Equitable Estoppel

ASPEX EYEWEAR INC. V. CLARITI EYEWEAR, INC.

• “In the context of patent infringement, the three elements of equitable estoppel that must be established are: (1) the patentee, through misleading conduct, led the alleged infringer to reasonably believe that the patentee did not intend to enforce its patent against the infringer; (2) the alleged infringer relied on that conduct; and (3) due to its reliance, the alleged infringer would be materially prejudiced if the patentee were permitted to proceed with its charge of infringement.”
• “Misleading ‘conduct’ may include specific statements, action, inaction, or silence when there was an obligation to speak.”
• “[The accused infringer] need not show a total loss of value in order to show material prejudice. Prejudice may be shown by a change of economic position flowing from actions taken or not taken by the patentee”