A patent for an invention is the grant of a property right to the inventor. Generally, the term of a new patent is 20 years from the date on which the application for the patent was filed in the United States. There are three types of patents: (1) Utility, covering function; (2) Design, covering ornamental design; and (3) Plant, for a new variety of plant.

Prior art refers to publicly available documentation such as existing patents or articles in journals or newspapers that describe technologies already in use. In order to grant a patent, the examiner will search for prior art to insure that the invention is novel. For additional information, see First Inventor to File video.

Once a patent has been granted, the inventor has the right to exclude others from making use of that invention. A license is a lease agreement between a patent owner and another party granting permission to use the invention.

A trademark is a word, phrase, symbol, or design that identifies and distinguishes the source of the goods of one party from those of others. A service mark is the same as a trademark, except that it identifies and distinguishes the source of a service rather than goods. Trademarks differ from patents. For additional information, see the Basic Facts about Trademarks videos.

Search Trademarks
in the USPTO Trademark Database

• General Information Concerning Patents (from the USPTO)
• Understanding "Patentese"—A Patent Glossary

Google Patent Search
Google Patent Search covers United States and world patents.

The Lens
Discovery and analytics tool for the patent literature.

European and World Patents (espacenet)
The espacenet system is a searchable collection of of patent documents published around the world. English-language abstracts are usually available from 1970. Full text documents are provided if available.

USPTO Patent Database
The U.S. Patent and Trademark Office (USPTO) database includes full-page images beginning with the first U.S. patent issued in 1790. Issued patents starting from 1976 and patent applications are fully searchable. Patents issued between 1790 and 1975 are only searchable by the patent number or current U.S. classification.

Derwent Innovations Index
This resource includes value-added patent information and patent citation information. You can use additional descriptive information and coding to quickly understand a patent's significance and its relationship to other patents. Coverage from 1963 to present.

Orbis Intellectual Property
Use this tool for researching the application, ownership, valuation, and exchange of patents. Searchable by patent and companies.

• Resources for Inventors & Entrepreneurs (from the USPTO)
• Yale Ventures
• Patent and Trademark Resource Centers
  • New York Public Library Thomas Yoseloff Business Center. See Patents and Trademarks.

Patent Basics (from the U.S. Patent and Trademark Office)

Understanding "Patentese"—A Patent Glossary

Cooperative Patent Classification
The Cooperative Patent Classification (CPC) scheme is a partnership between the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO) to harmonize their existing classification systems. While it is possible to search patents using keywords, the best way to conduct a comprehensive patent search is by classification. Classification brings together similar concepts when different terms have been used to describe them. If you do not know the proper classification number, you can browse the CPC. Alternatively you can start with a keyword search in a patent database such as Google Patents, find a relevant patent and look at the cooperative classiifications numbers assigned to the patent.

PatentsView
PatentsView is a patent data visualization and analysis tool intended to increase the value, utility, and transparency of US patent data. For example, you can see all of the patents for which Yale University is the assignee along with which patents are most frequently cited, top inventors, etc. Try a search for "Yale University" in the assignee field.