April 6, 2010 by Essien Udokang
Essien Udokang is a J.D. Candidate 2010 at Osgoode Hall and is taking the Patent Law class.
Since the decision of the Supreme Court in Free World (2000 SCC 66,  2 S.C.R. 1024) it is supposedly settled law that courts are to construe the claims of a patent in a purposive manner in determining infringement and invalidity. However, courts since Free World have failed to demonstrate consistency in their application of purposive claim construction. What appears from the existing case law is a disparate collection of decisions that fuels litigation and consumes judicial resources. Some courts have kept tightly wed to claims, while others have liberally given more weight to non-claim material, even to the point of disregarding relevant claims and implying promises from the patent’s overall context. Subsequently, stakeholders are subjected to an unpredictable legal landscape with unfortunate consequences.