GB2168191A

GB2168191A - Video disc data storage

Info

Publication number: GB2168191A
Application number: GB08429767A
Authority: GB
Inventors: Ronald John Frederick Howard; Arthur George Gilbert Robinson
Original assignee: MICRODATADISC Ltd
Current assignee: MICRODATADISC Ltd
Priority date: 1984-11-26
Filing date: 1984-11-26
Publication date: 1986-06-11
Also published as: GB8429767D0

Abstract

A method for storing data comprises storing data on a video disc so that the data may be accessed by a computer and storing selected items of the data on another computer accessible data storage medium to form an index for the data stored on the video disc. A pre- master tape may be edited as required, and duplicate video discs produced from the master disc. Graphs in the original material may be expanded and text compressed, for example. <IMAGE>

Description

SPECIFICATION Improvements in or relating to data storage This invention relates to improvements in or relating to data storage.

Techniques are well known which enable data to be stored in a computer in the form of "databases", which permit the selection and retrieval of particular pieces of information according to a number of parameters entered into the computer. In many such databases the insertion and storage of a sufficient amount of information can become uneconomic because of the large number of key depressions involved in inserting the information and because of the large amount of magnetic disc storage space required for storing the information. In addition, particularly where the storage of technical information is involved (e.g. in databases related to materials, components, products and processes), the required information is frequently in diagrammatic or graphical form and this is very time consuming and may prove impossible to put onto computer magnetic storage discs.For these reasons the computer database is frequently backed up by some other form of data storage, for example a library of printed material.

This considerably reduces the advantages of a computer data system.

It is an object of the present invention to provide a method of storing data which overcomes or at least mitigates the above mentioned problems.

According to one aspect of the present invention, there is provided a method of storing data, which method comprises storing data on a video disc so that the data may be accessed by a computer and storing selected items of the data on another computer accessible data storage medium to form an index for the data stored on the video disc.

In a second aspect, the present invention provides a method of storing data, which method comprises digitizing original visually displayed data, processing the digitized data so that the processed data will occupy a different number of frames on a video tape than the original data, recording the processed data on video tape and transferring the processed data recorded on the vide tape to a video disc so that the data stored on the video disc may be accessed by a computer.

For a better understanding of the present invention, and to show how the same may be put into effect, exemplary embodiments thereof will now be described.

In one method in accordance with the invention, visually displayed information or data is recorded directly onto magnetic video tape using a high resolution black and white video camera. Alternatively, the visually displayed data may first be photographed using, for example, a 35mm camera and a commercially available telecine machine then used to transfer the data recorded on the photographic film onto magnetic video tape.

In either case, the visually displayed information will probably comprise an original document formed by a plurality of sheets of paper, each sheet carrying data in the form of text, graphics and/or artwork. The visually displayed information will be recorded on the magnetic video tape, either directly or indirectly as mentioned above, so that the data on each page or sheet of the visually displayed information is recorded so as to occupy a respective separate "frame", on the video tape, a "frame" being the section of video tape on which is stored the signals which will form a single frame when the recorded data is displayed on a visual display unit such as a video monitor or television.

Once recorded on video tape, the data or information is then transferred to a video disc with appropriate coding so that the data is in a computer-accessible form. The video tape is used as a pre-master tape from which a master video disc is produced. A large number of duplicate or replicate video discs can then be pressed using the maaster video disc. One advantage of this arrangement is that it simplifies the process of amending recorded data.

Thus although it is for all practical purposes impossible to modify a video disc, the premaster video tape stores the data as magnetic domains and it is relatively easy to "wipe" selected areas of tape and to record those areas with new data or information. Also, video tapes can be spliced to remove selected sections of tape or to add in selected new sections of tape. Once the pre-master video tape has been modified as desired, a new master video disc can then be produced and new replicate video discs pressed. Selected key items of the data stored on the video disc, for example headings or keywords, are also stored on another computer-accessible data storage medium, for example a floppy or hard disc.

A video disc player and a disc drive are interfaced to a computer in a conventional manner. The computer is programmed so as to be able to access the key or selected items of information stored on the other data storage medium and display the same on a visual display unit or monitor when appropriate instructions are supplied to the computer.

The computer will also be programmed to allow a user who wishes to know more about one of the key or selected items to access the data stored on the video disc and to display the same on the monitor. Thus, the other data storage medium acts as an index for the data or information stored on the video disc so that a user of the computer can rapidly select desired items from the index stored on the other data storage medium (which index may carry brief detail associated with each key item). If the user wishes to have further, more detailed, information on a selected key item, then the relevant information on the video disc can be accessed quickly using the computer and the index stored on the other data storage medium.

The bandwidths available in existing apparatus for producing video discs and machines for 'playing back' or displaying the information stored on a video disc limit the resolution available for the information stored on a video disc and it is not, for example, possible to display a full page of the A4 text printed in 12-point characters in one frame on a monitor so that the image displayed is clearly legible.

Also, it is desirable to be able to edit the data to be stored on the video disc so as to, for example, enlarge a diagram so that all the detail therein is clearly visible when it is displayed on the monitor or to compress pages with little data or information therein to save space on the video disc. Such manipulation of data is both time-consuming and expensive if conventional video camera techniques are used.

In a method embodying with the present invention, if it is desired to edit the data to be stored on a videodisc to, for example expand graphs and other diagrams and compress text, a video tape containing the desired data is played back using a conventional telecine machine so as to digitize the data. Of course, where the visually displayed information or data is first photographed and then transferred onto a video tape as described above, the digitizing step will be carried out by the telecine machine before the data is recorded onto the videotape. In either case, the telecine machine will convert each frame of the photographic or original video tape into digital signals.

These digital signals can then be edited using an editor of the telecine machine to modify, for example to expand or compress, the digital signals and then convert the processed digital signals into a form suitable for recording on magnetic video tape. Thus, the editor can be used to, for example, divide the digital sig nals representing a respective frame of the original data into a number of selected component parts and then expand the digital signals representing each selected part so that, when the digital signals are converted into a form suitable for recording an video tape and recorded onto videotape, each frame on the video tape will be occupied by the data which formed part of a frame on the original video tape.Alternatively, the digital signals can be compressed so that the data which occupied a plurality of frames on the original photographic film or videotape only occupies one frame on the final or master video tape. The processed data stored on the master video tape is then, as described above, transferred to video disc with appropriate coding so that the data on the video is readable by a computer interfaced to an appropriate video disc player.

Commercially available video disc players and monitors are designed primarily for the display of moving colour pictures and the resolution obtained is not adequate for displaying a static page of text. Accordingly, in the above method, a gate circuit using conventional electronic techniques is interposed between the video disc player and the grid of the cathode ray tube of the monitor. The gate circuit is only triggered when the voltage of the video signal reaches a certain level and so allows rapid transitions from black to white at a predetermined video signal level, improving both the resolution and the contrast of the image. However while the presentation of monochrome material is improved, the "soot and whitewash" effect means that the technique cannot be used for half tone or multicolor images.

The above described embodiments of the invention are illustrated in the accompanying diagram.

Claims

1. A method of storing data, which method comprises storing data on a video disc so that the data may be accessed by a computer and storing selected items of the data on another computer-accessible data storage medium to form an index for the data stored on the video disc.

2. A method according to Claim 1, wherein the other data storage medium comprises one or more magnetic discs.

3. A method according to claim 1 or 2, further comprising, prior to storing the data on video disc, digitizing original visually displayed data, processing the digitized data so that the processed data will occupy a different number of frames on a video tape than the original data and recording the processes data on video tape.

4. A method of storing data, which method comprises digitizing original visually displayed data, processing the digitized data so that the processed data will occupy a different number of frames on a video tape than the original data, recording the processed data on video tape and transferring the processed data recorded on the video tape to a video disc so that the data stored on the video disc may be accessed by a computer.

5. A method according to claim 3 or 4, wherein the step of digitizing the original visually displayed data comprises recording the data on photographic film and then digitizing the data recorded on the photographic film.

6. A method according to claim 3 or 4, wherein the step of digitizing the original visually displayed data comprises recording the data on video tape and then digitizing the data stored in the video tape.

7. A method according to any one of claims 3 to 6, wherein the data is processed so that data which would have occupied part of a frame on the video tape occupies a whole frame on the video tape when the data is recorded after being processed.

8. A method according to any one of claims 3 to 6, wherein the data is processed so that data which would have occupied a whole frame on the video tape occupies part of a frame on the video tape when the data is recorded after being processed.

9. A method according to any preceding claim, including displaying the data stored on the video disc on a visual display unit.

10. A method according to Claim 9 when dependent on claim 1, 2 or 3, wherein the data stored on the other data storage medium is displayed on the visual display unit and the data on the video disc related to a selected item on the other data storage medium is displayed when that selected item is chosen.

11. A method according to claim 9 to 10, wherein the data stored on the video disc comprises a monochrome signal for driving the visual display unit and the monochrome signal is supplied from the video disc to the visual display unit via a gating circuit which is triggered when the voltage of the video signal reaches a predetermined level.

12. A method of storing data substantially as hereinbefore described.

13. Any novel feature or combination of features described herein.