JP2003331556A - Recording tape cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording tape cassette capable of adequately supporting a recording tape delivered from a reel even if the recording tape set to coil on the reel wears thinner and has an easy tendency to deformation. <P>SOLUTION: The recording tape cassette 10 is formed by rotatably housing the reel 20 provided with a hub 26 wound with the recording tape T and a flange 24 attached to the end of the hub 26 and formed with recessed parts 25 for expelling the air incorporated into the recording tape T on its inside surface into a case 12, in which the recessed parts 25 comprise a plurality of long grooves 25A extended from the outer peripheral surface side of the hub 26 to the outer periphery edge side of the flange 24 and connecting grooves 25B connecting the long grooves 25A approximately in the circumferential direction of the flange 24. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording tape cassette in which a reel on which a recording tape such as a magnetic tape is wound is accommodated in a case. 2. Description of the Related Art Generally, in audio equipment and video equipment which are recording / reproducing apparatuses, a magnetic tape cassette having a magnetic tape as a recording tape is frequently used. For example, a magnetic tape cassette used for business use in a broadcasting station or the like has a pair of reels rotatably accommodated in a case formed by joining an upper case and a lower case made of synthetic resin, Normally, a magnetic tape is wound around one reel, the tip of the magnetic tape is attached to the other reel, and the magnetic tape is fed from one reel to the other reel, so that information on the magnetic tape is transferred. Recording or reproduction of information recorded on the magnetic tape is performed. Each reel on which a magnetic tape is wound is composed of a lower flange, a hub integrally fixed to the upper side of the lower flange, and an upper flange attached to the upper side of the hub. The tip is attached to the hub and wound around the outer peripheral surface of the hub. The magnetic tape wound around the hub is held by the lower flange and the upper flange. Also, as shown in FIG.
A gear 52 that engages with a reel locking brake member is formed on the outer peripheral edge of the lower flange 54, and a plurality of recesses (grooves) 50 having a substantially fan shape in plan view are formed on the inner surface of the lower flange 54 (not shown) 8). The recess 50 is for eliminating air (hereinafter referred to as entrained air) entrained between the magnetic tape and the magnetic tape wound around the hub 56, and is thereby wound around the reel. The appearance of the magnetic tape is improved when it is. However, when the magnetic tape becomes thinner as the recording capacity increases, the strength of the magnetic tape itself becomes weaker (the strength becomes weaker). When the area of the inner surface of the lower flange 54 that supports the magnetic tape wound on the inner surface is reduced by forming a plurality of concave fan portions 50 that are substantially fan-shaped when viewed in plan view, the air from the inner surface of the lower flange 54 is reduced. Since the supporting force is also reduced, the magnetic tape fed out from the reel cannot be sufficiently supported, the behavior becomes large, and the magnetic tape itself is easily deformed. Therefore, the present invention provides a recording tape cassette that can favorably support a recording tape fed out from a reel even when the recording tape such as a magnetic tape wound around the reel becomes thin and easily deforms. The purpose is to obtain. In order to achieve the above object, a recording tape cassette according to a first aspect of the present invention comprises a hub around which the recording tape is wound, and an end of the hub. In a recording tape cassette in which a reel having a recess formed on the inner surface and configured to exclude air trapped in the recording tape is rotatably accommodated in a case, the recess is connected to the hub. It is characterized by comprising a plurality of long grooves extending from the outer peripheral surface side to the outer peripheral edge side of the flange, and connecting grooves connecting the long grooves in a substantially circumferential direction of the flange. With such a construction, the air embraced by the recording tape is preferably excluded to the outside through the connecting groove and the long groove. In addition, the concave portion formed of the long groove and the connecting groove can reduce the area of the concave portion as compared with the conventional substantially fan-shaped concave portion, and therefore increases the area of the flange inner surface (excluding the concave portion). Can do. Therefore,
The recording tape fed out from the reel can be favorably supported on the inner surface of the flange excluding the concave portion, and even when the recording tape becomes thin, its deformation can be suppressed. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will now be described in detail with reference to examples shown in the drawings. For convenience of explanation, the loading direction of the recording tape cassette into the recording / reproducing apparatus (audio equipment, video equipment, etc.) is defined as the forward direction (FR), and the backward direction (RE), the upward direction (UP), and the downward direction based on the loading direction. Direction (LO), left direction (LE), and right direction (RI). Further, a magnetic tape is employed as the recording tape, and the following description will be given as a magnetic tape cassette 10. First, the outline of the magnetic tape cassette 10 will be described. As shown in FIG. 1, the magnetic tape cassette (beta cam L cassette) 10 used for business use in a broadcasting station or the like has a lateral direction that is greater than a longitudinal direction. A case 12 having a long, substantially rectangular box shape is provided. The case 12 is configured by joining an upper case 14 and a lower case 16 by a plurality of mounting screws 15 screwed from the lower surface of the lower case 16. ing. The front wall 12A of the case 12 is provided with a cover 18 that covers the front wall 12A. The cover 18 is provided on both side walls 12B of the case 12.
Both end portions thereof are pivotally supported at the front end and are provided so as to be rotatable upward. The magnetic tape T exposed at the center of the front wall 12A of the case 12 is covered.
That is, the cover 18 is disposed in front of the front wall 12A of the case 12 so as to cover the magnetic tape T when it is not loaded into the recording / reproducing apparatus, and when it is loaded into the recording / reproducing apparatus, a recording / reproducing head (not shown) is provided. The upper case 14 is pivoted and retracted so that it can slide on the magnetic tape T exposed at the center of the front wall 12A of the case 12. A pair of loose regulation walls 28 having a substantially cylindrical shape are erected on the inner surface of the lower case 16, and a pair of reels 20 are rotatably accommodated in the respective loose restriction walls 28. It is like that. Each reel 20 includes a lower flange 24, a hub 26 that is integrally fixed to the upper side of the lower flange 24, and an upper flange 22 that is attached to the upper side of the hub 26.
When the magnetic tape T is not used, one end of the magnetic tape T is usually attached and wound around the hub 26 of one of the reels 20, and the other end is attached to the hub 26 of the other reel 20. The lower flange 24 has a magnetic tape T.
A plurality of recesses (grooves) 25 are formed to exclude entrained air held between the magnetic tape T and the magnetic tape T. As shown in FIG. 2, the recesses 25 are formed in an approximately “V” or “U” shape in plan view, and the magnetic tape T wound around the hub 26 has the recesses 25. The lower flange 24 is held by the upper flange 22 and the lower flange 24 while being supported from below by the inner surface of the lower flange 24. A gear 24 </ b> A (see FIG. 2) that engages with a reel locking brake member (not shown) provided in the case 12 is formed at the peripheral edge of the lower flange 24. The upper flange 22 is formed of a transparent material, and a recess 22A is formed at the center of the upper surface.
A compression coil spring 32 is inserted into the recess 22A. The compression coil spring 32 has a lower end supported by the bottom surface of the recess 22A and an upper end supported by the inner surface of the upper case 14, and biases each reel 20 toward the lower case 16. A circular hole (not shown) is recessed in the lower surface of the shaft core of the hub 26, and a reel rotation gear (not shown) is formed on the inner periphery of the hole. . However, each reel 2 is attached to the lower case 16.
A pair of apertures 30 for exposing the reel rotation gear provided on the lower surface of 0 are formed, and when the magnetic tape cassette 10 is loaded into the recording / reproducing apparatus, it is provided in the recording / reproducing apparatus. A drive gear (not shown) enters the hole from the opening 30 and meshes with the reel rotation gear, so that the pair of reels 20 can rotate. A reference hole for positioning with respect to the recording / reproducing apparatus is provided on the lower surface of the front portion of the lower case 16. The reference hole is formed in the bag portions 46 and 48 protruding toward the inside of the case 12, and the reference hole formed in one (for example, the right side) bag portion 46 is circular in a plan view.
The reference hole formed in the other (left side) bag portion 48 has a substantially elliptical shape in plan view that is long in the left-right direction. When the magnetic tape cassette 10 is loaded into the recording / reproducing apparatus, positioning members (not shown) such as pins enter the reference holes, and the magnetic tape cassette 10 is moved in the front / rear / left / right directions in the recording / reproducing apparatus. The position is restricted. Further, on the inner surface of the front portion of the lower case 16, cylindrical bosses (not shown) protrude from the reference holes (the bag portions 46 and 48) at a predetermined height. A holding hole (not shown) having a substantially square shape in plan view is formed therein. A pair of elongated cylindrical metal shafts 36 are inserted into the holding holes, and the shafts 36 are erected vertically with respect to the lower case 16. Each shaft 36 is loosely fitted with a synthetic resin guide roller 34 having a circular through hole 34A formed in a plan view along the central axis. Further, cylindrical bosses (not shown) are provided on the inner surface of the front portion of the upper case 14 so as to project at a predetermined height, and the upper ends of the shafts 36 are inserted into the bosses. A circular holding hole (not shown) is formed.
Thus, the guide roller 34 is supported rotatably about the shaft 36, and the lower case 16 and the upper case 14 are supported.
Is held in a vertical state. The magnetic tape T is guided by the guide roller 34 while one of the reels 20
To the other reel 20 stably (feeding or rewinding). For this reason, it is desirable that the guide roller 34 be formed of a synthetic resin, such as POM, which is slidable and has relatively high mechanical strength. Further, in the vicinity of the guide roller 34, there are provided tape pads 40 that slide on the back side of the magnetic tape T and press the magnetic tape T from the back side to prevent the magnetic tape T from slackening. The magnetic tape T travels while being pressed by the tape pad 40 with an appropriate urging force. Therefore,
There is no problem that the magnetic tape T is bitten or damaged. The guide roller 34 and the reference hole (bags 46, 4 and 4) are located in front of the tape pad 40.
8), a pin 43 is erected at a predetermined height on the inner surface of the lower case 16, and the lower end of a metal cylindrical shaft 42 is fitted into the pin 43, and the upper end thereof is further connected to the upper case 1.
4 is inserted into a cylindrical protrusion (not shown) projecting from the inner surface, so that the shaft 42 is held (fixed) perpendicular to the upper case 14 and the lower case 16 and in a non-rotating state. ing. The shaft 42 is wound around the back surface, which is a non-recording surface of the magnetic tape T, and guides the magnetic tape T together with the guide roller 34. The magnetic tape cassette 1 constructed as described above.
Next, the lower flange 24 of the reel 20 will be described in detail. As shown in FIG. 2, the lower flange 24 of the reel 20 is formed with a plurality of recesses 25 for removing accompanying air. The concave portion 25 is formed of a plurality of elongated strips (16 in the drawing) extending in the substantially radial direction of the lower flange 24, that is, from the outer peripheral surface side of the hub 26 toward the outer peripheral edge (gear) 24A side of the lower flange 24. Long groove 25A and its long groove 2
Each of 5A is composed of a connecting groove 25B that is connected in the substantially circumferential direction of the lower flange 24 in the vicinity of the outer peripheral surface of the hub 26, and is substantially “V” in which the outer peripheral edge (gear) 24A side is opened in plan view. Or it is formed in a “U” shape. When the recess 25 is formed in such a shape,
Compared with the conventional substantially fan-shaped recess 50 shown in FIG. 4, the area of the inner surface of the lower flange 24 that supports the magnetic tape T from below can be increased. Can be supported by the magnetic tape T
The deformation of itself can be suppressed. In addition, in the process in which the magnetic tape T is wound around the hub 26, the entrained air held between the magnetic tapes T is connected to the connecting grooves 25B.
And the outer side through the inside of the long groove 25A (outer peripheral edge (gear) 2
4A side), it is efficiently and suitably eliminated. The shape of the recess 25 is not limited to the substantially "V" to "U" shape shown in FIG. 2, but is formed as a substantially star-shaped recess 27 as shown in FIG. Also good. That is, the concave portion 27 includes a plurality of long (27 in the drawing) long grooves 27A extending from the outer peripheral surface side of the hub 26 toward the outer peripheral edge (gear) 24A side of the lower flange 24, and the long grooves 27A. In the vicinity of the outer peripheral surface of the hub 26 and in the vicinity of the outer peripheral edge (gear) 24A of the lower flange 24.
7B, and is formed in a substantially star shape in plan view. Even with this configuration, the area of the inner surface of the lower flange 24 for supporting the magnetic tape T from below can be increased as compared with the conventional substantially sector-shaped recess 50 shown in FIG. Therefore, even if the magnetic tape T is configured to be thin, it can be favorably supported, and deformation of the magnetic tape T itself can be suppressed. In this case as well, the entrained air held between the magnetic tapes T in the process of winding the magnetic tape T around the hub 26 becomes the connecting groove 2.
7B and the long groove 27A are passed to the outer side (outer peripheral edge (gear) 24A side), so that they are efficiently and suitably eliminated. In any case, the shape of the concave portion for removing the entrained air formed in the lower flange 24 is not limited to that shown in the figure, but is substantially in the radial direction of the lower flange 24 (the outer peripheral surface of the hub 26). A long groove extending along the outer peripheral edge (gear) 24A side direction) of the lower flange 24 from the side, and the long groove in the vicinity of the outer peripheral surface of the hub 26, in the vicinity of the outer peripheral edge (gear) 24A of the lower flange 24, etc. Any shape may be adopted as long as it is configured with a short connecting groove that is connected along the substantially circumferential direction of the lower flange 24 and is capable of suitably eliminating entrained air. According to the present invention, air entrained in the recording tape can be suitably eliminated and the area of the recess formed on the inner surface of the flange can be reduced. The recorded tape can be suitably supported on the inner surface of the flange excluding the recess.
Therefore, even when the recording tape becomes thin, the deformation can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic exploded perspective view of a magnetic tape cassette according to the present invention viewed obliquely from above. FIG. 2 is a schematic plan view showing a lower flange of a reel. FIG. 4 is a schematic plan view showing a lower flange of a conventional reel. DESCRIPTION OF SYMBOLS 10 Magnetic tape cassette 12 Case 14 Upper case 16 Lower case 20 Reel 22 Upper flange 24 Lower flange 25 Recess 26 Hub 27 Recess

Claims (1)

What is claimed is: 1. A hub around which a recording tape is wound; and a flange attached to an end of the hub and having a recess formed on the inner surface to exclude air trapped in the recording tape. In a recording tape cassette in which a reel provided is rotatably accommodated in a case, a plurality of long grooves extending from the outer peripheral surface side of the hub to the outer peripheral edge side of the hub, and the long grooves are connected to the flange. And a connecting groove connected in a substantially circumferential direction of the recording tape cassette.