Washington (DC) - In a turning of tables in the ongoing battle over intellectual property in the field of flash memory, the US Court of Appeals for the Federal Circuit handed flash manufacturer SanDisk of Sunnyvale, California, a pair of victories this morning in acses with Memorex, Pretec, Ritek and Lexar.

First, the circuit court announced that reached a decision last Friday to overturn an August 2003 summary judgment against SanDisk, in favor of competitors Memorex, Pretec, and Ritek, which had ruled the companies did not infringe on SanDisk’s patent enabling a flash memory component to be accessed like a hard disk drive.

Later, the court threw out a request by Lexar Media for an injunction against Toshiba Corp., barring it from importing Toshiba-brand flash media into the US, manufactured at a plant Toshiba runs jointly with SanDisk. Last May, a California state court ruled that Toshiba violated Lexar’s flash media trade secrets by sharing them with SanDisk in the manufacture of CompactFlash, xD, and SD memory. At that time, Toshiba agreed to pay Lexar US$465.4 million in damages. Today, the appeals court ruled that the damage settlement was enough compensation, without having to impose further punishment on Toshiba.

In a press release this morning, SanDisk’s chief IP counsel, Earle Thompson, stated, "SanDisk will continue to protect its investment in intellectual property and vigorously enforce its patents against companies that seek to use SanDisk’s patented technology without a license." The press release did not offer any comment with regard to Lexar’s ongoing attempt to do the same for its IP.

SanDisk will now resume its legal pursuit of Memorex, Pretec, Ritek, and other named defendants, with regard to what SanDisk calles the "’987 patent," after the last three digits of the US patent number granted the company in 1997. According to SanDisk’s appeal, the ’987 patent focuses on two aspects of flash memory architecture : the mechanism by which it’s erased and rewritten, and the geometry by which memory is accessed. By minimizing rewrites, claimed the appeal, the useful life of a flash memory component is increased. This can be accomplished, it continued, by addressing flash memory cells as "sectors," like on a hard drive, enabling multiple sectors to be erased with one operation, rather than with individual cells successively. This method has the side-benefit of enabling flash memory to appear as virtual hard drives - a key aspect of virtualization necessary for USB memory readers today.

To accomplish this, the ’987 patent partitions memory into so-called "user data" and "overhead data," the latter being reserved for internal processes relevant to the partitioning process. SanDisk brought its original lawsuit in October 2001, claiming the defendants all utilized the same partitioning method to achieve the goal of virtualizing a hard disk. In its defense, Ritek argued that SanDisk’s patented claim applied only to memory devices where user and overhead partitioning applied to each sector individually, not to some collectively. The California state court agreed, issuing a judgment of non-infringement in favor of Ritek. Memorex and Pretec later petitioned for, and received, similar judgments. This morning, these lower court judgments were overturned.

States this morning’s appeals court ruling, "The district court erred in its claim construction. The limiting preambles...are written in open language, and the claims are not limited to memory systems in which every memory cell is grouped into a partitioned sector. The judgment of no infringement rests on an erroneous claim construction, and the court vacates it." From here, SanDisk’s case has been remanded to the lower court for further proceedings.