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Introduction to USPTO Patent Interference Practice

When two or more rival inventors/companies contest the right to a patent at the US Patent & Trademark Office or USPTO, the dispute is resolved by determining who was the first to actually invent the disputed subject matter.  A patent interference governed by 35 U.S.C. §135 is an administrative proceeding by which the first to invent is determined by the USPTO Board of Patent Appeals and Interferences.  The first to invent is either the first to conceive and the first to reduce to practice, or the first to conceive and the last to reduce to practice, if he worked on the invention with reasonable diligence from a date just prior to the other party’s conception to the date of his own reduction to practice.

A patent interference arises when two or more pending patent applications, or at least one pending patent application and an unexpired patent, contain patent claims covering the same or substantially the same subject matter.  An important point here is that a patent interference is appropriate only when both inventors claim the same invention.  It’s not enough that they describe the same subject matter.

The determination of who is the first to invent the claimed subject matter is referred to as determining priority.  The USPTO Patent Board of Appeals conducts the patent interference under the rules appearing at 37 C.F.R.§§1.601 – 1.690.  A patent interference usually includes motions, depositions, briefing, and an oral hearing before a panel of three administrative patent judges.  The USPTO Board of Patent Appeals is empowered to decide not only priority of invention but also the patentability of that invention.  In some cases the USPTO Board of Patent Appeals will decide that the invention is not patentable to either party and will enter judgment that neither is entitled to a patent.

A patent interference can be initiated in two ways: by suggestion of the patent examiner, or by request of the patent applicant. When a patent examiner determines that an invention claimed by a patent applicant is patentable, and that it is the “same patentable invention”[37 C.F.R. § 1.601(n)] as that claimed in an unexpired patent or another pending patent application, the patent examiner may then forward the patent application to the USPTO Board of Patent Appeals for declaration of a patent interference.  To seek a patent interference, a patent applicant must file a request addressed to the patent examiner that satisfies specific requirements of 37 C.F.R. § 1.607.  Such a request must suggest “counts” identifying patent claims corresponding to the counts, identify the other patent application or unexpired patent that claims the same or substantially the same invention, and explain why a patent interference should be declared.  Under 35U.S.C. §135(b), the applicant must have presented the claims for interference within one year of the issue date of the opponent’s patent, or within one year of the publication of the opponent’s application.

If the patent examiner determines that a patent interference might exist, the patent examiner forwards the patent application file to the USPTO Board of Patent Appeals with a memorandum of prescribed form and content.  Whether the interference will be declared is for the USPTO Patent Board to decide.  If the USPTO Patent Board is satisfied that a patent interference exists, a notice will be mailed to each involved party declaring a patent interference.  The notice identifies the patentable subject matter in dispute and sets a schedule for certain required actions by the parties.  Among other things, the notice identifies one of the parties as senior and all others as junior.  The senior party is the applicant or patentee who is entitled to rely on the earliest filing date and is therefore presumed – subject to contrary proof – to be the first inventor.

Under U.S. law, an inventor is a person who contributed to the conception of the subject matter defined by at least one claim in a patent or application.  Showing that you are the first to invent requires proving that you were the first to possess the complete invention. The complete invention consists of two elements: conception (the idea) and reduction to practice (putting the idea into a workable form).  So, proving priority of invention requires proof of the earliest dates for both conception and reduction to practice.  A complete conception is not simply the inventor’s idea, but an idea that is clearly defined so that a person of ordinary skill in the field of the invention would be able to reduce the invention to practice without undue experimentation.

A reduction to practice can take one of two forms: actual or constructive. An actual reduction to practice is a physical demonstration that the invention works for its intended purpose.  A constructive reduction to practice is the filing of a patent application that describes the invention and how to make and use it.  All testimony is initially submitted in affidavit form, but witnesses might be cross-examined in a deposition.  Any documentary evidence, such as copies of research records, correspondence, and analytical or other test data, must be filed with an affidavit.  An inventor’s testimony, the documents he creates, and any other evidence based entirely on information obtained from an inventor must be independently corroborated to prevent fraud.  Testimony and records of others, such as technicians, analysts, and others, who didn’t con-tribute to the conception of the invention, need not be independently corroborated.

It is possible to win a patent interference if you were the first to conceive but the last to reduce to practice.  Under 35 U.S.C. §102(g) an inventor has an opportunity to win the patent interference priority contest by proving that he had the earliest conception and showing that he exercised reasonable diligence during the critical period, which is just prior to the other party’s conception and continuing up to his own reduction to practice.  One can prove diligence by submitting evidence of reasonably continuous activity toward a reduction to practice.   Acceptable excuses may be reasonable delays in obtaining materials or personnel, or delays due to the need for regulatory clearance for the needed activity.  A purely business reason for a delay, such as, for example, postponing work on a project because of market conditions, is not an acceptable excuse for inactivity.

Even an inventor who shows that he was the first to invent can still lose the priority contest if the USPTO Patent Board decides that the completed invention was abandoned, suppressed, or concealed.  That can happen if the evidence shows that the inventor or company did not take steps within a reasonable time to make the invention public by filing a patent application, commercializing the invention, or using other means.

The patent interference proceeding ends with an opinion by the USPTO Patent Board stating which party is entitled to a patent containing claims covering the disputed invention.  A party not satisfied with the USPTO Patent Board’s judgment can request reconsideration or can pursue an appeal to the U.S. Court of Appeals for the Federal Circuit or to a U.S. District Court.

Declaring and winning a patent interference can offer many advantages, however, procedural complexities and strategic considerations can vary widely depending on individual circumstances. For legal advice on a patent interference, consult a registered patent attorney qualified to assist you in patent matters before the USPTO Board of Patent Appeals & Interferences.