28 Pages Posted: 20 Dec 2004 Last revised: 3 Oct 2015
Date Written: 2005
Determining the meaning of patent claims necessarily requires the judge to break the text of a claim into discrete elements or units of text corresponding to the elements or units that comprise the claimed invention - essentially, organizing the language of the claims into chunks or quanta of text. Define an element narrowly - limit it to a single word, say - and you will tend to narrow the resulting patent, because to prove infringement the patentee must show that each word has a corresponding structure in the accused device. By contrast, defining an element broadly tends to broaden the patent, because it permits the text to read on a greater range of accused devices.
For each discrete packet identified, the courts must determine the meaning of the constituent words. They can assign those words definitions that range from narrow, specific meanings to broad, general meanings. In determining the meaning of terms within a particular element, judges practicing patent claim interpretation are engaged in an exercise that to some degree resembles the famous levels of abstraction test articulated by Judge Learned Hand for analysis of infringement under copyright law's idea/expression doctrine.
There are no hard and fast standards in the law by which to make the right decision as to either the size of the textual element or the level of abstraction at which it will be evaluated. Indeed, the indeterminacy is so acute that courts generally don't acknowledge that they are even engaging in either inquiry. They define an element almost arbitrarily, and even when judges disagree as to the proper definition they can offer no principled basis for doing so. The problem may be worse than a simple failure to acknowledge subconscious decisions that affect the scope of a patent, however. This indeterminacy may well be inherent in the process of mapping words to things, as modern literary theorists suggest. While courts purport to rely on the ordinary or plain meaning of the words of a patent claim, there may simply be no such thing.
If we can't define the metes and bounds of the invention in any meaningful way, we might instead start with the patentee's invention itself, construing patent claims narrowly and in light of the actual invention when the claim terms are ambiguous. Courts could then supplement this narrower claim construction with a doctrine of equivalents analysis, which would permit them to decide how broadly to apply the principle of the invention.
Suggested Citation: Suggested Citation
Burk, Dan L. and Lemley, Mark A., Quantum Patent Mechanics (2005). Lewis & Clark Law Review, Vol. 9, p. 29, 2005 ; Stanford Public Law Working Paper No. 102. Available at SSRN: https://ssrn.com/abstract=628224 or http://dx.doi.org/10.2139/ssrn.628224
By Mark Lemley
By Mark Lemley