Much angst will be expressed in decisions over application of these principles, with a repeated tendency of claimants to focus the court’s attention on an explicit TSM in the form of a textual reference which “teaches” the claimed invention. The court consistently responds that this approach to the exclusion of an implicit TSM is incorrect. An implicit TSM - knowledge of the practitioner or the problem itself - may also satisfy the TSM test. Regardless of whether an implicit or explicit TSM is the basis of the claim of obviousness, the court will consistently focus on the reason and evidence in support of that reason as the determining factors. It is important to recognize that even if the court couches its decision in these cases in terms of a TSM to combine, the substance of the decision is a search for a reasonable rationale for obviousness supported by the prior art and/or Graham secondary factors.
Thus far, the context in which “invention” was defined was largely the combination of two or more elements from different pieces of prior art. There is however an additional context in which “invention/obviousness” arises. This is where one prior art reference discloses a device that is very similar to the device in question. The issue in such cases is not one of novelty as defined by the modern view in that the prior art disclosure does not have each and every element of the device in question.
Instead, the device is very similar, but somehow modified, often in the process of transferring it from one commercial context to another. The question is then if that modification qualifies is an “inventive” act. Often the court would use the term novelty when discussing this situation, but from a modern perspective it is more fairly characterized as an analysis of “invention/obviousness.” This situation could have been characterized as a problem of equivalents, though it is not often discussed in this manner.
This particular situation, which arises often, was addressed in Topliff v. Topliff.27 As with previous similar situations, the court framed the analysis in terms of what the device “suggested” to an ordinary mechanic skilled in the art.
The duplicate of the model from the patent office contains no suggestion of this kind, nor do the other models of the same patent, offered in evidence. While it is possible that the Stringfellow and Surles patent might, by a slight modification, be made to perform the function of equalizing the springs which it was the object of the Augur pattent to secure, that was evidently not in the mind of the patentees, and the patent is inoperative for that purpose. Their device evidently approached very near the idea of an equalizer; but this idea did not apparently dawn upon them, nor was there anything in their patent which would have suggested it to a mechanic of ordinary intelligence, unless he were examining it for that purpose. It is not sufficient to constitute an anticipation that the device relied upon might, by modification, by made to accomplish the function performed by the patent in question, if it were not designed by its maker, nor adapted, nor actually used, for the performance of such functions. 28
145 U.S. 156 (1892).
145 U.S. at 161.