Syntroleum Corp v Neste Oil Singapore Pte Ltd [2014] SGHCR 18

In the recent Singapore High Court Registry decision of Syntroleum Corp v Neste Oil Singapore Pte Ltd [2014] SGHCR 18, the learned Senior Assistant Registrar Mr Yeong Zee Kin (the “SAR”) considered the issue of whether an inventor’s notes are discoverable in a patent infringement action where the validity of the patent alleged to be infringed is challenged. The SAR also considered whether discovery of certain experimentation results should be granted.


The defendant, Neste Oil Singapore Pte Ltd, filed two applications for discovery, one each in two related suits. Both applications sought discovery of identical categories of documents. This article focuses on one critical category in the applications, namely, the inventor’s notes in relation to the patent cited in each respective suit.

The parties’ arguments

In support of its applications, the defendant argued that the inventor’s notes were relevant as evidence of what the state of the art was at the time of the invention and whether the steps taken by the inventor were obvious to the ordinary man skilled in the art.

The plaintiff argued that with the adoption of the objective standards in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59 (“Windsurfing”), the subjective knowledge and intentions of the inventors are no longer relevant and should therefore be excluded. The plaintiff also raised objections based on Order 87A rule 5(2)(b) of the Rules of Court, which limits disclosure relating to any ground on which the validity of a patent is put in issue to a period of four years on either side of the earliest claimed priority date. In response to the plaintiff’s solicitor’s arguments on this issue, the defendant sought to amend its prayers in relation to the inventor’s notes to comply with the procedural limits.

The plaintiff further objected to the disclosure of the inventor’s notes on the ground that these were private documents that did not form part of the publicly available state of the art and were accordingly irrelevant in establishing what the state of the art was at the time of the invention (as per the prevailingWindsurfing test) .

Discoverability of inventor’s notes

The SAR held that, in principle, an inventor’s notes are discoverable, citing Halcon International Inc v The Shell Transport and Trading Co & Ors (Discovery No 2) [1979] RPC 459, SKM SA & Anor v Wagner Spraytech (UK) Ltd & Ors [1982] RPC 497, Molnlycke AB v Proctor & Gamble Ltd (No 3) [1990] RPC 498 (“Molnlycke”) and Nichia Corp v Argos Ltd [2007] FSR 38 (“Nichia”).

However, the SAR cautioned against indiscriminate disclosure and expressed that an inventor’s notes are secondary evidence to the issue of obviousness which ought to be put through a fine sieve in order to avoid unnecessary disclosure. The SAR agreed with the views expressed in Molnlycke and Nichiathat secondary evidence should be kept firmly in its place and that discovery of secondary evidence should be properly managed in order to adhere to the principle of proportionality and to manage litigation costs.

The SAR further expressed that an inventor’s notes should not be discoverable during general discovery unless the issues for which they are required have been especially particularised. As obviousness is an objective analysis, the primary evidence relied upon should be documents that are publicly available and the issues faced by researchers in the field should similarly be evidenced through publicly available documents. Recourse should not be made to a private inventor’s notes unless it is necessary to do so. In the SAR’s view, the touchstone must be that an inventor’s notes only become discoverable when the issues on obviousness are sufficiently particularised such that it becomes evident that the inventor’s notes - or part of them - are relevant and material to identify issues in dispute and their disclosure will therefore be necessary for the fair disposal of the case or for the saving of costs.

The SAR took the view that, on the facts, the issues for which the inventor’s notes were sought had not been sufficiently particularised by the defendant and the applications were therefore premature. He accordingly dismissed the defendant’s applications in respect of the inventor’s notes without prejudice to the defendant’s rights to apply for discovery of the same at a subsequent stage of the proceedings.

Impact of this decision

While this is a first instance decision before the High Court Registry, this is the first time the Singapore courts have seriously considered the disclosure of an inventor’s notes. The courts have not precluded themselves from ordering the disclosure of inventor’s notes and all organisations should be aware that notes created by its employees during the course of employment in relation to an organisation’s inventions are potentially discoverable, even after a patent has been granted for the invention. Such notes (which can extend to e-mail discussions between co-inventors within and outside an organisation) can adversely diminish arguments that an invention is not obvious over the state of the art, even though these notes were not and have never been publicly available.

Whilst the Windsurfing test refers to an objective standard when answering the question whether an invention is not obvious and therefore patentable, the courts remain open to considering the subjective views of an inventor whilst maintaining that such views remain secondary evidence. It is conceivable that in an appropriate situation, the courts may find it material and place reliance on an inventor’s personal critique of an inventor’s own invention/patent application/granted patent.