Special optical element for camera to microscope adaptor

Claim 1

An optical article, comprising: an optically transparent material with a refractive index greater than 1.0 including, a pair of smooth parallel surfaces, a first reflecting surface for reflecting light, entering said article through a first of said smooth surfaces, along the channel defined by said smooth parallel surfaces, a second reflecting surface for reflecting said light coursing along said channel through the second of said smooth surfaces, and an intermediate reflecting surface for reflecting said light so as to change its direction within said channel toward said second reflecting surface, said article being configured so that the angle between said first smooth surface and said first reflecting surface is 521/2 °, the angle between said second smooth surface and said second reflecting surface is 45°, and said intermediate reflecting surface is normal to said parallel first and second smooth surfaces and the angle defined by the intersections of said second reflecting surface and said intermediate reflecting surface with said second smooth surface is 671/2 °; and a positive refracting surface on the portion of said second smooth surface through which said light emerges from said optically transparent material, whereby said reflecting surface changes the solid angle otherwise subtended by said light emerging from said second smooth surface.