投影用短弧超高压汞灯的调光特性研究

Research on the Dimming Characteristics of Short Arc Ultra-high Pressure Mercury Lamps for Projection Applications

测量了50Hz方波电源驱动的投影用250W短弧超高压汞灯(UHP)的电压、电流和功率,发现UHP总体上具有正的伏安特性,但调光至170W左右会出现负的伏安特性。另外用积分球和光谱仪系统测量了调光过程中UHP的光色电参数,结果表明,光通量随功率线性变化;调光后由于连续谱成分减少,导致光效、显色指数降低。利用546nm谱带宽度计算出UHP在43～258W功率范围内的汞蒸气压为15.3～25.8MPa。

The voltage,current and power are measured for short arc ultra-high pressure mercury lamps（UHP） with a rated power of 250W driven by 50Hz square waveform power supply.It is found that the curve slope of voltage-current characteristics is positive in most of the power range,and negative around 170W.The photometric,colorimetric and electric parameters are measured with an integrating sphere system coupled with a spectrometer in the UHP dimming experiments.The results show luminous flux increases with power linearly.The luminous efficacy and color rendering index（CRI） reduce with power reduction because of the decrease of spectral continuum.The mercury pressure are calculated with the full width at the half maximum of 546nm spectral band,which is 6.2~11.0nm.The pressure range from 15.3 to 25.8MPa corresponding to the UHP power from 43 to 258 Watts.