Patent classification
From Wikipedia, the free encyclopedia
A patent classification is a way the examiners of patent offices or other people arrange documents, such as patent applications, disclosing inventions according to the technical features of the inventions. They arrange documents using a patent classification so that they can quickly find a document disclosing the invention identical or similar to the invention for which a patent is claimed. The same document may be classified in several classes.
A patent classification is fixed under an agreement among people, otherwise it is useless. The International Patent Classification (IPC) is agreed internationally. The United States Patent Classification (USPC) is fixed by the United States Patent and Trademark Office. The European Classification (ECLA) is based on the IPC but adapted by the European Patent Office to its own requirements. The Derwent classification system is fixed by an enterprise.
[edit] Paradoxical nature
Patent classifications have a paradoxical nature, because they are requested to work well for classifying newly published documents disclosing inventions that are by nature novel, despite they are formed through organizing existent documents disclosing existent inventions. Inventing a complete patent classification that will remain useful for next 100 years is equivalent to inventing all inventions that will become available in next 100 years, which is apparently impossible.
This nature results in considerable amount of misclassified documents and frequent revision of classification system.
However the number of genuinely novel or groundbreaking and hence unclassifiable patents filed per year is actually quite low. The bulk of research and development is directed towards improving existing inventions which results in large numbers of incremental improvement inventions. E.g. instead of inventing a new novel method of rodent termination, instead multiple improved mousetraps are filed every year. This pattern allows the creator of the patent classification to group documents by general area with fine detail classifications used to highlight the novel features. Unfortunately this process is highly subjective and often results in the misinterpretation of the intended classification by the patent examiners. Add language and cultural differences for an international classification scheme such as the IPC and the result is often missclassified documents.
Another factor in the classification problem is the actual wording of the documents. The Patent attorney sets out to convey the invention in as general terms as possible both to conceal the actual novel features and to create as broad a scope as possible. Thus when the patent is granted, the owner has the best chance of enforcing it in court action against rivals.
Of course this also makes the classification of such documents very difficult.
The main reasons for the frequent revision of patent classification are twofold, revisions in light of court decisions on patentability and the continual migration of patent subject matter. Consider the mobile telephone, in the 1980's a wireless portable telephone was in itself a novel invention. Now they are common place and no longer considered novel, instead the mobile phone related patents tend to concentrate on adding new features or functions, novel shapes or improvements in signal processing / data streaming for example. Thus the patent classification system needs to be updated to allow for these changes in focus.
