Patents can give an interesting insight into the people that registered them, who may be scientists, engineers or in some cases untrained people with brilliant minds and ideas. Many patents can now be searched for online.
The major database is Espacenet, the European Patent Office gatway. Containing data on up to 60 million patent documents from around the globe, this free service is described as one of the world's biggest technology databases, and draws information from many nations' separately maintained databases.
The US Patent and Trademark Office has an online database with a full-text search of patents issued since 1976.
Google has begun to create an independent OCR-based index of the US patent images for the period 1790 to 1975.