IP Alerts

IP Alert
IP Alert: Interpreting "At Least One of A and B"

July 25, 2018

UPDATE: On August 7, 2018, this case was de-designated as informative by the PTAB.

On July 10, the Patent Trial and Appeal Board (PTAB) designated five decisions as informative. One of those decisions was Ex parte Dong-Shin Jung, Appeal No. 2016-008290, a decision from March 22, 2017.

This decision addressed the question of whether claim language in the form “at least one of A and B” should be interpreted to read “at least one of A or B,” or whether it should be interpreted to read “at least one of A and at least one of B.”

Following the Federal Circuit's decision in Superguide Corporation v. DirectTV Enterprises, Inc., the PTAB concluded that claim language in the form "at least one of A and B" should be interpreted to read "at least one of A and at least one of B." This decision is significant because it runs contrary to what many practitioners assume would be the correct interpretation of this language and the USPTO’s historical preference against using the word “or” in claims. For example, the USPTO has preferred the word “and” in Markush groups, even though such groups specify alternatives. The USPTO has softened its view in this regard and generally will allow the use of the word “or” in claims, and, more recently, the use of “and/or.”

In reaching its conclusion, the PTAB pointed out that “although numerous courts have followed Superguide, some courts and administrative bodies at times have distinguished Superguide on the basis that the normal conjunctive meaning of ‘at least one of . . . and’ does not apply when the patent's claims, specification, or prosecution history necessitate a broader meaning.”

Here neither the appellants nor the examiner directly addressed the appropriate claim construction, and the PTAB was critical of the examiner for presenting nothing more than a conclusory statement as a basis for deviating from the conjunctive construction preference of Superguide. The reply brief was also silent on this issue.

Thus, while the PTAB acknowledged that “an Examiner may adopt a different meaning if called for based upon the usual claim construction considerations, including analyzing the specification for any definition or disavowal,” the default rule should be to follow the teachings of Superguide and adopt a conjunctive construction. As such, the PTAB indicated the examiner must set forth reasoning for a different meaning, i.e., a disjunctive construction, including citations and explanations of relevant portions of the claims, specification, and prosecution history. Here, in the absence of this supporting analysis, the PTAB found that the claim should be interpreted to be consistent with Superguide and should be given a conjunctive construction.

In addition, the PTAB seemed to place particular weight on the fact that the specification never suggested that the claims must be interpreted in a disjunctive fashion, thus placing a high burden on the examiner and on the applicant to overcome the broad presumption that the conjunctive construction applies.

In fact, the PTAB went so far as to acknowledge that a conjunctive construction lacked support in the specification and asserted new grounds rejecting the claims for lack of written description. Thus, the PTAB found the lack of support in the specification for the conjunctive construction insufficient to overcome the presumption that the conjunctive construction applies. Specifically, the PTAB stated that a “mere example of ‘or’ in the Specification without more that would compel the disjunctive is insufficient to overcome the ordinary meaning of a claim using the conjunctive ‘and,’ even if such a claim construction results in the claim being unpatentable for lack of written description.”

Thus, practitioners may want to take advantage of the USPTO’s increasing willingness to use the term “or” in claims where a disjunctive construction is intended, lest they unwittingly find themselves forced into a “catch-22” where their claims are construed as conjunctive, and their specification only supports a disjunctive claim construction.

The PTAB’s decision here is in the context of an ex parte appeal, and as such the PTAB’s reasoning may not extend to other contexts such as litigation or after-grant review proceedings in the PTAB.

For more information on this ruling, please contact Fitch Even partner Thomas F. Lebens, author of this alert.


Fitch Even IP Alert®

Hosted on the FirmWisesm Platform | Designed by Charette Design