Abstract: A scanning optical device includes a deflector, a reflecting mirror, a housing to accommodate the deflector and the mirror; and an elastic member to urge the mirror toward the housing. The mirror includes a first surface urged by the elastic member, a second surface opposite to the first surface, a third surface and a fourth surface perpendicular to the first and second surfaces. The housing includes a bearing surface to support the second surface and a regulating portion to regulate movement of the mirror to a mirror widthwise direction, perpendicular to a mirror longitudinal direction and parallel with the second surface, and toward an opening of the housing. The regulating portion is provided opposite to only a part of the third surface so that a ridge line of the mirror between the second surface and the third surface does not contact the regulating member even an attitude of the mirror changes in a direction away from the bearing surface.

Abstract: An ion source, a first control electrode for controlling an ion beam emitted by the ion source, a detector for detecting scattered particles, and a second control electrode for controlling the ion beam, which is directed from the ion source toward a sample, as well as the scattered particles, are arranged on the same axis along with the sample. The ion beam directed from the ion source toward the sample, and the scattered particles, which are scattered from the sample and are directed toward the detector, are caused to converge. By using an Einzel-type lens as the second control electrode, charged particles and neutral particles constituting the scattered particles are provided with a difference in speed. The detector possesses an anode plate which is divided into the form of concentric, circular plates or concentric arc-shaped plates, and each divided anode plate provides a detection output which contains information relating to a distribution of the scattering angles of the scattered ions.

Abstract: A novel carrier material useful in conjunction with a toner for preparing a two-component developer for electrophotographic processes is provided. The carrier comprises a spherical magnetite particulate material having a reduced metallic iron outer layer which is coated with an outermost resinous layer for conditioning the copying properties of the carrier.

Abstract: A novel carrier material useful in conjunction with a toner for preparing a two-component developer for electrophotographic processes is provided. The carrier comprises a spherical magnetite particulate material having a reduced metallic iron outer layer which is coated with an outermost resinous layer for conditioning the copying properties of the carrier.

Abstract: A noval carrier powder for electrophotographic developers is provided. The carrier powder comprises spherical magnetite particles having a wustite (FeO) content of less than 10% by weight, a particle diameter of 30-200 .mu.m and a surface porosity of less than 20%.