公开(公告)号：DE3780271D1

公开(公告)日：1992-08-13

申请号：DE3780271

申请日：1987-10-16

Applicant: IBM

Inventor： BROOCKMAN ERIC CHARLES ,  CATO ROBERT THOMAS ,  GREGORY JR ,  LAURER GEORGE JOSPEH

IPC: G02B26/10 ,  G06K7/016 ,  G06K7/10 ,  G06K7/12

Abstract: Holographic scanner of the type having a coherent light source (18), a rotating holographic optical element (10) having a plurality of facets (16) for deflecting the coherent light beam along predetermined scan lines, said facets having the capability of focussing the coherent light beam at different focal lengths from the optical element (10), a photosensitive detector (34) for detecting light reflected from an object and a sampling circuit for periodically sampling signals produced by the detector (34), comprising an analog-to-digital converter (38) for sampling and digitizing the signals produced by the detector (34) and varying means (44) for varying the sampling frequency as a function of the focal length of the facet currently employed to generate a scan line.