TELEVISION CAMERA COAXIAL TYPE SCREEN DISPLAY DEVICE

PURPOSE:To allow the user to utilize a television telephone set without notifying a television camera by switching 2 liquid crystal shutters alternately synchronously with a vertical synchronizing signal of a television signal. CONSTITUTION:First and second liquid crystal shutters 7, 8 are switched alternately at a prescribed timing in synchronism with the vertical synchronizing signal of a television signal. The 1st liquid crystal shutter 7 is opened during the vertical scanning period to operate them, the light from a small sized screen display device 3 is directed in a direction 9 to allow the user to observe the video image from the small sized screen display device 3. Moreover, the 2nd liquid crystal shutter 8 is closed at the time to prevent a light reflected irregularly in a half mirror 2 and a protection glass 1 from going to a lens 5 and a television camera 6 thereby clearing the video image. Then the 1st liquid crystal shutter 7 is closed during the vertical blanking period and the 2nd liquid crystal shutter 8 is opened. Since the video image is displayed during the vertical blanking period, the television camera is not seen externally.