An optical scanning device includes a housing, a transparent cover, a cleaning member, a holding member, and a movement mechanism. The cleaning member slidably contacts with the surface of the transparent cover to clean the surface. The holding member holds the cleaning member. The movement mechanism allows the holding member to reciprocally move along the transparent cover in the aforementioned predetermined direction. The aforementioned holding member has an inside/outside double structure including an inner boss member and an outer boss member. The inner boss member receives power from the movement mechanism. The outer boss member internally receives the inner boss member. The outer boss member is longer than the inner boss member. The outer boss member reaches a moving end and stops earlier than the inner boss member, and the aforementioned inner boss member moves in the outer boss member reaches the moving end and stops.

An optical scanning device includes a rotating polygon mirror, a light source that irradiates first and second light beams at one side of the rotating polygon mirror and irradiates third and fourth light beams at the other side thereof, a first optical element that reflects the first light beam and allows the second light beam to pass therethrough, a second optical element that reflects the second light beam, a third optical element that allows the third and fourth light beams to pass therethrough, and a fourth optical element that reflects the fourth light beam. The second light beam is a light beam corresponding to yellow, the first, the third, and the fourth light beams are light beams corresponding to three colors other than the yellow. Between the third and fourth optical elements, a scanning lens is arranged. Between the first and second optical elements, a scanning lens is not arranged.

Disclosed are methods and systems for compensating for process direction banding associated with a document processing system including a ROS. According to one exemplary embodiment, a ROS driver uses a plurality of beam delay/advance values to compensate for banding caused by an interaction of a halftone pattern and process direction density variations associated with the ROS.

An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.

An optical scanning device includes a scanning member, a plurality of light sources, a first reflection mirror, and a second reflection mirror. The scanning member scans incident laser beams in a predetermined main scanning direction. The plurality of light sources emit the laser beams from positions that are different along a sub scanning direction that is perpendicular to an optical axis direction of the laser beams and the main scanning direction. The first reflection mirror is inclined around the main scanning direction as a rotation axis, is inclined around the sub scanning direction as another rotation axis, and reflects the laser beams emitted from the light sources. The second reflection mirror is inclined around the main scanning direction as a rotation axis, is inclined around the sub scanning direction as another rotation axis, and reflects the laser beams reflected by the first reflection mirror toward the scanning member.

The optical scanning device includes a light source unit, a polygon mirror, a first scanning lens, a second scanning lens, and a container unit. The light source unit has a plurality of light-emitting modules for each emitting a laser beam. The container unit contains the levitating unit, the polygon mirror, the first scanning lens, and the second scanning lens. Each light-emitting module includes a light-emitting element for emitting a laser beam, a coupling lens, and a bracket. The coupling lens converts the laser beam emitted from the light-emitting element into a direction generally parallel to a main scanning direction, and moreover condenses the laser beam to a sub scanning direction. The light-emitting modules are placed in array in an up/down direction between neighboring ones of the protruding portions, and the bracket is fixed to the protruding portions on both sides via adhesive.

An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.

Disclosed is a method for manufacturing an optical unit, including a step of bringing two side face portions of a ceramic package into contact with two contact portions of a jig, a step of placing plural light-receiving and light-emitting elements in a predetermined region of the ceramic package with reference to the contact portions of the jig, and a step of connecting the plural light-receiving and light-emitting elements to a wiring line part formed in the ceramic package by using a bonding wire, wherein at least one of the plural light-receiving and light-emitting elements is placed between one of the two contact portions of the jig and another one of the plural light-receiving and light-emitting elements in the step of placing the plural light-receiving and light-emitting elements.

In the structure of a shutter moving mechanism, if the inclination angle of an elongated hole with respect to a sliding direction of a shutter is increased, it is necessary to increase the size of a movement plate for moving the shutter. On the other hand, if the inclination angle of the elongated hole with respect to the sliding direction of the shutter is decreased, an urging force with which a user urges the door against an image forming apparatus when shutting the door is increased. A shutter moving mechanism includes a rotation mechanism and moves the shutter by rotation of the rotation mechanism.

In a reflector including an AlGaN layer, an InGaN layer, and a GaN layer placed therebetween, high reflectivity and a wide reflection band are achieved. A reflector includes a substrate containing GaN; first layers containing Al.sub.xGa.sub.1-xN; second layers containing In.sub.yGa.sub.1-yN; and a third layer containing GaN, the first, second, and third layers being stacked on the substrate. The first and second layers are alternately stacked, the third layer is placed between one of the first layers and one of the second layers, x and y satisfy a specific formula, the first layers have a thickness less than the thickness of the second layers, and the second layers have an optical thickness of /8 to 3/8, where is the central wavelength of the reflection. band of the reflector.