"...At the Consumer Electronics Show (CES) today, TDK Electronics (Garden City, N.Y.) announced that later this year it will debut a new generation of CD-ROM rewritable (CD-RW) drives that will use MultiLevel Recording technology to achieve a threefold improvement in storage capacity as well as recording speed over conventional CD-RW drives. According to TDK, ML technology will allow up to 2 Gbytes of data to be recorded at rates of up to 36X on specially formulated $2 ML blank discs, with up to 700 Mbytes of data on standard CD-RW discs at 12X rates. This is at least three times the capacity of current technology. TDK plans to scale this quickly to 2.6, then 3.2 Gbytes.

Key to the technology is the fact that it is IC-based, meaning no changes are required to the optics or hardware, beyond the addition of an extra IC to current drives — though special media are required. Mitsubishi has already developed a rewritable phase-change disc. The IC factor is where Sanyo comes in. According to Tadahiko Tanaka, president of Sanyo Electric's Semiconductor Division, this will allow Sanyo to leverage the fact that it is already a leading supplier of LSI technology for CD-RW drives. "As such," he said, "we are well positioned to help promote the benefits of ML Recording technology."

First demonstrated at Comdex Fall 2000, the premise of ML technology is the use of gray-scale disc encoding, with 3 bits per spot giving eight shades of gray. Under a microscope, the disc surface appears as a continuous blending of light to dark shading, versus the traditional disc appearance of either dark or bright spots. The technology depends on the ability to detect the smallest changes in reflectivity in a continuously changing pattern. The key lies in the media, which, according to TDK, requires no change to the existing manufacturing infrastructure.

Though the technology leads to a massive improvement in storage capability, according to Kuni Matsui, president of TDK, the technology is not intended as a replacement for DVD, but more as a low-cost bridge to extend the capabilities of low-cost CD technology for a number of years to come. "Eventually, however," said Matsui, "ML technology will migrate to the DVD platform."..."