| 摘要 |
PURPOSE:To enable to perform drawing of a trapezoidal pattern with favorable precision by a method wherein the desired trapezoidal pattern to be drawn is divided into two pieces, and the directions of line scanning are reversed mutually when drawing is performed. CONSTITUTION:Data necessary for respectively registers Rs (R1-R7) are set from a computer 1. A data control circuit 16 connects switch circuits 3 as shown with the solid lines to lead respective data into a trapezoidal drawing control circuit 8. A trapezoidal pattern drawn according to data thereof forms a divided left side pattern. After data are led in the circuit 8 thereof, scanning signals for drawing are fed to deflectors 11, 12 from the circuit 8 through D/A converters 9, 10 to draw the pattern. After drawing of the pattern thereof is finished, the circuit 16 changes the circuits 3 over the connecting condition as shown with the dotted lines. The shape of the pedestal drawn according thereto forms a divided right side pattern. Drawing of the trapezoidal types of two pieces thereof is controlled as to make the directions of line scanning in the X direction to be reversed mutually, and moreover respective line scannings are made as to be finished at the connecting parts, and drawing is executed with favorable precision. |
