如何使用

该测试卡用来检测书的可读性、细度和波形畸变。字母有各种尺寸，从800封/满屏到80000信/满屏显示。在线路板的最上部的字母适用于检查是否有拖影或条纹。此外，可以通过观察五颜六色的字母来确定亮度信号的相位偏移情况。

How to use

The image is useful to check readability of letters, fineness and waveform distortion. 

There are various sizes of letters, from 800letters/1screenful to 80,000letters/1screenful. The letters in uppermost part of the board are suitable for checking if there is smear or streaking. Also if you focus on colorful letters, you can find conditions of phase shifting of brightness signal.