Abstract: A system for controlling light emission of a LCD or an OLED TV includes an infrared light sensing assembly for detecting human presence in front of a TV within a predetermined detection angle and a power control circuit electrically connected to the infrared light sensing assembly, the TV's power supply and a backlight module (LCD TV) or an OLED assembly (OLED TV). The infrared light sensing assembly transmits a first signal to the power control circuit when human presence is detected, and transmits a second signal to the power control circuit when no human presence is detected. The power control circuit allows power to be transmitted from the power supply to the backlight module or the OLED assembly when the first signal is received and disallow power to be transmitted from the power supply to the backlight module or the OLED assembly when the second signal is received.