Photodetector of liquid crystal display and luminance control device using the same

摘要

A combination includes a liquid crystal module having a liquid crystal panel forming a front surface, an opposing back surface, and a backlight structured and arranged to transmit light between the front and back surfaces. A light sensor located behind the back surface detects light transmitted from the backlight through the back surface. The light sensor detects a quantity of light when the backlight is lit at a maximum luminance, and outputs a signal indicative of the quantity of light. A luminance setting means sets a desired luminance by a user as a function of a desired percentage of the maximum lumination of the backlight. A control means controls the luminance of the backlight using the signal as a reference so that the luminance set by the luminance setting means is achieved.