A display device is provided, including a signal transmission mechanism that makes it possible to reduce the number of pins on an FPC board connected to a TFT substrate or eliminate the necessity for the FPC board, and that can be readily applied to a compact device.
The present liquid crystal display device includes light detectors, a receiver circuit, a display control circuit, a video signal line drive circuit, a scanning signal line drive circuit, and a display portion, which are formed on a TFT substrate of a liquid crystal display panel, and it also includes white LEDs, and an LED drive circuit, which are included in a backlight portion. The LED drive circuit drives the white LEDs, each emitting a light (modulation) signal LS in accordance with an externally-provided video signal VS. The receiver circuit generates (demodulates) the video signal VS based on a signal received via the light detector. Such an optical transmission mechanism makes it possible to reduce the number of pins on the FPC board or eliminate the FPC board.