Description
Class G09G : ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
Subclass 1/20: Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators (cathode-ray oscilloscopes G01R 13/2; television H04N) using multi-beam tubes (G09G 1/26, G09G 1/28 take precedence)