Attacks on validity and defending patents

United Kingdom

"Parametritis" - or the obscure claim

Raychem Corp's patent

In Raychem Corp's patent (see also pages 8 and 9) there was a petition to revoke four patents with a total of 110 claims. 39 were originally said to be independently valid; but cut down to 16 by the end of the last day of the trial. The petitioners argued that most of the claims were merely claims to known or obvious desiderata and that the patentee had sought to re-patent the prior art by limiting his claims to a series of parameters not mentioned in the prior art (an exercise referred to as "Parametritis"), sometimes measured on test equipment which did not exist at the time of the prior art.

In finding all the claims relied upon in all four patents invalid the court held:


  • In all cases, and no matter what the nature of the attack on validity or arguments on infringement, the court must identify the inventive concept embodied in the claims. A properly drafted claim would state that concisely. The court was not required to substitute its own language for that of the patentee if the later was clear. But where the claims were prolix and obscure the court should break free of the language and concern itself with what they are really meant.

  • Unnecessary obscurity in drafting claims by dressing up known concepts in an elaborate clothing of quasi-science and complicated terminology was not a separate ground of invalidity. Within wide limits a patentee could use what language he liked to define his invention. But it was the substance of the patentee's alleged technical contribution, rather than the form and language of the claims, that must impress the court.

  • Selection of a group of compositions by reference to an essentially arbitrary parameter having little technical significance did not involve any inventive step. Although it might not be obvious, in the common use of that term, to limit a claim by reference to some particular meaningless and arbitrary parameter, that had nothing to do with patentability. The selection of a group of compositions by reference to such a parameter does not involve any inventive step. Patents were not given for skill in inventing technically meaningless parameters.

  • If the patent claim consists of no more than a product or process selected by reference to a set of obviously desirable parameters, then the technical contribution was the selection of those parameters. Since the selection was obvious, so was the claim.

Lubrizol v. Esso

The Court also considered a similar situation in Lubrizol -v- Esso, where the patent had a number of claims where the parameters intended to be applied were difficult to identify, and commented on the approach to be adopted. In particular, if the claim formulated a test which the skilled man could not understand, it was bad for ambiguity. A patentee who gave an instruction which in fact misled a significant proportion of the relevant addressees had not sufficiently and fairly described his invention.

The common general knowledge of the man skilled in the art

The Court of Appeal has expressed its views on the meaning of the phrase "man skilled in the art", the notional addressee of all patent specifications. The Patents Court - sensibly in our view - does not appear to have agreed entirely!

In Beloit (see also page 4) the Court of Appeal considered the notional addressee of a patent specification. They stated that a patent specification is addressed to an ordinary skilled man, rather than employees of large companies with libraries and patent departments who would become aware of information soon after publication in a variety of documents. A patent specification must contain sufficient information for such an ordinary skilled man to be able to work it, and would only lack inventive steps if obvious to such a man.

This decision appears to conflict with earlier judgements in the lower Courts which stated that, in appropriate circumstances, the notional addressee of a patent specification may be a team skilled in a variety of relevant disciplines, given that such a team is only likely to be found in a large company; and further that it must be very unlikely indeed in certain technologies that one individual will have all the necessary skill and knowledge required to develop the field.

In the later Union Carbide -v- BP Chemicals Judgement (see also page 9) the Patents Court considered that the notional skilled man in that case was a multi-disciplinary team, saying "In considering obviousness it is first necessary to consider the attributes of the notional 'person skilled in the art'. This can include a team of individuals."

The Court continued:-

"Patent law attributes to its notional skilled man a background technical knowledge which goes by the jargon 'common general knowledge'. Such knowledge is 'part of the mental attitude of a well-constructed representative of the class to whom the specification is addressed' or 'generally regarded as a good basis for further action'. It is not good enough to show that a matter was known to some but not to others and in particular it is not good enough to show that knowledge (or prejudice) was confined to one or a limited class of suggested exemplars of the skilled man."

Finally in Raychem Corp's Patent (see also pages 7 and 9) the Court considered that the common general knowledge was the technical background of the notional man in the art against which the prior art must be considered. This was not limited to material he had memorised and had at the front of his mind. It included all that material in the field he was working in which he knew existed, which he would refer to as a matter of course if he could not remember it and which he understood was generally regarded as sufficiently reliable to use as a foundation for further work or to help understand the pleaded prior art. This did not mean that everything on the shelf which was capable of being referred to without difficulty, or every word in a common text book, was common general knowledge. It was likely that all or most of the main text of standard text books would be common general knowledge. In many cases common general knowledge would include or be reflected in readily available trade literature which a man in the art would have been expected to have at his elbow and regard as basic reliable information.

"Don't Do It!" does not mean "Do It!"
Union Carbide Corporation -v- BP Chemicals

In Union Carbide Corporation -v- BP Chemicals (see also page 8 and below) the Court confirmed that a prior document is novelty-destroying if it contains "clear and unambiguous instruction to do what the patentee has invented" (General Tyre). Clear and unambiguous directions not to do what is claimed are not novelty destroying. The information given by a direction not to do X because it will have adverse consequences is not equivalent to a direction to do X because it has beneficial consequences or does not have the supposed adverse consequences. The information given by the publication is not equal to that given by the subsequent patent. Invention can lie in finding out that that which those in the art thought ought not to be done, ought to be done. From the point of view of the purpose of Patent Law it would be odd if there were no patent incentive for those who investigate the prejudices of the prior art.

Commercial success - not often a runner

The Patents Court has commented critically on agreements that commercial success was evidence of a Patent's validity.

In Raychem Corp's Patent (see also pages 7 and 8) the Court said that the commercial performance of products or processes covered by a patent was rarely a reliable indicator of non-obviousness. It was usually difficult to demonstrate that commercial success was attributable to inventiveness rather than some other commercial consideration such as improved marketing. Adding a plea of commercial success normally only added time and expense to the proceedings and served no useful purpose.

And in Union Carbide Corporation -v- BP Chemicals (see also page 8 and above) it said "One must always be chary of such a plea, for commercial success may be the product of many other factors. Moreover even where there is commercial success, it is often important (but not essential) to show that there was a prior need for the invention - long-felt want as it has been called. Furthermore the plea is seldom likely to be relevant if the prior art relied upon was published only shortly before the date of the invention: there is unlikely to have been enough time for the ordinary skilled man to have missed the point. Finally it is necessary to show that the success is due to the invention - the features of the claim in question. One must compare the features of what has achieved success with the features of the claim. If the claim is wider than that for which success is claimed, then normally a plea of commercial success is simply irrelevant."

Not much chance for commercial success agreements there!