| abstract |
A white light source includes: an insulating substrate; a light-emitting diode chip provided on the insulating substrate and that emits ultraviolet light with a wavelength of 330 nm to 410 nm; and a phosphor layer formed to cover the light-emitting diode chip, including a red emitting phosphor, a green emitting phosphor, and a blue emitting phosphor as a phosphor, and the phosphors are dispersed in a cured transparent resin, wherein when it is assumed that the shortest distance between a surface of the phosphor layer and a peripheral portion of the light-emitting diode chip is t(mm) and the mean free path defined by the following expression (1) is L(mm), the t and L satisfy 3.2≦t/L. n [Expression 1] n n L =1 /( n ×σ) (1)n n(n: number of phosphors per unit volume of the phosphor layer (pcs/mm 3 ), and σ: average cross section area of a phosphor in the phosphor layer (mm 2 )). |