Developmental investigation on Maxwellian optics system using personal computer.

用于呈现视觉刺激的Maxwell-view光学系统是一种设备，通过该设备，观察者可以提高到达观察者视网膜的无色/彩色光的质量。经典的麦克斯韦光学在使用中存在的问题包括：精确的光控制困难，机械快门操作的噪声，刺激模式变化和时间过程的手动操作。在目前的发展研究中，通过引入基于个人计算机系统的软件程序和数字输入/输出控制接口电路来避免这些困难。(1)通过引入基于反馈回路的程序控制，在亮度计和个人计算机之间使用IF.THEN程序来实现精确的光控制。(2)波长设置和读数可由基于脉冲电机的精密控制器完成，该控制器与PC机相连，在计算机控制下进行。这种单色仪扫描仪的最大扫描速度在380-780 nm的大范围可见光范围内最高可达17 nm/秒，因此扫描可见光谱只需要24秒。(3)采用PC机控制的无噪声液晶快门，可通过PC机的数字接口精确控制持续时间。这使得在没有机械快门噪声的情况下进行色调替换、短脉冲光呈现、视觉诱发电位记录等实验成为可能。基于个人计算机的光学系统可以用相对简单和廉价的低成本个人计算机来解决这些问题。

The Maxwellian-view optical system for presenting a visual stimulus is an apparatus by which an observer can increase the quality of achromatic/chromatic light reaching the retina of an observer. Problems involved in using the classical Maxwellian optics include difficulty of precise light control, noise from mechanical shutter operation, and manual operation of stimulus pattern change and time course.In the present developmental investigation, these difficulties have been avoided by introducing software program based on personal computer system coupled with digital input/ output controlling interface circuits.(1)Precise light control was performed by introducing feedback-loop-based program control using IF..THEN procedures between luminance meter and personal computer. (2) Wavelength settings and readout can be done by pulse-motor-based precise controller which was connected with personal computer and was under computer controls. The maximum scanning speed for this monochromator scanner is as fast as 17 nm/sec within a wide range of visible spectrum between 380 and 780 nm, thus/only 24 sec is necessary for scanning the visible spectrum. (3) By using personal-computer-controlled noise-free liquid crystal shutter, the duration time can be precisely controllable by digital interfaces of the personal computer. This enabled the experiments such as hue-substitution, brief pulse light presentation, visual evoked potential recording without mechanical shutter noise. A persinal-computer-based optical system could solve these problems with relatively easy and inexpensive using low-cost personal computer.