Real time measurement of an object’s small displacement by high speed video camera with moire pattern

The resolution of a high speed video camera is not so high as photographic film, therefore the measurement of a small shift, such as the vibration of object is sometimes impossible. Here we suggest to use a grids cover on the object and pass this image through another transparent grids to the camera. It will generate a moire fringe which produce the equivalent resolution thousand times than before. We also put a coordinate mask on the screen of the video TV, it is not only let us get a possibility to measure the small displacement of object which we cannot see by video camera before, but also gives us a real time 3 Dimensional data. The mask errors generated hr the curved screen are also discussed.