Patent Office Issues Guidance on Indefiniteness


In January, the US Patent Office (USPTO) issued binding guidance that aligns the approach taken by the Patent Trial and Appeal Board (PTAB) with the approach of the federal courts on the issue of indefiniteness.

35 U.S.C. § 112(b) provides:

The [patent] specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.

Patent claims that don’t meet this standard are said to be invalid for indefiniteness.

As the USPTO’s website states,

In patent examining parlance, the claim language must be "definite" to comply with 35 U.S.C. 112(b) …. Conversely, a claim that does not comply with this requirement of 35 U.S.C. 112(b) … is "indefinite."

The primary purpose of this requirement of definiteness of claim language is to ensure that the scope of the claims is clear so the public is informed of the boundaries of what constitutes infringement of the patent. A secondary purpose is to provide a clear measure of what the inventor or a joint inventor regards as the invention so that it can be determined whether the claimed invention meets all the criteria for patentability and whether the specification meets the criteria of 35 U.S.C. 112(a) … with respect to the claimed invention.

It is of utmost importance that patents issue with definite claims that clearly and precisely inform persons skilled in the art of the boundaries of protected subject matter. Therefore, claims that do not meet this standard must be rejected under 35 U.S.C. 112(b) … as indefinite.

Before this change, the PTAB used two different approaches when evaluating claims of indefiniteness.

The first approach was based on the Federal Circuit’s approach in In re Packard, finding “[a] claim is indefinite when it contains words or phrases whose meaning is unclear.”

The second approach followed the US Supreme Court’s approach in Nautilus, Inc. v. Biosig Instruments, Inc.:

In place of the ‘insolubly ambiguous’ standard, we hold that a patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.

The PTAB noted that there has been confusion over which of these standards should apply in AIA (America Invents Act) post-grant proceedings, and patent attorneys were making arguments based on either or both.

The USPTO announced that henceforth it would follow only the Nautilus approach:

The office now clarifies that the Board shall follow Nautilus in AIA post-grant proceedings. Because the office's claim construction standard in AIA post-grant proceedings now aligns with that used by courts in a civil action, and because indefiniteness questions are generally considered as part of the claim construction process, the office's approach to indefiniteness in AIA post-grant proceedings should likewise align with that used by the courts following the Supreme Court's decision in Nautilus. As with the claim construction standard, aligning the indefiniteness approach in AIA post-grant proceedings will promote consistency and efficient decision making among coordinate branches of government that decide similar issues in co-pending proceedings. This memorandum confirms, therefore, that Nautilus is the correct approach for analyzing indefiniteness in AIA post-grant proceedings.

Categories: Patents