Design Of A Zoom System For Dentistry And A Rear Projection Optical System

There are extensive applications of optical systems in many important fields. Zoom system, which was invented in the middle of last century, after more than a half century's development, has been much more adaptive than fixed-focus system, and applied widely in many fields of society. Rear projection technology, which is only as old as nearly 20 years, due to the never-ending perfection of design, has become more and more popular as well in our daily life. All of these rely on the perfection of optical design theory and the improvement of manufactural skills.The main point of the dissertation is to design a zoom system for dentistry and a rear projection system. At the beginning, the structures of the two types of optical systems have been reviewed, and also their history trend of development. Then, their design theories and methods are researched, in order to complete the design using optical sofeware Code V.According to user's demand, a zoom system applying for dentistry is designed. The entire system includes two lenses with different zoom ratios, which are combined as a centered optical system by a half transparent and half reflecting mirror. Both general image and special detail can be observed. The relation between system parameters and image quality is studied, to improve the image quality. Also, the relation between reduction ratio and depth of field is analysed, and how to lengthen the depth of field and improve the system is discussed. After the design is finished, a graph about zooming movement has been made, from which the mechanical design will benefit later.After learning the design theory of rear projection system, a camera lens mold is used to design the projection system. Then set a plat mirror in front of the system with a certain angle. The whole system becomes a simple mold of rear projection system. Try to change special restrains, turn the plat mirror into a spherical one, and finally a non-spherical one. The non-sphere theory in imaging is studied in the dissertation, and some useful trials are also mentioned.