Dated, but I believe this still is the proper way to look at the obviousness question. IMHO Opty

Attacking the claims

Attacks based on novelty

There are basically two ways to attack a claim: novelty and inventive step. For novelty the requirement holds that all measures from the independent claim are described in a single document. When even a single, possibly trivial measure is missing, the claim is novel anyway. It is also necessary that all measures are described in the same combination in the single document. An electrotechnical reference work will almost certainly show all (electronical) components of an electrotechnical invention, since such an invention almost always involves the use of known components, such as relays, resistors and capacitors. However, the reference work will most likely not contain the specific circuit according to the claim.

Attacks based on inventive step

The second way to attack a claim is on the basis of inventive step. This requires a combination of documents which describes all elements from a claim. The next step is to argue why a skilled person would (not merely could) combine those documents so as to arrive at the claimed invention. In this argumentation it is not permitted to apply hindsight. You must base the reasoning on the situation the day before the date of filing of the patent application and the knowledge a skilled person had on that day.

A combination of two documents is the most common. It is also possible to combine more documents, but it is often more difficult to present a reasonable case why someone would combine all those documents. The most common way to attack a claim based on lack of inventive step is to identify a problem in the first document that is solved by the second document. The argumentation then is that the skilled person would identify that problem, and while searching for a solution would encounter the second document and apply the solution described therein. This then results in the invention.

Apart from documents general technical knowledge can also be used. A handbook (such as Knuth's The Art of Computer Programming) is a useful proof of what constitutes general technical knowledge. If the above combination of document misses a measure, which can be considered to be common technical knowledge, then the invention is still obvious.

http://www.iusmentis.com/patents/obv...