Canon Kabushiki Kaisha

Takeshi Yamawaki

Hiroshi Sato

Takashi Suzuki

Kazumi Kimura

Osamu Koyama

Yuichi Tomioka

Hidekazu Shimomura

Kazuhiko Matsuoka

Kazuyuki Kondo

Makoto Fujimoto

Seiichiro Satomura

Yukio Takemura

Akira Miyashita

Seiichiro Mori

Katuya Yamazaki

Provided is an image forming apparatus including a light scanning apparatus that emits a light flux to photosensitive surfaces of a plurality of photosensitive bodies arranged so that longitudinal directions are the same direction and that optically scans the plurality of photosensitive surfaces in the longitudinal direction, wherein a diameter of at least one of the plurality of photosensitive bodies is different from diameters of the other photosensitive bodies in a cross section perpendicular to the longitudinal direction, and in the cross section perpendicular to the longitudinal direction, a sign ofand a sign ofare different, whereindenotes an incident angle of a light flux incident on a first photosensitive body with a smallest diameter among the plurality of photosensitive bodies, anddenotes an incident angle of a light flux incident on a second photosensitive body with a largest diameter, and a condition|&#x3e;0 is satisfied.

Image forming apparatus, including a light scanning apparatus that emits a light flux

A scanning optical apparatus capable of forming a preferable image, includes a light source unit, a rotational polygon mirror having a plurality of deflection surfaces for deflectively scanning a light flux emerged from the light source unit, an incident optical system for imaging the light flux as a line image on the deflection surfaces; and an imaging optical system which has one or more imaging lenses, images the light flux that has passed through the rotational polygon mirror on a surface to be scanned, and brings the deflection surfaces and the surface to be scanned into a conjugate relationship with each other in a sub scanning section, in which at least one of the imaging lenses of the imaging optical system has a lens surface formed into a non-arcked shape in the sub scanning section, and is held by a holding member so as to be movable.

Scanning optical apparatus and image forming apparatus using the same

An optical scanning apparatus, including an incident system that allows a beam from the light source to enter to deflector; and an imaging system that images the beam deflected by the deflector on a scanning surface, in which the incident system includes a first and second systems, the first system includes first and second elements each having a positive power with rotational symmetry, the light source is positioned at a shorter distance from the front focus position of the first element, the first element is formed integrally as a unit, powers of the second element and the first system, magnifications within main and sub-scanning sections of entire system, and focus movement within the main and sub-scanning sections on the scanning surface when the second element is moved in the optical axis direction are appropriately set.

Optical scanning apparatus and image forming apparatus using the same

The optical scanning apparatus has at least two scanning units Sand Swhich are arranged so as to oppose each other with a deflecting unit interposed therebetween. The scanning units include incident optical systems La and Lb that guide light beams emitted from light source unitsandto the deflecting unit, and imaging optical systems Ma and Mb that cause the light beams for scanning deflected on a deflecting surface of the deflecting unit to form images on surfacesandto be scanned. The two scanning units are configured such that the main scanning planes thereof including an optical reference axis Chave different heights from a bottom surfaceof the deflecting unit in the direction of the rotational axis of the deflecting unit.

Optical scanning apparatus and color image forming apparatus using the same

A compact optical scanning apparatus capable of desirably correcting an f characteristic, a field curvature, and other aberrations, and an image forming apparatus using the same, which includes an incident optical system (LA) for guiding a beam from a light source () to a deflector () and an imaging optical system (LB) for guiding the beam to a scanning surface (), wherein a scanning field angle region whereandare satisfied exists within effective scanning field angle region, where in a main scanning cross section and for a scanning field anglerepresents an angle between a principal ray of beam incident on an optical element included in the imaging optical system and located closest to the scanning surface and an optical axis of the imaging optical system andan angle between a principal ray of a beam from the optical element and the optical axis.

Optical scanning apparatus and image forming apparatus using the same including relationship between interval between deflector and scanned surface and a natural convergent point

A compact optical scanning apparatus capable of desirably correcting an f&#x3b8; characteristic, a field curvature, and other aberrations, and an image forming apparatus using the same, which includes an incident optical system (LA) for guiding a beam from a light source () to a deflector () and an imaging optical system (LB) for guiding the beam to a scanning surface (), wherein a scanning field angle region where &#x3b8;and &#x3b8;are satisfied exists within effective scanning field angle region, where in a main scanning cross section and for a scanning field angle &#x3b8;represents an angle between a principal ray of beam incident on an optical element included in the imaging optical system and located closest to the scanning surface and an optical axis of the imaging optical system and &#x3b8;an angle between a principal ray of a beam from the optical element and the optical axis.

An optical scanning apparatus includes a light source device, a rotating polygon mirror, a first optical system, and a second optical system. The light source device has at least one light emitter. The first optical system can cause a light beam emitted from the light source device to be incident on the rotating polygon mirror. The width of the incident light beam is larger than the width of the deflecting surface of the rotating polygon mirror in the main scanning direction. The second optical system leads the light beam deflected by the rotating polygon mirror to a surface to be scanned. The surface to be scanned is scanned with the light beam in the main scanning direction by the rotation of the rotating polygon mirror. The number of the deflecting surfaces of the rotating polygon mirror is ten or less, and each conditional expression is satisfied.

Optical scanning apparatus and image forming apparatus using same

An optical scanning apparatus includes a laser unit formed by integrating a semiconductor laser and collimator lens, an incident optical system for making a light beam emerging from the laser unit strike an optical deflector while keeping the light beam wider than the width of a deflecting surface of the optical deflector in the main scanning direction, and an imaging optical system for forming the light beam reflected/deflected by the optical deflector into an image on a scanned surface. The laser unit is shifted by a shift adjusting means in a predetermined direction with respect to the optical axis of the incident optical system so as to make an illuminance distribution of scanning lines on the scanned surface become substantially symmetrical about the scanning central axis.

Optical scanning apparatus, image forming apparatus, and methods of performing optical scanning using optical scanning apparatus and image forming apparatus

To provide a multibeam scanning optical device and an image forming apparatus using the same which can attain both of a large adjustment range and high adjustment accuracy using a plurality of adjusting units having sensitivities different from each other. There is provided a multibeam scanning optical device including: a first optical system which transforms a plurality of light beams emitted from a plurality of light source units into divergent light beams or convergent light beams; a second optical system which focuses a plurality of light beams emitted from the first optical system as a linear image in a main scanning direction in the vicinity of a deflection plane of a deflecting unit; the deflecting unit which deflects a plurality of light beams emitted from the second optical system in the main scanning direction; and a third optical system which focuses the plurality of light beams deflected by the deflecting unit on a surface to be scanned at a predetermined scanning lines gap, in which the multibeam scanning optical device further includes a plurality of adjusting units having sensitivities different from each other which change a relative gap in a sub-scanning direction of principal ray of a plurality of light beams incident in the second optical system.

Multibeam scanning optical device and image forming apparatus using the same

A color image reading apparatus has a 3-line sensor formed by setting a plurality of line sensors on a single substrate, an imaging lens for imaging an object, a diffraction grating which is inserted in the optical path between the imaging lens and 3-line sensor and color-separates a light beam coming from the object into a plurality of color light beams, and a first cylinder unit which is inserted in the optical path between the object and the imaging lens, and temporarily images the object in the sub-scanning direction in the optical path before the imaging lens.

Color image reading apparatus

A multi-beam light scanning optical system includes n (n&#x2267;2) light source means having m (m&#x2267;2) light emitting points; beam synthesizing means for synthesizing n&#xd7;m light beams emitted by the light source means; deflecting means for deflecting n&#xd7;m light beams from the beam synthesizing means; an imaging optical system for imaging the n&#xd7;m light beams from the deflecting means on a surface to be scanned, wherein the surface to be scanned is scanned in a main scan direction with n&#xd7;m light beams by a deflection scanning operation of the deflecting means; an aperture stop provided between the beam synthesizing means and the deflecting means, wherein principal rays of the n&#xd7;m light beams are intersected at a position of the aperture stop, and the light beams which are adjacent to each other in a sub-scan direction on the surface to be scanned are the beams emitted from different ones of the light source means.

Multi-beam light scanning optical system and image forming apparatus using same

An incident optical system introduces a plurality of laser beams to an optical deflector from within a scanning range, the width of the plurality of laser beams being larger than the width of a deflection surface of the optical deflector in a main scanning direction. Principal rays of the plurality of laser beams, separated by a predetermined angle, cross each other near the deflection surface in a main scanning cross-section. A scanning optical device satisfies the expression &#x394;&#x3b8;&#x3c;(4&#x3c0;/N)&#xd7;(1&#x2212;&#x3c1;), where &#x394;&#x3b8; represents the largest angle between principal rays of two of the plurality of laser beams, N represents the number of deflection surfaces of the optical deflector, and &#x3c1; represents the scanning efficiency of the deflection surface, which is the ratio of an image forming range to the theoretical maximum scanning width on the deflection surface of the optical deflector.

Scanning optical device and image forming apparatus using the same

An optical scanning device includes a first optical system, including a light source, for directing a light beam, emitted from the light source, to an optical deflector. A second optical system focuses the light beam deflected by the deflector on an effective scanning area of a scanning surface. The light source is continuously kept lit when scanning outside of the effective scanning area. A light shield member is positioned between the deflector and the scanning surface to block at least a portion of the light beam emitted during the period of time when the light source is continuously kept lit when scanning outside of the effective scanning area.

Optical scanning device and image forming apparatus wherein the light source is kept continuously lit between line scans

A scanning optical device to be used for an image forming apparatus such as a laser beam printer and a digital copying machine comprises a light source such as a semiconductor laser, an optical deflector having a deflection surface for deflecting the light beam emitted from the light source in the main-scanning direction, a first optical system for causing the light beam emitted from the light source to strike the deflection surface as a linear image extending in the main-scanning direction, and a second optical system for focussing the light beam deflected by the optical deflector on a surface to be scanned. The first optical system comprises a first lens, a second lens and a cylindrical lens showing refractive power only in the sub-scanning direction, preferably as well as part of the second optical system shared with the latter. The second lens and/or the cylindrical lens are movable along the optical axis to regulate the imaging position of the light beam on the surface to be scanned.

Scanning optical device and method of regulating imaging position thereof

An optical recording/reproducing apparatus includes an irradiation optical system for irradiating a light beam from a light source onto a predetermined track of an optical recording medium having a plurality of neighboring tracks as a fine light spot so as to perform recording/reproduction of information or reproduction of information, and a detection optical system for detecting a returned light beam from the optical recording medium. A mask is arranged in a far field region sufficiently separated from a focal plane of the detection optical system, for masking marginal rays, in a direction perpendicular to the track, of the returned light beam, so that information reproduced from a track adjacent to the predetermined track upon reproduction of information on the predetermined track is reduced.

Optical recording/reproducing apparatus including a mask device for masking marginal rays, in a direction perpendicular to a recording medium track, of a light beam returned from the recording medium

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Tokyo, Japan

Takeshi Yamawaki