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Federal Circuit clarifies ‘materiality’February 9, 2006

Rule 56 of the patent office rules of practice imposes a duty of candor before the patent office. This is mandated by all who are substantively involved in the prosecution of patent applications. In order to satisfy this duty, information that is material to patentability must be disclosed to the patent office. This rule was most recently amended in 1992, and defines material information as information that (1) establishes either alone or in combination with other information an initial showing of unpatentability of the invention, or (2) refutes or is inconsistent with a position taken by the applicant either supporting patentability or refuting an argument of unpatentability made by the examiner. If a material misrepresentation is made with deceptive intent, the individual making the misrepresentation has committed inequitable conduct, and the patent is unenforceable. Until the Federal Circuit decided Digital Control Inc. v. Charles Machine Works, the courts had not decided whether this amendment to the patent office rules was the exclusive standard by which materiality was to be measured, or whether tests uses prior to the rule change still had any force.The district court applied the prior version of Rule 56 to assess the materiality of misstatements made in an affidavit and prior art that was not disclosed, commonly referred to as the ‘reasonable examiner’ standard. Under this standard, information was material if ‘there was a substantial likelihood that a reasonable examiner would consider it important in deciding whether to allow the application to issue as a patent.’ Applying this standard, the district court found the applicant’s misstatement in his affidavit and nondisclosure of a prior art reference material.The Federal Circuit agreed that this standard may still be applied. In addition, they stated that the standards devised by courts prior to the old version of Rule 56 could likewise be used in order to assess whether an act or omission by an inventor was material. The court stated that ‘the PTO’s recent adoption of an arguably narrower standard of materiality does not supplant or replace our case law. Rather, it merely provides an additional test of materiality.’ Thus, there now appear to be five possible tests for whether an act or omission made during prosecution of a patent application is material: (1) the ‘new’ Rule 56 standard, (2) the ‘old’ Rule 56 ‘reasonable examiner’ standard, (3) the objective ‘but for’ standard, where the misrepresentation was such that no patent should have issued had it not been made, (4) the subjective ‘but for’ standard, where the misrepresentation actually caused the examiner to allow the application when he or she would not have done so otherwise, and (5) the ‘but it may have’ standard, where the misrepresentation may have influenced the patent examiner’s decision during prosecution.Even with all these methods of proving materiality, the level of materiality is still important. The more material the misrepresentation is deemed to be, the less intent to deceive is required for a finding of inequitable conduct. As a result, although more acts or omissions have the potential to be found to be ‘material’ now that the court has clarified the various tests that may be applied, it will still be necessary to determine the level of materiality before courts make a finding of inequitable conduct. The likely result of this is that courts may decide as a matter of law that a material misrepresentation was made, but leave the determination of how material the misrepresentation was and whether it was accompanied by the required deceptive intent to suffice for inequitable conduct to the jury.To read the complete decision, log on to

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