Relation between photometric characteristics of various VDTs and eye fatigue

本研究的目的是发展分析不同类型的VDR屏幕的以下特性的方法。1)VDT屏幕上字符的清晰度和抖动。2)在VDT屏幕上形成字母的亮度振荡。3)VDT屏幕上亮度频谱的时间过程。为了评估清晰度和抖动，测量系统开发了模块化面阵相机，控制器，视频监视器和个人计算机与CRT显示器。利用该系统对每一帧图像中的字符进行等亮度轮廓线的测量和分析，利用光纤器件、单色仪、光电倍增管、放大器和带模拟信号处理器的微机组成了一个测量系统，对不同型号的VDT进行了上述指标的测量。

The aim of the study was to develop the method to analyze the following characteristics of various type of VDRs' screen. 1)Sharpness and trembling of characters on a VDT screen. 2) Oscilation of the luminance forming letters on a VDT screen. 3) Time course of the spectrum of the luminance on a VDT screen. In order to evaluate the sharpness and trembling, measureing system was developed with modular area camera, controller, video monitor and personal computer with CRT display. By using this system the contour lines for equal luminance for a character of each frame were got and analyzed.In order to evaluate the cscillation and the time course of the spectrum, a measuring system was developed with optical fiber devices, monochrometer, photomultiplier, amplifier and personal computer with analoz signal processor.In the laboratory studies, the above indexes were measured for various VDT types from different makes.