Types of Patents

     There are three types of patents granted by the U.S. Patent Office, www.uspto.gov:
  •   utility patents
  •   design patents
  •   plant patents
     The most common type of patent is a "utility" patent. A utility patent covers what an invention is or how it functions.  A utility patent is effective from the date it is issued and generally lasts for 20 years from the date it was applied for.
     A design patent covers the ornamental features of a manufactured item. Design patents cover only how something looks, not how it works.  The term of a design patent is currently 15 years. 

     Plant patents cover asexually reproduced plants. Fruit trees and other flowering plants are the most common subjects for plant patents.