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  • Claiming Priority - Pitfalls and Poisonous Priorities

    The UK courts have made a U-turn over how strictly must a claimed invention be "the same" as that of its priority document if a claim to priority is to be valid. This is of major importance to the practice of patent law and is illustrated by a string of recent cases in which patents have been revoked for want of priority.

    Back in Autumn 2004 Patent issues, we wrote that the "strict" same-invention rule laid down by the EPO Enlarged Board of Appeal in Decision G2/98 was not being applied so strictly by the UK Court of Appeal. Unfortunately for patentees, there have been two decisions of that Court since then that have significantly changed the tone, and this is proving now to be a graveyard for patents, as illustrated by recent cases in the ongoing mobile phone wars and coffee wars. Samsung had three patents revoked on these grounds in its battle against Apple, and Nestle Nespresso similarly lost an important patent in the same way.

    The need to claim priority in the Samsung cases was acute, as Samsung had disclosed its inventions to standards committees shortly after filing the initial applications. Those disclosures became novelty-destroying when the Patents Court ruled that Samsung had changed the specifics of the invention being claimed and was not entitled to priority.

    The situation for Nestlé Nespresso was more alarming still. The Patents Court concluded that the priority document itself was novelty-destroying prior art. How can that be? If the priority document discloses the claimed invention, surely it must support the claim to priority? Not necessarily - not when the invention claimed in the later application is broader than that described in the earlier application. That creates a "poisonous priority" situation in which the later claimed invention is not entitled to priority but the earlier described invention falls within the scope of the claims and the claims are therefore not new.

    Did the law change, and if so, how?

    Back in 2004, Jacob LJ (as he then was) seemed to give a pragmatic and flexible approach to claiming priority. He ruled:

    "when features A+B+C are disclosed [in a priority application], a lot must turn on what they actually are. Some inventions consist of a combination of features - the invention consists in the very idea of putting them together. In other cases that is simply not so - the features are independent one from the other. Whether, given a disclosure of A+B+C, there is also a disclosure of A or B or C independently depends on substance, not a formula. The ultimate question is simply whether the skilled man can derive the subject-matter of the claim from the priority document as a whole."

    Unfortunately, this was embellished by Kitchen LJ in Abbot Laboratories v Evysio Medical Devices[2008] EWHC 800 (Pat):

    the important thing is . . . whether the disclosure as a whole . . . gives the skilled person what is in the claim whose priority is in question. I would add that it must "give" it directly and unambiguously.

    So the dreaded words "directly and unambiguously" have crept back into the test for claiming priority. These words are the bane of a European patent attorney's life, as they represent the ultra-strict test applied by the EPO when assessing added subject matter under Article 123(2), EPC. European examiners have a tendency, for example, to consider any amendment that might remove an ambiguity as adding subject matter. Even the addition of a comma can give rise to objection (see Examiner Eats Shoots and Leaves in Autumn 2011 Patent issues). Yet the Court of Appeal was clear in its decision in Unilin that the approach to claiming priority is not so formulaic (see Spring 2004 Patent issues): What then, if anything, is the difference between the "same invention" test for claiming priority and the "directly and unambiguously derivable" test for added subject matter?

    "Whether, given a disclosure of A+B+C, there is also a disclosure of A or B or C independently depends on substance, not a formula. The ultimate question is simply whether the skilled man can derive the subject-matter of the claims from the priority document as a whole."

    This is a question best answered by some examples. We have four. The first three are Samsung's. These were considered in two separate judgements delivered on 7 March 2013, referred to as "Judgement on the 726 and 675 patents" and "Judgment on the 404 patent". We will call them simply "Samsung I, II and III".The fourth is the Nestlé case, delivered on 22 April 2013 under the name "Nestec".

    Please click HERE for a pdf of the full article, including the examples.