Note: Large rotation measurement using half shaded square patterns

As the manufacturing technology ranging from micrometer to nanometer scale requires more planar motion devices, the demand for sensor measuring the planar motion is increasing. However, the previous sensors measuring the planar motion had a drawback in the measurement of rotation, especially regarding yaw angle. In this article, we present a novel method to measure large yaw angle with the planar position sensor based on the half shaded square patterns. The measuring range of the yaw angle is restricted to 45 deg. in this article, but it can be expanded to as much as 360 deg. with an improvement of the algorithm.