Patent ID: 8079733

Claim:
An indicator which emits a light, the indicator comprising: a plate-shaped member which has a stress-concentrating section which causes a stress concentration, and a stress-transmitting section which is connected to the stress-concentrating section and which transmits, to the stress-concentrating section, a stress generated due to an external force applied to the stress-transmitting section; a stress light-emitting section formed at the stress-concentrating section and formed of a stress light-emitting material which emits the light in response to a change of the stress; and an external force-applying section, to which the external force is applied, which is formed in the stress-transmitting section of the plate-shaped member; wherein the stress-concentrating section and the external force-applying section are arranged, on one surface of the plate-shaped member, at positions different from each other; and wherein the stress light-emitting section emits the light at least in a direction which is opposite to a direction of the external force.