Momentary adjusting methods for simulating the color temperature, hues and brightness of daylight illumination with RGB LEDs for indoor lighting

Abstract

Methods for simulating the color temperature, hue and brightness of daylight illumination for indoor lighting simply by adjusting the intensity of red, green, and blue light emitting diodes are proposed. We obtain uniform color mixing with a light box by adjusting the ratios between the intensities of red, green and blue LEDs. The intensity can be found by measuring the CIE chromaticity coordinates (x, y) and the luminance Y of the daylight with a chroma meter. After the chromaticity coordinates (x, y) and the luminance Y are found, the tristimulus values can be calculated and then transferred to red, green, and blue primaries by linear transformation. With the correct ratio of red, green, and blue intensities, the color temperature, hues and brightness of daylight can be rebuilt by red, green, and blue light emitting diodes.

LED diffused transmission freeform surface design for uniform illumination

“…Moreno had put forward an optical design method of direct lighting [6,7]. Compared with direct lighting methods, redistribution of emitted light by catadioptric is an effective way to improve illuminance performance [8][9][10][11][12][13]. However, the traditional reflector or refractive lens has a high requirement for the processing precision and the material.…”

The Design of Diffuse Reflective Free-Form Surface for Indirect Illumination With High Efficiency and Uniformity

“…In addition to the direct illumination method, indirect illumination could also be applied to the design of secondary optics. In order to overcome the discomfort glare effect and the over-exposure problem, Tsuei [18]- [20] developed a method for making the illumination more uniform in an indoor lighting environment and weakening the glare effect by using diffuse reflector. Zhu [21], [22] presented a design method of a diffuse reflection free-form surface by solving a series of nonlinear algebraic equations which are coming from a mathematical model.…”

Design of Diffuse Reflection Freeform Surface for Uniform Illumination

“…Hence, indirect illumination with diffusers is gradually adopted to overcome these problems above. Tsuei et al [22]- [24] developed a method for making the illumination more uniform in an indoor lighting environment and decaying the glare effect with LEDs by utilizing diffusers. Voigt et al [25] presented a relatively compact, large-area uniform source employing plate diffusers and a patterned mask.…”