Patents are government grants that give inventors exclusive rights to their inventions.
Patents are vital resources for businesses, researchers, inventors, academics, and others who need to keep abreast of developments in their fields.
Patents are also an important means of sharing know-how, because each patent document describes a new aspect of a technology in clear and specific terms and is available for anyone to consult.
There are some very good reasons to search patents:
Espacenet offers free access to more than 70 million patent documents worldwide (70+ countries including Canada and the U.S.), containing information about inventions and technical developments from 1836 to today, updated weekly. Often considered the best place to start a patent search.
The USPTO houses full text for patents issued in the U.S. from 1976 to the present and TIFF images for all patents from 1790 to the present. (You can install a free TIFF reader that is designed in part for reading U.S. patent office files).
The Canadian Patent Database lets you access over 75 years of patent descriptions and images. You can search, retrieve and study more than 2,000,000 Canadian patent documents.
Mike White, a librarian at Queen's University, is an expert on searching patent information. He has produced some excellent tutorials and has generously allowed us to link to them below.