An element comprising another element having a claimed characteristic is not a separate and independent element having that characteristic. Here, for example, an invocation function invoking a signal-dependent branch metric function in combination with the signal-dependent branch metric function itself was found to not anticipate the claimed “set” of such signal-dependent functions because both functions could only be hierarchically designated as signal-dependent by relying on one lone and common signal-dependency characteristic. This would be a good case to consult and cite in response to a rejection that effectively relies on the same element twice.
Background / Facts: The patents being asserted here deal with the difficulty of detecting densely packed data on hard disks by changing the way one calculates the branch metric functions used for retrieving that data. The claims provide multiple signal-dependent branch metric functions, reciting “selecting a branch metric function for each of the branches at a certain time index from a set of signal-dependent branch metric functions.” The prior art includes a brief comment that, rather than applying an identical branch metric function to every branch, its function “can be modified by multiplying the metrics which correspond to transitions by a fraction which depends on the transition [signal] noise standard deviation.”
Issue(s): Whether this passage in the prior art teaches two branch metric functions—one for branches that do not correspond to a transition and another, the same as the first but multiplied by a single fraction, for branches corresponding to a transition—which collectively form the claimed “set” of signal-dependent branch metric functions.
Holding(s): No. “[T]he branch metric function without the fraction does not account for signal-dependent noise” and “the branch metric function with the fraction is a single function: the fraction that distinguishes it from the original, non-signal-dependent [] function is a constant, not varying from time to time, and any branch assigned that function uses the same fraction-containing function.” Thus, the prior art “discloses at most one signal-dependent branch metric function—the one with the fraction—and not the claim-required ‘set’ [of more than one such function].” Moreover, one “cannot describe the choice between the two options as itself the ‘function,’ because that too would give [the prior art] only a single ‘function,’ not a ‘set.’”