Search the U.S. and European patent databases for ideas similar to yours (see the Resources section below). Many developers and inventors do this search before they embark on the development process.
Make a list of key terms associated with your potential invention. These words could describe the invention's purpose, use or composition.
Search the U.S. and European databases for these terms. In the U.S. Patent Classification Index, look up these key words to locate the classes and subclasses that might apply to your invention.
Review the Classification Schedule to double-check the pertinence of these different classes and subclasses. You can find this schedule in the Manual of Classification (see Resources below). Peruse the Classification Definitions to identify the range of the subclasses and carefully read any additional references.
Browse the appropriate classes and subclasses in the Issued Patents and the Published Applications databases (see Resources below). Search according to "Current U.S. Classification" or "CCL."
Access the full-text patents and published applications of any inventions that seem similar to your own. Carefully read through the patent's or application's claims to ensure infringement will not be an issue. If the claims match those of your potential invention, infringement is likely.
Contact a patent attorney if your idea or invention has passed your own Internet search. Ask your attorney to determine both the patentability of your idea or invention as well as potential infringement issues. This serves as your final due diligence in determining if a patent already exists for your invention.