35 U.S. Code § 251 Reissue of defective patents
(a) IN GENERAL.—Whenever any patent is, through error, deemed wholly or partly inoperative or invalid, by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than he had a right to claim in the patent, the Director shall, on the surrender of such patent and the payment of the fee required by law, reissue the patent for the invention disclosed in the original patent, and in accordance with a new and amended application, for the unexpired part of the term of the original patent. No new matter shall be introduced into the application for reissue.
(b) MULTIPLE REISSUED PATENTS. — The Director may issue several reissued patents for distinct and separate parts of the thing patented, upon demand of the applicant, and upon payment of the required fee for a reissue for each of such reissued patents.
(c) APPLICABILITY OF THIS TITLE.— The provisions of this title relating to applications for patent shall be applicable to applications for reissue of a patent, except that application for reissue may be made and sworn to by the assignee of the entire interest if the application does not seek to enlarge the scope of the claims of the original patent or the application for the original patent was filed by the assignee of the entire interest.
(d) REISSUE PATENT ENLARGING SCOPE OF CLAIMS. —No reissued patent shall be granted enlarging the scope of the claims of the original patent unless applied for within two years from the grant of the original patent.
The reissue statute, 35 U.S.C. § 251, permits the correction of wholly or partly inoperative or invalid patents by authorizing the Patent Office to reissue corrected patents where errors in the patents were made without any deceptive intention. A patent if deemed wholly or partly inoperative or invalid, due to defective specification or drawing, or due to the reason of the patentee claiming more or less than he had a right to claim in the patent, then the patentee can reissue the patent for the invention disclosed in the original patent. The patent term for the reissued patent will be equivalent to the unexpired part of the term of the original patent; there will be no extension in the patent term.
The patentee can also apply for multiple reissued patents for distinct and separate parts of the original patent. However, claims in any reissued patent must be directed toward the same invention as the original patent. Some indication must exist in the original patent specification that the patentee considered the subject matter claimed in the reissue patent application to be his or her invention.
Additionally, Section 251 allows either the inventors or the assignee of the entire interest to file for reissue, but if the application seeks to enlarge the scope of the claims of the original patent, the reissue must be filed in the name
of the inventors only. This is because only the inventors can declare a broader concept to actually be their invention. The reissue application must contain the entire original patent with changes notated properly and claims appropriately numbered. Each claim amendment must have an explanation supporting it.
The statute provides for the filing of “broadening reissue applications” in which the scope of the claims sought in reissue extends beyond the scope of the original patent’s claims. However, the reissue statute imposes a two-year time limit, beginning on the date of the grant of a patent, within which any broadening reissue application must be filed. But make sure the statute also objects addition of any new matter into the application for reissue.
Earlier the filing of a reissue application required a formal surrender of the granted patent. However, under the current law, a reissue application merely constitutes an offer to surrender the underlying patent, and actual surrender only takes effect if the patent is reissued. Until a reissue application is granted, the original patent remains in effect and will remain so even if a reissue application is abandoned.
What are the grounds of filing for reissued patent?
A reissue application is filed to correct an error in the patent as a result of which the patent is deemed wholly or partly inoperative or invalid.
So, there must be at least one error in the patent to provide grounds for reissue of the patent. If there is no error in the patent, the patent will not be reissued. Also, errors in the patent such as spelling, or grammar, or a typographical, editorial or clerical error which does not cause the patent to be deemed wholly or partly inoperative or invalid do not provide a basis for reissue.
The most common bases for filing a reissue application are:
the claims are too narrow or too broad
the disclosure contains inaccuracies
applicant failed to or incorrectly claimed foreign priority
applicant failed to make reference to or incorrectly made reference to prior copending applications
Can the patent term be extended through reissued patents?
35 U.S.C. 251 prescribes the effect of reissue on the patent term by stating that "the Director shall… reissue the patent… for the unexpired term of the original patent”. The maximum term of the original patent is fixed at the time the patent is granted, subject to any adjustments to the number of days of extension or adjustment. Therefore, a deletion in a reissue application of an earlier-obtained benefit claim will not operate to lengthen the term of the patent to be reissued.
Can we broaden the scope of the patent through filing a reissue?
The patentee surely can broaden the scope of the claims of the original patent, but there is a catch to that. The patentee can do so within two years from the grant of the original patent. You can add new claims in the reissued patent to broaden the scope of the invention. But make sure adding a new claim is not synonymous to adding new matter!
You need to make sure that no new matter is introduced in the reissued patents as the statute objects inclusion of any new matter. It is possible to add new claims if what you want to add is fairly described somewhere within the entirety of the patent application filed originally. If such is not a case, then you cannot add such claims.
Also, the patent holder also cannot recapture the surrendered subject matter via reissue if he/she gave up claim coverage during prosecution of the original patent.
What after the patent has been reissued?
After the patent has been reissued, the original patent is surrendered with an immediate effect. Thereafter, every reissued patent will have same effect and operation in law on the trial of actions as if the same had been originally granted in such amended form. As the claims of the original and reissued patents are substantially identical, surrender of an original patent will neither have any effect on any actions then pending nor abate any cause of action then existing.
However, if a claim has been substantially changed after reissuance, it is possible that a potential infringer has gained intervening rights. These rights allow the infringer to continue to sell, offer for sale, use, or purchase the product without a license despite the new claims, but do not allow the infringer to continue to make or import the infringing product. Intervening rights usually occur where a reissue claims are broader in some respect than the original claims. The rights may be granted to one who did not infringe the original claims but has become an infringer due to the reissue. If an infringer has made substantial preparations prior to the reissuance, the infringer might be granted not only the basic intervening rights but also equitable intervening rights, which include the ability to make and import the infringing product.