真空荧光显示器灯丝温度特性的研究

Investigation on Filament Temperature Characteristic for Vacuum Fluorescent Display

为了对真空荧光显示器(VFD)灯丝温度在排气、激活和老化等工艺过程中进行有效的参数控制和最优选择以提高产品合格率,基于实测每个步长电压下的灯丝电流数据,通过建立灯丝温度特性的基本算法模型,采用最小二乘法得到了灯丝电阻率随灯丝温度变化的公式,利用牛顿迭代法确定了每步电压下的灯丝温度.最终实现了只需根据每步电压便可完成灯丝温度特性的计算与分析,并自行开发了便于工程应用的计算软件.研究结果表明,灯丝电阻率和灯丝温度符合线性关系,灯丝温度分别随灯丝电压、电流变化的Weibull拟合公式很精确,灯丝电流计算值与实验值相比误差很小.提出的理论模型、实验方案和计算方法为VFD灯丝温度特性规范设计提供了理论依据和技术参考.

In order to carry out effective parameter control and optimal selection for filament temperature of Vacuum Fluorescent Display （VFD） during the process of exhausting, activating and aging, and improve product qualification rate, the data of filament current were measured at each step voltage. The calculation and analysis on filament temperature characteristic were achieved by applying fundamental algorithm model for establishing filament temperature characteristic, least square method for fitting the linear relationship between filament temperature and filament resistivity, and Newton iterative method for calculating filament temperature with each voltage. Furthermore, the software was self-developed for engineering application. Research results show that filament resistivity has a linear relation with filament temperature; the changes between filament temperature and filament voltage or filament current are accurately fitted by Weibull distribution, and the calculated ones have small errors and high accuracy comparing with the measured filament current. The proposed theoretical model, test planning and calculation method can provide significant theoretical foundation and technical guidance for VFD standard design on filament temperature characteristic.