3d glasses and 3d display apparatus using ir signal and rf signal

PURPOSE: 3D glasses and a display device are provided to watch a 3D image in various spaces by using one of an infra-red signal and a radio frequency signal as a synchronizing signal. CONSTITUTION: An infrared receiver(210) receives an infra-red signal from a 3D display device. A controller receives and controls a synchronizing signal from the 3D display device through one of the infra-red signal and a radio frequency signal. The controller measures receiving strength of the radio frequency signal and the infra-red signal. The controller receives synchronizing signal determination information through a radio frequency communications unit(215). The radio frequency communications unit communicates with the 3D display device by using the radio frequency signal.