| 摘要 |
<p>A lighting fixture to illuminate a target surface, particularly a surgical site, is provided which includes a light source, a reflector superposing and partially circumscribing the light source, a cylindrical filter surrounding the light source coaxial to the axis of symmetry of the lighting fixture and a refractor positioned beneath the reflector through which the light reflected from the reflector must pass to reach the target surface. The refractor is divided into a plurality of portions which radiate outwardly from the axis of symmetry. Each portion includes first, second and third prism means having individual prism members of varying configuration for focusing the light to first, second and third areas, respectively, within a cylinder of light defined by the light passing through the refractor, to provide small, medium and large patterns respectively, of the cylinder of light when it impinges upon the target surface. Means are provided for selectively blocking light from passing through certain areas of the refractor to achieve the desired pattern.</p> |
