§251 Reissue of Defective Patents

Summary

If a patent is found flawed because of errors in the description, drawings, or because the claims say more or less than they should, the Director must reissue the patent if the owner gives back the old patent and pays the fee. The reissued patent covers what the original disclosed and lasts for the rest of the original patent term. You cannot add new invention or facts in the reissue application. The Director can make separate reissued patents for different parts if the applicant asks and pays for each one. The same rules for regular patent applications mostly apply to reissue requests. A full-owner (assignee) may file and swear to the reissue if they are not asking to broaden the original claims, or if the assignee filed the original application. You cannot get a reissue that makes the claims broader unless you apply within two years of the original patent grant.