Abstract: A printing device is provided for printing bar code or other indicia on record media such as bank checks and similar documents. The bar code indicia consists of a series of symbols which may be "01" or "10", in which "1" is represented by the presence of a bar and "0" is represented by the absence of a bar in a possible bar position on the record media. The printing device includes a platen having two angled printing surfaces, each of which may be in the configuration of a bar, on one end and being rockable between two positions in each of which one of the printing surfaces is parallel to the path of movement of the record media, and the other of said surfaces is not. A hammer driven by a constant-speed cam coacts with the printing surfaces on the platen to print on the record media during each cycle of cam rotation, and suitable controls position the platen by means of a solenoid during each cycle to determine whether a first symbol or a second symbol will be printed.

Abstract: A data compression system is disclosed in which the left-hand boundary of a character is developed in the form of a sequence of Freeman direction codes, the codes being stored in digital form within a processor. The number of binary data bits required to define the character using different criteria is then generated and compared to determine which criteria defines the character in the minimum amount of binary data bits.