Character generating apparatus employing bit stream length correction

Claim 1

Character generating apparatus for controlling the deflection circuits of a cathode ray tube to move an electron beam across the screen of said cathode ray tube to display a character thereon, said character being formed by a plurality of straight line segments, said apparatus comprising means for receiving a character code and transforming said character code into an address code, memory means responsive to said address code for providing a word for a line segment of said character, said word containing horizontal and vertical components of the deflection increment and beam control signals for said line segment, counter means including a plurality of selectively enabled stages for providing signals defining a selectable number of bit stream positions, counter enabling means responsive to the magnitudes of the horizontal and vertical component increments of said line segment for selectively enabling said stages of said counter means so as to select the number of bit stream positions defined by said counter means, means responsive to said increment signals and said bit stream position defining signals for generating a horizontal bit stream and a vertical bit stream, each of said bit streams having as many 1''s as the magnitude of the respective coordinate component of said line segment, and means converting said bit streams into stroke signals and applying said stroke signals to the respective deflection circuits of said cathode ray tube.