Apparatus for controlling reproduction of text characters whose form depends on adjacency of other characters

Claim 1

Digital apparatus for controlling the reproduction by a graphic device of characters forming the words of a text in a typescript including characters which have several possible graphic forms depending on the adjacency of other characters, the characters being received from an external source as sequences of character identification codes, said apparatus comprising: a character generator including a character store having a base page section for storing codes identifying the base bodies of characters and at least one additional page section for storing codes identifying forms of the characters; and a digital control device including: first means for accepting and buffering the character identification codes from the external source, second means for accepting the character identification codes from the external source to produce category signals for each character to be reproduced, third means connected to receive the category signals from said second means for buffering the category signals of at least four successive characters, fourth means responsive to the category signals buffered in said third means for producing a first control signal having a first state when the identification code of the character to be reproduced is stored in the base page section of the character store and a second state when the identification code of the character to be reproduced is stored in an additional page section of said character store, and also for producing at least one second control signal for the graphic device to enable the addition of supplementary signs to a character form read out from the character store, and fifth means coupled to receive the character identification codes from the first means and said first control signal from the fourth means for producing a final character address code for the character store, thereby to select the character form to be reproduced.