公开(公告)号：DE1447208A1

公开(公告)日：1969-10-16

申请号：DE1447208

申请日：1964-06-16

Applicant: IBM

Inventor： KOSANKE KURT ,  WERNER KULCKE DR RER NAT

IPC: G02B5/18 ,  G02F1/23 ,  G02F1/29 ,  G02B27/00

Abstract: 1,061,257. Optical recording. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 4, 1964 [June 28, 1963], No. 23118/64. Heading G5R. [Also in Division H4] A horizontal line of digital information is recorded on a vertically moving thermoplastic web 6, Fig. 1, by means of a light source 1, a rotating mirror 4 and an electrically responsive focus adjusting device 9 which causes focusing to be correct at every lateral point on the web, the device 9 being electrically linked to the mirror 4. The device 9 comprises a plate of electro-optic material, Fig. 4, not shown, which exhibits the " fringent electro-optic effect " when electrical voltages are applied between pairs of electrodes attached to its surfaces such that a Fresnel zone plate is defined by the gaps between fringent effect areas as they extend from the electrodes (see Division H4). The point of focus of a plane polarized monochromatic light beam is varied as the gaps between the fringent effect areas are caused to vary in response to the electrical voltages.