The period of {HEAD ~ the effective wavelength degree} makes possible effective interference with the light emitted from the organic EL layer and improves {TAIL ~ the light extraction efficiency} of the organic EL light emitting device 
The period of { HEAD ~ the effective wavelength degree } makes possible effective interference with the light emitted from the organic EL layer and improves { TAIL ~ the light extraction efficiency } of the organic EL light emitting device
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH