DISPOSITIF DE COMMANDE D'EFFACEMENT DES CARACTERES DANS UNE MACHINE A ECRIRE A MEMOIRE

Dispositif de commande d'effacement de caractères dans une machine à écrire à mémoire. La machine à écrire 10 selon l'invention comporte un clavier 12 pour commander la frappe au moyen d'un élément porte-caractères 11 monté sur un chariot 13. La machine comporte une mémoire de ligne dans laquelle sont emmagasinés les codes de caractères et de fonctions afférents à une ligne d'impression. La machine est capable d'effacer les caractères qui précédent un espace résultant d'une opération de tabulation. An electronic typewriter which has the capability of erasing characters automatically and which has the further improved capability of being able to back through unused space on the line, which results after a tabulation command, thereby allowing the repositioning of the type element over the characters typed prior to the tab command thereby allowing automatic erasure of those characters. The improvement of the typewriter as described permits the retrieving of characters from an electronic memory and the use of that memory to control the erase cycle even where the carrier position and the character to be erased are on opposite sides of space without printed characters due to a tab command. This is accomplished by the electronic control of the mechanical hardware and the ability to determine where the tab command was entered on the typing line and to prevent erasure cycles in the unprinted space until the carrier has returned to the point at which the tabulation command was entered.