PTAB Establishes Plain Meaning of 'At Least One of A and B'

Update

Perhaps recognizing that the decision uses overly broad language, the PTAB de-designated the Ex parte Jung decision on August 7, 2018. Ex parte Jung has thus been removed from the PTAB’s list of informative decisions. Nonetheless, practitioners would be wise to continue to follow the practice pointers discussed below to help ensure that claim terminology aligns with the intended meaning.

On July 10, 2018, the U.S. Patent and Trademark Appeal Board (PTAB) designated a prior decision, Ex parte Jung, focused on the proper claim construction of "at least one of" as informative. Patent practitioners should thus be familiar with this decision, including the possible implications for claim construction by Examiners at the U.S. Patent and Trademark Office (USPTO).

The now-informative decision in Ex parte Jung says that the plain meaning of "at least one of A and B" is the conjunctive unless the record indicates otherwise (i.e., the plain meaning of this claim recitation is "at least one of A and at least one of B.") Ex parte Jung, 2016-008290 (PTAB Mar. 22, 2017). As discussed further below, the Ex parte Jung decision relies on (in overly broad terms) the Federal Circuit holding in SuperGuide as the basis for this decision. SuperGuide Corp. v. DirecTV Enters., Inc., 358 F.3d 870 (Fed. Cir. 2004). Future claim drafters must be aware of the Ex parte Jung decision regarding "at least one of A and B" to ensure that a claim is interpreted as intended.

SuperGuide

The SuperGuide holding is important to understand for proper context before turning to the Ex parte Jung decision.

The plaintiff SuperGuide Corp. asserted three different patents against several multimedia providers including DirecTV. SuperGuide, 358 F.3d at 873. One of these patents (U.S. Patent No. 5,038,211) (‘211 patent) defined an online television program schedule system. The basic invention of the ‘211 patent was to allow a user to selectively store only the television program schedule information that is desirable to the user.

One of the fundamental disputes regarding infringement of this patent involved interpreting several claim recitations of "at least one of" followed by a series of parameters. Id. at 885. For example, claim 1 included a recitation:

First means for storing at least one of a desired program start time, a desired program end time, a desired program service, and a desired program type.

Id. at 884.

SuperGuide asserted that the phrase should be interpreted in the disjunctive. That is, the first storing means stores one or more of the four listed criteria (start time, end time, service channel, and/or type). Id. at 885. The defendants argued that the "at least one of" should be interpreted in the conjunctive – the storing means stores at least one start time, at least one end time, at least one service channel, and at least one type.

The Federal Circuit agreed with DirecTV. The court looked at the specification, the prosecution history, and considered the plain meaning of the phrase. The following passages are particularly important:

The issue here is what does ‘at least one of’ modify? The criteria listed in the claim at issue consist of four categories . . . . Each category is further comprised of many possible values. . . .The phrase ‘at least one of’ precedes a series of categories of criteria, and the patentee used the term ‘and’ to separate the categories of criteria, which connotes a conjunctive list. . . . [T]he district court correctly interpreted this phrase as requiring that the user select at least one value for each category; that is, at least one of a desired program start time, a desired program end time, a desired program service, and a desired program type.

SuperGuide, 358 F.3d at 886.

Ex parte Jung

Ex parte Jung applies the holding of SuperGuide, but appears to take the holding one step further.

In Ex parte Jung, the Applicant appealed the rejection of U.S. Patent Application No. 12/541,524 (‘524 application). The subject matter of the ‘524 application relates to playing back a scene using Universal Plug and Play (UPnP). One example of the claim language at issue is:

Each scene object including metadata representing at least one of

[i.] a precedence relation indicating the scene object’s location in a sequence of scene objects, and

[ii.] a connection relation indicating one or more scene objects capable of replacing the scene object.

The Examiner treated these recitations in the disjunctive. The Examiner thus rejected the claim based on a prior art disclosure of only the precedence relation indicating the scene object’s location. The Applicant traversed, arguing that the "at least one of A and B" recitation should be interpreted to require both A and B, so that the prior art rejection was deficient.

The PTAB agreed with the Applicant. The decision relies heavily on SuperGuide to conclude that the plain meaning of this claim recitation that the metadata represents at least one of both the precedence relation indicating the scene object’s location and a connection relation indicating the scene objects capable of replacing the scene object. The PTAB further considered the specification and prosecution history, and does not find that this plain meaning is rebutted.

Of particular note, the decision broadly states the following:

For claims written in the format of ‘at least one A and B,’ the Federal Circuit made clear in SuperGuide that the plain and ordinary meaning is the conjunctive phrase ‘at least one of A and at least one of B.’ An Examiner may adopt a different meaning if called for based upon the usual claim construction considerations, including analyzing the specification for any definition of disavowal.

Ex parte Jung, pg. 8 (internal citations omitted).

The PTAB then analyzes the specification, concluding that the conjunctive "at least one of" recitation is not supported by the specification. The specification only discloses the terms (a connection branch and a contents connection list) in the disjunctive (i.e., one or the other in each embodiment). The PTAB thus overturns the prior art rejection, but issues a new rejection under 35 U.S.C. §112, first paragraph, based on lack of written description.

Ex parte Jung’s Language is Overly Broad

The statement in Ex parte Jung that the "Federal Circuit made clear in SuperGuide that the plain and ordinary meaning [of at least one of A and B] is the conjunctive phrase ‘at least one of A and at least one of B’" is overly broad. The Federal Circuit made no such broad proclamation.

SuperGuide instead draws a distinction in interpreting "at least one of" based on whether the "A and B" (or more) that follow the phrase are categories or individual items that may serve as replacements for each other. See e.g., SuperGuide, 358 F.3d at 886-87 (distinguishing a listed series of categories from replacement objects such as a rod and a bar). Throughout the entirety of the holding in SuperGuide, the Federal Circuit repeatedly discusses that the plain and ordinary meaning of "at least one of A and B" is "at least one of category A and at least one of category B" when A and B are categories of things. Id. at 886-87.

Ex parte Jung, however, entirely glosses over the "category" language in SuperGuide. Not once is the discussion of "at least one of A and B" based on whether A and B are categories. By way of explanation, consider the following two recitations:

A movie database including at least one of Ghostbusters and Gone with the Wind.
A movie database including at least one of a comedy and a drama."

The SuperGuide opinion seems to support a claim construction of the first example as meaning a move database including one or both of Ghostbusters and Gone with the Wind, while the meaning of the second example is a movie database that includes at least one comedy and at least one drama (i.e., at least two different movies, one of which is a comedy and one of which is a drama). But Ex parte Jung seems to ignore such a distinction. That is, Ex parte Jung seems to suggest that the plain and ordinary meaning of "at least one of" should always be in the conjunctive, and thus, the movie database in the first example includes at least one of Ghostbusters and at least one of Gone with the Wind. Thus, the Ex Parte Jung interpretation requires a movie database including both of Ghostbusters and Gone with the Wind.

Practice Pointers

Regardless of whether Ex parte Jung is overly broad, the decision has now been designated by the PTAB as informative. Therefore, the patent practitioner would be well served to expect that "at least one of A and B" will be interpreted to having a plain meaning of "at least one of A and at least one of B." When a disjunctive meaning is desired, practitioners are thus advised to consider using "or" more liberally than perhaps they are accustomed.

Ex parte Jung also provides three guiding examples, which are purported to provide a more clear meaning than "at least one of A and B":

At least one of A or B.
At least one of A or at least one of B.
At least one selected from the group of A and B.

A final consideration is to make a clear avowal on the record (preferably in the specification when filed) to guide the interpretation of "at least one of A and B" if this phrase is used (or may be used in the future) in a claim. For example, a specification could plainly state that "at least one of A and B" should be understood to mean "only A, only B, or both A and B." In a similar vein, responses could establish on the record the intended meaning of this claim language. Applicants should ensure that there is proper support in the specification, however, before taking this approach or a lack of written description rejection (similar to Ex parte Jung) could arise.