DE2517154A1 - PROTECTIVE DEVICE FOR RECORDING MEDIA AND APPLICATION DEVICE FOR USE OF THE PROTECTIVE DEVICE - Google Patents

Description

Dipl.-Ing. Egon Prinz _Λο »,», »· ι _1O no

p " r * ". Tu D - 8000 Munich 60, April 18, 1975

Dr. Gertrud Hauser _E , “, be, _ge r _t ., AB. ₁₉ 0 ς 1 7 1 He / Dipl.-Ing. Gottfried Leiser Z b 1 / I b 4

Patent attorneys

Telegrams: Labyrinth Munich

Telephone: 8315 10

Telex: 5 212 226 prhl d Postal checking account: Munich 117078-800 Bank: Deutsche Bark. Munich 66/05 COO

THOMS 01T - BRAEDI

175, vol. Haussmann

75008 PARIS / France

Our sign; M 1764

Protective device for recording media and placing device for using the protective device

The invention relates to a protective device for record carriers and in particular for record carriers in the form of flexible discs on which audio frequency or video frequency signals are recorded. The invention also relates to a device for automatically placing the recording medium on a scanner, in which the protective device is used.

The best-known protection system for records that carry audio frequency signals is the record cover. This system is satisfactory for the storage of the plates, but does not provide any protection in handling the plates during when placing it on the turntable or removing the records.

509844/0813

Lei / Gl

This "constitutes a disadvantage, which is particularly important then Weight falls if this system is to be applied to recording media for video frequency signals. These recording media are particularly sensitive to scratches, to friction, for example on the Internal surfaces of a record sleeve, or for various other surface damage.

The aim of the invention is to provide a protection device for record carriers in which these disadvantages be avoided. To solve this problem, the protective device according to the invention contains a protective pane which adheres the information-bearing surface of the disc by means of an electret layer; the disc can thereby placed vertically on the plate or lifted off the plate without any sliding. This training also enables a simple automatic system to be provided for placing the disk on the disk scanner.

Further features and advantages of the invention emerge from the following description of an exemplary embodiment based on the drawing. In the drawing show:

] Pig.1 is a perspective view of an embodiment the protective device according to the invention,

FIG. 2 is a sectional view through an arrangement that consists of the protection device, the platter, the support system and the platter of the scanner, and

Pig. 3 a modification of the arrangement of FIG. 2.

509844/081 3

Pig. 1 shows a recording medium 3, for example in the form of a flexible plate made of polyvinyl chloride, which is provided with a central hole 10 and carries information only on one surface. This area is by means of a material to be described later, a rigid or semi-rigid disc 2 applied, for example consists of cardboard and preferably has a central hole 20, the diameter of which is greater than the diameter of the central hole 10 of the plate 1 is.

Pig. 2 shows the plate 1 and the disk 2 in a sectional view. In this illustration, a layer 3 consists of one Material shown that has the effect of holding the disc 2 on the plate 1 and allows the plate to apply to disc 2 or to pull it off from this disc without sliding. Layer 3 is, for example, one Electret layer, the electrostatic attraction of which for a plate made of polyvinyl chloride treated in this way that it is antistatic is greater than the weight of the plate.

For example, in such a plate with a thickness of 150 µm, the attraction exerted by the electret is

/ 2

force of the order of 500 g / cra, while the

P.
weight of the plate is about 160 g / m.

In this way, a protective device has been created for the surface of the disk 1 carrying the information. If the recording takes place on the two surfaces of the disk, it is of course also possible to provide a second protective device on the second surface, which is the same as the first protective device.

JPig. 2 also shows an embodiment of the lay-up system for the plate. Is consists essentially of four

509844/0813 original inspected

Positioning pins 5 on the chassis 41 of the disk scanner are attached, and from a device with which a pressure can be exerted on the plate 1, so that it falls onto a rotatable turntable 4 carried by the chassis 41.

The four positioning pins 5 are firmly connected to the chassis and have corner-shaped cutouts; You have the Task to hold the disc 2 at its corners in the waiting position so that the central hole 10 of the plate 1 of the drive spindle 40 of the turntable 4 is opposite, concentric to the axis of rotation 42 of the spindle 40 and in one fairly small distance, for example of the order of a few millimeters, so that the plate 1 is safe damage can fall on the turntable 4.

As soon as the plate 1 is correctly positioned in this way with the aid of its protective disk 2, it is placed on the turntable 4 by pressing on that part of the platter 1 which is exposed in the central hole 20 of the disc 2; this can be done by hand or by an automatic device, for example with the closing of a Cover is connected to the disk scanner. The last solution is in Pig. 2 shown schematically by a cover 6, which has a projection 60 of such dimensions that it extends through the central hole 20 on the Plate 1 lays when the cover is placed on the chassis 41.

The removal of the disk 1 from the turntable 4 takes place in that the protective disk 2 is placed on the disk 1, either by the fact that the disk 1 is raised is, or by the fact that the positioning pins 5 are removed so that the disc 2 goes down.

509844/081 3

Pig. 3 shows a modification of the arrangement of FIG. 2, the waiting position of the plate being the same as in FIG Pig. 2 is, but the application is no longer done by mechanical pressure, but by lifting the electrical attraction of the electret layer.

For this purpose, the chassis 41 of the disk scanner again carries four positioning pins 5, which are intended for this purpose are to hold the disc 2 at its corners in the correct position. The chassis 41 also carries an electric conductive layer 8 connected to a terminal 80. The protective device for the plate 1 contains besides the Protective pane 2 and the electret layer 3 a metallization 7 at the interface between the pane 2 and the electret 3; This metallization can, as shown in the drawing, extend to the edge of the pane extend so that it can be conveniently electrically connected to an external terminal, for example via mnen the positioning spigot 5.

To place the plate 1 between the layers 7 and 8 with the help of the connections 70 and 80, an electrical connection is made DC voltage that is able to cancel the electrostatic force generated by the electret, for example a tension on the order of 200 to 300 YoIt; this releases the plate 1.

The lay-on system described is suitable for use with panels with different diameters: For this purpose, as many groups of positioning pins as possible are provided in diameter are available, and which can be switched manually or automatically.

509844/081 3

Claims (8)

Patent claims / ij Protective device for recording media, marked by at least one disc, one surface of which is covered with a layer of an electret material which the Disc on the record carrier on one of its surfaces, which surface holds at least part of the recording carries so that the recording medium frictionless in the direction perpendicular to the disk to this disk can be applied or removed from the disc. 2. Protection device according to claim 1, characterized in that in the case of a plate-shaped recording medium, the disc is rigid and has the shape of a square in which the plate is substantially inscribed. 3. Protection device according to one of the preceding claims, characterized by at least one second rigid disc, one surface of which is covered with a layer of an electret material, which the second disc to the other surface of the recording medium holds. 4. Protection device according to one of the preceding claims, characterized in that the disc has a central hole, in which the recording medium is accessible. 5. Arrangement for placing one with a protective device according to one of the preceding claims provided recording medium on a turntable, characterized in that that the chassis of the turntable with positioning pins for positioning the disc in relation to the axis of rotation of the turntable is provided. 609844/081 3 6. Arrangement naoh claim 5, characterized in that the positioning pin, the disc at their four Keep corners a short distance from the platter. 7. Arrangement according to claim 5 or 6, characterized by means for exerting a mechanical pressure the part of the recording medium exposed in the center hole of the disc. 8. Arrangement according to claim 5 or 6, characterized in that the protective device between the disc and the electret material has a first conductive IPiIm, that the chassis of the turntable has a second . conductive film, which is essentially the first PiIm opposite, and that between the two "films there is a direct electrical voltage of such value and such Sign is applied that thereby the electrostatic force generated by the electret material is canceled. 50S844 / 081 3 Blank page