The grant of a patent invariably follows a thorough examination
by expert patent examiners of the patent offices. In some
jurisdictions, this grant carries with it the presumption of
validity. In India, however, the validity of a patent is not
guaranteed by the grant according to section 13(4) of the Patents
Act, 1970. When the grant of a patent is challenged it requires
evidence to prove the grounds of invalidity taken by the opponent.
Most of these patent invalidity challenges, by nature of being
technical, require opinions of expert witnesses.
The Intellectual Property Appellate Board (IPAB), in a number of
cases, have remanded the cases back to the controller on this
ground alone. Non-consideration of expert evidence was treated as a
violation of the principle of natural justice. Appeal courts are
harsh to the decisions taken by lower courts, or IPAB, or
controllers without appreciating expert evidence.
