What is a patent?

A good, boiled-down definition comes from the Dialog Corporation:

A patent is a legal document between the inventor and the government in which the inventor agrees to disclose the invention in exchange for the rights to exclude others from making, using, offering for sale or selling the invention for a specific period of time.

Dialog also notes the idea behind having a patent system: Patents are awarded to encourage creativity. The purpose of the patent system is to stimulate the advancement of technological progress by rewarding inventors who disclose their inventions.

The notion of seeding technological progress is included in the U.S. Constitution. From Article I, Section 8: The Congress shall have Power ... To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries ....
 
How do patents differ from copyrights and trademarks?

Charting the essential differences [pdf, 14.6 kb]

How do I know if I need a patent?

Getting a patent seldom increases the chances for commercial success. Determining whether an invention warrants patenting should perhaps follow consideration of whether an invention is worth patenting. Edison said: "Anything that won't sell, I don't want to invent."

Mark Ellwood, founder of the Inventors' Alliance, suggests 16 possible first steps one could take with a new idea.

Here are a few books and websites on assessing the commercial value of an invention.

How much does a patent cost?

There are two fee schedules for patents. Small entities (individuals, non-profit institutions, and businesses with fewer than 500 employees) pay half the regular costs. Fees are due at filing, upon issue, and to maintain the patent at intervals over its term. USPTO fee information is outlined on this page.

Helpful definitions:

Some of these are taken from Delphion's Glossary of Patent Terms.

Disclosure: The first publicizing of details of an invention, as in a patent application.

Disclosure Document Program: A service provided by the USPTO that accepts and preserves invention papers for two years as evidence of the date of conception of an invention. It provides a more credible form of evidence than that provided by the mailing of a disclosure to oneself by registered mail--the so-called "poor man's patent."

Infringement: To make, use, or sell the patented item or process within the country covered by the patent without permission or license from the patentee.

Novelty: The concept that the claims must be totally new. The invention must never have been made public in any way, anywhere, before the date on which the application for a patent is filed.

Prior Art: Technology that is relevant to an invention and was publicly available at the time an invention was made.

Provisional Patent Application: In 1995 the USPTO created a new form of patent application called the "provisional application for patent." It allows for temporary (12 months) protection of intellectual property that may be publicly disclosed. It entitles an inventor to put "Patent Pending" on his or her invention, and must be followed up before that year expires by filing a non-provisional patent application (standard utility patent).