Legal Definitions - Reexamination

Reexamination refers to a formal process that can occur in two distinct legal contexts: patent law and trial procedure.

• In Patent Law: Reexamination is a procedure initiated at the Patent and Trademark Office (PTO) to review the validity of an already granted patent. This review is typically requested when new evidence, known as "prior art" (existing inventions, publications, or knowledge), comes to light that might invalidate one or more claims of the patent. The goal is to ensure that the patent was legitimately granted for a truly novel and non-obvious invention.

  • Example 1: A company successfully patents a unique design for a drone propeller. Several months later, a competitor discovers an old engineering journal from the 1980s that clearly illustrates an identical propeller design. The competitor could request a reexamination of the patent, presenting the journal article as prior art to challenge the patent's originality.

    Explanation: This example illustrates how newly discovered prior art can prompt a reexamination to determine if the drone propeller patent should remain valid, given that the design might not have been truly new.

  • Example 2: An inventor secures a patent for a new method of water purification. A non-profit environmental organization later uncovers a series of academic papers from a foreign university, published years before the patent application, detailing a very similar purification method. The organization could petition the PTO for a reexamination of the patent, arguing that the patented method was not novel.

    Explanation: Here, the reexamination process is used to challenge the patent's validity based on previously unknown or overlooked prior art, ensuring that the patent office's initial decision was correct.

• In Trial Procedure: Reexamination is an alternative term for "redirect examination." This occurs during a trial when a lawyer questions their own witness for a second time, immediately after the opposing lawyer has completed their cross-examination. The purpose of reexamination is typically to clarify any ambiguities or address new points raised during cross-examination, allowing the lawyer to rehabilitate their witness or reinforce key aspects of their testimony.

  • Example: During a criminal trial, a prosecutor's witness testifies that they saw the defendant near the crime scene. On cross-examination, the defense attorney questions the witness's eyesight and the poor lighting conditions. On reexamination, the prosecutor asks the witness to clarify their distance from the defendant and the specific details they observed, aiming to reaffirm the reliability of their identification despite the defense's challenge.

    Explanation: This demonstrates reexamination as a tool for a lawyer to clarify or expand upon testimony after cross-examination, addressing any doubts or new information introduced by the opposing counsel.