A controller capable of being located in a peripheral device or host, is capable of engaging in data communications with a host or peripheral device over a power line. The heat pipe is held tightly against the heat source by mounting holes which penetrate the structure of the heat pipe but are sealed off from the vapor chamber because they each are located within a sealed structure such as a pillar or the solid layers of the casing surrounding the vapor chamber. The aperture member includes a light passage opening formed so that a center position thereof substantially matches with a position of a center of curvature of the arc shape of the lower surface portion. A control gate and a passivation layer are disposed over and between the two isolated chargeable areas.