Drexler Technology Corp, the Mountain View, California-based company whose optical storage card technology has been boosted by increased sales to the US government recently, is warily eyeing Microsoft Corp’s intention to enter its territory, and has fired off a letter to Redmond warning of what it believes will be probable patent infringements. Microsoft invested in Bellevue, Washington-based optical storage start-up Ioptics Inc back in March (CI No 3,374), and at the time, Microsoft Windows CE marketing manager Joe Quagliani was quoted in numerous publications as saying I expect this technology to be widely deployed. Drexler says that five of its patents, plus additional foreign counterpart patents, are at issue. It says it’s willing to sell non-exclusive licenses for optical memory cards, readers and reader/writers on license terms and conditions normally offered to companies that have not infringed Drezler’s patents. This isn’t the first time Drexler has claimed on its patents: to date it has received optical memory card related patent license fees of over $35m. Its revenues from optical memory cards was boosted this year by the US Immigration and Naturalization Service’s decision to use 4 million of them for digital Green Cards and by a similar decision from the US State Department to use them as Laser Visa cards.