| 摘要 |
PURPOSE: To guarantee a good shadow in a wound, a shadow of depth and an illumination for depth upon a large workin depth by that, in a Fresnel lens, as a distance from an optic axis at a position of a light flux being launched becomes smaller, a light flux launched from the Fresnel lens made to cross the optic axis in the position of a more larger distance from the Fresnel lens. CONSTITUTION: A light flux launched from a Fresnel lens 60 is crossed with an optic axis 67 at the position of a more larger distance (a) as the position of launching the light flux and the distance (b) of the optic axis become smaller in the Fresnel lens 60. The light flux launched from the edge portion of the Fresnel lens 60 is crossed with the optic axis 67 at a distance (a1) by the most largely refracting against the optic axis 67. An intermediate light flux is launched from the Fresnel lens 60 at the position of a distance (b2) from the optic axis 67, and crossed with the optic axis 67 at a distance (a2). By variously focusing a different light flux, a uniformed light intensity is obtained upon a comparatively larger depth region, thus a uniformed illumination against a deep surgical wound is made possible, at the same time the undesirable fluctuation of a light distribution is widely eliminated. |
