Graphic display system for raster scanning involving wobbling

摘要

A graphic display system which is particularly applicable to a raster scanning type graphic display device is disclosed. The system extracts a given partial pattern from an original pattern by comparing a counted value of an input coordinate X axis counter for counting the number of picture elements of the original pattern with given preset values so as to select a picture element having an X coordinate value within a given range of input coordinates and by comparing a counted value of an input coordinate Y axis counter for counting the number of scanning lines of the original pattern with given preset values so as to select a picture element having a Y coordinate value within the given range of the input coordinates. The given values are preset to a display coordinate X axis counter and a display coordinate Y axis counter, respectively, so as to bring a leading picture element of the partial pattern extracted from the original pattern into correspondence with the given coordinates of the display coordinates. The contents of the display coordinate X axis counter are subjected to increment so as to determine a coordinate position of a picture element to be recorded next to a recorded picture element in correspondence with recording and display of each picture element and resetting the display coordinate X axis counter and subjecting contents of the display Y axis counter to increment when the contents of the display coordinate X axis counter exceed the given preset values. The recording and display is stopped when the contents of both display coordinate X axis counter and the display coordinate Y axis counter reach respective given preset values so as to control the recording of the partial pattern.