When must a broadening reissue be filed?

A broadening reissue must be filed within 2 years of the patent grant because this time frame is specified under U.S. patent law, particularly in 35 U.S.C. § 251. This statute allows a patentee to seek a reissue of a patent that is deemed partially invalid or defective, enabling the patentee to broaden the scope of the claims if necessary. This opportunity is limited to the first two years after the patent has been granted to prevent indefinite uncertainty regarding the patent's claim scope and to encourage prompt enforcement and clarification of intellectual property rights.

Filing beyond this 2-year period would not allow for broadening reissues; instead, the applicant would need to consider other avenues for addressing any issues with the patent claims that arise after that time limit. Balancing the interests of patent holders and the public, the legislative framework sets this strict window to ensure that patents can be effectively challenged and do not remain overly broad indefinitely without proper scrutiny.