Abstract: The invention is to provide a multi-beam light source where the interval of core portions is reduced and the core portions are arranged on a straight line. The multi-beam light source includes a first substrate where a plurality of optical fibers each having a core portion and a clad portion surrounding the core portion coaxially are fixed at predetermined intervals, and a second substrate where a plurality of similar optical fibers are fixed at predetermined intervals. The first and second substrates are put and bonded on top of each other so that the core portion of each optical fiber on the second substrate is inserted between core portions of adjacent optical fibers on the first substrate, and the core portions of the optical fibers on the first and second substrate are arranged substantially on a straight line.

Abstract: A buck-boost converter of an H bridge type having a function for initially charging a smoothing output capacitor without a relay and a rush current preventing resistance. A compact and flat power supply is attained by employing a current critical mode H bridge system for a PFC converter and providing a function of initially charging a smoothing output capacitor to a converter circuit.

Abstract: The invention provides a multi-beam light source including a light guide array by which the yield can be improved. An array pitch P2 of entrance surfaces of light guide pattern is 1/N as wide as an array pitch P1 of exit surfaces of optical fiber arrays. The number of the light guide patterns is N or more times as large as the number of optical fibers. The exit surfaces of a plurality of the optical fibers are coupled with the entrance surfaces of a plurality of the light guide patterns opposed thereto.

Abstract: A multi-beam image forming apparatus includes: first and second semiconductor laser arrays each having n laser elements; a multi-beam generation unit that generates 2n laser beams by synthesizing laser beams generated by the first and second semiconductor laser arrays; a beam detection unit that generates synchronous detection signals to obtain synchronous scanning of the respective laser beams; and a control unit. The beam detection unit includes first and second beam detection units disposed substantially at a same position in a main scanning direction and adjacently disposed in a sub-scanning direction. The n laser beams of the first and second semiconductor laser arrays are detected by the first and second beam detection unit, respectively. The control unit controls image formation start positions of the 2n laser beams on the basis of the synchronous detection signals output from the first and the second beam detection units.

Abstract: A light scanning unit by which misalignment in imaging caused by a scanning angle can be reduced. The light scanning unit includes a light source array device having a plurality of light sources, an imaging optics, and an optical deflection module. The plurality of light sources are used selectively in accordance with positions of light beams in a scanning direction on a to-be-scanned surface.

Abstract: A power transmission mechanism of a shaft and a hub, wherein a shaft tooth part comprises a ridge part formed of a crowning with varied tooth thickness, and a hub tooth part comprises a ridge part having tooth thickness formed in a specified linear shape and having an inner diameter varying from the end part thereof to a shaft shank side. A first step part swelling to the hub tooth part is formed in the bottom part of the shaft tooth part, and a second step part recessed in a direction opposite to the shaft tooth part is formed in the ridge part of the hub tooth part. The start point of the first step part and the start point of the second step part are set at positions offset by a specified distance from each other.

Abstract: A spline rolling tool including a plurality of forming teeth that are to bite into a cylindrical workpiece so as to roll splines in the workpiece. Each of the forming teeth has an incomplete toothed region in which a crest of each forming tooth is removed such that an upper end of each forming tooth in the incomplete toothed region is defined by an incomplete-toothed region surface that includes a curved surface portion, a flat surface portion and a slant surface portion. The incomplete-toothed region surface is defined at its periphery by a chamfered edge that has a surface roughness of not larger than about 3.2 ?m. Also disclosed is a process of manufacturing the spline rolling tool, which includes a chamfering step of forming the chamfered edge by using a wire brush having abrasive grains that are fixed to bristles of the wire brush.

Abstract: According to an aspect of the present invention, there is provided an optical scanning apparatus including a light source, an optical unit, a first controller and a second controller. The light source emits a predetermined number of laser beams, the laser beams to be arranged in a sub-scanning direction on a recording medium. The optical unit simultaneously scans the laser beams in parallel on the recording medium. The first controller changes a dot size of the laser beams in a main scanning direction. The second controller changes the predetermined number.

Abstract: An optical scanning apparatus includes a deflecting member that deflects and scans a light beam emitted from a light source, an optical element that scans and images the light beam on a medium to be scanned; and an opening member being disposed in a vicinity of the medium to be scanned. The opening member restricts both a scanning direction of the scanned and imaged light beam and a direction perpendicular to the scanning direction of the light beam.

Abstract: The invention aims at provision of an optical scanner in which an optics required for equalizing an optical magnification in a scanning range is produced with high accuracy, so that intervals among a plurality of scanning lines on a to-be-scanned surface are even in the scanning range. The scanning optics includes a refraction surface and a reflection surface whose sub-scanning-direction curvature radii vary continuously. The reflection surface is disposed on the to-be-scanned surface side of the refraction surface. The curvature radius of the reflection surface varies symmetrically with respect to the optical axis, and the curvature radius of the refraction surface varies asymmetrically with respect to the optical axis.

Abstract: The invention is to provide a light scanning unit designed to suppress the quantity of torsion of a light beam caused by an inclination angle of a cylindrical lens disposed between a light source and an optical deflecting element so as to suppress increase in diameter of the beam imaged on a to-be-scanned surface. The object is achieved by the light scanning unit in which a collimator lens, an aperture, a cylindrical lens, a spherical lens, a rotary polygon mirror, an F? lens and a to-be-scanned surface are disposed in an optical path between the light source and the optical deflecting element in order of increasing distance from the light source. The light scanning unit is designed to satisfy an expression of Mt?D/? when ? designates a diameter of the aperture, D designates a diffraction diameter of each beam focused on the to-be-scanned surface and scanning the to-be-scanned surface, ? designates a rotation angle with a generatrix of the cylindrical lens, and Mt designates a conjugate magnification.

Abstract: The invention is to provide a light scanning unit designed to suppress the quantity of torsion of a light beam caused by an inclination angle of a cylindrical lens disposed between a light source and an optical deflecting element so as to suppress increase in diameter of the beam imaged on a to-be-scanned surface. The object is achieved by the light scanning unit in which a collimator lens, an aperture, a cylindrical lens, a spherical lens, a rotary polygon mirror, an F? lens and a to-be-scanned surface are disposed in an optical path between the light source and the optical deflecting element in order of increasing distance from the light source. The light scanning unit is designed to satisfy an expression of Mt?D/? when ? designates a diameter of the aperture, D designates a diffraction diameter of each beam focused on the to-be-scanned surface and scanning the to-be-scanned surface, ? designates a rotation angle with a generatrix of the cylindrical lens, and Mt designates a conjugate magnification.

Abstract: The invention provides a multi-beam light source including a light guide array by which the yield can be improved. An array pitch P2 of entrance surfaces of light guide patterns is 1/N as wide as an array pitch P1 of exit surfaces of optical fiber arrays. The number of the light guide patterns is N or more times as large as the number of optical fibers. The exit surfaces of a plurality of the optical fibers are coupled with the entrance surfaces of a plurality of the light guide patterns opposed thereto.

Abstract: The invention is to provide a multi-beam light source where the interval of core portions is reduced and the core portions are arranged on a straight line. The multi-beam light source includes a first substrate where a plurality of optical fibers each having a core portion and a clad portion surrounding the core portion coaxially are fixed at predetermined intervals, and a second substrate where a plurality of similar optical fibers are fixed at predetermined intervals. The first and second substrates are put and bonded on top of each other so that the core portion of each optical fiber on the second substrate is inserted between core portions of adjacent optical fibers on the first substrate, and the core portions of the optical fibers on the first and second substrate are arranged substantially on a straight line.

Abstract: The invention aims at provision of an optical scanner in which an optics required for equalizing an optical magnification in a scanning range is produced with high accuracy, so that intervals among a plurality of scanning lines on a to-be-scanned surface are even in the scanning range. The scanning optics includes a refraction surface and a reflection surface whose sub-scanning-direction curvature radii vary continuously. The reflection surface is disposed on the to-be-scanned surface side of the refraction surface. The curvature radius of the reflection surface varies symmetrically with respect to the optical axis, and the curvature radius of the refraction surface varies asymmetrically with respect to the optical axis.

Abstract: A power transmission mechanism of a shaft and a hub, wherein a shaft tooth part having a plurality of linear spline teeth is formed at the end part of the shaft and a hub tooth part having a plurality of linear spline teeth fitted to the end part of the shaft is formed in the inner peripheral surface of a shaft hole in the hub. A first step part is formed by swelling the shaft tooth part toward the hub tooth part from a point (P1) horizontally moved from the center point (P0) of the shaft tooth part to a shaft shank side. On the ridge part side of the hub tooth part, a point is set at a position offset from the point (P1) horizontally to the opposite side of the shaft shank, and a second step part increased in a diameter from the point (P2) in the radial outer direction is formed.

Abstract: An optical scanning apparatus includes a deflecting member that deflects and scans a light beam emitted from a light source, an optical element that scans and images the light beam on a medium to be scanned; and an opening member being disposed in a vicinity of the medium to be scanned. The opening member restricts both a scanning direction of the scanned and imaged light beam and a direction perpendicular to the scanning direction of the light beam.

Abstract: A multi-beam image forming apparatus includes: first and second semiconductor laser arrays each having n laser elements; a multi-beam generation unit that generates 2n laser beams by synthesizing laser beams generated by the first and second semiconductor laser arrays; a beam detection unit that generates synchronous detection signals to obtain synchronous scanning of the respective laser beams; and a control unit. The beam detection unit includes first and second beam detection units disposed substantially at a same position in a main scanning direction and adjacently disposed in a sub-scanning direction. The n laser beams of the first and second semiconductor laser arrays are detected by the first and second beam detection unit, respectively. The control unit controls image formation start positions of the 2n laser beams on the basis of the synchronous detection signals output from the first and the second beam detection units.

Abstract: In an optical scanning apparatus, a light beam emitted from a light source is deflected and scanned by a light deflecting member, and then scanned and imaged with substantial speed uniformity onto a medium to be scanned by a scanning optical element. The apparatus is configured so that, when the angle formed by the light beam that is deflected and scanned and the optical axis of the scanning optical element is ?, the amount of positional deviation due to deviation from speed uniformity of the light beam on the medium to be scanned is ?(?), the spatial scan density on the medium to be scanned is P, and the maximum of an absolute value of the angle ? is ?o, an expression of |d?(?)/d?|?5.0×10/P?o holds.

Abstract: In an optical scanning apparatus, a light beam emitted from a light source is deflected and scanned by a light deflecting member, and then scanned and imaged with substantial speed uniformity onto a medium to be scanned by a scanning optical element. The apparatus is configured so that, when the angle formed by the light beam that is deflected and scanned and the optical axis of the scanning optical element is ?, the amount of positional deviation due to deviation from speed uniformity of the light beam on the medium to be scanned is ?(?), the spatial scan density on the medium to be scanned is P, and the maximum of an absolute value of the angle ? is ?o, an expression of |d?(?)/d?|?5.0×10/P?o holds.