JP2558682Y2 - Tape cassette - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a magnetic tape cassette for audio or video, and more particularly to a tape cassette (D) having an optical tape end detecting mechanism using a prism.
AT).

[0002]

2. Description of the Related Art In a conventional DAT, a pair of reel hubs on which a magnetic tape is wound are regulated by a hub brake member when not in use (during storage) by a hub brake member. That is, at the time of storage, the magnetic tape is sealed by the slider and the front lid and the cassette case, the hub brake is connected to the front lid via the arm portion, and when the front lid is opened, the hub brake is moved from the lock portion of the reel hub. Normally, it is constructed so as to slide away to the unlocked state, the hub brake is locked to the reel hub during storage, the reel hub is immobilized and there is no damage due to slack or breakage of the magnetic tape, The system is designed so that the hub brake is not disengaged during use so that the rotation operation is not hindered. And in this type of cassette,
The hub brake is supported by a hub brake holding piece provided in the case, and has a prism of a tape end detecting mechanism and a window for checking the remaining amount of tape.

[0003]

However, conventionally, the prism, the hub brake holding piece, and the tape remaining amount checking window are separately fixed in the case, so that the hub engaging portion and the prism of the tape remaining amount checking window are used. The dimensional accuracy of the position is poor, there is a gap between the upper case and the window, and the appearance is poor.Moreover, when forming the prism by two-color molding that is formed separately from the opaque case with transparent resin, molding The mold structure becomes complicated and the mold manufacturing cost increases. In particular, the molding die requires a sliding portion for forming a window portion, a sliding portion between the window portion and the prism, and a sliding portion for the prism. In addition, since most of the movable mold slides, cooling water cannot flow, so that the molding cycle time becomes longer and productivity cannot be improved.
Difficult due to the relationship between burrs and sink marks, and it is important that the prism has good light transmittance.However, dust and other impurities in the resin, mold, and molding machine are concentrated and mixed in the prism section. There is a problem that the quality is deteriorated due to poor light transmittance.

SUMMARY OF THE INVENTION The present invention is intended to solve these conventional problems. The dimensional accuracy can be remarkably improved, and the prism can be easily and correctly provided in a two-color molding with good appearance without causing molding failure. It is possible to accurately detect the end of the tape, significantly improving the reliability,
In addition, stable sliding operation of the hub brake is possible, which contributes to quality improvement by improving the hub brake function, simplification of the molding die, shortening of the molding cycle time, increasing the operating rate and improving productivity. It is an object of the present invention to provide an improved and significantly lower cost tape cassette.

[0005]

According to the present invention, a hub brake for regulating the rotation of the reel hub is slidably provided inside a case in which a pair of reel hubs around which a tape is wound are rotatably mounted. In the tape cassette provided with a prism for detecting the end of the tape, a holding piece having an opening on the front side and an inside side, and the prism are integrally formed on the front side thereof, and this is disposed on the inner surface of the upper case, and the hub is provided. The brake is provided with a protruding engaging portion which is inserted from the front opening side of the holding piece and slides in contact with the holding piece, and a forming die hole is formed below the engaging portion. Is a tape cassette. (Operation) In the present invention, the holding piece and the prism are integrally formed, and this is provided on the inner surface of the upper case. Further, a hub brake is inserted from a front opening portion of the holding piece, and the hub brake is supported by the holding piece such that an engaging portion provided on the hub brake and the holding piece slide. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is a magnetic tape cassette (DA).
T) will be described with reference to FIGS.
A hub brake 15 for regulating the rotation of the reel hub 11 is slidably provided inside a case in which a pair of reel hubs 11 and 11 around which are wound are housed rotatably, and a case composed of an upper case 1 and a lower case 2 is provided. A tape cassette having a tape end detection window hole 3 and a tape remaining amount confirmation window portion 5, a prism 4 provided at a position corresponding to the tape end detection window hole 3, and a hub brake holding piece 14 formed thereon. The upper case 1 is integrally formed by two-color molding of a primary resin and a secondary resin, and one of the primary resin and the secondary resin is formed of the prism 4 or the hub brake holding piece 14.
And a transparent resin including the window 5 for checking the remaining amount of tape, and an opaque resin for the other. The holding piece 14 for slidably supporting the hub brake 15 and the prism 4 are integrally formed, and this is lifted up. A tape cassette is integrally formed and provided on the inner surface of the case 1 separately from the case.

As the holding piece 14 and the prism 4, the holding pieces 14 and 14 are opposed to both sides of a substantially inverted U-shaped connecting piece 24, and the front pieces 24 ₁ and 24 ₁ are also connected to each other. It is preferable that the prisms 4 and 4 are integrally formed so as to face each other, and the case is configured so that the upper case 1 and the lower case 2 can be screwed together so as to be combined. A window 5 for checking the remaining amount of tape is provided separately, and a pair of reel hubs 11 around which a magnetic tape 10 is wound are rotatably mounted on hub receiving ribs 6 and 6 in the cassette case. A front cover 7 is pivotally mounted on the front opening of the cassette case so as to be openable and closable, and a shutter 8 for opening and closing the opening is slidably mounted on the lower case 2.

The prism 4 corresponding to the tape end detection window hole 3 provided on the outside of the cassette case is made of a transparent primary resin and is formed separately from the tape remaining amount confirmation window 5 in the upper case 1. The upper case 1 is made of an opaque secondary resin. (FIGS. 1 to 4). That is,
The upper case 1 is integrally molded by two-color molding of a primary resin and a secondary resin, and one of the primary resin and the secondary resin includes the prism 4 and the window 5 for checking the remaining amount of tape. The prism 4 and the window 5 for checking the remaining amount of tape may be provided on the upper case 1 by separating the prism 4 from the window 5 for checking the remaining amount of tape by using a transparent resin and the other being an opaque resin.

The prism 4 is made of a colorless and transparent primary resin. However, the molding of the upper case 1 is performed by selecting whether to use the primary resin or the secondary resin, or by coloring the case. Alternatively, transparency can be appropriately selected and used.
Further, the prism 4 and the hub brake holding piece 14 and the window 5 for checking the remaining amount of tape provided in the upper case 1 are formed of a transparent resin, and the other upper case portion is formed of an opaque or translucent resin. However, the upper case 1 and the prism 4 or the upper case 1 and the prism 4, the hub brake holding piece 14 and the tape remaining amount checking window 5 are simultaneously formed in two colors so that the prism 4 can easily obtain straightness. Is good. In this case, the resin of the primary side resin and the resin of the secondary side resin may be either transparent or opaque, and may be selected depending on whether the window is formed first or later depending on the mold.

Then, the magnetic tape 10 is placed in the cassette case.
Are mounted rotatably, and tape guide sheets 13 are vertically interposed between the inner surfaces of the cases 1 and 2 and the tape 10, respectively. A hub brake 15 for engaging and disengaging a locking tooth 12 provided on a small diameter portion above the winding surface and for controlling rotation of the hub is urged by a hub brake spring 16 to be slidably provided in the upper case 1 and the cassette A front cover 7 rotatably fitted to the case 1 and covering or opening the front surface of the cassette in accordance with the rotation;
As is interlocked with the rotation the magnetic tape cassette provided with a hub brake 15 to obtain a brake lock force, with provided with a claw piece 15 ₁ to be engaged with the engaging Tomeha 12 to the hub brake 15 and a pair parallel, the It has a pair of arm portions 15 ₃ with Kakari支projections 15 ₂ to be disengaged before the cover 7, the front lid 7
The protrusions 7 ₁ deployed inside surface engaging支突portion 15 ₂ is provided so as to move the arm portion 15 ₃ are disengaged in. Note the hub brake 15 is furnished to slide rotation axis perpendicular to inserted into the Rirubabu 11 in the cassette case 1, the outer surface of the arm portion 15 ₃ contraposed on both sides of the front cover 7 as it can abut the engagement支突portion 15 ₂ formed on the projections on the inside surface of the front cover 7,
The urging spring 16 of the hub brake 15 is a torsion spring provided with a coil wound around a support pole 17 provided on the upper case 1, and one end of the torsion spring is connected to the hub brake 1.
5, and the other end is urged to generate a locking force on the hub brake 15 by engaging the other end with the hook-shaped engagement portion provided on the hub brake 15. After the assembly (after the upper case 1 and the lower case 2 are fitted), the support pole 17 is provided with the abutting pole 1 provided on the lower case 2.
7 ′, thereby preventing the spring 16 from coming off. The holding piece 1 for guiding the hub brake 15
4 is provided on the inner surface of the upper case 1 of the combination case composed of the upper and lower cases, and is provided in a size within the moving range of the hub brake 15 in the area of the running path of the tape 10. Wherein the hub brake 15 is configured to be held in contact with the inner surface of the case,
The case 1 is disposed at both side positions, or at an interval between these positions and the center position. Further, the front side (the front lid 7 side) of the holding piece 14 is opened to insert the hub brake 15. The reason for this is that the hub brake 15 can be inserted from the front side of the holding piece 14, and the hub brake 15 does not interfere with the hub receiving rib 6 formed in the window 5 for checking the remaining amount of tape at the time of insertion. In order to Further, the holding piece 14 is attached to the hub brake 15.
Engaging portion 15 ₄ of the fitted to projecting (cross section L-shaped tongue) is provided. The engaging portion 15 _4, a pair of holding pieces 1
4. Thus, when the hub brake 15 slides and holding piece 14, the engagement portion 15 ₄ is able to contact sliding, it is possible to reduce the contact area therebetween, it is slid smoothly it can. Furthermore, in the present invention, the engagement portion 15 of the hub brake 15 is provided.
Below the _4, mold vent hole 15 5 corner shape _(see FIG. 7) is provided, engaging from this drain hole 15 ₅ two orthogonal sides vertical wall and a horizontal wall launched from an outer edge of the It forms a part 15 _4. Thus formed, even if provided with the engagement portion 15 _4, thereby preventing the occurrence of shrinkage in the uniform thickness of the entire hub brake 15, use a slide core to avoid undercutting It can be a punching die.

In the figure, reference numeral 9 denotes a case connecting boss, and reference numeral 18 denotes an elastic piece formed on the lower case and used as a shutter lock piece.

In the embodiment shown in FIG.
In order to integrally form the holding piece 14 that slidably supports the tape and the prism, a window 5 for checking the remaining amount of tape is also integrally formed, and this is disposed on the inner surface of the upper case.

[0013]

According to the present invention, there is provided a tape in which a hub brake for regulating the rotation of the reel hub is slidably provided inside a case in which a reel hub is rotatably mounted, and the case is provided with a prism for detecting a tape end. In the cassette, a holding piece having an opening on the front side and an inside side, and the prism are further integrally formed on the front side thereof, and this is disposed on the inner surface of the upper case. Excellent dimensional accuracy, excellent appearance without gaps between the upper case and the window, and significantly improved light transmittance of the prism, greatly improved moldability, and simplified molding dies The workability can be significantly improved, and the fixing structure of the case and the prism does not vary, and it is accurate, the position of the prism is accurate, and the straightness of the prism is easily obtained. The tape end can be used without any malfunction or non-operation to detect the end of the tape, and a reliable tape cassette that can guarantee a stable operation can be obtained. In addition, the molding cycle can be greatly shortened and the productivity can be significantly improved. There is. Also, since the front side of the holding piece was opened and the hub brake was inserted from the front side of the holding piece,
The hub brake can be inserted into the holding piece without interference between the hub receiving rib of the tape remaining amount checking window and the hub brake. Furthermore, since the protruding engagement portion of the hub brake and the holding piece slide, the contact area between them can be reduced, and the hub brake can slide smoothly. In addition, since a molding die hole is provided below the engaging part, the thickness of the hub brake is made uniform to prevent the occurrence of sink marks, and a die that does not use a slide core to avoid undercut. Thus, the quality of the hub brake can be improved, and the die cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a plan view showing an inner surface side of an upper case.

FIG. 3 is a partial perspective view.

FIG. 4 is a perspective view of the lower case in a separated state.

FIG. 5 is a plan view of a hub brake engagement state with a part of an upper case removed.

FIG. 6 is a plan view of a part of the hub brake in a detached state, excluding a part of an upper case.

FIG. 7 is an enlarged vertical sectional view taken along line AA of FIG.

FIG. 8 is a plan view showing an inner surface side of an upper case according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Upper case 2 Lower case 3 Tape end detection window hole 4 Prism 5 Tape remaining amount confirmation window 6 Hub receiving rib 7 Front lid 8 Shutter 9 Boss 10 Tape 11 Reel hub 12 Locking teeth 13 Sheet 14 Hub brake holding piece 15 Hub Brake 15 ₁ Claw piece 15 ₂ Engagement protrusion 15 ₃ Arm part 15 ₄ Engagement part 16 Hub brake spring 24 Connection piece

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-1386 (JP, A) JP-A-62-202378 (JP, A) JP-A 1-124985 (JP, U)

Claims (2)

(57) [Scope of request for utility model registration] A hub brake for restricting rotation of the reel hub is slidably provided inside a case in which a pair of reel hubs around which a tape is wound are rotatably mounted, and a prism for detecting a tape end is provided in the case. In the tape cassette provided, a holding piece having an opening on the front side and an inside side, and further, the prism is integrally formed on the front side thereof, and this is disposed on the inner surface of the upper case. A protruding engaging portion that is inserted from the opening side and slides in contact with the holding piece is provided,
A tape cassette, wherein a forming die hole is formed below the engaging portion. 2. The apparatus according to claim 1, wherein said holding piece and said prism are integrally formed with a holding piece opposing each other on both sides of a substantially inverted U-shaped connecting piece, and a prism opposing each other at both front ends. The tape cassette according to claim 1, wherein: