What are intervening rights in patent reexamination?

Intervening rights in patent reexamination are protections granted to individuals or entities who have used or prepared to use a patented invention before the patent was amended during reexamination. These rights are defined in 35 U.S.C. 307(b), which states:

Any proposed amended or new claim determined to be patentable and incorporated into a patent following a reexamination proceeding will have the same effect as that specified in section 252 for reissued patents on the right of any person who made, purchased, or used within the United States, or imported into the United States, anything patented by such proposed amended or new claim, or who made substantial preparation for the same, prior to issuance of a certificate under the provisions of subsection (a) of this section.

In essence, intervening rights protect those who acted in good faith before the patent was changed, allowing them to continue their activities without infringing the newly amended patent.

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Topics: MPEP 2200 - Citation Of Prior Art And Ex Parte Reexamination Of Patents, MPEP 2293 - Intervening Rights, Patent Law, Patent Procedure
Tags: intervening rights, patent amendment, patent law, patent reexamination