# The application of intermediate vision theory in night illumination

The application of the intermediate theory of lighting research in night lighting Chen Zhonglin, Yang Chunyu, He Zhengjun (Chengqing University School of Architecture and Urban Planning, Chongqing 400045) The results show that the impact of intermediate vision on night lighting effects must be considered when designing night lighting.

Seen from the Institute of Electric Light Sources, Fudan University, see the relative spectral power distribution; see the relative spectral power distribution of a typical 250W high pressure mercury lamp (transparent bulb lamp).

The luminous efficiency of the 400W standard high pressure sodium lamp and the 400W metal halide lamp (xenon lamp) calculated by equation (1) are shown in Table 1 under the different adaptation levels of the human eye; in Table 1, the 250W typical high pressure mercury lamp is also given. Luminous efficiency of the 180WS0X low pressure sodium lamp.

In night lighting, the range of adaptation of the human eye is often in the middle vision category, so the brightness value under bright visual conditions should not be used to evaluate the night lighting effect, especially the brightness value under the 2* field of view cannot be directly evaluated. That is, the brightness value measured by the luminance meter cannot be directly used for direct evaluation. Under intermediate vision conditions, the luminous efficiency of the light source is not only related to the spectral distribution of the light source, but also related to the adaptation level of the human eye. Therefore, in order to make the night illumination level more in line with the actual viewing effect, the night lighting energy saving requirement is met. It is necessary to reasonably determine the luminous efficiency of the light source at different levels of adaptation of the human eye.

1 Luminous efficiency of the light source When the accessory loss of the luminaire is not taken into account, the luminous efficiency of the light source can be calculated according to the spectral power distribution of the light source: Km* spectral optical performance maximum; 683 lm/W in bright vision, in dark vision 1 700 lm / W, determined by the corresponding calculation formula in the middle vision; YU) * spectral radiant flux of the light source, W / nm in the different adaptation levels of the human eye to calculate 400W standard high pressure sodium lamp and 400W metal halide lamp Luminous efficiency of light sources such as xenon lamps, spectral radiant fluxes of high pressure sodium lamps and metal halide lamps (as seen in Table 1, even at the different adaptation levels of the human eye, even the actual luminous efficiency of the same source is When the energy of the short-wavelength region of the visible light is small, the luminous efficiency of the light source will become smaller in the dark vision due to the influence of the Purkinye phenomenon, for example, the 180WSOX low-pressure sodium lamp emits light in dark vision. The efficiency is only 23% of the bright vision, and the luminous efficiency is 42 lm/W. On the contrary, when the energy of the short-wave region of the visible light is large, such as a metal halide with good color rendering. The light (xenon lamp) has more than double the luminous efficiency in dark vision than in the visual field. Therefore, in the night lighting design, it is better to use a light source that radiates more energy in the short-wave region of visible light, which is beneficial to obtain The actual large luminous efficiency achieves the purpose of saving electric energy.

Table 1 Luminous efficiency of different light sources at different adaptation levels of human eyes (lm/WO human eye adaptation level 1cd/m20.1cd/m2 dark visual naturalization coefficient, and relative spectral power distribution of K=S(X) source The spectral radiant flux of the light source (the measured values â€‹â€‹of the standard high-pressure sodium lamp and the xenon lamp are provided by the Fudan University Electric Light Source Institute); the color matching function in the color; the AX* wavelength interval, nm. The color in the CIE1931XYZ chromaticity system The product coordinates x and y are obtained by the following formula: metal halide lamp (400 W/typical fluorescent high-pressure mercury lamp (transparent bubble lamp) 52707572180W/SOX type low-pressure sodium lamp 18318176742, and the standard high-pressure sodium lamp is obtained by the formula (3). The chromaticity coordinates of the metal halide lamp (xenon lamp) are: 0.4350 for the standard high-pressure sodium lamp, golden color for the light color; the chromaticity coordinates of the metal halide lamp (xenon lamp) x= 0.4477, the color of the light is white Light yellow-green.

When the standard high-pressure sodium lamp and the metal halide lamp are respectively irradiated with the glazed glazed tile (from number 7) and the golden glazed tile (from number 17), it is possible to observe the color sensation effect of the surface color of the building facade. To be changed, such as improper handling, not only makes the brightness of the view smaller, but also causes the color to be distorted.

The chromaticity coordinates of the object color can be calculated from the three-color stimuli values â€‹â€‹X, Y, and Z calculated by the equal-wavelength interval method: 2 The color matching in the floodlighting and the floodlighting color visual effect of the building faÃ§ade are not only related to the color of the light source. However, it is also related to the color of the object, etc., so when designing the floodlighting, the light source color and the color of the object should be selected, so that it is possible to make the floodlighting effect better and achieve the purpose of lighting energy saving.

The chromaticity coordinates of the light source color can be calculated from the tristimulus values â€‹â€‹X, Y, Z and the spectral reflectance of the golden glazed tile (from number 17) is tested by the UV* type double beam ultraviolet visible spectrophotometer and is specified according to the national standard. The method is based on the observation condition of 0/d, and the spectral reflectance of the sample is measured.

When the meter is irradiated with a standard high-pressure sodium lamp and a metal halide lamp (xenon lamp) respectively, the chromaticity coordinates of the samples of 7 and 17 calculated by equation (4) are shown in Table 2. In Table 2, under the condition of standard illuminant D65 The object color is used as a standard. In addition, for comparison, the coordinates of the reflected light chromaticity of the high pressure mercury lamp (transparent bubble lamp) were calculated. It can be seen from Table 2 that in night illumination, the light color of the light source should be coordinated with the color of the object on the surface of the building, that is, the warm-toned building surface should be illuminated with warm light, and the cold-colored building surface should be illuminated with white light. When the warm color light high pressure sodium lamp is used to illuminate the golden yellow warm color glazed tiles, it is more coordinated, but when the rice is not coordinated by the high pressure mercury lamp, the surface color of the illuminated surface will be distorted, and the brightness of the reflected light will be greatly reduced, which wastes a lot. Electrical energy.

Table 2 Color change of samples when irradiated by different light sources Chromium coordinates Lighting source Milky white glazed tiles (7) Golden glazed tiles (17) Color Milky white gold Standard high pressure sodium lamp Gold yellow metal halide lamp (Xenon lamp) White yellowish green Yellow-green high-pressure mercury lamp (transparent blister) white gray white 83* object color measurement method Table 1.2 Typical transparent blister 250WA high-pressure mercury lamp is taken from "light source and illumination".

According to the brightness definition Wang Erzhen, and so on. Research and Improvement of Inductively Coupled Electrodeless Metal Halide Lamps J. Optoelectronic Technology, 2000 Upward J. Sakamoto Lighting Society, 2000, (Continued from page 16) in Table 3, with metal halide lamps ( The illumination condition of the xenon lamp is standard, and the relative reflection light brightness value is 1. Compared with other light sources, the smaller the relative reflection light brightness value, the less energy is saved. It can be seen from Table 3 that when the adaptation level of the human eye is <0.1 cd/m2, the brightness of the reflected light produced by the standard high-pressure sodium lamp and the high-pressure mercury lamp on both glazed tiles is less than that under the same power conditions. Metal halide lamps (xenon lamps) require the addition of power to make the viewing brightness comparable to that of metal halide lamps (xenon lamps). For example, for a high pressure mercury lamp, at a brightness level of 0.1 cd/m2, approximately one lamp power is required to be comparable to the viewing brightness level of the xenon lamp. When high-temperature sodium lamps are used to illuminate warm-colored glazed tiles, the colors are more matched, so the opaque glazed tiles (when the brightness is the same) are about 8%.

3 Summary In the night scene lighting, the use of intermediate vision theory to guide the floodlight design is more appropriate. Since the luminous efficiency of the light source changes under different human eye adaptation levels, that is, the luminous efficiency is different from the nominal bright vision, this phenomenon should be considered in the design of night lighting.

When the radiation spectrum of the light source contains more short-wave radiation, its luminous efficiency will increase as the level of adaptation of the human eye decreases. For example, metal halide lamps (xenon lamps) belong to this category, and their luminous efficiency is equivalent to that in dark vision. The visual time is about 2 times; due to the different spectral radiation power distribution, the luminous efficiency of some light sources fluctuates according to the level of human eye adaptation. For example, the dark vision of low-pressure sodium lamps has a luminous efficiency of about one-fifth of that of bright vision. The influence of the luminous efficiency of the light source on the level of adaptation of the human eye is not negligible in the design of night lighting.

In the night scene lighting, according to the color of the surface to be photographed, carefully select the appropriate light source as the light source for floodlighting, so that the surface color of the viewing can be natural and not distorted.

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