JPS5827415Y2 - cassette disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cassette disk in which a high-density information recording disk such as a video disk, PCM or FM modulated audio disk is accommodated in a cassette case.

Hitherto, high-density information recording disks (hereinafter simply referred to as disks) such as video disks, PCM or FM modulated audio disks have been developed, and there are various types of such disks, such as mechanical playback methods, electrostatic playback methods, optical playback methods, etc. is being developed.

However, since the information density of this type of disc is extremely high, if dust, fingerprints, etc. adhere to the recorded images, significant disturbances in the signal amount will occur during playback, especially when using mechanical playback methods or electrostatic playback methods. Dropouts caused by dust and fingerprints are a major problem in the field.

In order to prevent this, a system has been developed in which such a disc is conventionally stored in a case, and when playing, the case is inserted into a playback device, and the disc is mechanically removed and played.

However, with this mechanical loading and unloading method, dust gets stuck when mechanically loading and unloading the case! However, there were disadvantages such as the playback device having a complicated mechanism.

In this invention, the disc is stored in a cassette case, and during playback, the disc is rotated while it is stored in the cassette case, and the disc is rotated through the playback hole provided in the cassette case.
This relates to a cassette disk that extracts signals from the disk, and more specifically, a cassette disk that prevents dust from entering the cassette case through a rotation hole provided in the cassette case to rotate the disk inside the cassette case. It is related to.

To explain the present invention in detail with reference to the drawings, as shown in FIGS. 1 and 2, the disk 1 is made of hard vinyl chloride material, has a diameter of 300 mm, a thickness of about 2 mm at the inner circumference, and a diameter of 2 mm.
280 grooves from 90mm to 190mm in diameter/
The video signal 2 is formed in a spiral shape with pitches between.

A center hole 3 is formed in the center of the disk 1, through which a rotating shaft 31 provided on a turntable 30 for rotating the disk 1 passes.

As shown in FIGS. 3 and 4, a convex portion 22 is provided on the non-recording surface of the inner circumference of the portion of the disc 1 where the video signal 2 is engraved, all around the circumference.

This convex portion 22 is provided on both the front and back surfaces of the disk 10.

The cassette case 10 consists of an upper plate 11, a lower plate 12, etc. The lower plate 12 is formed by injection molding of styrene material.

However, it has been confirmed that similar effects can be obtained using other plastic materials such as acrylic resin and hard vinyl chloride.

A rotation hole 16 is formed in the center of each of the upper plate 11 and the lower plate 12 for fixing and rotating the disk 1 on the turntable 30.

As shown in FIG. 2, recesses 21 are formed around the entire circumference of the rotation holes 16 of the upper plate 11 and lower plate 12 at positions corresponding to the protrusions 22 of the disk 1.

A space 13 for storing the disc 1 is formed between the upper plate 11 and the lower plate 12, and the disc 1 is stored in the space 13.

FIG. 6 is an enlarged cross-sectional view of a main part showing a state in which the cassette case 10 containing the disc 1 is stored horizontally when not being played.

In this case, the disc 1 is attached to the lower plate 12 of the cassette case 10.
The thick portions of the outer and inner peripheries, that is, the areas other than the signal 2 recording surface are in contact with the top.

At this time, the convex portion 22 of the disk 1 on the side facing the lower plate 12 is fitted into the recess 21 of the lower plate 12.

Further, the convex portion 22 on the side facing the upper plate 11 faces the recessed portion 21 of the upper plate 11 with a constant interval.

During playback, the cassette disc is placed at a predetermined position in the playback device, as shown in FIG.

At this point, the disk 1 is fixed to the turntable 30 by fitting the center shaft 31 into the center hole 3 and being pressed from above by the holding shaft 32, so that the disk 1 and the cassette case 10 are in a non-contact state. becomes.

Further, the cassette case 10 is fixed to a board 40 within the playback device.

An enlarged sectional view of the main part showing this state is shown in FIG.

In this embodiment, the thickness of the disc 1 other than the signal 2 recording surface is 2.
In order, the height of the convex portion 22 is 1 my, the depth of the recess of each of the upper plate 11 and the lower plate 12 is 1, and the interval between the upper and lower plates is 3 my.

Therefore, the distance between the disk 1 and the upper plate 11 and the lower plate 12 is 0.5 spaces.

During playback, the disc 1 and the cassette case 10 must rotate without contact. During this rotation, a button is pressed on the outer periphery of the disc, causing the disc to vibrate in the vertical direction.
This vertical vibration width is 150 rpm at 450 rpm.
It can be suppressed to within μm, so it is 500μ in the vertical direction.
It was confirmed that an interval of m is sufficient.

The convex portion 22 provided on the disc 1 and the recessed portion 21 provided on the upper and lower plates 11° 12 do not come into contact with each other during playback, and moreover, when not playing, they enter the space 13 from the rotation hole 16 formed in the upper and lower plates 11° 12. It can reduce the amount of dust entering.

A reproduction hole 18 through which a pink-up for reproducing the signal is passed is formed at the signal 2 recording position of the disk 1 on the upper and lower plates 11 and 12, and a lid 19 is attached to the reproduction hole 18 by a hinge.

In this embodiment, the signal 2 is recorded on both sides of the disc 1, but if the signal 2 is recorded on only one side, the reproducing hole 18 may be provided on only one side.

In the figure, 20 is a screw for fixing the upper and lower plates 11 and 12.

In the above explanation, the convex part 22 was formed on the disk 1 and the concave part 21 was formed on the upper and lower plates 11.12, but as shown in FIG. A similar effect can be obtained.

Since the present invention has the above configuration, it has excellent effects as shown below.

In other words, since the disc of this cassette disc is covered with a cassette case, it not only prevents dust and fingerprints from adhering to it during handling, but also prevents convex parts from forming on the disc, which protects the upper and lower plates. Concave parts are formed at positions corresponding to the convex parts, which prevents dust from entering through the rotation hole of the cassette case, not only when not playing, but especially during playback, ensuring stable image playback over long periods of time. Ru.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the cassette disk, FIG. 2 is a sectional view taken along line A-A in FIG. 1, FIG. 3 is a plan view of the disk, and FIG. It is a cross-sectional view taken along line B, FIG. 5 is a cross-sectional view of the cassette disk during playback, and FIG. 6 is an enlarged cross-sectional view of main parts showing the relationship between the disk and the cassette during non-playback. , 7th
The figure is an enlarged sectional view of the main part showing the relationship between the disc and the cassette during reproduction, and FIG. 8 is an enlarged sectional view of the main part showing another embodiment. DESCRIPTION OF SYMBOLS 1...Disk, 2...Signal, 10...Cassette case, 11...Upper plate, 12...Lower plate, 16...
Rotation hole, 22... Convex part, 21... Concave part.

Claims (1)

[Scope of utility model registration request] In a cassette disc, which is made by storing a disc in the disc storage space of a cassette case consisting of an upper and lower plate, rotation holes are provided in the upper and lower plates to rotate the disc, and the signal engraved part of the disc is Convex part (or concave part) on inner circumference
A cassette disk in which concave portions (or convex portions) are formed at positions corresponding to the convex portions of the upper and lower plates.