Method and device for generation of quadratic curve signal

Claim 1

A system for generating a quadratic signal, comprising at least two registers to store a coefficient and variable; an arithmetic circuit to operate for addition and subtraction of signals from said registers and to store the operation result in said registers; a sign register to input data relevant to a sign of said operation result from said arithmetic circuit; a logic circuit to give an operation indicating signal to said arithmetic circuit through a combination of a signal from said sign register with a microprogram indicating a given operation sequence; two updown counters given data of X coordinate position and Y coordinate position to indicate a start point at first and updating the data in sequence according to information from said arithmetic circuit; a circuit means to give data to said two updown counters from said arithmetic circuit, logic for deciding signs of linear micro-coefficients fx,fy in the directions of x and y on the quadratic curve f(x,y)=0 or at points (x,y) close to said curve, logic for comparing fx,fy for dimensions, logic for calculating new f(x, y) for two points G o and G 1 , having determined a point G to select next beforehand, logic for comparing absolute values of the two points G o , G 1 of the new f(x,y), logic for selecting from points G o , and G 1 , the point giving the smaller absolute value as the next point; and end point detection circuit means to detect points selected in sequence as an end point upon satisfying the following conditions, thereby producing said quadratic curve signal expressed by f(x,y)=0, from said two updown counters, (X=XE).solthalfcircle.(SFY=SFYE) at |FX|≦|FY| (Y=YE).solthalfcircle.(SFX=SFXE) at |FX|>|FY| wherein micro-coefficients for x,y at points (x,y) selected in sequence are FX,FY; the signs are SFX, SFY; and micro-coefficients for x, y at end points (XE,YE) set beforehand are FXE, FYE, and the signs are SFXE, SFYE.

Claim 2

A system for generating a quadratic signal, comprising at least two registers to store a coefficient and variable; an arithmetic circuit to operate for addition and subtraction of signals from said registers and to store the operation result in said registers; a sign register to input data relevant to a sign of said operation result from said arithmetic circuit; a logic circuit to give an operation indicating signal to said arithmetic circuit through a combination of a signal from said sign register with a microprogram indicating a given operation sequence; two updown counters given data of X coordinate position and Y coordinate position to indicate a start point at first and updating the data in sequence according to information from said arithmetic circuit; a circuit means to give data to said two updown counters from said arithmetic circuit, logic for deciding signs of linear micro-coefficients fx,fy in the directions of x and y on the quadratic curve f(x,y)=0 or at points (x,y) close to said curve, logic for comparing fx,fy for dimensions, logic for calculating new f(x, y) for two points G o and G 1 , having determined a point G to select next beforehand, logic for comparing absolute values of the two points G o , G 1 of the new f(x,y), logic for selecting from points G o , and G 1 , the point giving the smaller absolute value as the next point; and end point detection circuit means to detect points selected in sequence as an end point upon satisfying the following conditions, thereby producing said quadratic curve signal expressed by f(x,y)=0, from said two updown counters, (X=XE).solthalfcircle.(SFY=SFYE) at |FX|≦|FY| (Y=YE).solthalfcircle.(SFX=SFXE) at |FX|>|FY| wherein micro-coefficients for x,y at points (x,y) selected in sequence are FX,FY; the signs are SFX, SFY; and micro-coefficients for x, y at end points (XE,YE) set beforehand are FXE, FYE, and the signs are SFXE, SFYE.