U.S. Patent Sites (free)

• United States Patent and Trademark Office
  Full-image patents from 1790 to present. Requires installation of TIFF viewer plug-in in order to view images.
• FreePatentsOnline
  Full-text US patents and patent applications (PDF and TIFF).
• Google Patent Search
  The content is provided by the United States Patent and Trademark Office (USPTO) and consists of patents issued in the 1790s through middle of 2006. Images of the entire database of U.S. patents are readily available via the USPTO website. The Google Patent Search does not include patent applications, international patents, or U.S. patents issued over the last few months. Images can only be printed one page at a time and there is no downloading or saving feature.

Princeton University Databases Which Include Patent Information

• SciFinder Scholar -- access at selected Library Web computers in Chemistry, Engineering, Geosciences, Biology, Astrophysics and Plasma Physics Libraries. At these selected computers, go to Start button and choose SciFinder from the list of programs. Patent coverage limited to chemistry only.
• BIOSIS Previews -- coverage of biomedical and life sciences journals, patents, and meetings.

Patent Services (paid)

• ISI Thomson Delphion Patent Server
  • Quick searching against the US granted bibliographic collection
  • Patent number searching against worldwide collections
  • Free Work Files that let you save, manage and organize your patent research
  • PDF Express for downloading in bulk, plus single PDF or TIFF downloads on a pay-per-use basis
    
• Derwent Scientific and Patent Information - Searching and document delivery for U.S. and International patents.
• Micro Patent Web Service - Searching and document delivery for U.S. and International patents and U.S. trademarks.
• Questel Orbit
• LexiNexis Patent and Trademark Solutions

Non-U.S. Patent Office Sites (free resources)

• esp@cenet - Europe's network of patent databases
  
• Australian Industrial Property Office
• CIPO-OPIC / Canadian Intellectual Property Office
• European Patent Office
• Directory of European Union Patent Offices (PATLIB)
  
• Japanese Patent Office
• New Zealand Patent Office

Intellectual Property Offices

• Directory of Intellectual Property Offices (from World Intellectual Propery Organization)

Websites of Interest

• USPTO Manual of Classification
• Selected Resources for Patents, Inventions, and Technology Transfer
  Swain Chemistry & Chemical Engineering Library, Stanford University
  
• Patents at MIT: What Do You Want to Do?
• Guide to Patents and Trademarks
  Art, Architecture & Engineering Library, University of Michigan
• Searching U.S. Patents - Rolf Claessen's Chemistry Index
• Statistical Reports from the U.S. Patent and Trademark Office (USPTO), Technology Assessment and Forecast (TAF) Program