Fuji Photo Film Company, Limited

Thomson-csf

Fjui Photo Film Co., Ltd.

Hidetoshi Shinada

Katsuto Sumi

Hiroyuki Hiiro

Kiichi Kato

Noboru Arai

Hiroshi Matsuoka

Katsumi Asanuma

An optical beam scanning apparatus which includes: an optical modulator which emits an optical beam in a direction corresponding to the frequency of an inputted signal; scanning device for scanning the optical beam; a scanning lens; a storage device which stores data for correcting the displacement of the optical beam passing through the scanning lens caused by an aberration of the scanning lens for each scanning position of the optical beam; and a device which, based on the data stored in the storage device, alters the frequency of the signal to be inputted to the optical modulator for each scanning position of the optical beam so as to correct the displacement of the optical beam caused by the aberration of the scanning lens.

Optical beam scanning apparatus

Parallel laser beams #1, #2 and #3 produced by splitting one laser beam into three, are introduced to an optical scanning device along the central axis of a recording cylinder, the optical scanning device being disposed on the central axis of the recording cylinder and rotated thereabout, having an inclined mirror surface, the recording cylinder holding a recording sheet on an interior surface thereof. The laser beam #2 incident upon the mirror surface at its center of rotation is reflected at the point of incidence, while the laser beams #1 and #3 are deflected by acousto-optical devices back and forth in the opposite directions in synchronism with the rotation of the optical scanning device, in parallel planes held at a distance and including the laser beams #1 and #3 therein, thereby to give the laser beams #1 and #3 angles of incidence upon the mirror surface necessary in order for the laser beams #1, #2 and #3 after reflected to produce scanned loci running parallel to each other at a given interval on the recording sheet, regardless of rotational positions of the optical scanning device. To adjust a relative difference in the lengths of the scanned loci, timing at which the laser beams #1, #2 and #3 are turned on/off is controlled. When the laser beams #1 and #3 are deflected so as to gyrate along a conical plane whose central axis is that of the recording cylinder, the laser beams #1, #2 and #3 produce scanned loci always running parallel to each other at a given interval with the same scanning lengths on the recording sheet.

Apparatus for recording images on interior surface of cylinder

A light beam recording device. A light beam irradiated from a light beam irradiating device is scanned onto an object to be illuminated, which is provided in a vicinity of a focal position, while being focussed by a scanning optical system. A converging member is disposed on an optical path between the light beam irradiating device and the scanning optical system, and converges a light beam which is incident on the converging member. An optical path changing device is disposed in a vicinity of a converging position of a light beam which is converged by the converging member, and changes an optical path of the light beam.

Disk for light beam recording device and light beam recording device

A light beam recording device. A light beam irradiated from a light beam irradiating device is scanned onto an object to be illuminated, which is provided in a vicinity of a focal position, while being focused by a scanning optical system. A converging member is disposed on an optical path between the light beam irradiating device and the scanning optical system, and converges a light beam which is incident on the converging member. An optical path changing device is disposed in a vicinity of a converging position of a light beam which is converged by the converging member, and changes an optical path of the light beam.

Light beam recording device having a reflecting mirror movable a long an

A method and apparatus for scanning and exposing in which m laser beams which are arranged in an array so that part of a adjacent laser beams overlap on the photosensitive surface, are main-scanned in a direction intersecting the line along which the laser beams are arranged, while being sub-scanned in the direction in which they are arrayed, to carry out a two-dimensional exposure. The power of at least one of the mth laser beam for the Nth main scanning and the first laser beam for the (N+1)th main scanning is changed, or the distance between the mth laser beam for the Nth main scanning and the first laser beam for the (N+1)th main scanning is changed, to correct density unevenness at the overlapping portion of the mth and the first laser beams.

Scanning and exposing method using a plurality of optical beams and

Disclosed herein is a method of mixing together a plurality of inputted high-frequency signals whose frequency intervals are equal to each other so as to input the thus-mixed high-frequency signals to a multi-frequency acousto-optic device for dividing incident laser beams with the density according to the amplitude of each of the inputted high-frequency signals and in the direction corresponding to the frequency of each inputted high-frequency signal so as to radiate the thus-divided laser beams therefrom. The high-frequency signals whose frequencies are free from being adjacent to each other are mixed together, and the thus-mixed high-frequency signals are further mixed into one, thereby inputting the mixture to the acousto-optic device. Since the frequencies of high-frequency signals to be mixed first are not adjacent from each other, third-order harmonic signals appear at positions where they are dispersed. It is therefore possible to suppress the influence of third-order harmonic distortion upon the density of an image to the utmost.

Method of inputting signals to light modulator and simultaneous

A simultaneous multi-beam optical modulator device which has first modulators for amplitude modulating a plurality of carrier waves according to a plurality of input signals to produce a plurality of modulated signals and an audio optical device for separating an incoming beam of light into a plurality of sub-beams and for, at the same time, optically modulating the sub-beam upon receiving the modulated signals from their respective first modulators, is provided, further comprising an output device for storing indicator signals corresponding to the number of input signals fed to the first modulators and for selecting from these stored signals a signal corresponding to the number of the input signals to the first modulators, a digital/analog converter for converting the signal transmitted from the output device into an analog output which is used to varies the intensity of output light, and a second modulator for amplitude modulating the plural modulated signals transmitted from the first modulators according to the analog output of the digital/analog converter. Accordingly, the intensity of a light output from the audio optical device can be maintained constant.

Simultaneous multi-beam optical modulator device using memory mapped

An optical system featuring a semiconductor laser for oscillating a beam which has, in a far field pattern, two lobes in the direction aligned with a pn junction interface of the semiconductor laser. The optical system is provided with a total reflection mirror for reflecting part of the beam in such a manner that one of the two lobes is separated as a result of the reflection of part of the beam from the other, and with a polarization beam splitter having a junction for synthesizing rays in such a manner that the lobes which have been separated by the total reflection mirror are superimposed. The apparatus is thus capable of forming a single beam spot at which the two lobes are superimposed.

Semiconductor laser optical system

A laser beam recorder arranged to record data with dots of a constant size, constant pitch and constant density, irrespective of possible differences in scanning speed between the middle and peripheral portions of a recording medium. The timing of irradiating the recording medium with the light beam is precipitated and the duration of the irradiation with the light beam is shortened as the scanning speed increases, whereby the dot size and dot pitch can be made constant irrespective of variation in the scanning speed. Further, the light beam is intensified as the scanning speed increases. Though the duration of the irradiation with the light beam is reduced with the increasing scanning speed, the amount of energy for recording one dot is maintained constant by intensifying the light beam as described, whereby the dot density can be maintained constant.

Light beam recorder having beam duration and intensity controlled in

A method of and an apparatus for projecting an incident laser beam into a broad contact-type light amplifier. The laser beam is projected after the intensity distribution of the laser beam is made to coincide with the electromagnetic field distribution in the fundamental mode of the light amplifier. Since only the fundamental mode is used as the propagation mode of the light amplifier, a Gaussian beam amplified by the light amplifier is emitted. Consequently, the laser beam emitted from the light amplifier can be made into a several-micron spot by condensing the laser beam to a diffraction limit.

Method of and apparataus for projecting a laser beam into light amplifier

An optical semiconductor device of broad area structure comprising an active region positioned between a p-type semiconductor region having a stripe-like anode electrode and an n-type semiconductor region having a cathode electrode, the anode electrode having a broad stripe width in which the photon density is increased to amplify the light with the aid of injected into the active region dependent on the current density flowing between the anode and cathode electrodes, wherein the density distribution of the injected carriers exhibits Gauss distribution in the widthwise direction of the stripe width. Therefore, it is possible to supply such a current as to produce the density distribution of the injected carriers with no excess or shortage.

Optical semiconductor device

An optical semiconductor device having an active region defined between a pair of semiconductor regions, the active region having an incident end face through which light is introduced and an emission end face through which light is emitted. This device is designed to continuously change the distribution of the density of carriers injected in the active region over the area between the light incident side and the light emission side, thereby changing the density of carriers in the active region from the incident end face to the emission end face.

A method and apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, characterized in that the linear drive signal for driving the galvanometer is converted into a non-linear drive signal in accordance with predetermined correction data to thereby reduce the deviation to zero.

Apparatus for correcting scanning rate deviation of a galvanometer and

An information compression method and apparatus for information forms in which each from is divided into raster lines. Each raster line is divided into multi-bit units. The information of each unit is compared with that of a preceding unit. Agreement and disagreement codes are stored in a unit memory. The pattern information of disagreeing units only is stored in a pattern memory. Each raster line is then compared with all preceding raster line of this and preceeding forms by means of comparing the respective locations of the unit memory and the pattern memory. When inter-raster agreement is found, the respective locations in a raster memory are given the same address used to access the unit memory and only one set of redundant raster data is stored in the unit and pattern memories.

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Kanagawa, Japan

Hidetoshi Shinada