Graphical data reading method - uses optical detector linked to position control servo system

摘要

The graphical data system uses a reference surface (11, 12) to carry the graphical information (C) and on which is defined two coordinate axes (OX, OY). A sweep support (13) is mounted so as to move parallel to the reference surface along a direction parallel to one of the two axes. The sweep support has a guidance path (18) parallel to the other coordinate axis. The system uses an optical reader (16) having a movable part connected to a support (17) which is displaced along the guidance path (18). The system also uses a position servo-mechanism circuit (21) whose servo is a means of displacing the support of the movable part and a control detector (22) forming part of the optical read system. Equilibrium of the servo system is regulated for an extreme reception level of the control detector.