DISPLACEMENT MEASURING SENSOR

摘要

PURPOSE: A displacement measuring sensor is provided to precisely measure a displacement of an object to be measured by using a confocal principle and astigmatism. CONSTITUTION: A displacement measuring sensor(100) includes a light source(10) for radiating light. An objective lens(20) is positioned at the front of the light source(10) to allow light radiated from the light source(10) to be focused on an object to be measured. A beam splitter(30) changes a path of light reflected from the object. A collecting lens is provided to collect light passing through the beam splitter(30). A quantity of light focused by the focusing lens is measured by means of a photo detector(60). A slit(50) is formed between the collecting lens and the photo detector(60) in such a manner that the slit(50) is positioned in the path of light. The collecting lens includes an astigmatism lens.