An optical scanning device includes a rotary polygon mirror, a plurality of light sources, a light detecting portion, an obtainment processing portion, an a switching processing portion. The rotary polygon mirror has a reflection surface that reflects incident light, and scans, in a scanning cycle, the light reflected on the reflection surface. The light sources emit, toward the reflection surface, a plurality of light beams. The light detecting portion detects a light amount of each light beam reflected on the reflection surface. The obtainment processing portion obtains a switching timing to switch a light emission amount of each of the light sources in the scanning cycle, based on light amounts of the light beams detected by the light detecting portion. The switching processing portion switches the light emission amount of each of the light sources based on the switching timing obtained by the obtainment processing portion.

The detector that detects a light beam emitted from a light source of a second image forming device and reflected by a polygon mirror, and an adjustment device that performs adjustment processing of adjusting the velocity of the polygon mirror based on an output of the detector are provided. Before a first image forming device performs the image forming processing, the adjustment device performs the adjustment processing while causing the light source of the second image forming device to emit the light beam during a time period including at least a time period in which a photosensitive member of the second image forming device is emitted with the light beam. Before the adjustment processing is finished, the first image forming device starts to move a developing member to a developing position.

In an image-forming apparatus, an optical scanning device that is adjustable in a turn available manner around a turn axis line parallel to an axis line orthogonal to a main scanning direction of a light beam is attached to an image-forming apparatus body. The image-forming apparatus body has a shaft support that supports the optical scanning device in a turn available manner around a turn axis line and a holder facing a housing at a position different from that of the shaft support. The optical scanning device is held by the image-forming apparatus body in a state in which an elastic member is sandwiched between the housing and the holder in a pressed manner.

The present invention relates to a multichannel head assembly for a three-dimensional modeling apparatus which can improve productivity by simultaneously or synchronously modeling a plurality of three-dimensional shaped objects having the same shape or different shapes, and a three-dimensional modeling apparatus using the same, the present invention comprising: a modeling light source unit for allowing N modeling beams to be incident to a light guide unit; the light guide unit for receiving the N incident modeling beams and having a function of guiding each of the N modeling beams along a predetermined path so as to allow the N modeling beams to be incident to N modeling planes in one-to-one correspondence with each other; and a control unit for controlling driving of the modeling light source unit and driving of the light guide unit to be linked with each other.

An image forming apparatus includes a controller. The controller is configured to switch between (i) first speed printing in which a rotation speed of the polygon mirror is a first speed and the power of a laser beam from a first and second laser light sources is a first laser power, and (ii) second speed printing in which the speed of the mirror is slower than the first speed and the power of laser beam from the light sources is a second power weaker than the first power. The controller is configured to control an output timing of the laser beam from the light sources in the second speed printing based on the timings at which the laser beam is detected by first photodetector and second photodetectors when the laser powers of the first laser light source and the second laser light source are changed, respectively.

A scanning optical system, includes a mirror unit having a first mirror surface and a second mirror surface which incline to a rotation axis; and a light projecting system having a light source. A light flux emitted from the light source is reflected on the first mirror surface of the mirror unit, thereafter, reflected on the second mirror surface, and then, projected so as to scan in a main scanning direction onto an object in accordance with rotation of the mirror unit. The light flux emitted from the second mirror surface becomes a plurality of spot lights on the object side, and the plurality of spot lights are arranged along a direction intersecting with the main scanning direction.

An optical scanning device includes a deflector for deflecting a light beam to optically scan a scanned region on a scanned surface in a main scanning direction, and an imaging optical system for guiding the light beam deflected by the deflector, to the scanned surface. The imaging optical system includes an imaging optical element in which, in the main scanning direction, a distance to an optical axis from one effective end portion through which a light beam that enters one end portion of the scanned region passes is longer than a distance to the optical axis from another effective end portion through which a light beam that enters another end portion of the scanned region passes. In the imaging optical element, a thickness in an optical axis direction of the one effective end portion is thinner than a thickness in the optical axis direction of the other effective end portion.

A scanning optical system, includes a mirror unit equipped with a first mirror surface and a second mirror surface each of which inclines to a rotation axis; and a light projecting system which includes at least one light source to emit a light flux toward the first mirror surface. A light flux emitted from the light source is reflected on the first mirror surface of the mirror unit, thereafter, reflected on the second mirror surface, and then, projected so as to scan in a main scanning direction onto an object in accordance with rotation of the mirror unit, and in a case where a direction included in a main scanning plane is set to 0 degree, the light flux reflected on the second mirror surface is polarized in a range within an angle of ±30 degrees to the main scanning plane.

A scanning optical device proposed herein includes first and second semiconductor lasers, first and second coupling lenses, a polygon mirror, and first and second holders. The first and second coupling lenses convert light emitted by the first and second semiconductor lasers into light beams, respectively. The polygon mirror deflects the light beams received from the first and second coupling lenses. The first holder has a seating surface on which the first coupling lens is fixed by a photo-curable resin. The second holder is configured to hold the second coupling lens in such a position that the first and second coupling lenses are arranged in a line parallel to a rotation axis of the polygon mirror. The second holder is fixed to the first holder by a photo-curable resin.

A scanning optical device includes a semiconductor laser, a coupling lens, a condenser lens, a deflector, a scanning optical system, a frame, and a first cover. The coupling lens converts light emitted by the first semiconductor laser to a light beam. The light beam received from the coupling lens is concentrated through the condenser lens. The deflector includes a polygon mirror configured to deflect the light beam received from the condenser lens. The scanning optical system directs the light beam deflected by the deflector toward an image plane. The deflector and the scanning optical system are fixed to the frame. The first cover covers at least a portion of the frame on which the deflector is located. The frame includes a wall having an opening through which a light beam traveling toward the polygon mirror passes. The condenser lens closes the opening.