Ever think about why the label "patent pending" is such a powerful marketing tool?
In the USA and some other countries, the assignees of a patent may have rights to require a license and obtain payment or other considerations for use of technology described in a pending patent application. Thus, partnering and sales decisions are very often made on the basis that the technology of interest is "patent pending". A savvy investor will avoid technology in published patent applications that might be subject to someone else's patent rights!
The US law (35 U.S.C. 154) is as follows:
(1) IN GENERAL - In addition to other rights provided by this section, a patent shall include the right to obtain a reasonable royalty from any person who, during the period beginning on the date of publication of the application for such patent under section 122(b), or in the case of an international application filed under the treaty defined in section 351(a) designating the United States under Article 21(2)(a) of such treaty, the date of publication of the application, and ending on the date the patent is issued-
(A) (i) makes, uses, offers for sale, or sells in the United States the invention as claimed in the published patent application or imports such an invention into the United States; or
(ii) if the invention as claimed in the published patent application is a process, uses, offers for sale, or sells in the United States or imports into the United States products made by that process as claimed in the published patent application; and
(B) had actual notice of the published patent application and, in a case in which the right arising under this paragraph is based upon an international application designating the United States that is published in a language other than English, had a translation of the international application into the English language.
(2) RIGHT BASED ON SUBSTANTIALLY IDENTICAL INVENTIONS - The right under paragraph (1) to obtain a reasonable royalty shall not be available under this subsection unless the invention as claimed in the patent is substantially identical to the invention as claimed in the published patent application.
(3) TIME LIMITATION ON OBTAINING A REASONABLE ROYALTY- The right under paragraph (1) to obtain a reasonable royalty shall be available only in an action brought not later than 6 years after the patent is issued. The right under paragraph (1) to obtain a reasonable royalty shall not be affected by the duration of the period described in paragraph (1).