Ricoh Company, Ltd.

National Aerospace Laboratory of Science & Technology Agency

National Aerospace Laboratory of Japan

National Space Development Agency of Japan (nasda)

Tokyo Aircraft Instrument Co., Ltd.

Ricoh Technology Research, Inc.

Rioch Company, Limited

National Aerospace Laboratory of Science & Technology

Kawasaki Industries, Ltd.

National Aerospace Laboratory of Science &technology Agency&national

Seizo Suzuki

Yoshinori Hayashi

Hiromichi Atsuumi

Kohji Sakai

Magane Aoki

Satoru Itoh

Teruomi Nakaya

Taku Amada

Kazuyuki Shimada

Kenichi Takanashi

Osamu Okamoto

Naoki Miyatake

Hiroyuki Suhara

Akihisa Itabashi

Naoaki Kuwano

Mitsuo Suzuki

Kouji Masuda

Tomohiro Nakajima

Shigeaki Imai

Takeshi Ueda

Taira Kouchiwa

Shuichi Sasa

Takao Yamaguchi

Masaaki Ishida

Tatsuya Ito

Koji Hirakura

Hidehiko Nakayasu

Masakazu Sagisaka

Isao Yamaguchi

Atsushi Kawamura

Atsufumi Omori

Daisuke Ichii

Yasuhiro Nihei

Toshiaki Tokita

Nobuo Sakuma

Koji Masuda

Akira Kojima

Kazuhiro Akatsu

Ikuko Yamashiro

Masahiro Soeda

Heihachiro Kamimura

Junichi Yazawa

Mitsuharu Izaki

Yoshio Hayashi

Goji Iba

Katsuhiko Renbutsu

Yasuoki Usui

Jyunichi Ueno

Hiroaki Nagano

Toshihiro Suzuki

Hideaki Hirai

Hayato Fujita

Makoto Hirakawa

Kenichiroh Saisho

Nobuaki Kubo

Muneaki Iwata

Jun Tanabe

Katsumi Yamaguchi

Osamu Endo

Masako Yoshii

Hironobu Mifune

Yasutaka Izumi

Kazuyoshi Yabuuchi

Toru Iwata

Asao Hanzawa

Hiroyoshi Tanaka

Tadashi Kishimoto

Kotaro Matsumoto

Sachiko Wakabayashi

Kobji Sakai

Mitsuo Usami

Takashi Saitow

Masao Ebihara

Yasuaki Taniguchi

Ryuji Sakata

Kenji Ogimoto

Masao Uegusa

Hiroshi Oda

Yoshinori Sakai

Each light source has plural light emitting portions that are arranged at the different positions in at least a sub-scanning corresponding direction. A memory of a scanning control device stores correction data of the deviation of the beam pitch, correction data of the light amount difference, and correction data to decrease an influence of a reciprocity failure, for each combination of pixel forming light emitting portions. When a write signal is generated, a write control circuit of the scanning control device reads the correction data of the deviation of the beam pitch, the correction data of the light amount difference, and the correction data of the reciprocity failure according to the combination of the pixel forming light emitting portions from the memory, overlaps the read correction data to correction data of an APC, and outputs the overlapped data to a corresponding light source unit as light amount correction data.

Optical scanning device and image forming apparatus

An optical scanning device, arranged on one side of at least two to-be-scanned members in a second direction, and the two to-be-scanned members being arranged in a first direction perpendicular to the second, includes: an illuminating system that emits beams including a first beam and a second beam whose polarization directions are different from each other; an optical deflector that deflects the beams; and a scanning optical system that includes a polarization separation element that transmits one of the first and second beams and reflects the other; a first mirror group including reflecting mirrors for guiding the first beam to a to-be-scanned member; and a second mirror group including reflecting mirrors for guiding the second beam to a to-be-scanned member. Last-stage reflecting mirrors in the first and second mirror groups are arranged on one side of the beams deflected by the optical deflector in the second direction.

Optical scanning device and image forming apparatus including a plurality of scanned members

An optical scanning apparatus and an image forming apparatus having the optical scanning apparatus includes a before-light-deflecting-unit optical system and a scanning optical system. The optical system includes a first optical device, a second optical device made of a resin material which has an anamorphic negative refracting power in a deflection scanning direction and a deflection scan perpendicular direction and has a larger refracting power in the deflection scan perpendicular direction than a refracting power in the deflection scanning direction, and a third optical device made of a glass material which has substantially no refracting power in the deflection scanning direction and a positive refracting power in the deflection scan perpendicular direction. An interval of the scanning lines formed on the scanned surface is adjusted by displacement of the second and third optical devices in an optical axis direction of the before-light-deflecting-unit optical system.

Optical scanning apparatus and image forming apparatus

An optical scanning device including a light source having multiple light emitters; an optical element to reflect and transmit the emitted light beams; a photodetector to receive the reflected light beams; an aperture having an opening to shape the transmitted light beams; a light deflector to deflect the transmitted light beams; and a scanning optics to guide the deflected light beams to a scanning surface. The quantity of each of the light beams received by the photodetector is not less than 0.01 mW, and the size of a light receiving surface of the photodetector is determined such that even when the full width at half maximum of the emitted light beams changes, the rate of change of the ratio of the quantity of the light beams detected by the photodetector to the quantity of the light beams passing through the opening of the aperture is not greater than 4%.

Optical scanning device, image forming apparatus, and optical scanning device designing method

Apparatus that forms an image according to image information includes density sensors that detect image density variations in main and sub-scanning directions. A processing device generates correction data for correcting a light source output to suppress the density variations based on detection results. The processing device modifies the correction data such that the light source output after the correction is at least a minimum rated output at a position at which the output after the correction is lower than the minimum rated output, in the relation between a position on the surface of the photosensitive element in the main-scanning direction and the output after the correction, and modifies the correction data such that the light source output after the correction is at most a maximum rated output at a position at which the output after the correction is higher than the maximum rated output.

Image forming apparatus to detect and correct density variations in a developed image

A polarization splitting device includes a polarization beam splitter having a polarization splitting surface and allows P-polarized light to transmit therethrough and reflects S-polarized light. A subwavelength structure grating is formed on the polarization splitting surface with a grating pitch smaller than wavelength of incident light. The polarization splitting device also includes a polarizer that is arranged on an optical path of light reflected from the polarization beam splitter and has a transmission axis that is parallel to a polarization direction of the S-polarized light.

Polarization splitting device, method of manufacturing polarization beam splitter, optical scanning device, and image forming apparatus

An optical scanning apparatus, an image formation apparatus, and a phase modulation method are disclosed. The optical scanning apparatus includes a liquid crystal device for deflecting an optical beam irradiated by a semiconductor laser. The driving voltages for the liquid crystal device are controlled based on, e.g., the temperature of the liquid crystal device so that degradation of the diameter of a spot of the optical beam due to wavefront aberration is prevented.

Optical scanning apparatus, an image formation apparatus, and a phase modulation method

A light source unit is disclosed. The light source unit includes a phase type optical element which modulates a phase distribution of laser beams emitted from a light source. The phase type optical element has a phase distribution so that a first ratio of the peak intensity of side lobe laser beams to the peak intensity of main lobe laser beams in a beam intensity profile at a focal position of the laser beam condensing element is greater than a second ratio of the peak intensity of side lobe laser beams to the peak intensity of main lobe laser beams in the beam intensity profile at the focal position of the laser beam condensing element when it is assumed that the phase type optical element is not disposed.

Light source unit, phase type optical element, and laser beam scanning device

An optical scanner includes a light source modulated based on image data, an optical deflection and scanning part deflecting a light beam emitted from the light source, and a scanning and imaging optical system condensing the deflected light beam toward a scanning surface so as to form a light spot optically scanning the scanning surface. The effective scanning region of the scanning surface is divided into a plurality of regions according to a scanning line curving characteristic. Suitable image data for optically scanning the divided regions are selected from image data of a plurality of image lines every time the light spot optically scans the effective scanning region, so that the image data of each of the image lines is written with scanning line curving being corrected.

Optical scanner and imaging apparatus using the same

In an optical scanning device, when pixel density is taken to be n, number of the light beams is taken to be b, and number of the deflection surfaces of a deflecting unit is taken to be p, a spatial frequency S denoted by S=1/(1/(25.4/n&#xd7;b&#xd7;p) is within a range of a spatial frequency characteristic for a visual perception system of a high relative luminous efficiency. When spacing between ends in a sub-scanning direction of a scanning line formed by one scan by the deflection unit is taken to be L, and spacing between all progressive scanning lines at the surface to be scanned is taken to be L, then L&#x3e;(k&#x2212;1)&#xd7;Lis satisfied, where k is a total number of light emitting points of a light source.

An optical scanning device acquires a displacement amount of each of scanning light beams in the main scanning direction, and corrects, based on the displacement amount, writing energy density at a write position such that a variation in image density due to a variation of the displacement amount is reduced. The light beams are used for scanning a target surface to write image data on the target surface. The writing energy density is an amount of light per unit surface area of the target surface.

Optical scanning device, image forming apparatus, and write method

An optical scanning characteristic control method is applied to an optical scanning system in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam. The method comprising the steps of a) disposing a beam deflection control device on the light path of the beam before it is incident on the scanning surface; and b) controlling a beam deflection amount of the beam deflecting device provide to an incident beam so as to control a scanning characteristic of the optical scanning.

Image forming system employing effective optical scan-line control device

An optical scanning device which scans a scanned surface by a plurality of light beams in a main-scanning direction includes a light source having a plurality of light-emitting portions which emit the light beams, the light-emitting portions being two-dimensionally arranged in a plane parallel to the main-scanning direction and a sub-scanning direction orthogonal to the main-scanning direction via arrangement intervals in the main-scanning direction and the sub-scanning direction, a deflector which scans the light beams in the main-scanning direction; and a scanning optical system which images the scanned light beams onto the scanned surface.

Optical scanning device and image forming apparatus for optimizing arrangement intervals in a main-scanning direction and a sub-scanning direction

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Kanagawa, Japan

Seizo Suzuki