Res judicata in a rejection

If you get an adverse decision from the BPAI, you can continue prosecution by filing an RCE with claim amendments and/or new evidence. I came across an application (Appl. No. 10/023,117) in which the Applicant did this, and the Examiner invoked res judicata to reject a claim, even though amendments were made.

Although I've never come across res judicata in patent prosecution, the MPEP specifically provides for it in section 706.03(w). It does make sense to me that once the Board has affirmed a claim rejection, that rejection can be applied again with no further explanation because the issue has already been decided.

What struck me as strange is that the Applicant had amended the claims. But the Examiner took the position that the amended claim was not patentably distinct from the claim presented at appeal:

The sole change to claim 6 is changing the final clause from "outputting ... to a destination identified in the ... instruction" to "outputting ... to a destination register identified in the ... instruction". As it was shown in the examiner's answer to appeal mailed November 14, 2007 that Abbott output to a destination register, the claim is not patentably distinct from that affirmed by the Board of Patent Appeals and Interferences.

I think it's clear that "destination register" has different scope than "destination," such that the Examiner must make a new finding in the post-RCE Office Action that the reference discloses the added feature. Certainly it's not enough that the Examiner's Answer "shows" that the reference teaches the amended feature, because a statement in an Examiner's Answer is an allegation, not a judicially established fact.

In fact, I think the Board's decision implied that the claim on appeal ("outputting to a destination) was patentably distinguishable from the claim in the RCE ("outputting to a destination register"). This happened when the Board pointed out that the Applicant was arguing about a feature which was not present in the claim on appeal:

Initially, we note that although Appellants argue that Abbott does not teach that the output of the transposition circuit 410 is provided to a destination register that is specified in an instruction ... the Appellants have chosen to draft the claims, claim 1 in particular, far more broadly.

By pointing out that the claim on appeal did not specify "destination register", I think the Board in effect said that a claim without this feature is patentably distinct from a claim with this feature. Thus, res judicata does not apply to the amended claim.

I should note that the Examiner did not solely rely on res judicata. As recommended by the MPEP, a prior art rejection which was applied also, in this case, the same rejection which was appealed was "maintained and incorporated by reference."