In April 2012, EVERLIGHT filed for declaratory judgment
of invalidity and non-infringement of Nichia’s U.S.
patents related to white LEDs, including U.S. Patent Nos. 5998925 and
7531960. These two patents are directed to YAG phosphor being used with blue
LED chip to emit white light, and its phosphor concentration. The jury
before the U.S. District Court for the Eastern District of Michigan found on
April 22, 2015 that all asserted claims of these patents are invalid for
obviousness and/or lack of enablement.
In March 2012, EVERLIGHT also filed for invalidation trial against Nichia’s
corresponding white LED patent in Germany (German Patent No. DE69702929
(EP0936682)). The German Patent Court in September 2014 also declared all
the claims of the patent invalid and Nichia has to bear the litigation fee.