Copyright 2000-2010.  Frederic M. Douglas.  All Rights Reserved.

Determining whether a patent is infringed should entail the same process that a court would use.  Generally, a court would make findings on validity, infringement, and enforceability.  Below is a list of nineteen specific defenses to patent infringement claims:

 (1)       Expired Patent,

(2)       Noninfringement under 35 USC § 271,

(3)       Anticipation by prior art under 35 USC § 102 (a), (b), (d), (e), or (g),

(4)       Obvious over prior art under 35 USC § 103,

(5)       Double patenting,

(6)       Improper inventorship under 35 USC § 102 (f),

(7)       Improper scope of claims under 35 USC § 112,

(8)       Fraud,

(9)       Antitrust violation,

(10)   Plaintiff does not own the patent,

(11)   License to the patent,

(12)   Abandonment under 35 USC § 102 (c),

(13)   Misuse,

(14)   Laches,

(15)   Intervening Rights,

(16)   Lack of utility under 35 USC § 101,

(17)   Inoperable invention under 35 USC § 112,

(18)   Not statutory subject matter under 35 USC § 101,

(19)    Foreign filing after non-publication request.