Patent infringement is when a patented invention is produced without the consent of the patent holder by the producer. Patents protect the patent holder in the country in the country where the patent was issued. This means that the patented invention can be legally reproduced in another country without the consent of the patent holder but can't be imported to the country where the item is patented.

Valid Infringement Claim

For an infringement claim to be considered valid, the alleged infringing product must have all of the same elements or parts as the original product. If it lacks one or more parts of the original product, it is not infringing upon the patent.

Indirect Infringement

Indirect infringement is when a product released to the marketplace can be used to manufacture an already patented product. The claimant of the indirect infringement must prove that the alleged indirectly infringing product can be used to manufacture their product.

Clearance Search

A clearance search is when patent applications are compared with products that already patented. If the patent being applied for contains all the elements of an existing patent, it will be denied by the U.S. patent office.

Clearance Opinion

A clearance opinion is what follows a clearance search. It is a legal opinion made by an attorney that can be issued to a court as either proof of infringement or non-infringement.

Patent Infringement Insurance

Patent infringement insurance is insurance issued by one or more insurance companies to an inventor to protect her from patent infringement claims. It covers the legal costs of the insured, should she be sued for patent infringement.

Source:

U.S. Patent Office: Patent Laws

The Minerals, Metals & Materials Society: Undestanding Infringement Legal Opinions

Lectric Law Library: Legal Definition of Infringement

More Information:

How to Patent Your Idea Online - LegalZoom