For complete information about patents see the US Patent and Trademark Office's Web pages and see a patent attorney or agent to ensure a thorough understanding.
Brief Definition: A (U.S.) patent is a grant of a property right by the (U.S.) Government to you, the inventor, "to exclude others from making, using or selling the invention." Patents differ significantly from copyrights and trademarks.
All patents must be "maintained" by paying a fee to the US Patent & Trademark Office at certain intervals. If you fail to pay the maintenance fee, your patent expires and you lose exclusive rights to your invention.
Three Categories
In the U.S., according to the current patent law, the US Patent & Trademark Office grants utility patents and plant patents that last for 20 years; and design patents that last for 14 years.
International Patent Protection
Patent protection granted to an inventor by a government is only valid in the country where the inventor requested it. The rights do not extend beyond that country. For example, U.S. patents are valid only in the 50 states and its territories and do not provide legal protection in any other countries. When you wish to obtain patent protection for the same invention in other countries, you must file an application in each country separately. Attempting to pursue patent protection individually in several countries, however, can be complex and expensive, since each country has its own unique patent laws and practices. Important features in patent laws and practices that are significantly different among various nations are being negotiated under the auspices of the World Intellectual Property Organization (WIPO).
Patent Databases:
Seven Step Strategy (from the USPTO):
Patent Searching Guide:
For more detailed information, see the Patent Searching @ Pitt guide.