The present invention relates to a system and method for integrating and assembling plurality of service delivery tools created on disparate technologies on a product assembly platform. A parent unit having a receiver for receiving the video signals and the audio signals, a video screen for displaying the video images, and a speaker for emitting the sounds. By supplying an electric current to the ITO film at the time of staring an operation of the liquid crystal display panel, a temperature of the liquid crystal layer is elevated to a level which allows the liquid crystal layer to perform a normal operation within a short time.