Substrate for optics and light emitting device

A substrate for optics applied to an organic EL light emitting device comprised of at least an anode, a cathode and a light emitting layer in which the light emitting layer has one or more organic layers, comprising:

• a base substrate;
• and
• a fine-structure layer formed on a main surface of the base substrate facing the light emitting layer, the fine-structure layer including a plurality of dots comprised of a plurality of convex portions or concave portions extending in a direction of from the main surface of the base substrate to outside the surface,
• wherein the fine-structure layer forms a plurality of dot lines in which the plurality of dots is arranged with a pitch Py in a first direction inside the main surface of the substrate, while the plurality of dot lines forms a plurality of dot lines arranged with a pitch Px in a second direction orthogonal to the first direction inside the main surface of the substrate, and
• one of the pitch Py and the pitch Px is a constant interval of nano-order, while the other one is an inconstant interval of nano-order, or both are inconstant intervals of nano-order,
• wherein the pitch Py with the inconstant interval is equal to a distance between centers of respective dots, the pitch Px with the inconstant interval is equal to a distance among centers of adjacent dot lines that the plurality of dots are arranged with the pitch Py, the pitch Py and the pitch Px are larger than a diameter of each dot,
• pitches Pyn among at least four or more and m or less of adjacent dots (3≦n≦2a or 3≦n≦2a+1, in addition, m and a are positive integers, m>4, and n=m−1) meet a relationship of following equation (1) while dot groups formed with the pitches Py1 to Pyn are repeatedly arranged in the first direction when the pitch Py is the inconstant interval, and
• when the pitch Px is the inconstant interval, pitches Pxn among at least four or more and m or less of adjacent dots (3≦n≦2a or 3≦n≦2a+1, in addition, m and a are positive integers, m>4, and n=m−1) meet a relationship of following equation (2) while dot line groups formed with the pitches Px1 to Pxn are repeatedly arranged in the second direction,
• Py1<Py2<Py3< . . . <Pya> . . . >Pyn (1), and
• Px1<Px2<Px3< . . . <Pxa> . . . >Pxn (2).