insertion holes 2a, 2b (and 3a, 3b)
It is a hole formed corresponding to. Also, sheet 3
In 0, the portion corresponding to the rear surface side of the cassette housing is formed so as to be bilaterally asymmetric. That is, the step portion 33 is formed only on the right side portion in the drawing.

The shape of the inner surface of the upper half 2 is shown in FIG.
As can be seen from (a), the inner wall portion 2q of the portion corresponding to the back side of the housing is left-right asymmetric. That is, the step portion 2r is formed only on the right side portion in the drawing. Further, as can be seen from FIGS. 2B and 5, the shape of the inner surface side of the lower half 3 is also the inner wall portion 3 of the portion corresponding to the rear surface side of the housing.
q is left-right asymmetric. That is, the step portion 3r is formed only on the right side portion in the drawing.

As described above, since the step portions 2r and 3r are set on the rear side inner wall portions 2q and 3q of the upper and lower halves 2 and 3, and the step portion 33 is set on the seat 30, the seat 3 is formed.
On the inner wall side of the upper half 2, 0 is shown in FIG.
The seat 30 can be mounted only in the state shown in (a), and on the inner wall side of the lower half 3, the seat 30 can be mounted only in the state shown in FIG. That is,
It cannot be installed upside down.

2 (a) and 2 (b) respectively show ridges 31
Is not in contact with the inner surfaces of the upper and lower halves 2 and 3,
By mounting the sheet 30 in the front-back direction, as in the case shown in FIG. 9, in the gaps between the upper and lower halves 2 and 3 and the reel hubs 7 and 8, two convex portions formed in parallel are formed. The strip 31 is arranged so as to project toward the reel hubs 7 and 8. As described above, in this embodiment, it is impossible to mount the sheet in the cassette housing in the wrong direction in the front and back directions, and a defective product due to the reverse mounting of the seat does not occur.

In the case of this embodiment, the portions which are asymmetrical to each other, that is, the step portions 2r and 3r are set in the vicinity of the erroneous erasure prevention mechanism 12 or 13 in the back side inner wall portions 2q and 3q of the upper and lower halves. The area is the portion with the most wall thickness in the micro tape cassette of this embodiment. Further, the molding accuracy requirement is not so strict on the back side of the housing as on the front side where the head drum 42 is inserted. From these things, it is most suitable as the setting position of the steps 2r and 3r. However, it goes without saying that the portion which is left-right asymmetric is not limited to the vicinity of the erroneous erasure prevention mechanism 12 or 13, and the shape of the sheet 30 is not limited to the above-described embodiment, and the upper and lower halves 2 and 3 can be formed. It may be changed corresponding to the asymmetrical shape portion.

In the case of the embodiment shown in FIGS. 2A and 2B, when the upper and lower halves 2 and 3 are fitted, the stepped portion 2
Since r and the stepped portion 3r are located in the left and right directions opposite to each other, the strength problem caused by providing the stepped portions 2r and 3r by cutting out the inner wall portions 2q and 3q hardly occurs. Further, the same molded product can be used for the sheet 30 on the upper half 2 side and the sheet 30 on the lower half 3 side.

The present invention is not limited to the ultra-compact tape cassette as in the embodiments, but can be applied to various tape cassettes for mounting sheets.

[0034]

As described above, in the tape cassette of the present invention, the inner wall portions of the upper half member and the lower half member corresponding to the back side of the cassette housing are formed asymmetrically, and the shape of the sheet member is changed to the upper and lower half members. Since the planar shape is formed asymmetrically to correspond to the left-right asymmetrical shape of the member, and the seat member can be arranged in the upper and lower halves only in a specific front-back direction state, reverse mounting of the seat member is completely eliminated, This has the effect of eliminating the occurrence of defective products due to reverse mounting.

[Brief description of drawings]

FIG. 1 is a plan view and a side view of a sheet in an embodiment of a tape cassette of the present invention.

FIG. 2 is a plan view showing a state in which sheets are attached to the upper and lower halves of the tape cassette of this embodiment.

FIG. 3 is a perspective view of the tape cassette of this embodiment.

FIG. 4 is a perspective view showing the relationship between the tape cassette and the head drum of this embodiment.

FIG. 5 is a plan view of the lower half side of the tape cassette of this embodiment.

FIG. 6 is a plan view showing a state in which a head drum is inserted in the tape cassette of this embodiment.

FIG. 7 is an explanatory diagram of a hub brake operation of the present embodiment.

FIG. 8 is a plan view and a side view of a conventional seat.

FIG. 9 is a cross-sectional view showing a mounted state of a sheet in a cassette housing.

[Explanation of symbols]

 2 upper half 2q back side inner wall 2r step 3 lower half 3q back inner wall 3r step 30 seat 31 convex streak 33 step

Claims (1)

[Claims] 1. A pair of reel hubs around which a tape-shaped recording medium is wound are housed in a cassette housing formed by fitting and fixing upper and lower half members, and a gap portion between the pair of reel hubs and the upper half member, and In a tape cassette in which a sheet member is arranged in a gap between the pair of reel hubs and the lower half member, an inner wall portion of the upper half member and the lower half member corresponding to the back side of the cassette housing is formed asymmetrically. In addition, the shape of each of the sheet members, the planar shape is formed asymmetrical so as to correspond to the back side inner wall portion formed asymmetrically in the upper half member and the lower half member, each sheet member, The gap between the pair of reel hubs and the upper half member and the pair of reel hubs only in a specific front-back direction The gap portion between the serial lower half member, the tape cassette, characterized in that there is a respective possible arrangement.