Patents Databases
A collection open to the world. Pre-1976 US Patents do not require a TIFF image viewer plug-in. (Includes US patents!)
Patent Full-Text and Full-Page Image Databases
US Patent and Trademark Office (USPTO). Patents prior to 1976 require a TIFF image viewer plug-in.
Click on US Legal and drop down to Patents on the left for patent search options.
Ability to search more than 8 million patents, although searchability is sometimes imperfect.
The FreePatentsOnline search engine is one of the most powerful, fastest, and easiest patent search engines on the web.
Official site of the Japan Patent Office.
Japanese, Chinese or Korean Patent Help
This virtual help desk provides answers to the most frequently asked questions on patents and patent information in China, India, Japan, and Korea. You can also find background information on filing trends and granting procedures and some guidance on common patent terminology of Asian patents.
Related Web Resources
Comparison of Free Patent Databases
A blog offering an interesting comparison of Google Patents, FreePatentsOnline, Patents.com, Patents Lens, and the USPTO patent databases. The European Patent office is not included in the comparison.