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*Engineering Research

This research guide offers an introduction to engineering research, helping you find and evaluate a wide range of technical and scholarly sources.

What is a Patent?

A patent is a legal document that grants an inventor exclusive rights to their invention for a limited period, typically 20 years. Patents are a valuable source for researching new technology and trends because they often contain information not found in academic journals. A thorough patent search can help you determine if your invention already exists or if it infringes on another's patent.

Patent Research

Finding patents in the U.S. Patent & Trademark Office (USPTO) Patent Database:

By Terms or Keywords

  1. Go to CPC Classification System Scheme and search for common terms or keywords.
  2. Use the Class/Subclass numbers you found to check the CPC Classification System Scheme to see if they are on target.
  3. Search by Class/Subclass numbers in the USPTO Database.

By Patent Number

  1. Go to the USPTO Database.
  2. Select Patent Number Search or Publication Number Search.

By Subject

  1. Go to the USPTO Database and select Quick Search. Enter keywords in the search box.
  2. Find a patent that is close to what you're looking for.
  3. Note the Cooperative Patent Classification (CPC) number/Subclass for that patent, such as A01D 711/111.
  4. Search for that Class/Subclass in the USPTO Database to find more patents on that subject.

Finding patents in the European Patent Office Online:

The European Patent Office (EPO) maintains a free database of worldwide patents (including U.S. patents) called Espacenet. Images of patents are provided in PDF format, but can only be printed one page at a time.

By Keyword or Classification

  1. Go to Espacenet and select Classification Search.
  2. Enter a keyword or select a Classification by "symbol" or "title and description".
  3. Patent classification is a system of sorting inventions and their documents into technical fields covering all areas of technology. This resource uses the International Patent Classification (IPC) and the Cooperative Patent Classification (CPC). Searching by classification may produce more accurate results.

By Patent Number

  1. Go to Espacenet and enter the patent number (with or without the country code) in the Smart Search box.
  2. All documents with that number will be listed. 
  3. Choose the patent record you are looking for.

By Subject

  1. Go to Espacenet: Advanced Search page and enter your keywords in the "Title or abstract" box.
  2. Find a patent that's close to what you're looking for.
  3. Note the International Classification number/Subclass for that patent, such as H04B1/59.
  4. Search for that Class/Subclass in the search box at the Espacenet Classification Search page to find more patents on that subject.

Finding Chemical Patents in SciFinder Scholar?

Chemical Abstracts Service (CAS) indexes chemical patents from approximately 25 countries and patent organizations. UCSD affiliates may search the online CAS database, Scifinder Scholar (link below). You have to register with SciFinder (create an account) before you can access this resource.

Once you have obtained access to SciFinder Scholar, go to Explore References.  To search by patent number, assignee name, or inventor name, select  Patent and enter the information you have. To search by subject, select Research Topic and limit to document type Patent.