moving object moving object photoelectric light j photoelectric sensor source] sensor Method A Method B

B. Lateral Effect Position Sensitive Detector (PSD) The lateral-effect position sensitive detector (PSD) is widely used for high preci­ sion position measurement. This type o f position detector has some prominent advantages compared wi th other optical and photoelectric sensors. I t can measure displacement in a spatially continuous manner, unlike other types o f large sensi­ tive area detectors such as charge-coupled devices (CCDs). I t provides either onedimensional or two-dimensional, highly linear, spatially continuous, fast, real time position/displacement measurement. Submicron resolution over a large working range can be obtained. These advantages make this type o f position sensor very suitable for mechatronics applications that require very high precision posi­ tion/displacement measurement over a large working space.