A Surprising Effect

Submitted by patentadmin on Wed, 01/26/2011 - 11:43

If a claim in a reissued or re-examined patent is not “substantially identical” in scope to the same claim in the underlying, previously issued patent, a defense of “intervening rights” may arise with respect to infringement of that claim. In other words, if an amendment results in a substantial change in claim scope, the patentee may not be entitled to damages despite the infringement of the amended claim. This is well-settled law. We now have a case, however, where an unamended claim has been held to have been substantially altered in scope, giving rise to the dreaded “intervening rights.” (University of Virginia Patent Foundation v. General Electric Company)

The University asserted claim 1 of a re-examined patent against GE. The patent was directed to a method of magnetic resonance imaging (MRI). This claim, which recited a “magnetization recovery period,” had survived re-examination without amendment. Claim 4 of the original patent, which depended from claim 1, specified a “magnetization recovery period” of zero time. This claim was deemed to be not allowable and was canceled during the re-examination.

Prior to the re-examination, claim 1 included a “magnetization recovery period” of zero time. After the re-examination and the cancellation of claim 4, it no longer covered such a period. Thus, the scope of the claim had been changed, even though not a word of the claim had been amended. “Although no formal amendment was made to Claim 1, it was amended in effect when Claim 4 was canceled and the scope of Claim 1 changed.” GE got the benefit of the intervening rights defense.

THE LESSON TO BE LEARNED: The scope of a claim can be changed even if the claim is not amended.

Add new comment