1/f fluctuation control of illuminance for comfortable luminous environments

In order to produce a comfortable luminous environment, 1/f fluctuation control of illuminance is proposed. It is shown that natural light which is comfortable to humans, such as sunlight streaming through leaves toward the ground, has 1/f fluctuation characteristics. On the other hand, artificial lights such as fluorescent lamps have near white-noise characteristics at frequencies below 10 Hz. It is also shown that the same fluctuation of natural light can be easily reproduced artificially by fluctuating the pulse width of the inverter output voltage. It is expected that 1/f fluctuation control of light can be applied to relaxation rooms in offices, hospitals, or schools to produce comfortable and relaxing environments for humans.<>