Issues in Science and Technology Librarianship Summer 1998

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Patents and Patent Searching

Alice K. Kawakami
Information Specialist
Norris Medical Library
University of Southern California


The definition, requirements for and types of patents are discussed as well as tools available to access patents. Steps needed to perform a patent subject search are delineated. Includes World Wide Web resources for information on patents and searching access to patents.


Researchers in the sciences often have need of patent literature as an information source. This data is used to promote new directions in research, for new uses for existing technologies and to predict growth industries. In addition, patents can be the sole source of technical information on a particular invention or process. In the growing field of biotechnology securing research and development funds from both private and public sectors have pressured inventors to become proprietary about medical advances that traditionally been have shared for the common good. For librarians and researchers in the sciences, it is becoming more essential to understand fundamental patents data and the tools available to search and access patents information.

General Information on Patents

A patent is a legal agreement between a country and an inventor giving the inventor the right to exclude others from making, using, or selling an invention for a limited time in that country. There are three main international patent offices: the United States [http://www.uspto.gov/], Japan [{http://www.jpo-miti.go.jp/}] and the European Union [http://www.european-patent-office.org/]. In the United States, patents are usually granted for a term of 20 years from filing or 17 years from date of issuance, whichever is longer. The time periods differ in other countries. Patents, trademarks and copyrights are a form of intellectual property protection. A trademark is a name, symbol, phrase, scent or sound used in foreign or interstate commerce to identify a product or service, whereas a copyright protects artistic and literary works such as books, motion picture, visual and performing arts, computer software and sound recordings. In some countries, patents can also be filed for software applications which may be claimed to constitute an inventive leap and are therefore patentable.

A patentable invention must satisfy three criteria:

  1. Novelty - the invention must be different from anything known before; it must not have been described in a prior publication and it must not have been publicly used or sold.
  2. Utility - the claimed invention must be useful. If it is a machine, it must function according to its intended purpose; if it is a novel chemical, it must exhibit an activity or have some utility.
  3. Nonobviousness - the invention must not be a logical extension of that which has been done before, i.e., it must not be readily apparent to one who is skilled in the particular art to which the invention pertains.

There are three major categories of patents:

  1. Utility - for any "new and useful process, machine, manufacture, composition of matter or any new and useful improvement thereof". The term "composition of matter" relates to chemical compositions and may include mixtures of ingredients as well as new chemical compounds. Utility patents can be further divided into three types: chemical, mechanical and electrical. The vast majority of patents are in this category.
  2. Design - granted to any new, original and ornamental design for an article of manufacture. E.g., a chair is recognized as something on which to sit but its design can take many forms. The appearance of the item is what is protected.
  3. Plant - patents are granted for an invented or discovered and asexually reproduced distinct and new variety of plant. Asexually propagated plants are those that are reproduced by means other than from seeds, such as by the rooting of cuttings, budding, grafting, etc. Design and plant patents are granted for shorter terms than utility patents.

The text of a patent application must contain claims, which describe the subject matter and form the legal description and boundaries of the invention. These claims are what is unique about an invention and are the basis for a patent infringement suit. Investigating possible infringement is one reason to perform a patent search.

Access to Patents

Access tools to patents published by the United States Patent and Trademark Office (USPTO) include:
  1. Index to the U.S. Patent Classification, an alphabetical list of words or terms that refer to specific classes and subclasses used to categorize patents.
  2. Manual of Classification [{ http://www.ibiblio.org/patents/index.html}], a numerical list of classes and subclasses that shows interrelationships between class and subclass group.
  3. Official Gazette, published weekly, listing patents granted that week in numerical order with a drawing and one representative claim.
  4. Cassis (Classification and Search Support Information System), on CD-ROM, allows computerized access using truncation and keyword searching. The patent databases are contained on three separate discs entitled Patents ASSIST, Bibliographic, and Classification.

A subject search for U.S. patents requires a multi-step process:

The first series of steps are to discover the "field of search" which identifies the proper classifications to locate a particular patent. This consists of four steps:

  1. Identify the parts of an invention. Its component parts classify an invention and not necessarily by what you may think is its intended use.
  2. Search the Index to the U.S. Patent Classification. Look up the terms that most closely describe the invention or process's function, effect, end product, structure or use. Write down all relevant class and subclass numbers.
  3. Use the Manual of Classification. Look up the classes and subclasses you retrieved in the previous step. Revise your strategy as needed by eliminating any false leads.
  4. Consult the Patent Classification Definitions [{ http://www.uspto.gov/web/offices/ac/ido/oeip/taf/def/index.htm}]. Read the definitions to establish the scope of classes and subclasses. Note: design patents do not have definitions.

The next series of steps search the "Prior Art" which identifies patents within the designated classifications:

  1. Review the Subclass Listing. Retrieve a list of all patent numbers granted for every class and subclass to be searched.
  2. Locate patents by number e.g., in the Official Gazette. Use the OG to look at a claim of a patent and eliminate those unrelated to the invention.
  3. Obtain complete patent document. Complete patents are available, in print, microform, CD-ROM and online formats. It should be emphasized that currently not all years of all patents are available free of charge online. Complete patents are available from Patent and Trademark Depository Libraries (PTDLs) [{ http://www.uspto.gov/web/offices/ac/ido/ptdl/ptdlib_1.html}].

In the academic setting, the clientele of chemistry and engineering libraries have the greatest need for patent information. Among print indexes, Chemical Abstracts indexes chemical patents, and Food Science and Technology Abstracts includes summaries of food patents. An example of a food patent is the technology that makes a dessert sauce create a hard shell when poured over ice cream.

Patents are often accessed via a commercial vendor such as LEXIS/NEXIS [{http://www.lexisnexis.com/}], DIALOG [{http://www.dialog.com/}] or STN [http://www.cas.org/]. STN offers an academic discount for searching after 5:00 PM PST. Searchers who do not use these commercial databases frequently should call the vendor's helpline to verify search strategy before conducting a search.

Patent issues sometimes arise when faculty members are working on research projects wherein patentable products are developed. When this arises the university's office of technology licensing becomes involved. These operations contract with patent law firms who use their own resources to do patent searches. Generally an employee of a university signs an agreement at the time of hiring that cedes the ownership of a patent to the institution. A provision of the recent Bayh-Dole Act decrees that universities who retain royalties from licensing of a patent share a fraction of the royalties as personal income to the inventors. By law the university's share of the royalties must be used to further its research and educational activities. In actuality very few patents generate significant royalty income for the university. Notable exceptions include the Cohen-Boyer gene-splicing patent from Stanford University and the University of California, and the fax patent owned by Iowa State.

World Wide Web Patent Resources

Patents can also be used as a ready reference source as well as the result of a literature or state of the art search. With less demand for subject searching than for search by inventor, assignee or patent number, using one of the web-based patent search sites is often ideal. Patent-related sites could contain general patent information, lists of classes and subclasses, abstracts and full-text patents. Depending on the information need of the client, the abstract or "front page" information (patent number, title, date, inventor, assignee application number, application date, abstract, figures, number of claims, and references cited) of the patent may suffice. Selected sites for patent searching and patent information are listed below, with emphasis on those sites with free access.

Patent searching sites:

Chemical Patents Plus - [{http://casweb.cas.org/}]
Although a CAS account User ID and password are required to use Chemical Patents Plus, all searching is free. Display of patent titles and abstracts is also free. Other patent and related data may be displayed for a fee.

EDS Shadow Patent Office - [{http://www.spo.eds.com/}]
Provides a searchable database of full-text patents from 1972 to the present, updated weekly. Free services include browsing the current 52 weeks of patent titles and numbers and access to the Manual of Classification.

IBM Patent Search Site - [{ http://www.delphion.com/}]
IBM uses its own relational database technology to offer free searchable access to patents from 1971-. Patents can be searched by number, simple text search, Boolean text search in one or two patent fields or advanced text search in any searchable field. Searchers have mentioned that the server can be slow and that occasionally patents or pages are missing from the database.

MicroPatent - [http://www.micropat.com/]
Provides free access to the Online Gazette that provides brief summaries of patents issued in that week. Records include patent number, title, assignee, inventor, claim, abstract and drawing.

USPTO Patent Bibliographic and AIDS database - [{http://patents.cnidr.org/}]
Includes both the US Patent Bibliographic Database and the AIDS Patent Database. The Patent Bibliographic database provides free searching of "front-page" information from US patents issued from January 1, 1976 to the most recent issue date. 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.

Patent information sites:

Duke University Chemistry Library Patent Information - [{http://guides.library.duke.edu/patent}]
Links to patent information and patent searching sites. Includes comparison table of web patent searching sites.

Findlaw - [http://www.findlaw.com/]
General purpose legal search engine. Click on intellectual property in the topics section, then the patent subcategory. There are links to patent statutes and regulations.

Oppedahl & Larson Patent Law Web Server - [{http://www.patents.com/}]
Very good source of general information about patents. "Resources for patent searches" section includes links to commercial online services such as LEXIS/NEXIS, STN etc. and how to determine if a particular patent has expired.

Stanford University Swain Chemistry and Chemical Engineering Library Selected Resources for Patents, Inventions, and Technology Transfer - [http://www-sul.stanford.edu/depts/swain/patent/pattop.html]
Include many links to general patent information, searching aids and techniques, patent offices, and commercial database vendors.

University of Texas Engineering Library Patent Searching Tutorial - [{http://www.lib.utexas.edu/Libs/ENG/PTUT/ptut.html}]
Excellent step-by-step online tutorial on the basics of patents searching.

USPTO Patent Information - [{http://www.uspto.gov/main/patents.htm}]
Includes extensive general information, patent laws, and classification definitions. Links to the searchable USPTO Patent Databases listed above.


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