Discussion on the safety and comfort of indoor lighting (two)

Of course, due to the brightness of the LED light source and lighting should be larger, do lighting design should pay special attention to control glare. Overall, the general lighting with white LED light source and lighting as long as the control of brightness, the blue light hazards in the safe range.

Non visual biological effects have not been clearly defined. The domestic and international research results show that the rhythm efficiency of the light source is directly proportional to the color temperature. In order to adapt to the natural rhythm of the human body, indoor lighting at night should use low color temperature light source, so as not to interfere with the body's sleep.

2 light quality

The comfort is determined by the light quality of the light source, which includes spectrum, color temperature, color rendering index, color tolerance, spatial color uniformity, glare index, strobe and color stability during life.

Over millions of years of evolution, the human eye has adapted to the continuous spectrum of nature, including the sun, the sky and the moon. Early artificial light sources are continuous spectrum, such as fire, candles and oil lamps, as well as the first generation of electric light source incandescent lamp and halogen tungsten lamp. With the gas discharge light source, high light efficiency of the fluorescent lamp spectra and different degrees of continuous high pressure sodium lamp and metal halide lamp appeared in people's life, but the use of less than 80 years is only a moment in human history, is not enough to affect the human eye vision from a genetic perspective. From the nature point of view, the continuous spectrum light source is always more natural choice in interior lighting.

At present, the mainstream of the LED is to use the blue chip to stimulate the yellow phosphor to produce white light, which belongs to the continuous spectrum in the visible region, but the green area is weak, and the red light area is less. Therefore, the spectral continuity of LED is stronger than that of fluorescent lamp, but no more than the ceramic metal halide lamp.

General LED red special display index (R9) requires only >0, can not be good to restore the deep red. So the Great Hall of the people with LED lighting transformation, red or tungsten halogen lamps for lighting. If you want to improve the deep red color, should be added in the LED packaging device red phosphor or red chip.

Indoor color rendering index is very important. If the halogen tungsten lamp and ceramic metal halide lamps, LED color rendering index needs to be more than 90, also need to increase the red phosphor or red chips. In the lifetime, the color temperature and color coordinates must be stable. It has a high demand on the aging resistance of LED phosphor and encapsulated silica gel. Spatial color uniformity is not a problem for the traditional light source, but the LED is more difficult to solve. Because the LED chip Blu ray still has about 1/3 will exit and mixed into the white light, and chip and phosphor spatial uniformity of light are different, this will cause the space color offset, color light or even white light around. This problem is more serious for intelligent lighting multi-color LED light fixtures, is the future need to focus on solving the problem. Lighting comfort also need to consider the stroboscopic problem. The current AC LED program is directly after the rectification of the city to point the LED lamp, there is a frequency of 100Hz strobe, and the current is not zero at LED. This requires increased capacitance filtering to reduce the depth of light fluctuations.

LED can conquer the world? I personally think that the future may be possible, especially after the emergence of a very complex spectrum of multi chip LED, but it is not possible. LED is the most energy efficient and environmentally friendly light source, but there are still some deficiencies in the quality of light needs to be strengthened. Different applications require different lighting solutions, using the most appropriate light source is a wise choice.