Patents

Why search by classification?

 "Classification" is a method by which items with similar characteristics are grouped together in categories.  Libraries use classification schemes to put books on related topics together.  (The ASU Library uses the Library of Congress Classification Scheme; many public libraries use the Dewey Decimal System.)  All types of stores such as hardware, discount, department, grocery, clothing, book, etc., also group their wares.   

Patent classification systems group inventions with like features together.   The big advantage to classification searching is that you don't have to know (or guess) what obscure terminology is used by the inventor and his patent attorney.  Once you find the appropriate categories (sometimes called classes or symbols) for your invention, you'll easily retrieve patents with similar characteristics.  

Need to find a Classification?

The following 3 classification databases can be searched by keywords or you can browse through the outline (schedule) to locate categories. 

• Cooperative Patent Classification (CPC) 
  The most extensive/detailed patent classification system.  Currently used by the U.S. Patent and Trademark Office and the European Patent Office starting on January 1, 2013.  Older U.S. patents have had equivalent CPC classifications added for their main USPC category.   European patents have had the European Classifications (ECLA) replaced by CPC.   This system is not used by all countries so a thorough international search must use the IPC system, see below.   
   
• US Patent Classification (USPC)
  Used for U.S. patents only.  Starting on January 1, 2015 only design and plant patents will be given USPC categories; utility patents will only have CPC categories from 2015 on.   Use the USPC if you want the most detailed categorization of US design and plant patents and utility patents prior to 2015.
  • Index to the US Patent Classification System
    Browse through the USPC system using everyday language. 
  • Manual of Classification
    Browse through the USPC system starting with the main categories. 
  • Classification Search Page
    Use if you already have USPC class/subclass categories. Also contains concordances from USPC->IPC and mapping from USPC->CPC
     
• International Patent Classification (IPC)
  Developed by the World Intellectual Property Organization (WIPO), the IPC is used for all patents entered into the worldwide Espacenet database.  Although the IPC may look similiar to the CPC in format - the coverage is much less detailed.  Use IPC classification for finding patents from all countries.   
   

How to Search a Classification category in a Patent Database. 

• USPTO PatFT and AppFT databases
  Once you get to the USPTO database home page, select "Quick Search" for either the PatFT (issued patents) or the AppFT (patent applications) database. 
  
  For US classification, enter the class/subclass without spaces and change the field to "US Current Classification" ...
  
  
  For CPC classification, enter the full classification with all its segments with no spaces and set the field to Current CPC Classification"  ...
  
  
  For IPC classification, enter the full classification with all its segments with no spaces and set the field to "International Classification" ...
  
   
• Espacenet (Worldwide) database
  Once you get to the Espacenet database, in the left-hand column, click on "Advanced Search" then scroll the search form all the way down to the bottom.   Note: Only CPC and IPC classifications can be searched in Espacenet. 
  
  To search a CPC classification, in the CPC box put the full classification without spaces ...
  
  
  To search an IPC classification, in the IPC box put the full classification without spaces ...
  

Tips for Inventor Name Searching 

Several issues complicate inventor name searching:  

• Variations in naming conventions   
  Does the inventor use his/her middle name or initial?   Do they initialize their given name?   For international inventors are you able to distinguish between the given name (aka first name) and the family name (aka surname or last name)?   Double surnames, whether hyphenated or not (ex., Albert Jones-Warburton, Robert Smyth Jones) as well as nobiliary particles in surnames (ex., James von Behrens, John de Boet) complicate matters further. 
  
  Before deciding that the individual does not have a patent(s), make sure your search strategy has covered all variant forms of an individual's name.    
   
• Changes in Name
  Has the inventor changed their name during the course of their career (such as a woman taking her husband's family name upon marriage)?  
  
  You must search all the inventor's known names as the patent databases will not connect the variants.  
   
• More than one inventor with the same name 
  How will you distinguish between what appear to be several inventors all with the same name?  Sometimes you can tell by the subject of the inventions but patents contain very little personal information, generally just the inventor's city/state and the assignee which could be the inventor's employer.  
  
  Do you know the subject field, employment history and cities/countries of residence for your inventor in case you need to differentiate individuals with the same name? If not search Google for personal information, especially the individual's CV.  For academics look at their university's site, and for all check social media such as Facebook. 

USPTO (PatFT and AppFT) databases

Select the "Quick Search" feature for either the PatFT or AppFT database.  Enter the individual's name in inverted format (familyname givenname) in the first search box and change the field at the right to "Inventor Name".   

Espacenet (Worldwide) database

In the SmartSearch box put in the inventor's name inverted (lastname firstname) and put quote marks (" ") around the whole name. 
 

USPTO (PatFT and AppFT)

Select the "Number Search" feature for either the PatFT or AppFT database.  Enter the patent number in the first search box; examples are given below the search for the different types of patents.

Espacenet (EPO)

In the SmartSearch box enter the two character country code followed by the number; do not put a space in between the country code and the number. 

Google Patents

Enter the two character country immediately followed by the patent number (do not put a space in between).  Notice how Google will suggest possible items immediately under the search box; click on the appropriate item.

Introduction

On this page you'll learn how to find patents by subject so that you can determine if your invention has already been patented or created.   Sometimes this type of search is called "prior art search" or "patentability search".   The key to a good patent search is understanding patent classification systems. 

What is  patent classification?

Patents use both legal and technical terms in their titles and text; additionally, many patents have generic titles that provide no guidance as to the content of the patent. Consequently, keyword searching is very unreliable and not recommended as the sole search strategy for finding patents.   The primary type of patent searching is by classification.

"Classification" is a method by which items with similar characteristics are grouped together in categories.  Libraries use classification schemes to put books on related topics together.  (The ASU Library uses the Library of Congress Classification Scheme; many public libraries use the Dewey Decimal System.)  All types of stores such as hardware, discount, department, grocery, clothing, book, etc.,  group their wares; groupings could be by type of product, manufacturer or the brand.  

Patent classification systems group inventions with like features together.   The big advantage to classification searching is that you don't have to know (or guess) what obscure terminology is used by the inventor and his patent attorney.  Once you find the appropriate categories (sometimes called classes or symbols) for your invention, you'll easily retrieve patents with similar characteristics.  

The Subject Search Process

Simply put, the search process involves determining the most appropriate categories (sometimes called classes or symbols) for your invention and then searching patent database(s) by that category.   

Step 1: Brainstorm keywords that describe your invention.  Focus on "what it is"; other keywords could describe the purpose, use or composition.

Step 2: Use those keywords to search:

• Patent databases to find patents using that terminology in the title or abstract; note the categories to which they have been assigned.
• Classification databases to find categories that use those keywords.

Step 3: Verify the relevancy of the categories you found in Step #2  by examining the classification outline as well as the classification definitions.

Step 4: Search the patent databases by the appropriate classifications you found in Step #3 to find patents that are potentially relevant to your invention. 

Step 5: For each patent in those classifications determine relevancy by viewing/reading the claims, specifications and drawings.  

Step 6: For each relevant patent from Step #5, check:

• The References Cited/Cited Documents (what patents, books, journal articles, etc. that were cited by the patent)
• The Referenced By/Citing Documents (what recent patents have cited this patent) 

Tutorials 

• The Patent Search:
  • How to Do a Preliminary Patent Search  (42m 26s; video)
    From the US Patent and Trademark Office, this power point video details how to do a prior art search in the USPTO databases starting with USPC categories and then including CPC categories.   Long but worth the time. 
     
  • How to Search for Patents (7m 25s; video)
    Shows how to do an international patent classification search with the Espacenet database. Created by the University of Central Florida Libraries in August 2014 - ignore the information at the end for getting help at UCF and instead, contact one of your ASU Librarians, listed in the right-hand column on this page. 
    ​
• Database Tutorials:
  • Espacenet (3m 22s; video)
    A brief introduction to EPO's worldwide patent database. 
     
  • A Guided Tour Through Espacenet (Self-paced slides, no audio; approximately 20m)
    Detailed instructions on using the Espacenet database. 
    ​
• Understanding the Patent Document: 
  • Patent Basics (1): Understanding a Claim
    The audio is uneven but otherwise an easy to understand demonstration for how to read a patent claim - a critical part of the patent search process. 

Databases

• Patent Databases
  ​Can be searched by keyword and/or classification.  Provides links to full text (when available).
  • USPTO Patents
    Access from the left-hand column. Granted U.S. patents can be searched by keyword from 1976 to the present and by classification (CPC and USPC) from 1790 to the present.  Updates every Tuesday. 
     
  • USPTO Applications
    Access from the right-hand column.  Published U.S. patent applications can be searched by either keyword or classification (CPC and USPC) from March 15, 2001 to the present.  Note: applications from the most recent 18 months may not be in the database on request of the inventor. 
     
  • Espacenet Worldwide 
    Granted patents and published applications from over 80 countries may be searched by keyword or classification (CPC and IPC).  Years covered and full text availability varies by country.  
    ​

• Classification Databases
  ​Can be searched by keyword or category number.  Used for determining the appropriate classifications for searching in the patent databases above. 

  • Cooperative Patent Classification (CPC) 
    The most extensive/detailed patent classification system.  Currently used by the U.S. Patent and Trademark Office and the European Patent Office starting on January 1, 2013.  Older U.S. patents have had equivalent CPC classifications added for their main USPC category.   European patents have had the European Classifications (ECLA) replaced by CPC.   This system is not used by all countries so a thorough international search must use the IPC system, see below.   
     
  • US Patent Classification (USPC)
    Used for U.S. patents only.  Starting on January 1, 2015 only design and plant patents will be given USPC categories; utility patents will only have CPC categories from 2015 on.   Use the USPC if you want the most detailed categorization of US design and plant patents and utility patents prior to 2015.
    • Index to the US Patent Classification System
      Browse through the USPC system using everyday language. 
    • Manual of Classification
      Browse through the USPC system starting with the main categories. 
    • Classification Search Page
      Use if you already have USPC class/subclass categories. Also contains concordances from USPC->IPC and mapping from USPC->CPC
       
  • International Patent Classification (IPC)
    Developed by the World Intellectual Property Organization (WIPO), the IPC is used for all patents entered into the worldwide Espacenet database.  Although the IPC may look similiar to the CPC in format - the coverage is much less detailed.  Use IPC classification for finding patents from all countries.