ABSTRACT
Visible-light-emitting diodes (VLED) usage has accelerated at differing levels depending on the country doing the design and the car or truck model. Solid state lighting using VLEDs is better for the environment. Die size determines the current capability and can be increased by how well the packaged VLED and overall system is thermally managed. Phosphor has become the industry standard for white light conversion from a blue or UV LED. Photometry is the measurement of visible light based on the response of the average human observer. Colors are the wavelength, and the brightness of that color is the intensity of light. The optical radiation emitted by a source is read by the combination of an integrating sphere and a computerized spectroradiometer system. Luminous flux is measured by placing a spectroradiometer at the exit port of an integrating sphere and measuring the visible light energy per second emitted by the source.
