InterDigital AV1 patent held invalid after 2nd appeal in China

On June 29, 2026, in the second appeal of Unified’s challenge of InterDigital’s CN101491099, the Beijing Intellectual Property Court confirmed the invalidity of all challenged claims (1, 2, 5-9, 15, 19-21, 24-28, 34, 38-40, 43-48, 54, 57-59, 62-67, 73, and 76). The CN’099 patent was previously deemed essential in SISVEL’s VP9 and AV1 pools.

Unified was represented by Tao Chen, Yu Yan, and Peter Zhang of the Beijing Wei Chixue Law Firm, and the case was managed by in-house counsel, Jessica L.A. Marks and Roshan Mansinghani.

The trials and tribulations of Chinese patent invalidation proceedings

Unified’s senior patent counsel, Jessica Marks, explains Chinese oppositions and some of the unexpected issues that can crop up.

Validity challenges at the China National IP Administration are an increasingly important part of the Chinese patent landscape, but they can be confusing affairs. With regulations and guidelines, the process that PRID follows is intended to be efficient and many Chinese practitioners will advise that invalidations can be accomplished in six to nine months. However, Unified Patents has filed 18 such challenges since 2020 in China but, based on its experiences, the reality can be very different to expectations.

Read the article HERE, published by IAM.