Abstract: A magnetic iron oxide powder which has high coercive force and stable magnetic characteristics is produced by forming a surface layer of the magnetic iron oxide powder which comprises a cobalt compound as a main component. The magnetic iron oxide powder is treated with an aqueous solution of a cobalt ion for two times or more to form at least two surfaces comprising the cobalt compound.

Abstract: A magnetic tape cassette holding a wound magnetic tape comprising a transparent base film and a magnetic layer having a thickness of 5.mu. or less coated on the base film comprises a hole facing a light source for detecting the tape position, a hole facing a photosenser provided so as to form a light path passing to the hole for light source through which the magnetic tape is passed and a light-shielding filter having a light transmittance in the range between 0.5 and 10 percent placed in the light path.

Abstract: The invention provides a novel electric power source unit such as a high-speed pulse power source unit built with a pulse-forming circuit and a DC electric power source unit built with a high-frequency voltage-multipler rectifying circuit having high performance in comparison with conventional units. The inventive unit comprises, as a part of the circuit, at least one ceramic capacitor composed of a ceramic dielectric body made of a strontium titanate-based composition unlike the conventional ones in the prior art comprising barium titanate-based ceramic capacitors. Four classes of the preferred compositions are disclosed each containing strontium titanate as the principal component.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer formed by using a magnetic composition comprising a binder and a magnetic powder adsorbing ricinoleic acid or an ester thereof.

Abstract: A magnetic tape cassette includes a magnetic tape and two reels in a casing. The reel is formed by a reel substrate, a jaw and a tape clamping member. An exterior angle .alpha. between a prolonged line D.sub.1 of a contact surface of the reel substrate and an axial line E.sub.1 for dividing the tape clamping member into two half parts is less than 90 degrees.

Abstract: An improved starter switch which provides a rapid firing of a fluorescent lamp within 0.8 second has been found. An external appearance and the size of the present starter switch are almost the same as those of a prior glow switch which is slow to fire a fluorescent lamp, therefore, the present starter switch is replaceable to a prior glow switch by merely inserting the present starter switch to a socket of a prior glow switch. The present starter switch has a connector cap which is to be able to be engaged with a socket for a glow switch, a printed circuit board mounting circuit components and connected to said connector cap by lead lines, and a housing fixed to said cap and covering said printed circuit board.

Abstract: Positive feedback is applied from the piezo-electric vibrator in an ultrasonic nebulizer to the control electrode in the oscillator circuit for improved performance.

Abstract: A tape cassette formed from a cassette body having sections thereof which are adapted to be contacted by a tape and which have a surface roughness within the range of about 3 to 15 microns. In the production of such a cassette, those sections of the case which are adapted to be contacted by the tape are honed to provide a surface roughness within the specified micron range.

Abstract: A magnetic tape cassette comprises a tape running plane for a magnetic tape provided in the front of the casing assembly consisting of an upper half casing and a lower half casing, said magnetic tape being held in wound form and being capable of running inside the casing assembly and a front cover mounted to the casing assembly so as to open and close at the front of the assembly, said front cover being actuated by spring action in the direction closing the front part of the casing assembly by positioning one end of a coil spring fitted to the pivot pin in a rectangular groove formed in an inner surface of the upper half casing, wherein a rib having a slanted surface which is lowered toward said groove is provided at the side of said groove.

Abstract: A magnetic recording medium is provided which satisfies electromagnetic conversion characteristics and typical physical properties such as bonding strength, repeated-passage stability, still-playback characteristics, etc. without unfavorably affecting the surface smoothness. The binder in the magnetic coating contains in combination specific proportions of three components, a polyurethane resin, an epoxy resin, and a nitrocellulose whose protective ingredient has been replaced by a vinyl chloride-vinyl acetate copolymer is used as a resin binder in magnetic coating material together with a polyisocyanate curing agent.

Abstract: A ceramic capacitor having an extremely thin plate (as little as 10 .mu.m) with a pair of electrodes on both the surfaces of the plate, said thin plate is supported by the thick dielectric plate which is laminated with said thin plate. The thick plate has a through hole, in the vertical direction of the same, and said through hole is filled with a through hole conductor which connects electrically the external terminal on the outer surface of the thick plate and the inner electrode on the thin plate. The material of the thick plate is the same as that of the thin plate, and a pair of lead lines are soldered to the external terminal and the outer electrode on the thin plate.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin or a polyester and a vinyl chloride type copolymer of vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer or vinyl chloride-vinylidene chloride copolymer having a polymerization degree of up to 300.

Abstract: The new structure of a ferrite core for the use of a power transformer and/or a choke coil has been found. The core is assembled by a pair of identical core halves, and each of core half comprises (a) a circular center boss(12), (b) a pair of outer walls(14,16) positioned at both the sides of said boss(12) so that a fan-shaped empty space is provided between the circular boss(12) and a pair of outer walls(14,16) for mounting a coil, (c) a pair of base plates(18,20) coupling said boss(12) with said outer walls(14,16) at the extreme end of those members so that those members conform substantially with the E-shaped structure, (d) the other extreme end of said boss(12), the outer walls(14,16) and the base plates(18,20) residing on a single plane, (e) each of said outer walls(14,16) being essentially rectangular with the external linear wall and the inner curved wall which is coaxial with the circular boss(12), and the width(d.sub.2) of said external linear wall is larger than the diameter(d.sub.

Abstract: In the method for manufacturing annular portions of magnetic heads, a gap between the confronting end surfaces of the magnetic heads is filled with glass. In one of the conventional processes, the glass is sucked into the gap by a capillary action of the gap, but bubbles are liable to form in the glass. The method according to the present invention comprises a step of heating the glass to a relatively low temperature capable of causing the glass to be flowable and applying a centrifugal force to the glass being heated in a rotatable support of a heating furnace. As a result of the centrifugal force, the tendency to form bubbles is considerably reduced as compared with the conventional methods.

Abstract: A magnetic tape cassette comprises an upper half casing and a lower half casing provided with a screw holder having a threaded hole at the corner of the lower half casing for connecting said upper half casing, wherein the thickness of the wall of the screw holder facing inside the casing is reduced and at least one rib having a level flush with the fitting surface of the lower half casing is formed at the inside portion of the screw holder.

Abstract: A case for holding a magnetic tape cassette has flat locking projections or tabs upright from the inner wall surface thereof to engage the hubs of the magnetic tape cassette and thereby lock the hubs unrotatably. The locking tabs are formed with a step each in the upper part. The step of each said tab is parallel or inclined to the place of the inner wall surface.

Abstract: A magnetic recording medium is produced by forming an alkaline aqueous slurry of an acicular hydrated iron oxide or an acicular iron oxide as a starting material; adding a water soluble silicate to said slurry; treating it by a hydrothermal reaction in a closed reactor as an autoclave at elevated temperature and pressure; dehydrating and drying said slurry to obtain a dry iron oxide containing SiO.sub.2 component; converting it into a magnetic metallic iron powder by a reduction in a reducing atmosphere as hydrogen atmosphere; and coating a magnetic composition obtained by mixing said magnetic metallic iron powder with a binder.