In Nichia Corporation v Argos Limited, [2007] EWCA Civ 741, 19 July 2007, the majority LJs refused to follow Jacob LJ's opinion that there should normally be a limitation of disclosure on obviousness, where there was no attempt to rebut a claim of obviousness with evidence of long felt want or commercial success. The standard disclosure rules must be closely followed and the extent of disclosure in each case should be decided on its own facts.

The facts

Nichia Corporation owns two patents for white light emitting diodes. In 2005 – 2006, Argos, the retailer, sold chains of Christmas tree lights consisting of 120 white light emitting diodes. Nichia claimed that the lights sold by Argos infringed two of its patents, and in turn Argos claimed that the patents were invalid for obviousness in light of the common general knowledge and certain prior art publications. Nichia did not argue long felt want or commercial success. The trial of this case will be heard later in the year.

A dispute arose at a CMC before Pumfrey J as to the extent of disclosure. Nichia argued it should not give any disclosure at all, but Argos maintained that Nichia should have to disclose documents concerning the making of the invention and experiments conducted to prove infringement. Pumfrey J agreed with Nichia and refused to order disclosure of either kind (Judgment of 23 February 2007, [2007] EWHC 545 (Pat)). Argos appealed.

The Court of Appeal's differing Opinions

Jacob's dissenting judgment: Jacob LJ, with the minority decision, felt that disclosure of inventors' documents was rarely relevant to obviousness and as such should not usually form part of standard disclosure. He agreed with Pumfrey J that disclosure of inventors' records should not be given, on the grounds of the large costs of the proposed disclosure and the "peripheral" nature of such secondary evidence.

The majority judgment: Pill LJ and Rix LJ, while accepting that evidence of what the inventor did was likely to be of limited use in most cases, disagreed with Jacob and found that it was not in the interests of justice to automatically restrict disclosure as Jacob LJ proposed. This would make way for the non-disclosure of documents, which are known to exist and which would harm a party's own case or assist another party's case, due to a blanket rule against any standard disclosure in this area. Rix LJ said: "Once such a principle of disclosure is known to hold sway, dishonest or cavalier litigants would reap an unmerited advantage, contrary to the interests of justice".

The LJs were not happy with a general rule being introduced that there will normally be a limitation on disclosure, and felt that the extent of disclosure needed to be assessed in light of the individual circumstances of each case. Both pointed out that neither Pumfrey J nor Jacob LJ had made their decisions based on the specific facts of this case before them. Pill LJ and Rix LJ in fact note Pumfrey J's approach to this as a matter of principle, picking up on Pumfrey J's statement: "I have waited nine years actually to do this".

The appeal was allowed, and the issue returned to the High Court for disclosure to be considered in light of the specific facts of this case, and the CPR.

Standard Disclosure

A reminder of the CPR

Under the CPR standard disclosure requirements of rule 31.6, a party must disclose documents on which he relies, that adversely affect his case or another party's case, and which support another party's case. A party must make a reasonable search for the relevant categories of documents. In order to assess the reasonableness of a search, CPR r.31.7 states that a party must take into account factors such as the number of documents involved, the nature and complexity of the proceedings, the ease and expense of retrieval of any particular document, and the significance of any document which is likely to be located during the search.

The CPR contains a further restriction on the documents to be disclosed in patent proceedings where validity is at issue. Rule 63.8 and paragraph 5.1(2) of Practice Direction 63 state that only documents which came into existence in the four year window of two years before the priority date and two years after the priority date need be disclosed.

Application of the rules

Jacob LJ considered that the introduction of the CPR standard disclosure rules had made little or no difference to the way disclosure is carried out. Rix LJ and Pill LJ did not go as far, but did emphasise the importance of the parties and their advisers adhering to the principles of CPR, in adopting proportionate procedures. Both agreed there should be a more rigorous application of the standard disclosure rationale, and a reasonable search should be tailor-made to the value and significance of the likely product of such a search. Judges at case management conferences should be pragmatic and tailor orders appropriate to the individual case.

Disclosure of inventor evidence

Jacob LJ argues convincingly that proportionality requires that normally inventor disclosure should not be ordered since, in the case of alleged obviousness, it is not relevant to the issue the Court has to decide. Jacob LJ concluded: "…what matters is that this basic formulation [of obviousness] does not involve expressly what the inventor actually did or thought … the test is not what he did or thought but whether the step would have been obvious to the man skilled in the art". Rix LJ and Pill LJ did not disagree with this.

Whether such work was inventive will depend on expert evidence establishing the common general knowledge of the skilled man, and the prior art teaching. The structured approach to considering obviousness is well defined in the Windsurfing test1 and recently restated by Jacob LJ in Pozzoli2. This formulation is based on the legal construct of the "person skilled in the art" and does not involve expressly what the inventor actually did or thought.

Previous authorities had not been consistent with regard to the relevance of inventor evidence – is obviousness purely objective, or should evidence be heard from the inventor on the struggle to find a solution to the particular problem? The Court of Appeal addressed this discrepancy in Mölnlycke AB v Proctor & Gamble Ltd3, and felt that primary evidence on obviousness would be that of expert witnesses. Evidence from the inventor would be "secondary" and "must be kept firmly in its place". Jacob extended this thinking to say that inventor evidence should be used only very rarely, and hence disclosure on this issue should not form part of standard disclosure in patent actions.


The consequence of this judgment is that there will be no practical change to the way that disclosure on obviousness should be conducted.

In may appear proportionate to limit disclosure, as per Jacob LJ, in circumstances where the argument of commercial success is not at issue. This is especially so since disclosure of inventor evidence is usually very time consuming and thus costly to review for the advisers of both parties. The type of documents involved tend to require detailed analysis: by way of example, in high value pharmaceutical cases (where the value at stake may in fact mean that disclosure of inventors' evidence may be proportionate), documents are often hand written laboratory notebooks which can date back 20 years. The need to consider further issues and documents is often highlighted during the review of an inventor's documents, and complicated disputes can arise regarding the formation of confidentiality clubs to include solicitors, counsel, patent agents, clients and independent experts.

However, the majority LJs did not support an approach to disclosure where the starting point was to assume the non-disclosure of inventor evidence. This was considered to be too much of a risk, and each case must still be analysed appropriately on its own facts. If carried out properly, then the analysis will involve consideration of the very factors mentioned above. The strength of feeling from all the judges on the responsibility of advisers to keep standard disclosure within the limits of proportionality should prompt us to ensure we consider CPR r. 31.6 and 31.7 and focus our minds on the factors to be considered when embarking on the disclosure exercise.