Unedited press release follows:
Philips and Sony Propose Specifications for High Density Multimedia Compact Disc
December 16, 1994 — Philips Electronics and Sony Corporation today jointly proposed specifications for a 12 cm high density Multimedia CD. The two companies hope that these will become the basis of optical media for the coming multimedia era.
The new high density CD will be able to store approx. 3.7 Gigabytes (GB) of data. This storage capacity – more than five times that of CD – has been achieved by incorporating a 635 nanometer (red) laser, reducing both the distances between the tracks and the sizes of the pits and by using highly sophisticated error correction and improved modulation techniques. The new specifications would allow discs to be produced at conventional manufacturing facilities with only minor modifications. As a result, production costs of the proposed new discs will be similar to that of conventional CD, a major advantage for consumers, media manufacturers as well as for the hardware and software industry.
To enable even further enhanced applications, the new specification includes a dual-layer disc which enables a doubling of disc capacity to approx. 7.4 GB. This technology is being developed in collaboration with 3M.
The vastly increased storage capacity and advanced features of high density CDs based on these physical specifications will enable a broad range of applications.
In the entertainment field, a video application of the high density CD, a ‘Digital Video Disc’ is also being proposed. The 3.7 GB disc can carry, for example, approximately 135 minutes of MPEG-2 quality video together with multitracks of compressed digital audio and subtitling. The use of a variable transfer rate for video of 1-10 Megabits per second (average 3 Megabits per second) means that picture quality will be superior to that of current consumer video systems. Philips and Sony have begun discussions with motion picture companies and consumer electronics manufacturers with the aim of preparing an acceptable application specification for the ‘Digital Video Disc’. The basic development concept will allow new hardware to play conventional audio and video CDs.
A voluntary group of experts from major computer hardware and software companies – IBM, Apple, Compaq and MicroSoft – are discussing extensions of the volume and file standard for a computer application based on the physical specifications: high density CD-ROM. The group is recommending that the ISO 9660 standard CD-ROM file structure with suitable extensions be used as the data interchange platforms for high density CD-ROM to facilitate support for existing CD-ROM applications. Proposed extensions, when completed, will be submitted to the ECMA TC15 standards committee for review and comment and then advanced to the International Standardization Organization.
Philips and Sony also imagine further applications based on these specifications in other areas of the multimedia industry. Such use may enable multimedia companies to benefit from the proposed format in a variety of applications such as interactive entertainment, games, or ultra high sound quality audio.
It is the intention of the companies to make a draft of the proposed high density CD basic specifications available to interested parties in January, 1995. The companies will gather input and finalize the proposed specifications by mid-1995.
Outline of specifications:
Disc diameter 120 mm
Disc thickness 1.2 mm
Disc capacity 3.7 gigabytes (single layer)
7.4 gigabytes (dual layer)
Wave length 635 nanometers
N.A. (numerical aperture) 0.52
Modulation EFM plus
Error Correction CIRC plus
Track pitch 0.84 microns