Sony plans to begin licensing the formats with its CD partner, Royal Philips Electronics, through Philips' channels in September.

Tentatively named "Double Density CD-ROM/-R/-RW," these recordable/rewritable disks will double capacity by modifying current CD formats, a Sony spokesman said. Among the major changes are a narrowing of track pitch from 1.6 micron today to 1.1 micron, and a shortening of minimum pit length from 0.833 micron at present to 0.623 micron. The numerical aperture (NA) is raised by 0.05, so the new formats will have 0.50 NA for playback and an 0.55 NA for recording.

Smaller pits are subject to errors. To cope with this, the current cross-interleave Reed-Solomon error-correction code (CIRC) will be modified. The depth parameter in the CIRC will change from 4 to 7 and the address format will be expanded.

A copy-control scheme will be included in the formats to meet increasing demands for content security. Sony did not disclose the kind of scheme to be employed,

The double-density CD products will be produced with current CD technologies and production facilities, Sony said, and will provide a natural migration path for consumers and manufacturers.

Manufacturers can upgrade current 650-Mbyte drives to a 1.3-Gbyte capacity just by changing a laser pickup with a higher numerical aperture lens and by altering a system-on-chip device with an error-correction block, the Sony spokesman said.

The CD-R/RW market grew 2.7 times to 16 million units in 1999, according to a survey by Trend Concept Inc. (Tokyo), a market-research company. The growth will continue this year to 27 million units, up by 68 percent, according to the group's forecast. On the other hand, DVD-RAM will grow by 29 percent this year, but to a volume of only about 360,000 units, the company projected.

The 1.3-Gbyte drive is reportedly part of Sony's long-term strategy to thwart DVD recordable drives. Sony is still developing rewritable 3-Gbyte DVD+RW for PC applications.

Not all market watchers agree with those projections. "DVD-RAM will take time to take off anyway without this double-density CD," said Hiroshi Motohashi, president of Trend Concept. "The market penetration of the double-density CD formats will be dependent on OEM prices. PC manufacturers may look on DDCD double-density CD favorably, but what's the merit for drive manufacturers?"

Drive manufacturers must use new components to upgrade their drives, Motohashi said, but strong pressure from PC manufacturers may make it difficult for them to increase prices.

Indeed, Korean and Taiwanese manufacturers already are increasing their share of the CD-R/-RW market with the help of highly competitive pricing. Japanese drive makers had once shifted their product portfolio from CD-ROM drives to CD-R/-RW drives when Korean and Taiwanese manufacturers entered the CD-ROM market. "This time, again, Japanese manufacturers may be forced to shift to the 1.3-Gbyte drive from 650-Mbyte drive market," said Motohashi.

Masaaki Moriyama, senior analyst of storage systems at IDC Japan Ltd., said that since the CD-ROM drive market has peaked and started to shrink, Sony should aim at the CD-R/RW market. Sony wants to prolong its CD-based business by introducing Gbyte-capacity drives, he said, but the demand for Gbyte-level removables remains limited in PC applications.

The 1.3-Gbyte CD-ROM won't be introduced any time soon, the Sony spokesman acknowledged, and the mainstream will be rewritable applications. Sony has not disclosed its product plans for 1.3-Gbyte CDs.