Abstract: A laser beam printer which includes a laser beam emitting device for emitting a laser beam which has been modulated in accordance with image information; a rotatable deflecting device for rotatably deflecting the laser beam emitted from the beam emitting device; a rotatable photosensitive member which is scanningly exposed to light by the laser beam deflected by the deflecting device; and a control device for controlling the rotation of the deflecting device and that of the photosensitive member. The control device starts the rotation of the deflecting device after starting the rotation of the photosensitive member, so that the deflecting device reaches a predetermined rotational speed simultaneously with completion of pre-rotation of the photosensitive member.

Abstract: An oscillation detector circuit detects an oscillating condition of a resonant light deflector having a reflecting mirror, and applies an oscillating condition signal to a reference signal generator, which generates a reference signal. An auxiliary scanning feed motor for feeding a scanned medium in an auxiliary scanning direction is controlled by the reference signal to adjust the speed at which the scanned medium is fed in the auxiliary scanning direction, depending on the oscillating condition of the resonant light deflector.

Abstract: An integrated galvanometer scanning device controllably deflects a beam of light. The device has a planar silicon wafer substrate with front and rear surfaces, first and second longitudinal slots extending from the front surface to the rear surface, and top and bottom grooves extending between the first and second longitudinal slots. The slots and grooves define a central portion of the wafer. A magnet is attached to the rear surface on the central portion of the wafer and a magnetic circuit is attached to the rear surface. A reflective surface is formed on the front surface on the central portion of the wafer. A strain gage on the wafer detects deflection of the reflective surface, and thus beam deflection. The components are integrated into the wafer or formed or mounted on the wafer forming an integrated unitary structure.

Abstract: An optical beam scanning apparatus comprises means of modulating the optical power of a laser beam produced by a laser beam source, means of shaping the laser beam profile, and means of deflecting and focusing the shaped laser beam on a scanning plane. The optical power of the laser beam is varied in synchronism with the variation of the optical power distribution so that the peak level of optical power of the laser beam is kept constant. The optical power of the laser beam on the photosensitive drum is kept constant irrespective of the beam diameter, and printed dots of intended diameters can be produced, whereby fine multi-tone images can be printed stably.