一种汽车前挡风玻璃防眩目试验研究

Experimental Research on an Automobile Front Windshield

针对眩目光线必须穿过前挡风玻璃的现实情况,把电控调光玻璃用作前挡风玻璃来适时降低透光率从而产生主动防眩目效果。试验所用材料和装置包括叠压超薄扭曲向列相液晶的调光玻璃、光敏传感器及其放大电路、防眩目控制电路、LED射灯及其调光电路、双踪示波器和照度计等。试验加载36 V逆变交流电驱动调光玻璃,液晶光阀在0.1 s内完全开启,玻璃透光率达到85%以上,驱动电压降低到18 V以下时液晶光阀在3.28 s内大幅关闭,玻璃透光率不低于70%,透光属性能够满足《机动车运行安全技术条件》中前风挡玻璃可见光透光率的规定。

In view of the fact that the blinding light must pass through the front windshield of automobile,the use of electrically controlled dimming glass as front windscreen can reduce transmittance at the right time and produce active anti-blinding effect.The materials and equipment used in the experiment includes superimposed ultrathin dimmer glass with twisted nematic liquid crystal,photosensitive sensors and amplifying circuits,anti-glare control circuits,LED spotlights and dimming circuits,dual trace oscilloscope and illuminometer,etc.When the glass is loaded 36 V inverter AC in the test,liquid crystal light valve can fully open within 0.1 s,and the glass transmittance is over 85%.Once the driving voltage drops below to 18 V,the valve would sharply close within 3.28 s,the glass transmittance is no less than 70%.The attribute of transmitting can meet the relevant provisions of transmittance of the windscreen in"motor vehicle safety technical conditions".