Federal Circuit Affirms Summary Judgment of Non­Infringement for Particle Detector Patents

Jan 29, 2015

Reading Time : 1 min

TSI distinguished the accused products by asserting that claim six requires a system that converts a light detector’s output into a digital voltage signal without comparing the light detector’s output to a predetermined reference voltage. While claim six of the originally issued patent did not recite any language or negative limitations regarding a reference voltage, the patent was subject to a reexamination proceeding where claim six was modified to include the limitation: “without using a reference voltage to convert each voltage value signals.” That limitation is echoed by the patent’s specification, which distinguishes the technique of using a reference voltage as a problematic prior art method—since it results in an insufficient signal­to­noise ratio, thereby limiting the device’s sensitivity—that the patent was meant to overcome. Because the court found that TSI’s accused devices utilize a reference voltage in converting the light signals into a digital voltage signal, it affirmed the district court’s grant of summary judgment of non­infringement.

Notably, last year the CAFC affirmed a district court ruling that Lockheed Martin did not infringe the same patent asserted here against TSI. Also, remarkably, the CAFC’s opinion here cited to Cybor Corp. v. FAS Techs., Inc.,138 F.3d 1448, 1456 (Fed. Cir. 1998) (en banc) for the proposition that claim construction is a question of law that reviewed de novo – even though Cybor was overturned just last week by the United States Supreme Court in Teva v. Sandoz, No. 13­854, slip op. (U.S. Jan. 20, 2015), which holds that factual conclusions that underpin claim construction rulings are no longer reviewed de novo but rather for clear error (i.e., claim constructions are now to be given deference on appeal).

Yufa v. TSI, Inc., No. 2015­1063, slip op. (Fed. Cir. Jan. 26, 2015).

Share This Insight

Categories

Previous Entries

IP Newsflash

February 24, 2026

The Southern District of Florida recently dismissed a complaint without prejudice because the allegations used a form of “shotgun pleading.” The court explained that a shotgun pleading includes those where every count incorporates every preceding paragraph into each cause of action, and that dismissal of such pleadings was required under Eleventh Circuit precedent.

...

Read More

IP Newsflash

February 20, 2026

The Federal Circuit recently addressed whether the PTO must conduct notice‑and‑comment rulemaking before issuing instructions that guide how the Board should exercise discretion at the institution stage of IPRs. The court held that no such rulemaking is required. Instructions to the Board regarding its use of the Director’s delegated discretionary authority not to institute review are merely general statements of policy exempt from notice-and-comment rulemaking.  

...

Read More

IP Newsflash

February 18, 2026

The District Court for the District of Delaware recently invalidated claims directed to a panoramic objective lens for lack of enablement, holding the claims impermissibly recited a single element in means‑plus‑function form. Under § 112, ¶ 6, “[a]n element in a claim for a combination may be expressed as a means or step for performing a specified function….” By its plain terms, the statute permits means‑plus‑function claiming only in the context of a “combination.” In other words, a claim may not consist solely of a single means‑plus‑function element. Claims drafted as a single means are invalid for lack of enablement as a matter of law.

...

Read More

IP Newsflash

February 13, 2026

In an ANDA litigation, the District of Delaware recently denied the defendants’ motion to compel the production of correspondence between the plaintiffs’ testifying expert and a third-party analyst who had performed experiments and provided data used by the testifying expert. The court found that the scope of material sought by the motion was overbroad and disproportionate to the needs of the case.

...

Read More

© 2026 Akin Gump Strauss Hauer & Feld LLP. All rights reserved. Attorney advertising. This document is distributed for informational use only; it does not constitute legal advice and should not be used as such. Prior results do not guarantee a similar outcome. Akin is the practicing name of Akin Gump LLP, a New York limited liability partnership authorized and regulated by the Solicitors Regulation Authority under number 267321. A list of the partners is available for inspection at Eighth Floor, Ten Bishops Square, London E1 6EG. For more information about Akin Gump LLP, Akin Gump Strauss Hauer & Feld LLP and other associated entities under which the Akin Gump network operates worldwide, please see our Legal Notices page.