Abstract: The present invention provides a small reflective type liquid crystal projection device, which comprises an X-prism, three PBSs, two dichroic mirrors, at least three totally reflective mirrors, three reflective type liquid crystal plates, and a projection object lens. The present invention uses the X-prism matched with the three PBSs and a newly invented 3D light projection system to combine polarized light beams of the three primary colors into one, hence accomplishing the highest use efficiency and the design of light splitting and combining paths and color separating and combining. The reflective type liquid crystal projection device of the present invention has both the advantages of small volume and reduced cost.

Abstract: The present invention provides a continuous-zoom imaging device of an interferometer. Reflected lights of a reference plane and a test plane interfere with each other to generate an interference pattern. A collimation device converts a parallel light of the interference pattern into a convergent light. An optical path adjustment means guides the light to a polarizing beam splitter. A continuous-zoom device adjusts the magnification ratio of the interference pattern on the imaging passageway and to output an object image, which is then imaged on a charge-coupled device. The present invention can improve the quality of the interference pattern without using any rotating diffuser, and thus has the characteristics of reduced number of components, lowered cost, and shrunk volume. Besides, the present invention can utilize a joint device to connect the continuous-zoom device and an attenuator so as to achieve automatic light adjustment and convenient operation.

Abstract: The present invention proposes a reflective type liquid crystal projection system, which comprises an incident light source providing an S-polarization light beam or a P-polarization light beam as the incident light beam. A polarization of color-splitting device having a first polarization of color splitter and a second polarization of color splitter is used to split the incident light beam of three primary colors into two sets of light beams, which respectively penetrate through or are reflected. The two sets of light beams split by the first polarization of color splitter are reflected by two reflective mirrors, traverse two polarizing plates arranged between the reflective mirrors and the second polarization of color splitter, and are then incident on the second polarization of color splitter. At least a retarder is arranged between the reflective mirrors and the polarization of color-splitting device.