<title>High-performance encoder using the encoder model in a computer</title>

We propose the analysis system and technique for the optical encoder which does not require an analysis of the incoherent light and the diffraction. This system is composed of an LED, a rotation disk, a CCD camera to detect the light intensity for which to transmit a rotation disk, and the photo detector model in the computer, it receives the same output signal as the real encoder. The optical system of the encoder is optimally designed by this analysis system and technique, and then, this high resolution encoder which has the resolution of 100 times and more than the conventional impulse wave encoder is realized.