A Study On Adaptive LED Office Lighting Environment For Young VDT Operators

The research belongs to funded project(CXTDX201601005)supported by funds for innovation team building,Chongqing Municipal Education Commission.And it is also an extended research of National Natural Science Found Project“Research on dynamic light environment of plant based on light exposure safety prediction”(51378518)and the open topics“Study on the environment of factory assembly line with day and night adaptability”(2016ZA02)funded by State Key Laboratory of Subtropical Building Science.In recent years,VDT work has become the most representative working form of modern office work.With science and technology developing rapidly,the young VDT operators' dream to have a more personalized and humanized office lighting system yearning has been gradually become possible.The young VDT operators' adaptabilities to office lighting environment have common features and individual differences.This study takes the young VDT operators' preference for office lighting environment as the starting point,discusses the common features and individual differences of the operators' adaptability.This research is divided into three parts: theoretical research,investigation research and experimental research.In the part of theoretical research,through a large number of literature studies,the study finds that the young VDT operators show the best adaptability to the office lighting environment with horizontal illumination 500 lx,vertical illumination 300 lx and color temperature 3800K(If the light source is LED,the color temperature is better not to exceed 4000K).In the part of investigation research,through a questionnaire survey for the young VDT operators who often need use computer in their work in large and medium-sized cities in China,the study finds that factors such as screen size,mood,season and fatigue degree may affect the young VDT operators' adaptabilities to office lighting environment.In the part of experimental research,through two laboratory simulation experiments——the preference color temperature selection experiment under the LED light source and the all day time interval cooperative dimming experiment based on preference under the LED light source,the study finds that the lighting environment with horizontal illumination 500 lx,vertical illuminance 300 lx and color temperature 3800 K is the most adaptive constant office lighting environment to the young VDT operators under specification.But for the computer office of the young VDT operators,the horizontal illuminance value of 500 lx in the standard is low while 750 lx ought to be a more appropriate value of horizontal illuminance.Furthermore,the study also find that the young VDT operators show the worst adaptability for the non preference dynamic light environment.As for the constant light environment and dynamic light environment adaptability preference both have their own advantages.Attention,memory,contrast sensitivity,distant vision and near vision are better under the constant light environment.Evaluation of subjective symptoms and color vision are better under the preference dynamic light environmentFinally,through the comprehensive analysis of the above three parts of research results,the study draws some conclusions and prospects the follow-up researches.So that the study can provide reasonable suggestions for the design on adaptive LED office lighting environment for young VDT operators and the further research work on the related areas,and it can play a positive role in promoting the development of office lighting design towards a more personalized and humanized direction in the future.