In Intellectual Pixels Ltd. v. Sony Interactive Entertainment LLC, No. 2024-2174 (Fed. Cir. July 10, 2026), the Federal Circuit affirmed a decision of the Patent Trial and Appeal Board (the “Board”) holding claims 1 through 12 of U.S. Patent No. 10,681,109 unpatentable as obvious. The panel held that, on remand, the Board could decide an issue that was not resolved in its first final written decision and was not reviewed in the first appeal. The opinion addresses the application of the mandate rule in administrative proceedings and the distinction between issues decided by an appellate judgment and issues discussed but not resolved by the tribunal below.
Background
The ’109 patent claims methods and systems for generating digital images on an external server and delivering them to a client device. The device sends user input to the server, receives a compressed image in return, and decompresses it for display. Two claim limitations drove the appeal: “generating at least one updated image at the server,” and “compressing the at least one updated image and transmitting the compressed updated image to the client device.”
Sony Interactive Entertainment LLC (“Sony”) petitioned for inter partes review of claims 1 through 12, asserting that the claims would have been obvious over U.S. Patent No. 6,409,602 (“Wiltshire”) in combination with additional prior art. Wiltshire disclosed a server-hosted gaming system that transmitted images to client computers and identified games such as Doom among its embodiments.
In its first final written decision, the Board resolved the case on the generating limitation alone. It found that Wiltshire did not disclose generating a new image, reasoning that the reference merely selected images from a predetermined set. Having decided the petition on that ground, the Board did not reach the compressing limitation. It observed only, in passing, that “Wiltshire’s disclosure [is] completely silent as to the content or origin of that ‘compressed video MPEG stream.’”
On the first appeal, the Federal Circuit vacated and remanded. The court held that substantial evidence did not support the Board’s finding on the generating limitation, because Wiltshire disclosed operation with Doom, which the parties agreed required generating new images. The court described the issue before it as follows: “The sole issue on appeal is whether the Board properly determined that Wiltshire does not teach the ‘generating’ limitation.” Sony Interactive Ent. LLC v. Intell. Pixels Ltd., No. 2022-2118, 2023 WL 6773879, at *2 (Fed. Cir. Oct. 13, 2023).
On remand, the Board addressed the generating limitation in light of the Federal Circuit’s decision and then considered the compressing limitation. The Board found the limitation disclosed by Wiltshire combined with U.S. Patent No. 6,404,817 (“Saha”) and held the challenged claims unpatentable. IPL appealed again, arguing that the Board exceeded the mandate by addressing compression and that the Board’s decision was not supported by substantial evidence.
The Federal Circuit’s Analysis
The Federal Circuit affirmed. The court explained that the mandate rule forecloses only “issues actually decided on appeal.” A tribunal “has no power or authority to deviate from the mandate issued [to it] by an appellate court.” Briggs v. Pa. Ry. Co., 334 U.S. 304, 306 (1948). The court also stated that the rule is limited to issues “actually decided, either explicitly or by necessary implication,” in the prior appeal. Banks v. United States, 741 F.3d 1268, 1276 (Fed. Cir. 2014).
The panel stated that the mandate rule applies to proceedings before the Patent and Trademark Office. It cited prior Federal Circuit precedent and the treatise statement that “[a]n administrative agency is bound by the mandate of a reviewing court much as a lower court is bound by the mandate of a higher court.” See Jewelers Vigilance Comm., Inc. v. Ullenberg Corp., 853 F.2d 888 (Fed. Cir. 1988); Atlanta Gas Light Co. v. Bennett Regulator Guards, Inc., 33 F.4th 1348 (Fed. Cir. 2022).
Applying that framework, the court held that the compressing limitation was outside the scope of the first appellate mandate. The Board’s first decision rested on the generating limitation. Its statement that Wiltshire was silent as to the origin of the MPEG stream was not treated by the Federal Circuit as an alternative holding, was not necessary to the judgment, and was not reviewed in the first appeal. The court therefore concluded that the Board was not precluded from considering the issue on remand.
The court distinguished IPL’s reliance on Bitmanagement Software GmbH v. United States, 124 F.4th 1368 (Fed. Cir. 2025). There, the findings the Court of Federal Claims could not revisit “were before us—but not disturbed by us—in [the first appeal],” and they formed the basis of an implied-license conclusion that had been appealed. Id. at 1377. The panel viewed those findings as part of the judgment under review in the prior appeal. By contrast, the compressing limitation in Intellectual Pixels had not been resolved in the first final written decision and was not part of the judgment reviewed in the first appeal.
The court also affirmed the Board’s obviousness determination on substantial-evidence grounds. It held that the Board could rely on Wiltshire, Saha, and expert testimony in finding that a skilled artisan would have combined Saha’s MPEG compression standard with Wiltshire’s system.
Takeaways
The decision illustrates that the scope of a remand may depend on whether an issue was actually decided in the prior appeal, either expressly or by necessary implication. Statements in an earlier decision may not have preclusive effect if they were not necessary to the judgment and were not reviewed on appeal. Parties in PTAB remand proceedings should therefore consider carefully which findings formed the basis of the judgment under review and which issues remain unresolved.
The opinion may be useful in disputes over the scope of a Federal Circuit remand to the Board, particularly where the first final written decision resolved fewer than all challenged limitations or grounds. Its application will likely depend on the procedural record, the issues presented in the first appeal, and whether the prior judgment necessarily decided the issue later raised on remand.
