Abstract: Apparatus for scanning a laser beam including a beam splitter for splitting a laser beam into a scale scanning beam and a read/write scanning beam, a modulator for applying information to the read/write scanning beam, lenses and mirrors, including a cylindrical lens for directing both beams onto the same facet of a rotating polygonal scanning mirror, and a lens for focusing the modulated beam to a spot on a scanned medium and for focusing the unmodulated beam through a scale onto a detector for providing timing pulses for the apparatus.

Abstract: A beam scanning type electronic copying apparatus is provided in which document information is read out according to a beam reflected based on a scanning laser beam, the laser beam is modulated according to the document information and a record medium is exposed while being scanned. The laser beam scans the document and record medium simultaneously through an aconstooptic element which permits simultaneous beam diffraction and beam modulation. The readout of the document information and recording are simultaneously effected using the same optical system.