According to one example, there is provided an imaging system that comprises a housing, a rotatable polygon comprising multiple mirrored facets located in the housing, a laser to generate a laser beam to shine onto the polygon mirror and to reflect onto a target, and wherein, in use, the density of gas within the housing is such that turbulence-related optical distortion within the housing is not greater than a predetermined limit.

In an optical deflector, a polygon mirror and a drive motor are covered by a cover body including a first cover portion and a second cover portion. The first cover portion includes a top wall disposed above the polygon mirror, and a peripheral wall formed having a cylindrical shape extending downward from an outer peripheral end edge of the top wall and having a first opening opened by facing the deflection surface of the polygon mirror. The peripheral wall has an upper-end edge-defining portion and a lower-end edge-defining portion defining an opening end edge of the first opening, and the top wall has, on an inner surface side of a specific portion connected to the upper-end edge-defining portion, a first slope portion inclined downward toward the upper-end edge-defining portion.

An optical scanning device includes a housing that houses an optical system for generating a light ray for optical scanning, and has a dustproof glass for emitting the light ray to an outside, and a cleaning system that is assembled to the housing and cleans the dustproof glass. The cleaning system includes a cleaning member, and a holder that holds the cleaning member, and with the holder moved in a specified movement direction relative to the dustproof glass, the cleaning member cleans the dustproof glass. The cleaning member includes a cleaner member that is adapted to contact a surface of the dustproof glass, and a pressing member that has a pressing surface for pressing the cleaner member toward the dustproof glass and is formed of an elastic body. In the movement direction, a width of the cleaner member is wider than a width of the pressing surface.

Each of first and second glasses to be cleaned has a first edge and a second edge. A cleaning system has a cleaning member having a contact surface adapted to contact a surface of the glass, and first and second holders that hold the cleaning member. A drive system moves the holder so as to perform an outward cleaning moving from the first edge toward the second edge and a return cleaning returning from the second edge to the first edge. At a start position of the outward cleaning, the holder is stopped so that a portion of the contact surface of the cleaning member is positioned inside the first edge, and at a start position of the return cleaning, the holder is stopped so that a portion of the contact surface is positioned inside the second edge.

A lens unit includes a first lens array including first lenses arranged in at least two lines; a second lens array including second lenses arranged in an arrangement relationship corresponding to the first lens array, the second lenses respectively facing the first lenses, the second lens array being arranged to face the first lens array so that each pair of the first and second lenses has a common optical axis; and a first light blocking member arranged between the first lens array and the second lens array and having first openings each being arranged to face the pair of the first and second lenses in a direction of the optical axis. An interval PXL from an array center position between two adjacent lines to the optical axis and an interval PXS from the array center position to an opening center of the first opening satisfy PXL<PXS.

An image forming apparatus includes a processor. The processor is configured to emit a laser beam reflected by a polygon mirror, the polygon mirror rotated by a polygon motor, form an image based on a latent image carried on a photoconductor by the laser beam, store an execution frequency of an image quality self-check of the image formed and a rotation duration of the polygon motor during a standby operation period of image formation, accept a change in the execution frequency, change the rotation duration based on the change in the execution frequency, execute the image quality self-check based on the execution frequency, and continuously rotate the polygon motor during the standby operation period based on the rotation duration stored.

An image forming apparatus includes an exposure device configured to form a latent image on a photoreceptor. The exposure device includes a polygon mirror motor, a polygon mirror pre-incidence optical system, a post-scan optical system, and a housing. The polygon mirror pre-incidence optical system includes a light source station configured to emit the light beam. The post-scan optical system is configured to irradiate the photoreceptor with the light beam. The housing includes a first holding portion, a second holding portion, and a slit. The slit is formed between the first holding portion and the second holding portion. The slit is configured to separate the first holding portion and the second holding portion in a region corresponding to a gap between the light source station and the polygon mirror motor.

An image forming apparatus to form a toner image on a recording material includes a photosensitive member and an optical scanning unit. The optical scanning unit includes an optical scanning unit, an optical box, a cover member, and a moving unit movable to an outside of the image forming apparatus. The optical scanning unit and the moving unit are arranged so that the moving unit and the optical scanning unit are opposed to each other when the moving unit is located in an inside of the image forming apparatus. The optical scanning unit is disposed so as to allow a user to touch the optical scanning unit through a space generated in the inside of the image forming apparatus when the moving unit is moved to the outside of the image forming apparatus. Between the optical box and the cover member, the cover member is opposed to the moving unit.

The plurality of surface light emitting element array chips in the first row and the plurality of surface light emitting element array chips in the second row are arranged in a staggered manner along the main scanning direction, and a space between the plurality of surface light emitting element array chips in the first row and the plurality of surface light emitting element array chips in the second row is set so as not to be an integral multiple of an image resolution pitch in the sub-scanning direction.

A scanline curvature correction mechanism includes a holding mechanism to extend in a main scanning direction and hold an optical element in the main scanning direction , a pressing member provided near a center of the optical element in the main scanning direction and press the optical element of the optical scanning device in the sub-scanning direction, and a curvature adjustment mechanism provided on an opposite side of the pressing member with the optical element interposed therebetween and to adjust a curvature of the optical element in the sub-scanning direction. The curvature adjustment mechanism includes an eccentric cam to rotate around a rotation axis parallel to an optical axis of the optical element and include a cam portion of which an outer peripheral surface is eccentric with respect to the rotation axis, and a fixing mechanism to stepwisely fix an angular position of rotation of the eccentric cam.