| 摘要 |
PURPOSE:To expand a light receiving angle, by providing a rotary elliptic mirror, which is arranged so that a converged light detecting means of scattered light occupies the first focal point in a detecting region, and providing a spherical mirror, which has a radius of curvature equal to the distance between the focal points of said rotary elliptic mirror. CONSTITUTION:A rotary elliptic mirror 19 is arranged so that a converged light detecting means of scattered light has the first focal point in a detecting region. A radius (v) of a spherical mirror 20 is made equal to the interval between two focal points S and R of the elliptic mirror 19. The center of the spherical mirror 20 is made to agree with the focal point S, i.e., the detecting region. At this time, the scattered light, which is reflected by an arbitrary point (m) of the elliptic mirror 19, is concentrated at the focal point R. Scattered light, which is reflected by an arbitrary point (n) of the spherical mirror 20, is reflected by a point (k) on the elliptic mirror 19 through the focal point S again and concentrated at the focal point R. When the gap at the connecting point of the elliptic mirror 19 and the spherical mirror 20 is eliminated, a total solid angle 4pisr can be made to be a light receiving solid angle. Thus the light receiving angle can be expanded to the limit. |
