Disclosed is an optical inspection system for inspecting the surface of a substrate. In a light emitting element made of a cathode, an organic compound layer and an anode, a protection film is formed in an interface between the anode that is a light exit electrode and the organic compound layer. In the event of a collision, the breakaway link will break to reduce the likelihood of breakage of any other part of the coating head assembly. Enhancement of function is useful in learning and memory. A method of mounting an electrical connector to a substrate. Because only a portion of the intermediate value is used, the division can be performed efficiently at the rectangular multiplier, and therefore the quotient can be determined more quickly and still achieve the desired level of precision.