Patents and Trademarks

US Patent Database includes searches including trademarks. From United States Patent and Trademark Office. This system provides an interface to search a database of U.S. Patent bibliographic data from 1976 to entries posted within the past few days. Try a search on "ink jet".
United States Patent and Trademark Office.
US Copyright Office.
US Patent Classes offers an index to the US patent classification system by subject area and retrieval of patent numbers and titles. From UNC MetaLab.
World Intellectual Property Organization offer information in English, French and Spanish on their activities plus information on conferences and WIPO publications. Includes details of patent, trademark and copyright protection treaties.