MULTIBEAM SCANNING SYSTEM FOR PICTURE FORMING DEVICE

PROBLEM TO BE SOLVED: To provide a beam scanning system for a picture forming device having a multi-scanning assembly movably engaged with a girder member and independently controlled for simultaneously scanning a medium. SOLUTION: A multi-beam scanning system for a picture forming device such as an optical plotter and scanner has plural numbers of scanning assemblies movably engaged with a girder member extended to the length of a scanning surface of an inner drum 12 and being parallel with the axis in the longitudinal direction, these project plural light beams 28, 30 on a medium plate on the scanning surface and simultaneously reflect them from the plate. The optical plotter has plural light beam generators 21, 22 radiating the beam to the corresponding scanning assembly and independently controlled for reflecting the light beam to the medium. The scanner has plural light beam receivers for receiving the light beam reflected from the medium by means of each scanning assembly and generating a picture forming signal shown by the light beam. The generator and receiver of light beam may be installed at one end of the inner drum. For materializing it, a rear scanning assembly including an optical periscope for reflecting a light beam parallel with the axis in the longitudinal direction of the inner drum is required.