Projection display system including a collimating tapered waveguide or lens with the normal to optical axis angle increasing toward the lens center

摘要

The present invention provides a lighting device including a light source; a reflecting mirror for reflecting light emitted by the light source in a determined direction; and a compensating element for receiving the light from the reflecting mirror and allowing the light to outgo in the form of parallel rays. Further, a projection type image display system including the above-mentioned lighting device and a display element for forming an image by receiving light from the lighting device is provided. According to the present invention, light can be emitted with a satisfactory degree of parallelization and an even illuminance, constant irregularity due to the photoelasticity can be degraded, and the degradation in brightness of a projected image due to a low ratio of aperture can be avoided. Thus, a uniform image with no illuminance irregularity can be projected.