OPTICAL DEVICE AS WELL AS PROJECTOR DEVICE, REAR PROJECTOR DEVICE AND MULTIPROJECTOR DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain an optical system with which an illuminance distribution having excellent intensity uniformity may be obtained even when a luminous flux is made incident from a direction having a prescribed inclination from the normal direction of a surface to be illuminated. SOLUTION: This optical device is an illumination device comprising a light source 1 which radiates light, a condenser means 2 which is composed of a reflection mirror 20 having a reflection surface shape consisting of quadrics of revolution and a condenser lens 21 for converging approximately parallel luminous fluxes, a mixing rod 3 having a square shape in cross section, a first lens means 4 comprising at least one element of lens and a reflection optical element 5 w is arranged near the position formed with plural cubic light sources and reflects the light toward a desired direction. The device illuminates a surface 6 to be illuminated which is arranged on the outside of the optical axis 70 of the illumination device.