White light emitter

Abstract

This invention relates to a white light emitting device which utilizes a blue or blue-green LED to excite two types of phosphors with the emitted wavelength sphere of 450 to 500nm to let them emit a yellow fluorescent light with the main wavelength sphere of 520 to 580nm and a red fluorescent light of 580 to 640nm. After matching the mixed proportion of the phosphor and the package material and packaging it, a white light emitting device with good emitting property is got. The blue light needed for matching in the phosphor used in a white light emitting device can be regulated to rather long wavelength and the light output is higher than the blue light with short wavelength, when excited by blue or blue-green light.

Description

technical field [0001] The invention relates to a high-brightness white light semiconductor light-emitting device, in particular to a technique for making a high-brightness white light light-emitting device by using blue or blue-green light-emitting diodes combined with two fluorescent powders that can emit yellow fluorescence and red fluorescence respectively. Background technique [0002] White light is mixed light of various colors, which can be perceived as white light by human eyes, and includes at least mixed light of more than two wavelengths. For example, when the human eye is stimulated by red, blue, and green light at the same time, or when it is stimulated by blue light and yellow light at the same time, it can be perceived as white light. Therefore, a semiconductor light emitting device capable of emitting white light can be manufactured according to this principle. There are mainly five known manufacturing methods of white light semiconductor light emitting dev...

AI Technical Summary

Problems solved by technology

[0008] The common disadvantage of the aforementioned first and second methods is that when one of the light-emitting diodes of different light colors breaks down, normal white light cannot be obtained.

In addition, since the forward bias voltage of each light-emitting diode is different, it is necessary to install multiple sets of control circuits, resulting in high cost, which are all unfavorable factors in practical applications.

[0009] The second and third methods both use the principle of complementary colors to produce white light, and the continuity of the spectral wavelength distribution is not as good as that of real sunlight. Therefore, after the color light is mixed, there will be color inhomogeneity in the visible light spectrum range (400nm ~ 700nm), resulting in low color saturation

These factors greatly limit the types of fluorescent materials that are applicable, making it difficult to select fluorescent materials

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