Focus and astigmatism adjustment arrangement for optical reader - utilises screws to position photo-cell in two horizontal directions while third screw positions lens vertically

摘要

A semi transparent mirror in the optical path between a moving information support and a luminous source directs a proportion of the luminous energy to a cylindrical lens (C). The lens is on a movable support which slides on a fixed base parallel to the optical axis of the lens. The lens forms a spot (8) near the observation plane (P) where a photocell (13) is located near the optical axis (2). An adjustment allows the cell to move in one direction (OX) to allow its axis (15) to align with the optical axis. A second adjustment operates on the other axis (OY) to align the spot with the optical axis. A third adjustment allows the lens to move in the vertical direction (OZ) to focus the spot.