CRT与LCD技术的视觉刺激显示性能评价

为了定量评价两种技术在视觉研究实验中的适用性,本文根据文献分析和视觉研究需求设计了显示器性能测试系统与测试流程,对一台阴极射线管(CRT)显示器和两台通用液晶显示器作为视觉刺激显示设备的关键性能进行测试。结合心理物理学理论,特别是韦伯定律,详细地分析和比较了各项测试结果。实验结果显示所有的显示器有不同的Gamma特性,需要进行相应的Gamma校正之后才能线性呈现图像的灰度级;CRT显示器在响应时间上具有绝对优势,但屏幕空间均匀性和独立性较差;相比于CRT显示器,LCD显示器具有较高的亮度和较好的空间均匀性和独立性,但是响应时间偏慢,而且相邻两帧图像之间独立性较差。这些测试结果表明,CRT显示器仍然是高动态特性视觉刺激显示的首选,而LCD显示器可以用于呈现对空间亮度一致性和空间的独立性要求高,但对响应速度要求不高的视觉刺激。

Assessment of CRT and LCD technologies for the presentation of visual stimuli

To quantitatively evaluate the suitability of LCD for vision research experiments, this study developed a display performance testing system and process inspired by relevant literature with consideration of visual research requirements, and measured the key performance of a cathode ray tube (CRT) display and two general-purpose liquid crystal displays (LCDs). We compared these displays in performance measurements and analyzed the data regarding psychophysical theories, the Weber's Law in particular. Experimental results demonstrated that these displays show different Gamma properties, required Gamma-correction to linearize the gray levels for visual stimulus presentation. The CRT display had the absolute advantage in terms of response time and temporal independence, but it was inferior to the LCDs in spatial uniformity and spatial independence. In contrast, the LCD monitors had higher brightness and better spatial uniformity and spatial independence, but their response time was longer and their adjacent frames were short of independence. These findings suggest that CRT monitors still be the preferred option for presenting dynamic stimuli, whereas the LCD monitors best be used for presenting static stimuli demanding spatial independence and spatial uniformity.