Patent and Trademark Depository Library Program: Conducting a Patent Search at a Patent and Trademark Depository Library (PTDL)
This article was edited and reviewed by FindLaw Attorney Writers
| Last reviewedLegally Reviewed
This article has been written and reviewed for legal accuracy, clarity, and style by FindLaw’s team of legal writers and attorneys and in accordance with our editorial standards.
Fact-Checked
The last updated date refers to the last time this article was reviewed by FindLaw or one of our contributing authors. We make every effort to keep our articles updated. For information regarding a specific legal issue affecting you, please contact an attorney in your area.
Patent and Trademark Depository Library Program
Conducting a Patent Search at a
Patent and Trademark Depository Library (PTDL)
The 7-Step Strategy
- Index to the U.S. Patent Classification (paper or CD-ROM)
Begin with this alphabetical subject index to the Manual of Classification. Look for common terms describing the invention and its function, effect, end-product, structure, and use. Note class and subclass numbers.
- Manual of Classification (paper or CD-ROM)
Locate class and subclass numbers in the Manual. Note where the terms fall within the U.S. Patent Classification System. Scan the entire class schedule, paying attention to the dot indent. Revise search strategy as needed.
- Classification Definitions (microfiche or CD-ROM)
Read the definitions to establish the scope of class(es) and subclass(es) relevant to the search. The definitions include important search notes and suggestions for further search.
- Patents BIB (CD-ROM or Automated Patent System (APS) Text)
Check if you are on the right path; search Patents BIB (1969-present) for a particular class/subclass; retrieve results and examine titles. Try other relevant classes/subclasses. Revise your search by using applicable keywords; note the classes and subclasses and go back to 2.
- Patents CLASS (CD-ROM or APS TEXT)
Once relevant class(es)/subclass(es) are identified, obtain a list of all patent numbers (1790-present) granted for every class and subclass to be searched.
- Official Gazette – Patent Section (paper or microform)
Go to the Gazette and look for exemplary claim(s) and a representative drawing for all patents on the list(s) to eliminate patents unrelated to the invention.
- Complete Patent Document (microfilm, paper, CD-ROM, or APS IMAGE)
Search the complete text and drawing(s) of closely related patents to determine how different they are from the invention.
Stay Up-to-Date With How the Law Affects Your Life
Enter your email address to subscribe:
Learn more about FindLaw’s newsletters, including our terms of use and privacy policy.