Polarization converter and projection system using same

Abstract

The invention provides a polarization converter with a novel structure and a projection system using the same. The polarization converter consists of seven small prisms which are arranged in an array and glued together; partial combining surfaces of the prisms are plated with polarization beam-splitting film layers or full reflective film layers; and light emergent surfaces of partial prisms are provided with half wave plates; the light incoming surfaces of other prisms except the first and the seventh prisms form an effective light receiving zone of the polarization converter, the light incoming surfaces of the prisms of the first and the seventh prisms are provided with a light blocking layer; therefore, the polarization converter can be used for converting all incident non-polarized light into S polarized light or P polarized light for emergence, and has good uniformity of emergent polarized light due to a PCS array. A micro lens system is not needed to adjust the beams emitted by the light source in the projection system, so the optical design is simplified and the cost is saved; and the projection system has high light utilization rate and improves the image display quality.

Description

technical field [0001] The present invention relates to a polarized light conversion device and a projection display system, in particular to a polarization conversion device capable of converting all non-polarized light emitted by a light source into uniform single polarized light, and a single-chip LCOS liquid crystal projection system using the polarization conversion device . Background technique [0002] The traditional single-chip reflective liquid crystal projection system can be summarized as follows: figure 1 As shown, it includes a light source 1 , a polarizing beam splitter 2 , a reflective liquid crystal chip 3 and a projection lens 4 . The light source 1 can be various types of light sources, which may contain a filter (to remove ultraviolet and infrared light), a focusing lens group or a light rod, etc. The light emitted by the light source 1 enters the polarization beam splitter 2 and then separates P-polarized light and S-polarized light , wherein only the ...

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Problems solved by technology

[0004] The above two PCS structures are very simple, both disclosed in Chinese patent CN02217355.2 and US patent US7281803, but there are defects: the S polarized light emitted from these two PCS is not uniform enough

Obviously, the light source part of the projection system using this PCS array 04 is still complicated in design and high in cost

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