PURPOSE: To process characters of high quality fast by providing a display memory with 1-bit capacity for each picture element of a display screen and a one-line buffer, storing the contours of character patterns as character information and generating picture element data with the character information and buffer data.

CONSTITUTION: A pattern generating device consists of a CPU 11, a display controller 12, a display pattern modifying circuit 13, a monitor 14 for screen display such as a CRT, and a display memory device 15 which is stored with the character information for character pattern generation. The memory 15 is provided with 1 bit capacity and stored with the contours of character patterns as the character information. Further, the line buffer 4 is incorporated in the circuit 13 and data corresponding to 1st - (m)th picture elements are stored in (0)-th - (m-1)th addresses. The output of a logic gate 22 is inputted to an FF 23, which outputs the buffer data. Thus, one picture element is made to corresponding to 1-bit character information and the start point, end point, internal painting-out points, etc., of the patterns are determined.