LEDs of different temperatures of white color

The color of white light can be very diverse, from warm white (for example, color temperature Tc=2700K or Tc=3000K) to cold (for example, Tc=6500K).

During LED production, the production dispersion of its usage parameters occur. Dispersion of light color is crucial. Due to the present LED manufacturing technology the execution of diodes producing the same ideal light color is not possible. In case of numerous LED usage at the same time, for example, in case of LED modules or LED housings type “wall washer” or LED matrix, the difference of light colors may be visible. Wherefore, manufacturers produce LED due to the dispersion of coordinates tristimulus within the same nomical color of the light, creating so called bins. In such case, the law developed by Mac Adam in 1937 is used. Mac Adam has defined fields in the chart of chromaticity (colors triangle) named ellipses of Mac Adam. Lighting colors, which are situated in the field of this ellipse, depending on its measurements are more or less distinguished by the human eye. Manufacturers use it while producing shining diodes in such a way that light colors are situated in the indicated fields (ellipses) in the chromaticity chart. Diodes are produced to the so called bins.

Bin is a definition related to LED division due to the color of produced light source. Depending on the selection process as well as tolerance range choosen by the manufacturer, LED diodes are situated in separate categories (bins).

Each bin includes diodes producing the light of the same color and is indicated with the specific code. LED producing white color light are being sorted on the basis of the color temperature of the light. LED producing colorful light are being sorted on the basis of the dominated wavelength.

The biggest manufacturers increase their criterions for division of bins, mainly in case of LED producing white light. Exacerbation is based on the decrease of tolerance range of color temperatures or the wavelength dominating highly lower than of ranges obtained from Mac Adam’s law. Exacerbated sorting criterions and tolerance range have allowed to improve LED quality.