GB2333884A

GB2333884A - Optical disc player cleaning apparatus

Info

Publication number: GB2333884A
Application number: GB9802147A
Authority: GB
Inventors: Trevor Burroughs
Original assignee: Optidisc International Ltd
Current assignee: Optidisc International Ltd
Priority date: 1998-01-30
Filing date: 1998-01-30
Publication date: 1999-08-04
Also published as: GB9802147D0; ZA99720B; WO1999039339A1; CN1296613A; AU2432499A; TW449740B

Abstract

The present invention concerns an optical disc player cleaning apparatus comprising a sheet 2 for releasable attachment to an exterior surface of an optical data storage carrier 10. The sheet has one or more cleaning elements 3;4 attached thereto for cleaning an optical component of a laser system within the player.

Description

OPTICAL DISC PLAYER CLEANING APPARATUS The present invention relates to devices for cleaning the exposed optical components of a laser system within the disc compartment of an optical disc player.

In this respect, within the disc compartment of an optical disc player, a laser beam is directed towards a read surface of a disc placed within the player. The read surface has tracks of circumferentially disposed pits formed therein which correspond to digital information stored on the disc. As the beam strikes the read surface, the variation in reflection of the beam back to a suitable receptor in the player, depending on whether the beam has fallen on a pit or not, determines the information retrieved from the disc.

If the path of the laser beam becomes obscured, for example by dirt or by condensation in the player, then the information retrieved may be corrupted, leading to skipping or other malfunctions of the player.

In this connection, there are known devices which are arranged to clean dirt and condensation from the exposed optical components of the laser system of an optical disc player within the disc compartment. Such devices generally comprise a specially manufactured compact disc (CD) which is injection moulded in the same way as a conventional playback compact disc but which carries no data or information apart from a standard time signal track which the laser uses to find the start segment of the CD and then to scan its way through the CD.

On the read side of the CD facing the laser apparatus, there are provided soft bristled brushes or areas of soft cloth padlike material. As the laser commences scanning the CD, it reads from the centre of the CD and follows the time signal track as it curves outwards towards the edge of the CD. By this movement, the laser beam will ultimately reach the area of the CD provided with the brushes or cloth.

At this point the CD will skip as the laser system is unable to correctly read the data on the CD through the brushes or cloth. Once it has passed over this area the laser system continues to scan normally again and thereby operation of the cleaning CD ends.

The intention of the optical component of the laser system passing over the brushes or cloth is that a lens cover (the exposed part of the laser system in the disc compartment) will come into contact with the brushes or cloth to thereby attempt to remove any dirt which has accumulated there.

A problem with such cleaning CDs is that they are relatively expensive in relation to their purpose, namely a complete ostensibly blank CD has to be manufactured in order to provide a product that has a simple cleaning effect. Also, such cleaning CDs can only be used infrequently since the brushes or cloths may after a single usage themselves become soiled to the extent that further cleaning therewith could cause damage the laser lens. Hence after a single usage it may be necessary to discard the whole cleaning CD, only because the brushes or cloths are unacceptably soiled. Further, such known CD cleaners are relatively bulky, taking up substantially the same volume as a standard CD thereby deterring storage of a number of such cleaners.

An object of the present invention is to provide an optical disc player cleaning apparatus which seeks to alleviate the problems associated with such known devices.

According to an aspect of the present invention, there is provided optical disc player cleaning apparatus comprising: a sheet for overlying an exterior surface of an optical data storage carrier; the sheet having one or more cleaning elements attached thereto for cleaning an optical component of a laser system within the player.

By way of such an arrangement, an optical disc player cleaning apparatus is provided which is simple to use and inexpensive to manufacture.

Preferably, the sheet is provided in the form of an annular transparent film member. The sheet can thereby be readily mounted on the optical data storage carrier.

In preferred embodiments, the said one or more cleaning elements are provided in the form of one or more small soft bristled brushes and/or pad-like cloths. Such cleaning elements afford suitable cleaning properties to the optical component of the laser system.

Conveniently, the cleaning elements extend radially outwardly from an inner edge of the sheet. As such, the optical component of the laser system can be subjected to a prolonged cleaning process as the laser beam processes towards the edge of the optical data storage carrier.

Preferably, the sheet is arranged for removable attachment to the conventional optical data storage carrier. Hence a conventional optical data storage carrier can be used in combination with the cleaning apparatus for the cleaning of the optical component of the laser system, there being no requirement to manufacture a dedicated blank CD.

In preferred embodiments, the sheet is provided with inner and outer rings of contact adhesive for fastening of the sheet to the optical data storage carrier. Alternatively or additionally an optical couplant adhesive or cohesive material may be provided to the sheet. In a further arrangement the sheet may be mechanically attached to the optical data storage carrier, for example by way of a rim.

Conveniently, the sheet is formed of a low birefringence material.

The apparatus may comprise a second sheet arranged for overlying a central raised portion of said optical data storage carrier; the second sheet having a specific thickness relationship with the thickness of the said sheet.

According to a further aspect of the present invention there is provided an optical data storage carrier provided with a sheet arranged to overlie an exterior surface thereof; the sheet being removably attached to the carrier and having one or more cleaning elements projecting outwardly therefrom for cleaning an optical component of a laser system within the disc compartment of an optical disc player.

An example of the present invention will now be described with reference to the accompanying drawings, of which: Figure 1 shows an optical disc player cleaning apparatus of the present invention; Figure 2 shows a side view of the cleaning apparatus as applied to a standard optical data storage carrier; and Figure 3 shows a focus correction means for use in conjunction with the cleaning apparatus of Figure 1.

As shown in Figure 1, a optical disc player cleaning apparatus 1 is provided which comprises an annular relatively thin transparent film member 2. An inside diameter of the film member is preferably in the order of 40 mm and an outside diameter is preferably around 80 mm, although this can be larger and may extend to the outside edge of an optical data storage carrier, e.g. a CD onto which the cleaning apparatus is to be applied.

Onto the film member are adhered cleaning elements in the form of small soft bristled brushes 3 or pad-like cloths 4. A combination of brushes and pad-like cloths may be provided for different cleaning effects. Any suitable alternative cleaning elements may of course be used. Whilst in the example the cleaning elements are adhered to the film member, they may be attached in any suitable manner, e.g. stitching. The cleaning elements may moreover be removably attached to the film member, for example using cooperating Velcro (Trade Mark) surfaces.

As shown in Figure 2 in use, the film member is removably attached to a conventional optical data storage carrier 10, such as a CD, CD-ROM, DVD etc by any suitable method. For example, the film member may be provided with rings of contact adhesive at the inner and outer diameters of the non-cleaning face (i.e. that face not afforded with cleaning elements).

Alternatively, an optical couplant type adhesive or cohesive material may be provided to the non-cleaning element face.

The film member itself and the means for attaching the film to the optical data storage carrier should allow at least some of the laser beam to pass into the optical data storage carrier, i.e. the beam should be able to pass through at least an area of the film reasonably unimpaired. Suitable materials for the film may include a low birefringence material, an acetate or a polycarbonate.

The film member is thus placed on to the optical data storage carrier 10. It is placed centrally on the side of the optical data storage carrier which is normally scanned - the playing side. The optical data storage carrier can, for example, be a CD from the user's own collection.

Those skilled in the art will be aware that, in the case of CDs, a circular area, coaxially surrounding the centre hole (which has a diameter of 15mm) and extending to a diameter of some 33mm, is raised relative to the remainder of the CD surface. The central raised circular area of the CD will project through the aperture formed by the inner diameter of the film member. In this regard, the central raised circular area of the CD can be used as a guide for correct positioning of the film member.

Once fitted with the film member, the optical data storage carrier is then positioned in the disc compartment of an optical disc player for normal playback, but with the volume turned down. As the optical data storage carrier has all the necessary standard time information, a laser 5 within the player will be able to commence normal playback until the cleaning elements are reached and then will begin to skip.

However, though it is skipping, the laser will continue to try to read the optical data storage carrier and at this time the exposed optical component of the laser system (i.e. laser lens 6) is cleaned in the same way as the known cleaning discs.

After cleaning is completed the optical data storage carrier can be stopped and removed from the player. The cleaning apparatus can then be removed from the optical data storage carrier 10 and depending on its condition can be disposed of or stored for a further usage.

The optical data storage carrier can, with the cleaning apparatus removed, be used again as per normal. In this regard, the means of attaching the film to the disc should not leave a residue on the disc, e.g. it should be removable without transference of adhesive.

The cleaning apparatus may be used in conjunction with a laser focus correction apparatus as shown in Figure 3. In this respect and as discussed above, those skilled in the art will be aware that, in the case of CDs, a central circular area 11 is raised relative to the remainder of the CD surface. There is a precise thickness relationship between this raised area and the rest of the CD (the playing area) which is critical, inter alia, to the maintenance of a set distance between the surface of the CD in its data-carrying area and a lens through which the laser beam impinges thereon, in order to maintain a set focal distance for the lens.

This has implications in the present case because, if the cleaning apparatus is applied only over the data-carrying area of the optical data storage carrier, the laser focussing, derived from the "virgin" raised area of the CD, will be incorrect. If, on the other hand, the cleaning apparatus is made to extend over both the data-carrying area and the raised area, it will not generally or reliably conform to the topography of the disc surface and, in particular, will tend to depart from this topography in the vicinity of the 33mm diameter circular step formed at the junction of the raised area and the remainder of the CD including its data-carrying surface. Unfortunately, the critical start-point of the recorded data usually occurs at or near this very location, and if that start-point cannot be found, through laser defocus or other optical problems attributable to the failure of the film to conform to the surface topography of the disc, the disc is rendered unreadable. A further problem can arise also, in that the film of the cleaning apparatus rather than the cleaning elements, may directly contact the laser lens in the vicinity of the start-point, since the film raises the level of the disc in relation to the raised area. Such contact may damage the laser lens and/or the film.

Hence as shown in Figure 3, a lens focus correction apparatus is provided comprising simply a further discoidal sheet of film 9 arranged to overlie the raised area 11 of disc. Such a focus correction sheet has a predetermined thickness arranged to set a suitable distance between the film member and the optical component of the laser system. For example, the thickness of the focus correction sheet may be less than that of the film member so as to reduce the spacing of the optical components of the laser system and the film member (and hence the cleaning elements). Thus the thickness of the focus correction member can be chosen to match a desired cleaning spacing. A selection of focus correction sheets with differing thicknesses may be provided for progressive cleaning of the optical component of the laser system.

It will further be understood that the examples illustrated show applications of the invention for the purposes of illustration. In practice, the invention may be applied to many different configurations, all straightforward for those skilled in the art to implement in the light of the foregoing.

For example, a number of optical disc player cleaning sheets may be provided together with a base disc having a suitable standard time signal track so as to provide a convenient cleaning system, the sheets being replaceable once soiled.

Claims

Claims: 1. A optical disc player cleaning apparatus comprising: a sheet for overlying an exterior surface of an optical data storage carrier; the sheet having one or more cleaning elements attached thereto for cleaning an optical component of a laser system within the player.
2. Apparatus according to claim 1, wherein the sheet is provided in the form of an annular transparent film member.
3. Apparatus according to claim 1 or 2, wherein the said one or more cleaning elements are provided in the form of one or more of small soft bristled brushes.
4. Apparatus according to claim 1 or 2, wherein the said one or more cleaning elements are provided in the form of one or more pad-like cloths.
5 Apparatus according to claims 1 or 2, wherein the cleaning elements are provided as a combination of brushes and pad-like cloths.
6. Apparatus according to any preceding claim, wherein the cleaning elements extend radially outwardly from an inner edge of the sheet.
7. Apparatus according to any preceding claim wherein the sheet is arranged for removable attachment to the conventional optical data storage carrier.
8. Apparatus according to claim 7, wherein the sheet is provided with inner and outer rings of contact adhesive.
9. Apparatus according to claim 7, wherein an optical couplant adhesive or cohesive material is provided to the sheet.
10. Apparatus according to any preceding claim, wherein the sheet is formed of a low birefringence material.
11. Apparatus according to any preceding claim, further comprising a second sheet arranged for overlying a central raised portion of said optical data storage carrier; the second sheet having a specific thickness relationship with the thickness of the said sheet.
12. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.
13. An optical data storage carrier provided with a sheet arranged to overlie an exterior surface thereof; the sheet being removably attached to the carrier and having one or more cleaning elements projecting outwardly therefrom for cleaning an optical component of a laser system within the disc compartment of an optical disc player.
14. An optical data storage carrier substantially ' as hereinbefore described with reference to the accompanying drawings.