A display apparatus includes an LCD panel, a PCB assembly placed behind the LCD panel and supplying electric current to the LCD panel, an LCD frame provided around the LCD panel, a plurality of first combining parts formed on peripheral sides of the LCD frame, and a plurality of second combining parts formed on the plane of the LCD frame. An evaporation source is used in which an evaporation cell, or a plurality of evaporation cells, having a longitudinal direction is formed, and by moving the evaporation source in a direction perpendicular to the longitudinal direction of the evaporation source, a thin film is deposited on a substrate. The short message gateway determines the location and availability of a second push-to-talk subscriber to which the presence information is directed. A backlight module using the light guide plate is also provided.