internal-drum laser scanning

internal-drum laser scanning

[in′tərn·əl ¦drəm ′lā·zər ‚skan·iŋ]
(graphic arts)
A method for the direct exposure of printing plates in which a laser beam is swept across a plate that is placed on the inside of a stationary drum by a rotating mirror inclined at an angle of 45° to the axis of the drum; the beam is modulated by video signals from a similar reading system or digital signals from a computer.