The USPTO houses full text for patents issued from 1976 to the present and TIFF images for all patents from 1790 to the present. Includes copyrights, trademarks and IP law and policy.
PatentScope enables you to do searches in 1,864,332 published international patent applications (PCT) and in 7,747,749 when including patent documents from Regional and National collections.
Espacenet offers free access to tens of millions of patent documents worldwide. It contains information about inventions and technical developments from the 19th century right up to today.