The complaint, filed in U.S. District Court in Delaware, charges that the keyboards on the Treo k180, Treo 270 and Treo 300 models infringe on a RIM patent. In its suit, RIM asks for a declaration that Handspring does infringe on RIM's patent, an injunction barring further infringement and unspecified damages.
"RIM is a pioneer in the development of wireless handhelds and has invested substantial research and development and marketing effort to build goodwill in the design and utility of its handhelds and wireless communications services," the company said in a statement late Wednesday.
In the suit, RIM notes that "many experts and those knowledgable in the industry have commented that the keyboard of the Treo series of products is remarkably similar to the keyboard in RIM's BlackBerry Wireless Handheld devices."
Treo features a small keyboard that can be typed on with one's thumbs, as does RIM's BlackBerry.
A Handspring representative said the company couldn't comment since it hasn't been formally served with the lawsuit.
Separately, RIM said Thursday that it has filed a fourth suit against upstart competitor Good Technology, whose software is designed to run on RIM devices. The latest suit, filed in California Superior Court, charges Good and one of its vice presidents with misappropriation of trade secrets, breach of contract and other actions. RIM is seeking an injunction against Good, as well as unspecified damages.
A representative for Good declined to comment.
In June, RIM filed the first patent infringement lawsuit against Good. In July, it two additional suits--one for copyright infringement and the other for trademark infringement.
RIM had also sued pager company Glenayre Technologies, but the two companies reached a settlement in February.
News.com's Richard Shim contributed to this report.