In patent law, a “product” or “article” claim covers (well, duh) a product. A “process” claim covers a method of doing something – like making a product. A product claim is infringed by the unauthorized making, using, selling, offering for sale or importing the patented product. A method claim is infringed by the unauthorized practice of the patented process. A third, less well-known, type of patent claim is the “product-by-process” claim which covers a product produced by a particular process¹. What infringes a product-by-process claim?
The Supreme Court, the Patent Office and various other courts have taken the position that “process terms in product-by-process claims serve as limitations in determining infringement.” Thus, unless the claimed product is made by the claimed process, it does not infringe. Products made by other processes do not infringe.
Is that clear? Perhaps not. Some courts, which apparently couldn’t take a hint, created an exception to this rule. If a new product could only be described, at the time of its invention, by reference to the manner of its production, then a product-by-process claim directed to such a product would be infringed if the product was later produced by some other process. This was known as the “rule of necessity” and was a means of providing patentability to products “whose structure was not fully known or not readily described.”
Well, no more. The CAFC has determined, en banc (despite a vigorous dissent), that technology has developed to the point where patentees are no longer unable to describe their inventions without reference to the process by which they are created. Henceforth, when a product claim includes process limitations, “such a product is not patented as a product, however it is produced, but is limited to the process by which it was obtained.” Abbott Laboratories, et al. v. Sandoz, Inc. et al.
THE LESSON TO BE LEARNED: Advances in technology can result in changes in the law.
¹ If the foregoing doesn’t sound familiar, the reader is advised to purchase a copy of Essentials Of Intellectual Property, co-written by the author.