真空荧光显示器阴极灯丝的可靠性设计分析

Reliability design and analysis of cathode filament for vacuum fluorescent display

摘要:

为了确保真空荧光显示器(vacuum fluorescent display, VFD)阴极灯丝发射电子的稳定性,建立了灯丝变形问题的简化模型,推导了在冲击载荷作用下挠度和最大应力的解析公式,通过与有限元计算结果对比证实了解析解的可靠性,并提出了灯丝关于结构参数可靠性设计的判据。结果表明：解析解准确地描述不同冲击载荷下VFD阴极灯丝的变形问题；最大挠度与最大应力发生在冲击载荷和VFD灯丝中点重合的位置,两者均随着灯丝加长或变细而增大,且直径对这一增大幅度的影响更明显；VFD灯丝关于长度和直径的设计判据精准高效、简单可行。研究结果可为真空荧光显示器灯丝的可靠性设计给予定性支持,并为改进灯丝性能提供了结构参数优化设计的定量依据。

Abstract:

In order to ensure the electron emission stability from cathode filament of vacuum fluorescent display (VFD), the simplified model of filament deformation was established, the analytical formulas of deflection and maximum stress under an impact load were deduced, and the reliability of the analytical solution was verified by comparing with the finite element results. The criterion of structural parameter design was proposed. The results show that the analytical formula accurately describes the mechanical properties of VFD cathode filament under different impact loads. The maximum deflection and the maximum stress occur at the position where the impact load and the midpoint of VFD filament coincide, both of them increase with the filament lengthening or thinning, and the diameter has more obvious effect on the increase. The design criterion related to length and diameter of VFD filament is accurate, efficient, simple and feasible. The research results can offer qualitative support to the reliability design of VFD filament, and provide quantitative basis for the optimization design of structural parameters to improve its performance.