A 7.4 kHz, 20-bit image encoder with a CMOS linear image sensor

This paper presents a unique CMOS linear image sensor for reading the pseudo-random code on the slit disc, focusing on the two aspects of low noise and readout rate. Each pixel is equipped with an exclusive integral readout circuit, and the shape of the pixel also matches the slit disc, making the output signal consistent by up to 99%. After subdivision, the absolute angle data can be captured with an angular resolution of 16 bits and a maximum speed of 7.4 kHz. In addition, decoding and subdivision methods are suitable for high-speed, inexpensive encoder systems.