Abstract: A lighting apparatus includes a metal mounting fixed to a needed place such as a ceiling or a wall, rod-shaped holding metal fixtures, and a lighting apparatus body constituted by a chassis to which one end portion of each holding metal fixture is loosely fitted, a board which is fixed to the chassis and on which light emitting diodes are mounted as luminous elements, a reflecting panel, a cover (diffusing panel) that covers the light emitting diodes, and so on. By inserting the lock section of the other end portion of each holding metal fixture into an insertion hole and then locking each holding metal fixture on the metal mounting, the lighting apparatus body is held in a state of being separated from the metal mounting.

Abstract: A slide member has a sliding surface made of ceramic and a has surface roughness of not more than 1.0 .mu.m in center line average roughness Ra. The ceramics includes a silicon nitride sintered body which contains crystal grains having a linear density of at least 35 per 30 .mu.m in length with a boundary phase volume ratio of not more than 15 volume %, and which contains pores of not more than 20 .mu.m in maximum diameter in a content of not more than 3%. In a method of manufacturing the slide member, it is possible to ensure smoothness of the sliding surface by grinding the sliding surface and thereafter heating the ceramic in an either an inert gas or atmospheric air. A slide member that can be used under severe sliding conditions of high-speed sliding or the like and that has excellent wear resistance is obtained.

Abstract: A composite bearing structure that has a high rotational accuracy and that can withstand high-speed rotation comprises first bearing means, second bearing means, third bearing means and fourth bearing means. The first bearing means supports a radial impact force which is applied to a rotator during rotation, and is formed by an inner ring (1) and an outer ring (2) consisting of silicon nitride ceramics sintered bodies. The second bearing means supports an axial load which is applied to the rotator while maintaining a prescribed clearance with the rotator, and is formed by a magnetic bearing body of two permanent magnets (12) and (13) which are thrust-directionally opposed to each other. The third bearing means maintains the radial rotational accuracy of the rotator, and is formed by a radial dynamic pressure producing groove (5) which is formed in a cylindrical surface of the inner ring (1).

Abstract: A slide member has a sliding surface made of ceramic and has a surface roughness of not more than 1.0 .mu.m in center line average roughness Ra. ceramic includes a silicon nitride sintered body, which contains crystal grains having a linear density of at least 35 per 30 .mu.m in length with a boundary phase volume ratio of not more than 15 volume %, and which contains pores of not more than 20 .mu.m in maximum diameter in a content of not more than 3%. In a method of manufacturing the slide member, it is possible to ensure smoothness of the sliding surface by grinding the sliding surface and thereafter heating the ceramic in either inert gas or an atmospheric air. A slide member that can be used under severe sliding conditions of high-speed sliding or the like and that has excellent wear resistance is obtained.

Abstract: There is provided a method and apparatus of detecting minute impurities in the entire body of a fluid. Part of the passage through which the fluid flows is constituted by a transparent member. Light is emitted in a direction substantially parallel to the longitudinal axis of this part of the fluid passage so as to envelop the same. Light scattered by impurities in the fluid is observed from a direction substantially perpendicular to the direction of the passage to detect any minute impurities in the fluid. The method and apparatus is well-suited for use in systems which extrude molten resin in the formation of plastic products used in an electrical environment in order to detect impurities in the resin which could adversely affect the performance of the products.

Abstract: A composite bearing structure can withstand high speed rotation has first, second and third bearing components. The first bearing component supports a radial impact force applied to a rotator during rotation, and is made of an inner ring (1) and an outer ring (2) of silicon nitride ceramic sintered bodies. The second bearing component supports an axial load applied to the rotator while maintaining a required clearance between itself and the rotator and is made of two permanent magnets (12, 13) positioned thrustdirectionally opposite to each other. The third bearing component maintains a radial rotational accuracy of the rotator, and is made of a radial dynamic pressure producing groove (5) provided on a cylindrical surface of the inner ring (1).

Abstract: A remote control device stores commands which are received through a telephone line and transmits command signals to operate designated apparatus according to the stored commands. These command signals may be transmitted by infrared light or supersonic waves through one or more transmitters.