decreasing the amount of light beams emitted upward from the first red and blue leds 104 r and 104 b and the amount of the decrease may vary according to the shape of the lens of the led or the package for example in a case of an led having a lens or a package for emitting light laterally it is preferable that the amount of upward light beam is decreased by about u00bd in addition in a case of an led having a dome or hemisphere shaped lens or package it is preferable that the amount of upward light beam is decreased by about u2153 the upper cover 112 can be configured such that it completely blocks the directly upward light beams from the first red and blue leds 104 r and 104 b depending on the purpose or the design of the backlight apparatus 100 in this case the cavity 122 completely houses the first red and blue leds 104 r and 104 b in the meantime instead of forming the cavity 120 in the sidewall 120 the entire portion of sidewall 120 can be shifted back to the position of the inner wall 118 to allow the substantially same effect the aforedescribed led backlight apparatus 100.