| 摘要 |
PURPOSE:To simply set up a screen angle only by main scanning by changing the starting position of reading of each threshold in a threshold matrix from a memory to obtain a prescribed screen angle. CONSTITUTION:A threshold matrix consisting of fine picture elements of m lines X n rows is previously stored in a memory 8 and a prescribed screen angle is obtained by changing the starting position of reading of an inputted picture element from said memory 8. If the initial value of an initial value setting counter 33H advances by (j) in the horizontal direction in a picture element consisting of mXn fine picture elements, a screen angle theta1 in the vertical direction is expressed by theta1=tan<-1>(j/m) and theta1 can be changed by changing (j). When an initial value setting counter 33V advances by K only in the vertical direction, the screen angle theta2 in the horizontal direction is expressed as theta2=tan<-1>(K/n). In the drawing, 3R and 7 show a frame memory and a comparator respectively. |
