The Research Of Confocal Probe Based On Time Difference Measurement

Non-contact measurement probe has been developed very fast recently and it has been one of the most important research fields of the measurement technology. When measuring, non-contact probe doesn't touch the object, it can do the scanning rapidly. It is no friction that the non-contact probe is usually adapted to measure tiny fragile elements.A new non-contact optical probe was developed in this thesis. For extending the measurement scale, it measured the excursion between the surface and the equation point of the system based on the activity confocal principle. Based on the principle of Time Difference, the probe was simplified in its structure and become higher in its measurement precision.The primary contents of the paper are:1,The principle of optical probe was explained in this paper.2,Concretely introduced the mechanical and optical structure. Based on the X-Y adjustment, the Z direction adjustment was added, which makes the pinhole locate on the focus.3,The analog circuit was improved and sluggish comparator was quoted to compare the photo electricity and tuning fork's signal, which advanced the quality of the pulse. For analyzing the signal and calculating the Time Difference, a FPGA system, controlled by CPU, was set up in the digital circuit system.4,Introduced the experiment and the data analyses.5,Pointed some cruces that need to be improved of the confocal probe.