Embodiments of a display device and a method of reducing optical leakage from a backlight unit of a display device are described. The display device includes a backlight unit, an image generating unit coupled to the backlight unit and a blocking structure. The backlight unit is configured to transit light to the image generating unit and the blocking structure is configured to prevent the light from reaching the image generating unit without passing through the optical processing unit. The backlight unit includes a light source unit and an optical processing unit having a quantum dot film coupled to the light source unit. The method of reducing optical leakage from the backlight unit of the display device includes providing a first blocking structure to a portion of the light source unit and providing a second blocking structure to a portion of the optical processing unit.