Light emitting diode lens and backlight apparatus having the same

A backlight apparatus provided in a rear part of a Liquid Crystal Display (LCD) for radiating light beams perpendicularly into an LCD panel, comprising:

• a substantially box-shaped housing opened toward the LCD panel;
• a reflector inclined slowly upward within the housing;
• and
• a Light Emitting Diode (LED) array including a board extended across the housing and erected on the reflector and at least one LED lens attached on the board for radiating light emitted from an LED chip to the outside,
• wherein the LED lens comprises:
• a planar bottom having a pair of halves symmetrically connected with each other about a reference line, and narrowed in the vicinity of the reference line;
• a pair of substantially semicircular reflecting surfaces extended from both edges of the bottom connected with both ends of the reference line;
• and
• a radiating surface connected with remaining edges of the bottom and semicircular edges of the reflecting surfaces,
• wherein the reflecting surfaces reflect light beams introduced from the LED chip through the bottom toward the radiating surface, and the radiating surface radiates the light beams to the outside, the light beams being introduced to the radiating surface through reflection from the reflecting surfaces and directly through the bottom, whereby the light beams are radiated to the outside in a predetermined beam angle.