An LCD device using LEDs as light sources provided herein is capable of reducing the manufacturing cost and the power consumption by a reduction in the number of LEDs used. A backlight according to the present invention includes LEDs mounted on a wiring board and a light guide plate having a matrix array of light guide plate blocks assigned the LEDs. The number of LEDs assigned to the block located in a peripheral area is smaller than the number assigned to the block located around the center to reduce the number of LEDs used in the backlight. If a ratio of the brightness in a peripheral area of the screen to the brightness in a central area is 60% or higher, the human eye does not perceive non-uniform luminance. Thus, the manufacturing cost and the power consumption of the LCD device can be reduced.