Abstract: Provided is a rotational position detection device including a position detection unit that is provided in a motor for driving a developing roll developing a latent image, detects a rotational position of the motor by using magnetism, and outputs a rotational position signal for each rotational position determined in advance, and a generation unit that generates a reference signal indicating a reference position of rotation of the developing roll using the rotational position signal, based on a transmission ratio of a transmission mechanism that transmits driving of the motor to the developing roll.

Abstract: An optical scanning device includes a housing, a light source that emits light, a rotatable polygon mirror that receives the light from the light source while rotating and deflects the light by reflecting the light in a direction corresponding to an angle of rotation thereof, a scanning optical system that guides the light from the rotatable polygon mirror to a scanning object in such a manner as to repeatedly scan the scanning object with the light, and an intermediate member that is provided between an optical member included in the scanning optical system and the housing. The intermediate member is connected to the optical member with rubber adhesive and is also connected to the housing with the rubber adhesive.

Abstract: An optical scanning device includes a housing, a light source, a rotatable polygon mirror deflecting a light beam from the light source, a scanning optical system scanning a scanning object with the light beam from the polygon mirror, first and second reflective mirrors one of which is provided inside a deflection area, and a photodetector detecting the timing of scanning of the scanning object with the light beam from the one of the first and second reflective mirrors. The scanning object is one of first and second scanning objects. The housing includes first and second supports configured to support the first and second reflective mirrors at first and second positions, respectively, that are outside first and second scan-use areas, respectively. The first position is also inside the second scan-use area. The first and second scan-use areas are used for the scanning of the first and second scanning objects, respectively.

Abstract: The present invention provides an optical scanning device that can suppress irregularity of the rotation of a polygon mirror and an image forming apparatus that is disposed with this optical scanning device. The optical scanning device includes: a rotating polygon mirror that rotates and deflects light that has been emitted from a light source; and a plate member that covers one surface of surfaces intersecting an axial direction of a rotating shaft of the rotating polygon mirror, wherein a projecting portion that projects in the axial direction of the rotating shaft away from the rotating polygon mirror is disposed in the plate member.

Abstract: An optical scanning apparatus includes a light source, a rotating polygonal mirror, a scanning optical system, a detector, and a light emission controller. The light source includes plural light emitting elements. The rotating polygonal mirror is irradiated with light beams. While rotating, the rotating polygonal mirror reflects and deflects, in a deflecting direction, light beams emitted from light emitting elements in a first direction to propagate through one point in the deflecting direction substantially at the same time. The scanning optical system causes the reflected and deflected light beams to scan over an object. The detector detects the timing at which a light beam propagates through a detection point. When the light beams propagate through the detection point, the light emission controller causes light emitting elements in a row in the first direction other than light emitting elements at both ends of a projection plane to emit light.

Abstract: An exposure device includes light emitting elements, a driving circuit, an image-signal connector, a power connector, and an adjustment-control-signal connector. The light emitting elements emit light which an exposure target member is exposed to. The driving circuit performs one of first and second drive operations. The image-signal connector has terminals connected to core wires of an image-signal cable, and relays, to the driving circuit, image signals transmitted through the image-signal cable. In the image-signal cable, the core wires are arranged at a first pitch. The power connector has terminals arranged at a pitch wider than the first pitch, and relays, to the driving circuit, power transmitted through power cables. The adjustment-control-signal connector has terminals arranged at a pitch wider than the first pitch, and relays, to the driving circuit, light-amount adjustment control signals transmitted through adjustment-control-signal cables.

Abstract: A structure for holding an optical component, includes: first and second flat plate portions provided in a state where the portions stand on a base plate, opposed to each other in a state where the flat plate portions are coupled to each other, and constituting first and second hierarchies, respectively; first and second positioning portions that are provided at the first flat plate portion, and that determine positions of directions of first and second coordinate axes of first, second, and third coordinate axes that intersect with each other; a third positioning portion that is provided at the second flat plate portion, and that determines a position of a direction of the third coordinate axis of the first, second, and third coordinate axes that intersect with each other; and a holding portion coupled to the first flat plate portion or the second flat plate portion, and holding the optical component.

Abstract: An image forming apparatus includes a photosensitive member that rotates and is subjected to exposure so that a latent image is formed thereon, a driver that rotates the photosensitive member, an exposure section that exposes the photosensitive member by irradiating the photosensitive member with light, a light intensity adjustment section that receives a part of the light from the exposure section and adjusts intensity of the light irradiated by the exposure section, and an adjustment controller that causes the driver to start rotating the photosensitive member and causes the light intensity adjustment section to start adjusting the intensity of the light after a rotation speed of the photosensitive member exceeds a predetermined threshold value.

Abstract: An optical scanning apparatus includes a light source, a rotating polygonal mirror, a scanning optical system, a detector, and a light emission controller. The light source includes plural light emitting elements. The rotating polygonal mirror is irradiated with light beams. While rotating, the rotating polygonal mirror reflects and deflects, in a deflecting direction, light beams emitted from light emitting elements in a first direction to propagate through one point in the deflecting direction substantially at the same time. The scanning optical system causes the reflected and deflected light beams to scan over an object. The detector detects the timing at which a light beam propagates through a detection point. When the light beams propagate through the detection point, the light emission controller causes light emitting elements in a row in the first direction other than light emitting elements at both ends of a projection plane to emit light.

Abstract: An exposure device includes light emitting elements, a driving circuit, an image-signal connector, a power connector, and an adjustment-control-signal connector. The light emitting elements emit light which an exposure target member is exposed to. The driving circuit performs one of first and second drive operations. The image-signal connector has terminals connected to core wires of an image-signal cable, and relays, to the driving circuit, image signals transmitted through the image-signal cable. In the image-signal cable, the core wires are arranged at a first pitch. The power connector has terminals arranged at a pitch wider than the first pitch, and relays, to the driving circuit, power transmitted through power cables. The adjustment-control-signal connector has terminals arranged at a pitch wider than the first pitch, and relays, to the driving circuit, light-amount adjustment control signals transmitted through adjustment-control-signal cables.

Abstract: An optical scanning device includes a housing, a light source, a rotatable polygon mirror deflecting a light beam from the light source, a scanning optical system scanning a scanning object with the light beam from the polygon mirror, first and second reflective mirrors one of which is provided inside a deflection area, and a photodetector detecting the timing of scanning of the scanning object with the light beam from the one of the first and second reflective mirrors. The scanning object is one of first and second scanning objects. The housing includes first and second supports configured to support the first and second reflective mirrors at first and second positions, respectively, that are outside first and second scan-use areas, respectively. The first position is also inside the second scan-use area. The first and second scan-use areas are used for the scanning of the first and second scanning objects, respectively.

Abstract: An optical scanning device includes a housing, a light source that emits light, a rotatable polygon mirror that receives the light from the light source while rotating and deflects the light by reflecting the light in a direction corresponding to an angle of rotation thereof, a scanning optical system that guides the light from the rotatable polygon mirror to a scanning object in such a manner as to repeatedly scan the scanning object with the light, and an intermediate member that is provided between an optical member included in the scanning optical system and the housing. The intermediate member is connected to the optical member with rubber adhesive and is also connected to the housing with the rubber adhesive.

Abstract: A structure for holding an optical component, includes: first and second flat plate portions provided in a state where the portions stand on a base plate, opposed to each other in a state where the flat plate portions are coupled to each other, and constituting first and second hierarchies, respectively; first and second positioning portions that are provided at the first flat plate portion, and that determine positions of directions of first and second coordinate axes of first, second, and third coordinate axes that intersect with each other; a third positioning portion that is provided at the second flat plate portion, and that determines a position of a direction of the third coordinate axis of the first, second, and third coordinate axes that intersect with each other; and a holding portion coupled to the first flat plate portion or the second flat plate portion, and holding the optical component.

Abstract: The present invention provides an optical scanning device that can suppress irregularity of the rotation of a polygon mirror and an image forming apparatus that is disposed with this optical scanning device. The optical scanning device includes: a rotating polygon mirror that rotates and deflects light that has been emitted from a light source; and a plate member that covers one surface of surfaces intersecting an axial direction of a rotating shaft of the rotating polygon mirror, wherein a projecting portion that projects in the axial direction of the rotating shaft away from the rotating polygon mirror is disposed in the plate member.

Abstract: An optical scanning device includes a light source that emits a light beam, an optical deflector at which a light beam emitted from the light source is incident, the optical deflector deflecting the incident light beam, an optical system that guides the deflected light beam to surface to be scanned by the deflected light beam, a driving device that drives at least a portion of the optical deflector, a thermal storage member mounted on the driving device, the thermal storage member absorbing and storing heat generated by the driving device, thereby controlling a temperature gradient of the driving device, and a casing body that accommodates the light source, the optical deflector, the optical system, the driving device, and the thermal storage member.

Abstract: An optical scanning device includes a light source that emits a light beam, an optical deflector at which a light beam emitted from the light source is incident, the optical deflector deflecting the incident light beam, an optical system that guides the deflected light beam to surface to be scanned by the deflected light beam, a driving device that drives at least a portion of the optical deflector, a thermal storage member mounted on the driving device, the thermal storage member absorbing and storing heat generated by the driving device, thereby controlling a temperature gradient of the driving device, and a casing body that accommodates the light source, the optical deflector, the optical system, the driving device, and the thermal storage member.

Abstract: An optical scanning apparatus comprises an optical deflector at which a light beam emitted from a light source is incident on a polygon mirror, and the polygon mirror is rotated for deflectingly scanning the light beam; an optical container accommodating the optical deflector, the optical deflector being disposed at a vicinity of an inner wall face of the optical container; and a baffle member disposed between an outer peripheral face of the polygon mirror and the inner wall face of the optical container, the baffle member regulating an airflow, which occurs along an outer periphery of the polygon mirror in accordance with the rotation.

Abstract: Discloses an optical deflector that enables a rotary polygon mirror to rotate at high speed with high reliability and a low noise level, and can prevent the rotary polygon mirror from disengaging from a stationary axis with a compact and simple construction, and an optical scanner including the optical deflector. A disengagement prevention member is mounted at the tip of a stationary axis. Since a gap is formed between the stationary axis and a rotary axis and prevents friction by rotation, a rotary polygon mirror can be rotated at higher speed. There is no or less noise and vibration due to the rotation of the rotary polygon mirror, so that durability and reliability are improved. Even if a rotor moves in the axial direction, the rotor is prevented from disengaging by the disengagement prevention member, so that it never disengages accidentally from the stationary axis.

Abstract: A motor drive control apparatus has a number of revolution setting circuit, a driving circuit for driving a motor to rotate at a predetermined number of revolution based on a number of revolution command signal output from the number of revolution setting circuit, a number of revolution detecting circuit for detecting the number of revolution of the motor, a driving voltage adjusting circuit for adjusting a level of the driving voltage of the motor to be supplied to the driving circuit, a motor control circuit including a PLL control circuit for controlling the number of revolution of the motor so that the phase difference between the phase of the number of revolution command signal and the phase of the number of revolution detection signal becomes within a predetermined range of value, and a voltage control circuit for instructing the driving voltage adjusting circuit to adjust the driving voltage of the motor to be at a level in the vicinity of the PLL controllable minimum level.

Abstract: A damping member is disposed between a motor cover attached near a rotary polygon mirror drive motor so as to cover a rotary polygon mirror and an optical cover attached to an optical box so as to cover the motor cover and a (f-.theta.) optical lens group. The damping member can absorb a vibration generated in the motor cover when the rotary polygon mirror and the rotary polygon mirror drive motor are driven to thereby alleviate a transmission of a vibration to the optical cover. Furthermore, a heat generated from the rotary polygon mirror drive motor is radiated from the optical cover through the damping member to thereby prevent a heat from being filled in the inside of the optical cover. In this way, it is possible to avoid the vibration and the heat from affecting the (f-.theta.) lens group or the like as much as possible. Thus, the light beam can be focused on the photosensitive material under satisfactory condition.