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Patents: Finding Patents By ...

A guide to help ASU students find patent information including what is a patent, the different sections of a patent, how to do a prior art search, where to find statistics and other sources of patent information.

Introduction

This section explains how to use the main free patent databases to find patents by assignee, classification, inventor, number or subject (aka prior art searching).   Instructions are provided for the USPTO databases, Espacenet, and in some cases, Google Patents.  Use the tabs in the box below for instructions on the different types of searching.  

There are other patent searching databases available, see the Intellogist for a comparison of these databases

Search Strategies

Tips For Assignee Name Searching 

When an inventor signs over his patent property rights to another individual or an organization, that individual or organization is called the assignee. The assignee is most likely to be an organization as most employers require an invention created on company time and equipment be automatically assigned to the company. 

If you are looking an individual as an assignee, consider all the name variations that are discussed under the "inventor" tab on this page.  

If you are looking for an organization as an assignee, you must also consider name variations: 

  • If the company has changed names, you must search under all the names even beyond the date of the name change.  Patents filed before the name change may issue afterwards and will probably contain the previous company name as the assignee.  
     
  • Company ownership also complicates searching.  If a company is bought out by another, even if the original company keeps its name, patents could be assigned to the parent company.  If a product is sold under the original company's name, it may contain components that were developed and patented by the parent company.   

Before beginning an assignee search, research the company to identify name changes, ownership and subsidiary/parent relationships.  Look at the company's website, check out its entry in wikipedia, or use specialized business database that contain company information. 

 

How to Search an Assignee in a Patent Database

  • USPTO (PatFT and AppFT) databases
    Once at the home page, select the database (PatFT for issued patents; AppFT for patent applications) and then select "Quick Search".  Enter the name in the search box and change the field to "Assignee Name"

    Screenshot of assignee name search in USPTO databases
     
  • Espacenet database
    Once in the database, click on "Advanced Search" in the left-hand column and scroll the search form down to the section labeled "Enter name of one or more persons/organisations".   In the "Applicant" box, enter the assignee name. 

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.
  • 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" ...
    Screenshot of searching US classification in USPTO databases

    For CPC classification, enter the full classification with all its segments with no spaces and set the field to Current CPC Classification"  ...
    Screenshot of CPC classification searching in USPTO databases

    For IPC classification, enter the full classification with all its segments with no spaces and set the field to "International Classification" ...
    Screenshot of searching IPC classification in USPTO databases
     
  • 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 ...
    Screenshot of searching CPC classifications in Espacenet

    To search an IPC classification, in the IPC box put the full classification without spaces ...
    Screenshot of IPC searching in Espacenet

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".   

screenshot of inventor search in US PatFT database

 

Espacenet (Worldwide) database

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

Screenshot of inventor search in the Espacenet database

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.

 

Screenshot of patent number search in PatFT

 

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. 

 

Screenshot of patent number search in Espacenet database

 

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: 

 

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.
    • 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.   
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