Study on comparing the signal processing of a linear CCD with a PSD for displacement measurement

The main concern for a displacement measurement is the performance of a sensor such as speed, resolution, accuracy and so on. The sensors mainly used for displacement measurement are a linear CCD (charge coupled device) and a PSD (position sensitive detection) as a noncontact type. Their structures are different very much, which means that the signal processing of both sensors should be applied in different ways. In the case of CCD, there are some limits in resolution and speed because of its structure, and it needs a complex image processing algorithm. Also, PSD has some disadvantages like sensitivity to environmental lights and nonlinearities. Like this, a linear CCD and PSD have their own characteristics which need different signal processing and if we know them well, we can choose one of the two sensors properly in some applications according to our purposes. This paper determines which one is superior to the other between the two sensors in terms of accuracy, resolution, measurement speed, signal to noise ratio.