UN METODO DE COMPROBAR LA CALIDAD DE MECANOGRAFIADO DE APARATOS DE ESCRIBIR, PREFERIBLEMENTE IMPRESORAS DE MATRIZ O DE CHORRO DE TINTA

摘要

A method and device for checking the printing quality of matrix or liquid jet printers (2). A character (3) is printed in the paper margin and is optically sensed in connection with line shift. The signal pattern from the symbol is compared with a predetermined pattern corresponding to a correct reproduction of the character. An alarm signal is sent if there is a difference between the signal patterns.