Types of Patents


The U.S. Patent and Trademark Office (PTO) issues several 
different types of patent documents offering different kinds 
of protection and covering different types of subject matter.

A recently issued PTO patent document is one of six types,
generally described below. See U.S. Code Title 35 - Patents, for
a full description of patents and patent laws.

    *     Utility Patent-  Issued for the invention of a new and
          useful process, machine, manufacture, or composition of
          matter, or a new and useful improvement thereof, it
          generally permits its owner to exclude others from
          making, using, or selling the invention for a period of
          up to twenty years from the date of patent application
          filing ++, subject to the payment of maintenance fees.
          Approximately 90% of the patent documents issued by the
          PTO in recent years have been utility patents, also
          referred to as "patents for invention."

    *     Design Patent-  Issued for a new, original, and
          ornamental design for an article of manufacture, it
          permits its owner to exclude others from making, using,
          or selling the design for a period of fourteen years
          from the date of patent grant.  Design patents are not
          subject to the payment of maintenance fees.

    *     Plant Patent-  Issued for a new and distinct, invented
          or discovered asexually reproduced plant including
          cultivated sports, mutants, hybrids, and newly found
          seedlings, other than a tuber propagated plant or a
          plant found in an uncultivated state, it permits its
          owner to exclude others from making, using, or selling
          the plant for a period of up to twenty years from the
          date of patent application filing ++.  Plant patents
          are not subject to the payment of maintenance fees.

    *     Reissue Patent-  Issued to correct an error in an
          already issued utility, design, or plant patent, it
          does not affect the period of protection offered by the
          original patent.

    *     Defensive Publication (DEF)-  Issued instead of a
          regular utility, design, or plant patent, it offers
          limited protection, defensive in nature, to prevent
          others from patenting an invention, design, or plant.
          The Defensive Publication was replaced by the Statutory
          Invention Registration in 1985-86.

    *     Statutory Invention Registration (SIR)-  This document
          replaced the Defensive Publication in 1985-86 and
          offers similar protection.

++   Although, the length of utility and plant patent protection
(patent term) was previously seventeen years from the date of
patent grant, utility and plant patents filed after June 8, 1995
now have a patent term of up to twenty years from the date of
filing of the earliest related patent application. Utility and
plant patents which were applied for prior to June 8, 1995, and
which were or will be in force after June 8, 1995, now have a
patent term of seventeen years from the date of patent grant or
twenty years from the date of filing of the earliest related
patent application, whichever is longer.  Utility patents are
subject to the payment of periodic maintenance fees to keep the
patent in force. Patent terms can be extended under some specific
circumstances.  See the U.S. Code Title 35 - Patents for a full
description of patent laws.

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Questions regarding this web page should be directed to:
(address as of 6/2000)
             U.S. Patent and Trademark Office
             Information Products Division
             Technology Assessment and Forecast Branch
             PK3-Suite 441
             Washington, DC  20231

             tel (703) 306-2600
             FAX (703) 306-2737

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SOURCE:   U.S. PATENT AND TRADEMARK OFFICE
          Technology Assessment and Forecast data base    (1 June 2000)