Patent leathering

2004 saw Lord Hoffmann do a U-turn on his Improver patent yardstick. Will it make patent law any easier to interpret? By Stephen Jones

The House of Lords last looked at patent law in 1997 in the case of Biogen v Medeva. Then, towards the end of 2004, there was a rush of judicial blood to the head, so to speak, and judgments (or more correctly, opinions) in two cases followed within a week of each other.

The leading opinion in each case was given by the redoubtable Lord Hoffmann, for many years our most senior judge, with vast experience in the patent field and the judge responsible for the Biogen decision. Lord Hoffmann is a fiendishly clever lawyer. When he speaks on any subject, you do well to listen. So his opinions in these cases were eagerly awaited by patent lawyers throughout the country and beyond.

The first case was Sabaf v Meneghetti, which was about a patent for burners in gas hobs. The burners need to be of very low height so that they could fit in hobs above work surfaces, which have to be as flat as possible. This was done by positioning the air intake above the hob and having a radial venturi (a diffusing device that cools and distributes heat) above the hob. The burners were successful and there was no prior art which showed a design having both these features. However, there was prior art showing the use of a radial venturi (but with an air intake below) and other art showing the air intake above but no radial venturi.

At first instance in July 2001, Mr Justice Laddie found the patent invalid. In doing so he did not follow the accepted analysis for obviousness (as laid down in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd (1985)), but instead relied on something which he called “the law of collocation”. This comes out of the 1935 case of British Celanese v Courtaulds, and says that if you have two machines or parts of machines functioning side by side, so that each does its known job but they do so independently and without interaction, you will not get a valid patent for the combination.

The Court of Appeal was affronted by the judge’s lack of respect for the Windsurfing analysis. It looked at the case as being one involving a novel combination of elements. The prior art did not show the two elements being combined in a single machine and it was not permissible to combine the separate elements of prior art unless it could be shown (which it was not) that it was obvious to do so. So the Court of Appeal said the patent was valid.

Enter Lord Hoffmann. Before we get to looking at the prior art, he said, we should decide what the patent is about, and in particular whether it is describing one invention or more than one. In this case he decided that there were two inventions, one for the air intake and one for the radial venturi. Since both of these had been described, separately, in the prior art, it was an easy matter for him to conclude that the patent could not be valid. The fact that this meant the Patent Office must have slipped up in letting the patent through, since each patent is supposed to relate to only one invention, did not concern his Lordship one bit.

Getting to complex areas of genetic engineering via gas burners and sausage machines is all in a day’s work for a patent lawyer – and so we come to Kirin-Amgen v Hoechst Marion Roussel, a horribly complex case, with the first instance judgment of Mr Justice Neuberger in April 2001 occupying three whole issues of the law reports.

There were lots of issues in the case, but I will discuss only one of them, which is of great importance. Lord Hoffmann had to consider the fundamental problem of claim interpretation. If you want to know whether somebody infringes your patent you must first construe your claim. Lord Hoffmann first treated us to a thorough review of the case law, looking at the situation in Germany, the Netherlands and the US along the way.

In the course of this he came to look at what a young Mr Justice Hoffmann had to say about interpreting claims in relation to so-called equivalents or variants back in the 1990 case of Improver v Remington. This case contained a careful formulation of three questions which Judge Hoffmann said the court ought to ask itself when considering this problem of variants. These have been dutifully followed by patent lawyers and judges for almost 15 years since, and become known to all as the ‘Improver questions’ (unless you are Lord Hoffmann, in which case you call them the ‘protocol questions’).

Back in 1978, the drafters of the European Patent Convention (EPC) had set forth their own formulation of questions for the interpretation of claims in something called the Protocol to Article 69 of the EPC. This says: “Does the interpretation give fair protection to the patentee? And does it give reasonable certainty to third parties?” You might be forgiven for thinking that these are the true protocol questions. Lord Hoffmann was uncomfortable with the fact that patent lawyers (and judges) might have been treating the three questions formulated by his youthful self in Improver as though they were enshrined in statute themselves. No, he explained, with the benefit of the experience of the last 15 years, they were only guidelines. They might not be useful in every case, and they are certainly not useful in this one.

So, with the condescension reserved only to the highest court in the land, he decided that he ought to ignore the questions urged upon him by his younger self and arrive at the breathtakingly simple proposition that the claims probably mean what somebody capable of understanding the technology would have thought the patentee meant them to mean. And no more than that. If you take that route you arrive at the conclusion that this probably fulfils the protocol as well, because such an interpretation ought to be fair to the patentee (because it ought to be what they meant) and give reasonable certainty to third parties (because it is what they would think the patentee meant) so everyone should be happy, including the patent lawyers, who will not have to wrestle with the Improver questions any more.

Lord Hoffmann was quite polite to Judge Hoffmann, who after all has probably made life more difficult for patent lawyers over the years (but more so for their clients, who have had to fund all this agonising over the Improver questions), but his learned fellow law lord Lord Walker of Gestingthorpe was a little less polite in criticising judicial summaries of principle which take on a life of their own and create their own problems of interpretation. He concluded that in a high-technology field, the Improver questions may have no useful function, and may indeed be a distraction from the questions set by Article 69 and the protocol.

It remains to be seen what the future will be like without the old Improver questions. It has been a long road, but it would seem we come back to the idea that if you want to know what a document (even a patent) means, you should read the words in it and give them a reasonable interpretation. Sounds easy? Perhaps it will not be quite so easy in practice and there will come a time when we look back with nostalgia at the unimproved world of Improver.

Stephen Jones is a partner in the IP group at Baker & McKenzie in London