展陈照明中的光辐照会对光敏文物材料造成褪色、 老化等辐照损伤, 尤其对字画、 染色丝绸、 彩绘陶器等颜色非常丰富的光敏性文物损伤巨大, 不利文物安全。 国内外展陈照明标准为减少对文物的辐照损伤, 严格控制照明标准水平, 如光敏文物的照度仅50lx, 不利于观众更加细致的欣赏这类文物。 随着半导体固态光源Light emitting diode （LED）技术的发展, 其光谱中不含对文物损伤最大的紫外和红外波段, 与传统光源相比具有天然优势, 能够实现在相同照度条件下对文物产生更小的伤害。 并使得在不增加对文物损伤的前提下, 提高照明环境亮度从而改善照明环境水平成为可能。 然而, 即使仅有可见光光谱, 可见光光子能量仍会对材料造成不可逆的损伤。 而LED光源光谱多样, 甚至有较大差异, 在LED光源大规模进入文物展陈照明领域时, 如何科学指导博物馆文物照明光源的研发与应用, 是改善文物展陈照明环境的关键问题。 该研究对常见光敏文物材料进行可见光连续辐照下表面颜色属性变化的测量研究, 通过制备常用的国画颜料和植物染料样品（国画颜料主要有硃磦、 赭石、 三青、 花青、 胭脂、 炭黑、 曙红、 酞青蓝; 植物染料主要有茜草、 黄檗、 栀子、 靛蓝、 槐米、 苏木、 紫草）, 利用不同波长单色光和不同色温复合光的LED作为光源, 对样品进行大剂量连续辐照实验。 辐照过程中, 定期测量材料表面颜色的色度学参数L*, a*, b*, 以CIE 1976 L*a*b*均匀色空间色差计算方法, 求算出不同光谱的LED光源辐照后样品的色差变化。 再分别从辐射度学和光度学出发, 对比分析具有不同光谱的LED光源对国画颜料和植物染料的长期辐照影响。 实验结果表明: 不论从辐射度学还是光度学角度分析, 相同辐照剂量或曝光量照射后, 单色光中短波长的蓝光辐照导致样品的色差最大, 绿光次之, 红光最小; 而在复合光中, 高色温LED光源由于蓝光占比较大, 对样品的辐照影响明显高于低色温LED光源; 目前利用光照度对博物馆照明环境进行评价时, 由于蓝光对应的人眼视见函数数值较低, 与辐射照度评价相比, 蓝光辐照对文物的影响会被进一步低估; 相同光照条件下, 植物染料的老化程度总体高于国画颜料; 黄色系的植物染料（黄檗、 槐米）和红色系的国画颜料（硃砂、 曙红）在光照过程中更易老化。 因此, 博物馆展陈照明的LED光源应严格控制蓝光成分, 采用低色温的光源更有助于对文物的保护。 在今后制定文物展陈照明标准时, 应对光源的蓝光占比进行限制。 此外, 对于黄色系、 红色系等光敏文物进行照明时, 相应的展陈照明标准应更为严格。 该研究对于LED光源在博物馆照明更加合理的研发与应用, 以及未来博物馆展陈照明标准改进及照明条件改善具有重要指导意义。

Light irradiation of display lighting can cause fading, aging and other radiation damage to photosensitive cultural relics, especially to calligraphy and painting, dyed silk, painted pottery and other cultural relics that are responsive to light. In order to reduce the radiation damage to cultural relics, the level of illumination is strictly controlled by standards at home and abroad. For example, the illumination level of cultural relics responsive to light is only 50 lx. This is very detrimental for the audience to appreciate those precious works of art. With the development of semiconductor solid-state light source Light emitting diode (LED) technology, the spectrum of semiconductor solid-state light source does not contain ultraviolet and infrared bands, which are the most harmful to cultural relics. So it has a natural advantage over traditional light source to achieve less damage to cultural relics under the same illumination condition, making it possible to improve the brightness of the lighting environment and thereby improving the level of the lighting environment without increasing the damage to the cultural relics. However, even if there is only visible light spectrum, the visible light photon energy will still cause irreversible damage to the material of culture relics. Nevertheless, the spectrum of the LED light source is diverse, leading to the fact that the damage will even be great different. When LED light source enters the field of exhibition lighting, how to scientifically guide the research, development and application of museum heritage lighting source is the key to improving the lighting environment of cultural relic exhibition. In this paper, the changes of surface color properties of common photosensitive cultural relic materials under continuous visible light irradiation were measured and studied. Through the samples preparation of traditional Chinese painting pigments and plant dyestuffs (Chinese painting pigments are mainly cinnabar, ochre, azurite, gallocyanine, rouge, charcoal black, eosine, phthalo blue; plant dyes are mainly madder, amur corktree, cape jasmine, indigo blue, Sophora japonica, sappanwood, puccoon), using monochromatic lights with different wavelengths and LED with different color temperature as light sources, a large dose continuous irradiation experiment was carried out on the samples. In the course of irradiation, the colorimetric parameters L*, a*, b* of the surface color for the materials were measured periodically, and the color differences of samples were calculated with CIE 1976 L*, a*, b* uniform color space chromatic difference calculation method, after irradiation by LED light sources with different spectra. The effects of long-term irradiation caused by LED light sources with different spectra for traditional Chinese painting pigments and plant dyes were analyzed respectively from radiometry and photometry. The experimental results showed that after the same irradiation or exposure, short wavelength blue light causes the largest color difference on the samples, the green light is the second, and the red light is the least, whether from the perspective of radiometry or photometry. In composite light experiments, because of the larger proportion of blue light, the effect of high color temperature LED light source for irradiation impact is obviously higher than that of low color temperature LED light source. At present, when the illumination degree is used to evaluate the illumination environment of the museum, compared with the radiation illumination evaluation, the effect of blue light irradiation on the cultural relics is further underestimated because of the low value of the human visual acuity function corresponding to the blue light. Under the same illumination condition, the aging degree of plant dyestuffs is higher than that of traditional Chinese painting pigments, and the yellow plant dyestuffs (amur corktree, sophora japonica) as well as red color traditional Chinese painting pigments (cinnabar, eosine) are more apt to aging in the process of irradiation. Therefore, the LED light source for museum display lighting should strictly control the composition of blue light, and the use of low color temperature light source is more conductive to the protection of cultural relics. In the future, when formulating the lighting standards for cultural relics exhibition and display, the proportion of blue light should be restricted. In addition, for the yellow, red and other cultural relics responsive to light, the corresponding display lighting standards should be more stringent. This study is of great significance to the development and application of LED light source in museum lighting, as well as the improvement of lighting standards and lighting conditions in the future.