GB2196467A

GB2196467A - Optical disc with added magnetic record/playback facility

Info

Publication number: GB2196467A
Application number: GB8723636A
Authority: GB
Inventors: Michael Kitley; Michael Bailey
Original assignee: LONDON WEEKEND TELEVISION
Current assignee: LONDON WEEKEND TELEVISION
Priority date: 1986-10-11
Filing date: 1987-10-08
Publication date: 1988-04-27
Also published as: GB8624444D0; GB8723636D0

Abstract

An optical disc has on the normally unscanned side or unused portion of its surface, a secondary magnetic surface which can receive and store signals from a magnetic record and playback head. Such a secondary magnetic surface may be deposited on the optical disc during manufacture, or a secondary disc 1 may be provided in combination with the optical disc 2 but initially separate therefrom, the secondary disc having one side coated with magnetic material and the other side coated with pressure adhesive, protected by a backing peeled-off by the user, so the secondary disc may be affixed to the optical disc. Apparatus is disclosed for recording onto and playing back from an optical disc having fixed thereto a secondary magnetic storage disc (Fig. 3). The disc enables storage of additional information and subsequent modification thereof by the user. The magnetic surface allows preprogramming of track playing order in compact/video discs for example, and storage of student's answers/questions when used educationally. <IMAGE>

Description

SPECIFICATION Optical disc with added magnetic record/playback facility This invention relates to audio and video recording and play back systems.

Recently optical storage discs, signals upon which usually recorded in digital form are read for video or audio play back by a laser, have been introduced onto the market, there being no means provided whereby the user may "write to" the disc. The reason for this last mentioned omission is almost certainly that equipment for recording onto an optical disc is very complex and the process involves precision of a high order; so much so that it cannot in practise be supplied to the user at an affordable price. Nevertheless, the use of optical discs will find it advantageous for a number of applications if he can "write to" the disc information or instructions for storage thereon. The following possible applications are given by way of example: Example 1~Compact Disc-audio playback control.

Compact discs may contain recordings of a plurality of discrete works, each work being recorded on its own "track" of the disc and players exist that allow the track playing order to be pre-programmed by the user before listening. The major drawback to this is that programming has to take place at each disc insertion. It would be advantageous to provide non-volatile storage of this track playing order information with each disc. The listener's favourite order of tracks could automatically be selected at each disc insertion, yet allow modification if required.

Example 2~Video Disc-playback control.

The viewing order of video segments may be selected and stored in the same way as for the example for Compact Disc audio playback.

Example 3~Computer Learning Systems Vast amounts of data may be stored on optical discs that together with a computer could provide an ideal educational tool. The order of a standard learning programme could be tailored by instructors to their students individual requirements. Student's answers to questions and time spent on each segment could also be stored for later retrieval by the instructor. It would be advantageous to allow considerable flexibility in such systems.

This invention has for its broad object to enable a user to store additional information or instructions on an optical storage disc, in a non-volatile manner, while allowing subsequent modification, eg by amendment, deletion, or re-recording, where desired.

According to one aspect of this invention an optical disc is provided which has affixed to or deposited on the normally unscanned side or unused portion of its surface, a secondary magnetic surface which can receive and store signals received from a magnetic record and playback head.

Such a secondary magnetic surface may be deposited on the optical disc permanently during manufacture.

Alternatively a separate secondary disc could be provided in combination with, and it could be sold with, such an optical disc, such secondary disc having one side coated with magnetic material and having its other side coated with pressure adhesive, protected by a backing which is peeled-off by the user, so that this secondary disc may be affixed to the optical disc on an unused portion thereof by the user.

According to a second aspect of this invention apparatus for recording and playing back an optical disc having affixed to it such a secondary magnetic storage disc will include, in addition to the usual system for playing back the recording on the optical storage disc using a high speed motor drive and optical laser pick-up, a separate system having a magnetic read/write head together with the conventional amplification, decoding and encoding stages, and there will be means for driving the disc in rotation at a speed suitable for such read/write facilities in the magnetic mode; either the same or a different motor being used, as that used for rotating the disc for playback in the optical mode.

Thus in this second aspect of the invention, the disc playing apparatus will include two systems, one for effecting playback only from the optical storage disc in the optical mode; and the other for recording to or playing back from the secondary magnetic storage disc affixed to the optical storage disc, such recording or playback being in the magnetic mode. The two systems may be quite separate, there being an appropriate user control circuit, whereby he can control the two systems. However and as outlined above, although the two systems, optical and magnetic, may be otherwise separate, there may be a common means for effecting disc rotation at the speeds required, i.e. for the optical and magnetic modes of operation.

The invention will be further described with reference to the accompanying schematic drawings in which Figs. 1 and 2 are schematic diagrams of a video disc provided in conjunction with a supplementary disc element or surface facilitating magnetic recording by the user of information and instructions, as now proposed; and Fig. 3 is a block diagram of video playback and magnetic recording and playback apparatus, also as now proposed.

Figure 1 is a simple diagram showing how a secondary disc with a magnetic recording coating may be affixed to a portion of an optical disc which is not used for optical recording. Shown also is a record/playback head for writing to and reading from the magnetic surface. The principal features of this invention are derivable from a consideration of Fig. 1 where there is shown a coated surface of magnetic material 1, constituted as a secondary disc and affixed to an unused portion of an optical storage disc 2. For convenience the secondary magnetic storage disc is on the top of the optical disc, the lower surface of the latter having the optical recording. The magnetic surface may be provided during manufacture; or it may be affixed to the disc by the user. Mounted close to the magnetic recording surface is a magnetic read/write head 3 of known form. When the optical disc rotates the secondary magnetic disc being fixed on it, also rotates. The speed of rotation will be such that playback in the optical mode can be achieved, and/or recording and playback in the magnetic mode.

Figure 2 illustrates radial movement required of a read/write head operating in the magnetic mode. In this case either concentric or spiral tracks may be employed.

Figure 3 is a block diagram showing on the left an optical scanner and signal processing system, and on the right, a magnetic read/write head, with an associated data record/replay chain having amplification, encoding and decoding stages.

Claims

1. An optical disc which has affixed to or deposited on the normally unscanned side or unused portion of its surface, a secondary magnetic surface which can receive and store signals received from a magnetic record and playback head

2. The disc of claim 1 and in which such a secondary magnetic surface is deposited on the optical disc during manufacture.

3. The disc of claim 1 and in which such a secondary disc is provided in combination with the optical disc but initially separate therefrom, such secondary disc having one side coated with magnetic material and its other side coated with pressure adhesive, protected by a backing which is peeled-off by the user, so that the secondary disc may be affixed to the optical disc on an unused portion thereof by the user.

4. Apparatus for recording onto and playing back from an optical disc having affixed to it such a secondary magnetic storage disc as defined in any preceding claims, the apparatus including, in addition to the usual system for playing back the recording on the optical storage disc using a high speed motor drive and optical laser pick-up, a separate system having a magnetic read/write head together with associated amplification, decoding and encoding stages, and there being means for driving the disc in rotation at a speed suitable for such read/write facilities in the magnetic mode; either the same or a different motor being used, as that used for rotating the disc for playback in the optical mode.

5. Apparatus according to claim 4, wherein the disc playing apparatus will include two systems, one for effecting playback only from the optical storage disc in the optical mode; and the other for recording to or playing back from the secondary magnetic storage disc affixed to the optical storage disc, such recording or playback being in the magnetic mode.

6. Apparatus according to claim 5, wherein the two systems are quite separate, there being an appropriate user control circuit, whereby he can control the two systems.

7. Apparatus according to claim 6, wherein although the two systems, optical and magnetic, are otherwise separate, there is a common means for effecting disc rotation at the speeds required, i.e. both for the optical and for the magnetic mode of operation.

8. Apparatus for recording onto and playing back from an optical disc having affixed to it such a secondary magnetic storage disc as defined in any of the preceding claims 1 to 3, and substantially as hereinbefore described with reference to the accompanying drawings.

9. An optical disc according to claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.