using the raster scan of a cathode-ray tube [CRT] for detecting the position of the member, e.g. light pens cooperating with CRT monitors

Full Title

Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements > Input arrangements or combined input and output arrangements for interaction between user and computer (G06F3/16 takes precedence) > Arrangements for converting the position or the displacement of a member into a coded form > Pointing devices displaced or positioned by the user ; Accessories therefor (digitisers characterised by the transducing means G06F3/041) > using the raster scan of a cathode-ray tube [CRT] for detecting the position of the member, e.g. light pens cooperating with CRT monitors