Abstract: A cylindrical roller bearing wherein the end surface of the rollers comes in contact with the guiding surface of the rib of the inner race with a contact ellipse therebetween, and at least one of the end surface and the guiding surface has a curved, convex surface, and provided that a second principal curvature plane passes through the center axis of the inner race and the center of the contact ellipse, that a first principal curvature plane perpendicularly crosses both the second principal curvature plane and the contact ellipse and extends through the center of the contact ellipse, that the cross sections of the end surface appearing in the first and second principal curvature planes have the principal radii (Rr2 and Rr1) of curvature, respectively, and that the cross sections of the guiding surface appearing in the first and second principal curvature planes have the proximal radii (Rf2 and Rf1) of curvature, respectively, the relationship between these principal radii of curvature is such that (1/Rf1)&min

Abstract: A semiconductor laser device with reduced threshold current and power consumption. Reflectivity Rr at a rear face of an optical cavity of the laser is set as large as possible. A monitor photodiode used for controlling an output form the laser is provided on a mount at a position to detect the main laser beam emitted from the front face of the optical cavity.

Abstract: A roller bearing comprising an outer ring having an outer ring raceway, an inner ring having an inner ring raceway, the inner peripheral surface at the end portion of the outer ring and/or the outer peripheral surface at the end portion of the inner ring formed with a flange portion, and a plurality of rollers having a rolling surface in contact with the outer and inner ring raceways, a sliding contact face in sliding contact with the inner face of the flange portion, and a chamfered portion provided between the sliding contact face and the rolling face, the sliding contact face smoothly connected to the chamfered portion in a curved surface the radius of curvature of which is at least 0.08 mm, and provided that the center line average height roughness of the sliding contact surface is .delta..sub.1 while the center line average height roughness of the inner face in contact with the sliding surface is .delta..sub.2, the composite roughness represented by the formula (.delta..sub.1.sup.2 +.delta..sub.2.sup.2).

Abstract: A rolling bearing for supporting a rotating shaft of a high speed rotating machine is provided with an outer race including an outer raceway on an inner face thereof, an inner race including an inner raceway on an outer face thereof, the inner race being rotated together with the rotating shaft, a plurality of rolling elements rotatably disposed between the outer raceway and the inner raceway, and a hole formed at a portion of the inner race, in which a section of the hole in a circumferential direction of the inner race has a shape of which a size in the circumferential direction of the inner race is greater than that in an axial direction of the inner race, and which are free from a sharp edge. The rolling bearing can relax stress concentration produced in the inner race during a high speed rotation and can increase the allowable rotation speed of the inner race.