IP Law Daily, PATENT NEWS: Supreme Court denies certiorari in dispute over LED lighting patent claims, (May 19, 2026)

By Carolin Dennis, B.Sc., LL.B., LL.M.

CAO Lighting, Inc.’s petition urged the Supreme Court to hold that the Federal Circuit must provide the reasons for its decisions that demonstrate independent and de novo review of questions of law decided by the Patent Trial and Appeal Board (PTAB).

The U.S. Supreme Court has denied CAO Lighting, Inc.’s petition for a writ of certiorari, leaving undisturbed a Federal Circuit decision that upheld the PTAB’s invalidation of CAO Lighting’s patent claims. The denial, issued on May 18, 2026, came without comment, concluding the conflict regarding the Federal Circuit's claim construction standards and its handling of PTAB rulings (CAO Lighting, Inc. v. Wolfspeed, Inc., No. 25-1068 (U.S. May 18, 2026)).

Background. Dr. Densen Cao owned U.S. Patent No. 6,465,961 (’961 patent) and U.S. Patent No. 6,634,770 (’770 patent) that provided how to replace traditional incandescent and fluorescent general purpose lights with high-powered light emitting diodes (LEDs). Dr. Cao later formed CAO Lighting, Inc. and assigned the patents to the company.

In April 2022, Cree Lighting filed petitions for inter partes review (IPR) of the ’961 and ’770 patents based on obviousness grounds that included the same Begemann/Krames 2000 combination rejected by the Delaware jury. CAO Lighting demonstrated that the proposed combination on which the IPRs were instituted would be catastrophically unworkable. However, on September 28, 2023, seven months after the Delaware jury found Dr. Cao’s patents valid, the PTAB issued one and another (two total) Final Written Decisions, invalidating all but one of the claims in the challenged patents. The PTAB held that the claims were invalid over a combination of Begemann and Krames 2000 because Cree proved “the capability of the Krames chip” to achieve a power output of over 170 mW at a drive current of 1.5 amps. The PTAB thus construed the limitation of “configured to output light at greater than about 40 milliwatts” to require only that the LED chip be “capable of the recited output.” The PTAB concluded, therefore, that the claim would be satisfied by any chip theoretically capable of the claimed output, without any requirement that “a chip, when placed in the bulb, actually operates at more than about 40 milliwatts.”

Although the PTAB contended it merely accepted the parties’ construction, it in fact dramatically broadened the claim scope by looking at the claim term in isolation from the rest of the claim elements. The PTAB’s construction was directly contrary to how the Delaware court construed and interpreted the claim term and how Cree and its experts interpreted and applied the claim term throughout the IPRs. Additionally, the PTAB gave no notice to CAO Lighting of this legal interpretation, provided no opportunity for CAO Lighting to respond, and thus deprived CAO Lighting of its rights under the Administrative Procedure Act (APA).

On appeal, the Federal Circuit summarily affirmed the PTAB final written decisions under Rule 36 without issuing any opinion. The Federal Circuit did not address the APA violations or the conflict with the Delaware court’s construction.

Petition for certiorari. On March 6, 2026, CAO Lighting filed petition for writ of certiorari before the U.S. Supreme Court, seeking review of the Federal Circuit’s decision. The petition presented the question: “Whether the Federal Circuit’s use of its Local Rule 36, which allows summary affirmance without opinion, (a) improperly defers to the Patent Trial and Appeal Board’s interpretations of law in inter partes review proceedings and so denies judicial review of agency decisions on questions of law as required by Loper Bright Enterprises v. Raimondo, (b) improperly insulates the PTAB from the de novo review required by the Administrative Procedure Act, and (c) violates Congress’s explicit direction in 35 U.S.C. § 144 requiring an “opinion” of all appeals from the Patent Office.”

CAO Lighting contended that the Federal Circuit’s Rule 36 summary affirmance improperly defers to the PTAB’s decisions on questions of law in violation of the Supreme Court’s decision Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024). The Federal Circuit’s Rule 36 summary affirmance procedure is, however, irreconcilable with Loper Bright’s requirement the court must decide legal questions, such as claim construction, by applying its own judgment. CAO Lighting argued that without an opinion explaining why the PTAB’s claim construction is correct and why the district court’s is not, it is difficult for a party to frame a certiorari petition and difficult for the Supreme Court to evaluate whether review is warranted.

The petition also noted that when the PTAB applies a construction for a claim term for the first time in its final written decision, the patent owner has had no opportunity to present rebuttal evidence or expert testimony tailored to that construction. CAO Lighting argued that this is a textbook violation of the APA: the agency has adjudicated a property right on a ground the affected party never had a chance to address. Rule 36 summary affirmances cannot provide the required de novo judicial review of violations of the APA. Rule 36 affirmance of such a decision compounds the separation-of-powers problem that the APA was enacted to cure. Not only does the PTAB resolve the existence of a private right, but the Federal Circuit’s summary affirmance denies any meaningful judicial review of the procedural deficiency. This is precisely the kind of deficit that Loper Bright sought to remedy by insisting that courts exercise independent judgment rather than defaulting to agency conclusions.

CAO Lighting also contended that the Federal Circuit’s silent adoption of the PTAB’s construction over the district court’s construction created an unjustified hierarchy in which an agency’s legal conclusion takes precedence over that of an Article III court’s, merely by virtue of which appeal reaches the Federal Circuit first. At a minimum, the Federal Circuit must demand an explanation from the agency when that agency’s findings contradict an Article III court’s legal conclusion, and then the Federal Circuit must provide its own reasoned analysis of that contradiction and which interpretation of a legal question (by the agency or by the district court) is correct. Rule 36 should never be used to insulate due process and APA violations by the PTAB; and it cannot be used to avoid judicial review of an agency’s interpretation of legal questions.

According to the petition, this case is of exceptional importance to the uniformity, certainty, and integrity of the patent system and is an ideal vehicle for the Supreme Court to address the proper limits on summary affirmance in PTAB appeals. Without the Supreme Court’s intervention, the Federal Circuit’s continuing use of Rule 36 in deference to PTAB decisions will harm the patent system and quell legitimate innovation.

Conclusion. With the denial of certiorari, the Supreme Court has declined to address the harms caused by the Federal Circuit’s repeated use of Rule 36 in PTAB appeals when it involves the PTAB’s decisions on questions of law or due process and APA violations—questions that demand a meaningful de novo review by the Federal Circuit.

The Case is No. 25-1068.

Judge: NA

Attorneys: Todd Gerald Vare (Barnes & Thornburgh LLP) for CAO Lighting, Inc. Matias Ferrario (Kilpatrick Townsend & Stockton LLP) for Wolfspeed, Inc.

Companies: CAO Lighting, Inc.; Wolfspeed, Inc.

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