What is a claims invention date?
Making an invention requires a conception and a reduction to practice. The invention date is normally the date upon which an inventor first conceives his or her invention as defined by a given claim – the “conception date.” The inventor must demonstrate diligence in reducing the invention to practice in order to preserve the conception date as the date of invention. Reducing the invention to practice means building a working example of the invention or filing a patent application that has an adequate disclosure of the invention. Sometimes under U.S. law, prior art must predate the invention date in order to invalidate the claim. In all other countries outside the U.S., the invention date has no significance; only the “priority date” is used to determine whether prior art invalidates a claim.
