| 摘要 |
PURPOSE:To increase the effective using rate of light from a light source by keeping the relation among an angle formed by light incident from the light source to a reflecting surface with an optical axis, the luminous intensity of the light source and an angle formed by the reflected light with the optical axis at a prescribed formula and setting up the angle formed by the reflected light with the optical axis so as to be reduced in accordance with the increment of the angle formed by the incident light with the optical axis. CONSTITUTION:The angle theta formed by the light incident from the light source F on the reflecting surface M with the optical axis Z, the luminous intensity IIo of the light source F and the angle alpha formed by the reflected light E, E' with the optical axis Z form the relation shown by the formula I . A continuous curve expressed by the formulas II, III about the relation between the coordinates x1, z1 of a point where the light projected from the light source F is made incident on the optical axis Z with the angle theta and the coordinates x2, z2 of a point of incident light to the optical axis Z with an angle (theta+DELTAtheta) is defined as a curved surface turned around the axis Z. The angles theta and alpha are set up so as to be theta>=0 and alpha<=0 respectively, and the angle alpha is reduced in accordance with the increment of the angle theta. In the formula I , A, B and C are constants to be fixedly selected to determine the light distribution characteristics of respective reflected light. |
