LED廣告看板的閃爍眩光與視覺舒適度評估

Investigation of Flicker Glare and Visual Comfort of LED Billboards

林孟緯(Meng-wei Lin)

指導教授 ： 陳怡君

國立中央大學/理學院/光電科學與工程學系/碩士(2014年)

摘要

由於LED在節約能源、環保以及動態顯示這幾點上的優勢，LED看板漸漸地取代了傳統廣告看板。然而，LED也有一些特性，像是光源面積小、高準直性以及藍光峰值，使得LED可能會對人眼感官造成不適甚至危害。此外，LED廣告看板常常在晚上使用過強亮度播放閃爍畫面，這些情況造成了不舒適眩光和光汙染的問題。
本論文探討LED看板在夜間住宅區造成的視覺不適程度，經由心理學實驗設計，以問卷方式獲得視覺舒適度之主觀評量。藉由調整閃爍頻率、看板亮度、看板視角和環境照度這四項因子來減少不舒適的感覺。實驗採用受試者內設計，以正交設計或拉丁方格結構排列實驗情境順序，並根據一般晚上的照明亮度和設備本身的條件限制來選擇變因水準。
實驗問卷獲得的分數，將其匯入統計軟體中分析。結果顯示，環境照度的改變沒有顯著差異，至於閃爍頻率、看板亮度和看板視角的改變都有達統計顯著水準，其中以看板亮度對舒適度的影響最顯著。另外，利用實驗的數據，建立了一個針對黑白畫面及一個針對彩色畫面的視覺舒適度模型，用來預估現有的LED看板顯示的視覺舒適度，並作為未來設計LED廣告看板操作條件的依據。

關鍵字

眩光 ； 光汙染 ； LED廣告看板的視覺舒適度 ； 視覺舒適度模型

並列摘要

Due to the advantages of LEDs in energy saving, eco-friendliness and dynamic display capability, traditional billboards are replaced by high brightness LED panels progressively. However, some distinct characteristics of LEDs, such as small source size, high directivity and the blue-peaked spectrum, make LEDs more probable to induce glare that disturbs human’s visual sensation. In addition, LED billboards usually display flashing advertisements with high brightness during the night; these conditions have led to concerns about discomfort glare and light pollution.
This study investigates the flicker glare and visual discomfort produced by the high brightness LED panel and aims to reduce discomfort feelings by modulating some important factors. Flicker frequency, luminance, visual angle and ambient illuminance are chosen as the independent variables. The experiment complies with the within-subjects design. The orthogonal design and Latin-square design are adopted to arrange the experimental conditions. Levels of these factors are selected according to the hardware specifications and common nighttime illumination conditions.
The results show that visual comfort is not affected by ambient illuminance, and significantly affected by flicker frequency, luminance, and visual angle. By analyzing the experimental results, we model the comfort ratings as functions of these factors and find the range of comfortable operating conditions.

並列關鍵字

Glare ； light pollution ； visual comfort of LED billboards ； model of visual comfort ratings

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