The object of the present invention is to prevent deformation in a light guide plate and display anomalies. When the light guide plate is disposed in the backlight, a cushion rubber abuts a side surface of the light guide plate and a side surface portion of a lower frame to be pressed (squeezed) into the light guide plate and the lower frame. The cushion rubber is disposed lower than the side surface of the light guide plate, and is formed at a height not interfering with optical sheets. A protrusion portion is formed from an upper surface portion of an upper frame in a space between an upper surface portion of the cushion rubber and the upper frame to face the upper surface portion of the cushion rubber.