GB2188474A - Electronic digital storage apparatus - Google Patents
Electronic digital storage apparatus Download PDFInfo
- Publication number
- GB2188474A GB2188474A GB08607837A GB8607837A GB2188474A GB 2188474 A GB2188474 A GB 2188474A GB 08607837 A GB08607837 A GB 08607837A GB 8607837 A GB8607837 A GB 8607837A GB 2188474 A GB2188474 A GB 2188474A
- Authority
- GB
- United Kingdom
- Prior art keywords
- optical
- record carrier
- digital data
- audio
- video
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
- G11B7/013—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track for discrete information, i.e. where each information unit is stored in a distinct discrete location, e.g. digital information formats within a data block or sector
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/005—Reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/14—Heads, e.g. forming of the optical beam spot or modulation of the optical beam specially adapted to record on, or to reproduce from, more than one track simultaneously
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
- H04N1/32106—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title separate from the image data, e.g. in a different computer file
- H04N1/32117—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title separate from the image data, e.g. in a different computer file in a separate transmission or protocol signal prior to or subsequent to the image data transmission, e.g. in digital identification signal [DIS], in non standard setup [NSS] or in non standard field [NSF]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/76—Television signal recording
- H04N5/7605—Television signal recording on discs or drums
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/79—Processing of colour television signals in connection with recording
- H04N9/80—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback
- H04N9/802—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving processing of the sound signal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
- H04N2201/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N2201/3201—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
- H04N2201/3261—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title of multimedia information, e.g. a sound signal
- H04N2201/3264—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title of multimedia information, e.g. a sound signal of sound signals
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Engineering & Computer Science (AREA)
- Optical Recording Or Reproduction (AREA)
Abstract
A compact disc has an audio component and a video component recorded on respective spiral tracks 2,3 which are concentric and closely interleaved. A compact disc player for reading the audio and video components has two pick-up elements 7,8, one for each track, which are controlled so as to read out from the disc at respective points which are diametrically opposite each other and at approximately equal distances from the centre of rotation of the disc. Video digital data may be omitted at each position corresponding to the start of audio passages so that a standard compact disc player will lock on to the audio track, or the video track may be suitably encoded. <IMAGE>
Description
SPECIFICATION
Electronic digital storage apparatus
This invention relates to electronic digital storage apparatus, and in particular to such apparatus of a type comprising an optical record carrier (commonly referred to as a compact disc) on which digital data is recorded in optically readable form, together with an optical read device for reading the digital data from the record carrier as the latter is rotated about a central axis.
The publication "Philips Technical Review",
Volume 40, 1982, No. 6, comprises four articles which describe various constructional and functional features of an electronic digital storage apparatus of the above type. The contents of this publication are hereby incorporated by reference into this specification.
Compact discs which are presently available to the public store digital data for audio reproduction only, this digital data usually representing (stereo) music. Recently, an audio-video compact disc has been proposed for reproducing music or other sound accompanied by a visual display on an associated television display device, for example a television monitor. The visual display might consist of still picture and/or text appropriate to being a visual accompaniment to reproduced music or the spoken word. Both the audio and the video components of the stored information would be recorded in digital form.
A conventional compact disc has a single spiral track of 'pits' and 'lands' which constitute the recorded digital data, and the latter is read out from the compact disc as a serial bit stream by the optical read device. In a suggested implementation of an audio-video compact disc, the recorded data for the audio component is re-formatted, compared with the recorded data on presently available compact discs, to provide storage space on the disc for the video component. The intention is that the playing time of the audio component remains approximately what it would be without the video component, that is, in excess of one hour. However, such reformatting requires the audio sampling rate and/or audio word length to be reduced, which degrades the quality of the audio reproduction and, furthermore, renders such an audio-video compact disc unplayable on standard compact disc players.
It is an object of the present invention to provide an audio-video compact disc that does not suffer from the above drawbacks.
According to a first aspect of the present invention, there is provided for an electronic digital storage apparatus of a type comprising an optical record carrier on which digital data is recorded in optically readable form, together with an optical read device for reading the digital data, an optical record carrier on which said digital data comprises an audio component and a video component which are recorded on respective concentric and closely interleaved spiral tracks of 'pits' and 'lands'.
The use of a separate spiral track for the video component reduces the playing time of the audio component compared with a conventional audio compact disc, but it does give the advantage of compatibility in that an audio-video disc in accordance with the invention would be playable on a standard compact disc player because its audio component has not been reformatted.
Thus, in carrying out this first aspect of the present invention, the spiral track for the video component can have digital data omitted at each position corresponding to a position on the spiral track for the audio component where digital data for the start of an active (musical or other sound) audio passage is recorded. This will ensure that a standard compact disc player (that is a compact disc player adapted to play a compact disc having only a single spiral track on which an audio component is recorded) will lock onto the spiral track for the audio component and ignore the spiral track for the video component.
Alternatively, the spiral track for the video component can be encoded at each position corresponding to the start position of an active audio passage on the spiral track for the audio component such that the standard compact disc player rejects the spiral track for the video component at that position and seeks out instead the spiral track for the autio component.
According to a second aspect of the present invention, there is provided for an electronic digital storage apparatus of a type comprising an optical record carrier on which digital data representing combined audio-video information is recorded in optically readable form on two concentric and interleaved spiral tracks according to said first aspect of the invention, together with an optical read device for reading the digital data, an optical read device comprising two optical pick-up elements which are operable to read out the digital data from a respective one of the two spiral tracks, which two optical pick-up elements are controlled so as to read out data at respective points which are at approximately equal distances from the centre of rotation of the optical record carrier. Suitably, said read out points are diametrically opposite each other.
Because of the positioning of the two pickup elements and the fact that the two spiral tracks are concentric and closely interleaved, the variation in the speed of rotation of the optical record carrier which is required to maintain a constant rate of data read out from one special track ensures that the rate of data read out from the other spiral track is also maintained constant.
The invention also extends to an electronic digital storage apparatus of the type referred to comprising in combination an optical record carrier and an optical read device according to said first and second aspects.
In order that the invention may be more fully understood reference will now be made by way of example to the accompanying drawings, of which:
Figure 1 shows diagrammatically an optical record carrier having two spiral tracks in accordance with the first aspect of the invention;
Figure 2 shows diagrammatically an optical read device in accordance with the second aspect of the invention;
Figure 3 illustrates the encoding of digital data on a spiral track of an optical record carrier;
Figure 4 shows diagrammatically a signal processing circuit for processing the audio component read from the combined audio-video optical record carrier; and
Figure 5 shows diagrammatically a signal processing circuit processing the video component read from the combined audio-video optical record carrier.
Referring to the drawings, there is shown in
Fig. 1 an optical record carrier 1 in the form of a compact disc on which two spiral tracks 2 and 3 are provided. These two spiral tracks 2 and 3 are concentric and closely interleaved and have the same pitch between adjacent turns. As shown in the sectional view in Fig.
3, the compact disc 1 has substrate 4 of transparent material, a reflecting layer 5 and a protective layer 6. The two spiral tracks are formed in the compact disc 1 as respective successions of 'pits' and 'lands' which constitute recorded digital data. In accordance with the first aspect of the invention the digital data on one of these two spiral tracks comprises an audio component and the digital data on the other of these two spiral tracks comprises a video component. The compact disc 1 shown in Fig. 1 is not drawn to scale.
Precise dimensions are given in the publication "Philips Technical Review" in respect of a compact disc having a single spiral track. Similar dimensions would apply for the two-track compact disc of the present invention but, of course, the pitch of each track would be doubled because of the track interleaving.
The optical read device shown in Fig. 2 comprises two optical pick-up elements 7 and 8, each of which may be implemented in the same manner as the optical pick-ups described in the publication "Philips Technical
Review". In accordance with the second aspect of the invention, these two pick-ups 7 and 8 have the laser spots 9 and 10 of their respective laser tracking systems focussed, as indicated by the dotted lines 11 and 12, at points which are diametrically opposite each other and at approximately equal distances from the centre of the compact disc 1. The optical two pick-up elements 7 and 8 are controlled by a common control system 13 such that their respective laser tracking systems each cause their laser spot 9 and 10 to describe a radial arc across the compact disc 1, so that each of the spiral tracks 2 and 3 is scanned completely.The dotted lines 14 and
15 represent the radial arc paths travelled by the laser spots 9 and 10, respectively. As indicated by the dotted line 16, the control system 13 also controls the drive for the compact disc 1 so as to vary the rotational speed of the latter in dependence on the radial position(s) of the laser spots 9 and 10 so that the two tracks are scanned optically at a constant velocity, thereby ensuring a constant rate of data read out from the compact disc
1.
For the sake of completeness, Fig. 3 illustrates the encoding of digital data on each of the spiral tracks 2 and 3. Fig. 3a is a crosssection through the compact disc 1 in the direction of the spiral tracks. This cross-section shows, as aforesaid, the substrate 4 of transparent material, the reflecting layer 5 and the protective layer 6. Pits such as 17 form each track in conjunction with lands such as 18 between successive pits. The combinations of pits and lands along a track are read optically by the relevant optical pick-up element to produce a bi-level signal. This bi-level signal is illustrated in idealised form in Fig. 3b in which
I, the intensity of the signal read by the pickup element, is plotted against time t.For a given clock rate c, after each land/pit or pit/land transition a 1 bit is produced at the next clock pulse, and a 0 bit is produced at each other clock pulse, to generate a series of data bits DB.
The series of data bits representing the audio component read from the relevant spiral track is processed by the signal processing circuit shown in Fig. 4. This processing circuit comprises a demodulator 19 which reconstitutes digital information, representing the audio component, from the applied series of data bits DB. This digital information is then stored temporarily in a buffer memory 20 from where is it read and applied to an errorcorrection circuit 21. After error-correction, the digital information is applied via an interpolation filter 22 to two digital-to-analogue converters 23 and 24 which are responsive to create analog audio output signals for two audio (stereo) channels L and R. The circuit elements 21, 23 and 24 are synchronised by a clock pulse generator 25. The bit stream is read from the buffer memory 20 into the error-correction circuit 21 at a rate determined by the clock pulse generator 25. However, the bit stream is written into the buffer memory 20 from the demodulator 19 at a rate that depends on the rotational speed of the compact disc. A control signal CS derived from the buffer memory 'fill' state is produced as a speed control reference for the disc speed control system (13-Fig. 2). This speed coritrol reference can ensure, for instance, that the buffer memory 20 is at all times filled to half its capacity.
The series of data bits representing the video component read from the relevant signal track is processed by the signal processing circuit shown in Fig. 5. This processing circuit has a demodulator 19', a buffer memory 20', an error-correction circuit 21' and an interpolator filter 22' which correspond respectively to the elements 19 to 22 in the processing circuit of Fig. 4. The processing circuit of Fig. 5 additionally comprises logic circuit 26 which is responsive to control information in the video component to write display information into a bit-map display memory 27. This display information is periodically read from the memory 27 in a recurrent cycle under the control of the clock pulse generator 25' and the information read out addresses a colour look-up table 28 the output from which is applied to three digital-to-analogue converter 29, 30 and 31 which are responsive to produce analog video signals R,G,B for deriving a colour television monitor.
Claims (9)
1. For an electronic digital storage apparatus comprising an optical record carrier on which digital data is recorded in optically readable form, together with an optical read device for reading the digital data from the record carrier as the latter is rotated about a central axis, an optical record carrier on which said digital data comprises an audio component and a video component which are recorded on respective concentric and closely interleaved spiral tracks of 'pits' and 'lands'.
2. An optical record carrier as claimed in
Claim 1, wherein the spiral track for the video component has digital data omitted at each position corresponding to a position on the spiral track for the audio component where digital data for the start of an active audio passage is recorded.
3. An optical record carrier as claimed in
Claim 1, wherein the spiral track for the video component is encoded at each position corresponding to the start position of an active audio passage on the spiral track for the audio component such that a standard compact disc player rejects the spiral track for the video component at that position and seeks out instead the spiral track for the audio component.
4. For an electronic digital storage apparatus comprising an optical record carrier on which digital data representing combined audio-video information is recorded in optically readable form on two concentric and interleaved spiral tracks according to Claim 1,
Claim 2 or Claim 3, together with an optical read device for reading the digital data, an optical read device comprising two optical pick-up elements which are operable to read out the digital data from a respective one of the two spiral tracks, which two optical pickup elements are controlled so as to read out data at respective points which are at approximately equal distances from the centre of rotation of the optical record carrier.
5. An optical read device as claimed in
Claim 4, wherein said read out points are diametrically opposite each other.
6. An electronic digital storage apparatus comprising, in combination, an optical record carrier as claimed in Claim 1, Claim 2 or Claim 3, and an optical read device as claimed in
Claim 4 or Claim 5.
7. An optical record carrier substantially as hereinbefore described with reference to Figs.
1 and 3 of the accompanying drawings.
8. An optical read device substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.
9. An electronic digital storage apparatus substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08607837A GB2188474A (en) | 1986-03-27 | 1986-03-27 | Electronic digital storage apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08607837A GB2188474A (en) | 1986-03-27 | 1986-03-27 | Electronic digital storage apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8607837D0 GB8607837D0 (en) | 1986-04-30 |
| GB2188474A true GB2188474A (en) | 1987-09-30 |
Family
ID=10595435
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08607837A Withdrawn GB2188474A (en) | 1986-03-27 | 1986-03-27 | Electronic digital storage apparatus |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2188474A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2603794A1 (en) * | 1986-09-12 | 1988-03-18 | Labourrau Jacques Philippe | Surgical staple and staple-holder for its use |
| EP0656626A2 (en) * | 1993-12-03 | 1995-06-07 | Sharp Kabushiki Kaisha | Information recording-reproduction method |
| EP0703574A3 (en) * | 1994-09-21 | 1996-04-03 | Sony Corporation | Disc recording device, disc playback device, and discshaped recording medium |
| WO1998037554A2 (en) * | 1997-02-20 | 1998-08-27 | Zen Research N.V. | Methods and apparatus for synchronously reading multiple tracks of an optical storage medium using multiple reading beams |
| US6028827A (en) * | 1995-11-15 | 2000-02-22 | Zen Research N.V. | Methods and apparatus for synchronizing read out of data from multiple tracks of an optical storage device |
| US6137763A (en) * | 1998-09-24 | 2000-10-24 | Zen Research N.V. | Method and apparatus for buffering data in a multi-beam optical disk reader |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1400274A (en) * | 1971-05-26 | 1975-07-16 | Agfa Gevaert Ag | Recording supports and reproduction apparatus |
| GB1446010A (en) * | 1972-09-04 | 1976-08-11 | Philips Electronic Associated | Information orecord and reading apparatus therof |
| GB1565829A (en) * | 1975-12-26 | 1980-04-23 | Sony Corp | Record medium and method and apparatus for recording information from said record medium |
| GB2036410A (en) * | 1978-11-08 | 1980-06-25 | Philips Nv | Optically Inscribable Record Carrier |
| EP0025277A2 (en) * | 1979-08-15 | 1981-03-18 | Discovision Associates | Record disc of video and audio information for stop-motion playback and methods and apparatus for making and playing such a record disc |
| GB2122406A (en) * | 1979-09-10 | 1984-01-11 | Mc Donnell Douglas Corp | Storing and reproducing video and audio information |
| GB2144257A (en) * | 1983-05-12 | 1985-02-27 | Victor Company Of Japan | Rotary recording medium |
-
1986
- 1986-03-27 GB GB08607837A patent/GB2188474A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1400274A (en) * | 1971-05-26 | 1975-07-16 | Agfa Gevaert Ag | Recording supports and reproduction apparatus |
| GB1446010A (en) * | 1972-09-04 | 1976-08-11 | Philips Electronic Associated | Information orecord and reading apparatus therof |
| GB1565829A (en) * | 1975-12-26 | 1980-04-23 | Sony Corp | Record medium and method and apparatus for recording information from said record medium |
| GB2036410A (en) * | 1978-11-08 | 1980-06-25 | Philips Nv | Optically Inscribable Record Carrier |
| EP0025277A2 (en) * | 1979-08-15 | 1981-03-18 | Discovision Associates | Record disc of video and audio information for stop-motion playback and methods and apparatus for making and playing such a record disc |
| GB2122406A (en) * | 1979-09-10 | 1984-01-11 | Mc Donnell Douglas Corp | Storing and reproducing video and audio information |
| GB2144257A (en) * | 1983-05-12 | 1985-02-27 | Victor Company Of Japan | Rotary recording medium |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2603794A1 (en) * | 1986-09-12 | 1988-03-18 | Labourrau Jacques Philippe | Surgical staple and staple-holder for its use |
| EP0656626A2 (en) * | 1993-12-03 | 1995-06-07 | Sharp Kabushiki Kaisha | Information recording-reproduction method |
| EP0656626A3 (en) * | 1993-12-03 | 1996-02-07 | Sharp Kk | Information recording-reproduction method. |
| US5659528A (en) * | 1993-12-03 | 1997-08-19 | Sharp Kabushiki Kaisha | Information recording-reproduction method |
| EP0703574A3 (en) * | 1994-09-21 | 1996-04-03 | Sony Corporation | Disc recording device, disc playback device, and discshaped recording medium |
| US5657309A (en) * | 1994-09-21 | 1997-08-12 | Sony Corporation | Video disc recording and playback system with two recording areas to record an information signal and a reference signal |
| US5907526A (en) * | 1995-11-15 | 1999-05-25 | Zen Research N.V. | Methods and apparatus for simultaneously reading multiple tracks of an optical storage medium |
| US6028827A (en) * | 1995-11-15 | 2000-02-22 | Zen Research N.V. | Methods and apparatus for synchronizing read out of data from multiple tracks of an optical storage device |
| US6111831A (en) * | 1995-11-15 | 2000-08-29 | Zen Research N. V. | Methods and apparatus for simultaneously reading multiple tracks of an optical storage medium |
| WO1998037554A2 (en) * | 1997-02-20 | 1998-08-27 | Zen Research N.V. | Methods and apparatus for synchronously reading multiple tracks of an optical storage medium using multiple reading beams |
| WO1998037554A3 (en) * | 1997-02-20 | 1998-11-26 | Zen Res Nv | Methods and apparatus for synchronously reading multiple tracks of an optical storage medium using multiple reading beams |
| US6137763A (en) * | 1998-09-24 | 2000-10-24 | Zen Research N.V. | Method and apparatus for buffering data in a multi-beam optical disk reader |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8607837D0 (en) | 1986-04-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |