Exemplary Claiming, Not Exemplary Claims

When drafting claims it is permissible to use exemplary language (“for example” or “such as”). According to MPEP 2173.05(d) use of such language “does not by itself render the claim indefinite,” although the section then rattles off five examples where exemplary language was found to be indefinite. Even if exemplary language is permissible, is it a good idea?

Modern patents occasionally issue with claims containing exemplary language. Consider claim 14 of U.S. Patent No. 11972683:

14. The tracking arrangement as claimed in claim 13, wherein the “cooperative awareness message <CAM>” has the following vehicle-specific, vehicle-characteristic message parameters: type of different vehicles belonging to the road users, for example bus, automobile, motorcycle, etc., in the group; time stamp of vehicles belonging to the road users in the group should be close in terms of time; position of different vehicles belonging to the road users in the group should be adjacent; direction of vehicles belonging to the road users in the group should be the same; speed of vehicles belonging to the road users in the group should be comparable; length of different vehicles belonging to the road users is used as a group identifying feature; width of different vehicles belonging to the road users is used as a group identifying feature; issuing authority of the cryptographic certificates for the signature of the status messages; certificate hierarchy for validating the certificate for the signature of the status messages; repetition rate of the change of the parameters.

What do the examples do for this claim? Does the absence of “trucks” is the list affect the meaning of “type of different vehicles”?

What about claim 11 of U.S. Patent No. 11965836:

11. The detection assembly as claimed in claim 10, wherein the matrix array of light-emitting diodes is made of a longitudinal succession of strips of LED tape which are secured, for example glued, transversely to the inner surface.

Does “glued” affect the meaning of “secured”? There is a presumption that every word in a claim is to be given meaning, so what does “glued” for claim 11.

Then there are claims structured like claim 13 of U.S. Patent No. 11965415:

13. The method as claimed in claim 1, wherein the injected current comprises an alternating current signal having a frequency of 1 Hz or lower, for example 0.5 Hz or lower, or 0.25 Hz or lower.

Does the claim cover all frequencies below 1Hz? What is the significance of 0.5 Hz? Of 0.25 Hz?

While claims can include exemplary language, it may not result in exemplary claims.

Federal Circuit Agrees that “The Invention” is the invention

In Chewy, Inc. v. International Business Machines Corp., [2022-1756] (Fed. Cir. 2024), the Federal Circuit affirmed in part. reversed in part, and remanded the distirct court’s summary judgment of non-infringement of claims of U.S. Patent No. 7,072,849, and summary judgment that claims of U.S. Patent No. 7,076,443 were directed to ineligible subject matter.

Non-Infringement of U.S. Patent No. 7,072,849

Claim 1 of the ‘849 patent stated:

Infringement of the claims ‘849 patent turned on whether the claims to improvements in web-based advertising required “prefetching” an advertising object, even though these words are not set forth in the claim. The “Summary of Invention” said:

‘849 patent, 3:6-21. The “Description of the Preferred Embodiment: said:

‘849 patent, 33:16-27.


‘849 patent, 34:38-44. The Federal Circuit concluded that in light of these “repeated descriptions of the present invention, a skilled artisan would understand the claimed invention requires pre-fetching of advertising objects,” citing Verizon Servs. Corp. v. Vonage Holdings Corp., 503 F.3d 1295, 1308 (Fed. Cir. 2007) (“When a patent . . . describes the features of the ‘present invention’ as a whole, this description limits the scope of the invention.”).

IBM tried to rely on Absolute Software, Inc. v. Stealth Signal, Inc., 659 F.3d 1121,
1136–37 (Fed. Cir. 2011), where the Federal Circuit explained that the use of the phrase “present invention” or “this invention” is not always limiting, such as where the references to a certain limitation as being the “invention’ were re not uniform, or where other portions of the intrinsic evidence do not support applying the limitation to the entire patent. However, the Federal Circuit said that these “narrow exceptions” referenced in Absolute Software were not applicable, because the ’849 patent uniformly referred to the pre-fetching of advertising objects as an aspect of the invention as a whole.

U.S. Patent No. 7,076,443 is Directed to Ineligible Subject Matter

The district court held at Alice step one the asserted claims were directed to the abstract idea of identifying advertisements based on search results. The Federal Circuit agreed, noting that it has held claims to targeted advertising were directed to an abstract idea at Alice step one. IBM argued its claims recited a specific solution to unique technical problems arising from advertising over a computer network. The Federal Circuit rejected this argument, noting that the claims were not directed to any challenges unique to computer networks, or specific improvements to the functionality of the computer itself. The claims merely recite the concept of identifying advertisements based on search results, without any specificity as to how this is accomplished. The Federal Circuit said that even accepting that the claimed invention improves the specificity and relevancy of online advertisements, this “is at most an improvement to the abstract concept of targeted advertising wherein a computer is merely used as a tool.”

Definition in Patent Incorporated by Reference, Results in Obviousness Determination

In Parkervision, Inc., v. Vidal, [2022-1548] (December 15, 2023) the Federal Circuit affirmed the PTAB’s determination that claim 3 of U.S. Patent No. 7,110,444 was unpatentable as obvious.

At issue on appeal was the construction of “storage element.” The Federal Circuit noted that in the ‘551 patent, incorporated by reference into the ‘444 patent, Parkervision acted as its own lexicographer to define the term “storage element.” The language expresses an intent to define the term “storage element.”  In particular the Federal Circuit said that the patentee’s use of the phrases “as used herein” and “refer to” conveys an intent for sentence 5 to be definitional.”  The language was found definitional because it did not refer to reference numerals, and referring to the document as a whole with the phrase “as used herein.”

The Federal Circuit found that the Board’s construction of “storage element”—“an element of a system that stores non-negligible amounts of energy from an input EM signal”— correctly tracks the lexicography provided in the specification.  Agreeing with the PTAB’s claim construction, the Federal Circuit affirmed their obviousness determination as well.

Extrinsic Evidence Needed to Construe Numerical Limitation in the Claims

Actelion Pharmaceuticals Ltd, v. Mylan Pharmaceuticals Inc., [2022-1889] (November 6, 2023), the Federal Circuit vacated the district court’s claim construction order with respect to the term “a pH of 13 or higher” in U.S. Patent Nos. 8,318,802 and 8,598,227 and the judgment of infringement, and remand for the district court to consider the extrinsic evidence and its impact on claim construction.  The patents in suit were directed to improved epoprostenol formulations.

The claim required “the bulk solution has a pH of 13 or higher.”  Both parties proposed the plain and ordinary meaning of the term but disagreed on what that means.  Actelion argued that “a pH of 13” in the context of the asserted claims is “a value of acidity that is given as an order of magnitude that is subject to rounding.”  More specifically, Actelion’s proposal would allow a pH of 12.5, which rounds to 13, to read on the claim limitation of “a pH of 13 or higher.” By contrast, Mylan argued that the proper construction cannot cover any pH values less than 13.

The Federal Circuit said that there was no blanket rule that ranges, or specifically open-ended ranges, must foreclose rounding.  Unlike other claim terms, the disputed claim term lacks approximation language like “about.”  Mylan argued, “13” and “about 13” would both imply rounding, making the approximation language superfluous.  Actelion argued that rounding is required because approximation language like “about” signals different variations than those of rounding. Actelion also argued that “it is not practically possible to measure exact pH values” because to get an “exact” measurement “one would have to count every hydrogen ion in solution, which is not scientifically possible.”  Ultimately, the Federal Circuit did not find the absence of approximation language dispositive here, and rejected any invitation to create a bright-line rule.

The specification revealed that the inventor inconsistently described the level of specificity for a pH of 13.  The specification explains that “[t]he pH of the bulk solution is preferably adjusted to about 12.5-13.5, most preferably 13.”  Mylan argues that this shows that the inventor (1) knew how to use approximation language when it wanted (“about 12.5-13.5”) and chose not to for a pH of 13; (2) distinguished a pH value of “12.5” from that of “13”; and (3) distinguished a range (“12.5-13.5”) from a definite value (“13”).  Actelion countered that “13” should allow rounding or else a preferred embodiment of the invention, meaning a pH of about 12.5 to 13.5, would be excluded from the claim scope.

The specification seems to equate a pH of “13.0” to that of “13.” Example 4 describes screening several “formulations with the pH of bulk solution . . . adjusted between 10.5 and 13.0.” ’802 patent col. 10 ll. 63–64. Tables 8 and 9 show the resulting stability data and display a bulk solution pH as “13” with no decimal point. Mylan argues that this shows that the inventor equated a pH of “13” with “13.0.”  The Federal Circuit noted that the specification uses both “13” and “13.0”—and various degrees of precision for pH values generally—throughout. In other words, the specification supplies the same clarity as to the desired level of precision as muddied water.

Turning to the prosecution history, the Federal Circuit note that the inventor amended the claim language at issue several times, and that the Examiner said that the inventor had demonstrated that for a pH of 13 “there is a significant difference.”

The Federal Circuit said that this case was one where the proper claim construction cannot be reached without the aid of extrinsic evidence, and that the district court should have considered, at minimum, the textbook excerpts offered and addressed by the parties. The Supreme Court has made clear that there are cases where the district court must “look beyond the patent’s intrinsic evidence and . . . consult extrinsic evidence in order to understand, for example, the background science or the meaning of a term in the relevant art during the relevant time period.” The Federal Circuit vacated the district court’s judgment of infringement, and remand for the district court to consider the extrinsic evidence and its impact on claim construction.

Co-owned, but Unrelated Application Cited in IDS Does not Inform the Meaning of the Claims

In Malvern Panalytical Inc., v. TA Instruments-Waters LLC, [2022-1439] (November 1, 2023), because the district court erred in construing “pipette guiding mechanism,” the Federal Circuit vacated the stipulated judgment of non-infringement of U.S. Patent Nos. 8,827,549 (“the ’549 patent”) and 8,449,175 and remanded for further proceedings.  These patents both disclose microcalorimeters, which are machines that measure the amount of energy absorbed or released during a chemical reaction between two compounds.

Malvern and Waters disputed whether the term “pipette guiding mechanism” encompasses only manual guiding mechanisms (Waters’s position) or covers both manual and automatic guiding mechanisms (Malvern’s position). The Federal Circuit agreed with Malvern that “pipette guiding mechanism” means a mechanism that guides the pipette assembly manually or automatically.

Starting with the claim language, the Federal Circuit concluded that “pipette guiding mechanism” has a plain and ordinary meaning—a mechanism that guides the pipette assembly.  It is appropriate to construe this term by looking to the words “pipette,” “guiding,” and “mechanism” individually.  Looking at the individual words in the claim, the immediately apparent meaning is that a “pipette guiding mechanism” is a mechanism that guides the pipette. The claim language contains no restrictions that would suggest that the “pipette guiding mechanism” is only manual. Instead, the broad claim language supports the conclusion that the “pipette guiding mechanism” encompasses both manual and automatic embodiments.

The specification confirms the broader understanding of the “pipette guiding mechanism.” It discloses two embodiments of the guiding mechanism. The first embodiment is a guide arm that can move only by way of a guide rod where permitted by guide grooves.  The second is a guide arm that can only move where permitted by a coaxial guide sleeve.  The specification contains no language describing the invention as limited to a manual guiding mechanism, stating that “the present invention ‘is,’ ‘includes,’ or ‘refers to’” a manual guiding mechanism, or “expressing the advantages, importance, or essentiality” of a manual guiding mechanism.

The district court took a different view, concluding that “pipette guiding mechanism” is a coined term with no commonly understood meaning in the art.  On this basis, the district court concluded that “pipette guiding mechanism” “cannot be construed broader than the disclosure in the specification.”  The Federal Circuit said that it has sparingly applied this principle of construction in other cases.  The district court’s analysis predominantly addressed whether “pipette guiding mechanism” has a plain and ordinary meaning broadly in the art. The Federal Circuit said that this analysis, however, did not answer the question of what plain and ordinary meaning a term has in the context of a patent, which is the focus of the Federal Circuit’s analysis.  The Federal Circuit said that it discerns plain and ordinary meaning by examining the claims themselves, the specification, and the prosecution history.

The district court relied heavily on the co-owned, but unrelated ’782 patent prosecution history to limit the guiding mechanism to manual embodiments.  The Federal Circuit concluded that merely listing the ’782 patent office actions in the IDS of the patent supplemental examination was insufficient to inform the meaning of “pipette guiding mechanism” in the unrelated ’175 and ’549 patents.  On this basis, the Federal Circuit concluded that the district court erred when it used the ’782 patent prosecution history statements to limit “pipette guiding mechanism” to manual guiding mechanisms.  The Federal Circuit said:

“In the absence of an incorporation into the intrinsic evidence, this court’s precedent takes a narrow view on when a related patent or its prosecution history is available to construe the claims of a patent at issue and draws a distinct line between patents that have a familial relationship and those that do not.”

The amount of characterization of that reference in the IDS impacts how informative we consider that reference when evaluating a patent. For example, listing of references in an IDS does no more than admit “that references in the disclosure may be material to prosecution of the pending claims,” but it does not admit materiality.  Likewise, a patentee has not necessarily admitted that a listed reference’s characterization or use of a claim term bears on the proper construction of that term in the patent.

The Federal Circuit noted that although the ’782 patent applicant argued that the ’968 application discloses only a manual guiding mechanism, the examiner clearly stated its rejection of this argument several times.  In these circumstances, where an applicant abandons its unsuccessful argument, the Federal Circuit concluded that the prosecution history lacks the clarity necessary to establish prosecution disclaimer.

Remand Because the Federal Circuit Could Not Determine whether Board’s Error was Merely Typographical and Harmless or an Error of Substance

In Corephotonics, Ltd., v. Apple Inc., [2022-1340, 2022-1341, 2022-1455, 2022-1456] (October 16, 2023) the Federal Circuit affirmed the PTAB’s determination that two references were analogous prior art, while vacating and remanding the Board’s obviousness determination for the Board to explain why a third reference — Martin — is (or is not) analogous art and how this finding affects its overall conclusion as to obviousness.  The Challenged Patents relate to dual-aperture camera systems and disclose techniques for using the images from both lenses when zooming while capturing video.

Prior art references are applicable to the obviousness inquiry only when they are analogous to the claims being challenged. See In re Clay, 966 F.2d 656, 658 (Fed. Cir. 1992); see also In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004). Art that is “too remote” from the patents being attacked cannot be treated as prior art.  The Federal Circuit uses two separate tests to define the scope of analogous art: (1) whether the art is from the same field of endeavor, regardless of the problem addressed and, (2) if the reference is not within the field of the inventor’s endeavor, whether the reference still is reasonably pertinent to the particular problem with which the inventor is involved.

Apple’s petitions were ambiguous; they did not make clear whether Apple was stating that Golan and Martin are in the same field of endeavor as the Challenged Patents or, instead, merely that Golan and Martin are in the same field of endeavor as one another. The Board wrote, “Martin is reasonably pertinent to the problem faced by the inventor: reducing an image jump effect seen in video output images when switching between cameras that have different fields of view. Apple and Corephotonics agree that these two sentences are, as written, incorrect: Martin does not disclose switching between cameras with different fields of view; rather, it is addressed to cameras with different points of view.  The Federal Circuit was unable We are unable to discern if the Board’s error was, in fact, merely typographical and harmless or, instead, a potentially-impactful error of substance. This prevented the Federal Circuit from concluding either that there is, or is not, substantial evidence to support the Board’s conclusion that Martin is analogous art to the Challenged Patents.  Accordingly, the Federal Circuit remanded to the Board for further explanation and, if needed, further fact finding.

An New (Old) Perspective on Claim Construction

In Century Electric Co. v. Westinghouse Electric & Mfg. Co., 191 F. 350 (8th Cir. 1911), the Eighth Circuit had in interesting perspective on claim construction. The Eighth Circuit said that a patent “is a contract made by the acceptance by the government of the offer which the patentee by his application makes to disclose his invention, in consideration that the United States will secure to him the exclusive use and sale of it for 17 years,”

The Court continued:

The offer embodied in the application becomes the specification of his patent, if his offer is accepted, and with his claims evidences the terms of the agreement. Such an agreement is interpreted by the same rules that determine other contracts. The court, should, as far as possible, place itself in the situation of the parties when they made their agreement and then seek to ascertain from the terms of their contract, in the light of the circumstances then surrounding them, what their intention was.

This intention should be deduced from the entire contract and not from any part of it or without any part of it, because they did not agree to it, or to any part of it, without every other part of it. The specification which forms a part of the same application as the claims must be read and interpreted with them, not for the purpose of limiting, or of contracting, or of expanding, the latter, but for the purpose of ascertaining from the entire agreement, of which each is a part, the actual intention of the parties and that intention when ascertained should prevail over the dry words and inapt expressions of the contract evidenced by the patent, its specification and claims.

Modern claim construction seem more rule-bound, and might be improved if animated by the purpose to determine what the inventor invented, not what the claims literally say.

Computer-Readable Recording Medium Is Not a Transitory Medium

In Sequoia Technology, LLC v. Dell, Inc., [2021-2263, 2021-2264, 2021-2265, 2021-2266] (April 12, 2022), the Federal Circuit disagreed with the district court’s claim construction for “computer-readable recording medium,” and thus reverses the district court’s ineligibility determination under 35 U.S.C. § 101. In addition, the Federal Circuit agreed with the district court’s claim construction for “disk partition” and “logical volume,” and thus affirmed the district court’s noninfringement determination.

The magistrate judge adopted and construed “computer-readable recording medium” to include transitory media (i.e., signals or waves),base upon the specification, which discusses “computer readable medium” as “including” a list of items—none of which are transitory— and interpreted that language as leaving the door open for media that could be transitory.

The Federal Circuit noted at the outset that the claim language does not actually recite a “computer-readable medium” or CRM. Instead, it more narrowly recites “computer-readable recording medium storing instructions. The Court said that a person of ordinary skill would not understand transitory signals, such as carrier waves, to record or store instructions in memory systems. This is because transitory signals, by their very nature, are fleeting and do not persist over time. Other elements in the claim confirm that the claim is directed to hardware as opposed to transitory waves or signals.  The Federal Circuit found that the claim language demonstrates that claim 8 is not directed to a transient signal, but rather to a non-transient storage medium.

The Federal Circuit then turned to the specification, which discloses only non-transitory media.  The Court said the use of a term denoting a nonexhaustive list does not eviscerate our obligation to construe terms in the context of the entire patent. The context

here makes clear that the term “computer-readable recording medium” cannot encompass transitory media.

The Federal Circuit declared that its decision rests solely on the intrinsic evidence, and that it was unpersuaded by arguments to the contrary, which rest on extrinsic evidence.  The Court further noted that not only was this extrinsic evidence was inconsistent with the intrinsic evidence and also based on different express definitions of CRM in patent specifications directed to different inventions.

The Federal Circuit disagreed with the district court’s claim construction and, consequently, reversed the district court’s holding that claims 8–10 are ineligible under § 101.

How Many?

An often critical issue in determining patent infringement is how many of a specified claim element are required by the claim. This issue can arise in a variety of ways:

A or An

The general rule is that “a” or “an” means one or more. In KCJ Corp. v. Kinetic Concepts, Inc., 223 F.3d 1351 (Fed. Cir. 2000), the Federal Circuit observed:

an indefinite article “a” or “an” in patent parlance carries the meaning of “one or more” in open-ended claims containing the transitional phrase “comprising.” … Unless the claim is specific as to the number of elements, the article “a” receives a singular interpretation only in rare circumstances when the patentee evinces a clear intent to so limit the article. … Under this conventional rule, the claim limitation “a,” without more, requires at least one.

See, also  Baldwin Graphic Sys., Inc. v. Siebert, Inc., 512 F.3d 1338 (Fed. Cir. 2008).

However, the Federal Circuit indicated that there are situations where “a” or “an” can mean “only one.” See, for example, Harari v. Lee, 656 F.3d 1331 (Fed. Cir. 2011), and Insituform Techs., Inc. v. CAT Contr., Inc., 99 F.3d 1098, 1106 (Fed. Cir. 1996).

How can the careful prosecutor ensure the interpretation he or she wants? One way is to provide a definition in the specification. Thousands of patents do.

  1.  As used herein, “a” or “an” or “the” can mean one or more than one. For example, “a” widget can mean one widget or a plurality of widgets. See, e.g., U.S. Patent No. 1082263.9
  2. As used herein, “a” or “an” may mean one or more than one. See, e.g., U.S. Patent No. 10525082.
  3. Unless otherwise indicated or the context suggests otherwise, as used herein, “a” or “an” means “at least one” or “one or more.” See, e.g., U.S. Patent No. 10546223.
  4.  As used herein, “a” or “an” means “at least one” or “one or more” unless otherwise indicated. See, e.g., U.S. Patent No.7465758.
  5. As used herein, “a” or “an” means at least one, unless clearly indicated otherwise. See, e.g., U.S. Patent No.11275080.
  6. As used herein, “a” or “an” means one or more unless otherwise specified. See, e.g., U.S. Patent No. 9540312.

A problem with definitions is that the prosecutor has to commit to a meaning, and do so by the time of filing. In the examples above definitions #1 and #2 aren’t really definitions at all – they merely state a possible meaning. No options are foreclosed, buy no certainty is achieved. Definitions #3 expresses a preference, but there is still some uncertainty. Definitions #4 – #6 provides a definition that is only superseded by an “indication” or a “specification” otherwise.

More certainty is obtained by specifying “one” or “at least one” when the element is described and claimed.


The simple word “or” has multiple, inconsistent meanings. In some contexts, “or” can express exclusive alternatives. In these cases “A or B” means either A and not B, or B and not A. See, Kustom Signals, Inc. v. Applied Concepts, 264 F.3d. 1326 (Fed. Cir. 2001). In other contexts, “or” can express non-exclusive alternatives. In these cases “A or B” means just A, A and B, or just B. Brown v. 3M, 265 F.3d 1349 (Fed. Cir. 2001).

As discussed above, definitions can help provide some certainty. There are numerous examples:

  1. The term “or” as used in this disclosure is to be understood to refer a logically inclusive or not a logically exclusive or, where for example the logical phrase (if A or B) is satisfied when A is present, when B is present or where both A and B are present (contrary to the logically exclusive or where when A and B are present the if statement is not satisfied). See, e.g., U.S. Patent No. 9747910.
  2. As used herein, “or” is understood to mean “inclusively or,” i.e., the inclusion of at least one, but including more than one, of a number or list of elements. In contrast, the term “exclusively or” refers to the inclusion of exactly one element of a number or list of elements. See, e.g., U.S. Patent No. 10639598.

The examples above provide definitions of an inclusive “or,” but also provide a template of how to define an exclusive “or.”

Alternatively, the careful prosecutor can be more precise in the specification and claims. One way is to claim “A and/or B” for an inclusive “or”, and “either A or B” for an exclusive “or.”


“And” has also caused problems for patent owners.  In Super Guide Corp. v. DirecTV Enters., Inc., 358 F.3d 870, 885-86 (Fed. Cir. 2004), the patent owner and the accused infringer disagreed over the effect of “and” in the claim limitation “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.” The patent owner argued that this language required at least one of any of the four list categories. The accused infringer argued that this language required at least one from each of the four listed categories. The Federal Circuit agreed with the accused infringer, noting that the phrase “at least one of” preceded a series of categories of criteria, and the patentee used the term “and” to separate the categories of criteria, which connotes a conjunctive list. The Federal Circuit cited William Strunk, Jr. & E.B. White, The Elements of Style 27 (4th ed. 2000). The TTAB has reached a similar result in Ex Parte Jung, Appeal 2016-008290 at 2 (P.T.A.B. Mar. 22, 2017).

Thus when enumerating a list, the careful prosecutor must be mindful choosing whether to join the list with “and” or “or”


If “or” and “and” can cause problems, it would seem that “and/or” can likewise cause problems. As Wikipedia notes, “and/or” has come under criticism in the courts. Judges have called it a “freakish fad”, an “accuracy-destroying symbol”, and “meaningless”. In Ex Parte Gross, Application No. 11/565,411, the Examiner rejected claim 1 as indefinite based upon the use of “and/or.” However, the PTAB reversed – finding that “A and/or B” does have a meaning and that meaning is A alone, B alone, or A and B together. The Board noted the “preferred verbiage” should be more simply “at least one of A and B.”

While not popular with legal purists, “and/or” may be the best choice to get the intended claim scope.

“A Processor” Can Mean More Than One Processor, But At Least One of Multiple Processors Has to be Capable of Performing All of “Said” Processor’s Functions

In Salazar v. AT&T Mobility LLC, [2021-2320, 2021-2376] (April 5, 2023), the Federal Circuit affirmed judgment of noninfringement of U.S. Patent No. 5,802,467 describing technology for wireless and wired communications.

Claim 1 of the ‘467 patent required “a microprocessor for generating a plurality of control signals used to operate said system, said microprocessor creating a plurality of reprogrammable communication protocols, for transmission to said external devices wherein each communication protocol includes a command code set that defines the signals that are employed to communicate with each one of said external devices.”  The district court construed the court construed “a microprocessor” to mean one microprocessor.”

On appeal, Salazar argued that the court should have interpreted a microprocessor” to require one or more microprocessors, any one of which may be capable of performing each of the “generating,” “creating,” and “retrieving” functions recited in the claims.

The Federal Circuit explained that the indefinite article “a” means “‘one or more’ in open-ended claims containing the transitional phrase ‘comprising.’” The Court said an exception to the general rule that “a”  means more than one only arises where the language of the claims themselves, the specification, or the prosecution history necessitate a departure from the rule.”   The Federal Circuit further explained that the use of the term “said” indicates that this portion of the claim limitation is a reference back to the previously claimed” term.  The claim term “said” is an “anaphoric phrase, referring to the initial antecedent phrase”. The subsequent use of the definite article ‘said’ in a claim to refer back to the same claim term does not change the general plural rule, but simply reinvokes that non-singular meaning.”

The Federal Circuit reviewed prior cases interpreting “a” and noted in particular In re Varma, 816

F.3d 1352 (Fed. Cir. 2016), which the district court had explained that the claim term provided certain functions that the “said microprocessor” must be “necessarily configured to perform as well as the structural relationship between ‘said microprocessor’ and other structural elements.”  Thus, the district court reasoned, “at least one microprocessor must satisfy all the functional (and relational) limitations recited for ‘said microprocessor.’ On appeal, Salazar’s argued that a correct claim construction would encompass one microprocessor capable of performing one claimed function and another microprocessor capable of performing a different claimed function, even if no one microprocessor could perform all of the recited functions.  The Federal Circuit rejected this argument, agreeing with the district court that while the claim term “a microprocessor” does not require there be only one microprocessor, the subsequent limitations referring back to “said microprocessor” require that at least one microprocessor be capable of performing each of the claimed functions, which the Court said was “entirely consistent” with it precedents. The Court noted that, as it stated in Varma, for a dog owner to have a dog that rolls over and fetches sticks, it does not suffice that he have two dogs, each able to perform just one of the tasks.