Patent Searching

• General Resources
• Online Patent Databases
• The Patent Classification System
• Public Search Services at the Patent and Trademark Office
• Patent and Trademark Depository Libraries

General Resources

Searching Patents
Available in Government Documents Reference Section (No Call Number: located next to C 21.12/2:)

A four-page summary of patent search strategy.

Patent Searching Online (Nolo Press)

How to use online and offline sources to find out if someone has already though of your invention, or to locate a copy of a patent for a specific invention or inventor.

An Introduction to U.S. Patent Searching: The Process, by Susan B. Ardis (Libraries Unlimited)
Available at Government Documents Service Desk, Call Number T210 .A73 1991

This comprehensive guide includes strategies for searching, a bibliography of reference tools, a glossary, and samples of the basic types of patents and other illustrations.

Index of Patents Issued from the United States Patent and Trademark Office (USPTO)
Available in Government Documents, Call Number C 21.5/2:

This index has two parts: the "List of Patentees" is an alphabetical name index of inventors and assignees; the "Index to Subjects and Inventions" is a class number index. Each year must be searched individually, and patents will be listed only as originally classed, even though the classification system has changed considerably over the years.

Official Gazette of the United States Patent and Trademark Office: Patents (USPTO)
Request recent issues at Government Documents Service Desk
Request issues earlier than May 1986 from Remote Storage at Main Circulation Desk in Willis Library.

This periodical contains abstracts of patents, which are identified by patent number and give the patent title, name and address of the patent holder, date filed, class and subclass, a drawing, and a brief description.

Online Patent Databases  

USPTO Patent Databases (USPTO)

This page is the starting point for the USPTO’s free patent databases. These include both the U.S. Patent Bibliographic Database (a freely searchable database of front page information from U.S. patents issued from 1/1/76 to the present), and the AIDS Patent Database (a freely searchable database of the full text and images of AIDS related patents issued by the US, Japanese and European patent offices).

Google Patent Search (Google)

This database covers the entire collection of patents made available by the USPTO—from patents issued in the 1790s through those issued in the middle of 2006. Doesn’t currently include patent applications, international patents, or U.S. patents issued over the last few months.

Free Patents Online

Full text of U.S. patents from 1976 to the present, searchable by keyword or by patent number. Images are accessible in either PDF or TIFF format.

ICO™Global Patent Search (PatentCafe)

This subscription-based search engine search engine lets you use either full text, natural language queries or Boolean keyword queries to search the world’s leading patent databases, then it ranks by relevancy, analyzes, and groups the search results. Requires payment of a fee.

WikiPatents Community Patent Review (WikiPatents, Inc.)

This interactive, online community provides reviews, ratings, and discussions of U.S. patents and pending patent applications. The public can add prior art references for a given patent, vote on the relevancy of both original and user-added references, and make comments about how the prior art is related to a patent. Users may also vote on various market and technical merits of patents and patent applications. Independent inventors can advertise offers to license their patent. Site also offers free downloadable patent records in  PDF format, file histories, and patent searching tools.

The Patent Classification System

If you choose to search patents by subject area, you must identify the general class and the subclass within the patent classification system, which classifies inventions by use or function.

The following works provide access to the classification system at increasing levels of complexity.

Examiner Handbook to the U.S. Patent Classification System (USPTO)

This online publication explains the structure of the patent classification system. It is designed primarily for the benefit of patent examiners, but other users—e.g., patent attorneys and agents, people involved in research and development, and the patrons of the Patent and Trademark Depository Library system—may find it useful as well.

Index to the U.S. Patent Classification System (USPTO)
Available in Government Documents Reference Section, Call Number C 21.12/2:

Alphabetical index to the classes and subclasses of the patent classification system as published in the Manual of Classification. Subject headings include keywords, product terms, and commonly used words. An alphabetical list of main classes at the beginning serves as an overview of the classification system. Instructions for using the Index are included in the preface.

Manual of Classification (USPTO)
Available in Government Documents Reference Section, Call Number C 21.12:

This looseleaf publication contains a comprehensive numerical list of all classes and subclasses in the patent classification system, with descriptive titles.

Patent Classification Definitions (USPTO)
Available at Government Documents Service Desk, Call Number C 21.3/2:

Detailed definition of each class and subclass, indicating what is included and excluded and including referrals to related classes and subclasses.

Public Search Services at the Patent and Trademark Office

A number of public search services are available at the U.S. Patent and Trademark Office, providing public access to collections of patents, trademarks, and other documents at its Public Search Facilities in Arlington, Virginia.

In addition to copies of patents and trademarks, the Search Facilities maintain a variety of reference materials to assist searchers, researchers, and potential applicants. These include manuals, indices, dictionaries, reference publications, and Official Gazettes. Access to paper files is available without charge.

Patent and Trademark Depository Libraries

The Patent and Trademark Depository Library Program (PTDLP) administers a nationwide network of public, state and academic libraries designated as Patent and Trademark Depository Libraries (PTDL), authorized by 35 U.S.C. 13 to disseminate patent and trademark information and support the diverse intellectual property needs of the public.

Libraries designated as PTDLs receive current issues of U.S. patents and maintain collections of earlier-issued patents. The scope of these collections varies from library to library, ranging from patents of only recent years to all or most of the patents issued since 1790.

These patent collections are available for use by the public free of charge. Each of the PTDLs, in addition, offers supplemental reference publications of the U.S. Patent Classification System and provides technical assistance in using such publications. CASSIS (Classification and Search Support Information System) and other CD-ROM products for searching patent and trademark information are available at all PTDLs. Facilities for making paper copies of patents and trademarks from either microfilm or paper collections are generally provided for a fee.

The Dallas Public Library is the nearest PTDL to those in the University of North Texas community. They have complete texts of United States patents,  as well as an Automated Patent System (APS) online search capability. For more information, call (214) 670-1461.