A source electrode and a metal pattern for a storage capacitor are formed on an insulating substrate, a silicon layer having a doped source region and a doped drain region is formed on the substrate and the source and the drain regions directly contact to the source electrode and the metal pattern. By arranging the first and second addresses to be reversely displaced from the center line of a groove track or a land track to the radial direction of the medium, the distance between the first and second addresses when they are adjacent is increased, which eliminates the influence of crosstalk. In addition, the modulated light is directed to display optics, and the reflected light is directed away from the display optics. An interface for accessing the end of line parameters provided. The cable binding members are attached to an outer surface of the installing plate. Apparatus output components include a receiver and a loudspeaker; optional input components include a microphone and a transceiver for sending responses back to alert originators.