ILLUMINATION DEVICE AND PROJECTION TYPE DISPLAY DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To enhance light condensing efficiency while controlling the illuminance of the center of a surface to be irradiated. SOLUTION: A reflection mirror 140 is composed of two parts of a curve M1 to a point B from a point A and a curve M2 to a point C from the point B. The curve M2 is the elliptic curve formed with the end point X0 of a light source 10 on the mirror 140 side as a second focal point and with the end point E of the surface to be irradiated 21 as a second focal point. The curve M1 is the elliptic curve formed with the end point X1 of the light source 10 on the surface to be irradiated 21 side as the first focal point and with a point P included in the surface 21 to be irradiated as the second focal point. The point P included in the surface 21 to be irradiated is the point where a light beam emitted from the end point X1 of the light source 10 is reflected by a reflection part extremely near to the point B on the curve M2 and the surface 21 to be irradiated is irradiated with the light beam.