The lawsuit was filed over a month ago, but only recently became known by company outsiders after San Jose, Calif.-based Adobe filed a quarterly report Thursday with the Securities and Exchange Commission.
The lawsuit was filed on June 2 in the U.S. District Court by a company called Information Technology Innovation LLC, which represents the four inventors.
The plaintiffs claim that Adobe's Acrobat products infringe on a 1996 technology patent that enables computer users to retrieve hyperlinked text without an Internet connection.
According to a description of U.S. Patent No. 5,892,908, titled "Method of Extracting Network Information," the technology can extract network information after first receiving an initial link address and then retrieves files associated with the initial link address. The file is then parsed to find a hypertext link and determines if the hypertext link has a link address that contains the network address as a root. When the link address contains the initial link address as the root, a link file associated with the link address is retrieved.
The plaintiffs seek unspecified compensatory damages, injunctive relief, and fees and costs, the SEC report states.
Adobe has not yet been served with the complaint.
"We believe the action has no merit, and if served, will vigorously defend against it," a representative for Adobe stated.