Abstract: An electrostatic image developer includes: a toner A to which silica particles (A) containing an elemental nitrogen-containing compound containing elemental molybdenum are externally added; and a carrier B including a core material and a coating resin layer that covers the core material and contains inorganic particles. In the silica particles (A), the ratio NMo/NSi of a Net intensity NMo of elemental molybdenum that is measured by X-ray fluorescence analysis to a Net intensity NSi of elemental silicon that is measured by the X-ray fluorescence analysis is from 0.035 to 0.45 inclusive.

Abstract: An optical element includes a plate portion including a reflecting surface on an upper surface in a direction of a vertically extending central axis, a shaft that extends in a direction of a first axis intersecting with the central axis and is fixed to a lower surface of the plate portion, a magnet below the shaft in the direction of the central axis, and plates that fix the plate portion and the shaft, the plate portion including a protruding portion that extends downward in the direction of central axis from a lower surface, the plate including a shaft fixing portion to which the shaft is fixed and a plate portion fixing portion to which the plate portion is fixed, the plate portion fixing portion being fixed to the protruding portion.

Abstract: An actuator that swings a swing portion about a first axis and a second axis perpendicular or substantially perpendicular to each other, includes a fixed portion, two first stator cores, two second stator cores, two first coils, and two second coils. The first coil is in the same region as a tooth portion of the first stator core, and the second coil is in the same region as a tooth portion of the second stator core. As viewed in a central axis direction, each extending portion of each of the first stator cores includes end surfaces that face a magnet and oppose each other with the magnet interposed therebetween along the first axis, and each extending portion of each of the second stator cores includes end surfaces that face the magnet and oppose each other with the magnet interposed therebetween along the second axis.

Abstract: An optical element includes a plate portion including a reflecting surface on an upper surface in a direction of a vertically extending central axis, a shaft that extends in a direction of a first axis intersecting with the central axis and is fixed to a lower surface of the plate portion, a magnet below the shaft in the direction of the central axis, and a holder below the plate portion to hold the magnet, the holder including a magnet accommodating portion in which the magnet is accommodated, the magnet accommodating portion including a magnet pressing portion that covers at least a portion of a lower surface of the accommodated magnet.

Abstract: An actuator includes a swing portion swingable about a first axis orthogonal to a central axis extending vertically and about a second axis orthogonal to the first axis and intersecting the central axis. An angle detector includes a pair of first angle detection elements above a non-magnetic structure and extending in the second axis direction with the first axis interposed therebetween when viewed from the central axis direction, and a pair of second angle detection elements extending in the first axis direction with the second axis interposed therebetween. Each of the first angle detection elements and each of the second angle detection elements include a columnar magnetic structure between the swing portion and the non-magnetic structure in the central axis direction, and a detection coil along the outer periphery of the magnetic structure.

Abstract: An optical element includes a plate portion including a reflecting surface on an upper surface in a direction of a vertically extending central axis, a shaft that extends in a direction of a first axis intersecting with the central axis and is fixed to a lower surface of the plate portion, a magnet below the shaft in the direction of the central axis, and a holder below the plate portion to hold the magnet, the holder including a magnet accommodating portion in which the magnet is accommodated, the magnet accommodating portion including a magnet pressing portion that covers at least a portion of a lower surface of the accommodated magnet.

Abstract: An actuator that swings a swing portion about a first axis and a second axis perpendicular or substantially perpendicular to each other, includes a fixed portion, two first stator cores, two second stator cores, two first coils, and two second coils. The first coil is in the same region as a tooth portion of the first stator core, and the second coil is in the same region as a tooth portion of the second stator core. As viewed in a central axis direction, each extending portion of each of the first stator cores includes end surfaces that face a magnet and oppose each other with the magnet interposed therebetween along the first axis, and each extending portion of each of the second stator cores includes end surfaces that face the magnet and oppose each other with the magnet interposed therebetween along the second axis.

Abstract: An optical element includes a plate portion including a reflecting surface on an upper surface in a direction of a vertically extending central axis, a shaft that extends in a direction of a first axis intersecting with the central axis and is fixed to a lower surface of the plate portion, a magnet below the shaft in the direction of the central axis, and plates that fix the plate portion and the shaft, the plate portion including a protruding portion that extends downward in the direction of central axis from a lower surface, the plate including a shaft fixing portion to which the shaft is fixed and a plate portion fixing portion to which the plate portion is fixed, the plate portion fixing portion being fixed to the protruding portion.

Abstract: A motor for a disk drive includes a stationary unit, a bearing mechanism attached to the stationary unit, and a rotation unit supported on the stationary unit rotatably around a central axis via the bearing mechanism. The stationary unit includes a base portion that is a part of a housing defining an internal space sealed in the disk drive and includes a recess portion recessed from a side of the internal space toward an outside of the housing and not penetrated. The bearing mechanism includes a shaft extending in a direction of the central axis and a sleeve surrounding at least a portion of an outer circumferential surface of the shaft. A lower end portion of the shaft is press-fit and glued into the recess portion, and a lower surface of the base portion including a base step portion extending toward an axially upper side.

Abstract: This rotary drive apparatus is arranged to cause incoming light coming from a light source to be emitted to an outside while changing the direction of the incoming light, and includes a motor including a hollow shaft arranged to extend along a central axis extending in a vertical direction, the hollow shaft including a through hole arranged to pass therethrough in an axial direction; a flywheel including at least one optical component arranged to reflect the incoming light or allow the incoming light to pass therethrough; and a laser module including the light source. At least a portion of the laser module is arranged below the base portion arranged to directly or indirectly support a stator. The through hole defines a light path along which the incoming light travels.

Abstract: A spindle motor includes a stationary unit and a rotating unit. The rotating unit is rotatable with respect to the stationary unit in a state in which the stationary unit is aligned with a central axis. The stationary unit includes a stator core and coils. The stator core includes a cylindrical core back and teeth units extending radially outward from an outer circumferential portion of the core back. The coils are defined by a conductive wire wound around each of the teeth units. The rotating unit includes a magnet located radially outside the teeth units. An axial length of the magnet is shorter than an axial length of the teeth unit. A first angle corresponding to a circumferential width of the teeth unit is smaller than a second angle corresponding to a circumferential gap between the adjacent teeth units.

Abstract: A spindle motor includes a stationary unit and a rotating unit. The rotating unit is rotatable with respect to the stationary unit in a state in which the stationary unit is aligned with a central axis. The stationary unit includes a stator core and coils. The stator core includes a cylindrical core back and teeth units extending radially outward from an outer circumferential portion of the core back. The coils are defined by a conductive wire wound around each of the teeth units. The rotating unit includes a magnet located radially outside the teeth units. An axial length of the magnet is shorter than an axial length of the teeth unit. A first angle corresponding to a circumferential width of the teeth unit is smaller than a second angle corresponding to a circumferential gap between the adjacent teeth units.

Abstract: This rotary drive apparatus is arranged to cause incoming light coming from a light source to be emitted to an outside while changing the direction of the incoming light, and includes a motor including a hollow shaft arranged to extend along a central axis extending in a vertical direction, the hollow shaft including a through hole arranged to pass therethrough in an axial direction; a flywheel including at least one optical component arranged to reflect the incoming light or allow the incoming light to pass therethrough; and a laser module including the light source. At least a portion of the laser module is arranged below the base portion arranged to directly or indirectly support a stator. The through hole defines a light path along which the incoming light travels.

Abstract: In a fluid dynamic bearing apparatus, an oil buffer is defined between a thrust gap and a pumping gap. The oil buffer has an axial dimension greater than that of the thrust gap, and/or has a radial dimension greater than that of the pumping gap. An air bubble generated in the thrust gap due to cavitation, for example, when a fluid dynamic bearing apparatus experiences a vibration can be dissolved in lubricating oil provided within the oil buffer. This prevents leakage of the lubricating oil due to the air bubble residing in the fluid dynamic bearing apparatus.

Abstract: A motor includes a rotating portion and a stationary portion. The stationary portion includes a shaft component which includes an inner shaft portion and an outer shaft portion, an upper plate portion, and a lower plate portion. The upper plate portion is disposed in one side of the shaft component and extends radially outward from the one side of the shaft component. The lower plate portion is disposed on the other side of the shaft component and extends radially outward from the other side of the shaft component. The rotating portion includes a sleeve portion. The inner shaft portion and the outer shaft portion are fixed by an adhesive. An adhesive retaining portion is provided between an outer peripheral portion of the inner shaft portion and an inner peripheral portion of the outer shaft portion.

Abstract: A motor includes a rotating portion including a sleeve portion and a stationary portion. The stationary portion includes a shaft component which includes an inner shaft portion and an outer shaft portion. A radial dynamic pressure generating groove array is provided on at least one surface of an inner circumferential surface of the sleeve portion and an outer circumferential surface of the outer shaft portion, which define the radial gap. The radial dynamic pressure generating groove array includes an upper radial dynamic pressure generating groove array and a lower radial dynamic pressure generating groove array. A range of a fixing region in an axial direction between the inner shaft portion and the outer shaft portion in an interference fit state is included in a range between the upper radial dynamic pressure generating groove array and the lower radial dynamic pressure generating groove array.

Abstract: A motor includes a rotating portion and a stationary portion. The stationary portion includes a shaft component which includes an inner shaft portion and an outer shaft portion, an upper plate portion, and a lower plate portion. The upper plate portion is disposed in one side of the shaft component and extends radially outward from the one side of the shaft component. The lower plate portion is disposed on the other side of the shaft component and extends radially outward from the other side of the shaft component. The rotating portion includes a sleeve portion. The inner shaft portion and the outer shaft portion are fixed by an adhesive. An adhesive retaining portion is provided between an outer peripheral portion of the inner shaft portion and an inner peripheral portion of the outer shaft portion.

Abstract: A motor includes a rotating portion including a sleeve portion and a stationary portion. The stationary portion includes a shaft component which includes an inner shaft portion and an outer shaft portion. A radial dynamic pressure generating groove array is provided on at least one surface of an inner circumferential surface of the sleeve portion and an outer circumferential surface of the outer shaft portion, which define the radial gap. The radial dynamic pressure generating groove array includes an upper radial dynamic pressure generating groove array and a lower radial dynamic pressure generating groove array. A range of a fixing region in an axial direction between the inner shaft portion and the outer shaft portion in an interference fit state is included in a range between the upper radial dynamic pressure generating groove array and the lower radial dynamic pressure generating groove array.

Abstract: Provided herein is an apparatus including a stationary portion having a thrust cup; a rotating portion having a sleeve configured to be rotatable with respect to the stationary portion; a first axially extending space defined by the thrust cup and the sleeve, wherein the first axially extending space includes a second portion positioned above a first portion of the first axially extending space; a capillary seal in the first portion of the first axially extending space; and a labyrinth seal, in the second portion of the first axially extending space.

Abstract: A motor includes a shaft component, an upper plate portion, a lower plate portion, and a sleeve portion. The shaft component includes an inner shaft portion and an outer shaft portion. The sleeve portion is disposed between the upper plate portion and the lower plate portion. A radial gap is defined between the sleeve portion and the outer shaft portion. A fixing range in which the outer shaft portion and the inner shaft portion radially overlap is provided. At least a portion in an axial direction of the fixing range radially overlaps with an existing range in the axial direction of the radial gap.