A COMPACTED BEAM PASS EXPANDER AND THE METHOD FOR EXPANDING BEAM PASS

摘要

The present invention relates to a configuration of a small beam path expander, a beam path expansion method, and a laser image projection apparatus using the same, and particularly, to insert a beam path extension between a focusing lens and an acoustic light modulator and between the acoustic light modulator and the collimator lens. Thus, the conventional laser image projection apparatus had to have a focusing lens having a considerably long focusing distance in order to maintain a sufficient optical signal processing speed in the acoustic light modulator, and the focused laser beam modulated in the acoustic light modulator is also the focusing point. The laser beam as a light source, the high reflection mirror 21 for changing the optical path of the laser beam, so as to prevent the volume of the laser image projection apparatus from being increased by restoring the collimated lens at intervals by a distance, and the Collimating lenses 22 for converting the changed laser beam into parallel light, and the parallel light An optical system 20 including magnification lens systems 230 and 240 for enlarging the size of the changed laser beam, and dichroic mirror systems 67a and 68a for separating the laser beam into red, green and blue monochromatic light. And a focusing lens 64a, 65a for focusing the optical separation 25 consisting of a high reflection mirror 69a and a laser beam separated by the red, green, and blue monochromatic light with the acoustic light modulators 61, 62, and 63. 66a) a beam path enlarger (100) positioned between the focusing lens and the acoustic light modulator; An acoustic light modulator (61, 62, 63) for modulating the focused laser beam according to an image signal and a collimating lens (64b, 65b, 66b) for restoring the modulated laser beam in parallel light form; A beam path expander (100) positioned between the acoustic light modulators (61, 62, 63) and the collimating lenses (64b, 65b, 66b); A light integrating portion (65) comprising dichroic mirror systems (67b, 68b) and high reflection mirrors (69b) for integrating the laser beam restored in the form of parallel light; A polygonal mirror (80) for horizontally scanning the laser beam integrated in the light integration unit; A galvanometer 70 for performing vertical scanning; Relay lens systems 31 and 32 positioned between the galvanometer and the polygonal mirror; An fθ lens system 34 positioned between the polygonal mirror and the screen 90; Finally, the present invention relates to a large-screen laser projection imaging apparatus having a small focusing optical system composed of a screen 90 for projecting an image, a beam path expanding apparatus, and a method.