The basic requirement for patenting is that the invention at hand is novel. Novelty is determined by comparing the features of the invention to prior solutions from which the invention must differ.
The invention must be novel over prior art that has become public before the filing date of the patent application. If the application claims priority from an earlier application, the invention is compared to prior art that has been made available to the public before the priority date. Read more about how an invention becomes public.
One publication is studied at a time and even one distinguishing feature is sufficient
Prior art publications are compared to the invention one at the time and determined whether all the features of the invention are found as one entity in the said publication. If the invention differs from the prior art solution by at least one feature, the invention is novel. If an independent claim is novel, all dependent claims referring to it are novel, because the scope of protection of dependent claims is narrower than of the independent claim. If an independent claim is not novel, the novelty of dependent claims is evaluated separately.
Technical features have the main role
Only the technical features of the invention are taken into consideration when establishing novelty. A technical feature is, as its name suggests, a technical solution to a technical problem. The features related to the purpose of the invention are usually treated as if the invention is suitable for said purpose and therefore the purpose is not limiting the claim when establishing novelty. For example, if the patent claim discloses a coating comprising substances A and B, all mixtures comprising substance A and B are novelty destroying even though the use as a coating would not be mentioned. On the other hand, if the purpose of the invention sets some technical limitations, these are taken into consideration. For example, if the invention is a mold for molten steel, a mold for ice cubes cannot be novelty destroying because its technical features are not suitable for molten steel.
An exception to what was said above is the medical use of compounds for which a so-called second medical use is known. This means that a compound that is already known to be used for treating one indication can be patented for use in another indication. For example if a compound is known to be used for treating headache, it can still be patented for use in the treatment of asthma.
Directly expressed or unambiguously suggested
Each feature must be included in the prior art document either explicitly, that is directly expressed, or implicitly, that is suggested unambiguously though not directly expressed. If it is not certain whether a feature is included in the prior art document, the document is not novelty destroying. Sometimes claims present alternative solutions to a feature. In these cases, the invention is not novel if even one of the alternative solutions is presented in the prior art document.
Typically mentioning a feature at a general level does not take away novelty from a specific example. For example if the prior art publication mentions using metal, the use of copper can still be novel. On the other hand, a specific example takes away novelty from the general level, e.g. mention of copper takes novelty away from metal.
Difficulty of selecting
In some cases the features of the invention are disclosed in the prior art publication in lists that have many optional features. According to the European practice, if the solution of the invention requires selecting features from at least two lists, the requirement for novelty is usually fulfilled. In other cases, the prior art publication may disclose a region for a parameter that overlaps with the invention. Here the European practice is that novelty is usually established if the region of the invention is narrower than what is disclosed in the prior art document and the region does not include any specific examples or end points that are mentioned in the prior art document. Further, the new region cannot be arbitrary selected but must have been selected for a reason (purposive selection). These practices can however greatly differ from what was said above in non-European countries.
When assessing the novelty of the invention the aim is to ensure that only new innovations are being patented. After ruling the invention novel, it has to be ensured that the solution would not be obvious to a skilled person in the art. Read more about determining inventiveness of an invention.