An LCD device has an LCD panel, a backlight unit for irradiating the rear surface of the LCD panel, and a backlight chassis for positioning the backlight unit with respect to the LCD panel. The backlight unit has a lamp, an optical conductive plate and an optical sheet assembly formed on the optical conductive plate. The optical sheet assembly includes a pair of light scattering sheets and a pair of lens sheets sandwiched between the pair of light scattering sheets. The edges of the lens sheets protrude from the edge of one of the light scattering sheet, which is flush with the edge of the optical conductive plate. A bright line degrading the image quality of the LCD device can be suppressed.