Patent ID: 7906904

Claim:
A light permeable fluorescent cover to be attached on a light emitting diode which emits a blue light having a first peak in a blue wavelength range, said cover comprising a fluorescent material for producing green and red lights upon excitation by said blue light, said green light having a second peak in a green wavelength range away from said first peak, and said red light having a third peak in a red wavelength range away from said first and second peaks, wherein said blue, green and red lights are mixed into a whitish or white light to be irradiated to outside of said cover, said fluorescent material comprises at least one of fluorescent lanthanoid aluminates activated with manganese shown by at least one selected from chemical formulae: LaAl 11 O 18 :Mn 2+ , La 2 O 3 11Al 2 O 3 :Mn 2+ , La 1−X Al 11(2/3)+X O 19 :Mn 2+ X (0.1≦X≦0.99), (La, Ce)Al 11 O 19 :Mn 2+ , and (La, Ce)MgA 1 11 O 19 :Mn 2+ , and said fluorescent material has 0.4 to 0.8 manganic content ratio for adjusting component ratio of said green and red lights in said whitish or white light.