Abstract: An image forming apparatus includes a housing, an image forming device, an image reading device coupled with the housing via a first hinge and switchable between an overlapping state and a standing state, the image reading device configured to read an image on an original document, an automatic document feeder coupled with the image reading device via a second hinge and switchable between an overlapping state overlapping the image reading device and a standing state standing at the image reading device, the automatic document feeder configured to turn the original document and convey the original document to an image position, and an automatic coupling device to couple the automatic document feeder and the image reading device when the image reading device is opened while the automatic document feeder is overlapped on the image reading device.

Abstract: An optical scanner includes a light source including a plurality of light emitting elements, a polygon mirror which deflects light from the light source for scanning a surface of a subject, an optical element arranged between the light source and the polygon mirror, having optical power in a sub scanning direction, a synchronous detector which detects the light deflected by the polygon mirror for synchronous detection and generates a signal for controlling a timing at which the scanning of the surface is started, and a fixing element which secures one end of the optical element. The light emitting elements of the light source are aligned with a certain tilt angle relative to the sub scanning direction. Light from one of the light emitting elements disposed closest to the fixing element in a main scanning direction is used for synchronous detection.

Abstract: P-polarized light beam passing through an f? lens passes through a polarization beam splitter, is converted into S-polarized light beam by a quarter-wave plate and a reflecting mirror, re-enters the polarization beam splitter, and is reflected at the polarization beam splitter in the ?Z direction. An optical path of a light beam between a polygon mirror and the f? lens, between the f? lens and the polarization beam splitter, between the polarization beam splitter and the quarter-wave plate, between the quarter-wave plate and a reflecting mirror, between the reflecting mirror and the quarter-wave plate, and between the quarter-wave plate and the polarization beam splitter are in the same plane.

Abstract: An image forming apparatus includes a plurality of image carriers and an optical writing device including light sources that emit light beams of different wavelengths, a deflector that deflects the light beams emitted from the light sources and synthesized on an identical axis in a sub-scanning direction, a first beam separator, a second beam separator, a first imaging device, and a second imaging device. The first beam separator and the second beam separator are located between the first imaging device and the second imaging device and transmit or reflect the light beams according to travel directions or wavelengths thereof. One of the targets is scanned with the light beam transmitted through the second beam separator. Another target is scanned with the light beam reflected by the second and first beam separators. The first and second imaging devices narrow the beams in the main scanning direction and the sub-scanning direction, respectively.

Abstract: A first beam separation device is arranged either to allow the light beams to enter and pass or to reflect the light beams in accordance with a direction of entrance of the light beams. A second beam separation device is provided either to allow or to reflect the light beams having passed through the first beam separation device in accordance a wavelength thereof. The light beam passing through the second beam separation device scans one of plural scan objectives and the light beam reflected by the second beam separation device is further reflected by the first beam separation device and then scans the other one of the plural scan objectives. A first imaging device is provided to correct a f-theta (f?) performance and a curvature of an imaging plane to enable the light beams to scan the plural scan objectives at a constant speed. The first imaging device is integral with the first beam separation device.

Abstract: P-polarized light beam passing through an f? lens passes through a polarization beam splitter, is converted into S-polarized light beam by a quarter-wave plate and a reflecting mirror, re-enters the polarization beam splitter, and is reflected at the polarization beam splitter in the ?Z direction. An optical path of a light beam between a polygon mirror and the f? lens, between the f? lens and the polarization beam splitter, between the polarization beam splitter and the quarter-wave plate, between the quarter-wave plate and a reflecting mirror, between the reflecting mirror and the quarter-wave plate, and between the quarter-wave plate and the polarization beam splitter are in the same plane.

Abstract: A first beam separation device is arranged either to allow the light beams to enter and pass or to reflect the light beams in accordance with a direction of entrance of the light beams. A second beam separation device is provided either to allow or to reflect the light beams having passed through the first beam separation device in accordance a wavelength thereof. The light beam passing through the second beam separation device scans one of plural scan objectives and the light beam reflected by the second beam separation device is further reflected by the first beam separation device and then scans the other one of the plural scan objectives. A first imaging device is provided to correct a f-theta (f?) performance and a curvature of an imaging plane to enable the light beams to scan the plural scan objectives at a constant speed. The first imaging device is integral with the first beam separation device.

Abstract: An image forming apparatus includes a plurality of image carriers and an optical writing device including light sources that emit light beams of different wavelengths, a deflector that deflects the light beams emitted from the light sources and synthesized on an identical axis in a sub-scanning direction, a first beam separator, a second beam separator, a first imaging device, and a second imaging device. The first beam separator and the second beam separator are located between the first imaging device and the second imaging device and transmit or reflect the light beams according to travel directions or wavelengths thereof. One of the targets is scanned with the light beam transmitted through the second beam separator. Another target is scanned with the light beam reflected by the second and first beam separators. The first and second imaging devices narrow the beams in the main scanning direction and the sub-scanning direction, respectively.