Optical printer having serializing buffer for use with variable length binary words

Claim 1

Printer apparatus for generating an image of a page, bearing rows of characters, on an image receiving member by means of a binary image generating means which successively scans said image receiving member in raster fashion to thereby generate columnar segments, each of said columnar segments being generated by a plurality of variable-length binary words which are uniquely related to the character content of said page and to a selected font, the improvement comprising: page memory means capable of storing a plurality of character identifying codes in accordance with the character content of said page; font memory means capable of storing a plurality of binary words which define possible characters in the character content of said page, the bit-length of said binary words being variable; a plurality N of shift registers, each having a plurality M of data storage stages; readout control means operable to continuously control said binary image generating means in closed loop read cycles in accordance with the binary content of the first stage of each of said registers in a recycling read-order; load control mEans operable to sequentially control the loading of said shift registers from said font memory means, one binary word at a time; said load control means being operable to load the first bit of word X in the first stage of one of said shift registers, the N+1 bit in the second stage of said one shift register, and so on progressively; being operable to load the shift register whose first stage is next in said read-order with the second bit of word X, the 2N+1 bit in its second stage, and so on progressively; and being operable to load the remaining shift registers in a similar manner until word X has been loaded into said shift registers, with the first stages of all shift registers having been loaded in progression with bits 1 through N in the said read-order; clock means; load/shift control means controlled by said clock means and operable to selectively shift or load said shift registers at times other than the time during which the first stage is being read; and pointer means controlling said load/shift control means such that the loading of the first bit of word X+1 is loaded into the next adjacent shift register to that shift register which received the last bit of word X.