Studies On The Chrominance Of LED Based Light Source With Daylight Spectrum

Daylight spectrum is a natural spectrum which people have adapted for generations, and itis suitable to the needs of human visual function. Now, the spectrum of the xenon lamp,bromine tungsten lamp and designed is close to the spectrum of the daylight, but there stillare some drawbacks. With the development of the technology of making semiconductorlight-emitting materials, the color of the monochromatic LED becomes much richer.Monochromatic LED has many advantages, such as the half-wave width is narrow, themonochromatic is good, the luminous intensity is stable, etc. So, it is possible to simulate thelight mixed with arbitrary spectrum.Based on the spectral characteristics of the monochromatic LED, then proposed a methodto produce a daylight by a reasonable arrangement of the monochromatic LED. The colortemperature of daylight source, the brightness and the chromaticity coordinates have beencalculated, and the system of the monochromatic LED daylight source was studied. The mainwork includes:The monochrome LED witch wavelength range is between380nm-780nm has beeninvestigated. The spectral data of monochromatic LED is summarized.In the part of fitting thespectrum of monochrome LED, a spectra test of monochromatic LED (blue) has been madeto analysis the characteristics of monochrome LED spectrum. The classical model-Gaussianmodel and Lorentz model is used to fit the spectrum of monochromatic LED. A mathematicalmodel is proposed to characterize the spectrum of monochromatic LED, which based on theenergy distribution of quantum wells. The measured spectral data of monochromatic LED isfitted, the experimental results show that this model has a better fit than the Gaussian modelLorentz model.Using the proposed mathematical model to fit the researched monochrome LED, the resultsshow that the model not only for the blue LED has a good fit degree, but also for otherasymmetric radiation energy LED light color distribution data have a good fit degree. Themonochrome LED spectral fitting model proposed in this paper is universal, so as to establish a monochrome LED fitting database.Using the proposed mathematical model to introduce the intervals of peak fitting andunequal spacing of peak fitting, and make a comparison between them.According to thedifferent refractive indexes of the different LED, a LED light emitting array is designed. Theoptical simulation software Tracepro is introduced to simulate the mixed light source. A LEDdimming control circuit is designed.