Abstract: A liquid crystal display apparatus includes a liquid crystal module for displaying an image thereon, a backlight for emitting light from the rear surface of the liquid crystal module, and an inverter for controlling the backlight. The inverter drives the backlight at a predetermined oscillation frequency, based on pulse signals which are pulse-width modulated and are in synchronization with vertical synchronization signals. The backlight is turned off while the liquid crystal module is being scanned for an image of the next field to be displayed, and is turned on when the scanning is complete and the liquid crystal module is ready to display the refreshed image. Accordingly, undesirable afterimages such as trailing do not appear in moving images.

Abstract: A user sensor allows a phototransistor to receive infrared rays that are emitted from an infrared diode in front of a display apparatus and reflected from a user, and a detection signal in response to a quantity of light is inputted to the positive input terminal of a correction circuit formed by a differential amplifier. An illumination sensor receives light in the environment of the display apparatus, and a detection voltage in response to the quantity of light is divided and inputted to the negative input terminal of the correction circuit. The quantity of infrared rays that are included in the environmental light detected by the illumination sensor is subtracted from the infrared rays that enter the user sensor, providing a correct sensor output representing a state of user detection.