No copycats
The US Supreme Court's recent decision to disallow close imitations of patented inventions has given back the holders of valuable patents their lost smile. Earlier, in 2000, a federal court had limited the 'doctrine of equivalents', which entailed that a patent on blue nails could be extended to cover red nails as well, as they have similar functions.
The lower court had said that if a patent's claim had been narrowed during review, it could not be widened again later by claiming equivalence. In the case, Festo Corporation, a machine-toolmaker, argued that its patent on a part for robotic arm should cover a similar device made by a Japanese rival. Patent holders feared that this would encourage more copycats. They requested the US apex court to reverse the lower court's verdict, which it eventually did.