Abstract: An image forming apparatus is disclosed, including a light source; a drum; an optical scanning apparatus; and an endless belt. The image forming apparatus further includes a pattern forming unit which forms, on the endless belt along a conveying direction of the endless belt, a density fluctuation detecting pattern having a period; a density sensor which detects the density fluctuating detecting pattern and outputs a density signal including information on density fluctuations in the conveying direction of the endless belt; and a period detecting sensor which detects the period included in the density fluctuations.

Abstract: An image forming apparatus includes: a density detection unit that detects densities of an image developed by a developing unit at a plurality of positions in a main-scanning direction; a processing unit that obtains at least one of an amplitude and a phase of a first periodical density change of the image, of which cycle is a rotation cycle of a photosensitive drum, at the plurality of positions in the main-scanning direction on the basis of an output signal of the density detection unit, and corrects a drive signal for the light source so as to suppress the first periodical density change of the image at each position in the main-scanning direction on the basis of the rotation cycle of the photosensitive drum and at least one of the amplitude and the phase.

Abstract: An optical scanning device including a light source having multiple light emitters; an optical element to reflect and transmit the emitted light beams; a photodetector to receive the reflected light beams; an aperture having an opening to shape the transmitted light beams; a light deflector to deflect the transmitted light beams; and a scanning optics to guide the deflected light beams to a scanning surface. The quantity of each of the light beams received by the photodetector is not less than 0.01 mW, and the size of a light receiving surface of the photodetector is determined such that even when the full width at half maximum of the emitted light beams changes, the rate of change of the ratio of the quantity of the light beams detected by the photodetector to the quantity of the light beams passing through the opening of the aperture is not greater than 4%.

Abstract: Apparatus that forms an image according to image information includes density sensors that detect image density variations in main and sub-scanning directions. A processing device generates correction data for correcting a light source output to suppress the density variations based on detection results. The processing device modifies the correction data such that the light source output after the correction is at least a minimum rated output at a position at which the output after the correction is lower than the minimum rated output, in the relation between a position on the surface of the photosensitive element in the main-scanning direction and the output after the correction, and modifies the correction data such that the light source output after the correction is at most a maximum rated output at a position at which the output after the correction is higher than the maximum rated output.

Abstract: An image forming apparatus includes: a density detection unit that detects densities of an image developed by a developing unit at a plurality of positions in a main-scanning direction; a processing unit that obtains at least one of an amplitude and a phase of a first periodical density change of the image, of which cycle is a rotation cycle of a photosensitive drum, at the plurality of positions in the main-scanning direction on the basis of an output signal of the density detection unit, and corrects a drive signal for the light source so as to suppress the first periodical density change of the image at each position in the main-scanning direction on the basis of the rotation cycle of the photosensitive drum and at least one of the amplitude and the phase.

Abstract: An image forming apparatus is disclosed, including a light source; a drum; an optical scanning apparatus; and an endless belt. The image forming apparatus further includes a pattern forming unit which forms, on the endless belt along a conveying direction of the endless belt, a density fluctuation detecting pattern having a period; a density sensor which detects the density fluctuating detecting pattern and outputs a density signal including information on density fluctuations in the conveying direction of the endless belt; and a period detecting sensor which detects the period included in the density fluctuations.

Abstract: An optical scanning device including a light source having multiple light emitters; an optical element to reflect and transmit the emitted light beams; a photodetector to receive the reflected light beams; an aperture having an opening to shape the transmitted light beams; a light deflector to deflect the transmitted light beams; and a scanning optics to guide the deflected light beams to a scanning surface. The quantity of each of the light beams received by the photodetector is not less than 0.01 mW, and the size of a light receiving surface of the photodetector is determined such that even when the full width at half maximum of the emitted light beams changes, the rate of change of the ratio of the quantity of the light beams detected by the photodetector to the quantity of the light beams passing through the opening of the aperture is not greater than 4%.

Abstract: A disclosed light source apparatus includes a light source including multiple light emitting devices; an optical element configured to transmit light emitted from the light source; a tube configured to hold the optical element; and a tube holder configured to fix the tube by holding an end of the tube close to the light source or by holding the end of the tube on the light emission side away from the light source. A positional displacement preventing member is provided at the other end of the tube on a light emission side away from the light source in such a manner as to be slidable on the tube in the direction of an optical axis and prevent positional displacement of the tube in all directions perpendicular to the optical axis.

Abstract: Apparatus that forms an image according to image information includes density sensors that detect image density variations in main and sub-scanning directions. A processing device generates correction data for correcting a light source output to suppress the density variations based on detection results. The processing device modifies the correction data such that the light source output after the correction is at least a minimum rated output at a position at which the output after the correction is lower than the minimum rated output, in the relation between a position on the surface of the photosensitive element in the main-scanning direction and the output after the correction, and modifies the correction data such that the light source output after the correction is at most a maximum rated output at a position at which the output after the correction is higher than the maximum rated output.

Abstract: Disclosed is an optical scanning device including a light source including multiple light-emitting elements, the multiple light-emitting elements being arranged in a linear manner, a collimator lens to collimate a light beam from the light source, a light-deflecting device to deflect a light beam having passed through the collimator lens to a medium to be scanned and scan the medium with the light beam, and a rear optical system arranged in an optical path between the collimator lens and the medium to be scanned, wherein the collimator lens deviates an image surface in a direction opposite to an image surface deviation on the medium to be scanned by a nearly same amount as the image surface deviation, the image surface deviation being caused by a change of an image height of the light source, and the change being caused by the rear optical system.

Abstract: A light scanning apparatus comprising a photosynthesis device having a first light source unit and a second light source unit with a plurality of light sources spaced at equal intervals side by side in one direction, respectively for emitting rays in parallel from the plurality of light sources, a photosynthesis device for synthesizing transmitted rays from the first light source unit and reflected rays from the second light source unit on a single light path, and a light receiving device for focusing first synthesized rays synthesized by the photosynthesis device through an imaging lens, and an optical deflecting device for deflecting and scanning second synthesized rays synthesized by the photosynthesis device, and the second synthesized rays passed through the optical deflecting device is being externally emitted, wherein the photosynthesis device and the light receiving device are displaced relative to the optic axis of the first synthesized rays so as to position focused spots of the first synthesized ra

Abstract: Disclosed is an optical scanning device including a light source including multiple light-emitting elements, the multiple light-emitting elements being arranged in a linear manner, a collimator lens to collimate a light beam from the light source, a light-deflecting device to deflect a light beam having passed through the collimator lens to a medium to be scanned and scan the medium with the light beam, and a rear optical system arranged in an optical path between the collimator lens and the medium to be scanned, wherein the collimator lens deviates an image surface in a direction opposite to an image surface deviation on the medium to be scanned by a nearly same amount as the image surface deviation, the image surface deviation being caused by a change of an image height of the light source, and the change being caused by the rear optical system.

Abstract: A disclosed light source apparatus includes a light source including multiple light emitting devices; an optical element configured to transmit light emitted from the light source; a tube configured to hold the optical element; and a tube holder configured to fix the tube by holding an end of the tube close to the light source or by holding the end of the tube on the light emission side away from the light source. A positional displacement preventing member is provided at the other end of the tube on a light emission side away from the light source in such a manner as to be slidable on the tube in the direction of an optical axis and prevent positional displacement of the tube in all directions perpendicular to the optical axis.

Abstract: A light scanning apparatus comprising a photosynthesis device having a first light source unit and a second light source unit with a plurality of light sources spaced at equal intervals side by side in one direction, respectively for emitting rays in parallel from the plurality of light sources, a photosynthesis device for synthesizing transmitted rays from the first light source unit and reflected rays from the second light source unit on a single light path, and a light receiving device for focusing first synthesized rays synthesized by the photosynthesis device through an imaging lens, and an optical deflecting device for deflecting and scanning second synthesized rays synthesized by the photosynthesis device, and the second synthesized rays passed through the optical deflecting device is being externally emitted, wherein the photosynthesis device and the light receiving device are displaced relative to the optic axis of the first synthesized rays so as to position focused spots of the first synthesized ra

Abstract: A light scanner has a light source 1 of a two-dimensional array consisting of a plurality of light source elements, a coupling lens system 2 for collimating a light flux from the light source 1, a shaping lens system (cylindrical lens 4 and lens 5) for shaping the light flux, light beam deflection means 6 for deflecting and scanning the post-shaped light flux, and a scanning lens system 7 for forming an image of the deflected and scanned light flux on a scanned medium 8. Assuming that the focal length of the coupling lens system 2 is f, a slit 3 for limiting the subscanning direction width as a member for shielding a part of the light flux is placed at a location at a distance of about f from the coupling lens system 2 in an opposite direction to the light source 1.

Abstract: A light scanner has a light source 1 of a two-dimensional array consisting of a plurality of light source elements, a coupling lens system 2 for collimating a light flux from the light source 1, a shaping lens system (cylindrical lens 4 and lens 5) for shaping the light flux, light beam deflection means 6 for deflecting and scanning the post-shaped light flux, and a scanning lens system 7 for forming an image of the deflected and scanned light flux on a scanned medium 8. Assuming that the focal length of the coupling lens system 2 is f, a slit 3 for limiting the subscanning direction width as a member for shielding a part of the light flux is placed at a location at a distance of about f from the coupling lens system 2 in an opposite direction to the light source 1.

Abstract: A laser beam scanning apparatus and method for providing controllable print density. The laser beam scanning apparatus includes a modulator for modulating a light beam, a rotating polygon mirror for deflectively scanning a light beam which is passed through the modulator, at least one lens unit having at least one lens which is movable to a position on the optical axis and a position completely off the optical axis, and a controller for switching the modulating clock frequency of the modulator and the rotating speed of the polygon mirror together with selective shifting of the at least one lens unit or lens thereof to a position on the optical axis or completely off the optical axis whereby the method effects control of the apparatus for controlling print density.

Abstract: A predetermined relationship has been found between a number of beams and a ratio a between magnifications in an sub scanning direction. During scanning with a small number of beams, the allowable range of magnification ratio becomes comparatively large. During scanning with a large number of beams, the allowable range of magnification ratio is around 1. By setting the magnification ratio a in the sub scanning direction so as to satisfy the aforementioned allowable ranges, printing with less pitch error can be implemented even with a small magnification.

Abstract: An exposure device of an electrophotographic apparatus which includes a rotary polyhedral mirror for scanning a plurality of laser beams on a photosensitive body, a beam interval adjusting member for adjusting an interval between the laser beams, a rotating mechanism for rotating the beam interval adjusting member, and an optical path position deciding device disposed on the side of the rotary polyhedral mirror in a laser beam advancing direction at the time of adjustment of the laser beam interval, the beam interval adjusting member being rotated so that the optical paths of the laser beams are decided by the optical path position deciding device. The optical path position deciding device may include a plate-like member with boresights or a CCD sensor and a CRT display.