Abstract: A rotor includes a first resin portion formed the periphery of a main shaft; a first core disposed the outer circumferential portion of the first resin portion; a magnet attached to the radial outside of the first core; and a second core disposed the radially outside end face of the magnet, wherein a plurality of structures in each of which the magnet is sandwiched between the first and second cores are disposed circumferentially around the main shaft, and a second resin portion is formed between the circumferential end faces of adjacent second cores and between the circumferential end faces of adjacent magnets, wherein the first core has a division surface on which the circumferential end faces of itself and an adjacent first core are in surface contact with each other, and wherein the second core is not in contact with an adjacent second core.

Abstract: A lens driving device includes a lens holder for holding a lens, a supporter portion for supporting the lens holder in a movable manner, a drive portion for driving the lens holder, and an elastic portion for supplying the lens holder with a force in a predetermined direction. The supporter portion includes a shaft engaging with a bearing of the lens holder, and the force in a predetermined direction includes a force in a direction perpendicular to the shaft and a force in a direction to rotate the lens holder about the shaft.

Abstract: A lens driving device includes a lens holder that holds a lens, a driving portion that drives the lens holder through a magnetic force produced using a coil and a magnet, and a guide shaft that supports the lens holder movably. When moving the lens holder to a target position, an AC voltage is applied to the coil over a specific interval from a beginning of movement of the lens holder. Further, an amplitude of the AC voltage is reduced stepwise with the passage of time.

Abstract: A vibration exciter is disclosed which includes a movable unit on which a test object is mounted and a fixed unit that has a flux path element, wherein the flux path element has a magnet and a yoke that has magnetic permeability, and the flux path element is disposed to produce a static magnetic field in a gap in the flux path element, the movable unit has a driving coil and is disposed with the driving coil being inserted in the gap. The vibration exciter further includes a cooling blower for cooling at least any one of the magnet and the driving coil, a controller for controlling the rate of rotation of the cooling blower, and a temperature gauge for measuring the temperature of at least any one of the magnet and the driving coil.

Abstract: A lens driving device includes a lens holder that holds a lens, a driving portion that drives the lens holder through a magnetic force produced using a coil and a magnet, and a guide shaft that supports the lens holder movably. When moving the lens holder to a target position, an AC voltage is applied to the coil over a specific interval from a beginning of movement of the lens holder. Further, an amplitude of the AC voltage is reduced stepwise with the passage of time.

Abstract: A lens driving device includes a lens holder for holding a lens, a supporter portion for supporting the lens holder in a movable manner, a drive portion for driving the lens holder, and an elastic portion for supplying the lens holder with a force in a predetermined direction. The supporter portion includes a shaft engaging with a bearing of the lens holder, and the force in a predetermined direction includes a force in a direction perpendicular to the shaft and a force in a direction to rotate the lens holder about the shaft.

Abstract: A dot-matrix line printer includes a printing shuttle which moves reciprocally to carry out a printing operation, and a balancing shuttle which moves in a direction opposite to the direction of the movement of the printing shuttle. The balancing shuttle is partly inserted in the printing shuttle so as not to interfere with the latter upon printing and so that the center of gravity of the balancing shuttle is located as close to the center of gravity of the printing shuttle as possible.

Abstract: High grade quaternary ammonium salts represented by the following General Formula II: ##STR1## (in which R.sub.1 represents a hydrogen atom or a methyl group; R.sub.2 and R.sub.3 independently represents an alkyl group containing 1 to 4 carbon atoms; A represents an oxygen atom or an --NH-- group; B represents an alkylene group containing 1 to 4 carbon atoms; R.sub.4 represents an alkyl group or a benzyl group; and X.sup.- represents a halogen anion) can be produced by reacting a cationic vinyl monomer represented by the following General Formula I: ##STR2## (in which R.sub.1, R.sub.2, R.sub.3, A and B have the same meanings as defined above) with an alkyl halide or an aralkyl halide in a medium consisting of a particular mixture of water and an aprotic organic solvent under a condition where the concentration of oxygen dissolved in the reaction system is lower than 1.8 ppm but not less than 0.3 ppm.