| 摘要 |
The machine preferably has a character matrix comprising a rotating drum with character-bearing film strips wrapped around it. The machine has a light source comprising a plurality of flash lamps and fiber-optic light pipes. The light-pipes are arranged in a linear array aligned parallel to the direction of travel of the film strips on the drum. Photographic film is formed into a semi-cylindrical arc and remains stationary during composition of up to a full newspaper page of text before the film is moved to another exposure position. Both character spacing and line spacing are performed by a combination of selective timing of the operation of the flash lamps, a lens and reflector traveling parallel to the film in a beam of collimated light, and a swinging mirror mounted on the axis of the semi-cylinder formed by the film. Both timing slits and base-line reference marks are located on the film strips near each character. The base-line reference marks are detected and used to make automatic corrections of the character image locations to ensure excellent base-alignment of the characters on the film. Other corrections of the character image locations are stored in a memory and are made automatically during composition. Several steps are taken to ensure accurate character spacing. A separate, independent timing circuit is used to time the flashing of each character. Also, the timing is determined by reference only to the timing slit immediately next to the character to be flashed. Furthermore, timing delay is controlled by a clock pulse source whose frequency is controlled by the drum rotation so as to compensate for instantaneous variations in drum speed and/or position. Each film strip bears coded indicia indicating the illumination level required for each different type face on the strip. Automatic adjustments are made to compensate for the divergence of the collimated light towards the end of very long lines of type composition. Special means are provided to compensate for the extension of italics and slanted characters to one side or the other of the normal character area. Means also are provided for the insertion of "pi" characters and forming rules.
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