Patent ID: 7899332

Claim:
A mobile terminal apparatus having a fixed housing and a moving housing linked via a hinge part in an openable and closable manner, the mobile terminal apparatus comprising: an optical communication unit that performs a bidirectional information transmission between a circuit device in the fixed housing and a circuit device in the moving housing with an optical signal, wherein the optical communication unit includes a light transmitting unit that transmits the optical signal; a light receiving unit that receives the optical signal from the light transmitting unit; and a light propagation path for propagating the optical signal from the light transmitting unit to the light receiving unit, and the light propagation path is formed inside a light-propagation-path forming member that is formed in a shape of a bottomed double-cylinder casing and functions as a bearing member for supporting a hinge shaft in a rotatable manner in the hinge part, on a same axis as an axis of the hinge shaft.