Backlight unit and display apparatus using the same

A display apparatus, comprising:

• a display panel;
• and
• an illumination system irradiating light onto the display panel,
• wherein the illumination system includes:
• a light guide plate having grooves, each of the grooves having at least one side surface and a bottom surface;
• light source modules disposed within the grooves of the light guide plate, wherein the light source modules comprise:
• substrates;
• and
• light sources disposed on the substrates;
• and
• stoppers disposed between a first surface of each of the light source modules and the at least one side surface of each of the grooves, the first surface of each of the light sources facing the at least one side surface,
• wherein a cross-sectional area of the grooves is larger than that of the stoppers.