An apparatus includes a detector, a light source configured to emit light, a reflecting apparatus having multiple reflective facets, and a mirror. The reflecting apparatus is configured to rotate around an axis and arranged to reflect the emitted light from the light source and reflect backscattered light. The mirror is arranged to reflect the backscattered light from the reflecting apparatus towards the detector.

An optical scanning device according to the present invention has a 2-beam type first laser diode and a 1-beam type second laser diode. When resolution in a sub-scanning direction is 600 dpi, exposure processing is executed by a first laser beam and a second laser beam emitted from the first laser diode. And when the resolution in the sub-scanning direction is 1200 dpi, the exposure processing is executed by the first laser beam and a third laser beam emitted from the second laser diode.

An optical writing device, and a method of controlling the optical writing device. The optical writing device and the method includes controlling speed of operation of a light deflector based on image magnifying-power information in a sub-scanning direction parallel to a direction in which a surface of a photoconductor moves, and controlling a prescribed write clock frequency such that a number of clock pulses of write light will become a target number of pulses over a period where the write light scans an area within a prescribed distance in a main scanning direction, the target number of pulses being maintained even when the speed of operation of the light deflector is changed in the controlling the speed of operation of the light deflector. The write clock frequency controller maintains the target number of pulses even when the speed of operation of the light deflector is changed by the light-deflector controller.

An optical scanning device includes a light source that emits a light beam, a lens member, and a housing that supports the lens member. The housing and the lens member are provided with a housing-side engagement and a lens member-side engagement respectively that engage with each other. The housing-side engagement and the lens member-side engagement are capable of pivoting the lens member around an axis along an optical axis direction of the light beam passing through a contact contacted through concavo-convex engagement with each other.

A system and method for scanning of coherent LIDAR. The system includes a motor, a laser source configured to generate an optical beam, and a deflector. A first facet of the plurality of facets has a facet normal direction. The deflector is coupled to the motor and is configured to rotate about a rotation axis to deflect the optical beam from the laser source. The laser source is configured to direct the optical beam such that the optical beam is incident on the deflector at a first incident angle in a first plane, wherein the first plane includes the rotation axis, wherein the first incident angle is spaced apart from the facet normal direction for the first facet. A second facet of the plurality of facets includes an optical element configured to deflect the optical beam at the first incident angle into a deflected angle.

The method of aligning a cylindrical lens in a lens assembly includes attaching the cylindrical lens to a lens fixture and interfacing the lens fixture to a support structure in which the cylindrical lens can be placed in a frontwards and backwards orientation. The method also includes capturing respective first and second line images of respective first and second focus lines as formed by the cylindrical lens in the forwards and backwards orientations. The method further includes establishing a relative orientation of the first and second line images and using the established relative orientation to determine an amount of angular misalignment of the cylindrical lens relative to a reference direction provided by the support structure. The method can include rotating the cylindrical lens relative to the lens fixture to reduce the amount of angular misalignment to be within an angular alignment tolerance.

An image forming apparatus includes a scanning means provided with a light source, a polygon mirror and a driving means for driving rotation of the polygon mirror; a photosensitive member, a developing means, and a detecting means for detecting a laser light from the light source. A controller controls to execute a light emission operation so that an area including an image forming area of the photosensitive member is irradiated with the laser light. The controller controls to execute a switching operation in which a rotational speed of the polygon mirror is switched from a first speed to a second speed different from the first speed. The controller controls to execute the light emission operation in a state in which the photosensitive member and the developing means are in contact and are rotating, and to execute the switching operation based on a detecting result of the detecting means in the light emission operation.

Optical scanner and electrophotographic image forming apparatus are provided. The optical scanner includes a light source, configured to emit a light beam; an optical deflector, configured to deflect the light beam emitted from the light source; a first optical unit, arranged there-between and including a refraction unit and a diffraction unit; and a second optical unit, arranged in a light exit direction of the optical deflector and configured to make the light beam deflected by the optical deflector form an image on a scanning target surface. A range of a ratio of a refractive power Φ.sub.r to a diffractive power Φ.sub.d of the first optical unit in a main scanning direction is 0.3<Φ.sub.r/Φ.sub.d<0.5; and a range of a ratio of a refractive power Φ.sub.s to a diffractive power Φ.sub.n of the first optical unit in a sub scanning direction is 0.7<Φ.sub.s/Φ.sub.n<1.0.

Optical scanner and electrophotographic image forming device are provided. The optical scanner includes a light source; and a first optical unit, a deflection apparatus, and an f-θ lens, which are sequentially arranged along a primary optical axis direction of a light beam emitted from the light source. The light beam emitted from the light source is focused onto a scanning target surface after sequentially passing through the first optical unit, the deflection apparatus, and the f-θ lens. Optical scanning directions of the light beam emitted from the light source include a primary scanning direction and a secondary scanning direction which are perpendicular to each other, and along the primary scanning direction, the f-θ lens satisfies following expressions: SAG1>0, SAG2>0, and 0<(SAG1+SAG2)/d<0.8.

A system and method for scanning of coherent LIDAR. The system includes a motor, a laser source configured to generate an optical beam, and a deflector. A first facet of the plurality of facets has a facet normal direction. The deflector is coupled to the motor and is configured to rotate about a rotation axis to deflect the optical beam from the laser source. The laser source is configured to direct the optical beam such that the optical beam is incident on the deflector at a first incident angle in a first plane, wherein the first plane includes the rotation axis, wherein the first incident angle is spaced apart from the facet normal direction for the first facet. A second facet of the plurality of facets includes an optical element configured to deflect the optical beam at the first incident angle into a deflected angle.