公开(公告)号：GB1299349A

公开(公告)日：1972-12-13

申请号：GB1465570

申请日：1970-03-26

Applicant: IBM

Inventor： KOSANKE KURT ,  SCHMACKPFERRER ARNO

IPC: G02F1/31

Abstract: 1299349 Deflecting light INTERNATIONAL BUSINESS MACHINES CORP 26 March 1970 [5 April 1969] 14655/70 Heading H4F In a light deflector formed of a plurality of stages each comprising an element which deflects an incident light beam in one of two directions depending on its plane of polarization, e.g. a Wollaston prism, and electro-optical means for varying the plane of polarization of the light beam, the position of each deflecting element is unimportant when the deflector is used for a collimated light beam and in conjunction with an objective lens since the final position of the deflected beam in the focal plane of the lens depends only on the angle, and not on the actual position, at which the beam is incident on the lens. In such a case the deflector causes the light source to appear as a selected one of a series of equi-angularly disposed virtual sources at infinity i.e. if the splitting angles of successive prisms form a binary progression. If however it is desired to deflect an image in a plane 16 to a series of equidistant positions in an object plane of a lens 17, the reasoning above does not apply since the source of light is not at infinity and the light from any point of the image diverges and converges before and after the lens respectively and it is necessary to arrange that the final deflected beams 1-8 generate equidistant virtual images in the plane 16. This is done either by modifying the deflection angles of the prisms so that they do not form a true binary series, i.e. coarse adjustment during manufacture, or by varying the distance of each prism from the plane 16 (fine adjustment when setting up), since these two quantities are interdependent. In a preferred embodiment the virtual images 4a, 10a, 13a generated by the beams 4, 10, 13 least deflected from the optical axis after every stage are spaced from the intersection of the optical axis 15 and plane 16 by relative distances corresponding to a binary series. The lens 17 may also be disposed between the deflector W0, W1, W2 and the plane 16. The Specification includes details of how to calculate the desired angles and positions of the prisms W0, W1, W2, including the case when the deflector is immersed in oil.