公开(公告)号：JPH0219822A

公开(公告)日：1990-01-23

申请号：JP12464389

申请日：1989-05-19

Applicant: ESSILOR INT

Inventor： DOMINITSUKU BOODO ,  PIEERU SHIYABUERU ,  DENI JIYUWAIOO ,  JIYAN DABUURI

IPC: G02B5/18 ,  G02C7/04 ,  G02C7/06

Abstract: PURPOSE: To attain near view and far view respectively by providing a diffracting component, which has various phase contours, with at least two concentric areas. CONSTITUTION: At least, two concentric areas 110 and 120 which have various phase contours are provided so as to cause diffraction of various degrees. The diffracting component is formed of a phase hologram by adjusting a relief or index. Further, the diffraction of a lens 10 and the concentric areas 110 and 120 are accompanied by a refracting element determined by the size and shape of the lens 100, and the refracting component is formed by the difference in radius of curvature between two main surfaces 130 and 140 of the lens. Namely, A diffracting efficiency ratio is obtained for far view and near view and varies as a function of a pupil diameter. Consequently, the new view with high illuminance and intermediate-distance and far view with low illuminance are possible.