OPTICAL PIPE, COLOR LIGHTING APPARATUS, AND PROJECTION SYSTEM USING THE SAME, IN WHICH P POLARIZATION AND S POLARIZATION ARE USED AS EFFECTIVE BEAMS

摘要

PURPOSE: An optical pipe, a color lighting apparatus, and a projection system using the same are provided to enhance the optical efficiency by dividing incident rays into colors and using beams of P polarization and S polarization as effective beams. CONSTITUTION: An optical pipe includes a first to a fifth polarization beam splitter, a first and a second color selection polarizer, a polarization converter, and a 1/2 wavelength plate. The first polarization beam splitter(16) is used for reflecting and transmitting incident rays according to the polarization direction of the incident rays. The second polarization beam splitter(17) is arranged at a lower side of the first polarization beam splitter. The third to the fifth polarization beam splitters(18,19,20) are arranged nearly to the first and the second polarization beam splitters. The first color selection polarizer(21) is arranged among the first and the second polarization beam splitters and the third polarization beam splitter in order to change the polarization direction of the first color beam. The second color selection polarizer(22) is arranged between the third and the fourth polarization beam splitters in order to change the polarization direction of the second color beam. The polarization converter(23) is arranged between the fourth and the fifth polarization beam splitters in order to change the polarization direction of the third color beam. The 1/2 wavelength plate(24) is arranged between the second polarization beam splitter and the first color selection polarizer.