Canon Kabushiki Kaisha

Hidekazu Shimomura

Hiroshi Sato

Keiichiro Ishihara

Manabu Kato

Ken Tanimura

Takashi Suzuki

Tokuji Takizawa

Masaki Sato

Kazumi Kimura

Mitsuru Kurita

Takeshi Yamawaki

Kazuyuki Kondo

Motomu Fukasawa

Takayuki Sugiyama

Shinichi Arita

Seiichiro Satomura

Yukio Takemura

Akihiro Fukutomi

Hidemi Takayama

Ken-ichi Tomita

Ken Nishimura

An optical scanning apparatus includes a light source, a deflector that deflects a light beam in a main scanning direction, an incident optical system that makes the light beam enter the deflecting surface in a sub-scanning section, and an imaging optical system that includes at least one imaging optical element and condenses the light beam onto a surface to be scanned, in which at least one of an incident surface and an exit surface of the at least one imaging optical element is decentered in the sub-scanning section such that an origin position line exists in a region sandwiched between marginal rays at two sub-scanning direction ends of the light beam, the origin position line being extended in the main scanning direction and passing through an origin of an aspherical surface formula defining a surface shape of each of the incident surface and the exit surface in the sub-scanning section.

Optical scanning apparatus having an optical element with at least one of an incident or exit surface thereof that is decentered in a sub-scanning section and image forming apparatus therewith

Provided is a method of manufacturing imaging optical elements which cause a plural light beams to enter a deflection unit, and guide those beams to corresponding surfaces to be scanned, the imaging optical elements being arranged optically at the same position, having the same optical performance, the method including: measuring, with respect to the imaging optical elements having the same optical performance, the optical performance at each of a plurality of positions of the different light beam passing states; calculating a correction shape of an optical functional surface of the imaging optical element based on a deviation amount from a design value of the optical functional surface of the imaging optical element; performing correction processing on a shape of a mirror-finish insert of a mold for molding based on the correction shape of the optical functional surface; and performing molding by using the mirror-finish insert subjected to the correction processing.

Method of manufacturing imaging optical elements and optical scanning apparatus using imaging optical elements manufactured by the method

A light scanning apparatus comprises a light source unit, a deflection unit, an incident optical system, and an imaging optical system including a transmission type imaging optical element and a reflection optical element are provided. A light beam deflected for scanning by the deflection unit passes through the imaging optical element in order of a first and a second transmission surfaces, and then passes through the imaging optical element again a third and fourth transmission surfaces. The first and fourth transmission surfaces of the imaging optical element are different in shape from another in the sub-scanning direction. Respective components are set so that, in a sub-scanning section, the light beam deflected for scanning is turned back by the reflection optical element and refracted/diffracted at the first transmission surface in a direction in which a reflected light beam passes through the third transmission surface, and that predetermined Conditional Expression is satisfied.

Optical scanning apparatus and image forming apparatus using the same

Light sources emit light beams onto deflecting surfaces of a deflecting unit through incident optical systems. The deflecting unit deflects the light beams in a uniform direction to form images onto different surfaces to be scanned through imaging optical systems. An optical path length, or a distance from a deflection point of the deflecting unit to a surface to be scanned, of an imaging optical system to form an image onto a surface to be scanned closest to the deflecting unit is different from that of an imaging optical system to form an image onto a surface to be scanned farthest from the deflecting unit. Also, the following condition is satisfied:0.85&#x3c;&#x3c;0.98where Kis a K&#x3b8; coefficient of an imaging optical system with a short optical path length, and Kis that of an imaging optical system with a long optical path length.

An image scanning apparatus includes a beam splitter disposed between a deflection surface and surfaces to be scanned. The beam splitter is formed of reflective surfaces and transmissive surfaces. One transmissive surface is disposed between the reflective surfaces in the sub-scanning direction, and an optical path of light beams reaching surfaces to be scanned that are physically closer to the deflection surface than a surface to be scanned located at the position physically farthest from the deflection surface between the reflective surfaces intersects with an optical path of a light beam reaching the surface to be scanned located at a position physically farthest from the deflection surface between the deflection surface and the transmissive surface in a sub-scanning cross section in the beam splitter.

Optical scanning apparatus

An optical scanning device includes a condensing optical system for collecting a light beam emitted from light source means, a deflecting system for scanningly deflecting the light beam collected by the condensing optical system, and an imaging optical system configured to image the light beam scanningly deflected by the deflecting means, on a surface to be scanned, the deflecting means having a deflecting surface reciprocally movable within a main-scan sectional plane to scanningly deflect the light beam from the condensing optical system, wherein, when the deflecting surface reciprocally moves within the main-scan sectional plane, the deflecting surface receives an angular acceleration which is able to cause deformation being asymmetric with respect to a sub-scan direction, and wherein the condensing optical system collects the light beam from the light source means to a region of the deflecting surface which is at a side of a central line of the deflecting surface with respect to the sub-scan direction where an amount of asymmetric deformation of the deflecting surface in the sub-scan direction is smaller than that at the other side.

Optical scanning device and image forming apparatus using the same

Light sources emit light beams onto deflecting surfaces of a deflecting unit through incident optical systems. The deflecting unit deflects the light beams in a uniform direction to form images onto different surfaces to be scanned through imaging optical systems. An optical path length, or a distance from a deflection point of the deflecting unit to a surface to be scanned, of an imaging optical system to form an image onto a surface to be scanned closest to the deflecting unit is different from that of an imaging optical system to form an image onto a surface to be scanned farthest from the deflecting unit. Also, the following condition is satisfied:0.85&#x3c;0.98where Kis a K&#x3b8; coefficient of an imaging optical system with a short optical path length, and Kis that of an imaging optical system with a long optical path length.

Optical scanners are configured so a principal ray of an incident beam from a light source device to a deflector and a principal ray of a scanning beam from the deflector to a scanned surface travel on the opposite sides of an optical axis of an optical element(s) wherein entrance and exit surfaces of the optical element(s) are both concave toward the deflector in the sub-scanning section. Embodiments may beneficially separate the scanning beam from ghost light and/or be incorporated in image forming apparatuses.

Optical scanner configured so a principal ray of an incident beam from a light source to a deflector and a principal ray of a scanning beam from the deflector to a scanned surface travel on opposite sides of an optical axis of optical element(s) having transmissive surfaces both concave toward the deflector in sub-scanning section, and image forming apparatus using the same

An optical scanning apparatus including a light source, deflection unit configured to deflect a light flux emitted by the light source, a first optical system configured to condense a divergent light flux emitted by the light source, a second optical system configured to focus the deflected light flux on a target scanning face, where the wavelength of the light flux is short, and the first and second optical systems include respective refractive optical elements.

Optical scanning apparatus and image forming apparatus employing this apparatus

An optical scanning apparatus and a color image forming apparatus using the same, in which streak-shaped density unevenness is reduced to prevent image deterioration: each of scanning surfaces is simultaneously scanned with light beams emitted from light source units and scanning lines are simultaneously drawn on the scanning surfaces; the light beams emitted from at least four light emitting portions of the corresponding light source unit are simultaneously deflected for scanning by a deflecting unit; and image data corresponding to a first scanning line, i.e. a scanning line located on an uppermost stream side in a direction in which the scanning surfaces move among scanning lines, on at least one of the scanning surfaces in a k-th scanning by the deflecting unit is displaced by at least one line space from image data corresponding to a first scanning line on another scanning surface in the k-th scanning.

Optical scanning apparatus and color image forming apparatus using the same

A light scanning apparatus including a semiconductor laser which emits a light beam having a wavelength equal to or less than 450 nm, an incidence optical system which makes the light beam, emitted from the semiconductor laser, incident on a deflector for scanning in deflection, an imaging optical system which images the light beam scanned in deflection by the deflector to a surface to be scanned, a light intensity detector which detects fluctuations in spectral transmittances of the incidence optical system and of the imaging optical system, which are caused as a concomitant of a fluctuation in wavelength of the light beam which is emitted from the semiconductor laser and passes through the incident optical system and the imaging optical system, and an automatic power controller which automatically controls a light emission output of the semiconductor laser on the basis of a detection value detected by the light intensity detector.

Light scanning apparatus and image forming apparatus using the light scanning apparatus

An optical scanning device and an image forming apparatus having the same include a light source, a deflecting system, an imaging optical system with at least one imaging optical element for imaging a light beam deflected by the deflecting system on a surface to be scanned, and at least one reflection type optical element disposed between the imaging optical element and the scanned surface, wherein the deflected light beam passes through a first transmission surface and a second transmission surface of the imaging optical element in this order and, after being reflected by the reflection type optical element, the light beam then passes through a third transmission surfaced and a fourth transmission surface of the imaging optical element in this order, and wherein a relation |&#xf8;M/&#xf8;|&#x3c;0.1 is satisfied where &#xf8; is an axial combined power within a main-scan section of the imaging optical element through which the light beam passes again, and &#xf8;M is an axial combined power within a main-scan section of the reflection type optical element.

An optical scanning device includes plural light source devices, a deflecting device having deflecting surfaces, an input optical system and a plurality of imaging optical systems, wherein a plurality of scan surfaces are simultaneously scanned by the deflecting device, wherein each of the plurality of imaging optical systems includes at least one transmission type imaging optical element and at least one reflection optical element, wherein each of at least two light beams scanningly deflected by the different deflecting surfaces of the deflecting device passes through the at least one transmission type imaging optical element constituting the imaging optical system and is thereafter reflected by the at least one reflection optical element and, subsequently, it passes again through the transmission type imaging optical element, and wherein, after passing again through the transmission type imaging optical element, the at least two light beams scanningly deflected by the different deflection surfaces of the deflecting means intersect with each other within a sub-scan section.

Optical scanners are configured so a principal ray of an incident beam from a light source device to a deflector and a principal ray of a scanning beam from the deflector to a scanned surface travel on the same side (or opposite sides) of an optical axis of an optical element(s) respectively wherein entrance and exit surfaces of the optical element(s) are both convex (or both concave) toward the deflector in the sub-scanning section. In various embodiments, the aforementioned principal rays travel on the same side, and surfaces are convex toward the deflector in the sub-scanning section. In various embodiments, the aforementioned principal rays travel on opposite sides, and surfaces are concave toward the deflector in the sub-scanning section. Embodiments may beneficially separate the scanning beam from ghost light and/or be incorporated in image forming apparatuses.

Optical scanner configured so a principal ray of an incident beam from a light source to a deflector and a principal ray of a scanning beam from the deflector to a scanned surface travel on same side (or opposite sides) of an optical axis of an optical element(s) having transmissive surfaces both convex (or both concave) toward the deflector in sub-scanning section respectively, and image forming apparatus using the same

At least one exemplary embodiment is directed to an optical scanning apparatus that employs a short wave light source to constantly maintain a spot having a tiny diameter, even when an environmental temperature change occurs, by employing a lens and/or a diffractive optical element.

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Yokohama, Japan

Hidekazu Shimomura