Searching for U.S. Patents on the Internet
The website of the U.S. Patent and Trademarks Office offers all the tools necessary to do a comprehensive search for previously issued U.S. patents, from 1790-present. The website contains a database of the images and drawings for all issued patents back to 1790, and keyword searchable full-text back to 1976.
Please review the following limitations of patent searching on the Internet before proceeding with this step-by-step guide:
A patent search is not an easy task to do.
If you are an inventor who will make decisions based on the results of a patent search, it is important to consider whether you want to attempt to do a patent search yourself. A thorough search could take many hours. You may want to consider hiring a patent attorney or a patent search firm. To perform a prior art search, the following research tools should be investigated:
U.S. and foreign patent databases;
Databases that contain journal articles and technical or government reports for the relevant subject area. You will want to utilize databases on the list of databases available statewide in Maine. These databases are made available by the Maine State Library and the Maine State Legislature;
Internet search engines;
Maine's Science, Technology and Business Portal for information on a wide variety of internet resources;
Company and product catalogs.
Searching patents that contain a specific word(s) almost guarantees that a searcher will miss several patents of interest. Here's why:
You will miss patents of interest that do NOT contain your search term(s). There are many ways to describe the same product or technology. Especially searching by title is not recommended because patent titles are often very short and not descriptive. It is difficult to assemble a comprehensive list of all synonyms and keywords.
You will miss patents of interest that were issued before 1976. Only patents issued after 1976 are searchable by keywords from the title, abstract and entire patent. You can also not search by inventor and company name before 1976.
For more information on the limitations of the U.S. Patent and Trademark Office's Web Patent Database see their Important Notices page.
Patent Search Assistance
Patent and Trademark Resource Center (PTRC) staff are available to provide training on patent search processes and research tools including PubEAST, PubWEST,† and the USPTO website. Additional information is available through the USPTO website at http://www.uspto.gov, by phone at 1-800-786-9199, or by e-mail at email@example.com. For legal matters, contact an attorney or agent registered to practice before the USPTO at https://oedci.uspto.gov/OEDCI/.
Preliminary U.S. Patent Search vs. Comprehensive Prior Art Search
This step by step guide provides a strategy for searching U.S. patents to locate and evaluate relevant prior art (earlier patents and published patent applications). A comprehensive search would also include foreign patents and non-patent literature (newspapers, magazines, dissertations, conference proceedings, and websites). PTRC staff can provide training on how to locate these additional resources.
Search Preparation and Documentation
Plan on spending a few hours learning the search process and additional hours for searching and evaluating results. The length of time depends on the complexity of the invention. Careful recording of the search process, including the databases used, date and time of search, classes searched, and patent and application numbers retrieved, is an important part of effective searching.
Brainstorm Terms Describing Your Invention
Begin by writing down a brief, accurate description of the invention. Avoid overly broad and generic terms such as "device," "process" and "system." Consider synonyms for the terms you initially select. Note important keywords and technical terms. Use the following questions to help identify keywords and concepts.
Let's say we invented an umbrella with a new rib design to eliminate the umbrella collapsing or inverting due to winds. Answers to the questions above might look like this:
Access and Review Cooperative Patent Classification Schema Using USPTO's Website Site Search Feature
Review Classification Definition Linked to the CPC Classification You Selected
If the selected classification title is underlined, it is hyperlinked to a CPC Classification Definition. CPC Classification Definitions are helpful in establishing the scope of the relevant classification and thus ensuring you have selected the most relevant classification. The definitions may include important search notes and suggestions for further searching. In this example, we click on A45B 25/22 and get the following definition, which is unusual in that it relies solely on images (most CPC definitions use text).
Retrieve and Review Issued Patents Using the CPC Classification You Selected
Having identified a relevant CPC classification, use the CPC classification to retrieve and review all the U.S. patents currently assigned to the CPC classification in the PatFT (Patents Full-Text and Image) database on the USPTO website. On the USPTO home page (www.uspto.gov), select "PatFT" under the drop-down "Quick Links" menu.
Enter the CPC classification in Term 1 Box (Important: Delete the space in the middle of any CPC classification when doing a PatFT search, so enter A45B25/22".). In the Field 1 drop down box select "Current CPC Classification." Leave the Term 2 Box blank. For Select Years, use the drop down box to select "1790 to present [entire database]". Click on the Search button to get results.
Click on either the patent number or the patent title to see the full-text of the patent (patents issued prior to 1970 will not have a full-text version, only a limited text entry). Review the front page of each patent in the Results List, paying special attention to the abstract and representative drawing. Jot down the number of those patents you feel are similar to your invention that will merit later closer review.
Click on the red "Images" button at the top of the page to veiw a pdf image of the patent.
Conduct In-Depth Review of Patents You Selected Based on Their Front-Page Information
Using this selected set of most relevant U.S. patents, now review each on in-depth for similarity to your own invention, paying close attention to the other sections of the patent--additional drawing pages, the specification and especially the claims. References cited by the applicant and/or patent examiner may lead you to additional relevant patents. Remeber the claims constitute the boundaries of legal property rights given to the patent holder. Print or download copies of the most relevant U.S. patents you find.
Retrieve and Review Published Patent Applications Using the CPC Classifications You Identified
Use the CPC classification you selected in Step 3 to retrieve and review all the U.S. published patent applications currently assigned to that CPC classification in the AppFT (Applications Full-Text and Image) database on the USPTO website. On the USPTO home page (www.uspto.gov), select "AppFT" under the drop-down "Quick Links" menu.
Enter the CPC classification in Term 1 Box (Important: Delete the space in the middle of any CPC classification when doing an AppFT search, so enter "A45B25/22".). In the Field 1 drop down box select "Current CPC Classification." Leave the Term 2 Box blank. For Select Years, you can only select "2001-present" since the U.S. has only been publishing applications since 2001. Click on the Search button to get results.
As you did in Step 4 with your Patent Results List, click on either the published patent application number or its title to see the full-text version. Click on the blue "Images" button at the top of the page to view a pdf image of the published application. Review the front page of each published patent application, paying special attention to the abstract and representative drawing. Jot down the number of those published patent applications you feel are similar to your invention.
Using this selected set of most relevant U.S. published patent applications, now review each one in-depth for similarity to your own invention, paying close attention to the other section of the published application--additional drawing pages, the specification and especially the claims,. Print or download copies of the most relevant U.S. published patent application to your inventions.
Options for Broadening Your Search
Having completed a preliminary U.S. Patent and Published Patent Applications search in which you did not find publications that disclosed what you hope to protect in your own patent application, you have several options to broaden your search--based on available time and resources.
† PubEAST and PubWEST are available at Patent and Trademark Resource Center libraries: http://www.uspto.gov/products/library/ptdl/index.jsp.
Disclaimer: The information contained in this guide is not intended as a substitute for professional legal advice. Use it as a general guide for conducting a preliminary patent search. The USPTO recommends that inventors consult a registered patent agent or attorney prior to filing an application.
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