Surface light-emitting device

A surface light-emitting device comprising:

• a circular transparent substrate;
• and
• a light-emitting element that is a laminated body including a transparent electrode which is positively charged and function as an anode, a negative electrode which is negatively charged and function as a cathode opposite the transparent electrode, and a light-emitting layer sandwiched between the transparent electrode and the negative electrode, the light-emitting element disposed on one surface of the transparent substrate, wherein
• a diameter and a thickness of the transparent substrate has a relationship such that if b denotes the thickness of the transparent substrate, then dividing the diameter by 4b results in a value ranging from 0.5 (inclusive) to 10 (inclusive).

A surface light-emitting device comprising:

• an ellipsoidal transparent substrate;
• and
• a light-emitting element that is a laminated body including an ellipsoidal transparent electrode which is positively charged and function as an anode, a negative electrode which is negatively charged and function as a cathode opposite the transparent electrode, and a light-emitting layer sandwiched between the transparent electrode and the negative electrode, the light-emitting element disposed on one surface of the transparent substrate, wherein
• a long axis, a short axis, and a thickness of the transparent substrate have a relationship such that if b denotes the thickness of the transparent substrate, then dividing the long axis by 4b results in a value ranging from 0.5 (inclusive) to 10 (inclusive) and dividing the short axis by 4b results in a value ranging from 0.5 (inclusive) to 10 (inclusive).