Let's first explore the optical rotary encoder.

让我们先来探索一下光学旋转编码器。

The key to the optical rotary encoder is that, as the wheel is rotated, the light emitted from  the IR LED is intermittently blocked by the encoding disk.

光学旋转编码器的关键在于，当轮子旋转时， 红外 LED 发出的光会被编码盘间歇性地阻挡。