Study On Optical System Of Phase-Shift Profilometry Based On Dmd

Non-contact optical three-dimensional (3D) sensings with structured illumination such as Phase-Measuring Profilometry(PMP), Fourier Transformation Profilometry(FTP), and Modulation Measuring Profilometry(MMP) have received great attention in recent years. Digital Micromirror Device(DMD) and Digital Light Processor(DLP) used as a new type of spatial light modulator have play a wide foreground in optical information processing and structured illumination three-dimensional sensing.Compared to the traditional sources, the LED has the irreplaceable advantages of high efficiency, no infrared irradiation, small size, low power consumption and long lifetime. But the layout and the luminance distribution of the LED are so different from the traditional sources that the conventional illumination systems are not directly suitable for the LED especially for the miniature style.In order to satisfy the requirement of measuring the small objects in industrial and research field,the thesis focuses on the study of DMD-based PMP which is used by LED as illumination source, fly-eye array as uniform device. The main results obtained can be summarized as follows:1 .The application of LED is expanded to a new field—3D profilometry. And the optical structure has been discussed in this field.2.The main optical components and their characteristics of the DMD—based PMP have been studied. The contrast and the its relation with illumination angle has been presented.3.A new illumination optical structure is introduced. This structure is the critical illumination structure composed of LED as light source, fly-eye arrays as uniform device and DMD as SLM.4.A miniature PMP system has been designed, assembled and tested.