AU3934397A

AU3934397A - Locating device

Info

Publication number: AU3934397A
Application number: AU39343/97A
Authority: AU
Inventors: Doukas Robert Fonias
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-08-29
Filing date: 1997-08-29
Publication date: 1998-03-19

Description

TITLE

Locating Device

FIELD OF THE INVENTION This invention relates to a locating device and in particular to a device and method for locating a protective cover on an optical disc.

DISCUSSION OF PRIOR ART Optical discs are a popular means of digitally storing information such as audio, visual, or graphics or any combination thereof. The most common form of optical disc is a compact disc which is popularly used for the recording of audio works but is now increasingly used in the storage of video and other visual representations in CD-ROMs (read only memory) and DVD (Digital Versatile Disc) . Compact discs come in variety of sizes and are used both in commercial and domestic situations. In domestic situations the discs are the most popular form of recording music.

Although when compact discs were first released, they were marketed as being extremely robust, durable and capable of producing an audio reproduction of high quality, experience has demonstrated that the operative surface of a disc has to be treated with care to ensure against scratching or build up of dust of other particulate material .

In my earlier patent application AUA 56203/94 I disclosed the application of a thin sheet of transparent plastics to the operative surface of an optical disc. In one embodiment this transparent cover is adhesively secured o the upper surface of the disc . The transparent cover operates to protect the surface of the disc from scratching or other damage and acts as a sacrificial cover which can be replaced when it becomes damaged without the need to replace the disc.

It is envisaged that the covers described in my earlier patent specification would be sold in packs so that owners of compact discs could apply the covers to their disc collection.

SUMMARY OF THE INVENTION

This invention relates to the problems encountered with a simple and effective application of a transparent cover to a disc.

According to one aspect of the present invention there is provided a device for locating a protective cover on an optical disc, the device comprising a flat surface having projecting upwardly therefrom a shouldered boss comprising a positioning spigot and a smaller location spigot, whereby a protective cover having a centre hole is positioned and located over the positioning spigot and an optical disc is positioned on the protective cover with the location spigot axially locating the disc over and coaxially with the cover whereby downward pressure on the disc towards the surface causes the disc to press against the cover for the cover to be accurately secured onto the disc.

Preferably, the spigots are co-axially positioned in the centre of a circular plate.

According to another aspect of the present invention there is provided a method of applying a protective cover to an optical disc, the protective cover comprising a plastics film with adhesive on one side, each side being covered by a masking sheet, the cover having a central aperture, the method comprising: a) positioning the cover, adhesive side up centrally onto a spigot projecting from a flat surface of an applicator, b) removing the upper masking sheet, c) placing and locating an optical disc, label side up, onto a locating spigot projecting from the flat surface of the applicator so that the optical disc is coaxially positioned over the cover, d) lightly pressing the optical disc against the adhesively coated cover, e) removing the optical disc from the applicator and pressing the cover against the optical disc, and f) removing the other masking sheet from the cover .

DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a side elevational view of a locating device,

Figure 2 is a plan view of the device, and

Figures 3 to 5 are perspective views illustrating how the locating device can be used to place a protective cover on an optical disc.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The locating device 10 shown in the accompanying drawings is for use to locate and position a protective cover 50 on an optical disc 100 especially a CD. The protective cover 50 is as described in my co-pending patent application AUA 56203/94 which is incorporated herein by reference .

The device 10 is in the form of a flat plate 11 of circular cross section. The diameter of the plate is preferably 120mm but is at least greater than the diameter of a conventional CD. It is understood that this device can be used with other optical discs and in consequence the diameter of the device will vary depending on the diameter of the disc. It is however important that the device 10 is of a diameter that approximates the disc 100. In a preferred embodiment the device 10 is larger than the disc 100. The plate 11 has a centrally positioned stepped upwardly projecting boss 12 which is in the form of a first positioning spigot 13 that terminates in a smaller diameter co-axial locating spigot 14. The positioning spigot 13 has a diameter of 40.85mm and has an upper surface 16 that extends upwardly by about 1mm from the upper surface 15 of the plate 11. The location spigot 14 has a diameter of 15mm and extends upwardly from the plate to a height of 3mm. The underside of the plate 11 terminates in a downwardly extending peripheral flange 18 and the upper surface 15 has a small arcuate cut-out 19 in the outer periphery.

The method of applying the cover 50 is shown with reference to Figures 3 to 5. The cover 50 comprises a flat sheet of clear plastics material having a central aperture 51 that equates to the diameter of a central portion of a CD 100 that does not generate an optical signal. One side 52 of the cover is coated with two annular rings of adhesive 53, 54 positioned respectively at the outer and inner peripheries of the cover. Both sides of the cover carry a masking sheet secured to a radially projecting tab 56 and 57, the masking sheets are numbered 1 and 2 in Figures 3 to 5. The masking sheets 1 , 2 protect the cover 50 while packaged and during assembly. To locate a cover 50 on a CD 100, the cover is first placed onto the positioning spigot 13 of the locating device 10 with the central aperture 51 of the cover fitting closely over the positioning spigot 13 so that the cover is accurately located centrally of the device 10. The cover 50 is placed on the device with the masking sheet 1 facing upwardly. By pulling on the tab 56, the masking sheet 1 can then be peeled off the cover 50 exposing the two rings of adhesive 53, 54. The operative surface of a clean CD 100, that is the surface that does not carry the label and the surface that is usually placed face down in playing devices, is then positioned face down against the upwardly facing surface of the cover 50 and is centrally located on the locating device by the small locating spigot 14 that is a close fit within the central aperture 101 of the CD 100. The centre of the CD 100 rests on the upper surface 16 of the spigot 12.

A slight downward pressure on the CD 100 evenly around the circumference of the CD causes the CD to flex against the cover 50 and ensures that there is good contact between the adhesive rings 53, 54 on the cover and the adjacent surfaces of the CD. Figure 4 shows the step of positioning the CD 100 onto the upper surface of the cover 50 that is already on the locating device 10. The CD 100 and cover 50 are then removed from the locating device and the cover is smoothly pressed into thorough and firm engagement against the CD. Since the adhesive is confined to the inner and outer peripheries, a smooth circular pressing action is carried out on those peripheries through the second masking sheet 2 thereby ensuring that there is no thumb or finger contact on the playing surface of the cover. As shown in Figure 5, the masking sheet 2 can then be peeled off using the tab 57 to leave the CD 100 with a clear plastics cover 50 accurately positioned on its playing surface.

The height of the upper surface 16 of the positioning spigot 13 above the flat surface 15 of the plate 11 of the locating device 10 is critical to ensure that there is an opportunity to place pressure on the playing surface of the CD 100 to ensure that it engages the adjacent surface of the cover 50.

In the preferred embodiment the locating device 10 is moulded in plastics. However it is understood that the device could also be machined in metals such as aluminium. Although the device 10 is preferable of circular cross section it is understood that other cross sectional shapes are envisaged as long as the base of the location device provides a planar surface that will support the whole of the cover and disc.

It is envisaged that the locating device 10 and sets of adhesively coated protective covers 50 would be sold as a kit so that users of CDs can simply and effectively cover the CDs.

In a more sophisticated version not shown in the accompanying drawing it is understood that the positioning spigot can be designed so that the distance between the upper surface 16 of the spigot and the upper surface 15 of the plate 11 can be reduced so that downward pressure on the CD is transferred more readily to the cover without the likelihood of the CD being bent into engagement with the cover. In other words to ensure that there is no bending of the CD during application of the downward pressure the upper surface 16 of the positioning spigot 12 is caused to move towards the upper surface 15 of the locating device. One means of effecting this feature is to use a disc for the upper surface 16 of the spigot 12. The disc is mounted to displaceable relative to the remainder of the spigot about biasing means such as a spring. Alternatively, the spigot could be made in resilient plastics that can be compressed to ensure the positive engagement. It is also understood that the locating device 10 could be provided in the base of the plastics case that usually houses the CD 100. A set of covers 50 could then be sold with the new CD 100 with the locating device 100 built into the case of the CD.

Claims

1. A device for locating a protective cover on an optical disc, the device comprising a flat surface having projecting upwardly therefrom a shouldered boss comprising a positioning spigot and a smaller location spigot, whereby a protective cover having a centre hole is positioned and located over the positioning spigot and an optical disc is positioned on the protective cover with the location spigot axially locating the disc over and co-axially with the cover whereby downward pressure on the disc towards the surface causes the disc to press against the cover for the cover to be accurately secured onto the disc.

2. The device according to Claim 1 wherein the spigots are co-axially positioned in the centre of a circular plate.

3. The device according to Claim 2 wherein the periphery of the plate is provided with at least one cutout. . The device according to any one of the preceding claims wherein the device is moulded in plastics so that the flat surface terminates in a peripheral downwardly extending flange.

5. The device according to any one of the preceding claims wherein the positioning spigot terminates at a height above the flat surface that is slightly greater than the thickness of the protective cover. . The device according to any one of the preceding claims wherein the diameter of the central hole in the cover is about the same as the diameter of the positioning spigot .

7. The device according to any one of the preceding claims wherein the diameter of the location spigot ensures that the spigot is a close fit within the central hole of an optical disc.

8. A protective case for an optical disc comprising a base including a recess into which an optical disc can be positioned characterised in that the base structure incorporates the device according to any one of the preceding claims.

9. A method of applying a protective cover to an optical disc, the protective cover comprising a plastics film with adhesive on one side, each side being covered by a masking sheet, the cover having a central aperture, the method comprising: a) positioning the cover, adhesive side up centrally onto a spigot projecting from a flat surface of an applicator, b) removing the upper masking sheet, c) placing and locating an optical disc, label side up, onto a locating spigot projecting from the flat surface of the applicator so that the optical disc is coaxially positioned over the cover, d) lightly pressing the optical disc against the adhesively coated cover, e) removing the optical disc from the applicator and pressing the cover against the optical disc, and f) removing the other masking sheet from the cover.