Aug 9 (Reuters) - A U.S. appeals court on Friday upheld

U.S. Patent and Trademark Office rulings for Micron, Dell

and HP, finding that the decisions could stand

even though the attorney who represented the tech companies

later became the office's director.

The U.S. Court of Appeals for the Federal Circuit said the

companies' adversary in the USPTO case, patent owner Unification

Technologies, had not shown that Kathi Vidal's previous

participation in the case influenced the administrative judges

who invalidated its patents.

Unification's lead attorney did not immediately respond to a

request for comment on the decision. Micron, Dell and HP's

attorney Linda Coberly of Winston & Strawn and a USPTO

spokesperson declined to comment.

Unification sued Micron, Dell and HP for infringing the

patents, which relate to managing and deleting data in memory

chips, in Texas federal court in 2020. The HP and Dell cases

have since been dismissed, while the Micron case is ongoing.

The tech companies -- represented by Vidal, then a partner

at Winston & Strawn -- asked the USPTO's Patent Trial and Appeal

Board (PTAB) to invalidate the patents later that year.

President Joe Biden nominated Vidal to head the office in 2021

and she was confirmed in 2022, after which she recused herself

from the case.

The board invalidated Unification's patents later that year.

Unification argued at the Federal Circuit that the case

improperly required PTAB judges to "evaluat the arguments of

their boss" and said they were "monetarily disincentivized" from

ruling against Vidal because she reviews their performance.

U.S. Circuit Judge Raymond Chen wrote for a three-judge

panel on Friday that Unification "provided no evidence that the

Director controls [PTAB judge] bonuses or performance reviews,"

and that a PTAB judge would have no reason to think that their

decision "could affect their bonus determination because of the

way that the Director might react."

The case is Unification Technologies LLC v. Micron

Technology Inc ( MU ), U.S. Court of Appeals for the Federal Circuit,

No. 23-1348.

For Unification: Jon Rastegar of Nelson Bumgardner Conroy

For Micron, Dell and HP: Linda Coberly of Winston & Strawn

For the USPTO: Robert McManus of the USPTO

(Reporting by Blake Brittain in Washington)