Leapfrog has filed suit against Mattel, charging that the new interactive book line introduced by Mattel's Fisher-Price subsidiary this summer violates Leapfrog's patents.

The lawsuit, filed in federal court in Wilmington, Del., alleges that Fisher-Price's PowerTouch Learning System infringes on Leapfrog's patents on interactive learning books aimed at toddlers and pre-schoolers. Leapfrog is asking the Delaware court to issue a court order to prevent Fisher-Price from selling PowerTouch products. A spokesperson for Fisher-Price told the AP that "we do not believe we are infringing the Leapfrog patent."