Defences and remedies in Canadian patent law

A patent holder in Canada has the exclusive right, privilege and liberty to making, constructing, using and selling the invention for the term of the patent, from the time the patent is granted. Any person who does any of these acts in relation to an invention without permission of the patent owner is liable for patent infringement.

When faced with an action for patent infringement, the defendant has a number of defences that they can use. These roughly fall into three categories:

Non-infringement, asserting that the defendant does not make, use or sell the patented invention;

Invalidity, asserting that the patent should not have been granted in view of prior art;

Defences based on user rights, statutory or otherwise.

Remedies in Canadian patent law generally track both common law and equitable remedies. Equitable remedies include injunctions (both final and interlocutory) and an accounting of profits. Common law remedies include damages aimed at putting the plaintiff in the position he would have occupied had the infringement not occurred.

Invalidity defences

In order to obtain a patent, an invention must be:

Allowable subject matter;

New;

Useful;

Not obvious to a person skilled in the art.

The Canadian Patent Act allows that:

59. The defendant, in any action for infringement of a patent may plead as matter of defence any fact or default which by this Act or by law renders the patent void, and the court shall take cognizance of that pleading and of the relevant facts and decide accordingly.