Tandon Loses a Key Decision in Patent Case

Tandon, a Chatwsorth-based maker of computer disk drives, Monday lost an important round in its patent infringement case against Mitsubishi Electric Corp. of Japan.

Judge Sidney Harris of the International Trade Commission ruled that Mitsubishi did not pirate disk-drive technology from Tandon, lawyers for the companies said Monday. The ruling by the federal administrative law judge ended a string of victories by Tandon in its yearlong case before the commission.

Tandon already has settled with two other companies that it accused of pirating its patent for its 3 1/2-inch and 5-inch double-sided floppy disk drives. This past summer, Sony and Teac agreed to pay royalties and other undisclosed payments to the company.

Mitsubishi said that it expects its U.S. sales of disk drives of the kind questioned by Tandon to exceed $50 million this year.

Lost $50 Million

Tandon, which has lost $50.2 million in the first nine months of this year, has in part attributed its woes to stiff foreign competition.

Last May, Tandon had won a motion for temporary relief against Sony, Mitsubishi and Teac. And, in September, the company was granted an injunction that required Mitsubishi to post a bond amounting to 25% of the value of the disk drives that it imports.

James Hamilton, Tandon’s lawyer in the case, said the company probably will ask the commission to review Harris’ findings. If the commission rules against Tandon, Hamilton said, the company can take its case to a special appeals court.

Disk drives use magnetic heads to store and retrieve information on floppy, or flexible, disks used by computers. Tandon alleges that the heads that Mitsubishi uses are modeled after its own.