Method and apparatus for displaying enlarged or enhanced dot matrix

Abstract

A method and apparatus for displaying enlarged or enhanced dot matrix characters is disclosed. Using stored sets of binary data elements which define the shape of the respective characters of a set, logical operations are performed to add additional binary data elements to provide the desired enlarged character. Characters may be enlarged in the vertical and horizontal directions by lengthening the horizontal, vertical, and diagonal linear components which together comprise the character. Characters may also be enhanced by thickening the linear components thereof in a direction orthogonal to that of the linear components, and made more dense with additional dots along the length of the linear components. The stored data defines the character with a high density in the horizontal direction and a lower density in the vertical and diagonal directions. The characters are enlarged, and enhanced, by defining a reference matrix which comprises a subset of the stored binary data elements, expanding the reference matrix by adding blank binary data elements to the defined reference matrix at locations between the stored binary data elements, and comparing portions of the expanded reference matrix with corresponding portions of a predetermined matrix, and converting to a dot those added binary data elements that match the elements of the predetermined matrix. Characters may be differentially enlarged, or enhanced in one manner but not another, or they may be thickened toward the middle of each character.