Abstract: A multi-beam light source device which can be used in an optical scanning device has less optical cross-talk and an improved stability in frequency response. The multi-beam light source device comprises a semiconductor laser array having a plurality of light emitting sources, a light receiving element array having a plurality of light receiving elements and a half mirror splitting a light beam emitted by the semiconductor laser array into at least two split light beams. A light converging unit is provided for converging one of the split light beams at a predetermined focal point. The light receiving element array is positioned at the focal point of the light converging unit for receiving the concentrated one of the split light beams. A controlling circuit is provided for controlling an output of the semiconductor laser array in accordance with the amount of light received by the light receiving element array.

Abstract: An optical recording apparatus comprises a laser diode array including a plurality of laser diodes for producing a plurality of laser beams in response to a drive signal indicative of an image, an optical system for scanning the laser beams on a surface of a photosensitive body, a beam splitting unit for splitting the laser beams produced by the laser diodes to form control laser beams; a driver for driving each of the laser diodes in the laser diode array, an optical detection unit provided for detecting the control laser beams, the optical detection unit including a plurality of photodetectors in correspondence to the laser diodes in the laser diode array in a one-to-one relationship, each of the photodetectors producing an output signal indicative of an optical power of the control laser beam incident thereto, and a control unit supplied with the output signals from the photodetectors in the optical detection unit for controlling the driver such that each of the laser diodes in the laser diode array produc

Abstract: A laser recording recording apparatus including a semiconductor laser as a light source and enabling half-tone recording. The apparatus includes a recording medium moving in a sub-scanning direction, M semiconductor lasers arranged along the sub-scanning direction at a slight distance to one another and enabled to be independently modulated according to image signals, where M is an integral number of at least two, a deflector for deflecting M laser beams emitted from the M semiconductor lasers toward the recording medium and for scanning the beams in a main scanning direction, and an image forming optical system for imaging the deflected laser beams at a predetermined distance between one another along the sub-scanning direction. An exposure pattern on the recording medium is represented by a pixel matrix comprising N.times.

Abstract: A half tone recording method has the steps of representing one picture element of image information including inputted density information by a matrix composed of K.times.

Abstract: An image forming apparatus using a plurality of laser beams having the same characteristic in order to form a predetermined color image. The predetermined color image consists of a plurality of image colors. The laser beams are shifted with respect to each other in a vertical scanning direction by a diameter of each laser beam divided by the number of the laser beams. Since a rotating of a polygon mirror which deflects the laser beams is asynchronous with a rotating of a photosensitive body on which each laser beam is radiated so as to form a latent image, image colors are shifted with respect to each other. According to the present invention, one of the laser beams is selected for each image color, based on a timing difference between the polygon mirror and the photosensitive body, so that image colors can be superimposed on each other.

Abstract: An image forming apparatus includes a semiconductor laser unit for emitting a laser beam, a photosensitive drum which rotates in a first direction, a scanning optical system for making the laser beam scan the photosensitive drum in a second direction perpendicular to the first direction, wherein an electrophotography process is carried out on the surface of the photosensitive drum, a data generator for generating intensity data for each dot in an image in accordance with image information supplied from an external controller, and a laser driver for outputting a driving signal which drives the semiconductor laser unit, the driving signal having a pulse width and a level for each dot in an image, the pulse width being a predetermined value less than a value corresponding to an interval between adjacent dots formed in a direction parallel to the first direction, and the level corresponding to the intensity data generated by the data generator.

Abstract: A focusing error detection apparatus for detecting a focusing error of a converging light beam on a surface of a recording medium in an image forming system.

Abstract: A synchronizing signal generating system for a laser scanner comprises a source for emitting a first laser beam for scanning and a second laser beam for synchronization of scans by the first laser beam, a deflector for causing a scan of a medium by the first laser beam and a scan of a grating by the second laser beam, a converging optical system for converging the second laser beam transmitted through the grating, a light receiving system for receiving the second laser beam converged by the converging optical system and for generating a reference pulse signal, a circuit for controlling the source responsive to the reference pulse signal so as to synchronize a scan timing of the first laser beam and comprising a PLL circuit for generating a synchronizing signal which has a frequency N times a frequency of the reference pulse signal in response to the reference pulse signal and a control circuit for controlling a value of N depending on the recording density, and a driving circuit for driving the source of sync

Abstract: A synchronizing signal generating system for a laser scanner includes a source for emitting a first laser beam for scanning and a second laser beam for synchronization of scans by the first laser beam, a polygonal mirror for causing the first laser beam to scan a medium and for causing the second laser beam to scan a grating which has bright portions and dark portions alternately arranged along a scanning direction of the second laser beam, a converging optical system for converging the second laser beam transmitted through the grating, a light receiving system for receiving the second laser beam converged by the converting optical system and for generating a synchronizing signal and a circuit for controlling the source responsive to the synchronizing signal so as to synchronize a scan timing of the first laser beam. A scan length of the second laser beam measured on the grating is set longer than a scan length of the first laser beam measured on the same plane.

Abstract: A synchronizing signal generating system for a laser scanner comprises a source for emitting a first laser beam for scanning and a second laser beam for synchronization of scans by the first laser beam, a polygonal mirror for causing the first laser beam to scan a medium and for causing the second laser beam to scan a grating which has bright portions and dark portions alternately arranged along a scanning direction of the second laser beam, a converging optical system for converging the second laser beam transmitted through the grating, a light receiving system for receiving the second laser beam converged by the converting optical system and for generating a synchronizing signal, and a circuit for controlling the source responsive to the synchronizing signal so as to synchronize a scan timing of the first laser beam. The converging optical system comprises a plurality of lenses or concave mirrors provided for a length corresponding to a scan length of the second laser beam on the grating.

Abstract: The present invention relates to a method of controlling the temperature of a semiconductor laser in an optical scanning device in which a light beam emitted from the semiconductor laser is deflected by a holographic scanner.

Abstract: The speed at which a desired surface is scanned by a light beam is rendered constant by correcting the frequency of an image scanning clock signal without using an f lens. The characteristics of correcting the image scanning clock frequency can be varied, or the image scanning clock signal can be brought into phase with a recording position signal.

Abstract: A modulated laser beam emitted from a semiconductor laser is deflected by a rotating light beam deflector to scan a desired surface. The frequency of an image scanning clock signal and the intensity of the laser beam from the semiconductor laser are varied according to a scanning rate at which the surface is scanned by the modulated laser beam.

Abstract: A scanning clock generating device for an optical scanner which scans a selected surface by a light beam to write optical information or read image information. The scanner scans the surface by a light beam which is deflected at a constant or a non-constant angular velocity and without resorting to an F-theta lens. The scanning clock generating device generates a scanning clock the frequency of which is continuously variable responsive to changes of scanning velocity on the surface to be scanned.