| 摘要 |
<p>Type characters are formed on a photo-sensitive surface by projecting a laser beam directly onto the photo-sensitive surface while moving the beam rapidly upwardly and downwardly, moving the beam steadily in a horizontal direction, and blanking the beam at selected times during the vertical movements. The horizontal movement gives horizontal dimensions to the characters and proportionally spaces them from one another to form composed lines of characters. The blanking of the beam is accomplished by providing a barrier near the optical path of the beam, and using an acoustooptic modulator to rapidly deflect the beam out of its path and against the barrier. A programmed computer is used to store information regarding the start and the stop of each blanking interval for each vertical stroke forming each of the characters of a substantial number of fonts of characters. An optical-electric feedback system is used to indicate the precise position of the laser beam relative to the photo-sensitive surface. Since the laser beam which is being moved in order form the characters is weightless, its movement can be very fast and its speed of type composition can be correspondingly fast.</p> |
