An optical scanning apparatus includes a light source, a deflector, an optical member, a supporting portion, a casing, a cover member, a first air current deflecting portion configured to deflect, to a direction from the bottom toward the cover member, an air current generated by rotation of the rotatable polygonal mirror and flowing along a longitudinal direction of the optical member; and a second air current deflecting portion provided on the cover member and configured to deflect, to a direction crossing the longitudinal direction, the air current deflected by the first air current deflecting portion and flowing in the longitudinal direction.

In the image forming apparatus, by rotation of a cover 558 from a closed position toward an open position, a pressing portion 561 urges a fourth portion-to-be-urged 568 (portion-to-be-urged), and a slidable portion 525 is slid (moved) from one end side toward the other end side with respect to a rotational axis direction of a photosensitive drum 103 by the urging, so that an optical print head 105 moves from an exposure position toward a retracted position.

An image forming apparatus includes a plurality of photosensitive members; a scanner unit including light sources, a rotatable polygonal mirror, and reflecting members; and a fixing portion. Parts of the laser beams emitted from the light sources are reflected by the rotatable polygonal mirror toward the fixing device side, and rest parts of the laser beams are reflected by the rotatable polygonal mirror toward a side opposite from the fixing device side. Of the parts of the laser beams reflected by the rotatable polygonal mirror toward the fixing device side, the laser beam reflected toward the reflecting member provided at a position remotest from the rotatable polygonal mirror travels downward relative to a horizontal direction. A rotational axis of the rotatable polygonal mirror is inclined relative to a vertical direction.

Provided is an information processing apparatus, which is configured to correctly detect a polygon face being scanned even when noise occurs in a synchronization signal. The information processing apparatus is connected to an image forming apparatus including: a laser light source configured to receive image data and output light; a photosensitive member; a polygon mirror, which has a plurality of reflection faces, and is configured to rotate to deflect a laser beam through use of the plurality of reflection faces, to thereby scan the photosensitive member; and a generator configured to generate a marking BD signal based on the deflected laser beam. The information processing apparatus receives a marking signal, and determines whether or not the received marking signal is a signal corresponding to a specific reflection face among the reflection faces of the polygon mirror.

In an optical scanning device, an optical deflector includes a base plate, a rotor having an axis of rotation orthogonal to the base plate, and a polygon mirror fixed to the rotor. The polygon mirror has a plurality of reflecting surfaces tilted at a predetermined angle with respect to the axis of rotation. Protrusions protruding from a bottom surface of a frame have bearing surfaces at respective distal ends thereof; and the bearing surfaces are in contact with the base plate. The bottom surface includes a first region on which a first protrusion is disposed, and a second region on which a second protrusion is disposed, and a distance between the first region and a scanning plane containing optical axes in cross sections taken along a sub scanning direction of a scanning lens is different from a distance between the second region and the scanning plane.

An optical scanning apparatus includes a light source, a deflector, an optical member, a supporting portion, a casing, a cover member, a first air current deflecting portion configured to deflect, to a direction from the bottom toward the cover member, an air current generated by rotation of the rotatable polygonal mirror and flowing along a longitudinal direction of the optical member; and a second air current deflecting portion provided on the cover member and configured to deflect, to a direction crossing the longitudinal direction, the air current deflected by the first air current deflecting portion and flowing in the longitudinal direction.

A micro lens array includes: a glass substrate; and a plurality of resin lenses arranged on at least one main surface of the glass substrate, wherein, among the plurality of lenses, resin lenses arranged on one main surface of the glass substrate are such that a plurality of lines of lenses arranged in a first direction is arranged side by side in a second direction different from the first direction, a core thickness, a radius of curvature, and a surface shape of a resin lens in a certain lens line are different from a core thickness, a radius of curvature, and a surface shape of a resin lens of another lens line, and the resin lenses have the same resin volume.

An image forming apparatus includes first and second photoconductive drums, and a laser scanning unit including a plurality of optical elements configured to direct a first scanning beam to the first photoconductive drum from a first side of, and at a first incidence angle with respect to, a first line passing through a center of the first photoconductive drum and a second scanning beam to the second photoconductive drum from a second side of, and at a second incidence angle with respect to, a second line passing through a center of the second photoconductive drum. Magnitudes of the first and second incidence angles are substantially the same, and a second side of the first line and a first side of the second line are each between the first side of the first line and the second side of the second line.

In an optical writing device that deflects light beams from first and second light source sections and performs scanning by first and second scanning optical systems, in reflective optical elements disposed in the optical axis direction from after the polygon mirror to before a separation mirror, a number of hold points on each of a writing start side and a writing end side in scanning is same, and in reflective optical elements disposed from after the separation mirror up to a surface to be scanned, a number of hold points on a writing start side of the first scanning optical system is same (one) with that on a writing end side of the second scanning optical system, and a number of hold points on a writing end side of the first scanning optical system is same (two) with that on a writing start side of the second scanning optical system.

A leaf spring configured to mount an optical element to a housing, the housing containing: a rotary polygon mirror configured to deflect a laser beam emitted from a light source; and the optical element configured to guide the laser beam deflected by the rotary polygon mirror to a member to be scanned, wherein an adhesive is applied to the leaf spring, the adhesive being configured to adhere separated material scraped from the housing, the separated material being scraped from the housing by rubbing between the leaf spring and the housing at a time of mounting the optical element to the housing.