The prior art is the information that available to the public in some form before a certain date, which was relevant to the claims of originality, maybe. If an invention has been disclosed in public areas, a patent on the invention is invalid. Therefore, the patent search and research of non-patent literature often before filling a patent, or before / during a patent dispute conducted.
Japanese patents are the most important source of prior art search. Japan’s No.1 country in the number of patent applications per year ranks. In 2009 there are approximately 400.00 patent applications in Japan (JPO), which represents about 20% of the total patent applications filed worldwide, the majority in all countries.
In comparison, there are approximately 370 000 178 600 and patent applications per year at the USPTO and EPO respectively.
Japanese patents are the richest sources of prior art in the world, with over 50 million searchable patent and trademark documents, the 200 million pages, stored in the database of the JPO. For comparison, the USPTO has saved about 10 million searchable documents, including patents and trademarks.
Applications filed in Japan are published (public access) 18 months after the priority date of filling or what to check and always. The invention described in the published application to a prior art publication.
Although they are hard to find Japanese sources are extremely important, as the richest sources of prior art in the world and Japan is one of the three largest economies with the advanced technology in many areas.
