عنوان مقاله [English]
Patents are one of the most important types of scientific and technological products and contain valuable information about invention, inventor or co-inventors, Assignee, classification (IPC, CPC or ...), etc. This kind of information is often not published in journal and other information sources. In fact, there are databases dedicated to patents and they collect all details of patents. Some are free to access such as USPTO and WIPO database some are subscription-based such as Derwent database.
In recent years, some journal databases or citation databases which normally focus on collecting scholarly works such as articles and books, etc. are also covering patents. Some of these databases are available for free and some are subscription-based. They provide sophisticated search tools which allow simple search, advanced search, semantic search or patent number search, name of materials and chemical compounds and other search methods to obtain the required information from patent. By using advanced tools, it is possible to visualize and analyze patent to understand the path of development and evolution of certain technologies. The present investigation endeavors to provide a comparative overview of important journal databases that cover patents too. These include lenz, Orbit, Chemical abstract service (SciFinder and PatentPAK), etc.