Patent ID: 8294639

Claim:
A display unit comprising an interlayer formed at least as one or more than one layers and arranged between a light-emitting layer and a diffractive element; the interlayer having a thickness not less than 500 nm and not more than 2,000 nm and an average refractive index greater than a refractive index of the light-emitting layer; an optical path length of the interlayer defined as a product of multiplication of the average refractive index of the interlayer by the thickness of the interlayer satisfying a requirement of the formula shown below: ( m + 0.1 ) · λ 0 ⁢ 2 · 1 - ( n L n m ) 2 ≤ n m ⁢ d ≤ ( m + 0.6 ) · λ 0 2 · 1 - ( n L n m ) 2 where m is an integer not less than 0; λ 0 is a wavelength in vacuum; n m is the average refractive index of the interlayer; d is the thickness of the interlayer; and n L is the refractive index of the light-emitting layer.