LED灯丝筛选方法研究

从商业途径获得的LED灯丝相互之间总光通量的偏差达到7%,电压偏差高达0.6%。若灯丝不经过筛选直接用来制作标准灯,将达不到预期的光强空间分布,且发光稳定性降低,有效寿命减小。实验分析了LED灯丝在低驱动电流与额定驱动电流下电压、光通量的相关性,提出了一种在低于灯丝额定驱动电流下对LED灯丝进行快速筛选的方法。实验表明:采用驱动电流5mA代替额定驱动电流10mA进行筛选,电压、光通量的最大偏差仅为0.09%和0.65%,能满足筛选需要。采用这种筛选方法及开发的专用软件使得筛选过程操作简单、结果判定准确可靠,且不会减小灯丝的有效寿命,为LED灯丝总光通量标准灯的研制奠定了良好的基础,还可推广应用到LED灯丝生产过程中的质量控制。

Research on Screening Methods of LED Filament

For a group of commercially obtained LED filaments without screening, the difference of total luminous flux is 7% and the difference of voltage is 0.6% . If the filament is directly used to make standard lamps without screening, it will not achieve the expected luminous intensity spatial distribution, the lamp stability and rated life will be reduced also. A screening method for LED filament has been prosed based on a series experiment, the voltage and luminous flux correlation between low driven current and rated driven current is analyzed. It shows that if 5 mA is used to instead of the rated driven current 10 mA for screening, the maximum deviations of voltage and luminous flux are 0.09% and 0.65%, respectively, which can meet the screening needs. The developed screening method and related software make the screening process fast to operate, accurate and reliable to determine the results, and does not reduce the rated life of the filament. This has laid a good foundation for the development of total luminous flux standard lamp using LED filament, that can also be applied to quality control in the production process of LED filament.