Patent ID: 6053621
Filing Date: 2000-04-25
Classification: F21K,F21V,G01N,G02B

Abstract:
A lighting unit comprising a ring-shaped transparent body for light diffusion and a plurality of illuminants, said transparent body having a light-emission surface and a light-introduction surface, said plurality of illuminants extending within said transparent body along said light-introduction surface for emitting light from said light-emission surface and for illuminating a surface of a product to be examined when the product is located at an under side of the lighting unit, said transparent body also including a center hole having a first end and a second end, said center hole being open between said first and second ends for performing visual inspection or taking of photographs of the surface of the product to be examined from an upper side of the lighting unit through the center hole, and a plurality of transparent body surfaces each having a reflective layer so as to reflect and return light into the transparent body.