| 摘要 |
<p>In one embodiment, a three-element biocular eyepiece system 40 having a first optical element 42 with at least one diffractive surface 44, a second optical element 48 having a refracting convex surface 50 and a refracting concave surface 52 is provided. A third optical element 54 having a refracting convex surface 56 and a refracting convex surface 58 is also employed. In another embodiment, a four-element biocular system 60 is disclosed as having an optical element 62 having a refracting concave surface 64 and a refracting convex surface 66, a refractive-diffractive hybrid optical element 68 having a diffractive surface 70 and a refracting convex surface 72, an optical element 74 having a refracting convex surface 76 and a refracting concave surface 78, and an optical element 80 having a refracting concave surface 82 and a refracting convex surface 84. The diffractive surfaces 44 and 70 have a kinoform profile 102a-d or approximated kinoform profiles 112a-d and 122a-d. Both versions of the biocular eyepiece 40 and 60 provide a biocular eyepiece which has fewer lens elements and a shorter overall length than conventional designs. Both versions of the biocular eyepiece 40 and 60 may be used in combination with a cathode ray tube 12 for magnification of images generated therein. <IMAGE></p> |
