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

An image forming apparatus includes an image forming device and a control device. The image forming device forms an image on a recording medium. The control device controls an image forming process. The control device includes circuitry. The circuitry changes a plurality of partial images in a target image into a certain state. The target image is to be formed on the recording medium. The plurality of partial images are to be formed peripheral to a plurality of pattern images. Each of the plurality of pattern images is to be formed at a certain position on the recording medium. The circuitry further controls the image forming device to form the target image including the changed plurality of partial images and the plurality of pattern images on the recording medium, and corrects a position of the target image based on a detection result of the formed plurality of pattern images.

An optical array includes a plurality of optical elements arrayed in a longitudinal direction of the optical array, each of the optical elements comprises a convex portion, a part of which is surrounded by a first groove, and a pair of flange sections between which the optical elements are arrayed. A second groove that communicates with the first groove of each optical element is formed on at least one of the flange sections.

An optical device includes a first light source emitting a first beam, a second light source emitting a second beam and arranged upstream in a scanning direction, a diaphragm including an opening passing portions of the first beam, the first portion having a first width from the light axis of the first beam on the upstream side, the second portion having a second width from the light axis on the downstream side, the first width narrower than the second width, and an opening passing portions of the second beam, the first portion having a third width from the light axis of the second beam on the upstream side, the second portion having a fourth width from the second light axis on the downstream side, the third width wider than the fourth width, and a deflector deflecting on a surface thereon the beams at positions shifted in a sub scanning direction.

An image forming apparatus includes a plurality of photosensitive members; a scanner unit which includes light sources, a rotatable polygonal mirror, and a plurality of reflecting members; a fixing unit; and a discharge tray. The scanner unit is provided between the plurality of photosensitive members and the discharge tray with respect to a vertical direction, and a rotational axis of the rotatable polygonal mirror is inclined relative to the vertical direction. Selected ones of the laser beams emitted from the light sources are reflected toward a side with the fixing unit, and remaining ones of the laser beams are reflected toward an opposite side. Of the selected ones of the laser beams, 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.

An optical device includes a first light source emitting a first beam, a second light source emitting a second beam and arranged upstream in a scanning direction, a diaphragm including an opening passing portions of the first beam, the first portion having a first width from the light axis of the first beam on the upstream side, the second portion having a second width from the light axis on the downstream side, the first width narrower than the second width, and an opening passing portions of the second beam, the first portion having a third width from the light axis of the second beam on the upstream side, the second portion having a fourth width from the second light axis on the downstream side, the third width wider than the fourth width, and a deflector deflecting on a surface thereon the beams at positions shifted in a sub scanning direction.

To provide a shading correction signal generation device including a correction amount setting signal generator that generates a correction amount setting signal, a modulator that modulates the correction amount setting signal by a predetermined modulation scheme and outputs the modulation signal, and a filter circuit that filters the modulation signal to generate a shading correction signal. During a transition period, the correction amount setting signal generator generates the correction amount setting signal in which a difference between a level at an end of a predetermined period and an average level during the transition period is larger than a difference between the level at the end of the predetermined period and a level at a start of a shading correction period.

An optical scanning apparatus includes a first light source, a second light source, a first driving element, a second driving element, a rotatable polygonal mirror, a first scanning optical portion, a second scanning optical portion, a detecting element, and a circuit board. The first light source, the first driving element and the detecting element are arranged in a named order on the circuit board. The following relationship is satisfied: 1>2, where 1 is an angle formed by a direction of the first laser light and a first direction, and 2 is an angle formed by a direction of the second laser light and a second direction.

An optical scanning device comprises an optical box that houses an optical component(s). The optical box includes a box main body and a cover member. A first engaging portion is formed on a side wall of the box main body, and a second engaging portion that engages with the first engaging portion is formed on a first fitting wall portion of the cover member. The box main body is provided with a vertical wall that is erected inside the first engaging portion. Moreover, there is formed on the cover member with a first barrier wall that is protruded downward from a top wall so as to enter a space between the first engaging portion and the vertical wall.

An optical scanning apparatus includes an optical scanning unit which includes a first light source, a first rotatable polygonal mirror for reflecting the beam emitted from the first light source, a second light source, a second rotatable polygonal mirror for reflecting the beam emitted from the second light source; and a housing accommodating the polygonal mirrors. The housing includes only three fixed portions fixed to a fixing portion for fixing the optical scanning unit. The first rotatable polygonal mirror and the second rotatable polygonal mirror are disposed such that a rotational axis of the first rotatable polygonal mirror and a rotational axis of the second rotatable polygonal mirror are in a triangular area defined by lines connecting the three fixed portions, as viewed in a rotation axial direction of the first rotatable polygonal mirror.