Study On The Influence Of Display Characteristics On Visual Comfort

In recent years,display devices have been greatly developed.As technology advances,visual health issues have attracted widespread attention.Therefore,exploring the impact of display technology on visual comfort has become an important issue.In this paper,a subjective questionnaire,objective physiological signal and eye movement signal measurements are combined to explore the effects of white level,dark level,color saturation and sharpness on visual comfort.When white level is 250 cd/m²,the visual comfort reaches its best.And when white level is between 130 cd/m²and 400 cd/m²,the visual comfort is acceptable.Beyond this range,the visual comfort is significantly reduced.At the same time,the blink frequency and average duration increase,and the average fixation duration decreases.Moreover,as the white level increases,the saccade amplitude,saccade velocity and scan path length increase accordingly.White level has no significant effects on percutaneous oxygen saturation(Sp O₂),galvanic skin response(GSR)and ECG signal.As the dark level decreases,the visual comfort increases.When the dark level is between 0.5 cd/m²and 4 cd/m²,the visual comfort is good.When the dark level is too high,the visual comfort is significantly reduced.Accordingly,the sympathetic nerve activity is significantly enhanced with increased LF power extracted from ECG signal.Additionally,as the the dark level increases,the saccade amplitude and saccade velocity also increase.However,dark level has no significant effects on blinking and fixation movements.From the perspective of visual comfort,higher color saturation doesn't mean the better visual comfort.In fact,the visual comfort reaches the highest at the medium-high level of color saturation.Moreover,the display quality and the viewing preference is the highest,and there is the most comfortable color experience at this color saturation.When the color saturation is too high,the visual comfort is reduced significantly with the inhibition of sympathetic and parasympathetic nerve activities.Thus,VLF power,SDNN,Alpha2,and Poincare?SD2 are reduced.Additionally,color saturation has no significant effects on blinking,fixation and saccade movements.As the sharpness increases,the visual comfort enhances,as well as the display quality and viewing preference.However,when the sharpness is relatively clear,subjects still feel comfortable.When the sharpness is medium or slightly lower,the visual comfort is reduced to the medium with the increase of pupil diameter and scan path length.Sharpness has no significant effects on Sp O₂,GSR and ECG indicators.The dissertation also explores the influence of time on visual fatigue evaluated by physiological signals before and after the four characteristics experiments(including white level,dark level,color saturation and sharpness).The results show that watching for forty minutes can bring obvious visual fatigue,resulting in the significant enhancement of sympathetic and parasympathetic activities.This is mainly reflected by the increase of Sp O₂,GSR,LF power,SDNN,RMSSD,Pioncare?SD1and Pioncare?SD2.There is no significant difference of physiological signal changes in different experimental settings.It means that the changes of physiological and eye movement parameters with different white level,dark level,color saturation and sharpness were caused by the change of visual comfort not by the visual fatigue.