| 摘要 |
PURPOSE:To obtain a clear picture by increasing the width of an electron beam from zero to the same speed as the beam scanning speed, scanning the beam when it becomes the prescribed width, and thereafter contracting it so that it becomes zero at the same speed from the end of the opposite end from the scanning direction. CONSTITUTION:An electron gun, means for scanning an electron beam emitted from an electron gun and a throttle for shaping the beam are provided in an electron beam deawing device, the beam is passed through the throttle while deflecting the beam in the direction reverse to the beam scanning direction at the start of the frawing, and the beam is deflected in the direction reverse to the scanning direction at the end of the drawing to shield the passage of the beam through the throttle to complete the drawing. That is, when the electron beam of wXd formed in a rectangular shape is scanned in the direction d to draw a figure of wXL the beam width is increased from zero to the start end S of the figure from the beam ON by employing the beam ON signal 15 and a shape deflecting signal 20, thereby continuing the drawing. When it reaches the end T, the beam is deenergized to be contracted to zero in width. |
