Light source module having LEDs
View Patent ↗A light source module includes a substrate, a first LED package and a second LED package. The first and second LED packages are disposed on the substrate. The first LED package includes a first blue LED chip and a first phosphor. The first blue LED chip emits light in the range of the wavelength for blue light. The first phosphor is used to convert the wavelength of a portion of the light emitted from the first blue LED chip. The second LED package includes a second blue LED chip and a second phosphor. The second blue LED chip emits light in the range of the wavelength for blue light. The second phosphor is used to convert the wavelength of a portion of the light emitted from the second blue LED chip. The wavelength associated with the second phosphor is greater than that associated with the first phosphor.
1. 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.
2. The light source module of claim 1 , wherein a ratio of a light flux of the first LED package to a light flux of the second LED package approximately ranges from 1 to 14.
3. The light source module of claim 2 , wherein the light flux of the first LED package is higher than the light flux of the second LED package.
4. The light source module of claim 1 , wherein there is a plurality of the first LED packages and a plurality of the second LED packages;
wherein a ratio of a total light flux of the first LED packages to a total light flux of the second LED packages approximately ranges from 1 to 14.
5. The light source module of claim 4 , wherein a ratio of the number of the first LED packages to the number of the second LED packages approximately ranges from 0.05 to 20.
6. The light source module of claim 1 , wherein the first light flux F 1 is determined by one of the first CIE coordinate points, and the second light flux F 2 is determined by one of the second CIE coordinate points.
7. The light source module of claim 1 , wherein an emission spectrum of the first blue LED chip and an emission spectrum of the second blue LED chip are different.
8. The light source module of claim 1 , wherein an emission spectrum of the first blue LED chip and an emission spectrum of the second blue LED chip are the same.
9. The light source module of claim 1 , wherein a CCT (correlated color temperature) of the light source module approximately ranges from 2700K to 6500K.
10. The light source module of claim 1 , wherein the first LED package and the second LED package are symmetrically and uniformly disposed on the substrate.
11. The light source module of claim 1 , wherein a peak wavelength associated with the first phosphor approximately ranges from 510 nm to 590 nm.
12. The light source module of claim 1 , wherein a peak wavelength associated with the second phosphor approximately ranges from 591 nm to 660 nm.
13. The light source module of claim 1 , wherein a FWHM (full width at half maximum) of each of the first phosphor and the second phosphor approximately ranges from 60 nm to 160 nm.
14. 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 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 packages is m, and a number of the at least one second LED packages is n, wherein m and n are both positive integers;
wherein each of the first LED packages emits a first light flux F 1 , and each of the second LED packages emits a second light flux F 2 ;
wherein the total light flux of the light source module, F_module, is a sum of the first light flux F 1 multiplied m and the second light flux F 2 multiplied by n;
wherein an arithmetic mean of an equivalent light flux of the light source module, F_mean is the total light flux of the light source module F_module divided by a sum of m and n;
wherein the first light flux F 1 , the second light flux F 2 , the number m of the first LED packages, and the number n of the second LED packages are chosen to optimize the equivalent light flux F_mean;
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;
wherein a slope of the first line is fixed and a slope of the second line is fixed.
15. The light source module of claim 14 , wherein the slope of the first line is greater than the slope of the second line.
16. The light source module of claim 15 , wherein a total light flux of the first LED packages is higher than a total light flux of the second LED packages.
17. The light source module of claim 15 , wherein the first LED packages and the second LED packages are symmetrically and uniformly disposed on the substrate.
18. The light source module of claim 15 , wherein a peak wavelength associated with the first phosphor approximately ranges from 510 nm to 590 nm, wherein a peak wavelength associated with the second phosphor approximately ranges from 591 nm to 660 nm.