Optical storage media often contain data structures for a menu suitable for selection of a title, a chapter, a parameter or others. As the reflective surface tilts with respect to a pre-determined reference position the gap lengths between the fiber ends and the reflective surface change and the differences in these gap lengths is used to calculate an angle of inclination with respect to a reference position. Therefore, when a user is desired to electrically charge the chargeable batteries, it needs not to take the chargeable batteries out of the electric appliance, but needs only to directly place the electric appliance in an effective wireless induction zone to make the battery cover generate electric power in a wireless inducing mode to charge the batteries. The emitter region has the second conductivity type and at least partially defines a channel region in the well region adjacent to the emitter region.