| 摘要 |
FIELD: optics. ^ SUBSTANCE: lens comprises two movable members. The members are arranged symmetrically one with respect to the other and their refraction surfaces are defined by moving the generatrix along the guide and represent arcs of circumferences or curves with varying radius of curvature. The first member moves toward the object, and the second member moves toward the plane of image so that the plane of image is unmovable. ^ EFFECT: enhanced quality of image. ^ 2 cl, 1 dwg |
