Research On The Technology Of Micro Projection Display Based On Polarization Multiplexing Method

The technology of micro projection display has been widely used in the commercial production, and it is gaining favor in the mass market. Recently, it is developing towards high brightness and uniformity, fine resolution, long service life and small volume. As a kind of frequently-used spatial light modulator(SLM),LCo S require linearly polarized light to operate, this causes at least half of the incident natural light lost. For the improvement of energy efficiency, a polarization multiplexing method based on light pipes is proposed. And with this method, the design of optical engine and the analysis of system performance are finished.Firstly, several polarization multiplexing methods are introduced including their advantages and disadvantages. To avoid the bad ones, a method based on light pipes is proposed. How to determine the optimal length of the light pipe for getting high efficiency and uniformity is introduced with the theories of virtual source array and light pipe etendue. After that, the structure design of PCS is finished.Next, the design of illumination system including splitting lens and integration lens is completed with this method. The role of splitting lens is imaging the virtual source produced by the light pipe on PCS correspondingly. And the role of integration lens is integrating the polarized light to match the size of LCoS panel.At last, the design of imaging optical system and the analysis of its performance is finished. The parameters of imaging optical system are determined at first and then the initial structure is selected. The optical system is designed in Zemax with the image quality evaluated and the tolerance analysis completed. The last step is the simulation of optical engine in TracePro. We could get the illumination distribution on the LCo S and projection screen. It’s shown that the energy efficiency on the LCo S and screen are 67% and 63% respectively. Calculating by 9 point ANSI standard for projector, the uniformity is 95%.From that, we get the conclusion that it’s valid for this polarization multiplexing method to improve energy efficiency of the illumination system with a suitable uniformity.