Subjective Evaluation Of VDT Reading Comfort In Library Lighting Environment

VDT(Visual Display Terminal)devices,such as computer display,mobile phone display and tablet computer display,have developed rapidly.Compared with traditional paper books,VDT reading has many outstanding advantages,and gradually become an important reading carrier tool in libraries.At present,"Building Lighting Design Standard" GB 50034-2013 does not put forward more requirements for VDT reading in the library.Providing a reading environment suitable for new VDT reading media is the future direction of Library lighting design.In the general reading room,the order of importance coefficient of different influencing factors is reading background brightness(0.24),reading tools(0.20),related color temperature(0.20),lighting mode(0.15),illumination(0.13),reading background reflectance(0.08),reading surface brightness has the greatest influence on reading comfort.The illumination has obvious influence on the comfort of VDT and paper-based reading;the color temperature of 4000k-5000 k light source can improve the comfort of VDT and paper-based reading at the same time;the desktop with lower reflection coefficient can improve the comfort of VDT and paper-based reading at the same time;the mixed lighting can improve the comfort of low illumination environment.VDT reading and paper book reading comfort;VDT reading and paper book reading comfort of the best illumination value inconsistent.In the electronic reading room,the order of importance coefficient of different influencing factors is brightness contrast(0.26),illumination(0.23),reading background brightness(0.22),correlation color temperature(0.20),screen brightness(0.07),reading background reflectance(0.01).When the desktop illumination is 300lx-550lx(the vertical screen center illumination is 163lx-300lx),the comfort of reading through a computer screen placed perpendicular to the desktop is best.When the color temperature of the light source is 4500 K and 6000 k,the comfort is relatively good.When the background reflection coefficient is low,it is most conducive to create more comfortable reading conditions for computer screen reading.According to the influence law and comfort prediction model,it can optimize the lighting design of Library in the new era,provide more comfortable lighting environment for VDT reading,and provide theoretical and data basis for multi-objective optimization of Library lighting quality.