This article discusses the recent software patent case, Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1313 (Fed. Cir. 2023). This article discusses the facts of the case, the issues addressed by the court, the holding of the case, the reasoning of the court, and some practice tips for software patent attorneys and agents.
FACTS OF THE CASE
Mr. Salazar owns U.S. Patent No. 5,802,467, which expired on September 28, 2015. Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1313 (Fed. Cir. 2023). In 2016, Mr. Salazar sued HTC Corp. alleging infringement of the ’467 patent by the HTC One phone. Id. A jury ultimately returned a verdict finding HTC Corp. did not infringe the ’467 patent. The jury did not decide whether the ’467 patent was valid. Id. The events of the current case begin in 2019, when Mr. Salazar sued AT&T and other wireless carriers over their use of certain phones. Id. at 1314.
The patent “describes technology for wireless and wired communications.” Id. Additionally, the patent has three independent claims. At the center of the dispute during claim construction was claim 1, particularly around the microprocessor and “said microprocessor.” The “technology for wireless and wired communications” includes “a microprocessor,” “a memory device,” “a user interface,” and “an infra-red frequency transceiver” all “coupled to said microprocessor.” Id. at 1313.
The district court constructed the term “said microprocessor” in claim 1 of the patent to mean “one or more microprocessors at least one of which is configured to perform the generating, creating, retrieving, and generating functions.” Id. That is, under the district court’s claim construction, “at least one microprocessor must satisfy all the functional (and relational) limitations recited for, ‘said microprocessor.’” Id. at 1314.
Before the district court trial, AT&T moved for summary judgment “arguing that Mr. Salazar’s claims were barred under claim preclusion and the Supreme Court’s decision in Kessler v. Eldred.” Id. The district court denied the motion. Id. At the conclusion of the trial, AT&T moved for judgment as a matter of law on infringement, damages, and preclusion but not regarding invalidity. Id. AT&T’s counsel explicitly stated that they did “not mov[e] under Rule 50(a) for anticipation.” Id. at 1319. The jury returned a verdict “finding that the accused products did not infringe the ‘467 patent and that the patent was not invalid.” Id. at 1314.
The subject matter of this case is an appeal from both Mr. Salazar and AT&T. During the appeal, the Court reviewed the district courts claim construction de novo. Id. at 1315.
ISSUE ADDRESSED BY THE COURT
The Court addressed three issues in Salazar. First, the Court addressed the district court’s claim construction regarding the meaning of the articles “a” and “said.” Second, the Court addressed AT&T’s challenge to the district court’s ruling that Mr. Salazar’s claims were not barred by claim preclusion or the Kessler doctrine. Third, the Court addressed AT&T’s argument that the district court erred when finding that claim 1-7, 27-30, and 34 were not anticipated.
HOLDING OF THE CASE
With respect to the first issue, the Court held that the district court’s claim construction was proper because “it does not suffice to have multiple microprocessors each able to perform just one of the recited functions; the claim language requires at least one microprocessor capable of performing each of the recited functions. With respect to the second issue, the Court affirmed the noninfringement and did not need to address the district court’s ruling that Mr. Salazar’s claims were not barred by claim preclusion or the Kessler doctrine. With respect to the third issue, the Court affirmed that claims 1-7, 27-30, and 34 were not anticipated because AT&T explicitly did not move under Rule 50(a) for judgement as a matter of law regarding invalidity.
REASONING OF THE COURT
With respect to the first issue, the Court upheld the district court’s claim construction of the articles “a” and “said” after reviewing it de novo because of precedent on what the articles mean. Id. at 1315. Generally, the article “a” means “‘one or more’ in open-ended claims containing the transitional phrase ‘comprising’” whereas “‘said’ indicate[s] that this portion of the claim limitation is a reference back to the previously claimed term.” Id. Further, using the article “said” in a claim “to refer back to the same claim term does not change the general plural rule but simply reinvokes that nonsingular meaning.” Id.
In support of this position, the Court references Baldwin Graphic Sys., Inc. v. Siebert, Inc., Harari v. Lee, Convolve, Inc. v. Compaq Comput. Corp., and In re Varma v. IBM Corp. First, the Court uses Baldwin to support that “said” reinvokes the non-singular meaning of the claim term. Salazar at 1315. First, the Court used Baldwin to support the meaning of the article “said”, highlighting that the Baldwin court’s holding that “‘a pre-soaked fabric roll’ meant ‘one or more’ pre-soaked fabric rolls, and that the subsequent ‘said fabric roll’ maintained that non-singular meaning.” Salazar at 1316. Second, the Court used Harari to support the meaning of the article “said” in claim construction, holding that “‘said bit line’ later in the claim must be the same, singular bit line as ‘a bit line’ earlier in the claim.” Salazar at 1316. Third, the Court highlighted the similar reasoning in Convolve, noting that they “interpreted ‘[u]ser interface for . . . working with a processor . . . comprising’… to require ‘a single processor’ having all of the subsequently recited characteristics.” Salazar at 1316. Lastly, the Court used at Varma, to support the claim construction, noting that in Varma the “structure may allow for more than a single instance of the claim element, it may nonetheless require that a single instance of the element be capable of performing all the recited functionality.” Salazar at 1317.
Using the referenced cases as precedent, the Court held that the district court properly interpreted “a microprocessor for generating . . ., said microprocessor creating . . ., a plurality of parameter sets retrieved by said microprocessor . . ., said microprocessor generating . . .” to mean “one or more microprocessors, at least one of which is configured to perform the generating, creating, retrieving, and generating functions.” Id. at 1317. That is, while “‘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.” Id. In the patent, “it does not suffice” to have “multiple microprocessors, each able to perform just one of the recited functions.” Id. at 1318. That is, the claim language requires at least one microprocessor capable of performing each of the recited functions.” Id. Thus, the system requires at least one microprocessor capable of performing all the functions as opposed to having at least one microprocessor for each of the functions (e.g., at least one microprocessor must perform the generating, creating, retrieving, and generating functions).
With respect to the second issue, the Court did not reach whether Mr. Salazar’s claims were barred by claim preclusion or the Kessler doctrine. In view of AT&T’s agreement that the Court “need not reach its preclusion argument if we affirm the district court’s judgement of noninfringement”, the Court did not address this issue. Id.
With respect to the third issue, the Court disagreed with AT&T’s argument that the district court erred when finding that claims 1-7, 27-30, and 34 were not anticipated. AT&T argues the district court erred because of the “substantial, clear, and convincing evidence” AT&T presented. Id. Rather than deciding this issue based on the disclosures of the prior art, the Court ruled on procedural grounds. Specifically, the Court noted that AT&T failed to move for judgement as a matter of law under Rule 50 and “a party must take proper motions under Rule 50 in order to appeal an adverse verdict on grounds relating to the sufficiency of the evidence.” Id. While AT&T moved for judgement as a matter of law regarding infringement, damages, and preclusion, they explicitly did not move for judgement as a matter of law regarding invalidity. Thus, AT&T “never challenged the sufficiency of the evidence with respect to anticipation before the district court” and “waived its anticipation challenge on appeal.” Id.
PRACTICE TIPS FOR SOFTWARE PATENT ATTORNEYS AND AGENTS
In drafting software patent applications, it is important to keep the Salazar case in mind. In Salazar, the court held that a reference to “a microprocessor” at the beginning of a computer system claim requires “one or more microprocessors, at least one of which is configured to perform [the steps of the independent claim].” This interpretation could impact the patent claims drafted by many attorneys which recite “a computer-readable medium” or “a system comprising a processor and a memory.” To clarify that a reference to a single element may include multiple elements that perform different parts of the claim, we recommend explicitly stating this in the text of the specification. The specification should state that any term specified in the singular may include its plural version, and that a term specified having multiple features may include a first object having some features and a second object having other features. For example, the specification may state that “a computer that stores data and runs software,” may include a single computer that stores data and runs software or two computers – a first computer that stores data and a second computer that runs software. Such a statement would clarify that a patent examiner or a court interpreting the claim language should not use the interpretation applied by the court in Salazar.
Furthermore, in drafting claims, we recommend, whenever possible, avoiding singular terms and instead using “one or more” or “at least one.” However, these terms might lead to awkward-sounding language. To avoid such awkward-sounding language, software patent attorneys or agents may consider using language that incorporates both singular and plural forms. The English language provides many such word, for example, “luggage,” and “information.” In the patent drafting space, references to a processor may be replaced with “processing circuitry” and references to a memory may be replaced with “memory subsystem.” Of course, the specification should include definitions to these terms that encompass both the singular and plural options. For example, “processing circuitry” may include a single processor or multiple processors in a single processing unit (e.g., a central processing unit) or multiple processing units (e.g., a central processing unit and a graphics processing unit).
Specifically, we recommend three claim types in software patent applications, as set forth below…
1. A method comprising: …
8. One or more non-transitory computer-readable media storing instructions which, when executed by processing circuitry, cause the processing circuitry to perform operations comprising: …
15. A system comprising:
processing circuitry; and
a memory subsystem storing instructions which, when executed by the processing circuitry, cause the processing circuitry to perform operations comprising: …
In patent prosecution practice, patent applications which are already pending may be amended to have the preambles set forth above. However, some pending patent applications might lack support for “processing circuitry” and a “memory subsystem.” For these patent applications, the phrase “processing circuitry” may be replaced with “one or more processors,” and the phrase “memory subsystem” may be replaced with “one or more memories.”
Incorporating these suggestions might lead to stronger patent applications that are more likely to be interpreted as the drafting attorney or agent intends, in view of the Salazar case.
This article has first been published here