Patent ID: 8803170

Claim:
A light source module having LEDs and a total light flux, F module, the light source module comprising: a substrate; at least one first LED (light emitting diode) package disposed on the substrate, the first LED package comprising: a first blue LED chip emitting light that is in the range of the wavelength for blue light; a first phosphor for converting the wavelength of a portion of the light emitted from the first blue LED chip; and at least one second LED package disposed on the substrate, the second LED package comprising: a second blue LED chip emitting light that is in the range of the wavelength for blue light; and a second phosphor for converting the wavelength of a portion of the light emitted from the second blue LED chip; wherein the wavelength associated with the second phosphor is greater than the wavelength associated with the first phosphor; wherein a number of the at least one first LED package is m, and a number of the at least one second LED package is n, wherein m and n are both positive integers; wherein each of the first LED package emits a first light flux F 1 , and each of the second LED package emits a second light flux F 2 ; wherein the total light flux of the light source module, F_module, satisfies: F_module=F 1 ×m+F 2 ×n; wherein an arithmetic mean of an equivalent light flux of the light source module, F_mean satisfies: F_mean=(F 1 ×m+F 2 ×n)/(m+n); wherein the arithmetic mean of the equivalent light flux of the light source module, F_mean is optimized by choosing the first light flux F 1 , the second light flux F 2 , the number m of the at least one first LED package, and the number n of the at least one second LED package, wherein a plurality of first CIE (CIE chromaticity diagram) coordinate points are provided based on different ratios of the first phosphor, a first line is drawn by the first CIE coordinate points, and the first line is substantially straight; wherein a plurality of second CIE (CIE chromaticity diagram) coordinate points are provided based on different ratios of the second phosphor, a second line is drawn by the second CIE coordinate points, and the second line is substantially straight.