US 6,641,448 B2Granted

Manufacturing method for white light source

AssigneeLite-On Technology Corporation

InventorsChien-Yuan Wang, Ru-Shi Liu, Hung-Yuan Su, Chen-Lun Hsing Chen

Life of this patent

Estimating the term…

Abstract

A manufacturing method for white light source utilizes an ultraviolet light source and suitable phosphors. One of the phosphors is directly excited by the ultraviolet light source and generates a radiation with longer wavelength. Other phosphors are excited by the radiation with longer wavelength and generate radiation with much longer wavelength. The lights generated by those phosphors are mixed to form a white light.

Claims10

Dependent claims

A method for manufacturing a white light source, the method comprising the steps of:

(a) synthesizing a first phosphor powder and a second phosphor powder;
(b) mixing the first phosphor powder and the second phosphor powder according to a mixing ratio into a phosphor mixture, the mixing ratio determined by the steps of:
(1) measuring at a first reference wavelength an emission response of the first phosphor powder to a plurality of excitation wavelengths within a first band of excitation wavelengths;
(2) selecting a first excitation wavelength from the first band of excitation wavelengths based upon the emission response measured in step (1);
(3) measuring a spectral response of the first phosphor powder to the first excitation wavelength over a first band of emission wavelengths, the first band of emission wavelengths including a first emission wavelength;
(4) indicating on a chromaticity chart a first color corresponding to the first emission wavelength;
(5) measuring at a second reference wavelength an emission response of the second phosphor powder to a plurality of excitation wavelengths within a second band of excitation wavelengths;
(6) selecting a second excitation wavelength from the second band of excitation wavelengths based upon the emission response measured in step (5);
(7) measuring a spectral response of the second phosphor powder to the second excitation wavelength over a second band of emission wavelengths, the second band of emission wavelengths including a second emission wavelength;
(8) indicating on a chromaticity chart a second color corresponding to the second emission wavelength;
(9) drawing a line on the chromaticity chart from the indication of the first color to the indication of the second color;
and
(10) determining the mixing ratio of the first phosphor powder and the second phosphor powder such that an emitted color thereof lies on a line on the chromaticity chart in a region of white light;
(c) providing a light source of the first excitation wavelength;
and
(d) applying the phosphor mixture to the light source.

13 more elements

Dependencies are inferred from the claim text.

patentgrep

Loading patent…

Abstract

A method for manufacturing a white light source, the method comprising the steps of:

(a) synthesizing a first phosphor powder and a second phosphor powder;
(b) mixing the first phosphor powder and the second phosphor powder according to a mixing ratio into a phosphor mixture, the mixing ratio determined by the steps of:
(1) measuring at a first reference wavelength an emission response of the first phosphor powder to a plurality of excitation wavelengths within a first band of excitation wavelengths;
(2) selecting a first excitation wavelength from the first band of excitation wavelengths based upon the emission response measured in step (1);
(3) measuring a spectral response of the first phosphor powder to the first excitation wavelength over a first band of emission wavelengths, the first band of emission wavelengths including a first emission wavelength;
(4) indicating on a chromaticity chart a first color corresponding to the first emission wavelength;
(5) measuring at a second reference wavelength an emission response of the second phosphor powder to a plurality of excitation wavelengths within a second band of excitation wavelengths;
(6) selecting a second excitation wavelength from the second band of excitation wavelengths based upon the emission response measured in step (5);
(7) measuring a spectral response of the second phosphor powder to the second excitation wavelength over a second band of emission wavelengths, the second band of emission wavelengths including a second emission wavelength;
(8) indicating on a chromaticity chart a second color corresponding to the second emission wavelength;
(9) drawing a line on the chromaticity chart from the indication of the first color to the indication of the second color;
and
(10) determining the mixing ratio of the first phosphor powder and the second phosphor powder such that an emitted color thereof lies on a line on the chromaticity chart in a region of white light;
(c) providing a light source of the first excitation wavelength;
and
(d) applying the phosphor mixture to the light source.

13 more elements