Patent Searches

Many inventors make a search of patents already granted to be sure that someone else has not already patented their idea. They may do this, or hire someone to do it for them, at the Public Search Room of the U.S. Patent and Trademark Office in Arlington, Virginia. It is open to the public from 8 a.m. to 8 p.m. Monday through Friday, except holidays. The USPTO Scientific and Technical Information Center, containing a vast collection of technical literature, is also available to the public. A Files Information Unit is maintained where the public may inspect open records, such as those for issued patents, and applicants and their attorneys may examine their own cases.

A system of Patent and Trademark Depository Libraries (PTDLs) has been established throughout the country, where collections of patents may be examined and researchers have access to a computerized data base.

Reference Collection of U.S. Patents Available for Public Use in Patent and Trademark Depository Libraries

The libraries, designated as Patent and Trademark Depository Libraries (PTDLs), receive current issues of U.S. patents and maintain collections of earlier-issued patents. The scope of these collections, which are organized in patent number sequence, 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, including the Manual of Classification, Index to the U.S. Patent Classification, Classification Definitions, and provides technical staff assistance in their use to aid the public in gaining effective access to information contained in patents. CD-ROM (Compact Disk-Read Only Memory), which provides direct, computerized access to U.S. Patent and Trademark Office data, is available at all PTDLs. Facilities for making paper copies of patents from either microfilm or paper collections are generally provided for a fee. Since there are variations in scope of patent collections among the PTDLs and their hours of service to the public, anyone contemplating use of patent information at a particular library is urged to contact that library, in advance, about its collection and hours in order to avert possible inconvenience.