Electrographic display apparatus

Claim 1

An electrographic display apparatus for editing coded information including an input unit for assembling the coded information applied to said apparatus into function and character codes, a code translation system coupled to said input unit for causing characters representative of said character codes to be sequentially displayed in a manner determined by said function codes on N (greater than or equal to two) display record surfaces, means for correcting the coded information displayed on at least one of said N display record surfaces, and means responsive to said correcting means for providing at the output of said apparatus coded information representative of the characters as displayed on the Nth display record surface, said code translation system including N line stores which are each associated with a separate one of said N display record surfaces and capable of storing a plurality of said codes, the output of said input unit being applied to one of said N line stores, the codes stored therein being passed therethrough and through each one of the other of said N line stores in turn, the code appearing at the input of each of said N line stores being sequentially applied to decoding means which generate on application of each code a discrete signal on either one of Y (number of characters the apparatus can generate) output wires thereof which is representative of a particular character and which is applied to a code translation matrix to form that particular character therein or one of Z (number of functions the apparatus can perform) output wires thereof which is representative of one particular function and which is applied to the appropriate level of an N-level function control unit, an interrogation unit for applying interrogation pulses to said code translation matrix in order to sense sequentially during each interrogation period the characters formed therein which appear at the inputs of each of said N line stores, said interrogation pulses resetting at least part of said code translation matrix to its original state and causing to be sequentially generated at the output of the matrix signals corresponding to the form of at least part of the N characters formed therein, and N-level character form controlling means, the input of each level of which is sequentially connected to the output of said code translation matrix and to the output of a separate level of said N-level function control unit, the output signals of said N-level character form controlling means which determine the form in which said N characters are to be displayed being sequentially applied via amplifying and modulating means to a selection matrix which in synchronism with the interrogation unit and said N-level function control unit sequentially directs the output signals to the appropriate input channels of a recording head which is associated with that one of the N display record surfaces on which a character represented by said output signals is to be displayed.