GB2389698A

GB2389698A - Compact disk with scratch protection

Info

Publication number: GB2389698A
Application number: GB0213283A
Authority: GB
Inventors: Richard Auty
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-06-11
Filing date: 2002-06-11
Publication date: 2003-12-17
Also published as: GB0213283D0

Abstract

A scratch resilient compact disk 1 having on its program side raised projections 2, 3 for preventing the program side from contacting a surface onto which the disk 1 is placed program side down. The raised projections 2 are preferably distributed around the outer rim, with further raised portions 3 disposed concentrically towards the centre of the disk. The raised portions 2, 3 are within the unrecorded lead in and lead out areas of the disk.

Description

COMPACT DISC WITH SCRATCH PROTECTION

this invention relates to compact discs and to minimizing scratching of discs. The "compact discs" may be of the commonplace size used for music or computers, of the 5 smaller so-called 'mini-discs" or more generally of any size.

Although compact discs are considered to have relatively high scratch resistance, it is becoming apparent that this is not the case. Often users of compact discs do not return them to protective covers or boxes, but put them down on a surface such as a table or 0 desk. In order to recognize the disc it is often put down label side up so that the recorded side contacts the surface. When a disc that is so placed is picked up, instead of careful vertical lifting, which is quite difficult in view of the thinness of the disc, the disc is often dragged towards the desk or table edge. This dragging can cause scratches, particularly if the disc has been placed on top of debris.

The present Invention is directed towards providing a discs with a reduced risk of being scratched.

The invention is now described by way of example with reference to the so accompanying drawings in which: Figure I is a schematic plan view of a disc according to a preferred embodiment of the invention, and 25 Figure 2 is a view from the side in the direction of arrow A of Figure 1.

Referring now to the Figures, a compact disc 1 has on its program side three small raised portions 2 disposed towards the outer rim or periphery of the disc. Three further raised portions 3 are disposed towards the centre of the disc. These two sets of raised 30 portions are each disposed around a notional circle, spaced evenly from the other raised portions in the set, i.e. for three raised portions per set spaced by a sector that

- 2 subtends an angle of 120 at the centre. Preferably, and as shown in the drawings, the sets are rotationally staggered with respect to one another.

In the preferred embodiment shown, the raised portions are hemispherical with a s height of I mm. Other heights may be used, but it is generally envisaged that heights of 0.7 to 1.5 mm are optimum for not impairing operation, and this may also depend on the size of the disc.

The raised portions prevent the program surface of the disc from touching a surface on 0 which it is placed, so that if the disc is dragged across that surface when being picked up, debris or roughness on the surface does not scratch the disc.

It is possible to have fewer raised portions, other configurations for the raised portions, or only one set of raised portions, but having a more inwardly and a more outwardly 5 disposed set reduces risk of flexing of the disc under finger pressure bringing the program surface into contact with the surface on which it is resting In order that the raised areas do not interfere with the program area they are located on the unused (digital silence) parts of the lead in and lead out areas of the disc. (The lead so in area is towards the centre, the lead out around the outer edge of the disc).

The arrangement shown with three raised areas in each set is generally well balanced for rotation, but other numbers of areas may be provided, or even continuous raised rings or more laterally extensive in the circumferential direction, raised areas. When 25 non-continuous raised portions are provided, there are preferably at least three in each set. The raised areas may be fabricated by providing corresponding recesses in a mold that is used to form the disc. Alternatively an adhesive cover carrying some or all of the 30 raised portions may be provided. Preferably a single cover carries all the raised portions. A further modification may be for a cover with raised portions that covers

( only the central part of the disc, with individual adhesive raised portions that can be positioned around the outer periphery.

The compact discs may be of any size although it is envisaged that they are of a size s that is generally able to be mounted or installed for use by the human hand, as in the case for standard computer or music CDs or mini-discs.

Claims

-4 CLAIMS

1. A compact disc having on its program side at least one raised portion distributed around at least one circular path concentric with the disc, the circular path 5 being located within an unused part of the disc.

2. A compact disc according to claim I in which the circular path is proximate the outer periphery of the disc.

lo

3. A compact disc according to claim I in which the circular path is disposed towards the centre of the disc.

4. A compact disc according to claim I comprising a first circular path proximate the outer periphery of the disc and a second circular path disposed towards the centre of the disc.

5. A compact disc according to any preceding claim in which the raised portion comprises a plurality of separate raised areas.

so

6. A compact disc according to claim 5 in which the raised areas comprise hemispherical projections.

7. A compact disc according to claim 5 or claim 6 in which each circular path has three equally spaced raised areas.

8. A compact disc according to any preceding claim in which the raised portion has a height of I mm.

9. A compact disc according to any preceding claim in which the raised portions 30 are moulded with the disc.

- 5

10. A compact disc according to any of claims 1 to 8 in which the raised portions are font ed separately from the disc and are provided with means for attachment to the disc.