LIGHT-EMITTING DEVICE

摘要

An illuminator includes a light-emitting element 110 and a light extraction sheet 120 which transmits light occurring from the light-emitting element 110. The light-emitting element 110 includes a first electrode 13 having a light transmitting property, a second electrode 11, and an emission layer 12 between the first and second electrodes. The light extraction sheet 120 includes a light-transmitting substrate 14 having a first principal face and a second principal face, a first light extraction structure 15 on the first principal face side of the light-transmitting substrate 14, and a second light extraction structure 16 on the second principal face side of the light-transmitting substrate 14. The first light extraction structure 15 includes a low-refractive index layer 15a having a lower refractive index than does the light-transmitting substrate 14 and a high-refractive index layer 15b having a higher refractive index than does the low-refractive index layer 15a, and an interface between the high-refractive index layer 15b and the low-refractive index layer 15a has bump-dent features. The second light extraction structure 16 is arranged so that light which is transmitted through the light-transmitting substrate and arrives at an incident angle of 40 degrees to 60 degrees has an average transmittance of 42% or more.