| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting system with high lighting efficiency and a projector with a bright projecting image. SOLUTION: A reflecting plane of a reflector 3 is formed by using a straight line B as a rotational axis AX between a point A a distance Δapart from a first focal point F of an ellipse to a short axis and a second focal point for rotating an elliptical curve on the side of not including the first focal point F out of the ellipse divided by the rotational axis AX. A light source 1 is located on the point A and a bulb 2 is a optical system which is rotationally symmetrical with the rotational axis AX and has an optical axis ax passing through the point A in a plane including the rotational axis AX. Conditional expressions 0<L<f, L2/ 2.(f-L)}<=Δ<=3. L2/ 2.(f-L)} are satisfied where f is a focal distance of the bulb 2 and L is a distance from the rotational axis AX to a main point of the bulb 2. |
