InterDigital Technology Corporation & Ors v Lenovo Group Ltd & Ors

In an obviousness appeal, the absence from a patent specification of a stated advantage over prior art does not generally prevent reliance on a claimed combination. The narrow prejudice exception applies only where the alleged prejudice concerns a claim feature, and requires the patent to dispel a belief that the feature would not work. It does not apply to intermediate proposals in an obviousness attack or to a design choice viewed as unattractive. A skilled person’s open-mindedness or ability to make a change does not itself establish motivation. Nor does disclosure that a message is used to request resources necessarily disclose a request communicated by the message’s presence rather than its contents.

InterDigital alleged that its patent for a wireless communications method was essential to the 4G/LTE standard. Lenovo challenged validity on several grounds. In [2021] EWHC 2152 (Pat), HHJ Hacon held the patent essential and rejected the validity challenges, including an obviousness challenge based on the Samsung standardisation document.

On appeal, Lenovo pursued only obviousness. The issues were whether the absence of a stated advantage engaged the prejudice principle, whether it was obvious to move from an 18-bit scheduling message to a one-bit transmission using on-off keying, and whether Samsung itself disclosed a request communicated by the presence of the message.

Appeal dismissed unanimously. Birss LJ gave the leading judgment. Warby LJ and Falk LJ agreed. The respondent’s notice did not require determination.

1. Advantage and prejudice. There is no general requirement under the Patents Act 1977 for a patent specification to state an advantage over prior art. The principle was supported by Conor v Angiotech [2008] UKHL 49. The narrow prejudice principle, reflected in Philips v Asustek [2019] EWCA Civ 2230 and Pozzoli v BDMO [2007] EWCA Civ 588, applies where the alleged prejudice concerns a claim feature. The patent must then explain why the feature is practical. It does not apply to an intermediate proposal in an obviousness argument, such as reducing an 18-bit message to one bit, or to a choice regarded as unattractive or a backward step. The proposed qualification in Dyson v Samsung [2009] EWHC 55 (Pat) therefore did not need to be applied.
2. Motivation. The trial judge was entitled to find that an open-minded skilled person, who could see arguments for either design, lacked the positive motivation required for Lenovo’s obviousness case. The evidence did not establish that reducing the message size was an obvious step.
3. On-off keying and Samsung. The finding that on-off keying was common general knowledge did not establish that the skilled person knew of its use in an implemented cellular network. The trial judgment, read as a whole, made no finding that the particular cellular scheme described in the textbook was commonly understood as on-off keying. Samsung’s proposal that a message serve as the mechanism for requesting uplink resources did not necessarily disclose a request communicated by the message’s presence rather than its contents. A signal within the message could perform that function.
4. Appellate review. The obviousness conclusions were amply supported by the evidence, involved no appealable error, and fell within the range of outcomes open to the trial judge.

1. Court of Appeal (Civil Division) — The court dismissed Lenovo’s appeal against the rejection of its obviousness challenge.
2. High Court of Justice, Patents Court — In [2021] EWHC 2152 (Pat), HHJ Hacon held the patent essential and rejected the pleaded validity challenges, including obviousness over Samsung.