Backlight module and display device for privacy protection

A display device comprising:

• a back plate;
• a middle frame disposed on the back plate;
• a substrate encompassed by the back plate;
• and
• a plurality of backlight units disposed on the substrate, wherein each of the backlight units comprises:
• a first light emitting unit having a first beam angle;
• a plurality of second light emitting units, wherein a size of each of the second light emitting units is smaller than a size of the first light emitting unit, each of the second light emitting units has a second beam angle which is narrower than the first beam angle;
• and
• a support unit disposed on the first light emitting unit, wherein the support unit is a polygonal frustum having an upper surface and a lower surface, the upper surface of the polygonal frustum is rotated a particular degree relative to the lower surface of the polygonal frustum, and the particular degree is greater than 0 degree,
• wherein in a first mode, a light intensity of the first light emitting unit is equal to a first intensity, a light intensity of the second light emitting units is equal to a second intensity,
• wherein in a second mode, the light intensity of the first light emitting unit is equal to a third intensity, the light intensity of the second light emitting units is equal to a fourth intensity,
• wherein the first intensity is greater than the third intensity, and the second intensity is less than the fourth intensity.