公开(公告)号：US3571602A

公开(公告)日：1971-03-23

申请号：US3571602D

申请日：1968-12-30

Applicant: BOFORS AB

Inventor： OHLSSON AXEL ERIK LUDVIG ,  SKAGERLUD LARS-ERIK

IPC: H01J40/06 ,  H01J43/28

CPC classification number: H01J40/06

Abstract: A photodetector system including a photocell of the type having a photosensitive coating on the internal surface of a plane transparent wall forming part of the envelope of the cell. At least one prism whose principal section has the form of a trapezoid is attached to the wall so that the shorter one of the two parallel sides of the prism is in contact with the exterior surface of the wall in front of a central portion of the coating. The lengths of the sides and the angles of the principal section of the prism are so chosen that a bundle of light entering the longer one of the parallel sides at right angles to that side, is in part reflected by a first one of the nonparallel sides towards the other one of the nonparallel sides and reflected towards the wall by the last-mentioned side, while another part of the light bundle is reflected by the first one of the nonparallel sides directly towards the wall, both parts entering the wall under an angle of about 45*.