JPH0140428B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape device such as a video tape recorder that uses a magnetic tape cassette containing a reel hub on which a magnetic tape can be wound.

In recent years, there has been remarkable technological development in making magnetic tape devices such as cassette-type video tape recorders thinner and lower in cost, and there are also increasing demands from the market for making devices smaller and lighter. . In view of such points, the present invention
With an extremely simple configuration, magnetic tape devices such as video tape recorders can be made thinner and lower in cost.

FIG. 1 shows a side sectional view of the main parts of a conventional example. In the figure, a reel stand 14 is rotatably fitted loosely into a shaft 12 embedded in a substrate 10 of the magnetic tape device main body, and a hook 16 formed on the upper part of the reel stand 14 is connected to a circle formed on a magnetic tape cassette 18. Through the hole 19, it can be engaged with a pawl 26 of a recess 24 provided in the center of a reel hub 22 located inside the cassette and around which the magnetic tape 20 is wound. A roller 28 for rotationally driving the reel stand 14 is located between the substrate 10 and the magnetic tape cassette 18, is rotatably supported by a shaft 32 installed in a lever 30, and rolls into contact with the outer periphery of the reel stand 14. It is arranged like this. The roller 28 is connected to the relay belt 34 and the board 10
It is rotated by a motor 42 via a relay pulley 38 and a motor belt 40, which are loosely and rotatably fitted onto a shaft 36 installed in the shaft 36. The motor 42 is held on a mounting plate 44 and fixed to the base plate 10 with screws 46 and 48.

In the above configuration, the rotation of the motor 42 is transmitted to the roller 28 via the motor belt 40, the relay pulley 38, and the relay belt 34. Therefore, the reel base 14 on which the roller 28 is in rolling contact
Rotate. Since the hook 16 of the reel stand 14 and the claw part 26 provided on the reel hub 22 are engaged, the reel stand 14 and the reel hub 22 are connected to the shaft 12.
The magnetic tape 20 is rotated integrally around the reel hub 22 to wind the magnetic tape 20 onto the reel hub 22.

In the structure of the conventional magnetic tape cassette and magnetic tape device as described above, in order to rotationally drive the reel hub 22 within the magnetic tape 18, the hook 1 is
It is necessary to engage the reel stand 14 having the reel 6 with the claw part 26 of the recess 24 of the reel hub 22, and then drive the reel stand 14 to rotate the reel hub 22, and the reel stand 14 is indispensable. It was becoming. Therefore, magnetic tape cassette 1
The reel stand 14, roller 28, etc. for rotationally driving the reel hub 22 must be disposed below the magnetic tape device 8, and therefore the thickness h of the magnetic tape device inevitably becomes large.

In addition to the conventional example described above, we have also proposed a structure in which a reel hub driving roller, a relay roller, etc. are provided inside the magnetic tape cassette, and the reel hub is rotatably fitted onto a shaft embedded in the cassette and is rotationally driven via a belt. However, this has resulted in the problem that the structure of the magnetic tape cassette itself is complicated and expensive, and the running cost of the magnetic tape drive system is high.

The present invention solves the above-mentioned conventional drawbacks, uses a magnetic tape cassette that is inexpensive and has a simple structure, and eliminates the need for a reel stand, thereby making the device thinner, smaller, and lighter. Hereinafter, a detailed explanation will be given based on the embodiment of the present invention shown in FIG.
In FIG. 2, the board 52 of the magnetic tape device main body
A drive pulley 56 is rotatably fitted loosely onto a shaft 54 implanted in the drive pulley 56, and a disk 60, which is a drive rotary body having a gear portion 58 on the outer periphery, is integrally formed with the drive pulley 56. . Further, a pulley 64 on which a belt 62 is hung is also provided above the driving pulley 56. Furthermore, a motor 68 held by a mounting bracket 66 is fixed to the board 52 with screws 70 and 72. motor 68
The rotating shaft 74 is provided with a pulley 76 that rotates integrally therewith, and a belt 62 is placed between the pulley 76 and the above-mentioned pulley 64. The magnetic tape cassette used in the present invention has the following structure. That is, a reel hub 82 around which a magnetic tape 80 is wound is rotatably fitted onto a shaft 78 implanted between one main flat plate part 50a and the other main flat plate part 50b of the magnetic tape cassette 50. Of the reel flanges 83 and 84 integrally formed with the reel hub 82, a gear portion 86 provided on the outer periphery of the reel flange 84 and the gear portion 58 of the disk 60 are connected to the side surface 5 of the magnetic tape cassette 50.
0c and a notch 88 formed in the main flat plate portion 50b following this so that they can be engaged with each other.

The disk 60 having the gear portion 58 is configured to move the cassette when the magnetic tape cassette 50 is transferred in a direction perpendicular to the plane of the main flat plate portion 50b, that is, in a direction from the cassette 50 side of the substrate 52 toward the substrate 52 in FIG. The gear part 86 of the reel flange 84 built inside the outer wall surface of the reel 50 can be meshed with the gear part 86 through the notch part 88. Further, even when the magnetic tape cassette 50 is transferred from the right direction to the left direction in FIG. ing. In this way, the reel flange 8
4 and the disk 60 are gear-coupled, so reliable rotation transmission without slipping is possible, and there is no need for them to be brought into pressure contact with each other using elastic force, and mechanisms such as elastic pressure contact means can be omitted. Therefore, it is possible to realize a compact magnetic tape device with a small number of parts, and since no side pressure is applied to the shaft 78 via the reel flange 84, it is possible to prevent deformation of the magnetic tape cassette 50 or irregular rotation of the reel flange 84. It does not cause Further, the reel flange 84 is attached to the magnetic tape cassette 5.
Since the reel flange 84 is built in inside the outer wall of the magnetic tape cassette 50, the user cannot easily turn the reel flange 84 from the outside, which prevents the magnetic tape 80 from becoming slack or being cut inside the magnetic tape cassette 50. There is no fear that it will.

Furthermore, the tooth thickness of the gear portion 58 is made larger than the tooth thickness of the gear portion 86 of the reel flange 84 to ensure reliable meshing even if there is a positioning error in the gear thickness direction when the cassette is attached, or an error in the thickness of the gear itself. In other words, the gear portion 86 of the reel flange 84
Since the tooth thickness is configured so that it can necessarily mesh with the gear portion 58, driving force can be transmitted with high reliability.

Further, the reference pitch circle diameter of the gear portion 58 is smaller than the reference pitch circle diameter of the gear portion 86, so that the number of teeth or the tip circle diameter of the gear portion 58 is smaller than the reference pitch circle diameter of the gear portion 86.
Since the number of teeth is less than or smaller than the number of teeth or the tip circle diameter of 6, the rotational force of the motor can be transmitted at a reduced speed. That is, since the rotational torque of the motor can be set low, the motor can be made smaller and its power consumption can be reduced.

Next, the operation of this embodiment will be explained. When the motor 68 rotates in the illustrated state in which the magnetic tape cassette 50 is mounted at a predetermined location on the magnetic tape apparatus main body so that the gear part 86 of the reel flange 84 meshes with the gear part 58 of the disk 60,
The rotational force of the motor 68 is transmitted through the pulley 76 and the belt 6.
2. It is transmitted to the drive pulley 56 via the pulley 64. When the drive pulley 56 rotates, the disk 60 having the gear portion 58 rotates around the drive pulley 56.
Since the disk 60 is configured to rotate integrally with the disk 60, the rotational force of the motor 68 is transmitted to the disk 60. The gear portion 58 of the disk 60 is connected to the magnetic tape cassette 50.
Since the gear part 86 of the inner reel flange 84 and the notch part 88 of the magnetic tape cassette 50 are engaged with each other, the rotation of the disk 60 is transmitted to the reel hub 82 at a reduced speed, and the magnetic tape 80 is wound up.

As described above, in the present invention, a reel hub with a reel flange for winding a magnetic tape is rotatably supported by a support shaft provided on a flat plate part and is housed inside the outer wall surface of the cassette, and A magnetic tape cassette is used in which a notch is formed in the side surface of the cassette that faces the teeth provided on the cassette, and in a part of the flat plate part following this, and when the magnetic tape cassette is installed at a predetermined mounting position, the The magnetic tape cassette is provided with a drive gear meshing with the teeth of the reel flange so as to transmit rotation through the notch of the magnetic tape cassette, and a motor for rotationally driving the drive gear. The reel stand used in conventional magnetic tape devices has a tooth thickness larger than the tooth thickness of the tooth portion and is configured to mesh with the tooth portion of the reel flange at a predetermined position within the tooth thickness range. 1
4 can be eliminated, and there is no need to incorporate a mechanism for driving the reel hub 82 between the magnetic tape cassette 50 and the substrate 52, so the thickness H of the device can be significantly reduced compared to h in FIG. It is possible to realize a thin, compact, lightweight magnetic tape device at low cost, and the structure of the magnetic tape cassette itself is extremely simple, so magnetic tape cassettes can also be supplied at low cost.
Excellent effects can be obtained by reducing the running cost of the system, and furthermore,
This has an excellent effect in that the rotational force of the motor can be reliably transmitted to the reel flange without being affected by positioning errors of the cassette or thickness errors of each tooth portion.

It goes without saying that the above can be carried out not only on the winding side but also on the reel on the supply side.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the main part of a conventional magnetic tape device, and FIG. 2 is a side sectional view of the main part of an embodiment of the present invention. 50... Magnetic tape cassette, 50b... Main flat plate part, 50c... Side part, 52... Substrate, 56...
... Drive pulley, 58 ... Gear part, 60 ... Disk, 62 ... Belt, 64, 76 ... Pulley, 68 ... Motor, 78 ... Shaft, 80 ... Magnetic tape, 82 ... Reel hub, 84 ... ... Reel flange, 86 ... Gear part, 88 ... Notch part.

Claims (1)

[Scope of Claims] 1. A reel hub with a reel flange for winding a magnetic tape is rotatably supported by a support shaft provided on a flat plate portion and is built inward from the outer wall surface of the cassette,
In addition, a magnetic tape cassette is used in which a notch is formed in a side surface of the cassette facing the teeth provided on the outer periphery of the reel flange, and in a part of the flat plate portion following this, and the magnetic tape cassette is mounted in a predetermined position. a drive gear that meshes with the teeth of the reel flange through the notch of the magnetic tape cassette so that rotation can be transmitted when the magnetic tape cassette is mounted in the position; and a motor for rotationally driving the drive gear; The gear has a tooth thickness greater than that of the teeth of the reel flange, and meshes with the teeth of the reel flange at a predetermined position within the range of the tooth thickness. 2. The magnetic tape device according to claim 1, wherein the reference pitch diameter of the drive gear is smaller than the reference pitch diameter of the teeth of the reel flange that mesh with the drive gear.