Design Of Lithography Lens And Study Of Micro-Projector Optical System Based On DLP Application

With the development of information technology and arrival of digital era, DLP(Digital Light Processing) technology as the world’s leading digital projection display technology, in addition to be widely used in familiar including the application scenarios of digital cinema, business, education, and home theater, now it has also infiltrated the industrial, personal consumer electronics products, medical, automotive, and many other fields. In recent years, applying the DLP technology in PCB lithography field gets high attention by people. Although the traditional PCB lithography has been developed very maturely, no matter in the aspect of efficiency, cost, accuracy, or environmental protection, it has not been able to keep pace with the times, whereas, on the basis of the traditional lithography, DLP-based lithography is added into the digital modernization this factor precisely, making PCB lithography keep up with the rhythm of the times again. For this reason, specific to fabrication of the high precision PCB, the research and development of DLP digital lithography system appears particularly important at present. Furthermore, in the field of projection display, with people’s increasing demand for movabiliry and portability of projection display device, large and heavy volume of traditional projector could not satisfy the use of this kind of portable scene at all, therefore, as DLP-based micro-projector become a hot spot of projection market at this moment, specific research for it also appears much more practical and has market value.For the DLP digital lithography, a ten-lenses projection objective for DMD of model 0.7XGA by using Zemax optical design software was designed. On the basis of non-symmetrical structure, the projection objective has a improved air-spaced triplet as front group and a petzval objective with flat field lens as back group. After image evaluation for the design result of the projection lens, we can know it has better imaging performance, in the meanwhile, its resolution achieves to 2 μm, satisfying the demand of the use of micron scale PCB lithography. After tolerance analysis for the projection lens, we demonstrates the possibility of fabricating and assembling such a non-symmetrical structure. If applying the projection lens to DLP digital lithography system, we believe that it can provide strong guarantee for high quality of image transfer.For the DLP micro-projector optical system, this paper analysed three optical structures divided on the basis of ways of combination of light, and here employs three channel beam combination as optical structure of this system. Then the main composition of micro-projector illumination system was introduced and studied, including illumination source, collimination system, beam homogenizing system, total reflection prism. For the imaging system, according to use demand, a projection lens for micro projection display was designed. After analysing the deign result of the projection lens, we can draw a conclusion that it meets the requirements of the projection specifications and has excellent image quality. Finally, after modeling and simulation of the whole DLP micro-projector optical system, the overall performance was analysed, indicating that it meets demands in practical use.